Evaluation of Microbiological Test Kits for Hydrocarbon Fuel Systems

Commercially available kits were tested for their ability to detect bacterial and fungal contamination in hydrocarbon fuel systems. The handling ease of the kits was evaluated, and their sensitivity was compared with that of conventional methods. Most kits in both laboratory and field studies compared well with laboratory methods and were sufficiently sensitive to determine contamination in shipboard fuel tanks.     

Comparison of Three Dissolution Apparatuses for Testing Calcium Phosphate Pellets used as Ibuprofen Delivery Systems

Porous calcium phosphate pellets were produced according to two granulation processes (low and high shear wet granulations) and drug loaded with five ibuprofen contents (1.75%, 7%, 12.5%, 22%, and 36%) in order to ensure both bone defect filling and local drug delivery. The drug-release kinetics from the two types of pellets was studied using three dissolution apparatuses: paddle apparatus, reciprocating cylinder, and flow-through cell. The paper compared the three dissolution methods and considered the effect of the granulation process on the ibuprofen-release kinetics. Dissolution data were analyzed using the Weibull function as well as the difference (f1) and similarity (f2) factors. Dissolution kinetics was not influenced by the granulation process, regardless of the dissolution apparatus and of the drug content. The comparison of the three dissolution devices indicated that ibuprofen was released faster from granules loaded with 36% of drug content with the reciprocating apparatus, due to the disintegration of the granules occurring during the dissolution test. For the other drug contents, dissolution profiles were not significantly different from one apparatus to another. However, the flow-through cell seemed to be more suitable for the drug-release study of implantable materials.     

MicroRNAs 9 and 370 Association with Biochemical Markers in T2D and CAD Complication of T2D

BackgroundMicroRNAs (miRNAs) are small non coding RNAs with essential roles, of which any alteration leads to several conditions. Their roles in diabetes (DM) and its vascular complications have not been completely assessed.Aimto study the association of two miRNAs; 9 and 370, with biochemical parameters of type 2 diabetic (T2D), dyslipidemia and coronary artery disease (CAD).ResultsmiRNA 9 levels were significantly higher in T2D patients and T2D patients with CAD, (1.18±0.07, and 1.31±0.08 respectively), while miRNA 370 levels were significantly higher in T2D patients, CAD patients, and T2D patients with CAD (0.59±0.05, 1.00±0.05, and 1.20±0.06 respectively), compared to control group at p = 0.000. In addition both miRNAs were still significantly associated with each other even after conducting multiple regression analysis.ConclusionThis study associates the possible role of miRNAs in the diagnosis/prognosis of CAD complication of T2D.     

Effect of Plasticizer on Release Kinetics of Diclofenac Sodium Pellets Coated with Eudragit RS 30 D

The present study was designed to investigate the effect of two plasticizers, i.e., triethyl citrate (TEC) and polyethylene glycol 6000 (PEG 6000) on the in vitro release kinetics of diclofenac sodium from sustained-release pellets. Ammonio methacrylate copolymer type B (Eudragit RS 30 D) is used as the release-retarding polymer. Both plasticizers were used at 10% and 15% (w/w) of Eudragit RS 30 D. Pellets were prepared by powder layering technology and coated with Eudragit RS 30 D by air suspension technique. Thermal properties of drug and drug-loaded beads were studied using differential scanning calorimeter (DSC). DSC thermogram represented the identity of raw materials and exhibited no interaction or complexation between the active and excipients used in the pelletization process. Dissolution study was performed by using USP apparatus 1. No significant difference was observed among the physical properties of the coated pellets of different batches. When dissolution was performed as pure drug, about 8.22% and 90% drug was dissolved at 2 h in 0.1 N HCl and at 30 min in buffer (pH 6.8), respectively. From all formulations, the release of drug in acid media was very negligible (maximum 1.8 ± 0.08% at 2 h) but in buffer only 12% and 30% drug was released at 10 h from coated pellets containing TEC and PEG 6000, respectively, indicating that Eudragit RS 30 D significantly retards the drug release rate and that drug release was varied according to the type and amount of plasticizers used. The amount of TEC in coating formulation significantly effected drug release (p < 0.001), but the effect of PEG 6000 was not significant. Formulations containing PEG 6000 released more drug (98.35 ± 2.35%) than TEC (68.01 ± 1.04%) after 24 h. Different kinetic models like zero order, first order, and Higuchi were used for fitting drug release pattern. Zero order model fitted best for diclofenac release in all formulations. Drug release mechanism was derived with Korsmeyer equation.     

Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

The utilization of wheat straw as a renewable energy resource is limited due to its low bulk density. Pelletizing wheat straw into fuel pellets of high density increases its handling properties but is more challenging compared to pelletizing woody biomass. Straw has a lower lignin content and a high concentration of hydrophobic waxes on its outer surface that may limit the pellet strength. The present work studies the impact of the lignin glass transition on the pelletizing properties of wheat straw. Furthermore, the effect of surface waxes on the pelletizing process and pellet strength are investigated by comparing wheat straw before and after organic solvent extraction. The lignin glass transition temperature for wheat straw and extracted wheat straw is determined by dynamic mechanical thermal analysis. At a moisture content of 8%, transitions are identified at 53°C and 63°C, respectively. Pellets are pressed from wheat straw and straw where the waxes have been extracted from. Two pelletizing temperatures were chosen??one below and one above the glass transition temperature of lignin. The pellets compression strength, density, and fracture surface were compared to each other. Pellets pressed at 30°C have a lower density and compression strength and a tendency to expand in length after the pelletizing process compared to pellets pressed at 100°C. At low temperatures, surface extractives have a lubricating effect and reduce the friction in the press channel of a pellet mill while no such effect is observed at elevated temperatures. Fuel pellets made from extracted wheat straw have a slightly higher compression strength which might be explained by a better interparticle adhesion in the absence of hydrophobic surface waxes.     

Cellular Ras and Cyclin D1 Are Required during Different Cell Cycle Periods in Cycling NIH 3T3 Cells

Novel techniques were used to determine when in the cell cycle of proliferating NIH 3T3 cells cellular Ras and cyclin D1 are required. For comparison, in quiescent cells, all four of the inhibitors of cell cycle progression tested (anti-Ras, anti-cyclin D1, serum removal, and cycloheximide) became ineffective at essentially the same point in G1 phase, approximately 4 h prior to the beginning of DNA synthesis. To extend these studies to cycling cells, a time-lapse approach was used to determine the approximate cell cycle position of individual cells in an asynchronous culture at the time of inhibitor treatment and then to determine the effects of the inhibitor upon recipient cells. With this approach, anti-Ras antibody efficiently inhibited entry into S phase only when introduced into cells prior to the preceding mitosis, several hours before the beginning of S phase. Anti-cyclin D1, on the other hand, was an efficient inhibitor when introduced up until just before the initiation of DNA synthesis. Cycloheximide treatment, like anti-cyclin D1 microinjection, was inhibitory throughout G1 phase (which lasts a total of 4 to 5 h in these cells). Finally, serum removal blocked entry into S phase only during the first hour following mitosis. Kinetic analysis and a novel dual-labeling technique were used to confirm the differences in cell cycle requirements for Ras, cyclin D1, and cycloheximide. These studies demonstrate a fundamental difference in mitogenic signal transduction between quiescent and cycling NIH 3T3 cells and reveal a sequence of signaling events required for cell cycle progression in proliferating NIH 3T3 cells.     

3D Modelling of Biological Systems for Biomimetics

1　IntroductionBasedonthereviewofthepreviousworkof 3Dgeometricalmodellingtechniquesandsystemsdevelopedforindustrial,medicalandanimationapplications,thispaperdiscussestheproblemsassociatedwiththeexist ingtechniquesandsystems ,especiallywhenappliedto3Dmodellingof plants ,insectsandanimalsforbiomimeticsresearchanddevelopment .Then ,paperproposessomeareasofresearchinterestsin 3Dmod ellingofplants ,insectsandanimalsforBiomimetics .Toavoidtherepeating ,inthispaper ,biologicalobjectswillbeusedtorep…     

MHD Simulation of Physical Processes in Spherical Plasma-Focus Chambers with Allowance for Neutron Generation

Plasma Physics Reports - The results of the development of a two-dimensional MHD code for carrying out computational studies of the dynamics of plasma current sheath in spherical chambers with a...     

Life Cycle Assessment of Electric and Fuel Cell Vehicle Transport Based on Forest Biomass

Use of biomass‐based electricity and hydrogen in alternative transport could provide environmentally sustainable transport options with possible improvements in greenhouse gas balance. We perform a life cycle assessment of electric vehicle (EV) and fuel cell vehicle (FCV) powered by bioelectricity and biohydrogen, respectively, derived from Norwegian boreal forest biomass, considering the nonclimate neutrality of biological carbon dioxide (CO₂) emissions and alteration in surface albedo resulting from biomass harvesting—both with and without CO₂ capture and storage (CCS)—while benchmarking these options against EVs powered by the average European electricity mix. Results show that with due consideration of the countering effects from global warming potential (GWP) factors for biogenic CO₂ emissions and change in radiative forcing of the surface for the studied region, bioenergy‐based EVs and FCVs provide reductions of approximately 30%, as compared to the reference EV powered by the average European electricity mix. With CCS coupled to bioenergy production, the biomass‐based vehicle transport results in a net global warming impact reduction of approximately 110% to 120% (giving negative GWP and creating a climate‐cooling benefit from biomass use). Other environmental impacts vary from ?60% to +60%, with freshwater eutrophication showing maximum reductions (40% for the EV case and 60% for the FCV case) and photochemical oxidation showing a maximum increase (60% in the FCV value chain).     

Human and Ecological Life Cycle Tools for the Integrated Assessment of Systems (HELIAS)

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DOI: http://dx.doi.org/10.1065/lca2006.04.008

Goal, Scope and Background

CML has contributed to the development of life cycle decision support tools, particularly Substance / Material Flow Analysis (SFA respectively MFA) and Life Cycle Assessment (LCA). Ever since these tools emerged there have been discussions on how these tools relate to each other, and how they relate to more traditional tools. Remarkably little, however, has been published on these relationships from an empirical side: which combinations of tools have actually been used, and what is the added value of combining tools in practical case studies. In this paper, we report on CML's experience in this field by presenting a number of case studies with their related research questions, for which different tools were deployed.

Methods

Three case studies are discussed: 1) Waste water treatment: various options for waste water treatment have been assessed on their eco-efficiency, using SFA to comment on the influence of these options on the flows of certain substances in the water system of a geographical area and a combination of LCA and life cycle costing (LCC) to assess the life-cycle impacts and costs of these options; 2) Prioritization of environmental policy measures: A methodology has been developed to prioritize environmental policy measures and investments within companies based on both the environmental impacts and the costs of these measures; and 3) Environmental weighting of materials: to add an environmental dimension to standard MFA accounts, materials were weighted with cradle-to-grave impact factors based on LCA data and impact assessment factors.

Results and Discussion

For each of these cases, the research questions at stake, the tools applied, the results and the added value, limitations and problems of combining the tools are reported.

Conclusions

and Perspective. Based on these experiences, it is concluded that using several tools to address a complicated problem is not only a theoretical proposal, but also something that has been applied successfully in a variety of practical situations. Furthermore, using several tools in combination does not necessarily lead to an increased information supply to decisionmakers. Instead, it may contribute to the comprehensibility and ease of interpretation of the information that would have been provided by using a single tool. Finally, it is concluded that there is not one generally valid protocol for which tools to use for which question. The essential idea of using a combination of tools is exactly the fact that research questions are not simple by nature and cannot be generalized into protocols.

     

Coupling of the Cell Cycle and Apoptotic Machineries in Developing T Cells

Proliferation and apoptosis are diametrically opposite processes. Expression of certain genes like c-Myc, however, can induce both, pointing to a possible linkage between them. Developing CD4⁺CD8⁺ thymocytes are intrinsically sensitive to apoptosis, but the molecular basis is not known. We have found that these noncycling cells surprisingly express many cell cycle proteins. We generated transgenic mice expressing a CDK2 kinase-dead (CDK2-DN) protein in the T cell compartment. Analysis of these mice showed that the CDK2-DN protein acts as a dominant negative mutant in mature T cells as expected, but surprisingly, it acts as a dominant active protein in CD4⁺CD8⁺ thymocytes. The levels of CDK2 kinase activity, cyclin E, cyclin A, and other cell cycle proteins in transgenic CD4⁺CD8⁺ thymocytes are increased. Concurrently, caspase levels are elevated, and apoptosis is significantly enhanced in vitro and in vivo. E2F-1, the unique E2F member capable of inducing apoptosis when overexpressed, is specifically up-regulated in transgenic CD4⁺CD8⁺ thymocytes but not in other T cell populations. These results demonstrate that the cell cycle and apoptotic machineries are normally linked, and expression of cell cycle proteins in developing T cells contributes to their inherent 1sensitivity to apoptosis.     

The Systems I, II and III in the Photosynthetic Cycle of Electron Transfer

• 1 Two separate light reactions may be distinguished: (I) the reduction of ferredoxin and NADP probably by oxidation of carotene to xanthophyll; (II) the oxida tion of cytochrome f by chlorophyll (probably a). Reaction II implies a return of electrons to the pigments, system III, thus maintaining its normal steady state of oxidation-reduction. The xanthophyll is hereby again reduced to carotene.
• 2 System I is sensitive to violet-blue-green and probably also infrared light. Carotene absorbs in these regions, ferredoxin in blue-violet. System II is primarily sensitive to red light but also to blue-violet. Both chlorophyll and cytochromes absorb in the latter region, the cytochromes also in green.
• 3 The response of systems I and II to different spectral regions was studied by means of a special spectrophotometric flash technique, enabling precise measure ments of the band-height of the enzymes involved. The initial photic reactions of systems I and II, viz., the reduction of ferredoxin-NADP and the oxidation of cyto chrome f show a full turnover in less than 0.1 ms but the transfer between systems I and II by means of which the cytochromes are reduced is slowed down to about 10^?1-10^?2 s. The initial effect may thus be observed during ca. 0.1 s. At continuous illumination the displacement of the steady states of the enzymes may last up to several seconds and then return to a state of only partial reduction. Erroneous inter pretations of these phenomena are corrected.
• 4 In the blue-sensitive system I ferredoxin alone mediates the reduction of NADP but the possibility of the presence of other factors capable of dark chemical elec tron transfer is discussed. In the red-sensitive system II three cytochromes operate, viz., f, b₃ and b₆. Spectrophotometric evidence for the existence of two cytochromes b is presented. Cytochromes b₆ and f are approximately synchronously oxidized and reduced, whereas b₃ reacts somewhat independently. Cytochrome b₃ probably acts as a decharger of OH^? and compensates for the capture of H⁺+ e^? at the reduction of triphosphopyridine nucleotide (NAD) or of electrons by other oxidants.
• 5 The transfer of electrons between systems I and II maintains a reversible steady state of oxidation-reduction that may be moved to one side or the other not only by monochromatic light but also in the dark under influence of N₂, O₂, the ratios NADP/NADPH and ADP/ATP, and various added substances. Spectrophotometric measurements in UV show that a flavoprotein participates in the multiple steady state.
• 6 The investigations illustrate many intricate technical problems that are too frequently overlooked. Photostructural reactions must be eliminated by referring band-heights to an isosbestic level. The photosynthetic activity is strongly dependent on light-scattering. Reliable measurements of cytochromes must be made in the α-region owing to a strong interference of rapid changes of the ratio carotene/xanthophyll in the region of the γ-bands.

     

Allowance for antibody bivalence in the characterization of interactions by ELISA

The objective of this review is to remove empiricism from the characterization of immunospecific interactions by enzyme‐linked immunosorbent assay (ELISA). In place of the original presumption that the absorbance generated by the enzyme‐linked assay could be regarded as a measure of free antibody concentration, the stance is taken that the parameter being monitored is the concentration of antibody complexed with immobilized antigen on the microtiter plate. After the presentation of general binding theory that takes ligand multivalence into account, that theory is adapted to incorporate the simplifying circumstances that prevail in an ELISA study. Validity of the original expressions for characterizing antigen–antibody interactions by competitive ELISA is confirmed, thereby refuting reported concerns about the need for amendment of the theoretical expressions to take into account bivalence of the antibody. Copyright © 2010 John Wiley & Sons, Ltd.     

热毒宁注射液联合更昔洛韦注射液对呼吸道合胞病毒感染肺炎患儿血清炎症因子和T细胞亚群的影响

摘要 目的：观察热毒宁注射液联合更昔洛韦注射液对呼吸道合胞病毒（RSV）感染肺炎患儿血清炎症因子和T细胞亚群的影响。方法：60例RSV感染肺炎患儿均来自我院2017年1月-2020年12月期间收集的病例,依据随机数字表法分为对照组和研究组,各30例。对照组患儿接受更昔洛韦注射液治疗,研究组患儿接受热毒宁注射液联合更昔洛韦注射液治疗,均治疗7d。对比两组患儿疗效、血清炎症因子、T细胞亚群、症状缓解时间和不良反应。结果：研究组的总有效率为93.33%,高于对照组的66.67%（P<0.05）。治疗后,研究组降钙素原（PCT）、C反应蛋白（CRP）、白介素-6（IL-6）的表达水平低于对照组（P<0.05）。治疗后,研究组CD8⁺低于对照组,CD3⁺、CD4⁺、CD4⁺/CD8⁺高于对照组（P<0.05）。研究组的咳嗽、呼吸困难、喘鸣音症状缓解时间短于对照组（P<0.05）。两组不良反应发生率比较无差异（P>0.05）。结论：RSV感染肺炎患儿采用热毒宁注射液联合更昔洛韦注射液治疗,疗效确切,能有效降低血清炎症因子水平,改善机体免疫功能,改善患儿临床症状,安全性较好。     

黄芪对儿童哮喘T细胞亚群细胞周期的影响

目的:观察黄芪对发作期哮喘患者T细胞亚群细胞周期的影响,揭示黄芪在哮喘治疗中的意义。方法:课题以儿童哮喘病人T细胞亚群为研究对象,对CD4+、CD8+T细胞进行分离,采用细胞培养技术,用黄芪对其进行体外处理,使用流式细胞仪测定经黄芪处理和未经黄芪处理的CD4+、CD8+T细胞的细胞周期分布情况。结果:儿童哮喘患者CD4+、CD8+T细胞分别在经黄芪处理和未经黄芪处理的条件下培养,在CD4+T细胞中,黄芪组的S期CD4+T细胞百分比显著低于对照组,有统计学意义(P<0.01);G1期细胞百分比显著高于对照组,有统计学意义(P<0.01)。在CD8+T细胞中,黄芪组的S期CD8+T细胞百分比低于对照组,有统计学差意义(P<0.05);G1期细胞百分比高于对照组,有统计学意义(P<0.05)。结论:黄芪抑制发作期哮喘患者CD4+、CD8+T细胞DNA合成,进而调节细胞周期使之停滞在G1期。黄芪对发作期儿童哮喘患者有一定的治疗意义。