Structural Characterization of Daunomycin-Peptide Conjugates by Various Tandem Mass Spectrometric Techniques

The use of peptide-drug conjugates has generated wide interest as targeted antitumor therapeutics. The anthracycline antibiotic, daunomycin, is a widely used anticancer agent and it is often conjugated to different tumor homing peptides. However, comprehensive analytical characterization of these conjugates via tandem mass spectrometry (MS/MS) is challenging due to the lability of the O-glycosidic bond and the appearance of MS/MS fragment ions with little structural information. Therefore, we aimed to investigate the optimal fragmentation conditions that suppress the prevalent dissociation of the anthracycline drug and provide good sequence coverage. In this study, we comprehensively compared the performance of common fragmentation techniques, such as higher energy collisional dissociation (HCD), electron transfer dissociation (ETD), electron-transfer higher energy collisional dissociation (EThcD) and matrix-assisted laser desorption/ionization–tandem time-of-flight (MALDI-TOF/TOF) activation methods for the structural identification of synthetic daunomycin-peptide conjugates by high-resolution tandem mass spectrometry. Our results showed that peptide backbone fragmentation was inhibited by applying electron-based dissociation methods to conjugates, most possibly due to the “electron predator” effect of the daunomycin. We found that efficient HCD fragmentation was largely influenced by several factors, such as amino acid sequences, charge states and HCD energy. High energy HCD and MALDI-TOF/TOF combined with collision induced dissociation (CID) mode are the methods of choice to unambiguously assign the sequence, localize different conjugation sites and differentiate conjugate isomers.     

A Graph-Theoretic Framework for Assessing the Resilience of Sectorised Water Distribution Networks

Water utilities face a challenge in maintaining a good quality of service under a wide range of operational management and failure conditions. Tools for assessing the resilience of water distribution networks are therefore essential for both operational and maintenance optimization. In this paper, a novel graph-theoretic approach for the assessment of resilience for large scale water distribution networks is presented. This is of great importance for the management of large scale water distribution systems, most models containing up to hundreds of thousands of pipes and nodes. The proposed framework is mainly based on quantifying the redundancy and capacity of all possible routes from demand nodes to their supply sources. This approach works well with large network sizes since it does not rely on precise hydraulic simulations, which require complex calibration processes and computation, while remaining meaningful from a physical and a topological point of view. The proposal is also tailored for the analysis of sectorised networks through a novel multiscale method for analysing connectivity, which is successfully tested in operational utility network models made of more than 100,000 nodes and 110,000 pipes.     

Effects of fruit juice concentrate production on individual anthocyanin species in elderberry

Elderberry concentrate is widely used for food colouring. Its production includes several processing steps, which influence pigment composition, thus affecting the quality of final product. In this study, qualitative and quantitative changes in anthocyanin components were followed during the production of elderberry juice concentrate using Haschberg and Samocco varieties. Juice concentration resulted in more than five‐fold concentration increase in anthocyanins; however, clarification, filtration and evaporation steps caused slight but continuous decrease in anthocyanins relative to the dry matter of the product. Pectolytic enzymatic treatment was found to be one of the most critical processing steps that affects anthocyanin yield during production, and this effect on yield can be variety‐dependent. Additionally, two condensed dimeric anthocyanin species generated after heat treatment are reported for the first time to be present in elderberry juice concentrate. Our results suggest that cyanidin‐based anthocyanin conjugates with more complex saccharide moieties are more robust during production.     

Characteristic Analysis of a Micro DC‐DC Converter for Portable Electronic Devices and an Improvement of Transient Response Characteristic

This paper describes the characteristic analysis of a micro DC‐DC converter which integrates inductor, controller and switching devices, and the improvement of the transient response characteristic. The steady‐state operation and the efficiency characteristics of the micro DC‐DC converter are presented as experimental data. The static characteristics are theoretically analyzed with consideration of the DC current characteristics of the inductor. The load transient response characteristics of the micro DC‐DC converter are also analyzed experimentally and theoretically. In addition, the factors responsible for the overshoot and undershoot of the output voltage when the load changes are discussed. Finally, a clamp circuit for reducing the overshoot and undershoot of the output voltage when the load changes is proposed. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(3): 56–64, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21081     

Analysis of mir-9 Expression Pattern in Rat Retina during Postnatal Development

It is well established that miR-9 contributes to retinal neurogenesis. However, little is known about its presence and effects in the postnatal period. To expand our knowledge, miRNA-small RNA sequencing and in situ hybridization supported by RT-qPCR measurement were carried out. Mir-9 expression showed two peaks in the first three postnatal weeks in Wistar rats. The first peak was detected at postnatal Day 3 (P3) and the second at P10, then the expression gradually decreased until P21. Furthermore, we performed in silico prediction and established that miR-9 targets OneCut2 or synaptotagmin-17. Another two microRNAs (mir-135, mir-218) were found from databases which also target these proteins. They showed a similar tendency to mir-9; their lowest expression was at P7 and afterwards, they showed increase. We revealed that miR-9 is localized mainly in the inner retina. Labeling was observed in ganglion and amacrine cells. Additionally, horizontal cells were also marked. By dual miRNA-in situ hybridization/immunocytochemistry and qPCR, we revealed alterations in their temporal and spatial expression. Our results shed light on the significance of mir-9 regulation during the first three postnatal weeks in rat retina and suggest that miRNA could act on their targets in a stage-specific manner.     

INFRARED TRANSIENT THERMOGRAPHY FOR NON-CONTACT,NONDESTRUCTIVE INSPECTION OF WHOLE AND DISSECTED APPLES AND OF CHERRY TOMATOES AT DIFFERENT MATURITY STAGES

Introduction

Fruits and vegetables used in various processed products, as well as in fresh market sales, are expected to comply with the certain quality standards. However. quality is everything but a single parameter state and, therefore, a variety of subjective and objective measurements are usually performed. In particular, the firmness and maturity are considered important attributes to the quality of fruits and vegetable crops. Presently. these parameters are usually determined either destructively (by a pressure tester) or by means of ultrasound; a development of alternative methods has been strongly encouraged in the recent years.     

Compressibility and flow properties of a cohesive limestone powder in a medium pressure range

The most important design parameters for roller presses can be referred to flow characteristic of bulk materials. Usually the flow properties are measured in the low stress range 1–50 kPa at the shear rate about 1 mm/min. But this does not fit the stressing conditions in the roller press. Press shear cell was used for shear tests with cohesive limestone powder from Gummern in the so-called medium pressure range 50–1000 kPa.     

Dietary fat composition and tocopherol requirement: III. Quantitative studies on the relationship between dietary linoleate and vitamin E

The present study has involved biologically titrating linoleate vs. vitamin E using the male rat as the indicator. In the first of the titration studies, the dietary tocopherol level was held constant, while in the second study the linoleate intake was held constant. The investigation was conducted with male rats since these have a much higher linoleate requirement than females. By first depleting such animals of their stores of essential fatty acids by feeding a fat-free diet from weaning, a sensitive test organism was provided. These animals have an immediate need for linoleate during the repletion periods. If an imbalance between linoleate and vitamin E content existed in any of the dietary regimens, such an imbalance would have been more likely noted in test animals actively metabolizing the ingested linoleate. Based upon various nutritional and biochemical indices, the amount of tocopherol ordinarily included in the basic diets fed to our rats, 0.01% as dl-alphatocopheryl acetate, was adequate even when the diet provided up to 5% linoleate; an amount corresponding to ca. 12% of the total calories and providing a ratio of linoleate to the tocopherol of ca. 500:1. In the reverse biological titration with all test diets now providing the constant level of 5% linoleate, ratios of linoleate to vitamin E were satisfactory even in a ratio of as much as 2500:1 (or 0.4 mg gram of vitamin E per polyunsaturated fatty acid). The control animals continued on the fat-free diet indicated that there is a need for added tocopherols even in the absence of linoleate according to a number of biochemical indices. Based upon a number of accepted bioanalytical approaches, the minimum requirement for linoleate by the fat-depleted male rat was found to be between 100–200 mg/day or ca. 1–2% of the caloric intake. Although the fatty acid composition of tissue lipid fractions is markedly affected by the amount of linoleate in the diet, dietary tocopherol supplements have little effect on these values.     

Proteomic and peptidomic characterisation of beer: Immunological and technological implications

In this study, the protein and peptide fractions of two commercial Italian barley malt beers, made with different processes by the same producer, have been analysed with a combined immunochemical and mass spectrometry approach. The “gluten” content of beer samples, measured with the R5 monoclonal antibody, was below the caution limit proposed by the Codex Alimentarius for gluten-free foods. The proteomic approach allowed to identify a 17 kDa avenin-like protein partially homologous to hordeins, that was particularly abundant in foam, in addition to the already reported barley albumins (Z₄-barley and ns-LTPs) and to minor amounts of yeast glycolytic enzymes. No intact hordeins were detected, although fragments derived from γ₃- and B-hordein were present. In consideration of the many implications of the protein/peptide pattern, these data provide useful information to improve quality and safety of beer.