A Comparison of Energy-Resolved Vibrational Activation/Dissociation Characteristics of Protonated and Sodiated High Mannose N-Glycopeptides

Fragmentation of glycopeptides in tandem mass spectrometry (MS/MS) plays a pivotal role in site-specific protein glycosylation profiling by allowing specific oligosaccharide compositions and connectivities to be associated with specific loci on the corresponding protein. Although MS/MS analysis of glycopeptides has been successfully performed using a number of distinction dissociation methods, relatively little is known regarding the fragmentation characteristics of glycopeptide ions with various charge carriers. In this study, energy-resolved vibrational activation/ dissociation was examined via collision-induced dissociation for a group of related high mannose tryptic glycopeptides as their doubly protonated, doubly sodiated, and hybrid protonated sodium adduct ions. The doubly protonated glycopeptide ions with various compositions were found to undergo fragmentation over a relatively low but wide range of collision energies compared with the doubly sodiated and hybrid charged ions, and were found to yield both glycan and peptide fragmentation depending on the applied collision energy. By contrast, the various doubly sodiated glycopeptides were found to dissociate over a significantly higher but narrow range of collision energies, and exhibited only glycan cleavages. Interestingly, the hybrid protonated sodium adduct ions were consistently the most stable of the precursor ions studied, and provided fragmentation information spanning both the glycan and the peptide moieties. Taken together, these findings illustrate the influence of charge carrier over the energyresolved vibrational activation/dissociation characteristics of glycopeptides, and serve to suggest potential strategies that exploit the analytically useful features uniquely afforded by specific charge carriers or combinations thereof

Südafrikas Atomwaffenprogramm

Die Arbeit zeichnet Südafrikas Weg zu seinen Atomwaffen und dem anschließenden nuklearen Abrüsten nach und versucht, den Motiven der Entscheidungsträger auf den Grund zu gehen. Das Atomprojekt begann und endete parallel mit der Apartheid. Der Schritt vom zivilen zum militärischen Atomprogramm fiel im Lauf der 1970er und war von äußeren (Hegemonie-Streben des Apartheid-Regimes im südlichen Afrika, zunehmende sowjetische Einflußnahme in der Region) und inneren Faktoren (innere Konkurrenz, Prestige-Streben, technische Herausforderung) bestimmt. Die Bomben waren der Bau- und Funktionsweise nach einfach, an Trägersystemen standen nur Flugzeuge (zum Abwurf der Bomben) zur Verfügung; sowohl bei den Bomben als auch bei den Trägersystemen wurde an Verbesserungen gearbeitet, die Einstellung des Programms kam Resultaten zuvor. Die Hilfe verschiedener westlicher Staaten für das Regime im nuklearen Bereich war von großer Bedeutung. Die offiziellen Darstellungen über das Programm nach dem Abrüsten waren lückenhaft und ungenau

Lung cancer and kidney injury: An updated review

Lung cancer is the leading cause of cancer deaths worldwide, accounting for an estimated 1.8 million deaths. Lung cancer is also the most common primary cancer leading to soft tissue (ST) metastasis. Renal disease may occur as a direct or indirect consequence of the cancer itself (e.g., post-renal obstruction, compression, or infiltration), its treatment (e.g., radiotherapy or chemotherapy), or its related complications (e.g., opportunistic infection). Existing evidence shows that the most frequent primary solid tumor responsible for renal metastasis is pulmonary carcinoma, followed by gastric, breast, soft tissue, and thyroid carcinomas. Chronic kidney disease is a potential risk factor in the survival of patients with lung cancer. In this review, we will discuss causes of kidney injury in relation to lung cancer, potential mechanisms of kidney injury, and treatment options

An online learning algorithm for adapting leg stiffness and stride angle for efficient quadruped robot trotting

Animals adjust their leg stiffness and stride angle in response to changing ground conditions and gait parameters, resulting in improved stability and reduced energy consumption. This paper presents an online learning algorithm that attempts to mimic such animal behavior by maximizing energy efficiency on the fly or equivalently, minimizing the cost of transport of legged robots by adaptively changing the leg stiffness and stride angle while the robot is traversing on grounds with unknown characteristics. The algorithm employs an approximate stochastic gradient method to change the parameters in real-time, and has the following advantages: (1) the algorithm is computationally efficient and suitable for real-time operation; (2) it does not require training; (3) it is model-free, implying that precise modeling of the robot is not required for good performance; and (4) the algorithm is generally applicable and can be easily incorporated into a variety of legged robots with adaptable parameters and gaits beyond those implemented in this paper. Results of exhaustive performance assessment through numerical simulations and experiments on an under-actuated quadruped robot with compliant legs are included in the paper. The robot platform used a pneumatic piston in each leg as a variable, passive compliant element. Performance evaluation using simulations and experiments indicated that the algorithm was capable of converging to near-optimal values of the cost of transport for given operating conditions, terrain properties, and gait characteristics with no prior knowledge of the terrain and gait conditions. The simplicity of the algorithm and its demonstrably improved performance make the approach of this paper an excellent candidate for adaptively controlling tunable parameters of compliant, legged robots

Extending the Capabilities of Tandem Mass Spectrometry for Glycoanalysis: Studies of the Parameters That Dictate the Collision-Induced Dissociation and Surface-Induced Dissociation of Glycopeptides and Oligosaccharides

Tandem mass spectrometry (MS/MS) is among one of the most powerful tools in glycoconjugate and carbohydrate analysis. With a need for further structural characterization of such analytes, there is a rising demand for enhancing the information content of MS/MS spectra. Therefore, in recent years, there have been many efforts to increase glycoprotein sequence coverages and in turn provide more structural and bioanalytical insights toward the functions and bioactivities of glycoproteins. A variety of ion activation and dissociation techniques have been implemented to achieve this goal, though some are subjected to limitations arising from the fragmentation pathways available in the ion activation process. A comprehensive understanding of the key parameters that govern fragmentation channels can allow for prediction of the product ions formed in gas-phase activation routes. This dissertation centers on the development of experimental designs that allow for the investigation into fundamentals of glycopeptide dissociation and major factors that influence the dissociation mechanisms. Chapter I is an overview on MS/MS strategies that are utilized to obtain vast information on peptide composition, attached glycan structure, and the glycosylation site of a glycoprotein. Chapter II describes a study on the effect of glycopeptide charge carrier on vibrational activation / dissociation characteristics of N-linked high mannose glycopeptides. Chapter III illustrates the impact of glycan size on the fragmentation pattern of high mannose N-linked glycopeptides via low energy collision-induced dissociation (CID). Chapter IV discusses the incorporation of surface-induced dissociation (SID) inside Synapt G2-S HDMS quadrupole time-of-flight (Q-TOF) instrument. The resulting comparison of the energy deposition processes in multi-collision (CID) and single event (SID) activation confirms the involvement of diverse energy deposition channels in each method. Chapter V describes the use of energy-sudden activation dissociation to circumvent the limitations of CID in carbohydrate sequencing. Overall, this dissertation works to address some of the ambiguity in glycopeptide and carbohydrate fragmentation processes

Within-day and between-day reliability of thickness measurements of abdominal muscles using ultrasound during abdominal hollowing and bracing maneuvers

Ultrasonography imaging has been used as a non-invasive method to estimate the thickness and relative activities of the abdominal muscles in patients with lower back pain (LBP). However, the statistical reliability of US thickness measurements of abdominal muscles, including transversus abdominis (TrA), internal oblique (IO) and external oblique (EO) muscles during abdominal hollowing (AH) and abdominal bracing (AB) maneuvers has not been well-investigated. This study was performed on a total of 20 female subjects (10 with LBP and 10 without LBP) in the age range of 25�55 years to assess within-day and between-day reliability of the measurements. US measurements on maneuvers were repeated after two hours for the within-day reliability and after five days for the between-day reliability assessment. High intra-class correlation coefficient (ICC) values (>0.75) for within-day and between-day reliability assessments during AH maneuver were concluded. The ICC values were moderate for reliability assessment during AB. The ICC values for AH were greater than AB both for within- and between-day reliabilities. The small standard error of measurement and minimal detectable change values (0.16�0.78 and 0.44 to 2.15, respectively) were found for both AH and AB. We recommend real-time US imaging as a reliable way of determining the thicknesses of the TrA and IO muscle (and to some extent, EO muscle) for both healthy and LBP patients. © 2017 Elsevier Lt

Within-day and between-day reliability of thickness measurements of abdominal muscles using ultrasound during abdominal hollowing and bracing maneuvers

Ultrasonography imaging has been used as a non-invasive method to estimate the thickness and relative activities of the abdominal muscles in patients with lower back pain (LBP). However, the statistical reliability of US thickness measurements of abdominal muscles, including transversus abdominis (TrA), internal oblique (IO) and external oblique (EO) muscles during abdominal hollowing (AH) and abdominal bracing (AB) maneuvers has not been well-investigated. This study was performed on a total of 20 female subjects (10 with LBP and 10 without LBP) in the age range of 25�55 years to assess within-day and between-day reliability of the measurements. US measurements on maneuvers were repeated after two hours for the within-day reliability and after five days for the between-day reliability assessment. High intra-class correlation coefficient (ICC) values (>0.75) for within-day and between-day reliability assessments during AH maneuver were concluded. The ICC values were moderate for reliability assessment during AB. The ICC values for AH were greater than AB both for within- and between-day reliabilities. The small standard error of measurement and minimal detectable change values (0.16�0.78 and 0.44 to 2.15, respectively) were found for both AH and AB. We recommend real-time US imaging as a reliable way of determining the thicknesses of the TrA and IO muscle (and to some extent, EO muscle) for both healthy and LBP patients. © 2017 Elsevier Lt

Preparation of Stable Plurilamellar Liposomes Dispersed in Two Soluble Types of Collagens and the Effect of Collagens on the Release Rate of Entrapped Sodium Chromate

Abstract Combination formulations of liposomes with collagen have been previously introduced as a means of obtaining more stable and less permeable liposomes. In this study, the effect of aqueous solutions of the collagen products COLLAPUR ® (COL) and COLLAPURON-DAK ® (COLD) from Henkle Co., on the release rate of sodium chromate (CHR) as a water-soluble model drug from stable plurilamellar vesicles (SPLVs) was evaluated. Results showed that dispersing SPLVs in diluted solutions (10%) of the collagens, increased the release rate from liposomes at 32°C. It is speculated that after binding to the hydrophilic surface of liposomes, the structure of the collagen changes and the hydrophobic portions become more exposed. This is likely to cause a penetration of these portions into the bilayer structure (which is fluid at this temperature), thus causing an expansion in the membrane and an increase in permeability. In higher concentrations (30% and 50%), this increasing effect is not observed, which is suggested to be due to the aggregation of collagen fibrils and the resultant higher viscosity. It is concluded that these collagens in optimum concentrations could find a good place in the preparation of topical liposomes, due to their flexible effects on the release rate of liposomes, as well as the dermatological effects of collagen itself

Functional alterations in gluteal muscles due to low back pain: A qualitative review of the literature

One of the biggest problem in clinical examination of the patients with LBP symptoms is the lack of a comprehensive diagnosis protocol comprising all muscular alterations responsible for LBP. Connected to lumbar pelvis region, gluteal muscles perform the important role of transferring the upper-body movements as forces to the lower-body limbs. Therefore, the gluteal muscles have received an increasing attention by clinicians and researchers diagnosing LBP. However, there has been a scattered list of studies using electromyography, image scanning and physical examination techniques for monitoring the gluteal muscles of gluteus maximus (GMax), gluteus medius (GMed). In the present research, we reviewed the literature comprehensively, discussed the advantages and disadvantages of the measurement methods. By discovering the disagreements reported by different researchers, the resultant mutual findings across all studies were identified. This study concluded a strong relationship between a dysfunction in operation of the gluteal muscles and occurrence of LBP. The functional changes in gluteal muscles include fatigability in the GMax muscles, neuromuscular alterations and a decrease in abduction strength of the GMedmuscles. © 2018 Lahore Medical And Dental College. All rights reserved