Materials and devices for spatial multi-dimensional liquid chromatography

In this thesis, the potential of spatial multi-dimensional liquid chromatography is explained, culminating in the “Separation Technologies for A Million Peaks” (STAMP) project. Different kinds of stationary phases were developed and taken into consideration, with the simplicity of the in-situ creation of monoliths being highlighted. Their applications in a hydrophilic-interaction-liquid-chromatography – high-resolution-mass-spectrometry method for the separation of intact proteins and, specifically, intact glycoforms are described in two chapters of this work. Glass, PEEK and titanium were explored as materials for 3D-printing column housings and microfluidic devices, with titanium providing the most successful applications. Titanium devices, with different designs, were successfully used to confine the thermal polymerization of monolithic stationary phases. The most successful design was then implemented in complex microfluidic titanium devices in order to perform spatial multi-dimensional liquid chromatography

Persistent postural-perceptual dizziness: a useful new syndrome.

In this issue of Practical Neurology, Popkirov, Staab and Stone illuminate a newly defined condition—persistent postural-perceptual dizziness or ‘PPPD’, a maladaptive functional syndrome in which patients feel unbalanced despite not falling, and feel that they are moving, despite being stationary. PPPD is common in specialist dizzy clinics, accounting for 10% of cases as a primary diagnosis of dizziness. PPPD can coexist with other causes of dizziness, such as vestibular migraine or benign paroxysmal positional vertigo, and it is in this form that it most commonly presents to a specialist dizzy clinic.BMS: funded by the Medical Research Council, the NIHR Imperial Biomedical Research Centre, and the Imperial Health Charity. LP: funded by the Medical Research Council (MRC) (MR/P01271X/1) at the University of Cambridge, UK

Mito-nuclear coevolution and phylogenetic artifacts: the case of bivalve mollusks

Mito‐nuclear phylogenetic discordance in Bivalvia is well known. In particular, the monophyly of Amarsipobranchia (Heterodonta + Pteriomorphia), retrieved from mitochondrial markers, contrasts with the monophyly of Heteroconchia (Heterodonta + Palaeoheterodonta), retrieved from nuclear markers. However, since oxidative phosphorylation nuclear markers support the Amarsipobranchia hypothesis instead of the Heteroconchia one, interacting subunits of the mitochondrial complexes ought to share the same phylogenetic signal notwithstanding the genomic source, which is different from the signal obtained from other nuclear markers. This may be a clue of coevolution between nuclear and mitochondrial genes. In this work we inferred the phylogenetic signal from mitochondrial and nuclear oxidative phosphorylation markers exploiting different phylogenetic approaches and added two more datasets for comparison: genes of the glycolytic pathway and genes related to the biogenesis of regulative small noncoding RNAs. All trees inferred from mitochondrial and nuclear subunits of the mitochondrial complexes support the monophyly of Amarsipobranchia, regardless of the phylogenetic pipeline. However, not every single marker agrees with this topology: this is clearly visible in nuclear subunits that do not directly interact with the mitochondrial counterparts. Overall, our data support the hypothesis of a coevolution between nuclear and mitochondrial genes for the oxidative phosphorylation. Moreover, we suggest a relationship between mitochondrial topology and different nucleotide composition between clades, which could be associated to the highly variable gene arrangement in Bivalvia

Mitochondrial selfish elements and the evolution of biological novelties.

We report the present knowledge about RPHM21, a novel male-specific mitochondrial protein with a putative role in the paternal inheritance of sperm mitochondria in the Manila clam Ruditapes philippinarum, a species with doubly uniparental inheritance of mitochondria (DUI). We review all the available data on rphm21 transcription and translation, analyze in detail its female counterpart, RPHF22, discuss the homology with RPHM21, the putative function and origin, and analyze their polymorphism. The available evidence is compatible with a viral origin of RPHM21 and supports its activity during spermatogenesis. RPHM21 is progressively accumulated in mitochondria and nu- clei of spermatogenic cells, and we hypothesize it can influence mitochondrial inheritance and sex- ual differentiation. We propose a testable model that describes how the acquisition of selfish fea- tures by a mitochondrial lineage might have been responsible for the emergence of DUI, and for the evolution of separate sexes (gonochorism) from hermaphroditism. The appearance of DUI most likely entailed the invasion of at least 1 selfish element, and the extant DUI systems can be seen as resolved conflicts. It was proposed that hermaphroditism was the ancestral condition of bi- valves, and a correlation between DUI and gonochorism was documented. We hypothesize that DUI might have driven the shift from hermaphroditism to gonochorism, with androdioecy as transi- tion state. The invasion of sex-ratio distorters and the evolution of suppressors can prompt rapid changes among sex-determination mechanisms, and DUI might have been responsible for one of such changes in some bivalve species. If true, DUI would represent the first animal sex-determination system involving mtDNA-encoded proteins

Fiber Bragg Grating sensors for deformation monitoring of GEM foils in HEP detectors

Fiber Bragg Grating (FBG) sensors have been so far mainly used in high energy physics (HEP) as high precision positioning and re-positioning sensors and as low cost, easy to mount, radiation hard and low space- consuming temperature and humidity devices. FBGs are also commonly used for very precise strain measurements. In this work we present a novel use of FBGs as flatness and mechanical tensioning sensors applied to the wide Gas Electron Multiplier (GEM) foils of the GE1/1 chambers of the Compact Muon Solenoid (CMS) experiment at Large Hadron Collider (LHC) of CERN. A network of FBG sensors has been used to determine the optimal mechanical tension applied and to characterize the mechanical stress applied to the foils. The preliminary results of the test performed on a full size GE1/1 final prototype and possible future developments will be discussed.Comment: Four pages, seven figures. Presented by Michele Caponero at IWASI 2015, Gallipoli (Italy

LA MUTAZIONE JAK2 (V617F) E LA TROMBOSI VENOSA CEREBRALE

ABSTRACT Whether or not cerebral venous thrombosis can be the first manifestation of an underlying myeloproliferative neoplasm is currently unclear. Patients with cerebral venous thrombosis were tested for the JAK2 (V617F) mutation and were followed until the development of a myeloproliferative neoplasm or censored at the end of follow-up. Ten of 152 patients (6.6%) carried the JAK2 (V617F) mutation. Three of them had known acquired risk factors for thrombosis and 5 had thrombophilia. Six patients met the diagnostic criteria for myeloproliferative neoplasm at the time of cerebral venous thrombosis, while three additional patients developed the disease during the follow-up (median duration 7.8 years, 6 months to 21.3 years), for an annual incidence of 0.26% patient-years (95% CI 0.05-0.64). The last patient has no evidence of disease after three years of follow-up. Patients without JAK2 (V617F) at the time of cerebral venous thrombosis were re-tested at the end of the follow-up and remained negative, with normal blood counts [log-rank test \uf0632: 159 (p<0.0001)]. Cerebral venous thrombosis can be the first symptom of a myeloproliferative neoplasm. Thus, patients with cerebral venous thrombosis should be tested for the JAK2 (V617F) mutation, irrespective of blood counts and the presence of other risk factors for thrombosis

Eco-friendly gas mixtures for Resistive Plate Chambers based on Tetrafluoropropene and Helium

Due to the recent restrictions deriving from the application of the Kyoto protocol, the main components of the gas mixtures presently used in the Resistive Plate Chambers systems of the LHC experiments will be most probably phased out of production in the coming years. Identifying possible replacements with the adequate characteristics requires an intense R&D, which was recently started, also in collaborations across the various experiments. Possible candidates have been proposed and are thoroughly investigated. Some tests on one of the most promising candidate - HFO-1234ze, an allotropic form of tetrafluoropropane- have already been reported. Here an innovative approach, based on the use of Helium, to solve the problems related to the too elevate operating voltage of HFO-1234ze based gas mixtures, is discussed and the relative first results are shown.Comment: 9 pages, 6 figures, 1 tabl

Cms gem detector material study for the hl-lhc

A study on the Gaseous Electron Multiplier (GEM) foil material is performed to determine the moisture diffusion rate, moisture saturation level and the effects on its mechanical properties. The study is focused on the foil contact with ambient air and moisture to determine the value of the diffusion coefficient of water in the foil material. The presence of water inside the detector foil can determine the changes in its mechanical and electrical properties. A simulated model is developed with COMSOL Multiphysics v. 4.3 [1] by taking into account the real GEM foil (hole dimensions, shapes and material), which describes the adsorption of water. This work describes the model, its experimental verification, the water diffusion within the entire sheet geometry of the GEM foil, thus gaining concentration profiles and the time required to saturate the system and the effects on the mechanical properties

Psychopathic traits influence amygdala-anterior cingulate cortex connectivity during facial emotion processing

There is accumulating evidence that youths with antisocial behavior or psychopathic traits show deficits in facial emotion recognition, but little is known about the neural mechanisms underlying these impairments. A number of neuroimaging studies have investigated brain activity during facial emotion processing in youths with Conduct Disorder (CD) and adults with psychopathy, but few of these studies tested for group differences in effective connectivity – i.e., changes in connectivity during emotion processing. Using functional magnetic resonance imaging and psycho-physiological interaction methods, we investigated the impact of CD and psychopathic traits on amygdala activity and effective connectivity in 46 male youths with CD and 25 typically-developing controls when processing emotional faces. All participants were aged 16-21 years. Relative to controls, youths with CD showed reduced amygdala activity when processing angry or sad faces relative to neutral faces, but the groups did not significantly differ in amygdala-related effective connectivity. In contrast, psychopathic traits were negatively correlated with amygdala-ventral anterior cingulate cortex connectivity for angry versus neutral faces, but were unrelated to amygdala responses to angry or sad faces. These findings suggest that CD and psychopathic traits have differential effects on amygdala activation and functional interactions between limbic regions during facial emotion processing