Epilepsy and Vitamin D

Summary Several disorders, both systemic and those of the nervous system, have been linked with vitamin D deficiency. Neurological disorders with a vitamin D link include but are not limited to multiple sclerosis, Alzheimer and Parkinson disease as well as cerebrovascular disorders. Epilepsy which is the second leading neurological disorder received much less attention. We review evidence supporting a link between vitamin D and epilepsy including those coming from ecological as well as interventional and animal studies. We also assess the literature on the interaction between antiepileptic drugs and vitamin D. Converging evidence indicates a role for vitamin D deficiency in the pathophysiology of epilepsy

Results, Old and New, in Computed Tomography

Introduction Computed tomography (CT) entails the reconstruction of a function f from line integrals of f . This mathematical problem is encountered in a growing number of diverse settings in medicine, science, and technology, ranging from the famous application in diagnostic radiology to recent research in quantum optics. As a consequence, many aspects of CT have been extensively studied and are now well understood, thus providing an interesting model case for the study of other inverse problems. Other aspects, notably three-dimensional reconstructions, still provide numerous open problems. The present article grew out of a series of tutorial talks given by the author at the IMA. In the spirit of such talks, it attempts to provide a brief introduction to the subject, highlight some aspects of general interest, sketch some recent developments, and point out references for further study. In practice only integrals over finitely many lines can b

Ultrafast X-ray probing of water structure below the homogeneous ice nucleation temperature

Water has a number of anomalous physical properties, and some of these become drastically enhanced on supercooling below the freezing point. Particular interest has focused on thermodynamic response functions that can be described using a normal component and an anomalous component that seems to diverge at about 228 kelvin. This has prompted debate about conflicting theories that aim to explain many of the anomalous thermodynamic properties of water. One popular theory attributes the divergence to a phase transition between two forms of liquid water occurring in the ‘no man’s land’ that lies below the homogeneous ice nucleation temperature (TH) at approximately 232 kelvin and above about 160 kelvin, and where rapid ice crystallization has prevented any measurements of the bulk liquid phase. In fact, the reliable determination of the structure of liquid water typically requires temperatures above about 250 kelvin. Water crystallization has been inhibited by using nanoconfinement, nanodroplets and association with biomolecules to give liquid samples at temperatures below TH, but such measurements rely on nanoscopic volumes of water where the interaction with the confining surfaces makes the relevance to bulk water unclear18. Here we demonstrate that femtosecond X-ray laser pulses can be used to probe the structure of liquid water in micrometre-sized droplets that have been evaporatively cooled below TH. We find experimental evidence for the existence of metastable bulk liquid water down to temperatures of  kelvin in the previously largely unexplored no man’s land. We observe a continuous and accelerating increase in structural ordering on supercooling to approximately 229 kelvin, where the number of droplets containing ice crystals increases rapidly. But a few droplets remain liquid for about a millisecond even at this temperature. The hope now is that these observations and our detailed structural data will help identify those theories that best describe and explain the behaviour of water

Emergent Properties and Functions of Nanoconfined Nucleic Acid Architectures

6siThe facile ability of DNA to self-assemble has enabled the creation of complex architectures with diverse functions on surfaces or in solution. This approach provides a powerful design tool for the development of nanoscale devices with transformative applications in multiple areas, including the detection of complex biomolecules, drug delivery, and in situ biomolecular synthesis. However, little is known of the effect of confinement on the function of complex nucleic acid architectures, which exhibit unanticipated behaviors that presumably reflect high-level molecular crowding. In this chapter, we review selected recent studies that describe the application and atypical behaviors of nanoconfined nucleic acids, in particular with respect to hybridization, denaturation, conformation, stability, and enzyme accessibility. We argue that the novel behavior of dense nucleic acid arrays naturally emerge as a result of immobilization and reduction in spatial degrees of freedom. We summarize by emphasizing the need for basic physical–chemical studies of dense nucleic acid architectures, involving an interplay of experimental and theoretical approaches, in order to effectively guide the successful technological development of nucleic acid nanodevices.reservedmixedNicholson, Allen W.; Redhu, Shiv K.; Stopar, Alex; Coral, Lucia; Carnevale, Vincenzo; Castronovo, MatteoNicholson, Allen W.; Redhu, Shiv K.; Stopar, Alex; Coral, Lucia; Carnevale, Vincenzo; Castronovo, Matte