Sökresultat

Filtyp

Din sökning på "*" gav 532197 sökträffar

The thermal alteration by pyrolysis of the organic component of small projectiles of mudrock during capture at hypervelocity

In a series of experiments the pyrolytic effects of the heating induced during the hypervelocity impact (HVI) of small projectiles of high TOC mudrock were observed. Impacts at these high speeds (km s-1) release sufficient energy to vaporise metal projectiles, and the temperatures created greatly exceed the pyrolysis temperatures typically employed during laboratory studies of the thermal alterati

Treating Parkinson's disease in the 21st century : can stem cell transplantation compete?

The characteristic and selective degeneration of a unique population of cells-the nigrostriatal dopamine (DA) neurons-that occurs in Parkinson's disease (PD) has made the condition an iconic target for cell replacement therapies. Indeed, transplantation of fetal ventral mesencephalic cells into the DA-deficient striatum was first trialled nearly 30 years ago, at a time when other treatments for th

Mild cognitive impairment and Parkinson's disease - something to remember

Cognitive impairment is common in Parkinson's disease (PD), and many patients will eventually develop a dementia, which has a devastating impact on the patient and their family. As such, there has been much interest in identifying a prodromal state to inform prognosis and facilitate earlier management, similar to the concept of 'MCI' in the Alzheimer's field. However, grouping the early cognitive

A retrospective analysis of hand tapping as a longitudinal marker of disease progression in Huntington's disease

BACKGROUND: Current clinical assessments of motor function in Huntington's Disease (HD) rely on subjective ratings such as the Unified Huntington's Disease Rating scale (UHDRS). The ability to track disease progression using simple, objective, inexpensive, and robust measures would be beneficial.METHODS: One objective measure of motor performance is hand-tapping. Over the last 14 years we have rou

Growth hormone is secreted by normal breast epithelium upon progesterone stimulation and increases proliferation of stem/progenitor cells

Using in vitro and in vivo experimental systems and in situ analysis, we show that growth hormone (GH) is secreted locally by normal human mammary epithelial cells upon progesterone stimulation. GH increases proliferation of a subset of cells that express growth hormone receptor (GHR) and have functional properties of stem and early progenitor cells. In 72% of ductal carcinoma in situ lesions, an

A high-precision 40Ar/39Ar age for hydrated impact glass from the Dellen impact, Sweden

The dating of terrestrial impact craters and impact glasses that exhibit high degrees of mineralogical complexity can be problematic. However, if the maximum potential of the terrestrial impact crater record is to be realized, accurate and precise ages for crater-forming events are critical. Here we report a high-precision 40Ar/39Ar age for the Dellen impact structure, Sweden. Previous radio-isoto

Genetic impact on cognition and brain function in newly diagnosed Parkinson's disease : ICICLE-PD study

Parkinson's disease is associated with multiple cognitive impairments and increased risk of dementia, but the extent of these deficits varies widely among patients. The ICICLE-PD study was established to define the characteristics and prevalence of cognitive change soon after diagnosis, in a representative cohort of patients, using a multimodal approach. Specifically, we tested the 'Dual Syndrome'

The glial response to intracerebrally delivered therapies for neurodegenerative disorders : is this a critical issue?

The role of glial cells in the pathogenesis of many neurodegenerative conditions of the central nervous system (CNS) is now well established (as is discussed in other reviews in this special issue of Frontiers in Neuropharmacology). What is less clear is whether there are changes in these same cells in terms of their behavior and function in response to invasive experimental therapeutic interventi

Quality of life and mild cognitive impairment in early Parkinson's disease : does subtype matter?

We evaluated the association between mild cognitive impairment (MCI) subtypes and quality of life (QoL) in 219 newly diagnosed Parkinson's disease (PD) patients without dementia. Participants completed neuropsychological tests of attention, executive function, visuospatial function, memory, and language, and reported QoL using the Parkinson's Disease Questionnaire. Impairments were most common in

The incidence of Parkinson's disease in the North-East of England

BACKGROUND: Parkinson's disease is a common disorder among older people. Accurate epidemiological information is essential to identify possible aetiological factors, plan health services and set priorities for medical research.OBJECTIVE: to determine the incidence of idiopathic Parkinson's disease in a defined geographical area in the North-East of England.METHODS: using a prospective, longitudina

Haemoglobin Koln as de novo mutations in Sweden : Diagnosis by PCR and specific enzymatic cleavage

Three independent cases of chronic haemolytic anaemia in Sweden have recently been demonstrated to be due to the unstable haemoglobin variant Hb Koln. The patients, all of whom have partially compensated chronic haemolytic anaemia, presented with aggravated haemolysis during acute infections in childhood. In one case, acute B19 parvovirus infection induced an aplastic crisis. The substitutions all

InAs/GaSb vertical nanowire TFETs on Si for digital and analogue applications

Vertical InAs/GaSb nanowire TFETs with diameters of 20 nm and 25 nm have been fabricated and characterized. The influence of diameter, gate-placement, and nanowire numbers have been studied. The best device shows a subthreshold swing of 68 mV/dec at VDS = 0.3 V and 26 μA/μm at VDS = 0.3 V and VGS = 0.5 V. It achieves a self-gain larger than 100 with high transconductance efficiency.

Rapid heating of carbonaceous matter by igneous intrusions in carbon-rich shale, Isle of Skye, Scotland : An analogue for heating of carbon in impact craters?

The response of organic matter to high-temperature events is important to astrobiology, as it governs the survival of carbon during several processes that may be critical to the origin and spread of life. Impact cratering is a widespread high-temperature process. The behaviour of carbon during impact events is not well understood. But there is the potential to examine other examples of the respons

Alterations of striatal indirect pathway neurons precede motor deficits in two mouse models of Huntington's disease

Striatal neurons forming the indirect pathway (iSPNs) are particularly vulnerable in Huntington's disease (HD). In this study we set out to investigate morphological and physiological alterations of iSPNs in two mouse models of HD with relatively slow disease progression (long CAG repeat R6/2 and zQ175-KI). Both were crossed with a transgenic mouse line expressing eGFP in iSPNs. Using the open-fie

Measurement of the ZZ production cross section in proton-proton collisions at √s=8 TeV using the ZZ → ℓ−ℓ+ℓ′−ℓ′+ and ZZ→ ℓ−ℓ+νν¯ decay channels with the ATLAS detector

A measurement of the ZZ production cross section in the ℓ−ℓ+ℓ′ −ℓ′ + and ℓ−ℓ+νν¯ channels (ℓ = e, μ) in proton-proton collisions at s=8TeV at the Large Hadron Collider at CERN, using data corresponding to an integrated luminosity of 20.3 fb−1 collected by the ATLAS experiment in 2012 is presented. The fiducial cross sections for ZZ → ℓ−ℓ+ℓ′ −ℓ′ + and ZZ→ ℓ−ℓ+νν¯ are measured in selected phase-spac

Learned response sequences in cerebellar Purkinje cells

Associative learning in the cerebellum has previously focused on single movements. In eyeblink conditioning, for instance, a subject learns to blink at the right time in response to a conditional stimulus (CS), such as a tone that is repeatedly followed by an unconditional corneal stimulus (US). During conditioning, the CS and US are transmitted by mossy/parallel fibers and climbing fibers to cere