University of Cambridge

About: University of Cambridge is a education organization based out in Cambridge, United Kingdom. It is known for research contribution in the topics: Population & Galaxy. The organization has 118293 authors who have published 282289 publications receiving 14497093 citations. The organization is also known as: Cambridge University & Cambridge.

Medicinal Plants and Alzheimer's Disease: from Ethnobotany to Phytotherapy**

Abstract: The use of complementary medicines, such as plant extracts, in dementia therapy varies according to the different cultural traditions. In orthodox Western medicine, contrasting with that in China and the Far East for example, pharmacological properties of traditional cognitive- or memory-enhancing plants have not been widely investigated in the context of current models of Alzheimer's disease. An exception is Gingko biloba in which the gingkolides have antioxidant, neuroprotective and cholinergic activities relevant to Alzheimer's disease mechanisms. The therapeutic efficacy of Ginkgo extracts in Alzheimer's disease in placebo controlled clinical trials is reportedly similar to currently prescribed drugs such as tacrine or donepezil and, importantly, undesirable side effects of Gingko are minimal. Old European reference books, such as those on medicinal herbs, document a variety of other plants such as Salvia officinalis (sage) and Melissa officinalis (balm) with memory-improving properties, and cholinergic activities have recently been identified in extracts of these plants. Precedents for modern discovery of clinically relevant pharmacological activity in plants with long-established medicinal use include, for example, the interaction of alkaloid opioids in Papaver somniferum (opium poppy) with endogenous opiate receptors in the brain. With recent major advances in understanding the neurobiology of Alzheimer's disease, and as yet limited efficacy of so-called rationally designed therapies, it may be timely to re-explore historical archives for new directions in drug development. This article considers not only the value of an integrative traditional and modern scientific approach to developing new treatments for dementia, but also in the understanding of disease mechanisms. Long before the current biologically-based hypothesis of cholinergic derangement in Alzheimer' s disease emerged, plants now known to contain cholinergic antagonists were recorded for their amnesia- and dementia-inducing properties.

Van der Waals forces between an atom and a surface

Abstract: The theory of electrical images is used to derive Van der Waals forces at the surface of a solid, which is treated as a continuous dielectric medium. The theory gives the attraction between a single atom and the surface, between two atoms which are both close to the surface and between two bodies separated by a gap. The forces come out in terms of the dielectric constant of the solid and the electric polarizability of the atom at imaginary frequencies. The method of images breaks down at distances greater than about 500 a, and an exact treatment of the electromagnetic field fluctuations near the surface leads to the same force as Lifshitz's general theory.

Inoculating Against Fake News About COVID-19.

Abstract: The outbreak of the SARS-CoV-2 novel coronavirus (COVID-19) has been accompanied by a large amount of misleading and false information about the virus, especially on social media. In this article, we explore the coronavirus "infodemic" and how behavioral scientists may seek to address this problem. We detail the scope of the problem and discuss the negative influence that COVID-19 misinformation can have on the widespread adoption of health protective behaviors in the population. In response, we explore how insights from the behavioral sciences can be leveraged to manage an effective societal response to curb the spread of misinformation about the virus. In particular, we discuss the theory of psychological inoculation (or prebunking) as an efficient vehicle for conferring large-scale psychological resistance against fake news.

The uptake of noradrenaline by the isolated perfused rat heart.

Abstract: The uptake of noradrenaline by the isolated perfused rat heart was studied after perfusion with a medium containing various concentrations of (+/-)-[(3)H]-noradrenaline. Simultaneous measurement of the uptake of [(3)H]-noradrenaline and of the net increase in the noradrenaline content of the heart showed that [(3)H]-noradrenaline entering the heart both increased the tissue content and exchanged with endogenous noradrenaline. A large part (about 75%) of the endogenous noradrenaline pool, however, exchanged very slowly if at all with exogenous noradrenaline. The initial rates of noradrenaline uptake satisfied Michaelis-Menten kinetics with a Km for (+/-)-noradrenaline of 6.64x10(-7) M. Further analysis of the uptake process indicated that noradrenaline entered into at least two intracellular pools at different rates. Measurement of the initial rates of noradrenaline uptake during perfusion with various concentrations of nonradioactive (+)- and (-)-noradrenaline showed that the uptake process exhibited stereochemical specificity. The Km values for (+)- and (-)-noradrenaline were 13.9x10(-7) and 2.66x10(-7) M respectively. Cocaine acted as a potent competitive inhibitor of noradrenaline uptake. This finding suggested that diffusion did not play any significant role in the entry of noradrenaline into the tissue.