An Effective Approach to Improving Day-Case Rates following Laparoscopic Cholecystectomy

Background. Day-case laparoscopic cholecystectomy (LC) is a safe and cost-effective treatment for gallstones. In 2006, our institution recorded an 86% laparoscopic, 10% day-case, and 5% readmission rate. A gallbladder pathway was therefore introduced in 2007 with the aim of increasing daycase rates. Methods. Patients with symptomatic gallstones, proven on ultrasound, were referred to a specialist-led clinic. Those suitable for surgery were consented, preassessed, and provided with a choice of dates. All defaulted to day case unless deemed unsuitable due to comorbidity or social factors. Results. The number of cholecystectomies increased from 464 in 2006 to 578 in 2008. Day-case rates in 2006, 2007, 2008, and June 2009 were 10%, 20%, 30%, and 61%, respectively. Laparoscopic and readmission rates remained unchanged. Conversion rates for elective cholecystectomy fell from 6% in 2006 to 3% in 2009. Conclusions. Development of a gallbladder pathway increased day-case rates sixfold without an associated increase in conversion or readmission rates

Tet2 Rescues Age-Related Regenerative Decline and Enhances Cognitive Function in the Adult Mouse Brain.

Restoring adult stem cell function provides an exciting approach for rejuvenating the aging brain. However, molecular mechanisms mediating neurogenic rejuvenation remain elusive. Here we report that the enzyme ten eleven translocation methylcytosine dioxygenase 2 (Tet2), which catalyzes the production of 5-hydroxymethylcytosine (5hmC), rescues age-related decline in adult neurogenesis and enhances cognition in mice. We detected a decrease in Tet2 expression and 5hmC levels in the aged hippocampus associated with adult neurogenesis. Mimicking an aged condition in young adults by abrogating Tet2 expression within the hippocampal neurogenic niche, or adult neural stem cells, decreased neurogenesis and impaired learning and memory. In a heterochronic parabiosis rejuvenation model, hippocampal Tet2 expression was restored. Overexpressing Tet2 in the hippocampal neurogenic niche of mature adults increased 5hmC associated with neurogenic processes, offset the precipitous age-related decline in neurogenesis, and enhanced learning and memory. Our data identify Tet2 as a key molecular mediator of neurogenic rejuvenation

Effects of halothane and isoflurane anaesthesia on microcirculatory blood flow in musculocutaneous flaps

Hypoperfusion and necrosis in musculocutaneous flaps used for reconstruction of tissue defects is still a significant clinical problem. Although the causes of hypoperfusion are frequently surgical in nature, little is known about the effects of anaesthetic management on blood flow in flaps or the outcome of flap surgery. We compared in minipigs the effects of halothane and isoflurane anaesthesia in equipotent doses on microcirculatory blood flow (MBF) in the skin and muscle part of musculocutaneous flaps and also in intact (control) skin and muscle. Measurements were made during stable normovolaemic conditions and during mild to moderate hypovolaemia (withdrawal of 5%, 10% and 15% of total blood volume). Multi-channel laser Doppler flowmetry (LDF) was used to measure MBF and electromagnetic flowmetry (EMF) for total flap blood flow. During normovolaemic conditions there was no significant difference between the two groups in central haemodynamic or respiratory data. After 15% blood loss, however, there was a significant decrease in mean arterial pressure and cardiac output in the halothane group while there was no significant change in the isoflurane group (P < 0.05). MBF in control skin, control muscle and flap muscle remained approximately 10−15% higher in the isoflurane than in the halothane group throughout the study. In the isoflurane group, MBF in flap skin was unchanged during normovolaemia and there was less than 10% decrease during hypovolaemia. In the halothane group hypovolaemia caused a significant decrease in MBF in flap skin: 27% decrease after 5% blood loss, 45% decrease after 10% blood loss and 49% decrease after 15% blood loss compared with 5%, 20% and 21%, respectively, in intact skin. We conclude that during normovolaemic conditions MBF was well maintained in musculocutaneous flaps in minipigs both with halothane and isoflurane anaesthesia; however, during mild to moderate hypovolemia MBF decreased markedly in flap skin with halothane anaesthesia while it remained unchanged with isofluran

Propeller-activated resonances and the fate of short-period cataclysmic variables

We show that the combination of a weak magnetic propeller and accretion disc resonances can effectively halt accretion in short-period cataclysmic variables (CVs) for large fractions of their lifetimes. This may help to explain the discrepancy between the observed and predicted orbital period distributions of CVs at short periods. Orbital resonances cause the disc to become eccentric, allowing material to fall back on to the donor star or out of the system. A weak magnetic field on a rapidly spinning primary star propels disc material outwards, allowing it to access these resonances. Numerical and analytic calculations show that this state can be long lived (∼1011 yr). This is because the magnetic propeller is required only to maintain access to the resonances, and not to push matter out of the Roche lobe, so that the spin-down time-scale is much longer than that for a classical propeller mode

Spin-Charge Separation in Two Dimensions - A Numerical Study

The question of spin-charge separation in two-dimensional lattices has been addressed by numerical simulations of the motion of one hole in a half-filled band. The calculations have been performed on finite clusters with Hubbard and t-J models. By comparing the time evolution of spin and charge polarisation currents in one and two dimensions, evidence in favor of spin-charge separation in two dimensions is presented. In contrast with this, spin-charge separation is absent in a highly doped, metallic, system.Comment: RevTeX 3.0, 10 Pages, 6 PostScript Figures (on request

An XMM-Newton observation of the nova-like variable UX UMa: spatially and spectrally resolved two-component X-ray emission

In the optical and ultraviolet regions of the electromagnetic spectrum, UX Ursae Majoris is a deeply eclipsing cataclysmic variable. However, no soft X-ray eclipse was detected in ROSAT observations. We have obtained a 38 ksec XMM-Newton observation to further constrain the origin of the X-rays. The combination of spectral and timing information allows us to identify two components in the X-ray emission of the system. The soft component, dominant below photon energies of 2 keV, can be fitted with a multi-temperature plasma model and is uneclipsed. The hard component, dominant above 3 keV, can be fitted with a kT ~ 5 keV plasma model and appears to be deeply eclipsed. We suggest that the most likely source of the hard X-ray emission in UX UMa, and other systems in high mass transfer states, is the boundary layer.Comment: To appear in MNRAS Letter

Upper Critical Field in a Spin-Charge Separated Superconductor

It is demonstrated that the spatial decay of the pair propagator in a Luttinger liquid with spin charge separation contains a logarithmic correction relative to the free fermi gas result in a finite interval between the spin and charge thermal lengths. It is argued that similar effects can be expected in higher dimensional systems with spin charge separation and that the temperature dependence of the upper critical field $H_{c2}$ curve is a probe of this effect.Comment: 3 pages, postscript file (compressed and uuencoded

Shaping the Future of Fuel: Monolithic Metal-Organic Frameworks for High-Density Gas Storage.

The environmental benefits of cleaner, gaseous fuels such as natural gas and hydrogen are widely reported. Yet, practical usage of these fuels is inhibited by current gas storage technology. Here, we discuss the wide-ranging potential of gas-fuels to revolutionize the energy sector and introduce the limitations of current storage technology that prevent this transition from taking place. The practical capabilities of adsorptive gas storage using porous, crystalline metal-organic frameworks (MOFs) are examined with regard to recent benchmark results and ultimate storage targets in this field. In particular, the industrial limitations of typically powdered MOFs are discussed while recent breakthroughs in MOF processing are highlighted. We offer our perspective on the future of practical, rather than purely academic, MOF developments in the increasingly critical field of environmental fuel storage