The on-shell self-energy of the uniform electron gas in its weak-correlation limit

The ring-diagram partial summation (or RPA) for the ground-state energy of the uniform electron gas (with the density parameter $r_s$) in its weak-correlation limit $r_s\to 0$ is revisited. It is studied, which treatment of the self-energy $\Sigma(k,\omega)$ is in agreement with the Hugenholtz-van Hove (Luttinger-Ward) theorem $\mu-\mu_0= \Sigma(k_{\rm F},\mu)$ and which is not. The correlation part of the lhs h as the RPA asymptotics $a\ln r_s +a'+O(r_s)$ [in atomic units]. The use of renormalized RPA diagrams for the rhs yields the similar expression $a\ln r_s+a''+O(r_s)$ with the sum rule $a'= a''$ resulting from three sum rules for the components of $a'$ and $a''$. This includes in the second order of exchange the sum rule $\mu_{2{\rm x}}=\Sigma_{2{\rm x}}$ [P. Ziesche, Ann. Phys. (Leipzig), 2006].Comment: 19 pages, 10 figure

Many-body interactions among adsorbed atoms and molecules within carbon nanotubes and in free space

This paper assesses the importance of three-body triple dipole interactions for quasi-one dimensional phases of He, Ne, H_2, Ar, Kr and Xe confined within interstitial channels or on the external surfaces of nanotube bundles. We find the substrate-mediated contribution to be substantial: for interstitial H_2 the well depth of the effective pair potential is reduced to approximately one half of its value in free space. We carry out ab initio calculations on linear and equilateral configurations of H_2 trimer and find that overlap interactions do not greatly change the DDD interaction in the linear configuration when the spacing is greater than about 3 A. However, the DDD interaction alone is clearly insufficient for the triangular configurations studied.Comment: 11 pages, 5 figure

Abraham Geiger

ABRAHAM GEIGER Abraham Geiger / Geiger, Ludwig (Public Domain) ( - ) Cover front ( - ) Photograph: Abraham Geiger, L. ( - ) Title page ( - ) Contents ( - ) Preface ( - ) Erste Abteilung. Leben ( - ) Einleitung zur Biographie ([1]) I. Kapitel 1810-1832 ([5]) II. Kapitel. Wiesbaden 1832-1838 ([19]) III. Kapitel. 1838-1840 ([50]) IV. Kapitel. Breslau 1840-1844 ([70]) V. Kapitel. Breslau 1844-53 ([96]) VI. Kapitel. 1854-1863 ([139]) VII. Kapitel. Frankfurt a. M. 1863-70 ([175]) VIII. Berlin 1870-1874 ([204]) Zweite Abteilung. Lebenswerk ([233]) I. Der Theologe ([235]) 1. Einleitung ([235]) 2. Systematische Theologie ([243]) 3. Sprachwissenschaft ([400]) II. Der Gelehrte ([316]) 3. Praktische Theologie ([277]) 1. Bibel ([316]) 2. Geschichte ([328]) Anhang. Verzeichnisse ([413]) Table of abbreviations ([414]) 1. Bibliographie der Schriften A. Geigers ([415]) 2. Verzeichnis der Bibelstellen in A. Geigers Schriften ([471]) 3. Verzeichnis der hebräischen und aramäischen Wörter in Abraham Geigers Schriften ([492]) 4. Personennamen in Leben und Lebenswerk ([503]) Cover back ( - ) ColorChart ( -

Modelling and characterisation of a ultrasound-actuated needle for improved visibility in ultrasound-guided regional anaesthesia and tissue biopsy

AbstractClear needle visualisation is recognised as an unmet need for ultrasound guided percutaneous needle procedures including regional anaesthesia and tissue biopsy. With inadequate needle visibility, these procedures may result in serious complications or a failed operation. This paper reports analysis of the modal behaviour of a previously proposed ultrasound-actuated needle configuration, which may overcome this problem by improving needle visibility in colour Doppler imaging. It uses a piezoelectric transducer to actuate longitudinal resonant modes in needles (outer diameter 0.8–1.2mm, length>65mm). The factors that affect the needle’s vibration mode are identified, including the needle length, the transducer’s resonance frequency and the gripping position. Their effects are investigated using finite element modelling, with the conclusions validated experimentally. The actuated needle was inserted into porcine tissue up to 30mm depth and its visibility was observed under colour Doppler imaging. The piezoelectric transducer is able to generate longitudinal vibration with peak-to-peak amplitude up to 4μm at the needle tip with an actuating voltage of 20Vpp. Actuated in longitudinal vibration modes (distal mode at 27.6kHz and transducer mode at 42.2kHz) with a drive amplitude of 12–14Vpp, a 120mm needle is delineated as a coloured line in colour Doppler images, with both needle tip and shaft visualised. The improved needle visibility is maintained while the needle is advanced into the tissue, thus allowing tracking of the needle position in real time. Moreover, the needle tip is highlighted by strong coloured artefacts around the actuated needle generated by its flexural vibration. A limitation of the technique is that the transducer mode requires needles of specific lengths so that the needle’s resonance frequency matches the transducer. This may restrict the choice of needle lengths in clinical applications

Mouse mitochondrial lipid composition is defined by age in brain and muscle

Functionality of the lipid rich mitochondrial organelle declines with increased age. Recent advances in lipidomic technologies allowed us to perform a global characterisation of lipid composition in two different tissue types and age ranges. Ultra-high performance liquid chromatography coupled with high resolution mass spectrometry was used to establish and compare mitochondrial lipidomes of brain and skeletal muscle from young (4-11 weeks old) and middle age (78 weeks old) healthy mice. In middle age the brain mitochondria had reduced levels of fatty acids, particularly polyunsaturated fatty acids, while skeletal muscle mitochondria had a decreased abundance of phosphatidylethanolamine, but a pronounced increase of triglyceride levels. Reduced levels of phosphatidylethanolamines are known to decrease mitochondrial membrane fluidity and are connected with accelerated ageing. In mitochondria from skeletal muscle we propose that increased age causes a metabolic shift in the conversion of diacylglycerol so that triglycerides predominate compared with phosphatidylethanolamines. This is the first time mitochondrial lipid content in normal healthy mammalian ageing brain and muscle has been catalogued in detail across all lipid classes. We identify distinct mitochondrial lipid signatures that change with age, revealing tissue-specific lipid pathways as possible targets to ameliorate ageing-related mitochondrial decline

Ab initio alpha-alpha scattering

Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.Comment: 6 pages, 6 figure

A systematic review of the use of quality-of-life instruments in randomized controlled trials for psoriasis

This is the peer reviewed version of the following article: F. M. Ali, A. C. Cueva, J. Vyas, A. A. Atwan, M. S. Salek, A. Y. Finlay, and V. Piguet, ‘A systematic review of the use of quality-of-life instruments in randomized controlled trials for psoriasis’, British Journal of Dermatology, Vol. 176 (3): 577-593, March 2017, which has been published in final form at https://doi.org/10.1111/bjd.14788. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Planners of interventional studies in psoriasis face the dilemma of selecting suitable quality-of-life (QoL) measures. Systematic reviews have the potential of identifying psychometrically sound measures in a given therapeutic area, while guiding the development of practice guidelines. The aim of this systematic review was to generate evidence of the use of QoL instruments in randomized controlled trials (RCTs) for interventions in psoriasis. The methodology followed the PRISMA guidelines. Six databases were searched with 388 search terms. Abstracts of articles were reviewed independently by two assessors, and a third adjudicator resolved any opinion differences. Risk of bias was assessed using the Jadad scale. Of 3646 screened publications, 99 articles (100 trials) met the eligibility criteria for inclusion, describing research on 33 215 patients. Thirty-three trials tested topical therapy, 18 systemic, 39 biologics, nine phototherapy and 10 other interventions. The Dermatology Life Quality Index (DLQI) was the most commonly used QoL instrument (83 studies, 83%), followed by the 36-Item Short Form Survey (SF-36) (31, 31%), EuroQoL-5D (EQ-5D) (15, 15%), Psoriasis Disability Index (14, 14%) and Skindex (five, 5%). There was widespread inconsistency in the way that QoL data were reported. Of the 100 trials identified, 37 reported minimal clinically important difference (MCID): 32 for DLQI, 10 for SF-36 and six for EQ-5D. QoL measurement is increasingly being reported in RCTs of psoriasis. Formal guidelines are needed for assessment and publishing of QoL data. Researchers should consider whether MCID information is available, and development of MCID data should be encouraged.Peer reviewedFinal Accepted Versio

Renal Dysfunction in Acute Heart Failure

During treatment of acute heart failure (AHF), worsening renal function is often complicated and results in a complex clinical course. Furthermore, renal dysfunction is a strong independent predictor of long-term adverse outcomes in patients with AHF. Traditionally, the predominant cause of renal dysfunction has been attributed to impairment of cardiac output and relative underfilling of arterial perfusion. Recently, emerging data have led to the importance of venous congestion and elevated intra-abdominal pressure rather than confining it to impaired forward cardiac output as the primary driver of renal impairment. Relief of congestion is a major objective of AHF treatment but therapy is still based on the administration of loop diuretics. The results of the recently performed controlled studies for the assessment of new treatments to overcome resistance to diuretic treatment to protect kidneys from untoward effects have been mostly neutral. Better treatment of congestion in heart failure remains a major problem

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Coactivator complexes SAGA and NuA4 stimulate transcription by post-translationally modifying chromatin. Both complexes contain the Tra1 subunit, a highly conserved 3744-residue protein from the Phosphoinositide 3-Kinase-related kinase (PIKK) family and a direct target for multiple sequence-specific activators. We present the Cryo-EM structure of Saccharomyces cerevsisae Tra1 to 3.7 Å resolution, revealing an extensive network of alpha-helical solenoids organized into a diamond ring conformation and is strikingly reminiscent of DNA-PKcs, suggesting a direct role for Tra1 in DNA repair. The structure was fitted into an existing SAGA EM reconstruction and reveals limited contact surfaces to Tra1, hence it does not act as a molecular scaffold within SAGA. Mutations that affect activator targeting are distributed across the Tra1 structure, but also cluster within the N-terminal Finger region, indicating the presence of an activator interaction site. The structure of Tra1 is a key milestone in deciphering the mechanism of multiple coactivator complexes