Carotid plaque morphology: A review

The recent North American Symptomatic Carotid Endarterectomy Trial has answered fairly conclusively the questions concerning the optimal management of patients with symptoms who have a > 70% stenosis of the internal carotid artery. It has also had the effect of refocusing attention on carotid pathology. The main question still to be answered is whether surgical management is the optimum treatment for other groups of patients with carotid disease. From various studies done on the natural history of carotid plaques it is apparent that there are subgroups who may benefit from surgery, namely those who will progress to stroke if not treated. The problem comes in identifying these subgroups by the factors which cause them to progress. This paper aims to review the role that plaque morphology has in the development of symptoms and whether it should be included with degree of stenosis in assessing the risk of a carotid plaque. The non-invasive assessment of plaque morphology is also reviewed. The evidence from this review does not support the use of plaque morphology as a discriminating factor for carotid endarterectomy at present

Late reoperation in vascular surgery

Objectives:Assessment of late reoperation (after 30 days) following vascular surgery.Design:Analysis of a prospectively collected database of consecutive patients undergoing vascular surgery.Setting:A single teaching unit's experience between 1986–1993.Materials:Patients undergoing 2501 primary arterial reconstructions.Chief outcome measures:Reoperation after 30 days.Main results:One hundred and fifty eight patients (6%) underwent further operations, at more than 1 month after the primary procedure. Primary procedures at highest risk for reoperations were axillobifemoral bypasses and femorodistal bypasses with respective late reoperation rates of 20% and 16%. The majority of patients required late reoperation because of graft occlusion or stenosis. Overall, of the 158 late reoperations performed, 114 were related to the same arterial segment with the same presenting symptoms as the primary operation, and 44 for a different indication. A second or subsequent reoperation was required in 54 patients and the overall operative mortality was 11%.Conclusion:Patients undergoing certain vascular procedures, should be informed of the high risk of a subsequent procedure when consent is obtained

A model for single electron decays from a strongly isolated quantum dot

Recent measurements of electron escape from a non-equilibrium charged quantum dot are interpreted within a 2D separable model. The confining potential is derived from 3D self-consistent Poisson-Thomas-Fermi calculations. It is found that the sequence of decay lifetimes provides a sensitive test of the confining potential and its dependence on electron occupation.Comment: 9 pages, 10 figure

Direct health costs of inflammatory polyarthritis 10 years after disease onset:Results from the Norfolk Arthritis Register

Objectives: To explore the change in direct medical costs associated with inflammatory polyarthritis (IP) 10 to 15 years after its onset. Methods: Patients from the Norfolk Arthritis Register who had previously participated in a health economic study in 1999 were traced 10 years later and invited to participate in a further prospective questionnaire-based study. The study was designed to identify direct medical costs and changes in health status over a 6-month period using previously validated questionnaires as the primary source of data. Results: A representative sample of 101 patients with IP from the 1999 cohort provided complete data over the 6-month period. The mean disease duration was 14 years (SD 2.1, median 13.6, interquartile range 12.6–15.4). The mean direct medical cost per patient over the 6-month period was £1496 for IP (inflated for 2013 prices). This compared with £582 (95% CI £355–£964) inflated to 2013 prices per patient with IP 10 years earlier in their disease. The increased cost was largely associated with the use of biologics in the rheumatoid arthritis subgroup of patients (51% of total costs incurred). Other direct cost components included primary care costs (11%), hospital outpatient (19%), day care (12%), and inpatient stay (4%). Conclusion: The direct healthcare costs associated with IP have more than doubled with increasing disease duration, largely as a result of the use of biologics. The results showed a shift in the direct health costs from inpatient to outpatient service use

Compression ultrasonography for false femoral artery aneurysms: Hypocoagulability is a cause of failure

Objectives:false femoral artery aneurysm is an occasional complication of percutaneous cardiovascular radiological procedures. Compression ultrasonography causes thrombosis non-invasively, reducing need for operative intervention. The technique fails in a proportion of cases. Analysis was undertaken to identify causes of failure.Design:prospective open study.Materials and Methods:patients presenting with false femoral artery aneurysm since 1984 were identified from a computerised database (BIPAS). Since 1993 compression ultrasonography has been performed as first line treatment according to a standard protocol. Prospectively collected ultrasonographic data and case notes were reviewed to identify causes of failed compression.Results:false femoral artery aneurysm occurred as a complication in 32/26 687 (0.12%) cardiovascular radiological procedures. Eighteen aneurysms were treated by compression. The technique was successful in 11/18 (61%) cases but primary failure occurred in seven cases. Six out of seven had bleeding abnormalities (Chi-squared analysis with Yates correction 10.55, p=0.0012), four were anticoagulated and compression was subsequently successful following reversal of warfarin therapy in three of these patients. In 4/18 cases surgical repair was necessary.Conclusions:compression ultrasonography is an effective treatment of false femoral aneurysms, however, hypocoagulability is a significant cause of failure. For patients in whom anticoagulation cannot be reversed, primary surgical repair should be considered

Direct composition profiling in III-V nanostructures by cross-sectional STM

Using cross-sectional STM we have studied the local composition in III–V nanostructures such as GaAs/InGaAs quantum wells, InGaNAs/InP quantum wells and quantum dots, and InAs/GaAs self-assembled quantum dots. We are able to determine the local composition by either simply counting the constituent atoms, measuring the local lattice constant or measuring the relaxation of the cleaved surface due to the elastic field of the buried strained nanostructures

Scale setting for alpha_s beyond leading order

We present a general procedure for incorporating higher-order information into the scale-setting prescription of Brodsky, Lepage and Mackenzie. In particular, we show how to apply this prescription when the leading coefficient or coefficients in a series in the strong coupling alpha_s are anomalously small and the original prescription can give an unphysical scale. We give a general method for computing an optimum scale numerically, within dimensional regularization, and in cases when the coefficients of a series are known. We apply it to the heavy quark mass and energy renormalization in lattice NRQCD, and to a variety of known series. Among the latter, we find significant corrections to the scales for the ratio of e+e- to hadrons over muons, the ratio of the quark pole to MSbar mass, the semi-leptonic B-meson decay width, and the top decay width. Scales for the latter two decay widths, expressed in terms of MSbar masses, increase by factors of five and thirteen, respectively, substantially reducing the size of radiative corrections.Comment: 39 pages, 15 figures, 5 tables, LaTeX2

The impact of deep-sea fisheries and implementation of the UNGA Resolutions 61/105 and 64/72. Report of an international scientific workshop

The scientific workshop to review fisheries management, held in Lisbon in May 2011, brought together 22 scientists and fisheries experts from around the world to consider the United Nations General Assembly (UNGA) resolutions on high seas bottom fisheries: what progress has been made and what the outstanding issues are. This report summarises the workshop conclusions, identifying examples of good practice and making recommendations in areas where it was agreed that the current management measures fall short of their target

Partitioned trace distances

New quantum distance is introduced as a half-sum of several singular values of difference between two density operators. This is, up to factor, the metric induced by so-called Ky Fan norm. The partitioned trace distances enjoy similar properties to the standard trace distance, including the unitary invariance, the strong convexity and the close relations to the classical distances. The partitioned distances cannot increase under quantum operations of certain kind including bistochastic maps. All the basic properties are re-formulated as majorization relations. Possible applications to quantum information processing are briefly discussed.Comment: 8 pages, no figures. Significant changes are made. New section on majorization is added. Theorem 4.1 is extended. The bibliography is enlarged

Soft parton radiation in polarized vector boson production: theoretical issues

Accurate measurement of spin-dependent parton distributions in production of electroweak bosons with polarized proton beams at the Relativistic Heavy Ion Collider depends on good understanding of QCD radiation at small transverse momenta $q_T$ of vector bosons. We present a theoretical formalism for small-$q_T$ resummation of the cross sections for production of virtual photons, W, and Z bosons, with the subsequent decay of these bosons into lepton pairs, for arbitrary longitudinal polarizations of the proton beams.Comment: 35 pages, 2 figures; minor modifications; bibliography references adde