Systematic review of prognostic importance of extramural venous invasion in rectal cancer

AIM: To systematically review the survival outcomes relating to extramural venous invasion in rectal cancer. METHODS: A systematic review was conducted using PRISMA guidelines. An electronic search was carried out using MEDLINE, EMBASE, CINAHL, Cochrane library databases, Google scholar and Pubmed until October 2014. Search terms were used in combination to yield articles on extramural venous invasion in rectal cancer. Outcome measures included prevalence and 5-year survival rates. These were graphically displayed using Forest plots. Statistical analysis of the data was carried out. RESULTS: Fourteen studies reported the prevalence of extramural venous invasion (EMVI) positive patients. Prevalence ranged from 9%-61%. The pooled prevalence of EMVI positivity was 26% [Random effects: Event rate 0.26 (0.18, 0.36)]. Most studies showed that EMVI related to worse oncological outcomes. The pooled overall survival was 39.5% [Random effects: Event rate 0.395 (0.29, 0.51)]. CONCLUSION: Historically, there has been huge variation in the prevalence of EMVI through inconsistent reporting. However the presence of EMVI clearly leads to worse survival outcomes. As detection rates become more consistent, EMVI may be considered as part of risk-stratification in rectal cancer. Standardised histopathological definitions and the use of magnetic resonance imaging to identify EMVI will improve detection rates in the future

Extramural venous invasion is a potential imaging predictive biomarker of neoadjuvant treatment in rectal cancer

BACKGROUND: Extramural venous invasion (EMVI) is a poor prognostic factor in rectal cancer and identified on magnetic resonance imaging (MRI) (mrEMVI). The clinical relevance of improvement in mrEMVI following neoadjuvant therapy is unknown. This study aimed to demonstrate that regression of mrEMVI following neoadjuvant chemoradiotherapy (CRT) results in improved outcomes and mrEMVI can be used as an imaging biomarker METHODS: Retrospective analysis of prospectively collected data was conducted examining the staging and post-treatment MRIs of patients who had presented with EMVI-positive rectal cancer. All patients had undergone neoadjuvant CRT and curative surgery. Changes in mrEMVI were graded with a new MRI-based TRG scale–mr-vTRG; and related to disease-free survival (DFS). The study fulfilled Reporting Recommendations for Tumour Marker Prognostic Studies criteria for biomarkers. RESULTS: Sixty-two patients were included. Thirty-five patients showed more than 50% fibrosis of mrEMVI (mr-vTRG 1-3); 3-year DFS 87.8% and 9% recurrence. Twenty-seven patients showed less than 50% fibrosis (mr-vTRG 4-5); 3-year DFS 45.8% with 44% recurrence – P<0.0001. On multivariate Cox-regression, only mr-vTRG 4-5 increased risk of disease recurrence – HR=5.748. CONCLUSION: Patients in whom there has been a significant response of EMVI to CRT show improved DFS. Those patients with poor response should be considered for intensive treatment. As an imaging biomarker in rectal cancer, mrEMVI can be used

Constraints on quintessence and new physics from fundamental constant

Changes in the values of the fundamental constants mu, the proton to electron mass ratio, and alpha, the fine structure constant due to rolling scalar fields have been discussed both in the context of cosmology and in new physics such as Super Symmetry (SUSY) models. This article examines the changes in these fundamental constants in a particular example of such fields, freezing and thawing slow roll quintessence. Constraints are placed on the product of a cosmological quantity, w, the equation of state parameter, and the square of the coupling constants for mu and alpha with the field, zeta_x, x = mu,alpha, using the existing observational limits on the values of Delta x/x. Various examples of slow rolling quintessence models are used to further quantify the constraints. Some of the examples appear to be rejected by the existing data which strongly suggests that conformation to the values of the fundamental constants in the early universe is a standard test that should be applied to any cosmological model or suggested new physics.Comment: Accepted for publication in the Monthly Notices of the Royal Astronomical Society Letter

Herding predators using swarm intelligence

Swarm intelligence, a nature-inspired concept that includes multiplicity, stochasticity, randomness, and messiness is emergent in most real-life problem-solving. The concept of swarming can be integrated with herding predators in an ecological system. This paper presents the development of stabilizing velocity-based controllers for a Lagrangian swarm of n∈N individuals, which are supposed to capture a moving target (intruder). The controllers are developed from a Lyapunov function, total potentials, designed via Lyapunov-based control scheme (LbCS) falling under the classical approach of artificial potential fields method. The interplay of the three central pillars of LbCS, which are safety, shortness, and smoothest course for motion planning, results in cost and time effectiveness and efficiency of velocity controllers. Computer simulations illustrate the effectiveness of control laws

The Correlation between X-ray spectral slope and FeKalpha line energy in radio-quiet active galactic nuclei

A significant correlation between FeKalpha line energy and X-ray spectral slope has been discovered among radio-quiet active galactic nuclei. The ionization stage of the bulk of the FeKalpha emitting material is not the same in all active galactic nuclei and is related to the shape of the X-ray continua. Active galactic nuclei with a steep X-ray spectrum tend to have a fluorescence FeKalpha line from highly ionized material. In the narrow-line Seyfert 1 galaxies with steeper X-ray spectrum (Gamma_X > 2.1), the FeKalpha line originates from highly ionized material. In the Seyfert 1 galaxies and quasars with flatter X-ray spectrum (Gamma_X < 2.1), bulk of the FeKalpha emission arises from near neutral or weakly ionized material. The correlation is an important observational characteristic related to the accretion process in radio quiet active galactic nuclei and is driven by a fundamental physical parameter which is likely to be the accretion rate relative to the Eddington rate.Comment: 4 pages, To apear in ApJ Letter

First measurement of Mg isotope abundances at high redshifts and accurate estimate of Delta alpha/alpha

(Abridged) We use a high-resolution spectrum of the quasar HE0001-2340 observed with the UVES/VLT to measure Mg isotope abundances in the intervening absorption-line systems at high redshifts. Line profiles are prepared accounting for possible shifts between the individual exposures. Due to unique composition of the selected systems - the presence of several transitions of the same ion - we can test the local accuracy of the wavelength scale calibration which is the main source of errors in the sub-pixel line position measurements. In the system at zabs = 0.45 which is probably a fragment of the outflow caused by SN Ia explosion of high-metallicity white dwarf(s) we measured velocity shifts of MgII and MgI lines relative to other lines (FeI, FeII, CaI, CaII): Delta V(MgII) = -0.44 +/- 0.05 km/s and Delta V(MgI) = -0.17 +/- 0.17$ km/s. This translates into the isotopic ratio 24Mg:25Mg:26Mg = (19 +/- 11):(22 +/- 13):(59 +/- 6) with a strong relative overabundance of heavy Mg isotopes, (25Mg+26Mg)/24Mg = 4, as compared to the solar ratio 24Mg:25Mg:26Mg = 79:10:11, and (25Mg+26Mg)/24Mg = 0.3. At zabs = 1.58, we put a strong constraint on a putative variation of alpha: Delta alpha/alpha = (-1.5 +/- 2.6)x10^{-6} which is one of the most stringent limits obtained from optical spectra of QSOs. We reveal that the wavelength calibration in the range above 7500 A is subject to systematic wavelength-dependent drifts.Comment: 20 pages, 13 figures, 7 tables. Accepted for publication in Astronomy and Astrophysic

Early experience with the ARTISENTIAL® articulated instruments in laparoscopic low anterior resection with TME

Background: The notion of articulation in surgery has been largely synonymous with robotics. The ARTISENTIAL® instruments aim at bringing advanced articulation to laparoscopy to overcome challenges in narrow anatomical spaces. In this paper, we present first single-center results of a series of low anterior resections, performed with ARTISENTIAL®. Methods: Between September 2020 and August 2021, at the Department of Surgery, St. Marienkrankenhaus Siegen, Siegen, Germany, patients with cancer of the mid- and low rectum were prospectively enrolled in a pilot feasibility study to evaluate the ARTISENTIAL® articulated instruments in performing a laparoscopic low anterior resection. Perioperative and short-term postoperative data were analyzed. Results: Seventeen patients (10 males/7 females) were enrolled in this study. The patients had a median age of 66 years (range 47–80 years) and a median body mass index of 28 kg/m2 (range 23–33 kg/m2). The median time to rectal transection was 155 min (range 118–280 min) and the median total operative time was 276 min (range 192–458 min). The median estimated blood loss was 30 ml (range 5–70 ml) and there were no conversions to laparotomy. The median number of harvested lymph nodes was 15 (range 12–28). Total mesorectal excision (TME) quality was ‘good’ in all patients with no cases of circumferential resection margin involvement (R0 = 100%). The median length of stay was 9 days (range 7–14 days). There were no anastomotic leaks and the overall complication rate was 17.6%. There was one unrelated readmission with no mortality. Conclusions: Low anterior resection with ARTISENTIAL® is feasible and safe. All patients had a successful TME procedure with a good oncological outcome. We will now seek to evaluate the benefits of ARTISENTIAL® in comparison with standard laparoscopic instruments through a larger study