252 research outputs found
High-Frequency Gravitational Waves from Spinning Non-Abelian Cosmic-Strings
We investigated the SU(2) Einstein-Yang-Mills system on a time-dependent
non-diagonal cylindrical symmetric space-time. From the numerical
investigation, wave-like solutions are found, consistent with the familiar
string-like features. They possess an angle-deficit which depends on the
initial form of the magnetic component of the YM field, i.e., the number of
times it crosses the r-axis. The soliton-like behavior of the gravitational and
YM waves show significant differences from the ones found in the
Einstein-Maxwell system. The stability of the system is analyzed using the
multiple-scale method. To first order a consistent set of equations is
obtained.Comment: 26 pages in Revtex+ 10 eps figures. The other pictures can be
obtained at http://www.asfyon.nl/slagt.html/webdoc.ht
Leveraging Spiking Deep Neural Networks to Understand the Neural Mechanisms Underlying Selective Attention
Melvin solution with a dilaton potential
We find new Melvin-like solutions in Einstein-Maxwell-dilaton gravity with a
Liouville-type dilaton potential. The properties of the corresponding solution
in Freedman-Schwarz gauged supergravity model are extensively studied. We show
that this configuration is regular and geodesically complete but do not
preserve any supersymmetry. An exact solution describing travelling waves in
this Melvin-type background is also presented.Comment: 12 pages, LaTeX, no figure
Outcomes of the One Anastomosis Gastric Bypass with Various Biliopancreatic Limb Lengths:a Retrospective Single-Center Cohort Study
Introduction: One anastomosis gastric bypass (OAGB) is an effective and safe treatment for morbidly obese patients. Longer biliopancreatic (BP) limb length is suggested to result in better weight loss outcomes, but to date, no data are available for the OAGB to substantiate this. We hypothesized that applying a longer BP-limb length in the higher BMI classes would result in more weight reduction so that the attained BMI would be comparable to patients with a lower BMI, thereby compensating for differences in baseline BMI. Method: A retrospective cohort study in patients who underwent a primary OAGB at a teaching hospital in the Netherlands between January 2015 and December 2016. BP-limb length was tailored based on preoperative BMI. Patients were divided into three different groups depending on the length of the BP-limb: 150, 180, and 200 cm. Weight loss outcomes after 1 and 3 years and resolution of comorbidities were compared between these groups. Results: Of the 632 included patients, a BP-limb length of 150 cm was used in 172 (27.2%), 180 cm in 388 (61.4%), and 200 cm in 72 (11.4%) patients. Despite more BMI loss, %EWL was lower and attained BMI remained higher in the groups with longer BP-limb lengths. After adjustment for the confounder preoperative BMI, longer BP-limb lengths were not associated with higher BMI loss. There was no difference in remission rates of comorbidities. Conclusion: Attained BMI remained higher in spite of tailoring BP-limb length according to baseline BMI with no differences in remission rates of comorbidities
Tailoring limb length based on total small bowel length in one anastomosis gastric bypass surgery (TAILOR study):study protocol for a randomized controlled trial
Background: The one anastomosis gastric bypass (OAGB) is being performed by an increasing number of bariatric centers over the world. However, the optimal length of the biliopancreatic (BP) limb remains a topic of discussion. Retrospective studies suggest the benefit of tailoring BP-limb length; however, randomized trials are lacking. The aim of this study is to investigate whether tailoring the length of the BP-limb based on total small bowel length (TSBL) leads to better results in terms of weight loss, vitamin deficiencies, and bowel movements compared to a fixed BP-limb length. Methods: The TAILOR study is a double-blind single-center randomized controlled trial. Patients scheduled for primary OAGB surgery will be randomly allocated either to a standard BP-limb of 150 cm or to a BP-limb length based on their TSBL: TSBL 700 cm, BP-limb 210 cm. The primary outcome is to compare the percent total weight loss (%TWL) at 5 years between the two groups. Secondary outcomes include nutritional deficiencies, remission of comorbidities, symptoms of dumping, quality of life, and daily bowel movements. The study includes a total of 212 patients and is designed to detect a 5% difference in the primary endpoint. Discussion: The TAILOR study will provide new insights into the effect of different BP-limb lengths and the role of the TSBL in the OAGB. The study is designed to provide guidance for bariatric surgeons to determine the optimal BP-limb length in the OAGB
Standardised Ki-67 proliferation index assessment in early-stage laryngeal squamous cell carcinoma in relation to local control and survival after primary radiotherapy
ObjectivesAmbiguous results have been reported on the predictive value of the Ki-67 proliferation index (Ki-67 PI) regarding local control (LC) and survival after primary radiotherapy (RT) in early-stage laryngeal squamous cell cancer (LSCC). Small study size, heterogenic inclusion, variations in immunostaining and cut-off values are attributing factors. Our aim was to elucidate the predictive value of the Ki-67 PI for LC and disease-specific survival (DSS) using a well-defined series of T1-T2 LSCC, standardised automatic immunostaining and digital image analysis (DIA). MethodsA consecutive and well-defined cohort of 208 patients with T1-T2 LSCC treated with primary RT was selected. The Ki-67 PI was determined using DIA. Mann-Whitney U-tests, logistic and Cox regression analyses were performed to assess associations between Ki-67 PI, clinicopathological variables, LC and DSS. ResultsIn multivariate Cox regression analysis, poor tumour differentiation (HR 2.20; 95% CI 1.06-4.59, P = .04) and alcohol use (HR 2.84, 95% CI 1.20-6.71; P = .02) were independent predictors for LC. Lymph node positivity was an independent predictor for DSS (HR 3.16, 95% CI 1.16-8.64; P = .03). Ki-67 PI was not associated with LC (HR 1.59; 95% CI 0.89-2.81; P = .11) or DSS (HR 0.98; 95% CI 0.57-1.66; P = .97). In addition, continuous Ki-67 PI was not associated with LC (HR 2.03; 95% CI 0.37-11.14, P = .42) or DSS (HR 0.62; 95% CI 0.05-8.28; P = .72). ConclusionThe Ki-67 PI was not found to be a predictor for LC or DSS and therefore should not be incorporated in treatment-related decision-making for LSCC
Laparoscopic Small Bowel Length Measurement in Bariatric Surgery Using a Hand-Over-Hand Technique with Marked Graspers:an Ex Vivo Experiment
Introduction Tailoring limb length in bariatric surgery is a subject of many studies. To acquire the optimal limb length, accurate measurement of the small bowel length is essential. Objective To assess the intra- and inter-individual variability of laparoscopic bowel length measurement using a hand-over-hand technique with marked graspers. Method Four bariatric surgeons and four surgical residents performed measurements on cadaver porcine intestine in a laparoscopic box using marked graspers. Each participant performed 10 times a measurement of three different lengths: 150, 180, and 210 cm. Acceptable percentage deviation from the goal lengths was defined as less than 10%, while unacceptable deviations were defined as more than 15%. Results The bariatric surgeons measured the 150-, 180-, and 210-cm tasks with 4% (CI 0.4, 9), - 6% (CI - 11, - 0.8), and 1% (CI - 4, 6) deviation, respectively. In total, the bariatric surgeons estimated 58 out of 119 times (49%) between the margins of 10% deviation and 36 times (30%) outside the 15% margin. Considerable inter-individual differences were found between the surgeons. The surgical residents underestimated the tasks with 12% (CI - 18, - 6), 16% (CI - 19, - 13), and 18% (CI - 22, - 13), respectively. Conclusion Bariatric surgeons estimated bowel length with on average less than 10% deviation. However, this still resulted in 30% of the measurements with more than 15% deviation. There were considerable inter-individual differences between the surgeons and residents structurally underestimated the bowel length. Ascertainment of measurement accuracy and adequate training is essential for bariatric procedures in which limb length is of importance
High DNMT1 Is Associated With Worse Local Control in Early-Stage Laryngeal Squamous Cell Carcinoma
OBJECTIVES/HYPOTHESIS: Early-stage laryngeal squamous cell carcinoma (LSCC) has yielded local control rates of 75% after radiotherapy. DNA methylation, in which DNA methyltransferases play an important role, has influence on tumorigenesis. In this study, we investigated the association between the expression of DNA methyltransferase 1 (DNMT1) and local control in early-stage LSCC treated with radiotherapy. STUDY DESIGN: Retrospective cohort study. METHODS: We analyzed a well-defined homogeneous series of 125 LSCC patients treated with radiotherapy with curative intent. The association of immunohistochemical expression of DNMT1 with local control was evaluated using Cox proportional hazard regression models. RESULTS: With a median follow-up of 58 months, 29 local recurrences (23%) were observed. On univariate analysis, worse local control was associated with high DNMT1 expression (hazard ratio [HR] 2.57, 95% confidence interval [CI] 1.10-6.01). Also, higher T-stage (HR 2.48, 95% CI 1.06-5.80) and positive N-status (HR 2.62, 95% CI 1.06-6.47) were associated with worse local control. Multivariate Cox regression demonstrated that high DNMT1 (HR 2.81; 95% CI 1.20-6.58) was independently associated with worse local control. CONCLUSIONS: We found an association between high DNMT1 expression and worse local control in a homogeneous well-defined cohort of early-stage LSCC patients treated with definitive radiotherapy. The association between DNA methylation status as determined by DNMT1 expression and local control suggests that DNMT1 acts as a potential prognostic tumor marker in treatment decision-making in early-stage laryngeal carcinoma. LEVEL OF EVIDENCE: NA Laryngoscope, 2021
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