An Improved Upper Bound for the Ring Loading Problem

The Ring Loading Problem emerged in the 1990s to model an important special case of telecommunication networks (SONET rings) which gained attention from practitioners and theorists alike. Given an undirected cycle on $n$ nodes together with non-negative demands between any pair of nodes, the Ring Loading Problem asks for an unsplittable routing of the demands such that the maximum cumulated demand on any edge is minimized. Let $L$ be the value of such a solution. In the relaxed version of the problem, each demand can be split into two parts where the first part is routed clockwise while the second part is routed counter-clockwise. Denote with $L^*$ the maximum load of a minimum split routing solution. In a landmark paper, Schrijver, Seymour and Winkler [SSW98] showed that $L \leq L^* + 1.5D$, where $D$ is the maximum demand value. They also found (implicitly) an instance of the Ring Loading Problem with $L = L^* + 1.01D$. Recently, Skutella [Sku16] improved these bounds by showing that $L \leq L^* + \frac{19}{14}D$, and there exists an instance with $L = L^* + 1.1D$. We contribute to this line of research by showing that $L \leq L^* + 1.3D$. We also take a first step towards lower and upper bounds for small instances

Solitary Necrotic Nodules of the Liver Mimicking Hepatic Metastasis: Report of Two Cases

We present two cases of solitary necrotic nodules of the liver which on radiologic images mimicked hepatic metastasis. Solitary necrotic nodule of the liver is a rare but benign entity which histopathologically consists of an outer fibrotic capsule with inflammatory cells and a central core of amorphous necrotic material. The lesion was seen on contrast-enhanced CT as an ovoid-shaped hypoattenuating nodule; on CT during hepatic arteriography as enhancing nodule; on intraoperative US as a target-appearing hypoechoic nodule; on T2WI as a hyperintensity nodule, and on dynamic MR as a subtle peripheral enhancing nodule. Although the radiologic features are not specific, solitary necrotic nodule of the liver should be included in the differential diagnosis of hepatic metastasis

Crohn's disease activity index and Vienna classification - Is it worthwhile to calculate before surgery?

Background: Crohn's disease (CD) patients with increased disease activity may reveal an increased risk for perioperative complications. The `Crohn's disease activity index' (CDAI) and the `Vienna classification' (VC) were developed for standardized disease activity estimations. The significance of these scores to predict extent, type and early outcome of surgery in CD patients was analyzed. Methods: In 179 surgically treated CD patients, the CDAI and VC were assessed from a prospective database. Relations of the scores with CD risk factors, type, number, location and complications of surgery were analyzed. Results: VC behavior and location subtypes were associated with distinct types of surgery (i.e. `strictureplasty' in `stricturing disease', `colon surgery' in `colon involvement'), but not with surgery type and extent or outcome. Surgery extent (i.e. with 5 vs. 3 `surgical sites' 425 +/- 25 vs. 223.3 +/- 25) and complications (357.1 +/- 36.9 (with) vs. 244.4 +/- 13 (without)) were associated with elevated CDAI levels; however, nicotine abuse remained the only significant risk factor for perioperative complications after multiple logistic regression. Conclusion: The significance of VC or CDAI for predicting the extent of surgery or complications is limited. None of the tested variables except preoperative nicotine abuse influenced the likelihood for perioperative complications. Copyright (c) 2006 S. Karger AG, Base

Silver(I) N-Heterocyclic Carbene Complexes Derived from Clotrimazole: Antiproliferative Activity and Interaction with an Artificial Membrane-Based Biosensor

With the aim of combining the potential anticancer properties of both clotrimazole, an imidazole based antifungal agent, and silver(I) N-heterocyclic carbenes, 13 novel silver(I) N-heterocyclic carbene complexes derived from clotrimazole were synthesized. The complexes were fully characterized, and the partition coefficient of each was determined to provide a measure of hydrophobicity. The antiproliferative properties of the complexes against cancerous and noncancerous cell lines found optimum cytotoxicity when the complex displays an “intermediate lipophilicity”, which describes a complex that possesses both water-soluble groups and lipophilic aromatic groups. The silver complexes were screened on a synthetic biomembrane-like device using a chip-based phospholipid-coated Pt/Hg electrode embedded in a flow cell system. The results are recorded as rapid cyclic voltammograms (RCVs), which give insight into the interactions of the complexes with a cell membrane. Interestingly the principle of “intermediate lipophilicity” also applies to the monolayer interaction to which the silver atom significantly implements an irreversibility

Clinical Outcomes of Cochlear Reimplantation Due to Device Failure

ObjectivesThe aim of this study was to evaluate the clinical features of cochlear reimplantation due to device failure.MethodsThe medical records of 30 patients who had undergone a revision cochlear implantation were retrospectively reviewed. Causes of revision operations, number of electrode channels inserted, and postoperative speech performances were analyzed.ResultsDevice failure (N=12, 38.7%) and hematoma (N=3, 9.6%) were the two most common reasons for revision surgery. In patients with device failure, the number of electrode channels reinserted was equal to, or more than the number of channels inserted during initial implantation. Speech performance scores remained the same, or improved after reimplantation in patients with device failure.ConclusionDevice failure was the most common cause of revision operation in patients with cochlear implanttion. Contrary to expectation, new electrodes were fully inserted without difficulty in all reimplantation cases. Intracochlear damage due to reimplantation appeared to be clinically insignificant

Epidermal Growth Factor Receptor Mutations and the Clinical Outcome in Male Smokers with Squamous Cell Carcinoma of Lung

Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) have been reported to be related to certain clinical characteristics (i.e., female, non-smokers with adenocarcinoma) and gefitinib responsiveness. This exploratory analysis was performed to determine the incidence of EGFR mutations in male smokers with squamous cell carcinoma, who were treated with EGFR tyrosine kinase inhibitor, gefitinib. Sixty-nine Korean NSCLC patients were treated with gefitinib in a prospective study. For a subset of 20 male patients with squamous cell carcinoma and a history of smoking, pretreatment tumor tissue samples were obtained and analyzed for EGFR mutations (exons 18 to 21). EGFR mutations were found in 3 (15%) patients, including in-frame deletions within exon 19 (n=2) and L858R missence mutation in exon 21 (n=1). These 3 patients with EGFR mutations responded to gefitinib, whereas only one of remaining 17 patients with wild-type EGFR achieved clinical response. Trend toward longer progression-free (5.8 vs. 2.4 months; P=0.07) was noted in patients with EGFR mutations compared to those with wild-type EGFR. Although male smokers with squamous cell carcinoma have not been considered ideal candidates for gefitinib treatment, significant incidence of EGFR mutations was observed. The molecular markers should be considered to predict clinical benefits from gefitinib

Combined written and oral information prior to gastrointestinal endoscopy compared with oral information alone: a randomized trial

BACKGROUND: Little is known about how to most effectively deliver relevant information to patients scheduled for endoscopy. METHODS: To assess the effects of combined written and oral information, compared with oral information alone on the quality of information before endoscopy and the level of anxiety. We designed a prospective study in two Swiss teaching hospitals which enrolled consecutive patients scheduled for endoscopy over a three-month period. Patients were randomized either to receiving, along with the appointment notice, an explanatory leaflet about the upcoming examination, or to oral information delivered by each patient's doctor. Evaluation of quality of information was rated on scales between 0 (none received) and 5 (excellent). The analysis of outcome variables was performed on the basis of intention to treat-analysis. Multivariate analysis of predictors of information scores was performed by linear regression analysis. RESULTS: Of 718 eligible patients 577 (80%) returned their questionnaire. Patients who received written leaflets (N = 278) rated the quality of information they received higher than those informed verbally (N = 299), for all 8 quality-of-information items. Differences were significant regarding information about the risks of the procedure (3.24 versus 2.26, p < 0.001), how to prepare for the procedure (3.56 versus 3.23, p = 0.036), what to expect after the procedure (2.99 versus 2.59, p < 0.001), and the 8 quality-of-information items (3.35 versus 3.02, p = 0.002). The two groups reported similar levels of anxiety before procedure (p = 0.66), pain during procedure (p = 0.20), tolerability throughout the procedure (p = 0.76), problems after the procedure (p = 0.22), and overall rating of the procedure between poor and excellent (p = 0.82). CONCLUSION: Written information led to more favourable assessments of the quality of information and had no impact on patient anxiety nor on the overall assessment of the endoscopy. Because structured and comprehensive written information is perceived as beneficial by patients, gastroenterologists should clearly explain to their patients the risks, benefits and alternatives of endoscopic procedures. Trial registration: Current Controlled trial number: ISRCTN34382782

Maxillofacial injuries associated with intimate partner violence in women

<p>Abstract</p> <p>Background</p> <p>The facial region has been the most common site of injury following violent episodes. The purpose of this study was to determine the prevalence and pattern of maxillofacial injuries associated with intimate partner violence (IPV) in women treated at a single facility in Malaysia.</p> <p>Methods</p> <p>A retrospective review of 242 hospital records of female IPV victims who were seen at the One-Stop Crisis Centre (OSCC) in Hospital Raja Perempuan Zainab II, Kelantan over a two-year period (January 1, 2005 to December 31, 2006) was performed. A structured form was used for data collection. Information regarding the anatomical sites of injuries, types of injuries, and mechanisms of assault were obtained.</p> <p>Results</p> <p>Most victims were married (85.1%), were injured by the husband (83.5%), and had at least one previous IPV episode (85.5%). Injury to the maxillofacial region was the most common (50.4%), followed by injury to the limbs (47.9%). In 122 cases of maxillofacial injuries, the middle of the face was most frequently affected (60.6%), either alone or in combination with the upper or lower third of the face. Injury to soft tissues (contusions, abrasions and lacerations) was the most common (87.7%).</p> <p>Conclusions</p> <p>This study indicates there is a high prevalence of maxillofacial injuries associated with IPV among women treated at the OSCC in Kelantan, Malaysia.</p

Percutaneous acetabuloplasty for metastatic acetabular lesions

Osteolytic metastases around the acetabulum are frequent in tumour patients, and may cause intense and drug-resistant pain of the hip. These lesions also cause structural weakening of the pelvis, limping, and poor quality of life. Percutaneous acetabuloplasty is a mini-invasive procedure for the management of metastatic lesions due to carcinoma of the acetabulum performed in patients who cannot tolerate major surgery, or in patients towards whom radiotherapy had already proved ineffective