120 research outputs found

    Hindered Rotation of Dihydrogen on Synthesized Metal Oxides

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    A MATLAB program was written to calculate the hindered rotational energies of the hydrogen and deuterium molecules interacting with an anisotropic potential, which may be thought of as a potential energy surface of a metal oxide substrate. It was found that an increase in the hindering potential of the rotation about the azimuthal angle lifted the degeneracy of the j = 1,mj [magnetic quantum number] = plus or minus 1 states. A better understanding of how the rotational states of these systems change as a function of the hindering potential can help to explain features in rotational inelastic neutron scattering spectra of hydrogen on ZnO. An attempt to produce single morphology zinc and magnesium oxide nanoparticles using a patented method by Larese and Kunnmann is discussed. The synthesis of magnesium oxide consistently produced single morphology MgO nanocubes. Zinc oxide synthesis produced a mixture of morphologies consisting of tetrapods, kites, and hexagonal pillars. The contents of the production cell w re modified using a 50/50 graphite powder to chip ratio to decrease the diffusion rate of the metal vapor. Qualitative results suggest an increase in tetrapod concentration was realized via this modification

    Impact of obesity on the outcomes after gastrectomy for gastric cancer: A meta-analysis.

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    Summary: The impact of body mass index (BMI) on surgical outcomes has previously been studied in relation to several oncological procedures. Regarding gastric cancer surgery, published results have been contradicting in terms of degree of technical difficulty, risk of postoperative complications and survival. In an attempt to clarify these issues, we performed a meta-analysis to evaluate the impact of obesity (defined as BMI ≥ 30 kg/m2) on outcomes after gastrectomy for gastric cancer. The meta-analysis was performed according to the PRISMA guidelines. Eligible studies were identified through search of PubMed, EMBASE, Web of Science and Cochrane Library databases. Quality assessment was performed using the Newcastle-Ottawa scale. The meta-analysis was conducted using random-effects modeling. A total of 11 studies with 13 538 patients were eligible for analysis. Obesity was associated with a significantly longer operation time (WMD = 19.38 min, 95% CI 12.72–26.04; p < 0.001), increased risk of overall complications (RR = 1.23, 95% CI 1.06–1.42; p = 0.005) and pulmonary complications (RR = 3.81, 95% CI 2.24–6.46; p < 0.001). These findings remained irrespective type of surgery (laparoscopic vs. open) and type of gastrectomy. No differences were found regarding blood loss, number of resected lymph nodes, anastomotic leakage, hospital stay, 30-day mortality and 5-year overall survival. The conclusion of the current meta-analysis is that high BMI in gastric cancer patients is associated with longer operative time and more frequent overall postoperative complications. However, it has no negative impact on survival, indicating that gastrectomy is a safe procedure for this group of patients

    Cardiorespiratory comorbidity and postoperative complications following esophagectomy: a European multicenter cohort study

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    BACKGROUND: The impact of cardiorespiratory comorbidity on operative outcomes after esophagectomy remains controversial. This study investigated the effect of cardiorespiratory comorbidity on postoperative complications for patients treated for esophageal or gastroesophageal junction cancer. PATIENTS AND METHODS: A European multicenter cohort study from five high-volume esophageal cancer centers including patients treated between 2010 and 2017 was conducted. The effect of cardiorespiratory comorbidity and respiratory function upon postoperative outcomes was assessed. RESULTS: In total 1590 patients from five centers were included; 274 (17.2%) had respiratory comorbidity, and 468 (29.4%) had cardiac comorbidity. Respiratory comorbidity was associated with increased risk of overall postoperative complications, anastomotic leak, pulmonary complications, pneumonia, increased Clavien-Dindo score, and critical care and hospital length of stay. After neoadjuvant chemoradiotherapy, respiratory comorbidity was associated with increased risk of anastomotic leak [odds ratio (OR) 1.83, 95% confidence interval (CI) 1.11-3.04], pneumonia (OR 1.65, 95% CI 1.10-2.47), and any pulmonary complication (OR 1.52, 95% CI 1.04-2.22), an effect which was not observed following neoadjuvant chemotherapy or surgery alone. Cardiac comorbidity was associated with increased risk of cardiovascular and pulmonary complications, respiratory failure, and Clavien-Dindo score ≥ IIIa. Among all patients, forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio > 70% was associated with reduced risk of overall postoperative complications, cardiovascular complications, atrial fibrillation, pulmonary complications, and pneumonia. CONCLUSIONS: The results of this study suggest that cardiorespiratory comorbidity and impaired pulmonary function are associated with increased risk of postoperative complications after esophagectomy performed in high-volume European centers. Given the observed interaction with neoadjuvant approach, these data indicate a potentially modifiable index of perioperative risk

    Survival benefit and additional value of preoperative chemoradiotherapy in resectable gastric and gastro-oesophageal junction cancer: a direct and adjusted indirect comparison meta-analysis

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    Several phase I/II studies of chemoradiotherapy for gastric cancer have reported promising results, but the significance of preoperative radiotherapy in addition to chemotherapy has not been proven. In this study, a systematic literature search was performed to capture survival and postoperative morbidity and mortality data in randomised clinical studies comparing preoperative (chemo)radiotherapy or chemotherapy versus surgery alone, or preoperative chemoradiotherapy versus chemotherapy for gastric and/or gastro-oesophageal junction (GOJ) cancer. Hazard ratios (HRs) for overall mortality were extracted from the original studies, individual patient data provided from the principal investigators of eligible studies or the earlier published meta-analysis. The incidences of postoperative morbidities and mortalities were also analysed. In total 18 studies were eligible and data were available from 14 of these. The meta-analysis on overall survival yielded HRs of 0.75 (95% CI 0.65–0.86, P < 0.001) for preoperative (chemo)radiotherapy and 0.83 (95% CI 0.67–1.01, P = 0.065) for preoperative chemotherapy when compared to surgery alone. Direct comparison between preoperative chemoradiotherapy and chemotherapy resulted in an HR of 0.71 (95% CI 0.45–1.12, P = 0.146). Combination of direct and adjusted indirect comparisons yielded an HR of 0.86 (95% CI 0.69–1.07, P = 0.171). No statistically significant differences were seen in the risk for postoperative morbidity or mortality between preoperative treatments and surgery alone, or preoperative (chemo)radiotherapy and chemotherapy. Preoperative (chemo)radiotherapy for gastric and GOJ cancer showed significant survival benefit over surgery alone. In comparisons between preoperative chemotherapy and (chemo)radiotherapy, there is a trend towards improved survival when adding radiotherapy, without increased postoperative morbidity or mortality

    Presence of symptom clusters in surgically treated patients with esophageal cancer

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    BACKGROUND: It is not known whether symptoms cluster together after esophageal cancer surgery or whether such symptom clusters are associated with survival in patients with esophageal cancer who are treated surgically. METHODS: Data from a prospective Swedish nationwide cohort study of surgically treated patients with esophageal cancer recruited between 2001 and 2005 were used. General and esophageal cancer-specific symptoms were assessed using the European Organization for Research and Treatment of Cancer QLQ-C30 quality of life questionnaire and the QLQ-OES18 module at 6 months after surgery. Associations between symptom clusters and survival were analyzed using Cox proportional hazards models, providing hazards ratios with 95% confidence intervals, adjusted for other known prognostic factors. RESULTS: Among 402 patients reporting symptoms 6 months after surgery, 3 symptom clusters were identified. The first symptom cluster (“fatigue/pain”) was characterized by symptoms of pain, fatigue, insomnia, and dyspnea and was present in 30% of patients. The second symptom cluster (“reflux/cough”) was characterized by symptoms of dry mouth, problems with taste, coughing, and reflux and was present in 27% of patients. The third symptom cluster (“eating difficulties”) was characterized by appetite loss, dysphagia, eating difficulties, and nausea/vomiting and was present in 28% of patients. The presence of the reflux/cough and eating difficulties symptom clusters was associated with a statistically significantly increased risk of mortality (adjusted hazards ratio, 1.43 [95% confidence interval, 1.08-1.89] and adjusted HR, 1.41 [95% confidence interval, 1.06-1.87], respectively). CONCLUSIONS: Symptoms experienced by surgically treated patients with esophageal cancer appear to cluster together, and the presence of these symptom clusters appears to have strong prognostic value.Vetenskapsrådet, Cancerfonden, Radiumhemmets forskningsfonderPublishe

    Role of Radiology in the Preoperative Detection of Arterial Calcification and Celiac Trunk Stenosis and Its Association with Anastomotic Leakage Post Esophagectomy, an Up-to-Date Review of the Literature

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    Surgical resection of the esophagus remains a critical component of the multimodal treatment of esophageal cancer. Anastomotic leakage (AL) is the most significant complication following esophagectomy, in terms of clinical implications. Identifying risk factors for AL is important for modifying patient management and improving surgical outcomes. This review aims to examine the role of radiological risk factors for AL after esophagectomy, and in particular, arterial calcification and celiac trunk stenosis. Eligible publications prior to 25 August 2021 were retrieved from Medline and Google Scholar using a predefined search algorithm. A total of 68 publications were identified, of which 9 original studies remained for in-depth analysis. The majority of these studies found correlations between calcifications in the aorta, celiac trunk, and right post-celiac arteries and AL following esophagectomy. Some studies suggest celiac trunk stenosis as a more appropriate surrogate. Our up-to-date review highlights the need for automated quantification of aortic calcifications, as well as the degree of celiac trunk stenosis in preoperative computed tomography in patients undergoing esophagectomy, to obtain robust and reproducible measurements that can be used for a definite correlation.publishedVersionPeer reviewe

    Expression of chemokine receptor CXCR4 in esophageal squamous cell and adenocarcinoma

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    BACKGROUND: Prognosis of esophageal cancer is poor despite curative surgery. The chemokine receptor CXCR4 has been proposed to distinctly contribute to tumor growth, dissemination and local immune escape in a limited number of malignancies. The aim of our study was to evaluate the role of CXCR4 in tumor spread of esophageal cancer with a differentiated view of the two predominant histologic types – squamous cell and adenocarcinoma. METHODS: Esophageal cancer tissue samples were obtained from 102 consecutive patients undergoing esophageal resection for cancer with curative intent. The LSAB+ System was used to detect the protein CXCR4. Tumor samples were classified into two groups based on the homogeneous staining intensity. A cut-off between CXCR4w (= weak expression) and CXCR4s (= strong expression) was set at 1.5 (grouped 0 – 1.5 versus 2.0 – 3). Long-term survival rates were calculated using life tables and the Kaplan-Meier method. Using the Cox's proportional hazards analysis, a model of survival prediction was established. RESULTS: The overall expression rate for CXCR4 in esophageal squamous cell carcinoma was 94.1%. Subdividing these samples, CXCR4w was found in 54.9% and CXCR4s in 45.1%. In adenocarcinoma, an overall expression rate of 89.1% was detected with a weak intensitiy in 71.7% compared to strong staining in 29.3% (p = 0.066 squamous cell versus adenocarcinoma). The Cox's proportional hazards analysis identified the pM-category with a hazard ratio (HR) of 1.860 (95% CI: 1.014–3.414) (p = 0.045), the histologic tumor type (HR: 0.334; 95% CI: 0.180–0.618) (p = 0.0001) and the operative approach (transthoracic > transhiatal esophageal resection) (HR: 0.546; 95% CI: 0.324–0.920) (p = 0.023) as independent factors with a possible influence on the long-term prognosis in patients with esophageal carcinoma, whereas CXCR4 expression was statistically not significant (>0.05). CONCLUSION: Expression of the chemokine receptor CXCR4 in esophageal cancer is of major relevance in both histologic entities – squamous cell and adenocarcinoma. Though with lack of statistical significance, strong CXCR4 expression revealed a poorer long-term prognosis following curative esophagectomy in both histologic subtypes. Thus, the exact biological functions of CXCR4 in terms of tumor dissemination of esophageal cancer is yet undetermined. Inhibition of esophageal cancer progression by CXCR4 antagonists might be a promising therapeutic option in the future
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