266 research outputs found

    Electron Microprobe Analysis and Proton Induced X-Ray Spectrometry Applied to Trace Element Analysis in Sulfides: Problems and Prospects

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    The complementary techniques of EPMA and micro-PIXE are reviewed in the context of spatially resolved trace element analysis of sulfide minerals. Attention is focussed on methods of standardization and of fitting EDX spectra. Sphalerites and chalcopyrites from various sources are used as specimens. For Ag in chalcopyrites, the two techniques agree well. Sphalerites pose problems such as Zn-Fe replacement and the presence of minor elements, both of which influence matrix corrections ; these are addressed in detail. The necessity for absorbers in the micro-PIXE work prevents detection of minor elements lighter than Zn ; these are determined by EPMA and the results used in the micro-PIXE fitting and matrix corrections. For Cd, Ag, Ga, Ge there is acceptable agreement between the two techniques given uncertainties and constraints on samples, but EPMA results for Hg are notably lower than micro-PIXE results. The improvement in detection limits afforded by micro-PIXE over EPMA in these sulfide minerals ranges from ~ 3 for Ga, Ge, Hg to 10-30 for Se, Ag, Cd, In ; possible further gains are discussed for both techniques

    Sigmoid stricture associated with diverticular disease should be an indication for elective surgery with lymph node clearance

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    BACKGROUND: The literature concerning stricture secondary to diverticulitis is poor. Stricture in this setting should be an indication for surgery because (a) of the potential risk of cancer and (b) morbidity is not increased compared to other indications for colectomy. The goal of this report is to study the post-surgical morbidity and the quality of life in patients after sigmoidectomy for sigmoid stricture associated with diverticular disease. METHOD: This is a monocenter retrospective observational study including patients with a preoperative diagnosis of sigmoid stricture associated with diverticular disease undergoing operation between Jan 1, 2007 and Dec 31, 2013. The GastroIntestinal Quality of Life Index was used to assess patient satisfaction. RESULTS: Sixteen patients were included of which nine were female. Median age was 69.5 (46-84) and the median body mass index was 23.55kg/m(2) (17.2-28.4). Elective sigmoidectomy was performed in all 16 patients. Overall, complications occurred in five patients (31.2%) (4 minor complications and 1 major complication according to the Dindo and Clavien Classification); none resulted in death. Pathology identified two adenocarcinomas (12.5%). The mean GastroIntestinal Quality of Life Index was 122 (67-144) and 10/11 patients were satisfied with their surgical intervention. CONCLUSION: Sigmoid stricture prevents endoscopic exploration of the entire colon and thus it may prove difficult to rule out a malignancy. Surgery does not impair the quality of life since morbidity is similar to other indications for sigmoidectomy. For these reasons, we recommend that stricture associated with diverticular disease should be an indication for sigmoidectomy including lymph node clearance

    Development of multilocus variable-number tandem repeat analysis (MLVA) for Xanthomonas arboricola pathovars

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    Xanthomonas arboricola is an important bacterial species, the pathovars of which are responsible for bacterial blight diseases on stone fruit, hazelnut, Persian walnut, poplar, strawberry, poinsettia and banana. In this study, we evaluated variable number tandem repeats (VNTR) as a molecular typing tool for assessing the genetic diversity within pathovars of X. arboricola. Screening of the X. arboricola pv. pruni genome sequence (CFBP5530 strain) predicted 51 candidate VNTR loci. Primer pairs for polymerase chain reaction (PCR) amplification of all 51 loci were designed, and their discriminatory power was initially evaluated with a core collection of 8 X. arboricola strains representative of the different pathovars. Next, the 26 polymorphic VNTR loci present in all strains were used for genotyping a collection of 61 strains. MLVA is a typing method that clearly differentiates X. arboricola strains. The MLVA scheme described in this study is a rapid and reliable molecular typing tool that can be used for further epidemiological studies of bacterial diseases caused by X. arboricola pathovars

    Noninvasive liver steatosis quantification using MRI techniques combined with blood markers:

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    Aims: To evaluate the accuracy of different techniques of MRI steatosis quantification, based on histological grading and quantification of liver steatosis.Patients and methods: Twenty-three patients (21 with nonalcoholic fatty liver disease and two controls) were included. Steatosis was evaluated in liver specimens using histological grading (five grades) and steatosis area (% of liver surface) was computed using an inhouse automated image analysis. The following five MRI quantification techniques were performed: two-point Dixon, three-point Dixon, DUAL, spin echo method and a new technique called multi-echo gradient-echo (MFGRE). Interobserver (two observers) and intersite (three different liver sites) agreements were evaluated for the two best-performing methods. Results: Steatosis area was correlated with steatosis grade: Rs (Spearman coefficient)=0.82, P value of less than 0.001. The steatosis area was significantly different between S0–S2 and S3–S4 grades: 4.2±2.4 versus 16.4±8.9% (P<0.001). Correlations between the MRI techniques and steatosis area (or grading) were: MFGRE, Rs=0.72 (0.78); spin echo method, Rs=0.72 (0.76); DUAL, Rs=0.71 (0.76); two-point Dixon, Rs=0.71 (0.75); three-point Dixon, Rs=0.67 (0.77). Interobserver (Ric=0.99) and intersite (Ric=0.97) agreements were excellent for the liver steatosis measurement by MFGRE. The noninvasive diagnosis of the steatosis area was improved by adding blood markers like ALT and triglycerides to MFGRE (aR2: 0.805). Conclusion: MRI, and in particular the MFGRE method, provides accurate and automatic quantification for the noninvasive evaluation of liver steatosis, either as a single measurement or in combination with blood variables

    Distribution of abdominal adipose tissue as a predictor of hepatic steatosis assessed by MRI

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    AIM: To evaluate the relationship between the distribution of visceral and subcutaneous adipose tissue and hepatic steatosis assessed using magnetic resonance imaging (MRI). MATERIALS AND METHODS: One T1-weighted, in-/out-of-phase, single-section sequence at the L3/L4 level and one multi-echo gradient MRI (MGRE) sequence were performed on 65 patients [19 females and 46 males; age 57+/-9.5 years; body mass index (BMI) 31+/-5.1kg/m(2)]. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) surfaces, and hepatic steatosis were automatically calculated using in-house software. Weight, height, BMI, waist circumference, hip circumference, and waist:hip ratio were recorded. The probability of having a steatosis greater than 10% on MRI was evaluated by receiver operating characteristic (ROC) curves. RESULTS: The anthropometric parameter best correlated to hepatic steatosis was the waist-to-hip ratio (r=0.301). VAT and proportion of VAT were correlated to liver fat content (r=0.307 and r=0.249, respectively). No significant correlations were found for BMI, hip circumference, and SAT. The area under the receiver operating characteristics (AUROCs) for the relationship between liver steatosis and BMI, waist circumference, waist:hip ratio, VAT surface, and proportion of VAT, were respectively 0.52, 0.63, 0.71, 0.73 and 0.75. CONCLUSION: Adipose tissue distribution is more relevant than total fat mass when assessing the possibility of liver steatosis in overweight patients

    Long-term follow-up after endoscopic resection for superficial esophageal squamous cell carcinoma: a multicenter Western studyAbstract

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    Background Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are the first-line treatments for superficial esophageal squamous cell carcinoma (SCC). This study aimed to compare long-term clinical outcome and oncological clearance between EMR and ESD for the treatment of superficial esophageal SCC. Methods We conducted a retrospective multicenter study in five French tertiary care hospitals. Patients treated by EMR or ESD for histologically proven superficial esophageal SCC were included consecutively. Results Resection was performed for 148 tumors (80 EMR, 68 ESD) in 132 patients. The curative resection rate was 21.3 % in the EMR group and 73.5 % in the ESD group (P < 0.001). The recurrence rate was 23.7 % in the EMR group and 2.9 % in the ESD group (P = 0.002). The 5-year recurrence-free survival rate was 73.4 % in the EMR group and 95.2 % in the ESD group (P = 0.002). Independent factors for cancer recurrence were resection by EMR (hazard ratio [HR] 16.89, P = 0.01), tumor infiltration depth ≄ m3 (HR 3.28, P = 0.02), no complementary treatment by chemoradiotherapy (HR 7.04, P = 0.04), and no curative resection (HR 11.75, P = 0.01). Risk of metastasis strongly increased in patients with tumor infiltration depth ≄ m3, and without complementary chemoradiotherapy (P = 0.02). Conclusion Endoscopic resection of superficial esophageal SCC was safe and efficient. Because it was associated with an increased recurrence-free survival rate, ESD should be preferred over EMR. For tumors with infiltration depths ≄ m3, chemoradiotherapy reduced the risk of nodal or distal metastasis

    Overexpression of RoDELLA impacts the height, branching, and flowering behaviour of Pelargonium × domesticum transgenic plants

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    Key message We reported the cloning of a rose DELLA gene. We obtained transgenic Pelargonium lines overexpressing this gene which presented several phenotypes in plant growth, root growth, flowering time and number of inflorescences. Abstract Control of development is an important issue for production of ornamental plant. The plant growth regulator, gibberellins (GAs), plays a pivotal role in regulating plant growth and development. DELLA proteins are nuclear negative regulator of GA signalling. Our objective was to study the role of GA in the plant architecture and in the blooming of ornamentals. We cloned a rose DELLA homologous gene, RoDELLA, and studied its function by genetic transformation of pelargonium. Several transgenic pelargonium (Pelargonium × domesticum ‘Autum Haze’) lines were produced that ectopically expressed RoDELLA under the control of the 35S promoter. These transgenic plants exhibited a range of phenotypes which could be related to the reduction in GA response. Most of transgenic plants showed reduced growth associated to an increase of the node and branch number. Moreover, overexpression of RoDELLA blocked or delayed flowering in transgenic pelargonium and exhibited defects in the root formation. We demonstrated that pelargonium could be used to validate ornamental gene as the rose DELLA gene. RoDELLA overexpression modified many aspects of plant developmental pathways, as the plant growth, the transition of vegetative to floral stage and the ability of rooting
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