241 research outputs found

    Dynamic Model Tests on Gravity Retaining Walls with Various Surcharge Conditions

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    Seismic design of retaining walls is traditionally based on the Mononobe-Okabe method of analysis. In recent years a number of theoretical analyses have been presented to predict the seismic behaviour of gravity retaining walls. In this paper some shaking table tests performed on a small prototype of gravity wall retaining dry sand are described and the experimental results are presented with the aim to provide, though qualitatively, an insight into some important aspects of the dynamic behaviour of retaining structures resting on rigid foundation soil. The M-O theory do not consider the particular boundary condition that in the practical design of retaining structures are often in use like backfill geometries or loading condition. Shaking table studies were carried out in order to study the dynamic behaviour of gravity retaining walls resting on rigid foundation soil. Two different system have been taken into consideration namely, a wall retaining a horizontal backfill on which uniform surcharge was placed and a wall on which the uniform surcharge was placed to a distance «d» to the head of the wall

    Flash spark plasma sintering of pure TiB2

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    Abstract Flash Spark Plasma Sintering (FSPS) was used to rapidly sinter pure titanium diboride (TiB2). A pre-sintered sample (O = 20 mm with relative density 60%) was crossed under a current of 2–2.5 kA flowing entirely across the sample. The samples were locally densified up to 98% of relative density in a very short time of 20 s. The rapid heating (≈6000 °C/min) prevented the complete evaporation of B2O3, leading to the formation of rarely seen segregation of boron at the grain boundaries. Compared to SPS or hot press, the rapid FSPS processing promoted the formation boron rich grain boundaries during sintering, thus enhancing consolidation. The FSPS approach might be suitable to consolidate other refractory borides

    Reduction in PSA messenger-RNA expression and clinical recurrence in patients with prostatic cancer undergoing neoadjuvant therapy before radical prostatectomy

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    BACKGROUND: We assessed the incidence of micro-metastases at surgical margins (SM) and pelvic lymph nodes (LN) in patients submitted to radical retropubic prostatectomy (RP) after neoadjuvant therapy (NT) or to RP alone. We compared traditional staging to molecular detection of PSA using Taqman-based quantitative real-time PCR (qrt-PCR) never used before for this purpose. METHODS: 29 patients were assigned to NT plus RP (arm A) or RP alone (arm B). Pelvic LN were dissected for qrt-PCR analysis, together with right and left lateral SM. RESULTS: 64,3% patients of arm B and 26.6% of arm A had evidence of PSA mRNA expression in LN and/or SM. 17,2% patients, all of arm B, had biochemical recurrence. CONCLUSIONS: Qrt-PCR may be more sensitive, compared to conventional histology, in identifying presence of viable prostate carcinoma cells in SM and LN. Gene expression of PSA in surgical periprostatic samples might be considered as a novel and reliable indicator of minimal residual disease after NT

    The Susceptibility of Candida albicans to Gamma-Radiations and Ketoco-nazole Depends on Transitional Filamentation

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    The virulence of C. albicans is associated with the transitional evolution from yeast to filamentous forms. We were interested in the effects amphotericin B (AMB), ketoconazole (KTC) and Îł-radiations might have on these broadly defined phenotypes as determined by the CFU procedure. By using collagen gel as the 3-dimensional support of cell culture, diverse experimental conditions were contemplated in order to modulate the differentiation of Candida during sessile and planktonic growth. These conditions included the co-culture with human epithelial and endothelial cells and treatment with farnesol, tyrosol and conditioned medium from P. aeruginosa. The overall results were as follows: 1) The survival of Candida was inhibited by the exposure to Îł-radiations, but only after the organism was induced to progress into excess filamentation, while in normal growth conditions it proved to be radioresistant; 2) AMB inhibited the growth of yeast forms, while KTC was specifically toxic to filamentous forms and 3) the combined treatment of filamentous Candida with KTC and Îł-radiations resulted in the synergistic inhibition of the organism. These findings indicate that both the radiosensitivity of C. albicans and its response to the synergistic effects of Îł-radiations and KTC are filamentation-dependent pharmacological processes

    Evaluation of a multisensorial system for a rapid preliminary screening of the olive oil chemical compounds in an industrial process

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    In this study, a sensory system, named BIONOTE, based on gas and liquid analyses was used to analyse the headspace of olive oil samples obtained at the end of the extraction process for a preliminary screening of the volatile and phenolic compounds. Olive oil samples were obtained using different olive paste conditioning systems, including microwave and megasound machines at different processing time. The same olives batch was used for the entire test. BIONOTE showed the ability to discriminate between 64 virgin olive oils originated from different technologies or by using different process parameters, as demonstrated by the partial least square discriminant analysis (PLS-DA) models calculated. The percentage of correct classification in different conditions are in a range from 92.19% to 100%. In addition, the research shown that the multisensorial system can provide a preliminary estimation of some volatile and phenolic compounds concentrations detected by laboratory analysis. Data analysis has been performed using multivariate data analysis techniques: PLS-DA cross validation via leave one out criterion. Future perspectives are to further develop BIONOTE in order to increase the number of detected chemical compounds and finally to include the mathematical models obtained in the BIONOTE microcontroller for a rapid chemical characterization of olive oil in the mill

    Accuracy of magnetic resonance imaging to identify pseudocapsule invasion in renal tumors

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    Purpose: To evaluate accuracy of MRI in detecting renal tumor pseudocapsule (PC) invasion and to propose a classification based on imaging of PC status in patients with renal cell carcinoma. Methods: From January 2017 to June 2018, 58 consecutive patients with localized renal cell carcinoma were prospectively enrolled. MRI was performed preoperatively and PC was classified, according to its features, as follows: MRI-Cap 0 (absence of PC), MRI-Cap 1 (presence of a clearly identifiable PC), MRI-Cap 2 (focally interrupted PC), and MRI-Cap 3 (clearly interrupted and infiltrated PC). A 3D image reconstruction showing MRI-Cap score was provided to both surgeon and pathologist to obtain complete preoperative evaluation and to compare imaging and pathology reports. All patients underwent laparoscopic partial nephrectomy. In surgical specimens, PC was classified according to the renal tumor capsule invasion scoring system (i-Cap). Results: A concordance between MRI-Cap and i-Cap was found in 50/58 (86%) cases. ρ coefficient for each MRI-cap and iCap categories was: MRI-Cap 0: 0.89 (p < 0.0001), MRI-Cap1: 0.75 (p < 0.0001), MRI-Cap 2: 0.76 (p < 0.0001), and MRI-Cap3: 0.87 (p < 0.0001). Sensitivity, specificity, positive predictive value, negative predictive value, and AUC were: MRI-Cap 0: Se 97.87% Spec 83.3%, PPV 95.8%, NPV 90.9%, and AUC 90.9; MRI-Cap 1: Se 77% Spec 95.5%, PPV 83.3%, NPV 93.5%, and AUC 0.86; MRI-Cap 2- iCap 2: Se 88% Spec 90%, PPV 79%, NPV 95%, and AUC 0.89; MRI-Cap 3: Se 94% Spec 95%, PPV 88%, NPV 97%, and AUC 0.94. Conclusions: MRI-Cap classification is accurate in evaluating renal tumor PC features. PC features can provide an imaging-guided landmark to figure out where a minimal margin could be preferable during nephron-sparing surgery

    Child-Pugh Class and Not Thrombocytopenia Impacts the Risk of Complications of Endoscopic Band Ligation in Patients with Cirrhosis and High Risk Varices

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    : Background and Aims: Endoscopic band legation (EBL) is an effective method for the prophylaxis of acute variceal bleeding (AVB). This procedure may be associated with several complications, particularly bleeding. Our analysis aimed to evaluate the risk of complications due to EBL in a cohort of patients who underwent EBL for the prophylaxis of variceal bleeding and the eventual presence of risk predictors. Patients and Methods: We retrospectively analysed data from consecutive patients who underwent EBL in a primary prophylaxis regimen. For all patients, simultaneously with EBL, we recorded the Child-Pugh and MELD score, platelet count and US features of portal hypertension. Results: We collected data from 431 patients who performed a total of 1028 EBLs. We recorded 86 events (8.4% of all procedures). Bleeding after EBL occurred 64 times (6.2% of all procedures), with the following distribution: intraprocedural bleeding in 4%; hematocystis formation in 17 cases (1.7%); 6 events (0.6%) of AVB due to post-EBL ulcers. None of these events presented a correlation with platelet count (84,235 ± 54,175 × 103/mL vs. 77,804 ± 75,949 × 103/mL; p = 0.70) or with the condition of severe thrombocitopenia established at PLT < 50,000/mmc (22.7% with PLT ≀ 50,000/mmc vs. 15.9% with PLT ≄ 50,000/mmc; p = 0.39). Our results showed a relationship between cumulative complications of EBL and Child-Pugh score (6.9 ± 1.6 vs. 6.5 ± 1.3; p = 0.043). Conclusions: EBL in cirrhotic patients is a safe procedure. The risk of adverse events depends on the severity of liver disease, without a relationship with platelet count

    Biosensors for Detection and Monitoring of Joint Infections

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    The aim of this review is to assess the use of biosensors in the diagnosis and monitoring of joint infection (JI). JI is worldwide considered a significant cause of morbidity and mortality in developed countries. Due to the progressive ageing of the global population, the request for joint replacement increases, with a significant rise in the risk of periprosthetic joint infection (PJI). Nowadays, the diagnosis of JI is based on clinical and radiological findings. Nuclear imaging studies are an option but are not cost-effective. Serum inflammatory markers and the analysis of the aspirated synovial fluid are required to confirm the diagnosis. However, a quick and accurate diagnosis of JI may remain elusive as no rapid and highly accurate diagnostic method was validated. A comprehensive search on Medline, EMBASE, Scopus, CINAH, CENTRAL, Google Scholar, and Web of Science was conducted from the inception to June 2021. The PRISMA guidelines were used to improve the reporting of the review. The MINORS was used for quality assessment. From a total of 155 studies identified, only four articles were eligible for this study. The main advantages of biosensors reported were accuracy and capability to detect bacteria also in negative culture cases. Otherwise, due to the few studies and the low level of evidence of the papers included, it was impossible to find significant results. Therefore, further high-quality studies are required

    Episodic memory and learning rates in amyotrophic lateral sclerosis without dementia

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    In amyotrophic lateral sclerosis (ALS), memory deficits may be primary or secondary to executive dysfunction. We assessed episodic memory and executive function of nondemented ALS patients, comparing episodic memory profiles and learning rates of ALS patients with those of mild cognitive impairment (MCI) subjects and cognitively healthy controls (HC). In a multidisciplinary tertiary centre for motor neuron disease, 72 nondemented ALS patients, 57 amnestic MCI (aMCI), 89 single non amnestic MCI with compromised executive functions (dysexecutive MCI), and 190 HC were enrolled. They were screened using the Frontal Assessment Battery and Mini Mental State Examination. Episodic memory performances and learning rates were tested using the Rey Auditory Verbal Learning Test (RAVLT). Episodic memory dysfunction (immediate recall) was found in 14 ALS patients (19.4%). The ALS group had lower performance than HC on immediate recall, without differences in learning rate, and better performance than aMCI subjects on all RAVLT measures. Compared to dysexecutive MCI subjects, ALS patients had only better verbal learning abilities. ALS patients with executive dysfunction had a lower score on immediate and delayed recalls, verbal learning, and primacy effect than ALS patients without executive dysfunction. The immediate recall among couples of diagnostic groups differed in a statistically significant way except for the ALS/dysexecutive MCI groups. In ALS patients, episodic memory performances and learning rates appeared to be better than in aMCI subjects and similar to those with dysexecutive MCI, suggesting also a secondary functional damage due to executive impairment
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