811 research outputs found

    Large-scale numerical modeling of hydro-acoustic waves generated by tsunamigenic earthquakes

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    Abstract. Tsunamigenic fast movements of the seabed generate pressure waves in weakly compressible seawater, namely hydro-acoustic waves, which travel at the sound celerity in water (about 1500 m s−1). These waves travel much faster than the counterpart long free-surface gravity waves and contain significant information on the source. Measurement of hydro-acoustic waves can therefore anticipate the tsunami arrival and significantly improve the capability of tsunami early warning systems. In this paper a novel numerical model for reproduction of hydro-acoustic waves is applied to analyze the generation and propagation in real bathymetry of these pressure perturbations for two historical catastrophic earthquake scenarios in Mediterranean Sea. The model is based on the solution of a depth-integrated equation, and therefore results are computationally efficient in reconstructing the hydro-acoustic waves propagation scenarios

    Genetic Connectivity in Scleractinian Corals across the Northern Gulf of Mexico: Oil/Gas Platforms, and Relationship to the Flower Garden Banks

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    The 3,000 oil/gas structures currently deployed in the northern Gulf of Mexico (GOM) provide hard substratum for marine organisms in a region where such has been rare since the Holocene. The major exception to this are the Flower Garden Banks (FGB). Corals are known to have colonized oil/gas platforms around the FGB, facilitating biogeographic expansion. We ask the question, what are the patterns of genetic affinity in these coral populations. We sampled coral tissue from populations of two species occurring on oil and gas platforms: Madracis decactis (hermatype) and Tubastraea coccinea (invasive ahermatype). We sampled 28 platforms along four transects from 20 km offshore to the continental shelf edge off 1) Matagorda Island, TX; 2) Lake Sabine, TX; 3) Terrebonne Bay, LA; and 4) Mobile, AL. The entire population of M. decactis was sampled between depths of 5 m and 37 m. T. coccinea populations were sub-sampled. Genetic variation was assessed using the PCR-based Amplified Fragment Length Polymorphisms (AFLPs). Data were analyzed via AFLPOP and STRUCTURE. Genetic connectivity among M. decactis platform populations was highest near the FGB and decreased to the east. Connectivity increased again in the eastern sector, indicating isolation between the populations from different sides of the Mississippi River (Transects 3 and 4). A point-drop in genetic affinity (relatedness) at the shelf edge south of Terrebonne Bay, LA indicated a population differing from all others in the northern GOM. Genetic affinities among T. coccinea were highest in the west and decreased to the east. Very low genetic affinities off Mobile, AL indicated a dramatic difference between those populations and those west of the Mississippi River, apparently a formidable barrier to larval dispersal

    New insights into North Sea deep crustal structure and extension from transdimensional ambient noise tomography

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    SUMMARY The deep crustal structure beneath the North Sea is poorly understood since it is constrained by only a few seismic reflection and refraction profiles. However, it is widely acknowledged that the mid to lower crust plays important roles in rift initiation and evolution, particularly when large-scale sutures and/or terrane boundaries are present, since these inherited features can focus strain or act as inhibitors to extensional deformation. Ancient tectonic features are known to exist beneath the iconic failed rift system of the North Sea, making it an ideal location to investigate the complex interplay between pre-existing regional heterogeneity and rifting. To this end, we produce a 3-D shear wave velocity model from transdimensional ambient seismic noise tomography to constrain crustal properties to ∼30 km depth beneath the North Sea and its surrounding landmasses. Major North Sea sedimentary basins appear as low shear wave velocity zones that are a good match to published sediment thickness maps. We constrain relatively thin crust (13–18 km) beneath the Central Graben depocentres that contrasts with crust elsewhere at least 25–30 km thick. Significant variations in crustal structure and rift symmetry are identified along the failed rift system that appears to be related to the locations of Laurentia–Avalonia–Baltica palaeoplate boundaries. We constrain first-order differences in structure between palaeoplates; with strong lateral gradients in crustal velocity related to Laurentia–Avalonia–Baltica plate juxtaposition and reduced lower crustal velocities in the vicinity of the Thor suture, possibly representing the remnants of a Caledonian accretionary complex. Our results provide fresh insight into the pivotal roles that ancient terranes can play in the formation and failure of continental rifts and may help explain the characteristics of other similar continental rifts globally.</jats:p

    Esophageal resection in the ederly

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    The aging of the population and longer life expectancy entails an increased number of elderly patients with esophageal cancer and benign pathologies referred for surgical treatment. Esophageal cancer is a pathology that mainly involves elderly patients. The aim of this study is to assess the effects of age on the outcome of surgery for esophageal cancer and benign pathologies in patients treated in our departmen

    Heat-transfer analysis of microfabricated thermocapillary pumping and reaction devices

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    A heat-transfer analysis was performed on thermocapillary pumping, a surface-tension-based drop pumping mechanism. The analysis, which incorporates both fluid flow and energy transport through multiple device layers, reveals effective material, design, and operational choices that result in improved pumping performance. Important design factors include thermal conductivity, channel/substrate thickness, and the velocity of the liquid drops. Results for pumping a drop of water on a fused silica substrate with a glass channel show that uniform interface temperatures can be achieved with bottom heating as long as drop velocities remain below ~0.1 cm s-1 . The analysis was also extended to include thermal reaction channels. The reactor analysis verified that relatively uniform reaction temperatures were attainable with bottom heating as long as channel heights were below ~100 µm.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49025/2/jm0107.pd

    Endoscopic Pilonidal Sinus Treatment. A Tertiary Care Academic Center Experience

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    Background: Pilonidal disease (PD) represents one of the most common proctological diseases in young adults. Although several approaches to treating PD have been described, there is still a lack of agreement on which is the best. The aim of this study was to evaluate the long-term efficacy of endoscopic pilonidal sinus treatment (EPSiT) at a tertiary care academic center. Methods: Between June 2017 and January 2021, a total of 32 patients [12 women (37.5%) and 20 men (62.5%)] with a mean age of 29.22 ± 12.98 years were treated with EPSiT. Pre- and post-operative symptoms were assessed with a score of 0–5. Success was defined as the absence of any subjective symptoms, as well as by complete post-operative wound healing. Results: Most of the patients had a midline external opening (17/32; 53.1%), with a mean number of external openings of 2.41 (1–4) ± 1.04. The median post-operative pain score was 0, and the mean follow-up period was 22 (4–42) ± 11.49 months. The time to wound healing was reduced in patients with one opening (28.14 ± 4.06 days) compared to patients with two or more openings (33.64 ± 7.3 days) (p = 0.067). The mean operative time was longer in patients who subsequently had a recurrence (41.75 ± 6.24 vs. 34.18 ± 6.24 min; p = 0.031). The overall success rate was 87.5% (28/32), and the mean time to recurrence was 3.25 (2–5) ± 1.26 months. Conclusions: EPSiT represents a viable option for the treatment of PD. More evidence and a longer follow-up period are needed to validate the results

    Mast cells, microRNAs and others: The role of translational research on colorectal cancer in the forthcoming era of precision medicine

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    Colorectal cancer (CRC) is a heterogeneous disease, molecularly and anatomically, that develops in a multi-step process requiring the accumulation of several genetic or epigenetic mutations that lead to the gradual transformation of normal mucosa into cancer. In fact, tumorigenesis is extremely complex, with many immunologic and non-immunologic factors present in the tumor microenvironment that can influence tumorigenesis. In the last few years, a role for mast cells (MCs), microRNAs (miRNAs), Kirsten rat sarcoma (KRAS) and v-raf murine sarcoma viral oncogene homologue B (BRAF) in cancer development and progression has been suggested, and numerous efforts have been made to thoroughly assess their correlation with CRC to improve patient survival and quality of life. The identification of easily measurable, non-invasive and cost-effective biomarkers, the so-called “ideal biomarkers”, for CRC screening and treatment remains a high priority. The aim of this review is to discuss the emerging role of mast cells (MCs), microRNAs (miRNAs), KRAS and BRAF as diagnostic and prognostic biomarkers for CRC, evaluating their influence as potential therapy targets in the forthcoming era of precision medicine

    Genetic tools discriminate strains of leishmania infantum isolated from humans and dogs in Sicily, Italy

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    Background Leishmaniasis is one of the most important vector-borne diseases and it represents a seri-ous world health problem affecting millions of people. High levels of Leishmania infections, affecting both humans and animals, are recognized among Italian regions. Among these, Sicily has one of the highest prevalence of Leishmania infection. Methodology/Principal Findings Seventy-eight Leishmania strains isolated from human and animal samples across Sicily, were analyzed for the polymorphic k26-gene and genotypes were assigned according to the size of the PCR products. A multilocus microsatellite typing (MLMT) approach based on the analysis of 11 independent loci was used to investigate populations structure and genetic diversity of the isolated strains. Six L. infantum reference strains were included in the analysis for comparison. Bayesian clustering analysis of microsatellite data showed that all the isolated strains clustered in two genetically distinct populations, corresponding to human and canine isolates respectively. A further subdivision was observed between the two main groups, giving a good correlation between human strains and their geographic origin, conversely canine population showed a great genetic variability diffused in the territory. Conclusions/Significance Among the 78 Leishmania isolates, K26 analysis detected 71 samples (91%) as MON-1 zymodeme, confirming it as the predominant strain in Mediterranean area and 7 human samples (9%) as non-MON-1. MLMT gives important insights into the epidemiology of leish-maniases and allows characterization of different strains to a higher resolution than possible with zymodeme typing. Two main populations presented a strong correlation respect to the different hosts, exhibiting a co-circulation of two distinct populations of L. infantum. The population found in infected humans exhibited a correlation with geographic origin. These clusters could represent a geographically restricted population of strains with the same or related genotypes. This study can contribute to an understanding of Leishmania epidemiol-ogy, including the spread of reservoirs and sand fly vectors in the different foci of infection, characterizing parasites within the different hosts

    Retrospective evaluation of metformin and/or metformin plus a new polysaccharide complex in treating severe hyperinsulinism and insulin resistance in obese children and adolescents with metabolic syndrome

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    Background: Pharmacological treatment of obesity and glucose-insulin metabolism disorders in children may be more difficult than in adults. Thus, we evaluate the effects of metformin in comparison with metformin plus a polysaccharide complex (Policaptil Gel Retard®, PGR) on body weight and metabolic parameters in obese children and adolescents with metabolic syndrome (MetS). Patients and methods: We retrospectively collected 129 children and adolescents (67 girls, 62 boys; median age 12.6 years) treated for a minimum of two years with metformin and low glycemic index (LGI) diet. Of these, 71 patients were treated with metformin plus PGR after at least 12 months of metformin alone. To minimize the confounding effect of the LGI on auxological and metabolic parameters, the patients were compared with age-, sex-, and BMI-matched control group with obesity and MetS (51 subjects; 24 males, 27 females) treated only with a LGI diet. Assessments included lipids, glucose and insulin (fasting and after oral glucose tolerance test) concentrations. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Matsuda, insulinogenic and disposition indices were calculated. Results: Metformin treatment led to a significant reduction in BMI SDS (p &lt; 0.0001), with a significant difference in ΔBMI SDS between patients and controls (p &lt; 0.0001). Moreover, metformin treated patients showed a reduction in HOMA-IR (p &lt; 0.0001), HbA1c levels (p &lt; 0.0001) and a significant increase in Matsuda index (p &lt; 0.0001) in respect to the reduction discovered in controls (p &lt; 0.05). Moreover, in contrast to the group treated with metformin alone and controls, patients treated with metformin plus PGR showed a further reduction in BMI SDS (p &lt; 0.0001), HOMA-IR (p &lt; 0.0001), HbA1c (p &lt; 0.0001), total, HDL and LDL cholesterol (p &lt; 0.0001), as well as an increase in Matsuda (p &lt; 0.0001), disposition (p &lt; 0.005) and insulinogenic (respectively, p &lt; 0.05 and p &lt; 0.0001) indices. Conclusions: Metformin appears to show short-term efficacy in reducing BMI, adiposity and glucose and insulin parameters in obese children and adolescents with MetS. However, PGR added to metformin may be useful to potentiate weight loss and to improve glucose-insulin metabolism and adiposity parameters in these patients

    Mesoglycan for pain control after open excisional HAEMOrrhoidectomy (MeHAEMO). An observational multicentre study on behalf of the Italian Society of Colorectal Surgery (SICCR)

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    Background: Excisional haemorrhoidectomy is the gold standard technique in patients with III and IV degree haemorrhoidal disease (HD). However, it is associated with a significant rate of post-operative pain. The aim of our study was to evaluate the efficacy of mesoglycan in the post-operative period of patients who underwent open excisional diathermy haemorrhoidectomy (OEH). Methods: This was a retrospective multicentre observational study. Three hundred ninety-eight patients from sixteen colorectal referral centres who underwent OEH for III and IV HD were enrolled. All patients were followed-up on the first post-operative day (T1) and after 1 week (T2), 3 weeks (T3) and 6 weeks (T4). BMI, habits, SF-12 questionnaire, VAS at rest (VASs), after defecation (VASd), and after anorectal digital examination (VASe), bleeding and thrombosis, time to surgical wound healing and autonomy were evaluated. Results: In the mesoglycan group, post-operative thrombosis was significantly reduced at T2 (p &lt; 0.05) and T3 (p &lt; 0.005), and all patients experienced less post-operative pain at each time point (p &lt; 0.001 except for VASe T4 p = 0.003). There were no significant differences between the two groups regarding the time to surgical wound healing or post-operative bleeding. There was an early recovery of autonomy in the mesoglycan group in all three follow-up periods (T2 p = 0.016; T3 p = 0.002; T4 p = 0.007). Conclusions: The use of mesoglycan led to a significant reduction in post-operative thrombosis and pain with consequent early resumption of autonomy. Trial registration NCT0448169
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