Partially Isometric Immersions and Free Maps

In this paper we investigate the existence of ``partially'' isometric immersions. These are maps f:M->R^q which, for a given Riemannian manifold M, are isometries on some sub-bundle H of TM. The concept of free maps, which is essential in the Nash--Gromov theory of isometric immersions, is replaced here by that of H-free maps, i.e. maps whose restriction to H is free. We prove, under suitable conditions on the dimension q of the Euclidean space, that H-free maps are generic and we provide, for the smallest possible value of q, explicit expressions for H-free maps in the following three settings: 1-dimensional distributions in R^2, Lagrangian distributions of completely integrable systems, Hamiltonian distributions of a particular kind of Poisson Bracket.Comment: 19 pages, 1 figur

Risk of appendiceal neoplasm after interval appendectomy for complicated appendicitis: A systematic review and meta-analysis

Background: Non-operative management is often the treatment of choice in cases of complicated appendicitis and routine interval appendectomy is not usually recommended. Actually, recent studies show an alarming number of appendiceal neoplasms following interval appendectomy. The aim of this study is to evaluate the prevalence of appendiceal neoplasms and their histological types after interval appendectomy for complicated appendicitis in adults. Methods: A comprehensive literature search of the PubMed, Scopus and Web of Science databases was conducted according to the PRISMA statement. Studies reporting appendiceal neoplasm rates after interval appendectomy and histopathological characteristics were included. The most recent World Health Organization (WHO) classification of malignant tumours was considered. A pooled prevalence analysis for both prevalence and pathology was performed. Results: A total of eight studies was included: seven retrospective series and one randomized controlled trial. The pooled prevalence of neoplasms after interval appendectomy was 11% (95% CI 7-15; I2 = 37.5%, p = 0.13). Appendiceal mucinous neoplasms occurred in 43% (95% CI 19-68), adenocarcinoma in 29% (95% CI 6-51), appendiceal neuroendocrine neoplasm in 21% (95% CI 6-36), globet cell carcinoma in 13% (95% CI -2-28), adenoma or serrated lesions in 20% (95% CI -0-41) of cases. Conclusion: The risk of appendiceal neoplasm in patients treated with interval appendectomy for complicated appendicitis is 11%; mucinous neoplasm is the most common histopathological type. Further studies should investigate this association in order to clarify the biological pathway and clinical implications

Versatile Application of rfid technology to commercial and laboratory research contexts: fresh fish supply-chain and behavioural tests

Peer Reviewe

TEXTAROSSA: Towards EXtreme scale Technologies and Accelerators for euROhpc hw/Sw Supercomputing Applications for exascale

International audienceTo achieve high performance and high energy efficiency on near-future exascale computing systems, three key technology gaps needs to be bridged. These gaps include: energy efficiency and thermal control; extreme computation efficiency via HW acceleration and new arithmetics; methods andtools for seamless integration of reconfigurable accelerators in heterogeneous HPC multi-node platforms. TEXTAROSSA aims at tackling this gap through a co-design approach to heterogeneous HPC solutions, supported by the integration and extension of HW and SW IPs, programming models and tools derived from European research

Risk of anastomotic bleeding after left colectomy with preservation of inferior mesenteric artery for diverticular disease: preliminary results

Background: The inferior mesenteric artery (IMA) preservation in elective laparoscopic left colectomy for diverticular disease may reduce the risk of anastomotic leakage. However, an increased risk of bleeding is assumed. The aim of this study was to investigate the risk of colorectal anastomosis bleeding when IMA is resected or preserved during left colectomy. Methods: A retrospective study of a prospectively collected database was performed. All patients who underwent elective left colectomy, from December 2018 to September 2020 were included. Patients' data and clinical information were collected and analyzed. Patients were categorized in two groups: IMA resected (IMA-R) and IMA preserving (IMA-P) left colectomy. Perioperative outcomes between the two groups were compared. Results: Sixty-three consecutive patients who underwent left colectomy over a period of three years were enrolled: 42 in IMA-R group and 22 in the IMA-P group. There were no significant differences in demographic and intraoperative characteristics between the two groups, except for patients' age and primary disease. Six patients (9.37%) developed anastomotic bleeding during recovery, more frequently in the IMA-P than IMA-R group, although the difference is not statistically significative (13.6% and 7.3%; P=0.406). All bleedings were self-limited and only one needed red blood cells transfusion. Using the bioabsorbable staple line reinforcement (BSLR) has proved to be advantageous in preventing anastomotic bleeding in the IMA-P group. Conclusions: IMA preserving left colectomy seems to be associated with a higher risk of mostly self-limited anastomotic bleeding during recovery. BSLR seems to be effective in this group of patients

Prevention of incisional hernia at the site of stoma closure with different reinforcing mesh types: a systematic review and meta-analysis.

Purpose: To evaluate safety and efficacy of a mesh reinforcement following stoma reversal to prevent stoma site incisional hernia (SSIH) and differences across the prostheses used. Methods: A systematic search of PubMed/MEDLINE, EMBASE, SCOPUS and Cochrane databases was conducted to identify comparative studies until September 2020. A meta-analysis of postoperative outcomes and a network meta-analysis for a multiple comparison of the prostheses with each other were performed. Results: Seven studies were included in the analysis (78.4% ileostomy and 21.6% colostomy) with a total of 1716 patients with (n = 684) or without (n = 1032) mesh. Mesh placement was associated with lower risk of SSIH (7.8%vs18.1%, OR0.266,95% CI 0.123–0.577, p < 0.001) than no mesh procedures but also with a longer operative time (SMD 0.941, 95% CI 0.462–1.421, p < 0.001). There was no statistically significant difference in terms of Surgical Site infection (11.5% vs 11.1%, OR 1.074, 95% CI 0.78–1.48, p = 0.66), seroma formation (4.4% vs 7.1%, OR 1.052, 95% CI 0.64–1.73, p = 0.84), anastomotic leakage (3.7% vs 2.7%, OR 1.598, 95% CI 0.846–3.019, p = 0.149) and length of stay (SMD − 0.579,95% CI − 1.261 to 0.102, p = 0.096) between mesh and no mesh groups. Use of prosthesis was associated with a significant lower need for a reoperation than no mesh group (8.1% vs 12.1%, OR 0.332, 95% CI 0.119–0.930, p = 0.036). Incidence of seroma is lower with biologic than polypropylene meshes but they showed a trend towards poor results compared with polypropylene or biosynthetic meshes. Conclusion: Despite longer operative time, mesh prophylactic reinforcement at the site of stoma seems a safe and effective procedure with lower incidence of SSIH, need for reoperation and comparable short-term outcomes than standard closure technique. A significant superiority of a specific mesh type was not identified