A Bi-Modulus Material Model for Bending Test on NHL3.5 Lime Mortar

The research provides an innovative contribution to the interpretation of three-point and four-point bending tests on mortars by employing a bi-modulus material model, which assumes an asymmetric constitutive law, i.e., different elastic moduli in tension and in compression. To this aim, Euler–Bernoulli and Timoshenko bi-modulus beam models are defined, and the related displacement fields are reported for three-point loading, and provided for the first time for the four-point bending layout. A wide experimental campaign, including uni-axial tensile and compressive tests, three-point and four-point bending tests, and on notched specimens three-point tests for mode-I fracture energy, has been carried out on lime mortar specimens exploiting traditional contact (CE-DT) and contactless (DIC) measurement systems. Experimental results provided the values of tensile and compressive mechanical characteristics, which are employed to validate estimations of the analytical model. The tension-to-compression moduli ratio experimentally observed is on average 0.52. Experimental outcomes of the DIC analysis proved the bi-modulus behaviour during the four-point bending tests showing visible shifting of the neutral axis. The bi-modulus analytical model provides closer results to the experimental ones for the slender specimens subjected to four-point bending

Structural characterization and seismic performance of San Francisco Church, the most ancient monument in Santiago, Chile

The Church of San Francisco is the oldest religious building in use in Chile and an iconic and historical heritage landmark of the capital Santiago. The church, the result of joint work between the Spanish and local indigenous people, was built in stone and brick masonry and has been modified by additions and constructive changes since its construction in 1586. The building has shown a remarkable resilience, withstanding about 15 destructive earthquakes. As part of research whose goal is to discover the basis of the structural behavior of the church, in this article a safety assessment of the monument is carried out based on a multi-disciplinary approach. Main fields comprises historical research, in situ surveys, crack pattern analysis, physical and mechanical characterization of materials, and multi-level structural analyses. The results highlight the particularities of the building and the current seismic vulnerabilities in order to provide a robust knowledge basis on which possibly pivoting future consolidation and safeguarding strategies could be done.NATIONAL COMMISSION FOR SCIENTIFIC & TECHNOLOGICAL RESEARCHFONDECYT for funding the research project ‘Initiation into Research 2013 number 1113062

Experimental investigation on masonry arches strengthened with PBO-FRCM composite

In the last two decades, Fiber Reinforced Polymer (FRP) composites were effectively used for increasing the load-carrying capacity of masonry arches and for improving their mechanical response against the most critical arch failure mechanisms. More recently, Fabric Reinforced Cementitious Matrix (FRCM) composites are appearing significantly promising for the strengthening of masonry arches, providing an alternative to the FRP composites, but only few experimental contributions are available to date. In the present paper, the structural performance of masonry arches strengthened both at intrados and at extrados by using a polybenzoxazole (PBO) fabric reinforced cementitious mortar composite was experimentally investigated. Results, in terms of load-carrying capacity, post peak behavior and failure mechanism, were compared with those determined by using a Carbon Fiber Reinforced Polymer (CFRP) composite. The present experimental study contributes to improve the knowledge of the innovative PBO- FRCM composites and it provides mechanical data useful for defining masonry strengthening design guidelines

Antibodies Generated in Cats by a Lipopeptide Reproducing the Membrane-Proximal External Region of the Feline Immunodeficiency Virus Transmembrane Enhance Virus Infectivity▿

The immunogenicity of a lipoylated peptide (lipo-P59) reproducing the membrane-proximal external region (MPER) of the transmembrane glycoprotein of feline immunodeficiency virus (FIV) was investigated with cats. In the attempt to mimic the context in which MPER is located within intact virions, lipo-P59 was administered in association with membrane-like micelles. Analyses showed that in this milieu, lipo-P59 had a remarkable propensity to be positioned at the membrane interface, displayed a large number of ordered structures folded in turn helices, and was as active as lipo-P59 alone at inhibiting FIV infectivity in vitro. The antibodies developed differed from the ones previously obtained by immunizing cats with the nonlipoylated version of the peptide (G. Freer, S. Giannecchini, A. Tissot, M. F. Bachmann, P. Rovero, P. F. Serres, and M. Bendinelli, Virology 322:360-369, 2004) in epitope specificity and in the fact that they bound FIV virions. However, they too lacked virus-neutralizing activity and actually enhanced FIV infectivity for lymphoid cell cultures. It is concluded that the use of MPER-reproducing oligopeptides is not a viable approach for vaccinating against FIV

Laparoscopic entry techniques: Which should you prefer?

Background Despite a debate spanning two decades, no consensus has been achieved about the safest laparoscopic entry technique. Objectives To update the evidence about the safety of the main different laparoscopic entry techniques. Search Strategy Six electronic databases were searched from inception to February 2021. Selection Criteria All randomized controlled trials (RCTs) comparing different laparoscopic entry techniques were included. Data Collection and Analysis Entry-related complications and total time for entry were compared among the different methods of entry calculating pooled odds ratios (ORs) and mean differences, with 95% confidence intervals (CIs); P < 0.05 was considered significant. Main Results In total, 25 RCTs (6950 patients) were included. Complications considered were vascular, visceral and omental injury, failed entry, extraperitoneal insufflation, bleeding and infection at the trocar site bleeding, and incisional hernia. Compared to direct trocar, the OR for Veress needle was significantly higher for omental injury (OR 3.65, P < 0.001), for failed entry (OR 4.19, P < 0.001), and for extraperitoneal insufflation (OR 5.29, P < 0.001). Compared to the open method, the OR for Veress needle was significantly higher for omental injury (OR 4.93, P = 0.001), for failed entry (OR 2.99, P < 0.001), for extraperitoneal insufflation (OR 4.77; P = 0.04), and for incisional hernia. Compared to the open method, the OR for direct trocar was significantly lower for visceral injury (OR 0.17, P = 0.002) and for trocar site infection (OR 0.27, P = 0.001). Conclusions The direct trocar method may be preferred over Veress needle and open methods as a laparoscopic entry technique since it appears associated to a lower risk of complications

Sentinel Lymph Node Biopsy in Surgical Staging for High-Risk Groups of Endometrial Carcinoma Patients

Background: In endometrial carcinoma (EC) patients, sentinel lymph node (SLN) biopsy has shown the potential to reduce post-operative morbidity and long-term complications, and to improve the detection of low-volume metastasis through ultrastaging. However, while it has shown high sensitivity and feasibility in low-risk EC patient groups, its role in high-risk groups is still unclear. Aim: To assess the role of SLN biopsy through the cervical injection of indocyanine green (ICG) in high-risk groups of early-stage EC patients. Materials and methods: Seven electronic databases were searched from their inception to February 2021 for studies that allowed data extraction about detection rate and accuracy of SLN biopsy through the cervical injection of ICG in high-risk groups of early-stage EC patients. We calculated pooled sensitivity, false negative (FN) rate, detection rate of SLN per hemipelvis (DRh), detection rate of SLN per patients (DRp), and bilateral detection rate of SLN (DRb), with 95% confidence interval (CI). Results: Five observational cohort studies (three prospective and two retrospective) assessing 578 high risk EC patients were included. SLN biopsy sensitivity in detecting EC metastasis was 0.90 (95% CI: 0.03-0.95). FN rate was 2.8% (95% CI: 0.6-11.6%). DRh was 88.4% (95% CI: 86-90.5%), DRp was 96.6% (95% CI: 94.7-97.8%), and DRb was 80% (95% CI: 75.4-83.9). Conclusion: SLN biopsy through ICG cervical injection may be routinely adopted instead of systematic pelvic and para-aortic lymphadenectomy in surgical staging for high-risk groups of early-stage EC patients, as well as in low-risk groups

TT virus levels in the plasma of infected individuals with different hepatic and extrahepatic pathology

TT virus (TTV) infection is extremely widespread in the general population. A sensitive real-time PCR assay was developed that quantitated accurately the most prevalent TTV genotypes in Italy. When used to test 217 individuals for TTV viraemia, the overall prevalence was 94%. Viraemia levels varied widely amongst individual subjects, with no major differences related to gender or age. The highest TTV titres were in haemophiliacs and in patients with non-A-E hepatitis, but they did not differ from the group with miscellaneous diseases. HIV- and HCV-infected subjects and patients with primary liver diseases had TTV loads similar to those of healthy individuals. (C) 2001 Wiley-Liss, Inc