Multi-damage detection in composite space structures via deep learning

The diagnostics of environmentally induced damages in composite structures plays a critical role for ensuring the operational safety of space platforms. Recently, spacecraft have been equipped with lightweight and very large substructures, such as antennas and solar panels, to meet the performance demands of modern payloads and scientific instruments. Due to their large surface, these components are more susceptible to impacts from orbital debris compared to other satellite locations. However, the detection of debris-induced damages still proves challenging in large structures due to minimal alterations in the spacecraft global dynamics and calls for advanced structural health monitoring solutions. To address this issue, a data-driven methodology using Long Short-Term Memory (LSTM) networks is applied here to the case of damaged solar arrays. Finite element models of the solar panels are used to reproduce damage locations, which are selected based on the most critical risk areas in the structures. The modal parameters of the healthy and damaged arrays are extracted to build the governing equations of the flexible spacecraft. Standard attitude manoeuvres are simulated to generate two datasets, one including local accelerations and the other consisting of piezoelectric voltages, both measured in specific locations of the structure. The LSTM architecture is then trained by associating each sensed time series with the corresponding damage label. The performance of the deep learning approach is assessed, and a comparison is presented between the accuracy of the two distinct sets of sensors: accelerometers and piezoelectric patches. In both cases, the framework proved effective in promptly identifying the location of damaged elements within limited measured time samples

The phylogenetic and evolutionary history of Kokobera virus.

Abstract Objective To estimate the genetic diversity of Kokobera virus, the date of origin and the spread among different viruses in the endemic regions of Australia. Methods Two datasets were built. The first consisting of 29 sequences of the NS5/3′ UTR region of Kokobera group downloaded from GenBank, the second including only 24 sequences of Kokobera viruses, focus is on this group. Results Bayesian time analysis revealed two different entries in Australia of Kokobera virus in the 50s years with the dated ancestor in 1861 year. Clades A and B showed a clear separation of the Kokobera sequences according to the geographic region. Conclusions Data from the study showed as Kokobera virus, despite of its ancient origin and its circulation before the European colonization, remained limited to the Australian country and nowadays limited mostly to the regions were Australian marsupials are mostly found

HIV-2 infection in a migrant from Gambia: the history of the disease combined with phylogenetic analysis revealed the real source of infection

Human immunodeficiency virus type 2 (HIV-2) infection prevalence is increasing in some European countries. The increasing migratory flow from countries where HIV-2 is endemic has facilitated the spread of the virus into Europe and other regions. We describe a case of HIV-2 infection in a migrant individual in the Asylum Seeker Centre (ASC) in Italy. The patient's virus was sequenced, and found to be a typical HIV-2 genotype A virus. Bayesian evolutionary analysis revealed that the HIV-2 sequence from migrant dated back to 1986 in a subcluster including sequences from Guinea Bissau. This was coherent with the migrant history who lived in Guinea Bissau from his birth until 1998 when he was 13 years old. Monitoring for HIV-2 infection in migrants from western Africa is necessary using adequate molecular tools to improve the diagnosis and understand the real origin of infection

Sars-cov-2 envelope and membrane proteins: structural differences linked to virus characteristics?

The Coronavirus Disease 2019 (COVID-19) is a new viral infection caused by the severe acute respiratory coronavirus 2 (SARS-CoV-2). Genomic analyses have revealed that SARS-CoV-2 is related to Pangolin and Bat coronaviruses. In this report, a structural comparison between the Sars-CoV-2 Envelope and Membrane proteins from different human isolates with homologous proteins from closely related viruses is described. The analyses here reported show the high structural similarity of Envelope and Membrane proteins to the counterparts from Pangolin and Bat coronavirus isolates. However, the comparisons have also highlighted structural differences specific of Sars-CoV-2 proteins which may be correlated to the cross-species transmission and/or to the properties of the virus. Structural modelling has been applied to map the variant sites onto the predicted three-dimensional structure of the Envelope and Membrane proteins

Treatment of relapses of benign latero-cervical pathology: a narrative literature review

Benign laterocervical pathologies are not without pitfalls. Many may relapse after many years and, sometimes, they cannot be predicted. The purpose of this review is to describe the surgical measures necessary for the treatment of relapses of the most common benign laterocervical masses. We searched PubMed, Embase and Cochrane Central Register of Controlled Trials databases for articles describing the treatment of the most common benign cervical disease recurrences, and summarised available evidence in this narrative review. We overviewed observations about recurrent benign mixed tumour (pleomorphic adenoma), parapharyngeal space tumours and carotid body paragangliomas, thyroglossal duct anomalies and branchial cleft anomalies. Proper surgical technique is crucial for safely and effectively managing the relapses of benign latero-cervical diseases. Radiotherapy is indicated in several cases of recurrence such as pleomorphic adenoma and unresectable paraganglioma. Long-term follow-up is of utmost importance to promptly recognise and treat recurrencies

Validations of new cut-offs for surgical drains management and use of computerized tomography scan after pancreatoduodenectomy: The DALCUT trial

BACKGROUND Postoperative pancreatic fistula (POPF) is the most fearful complication after pancreatic surgery and can lead to severe postoperative complications such as surgical site infections, sepsis and bleeding. A previous study which identified cut-offs of drains amylase levels (DALs) determined on postoperative day (POD) 1 and POD3, was able to significantly predict POPF, abdominal collections and biliary fistulas, when related to specific findings detected at the abdominal computerized tomography (CT) scan routinely performed on POD3. AIM To validate the cut-offs of DALs in POD1 and POD3, established during the previous study, to assess the risk of clinically relevant POPF and confirm the usefulness of abdominal CT scan on POD3 in patients at increased risk of abdominal collection. METHODS The DALCUT trial is an interventional prospective study. All patients who will undergo pancreatoduodenectomy (PD) for periampullary neoplasms will be considered eligible. All patients will receive clinical staging and, if eligible for surgery, will undergo routine preoperative evaluation. After the PD, daily DALs will be evaluated from POD1. Drains removal and possible requirement of abdominal CT scans in POD3 will be managed on the basis of the outcome of DALs in the first three postoperative days. RESULTS This prospective study could validate the role of DALs in the management of surgical drains and in assessing the risk or relevant complications after PD. Drains could be removed in POD3 in case of POD1 DALs < 666 U/L and POD3 DALs < 207 U/L. In case of POD3 DALs & GE; 252, abdominal CT scan will be performed in POD3 to identify abdominal collections & GE; 5 cm. In this latter category of patients, drains could be maintained beyond POD3. CONCLUSION The results of this trial will contribute to a better knowledge of POPF and management of surgical drains

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

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

Utility of preoperative systemic inflammatory biomarkers in predicting postoperative complications after pancreaticoduodenectomy: Literature review and single center experience

BACKGROUNDThe role of preoperative inflammatory biomarkers (PIBs) in predicting postoperative morbidity has been assessed in colorectal and otorhinolaryngeal surgery. However, data regarding the role that preoperative inflammatory biomarkers have on morbidity after pancreaticoduodenectomiy (PD) are less consistent.AIMTo assess the utility of PIBs in predicting postoperative complications after pancreaticoduodenectomy.METHODSA database of 317 consecutive pancreaticoduodenectomies performed from April 2003 to November 2018 has been retrospectively analyzed. Data regarding preoperative neutrophil-to-lymphocyte ratio (NLR), derived NLR and C-reactive protein (CRP), and postoperative complications of 238 cases have been evaluated. Exclusion criteria were: age < 18-years-old, previous neoadjuvant treatment, absence of data about PIBs, concomitant hematological disorders, and presence of active infections at the moment of the surgery. PIBs were compared using Mann-Whitney's test and receiver operating characteristic (ROC) analysis was performed to define the cutoffs. The positive predictive value (PPV) was computed to evaluate the probability to develop complication. P-values < 0.05 were considered statistically significant.RESULTSAccording to the literature findings, only four papers have been published reporting the relation between the inflammatory biomarkers and PD postoperative morbidity. A combination of preoperative and postoperative inflammatory biomarkers in predicting complications after PD and the utility of preoperative NLR in the development of postoperative pancreatic fistula (POPF) have been reported. The combination of PIBs and postoperative day-1 drains amylase has been reported to predict the incidence of POPF. According to our results, CRP values were significantly different between patients who had/did not have postoperative complications and abdominal collections (P < 0.05). Notably, patients with preoperative CRP > 8.81 mg/dL were at higher risk of both overall complications and abdominal collections (respectively P = 0.0037, PPV = 0.95, negative predictive value [NPV] = 0.27 and P = 0.016, PPV = 0.59, NPV = 0.68). Preoperative derived neutrophil-to-lymphocyte ratio (dNLR) (cut off > 1.47) was also a predictor of abdominal collection (P = 0.021, PPV = 0.48, NPV = 0.71). Combining CRP and dNLR, PPV increased to 0.67. NLR (cut off > 1.65) was significantly associated with postoperative hemorrhage (P = 0.016, PPV = 0.17, NPV = 0.98).CONCLUSIONPIBs may predict complications after PD. During postoperative care, PIB levels could influence decisions regarding the timing of drains removal and the selection of patients who might benefit from second level diagnostic exams

Phylogeny of Murray Valley encephalitis virus in Australia and Papua New Guinea

Abstract Objective To study the genetic diversity of Murray Valley encephalitis virus (MVEV) in Australia and Papua New Guinea. Methods MVEV envelope gene sequences were aligned using Clustal X and manual editing was performed with Bioedit. ModelTest v. 3.7 was used to select the simplest evolutionary model that adequately fitted the sequence data. Maximum likelihood analysis was performed using PhyML. The phylogenetic signal of the dataset was investigated by the likelihood mapping analysis. The Bayesian phylogenetic tree was built using BEAST. Results The phylogenetic trees showed two main clades. The clade Ⅰ including eight strains isolated from West Australia. The clade Ⅱ was characterized by at least four epidemic entries, three of which localized in Northern West Australia and one in Papua New Guinea. The estimated mean evolutionary rate value of the MVEV envelope gene was 0.407 × 10−3 substitution/site/year (95% HPD: 0.623 × 10−4–0.780 × 10−3). Population dynamics defines a relative constant population until the year 2000, when a reduction occurred, probably due to a bottleneck. Conclusions This study has been useful in supporting the probable connection between climate changes and viral evolution also by the vector point of view; multidisciplinary monitoring studies are important to prevent new viral epidemics inside and outside new endemic areas

Coupling of the oxygen-linked interaction energy for inositol hexakisphosphate and bezafibrate binding to human HbA0.

The energetics of signal propagation between different functional domains (i.e. the binding sites for O2, inositol hexakisphospate (IHP), and bezafibrate (BZF)) of human HbA0 was analyzed at different heme ligation states and through the use of a stable, partially heme ligated intermediate. Present data allow three main conclusions to be drawn, and namely: (i) IHP and BZF enhance each others binding as the oxygenation proceeds, the coupling free energy going from close to zero in the deoxy state to -3.4 kJ/mol in the oxygenated form; (ii) the simultaneous presence of IHP and BZF stabilizes the hemoglobin T quaternary structure at very low O2 pressures, but as oxygenation proceeds it does not impair the transition toward the R structure, which indeed occurs also under these conditions; (iii) under room air pressure (i.e. pO2 = 150 torr), IHP and BZF together induce the formation of an asymmetric dioxygenated hemoglobin tetramer, whose features appear reminiscent of those suggested for transition state species (i.e. T- and R-like tertiary conformation(s) within a quaternary R-like structure)