Evaluating Structural Details' Influence on Elastic Wave Propagation for Composite Structures via Ray Tracing.

This study presents a novel method based on ray tracing for analyzing wave propagation in composites specifically tailored for structural health monitoring applications. This method offers distinct advantages over the commonly used finite element method mainly in computational resource utilization, which has become a limiting factor for these kinds of analyses. The ray tracing method is evaluated against a number of example cases representing structural details such as thickness changes, stringers, or simulated damage, and the significance of ray tracing to study wave propagation under these conditions and how it can serve as a valuable tool for structural health monitoring are highlighted. This model has been developed as part of a complete SHM framework with the intention of being an efficient and simple way to calculate wave propagation and therefore it could be used as a way to determine relevant damage indicators or train an artificial intelligence model.

Study of the Feasibility of Decoupling Temperature and Strain from a ϕ-PA-OFDR over an SMF Using Neural Networks.

Despite several existing techniques for distributed sensing (temperature and strain) using standard Single-Mode optical Fiber (SMF), compensating or decoupling both effects is mandatory for many applications. Currently, most decoupling techniques require special optical fibers and are difficult to implement with high-spatial-resolution distributed techniques, such as OFDR. Therefore, this work's objective is to study the feasibility of decoupling temperature and strain out of the readouts of a phase and polarization analyzer OFDR (ϕ-PA-OFDR) taken over an SMF. For this purpose, the readouts will be subjected to a study using several machine learning algorithms, among them Deep Neural Networks. The motivation that underlies this target is the current blockage in the widespread use of Fiber Optic Sensors in situations where both strain and temperature change, due to the coupled dependence of currently developed sensing methods. Instead of using other types of sensors or even other interrogation methods, the objective of this work is to analyze the available information in order to develop a sensing method capable of providing information about strain and temperature simultaneously.

Three-Dimensional Digital Image Correlation Based on Speckle Pattern Projection for Non-Invasive Vibrational Analysis.

Non-contact vibration measurements are relevant for non-invasively characterizing the mechanical behavior of structures. This paper presents a novel methodology for full-field vibrational analysis at high frequencies using the three-dimensional digital image correlation technique combined with the projection of a speckle pattern. The method includes stereo calibration and image processing routines for accurate three-dimensional data acquisition. Quantitative analysis allows the extraction of several deformation parameters, such as the cross-correlation coefficients, shape and intensity, as well as the out-of-plane displacement fields and mode shapes. The potential of the methodology is demonstrated on an Unmanned Aerial Vehicle wing made of composite material, followed by experimental validation with reference accelerometers. The results obtained with the projected three-dimensional digital image correlation show a percentage of error below 5% compared with the measures of accelerometers, achieving, therefore, high sensitivity to detect the dynamic modes in structures made of composite material.

Surgical acute abdomen and COVID-19 vaccination.

In response to the publication "Acute appendicitis, foreign bodies and COVID-19 vaccination: correspondence", we reviewed the association between acute surgical abdomen and COVID-19 vaccination.

Evaluation of health outcomes after the implementation of rotational thromboelastometry in patients undergoing cardiac surgery.

BACKGROUND: Viscoelastic tests (rotational thromboelastometry, ROTEM®), together with the implementation of a specific algorithm for coagulation management in cardiac surgery, enable perioperative coagulopathy to be better controlled. METHODS: Retrospective cohort study including 675 patients who underwent cardiac surgery with cardiopulmonary bypass. The incidence of allogeneic blood transfusions and clinical postoperative complications were analyzed before and after ROTEM® implementation. RESULTS: Following viscoelastic testing and the implementation of a specific algorithm for coagulation management, the incidence of any allogeneic blood transfusion decreased (41.4% vs 31.9%, p = .026) during the perioperative period. In the group monitored with ROTEM®, decreased incidence of transfusion was observed for packed red blood cells (31.3% vs 19.8%, p = .002), fresh frozen plasma (9.8% vs 3.8%, p = .008), prothrombin complex concentrate administration (0.9% vs 0.3%, p = .599) and activated recombinant factor VII (0.3% vs 0.0%, p = .603). Increased incidence was observed for platelet transfusion (4.8% vs 6.8%, p = .530) and fibrinogen concentrate (0.9% vs 3.5%, p = .066), tranexamic acid (0.0% vs 0.6%, p = .370) and protamine administration (0.6% vs 0.9%, p = .908). Similar results were observed in the postoperative period, but with a decreased incidence of platelet transfusion (4.8% vs 3.8%, p = .813). In addition, statistically significant reductions were detected in the incidence of postoperative bleeding (9.5% vs 5.3%, p = .037), surgical reexploration (6.0% vs 2.9%, p = .035), and length of Intensive Care Unit (ICU) stay (6.0 days vs 5.3 days, p = .026). CONCLUSIONS: The monitoring of hemostasis by ROTEM® in cardiac surgery, was associated with decreased incidence of allogeneic blood transfusion, clinical hematologic postoperative complications and lengths of ICU stay.

Uncommon causes of acute appendicitis: foreign bodies in the cecal appendix.

A 50-year-old woman with a history of hysterectomy for endometrial cancer in 2015 visited because of abdominal pain for 1 week and fever simultaneous with her third dose of the COVID-19 vaccine. Physical examination revealed a mobile mass in the right iliac fossa, and laboratory testing showed C-reactive protein at 3 mg/dL, with no further changes. Ultrasound results were consistent with an appendiceal inflammatory mass, and a CT scan revealed an appendicolith as likely cause. The patient was subjected to laparoscopy, which found inside the mass a metallic piece (dental prosthesis) that perforated the appendiceal lumen at the mid portion of the appendix. Appendectomy was completed and the patient was discharged on the third day post-procedure.

Role of Isolated Limb Perfusion in the Era of Targeted Therapies and Immunotherapy in Melanoma. A Systematic Review of The Literature.

BACKGROUND: Isolated limb perfusion (ILP) is a locoregional procedure indicated by the unresectable melanoma of the limbs. Its complexity and highly demanding multidisciplinary approach means that it is a technique only implemented in a few referral centers around the globe. This report aims to examine its potential role in the era of targeted therapies and immunotherapy by conducting a systematic review of the literature on ILP. METHODS: PubMed, Embase and Cochrane Library were searched. The eligibility criteria included publications from 2000-2020 providing valid data o effectiveness, survival or toxicity. Studies in which the perfusion methodology was not clearly described, letters to the editor, non-systematic reviews and studies that applied outdated clinical guidelines were excluded. To rule out studies of a low methodological quality and assess the risk of bias, the following aspects were also required: a detailed description of the applied ILP regimen, the clinical context, follow-up periods, analyzed clinical endpoints, and the number of analyzed ILPs. The disagreements were resolved by consensus. The results are presented in tables and figures. RESULTS: Twenty-seven studies including 2637 ILPs were selected. The median overall response rate was 85%, with a median complete response rate of 58.5%. The median overall survival was 38 months, with a 5-year overall survival of 35%. The toxicity was generally mild according to Wieberdink toxicity criteria. DISCUSSION: ILP still offer a high efficacy in selected patients. The main limitation of our review is the heterogeneity and age of most of the articles, as well as the absence of clinical trials comparing ILP with other procedures, making it difficult to transfer its results to the current era. CONCLUSIONS: ILP is still an effective and safe procedure for selected patients with unresectable melanoma of the limbs. In the era of targeted therapies and immunotherapy, ILP remains an acceptable and reasonable palliative treatment alternative, especially to avoid limb amputations. The ongoing clinical trials combining systemic therapies and ILP will provide more valuable information in the future to clarify the potential synergism of both strategies.

Disposition of Dietary Polyphenols in Breast Cancer Patients' Tumors, and Their Associated Anticancer Activity: The Particular Case of Curcumin.

SCOPE: Some polyphenol-derived metabolites reach human breast cancer (BC) tissues at concentrations that induce cell senescence. However, this is unknown for isoflavones, curcuminoids, and lignans. Here, their metabolic profiling in normal (NT) and malignant (MT) mammary tissues of newly-diagnosed BC patients and the tissue-occurring metabolites' anticancer activity are evaluated. METHODS AND RESULTS: Patients (n = 26) consumed 3 capsules/day (turmeric, red clover, and flaxseed extracts plus resveratrol; 296.4 mg phenolics/capsule) from biopsy-confirmed diagnosis to surgery (5 ± 2 days) or did not consume capsules (n = 13). NT and MT, blood, and urine are analyzed by UPLC-QTOF-MS using targeted metabolomics. Anticancer activity was tested in MCF-7 and MDA-MB-231 BC cells. Mainly phase-II metabolites were detected (108, 84, 49, and 47 in urine, plasma, NT, and MT, respectively). Total metabolite concentrations reached 10.7 ± 11.1 and 2.5 ± 2.4 µmol L-1 in NT and MT, respectively. Free curcumin, but not its glucuronide, was detected in the tissues (1.1 ± 1.8 and 0.2 ± 0.2 µmol L-1 in NT and MT, respectively). Breast tissue-occurring metabolites' antiproliferation was mainly exerted in p53-wild-type MCF-7 cells by curcuminoids through cell cycle arrest, senescence, and apoptosis induction via p53/p21 induction, while isoflavone-derived metabolites exerted estrogenic-like activity. CONCLUSION: Curcuminoids could be coadjuvants that might help fight BC upon regular consumption.

Directional Response of Randomly Dispersed Carbon Nanotube Strain Sensors.

Tests on a double lap bonded joint, with transverse strips of randomly oriented carbon nanotubes (CNT) sprayed onto an epoxy adhesive film, showed a positive increment in electrical resistance under tensile load, even though the transverse strains were negative. Other experiments included in this work involved placing longitudinal and transversal CNT sensors in a tensile loaded aluminum plate, and, as reported by other authors, the results confirm that the resistance change is not only dependent on the strains oriented with the electrode line, while the other strain components also influence the response. This behavior is quite different to that of conventional strain gages which have a near zero sensitivity to strains not aligned to the sensor direction. The dependence of the electrical response on all the strain components makes it quite difficult, possibly unfeasible, to experimentally determine the individual strain components with this kind of sensors; however, the manufacturing of aligned CNT sensors could deal with this issue.

Management of duodenal perforations after endoscopic retrograde cholangiopancreatography.

OBJECTIVE: To describe our experience regarding post-endoscopic retrograde cholangio-pancreatography (ERCP) perforations and its conservative management. MATERIAL AND METHODS: Retrospective study of the therapeutic management of post-ERCP perforations occurred over the period 2012-2017 in our hospital. RESULTS: There were 12 perforations after ERCP, with choledocholithiasis being the main indication for the test (66.6%). In 9 cases (75%) an initial conservative attitude was attempted, but only 3 of them (25%) managed to solve the problem with broad-spectrum antibiotics, parenteral nutrition and close monitoring of the patient. DISCUSSION: Management of post-ERCP perforations must be individualized for each patient, depending on the clinical situation. Surgery remains the best option for the treatment of post-ERCP perforations, although conservative medical management is an option to be assessed, assuming that if it fails, delaying surgery is associated with high morbidity and mortality rates.

Structural Health Monitoring in Composite Structures by Fiber-Optic Sensors.

Fiber-optic sensors cannot measure damage; to get information about damage from strain measurements, additional strategies are needed, and several alternatives are available in the existing literature. This paper discusses two independent procedures. The first is based on detecting new strains appearing around a damage spot. The structure does not need to be under loads, the technique is very robust, and damage detectability is high, but it requires sensors to be located very close to the damage, so it is a local technique. The second approach offers wider coverage of the structure; it is based on identifying the changes caused by damage on the strain field in the whole structure for similar external loads. Damage location does not need to be known a priori, and detectability is dependent upon the sensor's network density, the damage size, and the external loads. Examples of application to real structures are given.

Bamboo-Polylactic Acid (PLA) Composite Material for Structural Applications.

Developing an eco-friendly industry based on green materials, sustainable technologies, and optimum processes with low environmental impact is a general societal goal, but this remains a considerable challenge to achieve. Despite the large number of research on green structural composites, limited investigation into the most appropriate manufacturing methodology to develop a structural material at industrial level has taken place. Laboratory panels have been manufactured with different natural fibers but the methodologies and values obtained could not be extrapolated at industrial level. Bamboo industry panels have increased in the secondary structural sector such as building application, flooring and sport device, because it is one of the cheapest raw materials. At industrial level, the panels are manufactured with only the inner and intermediate region of the bamboo culm. However, it has been found that the mechanical properties of the external shells of bamboo culm are much better than the average cross-sectional properties. Thin strips of bamboo (1.5 mm thick and 1500 mm long) were machined and arranged with the desired lay-up and shape to obtain laminates with specific properties better than those of conventional E-Glass/Epoxy laminates in terms of both strength and stiffness. The strips of bamboo were bonded together by a natural thermoplastic polylactic acid (PLA) matrix to meet biodegradability requirements. The innovative mechanical extraction process developed in this study can extract natural strip reinforcements with high performance, low cost, and high rate, with no negative environmental impact, as no chemical treatments are used. The process can be performed at the industrial level. Furthermore, in order to validate the structural applications of the composite, the mechanical properties were analyzed under ageing conditions. This material could satisfy the requirements for adequate mechanical properties and life cycle costs at industrial sectors such as energy or automotive.

Sternal cutaneous metastasis of hilar cholangiocarcinoma.

Subcutaneous metastasis is a rare initial manifestation of visceral tumors, and represent advanced stages with poor prognosis. We report the case of a female patient with a subcutaneous nodule over the sternum, which was ultimately found to be a metastasis of hilar cholangiocarcinoma. Only 20 cases of subcutaneous metastasis from Klatskin tumors have been reported - a rare occurrence with poor survival rates.

Esophageal perforation by a Sengstaken balloon.

Iatrogenic esophageal perforations are rare but associated with a high morbidity and mortality. Secondary to placing a Sengstaken ballon are even more extraordinary because of the infrequency which this measure is used to control upper gastrointestinal bleeding. Therefore, we think it is of interest to communicate this complication, to remember the need to check the correct placement of the Sengstaken ballon before insufflation, since it would help further decrease this complication.

[Laparoscopic cleavage in splenic symptomatic cyst]. / Escisión laparoscópica en quiste esplénico sintomático.

BACKGROUND: Splenic cysts are rare diseases that are diagnosed incidentally during imaging studies. When cysts are recognized, surgical treatment is recommended adapted to the particular case, depending on the size and location of the cyst and the age of the patient in order to avoid dangerous complications such as spleen rupture or cyst infection with abscess. CLINICAL CASE: We report 2patients with symptomatic splenic epidermoid cyst treated by laparoscopic cleavage. CONCLUSIONS: Laparoscopic cleavage is a surgical option for splenic cyst, with the goal of reducing postoperative complications while preserving splenic function.

Acute abdomen from duodenal diverticulitis. A case report.

Duodenal diverticula are a rare, usually asymptomatic clinical condition. When a complication arises clinical suspicion is key for the diagnosis. On occasion these patients receive a delayed diagnosis and undergo inadequate medical therapy. We report the case of a patient with evidence of duodenal diverticulitis in association with gallbladder inflammation by contiguity, as well as his diagnosis and management.

Small bowel mesenchymal tumors: description of two unusual cases.

We present two cases of intestinal ileal GIST who developed complications of nonspecific signs and required to be operated urgently, providing unusual images of tumors because of its characteristics.

Management of non-surgical pneumoperitoneum.

Percutaneous endoscopic gastrostomy (PEG) is the best approach to feeding patients not eligible for oral nutrition who have a functioning digestive system. Pneumoperitoneum after PEG is a relatively common complication. As regards management, the most important decision is whether conservative therapy or an exploratory laparotomy should be indicated. We report the case of a patient with giant pneumoperitoneum following PEG, who was successfully managed with percutaneous air drainage.