Pseudo-equivalent deterministic excitation method application for experimental reproduction of a structural response to a turbulent boundary layer excitation

In the transportation engineering field, the turbulent boundary layer over a structure is one of the most relevant sources of structural vibration and emitted noise. Wind tunnels are still one of the best options for vibroacoustic experimental analyses for this specific problem. However, it is also true that this experimental method is not always affordable, due to several limitations-settings hard to control, time and money consumption, discrepancies among laboratories-that wind tunnel facilities present. It has already developed different methodologies to address this necessity, most of them based on the use of loudspeakers or shakers. In this work, an existing numerical method, called the pseudo-equivalent deterministic excitation method (PEDE_M), is further developed for the experimental purpose of reproducing the experimental structural response of a panel subjected to a turbulent boundary layer (TBL) excitation, by using an equivalent rain-on-the-roof excitation instead; different formulations are used for the application of this approximated TBL excitation. The experimental application of PEDE_M, here called X-PEDE_M, is validated by comparison with experimental results of two different panels analysed in two different wind tunnel facilities.

Hypernatraemia and low eGFR at hospitalization in COVID-19 patients: a deadly combination

Background

The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on the general population and the burden of pre-existing comorbidities has heavily affected the outcome of the infection. Hyponatraemia has been frequently described. Conversely, hypernatraemia has rarely been described in COVID-19.

Methods

The studied cohort encompasses all COVID-19 patients consecutively admitted to the Messina Hospital, Italy, during the first wave of the epidemic. Since healthcare structures were not overwhelmed at that time, indications for hospitalization were homogeneous throughout the study period. Serum sodium levels, kidney function [estimated glomerular filtration rate (eGFR)], demographic and clinical characteristics were recorded at admission. Correlation between mortality, sodium and eGFR was evaluated by survival curves and univariate and multivariate regression models.

Results

Baseline biochemical and clinical data at the time of admission were available for 115 COVID-19-confirmed patients. The median age at admission was 73 years (48% men), with a median Charlson Comorbidity Index of 4. A total of 23.5% of patients presented with a sodium level ≥146 mmol/L, while 7.8% had sodium <135 mmol/L. Hypernatraemic patients were older, with higher comorbidity. Age, hypernatraemia and reduced eGFR were associated with increased mortality in both univariate and multivariate regression models (P < 0.001). The combination of hypernatraemia and reduced renal function at admission had an odds ratio of 47.67 (95% confidence interval 10.08–225.43) of dying compared with patients with an eGFR ≥60 mL/min and sodium <145 mmol/L.

Conclusions

Our study suggests that the association between hypernatraemia and reduced eGFR at referral is a highly relevant prognostic marker for death during hospitalization. The role of this association should be further tested in larger, multicentre cohorts.

Pleomorphic Carcinoma of the Gallbladder: Report of a Case

The authors report a rare case of primary pleomorphic carcinoma of the gallbladder in a 70-year-old woman. A polypoid tumor protruded into the lumen from the fundus of the gallbladder. Characteristic histologic findings Included a general lack of architectural cohesiveness, marked pleomorphism, presence of mononucleated and multinucleated giant cells, extensive necrosis, leukocyte-tumor cell phagocytosis or cannibalism. Immunoreactivity for cytokeratin, carclnoembryonic antigen and epithelial membrane antigen as well as histochemical positivity for mucins demonstrated the epithelial nature of the tumor. The neoplasm behaved aggressively; the patient died of metastases 9 months after the operation.

Pneumotrabeculoplasty as treatment for primary open angle glaucoma: critical review of the literature

PURPOSE

To evaluate with criticism the available evidence shown in the literature about the efficacy of pneumotrabeculoplasty (PNT) as a treatment for primary open angle glaucoma.

MATERIALS AND METHODS

PNT is a recent non-surgical and noninvasive technique to safely reduce the intraocular pressure (IOP) in eyes suffering from ocular hypertension or primary open angle glaucoma. The technique consists in the application on the ocular surface of a disposable suction ring that induces a temporary trabecular meshwork stretching, increasing outflow of aqueous humor in the Schlemm's canal. In our study, we compared the results on the efficacy and safety of this treatment published to date in the literature.

RESULTS

During follow-up, Authors have observed significant reductions in IOP in about 70% of treated eyes. The first treatment consists in 3 applications at day 0, 7 and 90, repeatable every 90 days. Immediately after suction ring application there is a significant elevation of IOP, however, of short duration and without demonstrable visual field worsening. Side effects observed are of little clinical significance and spontaneously resolving in a short time.

CONCLUSIONS

The PNT is a safe and effective technique to reduce IOP in patients with ocular hypertension or open-angle glaucoma. It is repeatable, but can not replace drug treatment in patients already receiving topical therapy for glaucoma; however, it has proven effectiveness in maintaining an IOP target over time if accompanied with only a single topical drug, favoring a reduction of antiglaucoma drugs in polytherapy and increasing the compliance with treatment.

Central venous catheters and infections

The indications to the positioning of central venous catheters (CVCs) are various: parenteral nutrition, chemotherapy, infusion of large amount of fluids or blood products, chronic access for hemodialysis, invasive measurement of hemodynamic variables. Infection is the most important clinical complication associated with the use of CVC, both in terms of incidence and of gravity. Despite the efforts for the optimization of the materials that are more and more biocompatible, the presence of a foreign body in the organism is an ideal substratum for the microbial colonization. The Catheter-Related-Bloodstream-Infections (CRBI) involve a pro-longation of recovery stay, the increase in costs of hospitalization and an increase in morbidity and mortality. The infections are caused by: Staphylococcus aureus and Staphylococcus epidermidis (60%), other bacteria (Enterococ-cus faecalis and Faecium, Pseudomonas aeruginosa; 25%) and among fungi by Candida albicans and Parapsilosis (15%). In order to prevent the CRBI it's important to follow some behavioural norms, both during the positioning of the catheter and in the subsequent assistance to the patient. In case of CRBI it is fundamental to make a sure diagnosis with the positivity for the same pathogen of 2 hemocultures obtained from CVC and from a peripheral vein and then with the microbiological analysis of the tip of the catheter, in order to carry out the specific antibiotic therapy.

Critical behavior of the two-dimensional spin-diluted Ising model via the equilibrium ensemble approach

The equilibrium ensemble approach to disordered systems is used to investigate the critical behavior of the two-dimensional Ising model in the presence of quenched random site dilution. The numerical transfer matrix technique in semi-infinite strips of finite width, together with phenomenological renormalization and conformal invariance, is particularly suited to putting the equilibrium ensemble approach to work. A method by which to extract with great precision the critical temperature of the model is proposed and applied. A more systematic finite-size scaling analysis than in previous numerical studies has been performed. A parallel investigation, along the lines of the two main scenarios currently under discussion, namely, the logarithmic corrections scenario (with critical exponents fixed in the Ising universality class) versus the weak universality scenario (critical exponents varying with the degree of disorder), is carried out. In interpreting our data, maximum care is constantly taken to be open to both possibilities. A critical discussion shows that an unambiguous discrimination between the two scenarios is still not possible on the basis of the available finite-size data.

Palliative endoscopic treatment of malignant esophagorespiratory fistula: case report

The authors report on a case of esophagorespiratory fistula due to squamous carcinoma of the esophagus treated on an emergency basis by endoscopic insertion of an Atkinson prosthesis following dilation of the malignant stenosis with Savary dilators. The authors suggest the endoscopic insertion of a prosthesis as the first approach in the emergency treatment of a malignant esophagorespiratory fistula because of the easiness of the technique, and its low morbidity and mortality rates; furthermore, this procedure relieves digestive and respiratory symptoms rapidly and reduces hospital stay while providing the patient with a better quality of remaining life.

[Treatment of gastric cancer in the aged]

The A. suggest a modification of Stojanovick primary technique in the treatment of gastric cancer in the elderly. They reviewed pathology of gastric resected patients with exclusion of duodenal transit and they foretell such a technique because of a quicker performance, the scantiness of post-operative complication and, at the end, the complete lack of malabsorption syndromes which are so frequent in gastric resected patients.