Three-dimensional simulations of premixed hydrogen/air flames in microtubes

The dynamics of fuel-lean (equivalence ratio φ = 0.5) premixed hydrogen/air atmospheric pressure flames are investigated in open cylindrical tubes with diameters of d = 1.0 and 1.5 mm using three-dimensional numerical simulations with detailed chemistry and transport. In both cases, the inflow velocity is varied over the range where the flames can be stabilized inside the computational domain. Three axisymmetric combustion modes are observed in the narrow tube: steady mild combustion, oscillatory ignition/extinction and steady flames as the inflow velocity is varied in the range 0.5 ≤ UIN ≤ 500 cm s−1. In the wider tube, richer flame dynamics are observed in the form of steady mild combustion, oscillatory ignition/extinction, steady closed and open axisymmetric flames, steady non-axisymmetric flames and azimuthally spinning flames (0.5 ≤ UIN ≤ 600 cm s−1). Coexistence of the spinning and the axisymmetric modes is obtained over relatively wide ranges of UIN. Axisymmetric simulations are also performed in order to better understand the nature of the observed transitions in the wider tube. Fourier analysis during the transitions from the steady axisymmetric to the three-dimensional spinning mode and to the steady non-axisymmetric modes reveals that the m = 1 azimuthal mode plays a dominant role in the transition

Sleep disturbances and sleep disorders as risk factors for chronic postsurgical pain: A systematic review and meta-analysis

This systematic review and meta-analysis aimed at evaluating the role of sleep disturbances and sleep disorders in influencing presence and intensity of chronic postsurgical pain (CPSP). We included cohort studies which enrolled adults, assessed sleep disturbances or disorders before surgery, measured pain intensity, presence of pain, or opioid use at least three months after surgery. Eighteen studies were included in a narrative synthesis and 12 in a meta-analysis. Sleep disturbances and disorders were significantly related to CPSP, with a small effect size, r = 0.13 (95% CI 0.06–0.20). The certainty of evidence was rated low due to risk of bias and heterogeneity. In subgroup analyses the above association was significant in studies that used pain intensity as the outcome, but not in those that used presence of pain; in studies on patients who underwent total knee arthroplasty or other surgeries, but not in those on patients who had breast cancer surgery or total hip arthroplasty; in the single study that assessed insomnia and in studies that assessed sleep disturbances as predictors. A meta-regression showed that the follow-up length was positively associated with the overall estimate. Our findings suggest that presurgical sleep disturbances and disorders should be evaluated to detect patients at risk for CPSP. Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=27265

Plant Metabolites. Structure and In Vitro Antiviral Activity of Quinovic Acid Glycosides from Uncaria tomentosa and Guettarda platyipoda

Abstract: A reinvestigation of the bark of Uncaria tommtosa afforded, in addition to the major quinovic acid glycosides 1-3, three further glycosides 4-6. The structures were elucidated by spectral and chemical studies. Furthermore, a series of antiviral tests were performed on all these glycosides and on the related glycosides 7-9, previously isolated from Guettarda platypoda

Structure and cytotoxic activity of sesquiterpene glycoside esters from Calendula officinalis L.: studies on the conformation of viridiflorol

Topic applications of Calendula officinalis L. lipophilic extracts are used in phytotherapy to relieve skin inflammatory conditions whereas infusions are used as a remedy for gastric complaints. Such a different usage might be explained by some cytotoxicity of lipophilic extracts at gastric level but little is known about this. Therefore, we screened the CH2Cl2 extract from the flowers of C. officinalis by MTT and LDH assays in human epithelial gastric cells AGS. This bioassay-oriented approach led to the isolation of several sesquiterpene glycosides which were structurally characterized by spectroscopic measurements, chemical reactions and MM calculations. The conformational preferences of viridiflorol fucoside were established and a previously assigned stereochemistry was revised. The compounds 1a, 2a and 3f showed comparably high cytotoxicity in the MTT assays, whereas the effect on LDH release was lower. Our study provides new insights on the composition of C. officinalis extracts of medium polarity and identifies the main compounds that could be responsible for cytotoxic effects at gastric level

Characterization of Contractile Forces Generated by Stretch Marks Fibroblasts: In Vitro Study

Abstract: Authors present a study about the contraction forces observed in striae distensae fibroblasts (SMF) in a collagen scaffold. Collagen lattices were used to study the mechanical behavior of SDF within the collagen matrix compared to the lattices produced using the healthy skin derived fibroblasts (NSF). A Forcebox device was used to measure the contractile forces. Striae Rubrae fibroblast’s contractile force was by 28% greater than that generated by the NSF and striae albae fibroblasts (P<0.05). Anomalies and especially differences in forces generated by SMF were observed through all our experiments. These findings complete and corroborate the results and information published in our previous studies. Level of Evidence V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266

The Outcomes Assessment of the Plasma Blade Technology in Upper Blepharoplasties: A Prospective Study on a Series of 25 Patients

Background: The Dermo Ablation Surgery (DAS) Medical® (Technolux, Italy) device is a plasma blade which induces a plasma voltaic arc causing a retraction in the epidermis and superficial dermis. Objective: The aim of our study is to prove the efficacy and safety of the DAS Medical® device in dermatochalasis size reduction. Methods: Our prospective study included 25 adult patients presenting with upper eyelid dermatochalasis undergoing a two-session treatment protocol with the DAS Medical® device (with a month treatment-free interval). The primary end point was the reduction in the size of the dermatochalasis. The secondary end points were patient satisfaction, and a blinded assessment of the outcomes was carried out by 15 plastic surgery specialists on post-procedural pictures. Results: The mean reduction in the size of the dermatochalasis was estimated at 2.47 mm on a 6-month follow-up (13.5 mm at T0 vs. 11.03 mm at 6 months, p = 0.0002) and 1.97 mm on a 12-month follow-up ((13.5 mm at T0 vs. 11.53 mm at 12 months, p = 0.0055). Eighty per cent of the patients and 78% of the assessing clinicians were globally satisfied with the results on a 12-month follow-up. The mean visual analogue pain score reported during the treatment was 4.5/10; MEOPA® was used in 23% of cases. No irreversible post-procedural sequelae (complications) were observed. Conclusion: Voltaic plasma arc treatment with DAS Medical® is an effective technique for non-invasive blepharoplasty on moderate dermatochalasis patients not suffering from palpebral lipoptosis and is very well tolerated. It can be usefully and successfully associated with surgery. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266

The role of bacterial colonization of the suture thread in early identification and targeted antibiotic treatment of surgical site infections: A prospective cohort study

Background: The aim of the present study is to investigate the role of the colonization of suture thread to identify patients at risk of developing a surgical site infection (SSI) after clean surgical procedures. Methods: Patients who underwent elective clean surgery procedures at the Surgery Unit of the AOU-University of Campania Luigi Vanvitelli in a 21-month period were prospectively enrolled. For each patient, a synthetic absorbable thread in Lactomer 9-1 was inserted into the surgical site at the end of surgery and microbiologically evaluated after 48 h. Antibiotic prophylaxis was chosen according to international guidelines. Results: A total of 238 patients were enrolled; 208 (87.4%) of them were subjected to clean procedures without the placement of prosthesis, and 30 (12.6%) with prosthesis. Of the 238 patients, 117 (49.2%) underwent an antimicrobial prophylaxis. Overall, 79 (33.2%) patients showed a bacterial colonization of the thread: among the 208 without the implantation of prosthesis, 19 (21.8%) of the 87 with antibiotic prophylaxis and in 58 (47.9%) of the 121 without it; among the 30 patients with the implantation of prosthesis, only two patients showed a colonized thread. The patients with antibiotic prophylaxis developed a colonization of the thread less frequently than those without it (17.9% vs. 47.9%, p &lt; 0.001). SSI was observed in six (2.5%) patients, all of them showing a colonized thread (7.6% vs. 0%, p &lt; 0.001). The bacteria identified in colonized threads were the same as those found in SSIs. Conclusions: Our study presents a new method that is able to precociously assess patients who have undergone clean procedures who may develop SSI, and identify the microorganism involved