Crosslinking Rapidly Cured Epoxy Resin Thermosets: Experimental and Computational Modeling and Simulation Study

The power of computational modeling and simulation for establishing clear links between materials' intrinsic properties and their atomic structure has more and more increased the demand for reliable and reproducible protocols. Despite this increased demand, no one approach can provide reliable and reproducible outcomes to predict the properties of novel materials, particularly rapidly cured epoxy-resins with additives. This study introduces the first computational modeling and simulation protocol for crosslinking rapidly cured epoxy resin thermosets based on solvate ionic liquid (SIL). The protocol combines several modeling approaches, including quantum mechanics (QMs) and molecular dynamics (MDs). Furthermore, it insightfully provides a wide range of thermo-mechanical, chemical, and mechano-chemical properties, which agree with experimental data.

Diaporthe sp. F18; a new source of camptothecin-producing endophytic fungus from Nothapodytes nimmoniana growing in Sri Lanka

An endophytic fungus producing camptothecin (CPT) was isolated from the leaf of Nothapodytes nimmoniana (Sri Lanka), and culture conditions were optimised to enhance the yield of CPT. The TLC, HPLC-PDA, LC-MS/MS and spectroscopic data were used to identify and quantify CPT. Solvent extraction (chloroform: methanol 4:1 v/v) of submerged cultures in Sabouraud Dextrose Broth (SDB) detected CPT in the mycelial extract but not in the culture broth. The fungus was (KX212080) closely related to Diaporthe guangxiensis (MK335772) with 99% sequence similarity, thus tentatively identified as Diaporthe sp. F18. A significantly high CPT content (72.0 ± 0.2 µg/g) was produced in SDB, pH, 5.6 incubated at 30 °C under shake flask condition (150 rpm) for 14 days. Tryptophan significantly (p > 0.05) enhanced CPT production while ethanol increased it by 8-fold. This endophytic source produced higher CPT content than what has been reported hitherto in the literature, with fairly stable production up to sixth subculture generations.

Cesarean Law: a turning point in the fight against the Brazilian epidemic of cesarean section?

In the opposite direction to the process that had been gradually changing birth forms and indicators in Brazil, in 2019 the State of São Paulo (located in southeastern Brazil) enacted Law 17. 137, which guarantees all pregnant women the choice of a cesarean section from the 39 weeks of pregnancy, regardless of the obstetric indication. That is a preliminary qualitative analysis of a doctoral investigation, we are looking for show some points of inflection of this law to combat the cesarean epidemic. Affiliated to the theoretical-methodological approach of discursive practices and the production of meanings in daily, it investigates the discourses that support the current policies to encourage humanized obstetric care based on scientific evidence, built over the last 20 years, and those who supported the approval of this legal norm, known as the Cesarean Law. One of the inflection points of Law concerns the quality of prenatal care and the way that women receive information about childbirth during pregnancy. Because lack of information and insecurity are important factors in the choice of women by the type of delivery. Iatrogenic prematurity is one of the biggest problems of Brazilian cesarean section epidemic. Thus, even after 39 weeks of pregnancy, there is no guarantee of baby's maturity. Since the 90's, the Brazilian government had been encouraging the insertion of midwives and nurse midwives in the childbirth care of all women at regular risk and encouraged the creating of childbirth centers as well an adequate classification of gestational risk. At this point, the law affronts the current organization of the system, as it prioritizes attendance by doctors over professional midwives. The cesarean rates and other health indicators are not available yet after the approval of the law in São Paulo state. However, we can postulate that it will mean a setback in the fight against the epidemic of cesarean sections in Brazil.

Key messages

The Cesarean law approved in the state of São Paulo / BR presents inflection points in the fight against the cesarean section epidemic. The Cesarean law approved in the state of São Paulo / BR ignores important issues in the Brazilian obstetric scenario.

Blood Pressure Sensors: Materials, Fabrication Methods, Performance Evaluations and Future Perspectives

Advancements in materials science and fabrication techniques have contributed to the significant growing attention to a wide variety of sensors for digital healthcare. While the progress in this area is tremendously impressive, few wearable sensors with the capability of real-time blood pressure monitoring are approved for clinical use. One of the key obstacles in the further development of wearable sensors for medical applications is the lack of comprehensive technical evaluation of sensor materials against the expected clinical performance. Here, we present an extensive review and critical analysis of various materials applied in the design and fabrication of wearable sensors. In our unique transdisciplinary approach, we studied the fundamentals of blood pressure and examined its measuring modalities while focusing on their clinical use and sensing principles to identify material functionalities. Then, we carefully reviewed various categories of functional materials utilized in sensor building blocks allowing for comparative analysis of the performance of a wide range of materials throughout the sensor operational-life cycle. Not only this provides essential data to enhance the materials' properties and optimize their performance, but also, it highlights new perspectives and provides suggestions to develop the next generation pressure sensors for clinical use.

[Repetitive resection and intrasurgery radiation therapy of brain malignant gliomas: history of question and modern state of problem]

Numerous studies have shown that the degree of primary resection of malignant gliomas of the brain (MG) directly correlates with rates of relapse-free and overall patient survival. Currently, there is no unequivocal opinion regarding the indications and effectiveness of repeated resection in relapse of MG after combined treatment. Surgical intervention, taking into account the pathomorphological features of these tumors, is not healing and should be supplemented with certain methods of adjuvant treatment. The article reviews and analyzes publications devoted to repeated resection and various methods of intraoperative radiation therapy in the treatment of MG. Based on the analysis, the authors of the article came to the conclusion that it is advisable to start their own research on the use of intraoperative balloon brachytherapy in the treatment of recurrent MG based on modern technological solutions.

High-intensity interval training induced PGC-1∝ and AdipoR1 gene expressions and improved insulin sensitivity in obese individuals

INTRODUCTION

High-intensity interval training (HIIT) has been found to improve cardiometabolic health outcome as compared to moderate-intensity continuous exercise. However, there is still limited data on the benefits of HIIT on the expression of regulatory proteins that are linked to skeletal muscle metabolism and insulin sensitivity in obese adults. This study investigated the effects of HIIT intervention on expressions of peroxisome proliferatoractivated receptor-γ coactivator 1-∝ (PGC-1∝) and adiponectin receptor-1 (AdipoR1), insulin sensitivity (HOMAIR index), and body composition in overweight/obese individuals.

METHODS

Fifty overweight/obese individuals aged 22-29 years were assigned to either no-exercise control (n=25) or HIIT (n=25) group. The HIIT group underwent a 12-week intervention, three days/week, with intensity of 65-80% of age-based maximum heart rate. Anthropometric measurements, homeostatic model of insulin resistance (HOMA-IR) and gene expression analysis were conducted at baseline and post intervention.

RESULTS

Significant time-by-group interactions (p<0.001) were found for body weight, BMI, waist circumference and body fat percentage. The HIIT group had lower body weight (2.3%, p<0.001), BMI (2.7%, p<0.001), waist circumference (2.4%, p<0.001) and body fat percentage (4.3%, p<0.001) post intervention. Compared to baseline, expressions of PGC-1∝ and AdipoR1 were increased by approximately three-fold (p=0.019) and two-fold (p=0.003) respectively, along with improved insulin sensitivity (33%, p=0.019) in the HIIT group.

CONCLUSION

Findings suggest that HIIT possibly improved insulin sensitivity through modulation of PGC-1∝ and AdipoR1. This study also showed that improved metabolic responses can occur despite modest reduction in body weight in overweight/obese individuals undergoing HIIT intervention.

Acute anti-inflammatory and anti-nociceptive activities of crude extracts, alkaloid fraction and evolitrine from Acronychia pedunculata leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Acronychia pedunculata (family: Rutaceae) is one of the commonly used medicinal plants in Sri Lankan traditional medicine. Different parts of this plant are used for the treatment of inflammatory conditions in the form of medicinal oils and herbal porridge.

AIM OF THE STUDY

The present study aimed to evaluate the anti-nociceptive activity and anti-inflammatory activity with their mechanisms and the acute toxicity of crude extracts of the fresh leaves of A. pedunculata for scientific validation of the ethnopharmacological claims for this plant. Further, attention has been focused on the isolation of active compounds from active fractions of the crude extracts.

MATERIALS AND METHODS

The acute anti-inflammatory effect of the aqueous (AELA) and 70% ethanol crude extracts (EELA) and alkaloid fraction of A. pedunculata leaves were evaluated by the determination of inhibition of hind paw oedema induced by carrageenan in Wistar rats. Evolitrine was identified as the major alkaloid with significant bioactivities by column chromatography and NMR. The anti-nociceptive and anti-histamine activities of EELA and evolitrine were evaluated by acetic acid induced writhing and wheal formation tests respectively. In addition, in-vitro (2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay) and in-vivo (lipid peroxidation assay) anti-oxidant activity, nitric oxide (NO) inhibitory activity and acute toxicity of EELA were evaluated.

RESULTS

Acute anti-inflammatory activity of AELA and EELA were dose-dependent. EELA was more active than AELA. The 200 mg/kg body weight (b. w.) dose of EELA was found as the minimum effective dose with maximum inhibition (78%) of oedema at 5th hour compared to the negative control (p < 0.05). Evolitrine was isolated and identified as an active anti-inflammatory and analgesic compound from active alkaloid fraction of EELA. Evolitrine showed activity enhancement when compared with crude EELA. The anti-inflammatory and analgesic activities of evolitrine (50 mg/kg b. w.) were comparable to that of reference drugs indomethacin (5 mg/kg b. w) and acetylsalicylic acid (100 mg/kg b. w.). The significant (p < 0.05) anti-histamine activity, DPPH scavenging in-vitro anti-oxidant activity, in-vivo lipid peroxidation inhibitory activity in-vivo, NO inhibitory activity of EELA as compared with relevant negative controls, were identified as probable mechanisms which mediated its anti-inflammatory action. Further, EELA showed a high safety margin in the limited dose acute toxicity study.

CONCLUSION

The findings of the current study rationalize the usage of leaves of A. pedunculata in Sri Lankan traditional medicine as an analgesic and anti-inflammatory agent. Possible mechanisms mediating this activity included anti-histamine, anti-oxidant and NO inhibitory activities. Evolitrine is the major analgesic and anti-inflammatory compound isolated from the active alkaloid fraction of EELA.

Alteration of cell cytoskeleton and functions of cell recovery of normal human osteoblast cells caused by factors associated with real space flight

Experiments involving short-term space flight have shown an adverse effect on the physiology, morphology and functions of cells investigated. The causes for this effect on cells are: microgravity, temperature fluctuations, mechanical stress, hypergravity, nutrient restriction and others. However, the extent to which these adverse effects can be repaired by short-term space flown cells when recultured in conditions of normal gravity remains unclear. Therefore this study aimed to investigate the effect of short-term spaceflight on cytoskeleton distribution and recovery of cell functions of normal human osteoblast cells. The ultrastructure was evaluated using ESEM. Fluorescent staining was done using Hoechst, Mito Tracker CMXRos and Tubulin Tracker Green for cytoskeleton. Gene expression of cell functions was quantified using qPCR. As a result, recovered cells did not show any apoptotic markers when compared with control. Tubulin volume density (p<0.001) was decreased significantly when compared to control, while mitochondria volume density was insignificantly elevated. Gene expression for IL-6 (p<0.05) and sVCAM-1 (p<0.001) was significantly decreased while alkaline phosphatase (p<0.001), osteocalcin and sICAM (p<0.05) were significantly increased in the recovered cells compared to the control ones. The changes in gene and protein expression of collagen 1A, osteonectin, osteoprotegerin and beta-actin, caused by short-term spaceflight, were statistically not significant. These data indicate that short term space flight causes morphological changes in osteoblast cells which are consistent with hypertrophy, reduced cell differentiation and increased release of monocyte attracting proteins. The long-term effect of these changes on bone density and remodeling requires more detailed studies.

Outcome of corticosteroid injection versus physiotherapy in the treatment of mild trigger fingers

We compared the effectiveness of physiotherapy and corticosteroid injection treatment in the management of mild trigger fingers. Mild trigger fingers are those with mild crepitus, uneven finger movements and actively correctable triggering. This is a single-centred, prospective, block randomized study with 74 patients; 39 patients for steroid injection and 35 patients for physiotherapy. The study duration was from Jun 2009 until August 2010. Evaluation was done at 6 weeks, 3 months and 6 months post-treatment. At 3 months, the success rate (absence of pain and triggering) for those receiving steroid injection was 97.4% and physiotherapy 68.6%. The group receiving steroid injection also had lower pain score, higher rate of satisfaction, stronger grip strength and early recovery to near normal function (findings were all significant, p < 0.05). At 6 months, only those who were successfully treated were further questioned on recurrence (presence of pain and triggering). Those who received corticosteroid injections had a significant recurrence rate of pain but not triggering. The physiotherapy group had no recurrence of pain or triggering due to the type of triggering responsive to physiotherapy or possibly due to awareness of physiotherapy exercises. Perhaps they were able to institute self-treatment on early onset of symptoms of trigger fingers. We conclude that corticosteroid injection has a better outcome compared to physiotherapy in the treatment of mild trigger fingers but physiotherapy may have a role in prevention of recurrence.

Rapid non-equilibrium aluminium-ligand interactions: studies on the precipitation of aluminium by laser light scattering, ultrafiltration and centrifugation

The study aimed to develop simple assays to study aluminium-ligand interactions in natural/biological systems where equilibrium is rarely reached and thus where the initial seconds or hours of interactions are important. The immediate and non-equilibrium precipitation of aluminium hydroxide, in aqueous solution at neutral pH, was therefore studied by laser light scattering (diffraction), ultrafiltration and centrifugation. The interaction of weak ligands, present in the gastrointestinal lumen, on the precipitation of aluminium hydroxide was also investigated. The initial kinetics and particle sizes of precipitated aluminium hydroxide were sensitive to a number of external factors, including the presence of weak ligand (bicarbonate), sheer force (stirring), electrolyte concentration and initial (i.e. added) aluminium concentration. However, after a few seconds (no weak ligand), or several hundred seconds (with weak ligand), the subsequent observed changes to the solid phase were of small magnitude and occurred slowly. Thus, a 25-min window, within 5 and 30 min of pH adjustment, can be used to study the interactions of aluminium-ligand. This may approximate better to most natural systems where unperturbed aluminium-ligand equilibrium must rarely exist.

The goat as a model for studies of pneumonic pasteurellosis caused by Pasteurella multocida

A model of pneumonic pasteurellosis has been established in goats using Pasteurella multocida harvested from pneumonic lungs of goats (types A and D), rabbits (type A) and sheep (type D). The resultant infections were acute, subacute or chronic. The gross and histological lesions of the subacute and chronic infections were typical of pneumonic pasteurellosis. P. multocida type D produced significantly (P < 0.01) more severe lesions when compared with other isolates. There were strong correlations between the clinical signs and the severity of lesions.