Influence of Spontaneous and Mechanical Ventilation on Frequency-Based Measures of Heart Rate Variability

Frequency-based measures of heart rate variability have been shown to be a useful physiological marker in both clinical and research settings providing insight into the functioning of the autonomic nervous system. Ongoing interactions between the autonomic nervous system control of the heart and lung occurs during each ventilation cycle because of their anatomical position within the closed thoracic cavity. Mechanical ventilation and subsequent removal change the normal ventilator mechanics producing alterations in the tidal volume, intrathoracic pressure, and oxygen delivery. A noninvasive method called heart rate variability (HRV) can be used to evaluate this interaction during ventilation and can be quantified by applying frequency-based measures of the variability between heartbeats. Although HRV is a reliable method to measure alteration of the autonomic nervous system (ANS) function and cardiopulmonary interaction, there have been limited reports concerning the changes in the frequency-based measure of HRV during both spontaneous and mechanical ventilation. The purpose of this methodological study is therefore to describe the physiological influence of both spontaneous and mechanical ventilation on frequency-based measures of HRV.

The effect of various fluoride products on dentine lesions during pH-cycling

This study compared the effect of topically applied fluoride products on dentine lesions in an in vitro experiment. Demineralized bovine dentine specimens were treated once with either SDF solution (35,400 ppm F), NaF varnish (22,600 ppm F), TiF4 solution (9,200 ppm F), SnF2 gel (1,000 ppm F), no treatment (control) or preserved as baseline lesions. After the application and subsequent removal of the fluoride products, the specimens were subjected to pH-cycling. Calcium loss and uptake in the de- and remineralization buffers were assessed daily. Fluoride release into the buffers was analyzed on day 1, 2, 3, 5, 8 and 13. After the pH-cycling period, mineral distribution throughout the lesion depth was analyzed using transversal microradiography (TMR). X-ray energy-dispersive spectroscopy (EDS) examined the deposition of silver, titanium and tin after application of SDF, TiF4, and SnF2, respectively. Overall, calcium loss and uptake analysis in the de- and remineralization buffers revealed that the SDF product was the most effective in inhibiting lesion progression, followed by the TiF4, NaF, and SnF2 products. Fluoride analysis disclosed a steep reduction of the amount of fluoride released into de- and remineralization buffers with time. The fluoride effects on de- and remineralization continued beyond the days that fluoride was released into the buffers. TMR analysis showed significant remineralization in the outer zone of the dentine lesions for all fluoride products, with SDF giving hyper-mineralization in this zone. In the inner zone, lesions developed in all fluoride groups, with the smallest in the SDF group. EDS showed silver and titanium deposition in depth up to 85 μm and 8 μm, respectively, while no tin deposition was observed. The silver in the dentine lesions did not contribute significantly to the density of the TMR profiles in the SDF group. In conclusion, all topical fluoride products protected the dentine lesions against lesion progression, but at different degrees. SDF showed a superior effect in protection against further demineralization and enhancement of remineralization. This was probably attributed to its fluoride concentration that was the highest among the fluoride products.

Phenolic Compounds and Oxidative Enzymes Involved in Female Fertility in Banana Plants of the Cavendish Subgroup

The present study investigated phenolic compounds and enzymes involved in female fertility in banana plants of the Cavendish subgroup. The wild diploid Calcutta 4 and commercial cultivar Grand Naine (Cavendish subgroup) were used. The following five stages of floral development were proposed: S1 (partial vertical emission), S2 (total vertical emission), S3 (total horizontal emission), S4 (pre-anthesis), and S5 (anthesis). Following collection, pistillate (female) flowers were freeze-dried for the subsequent removal of nectaries and the analysis of phenolic compounds (PCs), antioxidant activity (DPPH and ABTS), enzymatic activity [peroxidase (POD) and polyphenol oxidase (PPO)], and total proteins (TPs). The highest values were recorded at the S3 stage, with the values decreasing as the stages progressed (until S5). At the S3 stage, the following results were obtained for Calcutta 4 and Grand Naine, respectively: PCs (32.4 and 36.1 mg GAE·g−1); DPPH (735.2 and 454.4 µM TE·g−1); ABTS (647.8 and 555.5 µM TE·g−1); POD (0.8 and 0.7 µmol·min−1·g−1); PPO (3.7 and 2.7 µmol·min−1·g−1); and TP (3.2 and 2.4 µmol·min−1·g−1). These results indicate that PCs and enzymes regulate female fertility, suggesting that crossbreeding should be performed from the S3 stage in cultivars of the Cavendish subgroup to achieve fruits with seeds.

EP.FRI.749 Facial augmentation surgery: Perception vs. Reality

Background In recent years, aesthetic surgeries have gained significant momentum. A recent audit identified that more than 28,000 cosmetic surgeries were performed in the United Kingdom (UK) in 2018.1. We present an unfortunate case of morbid complications related to the use of malar implant for cosmesis. Case Presentation A 63-year-old Caucasian female presented to the Emergency department with sepsis related to a large painful, tender swelling of the right side of the face. There was discharge of pus from two cutaneous sinuses with additional ectropion/chemosis of the right eye. An orocutaneous communication due to infection/migration of the implant was also noted. The patient reported a history of bilateral malar implants placement three years ago. The patient initially required emergency drainage & subsequent removal of the infected malar implant. Discussion Malar implants provide suitable volume enhancement providing structural and aesthetic benefits including the ‘high cheek bone’ appearance. It is generally considered to be a safe surgical technique with multiple approaches possible to insert the implant. including transoral approach). Spadafora (1971) & Hinderer (1972) first described the use of malar implants for facial augmentation.2,3 Rayess et al.(2017) conducted a 10 year review of complications related to facial implants & noted that 75% of complications related to malar implants were due to infection with 38% of these implants needing removal.4 Conclusion There is a surge in presentations of complications related to cosmetic facial surgery and knowledge of these adverse effects is essential to appropriately manage these patients & their concerns.

Taxane-Induced Upper Gastrointestinal Bleeding

Docetaxel is a taxane, which is a class of chemotherapy agent used in the treatment of multiple malignancies. It is known to have gastrointestinal side effects which can range from mild symptoms such as nausea and diarrhea to more severe complications such as neutropenic enterocolitis. In the current literature, taxanes have not been described to cause upper gastrointestinal bleeding and melena. Here, we present a case of a 54-year-old woman with breast cancer who developed dizziness, fatigue, and melena after receiving chemotherapy. Esophagogastroduodenoscopy revealed diffuse gastric erosions as well as ulceration and linear superficial lesions in the duodenum; biopsies from these sites showed taxane-induced toxicity. Her bleeding resolved with medical therapy and subsequent removal of docetaxel from her chemotherapy regimen. This case identifies upper gastrointestinal bleeding as a previously undescribed side effect of docetaxel therapy. Recent docetaxel use should be included in the differential diagnosis for upper gastrointestinal bleed, and diagnosis should lead to consideration of cessation of docetaxel or substitution with another chemotherapeutic agent.

The nature and origin of cratons constrained by their surface geology

To the memory of Nicholas John (Nick) Archibald (1951−2014), master of cratonic geology. Cratons, defined by their resistance to deformation, are guardians of crustal and lithospheric material over billion-year time scales. Archean and Proterozoic rocks can be found in many places on earth, but not all of them represent cratonic areas. Some of these old terrains, inappropriately termed “cratons” by some, have been parts of mobile belts and have experienced widespread deformations in response to mantle-plume-generated thermal weakening, uplift and consequent extension and/or various plate boundary deformations well into the Phanerozoic. It is a common misconception that cratons consist only of metamorphosed crystalline rocks at their surface, as shown by the indiscriminate designation of them by many as “shields.” Our compilation shows that this conviction is not completely true. Some recent models argue that craton formation results from crustal thickening caused by shortening and subsequent removal of the upper crust by erosion. This process would expose a high-grade metamorphic crust at the surface, but greenschist-grade metamorphic rocks and even unmetamorphosed supracrustal sedimentary rocks are widespread on some cratonic surfaces today, showing that craton formation does not require total removal of the upper crust. Instead, the granulitization of the roots of arcs may have been responsible for weighing down the collided and thickened pieces and keeping their top surfaces usually near sea level. In this study, we review the nature and origin of cratons on four well-studied examples. The Superior Province (the Canadian Shield), the Barberton Mountain (Kaapvaal province, South Africa), and the Yilgarn province (Western Australia) show the diversity of rocks with different origin and metamorphic degree at their surface. These fairly extensive examples are chosen because they are typical. It would have been impractical to review the entire extant cratonic surfaces on earth today. We chose the inappropriately named North China “Craton” to discuss the requirements to be classified as a craton.

Sirt1 and Nrf2: Regulation of Leydig cell oxidant/antioxidant intracellular environment and steroid formation

Previous studies reported that, with aging, Leydig cell intracellular antioxidants are reduced in concentration and intracellular ROS levels increase, suggesting that oxidant/antioxidant imbalance may contribute to the reduced testosterone production that characterizes the aging cells. As yet, little is known about how the Leydig cell oxidant/antioxidant environment is regulated. Sirt1, an enzyme that deacetylates transcription factors, and the transcription factor Nrf2, have been shown to be associated with cellular response to oxidative stress. We hypothesized that Sirt1 and/or Nrf2 might be involved in regulating the oxidant/antioxidant environment of Leydig cells, and therefore testosterone production. We found that Sirt1 and Nrf2 are present in the Leydig cells of Brown Norway rats, though reduced in aged cells. In MA-10 cells in which Sirt1 or Nrf2 were suppressed by nicotinamide (NAM) or ML385, respectively, or in which siRNAs were used for knockdown of Sirt1 or Nrf2, increased ROS levels and decreased progesterone production occurred. In rat Leydig cells, inhibition of Sirt1 by culturing the cells with NAM resulted in increased ROS and reduced testosterone production, and subsequent removal of NAM from the culture medium resulted in increased testosterone production. Activation of rat Leydig cells Sirt1 with honokiol or of Nrf2 with sulforaphane resulted in the maintenance of testosterone production despite the exposure of the cells to oxidizing agent. These results, taken together, suggest that Sirt1 and Nrf2 are involved in maintaining the Leydig cell oxidant/antioxidant environment, and thus in maintaining steroid production.

Patience Alone is not Enough – A Guide for the Preparation of Low-Defect Sections from Pure Copper

The preparation of metallographic sections from soft metals such as pure copper constitutes a particular challenge: the high degree of ductility promotes the formation of preparation artifacts and complicates the preparation of homogeneous, low-deformation surfaces. A metallographic preparation routine is therefore presented which has proven effective for pure copper and which can also be applied to additionally soft annealed samples. The subsequent removal of fine crystalline deformation layers is discussed and different setups for electropolishing and its optimization are presented.

Synthesis and Antiproliferative Evaluation of 2-Deoxy-N-glycosylbenzotriazoles/imidazoles

A series of 2-deoxy-2-iodo-α-d-mannopyranosylbenzotriazoles was synthesized using the benzyl, 4,6-benzylidene and acetyl protected D-glucal in the presence of N-iodosuccinimide (NIS). Subsequent removal of the iodine at the C-2 position using tributyltin hydride under free radical conditions afforded the 2-deoxy-α-d-glucopyranosylbenzotriazoles in moderate to high yields. This method was extended to the preparation of substituted 2-deoxy-β-d-glucopyranosylimidazoles as well. The stereoselectivity of the addition reaction and the effect of the protecting group and temperature on anomer distribution of the benzotriazole series were also investigated. The anticancer properties of the newly synthesized compounds were evaluated in a series of viability studies using HeLa (human cervical adenocarcinoma), human breast and lung cancer cell lines. The N-[3,4,6-tri-O-benzyl-2-deoxy-α-d-glucopyranosyl]-1H-benzotriazole and the N-[3,4,6-tri-O-acetyl-2-deoxy-α-d-glucopyranosyl]-2H-benzotriazole were found to be the most potent cancer cell inhibitors at 20 µM concentrations across all four cell lines.

Template-Free Self-Assembly of Two-Dimensional Polymers into Nano/Microstructured Materials

In the past few decades, enormous efforts have been made to synthesize covalent polymer nano/microstructured materials with specific morphologies, due to the relationship between their structures and functions. Up to now, the formation of most of these structures often requires either templates or preorganization in order to construct a specific structure before, and then the subsequent removal of previous templates to form a desired structure, on account of the lack of “self-error-correcting” properties of reversible interactions in polymers. The above processes are time-consuming and tedious. A template-free, self-assembled strategy as a “bottom-up” route to fabricate well-defined nano/microstructures remains a challenge. Herein, we introduce the recent progress in template-free, self-assembled nano/microstructures formed by covalent two-dimensional (2D) polymers, such as polymer capsules, polymer films, polymer tubes and polymer rings.