Effect of Starch and Paperboard Reinforcing Structures on Insulative Fiber Foam Composites

Single-use plastic foams are used extensively as interior packaging to insulate and protect items during shipment but have come under increasing scrutiny due to the volume sent to landfills and their negative impact on the environment. Insulative compression molded cellulose fiber foams could be a viable alternative, but they do not have the mechanical strength of plastic foams. To address this issue, a novel approach was used that combined the insulative properties of cellulose fiber foams, a binder (starch), and three different reinforcing paperboard elements (angular, cylindrical, and grid) to make low-density foam composites with excellent mechanical strength. Compression molded foams and composites had a consistent thickness and a smooth, flat finish. Respirometry tests showed the fiber foams mineralized in the range of 37 to 49% over a 46 d testing period. All of the samples had relatively low density (Dd) and thermal conductivity (TC). The Dd of samples ranged from 33.1 to 64.9 kg/m3, and TC ranged from 0.039 to 0.049 W/mk. The addition of starch to the fiber foam (FF+S) and composites not only increased Dd, drying time (Td), and TC by an average of 18%, 55%, and 5.5%, respectively, but also dramatically increased the mechanical strength. The FF+S foam and paperboard composites had 240% and 350% higher average flexural strength (σfM) and modulus (Ef), respectively, than the FF-S composites. The FF-S grid composite and all the FF+S foam and composite samples had equal or higher σfM than EPS foam. Additionally, FF+S foam and paperboard composites had 187% and 354% higher average compression strength (CS) and modulus (Ec), respectively, than the FF-S foam and composites. All the paperboard composites for both FF+S and FF-S samples had comparable or higher CS, but only the FF+S cylinder and grid samples had greater toughness (Ωc) than EPS foam. Fiber foams and foam composites are compatible with existing paper recycling streams and show promise as a biodegradable, insulative alternative to EPS foam internal packaging.

GTPases, genome, actin: A hidden story in DNA damage response and repair mechanisms

The classical small Rho GTPase (Rho, Rac, and Cdc42) protein family is mainly responsible for regulating cell motility and polarity, membrane trafficking, cell cycle control, and gene transcription. Cumulative recent evidence supports important roles for these proteins in the maintenance of genomic stability. Indeed, DNA damage response (DDR) and repair mechanisms are some of the prime biological processes that underlie several disease phenotypes, including genetic disorders, cancer, senescence, and premature aging. Many reports guided by different experimental approaches and molecular hypotheses have demonstrated that, to some extent, direct modulation of Rho GTPase activity, their downstream effectors, or actin cytoskeleton regulation contribute to these cellular events. Although much attention has been paid to this family in the context of canonical actin cytoskeleton remodeling, here we provide a contextualized review of the interplay between Rho GTPase signaling pathways and the DDR and DNA repair signaling components. Interesting questions yet to be addressed relate to the spatiotemporal dynamics of this collective response and whether it correlates with different subcellular pools of Rho GTPases. We highlight the direct and indirect targets, some of which still lack experimental validation data, likely associated with Rho GTPase activation that provides compelling evidence for further investigation in DNA damage-associated events and with potential therapeutic applications in translational medicine.

Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the essential oils from Piper arboreum Aubl., Piper aduncum L. e Piper gaudichaudianum Kunth

The objective of this study was to determine the chemical profile and to evaluate the antibacterial activity of the essential oils of Piper species and modulation of the antibiotic activity, using the microdilution method to determine the minimum inhibitory concentration. The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed β-copaen-4-α-ol (31.38%), spathulenol (25.92%), and germacrene B (21.53%) as major constituents of the essential oils of Piper arboreum, Piper aduncum, and Piper gaudichaudianum, respectively. The essential oils analyzed in this study did not present a clinically relevant activity against standard and multiresistant Escherichia coli. However, in the case of multiresistant Staphylococcus aureus, there was a significant activity, corroborating with reports in the literature, where Gram-positive bacteria are more susceptible to antimicrobial activity. The essential oils modulated the effect of the antibiotics norfloxacin and gentamicin, having on the latter greater modulating effect; however, for erythromycin, no statistically significant effect was observed. In conclusion, the results obtained in this study demonstrated that the essential oils of the analyzed Piper species present an inhibitory effect against S. aureus and modulate antibiotic activity, most of which presents synergistic activity.

Pathological profiles of systemic infections by Panton-Valentine leukocidin-positive, methicillin-resistant Staphylococcus aureus strains in a murine model

AIMS

Staphylococcus aureus is one of the most common pathogens in hospital environment and community. Panton-Valentine leukocidin (PVL) production is clinically associated with skin abscesses, soft tissues infections, bacteraemia and sepsis. This study aimed to investigate the effects of the presence of genes lukF/S-PV coding for PVL, in histological and haematological features during systemic infection, using a Swiss mice experimental model.

METHODS AND RESULTS

Experiments were performed using 25 mice distributed into five experimental groups, intravenously inoculated with 50 µl suspensions at density 1·0 × 10⁷  CFU per ml of strains: methicillin-susceptible (MSSA) and pvl-negative strains isolated from nasal colonization; MSSA pvl-positive strains isolated from nasal colonization; methicillin-resistant (MRSA) and pvl-positive strains isolated from peripheral blood of a patient with severe pulmonary infection; and a MRSA pvl-positive strains isolated from a peripheral blood culture of a patient with bacteraemia. Haematological analysis was performed at 24, 48, 72 and 96 h post-infection. Morphoanatomy and histopathological analyses were performed at 96 h post-infection. For all S. aureus strains tested, the capability of intravenous dissemination and survival into mice tissues was demonstrated. Inflammatory processes at different levels were related to the presence of pvl genes, and included alterations in the format, size and colour of the organs. Staphylococcus aureus pvl-positive strains were detected in greater numbers in the organs of the infected animals.

CONCLUSIONS

The pvl-positive strains isolated from blood cultures were capable to induce the greatest modifications in both haematological and histopathological profiles, and seemed to aggravate the systemic infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings are valuable in characterizing infections caused by S. aureus in humans and murine.

Abstract P2065: Effect of Denture-Related Stomatitis on Blood Pressure and Heart Rate Variability

Denture-related stomatitis (DRS) has recently been associated with harmful cardiovascular effects, including arterial hypertension. This study evaluated salivary parameters, blood pressure (BP) and heart rate variability (HRV), before and after the DRS treatment in edentulous patients (n=14). Collection of unstimulated and stimulated saliva, as well as blood pressure BP measurements and electrocardiogram recordings, were performed before and after ten days of DRS treatment. The salivary flow (mL/min) was found similar at both times while the pH was smaller (more neutral) after the treatment (7.3±2.2 vs. 7.1±0.24). The systolic BP (mmHg) showed a trend, but not a significant reduction after the DRS treatment (158±25.68 vs. 148±16,72, p=0,062) while diastolic BP was found similar in both times (86±13.93 and 84±9.38). Overall, the HRV measured by the standard deviation of RR intervals was not affected by DRS treatment (24±4 vs. 18±2 ms); but the differences of successive RR intervals (an index of parasympathetic cardiac modulation) increased after the treatment (26±4 vs. 19±2 ms). Moreover, another index of vagal modulation of the heart, i.e., the power of RR interval spectra at high-frequency, was also markedly higher after the DRS treatment (236±63 vs. 135±32 ms 2 ). Overall, these findings strongly suggest that the DRS is associated with an autonomic imbalance, particularly with sympathetic overactivity. Therefore, the DRS may be significantly harmful, increasing cardiovascular risk and the incidence of several diseases, for instance, arterial hypertension.

Assessing the Roles of Rho GTPases in Cell DNA Repair by the Nucleotide Excision Repair Pathway

Ultraviolet light crossing the ozone layer in the atmospheric barrier affects all forms of living beings on earth. In eukaryotic cells, the nucleotide excision repair (NER) pathway protects the DNA by removing cyclobutane pyrimidine dimers (CPDs) and 6-4-photoproduct (6-4-PP) lesions caused by ultraviolet (UV) light, allowing cells to proliferate. On the other hand, adhesion and invasion processes, primarily regulated by the typical Rho GTPases Rho, Rac, and Cdc42, are also affected by UV radiation effects. Studies focused on determining whether or not these GTPases might affect the NER pathway in different cell models are enlightening and should start with classical experimental methodologies. In this chapter we describe two methods (host cell reactivation assay, or HCR, and slot-blots for CPDs and 6-4-PPs) to assess the direct or indirect involvement of these three GTPases on the NER pathway.

Abstract P422: Two-kidney One Clip (2k1c) Hypertension Reduces Complexity of Heart Rate Variability in Mice

Introduction: Hypertension is the most common chronic cardiovascular disease, being multifactorial in origin and an important cause of morbidity and mortality worldwide. Complex behaviors of heart rate series have been widely recognized and the loss of complexity in heart rate variability (HRV) has been shown to predict adverse cardiovascular outcomes. We hypothesized that two-kidney one clip (2K1C) hypertension reduces the HRV complexity in mice.

Methods and Results: C57BL/6 mice were anesthetized with isoflurane and submitted to 2K1C hypertension by placing a silver clip (0.12 mm) around left renal artery. After 4 weeks, mice were implanted with subcutaneous electrocardiogram (ECG) electrodes and allowed to recover for 48 h. On the day of the experiment, the ECG was recorded for 30 minutes in conscious, unrestrained mice. At the end of the recording, arterial pressure (AP) was directly measured in each mouse under isoflurane anesthesia. RR interval time series were generated and the complexity of HRV was determined using detrending fluctuation analysis (DFA) and multiscale entropy (MSE). Mean AP was higher in 2K1C mice (133±2 vs 93±4 mmHg) while the HR was similar between groups. DFA scaling exponents were calculated in short (5 to 15), mid (30 to 200) and long (200 to 1500) window sizes, but only the long-term exponent was different between groups (1.27±0.09 vs 0.89±0.08 in 2K1C and sham mice, respectively). MSE was calculated up to scale 20 and averaged in short (1 to 5) and long (6 to 20) time scales. In both short (0.75±0.16 vs 1.25±0.11) and long (0.76±0.17 vs 1.22±0.09) ranges, entropy is lower in hypertensive mice.

Conclusions: The complexity of HRV dynamics was found lower in renovascular hypertensive mice. Both sympathetic and vagal control of the heart seems to be involved in this process, as predictability (MSE) and fractality (DFA) is affected in various temporal scales. Nevertheless, the greatest entropy difference between groups is found at scale 6, which is closely related to respiration.

Modulation of the antibiotic activity against multidrug resistant strains of 4-(phenylsulfonyl) morpholine

The compound 4-(Phenylsulfonyl) morpholine belongs to the class of sulfonamides, which are widely used in the treatment of a large number of diseases caused by microorganisms. This compound has a morpholine group, which is also known for its antimicrobial properties. The aim of the present study was to investigate the antimicrobial and modulating activity of 4-(Phenylsulfonyl) morpholine against standard and multi-resistant strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and strains of the fungi Candida albicans, C. tropicalis and C. krusei. Antimicrobial activity was assessed based on the minimum inhibitory concentration (MIC) using the microdilution method. MIC was ⩾1024 μg/mL for all microorganisms. Regarding modulating activity, the most representative effect occurred with the combination of 4-(Phenylsulfonyl) morpholine at a concentration of 128 μg/mL (MIC 1/8) and amikacin against P. aeruginosa 03, with a reduction in MIC from 312.5 to 39.06 μg/mL.

Vibrational spectroscopy, ab initio calculations and Frontier Orbital analysis of 4,5,6,8,9-pentachloropyrimido-[1,2-a][1,8]naphthyridin-10-one

In this work we present a study of the vibrational spectra of 4,5,6,8,9-pentachloropyrimido-[1,2-a][1,8]naphthyridin-10-one, C11H2Cl5N3O, a substance belonging to the important pharmacological class of 1,8-naphthyridine derivatives. The Fourier transform infrared and the Fourier transform Raman spectra of the crystal were recorded at room temperature in the regions 400-4000 and 50-4000 cm(-1), respectively. Vibrational wavenumbers were predicted using Density Functional Theory calculations with the B3LYP functional on 6-31G(d,p) and 6-311++G(d,p) basis sets. The descriptions of the normal modes were made after calculating the potential energy distribution. Additionally, potential reaction sites were evaluated through Mulliken population and Frontier Orbital analysis.

Synthesis and antibacterial activity of a new derivative of the Meldrun acid: 2,2-dimethyl-5-(4H-1,2,4-triazol-4-ylaminomethylene)-1,3-dioxane-4,6-dione (C9H10N4O4)

The discovery of new substances with proven antimicrobial activity is the current study goal of various researchers. Usage of synthetic products has grown considerably in the past few years due to processing agility, and capability of going through previous chemical modifications in order to enhance its biological activity. Widespread careless use of antimicrobials has made the number of resistant microorganisms rise significantly, thus demanding more efficient drugs to fight them. One of these synthetic candidates for this purpose is the substance 2,2-Dimethyl-5-(4H-1,2,4-triazol-4-ylaminomethylene)-1,3-dioxane-4,6-dione (C9H10N4O4), aminomethylene derivative from Meldrum's acid. This substance, alone and in association with common antibiotics, were evaluated in vitro for antimicrobial activity, and had their minimum inhibitory concentration (MIC) towards Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 10536 and Pseudomonas aeruginosa ATCC 15442, as well as multiresistant strains Escherichia coli 27, Staphylococcus aureus 358 and Pseudomonas aeruginosa 03 determined. The antimicrobial modulation action tests of the aminoglycosides with C9H10N4O4 were performed according to the microdilution method, and resulted in observation of a positive synergic effect.

Genetic variations in the leptin gene associated with growth and carcass traits in Nellore cattle

The aim of the study was to detect polymorphisms in the leptin gene and to determine the association of these polymorphisms with growth and carcass traits in Nellore cattle. The single nucleotide polymorphisms (SNPs) -1457 (AJ571671:g.-1457A>G) and A59V (AF536174.1:g. 321C>T), as well as the microsatellite BM1500 (3.9 kb downstream), were genotyped. The measures of body weight and ultrasound examinations (rib eye area, back, and rump fat thickness) were performed in 3 different periods of animal management. During the first period, the animals were fed with grass and mineralized salt ad libitum. In the second period, they received grass and concentrate, and in the third, only concentrate. After the slaughter of animals, data were collected for classification and typification of carcasses. No significant association was found between the variables assessed and SNP -1457. Conversely, SNP A59V was associated with rump fat thickness and muscle color post-slaughter. BM1500 was associated with rump fat thickness in the first period (pre-slaughter), subcutaneous fat thickness in the second, weight of the animals in the third, and length of the carcass after slaughter. These results suggest that SNP A59V and the microsatellite BM1500 might be useful for marker-assisted selection in Nellore cattle.

Polymerase chain reaction genotyping of Epstein-Barr virus in scraping samples of the tongue lateral border in HIV-1 seropositive patients

The Epstein-Barr virus (EBV) is the etiological agent of oral hairy leukoplakia (OHL), an oral lesion with important diagnostic and prognostic value in acquired immunodeficiency disease syndrome. The two EBV genotypes, EBV-1 and EBV-2, can be distinguished by divergent gene sequences encoding the EBNA-2, 3A, 3B, and 3C proteins. The purpose of this study was to identify the EBV genotype prevalent in 53 samples of scrapings from the lateral border of the tongue of HIV-1 seropositive patients, with and without OHL, and to correlate the genotypes with presence of clinical or subclinical OHL with the clinic data collected. EBV-1 and EBV-2 were identified through PCR and Nested-PCR based on sequence differences of the EBNA-2 gene. EBV-1 was identified in the 31 samples (15 without OHL, 7 with clinical OHL and 9 with subclinical OHL), EBV-2 in 12 samples (10 without OHL, 1 with clinical and 1 subclinical OHL), and a mixed infection in 10 samples (2 without OHL, 3 with clinical and 5 with subclinical OHL). The presence of EBV-1 was higher in women, but a significant statistical result relating one the EBV genotypes to the development of OHL was not found. We conclude that the oral epithelium in HIV-1 seropositive patients can be infected by EBV-1, EBV-2 or by a mixed viral population.

4,5,6,8,9-Pentachloropyrimido[1,2-a][1,8]naphthyridin-10-one

The title compound, C11H2Cl5N3O, crystallizes in the monoclinic system with two molecules in the asymmetric unit. The molecules are chemically identical but have different structural parameters. In the three-dimensional packing, the molecules are arranged in dimers that are connected by slipped pi-pi stacking, and these dimers are connected to one another through several C-H...O and Cl...Cl interactions.

Radioisotope blood volume measurement in uncontrolled retroperitoneal haemorrhage induced by a transfemoral iliac artery puncture

Standard-of-care, large volume crystalloid infusion, in the setting of uncontrolled bleeding, has been challenged and it is not known if fluid resuscitation increases retroperitoneal hemorrhage. We developed an experimental model of retroperitoneal haemorrhage to correlate haemodynamic and metabolic alterations with the blood volume loss. Anaesthetised, spontaneously breathing dogs (17.1+/-0.56 kg) were randomised to unilateral (UL, n=11) or bilateral (BL, n=11) iliac artery puncture, using a metallic device introduced through the femoral arteries and followed for 120 min. Initial and final blood volumes were determined using radioactive tracers, 99mTC and 51Cr, respectively. UL was associated with a stable arterial pressure and a moderate decrease in cardiac output and oxygen delivery. BL induced an abrupt and sustained decrease in mean arterial pressure, from 131.9+/-5.9 to 88.6+/-10.8 mmHg, and a much greater reduction in cardiac output, oxygen delivery and consumption than UL throughout the experiment. Total retroperitoneal blood loss after BL was 36.8+/-3.2 ml/kg, while after UL was 25.1+/-3.4 ml/kg (P=0.0262). We conclude that a transfemoral bilateral iliac artery puncture produces a clinically relevant model of uncontrolled retroperitoneal haemorrhage, with hypotension and low flow state, while a unilateral iliac artery lesion causes a compensated shock state.