Effect of Concentration and Residence Time of Joncryl■ADR4368 on Melt Processability of Poly(3-hydroxybutyrate)

Poly(3-hydroxybutyrate)(PHB)is a biothechnological and biodegradable thermoplastic polymer from the polyhydroxyalkanoates(PHAs)family,whose chain regularity,high molecular weight,and physical and mechanical properties comparable to polypropylene(PP)are characteristics that have made PHB a prominent commercial bioplastic.Nevertheless,its susceptibility to thermal degradation and hydrolysis has limited many applications.To address the challenges associated with processing,a random copolymer of 95.86 mol%3-hydroxybutyrate and 4.14 mol%3-hydroxyvalerate(referred as PHB)was compounded without(neat PHB)and with 0.25,0.5,1,and 1.5 wt%of chain extender(Joncryl■ADR 4368),consisting of multifunctional epoxy groups,and melt mixed in an internal mixer at 170℃,50 rpm,and residence times of 5,10,and 15 min.The effect of chain extender concentration and residence time on the effectiveness of Joncryl■ADR 4368 to recover the pristine PHB properties were investigated through torque rheometry,melt flow index(MFI),differential scanning calorimetry(DSC),tensile testing,and thermogravimetric analysis.The results indicated that an increase in residence time strongly influenced the prevalence of thermomechanical degradation reactions over chain extension reactions of PHB during processing in the molten state.Shorter residence times favored chain extension,while longer times favored chain scission.This trend led to no enhancement of PHB mechanical properties processed for 10 and 15 min,regardless of additive content used.Melt flow index,thermogravimetric analysis and tensile strength exhibited an asymptotic behavior with the increase in additive concentration,exhibiting a noteworthy improvement in tensile strength and temperature at the highest rate of thermal degradation(TMAX),and a decrease in melt flow index of neat PHB with only 0.25 wt%of additive mixed for 5 min.The results found in this work allow additional data for processing PHB by manipulating the ratios of multifunctional chain extender and mixing time,which can create new approach in various applications.

What have we learned about the kallikrein-kinin and renin-angiotensin systems in neurological disorders?

The kallikrein-kinin system(KKS) is an intricate endogenous pathway involved in several physiological and pathological cascades in the brain. Due to the pathological effects of kinins in blood vessels and tissues, their formation and degradation are tightly controlled. Their components have been related to several central nervous system diseases such as stroke, Alzheimer's disease, Parkinson's disease, multiple sclerosis, epilepsy and others. Bradykinin and its receptors(B1R and B2R) may have a role in the pathophysiology of certain central nervous system diseases. It has been suggested that kinin B1R is up-regulated in pathological conditions and has a neurodegenerative pattern, while kinin B2R is constitutive and can act as a neuroprotective factor in many neurological conditions. The renin angiotensin system(RAS) is an important blood pressure regulator and controls both sodium and water intake. AngⅡ is a potent vasoconstrictor molecule and angiotensin converting enzyme is the major enzyme responsible for its release. AngⅡ acts mainly on the AT1 receptor, with involvement in several systemic and neurological disorders. Brain RAS has been associated with physiological pathways, but is also associated with brain disorders. This review describes topics relating to the involvement of both systems in several forms of brain dysfunction and indicates components of the KKS and RAS that have been used as targets in several pharmacological approaches.

Burn injury induces histopathological changes and cellproliferation in liver of rats

AIM: To investigate effects of severe burn injury(BI) in rat liver through the histopathological and inflammatory markers analysis. METHODS: Forty-two male Wistar rats were distributed into two groups, control(C) and subjected to scald BI(SBI). The animals were euthanized one, four and 14 d post sham or 45% of the total body surface BI. Liver fragments were submitted to histopathological, morphoquantitative(hepatocyte area and cell density), ciclooxigenase-2(COX-2) immunoexpression, and gene expression [real-time polymerase chain reaction for tumor necrosis factor(TNF)-α, inducible nitric oxide synthase(i NOS) and caspase-3] methods. RESULTS: Histopathological findings showed inflammatory process in all periods investigated and hepatocyte degeneration added to increased amount of connective tissue 14 d post injury. Hepatocyte area, the density of binucleated hepatocytes and density of sinusoidal cells of SBI groups were increased when compared with control. COX-2 immunoexpression was stronger in SBI groups. No differences were found in TNF-α, i NOS and caspase-3 gene expression. CONCLUSION: BI induces histopathological changes, upregulation of COX-2 immunoexpression, and cell proliferation in liver of rats.

Incorporation of Bromelain into Dermatological Bases： Accelerated Stability Studies

This work aimed the incorporation of the enzyme bromelain from pineapple peel into dermatological bases for potential therapeutic application. The enzyme was incorporated into Lanette cream and lotion, as well as Carbopol gel and Chemyunion cream and lotion, at a concentration of 0.5% （w/w）. These bases were subjected to centrifugation test and accelerated stability test during 90 days at 25 ℃（with and without sunlight）, 37 ℃ and 4 ℃, in order to evaluate bromelain stability in dermatological bases. Total protein content and enzymatic activity were measured. The bases were stable as its organoleptic characteristics （appearance, color, smell and sensitivity to touch） only when kept at 4 ℃ with activity remaining 95.5%, 84,9%. 77.7%, 73.8% and 72.3%, alter 90 days of testing in Carbopol gel, Lanette and Chemyunion cream, and Lanette and Chemyunion lotion, respectively. Based on the results, it was possible to incorporate bromelain into dermatological bases, and the activity was well preserved when these bases were kept in refrigerator at 4 ℃.

Evaluation of Biodegradation in Aqueous Medium of Poly(Hydroxybutyrate-Co-Hydroxyvalerate)/Carbon Nanotubes Films in Respirometric System

Biodegradable polymers have been increasingly used for scientific and commercial applications because they are similar to some conventional thermoplastics and exhibit the ability of self-degradation.Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)nanocomposites films with 1 and 2 wt% of carbon nanotubes(CNT)were prepared by solution mixing,followed by solvent evaporation.In this work,PHBV/CNT nanocomposites were submitted to biodegradation in an aqueous medium for 34 days through a respirometric system.Then,the PHBV films were analyzed by the CO2 production and mineralization as a response of a microbial attack,which was monitored by back titration during all the experiment.The films were also characterized by measuring the weight loss;crystallinity was evaluated by differential scanning calorimetry(DSC)and the surface morphology by scanning electron microscopy(SEM).By analyzing the weight loss of the films,it was observed that adding CNT increases the resistance to biodegradation process.The obtained values of CO2 production and mineralization of the samples,as well as the values of weight loss,showed that the biodegradation of PHBV/CNT nanocomposites was minor in comparison to neat PHBV.The addition of CNT in PHBV matrix influences the surface morphology,causing the presence of cavities and an increase of roughness.

Terpenes extracted from marine sponges with antioxidant activity:a systematic review

Marine biodiversity has emerged as a very promising resource of bioactive compounds and secondary metabolites from different sea organisms.The sponge’s secondary metabolites demonstrated various bioactivities and potential pharmacological properties.This systematic review of the literature focuses on the advances achieved in the antioxidant potential of marine sponges in vitro.The review was performed in accordance with PRISMA guidelines.The main inclusion criterion for analysis was articles with identification of compounds from terpene classes that demonstrate antioxidant activity in vitro.Searching in three different databases,two hundred articles were selected.After screening abstracts,titles and evaluating for eligibility of manuscripts 14 articles were included.The most performed analyzes to detect antioxidant activity were scavenging activity 2,2-diphenyl-1-picrylhydrazyl(DPPH)and measurement of intracellular reactive oxygen species(ROS).It was possible to identify 17 compounds of the terpene class with pronounced antioxidant activity in vitro.Scientific evidence of the studies included in this review was accessed by the GRADE analysis.Terpenes play an important ecological role,moreover these molecules have a pharmaceutical and industrial application.

Fast Radio Bursts as Crustal Dynamical Events Induced by Magnetic Field Evolution in Young Magnetars

We revisit in this work a model for repeating Fast Radio Bursts based of the release of energy provoked by the magnetic field dynamics affecting a magnetar’s crust.We address the basics of such a model by solving the propagation of the perturbation approximately,and quantify the energetics and the radiation by bunches of charges in the so-called charge starved region in the magnetosphere.The(almost)simultaneous emission of newly detected X-rays from SGR 1935+2154 is tentatively associated with a reconnection behind the propagation.The strength of f-mode gravitational radiation excited by the event is quantified,and more detailed studies of the nonlinear(spiky)soliton solutions are suggested.

Freeze-dried jaboticaba(Myrciaria jaboticaba)peel powder,a rich source of anthocyanins and phenolic acids,mitigates inflammation-driven colorectal cancer in mice

This study aimed to characterize the peel of jaboticaba(Myrciaria jaboticaba(Vell.)O.Berg)by spectropho-tometry and chromatography,and investigate its effects on mice with inflammation-driven colorectal cancer(CRC).Freeze-dried jaboticaba peel(FDJP)showed a high antioxidant capacity in vitro,and to be mostly a source of cyanidin-3-O-glucoside,gallic acid,and ellagic acid.In the animal bioassay,FDJP added at 5%in the diet during 114 days completely abolished the formation of adenocarcinoma,which had an incidence of 75%in the non-treated group.Animals consuming FDJP showed low histology damage regarding inflammatory infiltrate,edema,and crypt distortion.FDJP significantly reduced the colonic levels of proinflammatory markers interleukin-1beta and cyclooxygenase-2,and demonstrated a probability to decrease the expressions of inducible nitric oxide synthase and nuclear factor kappa B.In summary,FDJP mitigated CRC,possibly by avoiding trig-gering inflammation.Such benefit may come from its rich content in anthocyanins and phenolic acids.

Musical and Photographic Stimulations on the Symptomatology of Alzheimer’s Disease in Elderly

Background: Alzheimer’s disease is a progressive and neurodegenerative disorder characterized by deterioration of brain functions. Psychosocial interventions such as music and photographic stimuli may contribute to cognitive and sensory exercise or rehabilitation. Objective: Evaluate musical and photographic stimuli in elderly people with Alzheimer’s disease. Methods: It is an uncontrolled clinical trial, before-after type, eleven subjects composing the sample. Participants were submitted to Katz Index, Autobiographical Memory Test, GDS-15, Mini-Mental State Examination. The collection instruments were used on the first and last day of intervention, individually. There were 2 sessions in the week with duration of 50 minutes totaling 20 sessions. Data were analyzed by descriptive and inferential statistics and as variables expressed as mean standard deviation. Results: There was a significant effect of cognitive activity (P < 0.01), it was observed that a small advance (P = 0.05) of the daily life activities. With the analysis of GDS-15, it is verified that they are more effective for the increase of the previous self-estimation of the therapy (P = 0.94). In the application of the AMT, it is observed that there was a better recruitment of the memory for the neutral words. Conclusion: Musical and photographic stimuli had a positive effect on the cognitive level, daily life activities and autobiographical memory in seniors with Alzheimer’s disease.

Identification of New Genes Related to Virulence of <i>Xanthomonas axonopodis</i>Pv. <i>Citri</i>during Citrus Host Interactions

A mutant library of the bacterium Xanthomonas citri subsp. citri strain 306 pathotype A (Xac), the causative agent of most aggressive Asiatic type A citrus canker, was screened regarding altered canker symptoms after inoculations into Citrus sinensis and Citrus limonia host leaves. Twenty-six mutants have shown phenotypic virulence changes and have respectively knocked out gene identified by sequencing. In vivo growth curves were obtained for nine mutants to quantify how the mutations could affect pathogen’s adaptability to growth inside and attack host plant infected tissue. Among identified genes in mutated strains, we could find those that until now had not been reported as being involved in Xac adaptation and/or virulence, such as predicted to encode for xylose repressor-like protein (XACΔxylR), Fe-S oxidoredutase (XACΔaslB), helicase IV (XACΔhelD), ubiquinol cytochrome c oxidoreductase iron-sulfur subunit (XACΔpetA), chromosome partitioning protein (XACΔparB) and cell division protein FtsB (XACΔftsB), in addition to genes predicted to encode for hypothetical proteins. The new genes found in this study as being relevant to adaptation and virulence, improve the understanding of Xac fitness during citrus plant attack and canker symptoms development.

Does Locomotive Syndrome, Associated with Sarcopenia or otherwise, Influence Quality of Life in Individuals Aged over 80 years? Third Wave of the LOCOMOV Project

Introduction:Locomotion is a determinant of intrinsic capacity of older people and can be limited by dysfunction in locomotory organs,characterizing Locomotive Syndrome(LoS).Knowledge on locomotive problems and sarcopenia,and their interface with quality of life,in the oldest old in the literature is scarce.Objective:To evaluate the correlation between LoS and sarcopenia and their influence on quality of life in oldest old.Methods:A cross-sectional study of an observational,descriptive and analytical epidemiological survey in independent older adults aged 80 and over from São Paulo,Brazil and who participated in the third wave of the LOCOMOV Project,was carried out.Sociodemographic data,comorbidities,functioning in activities of daily living,physical functioning,quality of life,and presence of sarcopenia and LoS were assessed.The statistical analyses included the Test-for-Comparing-Two-Proportions,Pearson's Correlation Coefficient,the chi-Square test and Student´s t-test.Results:Thirty oldest old with a mean age of 89.1 years were evaluated.The prevalence of LoS was high(53.3%)and correlated significantly with chronic pain(p-value 0.024),worse performance on the SPPB and Gait speed(p-value<0.001).Sarcopenia was not correlated with LoS,but worse quality of life on the physical domain was significantly associated with LoS(p-value<0.001)regardless of the presence of sarcopenia.Conclusions:LoS was highly prevalent among the oldest old studied and negatively impacted their quality of life,regardless of the presence of sarcopenia.

Gelatin methacryloyl granular scaffolds for localized mRNA delivery

Messenger RNA(mRNA)therapy is the intracellular delivery of mRNA to produce desired therapeutic proteins.Developing strategies for local mRNA delivery is still required where direct intra-articular injections are inappropriate for targeting a specific tissue.The mRNA delivery efficiency depends on protecting nucleic acids against nuclease-mediated degradation and safe site-specific intracellular delivery.Herein,novel mRNA-releasing matrices based on RGD-moiety-rich gelatin methacryloyl(GelMA)microporous annealed particle(MAP)scaffolds are reported.GelMA concentration in aerogel-based microgels(μgels)produced through a microfluidic process,MAP stiffnesses,and microporosity are crucial parameters for cell adhesion,spreading,and proliferation.After being loaded with mRNA complexes,MAP scaffolds composed of 10%GelMAμgels display excellent cell viability with increasing cell infiltration,adhesion,proliferation,and gene transfer.The intracellular delivery is achieved by the sustained release of mRNA complexes from MAP scaffolds and cell adhesion on mRNA-releasing scaffolds.These findings highlight that hybrid systems can achieve efficient protein expression by delivering mRNA complexes,making them promising mRNA-releasing biomaterials for tissue engineering.

Sleep disturbances as an adverse effect of propranolol use in children with infantile hemangioma

Infantile hemangiomas(IHs)are the most prevalent benign vascular tumor in children,with an estimated rate of 5-10%.Most IHs resolve spontaneously after the proliferation stage,but about 12-24%develop with sequelae and complications which require pharmacological interventions[1].The beta blocker propranolol is considered as the first-line treatment for complicated cases of IHs[2].

Waste Tire Rubber-based Refrigerants for Solid-state Cooling Devices

Management of discarded tires is a compelling environmental issue worldwide.Although there are several approaches developed to recycle waste tire rubbers,their application in solid-state cooling is still unexplored.Considering the high barocaloric potential verified for elastomers,the use of waste tire rubber(WTR)as a refrigerant in solid-state cooling devices is very promising.Herein,we investigated the barocaloric effects in WTR and polymer blends made of vulcanized natural rubber(VNR)and WTR,to evaluate its feasibility for solid-state cooling technologies.The adiabatic temperature changes and the isothermal entropy changes reach giant values,as well as the performance parameters,being comparable or even better than most barocaloric materials in literature.Moreover,pure WTR and WTR-based samples also present a faster thermal exchange than VNR,consisting of an additional advantage of using these discarded materials.Thus,the present findings evidence the encouraging perspectives of employing waste rubbers in solid-state cooling based on barocaloric effects,contributing to both the recycling of polymers and the sustainable energy technology field.

前庭诱发的肌源性电位在单侧前庭功能低下患者中的应用

目的:分析前庭诱发的肌源性电位(VEMP)在慢性头晕患者和单侧前庭功能低下患者中的表现,明确VEMP异常和病变侧别及受累结构的关系。方法:在本观察性研究中,我们对66例受试者进行了VEMP检查(短纯音刺激,强度100dB nHL,频率1 000Hz,带通滤波10～1 500Hz,刺激率4.3Hz)。根据临床表现和冷热试验,其中33例患者被诊断为单侧前庭功能低下,另外33例受试者为年龄性别匹配的对照。分析p13-n23的振幅、不对称率、潜伏期、耳间差异和阈值。统计学分析采用t检验,Shapiro-Wilks检验和Mann-Whitney检验,P<0.05有统计学意义。结果:63.63%的慢性前庭功能低下的患者存在VEMP异常,其中13例患者VEMP异常出现在前庭功能低下侧,3例患者出现在病变对侧。5例患者双侧VEMP异常。结论:冷热试验诊断为单侧慢性前庭功能低下的患者中,63.63%存在不同程度的VEMP的改变。54.54%的患者VEMP异常出现在前庭功能低下侧,24.24%的患者的VEMP异常出现在病变对侧。VEMP能够增强对单侧前庭功能低下患者的功能评价。