Insights into chalcone analogues with potential as antioxidant additives in diesel-biodiesel blends

Biodiesel production is one of the promising strategies to reduce diesel consumption and an important contribution to climate change. However, biodiesel stability remains a challenging problem in biofuel use in the global energy matrix. In this context, organic additives have been investigated to minimize these problems and reduce harmful emissions to comply with fuel requirement standards. In this study, we discuss a comprehensive structural description, a behavior of B15 [85% volume of diesel and 15% volume of biodiesel (B100)] stability in the presence of antioxidants (chalcone analogues), and a theoretical calculation to pave the way for clarifying and expanding the potential of title compounds as an antioxidant additive for diesel-biodiesel blends. Finally, a systematic description of the oxidation stability was undertaken using a specialized machine learning computational pySIRC platform.

Fatigue Properties of Weakened and Non-weakened Roots Restored with CAD-CAM Milled Fiber Post, Prefabricated Fiber Post, or Cast Metal Post

STATEMENT OF PROBLEM

Customized glass fiber posts using CAD-CAM technology have been suggested for restoring endodontically treated teeth. However, how weakened or non-weakened roots restored with anatomical CAD-CAM posts behave under cyclic fatigue is not clear.

OBJECTIVE

To evaluate the load-bearing capacity under fatigue (fatigue failure load [FFL], the number of cycles for failure [CFF], and survival probabilities) and fracture pattern of weakened and non-weakened roots restored with CAD-CAM fiber post and cores, metal cast-post-core, and prefabricated fiber post and resin core.

METHODS AND MATERIALS

A total of 60 crack-free bovine incisor roots (13 mm in length) with standard geometry were obtained and randomly allocated considering the factor "root condition" in two levels (weakened and non-weakened). Thus, half of the roots were weakened to obtain a wall thickness of 0.5 mm. After that, the endodontic treatment was executed, all roots embedded with acrylic resin and the specimens randomly allocated (n=10) considering the factor "post system" in three levels (CAD-CAM: CAD-CAM milled glass-fiber post and core; MBC: metallic-based post and core; and FRC: prefabricated glass-fiber post and composite resin core). The posts were luted with a dual-cure self-adhesive luting agent. Then, all teeth received a metallic crown. An initial load of 100 N at 20 Hz for 5000 cycles was applied for the step-stress fatigue test, followed by incremental steps of 50 N for 20,000 cycles each step, up to failure. A fracture pattern analysis was performed.

RESULTS

CAD-CAM fiber post (FFL: 865 N; CFF: 311,000 cycles) presented similar fatigue performance (p>0.05) to FRC (FFL: 925 N; CFF: 335,000 cycles), with 100% of repairable fractures for non-weakened roots; however, both groups presented worse performance than MBC (p<0.05; FFL: 1265 N; CFF: 471,000 cycles) which led to 100% of catastrophic failures. No statistical difference was found in fatigue performance among the three systems for weakened roots (p>0.05; FFL: 1035-1170 N; CFF: 379,000-433,000 cycles), with a high rate of catastrophic failures.

CONCLUSIONS

CAD-CAM fiber post presented similar fatigue performance to MBC and FRC approaches when restoring weakened roots. CAD-CAM was similar to FRC when restoring non-weakened roots, while MBC enhanced fatigue properties in this scenario.

QSAR-driven design, synthesis and discovery of potent chalcone derivatives with antitubercular activity

New anti-tuberculosis (anti-TB) drugs are urgently needed to battle drug-resistant Mycobacterium tuberculosis strains and to shorten the current 6-12-month treatment regimen. In this work, we have continued the efforts to develop chalcone-based anti-TB compounds by using an in silico design and QSAR-driven approach. Initially, we developed SAR rules and binary QSAR models using literature data for targeted design of new heteroaryl chalcone compounds with anti-TB activity. Using these models, we prioritized 33 compounds for synthesis and biological evaluation. As a result, 10 heteroaryl chalcone compounds (4, 8, 9, 11, 13, 17-20, and 23) were found to exhibit nanomolar activity against replicating mycobacteria, low micromolar activity against nonreplicating bacteria, and nanomolar and micromolar against rifampin (RMP) and isoniazid (INH) monoresistant strains (rRMP and rINH) (<1 μM and <10 μM, respectively). The series also show low activity against commensal bacteria and generally show good selectivity toward M. tuberculosis, with very low cytotoxicity against Vero cells (SI = 11-545). Our results suggest that our designed heteroaryl chalcone compounds, due to their high potency and selectivity, are promising anti-TB agents.

Synthesis, structural characterization and computational study of a novel amino chalcone: a potential nonlinear optical material

The interest for novel chalcone-based materials in nonlinear optics is dependent on strong second harmonic generation in organic systems.

Synthesis, characterization, and third-order nonlinear optical properties of a new neolignane analogue

This paper presents an extensive study of a new neolignane analogue using experimental and theoretical approach and brings highlights in solid state characterization and electronic properties.

Nursing home care: exploring the role of religiousness in the mental health, quality of life and stress of formal caregivers

Despite the high number of studies on family caregivers, there is little research on the impact of religiosity on formal caregiving (paid providers). We examine the role of religiousness in the mental health, quality of life and stress of nurse aides (NA) who provide care for patients in a nursing home. NA in a Brazilian nursing home were invited to participate. Because of its coping function, we hypothesized that religiousness was related to better mental health and quality of life. Linear regression was used to test this hypothesis and control for confounders. Compared with the Brazilian general population, NA scored higher on measures of religious involvement. Intrinsic religiosity was associated with better mental health and quality of life. Organizational religiosity was associated with better social functioning, better general mental health and fewer anxiety symptoms. Non-organizational religiosity (prayer), however, was associated with negative outcomes, such as higher stress, poorer general health perceptions and more anxiety symptoms. Most NA indicated that they had prayed for and with their patients. In conclusion, paid caregivers (NA) have a strong sense of religiousness, which plays an important role in many ways, including the type of care they provide, their mental health and their quality of life.

Venous compression syndromes: clinical features, imaging findings and management

Extrinsic venous compression is caused by compression of the veins in tight anatomic spaces by adjacent structures, and is seen in a number of locations. Venous compression syndromes, including Paget-Schroetter syndrome, Nutcracker syndrome, May-Thurner syndrome and popliteal venous compression will be discussed. These syndromes are usually seen in young, otherwise healthy individuals, and can lead to significant overall morbidity. Aside from clinical findings and physical examination, diagnosis can be made with ultrasound, CT, or MR conventional venography. Symptoms and haemodynamic significance of the compression determine the ideal treatment method.

(2E,4E)-1-(2-Hy-droxy-phen-yl)-5-phenyl-penta-2,4-dien-1-one

In the structure of the title chalcone, C₁₇H₁₄O₂, derived from cinnamaldehyde, the olefine group has a trans configuration. The mol­ecular conformation is stabilized by an intra­molecular O—H⋯O hydrogen-bond inter­action with graph-set motif S(6).

Peripheral neuropathy and neurological disorders in an unselected Brazilian population-based cohort of IBD patients

BACKGROUND

Several neurological disorders have been described in inflammatory bowel disease (IBD) patients, but their exact frequency is unknown.

METHODS

We prospectively studied the prevalence of neurological disorders (especially peripheral neuropathy) in a group of 82 patients with Crohn's disease (CD, n = 31) or ulcerative colitis (UC, n = 51) from 2 Brazilian tertiary care university clinics and followed them through a period of at least 1 year. All patients were interviewed and had complete neurological evaluations.

RESULTS

Large-fiber sensory or sensorimotor polyneuropathy (PN) was observed in 16.1% of the CD and 19.6% of the UC patients. PN was usually mild, predominantly symmetric, and distal with axonal involvement. One patient had demyelinating PN at the diagnosis of CD. Mild carpal tunnel syndrome was common in female UC patients. Sensory symptoms without electromyography abnormalities, suggestive of small-fiber neuropathy or subclinical myelopathy, affected 29% and 11.8%, respectively. After excluding other known etiological or contributory factors for PN, 13.4% of the IBD patients had otherwise unexplained large-fiber or small-fiber PN (7.3% with large-fiber SM PN). Nondebilitating headache was the most common neurological complaint. Three patients had ischemic strokes, 5 were epileptic, and 1 transient chorea.

CONCLUSIONS

Neurological disorders, especially PN, are common in our Brazilian cohort of IBD patients. They are diverse, multifactorial, and more common in women. Despite the mild phenotype in most cases, attention should be given by the general practitioner and gastroenterologist since they are frequently undiagnosed. Further studies are necessary to confirm these findings in populations with different genetic and nutritional backgrounds.

Proregion of Acanthoscelides obtectus cysteine proteinase: a novel peptide with enhanced selectivity toward endogenous enzymes

Acanthoscelides obtectus is a devastating storage insect pest capable of causing severe bean crop losses. In order to maintain their own development, insect pest larvae feed continuously, synthesizing efficient digestive enzymes. Among them, cysteine proteinases (CPs) are commonly produced as inactive precursors (procysteines), requiring a cleavage of the peptide proregion to become active. The proregion fits tightly into the active site of procysteines, efficiently preventing their activity. In this report, a CP cDNA (cpao) was isolated from A. obtectus midgut larvae. In silico studies indicated that the complete CP sequence contains a hydrophobic signal peptide, a prodomain and a conserved catalytic region. Moreover, the encoding cDNA contains 963bp translating into a 321 residue protein, CPAo, which was expressed in E. coli, fused with thioredoxin. Enzymatic assays using the recombinant protein revealed that the enzyme was catalytically active, being able to cleave the synthetic substrate Z-Phe-Arg-7-AMC. Additionally, this report also focuses the cpao propeptide (PCPAo) subcloning and expression. The expressed propeptide efficiently inhibited CPAo, as well as digestive CP of other bean bruchids. Little or no activity was found against proteolytic enzymes of two other coleopterans: Rhyzopertha dominica and Anthonomus grandis. The data reported here indicate the possibility of endogenous propeptides as a novel strategy on bruchids control, which could be applicable to bean improvement programs.

Effect of hyperbaric oxygen on liver regeneration in a rat model

Hyperbaric oxygen therapy is a treatment that has been gradually implemented for the treatment of several pathologic conditions. The present study evaluated the effect of hyperbaric oxygen therapy for hepatic regeneration and its relationship to mitochondrial function. Male Wistar rats underwent partial hepatectomy (70%) and subsequently underwent two sessions of hyperbaric oxygen (90 minutes each, at a pressure of 2 ATA). The animals were sacrificed at 24 and 48 hours after surgery. Hepatic regeneration was evaluated by the dry weight of the remaining liver, the hepatic regeneration rate, the hepatic DNA content, and the hepatocyte proliferation rate using the "proliferating cell nuclear antigen" (PCNA) content. Function of the mitochondria was evaluated by its oxygen consumption during respiratory states 3 and 4, its respiratory control ratio (RCR), its membrane potential, as well as its osmotic swelling. We also measured serum levels of aminotransferases. The results revealed an increased dry weight of the remaining liver, regeneration rate, and DNA content at 24 and 48 hours after hepatectomy. The hepatocyte proliferation rate was significantly higher among animals treated with hyperbaric oxygen therapy at 48 hours after surgery. There was no significant difference in aminotransferase levels. Mitochondrial respiration revealed reduced oxygen consumption in state 3 after 48 hours. These results demonstrated that hyperbaric oxygen stimulates hepatic regeneration at 24 and 48 hours after 70% hepatectomy. The effect of hyperbaric oxygen on hepatic tissue occurs without tissue damage and protects mitochondria after 48 hours.

Therapeutic Effect of Hyperbaric Oxygen in Hepatic Artery Thrombosis and Functional Cholestasis After Orthotopic Liver Transplantation

Among the postoperative complications, hepatic artery thrombosis can occur in up to 10% of adult orthotopic liver transplants and intervention is indicated when this occurs within 30 days by retransplantation. Primary graft dysfunction, which can occur in up to 30% of the cases and is another potential complication, although reversible, has a relatively high mortality rate. Hyperbaric therapy, an efficient mode of tissue oxygenation, is being used in an increasing number of clinical situations. We report here two cases where hyperbaric oxygen therapy greatly benefited patients with complications after orthotopic liver transplantation: one with hepatic artery thrombosis and the other with primary graft dysfunction. Both patients showed rapid clinical recovery with gradual reduction of liver and canalicular enzymes soon after commencing hyperbaric oxygen therapy.

Position-dependent levitation of the dominant arm after left parietal stroke: An unreported feature of posterior alien limb syndrome?

We describe a patient with an unreported feature of posterior alien limb phenomenon characterized by position-dependent levitation of the dominant arm exacerbated by tactile stimulation and associated with low-amplitude tremor of the fingers of the right hand in addition to a sensation of strangeness in the arm, secondary to a left parietal stroke.

Gastrointestinal bleeding during liver transplantation--report of two cases

A few authors have reported, especially as intraoperative complications, gastrointestinal hemorrhage related to liver transplantation. The aim of this study was to show two cases of gastrointestinal hemorrhage, which occurred during surgery. The first patient was male, 46 years old, with viral hepatic cirrhosis. He had previously presented two episodes of digestive bleeding. Upper digestive endoscopy showed esophageal gastric varices. During the hepatectomy there was bleeding inside the nasogastric tube associated with severe hemodynamics instability without other sources of bleeding. Intraoperative endoscopy evidenced bleeding gastric varices. Gastrectomy was carried out and the varices were tied. The piggyback technique was used in the liver transplantation. The surgery was concluded without problems and in the following four and a half years his condition has evolved well. In the second case, the patient was aged 17, female, with autoimmune hepatic cirrhosis. She had previously presented one episode of digestive bleeding. Intraoperative endoscopy showed median esophageal varices. During the anesthetic induction she presented an episode of hematemesis. A Sengstaken-Blakemore balloon was introduced. The transplant was performed without further problems. Her case has been followed for 14 months in the outpatients' clinic with a good postoperative course. To sum up, gastrointestinal hemorrhage can be due to portal hypertension during the liver transplantation and must be treated quickly. In these cases the surgery must be ongoing.

Fou rire prodromique and history of pathological laughter in the XIXth and XXth centuries

Fou rire prodromique (prodrome of crazy laughter) is a rarely described nosological entity. In 1903, Charles Féré, a French neurologist, introduced the term fou rire prodromique to describe pathological laughter heralding an apoplectic event. He was also among the first to describe gelastic epilepsy. His description was influenced by Edouard Brissaud, who supported the existence of a thalamic center for laughter regulation and suggested that spasmodic laughter and crying were due to lesions of the faisceau psychique (anterior internal capsule) or to irritation of the faisceau géniculé (corticobulbar tract). One hundred Years later, we review the evolution of the theories about pathological laughter and crying from Charles Bell in the early XIXth Century, up to the seminal works of Kinnier Wilson and James Papez and the era of modern neuroscience.

Cardiovascular Control After Spinal Cord Injury

Spinal cord injury (SCI) leads to profound haemodynamic changes. Constant outflows from the central autonomic pattern generators modulate the activity of the spinal sympathetic neurons. Sudden loss of communication between these centers and the sympathetic neurons in the intermediolateral thoracic and lumbar spinal cord leads to spinal shock. After high SCI, experimental data demonstrated a brief hypertensive peak followed by bradycardia with escape arrhythmias and marked hypotension. Total peripheral resistance and cardiac output decrease, while central venous pressure remains unchanged. The initial hypertensive peak is thought to result from direct sympathetic stimulation during SCI and its presence is anaesthetic agent dependent. Hypotension improves within days in most animal species because of reasons not totally understood, which may include synaptic reorganization or hyper responsiveness of alpha receptors. No convincing data has demonstrated that the deafferented spinal cord can generate significant basal sympathetic activity. However, with the spinal shock resolution, the deafferented spinal cord (in lesions above T6) will generate life-threatening hypertensive bouts with compensatory bradycardia, known as autonomic hyperreflexia (AH) after stimuli such as pain or bladder/colonic distension. AH results from the lack of supraspinal control of the sympathetic neurons and altered neurotransmission (e.g. glutamatergic) within the spinal cord. Despite significant progress in recent years, further research is necessary to fully understand the spectrum of haemodynamic changes after SCI.

Neural mechanisms involved in the delay of gastric emptying of liquid elicited by acute blood volume expansion in awake rats

We have previously reported that acute blood volume expansion in awake rats delays the gastric emptying of a liquid meal, using the phenol red method. In this study we attempted to investigate the neural mechanisms involved in this phenomenon. Blood volume expansion, due to Ringer-bicarbonate infusion up to a volume equivalent to 5% of body weight, decreased the gastric emptying of a liquid meal by half (38.2 +/- 1.8 vs 18.7 +/- 3.2%, P < 0.05). The blood volume expansion effect on gastric emptying of liquid was prevented by separate pretreatments, consisting of subdiaphragmatic vagotomy or i.v. injection of hexamethonium (20 mg kg-1) or yohimbine (3 mg kg-1). Intravenous injection of atropine (0.5 mg kg-1), guanethidine (10 mg kg-1), L-NAME (3 mg kg-1), prazosin (1 mg kg-1) or propranolol (2 mg kg-1) did not prevent the blood volume expansion effect on gastric emptying. Bilateral adrenalectomy or coeliac ganglionectomy were also ineffective. The results indicate that blood volume expansion decreases gastric emptying of liquid through vagal-dependent pathways, sensitive to hexamethonium and yohimbine. Evidence for the participation of the peripheral sympathetic nervous system was not found.

Erythrocruorin of Glossoscolex paulistus (Oligochaeta, Glossoscolecidae): modulation of oxygen affinity by specific antibodies

1) The Soret region absorption spectrum of erythrocruorin (ERC) obtained from Glossoscolex paulistus, shows that oxy-ERC has a maximum absorption peak at 416 nm while the deoxy-ERC from has a maximum at 427 nm. 2) In the presence of a specific antiserum (anti-ERC) and of anti-ERC immunoglobulin G raised in rabbits, there is a deviation to low wavelengths in the maximum absorption peak of deoxy-ERC while for the oxy form a red-shift is noticed. These shifts accompanied an increased affinity of the hemeprotein for oxygen, possibly because of changes in the overall macromolecular conformation. 3) A decrease in the oxygen affinity of erythrocruorin is observed when large amounts of non-specific serum are used. The same effect is observed in the presence of serum albumin, probably as a result of non-specific binding between the albumin and erythrocruorin. 4) The fluorimetric titration of erythrocruorin with anti-ERC Fab fragments results in a decrease in the intrinsic tryptophan fluorescence of the hemeprotein, a response indicative of a modification in the ERC's quaternary structure.