Extruded biocomposite films based on poly(lactic acid)/chemically-modified agricultural waste: Tailoring interface to enhance performance

In this work, a lignocellulosic filler, rice straw (RS), was thermoplasticized by acetylation modification process and compounded with plasticized poly(lactic acid) (PLA) through twin-screw extrusion process. The biocomposite films were prepared continuously by using a slit die for PLA/RS and PLA/acetylated RS (ARS) compounds. By the chemical reaction, thermoset microstructure of RS was changed to a more flexible one. Additionally, by the reaction, the interfacial adhesion of lignocellulosic filler/PLA matrix, filler hydrophobicity and PLA wettability was enhanced considerably. The miscibility of partially phase-separated PLA/poly(ethylene glycol) (PEG) mixtures was improved by adding RS-based microfillers, particularly by the acetylated RS. Compared with PLA/unmodified RS films, PLA/ARS biocomposites show better thermal stability, toughness, Young modulus and softening point, especially at certain filler loadings.

Effect of chia seed mucilage/bacterial cellulose edible coating on bioactive compounds and antioxidant activity of strawberries during cold storage

This study aimed to investigate the effect of chia seed mucilage (CSM) - bacterial cellulose nano-fiber (CNF) edible coating on bioactive compounds and antioxidant enzyme activity of strawberries. Strawberries were coated with CSM containing 0.6 and 8.0% (w/w) of CNF. The content of total phenol, flavonoids, anthocyanin, ascorbic acid, protein content, antioxidant activity and the activity of polyphenol oxidase, peroxidase, superoxide dismutase and phenylalanine ammonia-lyase enzymes were evaluated. The use of CSM - CNF edible coatings further preserved the phenolic, flavonoid, ascorbic acid and antioxidant activity of strawberries, and this effect was more evident in the CSM-coated sample containing CNF; However, the accumulation of anthocyanins in the coated samples was lower than the control sample. The activity of polyphenol oxidase and peroxidase enzymes, which lead to the degradation of phenolic compounds and brown color in the product, was also effectively controlled by the edible coating.

Investigating the relationship between tack and degree of conversion in DGEBA-based epoxy resin cured with dicyandiamide and diuron

The purpose behind this research was to determine the optimum formulation and investigate the cure kinetics of a diglycidyl ether of bisphenol-A (DGEBA)-based epoxy resin cured by dicyandiamide and diuron for use in prepregs. First, all formulations were examined by the tensile test, and then, the specimens with higher mechanical properties were further investigated by viscometry and tack tests. The cure kinetics of the best formulation (based on tack test) in nonisothermal mode was investigated using differential scanning calorimetry at different heating rates. Kissinger and Ozawa method was used for determining the kinetic parameters of the curing process. The activation energy obtained by this method was 71.43 kJ/mol. The heating rate had no significant effect on the reaction order and the total reaction order was approximately constant ( m + n ≅ 2.1 $m+n\cong 2.1$ ). By comparing the experimental data and the theoretical data obtained by Kissinger and Ozawa method, a good agreement was seen between them. By increasing the degree of conversion, the viscosity decreased; as the degree of conversion increased, so did the slope of viscosity. The results of the tack test also indicated that the highest tack could be obtained with 25% progress of curing.

HIV-1-infected T-cells dynamics and prognosis: An evolutionary game model

BACKGROUND AND OBJECTIVE

Understanding the dynamics of human immunodeficiency virus (HIV) is essential for depicting, developing, and investigating effective treatment strategies. HIV infects several types of immune cells, but its main target is to destroy helper T-cells. In the lymph nodes, the infected T-cells interact with each other and their environment to obtain more resources. According to infectivity and replicative capacity of T-cells in the HIV infection process, they can be divided into four phenotypes. Although genetic mutations in the reverse transcription that beget these phenotypes are random, the framework by which a phenotype become favored is affected by the environment and neighboring phenotypes. Moreover, the HIV disease has all components of an evolutionary process, including replication, mutation, and selection.

METHODS

We propose a novel structure-based game-theoretic model for the evolution of HIV-1-Infected CD4+T-cells and invasion of the immune system. We discuss the theoretical basis of the stable equilibrium states of the evolutionary dynamics of four T-cells types as well as its significant results to understand and control HIV infection. The results include the importance of genetic variations and the process of establishing evolutionary dynamics of the virus quasispecies.

RESULTS

Our results show that there is a direct dependency between some parameters such as mutation rates and the stability of equilibrium states in the HIV infection. This is an interesting result because these parameters can be changed by some pharmacotherapies and alternative treatments. Our model indicates that in an appropriate treatment the relative frequency of the wild type of virus quasispecies can be decreased in the population. Consequently, this can cause delaying the emergence of the AIDS phase. To assess the model, we investigate two new treatments for HIV. The results show that our model can predict the treatment results.

CONCLUSIONS

The paper shows that a structured-based evolutionary game theory can model the evolutionary dynamics of the infected T-cells and virus quasispecies. The model predicts certain aspects of the HIV infection process under several treatments.

Progressive delayed respiratory complications of sulfur mustard poisoning in 43 Iranian veterans, three decades after exposure

The most common delayed complication of sulfur mustard (SM) poisoning has been observed in the respiratory tracts. It was thus aimed to investigate the delayed respiratory complications in SM-exposed patients around 25 years before the study. Forty-three veterans with more than 25% disability of due to SM poisoning were investigated. Clinical examinations as well as pulmonary function test (PFT) were performed. High-resolution computed tomography (HRCT) of the lungs was done as clinically indicated. Triad of chronic cough, dyspnea, and expectoration were the most common symptoms that were recorded in 88.2%, 88.2%, and 64.7% of the patients, respectively. PFT abnormalities were detected in 44.18% of the patients. Restrictive pattern was the most common (41.86%), while pure obstructive pattern did not detect at all. Mixed pattern was significantly correlated with higher disability percentages among the veterans ( p < 0.001). Significant reverse correlation between the disability percentages and forced expiratory volume in 1 s/forced vital capacity ratio was obtained ( p = 0.010, r = −0.389). Air trapping was the most common abnormality in HRCTs (50%). Bronchiectasis (25%), pulmonary fibrosis (25%), and ground-glass attenuation (16.66%) were other common HRCT findings. Comparing with the previous studies on these patients, more restrictive and mixed pattern were observed. Moreover, bronchiolitis, bronchiectasis, and lung fibrosis were the main pathological findings in these patients.

Vulvar defect after pelvic trauma and its repair with reverse TRAM flap: report of a case

Vulvar defect and soft tissue loss secondary to pelvic trauma is rare. Many reconstructive procedures for large vulvoperineal defects have been described. The case of a woman with severe vulvar defect following a previous pelvic trauma and treatment with reverse TRAM flap is reported.

A unified approach for detection of induced epileptic seizures in rats using ECoG signals

OBJECTIVE

Epileptic seizure detection is a key step for epilepsy assessment. In this work, using the pentylenetetrazole (PTZ) model, seizures were induced in rats, and ECoG signals in interictal, preictal, ictal, and postictal periods were recorded. The recorded ECoG signals were then analyzed to detect epileptic seizures in the epileptic rats.

METHODS

Two different approaches were considered in this work: thresholding and classification. In the thresholding approach, a feature is calculated in consecutive windows, and the resulted index is tracked over time and compared with a threshold. The moment the index crosses the threshold is considered as the moment of seizure onset. In the classification approach, features are extracted from before, during, and after ictal periods and statistically analyzed. Statistical characteristics of some features have a significant difference among these periods, thus resulting in epileptic seizure detection.

RESULTS

Several features were examined in the thresholding approach. Nonlinear energy and coastline features were successful in epileptic seizure detection. The best result was achieved by the coastline feature, which led to a mean of a 2-second delay in its correct detections. In the classification approach, the best result was achieved using the fuzzy similarity index that led to Pvalue<0.001.

CONCLUSION

This study showed that variance-based features were more appropriate for tracking abrupt changes in ECoG signals. Therefore, these features perform better in seizure onset estimation, whereas nonlinear features or indices, which are based on dynamical systems, can better track the transition of neural system to ictal period.

SIGNIFICANCE

This paper presents examination of different features and indices for detection of induced epileptic seizures from rat's ECoG signals.

Concentrations of mercury, lead, chromium, cadmium, arsenic and aluminum in irrigation water wells and wastewaters used for agriculture in Mashhad, northeastern Iran

BACKGROUND

Contamination of water by toxic chemicals has become commonly recognized as an environmental concern. Based on our clinical observation in Mashhad, northeastern Iran, many people might be at risk of exposure to high concentrations of toxic heavy metals in water. Because wastewater effluents as well as water wells have been commonly used for irrigation over the past decades, there has been some concern on the toxic metal exposure of crops and vegetables irrigated with the contaminated water.

OBJECTIVE

To measure the concentrations of mercury, lead, chromium, cadmium, arsenic and aluminium in irrigation water wells and wastewaters used for agriculture in Mashhad, northeastern Iran.

METHODS

36 samples were taken from irrigation water wells and a wastewater refinery in North of Mashhad at four times--May 2008, March 2009, and June and July 2010. Atomic absorption spectrometry was used to measure the concentration of toxic metals. Graphite furnace was used for the measurement of lead, chromium, cadmium and aluminum. Mercury and arsenic concentrations were measured by mercury/hydride system.

RESULTS

Chromium, cadmium, lead and arsenic concentrations in the samples were within the standard range. The mean±SD concentration of mercury in irrigation wells (1.02±0.40 μg/L) exceeded the FAO maximum permissible levels. The aluminum concentration in irrigation water varied significantly from month to month (p=0.03). All wastewater samples contained high mercury concentrations (6.64±2.53 μg/L).

CONCLUSION

For high mercury and aluminum concentrations, the water sources studied should not be used for agricultural use. Regular monitoring of the level of heavy metals in water and employing the necessary environmental interventions in this area are strongly recommended.

Metal mercury poisoning in two boys initially treated for brucellosis in Mashhad, Iran

Elemental mercury (Hg) is the only metal which evaporates in room temperature and its inhalation may cause toxicity. Hg poisoning may occur by mishandling the metal, particularly in children who play with it. Wide-spectrum of the clinical presentations of chronic Hg poisoning may cause misdiagnosis, particularly when history of exposure is unknown. We report two cases of accidental Hg poisoning, which initially had been diagnosed and treated for brucellosis. The patients were two brothers (7 and 14 years old) who presented with pain in their lower extremities, sweating, salivation, weight loss, anorexia and mood changes on admission. Meticulous history taking revealed that they had played with a ball of Hg since 3 months before admission. The level of urinary Hg was 125.9 and 54.2 9 g/L in the younger and older brother, respectively (normal ≤25 g/L). The patients were successfully treated by dimercaprol and discharged in good condition 24 days after admission. These cases are being reported to emphasize the importance of acrodynia as a differential diagnosis for brucellosis in endemic areas.

The ethics of aesthetic surgery

Advances in plastic and reconstructive surgery have revolutionized the management of patients suffering from disfiguring congenital abnormalities, burns and skin cancers. The demand for aesthetic surgery has increased in recent years, as our culture has become more concerned with image and appearance. Several ethical considerations such as patient's right for informed counseling, beneficience and maleficience need to be given careful consideration.

A comparison between the results of fissurectomy and lateral internal sphincterotomy in the surgical management of chronic anal fissure

BACKGROUND

We compare lateral internal sphincterotomy as an effective treatment of chronic fissure in ano to fissurectomy, which is as an alternative surgical treatment.

METHODS

Sixty two consecutive patients were divided into two groups through sequential sampling. Thirty patients underwent fissurectomy and 32 underwent lateral internal sphincterotomy. After a median follow-up of 22 months, we compared the results of the two procedures. In addition to frequent visits on a predetermined basis, a telephone inquiry into fissure recurrence and continence status was made.

RESULTS

All patients in both groups were pain-free and without bleeding within 1 week. In both groups, urinary retention was noted in one patient. Incontinence to flatus was noted in the fissurectomy (F) group in two (6.2%) patients, but no incontinence was noted in the lateral internal sphincterotomy (LIS) group. There was one patient (3.1%) with fissure recurrence in the F group but none in the LIS group. No patient in either group was afflicted with anal stenosis or perianal infections. All wounds healed within 8 weeks. Twenty nine patients (96.6%) in the LIS group and 28 (87.5%) in the F group reported satisfactory results with their procedure.

CONCLUSION

In the surgical treatment of chronic anal fissure not responding to conservative management, LIS may be the better treatment and, perhaps, the preferable surgical technique with fewer total complications (P < 0.005).

Mixed-level orthogonal array design for the optimization of solid-phase extraction of some pesticides from surface water

An orthogonal array design (OAD), OA32(4(1) x 2(28)), was employed as a chemometric method for the optimization of the solid-phase extraction (SPE) of atrazine, diazinon, ametryn and fenthion in surface water. Seven parameters: the type of eluting solvent, type of sorbent, flow-rate of eluting solvent, sample pH, sample volume, elution volume, addition of modifier and flow-rate of water sample were studied and optimized by a mixed-level OAD. The effects of these factors and some two-variable interactions on the recovery of the pesticides were quantitatively evaluated by the analysis of variance and percentage contribution techniques. The final optimized condition was employed for the SPE of selected micro-organic pollutants from Karoun river water, south of Iran. Atrazine and ametryn were tentatively identified and determined at the 0.7 and 0.9 microg l(-1) level, respectively.