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Dec 2023 DOI 10.14302/issn.2690-4829.jen-23-4799
Polymer electrolyte membrane (PEM) technologies hold promise for sustainable energy solutions, yet pinhole-related challenges persist. Our research introduces a novel biohybrid approach to self-healing, enhancing multiple healing cycles with minimal membrane disruption. Initial steps involve immobilizing enzymes on a polymeric membrane. This study establishes the immobilization process and analytical framework through enzyme immobilization on polypropylene. Applicability and stability are investigated, laying groundwork for potential Nafion™ applications and advancing climate neutral energy. Qualitative analysis employs colorimetric p-NPA assay on polypropylene-immobilized lipase from Candida rugosa (CRL) and Lipase B from Candida antarctica (CALB). Both enzymes hold their temperature optimum at 50°C which is increased by 10°C via immobilization. Diisopropylcarbodiimide (DIC) is optimal for immobilization. Synchronous enzyme and DIC addition is advantageous. After 8 reuse cycles, immobilized enzymes retain 54.3% residual activity. Immobilizates exposed to PEM fuel cell conditions show better stability due to covalent immobilization than free CRL. Yet, declines occur under stressors like 60 °C and concentrated alcohol. Immobilizates remain resilient at pH 3 and under oxidizing as well as reducing conditions constituted by varied gas atmospheres. Considering PEM fuel cells' operational range, in-depth investigations across conditions are vital. Future studies target long-term PEM fuel cell lifespans, focusing on extremophilic enzymes or modifications for high-temperature stability. Subsequently, the transferability of the immobilization method to Nafion™ shall be deliberated based on the outcomes.
Jun 2023
The increasing demand for environmentally-friendly materials has led to a surge in research on the production of biodegradable polymers. In this study, we investigate the synthesis of a biodegradable polymer by graft copolymerization of gum Arabic (GA) and polyethylene glycol (PEG). GA, a natural polysaccharide and PEG, a synthetic water-soluble polymer, were used as the backbone and graft monomer, respectively. The graft copolymerization was carried out using benzoyl peroxide as an initiator and performed under nitrogen atmosphere. The resulting polymer was characterized by Fourier transform infrared (FTIR) spectroscopy, Xray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The FTIR spectra confirmed the formation of the graft copolymer, and TGA analysis showed that the copolymer had higher thermal stability than GA. The DTA thermograms indicated two thermal events. The evaporation of water and organic polyethylene glycol components was measured, and the first mass loss was due to the loss of adsorbed and structural water in the gum Arabic, which occurred between 31.87 and 180°C, while the second, corresponding to the pyrolysis of polyethylene glycol functional groups and polysaccharide decomposition, resulted in a 70% mass loss. SEM morphological analysis of gum Arabic showed aggregates of high irregularity in particle shape. The cracks and holes obtained in the Gum Arabic micrograph disappeared from the new gum Arabic-graft-polyethylene glycol, leaving a smooth surface with scattered particles in the image, which was due to the grafting copolymer. From the XRD patterns, the percentages of the amorphous and crystalline phases were determined. The results show that gum Arabic has a 78% degree of crystallinity, whereas gum Arabic-graft-polyethylene glycol has the lowest value of 51%. Biodegradation activity was observed using the fungus Aspergillus flavus on different days on gum Arabic-g-polyethylene glycol. The results clearly showed inhibition zones with a change in the state of the copolymer from solid to liquid from days 8 to 14. These results indicate that the GA-PEG copolymer has potential as a biodegradable material for use in various applications, such as packaging, agriculture, and medical industries.
Sep 2020 DOI 10.14302/issn.2835-513X.ijl-20-3454
We investigated physical steric and thermal stability effects induced by cholesterol and polyethylene glycol (PEG) in liposomes encapsulated with riboflavin. The composition of liposome was varied systematically to decipher the individual and combined effects of cholesterol and PEG on the stabilization of liposomes, specially the photopolymerizable liposomes for their potential applications in photo-treatments. Our results indicate that inclusion of PEG in the lipids enhances the steric stabilization by adopting a brush-like regime that prevents the agglomeration of encapsulated liposomes. A mechanistic differential scanning calorimetry studies reveal the phase transitions and enthalpy changes in the lipid bilayer due to the presence of cholesterol suggesting its role in regulating membrane fluidity. Supporting in- vitro studies confirm the efficacy of PEGylated formulations encapsulating riboflavin.
Jul 2016 DOI 10.14302/issn.2473-1005.jdoi-16-1080
When a composite resin restoration is photopolymerized, a considerable amount of heat can be produced, potentially causing pulpal injury. Objective: Evaluate the influence of the type of light source and remaining dentin thickness on the temperature increase in the pulp chamber while curing composite resin restorations. Material and Methods: Ninety-six tooth fragments obtained from bovine incisors were divided into groups/subgroups (n=12), according to the light source (LED and halogen light) and remaining dentin thickness (3.5, 3, 2, and 1mm). Class I cavities were prepared and restored with a composite resin. A temperature increase was obtained during photopolymerization of the adhesive and each composite increment. Data were analyzed using ANOVA and Fisher’s Test (α=5%). Results: LED promoted higher temperature increments when compared with the halogen light. Temperature levels were the lowest for 3.5mm-thick and the highest for 1mm-thick remaining dentin. Levels registered during the photopolymerization of each composite increment were superior for LED. Conclusions: Both light sources result in temperature increases above 5.5°C. Additionally, the remaining dentin thickness of 1mm promoted the largest temperature increase.
Jun 2016 DOI 10.14302/issn.2473-1005.jdoi-16-1079
The present study evaluated in vitro the influence of two light sources in composite resin microhardness in different distances of photopolymerization. Two light sources were used (halogen, LED) to photopolymerize the composite resin (Filtek Z250; Esthet-X) in different distances surface (1,2,3 and 4 mm), totalizing 96 specimens. Microhardness Knoop test’ were made on the specimens top and bottom faces. The data were submitted to ANOVA and Fisher tests (α=5%). It was observed a significant difference (p<0.05) between the resins, in which Z250 presented higher values than Esthet-X (p<0.05). There was difference also between the halogen and LED, where the halogen showed better results with Z250 and the LED with Esthet-X. The top surface presented better value (p<0.05) compared to the bottom surface. It can be concluded that the light source and the photopolymerization distance influenced the composite resin microhardness, which it had lower proprieties with increase of the photopolymerization distance.
Nov 2014 DOI 10.14302/issn.2377-2549.jndc-14-391
Oxidation of 1-Proponol, 1-butanol 1-Hexanol and benzyl alcohol using chloromethylated polystyrene (6% Cross link) DMG (Dimethylglyoxime) copper complex or Poly(S-DVB)-DMG-M Where M= Cu) as catalyst and tert.butylhydroperoxide(TBHP) as oxidant, was studied. The polymer supported Cu Complex was characterized by some physicochemical and spectroscopic methods like elemental analysis IR Scanning electron micrographs (SEM). In the oxidation of 1-propanol, 1-butanol, 1-hexanol and benzyl alcohol. It was found that Product yield of these alcohols corresponding the order 1-Butanal >1-hexanone >Benzyldehyde > 1-Propanone. Kinetic data indicates that catalyst could be recycled without significant degradation of polymer
Oct 2023 DOI 10.14302/issn.2641-4538.jphi-23-4622
The Ortho-poxvirus virus, which causes monkey pox, is a member of the Poxviridae genus. It was initially found in primates. In 1970, the Democratic Republic of the Congo reported the first instance of monkey pox. From there, it spread to a number of countries both inside and outside of Africa. There are two genetic varieties of monkey pox, which have been spread to people through respiratory droplets, and touch with objects contaminated by an affected person and consequently is often encountered in work situations. Among the countries with the worst effects are Nigeria and the Democratic Republic of the Congo. Non-human primates, rats, squirrel, and or mice are just a few of the creatures that can become infected by monkey pox. Although the origins of monkey pox infections are unknown, rodents from Africa and non-human primates like monkeys may contain the viruses and infect humans. Monkey pox is more likely to naturally infect rodents. Monkey pox has symptoms and lesions that are difficult to distinguish from smallpox in its clinical manifestations. Fever, chills, migraines, tiredness, tonia, swollen lymph nodes, back pain, and myalgia are some of the clinical symptoms of monkey-pox. A few examples of diagnostic tests include immune-fluorescent antibody assays, enzyme-linked immune-sorbent assays, and real-time polymerase chain reactions. A specialized vaccine that offers complete protection against by them on key-pox virus exists, yet there is no specific therapy for human monkey infection and interaction with the vaccinia virus. Smallpox vaccination can give cross-immunity with partial protection against infection and a reduction in symptom severity. Unfortunately, community health effects in the view of one health approach has not been addressed in vast. Therefore, the objectives of this review paper are to discuss the community health effects of monkey pox and to emphasize the role of one health approach against monkey pox.
Oct 2023 DOI 10.14302/issn.2575-1212.jvhc-23-4532
Camels are a significant source of income for nomadic populations in many developing countries, including Ethiopia. Camels are well adapted to dry and semi-dry regions, providing income, food security, and transportation. However, camel production and productivity are constrained by infectious diseases, such as brucellosis, which is a highly infectious bacterial disease that affects camels and humans worldwide. Brucellosis causes significant economic losses due to abortion, low herd fertility, and decreased milk production. In Ethiopia, the prevalence of camel brucellosis varies depending on factors related to the host, agent, climate, and management system, with a reported prevalence ranging from 0.5% to 11.9%. Accurate diagnosis of camel Brucellosis is essential for herd-based screening of animals. Although culturing the pathogen is the preferred method for diagnosis, serological tests such as Rose-Bengal plate test (RBPT), Enzyme-linked immunosorbent assay (ELISA), and Complement fixation test (CFT) and polymerase chain reaction (PCR) assays have been developed. Implementing effective diagnosis and surveillance systems to control the spread of brucellosis in animals and humans is very important, on top of awareness campaigns, vaccination programs, and suitable laboratory establishment recommended. Continued research is essential to maintain the health and productivity of camel populations, particularly in pastoral areas where camels play a significant role in the livelihood of communities. Therefore, the present paper views the seropositive prevalence and potential risk factors associated with camel brucellosis in Ethiopia.
May 2023 DOI 10.14302/issn.2575-1212.jvhc-23-4521
Background The emergence and spread of carbapenem-resistant gram-negative bacteria pose a serious threat to human health. Currently, little is known about the molecular mechanisms underlying carbapenem -resistance and their prevalence among APEC in Egypt. The aim of this study was to detect APEC in clinically diseased broiler chickens collected from broilers farms located at Dakahalia governorates, asses their virulence –associated genes, detect the antimicrobial susceptibility of recovered isolates and to detect genes encoding carbapenemase resistant. Methods A total of 100 organ tissue samples subjected to conventional culture technique for isolation of E. coli. The confirmed E. coli were subjected to disc diffusion method for detection their susceptibility to antimicrobials. Polymerase chain reaction (PCR) was used for detection of APEC virulence genes (hlyA, iutA, ompT, iss, iroN) and six carbapenem- resistant genes namely, blaIMP, blaVIM, blaKPC, blaOXA-48 blaGES and blaNDM,. Results Forty isolates were confirmed to be E. coli among them, three or more APEC virulence- genes were detected from all isolates. The hlyA gene was detected in 90% (36/40), iroN in 95% (38/40), ompT in 97.5% (39/40), iutA in 92.5% (35/40) and iss was detected in 95% (38/40) of APEC isolates The tested isolates exhibited a remarkable resistance to ampicillin (97.5%), cefuroxime (92.5%), clindamycin (90%), chloramphenicol (62.5%), doxycycline (45%), amikacin (25%) and ciprofloxacin (12.5%). While, the retrieved isolates displayed 100 % sensitivity against imipenem, meropenem, ertapenem, ceftazidime and colistin. Concerning carbapenemase-encoding genes, blaIMP, blaVIM, blaKPC, blaOXA-48, blaGES couldn’t be detected among the E. coli isolates, while, blaNDM was confirmed in three isolates . Conclusion The detection of NDM as one of the carbapenem resistant genes reveals that the resistant strains are not only capable of infecting humans, but that carbapenams- resistant E. coli (CREC) has also started to pose a threat to poultry farm and other livestock animals. This may give rise to worries that these food-carrying creatures could infect humans or colonize them.
Jul 2022 DOI 10.14302/issn.2691-6622.ijar-22-4221
Cyanobacteria are considered as one of the important group of organisms having significant ecological, industrial, and biotechnological importance. Cyanobacteria have gained a lot of atten ion in recent years because of their potential applications in biotechnology. This review presents an overview of uses of cyanobacteria in industry agriculture, environment pharmaceutical and medicinal roles and to provide future prospects of the field of cyanobacteria biotechnology. Nowadays cyanobacteria have gained attention researchers because of their various potential applications such as food and feed pharmaceutical industries in medicine, in bioremediation, soil conditioning, as biopolymers, bio adhesives, bioenergy and biofertilizers. Due to presence of wide spectrum of bioactive compounds cyanobacteria has possesses antiviral, antibacterial, antifungal and anticancer activities. Several strains of cyanobacteria are also rich in food supplements. Further nitrogen fixing and soil conditioning capacity of cyanobacteria attracted researchers. Recent studies have also shown that cyanobacteria have capability to degrade environmental pollutants and are also being used as a promising source of alternative energy. Cyanobacteria has also its limitations through bloom production it influnces on the nutrient availability and usage of phytoplankton plants. This review is an effort to forward the valuable information about the qualities of cyanobacteria and their potential role in solving the agricultural and environmental problems for the future welfare of the planet.Thus more efforts should be made in search of more potential strains of cyanobacteria to ensure maximum production of the desired products.
Dec 2021 DOI 10.14302/issn.2575-1212.jvhc-21-4034
In bovine tuberculosis (bTB), cellular, humoral, or both types of immune responses have been observed. The purpose of this study was to examine the immune status of tuberculous cows based on the differential cytokine gene expression associated with Th1 (IFN-γ, IL-2), or Th2 (IL-4, IL-10) responses. Twenty-three (23) cows belonging to a dairy herd located in a rural region of the State of Hidalgo, México, were selected for the study. Single Intradermal Comparative Cervical Tuberculin (SICCT) Test, Interferon-Gamma (IFN-γ) Release Assay (BOVIGAM), and Enzyme-Linked Immunosorbent Assay (ELISA) were used for detection of cattle infected by M. bovis. Thirteen cows were positive to all the tests (Group 1); ten cows were positive only to ELISA (Group 2), and the remaining Group (Group 3, control) included cows negative to all the tests. Peripheral blood mononuclear cells (PBMC) from animals were in vitro stimulated by bovin purified protein derivative (PPD), avian PPD, and Concanavalin A (Con A) mitogen for 72h. Changes in the levels of expression of mRNA of the respective cytokines was measured by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) using β-actin gene as internal control. In group 1, PPD bovis and Con A-stimulated cells exhibited high production of IFN-γ, IL-2 and IL-4, but not IL-10. In contrast, PPD avium-stimulated cells displayed a low production of cytokine transcripts. In group 2, cells showed a significant production of IL-10 in response to bovine PPD (P< 0.001). In the control group, a high production of IFN-γ and IL-2 was observed only in Con A-stimulated cells. Post-mortem examinations in animals of group 1 showed slight and medium lesions in lymph nodes, whereas in group 2, the lesions were more extensive. Results indicate differences on gene expression levels of cytokines considered to determine balance in Th1/Th2 response among the evaluated groups. In addition, high levels of antibodies against M. bovis and high IL-10 expression in PBMC together are indicators of progressive bTB when both tuberculin test and IFN-γ assay are negative in tuberculous anergic cattle. Inclusion of serology and IL-10 cytokine expression in in the diagnosis checklist improves detection of infected cattle to help control bovine tuberculosis.
Sep 2021 DOI 10.14302/issn.2639-3166.jar-21-3955
In the cultivation of vines the risk of hail appears to be increasing with the ongoing climate change. The use of protective plastic nets is spreading, but there is little knowledge on the additional processing costs and on the phenological and qualitative consequences, moreover, as depending on different colors of the nets. Thus, a randomized trial was carried out in Nebbiolo, a wine of great aging, testing three plastic anti-hail nets colored in green, gray and black. Results showed that 24% more-time was necessary for the canopy management practices under the nets. The black nets advanced the ripening process, with a berry weight decrease of about 13%. A significant decrease in the seed number per berry was observed under the black nets (-45%), while a rise (+102%) was observed under the green and gray nets with a parallel increase in the pH of the juice (+13%) and in malic acid (+28%) under the green nets. The berry skin did not show any significant differences in polyphenol and anthocyanin profiles, while the plants that matured in the upper part of the vineyard showed higher level in the berry skin extractable flavan-reactive to vanillin, and total polyphenol. On the other hand, in the seeds grown under green nets an increase in the extractable polyphenol compounds was observed, sign of a delay in seed ripening, with a higher tannin polymerization ratio, preserving the malic acid, and decreasing the acidity of the berry. In conclusion, the use of colored green may be a useful tool against excessive microclimatic warming and / or irradiation. The field internal variability affects much more the ripening dynamics than the nets used. A second aim was to develop a smart NIR SCiOTM model for polyphenols and the results were in line with the favorable expectations, providing R2 predictions of about 0.74 from the skin and 0.81 from the seeds.
Feb 2021 DOI 10.14302/issn.2328-0182.japst-21-3700
Objectives The present study addresses evaluation of acacia-guar gum combination as an enteric former for tablet coating aiming to add knowledge on how develop the ability of enteric forming ability of acacia-guar combination. Methods Five formulations of enteric coating solution incorporating guar gum as delayed release polymers along with film coating material acacia gum followed by CMC and glycerin as plasticizer and coloring agents were prepared to coat placebo tablet cores. Different enteric coating formulations organized in different acacia : guar gum ratios as 1:1, 1:2, 1:3, 1:4 and 1:6 were sprayed on placebo tablets surface resulted different delayed coated tablets (F1,F2,F3,F4 &F5) respectively. General appearance and physical parameters were evaluated of each. Enteric coated tablets that revealed promising properties were subjected to accelerated stability study for 3 months to explore the influences of physical aging on tablet coat properties. Results Physical parameters of enteric coated tablets post coating within the range of pharmacopeia specification. The disintegration test was carried out in pH 1.2 and pH 6.8 at 37ºC. F1, F2 and F3 enteric tablets disintegrated immediately with no acid resistance compared F4 and F5 enteric tablets showed good acid resistance coat with smooth tablet surfaces and no coat defects. F5 formula contain acacia: guar gum as 1:6 ratio showed delayed release for 30min in pH 1.2 and 15min in phosphate buffer. The study statistically analyzed and concluded that, an efficient and stable acacia-guar enteric coat is achievable with no effect on tablets physical parameters. Guar gum at 60% as a delayed tablet coating material capable of protecting the tablets core from being released in acidic media and be release in the alkaline buffer as well as stable coat under accelerated storage for three months.
Nov 2020 DOI 10.14302/issn.2689-2855.jan-20-3616
The composites of Cu, Carbonyl iron (CI), carbon nanofiber (CNF), graphite nanoflake (GNF)/polypyrrole (PPy) and [(Cu-CI-CNF-GNF) 0.5-PAA]-PPy0.5 were synthesized via different methods by in-situ polymerization on the surface of nanoparticles (NPs) with core-shell structure. This paper describes a method for polyacrylic acid (PAA) coating of NPs in aqueous solution. Then PPy coating was performed by template polymerization on NPs-PAA. Morphology, magnetic and conductivity properties were observed via scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and four probe method, respectively. The microwave characterization of nanocomposite was evaluated through arch test based on a network analyzer. The PPy nanocomposites possessed the excellent microwave multi absorbers properties in 2-18 GHz. It was also found that nanocomposites with 50% w/w and light weight exhibit good microwave absorbing properties in 2-3 GHz and 5-14 GHz frequency, so can be used to cellphone, radio frequency and radar shielding.
Mar 2020 DOI 10.14302/issn.2374-9431.jbd-20-3195
Purpose The goals of the present study were to assess the genotypic and allelic distribution of Bsm-I (rs1544410) and Apa-I (rs7975232) polymorphisms of the vitamin D receptor (VDR) gene in coronary artery disease (CAD) patients in comparison to control patients of the same age without CAD and to determine whether these gene variants are associated with dyslipidemia. Materials and Methods Based on a case-control design, 302 hospitalized patients with CAD and 194 people of comparable age without CAD were enrolled in the study. The BsmI and ApaI polymorphisms of VDR gene were studied using polymerase chain reaction followed by restriction analysis. The allele digested by the restriction enzyme was denoted by a lower letter, whereas that not digested was indicated by a capital letter. Determination of the level of vitamin D and immunoreactive insulin in the blood serum was carried out using the immuno-enzyme method. Results The bb genotype of Bsm-I VDR gene polymorphism was detected more often in patients with CAD than in the comparison group with an increased risk of CAD by 1.52 times (p=0.006, OR=1.52(1.05÷2.2). The level of HDL cholesterol was higher in CAD patients − carriers of BB genotype compared to its level in Bb genotype carriers and bb genotype carriers (1,13±0,05 mmol/l, 1,01±0,03 mmol/l, 1,02±0,03 mmol/l respectively, p<0,05). The level of vitamin D was higher in patients with BB genotype compared to its level in bb genotype carriers (45.12±3.73 nmol / l and 34.16±1.95 nmol/l respectively, p=0.008). The occurrence of a allele of Apa-I VDR gene polymorphism was higher in patients with CAD than in the control group (p=0.02, OR=1.21(0.93÷1.57). HDL cholesterol level was higher in CAD patients - AA genotype carriers compared with carriers of Aa and aa genotypes (1.18±0.08 mmol / l, 1,02±0.02 mmol / l and 1.01±0.03 mmol/l respectively, p<0,05). Immunoreactive insulin level was significantly higher in CAD patients – aa genotype carriers. No differences in LDL cholesterol and triglycerides were found. Vitamin D level was lower in CAD patients - Aa and aa genotype carriers (33,8±33,9 nmol/l ,p=0,02 and 24,7±4,9 nmol/l, p=0,05 respectively in comparison to vitamin D level = 43,3 ±4,2 nmol/l in AA genotype carriers). Conclusion The bb genotype of Bsm-I VDR gene polymorphism is associated with an increased risk of CAD. A carriage of b allele in CAD patients is associated with lower level of vitamin D and HDL cholesterol. A carriage of a allele of Apa-I VDR gene polymorphism in CAD patients is associated with lower level of vitamin D and HDL cholesterol.
Dec 2019 DOI 10.14302/issn.2326-0793.jpgr-19-3114
Background During the last two decades, the polymorphism of Angiotensin-Converting Enzyme (ACE) gene has been extensively studied among different human populations. In humans, several studies have shown the relationship between this polymorphism and the risk of many serious diseases with a heavy burden of health in developing countries. After analyzing the polymorphism in the population, the present study was also concerned with the investigation of an eventual association between hypertension, stroke, cancer prostate and I/D polymorphism of the ACE gene. Materials and Methods Our study population included 163 Baka (pygmy) and 158 Fang (Bantu) from Gabon to evaluate the polymorphism in the country. Concerning the diseases, we included 105 patients and 120 controls for hypertension, 37 patients stroke matched with 50 controls and 97 patients with prostate cancer were recruited. All participants in the study were genotyped for the ACE I/D polymorphism obtained by polymerase chain reaction amplification on genomic DNA. Results Our analysis showed that the ACE D allele DD genotype frequencies were highest of all the data so far in human populations. We obtained a frequency of 0.138 for I allele and 0.862 for D allele among pygmy and the frequencies of 0.313 and 0.687 respectively for the I and D alleles. This difference was significant (p<0.05). In patients, we revealed the predominance of D allele and DD genotype for hypertension (0.27 for I allele and 0.73 for D allele), for stroke (0.15 for I allele and 0.85 for D allele) and 83% of individuals with cancer prostate carry the D allele. D allele and DD genotype are associated with risk to hypertension whereas allele I seem protective at the occurrence of stroke (p<0.05 between healthy and controls). Conclusion We show that the D allele and DD genotype were higher in this population. Also theses two signatures may be associated at genetic risk of hypertension, stroke and prostate cancer in this country deprived of human resources for quality care of many patients.
Jun 2019 DOI 10.14302/issn.2374-9431.jbd-19-2788
Purpose The goal of this study is to determine the association of L162V polymorphism of PPAR-alpha gene, A603G polymorphism of tissue factor gene and the risk of coronary heart disease development in Russian population. Materials and Methods A clinical and genetic study of 414 patients with CHD and 220 people of comparable age without CHD which amounted to a control group was performed. L162L and L162V genotypes of L162V polymorphism of PPAR-α gene, A603A, A603G and G603G genotypes of A603G polymorphism of tissue factor gene were determined by polymerase chain reaction followed by restriction analysis. Results A carriage of L162V genotype and V allele of PPAR-α gene was associated with an increase risk of CHD in 2,13 times (L162V genotype) and in 2,21 times (V allele), with an increase in risk of CHD before the age of 45 years in 4,68 times (L162V genotype) and in 3,88 times (V allele). Significantly higher in patients with CHD compared with the general population and in patients with a carriage of G603G genotype and G allele of tissue factor gene was associated with the increase of CHD risk in 2,68 times (G603G genotype) and in 4,37 times (G allele), occurred more frequently in patients with debut of disease at age of 45 years and younger. The level of tissue factor was significantly higher in patients with CHD – carriers G603G genotype compared with carriers A603A genotype (217,9±15,2 pg/ml and 152,6±30,4 pg/ml, respectively, p=0,04). A carriage of the combination of L162V and G603G genotypes was associated with an increased risk of CHD in 3,04 times. Conclusion A carriage of V allele of L162V polymorphism of PPAR-α gene and G allele of A603G polymorphism of tissue factor gene, as well as their pair combination are associated with an increased CHD risk, especially at age 45 years or less.
Apr 2019 DOI 10.14302/issn.2377-2549.jndc-19-2720
Currently, enhanced oil recovery (EOR) acquire increased attention to recover more residual oil trapped after the primary and secondary process in petroleum reservoirs. EOR comprise different technologies involving chemical, thermal, miscible flooding techniques. Chemical flooding by the polymer is a widely implemented method on the academic and industrial scale. In this chapter, the authors discuss polymer flooding using polyacrylates that involve hydrolyzed polyacrylamide (HPAM), hydrophobically associated polyacrylamides (HAPAM), which grafted with different vinyl monomers such as acrylic acid, methyl methacrylates, and 2-acrylamido-2-methylpropane sulfonic acid (AMPS). These polymers increase the viscosity of injected brine solutions, as a result, decrease mobility ratio and enhance sweeping efficiency, so the water act as a piston, which pushes oil in front of it, and consequently increase the recovery factor. The advantages and disadvantages of these polymers as well as comparing different flooding scenarios are reported.
Sep 2018 DOI 10.14302/issn.2377-2549.jndc-18-2224
This paper describes the theoretical foundations for the electric power and hydrogen generator that functions with zero energy input without violating the laws of thermodynamics. This generation system is a combined energy cycle consisting of the H2O=H2+1/2O2 reduction reaction performed by the water electrolytic cell and the H2+1/2O2=H2O oxidation reaction performed by the fuel cell. This electrolytic method differs from the conventional electrolytic scheme in that if a quasi-static process is assumed, so that the theoretical power requirement is only 17% of the total energy required. This method performs electrostatic-to-chemical energy conversion by electrostatic-induction potential-superposed electrolytic scheme. If this electrolytic cell that delivers the pure stoichiometric H2-O2 mixture is combined with a fuel cell to form an energy cycle, then this may lead to the concepts of a hydrogen redox electric power generator and a hydrogen redox hydrogen generator that use alkaline water electrolyte or solid polymer electrolyte membrane (PEM) for both electrolytic cell and fuel cell. In the power generator, part of power delivered by the fuel cell is returned to the electrolytic cell, and the remainder represents the net power output. According to calculations based on data from the operational conditions for commercially available electrolytic cell and fuel cell, more than 70% of the power delivered from the fuel cell can be extracted outside the cycle as net power output without the use of any external source of energy.
Aug 2018 DOI 10.14302/issn.2377-2549.jndc-18-2187
Among the numerous potential uses of carbon nanotubes (CNT), its utilization to fortify polymers was given careful consideration. This reason can be because of the remarkable firmness, magnificent quality, and the low thickness of CNT. This has given various chances to the innovation of new material frameworks for applications requiring high quality and high modulus. Exact control over preparing factors, including safeguarding flawless CNT structure, uniform scattering of CNT inside the polymer grid, compelling filler– lattice interfacial communications, and arrangement/introduction of polymer chains/CNT, add to the composite strands' unrivalled properties. Consequently, manufacture techniques assume an imperative part in deciding the composite filaments' microstructure and extreme mechanical conduct. The present best in the class of polymer/CNT elite composite filaments, particularly concerning processing– structure– execution, were looked into in this commitment. Future requirements for material by configuration approaches for handling these nano-composite frameworks were likewise examined.
Jul 2018 DOI 10.14302/issn.2831-8846.j3dpa-18-2207
Additive manufacturing (AM) is reshaping fabrication in engineering and clinical settings. This editorial highlights metal AM routes—SLS, SLM, DMLS, and EBM—and their application to patient-specific NiTi implants, where biocompatibility and shape-memory behavior are compelling. We note the current gaps that matter in practice: process parameter tuning, post-processing (heat treatment, coating, machining/finishing), and their effects on mechanical performance and corrosion. We invite contributions that quantify these trade-offs and expand AM beyond metals into polymers and ceramics, with clear comparisons across processes and materials. Our goal is to surface actionable findings that improve part quality, reliability, and clinical/industrial readiness.
Jun 2018
Graphene-Ceramic Composites (GCCs) have been little studied compared to graphene-polymer composites 1. Recent reviews 23 indicate that both mechanical and electrical property ceramic improvements can be obtained by mixing small quantities, typically 1 to 15% of graphene material with a ceramic precursor, then compacting and sintering. The greatest effect is on the electrical properties. The electrical conductivity of a material was first shown to rise by several orders of magnitude for only a 1% volume addition of graphene as in polymer composites 4 but the stiffness, strength and toughness only increased by 20-160% or so at 5% addition, a rather minor improvement compared to significant increases caused by slight ceramic process changes. Some crack bridging and pull-out mechanism was observed by electron microscopy in graphene-alumina composites, though the effects were modest. Surface friction and wear improvements of around 100% were also notable. This paper seeks to show that much higher toughness increases might be produced using the method pioneered by Clegg et al 5, where the graphite interlayers are replaced with graphene to produce improved ordered interfaces with reliable coverage and consistent interface fracture energy, enabling an increase in the fracture resistance of the ceramic by two orders of magnitude.
May 2018 DOI 10.14302/issn.2690-4829.jen-18-2043
Disposal of chitin wastes from crustacean shell can cause environmental and health hazards. Chitin is a well known abundant natural polymer extracted after deproteinization and demineralization of the shell wastes of shrimp, crab, lobster, and krill. Extraction of chitin and its derivatives from waste material is one of the alternative ways to turn the waste into useful products. Chitinases are enzymes that degrade chitin. Chitinases contribute to the generation of carbon and nitrogen in the ecosystem. Chitin and chitinolytic enzymes are gaining importance for their biotechnological applications. The presence of surface charge and multiple functional groups make chitin as a beneficial natural polymer. Due to the reactive functional groups chitin can be used for the preparation of a spectrum of chitin derivatives such as chitosan, alkyl chitin, sulfated chitin, dibutyryl chitin and carboxymethyl chitin for specific applications in different areas. The present review is aimed to summarize the efficacy of the chitinases on the chitin and its derivatives and their diverse applications in biomedical and environmental field. Further this review also discusses the synthesis of various chitin derivatives in detail and brings out the importance of chitin and its derivatives in biomedical and environmental applications.
Mar 2018 DOI 10.14302/issn.2578-2371.jslr-18-1994
Tuberculosis involving the liver in the absence of active pulmonary tuberculosis is very rare. The inflammatory pseudotumoral form is an entity difficult to diagnose. We report a case of an inflammatory pseudotumor of the liver due to tuberculosis, who didn’t underwent hepatectomy because of the size of the tumor. The diagnosis of tuberculosis was made on biopsy and Polymerase Chain Reaction (PCR).
Nov 2017 DOI 10.14302/issn.2576-6694.jbbs-17-1744
Aim: Colorectal cancer is one of the most commonly diagnosed cancers in the world. Cell adhesion molecules play an important role in the progression of various cancers. It has been shown that the high level expression of some Cell adhesion molecule could be a new diagnostic factor for several cancers. Vascular cell adhesion molecule 1(VCAM1) is a cell surface glycoprotein that is expressed in the endothelium activated by cytokine. Generally, VCAM-1 expression level is very poor in normal adult tissue endothelial cells. According to the above explanation, this study was conducted to investigate the expression of VCAM-1 in tumoral tissues and adjacent normal tissues in Iranian colorectal cancer patients to its relation with clinicopathological Features in patients with cancer. Methods: In this study, 60 tumoral tissues and 39 adjacent normal tumor tissues were evaluated using reverse transcription-polymerase chain reaction (RT-PCR) technique. Conclusion: A significant correlation was found between VCAM-1 expression level and the stage, lymph nodes involvement, tumor progression factor of cancer and sex. Interestingly, VCAM-1 expression not observed in tumors with stage0. No association was seen between VCAM-1 expression and other clinical features such as age, size of the tumor, metastasis and the number of lymph nodes. These findings suggest that VCAM-1 expression level may reflected disease progression and elevation in VCAM-1 has prognostic significance in patients with colorectal carcinoma.
Sep 2017 DOI 10.14302/issn.2575-7881.jdrr-17-1749
Though, directed evolution/In vitro evolution has greatly enhanced the applicability of natural biomolecules, there is still a big void in synthetic biology, which could be filled only when we are able to make novel/synthetic functional biomolecules. Terminal deoxyribonucleotidyl transferase (TdT) is the only known DNA polymerase, which can add deoxyribonucleotides without the requirement of a DNA template. Here, we are introducing the concept of Template-Independent Synthesis of Nucleic Acids (TISNA), where we have exploited the property of terminal deoxyribonucleotidyl transferase to add deoxyribonucleotides to the 3’ end of an oligonucleotide for the generation of de novo libraries of ssDNA, dsDNA coding sequences and RNA. We are able to generate libraries that have diversity not only in sequence but also in length in a single library itself. The length of double stranded random gene libraries generated using this approach ranges from 200 base pairs to 10 kilobase pairs. The ability to make random nucleic acid libraries from scratch (independent of any template information) in the laboratory could open up new avenues and holds promise for the pharmaceutical and biotechnological sectors.
Oct 2016 DOI 10.14302/issn.2572-3030.jcgb-16-1190
Background: Gastric cancer (GC) ranks as the fourth most common cancer and the second leading cause of cancer deaths worldwide. Epstein-Barr virus is a well-known oncogenic virus, it is responsible for 10% of gastric carcinomas across the world. The aim of study was to determine the prevalence of EBV associated with GC in Sudanese patients. Method: Fifty Paraffin embedded blocks of gastric biopsy specimens diagnosed as gastric carcinoma were collected from Soba university hospital and Ribat teaching hospital, Khartoum, Sudan. DNA was extracted from the paraffin-embedded tissue, and then Epstein-Barr virus gene was detected by polymerase chain reaction (PCR). Result: Among the gastric biopsy specimens 27 (54.0%) were of male and 23(46.0%) were of female. Eleven EBV positive samples were found in gastric carcinomas (22.0%), 8 (72.7%) were of male and 3(27.2%) were of female. The mean age of the patients was 56 years, the most positive cases were between 50-59 years old, and (10%) of them are alive in Khartoum. Conclusions: There exists an association between EBV and gastric carcinoma in some Sudanese patients.
Feb 2016 DOI 10.14302/issn.2575-7881.jdrr-15-849
Reverse Transcription Polymerase Chain Reaction (RT-PCR) using new designed primers pair for Heat Shock Protein70 homologue (HSP70h) of Olive leaf yellowing-associated virus revealed 667 amplified product of 10 olive accessions collected from various olive-growing regions in Tunisia. Amplicons were cloned and sequenced. The sequences were deposited in the international databases. Pairwise sequence comparisons among 10 Tunisian isolates along with a reference sequence (AJ440010) extracted from GenBank revealed a nucleotide identity of 86.06-99.40 and an amino acid similarity of 91.89-99.55. Sequence multiple alignments were searched for evidence of recombination using three methods, ie. Differences of Sums of Squares (DSS) implemented in TOPALi v2.5 software and Single Breakpoint (SBP) along with GARD, a genetic algorithm, both incorporated in HyPhy package. All used methods pointed out the presence of putative breaking points in partially sequenced HSP70h-coding gene. Since failing to account for recombination can mislead the phylogeny inference and can elevate the false positive error rate in positive selection assessment, the use of GARD resulted in the reconstruction of different phylogenies on the left as well as on the right sides of putative recombination breaking points, and the 11 accessions were distributed into at least three clusters compared to MEGA6 software which delineated only two clades. Nonetheless, by dividing the aligned sequences at breakpoints into separate sequence sets, MEGA6 delineated a clustering pattern different from the former two. As a result, recombination reshuffled the affiliation of the different accessions to the clusters. Analysis of selection pressures exerted on HSP70h encoded protein using different models (SLAC, IFEL, FEL, REL, PARRIS, FUBAR, MEME, GA Branch, and PRIME) taking into account recombination, and implemented in HyPhy package, revealed that it underwent predominantly purifying selection as confirmed by Tajima’s D, Fu and Li’s D and F tests, and SNAP algorithm. However, a few sites were also under positive selection as assessed by various models such as FEL, IFEL, REL, MEME, and PRIME.
Jan 2016 DOI 10.14302/issn.2379-8572.joa-15-814
Background and Objective: The etiological factors for nasal polyps include infection, inflammation or an imbalance of a metabolic pathway. This study was designed to compare serum Helicobacter pyloriantibodies and H. pylori–DNAs between cases of nasal polyp and controls (nasal fracture). Patients and Methods: This case control study was carried out in ENT Department of Rasul Hospital in Tehran (2007-2008), upon nasal polyp tissues in 62 cases and inferior nasal turbinate mucosa in 25 controls. H. pylori–DNAs were searched by qualitative polymerase chain reaction (PCR) and serum specific H. pylori antibodies (ELISA IgG and IgA). Comparative tests were performed for the 2 groups, and P value < 0.05 was considered as statistically significant. Results: The mean age of cases and controls were 37.5 ± 13.7 and 31 ± 11.5 years, respectively. H. pylori–DNA was found in 32.3% (20/62) of the cases and 4% (1/25) of the controls (P value = 0.005). Serum H. pylori antibody (IgA) was found in 14.5% (9/62) of the cases and 4% (1/25) of the controls (P value = 0.27). However, previous immunity (IgG) was higher in 71% of the cases and 32% of the controls (P = 0.001). Conclusion: H. pylori infection may play a key role in the formation of nasal polyps. We recommend the PCR as the best method of searching for H. pylori infection. However, from the data obtained in this investigation it could not be determined whether or not H. pylori play a pathogenic role. Long-term antibiotics treatment in cases with nasal polyp, especially in cases with severe chronic rhinosinusitis where patients do not respond to surgery or steroids, may be useful. More randomized controlled trial (RCT) studies are necessary to validate the role of H. pylori infection in nasal polyp and the effect of antibiotics for eradication of H. pylori infection.
Feb 2014 DOI 10.14302/issn.2328-0182.japst-13-206
The purpose of this study was to investigate the effect of cremophor RH-40 and polysorbate 80 with hydroxypropyl methylcellulose (HPMC) F4M on the development of formulations of intranasal erythropoietin with low sialic acid content (Neuro-EPO) as a neuroprotective agent. Parameters such as pH, osmolality, apparent viscosity, and protein concentration were controlled for minimizing the differences between formulations. All Neuro-EPO formulations showed similar behaviour in the physicochemistry quality control. However significant differences between formulations were observed in the permanent unilateral ischemia model. The formulations and the vehicles containing cremophor RH-40 showed higher neurotoxicity levels than those containing polysorbate 80 as a nonionic surfactant. Formulations containing HPMC F4M at 0.6% as a bioadhesive polymer showed higher levels of survival and better neurological status than those without the polymer. The formulations with polysorbate 80 and HPMC F4M showed a higher index of survival, smaller incidence of clinical signs of stroke, and similar behavior in the learning and the memory to the false injured animals used as control. These findings suggest that the intranasal pathway constitutes a safe and alternative route of access of the Neuro-EPO to the brain.
Nov 2013 DOI 10.14302/issn.2328-0182.japst-12-119
The purpose of the research is to evaluate Sterculiaurens gum as a carrier for oral colon targeted drug delivery system. Sterculia gum has been reported to have wide pharmaceutical applications such as tablet binder, disintegrant, gelling agent and as a controlled release polymer, but it has not been exploited as colon targeting carrier. For evaluation as a carrier for colonic delivery of drugs characterization of gum was done. Microflora degradation studies of gum were conducted in phosphate buffer solution (PBS) pH 7.4 containing rat caecal content under anaerobic environment. Solubility, swelling index, viscosity and pH of the polymer solution were determined. Different formulation aspects considered were: gum concentration (10–40%), concentration of citric acid (10–30 %) on swelling index and in-vitro drug release. The results of the isothermal stress testing (IST) shows no degradation of samples of model drug, azathioprine, in the drug polymer mixture and the core tablet excipients. DSC and FT-IR study has proved the compatibility of the drug with Sterculia gum and other tablet excipients. Microflora degradation study revealed that Sterculia gum can be used as tablet excipient for drug release in the colonic region by utilizing the action of enterobacteria. Sterculia gum exhibits premature drug release in the upper GIT without enteric coating and may not reach to the colonic region. From the study, Sterculia gum as colon targeting carrier is possible via coating with chitosan/Eudragit mixed blend polymers which would provide acid as well as intestinal resistance; but undergo enzymatic degradation once it reaches the colon.