30 research outputs found

    Engineering of 2D nanomaterials to trap and kill SARS-CoV-2 : a new insight from multi-microsecond atomistic simulations

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    In late 2019, coronavirus disease 2019 (COVID-19) was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Spike protein is one of the surface proteins of SARS-CoV-2 that is essential for its infectious function. Therefore, it received lots of attention for the preparation of antiviral drugs, vaccines, and diagnostic tools. In the current study, we use computational methods of chemistry and biology to study the interaction between spike protein and its receptor in the body, angiotensin-I-converting enzyme-2 (ACE2). Additionally, the possible interaction of two-dimensional (2D) nanomaterials, including graphene, bismuthene, phosphorene, p-doped graphene, and functionalized p-doped graphene, with spike protein is investigated. The functionalized p-doped graphene nanomaterials were found to interfere with spike protein better than the other tested nanomaterials. In addition, the interaction of the proposed nanomaterials with the main protease (M-pro) of SARS-CoV-2 was studied. Functionalized p-doped graphene nanomaterials showed more capacity to prevent the activity of M-pro. These 2D nanomaterials efficiently reduce the transmissibility and infectivity of SARS-CoV-2 by both the deformation of the spike protein and inhibiting the M-pro. The results suggest the potential use of 2D nanomaterials in a variety of prophylactic approaches, such as masks or surface coatings, and would deserve further studies in the coming years.Peer reviewe

    Simultaneous doxorubicin encapsulation and in-situ microfluidic micellization of bio-targeted polymeric nanohybrids using dichalcogenide monolayers : A molecular in-silico study

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    The rate of Riboflavin (RF) consumption in cancerous cells is interestingly high and this might imply the use of RF ligand in nanocarriers in order to target anticancer drugs into cancer cells. This study aimed to develop a hybrid drug carrier of Doxorubicin (DOX) loaded on RF targeted micelles composed of hydrophobic polylacticglycolic acid (PLGA) and hydrophilic polyethylene glycol (PEG). In this regard, a simultaneous encapsulation of DOX and in-situ micellization as well as the self-assembly of PLGA-PEG-RF molecules were investigated. Moreover, the effects of microfluidic environment and transition metal dichalcogenide (TMD) nanolayers on the micellization properties (e.g., stability, size, and self-assembly interaction energies) of nanocarriers were simulated for the first time. To this purpose, the simulations were performed using two non-microfluidic methods as well as a novel microfluidic one. The molecular simulations revealed that all of the selected TMDs, especially MoSe2, had a great impact on the stability and size of nanocarriers. MoSe2 significantly enhanced the loading capacity as well as the stability of RF-targeted micelles and reduced the size of nanocarriers. Likewise, the results of various analyses demonstrated that the microfluidic method is the most effective way to synthesize nano carriers with higher stability and smaller particle size. Hence, the use of MoSe2 monolayer, micelle containing RF, and microfluidic method were believed to be the best approach in order to improve the quality of micelles. The present work sheds new light on the use of TMDs in the synthesis of smart carriers for cancer treatment.Peer reviewe

    Chewing lice of wild birds in Iran: new data and a checklist of avian louse species reported in Iran

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    Between September 2019 and December 2023, a total of 612 wild birds representing 16 orders, 33 families, 60 genera, and 78 species from nine provinces of Iran with different climates namely Hamedan (n = 54), Sistan-va-Baluchestan (n = 372), Kerman (n = 73), South Khorasan (n = 52), Mazandaran (n = 7), Chaharmahal-va-Bakhtiari (n = 2), Gilan (n = 2), Golestan (n = 18), North Khorasan (n = 9), and Razavi Khorasan (n = 23) were examined for chewing lice infestation. Naked eye examination revealed that 58 birds (9.5%) were infested with at least one chewing louse species. Collected lice specimens belonged to 28 species from the families Philopteridae, Menoponidae and Laemobothriidae including Strigiphilus strigis (n = 55, 15.6%), Falcolipeurus quadripustulatus (n = 41, 11.6%), Craspedorrhynchus platystomus (n = 40, 11.3%), Colpocephalum turbinatum (n = 36, 10.2%), Laemobothrion maximum (n = 25, 7.1%), Nosopon lucidum (n = 20, 5.6%), Degeeriella fulva (n = 18, 5.1%), Colpocephalum eucarenum (n = 16, 4.5%), Laemobothrion vulturis (n = 15, 4.2%), Anaticola crassicornis (n = 13, 3.7%), Craspedorrhynchus aquilinus (n = 9, 2.5%), Degeeriella fusca (n = 7, 2.0%), Aegypoecus trigonoceps (n = 7, 2.0%), Quadraceps obscurus (n = 6, 1.7%), Colpocephalum impressum (n = 6, 1.7%), Trinoton querquedulae (n = 6, 1.7%), Colpocephalum heterosoma (n = 5, 1.4%), Colpocephalum nanum (n = 5, 1.4%), Lunaceps holophaeus (n = 4, 1.1%), Quadraceps spp. (n = 4, 1.1%), Actornithophilus uniseriatus (n = 2, 0.6%), Nosopon chanabense (n = 2, 0.6%), Actornithophilus cornutus (n = 1, 0.3%), Cuclotogaster heterographus (n = 1, 0.3%), Falcolipeurus suturalis (n = 1, 0.3%), Laemobothrion atrum (n = 1, 0.3%), Colpocephalum gypsi (n = 1, 0.3%), and Rallicola cuspidatus (n = 1, 0.3%). All of these species except six, i.e., Trinoton spp., C. aquilinus, L. vulturis, L. maximum, C. impressum, C. turbinatum, and C. heterographus are recorded for the first time from Iran. This study is the largest epidemiological study to date performed in the country. Data reported herein contribute to our knowledge about diversity of avian chewing lice from wild birds in Iran. In this paper, an updated checklist of louse species reported from Iran according to their avian hosts is presented

    Bacteria of Phlebotominae Sand Flies Collected in Western Iran

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    Microorganisms particularly bacteria presenting in insects such as Phlebotominae may play an important role in the epidemiology of human infectious disease. Nowadays, because of vector implications, the routine methods of controlling and spraying have no more beneficial effects on vectors and reservoirs. Little knows about the prevalence and diversity of sand fly bacteria. The main objective of this study was to determine the presence of bacteria of phlebotominae sand flies collected in Hamadan, west of Iran. This information is important in order to development of vector control strategies. The microbial flora of Phlebotomus papatasi and P. sergenti the main vector of Cutaneous Leishmaniasis in the old world, were investigated. We characterized 8 bacteria, including 5 Gram-negative bacteria: Acinetobacter lwoffii, Pseudomonas aeruginosa, Enterobacter cloacae, Edvardsiela sp. and Proteus mirabilis and Gram-positive bacteria: Bacillus subtilis, Staphylococcus saprophyticus and Micrococcus luteus. Our study provides some data on the microbiota diversity of field-collected sand flies for the first time in Hamadan. Our results indicate that there is a range of variation of aerobic bacteria inhabiting sand fly, which possibly reflect the ecological condition of the habitat where the fly breeds. Microbiota is increasingly regarded as an important factor for modulating vector competence in insect vectors. So, mirobiota can be effects on the biology of phlebotominae and their roles in the sandfly-Leishmania interaction. Further experiments are required to clearly delineate the vectorial role of sand flies. Because it is probable that in the future, factors such as environmental changes, migration and urbanization can ease the transmission of leishmaniasis in this area

    Experimental and Computational Study on the Microfluidic Control of Micellar Nanocarrier Properties

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    Microfluidic-based synthesis is a powerful technique to prepare well-defined homogenous nanoparticles (NPs). However, the mechanisms defining NP properties, especially size evolution in a microchannel, are not fully understood. Herein, microfluidic and bulk syntheses of riboflavin (RF)-targeted poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG-RF) micelles were evaluated experimentally and computationally. Using molecular dynamics (MD), a conventional "random"model for bulk self-assembly of PLGA-PEG-RF was simulated and a conceptual "interface"mechanism was proposed for the microfluidic self-assembly at an atomic scale. The simulation results were in agreement with the observed experimental outcomes. NPs produced by microfluidics were smaller than those prepared by the bulk method. The computational approach suggested that the size-determining factor in microfluidics is the boundary of solvents in the entrance region of the microchannel, explaining the size difference between the two experimental methods. Therefore, this computational approach can be a powerful tool to gain a deeper understanding and optimize NP synthesis. © 2021 The Authors. Published by American Chemical Society

    An Epidemiological Survey of Setaria in the Abdominal Cavities of Iranian Sistani and Brahman Cattle in the Southeastern of Iran

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    Background: In this experiment, abdominal cavity of 518 Iranian Sistani cattle and 498 Brahman cattle were inspected for the presence of Setaria spp. from April 2012 - May 2013. Methods: The species were determined by microscopic examination of the mor-phological characteristics of the anterior and posterior parts of the parasites and authentic guidelines. Results: The overall prevalence of Setaria spp. was 28.6% and 36.5%, respectively and this difference was significant (P<0.05). Out of 148 Sistani cattle which were infected with Setaria, 51(34.4%) were infected with S. digitata, 31 (20.9%) were in-fected with S. labiatopapillosa, 65 (43.9%) showed mixed infection of S. digitata and S. labiatopapillosa and one case (0.6%) was infected with mixed infection of S. labiato-papillosa, S. digitata and S. marshalli. These values were 87 (47.8%), 27 (14.8%), 67 (36.8%) and 1 (0.5%) for 182 infected Brahaman cows, respectively. The propor-tion of infected cattle in spring and summer was greater than cooler season (au-tumn and winter) significantly (P<0.001). The prevalence of infection with Setaria in 2-3 years old Sistatni cattle (42.2 %) was greater than other age categories (P<0.05). Furthermore, the infection rate between males (25.5%) and females (37.3%) Iranian Sistani cattle showed significant difference (P =0.009). Conclusion: It is important to point out the presence of cerebrospinal setariosis, namely in sheep, goats and horses in the investigated area

    Prevalence and Intensity of Paramphistomum Spp. In Cattle from South-Eastern Iran

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     Background: Parasitological investigations on paramphistomosis were carried out over a 12-month period in the southeast of Iran to determine the prevalence and intensity of this disease. Methods: A total of 1000 cattle, Sistani breed (n= 450) and Brahman breed (n= 550) of all sex and age groups were inspected at random for the presence of paramphistomidae flukes in Zabol slaughterhouse from December 2012 to Octo-ber 2013. Results: Paramphistomes were found in 369 of 1000 necropsied cows (36.9%; 95% CI: 30.1-41.9%), with significant higher prevalence of infection in Brahman breed than in Sistani breed (51% vs 19.3%). No significant correlation between prevalence, intensity of infection, sex and age of cattle was noted. Despite the dif-ference in the seasonal variations of prevalence, and the relation between the inten-sity of infection and season, these were not statistically significant. The mean inten-sity of infection in Brahman breed was higher (652.66 ± 281.5) than Sistani breed (123.32 ± 32.2). The identification of stained trematodes to the species revealed 40, 20, 20, 15 and 5% Gastrothylax crumenifer, Cotylophoron cotylophorom, Paramphistomum cervi, Carmyerius spatiosus, Explanatum explanatum, respectively. Conclusion: The present results will contribute to our understanding of the epi-demiology of paramphistomumosis in southeastern Iran.  

    Epidemiological Survey of Bovine Thelaziosis in Southeastern of Iran

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    Background: This study aimed at investigating the prevalence and risk factors of bovine thelaziosis, performed in the southeast of Iran, an endemic area for Iranian Sistani cattle. Methods: Between September 2012 to October 2014, 1924 cattle, Sistani breed (n= 1235) and Brahman breed (n=689) of all sex and age groups collected from Sistan and Baluchestan Province were examined using visual observation of the eyes by flushing the conjunctival sac and lachrymal duct with sterile saline solution. Results: The overall prevalence for thelaziosis was 50 of 1924 cows (2. 6%; 95% CI: 1. 9-3. 3%), with significant higher prevalence of infection in Sistani breed than in Brahman breed (3. 15% vs 1. 59%). Sixty adult worms (84. 5% of females and 15. 5% of males) were collected from the conjunctiva of the infected cattle: Thelazia gulosa (50/60, 83. 3%) was the most represented species followed by Thelazia. rhodesi (10/60, 16. 7%). The number of worms collected per cow ranged from one to seven (average ± standard deviation: 2. 08 ± 1. 49). Worms were gathered from cows throughout all months of the year. The difference in the seasonal variations of prevalence and the intensity of infection were significant, however, no significant correlation between prevalence, sex and age of cattle was noted. Conclusion: Bovine thelaziosis needs special attention by veterinarians in the differential diagnosis of ocular manifestations and considering its impact on cattle production

    β-Amyloid Targeting with Two-Dimensional Covalent Organic Frameworks : Multi-Scale In-Silico Dissection of Nano-Biointerface

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    Cytotoxic aggregation of misfolded beta-amyloid (A beta) proteins is the main culprit suspected to be behind the development of Alzheimer's disease (AD). In this study, A beta interactions with the novel two-dimensional (2D) covalent organic frameworks (COFs) as therapeutic options for avoiding beta-amyloid aggregation have been investigated. The results from multi-scale atomistic simulations suggest that amine-functionalized COFs with a large surface area (more than 1000 m(2)/gr) have the potential to prevent A beta aggregation. Gibb's free energy analysis confirmed that COFs could prevent protofibril self-assembly in addition to inhibiting beta-amyloid aggregation. Additionally, it was observed that the amine functional group and high contact area could improve the inhibitory effect of COFs on A beta aggregation and enhance the diffusivity of COFs through the blood-brain barrier (BBB). In addition, microsecond coarse-grained (CG) simulations with three hundred amyloids reveal that the presence of COFs creates instability in the structure of amyloids and consequently prevents the fibrillation. These results suggest promising applications of engineered COFs in the treatment of AD and provide a new perspective on future experimental research.Peer reviewe

    The Relationship of Mind and Phenomenal Objects in the Epistemologies of Mulla Sadra and Kant

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    In Western and Islamic philosophy, one of the most complex and controversial ontological topics has do with the relationship between mind and phenomenal objects, that is the relationship between the form in the mind and the material and objective form. This issue has stirred great confusion for philosophers seeking to explain the relationship of knowledge and the "outside world". In this article we present and compare Kant and Mulla Sadra's philosophical solutions to this problem. Although in Mulla Sadra's philosophy, mind and phenomenal objects do not stand on the same ontological levels, however according to the "primacy of existence" (Aṣālat al-wujūd) principle, the two are alongside each other. Knowledge is not separate from ontology and relies on the outside world in its process of perception occurring through the help of the senses, the imagination, reason, and intuition. What occurs between the outside world and the mind is called by Mulla Sadra the construction of quiddity. Quiddity is neither bound to the mind or the outside world; however it is necessary on every ontological level and participates in all the levels of perception. Mulla Sadra can explain the relationship between the intuitions of the mind and the outside world first by positing a soul which creates forms and elements related to perception and secondly, by filling the gap between mind and phenomenal objects by postulating a division of ontological levels. According to Kant, knowledge requires two things: a) observation, which is given to us in space and time and b) the reception of an intelligible upon what has been observed. For the process to occur the phenomenal object and the intelligible must share a similarity. Some intelligibles have no similarity with anything from the experiential level. Kant, in trying to reconcile mind and the phenomenal objects uses the concept of Transcendental Schemata, that is forms produced in time by the imagination. By arguing for a direct reciprocity between the phenomena and the intelligible, Kant is bound to uphold the reciprocity between phenomena and transience
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