A novel and cost-effective method for fabrication of a durable superhydrophobic aluminum surface with self-cleaning properties.

A hierarchical superhydrophobic surface is prepared via a two-step boiling water immersion process and anodization of the treated aluminum substrate in a novel hydrophobic electrolyte of aluminum nitrate and stearic acid mixture at room temperature. The immersion time in boiling water had a significant influence on the morphology and durability of the sample. A pseudoboehmite coating is created on the aluminum surface during the boiling process, as revealed by the field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FTIR) spectrophotometer results. The energy-dispersive x-ray spectroscopy analysis confirmed the formation of hydrophobic coating surface after anodization. Also, the FE-SEM images and the atomic force microscopy (AFM) investigation proved the hierarchical nano-and microstructure stem from boiling and anodizing procedures, respectively. The successively boiled and anodized surface exhibited contact angle of about 155˚, sliding and hysteresis contact angles of <5˚ and 2˚, respectively. It also demonstrated a self-cleaning property and remarkable durability.

The effect of chitosan and PEG polymers on stabilization of GF-17 structure: A molecular dynamics study.

We examine the interactions of chitosan and polyethylene glycol (PEG) with antimicrobial peptide GF-17 to identify a suitable carrier to improve the peptide drug delivery systems. To this end, the molecular dynamics simulations are used to determine the interactions of a typical antimicrobial peptide GF-17 with the chitosan and PEG polymers. The findings indicate the great potential of the peptide to maintain its secondary structure in the adjacent to chitosan polymers. During the interaction with chitosan polymers, the structure of the peptide has smaller fluctuations compared to the PEG polymers. Also, in the presence of both the polymers, the PEG polymers are situated closer to the peptide than chitosan polymers. Moreover, the analysis indicates that the acidic residues and phenylalanine play a crucial role in peptide-polymer interactions. This research provides a valuable insight into the design of polymer surfaces for drug delivery applications such as controlled-release peptide delivery systems.

A systematic review and meta-analysis on the epidemiology, casual agents and demographic characteristics of onychomycosis in Iran.

Onychomycosis or fungal nail infection is one of the most common fungal infections. Nearly 50% of all nail disorders are caused by fungi. This systematic review and meta-analysis was conducted to determine the prevalence of onychomycosis across Iran. We searched English and Persian databases for studies reporting the epidemiologic features of onychomycosis in Iranian people from January 2000 to December 2018. Literature search revealed 307 studies, of which 24 studies met the eligibility criteria. In order to identifying the existence of publication bias among studies, funnel plots were used. The results of the meta-analysis were visualized as a forest plot representing the prevalence estimates of each study. Heterogeneity was also analyzed using the I2, Chi2, and Tau2 statistics. A high level of I2 and Chi2 was obtained among studies, which provides evidence of notable heterogeneity between studies. The results of current study revealed that the highest prevalence of onychomycosis was related to Mazandaran and Tehran provinces, respectively. As in the literature hypothesized shift in etiologic agents from yeasts to dermatophytes or molds could not be confirmed. Females were affected more frequently than males and in both sexes the highest incidence of infection occurrence was at the ages of >50 years. It seems the highest prevalence of onychomycosis in Mazandaran and Tehran provinces is due to the concentration of specialist doctors and research centers in these two provinces compared with others which leads to more detection and more care of the disease. Therefore, further educational strategies in order to accurate diagnosis in other provinces is necessary to reduce the risk of onychomycosis in Iran.

The frequency of fungi isolated from the skin and hair of asymptomatic cats in rural area of Meshkin-shahr-Iran.

BACKGROUND: Dermatophytosis is a frequent cutaneous infection affecting the keratinized tissues of humans, pets and livestock. Animals can carry dermatophytic elements asymptomatically and are considered to play an important role in the epidemiology of the disease. As exposure to any infected lesion free animals, especially cats, may lead to the development of infection in humans. OBJECTIVES: This study was done to determine the frequency of fungal agents isolated from skin and hair of cats living in rural areas of Meshkin-shahr, Iran. ANIMALS: A total of 103 asymptomatic cats living in rural areas of the region were studied. METHODS: This cross-sectional descriptive study was performed in Medical Mycology Laboratory, School of Public Health, Tehran University of Medical Sciences from February 2015 to July 2016. A total of 103 asymptomatic cats were studied. Mycological analysis including direct examination and culture on SC, SCC and DTM of the collected samples were conducted. For molecular confirmation when needed, panfungal PCR targeting the ITS1 region of the rDNA gene cluster using primers ITS1 and ITS4 were performed. Gender and age were also recorded. RESULTS: None of the 103 cats examined were positive for fungal elements on direct examination. However, 15 (14.5%) cases showed dermatophytes growth. T. verrucosum was the most common etiologic agents of dermatophytosis. Although the gender of the cats had not significant association with dermatophytosis prevalence, age was a significant influential risk factor (P=0.019). Aspergillus spp., Alternaria spp., Rhizopus spp., Penicillium spp.and paecilomyces spp. in descending frequency were the most predominantly identified saprophytic fungi. CONCLUSION: Our findings clearly highlighted the epidemiological role of asymptomatic cats in spreading dermatophytosis to humans and other animals.

Retention modes of manure-fecal coliforms in soil under saturated hydraulic condition.

Manures are important soil nutrient conditioners and source of several pathogenic bacteria that potentially contribute to groundwater and surface water pollution. The best management practices need a solid understanding of manure sources, concentrations, and strategies to limit the number of bacteria in natural soil environment. In this study, a series of soil column experiments were conducted to investigate how bacteria mobility can potentially be influenced by retention mechanisms while moving through undisturbed saturated soil. This was assessed by bacteria retention profiles and mobility indices including the maximum transported (Cmax-T) and retained (Cmax-R) concentrations, filtration coefficient (λf) and the maximum depth of bacteria transport (Zmax). Three different soil samples (sandy, loamy and silty clay loam) were enriched with three types of manures (cow, sheep, and poultry), placed on top of three soil columns (16 cm diameter, 30 cm height) with an equivalent of 10 Mg ha-1 (dry basis) summing up to a total of 36 columns. Leaching was performed under saturated steady-state conditions (i.e., 1.62 cm min-1) for a duration of 4 pore volumes. After percolation, soil columns were sliced into six 5-cm interval layers and slices were characterized for retained bacteria. Results showed irregular exponential or quasi-exponential bacteria retention profiles for cow and sheep manures, whereas uniform-shaped profiles occurred for poultry manure. The latter variant also switched to exponential shape for the sandy soil at the highest and lowest Cmax-T and Cmax-R values due to higher pore water velocity. The λf and the Zmax values were also found to be affected by soil texture and manure origin. The λf was higher for poultry manure due to higher free-cell transport of bacteria most probably induced by higher amount of soluble mobile components. However, the greater amounts of transported wooden materials released from cow and sheep manures acted as harbors for bacteria. Accordingly, the filtration rate decreased and tailing effects for bacteria transport increased. The results also suggest that the practices and strategies for using manures could be optimized according to the respective transport behavior to manage the bacteria retention with respect to soil and manure types to reduce soil and water pollution.

Bacterial mobilization and transport through manure enriched soils: Experiment and modeling.

A precise evaluation of bacteria transport and mathematical investigations are useful for best management practices in agroecosystems. In this study, using laboratory experiments and modeling approaches, we assess the transport of bacteria released from three types of manure (cow, sheep, and poultry) to find the importance of the common manures in agricultural activities in soil and water pollution. Thirty six intact soil columns with different textures (sandy, loamy, and silty clay loam) were sampled. Fecal coliform leaching from layers of the manures on the soil surface was conducted under steady-state saturated flow conditions at 20 °C for up to four Pore Volumes (PVs). Separate leaching experiments were conducted to obtain the initial concentrations of bacteria released from the manures (Co). Influent (Co) and effluent (C) bacteria concentrations were measured by the plate-count method and the normalized concentrations (C/C0) were plotted versus PV representing the breakthrough curves (BTCs). Transport parameters were predicted using the attachment/detachment model (two-kinetic site) in HYDRUS-1D. Simulations fitted well the experimental data (R2 = 0.50-0.96). The attachment, detachment, and straining coefficients of bacteria were more influenced by the soils treated with cow manure compared to the sheep and poultry manures. Influent curves of fecal coliforms from the manures (leached without soil) illustrated that the poultry manure had the highest potential to pollute the effluent water from the soils in term of concentration, but the BTCs and simulated data related to the treated soils illustrated that the physical shape of cow manure was more important to both straining and detachment of bacteria back into the soil solution. Detachment trends of bacteria were observed through loam and silty clay loam soils treated with cow manure compared to the cow manure enriched sandy soil. We conclude that management strategies must specifically minimize the effect of fecal coliform concentrations before field application, especially for the combination of poultry and cow manures, which has higher solubility and tailing behavior, respectively. Interestingly, the addition of sheep manure with all three soils had the lowest mobilization of bacteria. We also suggest studying the chemistry of soil solution affected by manures to present all relevant information which affect bacterial movement through soils during leaching.

Water electrolyte transport through corrugated carbon nanopores.

We investigate the effect of wall roughness on water electrolyte transport characteristics at different temperatures through carbon nanotubes by using nonequilibrium molecular dynamics simulations. Our results reveal that shearing stress and the nominal viscosity increase with ion concentration in corrugated carbon nanotubes (CNTs), in contrast to cases in smooth CNTs. Also, the temperature increase leads to the reduction of shearing stress and the nominal viscosity at moderate degrees of wall roughness. At high degrees of wall roughness, the temperature increase will enhance radial movements and increases resistance against fluid motion. As the fluid velocity increases, the particles do not have enough time to fully adjust their positions to minimize system energy, which causes shearing stress and the nominal viscosity to increase. By increasing roughness amplitude or decreasing roughness wavelength, the shearing stress will increase. Synergistic effects of such parameters (wall roughness, velocity, ion concentration, and temperature) inside corrugated CNTs are studied and compared with each other. The molecular mechanisms are considered by investigating the radial density profile and the radial velocity profile of confined water inside modified CNT.

Dewetting of evaporating thin films over nanometer-scale topographies.

A lubrication model is used to study dewetting of an evaporating thin film layer over a solid substrate with a nanometer-scale topography. The effects of the geometry of the topography, the contact angle, the film thickness, and the slippage on the dewetting have been studied. Our results reveal that the evaporation enhances the dewetting process and reduces the depinning time over the topography. Also it is shown that the depinning time is inversely proportional to the slippage and increasing the contact angle may considerably reduce the depinning time, while the film thickness increases the depinning time.

Interaction of 3D dewetting nanodroplets on homogeneous and chemically heterogeneous substrates.

Long-time interaction of dewetting nanodroplets is investigated using a long-wave approximation method. Although three-dimensional (3D) droplets evolution dynamics exhibits qualitative behavior analogous to two-dimensional (2D) dynamics, there is an extensive quantitative difference between them. 3D dynamics is substantially faster than 2D dynamics. This can be related to the larger curvature and, as a consequence, the larger Laplace pressure difference between the droplets in 3D systems. The influence of various chemical heterogeneities on the behavior of droplets has also been studied. In the case of gradient surfaces, it is shown how the gradient direction could change the dynamics. For a chemical step located between the droplets, the dynamics is enhanced or weakened depending on the initial configuration of the system.

Gravity-driven thin liquid films over topographical substrates.

We investigate the time-dependent evolution of thin liquid films over inclined substrates using a multi-component lattice Boltzmann algorithm. Substrates with and without grooves are considered and the effects of the inclination angle on the dynamics and the coating of the substrates are studied. Our results indicate that the dynamics is enhanced and the ridge height and its displacement are increased by increasing the inclination angle. However, by increasing the inclination angle the maximum depth that can be successfully coated is reduced. Also, although for any given groove depth the width should be larger than a critical value for successful coating, the critical width decreases for smaller inclination angles. For different inclination angles we derive and report the critical sizes of the grooves for successful coating of the substrates.

Thin liquid film flow over substrates with two topographical features.

A multicomponent lattice Boltzmann scheme is used to investigate the surface coating of substrates with two topographical features by a gravity-driven thin liquid film. The considered topographies are U- and V-shaped grooves and mounds. For the case of substrates with two grooves, our results indicate that for each of the grooves there is a critical width such that if the groove width is larger than the critical width, the groove can be coated successfully. The critical width of each groove depends on the capillary number, the contact angle, the geometry, and the depth of that groove. The second groove critical width depends on, in addition, the geometry and the depth of the first groove; for two grooves with the same geometries and depths, it is at least equal to that of the first groove. If the second groove width lies between the critical widths, the second groove still can be coated successfully on the condition that the distance between the grooves is considered larger than a critical distance. For considered contact angles and capillary numbers our results indicate that the critical distance is a convex function of the capillary number and the contact angle. Our study also reveals similar results for the case of substrates with a mound and a groove.

Coarsening dynamics of nanodroplets on topographically structured substrates.

Employing a biharmonic boundary integral method with linear elements, coarsening dynamics of nanodroplets on topographical step heterogeneity is investigated. It is shown that the step height and droplet configuration have an influential effect on the dynamics. Increasing the step height slows down the process while locating the droplets close to the step boosts the coarsening rate. Considering a slip boundary condition enhances the dynamics and reveals a transition in the droplet migration direction. Our results reveal that increasing the surface wettability weakens the dynamics. Various types of the disjoining pressure over the step are also considered and their effects on the coarsening are investigated.

Genetic variability of Blastocystis sp. isolated from symptomatic and asymptomatic individuals in Iran.

Blastocystis is an unusual enteric protozoan parasite of humans and many animals whose pathogenic potential is still controversial. To increase the understanding of the molecular epidemiology of this emerging parasite and due to its potential impact on public health, its subtypes (STs) in Iranian symptomatic and asymptomatic individuals were determined. A total of 100 Blastocystis isolates by microscopy and culture methods were obtained. DNA was extracted from the positive culture isolates, and the Blastocystis subtypes were identified using seven subtype-specific sequenced-tagged site (STS) primers. Four subtypes, ST3 as dominant (53 %), followed by ST1 (48 %), ST5 (33 %), and ST2 (7 %) were identified. In this study, ST1 in gastrointestinal patients compared to asymptomatic individuals was significantly dominant (p = 0.001). From 33 (33 %) mixed subtype infections, ST1, 3 (14 %) was significantly related to GI symptoms (p = 0.045), and eight mixed infections with three different STs, which are under reported, were also identified.

Coarsening dynamics of dewetting nanodroplets on chemically patterned substrates.

Mesoscopic hydrodynamic equations are solved to investigate coarsening dynamics of two interacting nanodroplets on chemically patterned substrates. The effects of different parameters such as the surface chemical pattern, the slip length, the profile of the disjoining pressure, the size of the droplets, and the contact angles on the coarsening are studied. Our results reveal that the presence of a chemical heterogeneity can enhance or weaken the coarsening dynamics depending on the pattern type and positions of the droplets on the substrate. Also increasing the contact angles to values larger than a critical value may qualitatively change the coarsening process, and the profile of the disjoining pressure and the slippage can appreciably modify the coarsening rate.

Nutritional value of raw soybeans, extruded soybeans, roasted soybeans and tallow as fat sources in early lactating dairy cows.

Thirty multiparous Holstein cows (29.8 ± 4.01days in milk; 671.6 ± 31.47 kg of body weight) were used in a completely randomized design to compare nutritional value of four fat sources including tallow, raw soybeans, extruded soybeans and roasted soybeans for 8 weeks. Experimental diets were a control containing 27.4 % alfalfa silage, 22.5% corn silage, and 50.1% concentrate, and four diets with either tallow, raw soybean, extruded soybean, or roasted soybean added to provide 1.93% supplemental fat. Dry matter and NEL intakes were similar among treatments, while cows fed fat diets had significantly (P<0.05) high NEL intakes when compared to control with no fat. Supplemental fat, whether tallow or full fat soybeans increased milk production (1.89-2.45 kg/d; P<0.01) and FCM production (1.05-2.79; P<0.01). Milk fat yield and percentage of cows fed fat-supplemented diets were significantly (P<0.01 and P<0.05 respectively) higher than control. Between fat-supplemented diets, roasted soybean caused highest milk fat yield and extruded soybean caused lowest milk fat yield. There was no significant effect of supplemental fat on the milk protein and lactose content and yield. Feed efficiency of fat-supplemented diets was significantly (P<0.01) higher than control. Body weight, body weight change and BCS (body condition score) of cows, as well as energy balance and energy efficiency were similar between treatments. In conclusion, while there was no significant effect of fat sources on production response of cows, fat originating from heat-treated soybean help to minimize imported RUP (rumen undegradable protein) sources level as fish meal in comparison with tallow and raw soybean oil. In the Current study, there was no statistical significance among nutritional values of oil from extruded soybeans and roasted soybeans.

Dynamics of nanodroplets on wettability gradient surfaces.

A lubrication model is used to study the dynamics of nanoscale droplets on wettability gradient surfaces. The effects of the gradient size, size of the nanodroplets and the slip on the dynamics have been studied. Our results indicate that the position of the center of mass of the droplets can be well described in terms of a third-order polynomial function of the time of the motion for all the cases considered. By increasing the size of the droplets the dynamics increases. It is also shown that the slip can considerably enhance the dynamics. The results have been compared with the results obtained using theoretical models and molecular dynamics simulations.

Prevalence and factors associated with Ecstasy use among college undergraduates in north of Iran-2005.

We conducted a cross sectional study of 3958 college students in north of Iran in 2005 with an anonymous questionnaire that was adapted from the questionnaires used in "Monitoring the future". Three thousand seven hundred students responded (93.5%). Lifetime prevalence use of ecstasy, opium and cannabis was 4.3%, 2.7% and 2.4% respectively. The prevalence of current cigarette smoking was 19.5%. After the logistic regression, the factors influencing ecstasy use were use of other illicit drugs, alcohol and cigarette smoking (P<0.000), widow or divorced (ρ=0.007) and higher educational background of mother (ρ=0.019).

Dynamics of nanodroplets on topographically structured substrates.

Mesoscopic hydrodynamic equations are solved to investigate the dynamics of nanodroplets positioned near a topographic step of the supporting substrate. Our results show that the dynamics depends on the characteristic length scales of the system given by the height of the step and the size of the nanodroplets as well as on the constituting substances of both the nanodroplets and the substrate. The lateral motion of nanodroplets far from the step can be described well in terms of a power law of the distance from the step. In general the direction of motion depends on the details of the effective laterally varying intermolecular forces. But for nanodroplets positioned far from the step it is solely given by the sign of the Hamaker constant of the system. Moreover, our study reveals that the steps always act as a barrier for transporting liquid droplets from one side of the step to the other.

Prevalence and risk factors of ecstasy use among college students in Astara, Islamic Republic of Iran.

We determined the prevalence and risk factors for 3,4-methylenedioxy-methamphetamine (MDMA, "ecstasy") use among college students in Astara, a northern border city of Iran. In a cross-sectional questionnaire survey of 1226 students, the lifetime prevalence of ecstasy use was 5.6%. The lifetime prevalence of use of other drugs, mostly cannabis and opium, was 4.6%. A fifth of students (21.8%) were current cigarette smokers and 24.8% had ever used alcohol. After logistic regression, the factors influencing ever use of ecstasy were ever use of other drugs, ever use of alcohol, current cigarette smoking and living alone or with friends. Targeted prevention programmes should be conducted in all colleges.

Prevalence and risk factors of ecstasy use among college students in Astara, Islamic Republic of Iran

We determined the prevalence and risk factors for 3,4-methylenedioxy-methamphetamine [MDMA, "ecstasy"] use among college students in Astara, a northern border city of Iran. In a cross-sectional questionnaire survey of 1226 students, the lifetime prevalence of ecstasy use was 5.6%. The lifetime prevalence of use of other drugs, mostly cannabis and opium, was 4.6%. A fifth of students [21.8%] were current cigarette smokers and 24.8% had ever used alcohol. After logistic regression, the factors influencing ever use of ecstasy were ever use of other drugs, ever use of alcohol, current cigarette smoking and living alone or with friends. Targeted prevention programmes should be conducted in all colleges