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The pervaporation separation of organic compounds from acetone-butanol-ethanol (ABE) fermentation model solutions was studied using activated carbon (AC) nanoparticle-poly (dimethylsiloxane) (PDMS) mixed matrix membranes (MMM). The effects of the operating conditions and nanoparticle loading content on the membrane performance have been investigated. While the separation factor increased continuously, with an increase in the concentration of nanoparticles, the total flux reached a maximum in the MMM with 8 wt % nanoparticle loading in PDMS. Both the separation factor for ABE and the total permeation flux more than doubled for the MMM in comparison to those of neat PDMS membranes prepared in this study.

Formerly the Turkmenian stone loach was the only member of the genus Metaschistura based on osteological characters. But recently, it is placed in the genus Paraschistura based on mtDNA COI data. To provide a detailed description of the osteological characteristics of Paraschistura cristata (Berg 1898), ten specimens of P. cristata were collected from the Hari River basin in Iran and their osteological characteristics were examined. According to the results, P. cristata is osteologically characterized by a foramen in the ventral part of the exoccipital, two extra urohyals, sesamoid ossifications, trapezoid-shaped prevomer, three basibranchials, five hypural, lack of bony bridge between the parietal and pterotic, having over 20 procurrent rays supporting the adipose crest. The detailed skeletal description of P. cristata showed that this species can be easily distinguished from the related genera. Despite the mtDNA COI result, the osteological data of this species showed some features to describe it as a distinctive genus, but this needs the osteological data of the all other Paraschistura species to be compared.

Alburnus mossulensis Heckel, 1843 is one of the eight species of the genus Alburnus found in Iran. This study was conducted to provide a detailed osteological description of A. mossulensis and comparing it with those of other related members of this genus in Iran i.e. A. atropatenae, A. chalcoides, A. filippii and A. amirkabiri. For this purpose, five specimens of A. mossulensis were collected, cleared and stained for osteological examination. Then, a detailed description of its skeletal structure is provided. Based on the results, A. mossulensis can be recognized from the other osteologicaly studied members of this genus in Iran by having a straight dorsal and posterior parts of the opercle, L-shaped preopercle with right-angled, by having a level dorsal and posterior parts of the opercle, an L-shaped preopercle with right-angled, blunt posterior part of the vomer, possessing 11 supraneural, having 43 centra, developed zygapophys process, short and thick anterior part of the palatine and dorsally bended the coronoid process.

This study was conducted to survey the allometric growth pattern of the swordtail (Xiphophorus helleri) during early developmental stage under rearing conditions. For this purpose, the fries were sampled after birth up to 60 day after birth (DAB), their left sides were photographed and morphometric parameters, including total length, head length, tail length, trunk length, eye diameter, snout length, and body depth were measured. The newly hatched fries were 8.3 ± 0.431 and 12.58 ± 0.234 mm in TL on 1 and 60 DAB, respectively. The results revealed growth priorities of this species during the early developmental stages. Based on the results, this species born with developed jaws and eyes that capable them to take the food immediately after birth and increasing the size of the mouth afterward to take larger food item. The inflection points of the most body segments are occurred during 30-35 days after birth showing a late morphological change in compare to oviparous species. These morphological changes are associated to head and snout lengths may be related to changing in feeding habit of this species. In addition, positive growth pattern of tail length is occurred earlier on 7 DAB improving its swimming capability to avoid predators and catch preys.

Effects of multi-walled carbon nanotubes (MWNTs) on flame retardation as well as thermal stabilization efficiency of two phosphorus-containing flame retardant systems i.e., ammonium polyphosphate/pentaerythritol (APP/PER) and red phosphorus (RP) in polypropylene (PP) have been investigated. Limiting oxygen index, thermo-gravimetric analysis, melt flow index, and tensile tests have been performed in this study. Moreover, the structure of the nanocomposites was characterized by scanning electron microscopy (SEM). SEM images revealed good dispersion of fillers in the polymer matrix. Furthermore, it was shown that the addition of MWNTs alone at a minimum loading level of 4 wt% improves thermal stability of PP considerably without any undesirable effect on its flow-ability and mechanical properties. Moreover, addition of MWNTs alone resulted in a slight improvement of flammability of the polymer. However, comparison between thermal stability and flame retardancy of PP samples containing a combination of MWNTs and APP/PER or RP and those of the samples containing APP/PER or RP alone proved that MWNTs interfere with thermal stabilization and flame retardation efficiency of both APP/PER and RP in the polymer.

Morphological developments, including fins, body proportions and pigmentation in Poecilia reticulata larvae, were described under rearing conditions. Body length of larvae were 4.5 to 5 mm just after birth (day-0), reaching 11.9 to 13.5 mm on day-30 after birth. The anal fin modified on day-23 in males and females. The caudal fin coloured on day-28 after birth in males. Male and female distinguished by gonopodium, body colour pattern and size on day-40. The majority of both sexes were sexually mature and fins are fully developed on day-50 after birth.

Investigation of the ecology of introduced species in new habitats can allow determinations of the degree, direction, and rate of evolutionary change. The introduction of Gambusia holbrooki in the southern Caspian Sea presents such a situation. We evaluated the life history traits of mosquitofish in the Tajan River basin. A total of 744 G. holbrooki specimens were collected between January and December 2008. The maximum observed ages are 0+ years for males and 1+ years for females. Both sexes grew allometrically (negative for males: b=2.442 and positive for females: b=3.232). The overall sex ratio is unbalanced and dominated by females. GSI values suggest that this population of G. holbrooki matures between February–July. The highest mean GSI value is 1.80 for males and 15.97 for females in May. Egg diameter ranges from 1.00 to 3.00 mm with a mean value of 2.098 mm. Absolute fecundity varied from 7 to 57 eggs. Both ova diameter and absolute fecundity were positively correlated to fish size (length and weight). Fecundity relative to total weight fluctuated from 34.44 to 582.64 eggs/g, and to total length from 2.33 to 12.95 eggs/cm. Both were negatively correlated with female size. The characteristics of this population are important with respect to life history of the species.

The time to diagnosis of multiple sclerosis (MS) is of great importance for early treatment, thereby reducing the disability and burden of the disease. The purpose of this study was to determine the time from the onset of clinical symptoms to the diagnosis of MS and to evaluate the factors associated with a late diagnosis in Iranian MS patients. The present cross-sectional study was conducted on patients with MS who were registered in the National MS Registry System of Iran (NMSRI). Overall, 23291 MS patients registered in 18 provinces of Iran were included in this study. The mean (standard deviation) interval between the onset of the disease and diagnosis of MS was 13.42 (32.40) months, and the median was one month. The diagnostic interval of 41.6% of patients was less than one month, and 14.8% of them had a one-month time to diagnosis. Patients with an age of onset below 18 years and those diagnosed after the age of 50 years had a longer time to diagnosis (P<0.001). Patients with primary progressive MS (PPMS) had the longest time to diagnose and those with relapsing-remitting MS (RRMS) had the shortest time (P<0.001). The results of negative binominal regression showed that the average rate of delay in diagnosis in women was 12% less than that in men. The average delay in diagnosis in patients with a positive family history of MS was 23% more than that in others. The rate of delay in the diagnosis of patients with PPMS and secondary progressive MS was 2.22 and 1.66 times higher, respectively, compared with RRMS. The findings of the present study revealed that more than half of the MS patients were diagnosed within a one-month interval from the symptom onset, which is an acceptable period. More attention should be paid to patients’ access to medical facilities and MS specialists. •The mean time from clinical symptoms onset to diagnosis of MS was 13.42 months.•in cases registered in the National MS Registry of Iran.•More than half of the MS cases were diagnosed within one-month interval.•Age at symptoms onset, age at the time of diagnosis, male sex and type of MS.•were associated factors to a late diagnosis in Iranian MS subjects.