Dental fear and its determinants in 7-11-year-old children in Tehran, Iran.

AIM: To assess dental fear and its determinants in 7-11-year-old children. METHODS: In this cross-sectional (descriptive-analytical) study, the standard Persian version of the Children's Fear Survey Schedule-Dental Subscale (CFSS-DS) questionnaire was completed by 240 parent-child (children aged 7-11 years) pairs referred to dental clinics in Tehran city, Iran. Background characteristics were also inquired. RESULTS: An equal number of boys and girls participated in the study. The mean score of fear among the children was 21.66 ± 8.33. The causes of fear among the children were, first, injection, and then, seeing the dentist's drill, choking feeling, and finally, filling the tooth. There was a significant correlation between the scores of children's dental fear and their experience of meeting with the dentist (p = 0.001). The result of the regression test showed that the age of the children (p = 0.022) and high levels of dental fear among their fathers (p < 0.001) was related to high levels of dental fear among the children. CONCLUSIONS: The present children revealed a moderate level of dental fear. Taking children's age into account in behavioural management and challenging father's fear seemed to play a key role to reduce the child's fear and prevent its long-term consequences.

Honey improves spermatogenesis and hormone secretion in testicular ischaemia-reperfusion-induced injury in rats.

This study was conducted to survey the protective effect of pre-treatment with Persian honey during post-ischaemia reperfusion on ischaemia-reperfusion (IR)-induced testis injury. Animals were divided into four groups of IR, honey + ischaemia- reperfusion (HIR), vitamin C + ischaemia- reperfusion (VIR) and carbohydrates + ischaemia- reperfusion (CIR). The testes were examined for spermatogenesis index. Detection of single- and double-stranded DNA breaks at the early stages of apoptosis was performed. Total serum concentration of FSH, LH and testosterone was measured using ELISA. All data were expressed as mean ± SD in each group, and significance was set at p ≤ .05. Spermatogenesis index was significant in the HIR group (p < .001). Serum levels of FSH and LH were significantly higher in the CIR and HIR groups. Serum levels of testosterone were significantly higher in VIR and HIR groups. Apoptotic cells in IR and CIR groups increased significantly statistically (p < .001), while in HIR and VIR groups, the number of apoptotic cells decreased and the positive cells of TUNEL staining were detected in spermatocytes and spermatid. The present study indicates that honey decreases the cellular damage and apoptosis during testicular I/R injury, with significant protective effects on reproductive hormone production.

Mobilization of malpositioned dental implant using segmental osteotomy: A case report.

By increasing the number of replaced tooth with dental implants, the number of poorly positioned implants is also increased. In this article, we present our experience about a 48-year-old female who was referred to our department for resolving prosthetic problem regarding two malpositioned implants inserted in the upper jaw. The interocclusal space was insufficient and the two adjacent implants had excessive buccal angulation. To overcome these problems, segmental osteotomy of the alveolar bone containing two implants has been done. After palatal and apical repositioning of the bone block, rigid fixation was performed using a 4-hole miniplate and four 5mm monocortical screws. Two weeks after the procedure, a conventional fixed prosthesis was constructed with regard to the esthetic and functional aspects. During the two-year follow-up, the patient was satisfied with the result and there were no complications, such as alveolar bone necrosis, marginal bone loss, implant failure or infection.

Immunogenicity of a fusion protein containing PilQ and disulphide turn region of PilA from Pseudomonas aeruginosa in mice.

Interference with bacterial adhesion is a new means to prevent or treat bacterial infections. In this experimental study we evaluated the immunogenic properties of a chimeric protein composed of PilQ and disulphide turn region of PilA from Pseudomonas aeruginosa in mice as an anti-adhesion based vaccine. First of all, a chimeric bivalent protein composed of PilQ and PilA was constructed and following subcutaneous immunization with merely the purified protein or in its admixed form with alum, the immunogenicity of the chimeric antigen was assessed in BALB/c mice. Then, the characteristics of the developed antibodies were studied by ELISA. Furthermore, the immunoreactivity of the purified recombinant protein was confirmed by immunoblotting. Alum as a common adjuvant boosted immunogenicity of the construct, resulting significantly greater anti-pili IgG titre. Mice antibody response consisted of IgG1, IgG2a, IgG2b and IgG3 subtypes with predominance of IgG1 subclass. The developed antibodies were capable to inhibit motility of PAO1 strain. In conclusion, our primary results revealed that the designed recombinant protein is a protective construct and may be used as a potential candidate for prophylactic purposes against P. aeruginosa infection. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study we examined the potential of integrated PilQ/PilA (QA) antigen as a vaccine candidate against Pseudomonas aeruginosa. Nowadays, anti-adhesion based vaccines are considered as new means to prevent or treat bacterial infections. Our study revealed that chimeric protein PilQ and disulphide turn region of PilA triggers production of specific antibodies. This humoral immune responses augmented when QA was administered in combination with an adjuvant. The results demonstrated efficacy of the designed recombinant chimeric antigen as an effective candidate in prevention of P. aeruginosa infection.

Oral Administration of Vitamin C, Cimetidine and Famotidine on Micronuclei Induced by Low Dose Radiation in Mouse Bone Marrow Cells.

BACKGROUND: In many studies, chemicals and natural materials were tested to reduce the harmful effects of radiation. It is known that Famotidine and vitamin C reduce DNA damage. OBJECTIVE: The aim of this study was to evaluate the radioprotective effect of vitamin C, Cimetidine and Famotidine on gamma-radiation-induced damage on mouse bone marrow. METHODS: Six-to-seven week male NMRI mice (28 g ±3) were randomly divided into fourteen groups: control, 2Gy irradiation, six group drugs without irradition (Famotidine, Cimetidine, vitaminC, Fam-Cim, Fam-Vit, Cim-Vit), six groups received drugs and 2Gy radiation with a 60Co |γ|-ray source at room temperature 22 ± 2 °C. The mice were killed 48 hours after irradiation by cervical dislocation. Slides were prepared from bone marrow cells and stained in May-Granwald and Giemsa. Finally, the cells were counted with microscope, frequencies of polychromatic erythrocyte (PCE), normochoromatic erythrocyte (NCE) and their micronuclated cell were recorded. PCE / PCE + NCE were calculated. RESULTS: There were significant differences of MNPCE/1000PCE, MNNCE/1000NCE and PCE/PCE+NCE among different groups with similar radiation doses (p≤0.01). Moreover, there were significant differences of MNPCE/1000PCE and PCE/PCE+NCE among different doses of radiation (p≤0.01). While considering MNNCE/1000NCE, there were no significant differences among silimar groups with radiation dose (p˃0.05). CONCLUSION: Oral administration of Famotidine, vitamin C and Cimetidine demonstrate reliable and similar radioprotective effects. Additionally, the protective effect of single use of these drugs was similar to the combination form. Thus, the oral use of combination, 48 hours after irradiation cannot induce more radioprotective effect.

Size-dependent inhibition of herpesvirus cellular entry by polyvalent nanoarchitectures.

Carbon-based architectures, especially graphene and its derivatives, have recently attracted much attention in the field of biomedicine and biotechnology for their use as pathogen inhibitors or biosensors. One of the major problems in the development of novel virus inhibitor systems is the adaption of the inhibitor to the size of virus particles. We here report the synthesis and biological testing of carbon-based inhibitors differing in size for evaluating the potential size effect on the inhibition of virus entry and replication. In this context, different sized nanomaterials were functionalized with polygylcerol through a "grafting from" polymerization to form new polyvalent nanoarchitectures which can operate as viral inhibitor systems after post-modification. For this purpose a polysulfation was carried out to mimic the heparan sulfates present on cell surfaces that we reasoned would compete with the binding sites of herpes simplex virus type 1 (HSV-1) and equine herpesvirus type 1 (EHV-1), which both cause major global health issues. Our results clearly demonstrate that the inhibitory efficiency is regulated by the size of the polymeric nanomaterials and the degree of sulfation. The best inhibiting graphene sheets were ∼300 nm in size and had a degree of sulfation of ∼10%. Furthermore, it turned out that the derivatives inhibited virus infection at an early stage during entry but did not affect cell-to-cell spread. Overall, tunable polyvalent nanomaterials are promising and efficient virus entry inhibitors, which can likely be used for a broad spectrum of enveloped viruses.

Stemness of spermatogonial stem cells encapsulated in alginate hydrogel during cryopreservation.

This study investigated the effect of spermatogonial stem cell encapsulated in alginate hydrogel during cryopreservation, as cells were protected against damage during cryopreservation within the hydrogel. Spermatogonial stem cells were isolated from the testes of Balb/c mice pups (6 days old), purified in laminin-coated dishes and CD90.1 microbeads, encapsulated in alginate hydrogel and then cryopreserved. After thawing, cell viability and Spermatogonial stem cell (SSC) colony diameter were evaluated. After RNA was isolated and cDNA was synthesised, the expression of stemness genes was considered using RT real-time PCR. Finally, spermatogonial stem cells labelled with BrdU were transplanted to busulfan azoospermic mouse models. Lin28a and Sall4 genes were significantly upregulated after cryopreservation in alginate hydrogel. However, cell viability was significantly decreased. The diameter of colonies consisting of spermatogonial stem cells freeze-thawed in alginate microbeads showed no significant difference with fresh spermatogonial stem cells and the control group. The injection of freeze-thawed spermatogonial stem cells encapsulated in alginate hydrogel resulted in spermatogenesis recovery. Alginate mimics the extracellular matrices (ECM) for spermatogonial stem cells; therefore, it can support stemness potential during the cell cryopreservation process and restart spermatogenesis after transplantation.

Allele specific-PCR and melting curve analysis showed relatively high frequency of ß-casein gene A1 allele in Iranian Holstein, Simmental and native cows.

There are two allelic forms of A1 and A2 of ß-casein gene in dairy cattle. Proteolytic digestion of bovine ß-casein A1 type produces bioactive peptide of ß-casomorphin-7 known as milk devil. ß-casomorphin-7 causes many diseases, including type 1 diabetes, cardiovascular disease syndrome, sudden death and madness. The aim of the present study was to determine the different allelic forms of ß-casein gene in Iranian Holstein, Simmental and native cattle in order to identify A1 and A2 variants. The blood samples were collected randomly and DNA was extracted using modified salting out method. An 854 bp fragment including part of exon 7 and part of intron 6 of ß-casein gene was amplified by allele specific polymerase chain reaction (AS-PCR). Also, the accuracy of AS-PCR genotyping has been confirmed by melting temperature curve analysis using Real-time PCR machinery. The comparison of observed allele and genotype frequency among the studied breeds was performed using the Fisher exact and Chi-squared test, respectively by SAS program. Obtained results showed the A1 allele frequencies of 50, 51.57, 54.5, 49.4 and 46.6% in Holstein, Simmental, Sistani, Taleshi and Mazandarani cattle populations, respectively. The chi-square test was shown that no any populations were in Hardy-Weinberg equilibrium for studied marker locus. Comparison and analysis of the test results for allelic frequency showed no any significant differences between breeds (P>0.05). The frequency of observed genotypes only differs significantly between Holstein and Taleshi breeds but no any statistically significant differences were found for other breeds (P>0.05). A relatively high frequency of ß-casein A1 allele was observed in Iranian native cattle. Therefore, determine the genotypes and preference alleles A2 in these native and commercial cattle is recommended.

[Evaluation of miR-122 level in the plasma of chronically HCV infected patients].

MicroRNAs (miRNAs) are small non-coding RNA molecules, which have an important function in regulating RNA stability and gene expression. They also can circulate in a cell-free form in the blood thatmakes them potential disease markers. The liver contains various classes of miRNAs in which miR-122 accounts for about 70% of all miRNAs and it has been proved that its level increases in case of liver damage. Here, we investigated plasma levels of miR-122 as a useful disease parameter in patients with chronic hepatitis C (CHC) infection. Thirty five hemophilia and thalassemia patients with CHC were studied. The total RNA was extracted from plasma samples, and miR-122 levels were measured by qPCR and then compared with the specific liver markers. The plasma levels of alanine transaminase (ALT) and aspartate transaminase(AST) were correlated with plasma miR-122 level in CHC patients, and the level of circulating miR-122 in healthy individual groups were rarely lower than those of patients with CHC. In our study, miR-122 levels correlated well with markers of liver inflammatory activity. Plasma miR-122 can be assumed to be another marker in liver similar to the currently used specific markers such as ALT and AST for evaluation of liver damage in hepatitis C virus (HCV) infected patients. Moreover, the correlation between miR-122 and ALT was shown to be higher than between miR-122 and AST.

Reduction of autophagy markers mediated protective effects of JNK inhibitor and bucladesine on memory deficit induced by Aß in rats.

Autophagy, the process of self-degradation of cellular components, has an important role in neurodegenerative diseases, such as Alzheimer's disease. In this study, we investigated the effects of SP600125 as c-Jun N-terminal kinase (JNK) inhibitor and bucladesine as a cyclic adenosine 3',5'-monophosphate (cAMP) analog on spatial memory and expression of autophagic factors in Aß-injected rats. Male Wistar rats were used. Rats were randomly allocated into five groups as following: amyloid beta (Aß)-only group, Aß + SP600125 (30 µg/1 µ/side, n = 7) and/or bucladesine (100 µM/1 µl/side, n = 7), and the normal control (vehicle only) group. The treatments were administered bilaterally to the CA1 sub-region of the hippocampus stereotaxically. Spatial reference memory was performed using Morris Water Maze 21 days later. The expression of authophagy markers (beclin1, Atg7, Atg12, and LC3 II/LC3 I) in the hippocampus was evaluated using western blotting. Compared to the vehicle group, Aß administration reduced spatial reference learning (P < 0.001) and memory (P < 0.01) and upregulated the expression of beclin1, Atg7, Atg12, and LC3 II/I (P < 0.0001). Compare to Aß-only group, the administration of SP600125 and/or bucladesine improved spatial reference learning (P < 0.001) and memory (P < 0.01). Compared to the Aß-only group, the treatment with SP600125 and/or bucladesine also reduced beclin1, Atg7, Atg12, and LC3 II/I (P < 0.0001) which was similar to amount of normal rats. In summary, it seems that the improvement of spatial memory by SP600125 and/or bucladesine in Aß-injected rats is in relation with normalizing of autophagy to the physiologic level, possibly through neuroprotection and/or neuroplasticity.

Using the variability of linkage disequilibrium between subpopulations to infer sweeps and epistatic selection in a diverse panel of chickens.

A whole-genome scan for identifying selection acting on pairs of linked loci is proposed and implemented. The scan is based on , one of Ohta's 1982 measures of between-population linkage disequilibrium (LD). An approximate empirical null distribution for the statistic is suggested. Although the partitioning of LD into between-population components was originally used to investigate epistatic selection, we demonstrate that values of may also be influenced by single-locus selective sweeps with linkage but no epistasis. The proposed scan is implemented in a diverse panel of chickens including 72 distinct breeds genotyped at 538 298 single-nucleotide polymorphisms. In all, 1723 locus pairs are identified as putatively corresponding to a selective sweep or epistatic selection. These pairs of loci generally cluster to form overlapping or neighboring signals of selection. Known variants that were expected to have been under selection in the panel are identified, as well as an assortment of novel regions that have putatively been under selection in chickens. Notably, a promising pair of genes located 8 MB apart on chromosome 9 are identified based on as demonstrating strong evidence of dispersive epistatic selection between populations.

Adenocarcinoma cells isolated from patients in the presence of cerium and transferrin in vitro.

AIM: Cerium as a trace element in the periodic table is a member of the lanthanide group. Cerium ionic radius and its binding properties are similar to ferric ions, which may be bound to transferrin. So it can be considered as a competitive element to iron and can interfere with iron absorption. The aim of this study was to investigate the inhibitory effect of Cerium in presence of transferrin on gastric adenocarcinoma cells in vitro. METHODS: The adenocarcinoma cells were obtained from patients after a pathological confirmation, then they were cultured in DMEM environment and cytotoxic effect of different concentrations of cerium were measured (0.1, 1, 10 and 100 µM) in the presence and absence of transferrin, on periods 24 and 48 hours by MTT and LDH cytotoxic assay. RESULTS: The results of MTT and LDH measurements showed that Cerium itself has a cytotoxic effect on cancer cells isolated from the patient as well as it increases significantly in the presence of transferrin carrying a mortality rate of cancer cells (P <.05). CONCLUSION: Cerium is competitive element in the mechanism of iron absorption and can interfere and inhibit the growth of adenocarcinoma cancer cells; also, the use of Cerium and transferrin simultaneously may cause a greater inhibitory effect.

Delamination of graphite oxide in a liquid upon cooling.

Graphite oxide (GO) in liquid acetonitrile undergoes a transition from an ordered phase around ambient temperature to a gel-like disordered phase at temperatures below 260 K, as demonstrated by in situ X-ray diffraction. The stacking order of GO layers is restored below the freezing point of acetonitrile (199 K). The reversible swelling transition between a stacked crystalline phase and an amorphous delaminated state observed upon cooling provides an unusual example of increased structural disorder at lower temperatures. The formation of the gel-like phase is attributed to the thermo-responsive conformational change of individual GO flakes induced by stronger solvation. Scanning force microscopy demonstrates that GO flakes deposited onto a solid substrate from acetonitrile dispersions at a temperature below 260 K exhibit corrugations and wrinkling which are not observed for the flakes deposited at ambient temperature. The thermo-responsive transition between the delaminated and stacked phases reported here can be used for sonication-free dispersion of graphene oxide, micro-container applications, or the preparation of new composite materials.

Decellularized human amniotic membrane: more is needed for an efficient dressing for protection of burns against antibiotic-resistant bacteria isolated from burn patients.

Human amniotic membranes (HAMs) have attracted the attention of burn surgeons for decades due to favorable properties such as their antibacterial activity and promising support of cell proliferation. On the other hand, as a major implication in the health of burn patients, the prevalence of bacteria resistant to multiple antibiotics is increasing due to overuse of antibiotics. The aim of this study was to investigate whether HAMs (both fresh and acellular) are an effective antibacterial agent against antibiotic-resistant bacteria isolated from burn patients. Therefore, a HAM was decellularized and tested for its antibacterial activity. Decellularization of the tissue was confirmed by hematoxylin and eosin (H&E) and 4,6-diamidino-2-phenylindole (DAPI) staining. In addition, the cyto-biocompatibility of the acellular HAM was proven by the cell viability test (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, MTT) and scanning electron microscopy (SEM). The resistant bacteria were isolated from burns, identified, and tested for their susceptibility to antibiotics using both the antibiogram and polymerase chain reaction (PCR) techniques. Among the isolated bacteria, three blaIMP gene-positive Pseudomonas aeruginosa strains were chosen for their high resistance to the tested antibiotics. The antibacterial activity of the HAM was also tested for Klebsiella pneumoniae (American Type Culture Collection (ATCC) 700603) as a resistant ATCC bacterium; Staphylococcus aureus (mecA positive); and three standard strains of ATCC bacteria including Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27833), and S. aureus (ATCC 25923). Antibacterial assay revealed that only the latter three bacteria were susceptible to the HAM. All the data obtained from this study suggest that an alternative strategy is required to complement HAM grafting in order to fully protect burns from nosocomial infections.

Isolation a new strain of Kocuria rosea capable of tolerating extreme conditions.

A new actinobacterial strain was isolated from Ab-e-Siah spring (dark water) taken from the Ramsar city in Iran, and subjected to several stress conditions investigation. The isolate, named MG2 strain, was Gram-positive, aerobic, diplococci or tetrad shaped, non-spore forming and non-motile. Phylogenetic analysis of the isolate using 16S rDNA sequence indicated that the organism matched best with the genus Kocuria and the highest sequence similarities (98.55%) being found with Kocuria rosea. The 16S rDNA sequence determined in this study has been deposited in the NCBI database with the accession no. JX534199, K. rosea strain MG2. The isolated strain was an alkaliphilic-mesophilic bacterium because the optimal growth was observed at pH 9.2 and temperature of 28 °C under aerobic condition. MG2 was a halotolerant strain and tolerated maximally to 15% NaCl concentraion. Viability analysis by flow cytometry indicated that this strain had highly resistance to UV-C radiation and moderately resistance to desiccation after 28 days. The viability of K. rosea strains MG2 and Deinococcus radiodurans R1 were determined D87 and D98 according to D index, respectively, by a dose radiation 25 J/cm (Appukuttan et al., 2006). Thus the UV resistance of strain MG2 was comparable with representative radiation resistant Deinococcus. Also MG2 was grown at 1-4% of H2O2 as an oxidant agent. This research is the first study on multiple extreme resistance of Kocuria rosea new strain (MG2) isolated in Iran.

C. zeylanicum aqueous extract induced apoptosis in the human myelocytic leukemia cell line (THP-1).

OBJECTIVE: The aim of this study was to evaluate the effect of C. zeylanicum aqueous extract on cell growth in the human myelocytic leukemia cell line (THP-1). BACKGROUND: Today, application of Cinnamon for treatment of cancer investigates extensively. Cinnamon has antioxidant, anti-apoptotic and anti-inflammatory properties. METHODS: In this experimental study, THP-1 was incubated in 2, 1, 0.1 and 0.01 mg/ml C. zeylanicum solutions for 24, 48 and 72 hours. Cell cycle was assessed with flow cytometry. Apoptotic cells were identified by Hoechst 33342 staining. Cell proliferation was assessed by the MTT assay. The data were analyzed using descriptive statistics and analytical tests. RESULTS: Samples that supplemented with 0.1 mg/ml C. zeylanicum aqueous extract enhanced induction of apoptosis in THP-1 cell line compared to samples that supplemented with 2, 1 and 0.01 mg/ml. According to flow cytometry analysis, after 24 and 72 hours of incubation in 0.1 and 2 mg/ml C. zeylanicum aqueous extract, respectively, the amount of cells in apoptosis phase was higher than that in the control sample. CONCLUSION: Supplemented C. zeylanicum aqueous extract induced apoptosis in the human myelocytic leukemia cell line (Fig. 4, Ref. 20).

Knowledge of and attitudes towards periodontal health among adults in Tehran.

Determining what people know and believe about periodontal health and disease is important in order to establish prevention practices. This study aimed to assess knowledge of and attitudes towards periodontal health among adults in Tehran, Islamic Republic of Iran. We conducted a cross-sectional face-to-face interview survey in 2011 of 791 adults aged 18-50 years using a stratified, multistage sampling method. We recorded demographic characteristics including age, sex, education, marital status, employment and economic status (housing density). The lowest percentage of correct answers was related to the definition of dental plaque (11.6%) and the highest was for the role of the dental visit in prevention (92.8%). Female sex, university education and higher economic status were significantly associated with a higher mean score on periodontal health knowledge. The regression analysis showed that positive attitudes were associated with higher periodontal health knowledge and having university education. In this study positive attitudes towards prevention were related to better knowledge.

A retrospective analysis of maxillofacial trauma in shiraz, iran: a 6-year- study of 768 patients (2004-2010).

STATEMENT OF PROBLEM: Information about the etiology and incidence of maxillofacial trauma is important for prevention and appropriate treatments of such injuries. PURPOSE: The purpose of this retrospective study was to conduct an analysis of maxillofacial injuries transferred and/or referred to the department of maxillofacial Surgery at Chamran emergency hospital, Shiraz, over a 6-year period with special reference to age, gender, occupation, date, type, site, etiology and clinical management. MATERIALS AND METHOD: The data for this study were collected and reviewed retrospectively from the records and radiographs of 768 patients who were treated for maxillofacial trauma in the department of maxillofacial surgery at the Shiraz Chamran Emergency Hospital, Iran, between 2004 and 2010. RESULTS: A total of 730 of the subjects were the patients with fractures of the facial skeleton. The mean age was 26.6± 12.6 years, ranging from 2 to 81 years. Traffic accident was the most frequent etiological factor of maxillofacial fractures irrespective of gender (69.9% for men and 54.2% for women), whereas the second most frequent cause of injuries was falling down (9.8% for men and 21.5% for women) .The other etiologies were assaults (5.2%), sport related injuries (1.3%) and firearm injuries (1%). Regarding the head injuries in patients with maxillofacial fractures, brain contusion was seen in 227(29.6%) patients and 13.5% of patients had lacerations in the facial soft tissue. The monthly distribution peaked in October, with 81 cases (10.5%), which would be for the reason that schools open in this month. The next highest incidence was in December, with 80 cases (10.4%), probably because of the changing weather's effect on road traffic. CONCLUSION: Isolated mandibular fracture due to the road traffic accident was the most common type of maxillofacial injuries in the city of Shiraz.

Incredible antibacterial activity of noble metal functionalized magnetic core-zeolitic shell nanostructures.

Functionalized magnetic core-zeolitic shell nanostructures were prepared by hydrothermal and coprecipitation methods. The products were characterized by Vibrating Sample Magnetometer (VSM), X-ray powder diffraction (XRD), Fourier Transform Infrared (FTIR) spectra, nitrogen adsorption-desorption isotherms, and Transmission Electron Microscopy (TEM). The growth of mordenite nanoparticles on the surface of silica coated nickel ferrite nanoparticles in the presence of organic templates was also confirmed. Antibacterial activity of the prepared nanostructures was investigated by the inactivation of Escherichia coli as a gram negative bacterium. A new mechanism was proposed for inactivation of E. coli over the prepared samples. In addition, the Minimum Inhibitory Concentration (MIC) and reuse ability were studied. TEM images of the destroyed cell wall after the treatment time were performed to illustrate the inactivation mechanism. According to the experimental results, the core-shell nanostructures which were modified by organic agents and then functionalized with noble metal nanoparticles were the most active. The interaction of the noble metals with the organic components on the surface of nanostructures was studied theoretically and the obtained results were used to interpret the experimental results.

Tinidazole removal from aqueous solution by sonolysis in the presence of hydrogen peroxide.

Aqueous solutions of the tinidazole (TNZ) have been treated by applying the combination of ultrasound irradiation and H2O2. Based on the results, the maximum removal efficiency of 75% was achieved under the optimum operating conditions (pH 3, 120 kHz frequency, 333 mM/L of H2O2 and 150 min of operating time) while, under the same conditions the minimum removal efficiency was found to be 8.5 by ultrasound radiation in the absence of H2O2. The results also revealed that the degradation of TNZ was enhanced with decreasing both TNZ initial concentrations and pH. Furthermore, TNZ removal efficiency in the case of actual wastewater was less than of synthetic wastewater (75% and 68% of synthetic and actual, respectively). According to the chromatographic analyses, no harmful intermediate compounds were observed. The chemical oxygen demand analysis (65% reduction) confirmed our findings.