Evaluation the thermodynamic behavior of nonionic polyoxyethylene surfactants against temperature changes

Micellization is the most important property of surface agents. It plays an important role in the manufacture of pharmaceutical products. The surfactants have many applications in industry, agriculture, mining and oil recovery with functional properties as wetting, foaming and emulsifier in pharmaceutical and cosmetic products. The micellization parameters of surfactants help the manufacture of pharmaceutical products to be appropriate and stable. Therefore, in this study, Polyoxyethylene lauryl ether [C[12]E[23]], Polyoxyethylene [10] cetyl ether [C[16]E[10]] and Polyoxyethylene [20] cetyl ether [C[16]E[20]] were chosen as the nonionic surfactants to examine the effect of temperature variation [10-80[degree]C] on the Critical Micelle Concentration [CMC]. The measurement of surface tension was done by a Du Nöuys ring method. The value of CMC was obtained from the surface tension vs. surfactant concentration curve. Since the temperature was increased, the CMC initially decreased and then increased for each surfactant because the formation of the hydrogen bond is harder in the high temperatures. The surface tension gamma CMC for all three surfactant solutions decreased monotonically as the temperature increased. delta G[degree]m, delta H[degree]m and delta S[degree]m as the thermodynamic parameters of micellization, were also estimated and analyzed. The delta G[degree]m was decreased [10-80[degree]C] if the temperature was increased. The entropy and enthalpy correlation of micellization showed a significant linearity. For C[12]E[23], C[16]E[20] and C[16]E[10], the compensation temperature [Tc] was obtained 309.5, 313.2 and 314.4 K, respectively. The calculated thermodynamic parameters showed that the entropy influenced on the micellization process at lower temperature, but it affected by enthalpy when temperature was increased

Antimicrobial effect of nano-zinc oxide and nano-chitosan particles in dental composite used in orthodontics

Incidence of white spots due to demineralization of enamel and gingival problems is an unacceptable result of orthodontic treatment. Plaque accumulation and bacterial biofilm growth are responsible for these phenomena. The resin-based dental composites used as bonding agents in orthodontics play a major role in mentioned problems. As recent researches assert the antimicrobial effects of chitosan [CS] and zinc oxide [ZnO] nanoparticles [NPs], it seems that adding these nanoparticles to the composite can be beneficial in reducing the number and function of microorganisms. The aim of this study was to evaluate the antimicrobial effects of ZnO-NP and CS-NP-containing orthodontic composite. Antibacterial effectiveness of ZnO-NPs and CS-NPs was assessed in four groups against Streptococcus mutans, Streptococcus sanguis and Lactobacillus acidophilus grown both planktonic and as a biofilm on composites. One group as the unmodified control group and three groups consisting of three different concentrations of ZnO-NPs and CS-NPs mixture: 1%, 5% and 10% [1:1 w/w]. 10[8] CFU/ml microorganism suspensions were provided with spectrophotometer. Biofilm formation was quantified by viable counts. Disc agar diffusion [DAD] test was carried out to determine antimicrobial effects of nanoparticles by measuring the inhibition diameter on brain heart infusion agar plates. Finally,viable counts of microorganisms on days 3, 15 and 30 were collected for the antimicrobial effects of eluted components from composite discs. In biofilm formation test, a reduction in bacterial counts was observed with 10% nanoparticle-containing composites compared with their unmodified counterpart. In the DAD test only 10% nanoparticle-containing specimens showed statistically significant inhibition. The only noticeable datain eluted component test was on day 30 for 10% nanoparticle-containing discs, inhibiting L. acidophilus. It seems that a mixture of ZnO-NPs and CS-NPs has induced an antibacterial activity in resin composite; especially in 10% weight concentrations which was significantly higher than other groups

Fracture and aspiration of tracheostomy tube

Methods of opening the airways like tracheostomy are used to provide appropriate ventilation for patients with upper airway problems. Tracheostomy may be accompanied by some complications. In the present study, we reported a 41- year-old man with progressive dyspnea and cyanosis induced by fracture of tracheostomy tube. He referred to our center and a chest x-ray was obtained showing fracture of tracheostomy tube within trachea. He underwent surgery and fractured tracheostomy was removed/ extracted. A plastic tracheostomy tube was placed for him and he discharged the day after. Fracture and aspiration of tracheostomy tube is a rare complication which requires a prompt and precise management. Patient education regarding the maintenance of tracheostomy tube for prevention of this complication is highly recommended

Comparison between CT-scan and trans-abdominal sonography in celiac and splanchnic plexus blocks in patients with advanced pancreatic head cancer

Malignant diseases are usually associated with severe pain during their course especially at the end stages. Pancreatic head cancer is one of these diseases which can be associated with severe intolerable pains in the end stages. Sometimes, these pains are extremely severe and interfere with patient's normal life. There are various techniques to control the pain out of which, celiac and splanchnic plexus blocks [temporary and permanent] are widely accepted procedures especially in severe cases and can control the pain efficiently. There are different approaches for performing this block which are all acceptable technically but are different in case of efficacy, accuracy and potential complications. Two groups were studied prospectively in 3 academic centers to evaluate different techniques of celiac plexus block in terms of feasibility and complications. For this purpose, 61 patients with a confirmed pancreatic head cancer who experienced severe pains were divided into two groups. CT- and sonographically-guided celiac and splanchnic plexus blocks were evaluated in group 1 [n=32] and group 2 [n=29], respectively. This study showed that the pain control and patients' satisfaction were greater in the CT-scan group [group A, p=0.18]. The success rate of performing a ganglion block was higher in the ultrasound group [group B, p=0.000]. The need for a re-block was also higher in the latter group. But, the quality of life improved more in the first group [CT-scan group]. However, no statistically significant difference was found between the two groups regarding these two variables. Pain relief started earlier and lasted longer in the CT-scan group. No complication was detected except for one case of abdominal infection in the sonography group and in some cases a mild pain [score<3] was reported which was not significant. Considering the limited number of cases, it seems that although there was no significant difference in the outcome of plexus block or related complications between the two above-mentioned procedures, the suggested imaging technique for celiac plexus block is CT-scan because of its feasibility, accuracy and lower number of trials to achieve a favorable result. More complementary assessments are recommended to obtain more precise results

Asthmatic pulmonary eosinophilia

The case of a 20 years old female suffering from pulmonary eosinphilia with bronchial asthma who had been on various drug regimes for a long time, is described. She was given antimycotic drugs resulting in prompt relief