Effect of foreign impurity and growth temperatures on hexagonal structure and fundamental properties of ZnO nanorods.

This study examined the influence of growth temperature and dopant concentration on the properties of Gd- and Ni-doped zinc oxide nanorods (ZnO NRs). ZnO seed layers were deposited on glass substrates using a sol-gel and dip-coating approach. Gd- and Ni-doped ZnO NRs were hydrothermally grown on the seed layers at different temperatures such as 75, 90, and 105°C for a constant growth time of 5 h. The crystal structure, optical, surface morphology views, and electrical properties of the NRs were extensively investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy, and four probe experimental methods. The XRD analysis confirmed the successful substitution of Zn2+ ions by Gd3+ and Ni2+ within the ZnO main matrices. The reordering of hexagonal structures with varied electronegativity, ionic radius dimensions, and valence electron states of Gd and Ni dopants affected seriously the fundamental characteristic features of NRs. The SEM images showed that the ZnO NRs grown at 90°C possessed a more favorable surface morphology and well-defined hexagonal shape compared with those grown at other growth temperatures. Higher dopant concentration led to an increase in NR diameter but a decrease in density depending on the increase in the space between the NRs. Additionally, the optical transmittance was found to generally enhance with increasing dopant concentration. The results obtained highlighted the interplay between growth temperature, dopant type and concentration in tailoring the structural, morphological, and optical properties of Gd- and Ni-doped ZnO NRs, paving the way for the development of optimized nanomaterials for various applications. RESEARCH HIGHLIGHTS: The XRD analysis confirmed the successful substitution of Zn2+ ions by Gd3+ and Ni2+ within the ZnO main matrices. The SEM images showed that the ZnO NRs grown at 90°C possessed a more favorable surface morphology and well-defined hexagonal shape compared with those grown at other growth temperatures. The optical transmittance was found to generally enhance with increasing dopant concentration. The results obtained highlighted the interplay between growth temperature, dopant type and concentration in tailoring the structural, morphological, and optical properties of Gd- and Ni-doped ZnO NRs, paving the way for the development of optimized nanomaterials for various applications.

School Teachers' Knowledge and Attitudes about the Emergency Management of Traumatic Dental Injuries in Turkey.

OBJECTIVE: The emergency management of traumatized teeth is critical to their long-term outcomes. In school-aged children, most traumatic dental injuries (TDI) occur at school and teachers are often required to manage dental trauma (DT) emergencies. Therefore, the aim of this study was to determine teachers' knowledge and attitudes about TDI. RESEARCH DESIGN: Survey in 147 randomly selected schools in 53 cities in Turkey. A questionnaire enquiring about demographic data, knowledge of DT, and knowledge of first aid related to DT was distributed to primary school teachers. RESULTS: 1,634 completed questionnaires were returned (65% response rate). 92.5% of the teachers were not satisfied with their DT knowledge, and almost all (97.8%) had never received DT training, although 28.1% had witnessed at least one case of DT. In the case of tooth avulsion, 26.4% believed that an avulsed tooth would be permanently lost, whereas 28.9% knew that a permanent tooth could be replanted. CONCLUSIONS: Knowledge of emergency management of TDI among schoolteachers in Turkey is inadequate, and training on their emergency management should be provided.

Comparison of postoperative pain after foraminal enlargement of necrotic teeth using continuous rotary system and reciprocating instrument: A randomized clinical trial.

OBJECTIVES: This single-blind, randomized clinical trial (RCT) aimed to compare the duration, intensity, and incidence of postoperative pain after foraminal enlargement (FE) with continuous rotary systems and reciprocating instruments. MATERIALS AND METHODS: Sixty qualified patients were randomly divided into the following two groups: the ProTaper Next group and the WaveOne group. Participants were selected from patients who had both asymptomatic necrosis and asymptomatic apical periodontitis with a single root canal. Endodontic treatment was performed in one visit, and the patients were asked to record their pain severity and analgesic consumption during a 7-day follow-up period using a visual analog scale (VAS). The data were analyzed using the Mann-Whitney U-test and Chi-square test (P < 0.05). RESULTS: A significant difference was observed between the two groups during the first two days of follow-up (P < 0.05). Pain experience was higher in FEs that had been created by reciprocating instruments than by continuous rotary systems. There were no significant differences in VAS pain scores over the other days (P > 0.05). None of the patients had severe postoperative pain during the follow-up period. No significant differences were observed in the prevalence of analgesic consumption between either group (P > 0.05). CONCLUSIONS: This RCT indicates that in the 2-day follow-up period after endodontic treatment, FEs created by reciprocated instruments associated more postoperative pain than continuous rotary systems.

eNOS and XRCC4 VNTR variants contribute to formation of nicotine dependence and/or schizophrenia.

BACKGROUND: This study aimed to evaluate whether VNTR variants in the Endothelial Nitric Oxide Synthase (eNOS) and the XRCC4 gene play any role in nicotine dependence (ND) and/or Schizophrenia+ND (Sch+ND) ethiopathogenesis. METHODS: Present study included 100 individuals with ND, 60 patients with Sch+ND, and 70 healthy controls. These variants were analyzed using PCR. RESULTS: The cases with ND had higher eNOS VNTR-BB genotype than the healthy control subjects (p = 0.001). eNOS-AA genotype was lower in cases with Sch+ND and ND groups compared to the controls (p = 0.001, p = 0.001, respectively). eNOS-B allele was found significantly more frequently in Sch+ND group compared to the controls (p = 0.001). eNOS-A allele was significantly lower in ND group than the controls (p = 0.001). XRCC4-ID genotype was more common in the ND group than the control group (p = 0.001) as heterozygosity disadvantage. XRCC4-DD genotype was more common in the Sch+ND group compared to the controls (p = 0.035). The frequency of XRCC4-I allele was lower in the Sch+ND group compared to the controls (p = 0.012). CONCLUSIONS: Our results showed that eNOS and XRCC4 VNTR variants might play a potential role in Sch+ND and/or ND pathophysiology (Tab. 2, Ref. 48).

Does systemic clarithromycin therapy have an inhibitory effect on tympanosclerosis? An experimental animal study.

OBJECTIVE: To demonstrate the inhibitory effects of clarithromycin on in vitro tympanosclerosis. METHOD: Twenty-eight rats were divided into three groups: a clarithromycin group, a non-clarithromycin group and a negative control group. Those in the first two groups were injected with Streptococcus pneumoniae following a myringotomy, and tympanosclerosis was experimentally induced. Oral clarithromycin therapy was administered in the clarithromycin group. The other groups received no medical treatment. RESULTS: All eardrums in the clarithromycin and non-clarithromycin groups developed myringosclerosis, but there was only one eardrum, in the clarithromycin group, with very severe myringosclerosis. In the clarithromycin group, 11 ears showed no inflammation and there were no ears with severe inflammation. In the non-clarithromycin group, there were 11 ears with severe inflammation. The mean eardrum thickness in the clarithromycin group was 20.93 µm and in the non-clarithromycin group it was 42.71 µm. CONCLUSION: Acute otitis media and myringotomies induced tympanosclerosis, but clarithromycin reduced the severity of tympanosclerosis.

Effects of lignocaine on pressor response to laryngoscopy and endotracheal intubation during general anaesthesia in rigid suspension laryngoscopy.

OBJECTIVE: This study aimed to compare the effects of topical and systemic lignocaine on the circulatory response to direct laryngoscopy performed under general anaesthesia. METHODS: Ninety-nine patients over 20 years of age, with a physical status of I-II (classified according to the American Society of Anesthesiologists), were randomly allocated to 3 groups. One group received 5 ml of 0.9 per cent physiological saline intravenously, one group received 1.5 mg/kg lignocaine intravenously, and another group received seven puffs of 10 per cent lignocaine aerosol applied topically to the airway. Mean arterial pressures, heart rates and peripheral oxygen saturations were recorded, and changes in mean arterial pressure and heart rate ratios were calculated. RESULTS: Changes in the ratios of mean arterial pressure and heart rate were greater in the saline physiological group than the other groups at 1 minute after intubation. Changes in the ratios of mean arterial pressure (at the same time point) were greater in the topical lignocaine group than in the intravenous lignocaine group, but this finding was not statistically significant. CONCLUSION: Lignocaine limited the haemodynamic responses to laryngoscopy and endotracheal intubation during general anaesthesia in rigid suspension laryngoscopy.

Endogenous subclinical hyperthyroidism may not lead to bone loss in premenopausal women.

BACKGROUND: Osteoporosis is defined as the decrease in bone mineral density. It is a serious health problem showing the predisposed person with increased bone fracture risk. Hyperthyroidism is one of the major causes of secondary osteoporosis. The aim of this study was to assess bone mineral density in premenopausal women with endogenous subclinical hyperthyroidism. METHODS: A total of 168 subjects were included in this case-control study, of whom 86 and 82 participants were premenopausal women with subclinical hyperthyroidism and healthy premenopausal subjects, respectively. The patients with subclinical hyperthyroidism who were not receiving L-thyroxine treatment were included. The women in postmenopausal state or having chronic disease were excluded. The bone mineral densities of all subjects with dual energy X-ray absorptiometry were examined. RESULTS: The Z scores (femur and L1-4) of the study group were -0.15 ± 1.15 and -0.23 ± 1.03, respectively. The Z scores of the control group were -0.39 ± 1.08 and -0.55 ± 0.98, respectively. The differences between the groups were not statistically significant (p=0.14, 0.34, respectively). CONCLUSION: Our data suggest that contrary to exogenous subclinical hyperthyroidism, endogenous subclinical hyperthyroidism may not decrease bone mineral density in premenopausal women and it may not a risk factor for osteopenia or osteoporosis. Hippokratia 2014; 18 (3): 240-244.