A model for oral health gradients in children: using structural equation modeling.

Detecting the underlying socioeconomic and behavioral determinants is essential for reducing oral health disparities in children. OBJECTIVE: To test a conceptual model in children to explore the interaction amongst social, environmental, behavioral factors and oral health outcomes. METHODS: This analytic cross-sectional study was performed in 2014-2015 in Shiraz, Iran. The sampling was conducted using a multistage stratified design to represent the whole 6-year-olds in Shiraz County. Participants were 830, 6-year-old first grade primary schoolchildren and their parents. Children were examined to register decayed, missing and filled teeth (dmft) and simplified oral hygiene index (OHI-S). Parents were asked for data on socio-cultural risk factors, oral health behaviors and children's oral health related quality of life (C-OHRQoL). Data on environmental risk factors were collected from several sources. The proposed model, a development of Peterson's, was tested using structural equation modeling (SEM). RESULTS: The tested model could empirically demonstrate the wide range of social and behavioral factors affecting C-OHRQoL. Socioeconomic status (SES) affected the OHRQoL of children through several pathways. Tooth brushing frequency, use of oral health services and consuming cariogenic foods were the mediators, through which SES affected dmft and subsequently C-OHRQoL. CONCLUSIONS: Using the modified Petersen's model and SEM, the paths in which different distal and proximal factors affect oral health outcomes in children could be clearly identified. It showed that addressing the underlying social, economic and behavioral determinants is essential for reducing oral health disparities among Iranian children.

Nanomechanical properties of MscL α helices: A steered molecular dynamics study.

Gating of mechanosensitive (MS) channels is driven by a hierarchical cascade of movements and deformations of transmembrane helices in response to bilayer tension. Determining the intrinsic mechanical properties of the individual transmembrane helices is therefore central to understanding the intricacies of the gating mechanism of MS channels. We used a constant-force steered molecular dynamics (SMD) approach to perform unidirectional pulling tests on all the helices of MscL in M. tuberculosis and E. coli homologs. Using this method, we could overcome the issues encountered with the commonly used constant-velocity SMD simulations, such as low mechanical stability of the helix during stretching and high dependency of the elastic properties on the pulling rate. We estimated Young's moduli of the α-helices of MscL to vary between 0.2 and 12.5 GPa with TM2 helix being the stiffest. We also studied the effect of water on the properties of the pore-lining TM1 helix. In the absence of water, this helix exhibited a much stiffer response. By monitoring the number of hydrogen bonds, it appears that water acts like a 'lubricant' (softener) during TM1 helix elongation. These data shed light on another physical aspect underlying hydrophobic gating of MS channels, in particular MscL.

Cutaneous application of menthol 10% solution as an abortive treatment of migraine without aura: a randomised, double-blind, placebo-controlled, crossed-over study.

OBJECTIVE: To investigate the efficacy and safety of the cutaneous application of menthol 10% solution for the abortive treatment of migraine. BACKGROUND: Peppermint and its active ingredient menthol have long been used for the treatment of various pain conditions including headache. METHODS: This is a randomised, triple-blind, placebo-controlled, crossed-over study conducted in the neurology Clinic of Nemazee Hospital, affiliated with Shiraz University of Medical Sciences, Shiraz, southern Iran, from March 2007 to March 2008. The patients were recruited via local newspaper advertisements. Eligible patients were categorised into two groups and a 10% ethanol solution of menthol (as drug) and 0.5% ethanol solution of menthol (as placebo) were applied to the forehead and temporal area in a crossover design. Pain free, pain relief, sustained pain free and sustained pain relief end-points were measured by questionnaires using a visual analogue scale. RESULTS: The intent-to-treat population consisted of 35 patients (80% women, 20% men, mean age: 29.6 +/- 6.2) with 118 migraine attacks. In the intent-to-treat population, the menthol solution was statistically superior to the placebo on 2-h pain free (p = 0.001), 2-h pain relief (p = 0.000), sustained pain free and sustained pain relief end-points (p = 0.008). The menthol solution was also more efficacious in the alleviation of nausea and/or vomiting and phonophobia and/or photophobia (p = 0.02). In the per-protocol population, there was significantly higher number of patients who experienced at least one pain free/pain relief after the application of menthol rather than the placebo (p = 0.002). No significant difference was seen between the adverse effects of the drug and the placebo groups (p = 0.13). CONCLUSION: Menthol solution can be an efficacious, safe and tolerable therapeutic option for the abortive treatment of migraine.

In vitro release behavior and cytotoxicity of doxorubicin-loaded gold nanoparticles in cancerous cells.

Doxorubicin (DOX), a common cancer chemotherapeutics, was conjugated to folate-modified thiolated-polyethylene glycol-functionalized gold nanoparticles. The in vitro, controlled release behavior of DOX-loaded gold nanoparticles was observed using porous dialysis membranes (cut-off = 2 kDa). DOX-loaded gold nanoparticles had higher cytotoxicity for folate-receptor-positive cells (KB cells) compared to folate-receptor-negative cells (A549 cells) which were 48 and 62% viable for 10 microM doxorubicin, respectively. This indicates the potential of these nano-carriers for targeted-delivery. In addition, healthy cell viability was 69% for 10 microM free doxorubicin whereas for the same content of drug in DOX-loaded nanoparticles healthy cell viability increased to 80%.

Degradation of phenanthrene and anthracene by Nocardia otitidiscaviarum strain TSH1, a moderately thermophilic bacterium.

AIMS: The metabolism of phenanthrene and anthracene by a moderate thermophilic Nocardia otitidiscaviarum strain TSH1 was examined. METHODS AND RESULTS: When strain TSH1 was grown in the presence of anthracene, four metabolites were identified as 1,2-dihydroxy-1,2-dihydroanthracene, 3-(2-carboxyvinyl)naphthalene-2-carboxylic acid, 2,3-dihydroxynaphthalene and benzoic acid using gas chromatography-mass spectrometry (GC-MS), reverse phase-high performance liquid chromatography (RP-HPLC) and thin-layer chromatography (TLC). Degradation studies with phenanthrene revealed 2,2'-diphenic acid, phthalic acid, 4-hydroxyphenylacetic acid, o-hydroxyphenylacetic acid, benzoic acid, a phenanthrene dihydrodiol, 4-[1-hydroxy(2-naphthyl)]-2-oxobut-3-enoic acid and 1-hydroxy-2-naphthoic acid (1H2NA), as detectable metabolites. CONCLUSIONS: Strain TSH1 initiates phenanthrene degradation via dioxygenation at the C-3 and C-4 or at C-9 and C-10 ring positions. Ortho-cleavage of the 9,10-diol leads to formation of 2,2'-diphenic acid. The 3,4-diol ring is cleaved to form 1H2NA which can subsequently be degraded through o-phthalic acid pathway. Benzoate does not fit in the previously published pathways from mesophiles. Anthracene metabolism seems to start with a dioxygenation at the 1 and 2 positions and ortho-cleavage of the resulting diol. The pathway proceeds probably through 2,3-dicarboxynaphthalene and 2,3-dihydroxynaphthalene. Degradation of 2,3-dihydroxynaphthalene to benzoate and transformation of the later to catechol is a possible route for the further degradation of anthracene. SIGNIFICANCE AND IMPACT OF THE STUDY: For the first time, metabolism of phenanthrene and anthracene in a thermophilic Nocardia strain was investigated.

The effects of Fe(II) and Fe(III) concentration and initial pH on microbial leaching of low-grade sphalerite ore in a column reactor.

In this study the effects of initial concentration of Fe(II) and Fe(III) ions as well as initial pH on the bioleaching of a low-grade sphalerite ore in a leaching column over a period of 120 days with and without bacteria were investigated. Four different modifications of medium were used as column feed solutions to investigate the effects of initial concentration of Fe(II) and Fe(III) ions on zinc extraction. The experiments were carried out using a bench-scale, column leaching reactor, which was inoculated with mesophilic iron oxidizing bacteria, Acidithiobacillus ferrooxidans, initially isolated from the Sarcheshmeh chalcopyrite concentrate (Kerman, Iran). The effluent solutions were periodically analyzed for Zn, total Fe, Fe(II) and Fe(III) concentrations as well as pH values. Bacterial population was measured in the solution (free cells). Maximum zinc recovery in the column was achieved about 76% using medium free of initial ferrous ion and 11.4 g/L of ferric ion (medium 2) at pH 1.5. The extent of leaching of sphalerite ore with bacteria was significantly higher than that without bacteria (control) in the presence of ferrous ions. Fe(III) had a strong influence in zinc extraction, and did not adversely affect the growth of the bacteria population.

Characterization of a moderate thermophilic Nocardia species able to grow on polycyclic aromatic hydrocarbons.

AIMS: Our goal was the characterization of a new moderate thermophilic polycyclic aromatic hydrocarbon (PAH)-utilizing Nocardia strain. METHODS AND RESULTS: A thermophilic bacterium, strain TSH1, was isolated from a contaminated soil. The macroscopic and microscopic features fit well with the description of Nocardia species. The results of 16S rRNA gene analysis showed 100% match to the type strain of N. otitidiscaviarum DSM 43242(T). Strain TSH1 showed the same mycolic acid pattern as the type strain of N. otitidiscaviarum but its fatty acid profile did not permit identification to the species level. The carbon utilization profile of strain TSH1 was different from N. otitidiscaviarum. The results of hydrophobicity measurements showed that PAHs-grown cells were significantly more hydrophobic than LB-grown cells. Furthermore, biosurfactant production was detected during bacterial growth on different culture media. CONCLUSIONS: Strain TSH1 is capable of growing on a range of PAHs. When grown in PAHs-supplemented media, strain TSH1 showed a high affinity for the organic phase, suggesting that it can develop a hydrophobic surface. SIGNIFICANCE AND IMPACT OF THE STUDY: High cell surface hydrophobicity and capability of strain TSH1 to degrade different PAHs at 50 degrees C may make it an ideal candidate to treat PAH-contaminated desert soils.

Environmental engineering: energy value of replacing waste disposal with resource recovery

Although in the past, environmental engineering has been primarily concerned with waste disposal, the focus of the field is now shifting toward viewing wastes as potential resources. Because reclamation usually consumes less energy than producing new materials, increasing reclamation not only reduces pollution but saves energy. Technological innovations contributing to this shift are summarized here, and are variously classified as emerging technologies or research topics, as either new departures or incremental improvements, and as opportunistic innovations, or examples of a unifying strategy. Both liquid and solid waste examples are given, such as a recent discovery of effects in disinfecting microfiltered reclaimed wastewater with ultraviolet light. In addition to its value in reducing pollution and conserving energy, this reorientation of environmental engineering could contribute to a more general shift toward greater cooperation among organizations dealing with the environment.

[Analytical study of the treatment of facial paralysis by hypoglossal-facial anastomosis. Apropos of 25 cases]. / Etude analytique du traitement de la paralysie faciale par anastomose hypoglosso-faciale. A propos de 25 cas.

Hypoglosso-facial anastomosis (HFA) is an already old alternative for the surgical treatment of facial paralysis. 25 patients, 17 men and 8 women, with complete facial paralysis were operated according to this technique, 6 to 12 months after onset of the paralysis. Based on analysis of the results, the authors describe the advantages and disadvantages of this technique. The advantages are: facial symmetry at rest, protection of the cornea, voluntary movements of facial muscles. The disadvantages are: paralysis and atrophy of one side of the tongue, absence of expression of emotional and involuntary states on one half of the face, synkinesia, disorders of mastication. Disorders of deglutition improve with time. In this series of 25 patients, the authors never observed eyelid movements independent of movements of the labial commissure. By comparing these advantages and disadvantages, the authors consider that HFA should no longer be proposed for the treatment of facial paralysis. In the current state of microsurgery, if the facial nerve cannot be repaired by direct suture or graft, the authors recommend revascularized, reinnervated muscle transfer onto the facial nerve of the healthy side.