Study of counter electrodes as an effective controlling factor of crystal orientation of TiO2 nanoarrays used as the anode in lithium-ion batteries

The morphology, crystal orientation, and Li ion electrochemical performance of TNAs strongly depend on the counter electrode.

An ultrahigh volumetric capacitance of squeezable three-dimensional bicontinuous nanoporous graphene

Graphene with a large specific surface area and high conductivity has a large specific capacitance. However, its volumetric capacitance is usually very low because the restacking of 2D graphene sheets leads to the loss of the large ion-accessible surface area. Here we report squeezable bicontinuous nanoporous nitrogen-doped graphene, which is extremely flexible and can tolerate large volume contraction by mechanical compression without the face-to-face restacking occurring. The compressed nanoporous N-doped graphene with a large ion accessible surface area and high conductivity shows an ultrahigh volumetric capacitance of ∼300 F cm^-3 together with excellent cycling stability and high rate performance.

Waist Circumference, Weight, and Body Mass Index of Iranians based on National Non-Communicable Disease Risk Factors Surveillance

BACKGROUND

Obesity is an important and life-threatening disease, associated with different chronic conditions such as cardiovascular disease, diabetes, and dyslipidemia. We sought to address the paucity of information on the trends of anthropometric indices such as weight, waist circumference, and body mass index in the adult population of Iran.

METHODS

We drew upon data from the First Non-communicable Disease Survey in Iran in 2005. In total, 79,611 participants between 20 and 64 years old were selected via the random multistage cluster sampling. The Lambda Median Scale method was applied to construct normal curves for anthropometric indices.

RESULTS

The mean of waist circumference in both genders increased with age and in all the age groups except those between 20 and 24 years old was higher in the women. The mean of body mass index was higher in all the age brackets in the women, but the means of weight and height were higher in the men. The association of theses indices with diabetes, hypertension, and dyslipidemia was stronger in men.

CONCLUSION

The ranges of waist circumference and body mass index in Iranian population are different from those of other countries. The higher body mass index and waist circumference in females and the direct association between obesity and chronic diseases, is advisable that the effects of this phenomenon be fully investigated and due heed be paid to the importance of lifestyle modification.

Knowledge, attitude and practice towards blood donation in Iranian population

BACKGROUND

The increase in demand for blood products because of new surgical and medical procedures seeks more research to find new ways to recruit people to donate blood.

OBJECTIVE/AIM

To determine the level of people's knowledge about donating blood considering its relation with infectious and chronic diseases, drug abuse, unsafe sexual intercourse, menstruation and anaemia. In addition, their attitude towards blood donation regarding their previous behaviour and factors such as altruism, religion, family, fears and availability of blood donation centres has been evaluated.

METHODS

This study was conducted in Tehran, Iran in 2009 on 1000 respondents. Data were collected through questionnaires that comprised 37 questions considering demographic and background characteristics, level of knowledge and positive and negative attitudes towards blood donation. Finally, data were analysed using SPSS software.

RESULTS

Of 1000 in this study, 26% were donors, of whom 55% had donated blood more than once. The mean knowledge score of the participants was 8·6, which was associated with the subjects' gender and level of education (P = 0·031 and P < 0·001, respectively). Age, gender and level of education were significantly associated with one's attitude towards blood donation (P = 0·021, P < 0·001 and P = 0·003,respectively). Ninety-five percent of people have stated that their main motivation to donate blood was altruism.

CONCLUSION

Altruism and being encouraged by others had the leading roles in peoples' positive attitude towards blood donation; whereas hard access to blood donation centres seemed to be the main inhibitory factor.

The reduction of image noise and streak artifact in the thoracic inlet during low dose and ultra-low dose thoracic CT

Increased pixel noise and streak artifact reduce CT image quality and limit the potential for radiation dose reduction during CT of the thoracic inlet. We propose to quantify the pixel noise of mediastinal structures in the thoracic inlet, during low-dose (LDCT) and ultralow-dose (uLDCT) thoracic CT, and assess the utility of new software (quantum denoising system and BOOST3D) in addressing these limitations. Twelve patients had LDCT (120 kV, 25 mAs) and uLDCT (120 kV, 10 mAs) images reconstructed initially using standard mediastinal and lung filters followed by the quantum denoising system (QDS) to reduce pixel noise and BOOST3D (B3D) software to correct photon starvation noise as follows: group 1 no QDS, no B3D; group 2 B3D alone; group 3 QDS alone and group 4 both QDS and B3D. Nine regions of interest (ROIs) were replicated on mediastinal anatomy in the thoracic inlet, for each patient resulting in 3456 data points to calculate pixel noise and attenuation. QDS reduced pixel noise by 18.4% (lung images) and 15.8% (mediastinal images) at 25 mAs. B3D reduced pixel noise by approximately 8% in the posterior thorax and in combination there was a 35.5% reduction in effective radiation dose (E) for LDCT (1.63-1.05 mSv) in lung images and 32.2% (1.55-1.05 mSv) in mediastinal images. The same combination produced 20.7% reduction (0.53-0.42 mSv) in E for uLDCT, for lung images and 17.3% (0.51-0.42) for mediastinal images. This quantitative analysis of image quality confirms the utility of dedicated processing software in targeting image noise and streak artifact in thoracic LDCT and uLDCT images taken in the thoracic inlet. This processing software potentiates substantial reductions in radiation dose during thoracic LDCT and uLDCT.

Multiscale deformable registration for dual-energy x-ray imaging

Dual-energy (DE) imaging of the chest improves the conspicuity of subtle lung nodules through the removal of overlying anatomical noise. Recent work has shown double-shot DE imaging (i.e., successive acquisition of low- and high-energy projections) to provide detective quantum efficiency, spectral separation (and therefore contrast), and radiation dose superior to single-shot DE imaging configurations (e.g., with a CR cassette). However, the temporal separation between high-energy (HE) and low-energy (LE) image acquisition can result in motion artifacts in the DE images, reducing image quality and diminishing diagnostic performance. This has motivated the development of a deformable registration technique that aligns the HE image onto the LE image before DE decomposition. The algorithm reported here operates in multiple passes at progressively smaller scales and increasing resolution. The first pass addresses large-scale motion by means of mutual information optimization, while successive passes (2-4) correct misregistration at finer scales by means of normalized cross correlation. Evaluation of registration performance in 129 patients imaged using an experimental DE imaging prototype demonstrated a statistically significant improvement in image alignment. Specific to the cardiac region, the registration algorithm was found to outperform a simple cardiac-gating system designed to trigger both HE and LE exposures during diastole. Modulation transfer function (MTF) analysis reveals additional advantages in DE image quality in terms of noise reduction and edge enhancement. This algorithm could offer an important tool in enhancing DE image quality and potentially improving diagnostic performance.

Effect of toothpicks with and without fluoride on De- and remineralization of enamel and dentine in situ

The aim of this investigation was to study the effect of the interproximal use of fluoride (F)-impregnated and non-impregnated birch toothpicks on the degree of de- and remineralization of enamel and dentine in situ. Ten volunteers with complete dentures in the upper jaw participated. Each subject had four specimens: (1) sound enamel, (2) demineralized enamel, (3) sound dentine and (4) demineralized dentine; placed pairwise at two approximal sites (15/16 and 25/26) of the maxillary prosthesis. The study involved three test periods (A, B and C), each lasting 4 weeks. In A, the subjects used F toothpicks (impregnated in 4% NaF) and, in B, nonimpregnated toothpicks 3 times daily. During period C, no toothpicks were used. Dentifrice or other F-containing products were not allowed during the 4-week periods. Transversal microradiography was used to determine lesion depth (ld) and mineral loss (DeltaZ). The results revealed that all the sound samples lost mineral during the three experimental periods; DeltaZ for both enamel and dentine was less for A and B compared with C (p<0.01) and less for A compared with B and C for dentine (p<0.05, p<0.01). The demineralized samples also lost mineral, apart from dentine, during periods A and B, i.e. when F-impregnated and non-impregnated toothpicks were used; ld for enamel and DeltaZ for dentine were less for A compared with C (p<0.05). Four weeks' use of toothpicks, especially F-impregnated toothpicks, thus reduces the demineralization of enamel and dentine at approximal sites in situ.

Effect of NaF-, SnF2-, and chlorhexidine-impregnated birch toothpicks on mutans streptococci and pH in approximal dental plaque

The antimicrobial effect of birch toothpicks impregnated with 4% NaF, 8% SnF2, or 2% chlorhexidine was studied both in vitro and in vivo. A non-impregnated toothpick served as a control. In vitro, suspensions of Streptococcus mutans were exposed to the various toothpicks for 20 min and then cultured on blood agar. The results of this susceptibility test revealed the following ranking order with respect to inhibition: chlorhexidine > SnF2 > NaF and non-impregnated; with significant differences in colony-forming units (CFU) between these three groups. In vivo, 12 individuals used the 4 types of toothpick 3 times a day for 5 days in a procedure with a crossover design. Saliva and approximal plaque samples were collected at baseline and on various occasions up to 23 days after the treatment. At the same time, plaque-pH was measured at approximal sites 10 min after rinsing with 10% sucrose. The results of these in vivo experiments revealed lower proportions of mutans streptococci after using all four types of toothpick, but the reduction was significant only after 2 days for the toothpicks impregnated with SnF2 and chlorhexidine (P< 0.05). On the sampling occasions 9 and 23 days after the treatment, the mutans streptococci were more or less back to baseline levels again. In saliva no significant differences in the number of mutans streptococci were found either within or between the four treatments. No significant differences were found regarding decline in the plaque-pH between the NaF-, SnF2-, chlorhexidine-, and non-impregnated toothpicks on any of the sampling occasions.

Studies on fluoridated toothpicks

The aim of this thesis was to evaluate the wooden toothpick as a vehicle for the delivery of fluoride to the approximal area. After two minutes use in vivo, the release of fluoride from the pointed section of a toothpick impregnated in 4% NaF was estimated to 0.15 mg. Toothpicks produced similar or somewhat higher fluoride concentrations in the approximal area compared with other fluoride-containing products, like dentifrice, mouthrinse solution and tablet. The mean fluoride concentration in an approximal area treated for two minutes with a toothpick impregnated in 4% NaF was around 11 mM/l. Toothpicks impregnated in 4% NaF, 8% SnF2 or 2% chlorhexidine had an effect on the proportion of mutans streptococci and on the decline of pH in dental plaque, but it was small and only of short duration. The recolonization of mutans streptococci was, however, slower after using the SnF2- and chlorhexidine-impregnated toothpicks than after using the NaF- and non-impregnated toothpicks. The effect of fluoridated toothpicks on the degree of de- and remineralization of enamel and dentine was measured using transversal microradiography in an in situ study. Four weeks' use of toothpicks, especially of NaF-impregnated toothpicks, reduced the degree of demineralization of enamel and dentine at approximal sites. Secondary ion mass spectrometry was also used to determine the fluoride content in the outer surface of dentine, which increased more than 10 times after using fluoride toothpicks compared with non-impregnated toothpicks. In a second in situ study, 4% NaF-, 2% chlorhexidine- and non-impregnated toothpicks had a similar effect on sound and demineralized enamel and on demineralized dentine. However, the NaF toothpicks were superior in terms of their effect on sound dentine. The effect on mutans streptococci and plaque-pH, on the other hand, was the same for all three types of toothpicks. The main conclusion from this thesis is that the wooden toothpick is a suitable vehicle for the delivery of fluoride to the approximal area.

Fluoride concentration in the approximal area after using toothpicks and other fluoride-containing products

The aim of this work was to study the fluoride (F) concentration in the approximal area after using toothpicks and other F-containing products. The exposure time was standardised to 2 min. 24 subjects participated, divided into 4 groups, with 6 individuals per group. In 3 of the groups, the following 4 products were compared: (1) a toothpick impregnated in 4% NaF; (2) a dentifrice containing 0.32% NaF; (3) a mouthrinse solution containing 0.025% NaF; (4) a tablet containing 0.55 mg NaF. In the 4th group, 3 commercial F toothpicks and 2 F dental flosses were compared. In all 4 groups, the F concentration was determined up to 60 min at 4 approximal sites. On each sampling occasion, 3 triangle-shaped paper points were used, absorbing 3 x 1 microl. In general, the toothpick gave similar or somewhat higher F concentrations in the approximal area than the dentifrice, mouthrinse solution and tablet. Comparing the various commercial toothpicks and dental flosses, 2 of the toothpicks gave higher approximal F concentrations than the other 3 products. When comparing the series in which the very first sample was collected from 2-20 min after the F treatment, it was found that the sampling procedure itself reduced the subsequent approximal F concentration. The main conclusion from this study is that an F-impregnated toothpick is a promising vehicle for delivery of fluoride to the approximal area.

Cocaine-associated rapid gingival recession and dental erosion. A case report

This case report chronicles the clinical presentation and unusual response to treatment of a patient with rapid gingival recession and dental erosion secondary to local cocaine application. The initial clinical diagnosis was necrotizing ulcerative periodontitis; only after several years of therapy did the patient voluntarily inform one of the therapists that cocaine had been regularly applied to the affected gingival sites. This case illustrates the importance of including cocaine application to gingival tissues in a differential diagnosis in cases of rapid gingival recession and dental erosion of unknown etiology.

Uptake and release of fluoride from birch and lime toothpicks

Birch and lime toothpicks were impregnated in a 4% sodium fluoride (NaF) solution for different periods of time, viz. 30 s, 30 min and 3 d. After impregnation for 30 min, an average of 4.1 mg NaF per birch toothpick was taken up. The corresponding value for lime toothpicks was 5.1 mg. About 60% of the fluoride (F) was released within 1 h in vitro when the toothpicks were kept in water. In vivo, the concentration of F was determined in whole saliva from five adults during 30 min after using birch toothpicks immersed in a 4% NaF solution. After 2 min, the mean salivary F concentration was 2.7 mM. Impregnation of birch toothpicks in 1, 2 or 3% NaF resulted in lower F concentrations both in vitro and in vivo, with a clear dose-response effect. When comparing the use of a 4% NaF impregnated birch toothpick, a mouthrinse with 10 ml of 0.025% NaF, sucking on a F tablet containing 0.55 mg NaF, and toothbrushing with 1 g of an 0.068% F (as NaF) dentifrice--all procedures carried out in the mouth during 2 min--the highest concentration of F in saliva was obtained after using the fluoridated toothpick. Thus, NaF impregnated birch and lime toothpicks show a quick release of F in vitro as well as in vivo and may be suitable as home care products for prevention of dental caries.