Influence of Thermal Treatment on the Chemical and Structural Properties of Geopolymer Gels Doped with Nd2O3 and Sm2O3.

In this research, the influence of the thermal treatment of geopolymer gels at 300 °C, 600 °C and 900 °C when incorporated with 5% rare earth elements (REEs) in the form of (GP-Sm) Sm2O3 and (GP-Nd) Nd2O3 was investigated. Changes in the chemical and structural properties of the geopolymer gels during thermal treatment for 1 h were monitored. Physico-chemical characterization was performed using the following methods: diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), scanning electron microscopy with energy dispersive spectrometry (SEM-EDS), and X-ray photoelectron spectroscopy (XPS). Besides the characterization of the fundamental properties, some practical macroscopic properties were analyzed as well: sorptivity, open porosity, and Archimedean density. The stretching vibrations of Nd-O-Si and Sm-O-Si were confirmed at a value of around 680 cm-1and an Nd-O-Si absorption band at a higher value, together with the most dominant band of Si-O stretching vibration similar for all the samples. No significant chemical changes occurred. Structural analysis showed that for GP-Nd, the largest pore diameter was obtained at 900 °C, while for GP-Sm, the largest pore diameter was obtained at 600 °C. EDS confirmed the amount of dopant to be about 5%. X-ray photoelectron spectroscopy showed that for GP-Nd, the ratio of Si and Al changed the most, while for GP-Sm, the ratio of Si and Al decreased with increasing temperature. The contributions of both dopants in the GP-gel structure remained almost unchanged and stable at high temperatures. The atomic percentages obtained by XPS analysis were in accordance with the expected trend; the amount of Si increased with the temperature, while the amount of Al decreased with increasing temperature. The sorptivity and open porosity showed the highest values at 600 °C, while the density of both geopolymers decreased linearly with increasing temperature.

Adsorption Efficiency of Cadmium (II) by Different Alkali-Activated Materials.

The objective of this study was to demonstrate the potential utilization of fly ash (FA), wood ash (WA), and metakaolin (MK) in developing new alkali-activated materials (AAMs) for the removal of cadmium ions from waste water. The synthesis of AAMs involved the dissolution of solid precursors, FA, WA, and MK, by a liquid activator (Na2SiO3 and NaOH). In concentrated solutions of the activator, the formation of an aluminosilicate gel structure occurred. DRIFT spectroscopy of the AAMs indicated main vibration bands between 1036 cm-1 and 996 cm-1, corresponding to Si-O-Si/Si-O-Al bands. Shifting vibration bands were seen at 1028 cm-1 to 1021 cm-1, indicating that the Si-O-Si/Si-O-Al bond is elongating, and the bond angle is decreasing. Based on the X-ray diffraction results, alkali-activated samples consist of an amorphous phase and residual mineral phases. The characteristic "hump" of an amorphous phase in the range from 20 to 40° 2θ was observed in FA and in all AWAFA samples. By the XRD patterns of the AAMs obtained by the activation of a solid three-component system, a new crystalline phase, gehlenite, was identified. The efficiency of AAMs in removing cadmium ions from aqueous solutions was tested under various conditions. The highest values of adsorption capacity, 64.76 mg/g (AWAFA6), 67.02 mg/g (AWAFAMK6), and 72.84 mg/g mg/g (AWAMK6), were obtained for materials activated with a 6 M NaOH solution in the alkali activator. The Langmuir adsorption isotherm and pseudo-second kinetic order provided the best fit for all investigated AAMs.

Microstructural Analysis of Thermally Treated Geopolymer Incorporated with Neodymium.

The following investigation presents the thermal treatment of geopolymer at 300 °C, 600 °C and 900 °C. We investigated what happens to the geopolymer base when incorporated with 1% and 5% of neodymium in the form Nd2O3. A total of six samples were synthesized. Geopolymer 1 contained 1% and geopolymer 2 contained 5% Nd2O3, and these samples were treated at 300 °C; then, samples geopolymer 3 and geopolymer 4 also had the same percentage composition of Nd2O3 and were treated at 600 °C, while samples geopolymer 5 and geopolymer 6were treated at 900 °C. Physical and chemical changes in the aluminosilicate geopolymer matrix were monitored. The incorporation of rare earths into the polymer network of aluminosilicates has been proven to disrupt the basic structure of geopolymers; however, with increased temperatures, these materials show even more unusual properties. Diffuse reflectance infrared Fourier transform (DRIFT) analysis showed that the intensity of the vibrational band decreases with the increase in temperature during thermal treatment, suggesting alterations in the chemical structure of the geopolymers. Transmission electron microscopy (TEM) analysis showed that the diameter of the nanoparticles containing Al2O3 is in the range 5-10 nm, while larger crystallites range from 30 to 80 nm. Scanning electron microscopy (SEM) analysis revealed that the temperature of the thermal treatment increases to 300 °C and 600 °C; the porosity of geopolymer increases in the form of the appearance of large pores and cracks in material. X-ray photoelectron spectroscopy (XPS) analysis was used to investigate the surface chemistry of geopolymers, including the chemical composition of the surface, the oxidation state of the elements, and the presence of functional groups. The UV/Vis spectra of the synthesized geopolymers doped with Nd3+ show interesting optical properties at 900 °C; the geopolymer matrix completely disintegrates and an amorphous phase with a rare-earth precipitate appears.

The perinatal factors that influence the excretion of fecal calprotectin in premature-born children.

This study aimed to provide additional information on the influence of perinatal factors on fecal (f)-calprotectin values in preterm infants. Calprotectin was determined from the first spontaneous stool (analyzed on the Alegria device by using the enzyme-linked immunosorbent assay [ELISA] method) obtained from neonates at a mean age of 3.41 ± 2.44 days of life. We analyzed 114 subjects who had a body weight of 1847.67 ± 418.6 g and were born at a gestational age of 32.6 ± 2.43 weeks, without intestinal and other congenital anomalies or any diseases other than those related to premature birth. The values of f-calprotectin are in a positive correlation with female subjects, intrauterine growth restriction, significant ductus arteriosus, enteral feeding intolerance, postnatal prolonged use of broad-spectrum antibiotics, and values ​​of bicarbonates (analyzed in a sample of capillary arterial blood). Measurement of f-calprotectin in the first 7 days after birth can help to early detect the intestinal distress or early staging of necrotizing enterocolitis in premature infants.

Age and gender associated changes in immunoglobulin subclass levels specific to S. pneumoniae, serotype 1.

S. pneumoniae is an important human pathogen which has a polysaccharide capsule with virulent properties. This work aims to estimate the titres of S. pneumoniae specific IgG and IgA isotypes, with respect to age and sex. An in-house whole bacterial cell ELISA was used for the determination of relative levels and endpoint titres of IgG subclasses and IgA1 subclass specific for S. pneumoniae serogroup 1, and to quantify specific IgG1 and IgG2 levels. Significantly lower anti-pneumococcus IgG1 titres were found in older individuals, which was more pronounced in men. Lower IgG2 titres were detected in men over 50 years of age, in comparison to women under 50 years of age. The levels of IgG3 and IgG4 did not differ between different sex and age groups. Lower IgA1 levels were detected in male individuals in both age groups in comparison to females under 50 years of age. The levels of IgG1 showed a moderate correlation with IgG4 in younger individuals of both sexes (r = 0.61 in men and 0.63 in women) which was not noted in the older age group. We highlight the deficiency in humoral immunity in older people, especially male and suggest immunization of this population with pneumococcal vaccines.

Cost of Medications Recommended by Canadian Acne Clinical Practice Guidelines.

BACKGROUND: Acne affects a large proportion of the Canadian population and has psychosocial and financial consequences. OBJECTIVE: We provide cost information for treatments recommended by the Canadian acne guidelines. METHODS: Highest level recommendations were selected for 3-month usage cost. RESULTS: Three-month estimated treatment costs were as follows: topical retinoids ($14.40-$73.80), benzoyl peroxide (BPO; $6.75), fixed-dose BPO-clindamycin ($40.95-$44.10) and BPO-adapalene ($73.80), oral antibiotics ($25.20 for tetracycline 250 mg qid; $52.20 and $52.74 for doxycycline 50 mg bid and 100 mg od, respectively), and hormonal therapy ($26.46-$37.80 for ethinyl estradiol [EE] 0.030 mg/drospirenone 3mg and $75.60-108.99 for EE 0.035 mg/cyproterone acetate 2 mg). Oral isotretinoin 3-month costs ranged from $393.96 to $478.80. CONCLUSIONS: Awareness of costs of recommended treatments may facilitate improved outcomes by increasing procurement and adherence.

Oral Isotretinoin: New Developments Relevant to Clinical Practice.

Oral isotretinoin is unrivalled in efficacy and remission capability for treatment of acne. In addition to appropriate monitoring and continued vigilance for safety concerns, appropriate dosing to mitigate avoidable dose-dependent adverse effects is the responsibility of prescribers. Low-dose regimens are better tolerated and effective in inducing acne clearance. Although much progress has been made since the advent of isotretinoin, there remain many unanswered questions regarding optimization to maximize response while minimizing the potential for avoidable adverse events. The ongoing availability of isotretinoin is imperative to patients with acne, their caregivers, and physicians.

Evaluation of Evidence for Acne Remission With Oral Isotretinoin Cumulative Dosing of 120-150 mg/kg.

BACKGROUND: Oral isotretinoin (ISO) is the standard of care for severe inflammatory acne and a threshold dose of 120-150 mg/kg is widely regarded as increasing remission potential. OBJECTIVE: Our objective was to evaluate the evidence underlying ISO dosing of 120-150 mg/kg in acne remission. METHODS: A systematic literature search was performed using keywords "acne," "isotretinoin," "efficacy," "dosing," "relapse," and "remission." RESULTS: Definitions for acne clearance, relapse/remission, and treatment endpoint vary widely across studies. Only 2 studies explicitly evaluated the cumulative dose of 120-150 mg/kg for induction of acne remission-both low grade. CONCLUSION: The threshold dose of 120-150 mg/kg for oral ISO is based on past parameters of treatment duration and prior studies used vague or inconsistent definitions of clearance and remission. Optimal cumulative doses of ISO required to induce remission appears to vary with severity.

The Relationship Between Dermatologist- and Patient-Reported Acne Severity Measures and Treatment Recommendations.

BACKGROUND: Acne treatment recommendations for individual patients may be derived from multiple factors including dermatologist- and patient-reported constructs. OBJECTIVES: To evaluate the effects of dermatologist- and patient-reported measures on acne treatment recommendations by dermatologists. METHODS: An observational cross-sectional survey of acne patients was conducted with patient-reported quality of life and dermatologist-reported measures of primary and secondary (scar) acne severity using 3 assessment approaches: maximal regional grade, total grade, and facial grade. RESULTS: The most highly associated factors with acne treatment recommendations were patient emotions, maximal regional acne severity, and total acne scar grade. Better acne-specific quality of life was negatively related to acne treatment recommendation intensity, while all 3 grading approaches were positively related to acne treatment recommendations. CONCLUSIONS: For dermatologists, overall acne severity is most highly associated with maximal regional acne grade, total scar grade, and patient's emotional response to acne.

Improving bioavailability with a novel isotretinoin formulation (isotretinoin-Lidose).

Current practice guidelines recommend administration of oral isotretinoin with high-fat meals, which may pose issues with patient compliance. Isotretinoin-Lidose (Epuris™), approved by Health Canada in November 2012 and scheduled for commercial release June 2013, is based on novel lipid encapsulation technology (Lidose®) to enclose isotretinoin, thereby increasing drug absorption during fasted states. An open label, single dose randomized crossover study demonstrated pharmacokinetic bioequivalence of isotretinoin-Lidose to standard isotretinoin formulations during fed states, with significantly greater absorption during fasting. Isotretinoin-Lidose, may lead to more consistent plasma levels of isotretinoin during variable dietary conditions, providing the potential for enhanced patient outcomes.

The importance of timely ophthalmologic examination in preterm infants at risk of retinopathy occurrence.

BACKGROUND/AIM: Retinopathy of prematurity (ROP) is a multifactorial disease in premature infants. The aim of this study was to determine the incidence of ROP in children treated at the Center of Neonatology, Pediatric Clinic, Clinical Center in Kragujevac, Serbia. METHODS: The study covered all children with birth weight below 2,000 g and/or gestational age below the 37th week, who from June 2006 to December 2009 underwent ophthalmological examination for ROP. The results of fundoscopy were classified in accordance with the International Classification of ROP. The treatment of infants and those with ROP was conducted in accordance with the early treatment of ROP study recommendations. We analyzed gestational age, birth weight and postconceptional age in two groups: healthy infants and those with severe form of ROP. Statistical analysis was performed using the SPSS 16. RESULTS: A total of 478 children met the criteria of screening for ROP. Severe stage of ROP, which required laser treatment, had 102 (21.3%) children. Out of the infants with severe ROP 14 (13.7%) of the infants with APD had aggressive posterior disease, while two (0.4%) remained blind. The differences in the mean values of gestational age between the healthy and the children with severe form of the disease were statistically significant (p < 0.0005). The mean value of gestational age for the healthy children was 33.33 +/- 2.28 weeks and for the seek infants 30.66 +/- 2.79 weeks. The mean value of the weight in healthy children was 1.981 +/- 407 g, and in sick children 1.535 +/- 434 g which was statistically significant (p < 0.0005). Multivariate binary logistic regression showed that the occurrence of the disease depends on body weight and gestational age. CONCLUSION: The incidence of severe forms of ROP was 21.3%. Aggressive form of ROP was present in 13.7% of the children. The cut-off value for body weight was 1.740 g, and for gestational age 32.5 weeks.

Analysis of risk factors in the development of retinopathy of prematurity.

INTRODUCTION: Retinopathy of prematurity (ROP) is a multifactorial disease that occurs most frequently in very small and very sick preterm infants, and it has been identified as the major cause of childhood blindness. OBJECTIVE: The aim of this study was to evaluate ROP incidence and risk factors associated with varying degrees of illness. METHODS: The study was conducted at the Centre for Neonatology, Paediatric Clinic of the Clinical Centre Kragujevac, Serbia, in the period from June 2006 to December 2008. Ophthalmologic screening was performed in all children with body weight lower than 2000 g or gestational age lower than 36 weeks. We analyzed eighteen postnatal and six perinatal risk factors and the group correlations for each of the risk factors. RESULTS: Out of 317 children that were screened, 56 (17.7%) developed a mild form of ROP, while 68 (21.5%) developed a severe form. Univariate analysis revealed a large number of statistically significant risk factors for the development of ROP, especially the severe form. Multivariate logistical analysis further separated two independent risk factors: small birth weight (p = 0.001) and damage of central nervous system (p = 0.01). Independent risk factors for transition from mild to severe forms of ROP were identified as: small birth weight (p = 0.05) and perinatal risk factors (p = 0.02). CONCLUSION: Small birth weight and central nervous system damage were risk factors for the development of ROP, perinatal risk factors were identified as significant for transition from mild to severe form of ROP.