Evaluation of wound healing effect of alginate film containing Aloe vera gel and cross-linked with zinc chloride

Abstract Purpose To develop a new wound dressing composed of alginate and Aloe vera gel and cross-linked with zinc ions. Methods The aloe-alginate film was characterized using scanning electron microscopy (SEM), swelling profile, mechanical properties, polysaccharide content and X-ray diffraction (XRD). Thirty Wistar rats were divided in two groups a) treated with aloe-alginate film and b) control (treated with sterile gauze). Wound contraction measurements and hystological analysis were performed on 7th, 14th and 21st days after wound surgery. Results The aloe-alginate film presented adequated mechanical resistance and malleability for application as wound dressing. There was no statistical difference in wound contraction between two groups. Histological assay demonstrated that aloe-alginate film presented anti-inflammatory activity, stimulated angiogenesis on proliferative phase and a more significant increased in collagen type I fibers and decreased type III fibers which promoted a mature scar formation when compared to control. Conclusions The aloe-alginate film showed adequate physicochemical characteristics for wound dressing applications. The in vivo assay demonstrated that aloe-alginate film enhanced the healing process of incisional skin wounds.

Nanotube synthesis from reaction of 4-chloro phenoxy acetate with zinc layered hydroxide

Objective: Intercalations of plant growth regulator 4-chloro phenoxy acetate [4CPA] with zinc oxide [ZnO], developed using ZnO-layered hydroxide [ZLH] as host material and 4CPA as a guest

Methods: Ion exchange technique via sol-gel method synthesized under aqueous environment, resulted in the formation of inorganic-organic nanotube materials

Results: The release of 4CPA from its nanohybrid was found to occur in a controlled manner, governed by pseudo-second order kinetics model. The maximum amount of 4CPA released was governed by pseudo-second order kinetics model. Powder X-ray diffraction showed that the basal spacing of the nanohybrid was developed with the increasing of 4CPA concentrations; the maximum concentration of 0.2M shows an interlayer basal of 1.9 nm. FTIR study showed that the intercalated 4CPA-ZnO spectral feature is generally similar to that of 4CPA, but with bands sightly shifted due to the formation of host-guest nanotubes

Conclusion: The resulted nanotubes were characterized by using scanning electron microscopy [SEM], and transmission electronic microscope [TEM], shows a uniform nanoparticles and monodisperse with average diameter of 35 nm, which correlated a very well with size scale obtained from XRD data. The development of crystals is the function of concentrations

La Escuela de Salud Pública de México: innovación educativa y tecnológica en el nuevo milenio / School of Public Health of Mexico: Educational and technological innovation in the new millennium

Este artículo fue concebido para analizar la función de la Escuela de Salud Pública de México (ESPM) desde el año 2000 hasta el presente. Uno de sus puntos centrales es el análisis del proceso de reorientación de la labor educativa de la escuela con la finalidad de responder a los retos en materia de salud y educación surgidos a finales del siglo XX. Para exponer cómo ha evolucionado dicho proceso, retomamos tres ejes rectores que caracterizan la labor de la escuela en la actualidad: el cambio de modelo pedagógico, la incorporación de las tecnologías de la información y las comunicaciones, y la profesionalización de la docencia. Con la exposición de este tema, y a través del contraste entre el pasado y el presente, buscamos completar la historia de trabajo ininterrumpido de la Escuela durante sus 92 años de existencia, que ha trascendido los confines del país.

This article was conceived to analyze the work of the School of Public Health of Mexico (ESPM for is acronym in Spanish) from the year 2000 to the present day. One of the highlights that we will examine is the reorientation of the educational work of the school in order to meet the challenges in health and education that emerged during the end of the twentieth century. In order to explain the evolution of this process, we will describe the three main guiding principles that characterize the present work of the school: the pedagogical model's change, the incorporation of the information and communication technologies, and the professionalization in teaching. The purpose of this work is to define those guiding principles, and to expose, through the contrast between past and present, the complete history of uninterrupted work of the School of Public Health of Mexico during its ninety-two years of existence, that has gone beyond the boundaries of the country.

Efecto del zinc aminoquelado y el sulfato de zinc en la incidencia de la infección respiratoria y la diarrea en niños preescolares de centros infantiles / Effect of zinc amino acid chelate and zinc sulfate in the incidence of respiratory infection and diarrhea among preschool children in child daycare centers

Introducción. El déficit de zinc es común en niños de poblaciones en desarrollo. La deficiencia de zinc altera el sistema inmunológico y la resistencia a las infecciones. Objetivo. Evaluar el efecto de dos compuestos de zinc en la prevención de la infección respiratoria y la diarrea agudas. Materiales y métodos. Se llevó a cabo un ensayo comunitario triple ciego en 301 niños entre dos y cinco años de edad de centros infantiles de Medellín. Fueron seis conglomerados distribuidos aleatoriamente en tres grupos de intervención que recibieron zinc aminoquelado, sulfato de zinc y placebo durante cinco días de la semana a lo largo de 16 semanas. Se evaluaron diariamente los síntomas de infección respiratoria, diarrea aguda y efectos secundarios. Resultados. La incidencia de la infección respiratoria fue menor con el zinc aminoquelado (1,42 por 1.000 días-niño) comparado con el sulfato de zinc (1,57 por 1.000 días-niño) (RR=0,90, IC 95% : 0,382 a 2,153 , p=0,999) y con el placebo (3,3 por 1.000 días-niño) ( RR=0,43, IC 95% : 0,196 a 0,950 , p=0,049). La incidencia de diarrea aguda con el zinc aminoquelado (0,15 por 1.000 días-niño) fue menor que con el sulfato de zinc (1,18 0,78 por 1.000 días-niño) (RR=0,20, IC 95% : 0,0043 a 1,662, p=0,361) y que la del grupo placebo (0,49 por 1.000 días-niño) (RR=0,32, IC 95% : 0,006 a 3,990 , p=0,346). Conclusiones. El zinc aminoquelado tuvo mejor efecto en la disminución de la incidencia de la infección respiratoria y la diarrea agudas en niños preescolares comparado con los otros grupos de estudio.

Introduction: Zinc deficiency is common in children among populations in developing areas. Zinc deficiency alters the immune system and the resistance to infections. Objective: To evaluate the effect of two zinc compounds in the prevention of acute respiratory infection and acute diarrhea. Materials and methods: Randomized triple-blind community trial with 301 children between 2-5 years of age from six child daycare centers in Medellin, Colombia. Children were distributed in three groups receiving zinc amino acid chelate, zinc sulfate and placebo five days a week for 16 weeks. Daily symptoms of respiratory infection, acute diarrhea and side effects were evaluated. Results: The incidence of respiratory infection was lower with zinc amino acid chelate (1.42 per 1,000 child-days) compared with placebo (3.3 per 1,000 child-days) (RR=0.43, 95% CI: 0.196 to 0.950, p=0.049) and with zinc sulfate (1.57 per 1,000 child-days) (RR=0.90, 95% CI 0.382 to 2.153, p=0.999). The incidence of acute diarrhea with zinc amino acid chelate (0.15 per 1,000 child-days) was lower than with placebo (0.49 per 1,000 child-days) (RR=0.32, 95% CI 0.006 to 3.990, p=0.346) and with zinc sulfate (0.78 per 1,000 child-days) (RR=0.20, 95% CI: 0.0043 to 1.662, p=0.361). Conclusions: Zinc amino acid chelate had a better effect in reducing the incidence of acute respiratory infection and acute diarrhea in preschool children when compared with the other groups.

Synthesis and bioactivity of the folate receptor targeted gamma-cyclodextrin-folate inclusion-coated CdSe/ZnS quantum dots / 药学学报

The gamma-cyclodextrin-folate (gamma-CD/FA) inclusion-coated CdSe/ZnS quantum dots (QDs) with folate-receptor (FR) targeted were synthesized by simple and convenient sonochemical method. The products were studied using Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), utraviolet-visible spectrometry (UV-vis), fluorescence spectrum and transmission electron micrographs (TEM). The results showed that the gamma-CD/FA-coated CdSe/ZnS QDs not only have good monodispersity and smaller size, but also have good optical performance, such as higher quantum yield (QY) and a long fluorescence lifetime. The cytotoxicity experiments showed that the gamma-CD/FA-coated CdSe/ZnS QDs have lower cytotoxicity and could more effectively enter cancer cells with FR over-expression. The QDs with 4-5 nm in diameter were relatively easy to enter the cell and to be removed through kidneys, so it is more suitable for biomedical applications for bioprobes and bioimaging.

Comparison of the retention of the full veneer casted gold crowns with varying convergence angle, crown length and dental cements / 대한치과보철학회지

PURPOSE: The aim of this research was to establish the effect and variation in differing convergence angle and length of abutment on the retention of full veneer casted gold crown. MATERIALS AND METHODS: Two different length,5 mm and 10 mm in height with convergence angles of 5, 10, 15 and 25 degrees crowns were fabricated. Cementation was done using cements; zinc phosphate cement (Fleck's zinc phosphate cement), resin-modified glass ionomer cement (Vitremer) and resin cement (Panavia 21). These were tested for tensile force at the point of separation by using Instron Universal Testing Machine. Statistical analysis was done by SAS 6.04 package. RESULTS: In all cements the mean retention decreased with significant difference on increase of convergence angle (P<.05). Increase in every 5 degree-convergence angel the retention rate decreased with resin-modified glass ionomer cement of 15.9% and resin cement of 14.8%. With zinc phosphate cement, there was largest decreasing rate of mean retention of 25.5% between convergence angles from 5 degree to 10 degree. When the crown length increased from 5 mm to 10 mm, the retention increased with the significant difference in the same convergence angle and in all types of cement used (P<.05). CONCLUSION: The retention was strongly dependent on geometric factors of abutment. Much care is required in choosing cements for an optimal retention in abutments with different convergence angles and crown lengths.

Modified methylene blue method for measurement of hydrogen sulfide level in plasma / 生理学报

In past decade, hydrogen sulfide (H₂S) as a novel gasotransmitter, covered many fields in biological and medical research. However, there is no effective, convenient and high-throughput method for determination of circulatory H₂S until now. Here, we aim to develop an easy method for measurement of circulatory H₂S by modified methylene blue method. In the present study, we added Zn²⁺ to plasma sample to deposit H₂S, HS⁻ and S²⁻, as well as plasma protein, then used NaOH to re-dissolve plasma protein. ZnS deposition was re-dissolved by the addition of N, N-dimethyl-p-phenylenediamine, and the remnant protein was deposited by trichloroacetic acid. After centrifugation, ferriammonium sulfate was added to the supernatant fluid to generate methylene blue, which was analyzed by spectrophotometer at 665 nm. Using the present method, we found that most ions including sulfate and thiosulfate did not affect detection of H₂S concentration, but albumin (physiological concentration) reduced the detection value, which suggested the binding of serum albumin and a certain amount of H₂S. The relative recovery ratio of present method is 81.9%, which implies that the method is relative accurate for the determination of H₂S concentration in plasma or serum. H₂S levels of frozen plasma samples from 65 healthy volunteers detected by the present method were (13.93 ± 4.98) µmol/L. There was no obvious difference between the detection values of fresh and frozen samples from the same SD rats. These results suggest the modified methylene blue assay is stable, sensitive, convenient and high-throughput. The method can be used to analyze the circulatory H₂S in clinical and basic research.

Antiplaque and antigingivitis effects of a mouthrinse containing cetylpyridinium chloride, triclosan and dipotassium glycyrrhizinate

PURPOSE: The goal of this study was to evaluate the clinical anitplaque and antigingivitis effects of a mouthrinse containing cetylpyridinium chloride (CPC), triclosan and dipotassium glycyrrhizinate (DPZ) in patients with gingivitis and mild periodontitis. METHODS: Thirty-two subjects were randomized into 2 groups. The test group used a mouthrinse containing 0.05% CPC, 0.02% triclosan and 0.02% DPZ, while the control group used a placebo mouthrinse. At baseline, 2 weeks and 4 weeks, the papillary bleeding index (PBI), Turesky-Quigley-Hein plaque index (PI) and Loe-Silness gingival index (GI) were assessed. During the experimental period, the patients used the mouthrinse for 30 seconds, 4 to 5 times/day (10 mL/time) within 30 minutes after toothbrushing. RESULTS: No adverse effects appeared in either the experimental or the control group. Regarding PBI, PI and GI values, statistical significance was detected between values at baseline and 2 weeks for both groups (P<0.05). In the experimental group, statistically significantly lower values were detected at 4 weeks compared to at 2 weeks. However, in the control group, no statistically significant difference was detected between the values at 2 weeks and 4 weeks. Additionally, the mean value after 4 weeks for the control group was slightly higher than the mean value after 2 weeks for the control group. CONCLUSIONS: This study for 4 weeks demonstrated that mouthrinses containing CPC, triclosan and DPZ may contribute to the reduction of supragingival plaque and gingivitis.

Antiplaque and antigingivitis effects of a mouthrinse containing cetylpyridinium chloride, triclosan and dipotassium glycyrrhizinate

PURPOSE: The goal of this study was to evaluate the clinical anitplaque and antigingivitis effects of a mouthrinse containing cetylpyridinium chloride (CPC), triclosan and dipotassium glycyrrhizinate (DPZ) in patients with gingivitis and mild periodontitis. METHODS: Thirty-two subjects were randomized into 2 groups. The test group used a mouthrinse containing 0.05% CPC, 0.02% triclosan and 0.02% DPZ, while the control group used a placebo mouthrinse. At baseline, 2 weeks and 4 weeks, the papillary bleeding index (PBI), Turesky-Quigley-Hein plaque index (PI) and Loe-Silness gingival index (GI) were assessed. During the experimental period, the patients used the mouthrinse for 30 seconds, 4 to 5 times/day (10 mL/time) within 30 minutes after toothbrushing. RESULTS: No adverse effects appeared in either the experimental or the control group. Regarding PBI, PI and GI values, statistical significance was detected between values at baseline and 2 weeks for both groups (P<0.05). In the experimental group, statistically significantly lower values were detected at 4 weeks compared to at 2 weeks. However, in the control group, no statistically significant difference was detected between the values at 2 weeks and 4 weeks. Additionally, the mean value after 4 weeks for the control group was slightly higher than the mean value after 2 weeks for the control group. CONCLUSIONS: This study for 4 weeks demonstrated that mouthrinses containing CPC, triclosan and DPZ may contribute to the reduction of supragingival plaque and gingivitis.

Comparison of effect of desensitizing agents on the retention of crowns cemented with luting agents: an in vitro study

PURPOSE: Many dentists use desensitizing agents to prevent hypersensitivity. This study compared and evaluated the effect of two desensitizing agents on the retention of cast crowns when cemented with various luting agents. MATERIALS AND METHODS: Ninety freshly extracted human molars were prepared with flat occlusal surface, 6 degree taper and approximately 4 mm axial length. The prepared specimens were divided into 3 groups and each group is further divided into 3 subgroups. Desensitizing agents used were GC Tooth Mousse and GLUMA(R) desensitizer. Cementing agents used were zinc phosphate, glass ionomer and resin modified glass ionomer cement. Individual crowns with loop were made from base metal alloy. Desensitizing agents were applied before cementation of crowns except for control group. Under tensional force the crowns were removed using an automated universal testing machine. Statistical analysis included one-way ANOVA followed by Turkey-Kramer post hoc test at a preset alpha of 0.05. RESULTS: Resin modified glass ionomer cement exhibited the highest retentive strength and all dentin treatments resulted in significantly different retentive values (In Kg.): GLUMA (49.02 +/- 3.32) > Control (48.61 +/- 3.54) > Tooth mousse (48.34 +/- 2.94). Retentive strength for glass ionomer cement were GLUMA (41.14 +/- 2.42) > Tooth mousse (40.32 +/- 3.89) > Control (39.09 +/- 2.80). For zinc phosphate cement the retentive strength were lowest GLUMA (27.92 +/- 3.20) > Control (27.69 +/- 3.39) > Tooth mousse (25.27 +/- 4.60). CONCLUSION: The use of GLUMA(R) desensitizer has no effect on crown retention. GC Tooth Mousse does not affect the retentive ability of glass ionomer and resin modified glass ionomer cement, but it decreases the retentive ability of zinc phosphate cement.

Comparison of solubility of zinc phosphate and glass ionomer cement in artificial saliva of varying pH values [in vitro study]

The aim of this study was to compare the solubility of Zinc Phosphate and Glass lonomer cements [conventional] in artificial saliva of different pH values. These cements are commonly used for permanent cementation of indirect restorations in dental practice at Peshawar, Pakistan and have to resist the harsh environment of oral cavity. The study was carried out at National Center of Excellence in Physical Chemistry, University of Peshawar, Pakistan. Both cements were mixed per manufacturer's directives to achieve excellent properties while using these as luting material. A total of 100 specimens were made for each dental cement and weighed prior to placement inpH medium of 2.46, 3.15, 3.56, 4.96 and 6.57 for 96 hours at 37°C temperature. After removal specimens were washed with doubly distilled water, dried in open air for 48 hours and reweighed. Percentage of solubility at each time period was calculated as 100 percent times weight loss divided by the initial weight of the specimen. It was found that the glass ionomer cement presented the highest solubility at low pH medium but was less soluble at high pH medium

Study of zinc phosphide intoxicated cases admitted to poison control centre - Ain shams university hospitals - Egypt [A retrospective study]

Acute poisoning with pesticides is a global public health problem and accounts for as many as 300.000 deaths worldwide yearly. Zinc phosphide has been widely used as a rodenticide since 1942-43 and its easy availability pushed up the incidence of self poisoning. This retrospective study was designed to highlight and evaluate the problem of zinc phosphide intoxicated cases presented and admitted to poison control centre [PCCA] during the year 2007, and was compared with its incidence during the previous 5 years, 2002-2006. The comparative study of the previous five years included the number of all cases of intoxication presented to the PCCA from 2002-2006, the number of zinc phosphide intoxication cases during the same period and their classification according to hospital admission: Intensive care unit [ICU], inpatient and emergency room [ER]. Regarding the retrospective study of zinc phosphide cases during the year 2007, it was carried out on the medical records of all patients admitted to PCCA during the year 2007, with a discharge disgnosis of zinc phosphide. The following parameters were reviewed and analyzed: Sociodemographic data [age, sex, residence and social class], intoxication data [delay time, mode and route of intoxication], presenting symptoms, vital signs, laboratory investigations and ECG monitoring. Different treatment modalities were analyzed and the outcome was recorded. The percentage of zinc phosphide poisoning during the period 2002-2006 in relation to the total number of poisoning cases admitted to PCCA ranged from 2.09%-5.38% and during 2007 it was 3.03%. The inpatient group showed the highest number of cases followed by the ER and then the ICU group. Death rate ranged from 0.3%-0.7% during the years 2002-2006, while during 2007, it was only 0.15%. The total number of cases during the year 2007 were 650 cases. The inpatient group comprised most of the cases followed by ER and ICU groups. The majority of patients were in the age group of 10-

Bio-oil production from biomass pyrolysis in molten salt / 生物工程学报

In order to investigate the effects of pyrolysis conditions on bio-oil production from biomass in molten salt, experiments of biomass pyrolysis were carried out in a self-designed reactor in which the molten salt ZnCl2-KCl (with mole ratio 7/6) was selected as heat carrier, catalyst and dispersion agent. The effects of metal salt added into ZnCl2-KCl and biomass material on biomass pyrolysis were discussed, and the main compositions of bio-oil were determined by GC-MS. Metal salt added into molten salt could affect pyrolysis production yields remarkably. Lanthanon salt could enhance bio-oil yield and decrease water content in bio-oil, when mole fraction of 5.0% LaCl3 was added, bio-oil yield could reach up to 32.0%, and water content of bio-oil could reduce to 61.5%. The bio-oil and char yields were higher when rice straw was pyrolysed, while gas yield was higher when rice husk was used. Metal salts showed great selectivity on compositions of bio-oil. LiCl and FeCl2 promoted biomass to pyrolyse into smaller molecular weight compounds. CrCl3, CaCl2 and LaCl3 could restrain second pyrolysis of bio-oil. The research provided a scientific reference for production of bio-oil from biomass pyrolysis in molten salt.

study of histological effects of solder fumes in rat lungs

To determine the potential toxic effects of manual soldering flux cored solder wire on lung of the rat as an experimental model. A total number of 48 adult male rats were divided into experimental [n=30] and control [n=18] groups. Based on exposure time to solder fume, each group was further subdivided into 2, 4 and 6 week subgroups. Rats of experimental groups were exposed to fume in exposure chamber for 1 hour/day [Research Center of Zahedan University of Medical Sciences, 12 Apr 2005 to 14 May 2005]. The amount of fumes were measured daily by standard methods. At the end of experiment, lung specimens were collected from each experimental and control subgroups. Tissue samples were processed routinely and thickness of epithelium in bronchioles and interalveolar septas were measured in stained microscopic slides. Obtained data were analyzed by SPSS. Statistical analysis of data for thickness of epithelium in bronchioles showed that there was only a significant difference between 4 week experimental and control subgroups [P< 0.001]. Analysis of data for thickness of interalveolar septa showed statistically significant differences between experimental and control subgroups of 4 and 6 weeks [P< 0.001]. Histological examination was also revealed an inflammatory process in bronchioles and disorganized architecture in alveoli of lung in experimental subgroups. The result showed that solder fume can change the normal architectures of epithelium in bronchioles and alveoli of the lung and it seems that the severities of changes were dependent on the exposure time

Effect of terbutaline on sodium transport in alveolar type I and type II cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of terbutaline on sodium transport in rat alveolar type I (ATI) and type II (ATII) cells of rats.</p><p><b>METHODS</b>The whole cell currents were recorded from ATII cells isolated from rat lungs perfused with or without amiloride (inhibitor of epithelial sodium channel) and ZnCl(2) (inhibitor of cyclic nucleotide-gated cation channel) in the whole cell recording mode using the patch-clamp technique. The effect of terbutaline on the currents was examined.</p><p><b>RESULTS</b>The main currents recorded from ATII cells were amiloride-sensitive and Zn(2+)-sensitive. The amiloride-sensitive and Zn(2+)-sensitive current shared a similar proportion (P>0.05). Both currents could be significantly increased by terbutaline (P<0.05), and the proportion of amiloride-sensitive current was 1.7 times that of Zn(2+)-sensitive current (P<0.05).</p><p><b>CONCLUSION</b>There are functional epithelial sodium channels (ENaC) and cyclic nucleotide-gated cation channels (CNG) on freshly isolated ATII cells, both serving as the main channels for sodium transport. Terbutaline increases the absorption of alveolar fluid primarily by increasing sodium transport of ENaC and CNG on ATI and AT II cells.</p>

Dislodgement resistance of modified resin-bonded fixed partial dentures utilizing tooth undercuts: an in vitro study

STATEMENT OF PROBLEM: Over the years, resin-bonded fixed partial dentures (RBFPDs) have gone through substantial development and refinement. Several studies examined the biomechanics of tooth preparation and framework design in relation to the success rate of RBFPDs and considered retention and resistance form essential for increase of clinical retention. However, these criteria required preparations to be more invasive, which violates not only the original intentions of the RBFPD, but may also have an adverse effect on retention due to loss of enamel, an important factor in bonding. PURPOSE: The object of this in vitro study was to compare the dislodgement resistance of the new types of RBFPDs, the conventional three-unit fixed partial denture, and conventional design of RBFPD (Maryland bridge). MATERIAL AND METHODS: Fifty resin mandibular left second premolars and second molars were prepared on dentiforms, according to the RBFPD design. After model fabrication (five group, n = 10), prostheses were fabricated and cemented with zinc phosphate cement. After cementation, the specimens were subjected to tensile loading at a cross head speed of 4 mm/min in a universal testing machine. The separation load was recorded and analyzed statistically using one-way analysis of variance followed by Duncan's multiple range test. RESULTS: Group V, the pin-retained RBFPDs, had the highest mean dislodgement resistance, whereas specimens of group II, the conventional RBFPDs, exhibited a significantly lower mean dislodgement resistance compared to the other 4 groups (P .05). Group V had the highest mean MPa (N/mm2) (P .05). CONCLUSION: Within the limits of the design of this in vitro study, it was concluded that: 1. The modified RBFPDs which utilizes the original tooth undercuts and requires no tooth preparation, compared with the conventional design of RBFPDs, has significantly high dislodgement resistance (P .05). 3. The pin-retained FPDs showed a high dislodgement resistance compared to the conventional three-unit FPDs (P < .05).

Serum zinc levels in celiac disease.

This study was done to determine the zinc levels in 30 children with celiac disease. Serum zinc level was estimated at inclusion and zinc supplementation was given for 3 months. Zinc levels were repeated at 3 and 6 months after inclusion. The serum zinc levels of newly diagnosed CD cases (0.64+/-0.34 microg/mL) versus controls (0.94+/-0.14 microg/mL) were significantly lower (95% CI -0.44 to -1.4), whereas in the old cases this difference was non-significant. The serum zinc level among severely malnourished and stunted celiac cases was also significantly lower irrespective of their treatment status. We conclude that serum zinc levels are low in newly diagnosed and severely malnourished children with celiac disease.

Adsorption of herbicide [pendimethalin] onto activated carbons developed from date pits

Phosphoric acid-activated carbons PI and P2 were prepared by impregnating crushed date pits with 50 and 75 wt% phosphoric acid followed by carbonization at 500°C in limited air. Zinc chloride-activated carbons Zland Z2 were obtained by impregnating crushed date pits with 100 and 200 wt% zinc chloride followed by carbonization at 600°C in limited air. Steam-activated carbons SI and S2 were obtained by gasifying date pits carbonization product with steam at 950°C to burn-off s = 17 and 48%, respectively. The textural properties of the activated carbons were determined from nitrogen adsorption at 77K and the chemistry of their surfaces were characterized by measuring their surface pH and by determining their acid and base-neutralization capacities. The equilibrium adsorption of pendimethalin at 293, 300, 310 and 320K was studied using different system variables. Generally activated carbons exhibited high adsorption capacities towards pendimethalin. The adsorption data followed Freundlich and Langmuir models. The adsorption of this herbicide decreased with the rise of adsorption temperature and the small values of delta H indicated the loose bonding between adsorbate molecules and adsorbent surface. The negative values of entropy change delta S although small, indicated that the adsorption complex formed was stable

Adsorption of phenol and some substituted phenols on chemically - activated carbons developed from apricot stones

Chemically activated carbons were prepared from apricot stones. Phosphoric acid [25 - 75 wt%] was used as activating agent at 400 - 600 °C. Zinc chloride - activated carbons were also prepared at 600 °C and at 700 °C using zinc chloride [50 - 200 wt%] as activating agent. The textural parameters were determined from nitrogen adsorption data at 77 K. The chemistry of the carbon surfaces was determined from the FTIR spectrograms and from the base and acid neutralization capacities. The adsorption of phenol, p -nitrophenol and 3,5-dinitrophenol was carried out at 298 K for all the prepared carbons and also at 308 and 317 K for some selected carbons. Chemically - activated carbons exhibited high adsorption capacity towards phenols. Phenols adsorption increased with the increase of the molecular weight of the phenol and with the decrease of its solubility in water. The adsorption of phenols increased also with the decrease of the surface density of carbon - oxygen group existing. Adsorption of phenols proceeds via physical adsorption on oxygen - free surface and via chemisorption on oxygen contaminated carbon surfaces. Activated carbons [AC's] are widely used as adsorbents in decontamination process because of their extended surface area, microporous structure high adsorption capacity and special surface reactivity[1-4]. The surface of AC is considered heterogeneous from the point of view of both porosity and surface chemistry. The heterogeneity of the pore structure is a result of the existence of a wide range of size from a few to a few hundred angstroms[5]. The heterogeneity of the chemistry of AC is attributed to the existence of heteroatoms such as oxygen, nitrogen, hydrogen and phosphorous[6-7]. The heteroatoms, particularly oxygen, consist of organic functional groups at the edges of carbon crystallites. Carbon-oxygen groups include carboxyls, phenols, ethers, lactones and carbonyl[8]. There has been an increasing interest in the study of adsorption of organic molecules on AC. This is due to the importance of the removal of organic pollutants from water streams and the atmosphere[9]. Adsorption of aromatic compounds from solution, particularly phenols, has been studied extensively[10-14]. Phenolic compounds exist widely in the industrial effluents such as those from oil refineries, cool tar, leather, paint, pharmaceutical and steel industries. Since they are highly toxic and, in general, not amenable to biological degradation, methods of treatment are continuously modified and developed at all treatments. Among adsorbents, granular or powder AC proved to be the most efficient[15-19]. Regardless of the enormous studies undertaken concerning the adsorption of phenols on carbon, it can be seen that more intensive investigations still need to be undertaken to find convincing answer for some problems still remaining on phenol uptake by AC. The objective of this paper is to study the effect of surface chemistry and surface area of carbons on their adsorption of phenols. The samples are different from the point of view of the activating agent used [Zinc chloride and phosphoric acid]. An important feature common for all the samples is their acidic surface pH. Under such condition phenols exist in their molecular form. Three phenols were studied, namely phenol [P], paranitrophenol [PNP] and dinitrophenol [DNP]