RESUMO
The increasing use of hexavalent chromium (Cr(VI)) has exposed large populations to this environmental and occupational carcinogenic agent. Therefore, researchers have been interested in removing this substance through adsorbents. This study aimed to investigate the efficiency of natural zeolite in the direct adsorption of Cr(VI) from airflow and its adsorption modeling. In this study, a nebulizer device produced the Cr(VI) mist. The efficiency of natural zeolite in Cr(VI) adsorption from airflow, modeling of fixed column adsorption, and the effective parameters on adsorption efficiency including the initial concentration of chromium, airflow rate, and adsorption bed depth were studied. To facilitate the prediction of the performance of natural zeolite's adsorption column, Yoon-Nelson, Thomas, BDST, and Buhart-Adams models were used. The results showed that the adsorption capacity diminished with increased airflow rate and initial concentration, while it increased with elevated height of the adsorption bed. Yoon-Nelson, Thomas, and BDST models corresponded to experimental data with a correlation coefficient of 0.9933, but the information of the Buhart-Adams model had a lower correlation coefficient (around 0.6677). In conclusion, natural zeolite can be used as an efficient low-cost adsorbent for directly Cr(VI) removing from the airflow in a fixed bed column.
Assuntos
Cromo , Zeolitas , Zeolitas/química , Cromo/química , Cromo/isolamento & purificação , Adsorção , Poluentes Atmosféricos/química , Poluentes Atmosféricos/isolamento & purificação , Modelos TeóricosRESUMO
A new method based on the immobilization of 2-(Aminomethyl) thiazole on the multi-walled carbon nanotubes (AMTZ@MWCNTs) was used to extract manganese (Mn) in the human blood, serum, and urine samples. First, 20 mg of AMTZ@MWCNTs, 0.2 mL of acetone, and 0.1 g of ionic liquid (IL) were completely mixed and injected into 2.0 mL human samples by a microscale syringe at pH 5.5. After shaking and centrifuging, the Mn ions were extracted and separated through the ultrasound-assisted- ionic liquid-dispersive micro solid-phase extraction (UAS-IL-D-µ-SPE) before being determined by the graphite furnace atomic absorption spectrometry (GF-AAS). According to the results, manganese in the blood of hepatic patients had higher concentrations than healthy people (Aged 25-60, 50 N). The Mn adsorption capacities for the AMTZ@MWCNTs and MWCNTs adsorbents were achieved at 192.5 mg/g and 26.3 mg/g, respectively. In the high enrichment factor (HEF), the limit of detection (LOD), linear range (LR), and mean relative standard division (RSD%) were calculated at 15 ng/L, 0.05-3.8 µg/L, and 2.34, respectively (n = 10). The methodology was validated using certified reference material (CRM) and spiking standard solutions to human samples.
Assuntos
Líquidos Iônicos , Nanotubos de Carbono , Humanos , Manganês , Líquidos Iônicos/química , Nanotubos de Carbono/química , Tiazóis , Extração em Fase Sólida/métodos , Íons , Limite de DetecçãoRESUMO
A rapid and efficient method based on a novel nitrogen-doped porous graphene nanostructure (NDPG) was used for the speciation of mercury in water and human blood samples by the CV-AAS. The mixture of the NDPG, ionic liquid, and acetone was rapidly injected into the human blood, water, and food samples for mercury separation by the cloud point assisted dispersive ionic liquid-micro solid-phase extraction (CPA-DIL-µ-SPE) at pH 7.5. The UV-microwave accessory converted the organic mercury (R-Hg) to inorganic mercury, and total mercury (TM) was determined. Finally, the organic mercury was calculated by subtracting the inorganic and entire mercury contents. By optimizing, the linear range, LOD, and enrichment factor were obtained (0.01-6.80 µg/L; 0.005-3.60 µg/L), (2.6 ng/L; 1.2 ng/L) and (9.8; 20.2) for the mercury species in human blood and water/food samples, respectively (Mean of RSD < 1.9 %). The CRM samples obtained the validation of the procedure.
Assuntos
Grafite , Líquidos Iônicos , Mercúrio , Nanoestruturas , Humanos , Mercúrio/química , Água/química , Líquidos Iônicos/química , Nitrogênio , Porosidade , PirróisRESUMO
Organophosphate pesticides (OPPs) are widely used all over the world in domestic and industrial settings, but these chemicals affect the nervous system, induce suicidal thoughts, depression and anxiety, and impair sleep quality. The purpose of this study was to investigate the relationship between the main toxicity mechanisms of OPPs, oxidative stress and cholinesterase inhibition, and psychological parameters in chronic exposure to OPPs. This cross-sectional study was conducted on 56 male OPPs factory workers as the worker group and 47 unexposed individuals within the same age range as the control group. Psychological factors were assessed using validated questionnaires. The activity of plasma cholinesterase and oxidative stress biomarkers, total antioxidant capacity of plasma, lipid peroxidation (LPO), and protein carbonylation were determined in blood samples by spectrophotometer. Sleep quality score in the factory workers was lower, and depression and suicidal ideation scores were higher than those in the control group. These factory workers showed 35% lower levels of plasma cholinesterase activity than did the controls. Compared to the control group, a significant impairment in oxidative stress biomarkers was also observed in the workers. Meanwhile, there was a significant relationship between the duration of employment and the level of LPO as well as a significant correlation between the quality of sleep and plasma cholinesterase in the workers. In conclusion, long-term exposure to OPPs could cause oxidative damages and neurobehavioral effects. The close monitoring of workplace exposure to organophosphates pesticides and also their respective solvents along with the reduction of working hours are of the necessities to avoid the adverse impacts of exposure to these pesticides.
Assuntos
Inseticidas , Exposição Ocupacional , Praguicidas , Biomarcadores/metabolismo , Colinesterases , Estudos Transversais , Humanos , Inseticidas/toxicidade , Masculino , Organofosfatos/toxicidade , Compostos Organofosforados , Estresse Oxidativo , Praguicidas/toxicidade , Medição de RiscoRESUMO
A new method based on graphene oxide modified (4-phenyl) methanethiol nanomagnetic composite (Fe3O4@4-PhMT-GO) was used for extraction and separation of aluminum from wastewater, food, and vegetable samples in aluminum cookware by microwave dispersive magnetic micro solid-phase extraction (MDM-µ-SPE). In optimized conditions, the working range (WR), the linear range (LR), the limit of detection (LOD), and enrichment factor (EF) were obtained 5-5200 µg L-1, 5-1600 µg L-1, 1.5 µg L-1, and 48.8, respectively (RSD% = 2.5). By MDM-µ-SPE procedure, the aluminum concentrations in baking rice and spinach with aluminum cookware were obtained 97.43 ± 2.57 mg g-1 and 131.64 ± 5.18 mg g-1, respectively which was analyzed by atom trap flame atomic absorption spectrometer (AT-FAAS). The results showed, the aluminum concentrations in cooked foods with Teflon cookware were less than aluminum cookware. The methodology was validated by standard reference materials (SRM) and inductively coupled plasma mass spectrometry analysis (ICP-MS).
Assuntos
Alumínio/análise , Análise de Alimentos/métodos , Microextração em Fase Sólida/métodos , Espectrofotometria Atômica , Verduras/química , Águas Residuárias/química , Adsorção , Alumínio/isolamento & purificação , Óxido Ferroso-Férrico/química , Grafite/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Magnetismo , Micro-Ondas , Sonicação , Compostos de Sulfidrila/químicaRESUMO
Investigation of exposure to toxic vanadium (V) in petrochemical workers is very important for human health, and it must be removed and determined in workplace air and human biological samples. In this research, the enriched adsorbent based on the thiol modified bimodal mesoporous silica nanoparticle (HS-UVM7) was used for the extraction vanadium in human blood by the dispersive sonication ionic liquid micro solid phase extraction (DS-IL-µ-SPE) at pH of 4.5. In addition, the vanadium (V) was removed from the industrial workplace air based on HS-UVM7 adsorbent by the liquid-solid phase-gas removal (LSP-GR). In the static and dynamic system, the vanadium (V) was removed from artificial air with HS-UVM7 and compared with the polyvinyl chloride membrane (PCM, sorbent in 7300 NIOSH). The LSP-GR procedure based on HS-UVM7 had more recovery and adsorption capacity as compared to PCM. The adsorption capacity of HS-UVM7 and UVM7 adsorbents were obtained 144.1 mg g-1 and 23.3 mg g-1, respectively. In addition, the main parameters effected on extraction vanadium in blood samples and removal from air were studied and optimized by ET-AAS. The LOD, RSD%, linear range (LR) and enrichment factor (EF) was achieved 0.03 µg L-1, 3.1, 0.1-4.5 µg L-1 and 48.7, respectively for extraction of vanadium in 10 mL of blood samples by the DS-IL-MSPE procedure. The validation of the methodology was confirmed by standard addition to gas phase and using certified reference materials (CRM, NIST) or ICP-MS in human blood samples.
Assuntos
Nanopartículas , Dióxido de Silício , Humanos , Limite de Detecção , Compostos de Sulfidrila , Vanádio/toxicidadeRESUMO
Some epidemiological studies have suggested that exposure to extremely low-frequency magnetic fields (ELF-MFs) can affect the immune system. This study aimed to investigate the effects of antioxidant vitamin consumption on proinflammatory cytokines and biochemical parameters changes. In this randomized, controlled double-blinded trial study, power plant workers exposed to ELF-MFs were enrolled based on inclusion criteria. Ninety-one eligible subjects were randomly divided into four groups: the first group (400 units of vitamin E/day), second group (1,000 mg of vitamin C/day), third group (400 units of vitamin E and 1,000 mg of vitamin C/day), and control group. The intervention was conducted for 3 months. Proinflammatory cytokines interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α), and biochemical parameters (fasting blood sugar, total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol [HDL-c], total protein, and albumin) were measured among the participants' serums, before and after the intervention. The mean level of IL-6 in all vitamin-receiving groups, the mean level of IL-1ß in vitamin C and E&C groups, and the mean level of TNF-α in the vitamin C group, decreased significantly after intervention. The arithmetic means of the effect sizes for IL-1ß, IL-6, and TNF-α were 0.71, 0.57, and 0.2, respectively. The level of HDL-c in the vitamin E and vitamin E&C groups and the level of triglyceride in the vitamin C group significantly increased after the intervention. Taking antioxidant vitamins can prevent an increase of proinflammatory cytokines induced by prolonged exposure to ELF-MFs. Bioelectromagnetics. 2021;42:18-26. © 2020 Bioelectromagnetics Society.
Assuntos
Antioxidantes , Citocinas , Humanos , Centrais Elétricas , Vitamina E/farmacologia , VitaminasRESUMO
In this study, the enrichment and novel sorbent based on functionalized bimodal mesoporous silica nanoparticles (HS-UVM7 and NH2-UVM7) was used for removal of lead aerosols pollution from air by solid liquid gas phase extraction method (SLGPE). In bench scale set up, the lead aerosols [(Pb (NO3)2, PbO] was generated by dispersive aerosols generator system (DAGS) and removed from air by reaction loop (RL) / impinger trap (IT) in a liquid phase which was mixed with nano adsorbent in optimized pH. The effect of parameters such as, flow rate, volume of liquid phase, time stirring, temperature, concentration, pH and amount of sorbent (mg) were studied and evaluated by flame atomic absorption spectrometry (FAAS). In optimized conditions, the adsorption capacity of HS-UVM7 and NH2-UVM7 for Pb(NO3)2 aerosols was obtained 255.6 mg g-1 and 177.6 mg g-1, respectively which was more than UVM7. The lead oxides aerosols (PbO) were extracted only by HS-UVM7 at acidic pH with the adsorption capacity of 271.2 mg g-1. The characterization of SEM, XRD, TEM, and FTIR showed that the HS-UVM7 has beneficial surfaces for removal of (Pb (NO3)2 and PbO aerosols from the air by SLGPE method at pH = 5. The method validation was confirmed by standard addition and NIOSH method. Graphical abstract.
RESUMO
Objective: To evaluate the effect of pharyngeal pack on postoperative throat pain and nausea in rhinoplasty patients. Material and Methods: Twenty-eight patients were randomly selected and divided into two groups (n=14). The participants were randomly divided into two groups: G1 - the pharyngeal pack was used (Intervention group) and G2: not used (Control group). Both groups were anesthetized by the same protocol. Throat pain was measured by visual analog scale and nausea by presence / absence. Fischer's exact test, ANOVA, Friedman and Wilcoxon test were used. Results: There was no significant difference in mean pain and presence or absence of nausea between the two groups (p>0.05). But there was a significant difference in mean pain and the presence or absence of postoperative nausea with the intervals (p<0.05). Mean pain had a significant difference 2 hours postoperatively with other times, 6 hours postoperatively with 24 and 72 hours postoperatively, and 24 hours postoperatively with 72 hours (p<0.05). There was no significant difference in the presence or absence of postoperative nausea, between 2 hours and 6 hours postoperatively (p>0.05). The presence or absence of postoperative nausea had a significant difference between 2 hours postoperatively with 24 and 72 hours postoperatively and 6 hours postoperatively with 24 and 72 hours postoperatively (p<0.05). There was no significant difference in nausea between 24 hours and 72 hours postoperatively (p>0.05). Conclusion: None of the two groups were significantly superior in terms of reduction of pain and nausea, but because of the possible effectiveness of the pharyngeal pack in preventing aspiration of objects and tissues during the operation, the use of pharyngeal pack is recommended in patients.
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Dor Pós-Operatória , Rinoplastia/métodos , Procedimentos Cirúrgicos Nasais , Escala Visual Analógica , Análise de Variância , Estatísticas não Paramétricas , Estudo de Avaliação , Irã (Geográfico)RESUMO
BACKGROUND: Mineral trioxide aggregate (MTA) has a high biocompatibility and its physical properties could be improved by adding the containing silica fume an amorphous silicon dioxide (condensed silica fume [CSF]). The aim of this study was to evaluate the cytotoxicity of MTA mixed with CSF on the viability of L929 mouse fibroblast cell using 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide reduction assay (MTT assay). MATERIALS AND METHODS: In this in vitro study white MTA was mixed with distilled water according to the manufacturer's instructions. Mixtures of White MTA with 10%, 15%, and 20% CSF by weight were prepared and mixed with distilled water. Cytotoxicity of mixtures was compared with MTT assay on L929 mouse fibroblast cell line after 24, 48, and 72 h. Differences in cytotoxicity were assessed by one-way analysis of variance (ANOVA). RESULTS: Mean ± SD of vital cell counts cultured in MTA, MTA + 10% CSF, MTA + 15% CSF, and MTA + 20% CSF were 98% ± 6%, 97% ± 6%, 94% ± 4%, and 98% ± 4%, respectively. One-way ANOVA did not reveal any statistically significant difference between the groups (P > 0.05). CONCLUSION: It may be concluded that addition of CSF to MTA may not influence its cytotoxicity.
RESUMO
Objective: To evaluate the effect of Anaheal (Bromelain) drug on the periodontal clinical indices in nonsurgical periodontal treatment of patients with chronic periodontitis. Material and Methods: In this double blind clinical trial, 80 patients with chronic moderate periodontitis and a healthy systemic status were chosen, and divided into two 40-subject groups. Thereafter, the standard treatment of periodontitis including scaling and root planning in one session by the unit operator was performed for all patients. Eventually, one group of the patients was administered Bromelain medication (500-mg capsule twice a day) one hour before food, while the other group was given placebo. Four and eight weeks after the treatment, the clinical periodontal indicators were measured and recorded in both groups. The data were assessed using descriptive statistics and analytical test methods (Mann-U-Whitney and Chi-square). P value less than 0.05 was considered statistically significant. Results: Gingival index, probing depth and plaque index before the treatment were similar in both groups (Anaheal and placebo). However, four and eight weeks after the treatment, the three studied indices were significantly lower in the Anaheal group as compared to the placebo (p<0.05). The index of bleeding on probing was also similar before the treatment and four weeks after the treatment in both groups. However, eight weeks after the treatment, this index was significantly lower in the Anaheal group as compared to the placebo group (p<0.05). Conclusion: Administration of oral Anaheal medication after nonsurgical periodontal treatments reduced all the clinical periodontal indices among patients with chronic periodontitis as compared to the control group. Therefore, it can be a suitable substitute for the common oral industrial antibiotics.
Assuntos
Humanos , Masculino , Feminino , Adulto , Bromelaínas/uso terapêutico , Índice Periodontal , Raspagem Dentária/métodos , Periodontite Crônica/diagnóstico , Distribuição de Qui-Quadrado , Estatísticas não Paramétricas , Ensaio Clínico Controlado , Irã (Geográfico)RESUMO
Objective: To evaluate the effects of combined and sequential consumption of chlorhexidine and listerine mouthwashes on plaque indices. Material and Methods: Sixteen dental students, both genders, were selected. After prophylaxis, four mouthwash regimens were used, such that in each period, mouthwash was used for 5 days and after each period there was 4 days of washing out. During the mouthwash period, the participants did not use any mechanical plaque control tool. The four regimens included: first regimen, first chlorhexidine then listerine; second regimen, listerine then chlorhexidine; third regimen, only listerine; fourth regimen, chlorhexidine alone. At the end of the period, individuals were evaluated for plaque indices and investigated for bleeding during probing using ANOVA variance analysis and post-hoc Tukey test. The level of significance was set at 5%. Results: Regimen 1 with a plaque mean of 0.55 ± 0.25 had significantly lower plaque than other regimens. The maximum rate of plaque was observed in regimen 3. Probing did not cause bleeding in any of the individuals who used the four mouthwash regimens. Conclusion: The use of 0.2% chlorhexidine and listerine has the highest effect on plaque reduction.
Assuntos
Humanos , Masculino , Feminino , Estudantes de Odontologia , Clorexidina/administração & dosagem , Placa Dentária/prevenção & controle , Antissépticos Bucais/uso terapêutico , Ensaio Clínico , Análise de Variância , Estatísticas não Paramétricas , Estudo de Avaliação , Irã (Geográfico)RESUMO
INTRODUCTION: The aim of this randomized double-blind study was to evaluate the efficacy of Tranexamic acid (TXA) on intraoperative bleeding, postoperative eyelid edema, and postoperative periorbital ecchymosis in rhinoplasty. MATERIALS AND METHODS: Sixty rhinoplasty patients who needed hump reduction and lateral osteotomy were included and then randomly assigned into two groups. In the intervention group (n = 30), 10 mg/kg of TXA was administered prior to the operation and in the control group, the patients were given 20 mL of normal saline. Intraoperative bleeding was evaluated by gravimetric method and pre and postoperative hemoglobin and hematocrit levels were determined. Eyelid edema and periorbital ecchymosis were evaluated using 0-4 points scoring system. Surgeon satisfaction was measured by asking questions of the surgeon. Data were analyzed by SPSS 20.0 (P < 0.05). RESULTS: In total, 10 participants were excluded from the research, and 50 patients were included in the study. Mean (SD) of intraoperative bleeding was 213 (65) mL and 254 (55) mL in the intervention and control group, respectively, based on the clinical methods (P = 0.013). Level of hemoglobin was 266.69 in the control group versus 241.25 in the TXA group, indicating that this effect on the intraoperative bleeding was not significant (P = 0.1). Hematocrit differences before and after operation were significant (P = 0.03) (247.06 mL in TXA vs. 279.2 mL in the control group). TXA had a statistically significant effect on the eyelid edema (P = 0.03), periorbital ecchymosis (P = 0.04), and surgeon satisfaction (P = 0.03). CONCLUSION: Administration of 10 mm/kg TXA had a significant effect in decreasing the intraoperative bleeding rate, eyelid edema, and periorbital ecchymosis in the rhinoplasty with minimal side effects.
Assuntos
Antifibrinolíticos/uso terapêutico , Complicações Pós-Operatórias/tratamento farmacológico , Rinoplastia/métodos , Ácido Tranexâmico/uso terapêutico , Adulto , Perda Sanguínea Cirúrgica/prevenção & controle , Método Duplo-Cego , Equimose/tratamento farmacológico , Edema/tratamento farmacológico , Feminino , Humanos , Masculino , Resultado do TratamentoRESUMO
Background. The present study was conducted to investigate the marginal bone loss around two different types of implantâabutment junctions, called platform-switched (Implantium system) and non-platform switched (XiVE system) after two years of loading. Methods. Sixty-four implants in 49 patients were included in the study. The implants were placed in the posterior mandibular region according to the relevant protocols. The extent of bone loss around the implants was measured and compared after 24 months, using digital parallel periapical radiographs. Results. The means ± SE of bone loss values in the platform-switched and non-platform-switched groups were 0.47 ± 0.048 mm and 1.87 ± 0.124 mm, respectively. The difference between the two groups was statistically significant (P < 0.0001). Conclusion . The platform-switching technique seems to reduce the periimplant crestal bone resorption, which supports the long-term predictability of implant therapy.
RESUMO
BACKGROUND: Peri-implant diseases have been recognized as being among the ever-increasing complications related to dental implants. The aim of this study was to evaluate the adjunctive use of enamel matrix derivative (EMD) to mechanical debridement (MD) in patients with these conditions in terms of clinical parameters and cytokine levels of peri-implant crevicular fluid (PICF). METHODS: In the present double-blind clinical trial, 46 patients with peri-implant mucositis (PM) were randomly divided into control and test groups. Two different therapeutic protocols, consisting of non-surgical MD alone (control group) and MD with the application of EMD (test group), were considered for the two groups. Clinical parameters [bleeding on probing (BOP) and probing depth (PD)] and sampling from PICF were carried out before treatment and 3 months postoperatively. The levels of IL-6 and IL-17 cytokines in PICF were evaluated by enzyme-linked immunosorbent (ELISA). RESULTS: Three-month post-interventional assay revealed significant improvements in BOP and PD in the test group in comparison to the control group (P < 0.0001). Relative to control, IL-6 and IL-17 levels were reduced significantly (p < 0.05) in the test group compared to the control group. CONCLUSION: Application of EMD can be considered an adjunct to MD in the non-surgical treatment of PM. However, complete recovery was not observed using either treatment approach showing that management of implant-associated disease is still a significant clinical problem.
Assuntos
Proteínas do Esmalte Dentário/uso terapêutico , Mucosite/tratamento farmacológico , Peri-Implantite/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Citocinas/metabolismo , Desbridamento , Método Duplo-Cego , Ensaio de Imunoadsorção Enzimática , Feminino , Líquido do Sulco Gengival/química , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do TratamentoRESUMO
BACKGROUND: The purpose of this study was to investigate of radiographic pattern and relative frequency of idiopathic osteosclerosis (IO) and condensing osteitis (CO) in panoramic radiographs. MATERIALS AND METHODS: Totally 411 panoramic radiographies were randomly selected from patients referred to Radiology Department of Faculty of Dentistry, Tabriz University of Medical Sciences. Descriptive characteristics of radiopacities, including shape, border, localization, and dental relationship, were recorded. The Chi-squared test was used. RESULTS: IO was detected in 31 (7.5%) patients and 22 (68.8%) lesions had exact border while their shape was mostly irregular. About 17 (53.1%) lesions were apical, and 13 (40.6%) lesions had no relation to the teeth. The most involved teeth were the second premolar (28.1%) and first molar (25%). Moreover, CO was detected in 32 (7.8%) patients. 17 (53.1%) lesions had an ill-defined border, and their shape was mostly irregular (65.6%) with ill-defined border. Around 18 (56.3%) lesions were apical, and 11 (34.4) lesions were apical and interradicular. The most involved teeth were the second premolar (59.4%) and the first molar (21.9%). CONCLUSION: The results demonstrated that relative frequency of IO in the selected population was 7.5% and for CO, it was 7.8%.
RESUMO
BACKGROUND: It was presented that Trichomonas tenax is one of the parasites which is responsible for oral infection. This study was considered to estimate the prevalence of this parasite in oral cavity of Down syndrome patients with periodontal lesions and in healthy population from welfare organization in Tabriz, Iran. MATERIALS AND METHODS: In the case-control study, 52 patients with periodontal disease (case group) and 52 individuals with healthy gingiva (control group) selected for the study. Examination was done by dental mirror and periodontal probe. After using plaque detector tablets, sampling was done by entering sterile paper into periodontal pocket for 20 seconds. The amount of plaque was measured by plaque index. Finally samples sent to laboratory for prepared PCR reaction. RESULTS: In the case group, 14 patients were infected and in the control group 5 individuals. Percentage of infection in case group was 18.8% and in the control group was 3% that difference was statically significant. Plaque index in the case group was 72 ± 10.2 and in the control group was 68 ± 11.4 and difference between two groups was not significant. CONCLUSION: Parasitic infections in Down syndrome were higher than healthy children while plaque index was not significantly different between the two groups. Therefore follow-up of orders are necessary in control of parasitic infection in Down syndrome that have intrinsic defect of immune systems.
RESUMO
BACKGROUND: Based on the noticeable toxicity and numerous application of mercury in industries, removal of mercury vapor through sorbent is an important environmental challenge. PURPOSE OF THE STUDY: Due to their highly porous and hollow structure, large specific surface area, light mass density and strong interaction, Single-Walled Carbon Nanotubes (SWCNTs) sorbent were selected for this investigation. METHODS: In this study, instrumental conditions, method procedure and different effective parameters such as adsorption efficiency, desorption capacity, time, temperature and repeatability as well as retention time of adsorbed mercury were studied and optimized. Also, mercury vapor was determined by cold vapor atomic absorption spectrometry (CV-AAS).Obtained data were analyzed by Independent T- test, Multivariate linear regression and one way-ANOVA finally. RESULTS: For 80 mg nanotubes, working range of SWCNT were achieved 0.02-0.7 mg with linear range (R2=0.994).Our data revealed that maximum absorption capacity was 0.5 mg g-1 as well as limit of detection (LOD) for studied sorbent was 0.006 mg. Also, optimum time and temperature were reported, 10 min and 250 °C respectively. Retention time of mercury on CNTs for three weeks was over 90%. Results of repeated trials indicated that the CNTs had long life, so that after 30 cycles of experiments, efficiency was determined without performance loss. CONCLUSION: Results showed that carbon nanotubes have high potential for efficient extraction of mercury from air and can be used for occupational and environmental purposes. The study of adsorption properties of CNTs is recommended.