جستجوی مقالات مرتبط با کلیدواژه « decontamination » در نشریات گروه « پزشکی »

During the early days of COVID-19 pandemic, due to the shortage of N95 respirators in hospitals and healthcare centers, the reuse of N95 respirators was posed as a crisis capacity strategy. Several studies have evaluated the efficacy of various decontamination methods on N95 respirators of well-known and approved brands. However, fundamental question is whether decontamination and reuse methods can be applied to all types of respirators.

Six types of respirators were selected from well-known and lesser-known brands which their manufacturers claimed to be N95. The selected respirators decontaminated with dry heat, ultraviolet germicidal irradiation, and ethylene oxide methods in seven consecutive cycles and their particle filtration efficiency and pressure drop were measured before and after each decontamination cycle.

As the initial measurements revealed, 4 respirators (group A) showed a sharp drop in efficiency and also, negative efficiency in removing 2.5 and 4 µm particles in most of the experiments. In these respirators (group A), the maximum efficiency in removing 0.5 µm particles was 74.4 %, while the last two respirators (group B) achieved an efficiency of 98 %. Subsequent experiments following the decontamination process revealed that the non-authentic N95 respirators within group A which were not resistant to decontamination. However, the second group demonstrated a removal rate of over 95 % of particles ranging from 0.5 to 10 µm after six consecutive decontamination cycles using all three methods. The results demonstrated that ultraviolet germicidal irradiation and ethylene oxide methods could eradicate the covid-19 virus from respirators.

The results indicated that decontamination can be successfully applied to original N95 respirators, not low-quality respirators, even under critical conditions.

Nosocomial infections may result from intensive care unit pulse oximeters. The descriptive study examined pulse oximeter sensor microbiological contamination and the efficacy of manual disinfection with alcohol and sodium hypochlorite in five hospital intensive care units. Sixty-eight reusable pulse oximeter sensors were swabbed, cultured, and evaluated after decontamination. In private and public hospitals, 12 (35.2%) and 13 (37.2%) pulse oximeters tested positive for bacteria. Alcohol 70% reduced the microbial load and more than 10% sodium hypochlorite. The study found that purposeful cleaning and disinfection reduce microorganisms. Alcohol was more efficacious than sodium hypochlorite. Critical care facilities should regularly clean reusable pulse oximeter sensors.

Decontaminating the implant surface, exposed to bacterial biofilm, is a concern in the treatment of peri‑implant inflammatory disease. The aim of this study was to compare the effect of several methods on reduction of the bacterial load, colonized on the surfaces of titanium discs.

In this in vivo study, seven titanium discs with Sandblasted, Large‑grit, acid‑etched (SLA) surface were placed in the mouth of each of ten patients with chronic periodontitis by an intra‑oral maxillary splint for 24 h. In each patient, the contaminated discs, except for the negative control ones, were randomly treated by one of the six antiseptic methods including sterile normal saline, plastic curette, air polisher, hydrogen peroxide, 980 nm diode laser, and Er‑YAG laser. A spectrophotometer was used to measure Optical Density (OD) in case of aerobic microorganisms. Colony‑Forming Units (CFUs) were used for anaerobic bacteria. Data were analyzed through Kruskal–Wallis and Mann–Whitney Tests at a significance level of α =0.05 by SPSS software.

Statistical analysis showed a significant decrease in OD of aerobic bacteria among the seven groups during a 0–24 h time interval (P < 0.001). Furthermore, these tests showed a significant difference in the CFU (P < 0.001) for anaerobic bacteria after 48 h.

The results of this study showed that all of the adopted methods significantly reduced microbial colonies on the surfaces of titanium discs with SLA surface. Er: YAG laser and normal saline had the highest and the lowest effects, respectively.

Oropharyngeal colonization with pathogenic organisms contributes to the development of ventilator-associated pneumonia (VAP) in intensive care units (ICUs). Oral hygiene care (OHC) is a very effective method for reducing the risk of VAP in these patients. This study aimed to evaluate recent OHC strategies to decrease VAP.

Randomized clinical trials (RCTs) published in the PubMed, Scopus, Embase, Cochrane Library, and Web of Science databases from inception to September 10, 2020 were reviewed to compare the effects of selective oropharyngeal decontamination (SOD) on the incidence of VAP in adult patients requiring mechanical ventilation.

Out of a total of 1098 articles reviewed, 17 eligible studies were included for final analysis. The results showed that the use of chlorhexidine for oropharyngeal decontamination reduces the incidence of VAP. However, it had a small effect on gram-negative resistant bacteria. Also, it was observed that the combined use of colistin and chlorhexidine was more effective than chlorhexidine alone in preventing VAP. The results of studies on the use of toothbrushes to reduce the incidence of pneumonia are unclear since they used chlorhexidine at the same time. However, tooth brushing is one of the best ways to maintain oral hygiene. Using povidoneiodine, Nanosil, and non-absorbable topical antibiotics reduced the incidence of VAP, while Iseganan did not show a significant effect in this regard.

The prophylactic use of topical bactericidal agents in critically-ill patients is effective in reducing the incidence of VAP. However, the use of non-absorbable topical antibiotics is more effective than other methods in oropharyngeal decontamination.

Implant surface disinfection is the most difficult phases in treatment of peri-implantitis. This study sought to assess the efficacy of antimicrobial photodynamic therapy (aPDT) with phycocyanin and diode laser for the reduction of Porphyromonas gingivalis.

In this in vitro, experimental study, first the minimum inhibitory concentration (MIC) of phycocyanin, the sub-lethal exposure time of the diode laser, and the sub-lethal dose of aPDT were determined. The wells containing P. gingivalis suspension were randomly divided into three experimental groups for exposure to ½ MIC phycocyanin for 5 minutes, minimum lethal dose of diode laser (635 nm, 4 minutes), and aPDT with phycocyanin and diode laser. The positive control group was exposed to 0.2% chlorhexidine (CHX) for 5 minutes, and the negative control group received no treatment. The colony count was calculated in the five groups and compared using one-way ANOVA and t test.

aPDT with a diode laser (635 nm, 4 minutes) and 125 μg/mL phycocyanin caused a significantly greater reduction in P. gingivalis count (mean reduction of 44.24%) compared with other groups (P < 0.0001). Minimum and maximum colony counts were noted in 0.2% CHX and negative control groups respectively. The reduction in the colony count was significant in all experimental groups, compared with the control group (P < 0.0001).

aPDT with 635-nm diode laser and phycocyanin can significantly decrease P. gingivalis count in vitro. Considering the conservative nature of this modality, it may be used for the decontamination of peri-implant.

Measures to prevent the emergence of hospital-acquired infections (HAIs) include a daily bath with chlorhexidine gluconate (CHG). The aim of this study was to determine the effect of patients bathing daily with CHG on the bacterial colonization on patient surfaces, environmental surrounding areas, and attending healthcare workers (HCWs).

Patients were randomized by a 1:1 in two groups. Patients in group 1 were bathed daily with CHG; patients in group 2 were bathed with a placebo. Microbiological sampling of patients, environment, and HCWs were carried out on days 0, 3, and 10. The clonal relatedness of selected isolates collected was determined through pulsed-field gel electrophoresis. Clinical and demographic data were obtained from medical files.

Thirty-three patients were included (18 in group 1 and 15 in group 2). The more common species was Acinetobacter baumannii (n=144), followed by Klebsiella pneumoniae (n=81). A. baumannii was isolated more frequently on environmental surfaces in group 2 than group 1 (day 0 vs. day 3 vs. day 10; p = 0.0388). Twelve clones of A. baumannii were detected, with predominant clone A detected in patients and environmental surfaces. No pathogens were detected in HCWs.

Our data support that CHG bathing decreases A. baumannii surviving on the environmental surfaces of critically ill patients.

Fruits are important parts of our daily diet to maintain a healthy life as they have potential nutritional values. But unfortunately, a number of foodborne diseases have been noticed due to the consumption of raw and contaminated fruits. The present study was carried out to isolate the pathogenic microorganisms from fruits sample and to determine the effects of some household cleaning methods including washing and various common chemical treatments for the removal of bacterial load. A conventional spread plate technique was performed for the detection of bacteria. Total heterotrophic bacteria, Escherichia coli, Staphylococcus spp. Salmonella spp. and Listeria spp. were found in 30 samples of 6 categories including Java apple (Syzygium cumini), Carambola (Averrhoa carambola), Indian gooseberry (Phyllanthus emblica), Olive (Olea europaea) Koromcha (Carissa carandas) and Pear (Pyrus). Tap water, hot water (50°C), 100mg/L sodium hypochlorite (NaOCl), 50 mg/L calcium lactate, 4% acetic acid and 2ml /L CleanAva were used as decontaminating agents. All samples were soaked in tested cleaning agents for 20 min at room temperature. All the tested solutions were found to be effective and reduced bacterial loads in fruits compared to the unwashed fruits samples (p<0.01). It was revealed, NaOCl, calcium lactate, acetic acid and CleanAva were more effective cleaning agents than water wash. Two to three log of the bacterial load was reduced when samples were subjected to treatment with decontaminating agents. Potable water, the types and concentration of the disinfectant solutions are important parameters for effective washing.

The aim of this study was to provide a suitable system for disposal of hospital waste and design and construction of a safe device for infectious waste using a combination of chemical and mechanical methods.

 This research is a laboratory study and based on the existing problems, design and construction of a decontamination device for hospital infectious waste was performed by combination of chemical and mechanical methods in a closed reactor. To determine the appropriate mixture of different compounds of sodium hydroxide with lime and sodium carbonate with lime, three treatments were selected and used.
 

The results of this study showed that the decontamination waste device by chemical and mechanical methods was effective in eliminating 98% of bacterial, fungal, and viral contaminants. The results showed that the neutralization rate for total bacterial contamination of the coliform, pathogenic viruses, Escherichia, Bacillus subtilis, Salmonella, and Shigella using a 30% ratio was related to the chemical composition of lime and sodium hydroxide, lime and sodium carbonate, respectively. In the designed device, the best temperature, humidity and pH conditions were determined to be 15°C, 45% and 12.8, respectively.

 The results of the decontaminated waste tests revealed that the simultaneous application of physical and chemical methods can be used as a safe and suitable alternative in infectious waste disposal systems.

Peri-implantitis is a common complication of dental implant treatment. A cause-and-effect relationship has been previously documented between microbial plaque and peri-implantitis and implant failure. A difference has been reported in the disinfection efficacy of erbium laser irradiation and air-flow abrasion for contaminated titanium surfaces. Also, the surface changes caused by lasers and air-flow abrasion have not been well studied. Thus, the purpose of this study was to compare the surface changes of contaminated titanium discs following decontamination by erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and air-flow abrasion.

Twenty-eight intact, sandblasted, and acid-etched (SLA) titanium discs were used. Twenty-four titanium discs were contaminated with Escherichia coli. Then, they were decontaminated by using Er:YAG laser irradiation and air-flow abrasion. Four discs remained intact. The mean and standard deviation of the contact angle and the weight percentage of aluminum, titanium, oxygen, carbon, phosphorus, and calcium were measured. Qualitative changes in surface topography of titanium discs were assessed by scanning electron microscopy (SEM).

The mean weight percentage of carbon in the air-flow abrasion group (4.98%) experienced a significant reduction compared with the contaminated (positive control) group (P = 0.035). The contact angles were 46.54° and 38.67° in the laser and air-flow abrasion groups respectively, which were significantly lower than the value in the positive control group (75.15°) (P ≤0.001). SEM micrographs showed no significant change in the surface area in either technique.

Air-flow abrasion was more successful in improving the surface characteristics of titanium discs with no alteration in surface topography or elements, compared with Er:YAG laser irradiation. Further studies regarding the safety of the Er:YAG laser for the decontamination of titanium surfaces are recommended.

 Recently, atmospheric pressure non-thermal plasma has been used as a new method for decontamination of medicinal plants. The aim of this research was to investigate the effects of atmospheric pressure floating-electrode dielectric-barrier discharge (FE-DBD) on Nigella sativa (N. sativa) which has many therapeutic properties.

 N. sativa seeds were exposed to atmospheric pressure FE-DBD plasma for 15, 30 and 40 min. and total microbial counting of the seeds was performed. Antioxidant activity and total phenol were measured to evaluate the chemical properties changes of N. sativa seeds under the exposure of plasma. Fatty acid analysis of the extracted oil from N. sativa was determined using gas-liquid chromatography in this research before and after the exposure to cold plasma.

 The results showed that the density of microorganisms significantly decreased at all three exposure times compared to the control (P˂0.05) and eliminate total microorganisms at 40 min of exposure. There was no significant change in the amount of total phenolic compounds and antioxidant activity before and after plasma exposure. Linoleic acid and oleic acid were decreased under the exposure of FE-DBD plasma for 40 min which indicate that cold plasma can lead to the oxidation of unsaturated fatty acids. The ratio of unsaturated fatty acids to saturated fatty acids were significantly decreased (P˂0.05).   

 In conclusion, exposure of cumin seeds to FE-DBD plasma can effectively reduce or eliminate microorganisms. On the other hand, cold plasma treatment brings about some biochemical changes. Total phenol content increased and antioxidant activity was decreased slightly. The unsaturated fatty acid contents of black cumin seeds samples decreased with FE-DBD plasma exposure at effective time for decontamination.

The successful synthesis and characterization of AlTiPbO Nanoparticles (ATPO-NPs) using a facile and straight forward co-precipitation method was reported in the present work. The detailed morphological characterization uncovered that the nanoparticles are of 28 nm in size. From the application perspective, the nanoparticles were utilized as a potential adsorbent to remove the toxic and hazardous dye from the aqueous phase. The point by point adsorption studies uncovered that the AlTiPbO nanoparticles made the Eriochrome black-T solution becomes colorless within 90 min. The outcome of the study verified by isotherms and kinetic study measurements and the adsorption system was examined. The nanoparticles have been effectively reused up to fifth cycle of the adsorption. A real sample analysis study revealed that ATPO-NPs could remove high concentrations (1000 mg/g) of dye from the industrial waste sample.

Antimicrobial photodynamic therapy (aPDT) has been suggested as a novel technique for decontamination of exposed implant surfaces. We aimed to evaluate the effect of aPDT on sandblasted, large-grit, acid-etched (SLA) titanium discs contaminated with Eikenella corrodens (Ec) and Aggregatibacter actinomycetemcomitans (Aa). In this in-vitro study, twenty-four sterile SLA titanium discs were contaminated with Ec (PTCC® 1391) and Aa )ATCC® 33384( and were randomly divided into the following groups: aPDT-treated group consisted of 12 discs submerged in 1 ml of toluidine blue and exposed to a low-level laser; negative control group comprised of 6 discs rinsed with physiological saline, and positive control group included 6 discs submerged in 2 ml of 0.2% chlorhexidine (CHX). After serial dilution, each sample was cultivated in an anaerobic environment (24 hours for Ec and 48 hours for Aa). Microbial reduction rate was calculated through colony-forming unit (CFU) counting according to Kruskal-Wallis test. The number of colonies for both bacterial strains in the aPDT-treated group was significantly reduced compared to the negative control group, showing the bactericidal potential of aPDT with toluidine blue (P<0.0001). The 0.2% CHX group showed a significantly smaller amount of colonies (CFU=1.089×107 for Ec and 3×107 for Aa) compared to the aPDT-treated group (CFU=3.73±1.19×109 for Ec and 52±13.6×105 for Aa; P<0.00001). aPDT with toluidine blue significantly reduces Ec and Aa contamination of SLA titanium discs; however, 0.2% CHX showed the highest bactericidal potential and is still considered the gold standard in antimicrobial treatment of peri-implant diseases.

Tissue engineering has been investigated as a potential method for healing traumatized tissues. Biomaterials are material devices or implants used to repair or replace native body tissues and organs. The present study was conducted to evaluate the effects of decontamination methods on biological/mechanical properties and degradation/adhesion test of the platelet‑-rich fibrin (PRF) membranes to compare these properties with intact membranes as a biological biomaterial.

The in vitro degradation tests were conducted by placing the equal sizes of (i) intact PRF membrane, (ii) PRF membrane sterilized by autoclave (iii), ultraviolet (UV), and (iiii) gamma irradiation in phosphate buffer solution on a shaker. The degradation profiles were expressed. Adhesion test was performed by counting adhered mouse fibroblast and sterilized fibrin membrane was compared to normal fibrin membrane by different sterilization methods.

The preliminary findings of sterilized PRF membranes showed that UV exposure (p Sterilization of fibrin membrane with different protocols does not have any adverse effects on cell adhesion; however, cell adherence is naturally very weak even in normal membranes. Also, it seems that ultraviolet ray polymerizes fibrin filaments and merges them to each other and increases the ability of fibrin membrane against degradation. Autoclaved fibrin membrane content proteins are denatured because of pressure and heat and show an increase in hardness and stability against degradation.

Cadmium poisoning has been reported from many parts of the world. It is one of the global health problems that affect many organs and in some cases it can cause deaths annually. Long-term exposure to cadmium through air, water, soil, and food leads to cancer and organ system toxicity such as skeletal, urinary, reproductive, cardiovascular, central and peripheral nervous, and respiratory systems. Cadmium levels can be measured in the blood, urine, hair, nail and saliva samples. Patients with cadmium toxicity need gastrointestinal tract irrigation, supportive care, and chemical decontamination traditional-based chelation therapy with appropriate new chelating agents and nanoparticle-based antidotes. Furthermore it has been likewise recommended to determine the level of food contamination and suspicious areas, consider public education and awareness programs for the exposed people to prevent cadmium poisoning.

As part of our ongoing interest in exploring the synthesis of antibacterial agent, we report an efficient, mild, one pot and chemoselective procedure for preparation of 3-poly (vinylbenzyl)-5,5-dimethylimidazolidine-2,4-dione as a antimicrobial agent from pol (vinylbenzyl chloride) and 5,5-dimethylhydantoin in the presence of a base in DMF as a solven. The FT-IR technique and melting point confirmed the desire product. Then, 3 poly (vinylbenzyl)-5,5-dimethylimidazolidine-2,4-dione nanofibers was produced by electrospinning process. To confirm the nanofiber materials, SEM image was applied. Then, these nanofibers were, chlorinated with sodium hypochlorite. Finally, the antibacterial activity of synthesized nanofibers was evaluated by against Staphylococcus aureus as gram-positive bacteria and Escherichia coli as gram-negative bacteria. The results from culture media and halo diameters of nanofibers showed that high biocidal effect of fibers against these bacteria. These nanofibes could be used in order to construct filters needed to clean and disinfect drinking water in emergency.