scholarly journals Early Polylysine Release from Dental Composites and Its Effects on Planktonic Streptococcus mutans Growth

2020 ◽  
Vol 11 (3) ◽  
pp. 53 ◽  
Author(s):  
Nikos N. Lygidakis ◽  
Elaine Allan ◽  
Wendy Xia ◽  
Paul F. Ashley ◽  
Anne M. Young
Keyword(s):  
Streptococcus Mutans ◽  
High Performance ◽  
Water Immersion ◽  
Dental Composites ◽  
Average Volume ◽  
Bacterial Counts ◽  
Initial Inoculum ◽  
Mass Fractions ◽  
Composite Filler ◽  
Filler Phase

The study aim was to assess the effect of incorporating polylysine (PLS) filler at different mass fractions (0.5, 1 and 2 wt%) on PLS release and Streptococcus mutans planktonic growth. Composite containing PLS mass and volume change and PLS release upon water immersion were assessed gravimetrically and via high-performance liquid chromatography (HPLC), respectively. Disc effects on bacterial counts in broth initially containing 8 × 105 versus 8 × 106 CFU/mL Streptococcus mutans UA159 were determined after 24 h. Survival of sedimented bacteria after 72 h was determined following LIVE/DEAD staining of composite surfaces using confocal microscopy. Water sorption-induced mass change at two months increased from 0.7 to 1.7% with increasing PLS concentration. Average volume increases were 2.3% at two months whilst polylysine release levelled at 4% at 3 weeks irrespective of composite PLS level. Early percentage PLS release, however, was faster with higher composite content. With 0.5, 1 and 2% polylysine initially in the composite filler phase, 24-h PLS release into 1 mL of water yielded 8, 25 and 93 ppm respectively. With initial bacterial counts of 8 × 105 CFU/mL, this PLS release reduced 24-h bacterial counts from 109 down to 108, 107 and 102 CFU/mL respectively. With a high initial inoculum, 24-h bacterial counts were 109 with 0, 0.5 or 1% PLS and 107 with 2% PLS. As the PLS composite content was raised, the ratio of dead to live sedimented bacteria increased. The antibacterial action of the experimental composites could reduce residual bacteria remaining following minimally invasive tooth restorations.

scholarly journals Effect of crack pattern on the self-healing capability in traditional, HPC and UHPFRC concretes measured by water and chloride permeability

2019 ◽  
Vol 289 ◽  
pp. 01006 ◽  
Author(s):  
Alberto Negrini ◽  
Marta Roig-Flores ◽  
Eduardo J. Mezquida-Alcaraz ◽  
Liberato Ferrara ◽  
Pedro Serna
Keyword(s):  
Reinforced Concrete ◽  
Water Permeability ◽  
High Performance ◽  
Water Immersion ◽  
Crack Pattern ◽  
The Self ◽  
Reinforced Concrete Beams ◽  
Multiple Cracks ◽  
Self Healing ◽  
High Performance Fibre

Concrete has a natural self-healing capability to seal small cracks, named autogenous healing, which is mainly produced by continuing hydration and carbonation. This capability is very limited and is activated only when in direct contact with water. High Performance Fibre-Reinforced Concrete and Engineered Cementitious Composites have been reported to heal cracks for low damage levels, due to their crack pattern with multiple cracks and high cement contents. While their superior self-healing behaviour compared to traditional concrete types is frequently assumed, this study aims to have a direct comparison to move a step forward in durability quantification. Reinforced concrete beams made of traditional, high-performance and ultra-high-performance fibre-reinforced concretes were prepared, sized 150×100×750 mm3. These beams were pre-cracked in flexion up to fixed strain levels in the tensioned zone to allow the analysis of the effect of the different cracking patterns on the self-healing capability. Afterwards, water permeability tests were performed before and after healing under water immersion. A modification of the water permeability test was also explored using chlorides to evaluate the potential protection of this healing in chloride-rich environments. The results show the superior durability and self-healing performance of UHPFRC elements.

Growth and Histamine Formation of Morganella morganii in Determining the Safety and Quality of Inoculated and Uninoculated Bluefish (Pomatomus saltatrix)

2001 ◽  
Vol 64 (12) ◽  
pp. 2015-2019 ◽  
Author(s):  
TATIANA A. LORCA ◽  
TODD M. GINGERICH ◽  
MERLE D. PIERSON ◽  
GEORGE J. FLICK ◽  
CAMERON R. HACKNEY ◽  
...  
Keyword(s):  
High Performance ◽  
Histidine Decarboxylase ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Decarboxylase Activity ◽  
Pomatomus Saltatrix ◽  
Morganella Morganii ◽  
Histamine Concentration ◽  
Bacterial Counts ◽  
Histamine Formation

The objective of this study was to determine the effect of normal microflora and Morganella morganii on histamine formation and olfactory acceptability in raw bluefish under controlled storage conditions. Fillets inoculated with and without M. morganii were stored at 5, 10, and 15°C for 7 days. Microbial isolates from surface swabs were identified and screened for histidine decarboxylase activity. Olfactory acceptance was performed by an informal sensory panel. Histamine levels were quantified using high-performance liquid chromatography and fluorescence detection. While olfactory acceptance decreased, histamine concentration and bacterial counts increased. Storage temperature had a significant effect on histamine levels, bacterial counts, and olfactory acceptance of the bluefish. Inoculation with M. morganii had a positive significant effect on histamine formation for bluefish held at 10 and 15°C (P < 0.0001). The results of the study will serve in supporting U.S. Food and Drug Administration (FDA) regulations regarding guidance and hazard levels of histamine in fresh bluefish.

scholarly journals Bacterial Counts and Weight Changes of Broiler Carcasses Chilled Commercially by Water Immersion and Air-Blast

1975 ◽  
Vol 54 (5) ◽  
pp. 1452-1460 ◽  
Author(s):  
J.E. Thomson ◽  
N.A. Cox ◽  
W.K. Whitehead ◽  
A.J. Mercuri ◽  
B.J. Juven
Keyword(s):  
Water Immersion ◽  
Weight Changes ◽  
Air Blast ◽  
Bacterial Counts

scholarly journals Pengaruh Ekstrak Kulit Jeruk Nipis (Citrus Aurantifolia Swingle) Konsentrasi 10% Terhadap Aktivitas Enzim Glukosiltransferase Streptococcus mutans

2013 ◽  
Vol 20 (2) ◽  
pp. 126
Author(s):  
Zenia Adindaputri U ◽  
Nunuk Purwanti ◽  
Ivan Arie Wahyudi
Keyword(s):  
Enzyme Activity ◽  
Streptococcus Mutans ◽  
High Performance ◽  
Positive Control ◽  
Chlorhexidine Gluconate ◽  
Citrus Aurantifolia ◽  
Significant Difference ◽  
Lime Peel ◽  
One Way Anova ◽  
Peel Extract

Streptococcus mutans merupakan bakteri yang berperan sebagai agen utama penyebab karies gigi, yang memiliki enzim glukosiltransferase (GTF). Enzim GTF akan mengubah sukrosa menjadi fruktosa dan glukan. Salah satu herbal tradisional yang dapat berperan sebagai antibakteri adalah kulit jeruk nipis (Citrus aurantifolia Swingle) yang mengandung polifenol terutama flavonoid. Tujuan penelitian ini untuk mengetahui pengaruh ekstrak kulit jeruk nipis (Citrus aurantifolia Swingle) konsentrasi 10% terhadap aktivitas enzim GTF Streptococcus mutans. Penelitian ini menggunakan ekstrak kulit jeruk nipis konsentrasi 10% sebagai perlakuan, chlorhexidine gluconate 0,12% sebagai kontrol positif, serta akuades steril sebagai kontrol negatif. Metode penelitian ini terdiri dari tiga tahap yaitu penyiapan ekstrak kulit jeruk nipis konsentrasi 10%, penyiapan enzim GTF dari supernatan Streptococcus mutans, dan pengujian aktivitas enzim GTF melalui analisis konsentrasi fruktosa dengan menggunakan High Performance Liquid Chromatography (HPLC). Pembacaan luas area fruktosa dilakukan berdasarkan waktu retensi. Satu unit aktivitas enzim GTF di definisikan sebagai 1 µmol fruktosa/ml dari enzim/jam. Selanjutnya data yang diperoleh dianalisis secara statistik dengan one way ANOVA.Hasil perhitungan aktivitas enzim GTF dengan one way ANOVA menunjukkan perbedaan yang signifikan antara kelompok perlakuan dengan kelompok kontrol negatif (p<0,05), dan tidak terdapat perbedaan yang signifikan dengan kontrol positif. Kesimpulan dari penelitian ini adalah ekstrak kulit jeruk nipis konsentrasi 10% dapat menghambat aktivitas enzim glukosiltransferase Streptococcus mutans. The Influence of 10% Concentrate of Citrus Aurantifolia Swingle on The Activities of Streptococcus Mutans Glucocyl Transferase Enzyme. Streptococcus mutans is a bacteria which has glucosyl transferase (GTF) enzyme and acts as the main agent that causes dental caries. GTF enzyme will convert sucrose into fructose and glucan. Lime peel (Citrus aurantifolia Swingle) is one of the traditional herbs which has flavonoid as an antibacterial agent. The purpose of this research is to investigate the effect of 10% concentration of lime peel extract (Citrus aurantifolia Swingle) to the activity of GTF enzyme Streptococcus mutans.This research used 10% concentration of  lime peel extract as the treatment, 0.12% chlorhexidine gluconate as a positive control, and distillate water as anegative control. The method of this research consists of three steps; preparing the lime peel extract concentration of 10%, preparing the GTF enzyme from the supernatant of Streptococcus mutans, and testing GTF enzyme activity by analyzing the fructose concentration using High Performance Liquid Chromatography (HPLC). Perusal of the fructose area was based on the retention time of fructose. One unit of GTF enzyme activity is defined as the 1 μmol fructose / ml of enzyme / hour.  The obtained data then were analyzed by one way ANOVA. The result showed a significant difference between treatment group with the negative control (p <0.05), and there are no significant difference with the positive control. This research concludes that 10% lime peel extract can inhibit the GTF enzyme activity of Streptococcus mutans.

scholarly journals Daya Hambat Aktivitas Enzim Glukosiltransferase (Gtf) Streptococcus mutans Oleh Ekstrak Temulawak (Curcuma Xanthorrhiza Roxb.)

2017 ◽  
Vol 7 (1) ◽  
pp. 32
Author(s):  
A. Amanda ◽  
Sri Kunarti ◽  
Agus Subiwahjudi
Keyword(s):  
Enzyme Activity ◽  
Streptococcus Mutans ◽  
Antibacterial Agent ◽  
High Performance ◽  
Chlorhexidine Gluconate ◽  
Control Group ◽  
Extract Concentration ◽  
Significant Difference ◽  
Curcuma Xanthorrhiza ◽  
Post Hoc

Background: Streptococcus mutans is a bacteria which has glucosyltransferase (GTF) enzyme and acts as the main agent that causes dental caries. GTF enzyme will convert sucrose into fructose and glucan. Temulawak (Curcuma xanthorrhiza Roxb.) is one of the traditional herbs which has xanthorrhizol, curcumin, flavonoid, tanin, and saponin as an antibacterial agent. Purpose: The purpose of this research is to investigate the effect of temulawak extract (Curcuma xanthorrhiza Roxb.) to the activity of GTF enzyme Streptococcus mutans. Method: This research used 25%, 37,5%, and 50% concentration of  temulawak extract as the treatment, and 0.12% chlorhexidine gluconate as a control. The method of this research consists of three steps; preparing the temulawak extract concentration of 25%, 37,5%, and 50%, preparing the GTF enzyme from the supernatant of Streptococcus mutans, and testing GTF enzyme activity by analyzing the fructose concentration using High Performance Liquid Chromatography (HPLC). Perusal of the fructose area was based on the retention time of fructose. One unit of GTF enzyme activity is defined as the 1 μmol fructose / ml of enzyme / hour. Result: The obtained data then were analyzed by Post-Hoc Tukey (HSD). The result showed a significant difference between each treatment group with the control group (p<0.05). Conclussion: This research concludes that temulawak extract with 25%, 37,5%, and 50% concentrationcan’t inhibit the GTF enzyme activity of Streptococcus mutans.

scholarly journals Effects of Thawing and Frying Methods on the Formation of Acrylamide and Polycyclic Aromatic Hydrocarbons in Chicken Meat

Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 573 ◽  
Author(s):  
Jong-Sun Lee ◽  
Ji-Won Han ◽  
Munyhung Jung ◽  
Kwang-Won Lee ◽  
Myung-Sub Chung
Keyword(s):  
Mass Spectrometry ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Water Immersion ◽  
Chicken Meat ◽  
Gas Chromatography Mass Spectrometry ◽  
Deep Fat Frying ◽  
Liquid Chromatography Tandem Mass ◽  
Polycyclic Aromatic

Air frying is commonly used as a substitute for deep-fat frying. However, few studies have examined the effect of air frying on the formation of potential carcinogens in foodstuffs. This study aimed to investigate the formation of acrylamide and four types of polycyclic aromatic hydrocarbons (PAHs) in air-fried and deep-fat-fried chicken breasts, thighs, and wings thawed using different methods, i.e., by using a microwave or a refrigerator, or by water immersion. The acrylamide and PAHs were analyzed by high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) and gas chromatography–mass spectrometry (GC-MS), respectively. Deep-fat-fried chicken meat had higher acrylamide (n.d.–6.19 μg/kg) and total PAH (2.64–3.17 μg/kg) air-fried chicken meat (n.d.–3.49 μg/kg and 1.96–2.71 μg/kg). However, the thawing method did not significantly affect the formation of either acrylamide or PAHs. No significant differences in the acrylamide contents were observed among the chicken meat parts, however, the highest PAH contents were found in chicken wings. Thus, the results demonstrated that air frying could reduce the formation of acrylamide and PAHs in chicken meat in comparison with deep-fat frying.

scholarly journals Development of Chlorhexidine Loaded Halloysite Nanotube Based Experimental Resin Composite with Enhanced Physico-Mechanical and Biological Properties for Dental Applications

2020 ◽  
Vol 4 (2) ◽  
pp. 81 ◽  
Author(s):  
Tejas Barot ◽  
Deepak Rawtani ◽  
Pratik Kulkarni
Keyword(s):  
Mechanical Properties ◽  
Resin Composite ◽  
Biological Properties ◽  
Degree Of Conversion ◽  
Dental Composites ◽  
Resin Composites ◽  
Dental Resin ◽  
Dental Resin Composites ◽  
Mass Fractions ◽  
Nih 3T3

Objective: The objective of this study was to explore the effect of Chlorhexidine-loaded Halloysite nanotubes (HNT/CHX) fillers (diverse mass fractions from 1 to 10 wt.%) on physicochemical, morphological and biological properties of newly developed experimental dental resin composite, in order to compare with the properties of composites composed of conventional glass fillers. Methods: The dental resin composites were prepared by incorporating various proportions of HNT/CHX. Six different groups of specimens: control group and five groups composed of varied mass fractions of HNT/CHX (e.g., 1.0, 2.5, 5.0, 7.5 and 10 wt.%) as fillers in each group were fabricated. Mechanical properties of the composites were monitored, using UTM. The degree of conversion of dental resin composites and their depth of cure were also evaluated. Antimicrobial properties of dental composites were studied in vitro by applying agar diffusion test on strain Streptococcus mutans and cytotoxicity were studied using NIH-3T3 cell line. Results: The incorporation of varied mass fractions (1.0 to 5.0 wt.%) of HNT/CHX in dental resins composites enhanced mechanical properties considerably with significant antibacterial activity. The slight decrease in curing depth and degree of conversion values of composites indicates its durability. No cytotoxicity was noticed on NIH-3T3 cell lines. Significance: Consistent distribution of HNT/CHX as a filler into dental composites could substantially improve not only mechanical properties but also biological properties of dental composites.

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