24-h Storage Research Articles

Effect of Span-80 to Moisture Resistance of Near-infrared Curing 3D Printing Sodium Silicate Foundry Sands

In this work, a new method of near-infrared curing 3D printing sodium silicate sands (NIRC3DPSSS) driven by photovoltaic cells was proposed, and the Span-80 moisture resistance modifier was studied. NIRC3DPSSS had the advantages of high strength, rapid curing and low residual strength. However, the 24h storage strength would reduce because Na+ in the bonding bridges could absorb moisture. The experimental results showed that the strength of Span-80 modified sands molds reached 0.95MPa after 4 hours in a humidistat with 99%RH (relative humidity) containing 2.2% sodium silicate, an increase of 97.9% comparing to common sands molds. In air(80%RH), the strength reached 1.25MPa, an increase of 40.4%. The optimal effect of modification was achieved when Span-80 was 0.066% of the raw sands. Additionally, the bonding film and bridges in sodium silicate sands modified with Span-80 were more stable, smoother and free of cracks when observed using scanning electron microscopy (SEM) and energy dispersive spectroscopy(EDS).

Riboflavin-ultraviolet-A collagen crosslinking treatments in improving dentin bonding and resistance to enzymatic digestion

Background/purposeThe efficacy of riboflavin-ultraviolet-A (RF-UVA) treatment in crosslinking collagen and improving dentin bonding has been proven. However, biodegradation of the hybrid layer may compromise the bonding. The purpose of this study was to evaluate different RF-UVA treatments regarding their ability to preserve dentin bonding from enzymatic digestion. Materials and methodsCollagen subjected to different RF (0.1 %, 1 %)-UVA (1, 2, 5 min) treatments and 5 % glutaraldehyde (GA), without or with enzymatic digestion, were examined by gel electrophoresis (SDS-PAGE). Twenty-five teeth with exposed dentin were primed with one of three RF-UVA treatments (0.1 %RF/1-minUVA, 0.1 %RF/2-minUVA, and 1 %RF/1-minUVA), GA, or distilled water after acid-etching, then restored with an adhesive and a resin composite. After 24-h storage, these teeth were sectioned into microbeams. Half of them received an early microtensile bond strength (μTBS) test, while the other half was stored in enzyme solution for 7 days before testing. Nanoleakage and hybrid layer degradation were examined by TEM. ResultsAccording to SDS-PAGE results, all groups showed the dissipation of intense γ bands of collagen after digestion. For the early bonded specimens and after enzymatic digestions, 0.1 %RF/2-minUVA treated group presented the highest μTBS and none of premature failure. Its TEM images showed less nanoleakage after digestion, which is contributed to the well suspended collagen fibrils and resin infiltration in the hybrid layer. ConclusionRF-UVA treatment attained collagen crosslinking effects to improve resin-dentin bonding. 0.1 %RF/2-minUVA effectively enhanced dentin bond strength and resistance to enzymatic digestion by optimally expanding dentinal collagen matrix to facilitate hybrid layer formation.

Mitigating Cold Ischemic Injury: HTK, UW and IGL-2 Solution's Role in Enhancing Antioxidant Defence and Reducing Inflammation in Steatotic Livers.

Liver transplantation remains the only definitive treatment for end-stage liver diseases. However, the increasing prevalence of fatty liver disease among potential donors exacerbates the shortage of suitable organs. This study evaluates the efficacy of the preservation solution Institut Georges Lopez-2 (IGL-2) compared to Histidine-Tryptophan-Ketoglutarate (HTK) and University of Wisconsin (UW) preservation solutions in mitigating ischemia-reperfusion injury (IRI) in steatotic livers. Using Zucker Obese rat livers, we assessed the impact of 24-h static cold storage (SCS) with each solution on transaminase release, glutathione redox balance, antioxidant enzyme activity, lipoperoxidation, and inflammation markers. IGL-2 and UW solutions demonstrated reduced transaminase and lactate levels compared to HTK, indicating better preservation of liver integrity. IGL-2 maintained a higher reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, suggesting more effective management of oxidative stress. Antioxidant enzyme activities catalase, superoxide dismutase, and glutathione peroxidase (CAT, SOD, GPX) were higher in IGL-2 preserved livers, contributing to decreased oxidative damage. Lipid peroxidation markers and inflammatory markers were lower in IGL-2 than in HTK, indicating reduced oxidative stress and inflammation. Additionally, improved mitochondrial function was observed in the IGL-2 group, correlating with reduced reactive oxygen species (ROS) production and lipid peroxidation. These findings suggest that IGL-2 offers superior preservation of liver viability, reduces oxidative stress, and minimizes inflammation compared to HTK and UW solutions. By maintaining a higher ratio of reduced glutathione and antioxidant enzyme activity, IGL-2 effectively mitigates the harmful effects of ischemia-reperfusion injury. The reduced lipid peroxidation and inflammation in the IGL-2 group further underscore its potential in improving liver transplant outcomes. These results highlight the importance of optimizing preservation solutions to enhance the viability and functionality of donor organs, potentially expanding the donor pool and improving the success rates of liver transplantation. Future research should focus on refining preservation techniques and exploring additional protective agents to further improve organ preservation and transplant outcomes.

Successful Extension of Vascularized Composite Allograft Perfusion Cold Storage to 24 h in a Rat Hindlimb Transplant Model.

Vascularized composite allograft transplantation is a treatment option for complex tissue injuries; however, ischemia reperfusion injury and high acute rejection rates remain a challenge. Hypothermic machine perfusion using acellular storage perfusate is a potential solution. This study evaluated the University of Wisconsin Kidney Preservation Solution-1 (KPS-1) compared with normal saline (NS) for preservation of donor rat hindlimbs subjected to 24 h of ex vivo perfusion cold storage. Hindlimbs were subjected to 24-h perfusion cold storage with heparinized KPS-1 (n = 6) or heparinized NS (n = 6). Flow, resistance, and pH were measured continuously. At the end of the 24-h period, tissue was collected for histological analysis of edema and apoptosis. KPS-1 perfused limbs showed significantly less edema than the NS group, as evidenced by lower limb weight gain (P < 0.001) and less interfascicular space (P < 0.001). KPS-perfused muscle had significantly less cell death than NS-perfused muscle based on terminal deoxynucleotidyl transferase dUTP nick-end labeling (P < 0.001) and cleaved caspase-3 staining (P = 0.045). During hypothermic machine perfusion, a significant decrease in pH over time was detected in both groups, with a significantly greater decline in pH in the KPS-1 group than in the NS group. There were no significant differences overall and over time in flow rate or vascular resistance between the KPS and NS groups. Perfusion with KPS-1 can successfully extend vascularized composite allograft perfusion cold storage for 24 h in a rat hindlimb model without significant edema or cell death.

Identification of the anthocyanin profile from butterfly pea (Clitoria ternatea L.) flowers under varying extraction conditions: Evaluating its potential as a natural blue food colorant and its application as a colorimetric indicator

This study aims to extract anthocyanins from BPF (Butterfly Pea Flower) to determine an effective solvent combination resulting in higher total anthocyanin content. Various solvent combinations were utilized to discern crucial characteristics of the obtained BPFE (Butterfly Pea Flower Extract). The BPFE from the optimal treatment was utilized as a pigment in colorimetric indicators, which were then evaluated for their initial response to seafood spoilage stored at room temperature for 24 h. The color change response of the colorimetric indicators employing BPFE pigment was compared with the pH and TVBN (Total Volatile base Nitrogen) values of the seafood initially and after 24 h. The highest total anthocyanin content was achieved with the combination of 96 % ethanol/1.5 N HCl (85:15, v/v) at 551.06 mg/L, followed by the combination of 96 % ethanol/distilled water (70:30, v/v) with pH adjustment to 1 using 1.5 N HCl at 484.27 mg/L. Subsequent combinations, in decreasing order, were 96 % ethanol/1.5 N HCl (99:1, v/v), 96 % ethanol/distilled water (70:30, v/v), and lastly, 96 % ethanol/distilled water (30:70, v/v), with total anthocyanin content of 275.53 mg/L, 200.39 mg/L, and 125.24 mg/L, respectively. BPFE applied in colorimetric indicators demonstrated responsiveness to seafood spoilage through color changes, with tested spoilage indicators being pH and TVBN. The initial (first hour) pH and TVBN values for each tested seafood were 5.5 and 9.42 mg/100 g (Scylla serrata), 6.4 and 4.23 mg/100 g (Litopenaeus vannamei), 5.4 and 11.29 mg/100 g (Uroteuthis sibogae), and 6.5 and 10.26 mg/100 g (Restrelliger kanagurta). Meanwhile, the pH and TVBN values after 24-h storage at room temperature became 7.9 and 57.01 mg/100 g, 7.4 and 76.65 mg/100 g, 7.5 and 216.44 mg/100 g, and 7.8 and 51.86 mg/100 g, respectively. The conclusion drawn is that the extraction of BPFE is more efficient when utilizing acidified ethanol solvent, and the resulting BPFE holds promise as a reliable pH indicator.

Evaluation of blastocyst re-expansion, quality in relation to storage temperature, and sexing using blastocoel fluid after manual perforation with a hand-held needle involving in vivo produced equine embryos

The present study was designed to evaluate equine blastocyst re-expansion rate, quality, and sex following perforation of the blastocoel, collection of blastocoel fluid (BF), and PCR amplification of free DNA. Experiment 1 tested the feasibility of the BF sample collection with a hand-held, small-gauged needle (26g) and subsequent PCR amplification of the TSP-Y gene for males and AMEL-Y gene for males and AMEL-X gene for females. Experiment 2 tested the application of the technique. Equine embryos were collected via uterine flushes 8d after ovulation. Thereafter, embryos (n = 19) were initially assessed and transferred to a 50 μL droplet of holding medium in which the blastocoel was manually perforated as in Experiment 1. Within 1 min of detecting a diameter decrease or collapse, the entire volume of each droplet of medium was collected and stored at −20 °C until PCR. In Experiment 1, amplification of the TSP-Y gene was positive for males at 60% (9/15) and negative for females at 40% (6/15). In Experiment 2, a total of 42 embryos were randomly assigned to a collapsed embryo (CE) or intact embryo (IE) groups and stored at room temperature (RT, 25 °C) or cold temperature (CT, 5 °C) for 24h as follows: 1) CERT, n = 11; 2) CECT n = 11; 3) IERT, n = 10; and 4) IECT, n = 10. After 24h, embryo diameter and quality were reassessed. For all collapsed embryos (n = 19), blastocoel fluid was subjected to double PCR amplification of the TSPY gene with blood from adult male and female horses as controls. Positive gene amplification indicated 57.9% (11/19) of embryos were male and negative amplification indicated 31.6% (6/19) of embryos were female. Relative to the least diameter (0%) after perforation of collapsed embryos or fullest diameter (100%) of intact embryos at T0, percentage change in diameter and quality Grade 1 or 2 embryos after 24h of storage for all groups were, respectively: 31.2% and 54% for CERT group, 28.2% and 0% for CECT group, 25.9% and 100% for IERT group, 4.3% and 80% for IECT group, respectively. Thus, needle-induced leakage and collapse of the blastocoel at T0 resulted in a high rate of blastocyst re-expansion (69%) with many embryos (54%) achieving good quality at T24 with potential for transfer as either male or female embryos. For both collapsed and intact embryos, it was observed that storage for 24h at room temperature (25 °C) was associated with improved embryo growth and morphological quality compared to storage at cold temperature (5 °C).

Dentin adhesion of bulk-fill composites and universal adhesives in class I-cavities with high C-factor

ObjectivesThe aim of this study was to compare the dentin adhesion of bulk-fill composites in high C-factor class I-cavities before and after thermocycling to a control group using incremental layering technique. MethodsA standardized class I-cavity was prepared into 195 human molars, then different universal adhesives were applied either in self-etch or etch & rinse mode, and the cavity was filled according to each materials application protocol. The material combinations used were a conventional layered composite as control, the respective bulk-fill product, two other bulk-fill composites made by different manufacturers, with one of them being tested using two different polymerization times. Furthermore, one thermoviscous bulk-fill composite and one self-adhesive restorative were examined of which the latter can only be applied in self-etch mode. In each group the dentin adhesion to the cavity bottom was measured using microtensile bond strength test initially (24 h water storage) and after thermocycling. All results were statistically analyzed using STATA 17.0. ResultsThe statistical analysis showed significant differences between the control and the experimental groups (p < 0.001). The highest mean bond strength before (14.8 ± 10.7 MPa) and after aging (14.2 ± 11.5 MPa) was measured for the etch & rinse-control group. Among the bulk-fill groups, the etch & rinse technique consistently showed higher bond strengths. Bond strength of groups with shortened polymerization did not exceed 2.1 MPa. The bond strength of the self-adhesive restoration material was low before and after thermocycling (2.7 MPa/ 0.0 MPa). Groups with low bond strength values showed a high number of pre-testing-failures. ConclusionsBulk-fill materials used in high C-factor class I-cavities showed lower bond strength during self-etch application. The same applies for a shortened polymerization regime, which cannot be recommended for high C-factor cavities. Clinical significanceToday, a large variety of materials and application techniques can be used when placing an adhesive restoration. Whether new instead of established procedures should be applied in high C-factor cavities has to be critically assessed, as they are a demanding scenario for adhesive restorations.

Evaluation of Microbiological Susceptibility and Long-term Adhesive Properties to Dentin of Primers with Terminalia catappa Linn.

To investigate the antibacterial effects of Terminalia catappa Linn (TCL) leaf extracts at different concentrations and the effects of these extracts used as primers on the long-term adhesive properties of two universal adhesives. After extract preparation, the antimicrobial and antibacterial activities of TCL against Streptococcus mutans (UA 159) were assessed in microdilution assays to provide the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Additionally, to provide quantitative data on the ability of TCL extract to reduce cell viability, colony forming units (CFU) were counted. To examine adhesive properties, 288 human molars were randomly assigned to 32 experimental conditions (n = 9) according to the following variables: (1) treatment agent: negative control (untreated surface), and primers at concentrations of 1xMIC, 5xMIC, and 10xMIC; (2) adhesives: Scotchbond Universal (SBU) and Futurabond Universal (FBU); (3) adhesive strategy: etch-and-rinse (ER) or self-etch (SE); and (4) storage time: 24 h or after 2 years. Primers were applied for 60 s, upon which the teeth were incrementally restored and sectioned into adhesive-dentin bonded sticks. These were tested for microtensile bond strength (μTBS) and nanoleakage (NL) after 24-h and 2-year water storage, as well as in-situ degree of conversion (DC) at 24 h. The chemical profile of the hybrid layer was determined via micro-Raman spectroscopy. Biofilm assay data were analyzed using the Kruskal-Wallis test; the pH of culture media and the chemical profile were analyzed by one-way ANOVA. The adhesive properties (µTBS, NL, DC) were evaluated using a four-way ANOVA and Tukey's test. Significance was set at 5%. Similar values of MIC and MBC were observed (2 mg/ml), showing bactericidal potential. CFU analysis demonstrated that concentrations of 5xMIC and 10xMIC significantly inhibited biofilm formation (p < 0.001). The application of the TCL primer at all concentrations significantly increased the immediate μTBS and DC, and decreased the immediate NL values when compared to the control group (p < 0.05), regardless of the adhesive and adhesive strategies. Despite an increase in the NL values for all groups after 2 years (p > 0.05), in groups where the TCL primer was applied, the μTBS remained constant after 2 years for both adhesives, while a decrease in the μTBS was observed in the control groups (p < 0.05). Usually, 10xMIC showed better results than 1xMIC and 5xMIC (p < 0.05). The application of TCL promoted cross-linking; cross-linking rates increased proportionally to the concentration of TCL (p < 0.05). Primers containing TCL promoted bactericidal and bacteriostatic action, as well as cross-linking with dentin, while maintaining the adhesive properties of the adhesive-dentin interface after 2 years of water storage.

High-concentration bovine serum albumin enhances fertilization ability of cold-stored rat sperm.

Cold transport of the cauda epididymides is a useful technique for shipping laboratory rat sperm. Cold transport of rat sperm avoids potential risks of microbiological infection, animal escape or death, and animal welfare issues. Previously, we reported that a cold-storage solution containing dimethyl sulfoxide and quercetin maintained the fertility of cold-stored rat sperm. However, cold-stored rat sperm exhibited a decreased fertilization rate after 24-h storage. To recover the fertility of cold-stored sperm, we focused on the effects of bovine serum albumin (BSA), a cholesterol acceptor that induces sperm capacitation. We sought to determine the optimal concentration of BSA in fertilization medium based on the fertility of cold-stored rat sperm. High concentrations of BSA (40 mg/ml) enhanced the fertilization rate of cold-stored rat sperm and maintained sperm fertility for 144 h. Embryos derived from cold-stored and BSA-treated sperm normally developed into pups after embryo transfer. In summary, high BSA concentrations enhanced the fertility of cold-stored rat sperm and prolonged the storage period to 144 h, thereby expanding the transportable region for genetically engineered rats.

Investigation of Oil in Water Emulsion properties depending on the change of Emulsifiers combinations

Oil in water emulsion formulations as dosage forms for topical application are intended to produce the therapeutic effect in the skin. Their quality features mainly depend on the choice of emulsifying combination composition. This work aimed at establishing a mixture of oil phase, water and combinations of different kinds of emulsifiers to screen factors that affect the quality features of oil in water emulsion cream`s formulations. Eleven formulations were prepared with different ratio of different kinds of emulsifiers by a high temperature method. The emulsions were prepared with oil phase having calculated HLB value range 10.96 and emulsifiers having HLB values ranged from 0.20 to 14.60. The formulated oil in water emulsion compositions were evaluated for physical stability, rheological properties, colloidal and thermodynamic stability, microscopy observation. The results showed that not all formulations were physically stable after 24h storage period. Stable formulations were subjected to rheological properties studies. Some of samples presented the flow which was close to the Newtonian fluid, others showed pseudo-plastic flow type. The results of colloidal and thermodynamic stability evaluations allowed to establish the regularities between the type of the flow and formulations` stability. When varying the ratio of emulsifiers, the total HLB range of the mixture changed, which also affected the dispersion properties of emulsion systems. With certain ratios of emulsifiers the dispersion of the system increased.

Apoptotic Pathway Inhibition in Cold-Stored Platelet Concentrates Facilitates Retained Ability to Form Thrombi

Introduction: Platelet concentrates (PCs) are used to treat or prevent bleeding in patients with impaired platelet function or after injury. However, the standard storage of PCs at room-temperature (RT) increases the risk of bacterial contamination and is associated with reduced platelet functionality due to storage lesions. Our group reported that cold-stored PCs have better functionality compared to RT-stored PCs but reduced in vivo circulation time due to cold-induced apoptosis. In order to investigate cold-stored PCs hemostatic functionality with and without apoptosis inhibition, we established an ex vivo model simulating physiological conditions of blood flow to evaluate the contribution of cold-stored PCs in thrombus formation. Methods: Apheresis-derived PCs were stored for 1, 4, 7 and 10 days under agitation at 4°C or RT either with or without the apoptosis inhibitor G04 (RhoA GTPase inhibitor). Next, PCs were stained with CD41 antibody, recalcified and incubated with TRAP6 (thrombin receptor-activating peptide 6) to initiate thrombus formation. Platelet-depleted whole blood samples from healthy donors were spiked-in with PCs and administered to the microfluidic channels of the ex vivo system (Bioflux), under physiological shear pressure. After five minutes of perfusion the resulting thrombi were imaged and analyzed. Ability to form thrombi was further assessed by thromboelastography and impedance aggregometry. Results: Platelets from 24h storage PCs showed stable thrombus formation upon activation with TRAP6. Unstimulated platelets did not form any thrombi during the entire period of perfusion. To evaluate the effect of cold storage on platelet functions we analyzed the extent of thrombus formation of PCs stored at RT and 4°C upon CD41 staining. Our results indicate that cold-stored platelets form larger clots under flow conditions and maintain higher functionality compared to PCs stored at RT. Moreover, incubation of cold-stored PCs with the apoptosis inhibitor G04 improved ex vivo thrombus formation compared to PCs stored without the inhibitor, without inducing any adverse effects (Figure 1). Conclusion: The results indicate that our ex vivo assay, which simulates PC transfusion in thrombocytopenic patients, is suitable to test the hemostatic functions of PCs under physiological flow conditions. We demonstrated that PCs stored at 4°C show better thrombus formation ability upon stimulation by agonists compared to RT-stored PCs and that the ability to form clots under shear stress is still preserved after incubation with the apoptosis inhibitor. To conclude, cold-storage of PCs in combination with apoptosis inhibition is a promising stragedy to reduce the risk of bacterial contamination and prolong in vivo survival time while preserving platelet's hemostatic functionality.

Online solid phase extraction high-performance liquid chromatography – Isotope dilution – Tandem mass spectrometry quantification of organophosphate pesticides, synthetic pyrethroids, and selected herbicide metabolites in human urine

Analytical methods to quantify pesticide biomarkers in human population studies are critical for exposure assessment given the widespread use of pesticides for pest and weed control and their potential for affecting human health. We developed a method to quantify, in 0.2 mL of urine, concentrations of 10 pesticide biomarkers: four organophosphate insecticide metabolites (3,5,6-trichloro-2-pyridinol (TCPy), 2-isopropyl-6-methyl-4-pyrimidinol, para-nitrophenol, malathion dicarboxylic acid); five synthetic pyrethroid insecticide metabolites (4-fluoro-3-phenoxybenzoic acid, 3-phenoxybenzoic acid, cis and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid); and the herbicide 2,4-dichlorophenoxyacetic acid.he method is based on enzymatic hydrolysis of conjugated urinary metabolites, extraction and pre-concentration of the deconjugated metabolites using automated online solid-phase extraction, and separation and quantification using liquid chromatography-isotope dilution tandem mass spectrometry.Depending on the analyte, method detection limits were 0.1–0.6 ng/mL; mean accuracy, calculated as spike recoveries, was 91–102%, and total precision, given as percent variation coefficient, was 5.9–11.5%. Percent differences associated with three freeze-thaw cycles, 24-h benchtop storage, and short-term processed sample stability were <14%.Method suitability was assessed by recurring successful participation in external quality assessment schemes and by analyzing samples from subjects with suspected exposure to pesticides (n = 40) or who self-reported consuming an organic diet (n = 50). Interquartile ranges were considerably lower for people consuming an organic diet than for those potentially exposed for cis-DCCA (0.37 ng/mL vs 0.75 ng/mL), trans-DCCA (0.88 ng/mL vs 1.78 ng/mL) and TCPy (1.81 ng/mL vs 2.48 ng/mL). This method requires one-fifth of the sample used in our previous method and is suitable for assessing background exposures to select pesticides in large human populations and for studies with limited sample volumes.

Effects of Surface Treatment and Thermocycling on the Shear Bond Strength of Zirconia-Reinforced Lithium Silicate Ceramic.

To investigate the effects of different surface treatments and thermocycling on shear bond strength (SBS) be-tween resin cement and zirconia-reinforced lithium-silicate (ZLS) ceramic. 96 ZLS ceramic specimens were randomly allocated to four different surface treatment groups: etch and silane (ES), etch and universal primer (EUP), self-etching primer (SEP), and sandblasting and silane (SS). Stan-dardized composite cylinders were bonded to surface-treated ZLS ceramic, after which SBS was obtained either after 24-h water storage only or with an additional 5000 thermal cycles (TC), resulting in eight subgroups (n = 12). After evaluation of failure mode under a stereomicroscope, representative SEM images were acquired. To examine areal average surface roughness (Sa), additional ZLS specimens were prepared and randomly allocated to 3 groups: hydrofluoric acid etching, self-etching primer, and sandblasting (n = 10). Supplementary specimens were examined using field-emission scanning electron microscopy (FE-SEM) (n = 2) and atomic force microscopy (AFM) (n = 2) to investigate their surface topographies. ANOVA showed a statistically significant difference in SBS following different surface treatment protocols after 24-h water storage (p < 0.001). However, TC groups revealed no statistically significant difference in their SBS (p = 0.394). All surface treated groups were significantly affected by TC (p < 0.001), except for the SS group (p = 0.48). Sa was signifi-cantly influenced by the different surface treatment protocols (p < 0.001). The ability of self-etching primer to achieve comparable bond strength with a less technique-sensitive ap-proach makes it a favorable alternative to ES for the surface treatment of ZLS ceramics.

Relationship between preoperative nitrogen balance and energy and protein intake in patients with esophageal cancer.

Nitrogen balance (NB) is an important indicator of protein utilization in the body, and a positive NB is essential for maintaining and improving nutritional status. However, information is lacking on the target values of the energy and protein levels required to maintain positive NB in cancer patients. This study aimed to verify the energy and protein requirements for positive NB in preoperative esophageal cancer patients. This study included patients for esophageal cancer surgery who were admitted for radical surgery. Urine urea nitrogen (UUN) levels were measured based on 24-h urine storage. Energy and protein intakes were calculated from the dietary intake during hospitalization and the amount administered from enteral and parenteral nutrition. The characteristics of the positive and negative NB groups were compared, and patients' characteristics related to UUN excretion were analyzed. Seventy-nine patients with esophageal cancer were included, and 46% of patients were negative NB. All patients with energy intake ≥30 kcal/kg/day and protein intake ≥1.3 g/kg/day had positive NB. Whereas, in the group with energy intake ≥30 kcal/kg/day and protein intake <1.3 g/kg/day, 67% of patients were positive NB. There was a significant positive relation between UUN excretion and retinol-binding protein in multiple regression analyses adjusted for several patients' characteristics (β = 0.28, p = 0.048). In preoperative esophageal cancer patients, 30 kcal/kg/day of energy and 1.3 g/kg/day of protein were the guideline values for positive NB. Good short-term nutritional status was a factor associated with increased UUN excretion.

EFFECT OF DELAYED PREPARATION OF PLATELET POOR PLASMA ON COAGULATION STUDIES AT ROOM TEMPERATURE

Objective: To determine the effect of delay in the preparation of platelet poor plasma (PPP) on prothrombin time (PT) and activated partial thromboplastin time (APTT) at room temperature (RT). Material and Methods: It was a cross sectional study, conducted at Chughtai Institute of Pathology from January 2022 to June 2022. Total 100 healthy individuals, both males and females, participated in the study. Centrifugation of four citrated blood samples was done at 4000 g for 10 minutes at RT; first sample at 0 hour (h), second sample at 4 h, third sample at 8 h and fourth sample at 24 h. PT and APTT were run on each PPP using Sysmex CS-1600.The values at different times were noted and compared through careful statistical analysis of the observed parameters. Results: There was statistically significant difference for PT at 24h storage time when compared with baseline value at 0h (P value 0.0017) but no clinically relevant change up to 24h (&lt;10% percent change). For APTT at RT, statistically significant difference was noted at storage time of 8h (P value 0.0001) and 24h (P value &lt;0.0001) but a clinically relevant change was noted only at 24h (&gt;10% percent change). Conclusion: Blood samples for PT and APTT without centrifugation can be stored for up to 24 hours for PT at RT and for up to 4 hours for APTT at RT. PT and APTT values will not be affected if centrifugation of citrated sample is done within 1 hour of collection and transported at RT in small aliquots. Key Words: Prothrombin time, Activated partial thromboplastin time, Platelet poor plasma, Pre analytical, Centrifugation

Effect of Chlorhexidine-containing Etch-and-Rinse Adhesives on Dentin Microtensile Bond Strength after Biological Loading.

This study compared a 2%-CHX dentin pre-treatment with three CHX adhesives (experimentally admixed 0.1% CHX in primer or bonding agent, or industrially added 0.2% CHX in universal adhesive) by evaluating dentin bond strengths after biological loading in a fully automated artificial mouth model. The occlusal dentin of 50 freshly extracted human third molars was exposed, and the teeth were randomly assigned to 5 groups according to the adhesive protocol (n = 10): 1. control, Scotchbond Multipurpose (3M Oral Care; CTRL); 2. 2% CHX dentin pre-treatment (DENT); 3. 0.1% CHX experimentally admixed into the primer (PRIM); 4. 0.1% CHX experimentally admixed into the bonding agent (BOND); 5. Peak Universal Bond containing 0.2% CHX (Ultradent; PEAK). The teeth were restored with composite resin. Microtensile bond strength testing (bonding area 0.46 mm2 ± 0.04 mm2, crosshead speed 1 mm/min) was performed after 24-h storage in distilled water (baseline) or after 2-day biological loading with S. mutans (demineralization 1 h / remineralization 5 h). The mode of fracture was recorded and exemplary sticks were evaluated under SEM. CTRL exhibited significantly higher μTBS at baseline in comparison to PRIM (p = 0.000), BOND (p = 0.002), and PEAK (p = 0.000). After undergoing the caries model, CTRL demonstrated significantly lower μTBS compared to DENT (p = 0.000), PRIM (p = 0.008), and PEAK (p = 0.000). The same behavior was observed for BOND vs DENT (p = 0.000), PRIM (p = 0.003), and PEAK (p = 0.001). After biological loading, DENT (p = 0.041), PRIM (p = 0.000), and BOND (p = 0.000) exhibited significantly fewer adhesive fractures than CTRL. CHX addition to the primer protects dentin bond strength from declining after biological loading. Thus, it may offer some clinical advantage in terms of secondary caries inhibition around composite restorations. However, since loss of adhesion at baseline was less when 2% CHX was used as a dentin pre-treatment, it can be suggested as a safer option. so that bonding is not undermined by potential chemical interactions from CHX with the adhesives.

Efficacy of organic and antioxidant agents to regain bond strength to bleached enamel in different dental adhesive solvents.

Materials like carbamide peroxide or hydrogen peroxide are commonly used for vital teeth bleaching. However, there have been concerns regarding their effect on composite-to-bleached enamel bonding strength. The study investigated the impact of organic and antioxidant agents on composite bond strength in bleached enamel with different dental adhesive solvents. Human third molar teeth were sectioned into buccal and lingual halves. The two main adhesive solvent groups evaluated were acetone and alcohol. Each main group was divided into six groups. The positive control group received no bleaching, the negative control group consisted of bleaching with no surface deoxidization; and other experimental categories involved post-bleach treatments with 95% ethanol, sodium ascorbate (10%), acetone solution, or sodium fluoride solution (1.1%). Following the surface treatment and enamel bonding procedure, nano-hybrid composite cylinders measuring 3 × 2 mm were directly cured over the bleached enamel substrate. The shear bond test was performed after 24-h storage and 12,000 thermocycles on a universal testing machine. In this study, one-way ANOVA was used along with Tukey's HSD tests at a significance level of 0.05. The negative control groups showed significantly lower bond strength than the positive control group. Ethanol surface treatment had superior mean bonding strength in acetone and alcohol-based adhesive solvent groups. The utilization of sodium ascorbate for surface treatment resulted in a significant enhancement of adhesion between the composite material and bleached enamel surface. Sodium fluoride application showed no significant recovery in shear bond strength in both dental adhesive groups. It was concluded that hydrogen peroxide severely compromised the immediate bond strength of composite resin. Surface treatment of bleached enamel with ethanol, sodium ascorbate, and acetone solutions is an effective option for restoring bond strength.

Surface roughness evaluation of composite materials polished with one- or multi-step systems

Aim: As the spectrum of composite materials expands in the dental market, it's becoming more challenging to differentiate the structural properties and to find suitable finishing-polishing (f-p) materials. The main goal is to evaluate the impact of one and multi-step f-p systems on the surface roughness (SR) of current composite materials. Methodology: In this study, nanohybrid bulk-fill (Filtek BulkFill Posterior [FBFP]), nanohybrid (Ceram.x One [CXO]), microhybrid (Filtek Z250 [FZ250]), and giomer bulk-fill (Beautifil Bulk Restorative [BBR]) composites were tested. After sample preparation and 24-h storage in 37 °C distilled water, each main group was assigned to one of two groups (n = 10): a one-step (One Gloss-PS) or a multi-step (Sof-Lex) f–p system. SR values (Ra, µm) were measured using a profilometer. Statistical analysis was done using Tukey HSD and ANOVA tests (p &lt; 0.05). Results: FZ250 showed the highest Ra values, regardless of the f–p system used. CXO showed statistically significantly lower SR scores than FZ250 (p &lt; 0.05). There were no significant differences among the Ra values of the one- or multi-step f–p systems for FBFP and FZ250. Both the material and f–p systems had a significant effect on the Ra values separately. Conclusion: FZ250 showed the highest Ra values, and composites polished with the multi-step f–p system exhibited slightly smoother surfaces than those polished with the one-step system. How to cite this article: Ozan G, Berkman M. Surface roughness evaluation of composite materials polished with one- or multi-step systems. Int Dent Res 2022;12(3):165-70. https://doi.org/10.5577/intdentres.2022.vol12.no3.9 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Microhardness and flexural strength of two 3D-printed denture base resins

Objectives: To evaluate the microhardness and flexural strength of printed and conventionally produced denture base acrylic resins. Methods: A total of 32 parallelepiped specimens (64×10×3.3 mm) were manufactured using two light-cured resins suitable for 3D printing (V-Print Dentbase and Denture 3D+) and two heat-cured resins for conventional production (Probase Hot and Villacryl Rapid) (n=8). After 24-h storage in water, Knoop microhardness (98.12 mN load for 30 s) and three-point flexural strength (1 kN load cell, at a crosshead speed of 5 mm/min and 50 mm between rods) were determined. Microhardness data were analyzed with one-way ANOVA followed by Tukey post-hoc tests. Flexural strength data were submitted to the Kruskal-Wallis test. A significance level of 5% was considered (α=0.05). Results: The resins showed statistically significant (p&lt;0.001) differences regarding microhardness (V-Print Dentbase &lt; Denture 3D+ &lt; Probase Hot &lt; Villacryl Rapid). No statistically significant (p=0.527) differences were found in flexural strength between the four resins. Conclusions: The printed resins had lower microhardness values than conventional resins, but all resins showed similar flexural strength.

Inhibition of matrix metalloproteinase-9 by 10-MDP and its calcium salt contributes to improved dentin-bonding durability

The activation of matrix metalloproteinases (MMPs) is responsible for degradation of the hybrid layer. The effect of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) on biodegradation of the hybrid layer remains unknown. This study aimed to evaluate the effects of 10-MDP and its Ca salt on MMP-9 activity and dentin-bonding durability. 10-MDP-Ca salt was synthesized and characterized by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR). The effects of chlorhexidine (CHX), 10-MDP, and 10-MDP-Ca salt on MMP activity were evaluated by in-situ zymography, MMP-9 inhibition assay, and hydroxyproline (HYP) assay. Dentin-resin bonded specimens were fabricated with using CHX or 10-MDP, including Single Bond 2 (Ctr), CHX + Single Bond 2 (CHX), 10-MDP + Single Bond 2 (10-MDP), and SBU (SBU). Micro-tensile bond strength (μTBS) and nanoleakage tests were performed after 24-h or two-years water storage. XRD and NMR confirmed the presence of 10-MDP-Ca salt. The relative inhibition percentages of recombinant MMP-9 for 10-MDP and 10-MDP-Ca salt were 8.04 ± 0.83% and 55.96 ± 1.82% respectively. HYP assay showed that 10-MDP, CHX, and 10-MDP-Ca salt conditioning decreased collagen degradation. Water storage weakened μTBS of all the groups, with the Ctr and CHX groups showing more significant decreases (P < 0.05). After aging, the Ctr and CHX groups also presented more nanoleakage, and the CHX group showed more in-situ zymography fluorescence than the 10-MDP and SBU groups. The capacity to inhibit MMP-9 activity, decrease HYP release, and reduce nanoleakage of 10-MDP and its salt contribute to improvement of dentin-bonding durability.