OBJECTIVES: The metabolomics technique of LC-MS/MS combined with data analysis was used to detect changes and differences in metabolic profiles in the vitreous humor of early rat carcasses found in water, and to explore the feasibility of its use for early postmortem submersion interval (PMSI) estimation and the cause of death determination. METHODS: The experimental model was established in natural lake water with 100 SD rats were randomly divided into a drowning group (n=50) and a postmortem (CO₂ suffocation) immediately submersion group (n=50). Vitreous humor was extracted from 10 rats in each group at 0, 6, 12, 18 and 24 h postmortem for metabolomics analyses, of which 8 were used as the training set to build the model, and 2 were used as test set. PCA and PLS multivariate statistical analysis were performed to explore the differences in metabolic profiles among PMSI and causes of death in the training set samples. Then random forest (RF) algorithm was used to screen several biomarkers to establish a model. RESULTS: PCA and PLS analysis showed that the metabolic profiles had time regularity, but no differences were found among different causes of death. Thirteen small molecule biomarkers with good temporal correlation were selected by RF algorithm. A simple PMSI estimation model was constructed based on this indicator set, and the data of the test samples showed the mean absolute error (MAE) of the model was 0.847 h. CONCLUSIONS The 13 metabolic markers screened in the vitreous humor of rat corpses in water had good correlations with the early PMSI. The simplified PMSI estimation model constructed by RF can be used to estimate the PMSI. Additionally, the metabolic profiles of vitreous humor cannot be used for early identification of cause of death in water carcasses.
Animals ; Biomarkers/metabolism* ; Cadaver ; Chromatography, Liquid ; Immersion ; Postmortem Changes ; Rats ; Rats, Sprague-Dawley ; Tandem Mass Spectrometry ; Vitreous Body/metabolism* ; Water/metabolism*

PURPOSE: This study evaluated color stability of Dentca 3D-printed denture teeth, in comparison to color stabilities of four conventional types of denture teeth, upon being immersed in various colorants.MATERIALS AND METHODS: Four types of conventional prefabricated denture teeth (Surpass, GC, Artic 6, Heraeus Kulzer, Premium 6, Heraeus Kulzer, Preference, Candulor), 3D-printed denture teeth (Dentca); and Z250 (Filtek Z250, 3M ESPE) were prepared for testing. The samples were immersed in erythrosine 3%, coffee, cola, and distilled water (DW) at 37℃. Color change (ΔE) was measured by spectrophotometer before immersion and at 7, 14, and 21 days after immersion. One-way analysis of variance was performed along with Tukey's honestly significant difference multiple comparisons test (P<.05).RESULTS: No great difference was observed between the color change of Dentca denture teeth and that of conventional denture teeth in most cases (P>.05). The color change of Dentca denture teeth immersed in erythrosine 3% was greater than that of Surpass (ΔE = 0.67 ± 0.25) after 1 week; Artic 6 (ΔE = 1.44 ± 0.38) and Premium 6 (ΔE = 1.69 ± 0.35) after 2 weeks; and Surpass (ΔE = 1.79 ± 0.49), Artic 6 (ΔE = 2.07 ± 0.21), Premium 6 (ΔE = 2.03 ± 0.75), and Preference (ΔE = 2.01 ± 0.75) after 3 weeks (P<.05).CONCLUSION: A color change was observed in Dentca denture teeth when immersed in some colorants; however, the maximum value of ΔE for Dentca denture teeth was within the clinically acceptable range.
Coffee ; Cola ; Dentures ; Erythrosine ; Immersion ; Printing, Three-Dimensional ; Tooth ; Water

Postmortem interval （PMI） estimation is one of the most important and difficult academic tasks in forensic sciences. Due to the influence of the corpse itself and the water environment, corpses in water have unique corruption phenomenon and laws. Based on the experience of traditional PMI studies of corpses on land, forensic practitioners across the world have proposed a variety of practical methods for estimating postmortem submersion interval （PMSI）. This paper summarizes the literatures related to PMSI in recent years, and introduces methods to infer PMSI according to the phenomenon of corpses, the development of insects, the succession pattern of aquatic organisms, and the changes of other physical and chemical indexes of corpses, in order to provide some reference for the study of PMSI of corpses in water.
Animals ; Autopsy ; Cadaver ; Forensic Medicine ; Immersion ; Postmortem Changes

OBJECTIVES: Self-adhesive resin cements contain functional monomers that enable them to adhere to the tooth structure without a separate adhesive or etchant. One of the most stable functional monomers used for chemical bonding to calcium in hydroxyapatite is 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). The aim of this study was to evaluate the influence of the10-MDP concentration on the bond strength and physical properties of self-adhesive resin cements. MATERIALS AND METHODS: We used experimental resin cements containing 3 different concentrations of 10-MDP: 3.3 wt% (RC1), 6.6 wt% (RC2), or 9.9 wt% (RC3). The micro-tensile bond strength of each resin cement to dentin and a hybrid resin block (Estenia C&B, Kuraray Noritake Dental) was measured, and the fractured surface morphology was analyzed. Further, the flexural strength of the resin cements was measured using the three-point bending test. The water sorption and solubility of the cements following 30 days of immersion in water were measured. RESULTS: The bond strength of RC2 was significantly higher than that of RC1. There was no significant difference between the bond strength of RC2 and that of RC3. The water sorption of RC3 was higher than that of any other cement. There were no significant differences in the three-point bending strength or water solubility among all three types of cements. CONCLUSIONS: Within the limitations of this study, it is suggested that 6.6 wt% 10-MDP showed superior properties than 3.3 wt% or 9.9 wt% 10-MDP in self-adhesive resin cement.
Adhesives ; Calcium ; Dentin ; Durapatite ; Immersion ; Resin Cements ; Solubility ; Tooth ; Water

PURPOSE: Although dental impression disinfection is determinant to reduce the cross-infection risk, some studies have shown that, in real practice, the disinfection procedures vary considerably. Thus, the aim of this study was to evaluate the antimicrobial effectiveness and the impact on the dimensional stability of addition silicone' impressions of water wash and the most clinically used disinfection solutions: 3% hydrogen peroxide, commercial disinfectant MD520 (Durr) and 1% and 5.25% sodium hypochlorite. MATERIALS AND METHODS: For this investigation, dental impressions were taken on 16 volunteer dental students. The antimicrobial effectiveness of each procedure was evaluated by pour plate method. The dimensional stability was evaluated using a standardized stainless-steel model, according to ANSI/ADA nº19 specification. RESULTS: The study results showed that water wash does not alter the dimensional stability of addition silicone impressions but doesn't reduce the microbial load of the material (P>.05). On the other hand, addition silicone disinfection by immersion with 3% hydrogen peroxide, MD520 (Durr), or sodium hypochlorite at 1% and 5.25% does not alter the dimensional stability significantly but reduces > 99.9% of the microbial load of the impressions (P<.001). CONCLUSION: Addition silicone impressions should always be disinfected after water wash in order to reduce effectively the cross-infection risk. All disinfectants tested showed high antimicrobial efficiency without significant changes in three-dimensional shape of impressions. Hydrogen peroxide and sodium hypochlorite are of particular importance because are easily accessible in dental setting. The less explored hydrogen peroxide could be a valuable alternative for silicone impressions disinfection.
Disinfectants ; Disinfection ; Hand ; Humans ; Hydrogen Peroxide ; Immersion ; Methods ; Silicon ; Silicone Elastomers ; Silicones ; Sodium Hypochlorite ; Students, Dental ; Volunteers ; Water

PURPOSE: To evaluate the polishing effect on roughness and color change of pressed and layering ceramics after immersion in coffee solution.
Ceramics ; Coffee ; Diamond ; Immersion ; Lithium ; Microscopy, Electron, Scanning ; Pigmentation ; Spectrophotometry

PURPOSE: To review the clinical features and natural courses of cold urticaria (ColdU) in a tropical country. METHODS: A retrospective chart review was performed of patients who visited Siriraj Urticaria Clinic, Siriraj Hospital, Bangkok, Thailand, and were diagnosed with ColdU between 2007 and 2018. Data on provocation and threshold tests, clinical courses, and laboratory work-up were analyzed and compared with data reported by studies in temperate countries. RESULTS: Of 1,063 chronic urticaria patients, 27 (2.5%) were diagnosed with ColdU, with a mean age of symptom onset of 34.8 years. Half of the patients had a history of atopy, and 1 (3.7%) had a history of anaphylaxis. All patients were positive to 1 of 3 provocation tests: an ice cube test; TempTest 4.0; or a tray filled with ice, salt and water. Thirteen patients underwent the ice cube test, and all had positive results. TempTest was performed on 15 patients, 8 of whom had positive results, with a mean critical temperature threshold (CTT) of 21.0°C. All of the 7 patients who had a negative TempTest result later produced positive results to the immersion of their hand and forearm in a tray filled with ice, salt, and water. All patients were treated with H1-antihistamines, the vast majority (96.3%) being non-sedating H1-antihistamines. Some (14.8%) needed to be administered oral corticosteroids, ciclosporin, or omalizumab. Six patients (22.2%) were in remission. A Kaplan-Meier survival curve demonstrated 5-year and 10-year remission rates of 13.8% and 42.6%, respectively. CONCLUSIONS: The rate of anaphylaxis in patients with ColdU in a tropical country was lower than those reported by other studies conducted intemperate climates. On the other hand, the number of female patients, mean age at symptom onset, atopy rate, rate of concomitant chronic spontaneous urticaria and mean CTT were higher.
Adrenal Cortex Hormones ; Anaphylaxis ; Climate ; Cyclosporine ; Female ; Forearm ; Hand ; Humans ; Ice ; Immersion ; Omalizumab ; Retrospective Studies ; Thailand ; Tropical Climate ; Urticaria ; Water

In this study, a restoration process was developed with potassium hydroxide (KOH), in order to improve each of the structures for their posterior fixation, through the use of new methods such as the Chilean conservative fixative solution (SFCCh), with exceptional results. Restore anatomical pieces corresponding to corpse and organs, being these last set with the SFCCh. In this work dealt with processes of restoration with potassium hydroxide, sodium chloride, and sodium hypochlorite, the process began with the cleanliness and suture of the structures for subsequent fixing in Chilean conservative fixative solution, making use of a corpse and different anatomical parts. Work based on items found in the database, Elsevier, Science Direct, ProQuest, and MEDLINE. At the end of the process of restoration and conservation of the anatomical pieces, was observed an improvement in muscle pigment with decrease of rigidity in the specimen, additionally a recovery of appearance in the vascular-nervous elements was achieved. The organs were much more malleable and the structures facilitate the identification of specific details, its subsequent immersion in SFCCh allows the longer preservation of the obtained results. The restoration with potassium hydroxide allows the improvement in the appearance of the different anatomical structures and simultaneously to facilitate its study. The SFCCh is an alternative that replaces partially the use of formaldehyde. In addition, it presents toxicity reduction.
Cadaver ; Formaldehyde ; Immersion ; Potassium ; Sodium Hydroxide ; Sodium Hypochlorite ; Sutures

PURPOSE: The aim of this study was to evaluate the influence of polishing methods on the color stability of composite resins. MATERIALS AND METHODS: Two bulk-fill and four conventional resin composites were filled in cylindrical molds (6 mm diameter, 4 mm height) and light-cured. The specimens were stored in 34℃ distilled water for 24 h. Spectrophotometer was used to determine the color value according to the CIE L(*)a(*)b(*) color space. Each group was divided into three groups according to polishing methods (n = 5). Group 1 was control group (Mylar strip group), group 2 was polished with PoGo, and group 3 was polished with Sof-Lex Spiral wheels. Color evaluation was performed weekly for 4 weeks after immersion in 34℃ distilled water. The results were analyzed by generalized least squares method (P < 0.05). RESULTS: Generalized least squares analysis revealed that Sof-Lex Spiral wheels group showed the significantly lower ΔE values compared to PoGo and control group (P < 0.05). The ΔE values of polished group showed the significantly lower than the ΔE values of unpolished group (P < 0.05). Regarding color changes of composite resins, there was no significant difference between the ΔE values of Filtek Z250 and Filtek Z350 XT Universal restorative in all time intervals (P < 0.05). Tetric N-Ceram Bulk Fill showed the significantly lower ΔE values compared to other composite resins in 1, 2, 3 weeks (P < 0.05). CONCLUSION: Within the limitations of this study, polishing methods influence the color stabilities of composite resins. The group polished with Sof-Lex Spiral Wheels showed more resistance to discoloration than group polished with PoGo.
Absorption ; Composite Resins ; Fungi ; Immersion ; Least-Squares Analysis ; Methods ; Water

PURPOSE: With the ever-changing cultural makeup of society, the ability to deliver culturally appropriate healthcare is essential. An educational method aimed at increasing cultural knowledge and sensitivity in the education of healthcare professionals is cultural immersion, which creates opportunities for transformational learning through direct interactions with culturally diverse populations. The purpose of this systematic review was to examine the qualitative effects of cultural immersion experiences on graduate-level healthcare professional students. METHODS: A search of the CINAHL (Cumulative Index to Nursing and Allied Health Literature) and ERIC (Education Resources Information Center) databases was performed, utilizing search terms including cultural immersion, cultural sensitivity, educational outcomes, and healthcare professionals. The search was limited to publications within the last 10 years. The articles were screened according to title, abstract, and full-text following the application of inclusion/exclusion criteria. Themes identified within each article were collected and categorized, using a qualitative methodology, into 5 overarching domains to assess the educational experiences. Studies were scored for quality using the qualitative portion of the McGill Mixed Methods Appraisal Tool–2011. RESULTS: Nine studies incorporating a total of 94 participants with experiences in 14 culturally diverse environments revealing 47 individually identified themes were included in the review. The results indicated that all cultural immersion experiences stimulated increased cultural awareness and sensitivity. CONCLUSION: Cultural immersion experiences produced a positive, multi-domain effect on cultural learning in students of the health professions. The results of this review provide support for implementing cultural immersion experiences into the education of healthcare professionals with the goal of increasing cultural sensitivity.
Delivery of Health Care ; Education ; Health Occupations ; Humans ; Immersion ; Learning ; Methods ; Nursing