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Effect of coffee thermal cycling on the surface properties and stainability of additively manufactured denture base resins in different layer thicknesses.
No full textPURPOSE
To compare the effect of coffee thermal cycling on surface roughness (Ra), Vickers microhardness (MH), and stainability of denture base resins additively manufactured in different layer thicknesses with those of subtractively manufactured denture base materials.
MATERIALS AND METHODS
Eighty disk-shaped specimens (Ø10×2 mm) were fabricated from two subtractively (Merz M-PM [SM-M] and G-CAM [SM-G]) and three additively (NextDent 3D+ [50 μm, AM-N-50; 100 μm, AM-N-100], FREEPRINT Denture [50 μm, AM-F-50; 100 μm, AM-F-100], and Denturetec [50 μm, AM-S-50; 100 μm, AM-S-100]) manufactured denture base materials (n = 10). Ra measurements were performed before and after polishing by using a non-contact optical profilometer, while MH values and color coordinates were measured after polishing. Specimens were then subjected to 5000 cycles of coffee thermal cycling, all measurements were repeated, and color differences (ΔE00) were calculated. A linear mixed effect model was used to analyze Ra and MH data, while one-way analysis of variance was used to analyze ΔE00 data (α = .05). Ra values were further evaluated according to a clinically acceptable threshold of 0.2 μm, while ΔE00 values were evaluated according to perceptibility (1.72 units) and acceptability (4.08 units) thresholds. The interaction between the material type and the time interval affected both Ra and MH (p ≤ 0.001). Tested materials had their highest Ra before polishing (p ≤ 0.029). Before polishing, AM-F-100 had the highest, and SM-M and SM-G had the lowest Ra (p < 0.001). After polishing and after coffee thermal cycling, SM-G mostly had lower Ra than those of other materials (p ≤ 0.036). SM-G mostly had higher MH than that of other materials before and after coffee thermal cycling (p ≤ 0.025). Coffee thermal cycling reduced the MH of SM-M and increased that of AM-S-100 (p ≤ 0.024). AM-N-100 had higher ΔE00 than AM-F, AM-S-100, and SM-G (p ≤ 0.009), while AM-F and SM-G had lower ΔE00 than AM-S-50 and AM-N-50 (p ≤ 0.024).
CONCLUSIONS
Polishing reduced the surface roughness of all materials, whereas coffee thermal cycling's effect was nonsignificant. Most of the tested materials had acceptable surface roughness after polishing and after coffee thermal cycling according to the reported threshold. Layer thickness only affected the microhardness of tested additively manufactured resins, which was material-dependent. Subtractively manufactured specimens mostly had high microhardness and that of nonreinforced subtractively manufactured resin decreased after coffee thermal cycling. When reported color thresholds are considered, all materials had acceptable color stability. This article is protected by copyright. All rights reserved
What Role Does PET/MRI Play in Musculoskeletal Disorders?
No full textMusculoskeletal disorders of nononcological origin are one of the most frequent reasons for consultation. Patients suffering from musculoskeletal disorders also consult more than once for the same reason. This results in multiple clinical follow-ups after several radiological and serum examinations, the main ones including X-rays targeting the painful anatomical region and inflammatory serum parameters. As part of their work up, patients suffering from musculoskeletal disorders often require multisequence, multi-parameter MRI. PET/MRI is a promising imaging modality for their diagnosis, with the added advantage of being able to be performed in a single visit. PET/MRI is particularly useful for diagnosing osteomyelitis, spondylodiscitis, arthritis, many pediatric pathologies, and a wide range of other musculoskeletal pathologies. PET/MRI is already used to diagnose malignant bone tumors such as osteosarcoma. However, current knowledge of the indications for PET/MRI in nononcological musculoskeletal disorders is based on studies involving only a few patients. This review focuses on the usefulness of PET/MRI for diagnosing nononcological musculoskeletal disorders
Barium isotope (re-)equilibration in the barite-fluid system and its implications for marine barite archives
No full textVariations in the Ba isotopic composition of seawater are largely driven by the extent of barite precipitation in the marine photic zone and replenishment of Ba by upwelling and/or continental inputs. Pelagic barites offer a robust tool for tracing sources and sinks of Ba in the (paleo)ocean as they record these isotopic variations. Knowledge of the Ba isotope fractionation between barite and ambient waters is therefore imperative. Here, the Ba isotope fractionation between barite and Ba2+ (aq) under equilibrium conditions has been estimated by the three-isotope method with a 135Ba-enriched reactive fluid. The estimated Ba isotope fractionation was BaBarite-Ba2+ = −0.07 ± 0.08‰. Textural observations of barite crystals recovered up to 756 days of reaction reveal smoothing of solid surfaces but also typical dissolution features such as development of pits and cracks. Thus, dissolution/re-precipitation is likely the mechanism controlling the observed isotope exchange that is facilitated by the further development of porosity in the crystals. Additionally, the isotope exchange in the experimental runs fits a second-order law yielding a surface normalized isotope exchange rate of ∼2.8 × 10−10 mol/m2/s. This exchange rate could theoretically result in complete isotope exchange between pelagic barite with a typical edge size of 1 μm and ambient seawater or pore fluid within years, altering the barite's Ba isotopic composition during settling towards the seafloor and/or after deposition in marine sediments. Although there is considerable uncertainty in extrapolating experimental results to natural conditions and longer time scales, the rapid rates of exchange observed experimentally over short timescales suggest that isotope exchange in pelagic barite should be considered during interpretation of the Ba isotope composition as a paleoarchive
Effect of resin cement selection on fracture resistance of chairside CAD-CAM lithium disilicate crowns containing virgilite: A comparative in vitro study.
No full textSTATEMENT OF PROBLEM
Studies on the fracture performance of a recently introduced computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate ceramic containing virgilite with different cements are lacking.
PURPOSE
The purpose of this in vitro study was to evaluate the fracture resistance of crowns made of a recently introduced chairside CAD-CAM lithium disilicate containing virgilite cemented with different types of adhesive luting cement.
MATERIAL AND METHODS
Sixty complete coverage crowns for a maxillary right central incisor were milled out of a lithium disilicate with virgilite (CEREC Tessera) (n=48) and a traditional lithium disilicate (e.max CAD) (n=12) using a chairside CAD-CAM system (Primescan). The central incisor tooth preparation included a 1.5-mm incisal reduction, a 1.0-mm axial reduction, and a 1.0-mm chamfer finish line. The restorations were bonded with different types of resin cement to 3D printed dies of the tooth preparation and were divided into 5 groups (n=12 per group): e.max CAD with Multilink Automix (E.Mu); Tessera with Multilink Automix (T.Mu); Tessera with Calibra (T.Ca); Tessera with Unicem (T.Un); and Tessera with Speedcem (T.Sp). The cemented restorations were stored in water for 30 days and then loaded until they were fractured in compression. The load at fracture was analyzed with a 1-way analysis of variance (ANOVA) and the honestly significant difference (HSD) Tukey test (α=.05).
RESULTS
The mean fracture resistance of traditional lithium disilicate and virgilite lithium disilicate anterior crowns significantly differed depending on the type of resin cement used (P<.05). Group E.Mu displayed the highest values (946.35 ±155 N), followed by group T.Un (819.59 ±232 N), group T.Sp (675.52 ±153 N), and group T.Mu (656.95 ±193 N). The lowest values were displayed by group T.Ca (567.94 ±184 N).
CONCLUSIONS
The fracture resistance of lithium disilicate containing virgilite and traditional lithium disilicate crowns cemented with the same cement displayed statistically similar values. However, significant differences were observed when the virgilite lithium disilicate crowns were cemented with different types of adhesive luting cement. The crowns in the T.Ca group displayed the lowest fracture resistance
[Application of extra- and intracochlear electrocochleography during and after cochlear implantation].
No full textElectrocochleography (ECochG) represents a promising approach for monitoring cochlear function during cochlear implantation and for investigating the causes of residual cochlear function loss after implantation. This paper provides an overview of the current research and application status of ECochG, both during and after cochlear implantation. Intraoperative ECochG can be conducted either via the implant itself or an extracochlear measuring electrode. Postoperative ECochG recordings are also feasible via the implant. Various studies have demonstrated that a significant decrease in ECochG amplitude during electrode insertion correlates with an increased risk of losing residual cochlear function, with critical cochlear events occurring primarily towards the end of the insertion. Postoperative data suggest that the loss of cochlear function mainly occurs in the early postoperative phase. Future research directions include the automation and objectification of signal analysis, as well as a more in-depth investigation into the underlying mechanisms of these signal changes
Characterising 24-h skeletal muscle gene expression alongside metabolic & endocrine responses under diurnal conditions.
Full text linkCONTEXT
Skeletal muscle plays a central role in the storage, synthesis, and breakdown of nutrients, yet little research has explored temporal responses of this human tissue, especially with concurrent measures of systemic biomarkers of metabolism.
OBJECTIVE
To characterise temporal profiles in skeletal muscle expression of genes involved in carbohydrate metabolism, lipid metabolism, circadian clocks, and autophagy and descriptively relate them to systemic metabolites and hormones during a controlled laboratory protocol.
METHODS
Ten healthy adults (9M/1F, mean ± SD: age: 30 ± 10 y; BMI: 24.1 ± 2.7 kg·m-2) rested in the laboratory for 37 hours with all data collected during the final 24 hours of this period (i.e., 0800-0800 h). Participants ingested hourly isocaloric liquid meal replacements alongside appetite assessments during waking before a sleep opportunity from 2200-0700 h. Blood samples were collected hourly for endocrine and metabolite analyses, with muscle biopsies occurring every 4 h from 1200 h to 0800 h the following day to quantify gene expression.
RESULTS
Plasma insulin displayed diurnal rhythmicity peaking at 1804 h. Expression of skeletal muscle genes involved in carbohydrate metabolism (Name - Acrophase; GLUT4 - 1440 h; PPARGC1A -1613 h; HK2 - 1824 h) and lipid metabolism (FABP3 - 1237 h; PDK4 - 0530 h; CPT1B - 1258 h) displayed 24 h rhythmicity that reflected the temporal rhythm of insulin. Equally, circulating glucose (0019 h), NEFA (0456 h), glycerol (0432 h), triglyceride (2314 h), urea (0046 h), CTX (0507 h) and cortisol concentrations (2250 h) also all displayed diurnal rhythmicity.
CONCLUSION
Diurnal rhythms were present in human skeletal muscle gene expression as well systemic metabolites and hormones under controlled diurnal conditions. The temporal patterns of genes relating to carbohydrate and lipid metabolism alongside circulating insulin are consistent with diurnal rhythms being driven in part by the diurnal influence of cyclic feeding and fasting
Severe hypocalcemia in the emergency department: a retrospective cohort study of prevalence, etiology, treatment and outcome.
No full textThe aim of this study was to evaluate the prevalence of severe hypocalcemia in patients attending the emergency department. Symptoms, causes, treatment, and outcome of severe hypocalcemia as well as course of calcium concentrations were assessed. This retrospective case series included all adult patients with measurements of serum calcium concentrations presenting to the emergency department of the Bürgerspital Solothurn between January 01 in 2017 and December 31 in 2020. Medical record reviews were performed of all patients with severe hypocalcemia, defined by a serum calcium concentration < 1.9 mmol/L, to assess clinical presentation and management. 1265 (3.95%) patients had a serum calcium concentration of < 2.1 mmol/L of which 139 (11%) had severe hypocalcemia of < 1.9 mmol/L. 113 patients had at least one measurement of albumin. Of these, 43 (3.4%) had an albumin-corrected serum calcium < 1.9 mmol/L defining true, severe hypocalcemia. Hypocalcemia was identified and documented in 35% of all cases. The mean serum calcium concentration was 1.74 ± 0.14 mmol/L. Calcium concentrations in malignancy-related hypocalcemia were similar to non-malignancy-related hypocalcemia. The main symptoms attributed to hypocalcemia were cardiac and neurologic. 12% of patients with severe hypocalcemia received intravenous and 23% oral calcium replacement. Active malignancy was the main cause of severe hypocalcemia in 28%, while in most cases, the main cause remained unclear. 41.9% of severely hypocalcemic patients reattended the emergency department for another episode of hypocalcemia within 1 year. Hypocalcemia is common in patients attending the emergency department, however, appears to be neglected frequently. The disorder is often a manifestation of severe disease, triggered by multiple causes. Calcium replacement was administered in less than half of the patients with severe hypocalcemia in this study. Due to frequent readmissions to the emergency department and a high mortality, increased awareness of the disorder and careful follow-up are desirable
Virologic Failure and Drug Resistance After Programmatic Switching to Dolutegravir-based First-line Antiretroviral Therapy in Malawi and Zambia.
No full textBACKGROUND
People with human immunodeficiency virus (PWH) on first-line, nonnucleoside reverse-transcriptase inhibitor-based antiretroviral therapy (ART) were routinely switched to tenofovir-lamivudine-dolutegravir. We examined virologic outcomes and drug resistance in ART programs in Malawi, where switching was irrespective of viral load, and Zambia, where switching depended on a viral load <1000 copies/mL in the past year.
METHODS
We compared the risk of viremia (≥400 copies/mL) at 1 and 2 years by viral load at switch and between countries using exact methods and logistic regression adjusted for age and sex. We performed HIV-1 pol Sanger sequencing on plasma samples with viral load ≥1000 copies/mL.
RESULTS
A total of 2832 PWH were eligible (Malawi 1422, Zambia 1410); the median age was 37 years, and 2578 (91.0%) were women. At switch, 77 (5.4%) were viremic in Malawi and 42 (3.0%) in Zambia (P = .001). Viremia at switch was associated with viremia at 1 year (adjusted odds ratio (OR), 6.15; 95% confidence interval [CI], 3.13-11.4) and 2 years (7.0; 95% CI, 3.73-12.6). Viremia was less likely in Zambia than in Malawi at 1 year (OR, 0.55; 0.32-0.94) and 2 years (OR, 0.33; 0.18-0.57). Integrase sequencing was successful for 79 of 113 eligible samples. Drug resistance mutations were found in 5 PWH (Malawi 4, Zambia 1); 2 had major mutations (G118R, E138K, T66A and G118R, E138K) leading to high-level dolutegravir resistance.
CONCLUSIONS
Restricting switching to dolutegravir-based ART to PWH with a viral load <1000 copies/mL may reduce subsequent viremia and, consequently, the emergence of dolutegravir drug resistance mutations.
CLINICAL TRIALS REGISTRATION
Clinicaltrials.gov (NCT04612452)
Speciation.
No full textWhat drives the emergence of new species has fascinated biologists since Darwin. Reproductive barriers to gene flow are a key step in the formation of species, and recent advances have shed new light on how these are established. Genetic, genomic, and comparative techniques, together with improved theoretical frameworks, are increasing our understanding of the underlying mechanisms. They are also helping us forecast speciation and reveal the impact of human activity
Consistencies in Follow-up After Radical Cystectomy for Bladder Cancer: A Framework Based on Expert Practices Collaboratively Developed by the European Association of Urology Bladder Cancer Guideline Panels.
No full textBACKGROUND AND OBJECTIVE
There is no standardized regimen for follow-up after radical cystectomy (RC) for bladder cancer (BC). To address this gap, we conducted a multicenter study involving urologist members from the European Association of Urology (EAU) bladder cancer guideline panels. Our objective was to identify consistent post-RC follow-up strategies and develop a practice-based framework based on expert opinion.
METHODS
We surveyed 27 urologist members of the EAU guideline panels for non-muscle-invasive bladder cancer and muscle-invasive and metastatic bladder cancer using a pre-tested questionnaire with dichotomous responses. The survey inquired about follow-up strategies after RC and the use of risk-adapted strategies. Consistency was defined as >75% affirmative responses for follow-up practices commencing 3 mo after RC. Descriptive statistics were used for analysis.
KEY FINDINGS AND LIMITATIONS
We received responses from 96% of the panel members, who provided data from 21 European hospitals. Risk-adapted follow-up is used in 53% of hospitals, with uniform criteria for high-risk (at least ≥pT3 or pN+) and low-risk ([y]pT0/a/1N0) cases. In the absence of agreement for risk-based follow up, a non-risk-adapted framework for follow-up was developed. Higher conformity was observed within the initial 3 yr, followed by a decline in subsequent follow-up. Follow-up was most frequent during the first year, including patient assessments, physical examinations, and laboratory tests. Computed tomography of the chest and abdomen/pelvis was the most common imaging modality, initially at least biannually, and then annually from years 2 to 5. There was a lack of consistency for continuing follow-up beyond 10 yr after RC.
CONCLUSIONS AND CLINICAL IMPLICATIONS
This practice-based post-RC follow-up framework developed by EAU bladder cancer experts may serve as a valuable guide for urologists in the absence of prospective randomized studies.
PATIENT SUMMARY
We asked urologists from the EAU bladder cancer guideline panels about their patient follow-up after surgical removal of the bladder for bladder cancer. We found that although urologists have varying approaches, there are also common follow-up practices across the panel. We created a practical follow-up framework that could be useful for urologists in their day-to-day practice
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