Can pure cellulose nanofibril films replace polyolefins as water vapor barriers in packaging?

Despite significant research into cellulose nanofibril (CNF) films as substitutes to synthetic plastic materials, commercial applications remain very limited. One major hindrance is the poor water vapor barrier properties of CNF films compared to polyolefins, a critical property for product protection, such as food safety and preservation. To date, it is unknown whether full moisture barrier properties can be achieved with materials made by the assembly of nanofibers and fibrils. A comprehensive understanding of the effect of film structure on water vapor transport properties is required. Here, over 200 films were produced with a wide range of grammages from 30 g/m2 to 580 g/m2 by casting and spray deposition. Their structures were quantified by µCT and SEM and related to their water vapor transmission rates (WVTRs). Porosity and pore connectivity decreased with increasing film grammage, which correlates with the exponential decrease in WVTR. However, the WVTR plateaued at 30 g/m2day, indicating that the known open space and adsorption diffusion mechanisms cannot be fully eliminated by producing high grammage films. Pure cellulose nanofibril films therefore cannot replace polyolefins in packaging applications, requiring modifications such as coating and nanofillers.

Fibre post removal using ultrasonic tips: A comparative in vitro study using different protocols.

This study evaluated the glass fibre post (GFP) removal using three different protocols with ultrasonic tips. Thirty-six extracted single-rooted teeth were endodontically treated and cemented with a 10-mm GFP. Three protocols were used for GFP removal: 20 s activated with cooling, 20 s activated without cooling and 40 s activated without cooling. The removal time and temperature increase on the external root surface were recorded. The amount of residual material and the volume of dentin loss were assessed using micro-computed tomography. Data were analysed using ANOVA with a 5% significance level. The removal time and the amount of residual material were not affected by the protocol. There was no difference in temperature increase between the 20-s groups. The 40s activated without cooling produced the highest temperatures, especially in the apical region, and greater dentin loss. It is not advisable to use the ultrasonic insert continuously for more than 20 s.

Evaluation of hard tissue characteristics and calcifications in pulp tissue of hypomineralized permanent molars using micro-computed tomography.

OBJECTIVES: To determine and compare pulp volume, dentin mineral density, presence of microcracks, pulp stones, and accessory canals, as well as their localizations in root regions for hypomineralized and healthy teeth. DESIGN: This study included 60 extracted permanent molar teeth, categorized into hypomineralized and healthy groups (n = 30 each). The hypomineralized group comprised molar teeth with limited white, yellow, or brown opacities, post-eruptive breakdown, or extensive restoration or crown damage. The healthy group included caries-free molar teeth without these characteristics. Using 3D micro-computed tomography images pulp volume, dentin mineral density, and the presence and locations of microcracks, pulp stones, and accessory canals were determined for each group. Statistical analyses were conducted using Independent T-test and Chi-square test, with significance set at p < 0.05. RESULTS: There was no statistically significant difference between the groups regarding pulp volume and microcracks (p ≥ 0.05). The number of accessory canals was significantly greater in the cervical (p = 0.011; p < 0.05) and middle (p = 0.010; p < 0.05) regions of the hypomineralized teeth than healthy teeth. Dentin mineral density was statistically higher in the apical, middle, and cervical root regions (p < 0.001; p < 0.05); however, the number of pulp stones was found to be greater in the cervical regions of healthy teeth compared with those with hypomineralization (p = 0.026; p < 0.05). CONCLUSION: There were lower dentin mineral density measurements, a decreased number of pulp stones in the cervical region, and a greater number of accessory canals in the middle and cervical regions of hypomineralized teeth compared with healthy teeth.

Middle mesial canal incidence and morphology in mandibular first molars: A cone-beam computed tomography and micro-computed tomography evaluation.

Background: Mandibular first molar (MFM) being the first permanent posterior tooth to erupt, quite often gets involved in dental caries, which subsequently requires endodontic treatment in many cases. Thus, it is essential that the clinicians be aware of the root canal and the morphology of these teeth in detail. Over a period of years, the cases reporting with middle mesial canals (MMCs) in the MFMs have been seen on the rise; thus, it is imperative to know its incidence so that the data can be passed on to the clinicians for better management. Aim: The aim of the current research was to evaluate the incidence of MMC in the MFMs using cone-beam computed tomography (CBCT) and further evaluating its morphology with micro-computed tomography (micro-CT). Materials and Methods: Five hundred and fifty extracted permanent MFMs were collected and subjected to CBCT scan. The teeth in which MMC was found, were further subjected to micro-CT to evaluate the detailed morphology. Observations and Results: The data exhibited the presence of MMC in 29 teeth out of 550 (5.27%). The most frequent morphological pattern observed in the MMC as per micro-CT was the confluent type (86.2%), followed by independent type (6.8%) and fin type (3.4%). Double MMC was observed in 1 tooth (3.4%). Conclusion: The incidence of MMC was observed to be 5.27% and the confluent type of morphological configuration was the most common type noticed.

The Correlation between the Elastic Modulus of the Achilles Tendon Enthesis and Bone Microstructure in the Calcaneal Crescent.

BACKGROUND: The calcaneal enthesis, an osseous footprint where the Achilles tendon seamlessly integrates with the bone, represents a complex interface crucial for effective force transmission. Bone adapts to mechanical stress and remodels based on the applied internal and external forces. This study explores the relationship between the elasticity of the Achilles tendon enthesis and the bone microstructure in the calcaneal crescent. METHODS: In total, 19 calcaneal-enthesis sections, harvested from 10 fresh-frozen human cadaveric foot-ankle specimens (73.8 ± 6.0 years old, seven female), were used in this study. Indentation tests were performed at the enthesis region, and Hayes' elastic modulus was calculated for each specimen. Micro-CT scanning was performed at 50-micron voxel size to assess trabecular bone microstructure within six regions of interest (ROIs) and the cortical bone thickness along the calcaneal crescent. RESULTS: Significant Spearman correlations were observed between the enthesis elastic modulus and trabecular bone thickness in the distal entheseal (ROI 3) and proximal plantar (ROI 4) regions (R = 0.786 and 0.518, respectively). CONCLUSION: This study highlights the potential impacts of Achilles tendon enthesis on calcaneal bone microstructure, which was pronounced in the distal calcaneal enthesis, suggesting regional differences in load transfer mechanism that require further investigation.

Freshwater Habitats Promote Rapid Rates of Phenotypic Evolution in Sculpin Fishes (Perciformes: Cottoidea).

AbstractInvasions of freshwater habitats by marine fishes provide exceptional cases of habitat-driven biological diversification. Freshwater habitats make up less than 1% of aquatic habitats but contain ∼50% of fish species. However, while the dominant group of freshwater fishes (Otophysi) is older than that of most marine fishes (Percomorphaceae), it is less morphologically diverse. Classically, scientists have invoked differences in the tempo and/or mode of evolution to explain such cases of unequal morphological diversification. We tested for evidence of these phenomena in the superfamily Cottoidea (sculpins), which contains substantial radiations of marine and freshwater fishes. We find that the morphology of freshwater sculpins evolves faster but under higher constraint than that of marine sculpins, causing widespread convergence in freshwater sculpins and more morphological disparity in marine sculpins. The endemic freshwater sculpins of Lake Baikal, Siberia, are exceptions that demonstrate elevated novelty akin to that of marine sculpins. Several tantalizing factors may explain these findings, such as differences in habitat stability and/or habitat connectivity between marine and freshwater systems.

Mouse Cardiovascular Imaging.

The mouse is the mammalian model of choice for investigating cardiovascular biology, given our ability to manipulate it by genetic, pharmacologic, mechanical, and environmental means. Imaging is an important approach to phenotyping both function and structure of cardiac and vascular components. This review details commonly used imaging approaches, with a focus on echocardiography and magnetic resonance imaging, with brief overviews of other imaging modalities. In this update, we also emphasize the importance of rigor and reproducibility in imaging approaches, experimental design, and documentation. Finally, we briefly outline emerging imaging approaches but caution that reliability and validity data may be lacking. © 2024 Wiley Periodicals LLC.

Biomedical Composites of Polycaprolactone/Hydroxyapatite for Bioplotting: Comprehensive Interpretation of the Reinforcement Course.

Robust materials in medical applications are sought after and researched, especially for 3D printing in bone tissue engineering. Poly[ε-caprolactone] (PCL) is a commonly used polymer for scaffolding and other medical uses. Its strength is a drawback compared to other polymers. Herein, PCL was mixed with hydroxyapatite (HAp). Composites were developed at various concentrations (0.0-8.0 wt. %, 2.0 step), aiming to enhance the strength of PCL with a biocompatible additive in bioplotting. Initially, pellets were derived from the shredding of filaments extruded after mixing PCL and HAp at predetermined quantities for each composite. Specimens were then manufactured by bioplotting 3D printing. The samples were tested for their thermal and rheological properties and were also mechanically, morphologically, and chemically examined. The mechanical properties included tensile and flexural investigations, while morphological and chemical examinations were carried out employing scanning electron microscopy and energy dispersive spectroscopy, respectively. The structure of the manufactured specimens was analyzed using micro-computed tomography with regard to both their dimensional deviations and voids. PCL/HAp 6.0 wt. % was the composite that showed the most enhanced mechanical (14.6% strength improvement) and structural properties, proving the efficiency of HAp as a reinforcement filler in medical applications.

Micro computed tomography analysis of barley during the first 24 hours of germination.

BACKGROUND: Grains make up a large proportion of both human and animal diets. With threats to food production, such as climate change, growing sustainable and successful crops is essential to food security in the future. Germination is one of the most important stages in a plant's lifecycle and is key to the success of the resulting plant as the grain undergoes morphological changes and the development of specific organs. Micro-computed tomography is a non-destructive imaging technique based on the differing x-ray attenuations of materials which we have applied for the accurate analysis of grain morphology during the germination phase. RESULTS: Micro Computed Tomography conditions and parameters were tested to establish an optimal protocol for the 3-dimensional analysis of barley grains. When comparing optimal scanning conditions, it was established that no filter, 0.4 degrees rotation step, 5 average frames, and 2016 × 1344 camera binning is optimal for imaging germinating grains. It was determined that the optimal protocol for scanning during the germination timeline was to scan individual grains at 0 h after imbibition (HAI) and then the same grain again at set time points (1, 3, 6, 24 HAI) to avoid any negative effects from X-ray radiation or disruption to growing conditions. CONCLUSION: Here we sought to develop a method for the accurate analysis of grain morphology without the negative effects of possible radiation exposure. Several factors have been considered, such as the scanning conditions, reconstruction, and possible effects of X-ray radiation on the growth rate of the grains. The parameters chosen in this study give effective and reliable results for the 3-dimensional analysis of macro structures within barley grains while causing minimal disruption to grain development.

Advancements in Subchondral Bone Biomechanics: Insights from Computed Tomography and Micro-Computed Tomography Imaging in Equine Models.

PURPOSE OF REVIEW: This review synthesizes recent advancements in understanding subchondral bone (SCB) biomechanics using computed tomography (CT) and micro-computed tomography (micro-CT) imaging in large animal models, particularly horses. RECENT FINDINGS: Recent studies highlight the complexity of SCB biomechanics, revealing variability in density, microstructure, and biomechanical properties across the depth of SCB from the joint surface, as well as at different joint locations. Early SCB abnormalities have been identified as predictive markers for both osteoarthritis (OA) and stress fractures. The development of standing CT systems has improved the practicality and accuracy of live animal imaging, aiding early diagnosis of SCB pathologies. While imaging advancements have enhanced our understanding of SCB, further research is required to elucidate the underlying mechanisms of joint disease and articular surface failure. Combining imaging with mechanical testing, computational modelling, and artificial intelligence (AI) promises earlier detection and better management of joint disease. Future research should refine these modalities and integrate them into clinical practice to enhance joint health outcomes in veterinary and human medicine.

Unveiling the correlation between in vivo endodontic reciprocate instrumentation and crack formation.

INTRODUCTION: Dentinal microcracks have been supposedly associated with unrestorable vertical root fractures and consequently long-term treatment failure. This study aimed to investigate whether in vivo root canal instrumentation in mandibular incisors with vital pulps causes dentinal microcracks using two different irrigating solutions. METHODS: Five patients with four vital mandibular incisors indicated for extraction were included. In vivo root canal preparation was performed using Reciproc R40 (tip #40 and taper 0.06). From these, two teeth were randomly assigned for root canal instrumentation irrigated with 5.25 % sodium hypochlorite irrigation (n = 10) or 2 % chlorhexidine gel with saline solution irrigation (n = 10). In sequence, all teeth were carefully extracted, stored in saline solution until microtomography (µCT) scan. Images were reconstructed and assessed for the presence or absence of dentinal microcracks where microcracks originating from the root canal lumen would be considered. All reconstructed samples were analysed dynamically and rendered in videos through the entire extension of the teeth, evaluating the axial cuts considering each third separately from the apex to the enamel-dentinal junction. Teeth were analysed using the DataViewer software at 100 % magnification without filters by three examiners blinded to the condition allocation. RESULTS: No complete dentinal microcracks were observed after root canal instrumentation of mandibular incisors with vital pulps using Reciproc R40 regardless the irrigating solutions, 5.25 % sodium hypochlorite or 2 % chlorhexidine gel. CONCLUSIONS: In vivo root canal instrumentation of mandibular incisors with vital pulps and bone/periodontal insertion does not cause dentinal microcracks and the irrigating solutions tested did not influence this occurrence. Microcrack evaluation must be performed in vivo conditions of dental tissue moist and periodontal support to avoid dryness dentinal alterations after extraction provoking false positive results. CLINICAL RELEVANCE: Reciprocating instrumentation performed in vivo is safe and do not induce dentinal microcracks in mandibular incisors.

Micro-computed tomography evaluation of minimally invasive root canal preparation in 3D-printed C-shaped canal.

This study aimed to evaluate and compare the shaping abilities and minimum dentin thickness of minimally invasive rotary instruments via micro-computed tomography. Twelve 3D-printed C-shaped canal models from a mandibular molar were divided into two groups, and root canals were prepared with either XP-endo Rise (XR) or TruNatomy (TN) systems. Pre- and post-preparation evaluations included canal volume, prepared area and minimum dentin thickness. No significant differences were found in canal volume change (XR: 22.66 ± 4.28%, TN: 23.02 ± 5.10%), prepared canal area (XR: 31.86 ± 10.72%, TN: 30.26 ± 11.59%) and minimum dentin thickness (XR: 0.30 ± 0.05 mm, TN: 0.28 ± 0.05 mm) between groups (p > 0.05). The canal volume change in the middle third was significantly higher than that in the coronal and apical thirds (p < 0.05) in both groups. In conclusion, XR demonstrated comparable shaping abilities and minimum dentin thickness to TN in preparing 3D-printed C-shaped canals.

Three-dimensional virtual histology of the rat uterus musculature using micro-computed tomography.

Contractions of the uterus play an important role in menstruation and fertility, and contractile dysfunction can lead to chronic diseases such as endometriosis. However, the structure and function of the uterus are difficult to interrogate in humans, and thus animal studies are often employed to understand its function. In rats, anatomical studies of the uterus have typically been based on histological assessment, have been limited to small segments of the uterine structure, and have been time-consuming to reconstruct at the organ scale. This study used micro-computed tomography imaging to visualise the muscle structures in the entire non-pregnant rat uterus and assess its use for 3D virtual histology. An assessment of the rodent uterus is presented to (i) quantify muscle thickness variations along the horns, (ii) identify predominant fibre orientations of the muscles and (iii) demonstrate how the anatomy of the uterus can be mapped to 3D volumetric meshes via virtual histology. Micro-computed tomography measurements were validated against measurements from histological sections. The average thickness of the myometrium was found to be 0.33 ± 0.11 mm and 0.31 ± 0.09 mm in the left and right horns, respectively. The micro-computed tomography and histology thickness calculations were found to correlate strongly at different locations in the uterus: at the cervix, r = 0.87, and along the horn from the cervical end to the ovarian end, respectively, r = 0.77, r = 0.89 and r = 0.54, with p < 0.001 in every location. This study shows that micro-computed tomography can be used to quantify the musculature in the whole non-pregnant uterus and can be used for 3D virtual histology.

Imaging the development of the human craniofacial arterial system - an experimental study.

BACKGROUND: The process of vascular development is essential for shaping complex craniofacial structures. Investigating the interplay between vascular development and orofacial morphogenesis holds critical importance in clinical practice and contributes to advancing our comprehension of (vascular) developmental biology. New insights into specific vascular developmental pathways will have far-reaching implications across various medical disciplines, enhancing clinical understanding, refining surgical techniques, and elucidating the origins of congenital abnormalities. Embryonic development of the craniofacial vasculature remains, however, under-exposed in the current literature. We imaged and created 3-dimensional (D) reconstructed images of the craniofacial arterial system from two early-stage human embryonic samples. OBJECTIVE: The aim of this study was to investigate the vascular development of the craniofacial region in early-stage human embryos, with a focus on understanding the interplay between vascular development and orofacial morphogenesis. MATERIALS AND METHODS: Reconstructions (3-D) were generated from high-resolution diffusible iodine-based contrast-enhanced computed tomography (diceCT) images, enabling visualization of the orofacial arterial system in human embryonic samples of Carnegie stages (CS) 14 and 18 from the Dutch Fetal Biobank, corresponding to weeks 7 and 8.5 of gestation. RESULTS: From two human embryonic samples (ages CS 14 and 18), the vascular development of the orofacial region at two different stages of development was successfully stained with B-Lugol and imaged using a micro-computed tomography (micro-CT) scanner with resolutions of 2.5-µm and 9-µm voxel sizes, respectively. Additionally, educational 3-D reconstructions of the orofacial vascular system were generated using AMIRA 2021.2 software. CONCLUSION: Micro-CT imaging is an effective strategy for high-resolution visualization of vascular development of the orofacial region in human embryonic samples. The generated interactive 3-D educational models facilitate better understanding of the development of orofacial structures.

Morphology and root canal configuration of maxillary lateral incisors: a systematic review and meta-analysis.

The purpose of this study was to explore maxillary lateral incisors (MxLI) intern morphology by analyzing existing literature. We searched five electronical databases (Cochrane, Embase, LILACS, Scopus, MEDLINE via PubMed) using keywords and predefined search terms. Additional studies were identified by cross-referencing and reviewing bibliographies of relevant articles. From 92 initial studies, 27 duplicates were removed, and 65 records screened. After full-text review and hand searching were 19 studies included. The most reported root canal configurations (RCC) of MxLI were Vertucci (Ve) I (1-1-1/1; 78.1-100%), Ve II (2-2-1/1; 0.2-5%), Ve III (1-2-1/1; 0.1-14.6%), Ve IV (2-2-2/2; 0.5%), and Ve V (1-1-2/2; 0.5-4.9%). A meta-analysis of six studies from Europe and Asia indicated sex-differentiated patterns in RCC prevalence: higher occurrences of Ve II (2-2-1/1; OR [95%CI] = 1.19 [0.51, 2.73]), Ve III (1-2-1/1; (OR [95%CI] = 1.72 [0.61, 4.85]), and Ve V (1-1-2/2; (OR [95%CI] = 2.95 [1.02, 8.55]) configurations were noted in males, whereas females predominantly exhibited Ve I (1-1-1/1; [95%CI] = 0.99 [0.97, 1.02]), and Ve IV (2-2-2/2; (OR [95%CI] = 0.11 [0.01, 2.02]). Examination methods varied, with cone beam computed tomography (CBCT) being most commonly (n = 11), followed by staining & clearing (n = 5), and radiographic analysis (n = 1). The predominant RCC in MxLI is type Vertucci I. CBCT is the most common method for assessing the morphology of root canals. However, up to 20% of cases may present with complex and sex-specific patterns, highlighting the need for clinicians to be aware of these differences to prevent complications during endodontic treatments.

Born suckers: the cibarial pump of Philaenus spumarius scales across ontogeny to ensure functional equivalence.

A select group of hemipterans within the suborder Auchenorrhyncha are the only animals that feed exclusively on xylem sap - a nutritionally poor liquid that exists under negative pressure within a plant's xylem vessels. To consume it, xylem-feeding bugs have evolved enlarged cibarial pumps capable of generating enormous negative pressures. A previous study examining the allometry of this feeding model suggested that small xylem feeders pay relatively higher energetic costs while feeding, favouring the evolution of larger-bodied species. However, this interspecific analysis only considered adult xylem-feeding insects and neglected the considerable intraspecific change in size that occurs across the insect's development. Here, we examine the changes in cibarial pump morphology and function that occur during the development of Philaenus spumarius, the common meadow spittlebug. We show that the cibarial pump scales largely as expected from isometry and that the maximum negative pressure is mass independent, indicating that size has no effect on the xylem-feeding capacity of juvenile spittlebugs. We conclude that a first instar nymph with a body mass 2% of the adult can still feed at the >1 MPa tension present in a plant's xylem vessels without a substantial energetic disadvantage.

Evaluation of the effect of self-assembling peptide and fluoride varnish, alone or in combination with laser irradiation, on artificial enamel caries: a SEM/EDS and Micro-CT study.

OBJECTIVE: The aim of this study was to investigate the effect of remineralization agents such as fluoride varnish and P11-4, alone and in combination with Er: YAG laser, on in-vitro hard tissue repair in artificial enamel lesions. MATERIALS AND METHODS: A total of sixty enamel surfaces of 4 × 5 mm in size were created on both the buccal and lingual sides of thirty extracted wisdom teeth. Remineralization agents were applied to the specimens that were grouped as follows: Group 1, control; Group 2, fluoride varnish (FV); Group 3, P11-4; Group 4, laser; Group 5, laser + FV; and Group 6, laser + P11-4. The fluorescence level was determined with DiagnoDent. The enamel mineral density, area and volume, and caries lesion area and volume were determined with micro-computed tomography (µCT), surface features were evaluated using scanning electron microscopy (SEM), and elemental analysis was performed using energy dispersive x-ray spectroscopy (EDS) . RESULTS: For specimens treated only with self-assembling peptide P11-4, the caries lesion area (mm2) values were 38.19 and 21.62, and the caries lesion volume (mm3) values were 6.27 and 2.99, respectively for pre- and post-treatment. In combination usage of self-assembling peptide P11-4 and laser, the caries lesion area (mm2) values were 38.39 and 16.91, and the caries lesion volume (mm3) values were 11.15 and 3.64, respectively for pre- and post-treatment. In the application of the P11-4 alone and in combination with laser, there was a statistically significant decrease in DiagnoDent values, an increase in enamel volume(mm3),enamel area(mm2) and mineral density(g/cm3) values and a decrease in caries lesion volume(mm3) and area(mm2) obtained by µCT, and an increase in %Ca and %F values obtained by SEM/EDS analysis (p < 0.05). It was discovered that the samples treated with P11-4 had a considerably higher rise in the Ca/P ratio than the samples treated with FV (p < 0.05). The calcium content increased significantly more when P11-4 application was combined with laser irradiation (p < 0.05). CONCLUSIONS: The combined use of self-assembling peptide P11-4 and laser accelerated the remineralization process and increased the remineralization capacity. CLINICAL RELEVANCE: FV and P11-4, alone or in combination with laser, can be successfully used as remineralization agents in initial enamel caries.

Mitigating aging and doxorubicin induced bone loss in mature mice via mechanobiology based treatments.

Aging leads to a reduced anabolic response to mechanical stimuli and a loss of bone mass and structural integrity. Chemotherapy agents such as doxorubicin exacerbate the degeneration of aging skeleton and further subject older cancer patients to a higher fracture risk. To alleviate this clinical problem, we proposed and tested a novel mechanobiology-based therapy. Building upon prior findings that i) Yoda1, the Piezo1 agonist, promoted bone growth in young adult mice and suppressed bone resorption markers in aged mice, and ii) moderate tibial loading protected bone from breast cancer-induced osteolysis, we hypothesized that combined Yoda1 and moderate loading would improve the structural integrity of adult and aged skeletons in vivo and protect bones from deterioration after chemotherapy. We first examined the effects of 4-week Yoda1 (dose 5 mg/kg, 5 times/week) and moderate tibial loading (4.5 N peak load, 4 Hz, 300 cycles for 5 days/week), individually and combined, on mature mice (∼50 weeks of age). Combined Yoda1 and loading was found to mitigate age-associated cortical and trabecular bone loss better than individual interventions. As expected, the non-treated controls experienced an average drop of cortical polar moment of inertia (Ct.pMOI) by -4.3 % over four weeks and the bone deterioration occurred in the majority (64 %) of the samples. Relative to no treatment, loading alone, Yoda1 alone, and combined Yoda1 and loading increased Ct.pMOI by +7.3 %, +9.5 %, +12.0 % and increased the % of samples with positive Ct.pMOI changes by +32 %, +26 %, and +43 %, respectively, suggesting an additive protection of aging-related bone loss for the combined therapy. We further tested if the treatment efficacy was preserved in mature mice following two weeks (six injections) of doxorubicin at the dose of 2.5 or 5 mg/kg. As expected, doxorubicin increased osteocyte apoptosis, altered bone remodeling, and impaired bone structure. However, the effects induced by DOX were too severe to be rescued by Yoda1 and loading, alone or combined, although loading and Yoda1 individually, or combined, increased the number of mice showing positive responsiveness by 0 %, +15 %, and +29 % relative to no intervention after doxorubicin exposure. Overall, this study supported the potentials and challenges of the Yoda1-based strategy in mitigating the detrimental skeletal effects caused by aging and doxorubicin.

Experimental glaucoma microstent implantation in two animal models and human donor eyes-an ex vivo micro-computed tomography-based evaluation of applicability.

Background: Minimally invasive glaucoma surgery (MIGS) has become an important treatment approach for primary open angle glaucoma. Restoration of aqueous humour drainage by means of alloplastic implants represents a promising treatment option and is itself subject of methodological development. An adequate positioning in the targeted tissue regions is essential is important for the performance of our in-house developed Rostock glaucoma microstent (RGM). The aim of this study was to evaluate the applicability of two animal models and human donor eyes regarding RGM placement. Methods: Eyes were obtained from rabbits, pigs, and human body donations. After orbital exenterations, RGMs were placed in the anterior chamber draining in the subconjunctival space. X-ray contrast was increased by incubation in aqueous iodine solution for subsequent detailed micro-computed tomography (micro-CT)-based visualization and analysis. Results: In contrast to the human and porcine eyes, the stent extended far to the posterior pole with a more pronounced curvature along the globe in the rabbit eyes due to their smaller size. However, dysfunctional deformations were not depicted. Adequate positioning of the stent's inflow area in the anterior chamber and the outflow area in the Tenon space was achieved in both the animal models and the human eye. Conclusions: Micro-CT has proven to be a valuable tool for postoperative ex vivo evaluation of glaucoma drainage devices in its entire complexity. With regard to morphology, the porcine eye is the ideal animal model to test implantation procedures of the RGM. Nevertheless, rabbit eye morphology facilitates successful implantation results and provides all prerequisites for preclinical animal studies.

Mineral trioxide aggregate obturation quality with two obturation techniques in severe curved root canals - a micro-CT study.

BACKGROUND: The existence of voids within the mineral trioxide aggregate (MTA) composition is one of the factors that can influence the treatment outcome. The primary objective of this study was to quantitatively assess and compare the MTA orthograde obturation quality in severe curved root canals using two different MTA compaction techniques: manual compaction with K-file, or Auger technique using micro-computed tomography (micro-CT) imaging. METHODS: For this study, 26 mandibular first molar teeth with severely curved mesiobuccal root canals were selected. These samples were randomly divided into two groups. All root canals were instrumented using ProTaper Gold rotary files up to the F3 file at the working length. In one group, OrthoMTA was compacted using a stainless steel K-file, while in the other group, the Auger technique was employed for compaction into the root canals. Once the MTA had completely set, the filled root canals were subjected to scanning using a high-resolution micro-CT scanner. The porosity volume was determined as a percentage in relation to the overal volume of the canal, and the collected data were subjected to analysis using SPSS software, with the significance level set at P < 0.05. RESULTS: The two techniques had no significant difference in open, closed, and total mean porosity. In both groups, the mean of open porosity was significantly more than closed porosity. CONCLUSIONS: According to the results of the present study, neither of these two techniques is preferred to the other, and factors such as working time, etc., can be considered to choose the more appropriate clinical technique.