bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumor-secreted LCN2 impairs gastric cancer progression via autocrine inhibition of the 24p3R/JNK/c-Jun/SPARC axis
Authors: Huang Zhixin , Li Ying , Qian Yan , Zhai Ertao , Zhao Zeyu , Zhang Tianhao , Liu Yinan , Ye Linying , Wei Ran , Zhao Risheng , Li Zikang , Liang Zhi , Cai Shirong , Chen Jianhui
Published: October 2024

Gastric cancer (GC) is one of the most lethal malignancies worldwide. Despite extensive efforts to develop novel therapeutic targets, effective drugs for GC remain limited. Recent studies have indicated that Lipocalin (LCN)2 abnormalities significantly impact GC progression; however, its regulatory network remains unclear. Our study investigates the functional role and regulatory mechanism of action of LCN2 in GC progression. We observed a positive correlation between LCN2 expression, lower GC grade, and better prognosis in patients with GC. LCN2 overexpression suppressed GC proliferation and metastasis both in vitro and in vivo. Transcriptome sequencing identified secreted protein acidic and rich in cysteine (SPARC) as a pivotal downstream target of LCN2. Mechanistically, c-Jun acted as a transcription factor inducing SPARC expression, and LCN2 downregulated SPARC by inhibiting the JNK/c-Jun pathway. Moreover, LCN2 bound to its receptor, 24p3R, via autocrine signaling, which directly inhibited JNK phosphorylation and then inhibited the JNK/c-Jun pathway. Finally, analysis of clinical data demonstrated that SPARC expression correlated negatively with lower GC grade and better prognosis, and that LCN2 expression correlated negatively with p-JNK, c-Jun, and SPARC expression in GC. These findings suggest that the LCN2/24p3R/JNK/c-Jun/SPARC axis is crucial in the malignant progression of GC, offering novel prognostic markers and therapeutic targets.
Novel platinum nanoclusters (Pt NCs) induce mitochondrial apoptosis and damaging autophagy for the treatment of osteosarcoma—from the perspective of P53 mutation status in different cell lines
Authors: Wang Jialin , Yue Haodi , Huang Xin , Liu Hongjian , Zhang Mengjun
Published: October 2024

This study aimed to investigate the anticancer efficacy and underlying mechanism of novel platinum nanoclusters (Pt NCs) in osteosarcoma cell lines exhibiting distinct P53 expression profiles, namely MG-63 (P53−) and U2-OS (P53+). The findings revealed that Pt NCs exerted an inhibitory effect on proliferation, migration, and colony formation while promoting apoptosis in both MG-63 (P53−) and U2-OS (P53+) cells. The inhibitory effect on the malignant characteristics of MG-63 (P53−) cells was more obvious, indicating that the potential anticancer effect of Pt NCs was not dependent on P53. Animal experiments have substantiated the in vivo anticancer properties of Pt NCs, while also revealing their lower toxicity on cells and tissues. Pt NCs possess the ability to impede cell proliferation by inducing DNA damage and arresting the cell cycle in the G1 phase and possess the ability to promote BAX/Bcl-2/Caspase-3/mitochondrial apoptosis. Pt NCs may promote mitochondrial apoptosis by promoting damaging autophagy, thereby promoting cellular demise. This study has confirmed the P53-independent anticancer impact of Pt NCs on osteosarcoma in vitro and in vivo. Pt NCs may play a therapeutic role in more sensitive MG-63 (P53−) cells by promoting DNA damage to arrest the cell cycle, stimulating BAX/Bcl-2/Caspase-3/mitochondrial apoptosis, and initiating damaging autophagy.
Ligand-induced conformational changes in the β1-adrenergic receptor revealed by hydrogen-deuterium exchange mass spectrometry
Authors: Toporowska Joanna , Kapoor Parth , Musgaard Maria , Gherbi Karolina , Sengmany Kathy , Qu Feng , Soave Mark , Yen Hsin-Yung , Hansen Kjetil , Jazayeri Ali , Hopper Jonathan T. S. , Politis Argyris
Published: October 2024

G Protein Coupled Receptors (GPCRs) constitute the largest family of signalling proteins responsible for translating extracellular stimuli into intracellular functions. They play crucial roles in numerous physiological processes and are major targets for drug discovery. Dysregulation of GPCRs is implicated in various diseases, making understanding their structural dynamics critical for therapeutic development. Here, we use Hydrogen Deuterium Exchange Mass Spectrometry (HDX-MS) to explore the structural dynamics of the turkey β1-adrenergic receptor (tβ1AR) bound with nine different ligands, including agonists, partial agonists, and antagonists. We find that these ligands induce distinct dynamic patterns across the receptor, which can be grouped by compound modality. Notably, full agonist binding destabilises the intracellular loop 1 (ICL1), while antagonist binding stabilises it, highlighting ICL1’s role in G protein recruitment. Our findings indicate that the conserved L72 residue in ICL1 is crucial for maintaining receptor structural integrity and stabilising the GDP-bound state. Overall, our results provide a platform for determining drug modality and highlight how HDX-MS can be used to dissect receptor ligand interaction properties and GPCR mechanism.
Effect of sub-micron deformations at opposing strain rates on the micromagnetic behaviour of non-oriented electrical steel
Authors: Winter Kieran , Liao Zhirong , Abbá Erik , Robles Linares Jose A. , Axinte Dragos
Published: October 2024

We are entering an era of re-electrification, seeking high-power density electrical machines with minimal resource use. Significant performance gains in electrical machines have been achieved through precise manufacturing processes, including the shaping/cutting of soft magnetic materials. However, most studies have evaluated magnetic performance at a macro level, focusing on components, while the fundamental mechanisms, e.g., how the micromagnetic behaviour is affected by mechanical interference, remain unclear. In this study, we examine the impact of sub-micron deformations at opposing strain rates (10−2 to 101 s−1) on the micromagnetic behaviour of soft magnetic non-oriented electrical steel. Using a diamond probe to indent within a single grain of polycrystalline material at different velocities, we induce quasi-static and dynamic mechanical loading. Our analysis, employing magnetic force microscopy, transmission Kikuchi diffraction, and scanning transmission electron microscopy with a pixelated detector, reveals that magnetic texture disturbances rely on the time-dependent dislocation dynamics of the Fe-BCC material. Additionally, we compress micro-pillars to further investigate these effects under bulk-isolated deformation. These findings highlight the importance of considering even ultra-small loads, such as nano-indentations and micro-pillar compressions, in the manufacturing of next-generation electric machines, as they can affect magnetic texture and performance.
A solution for constraining past marine Polar Amplification
Authors: Morley A. , de la Vega E. , Raitzsch M. , Bijma J. , Ninnemann U. , Foster G. L. , Chalk T. B. , Meilland J. , Cave R. R. , Büscher J. V. , Kucera M.
Published: October 2024

Most climate proxies of sea surface temperatures suffer from severe limitations when applied to cold temperatures that characterize Arctic environments. These limitations prevent us from constraining uncertainties for some of the most sensitive climate tipping points that can trigger rapid and dramatic global climate change such as Arctic/Polar Amplification, the disruption of the Atlantic Meridional Overturning Circulation, sea ice loss, and permafrost melting. Here, we present an approach to reconstructing sea surface temperatures globally using paired Mg/Ca - δ18Oc recorded in tests of the polar to subpolar planktonic foraminifera Neogloboquadrina pachyderma. We show that the fidelity of Mg/Ca-based paleoclimate reconstructions is compromised by variations in seawater carbonate chemistry which can be successfully quantified and isolated from paleotemperature reconstructions using a multiproxy approach. By applying the calibration to the last glacial maximum, we show that marine polar amplification has been underestimated by up to 3.0 ± 1.0 °C in model-based estimates.
Observation of super-Alfvénic slippage of reconnecting magnetic field lines on the Sun
Authors: Lörinčík Juraj , Dudík Jaroslav , Sainz Dalda Alberto , Aulanier Guillaume , Polito Vanessa , De Pontieu Bart
Published: October 2024

Slipping motions of magnetic field lines are a distinct signature of three-dimensional magnetic reconnection, a fundamental process driving solar and stellar flares. While being a key prediction of numerical experiments, the rapid super-Alfvénic field line slippage driven by the ‘slip-running’ reconnection has remained elusive in previous observations. New frontiers into exploring transient flare phenomena were introduced by recently designed high cadence observing programs of the Interface Region Imaging Spectrograph (IRIS). By exploiting high temporal resolution imagery (~2 s) of IRIS, here we reveal slipping motions of flare kernels at speeds reaching thousands of kilometres per second. The fast kernel motions are direct evidence of slip-running reconnection in quasi-separatrix layers, regions where magnetic field strongly changes its connectivity. Our results provide observational proof of theoretical predictions unaddressed for nearly two decades and extend the range of magnetic field configurations where reconnection-related phenomena can occur.
Deep learning based approach for actinidia flower detection and gender assessment
Authors: Pinheiro Isabel , Moreira Germano , Magalhães Sandro , Valente António , Cunha Mário , dos Santos Filipe Neves
Published: October 2024

Pollination is critical for crop development, especially those essential for subsistence. This study addresses the pollination challenges faced by Actinidia, a dioecious plant characterized by female and male flowers on separate plants. Despite the high protein content of pollen, the absence of nectar in kiwifruit flowers poses difficulties in attracting pollinators. Consequently, there is a growing interest in using artificial intelligence and robotic solutions to enable pollination even in unfavourable conditions. These robotic solutions must be able to accurately detect flowers and discern their genders for precise pollination operations. Specifically, upon identifying female Actinidia flowers, the robotic system should approach the stigma to release pollen, while male Actinidia flowers should target the anthers to collect pollen. We identified two primary research gaps: (1) the lack of gender-based flower detection methods and (2) the underutilisation of contemporary deep learning models in this domain. To address these gaps, we evaluated the performance of four pretrained models (YOLOv8, YOLOv5, RT-DETR and DETR) in detecting and determining the gender of Actinidia flowers. We outlined a comprehensive methodology and developed a dataset of manually annotated flowers categorized into two classes based on gender. Our evaluation utilised k-fold cross-validation to rigorously test model performance across diverse subsets of the dataset, addressing the limitations of conventional data splitting methods. DETR provided the most balanced overall performance, achieving precision, recall, F1 score and mAP of 89%, 97%, 93% and 94%, respectively, highlighting its robustness in managing complex detection tasks under varying conditions. These findings underscore the potential of deep learning models for effective gender-specific detection of Actinidia flowers, paving the way for advanced robotic pollination systems.
Enhanced optical and structural traits of irradiated lead borate glasses via Ce3+ and Dy3+ ions with studying Radiation shielding performance
Authors: Sallam O. I. , Rammah Y. S. , Nabil Islam M. , El-Seidy Ahmed M. A.
Published: October 2024

Lead borate glass is the best radiation shielding glass when lead is in high concentration. However, it has low transparency after radiation exposure. Radiation decreases transparency due to chemical and physical changes in the glass matrix, such as creating or healing defects in the glass network. The addition of rare earth elements like cerium and dysprosium oxides to lead borate glasses can improve their transparency and durability as radiation shielding barriers. The newly manufactured glasses’ optical absorption, structural, and radiation shielding properties were measured. The optical characteristics of the generated samples were examined to determine the effect of the cerium/dysprosium ratio on the structural alterations, specifically in the presence of bridging oxygen (BO) and non-bridging oxygen (NBO). Incorporating Ce3+ results in peaks at 195 nm for borate units, 225 nm for Ce3+, and a broadened peak at 393 nm due to overlapping peaks for Ce3+ and Ce4+ in the UV region. By adding Dy, multiple peaks are observed at 825, 902, 1095, 1275, and 1684 nm, corresponding to the transition from 6H15/2 ground state to 6F5/2, 6F7/2, 6F9/2, 6F11/2, and 6H11/2. The samples were also tested before and after exposure to gamma irradiation from a 60Co source at a dose of 75 kGy to assess their stability against radiation. The energy gap value during irradiation shows decreased non-bridging oxygen. The energy gap difference before and after irradiation for the M4 sample shows higher NBO to BO conversion, reducing radiation damage and improving structural stability. Furthermore, X-ray photoelectron spectroscopy was utilized to get insight into the coordination chemistry of the created glass samples. The half-value layer (HVL), radiation protection efficiency (RPE), neutron removal cross-section (FRNCS), mean free path (MFP), mass attenuation coefficients (MAC), and effective atomic numbers (Zef) of the glassy structure were calculated theoretically to assess its radiation shielding qualities. The linear attenuation coefficient order for the prepared samples was M1 > M2 > M3 > M4. The FRNCS values were 0.090, 0.083, 0.081, and 0.079 cm−1 for samples M1, M2, M3, and M4, respectively.
A multi-function glass shield for neutrons and gamma rays of boron- and bismuth-reinforced silicate glass
Authors: Din Hadeer M. Nasr El , Saeed Aly , Salem Eman , Shazly R. M. El , Wahab Magda Abdel
Published: October 2024

A successful attempt to produce a multi-function glass shield for attenuating neutrons and gamma rays by reinforcing a silicate glass network with boron and bismuth has been accomplished. A composition of 20SiO2-80Na2O (BSiBi0) was proposed to be used as a host glass network and prepared using the melt/annealing techniques. The low concentration of SiO2 in BSiBi0 was not sufficient to form a stable glass network. Then, the proposed BSiBi0 was modified with 10, 20, 30, and 40 mol% of each of B2O3 and Bi2O3 (BSiBi1, BSiBi2, BSiBi3, and BSiBi4) simultaneously. The structural effects of adding B3+ and Bi3+ were studied through X-ray diffraction, density, and FTIR, which all showed enhancement of glass forming ability, a former role of Bi3+ ions, and crowded the glass network by BO4 units. The derived structural parameters $$-$$
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molar volume, mean silicon – silicon separation, mean boron – boron separation, oxygen packing density, packing density, and number of bridging/non-bridging oxygen $$-$$
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were extensively discussed to explore the impact of B3+ and Bi3+ on the formed network. The richness of the proposed host glass network by B3+ and Bi3+ enhanced its thermal stability. The obtained elastic properties by ultrasonic measurements reflect the increase of the glass rigidity with increasing concentrations of B3+ and Bi3+ ions. The obtained glasses have high visible light transparency and almost complete UV absorption. The measured shielding parameters against two types of neutron energies (total slow and slow) and a wide range of gamma rays’ energies showed a significant improvement in the shielding efficiency of the considered glasses. The total slow neutrons, slow neutrons, and gamma rays’ attenuation abilities were improved by 22.9, 135.5, and 73.8 $$-$$
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199.5%. High thermal stability, elasticity, visible light transparency, and neutrons and gamma rays’ attenuation performance features give the produced glasses, especially BSiBi4 glass, preference as shielding materials in nuclear fields.
Visual imagination can influence visual perception – towards an experimental paradigm to measure imagination
Authors: Mozhdehfarahbakhsh Azadeh , Hecker Lukas , Joos Ellen , Kornmeier Jürgen
Published: October 2024

During visual imagination, a perceptual representation is activated in the absence of sensory input. This is sometimes described as seeing with the mind’s eye. A number of physiological studies indicate that the brain uses more or less the same neural resources for visual perception of sensory information and visual imagination. The intensity of visual imagination is typically assessed with questionnaires, while more objective measures are missing. Aim of the present study was, to test a new experimental paradigm that may allow to objectively quantify imagination. For this, we used priming and adaptation effects during observation of ambiguous figures. Our perception of an ambiguous stimulus is unstable and alternates spontaneously between two possible interpretations. If we first observe an unambiguous stimulus variant (the conditioning stimulus), the subsequently presented ambiguous stimulus can either be perceived in the same way as the test stimulus (priming effect) or in the opposite way (adaptation effect) as a function of the conditioning time. We tested for these conditioning effects (priming and adaptation) using an ambiguous Necker Cube and an ambiguous Letter /Number stimulus as test stimuli and unambiguous variants thereof as conditioning stimuli. In a second experimental condition, we tested whether the previous imagination of an unambiguous conditioning stimulus variant – instead of its observation – can have similar conditioning effects on the subsequent test stimulus. We found no systematic conditioning effect on the group level, neither for the two stimulus types (Necker Cube stimuli and Letter /Number stimuli) nor for the two conditions (Real and Imaginary). However, significant correlations between effects of Real and Imaginary Condition were observed for both stimulus types. The absence of conditioning effects at the group level may be explained by using only one conditioning time, which may fit with individual priming and adaptation constants of some of our participants but not of others. Our strong correlation results indicate that observers with clear conditioning effects have about the same type (priming or adaptation) and intensity of imaginary conditioning effects. As a consequence, not only past perceptual experiences but also past imaginations can influence our current percepts. This is further confirmation that the mechanisms underlying perception and imagination are similar. Our post-hoc qualitative observations from three self-defined aphantasic observers indicate that our paradigm may be a promising objective measure to identify aphantasia.
Involving citizens in monitoring the Kunming–Montreal Global Biodiversity Framework
Authors: Danielsen Finn , Ali Natasha , Andrianandrasana Herizo T. , Baquero Andrea , Basilius Umai , de Araujo Lima Constantino Pedro , Despot-Belmonte Katherine , Frederiksen Per Ole , Isaac Maxim , Jakobsen PâviâraK , Klimmek Helen , Mapendembe Abisha , Meng Han , Schmidt-Vogt Dietrich , Sophat Seak , Sulyandziga Rodion , Virnig Anne L. S. , Zhang Di , Burgess Neil D.
Published: October 2024

The Kunming–Montreal Global Biodiversity Framework (GBF) and its monitoring framework aims to reverse the decline of nature. The GBF tasks governments to report progress towards 23 targets and four goals but also “invites Parties and relevant organizations to support community-based monitoring and information systems and citizen science” to improve information for decision-making and build support for conservation efforts throughout society. We assessed how Indigenous Peoples, local communities and citizen scientists and professional scientists can help monitor the GBF. Of the 365 indicators of the GBF monitoring framework, 110 (30%) can involve Indigenous Peoples, local communities and citizen scientists in community-based monitoring programmes, 185 (51%) could benefit from citizen involvement in data collection and 180 (49%) require scientists and governmental statistical organizations. A smaller proportion of indicators for GBF targets are amenable to citizen monitoring than for the previous Aichi targets or other multilateral environment agreements—largely because 196 GBF indicators are analytically complex (54%) and 175 require legislative overview (48%). Greater involvement of citizens in the GBF would increase societal engagement in international agreements, harness knowledge from those living close to nature to fill data gaps and enhance local to national decision-making based on improved information, leading to better conservation actions.
Observer-independent registration of perspective projection prior to subtraction of in vivo radiographs
Authors: Lehmann T M , Gröndahl K , Gröndahl H G , Schmitt W , Spitzer K
Published: October 2024

OBJECTIVES

To prove that the model of perspective projection allows precise registration of intra-oral radiographs regardless of whether they have been acquired with or without individual adjustment aids and independent of the human observer or computer algorithm marking corresponding landmarks in the images and, based on in vivo radiographs, to introduce and evaluate a model-based registration method.

METHODS

Five observers (three experts and two non-experts) were asked to define corresponding points in 24 pairs of in vivo dental radiographs from the same region of the same patient. The landmarks were used to fit the model of perspective projection applying the least squares method. Misplaced landmarks were detected and suppressed by analysing the quality of all subsets of landmarks with respect to the minimal residual (leaving one out method). In addition, local correlation was used to optimize the quality of registration as well as observer independence.

RESULTS

Using six or more corresponding landmarks in both radiographs the correlation of the images registered was > 0.95 (S.D. < 0.063) irrespective of the observers' expertise.

CONCLUSIONS

Perspective projection is a reliable model for sequentially acquired intra-oral radiographs. The co-ordinates of anatomical landmarks are useful for determining the parameters of perspective projection. Local correlation and leaving one out techniques improve the geometrical adjustment as well as observer independence. Registration is nearly independent of the actual position of the landmarks and hence independent of the observer. Our algorithm will also be useful for registration techniques based on automatically detected landmarks.
Radiological features of hereditary opalescent dentin
Authors: Tanaka T , Murakami T
Published: October 2024

A case of hereditary opalescent dentin is described, which showed the same clinical and radiological features as those reported previously. However, there was no evidence of osteogenesis imperfecta. While a diagnosis of type II dentinogenesis imperfecta was therefore made, this case also had features characteristic of type III dentinogenesis imperfecta. Treatment by means of an overdenture is described.
Radiological features of primary intra-osseous carcinoma of the jaws. Analysis of the literature and report of a new case
Authors: Kaffe I , Ardekian L , Peled M , Machtey E , Laufer D
Published: October 2024

OBJECTIVES

To analyse the clinical and radiological features of primary intra-osseous carcinoma of the jaws (PIOC).

MATERIAL AND METHODS

Twenty-four cases (23 from the literature and one new case) of PIOC were reviewed.

RESULTS

Patient's age at time of diagnosis ranged from 4-76 years, (mean 50 years). Male to female ratio was 1.7:1. Most lesions (79%) were in the mandible and of these, 95% were in the posterior area, approximately 70% of the maxillary lesions were in the anterior region and crossed the midline. In 87% of the cases PIOC was radiolucent; the remainder were mixed radiolucent-radiopaque lesions. The radiological borders were defined but none corticated in 57% of the cases and diffuse in 43%. The lesion was unilocular in 61% and not loculated in 35%.

CONCLUSIONS

The variable radiological features of PIOC and its deceptive resemblance to odontogenic cysts and other tumours of the jaws suggests that despite its rarity, PIOC should be considered in the differential diagnosis of radiolucent lesions in the jaws.
Comparison of two methods for radiometric evaluation of resin-based restorative materials
Authors: Gürdal P , Akdeniz B G
Published: October 2024

OBJECTIVES

To compare radiographic densitometry with indirect digital image analysis for evaluating the radiopacity of nine different resin-based restorative materials.

METHODS

Discs of amalgam and nine different resin-based restorative material, 10 mm in diameter and 2 mm thick, were radiographed together with 2 mm thick discs of intact and carious human teeth and an aluminium stepwedge. Density was evaluated by digital transmission densitometry and with the histogram function of an image analysis programme (Image Tool 1.27, University of Texas Health Sciences Center, Texas, USA) following the digitization of the radiographs with a drum scanner.

RESULTS

The two methods produced essentially similar results. With both methods, Dyract (Dentsply De Trey, Konstanz, Germany) had the highest radiodensity and Estilux Hybrid (Kulzer, Werheim, Germany) the lowest.

CONCLUSION

Digital image analysis is a suitable alternative to transmission densitometry for evaluation of the radiopacity of restorative materials.
Radiological features of osteogenic sarcoma of the jaws. A comparative study of different radiographic modalities
Authors: Givol N , Buchner A , Taicher S , Kaffe I
Published: October 2024

UNLABELLED

OBJECTION: To evaluate the clinical and radiological features of osteogenic sarcoma of the jaws with particular reference to the effectiveness of the radiographic modalities used.

MATERIAL AND METHODS

A total of 66 cases (57 from the English-language literature and nine new cases) were critically evaluated for the features depicted with intra-oral and panoramic radiography and CT.

RESULTS

The mean age of the patients was 36 years (median 31.5 years). There were no differences in gender distribution. A ratio of 1:1.6 between the maxilla and the mandible was found. Lesions had diffuse borders in 78% of cases and defined but not corticated borders in 22%. Twenty-nine per cent were radiolucent, 29% radiopaque and 41% mixed density. Widening of the periodontal ligament space (PDL) was seen in 14 of the 47 (28%) lesions associated with teeth and structural changes in the mandibular canal in 34% of the mandibular lesions. There was a periosteal reaction in 48% and soft tissue involvement in 33% of the lesions.

CONCLUSIONS

Widening of the PDL space was best demonstrated on periapical radiographs. Structural changes in the mandibular canal were shown mainly with panoramic radiographs. Periosteal reaction was best demonstrated by occlusal radiographs and soft tissue involvement by CT. Thorough radiological examination using periapical, occlusal and panoramic radiography, and recognition of the radiological features of osteogenic sarcoma should lead to earlier diagnosis.
Development of a system for craniofacial analysis from monitor-displayed digital images
Authors: Gotfredsen E , Kragskov J , Wenzel A
Published: October 2024

OBJECTIVES

To develop a program for clinical craniofacial analysis directly on monitor-displayed digital images.

METHODS

The program was developed in VisualBasic (Microsoft, Redwood WA, USA), using Access (Microsoft) database, for landmark identification analysis and data storage. It runs on Windows95 (Microsoft).

RESULTS

The following established cephalometric analyses were included in the program: Bjork, Down, Frontal, Jarabak, Occlusogram, Rickett and Tweed. In addition, an orthodontist can simply define his own analyses. If he wants to identify a particular landmark, he clicks on its name at the top of the screen, and the definition including a drawing will be shown. If specified in the analysis selected, reference lines or templates are drawn using the identified landmarks. Soft tissues can be drawn either freehand or using the 'soft tissue detection' that generates an outline from the grey-level histogram. The program has been implemented at the Royal Dental College and at the Department of Maxillofacial Surgery and at the Cleft Palate Centre, Aarhus University Hospital.

CONCLUSION

A program (PorDiosW) has been developed which has facilitated cephalometric analysis from digital lateral and frontal skull radiographs and digital photographs. The program has been successfully applied in patients with cleft lip and palate and other developmental craniofacial anomalies before and after surgery.
Two- and three-dimensional imaging modalities for the detection of caries. A comparison between film, digital radiography and tuned aperture computed tomography (TACT)TM
Authors: Abreu Jr M , Tyndall D A , Platin E , Ludlow J B , Phillips C
Published: October 2024

OBJECTIVES

To compare the diagnostic performance provided by two- (film and digital radiography) and three-dimensional imaging modalities (TACT slices and TACT pseudoholograms) in the detection of primary caries.

METHODS

Forty-two extracted human posterior teeth were mounted and imaged with conventional film and direct digital radiography. Free-hand positioning of a dental X-ray source was used for all exposures. From the digital images, iteratively restored TACT slices and TACT pseudoholograms were generated. Film images were viewed on a viewbox. Digital format images were viewed on a high-resolution monitor. Eight observers used a five-point scale to score the presence or absence of occlusal and proximal caries using the four image modalities. Observers' assessments were compared with the histological examination of tooth sections. Possible differences in ROC curve areas among image modalities, observers, and surfaces were assessed by ANOVA. Intra- and interobserver reliability as indicated by intraclass correlation was also calculated.

RESULTS

There were no statistically significant differences between the diagnostic performances of film, digital radiography, TACT slices and TACT pseudoholograms in the detection of caries (P = 0.310). Intraclass correlation indicated the highest concordance both within and between observers when film was used for the evaluation.

CONCLUSIONS

Under the experimental conditions of this study, three-dimensional TACT images did not improve caries detection over film or digital radiography. Further research should investigate the effects of imaging variables on TACT's diagnostic efficacy.
The effect of periapical rarefying osteitis on cortical and cancellous bone. A study comparing conventional radiographs with computed tomography
Authors: Marmary Y , Koter T , Heling I
Published: October 2024

OBJECTIVE

To determine whether erosion of the cortical plate is necessary for successful radiographic identification of periapical rarefying osteitis.

METHODS

Forty-two periapical osteitic lesions were diagnosed from periapical radiographs of 26 patients who were subsequently examined by cross-sectional computed tomography (CT). The relation of the lesions to the buccal and lingual cortical plates was determined and their size measured.

RESULTS

The 42 lesions varied in size from 2 - 10 mm. Thirty one (74%) lesions diagnosed on the periapical radiographs were limited on CT to the cancellous bone with no erosion of the cortical plates. The 11 lesions with cortical erosion were randomly located throughout the jaws. Erosion was due to either the eccentric buccal or lingual location of the tooth apex, large size (>6 mm) of the lesion or narrowness of the jaw.

CONCLUSIONS

Periapical lesions can be diagnosed from periapical radiographs while they are limited to the cancellous bone and before they have eroded the cortices.
Dose response of a storage phosphor system for intraoral radiography
Authors: Stamatakis H C , Welander U , McDavid W D
Published: October 2024

OBJECTIVES

To determine the dose response function for the Digora(R) (Soredex Orion Corporation, Helsinki, Finland) storage phosphor system for intra-oral radiography.

METHODS

Specially designed software provided by the manufacturer was used to register data from the pre-scanning that takes place prior to readout. These data contain information about the signal from the photomultiplier and the amplification that forms the basis for the AD conversion to 8 bit image data. Dose response functions were determined for different calibration settings and also combined into one single function.

RESULTS

The dose response function is linear irrespective of calibration. The gray levels of the final radiographs are directly proportional to the amplified signal. The Digora(R) does not fully compensate for exposure differences. Increased exposure results in slightly darker radiographs.

CONCLUSIONS

Since the gray levels of the final radiographs are directly proportional to the amplified signal, the gray levels may be used as a relative measure of the exposure in the Digora(R) system provided that they are subtracted from the maximum value of 255.
Physical evaluation of a system for direct digital intra-oral radiography based on a charge-coupled device
Authors: Yoshiura K , Stamatakis H C , Welander U , McDavid W D , Shi X Q , Ban S , Kawazu T , Tatsumi M , Kanda S
Published: October 2024

OBJECTIVES

To determine technical properties of a direct digital intra-oral radiographic system, the Dixel(R) (J Morita Corporation, Kyoto, Japan).

METHODS

A dose response function and the dark current were calculated from two series of exposures to a homogeneous radiation field. The line spread function (LSF) and the modulation transfer function (MTF) were determined from radiographs of an edge. The noise power spectrum (NPS) was determined at three exposures from radiographs exposed to homogeneous radiation fields. Noise equivalent quanta (NEQ) were calculated from the one-dimensional NPS and the MTF. The detective quantum efficiency (DQE) was determined from the NEQ and a representative value of the photon fluence. Signal-to-noise ratios (SNR) were calculated from the NEQs and different signal contrasts.

RESULTS

The dose response function demonstrated a slight curvature. There was no effect of the dark current. NPS ranged from 10-5 - 10-7 mm2 depending on exposure and frequency. At a peak of about 2 cycles/mm the DQE is on an average about 30 per cent. SNRs are favorable.

CONCLUSION

The technical properties found in this study indicate that the Dixel(R) system is suitable for intra-oral dental radiography.
Imaging of fibrosis of the oral mucosa by 20 MHz sonography
Authors: Jackowski J , Jöhren P , Müller A M , Kruse A , Dirschka T
Published: October 2024

OBJECTIVES

To compare the ultrasonographic (US) appearances of the oral mucosa in health with patients with systemic sclerosis (SSc).

METHODS

An innovative 20 MHz US scanner was used to examine the lips, cheeks and oral vestibule of ten healthy persons and ten patients with SSc. The clinical, US and histopathological features of one patient with a fibro-epithelial polyp of the buccal mucosa are reported in detail.

RESULTS

Two patients with SSc displayed increased echogenicity due to fibrotic deposits. A similar echo pattern was seen in the case of the histopathologically verified fibro-epithelial polyp of the buccal mucosa.

CONCLUSION

20 MHz sonography may be suitable as a non-invasive tool for evaluation of fibrosis of the oral mucosa.
Decreased disk-eminence ratio is associated with advanced stages of temporomandibular joint internal derangement
Authors: Toyama M , Kurita K , Westesson P L , Sakuma S , Ariji E , Rivera R
Published: October 2024

OBJECTIVE

To examine the possible correlation between the stage of internal derangement and the antero-posterior length of the disk in relation to the length of the articular eminence.

STUDY DESIGN

Twenty asymptomatic volunteers with normal joints and 120 patients with TMJ dysfunction underwent MR imaging. The A-P length of the disk in relation to the length of the articular eminence (D/E ratio) was measured.

RESULTS

The D/E ratio was 0.95 in the asymptomatic volunteers, 0.83 in patients with disk displacement with reduction, 0.74 in those with disk displacement without reduction and 0.57 in the patients with disk displacement and osteoarthritis. The relationship between the D/E ratio and the stage of internal derangement was statistically significant (P<0.01).

CONCLUSION

The D/E ratio decreases with advancing internal derangement. We suggest that it is a reliable numerical method for staging the degree of the internal derangement.
Triple images on panoramic radiographs.
Authors: Reuter I , Ritter W , Kaeppler G
Published: October 2024

OBJECTIVE

To explain the formation of triple images on panoramic radiographs.

METHODS

A metal test object was placed in defined positions in relation to movement path of a panoramic X-ray beam.

RESULTS

The test object was portrayed once, twice or three times with varying degrees of distortion depending on its location. Triple images were formed when the test object was located in a specific diamond-shaped area distal to the path of the rotation centre of the X-ray beam.

CONCLUSIONS

The formation of triple images on panoramic radiographs can be explained on the basis of known projection geometry.
Idiopathic osteosclerosis in the jaws of Britons and of the Hong Kong Chinese: radiology and systematic review
Authors: MacDonald-Jankowski D S
Published: October 2024

AIM

To compare the prevalence of idiopathic osteosclerosis in the jaws in Hong Kong and Britain.

METHODS

The panoramic radiographs of consecutive patients who attended the primary care departments of the dental hospitals in Hong Kong in 1981 and 1990 and London in 1990 and of Edinburgh in 1993 were reviewed. The size of the Hong Kong lesions was measured. The literature was subjected to systematic review.

RESULTS

The prevalence of idiopathic osteosclerosis in Hong Kong in 1981 and 1990, London and Edinburgh was 6.7, 5.5, 2.7 and 4.1% respectively. The prevalence of idiopathic osteosclerosis was greater in the Oriental (Chinese and Japanese) than in Western surveys. The lesions in the 1990 Hong Kong survey in the third decade were significantly smaller than those in the 1981 survey. The decrease in size in Hong Kong 1990 was also accompanied by a reduction in overall prevalence. The predilection for the mandible, especially in the premolar area, was observed in the Chinese and London series; this feature was also common to all other reports.

CONCLUSION

The Chinese have a greater prevalence of idiopathic osteosclerosis than Western populations.
Interaction between noise and file compression and its effect on the recognition of caries in digital imaging
Authors: Janhom A , van der Stelt P F , van Ginkel F C
Published: October 2024

OBJECTIVES

To determine the interaction between image noise and file compression, with special emphasis on the accuracy of caries diagnosis.

METHODS

Fifty-nine bitewing radiographs of patients were taken simultaneously with Ektaspeed Plus (Eastman-Kodak, Rochester, NY, USA) film without lead foil and the Digora storage phosphor system (Soredex, Helsinki, Finland). Three different levels of Gaussian noise were added to the original digital images which were then compressed with JPEG 53. Seven observers evaluated the presence and depth of caries lesions on selected approximal surfaces on a 5-point scale. The results of JPEG 27 compression from a previous study were also included. ROC analysis was used together with multivariate analysis of variance (MANOVA).

RESULTS

JPEG 27 and 53 reduced the file size down to 7% and 4.6% of the original respectively. ROC curve analysis showed no significant difference between image conditions (original, JPEG 27, and JPEG 53) at the same noise level. JPEG 27 and 53 had larger Az scores than their original counterparts at the same noise level. However, MANOVA showed that for depth estimation of enamel lesions JPEG 53 resulted in a higher observer error.

CONCLUSIONS

Both JPEG 53 and 27 could reduce some of the adverse effect of noise from the image by removing high spatial frequencies. JPEG 53, resulting in a compression ratio of 1:21, does not compromise the diagnostic performance in general. JPEG 53 compression may however affect the ability to detect enamel lesions.
An objective comparison of four digital intra-oral radiographic systems: sensitometric properties and resolution
Authors: Araki K , Endo A , Okano T
Published: October 2024

OBJECTIVES

To compare the sensitometric properties and resolution of four digital intra-oral radiographic systems.

METHODS

Three CCD-based systems were evaluated, RVG-4 (Trophy Radiologic, Paris, France) CDR (Schick Technologies Inc, Long Island, NY, USA) and Dixel (Morita, Kyoto, Japan) and a photostimulable phosphor system (Digora, Soredex-Orion, Helsinki, Finland). The sensitometric properties were determined by measuring the gray levels at increasing exposures without making any gray-scale adjustments. MTF was measured using images of a 10 microns width slit inclined to the long and short axes of the detectors.

RESULTS

The CCD-based systems showed a linear relationship between exposure and gray level although there were some differences in sensitivity. In RVG-4, the gray level saturated at a lower exposure. Digora showed a logarithmic relationship at uniform exposure. However, there was a linear relationship when it was exposed below the calibration dose. The MTF was highest with RVG-4 and the lowest with the Digora.

CONCLUSIONS

Each system has its own specific properties; RVG-4 has the highest resolution with the narrowest latitude, whereas Digora has the wider latitude but the lowest resolution.
Digitisation and display of intra-oral films
Authors: Attaelmanan A , Borg E , Gröndahl H G
Published: October 2024

AIM

To determine the optimal parameters for the digitisation and display of intra-oral radiographs.

MATERIALS AND METHODS

Six intra-oral radiographs (EP size 2 dental film, Eastman Kodak Co., Rochester, NY, USA) were digitised using an Arcus II image scanner (Agfa-Gevaert N. V., Mortsel, Belgium). Each film was digitised at 8 bits, with and without a film mask, using three scanner resolutions (200, 400 and 600 p.p.i.), resulting in six versions of each radiograph. Seven experienced observers were asked to evaluate the quality of the resulting images as they were displayed on a Nokia 445Xi monitor (Nokia Display Products, Helsinki, Finland). Monitor settings were varied by changing the colour palette and screen resolution.

RESULTS

Digital images of masked films had a statistically significant (t-test with alpha 2 tail < or = 0.05) higher quality than those scanned without a mask. The best image quality was obtained at a resolution of 400 p.p.i. Display options were optimum with 256 colours and a screen size of 1152 x 864 pixels.

CONCLUSIONS

Better results were obtained when intra-oral radiographs were digitised with a mask at a resolution of 200 or 400 p.p.i. and displayed using 256 colours and the largest screen size possible. Further studies are needed to extend these results to other makes and models of scanner and monitor.
The adherence to guidelines for facial radiography in an Accident & Emergency Department
Authors: Webster K , Malins T J
Published: October 2024

OBJECTIVES

To evaluate the degree of adherence to guidelines for facial radiography.

METHODS

A retrospective review of 1538 facial radiographs from a consecutive series of 414 patients attending the Accident & Emergency Department of the North Staffordshire Hospital with suspected facial injuries over a 6 month period was undertaken. Information on age, sex and aetiology of injury was recorded along with the type of view and total number of films taken. The results were compared with guidelines from the Department of Oral & Maxillofacial Surgery.

RESULTS

Almost one-half of all injuries were due to assault. There was general adherence to the guidelines in terms of the number of films taken for mid-face and mandibular fractures.

CONCLUSIONS

There was a good adherence to the guidelines in terms of the number of films taken for midface and mandibular fractures. However, a small number of patients were still being exposed to a high radiation dose where combinations of skull and facial views were taken. Guidelines need to be subjected to regular audit.
Three-dimensional morphology of the masseter muscle in patients with mandibular prognathism
Authors: Ariji Y , Kawamata A , Yoshida K , Sakuma S , Nawa H , Fujishita M , Ariji E
Published: October 2024

OBJECTIVE

To compare the morphology of the masseter muscle in patients with mandibular prognathism with that of normal subjects.

METHODS

Three-dimensional X-ray computed tomography (CT) was performed on 69 patients with mandibular prognathism and compared with 91 normal subjects. The angle of the muscle direction in relation to the Frankfurt horizontal plane and the area and the ratio of length of the short to long axes (s/l ratio) on the section perpendicular to the muscle direction were measured.

RESULTS

The mean angle, area and s/l ratio in patients with mandibular prognathism was 76.6 degrees (s.d. 4.4 degrees), 318.3 mm2 (s.d. 77.2 mm2) and 0.312 (s.d. 0.049), respectively. Those of the normal subjects were 65.1 degrees (s.d. 4.4 degrees), 368.3 mm2 (s.d. 97.2 mm2) and 0.393 (s.d. 0.054), respectively. The angle was significantly larger, and the area and s/l ratio were significantly smaller than those of normal subjects (P < 0.001).

CONCLUSION

The morphology of the masseter muscle in mandibular prognathism is significantly different from that of normal subjects. Our results may be helpful in evaluating the results of orthognathic surgery.
Tumoral calcinosis of the temporomandibular joint region
Authors: Noffke C , Raubenheimer E , Fischer E
Published: October 2024

A rare case of tumoral calcinosis, discovered in the medial pterygoid muscle and around the temporomandibular joint on a routine panoramic radiograph is presented. CT was found to be ideal for the determination of the exact location of the calcifications. The differential diagnosis of tumoral calcinosis is discussed.
A case of glandular odontogenic cyst associated with ameloblastoma: correlation of diagnostic imaging with histopathological features
Authors: Hisatomi M , Asaumi J , Konouchi H , Yanagi Y , Kishi K
Published: October 2024

The glandular odontogenic cyst (GOC) is a rare odontogenic cyst. There has only been one reported case of the simultaneous presence of GOC and ameloblastoma. The radiographic features of GOC are well established but the MR findings have not been described. We report a case of GOC associated with ameloblastoma with special reference to the correlation of the diagnostic imaging with the histopathological features.