bluuebunny/crossref_metadata_2025 huggingface dataset:
Ghostly Galaxies: Accretion-dominated Stellar Systems in Low-mass Dark Matter Halos
Authors: Wang Chung-Wen , Cooper Andrew P. , Bose Sownak , Frenk Carlos S. , Hellwing Wojciech A.
Published: November 2023

Wide-area deep imaging surveys have discovered large numbers of extremely low surface brightness (LSB) dwarf galaxies, which challenge galaxy formation theory and, potentially, offer new constraints on the nature of dark matter. Here we discuss one as-yet-unexplored formation mechanism that may account for a fraction of LSB dwarfs. We call this the “ghost galaxy” scenario. In this scenario, inefficient radiative cooling prevents star formation in the “main branch” of the merger tree of a low-mass dark matter halo, such that almost all its stellar mass is acquired through mergers with less massive (but nevertheless star-forming) progenitors. Present-day systems formed in this way would be “ghostly” isolated stellar halos with no central galaxy. We use merger trees based on the extended Press–Schechter formalism and the Copernicus Complexio cosmological N-body simulation to demonstrate that mass assembly histories of this kind can occur for low-mass halos in ΛCDM, but they are rare. They are most probable in isolated halos of present-day mass ∼4 × 109
M
⊙, occurring for ∼5% of all halos of that mass under standard assumptions about the timing and effect of cosmic reionization. The stellar masses of star-forming progenitors in these systems are highly uncertain; abundance-matching arguments imply a bimodal present-day mass function having a brighter population (median M
⋆ ∼ 3 × 106
M
⊙) consistent with the tail of the observed luminosity function of ultradiffuse galaxies. This suggests that observable analogs of these systems may await discovery. We find that a stronger ionizing background (globally or locally) produces brighter and more extended ghost galaxies.
Limits on the Density of the Lunar Ionosphere: ARTEMIS Observations
Authors: Shen Han-Wen , Halekas Jasper S. , Poppe Andrew R.
Published: November 2023

The Moon of our Earth has a tenuous atmosphere, known as an exosphere. The ionization of this exosphere is speculated to possibly form a weak ionosphere. Some radio occultation (RO) experiments have suggested the presence of a dense ionosphere with an electron density on the order of hundreds of cm−3 near the surface. Using in situ measurements from the ARTEMIS mission during 2012–2021, we conduct statistical analyses and case studies to investigate the plasma density at near-surface altitudes. ARTEMIS measurements reveal no plasma densities at altitudes between 10 and 50 km that exceed 35 cm−3, and therefore they provide no evidence for a steady-state or global lunar ionosphere at the level suggested by some RO observations. Density profiles with local time and altitude show higher density in the sunlit sector than in the shadowed sector. These observations suggest that the natural variation of solar wind plasma flux with solar zenith angle plays a critical role in controlling the plasma population near the surface. This research provides a reference for a comparison with RO observations and a statistical view of the low-altitude plasma environment near the lunar surface.
JWST's PEARLS: Transients in the MACS J0416.1−2403 Field
Authors: Yan Haojing , Ma Zhiyuan , Sun Bangzheng , Wang Lifan , Kelly Patrick , Diego José M. , Cohen Seth H. , Windhorst Rogier A. , Jansen Rolf A. , Grogin Norman A. , Beacom John F. , Conselice Christopher J. , Driver Simon P. , Frye Brenda , Coe Dan , Marshall Madeline A. , Koekemoer Anton , Willmer Christopher N. A. , Robotham Aaron , D’Silva Jordan C. J. , Summers Jake , Nonino Mario , Pirzkal Nor , Ryan Russell E. , Ortiz Rafael , Tompkins Scott , Bhatawdekar Rachana A. , Cheng Cheng , Zitrin Adi , Willner S. P.
Published: November 2023

With its unprecedented sensitivity and spatial resolution, the James Webb Space Telescope (JWST) has opened a new window for time-domain discoveries in the infrared. Here we report observations in the only field that has received four epochs (spanning 126 days) of JWST NIRCam observations in Cycle 1. This field is toward MACS J0416.1−2403, which is a rich galaxy cluster at redshift z = 0.4 and is one of the Hubble Frontier Fields. We have discovered 14 transients from these data. Twelve of these transients happened in three galaxies (with z = 0.94, 1.01, and 2.091) crossing a lensing caustic of the cluster, and these transients are highly magnified by gravitational lensing. These 12 transients are likely of a similar nature to those previously reported based on the Hubble Space Telescope (HST) data in this field, i.e., individual stars in the highly magnified arcs. However, these 12 could not have been found by HST because they were too red and too faint. The other two transients are associated with background galaxies (z = 2.205 and 0.7093) that are only moderately magnified, and they are likely supernovae. They indicate a demagnified supernova surface density, when monitored at a time cadence of a few months to a ∼3–4 μm survey limit of AB ∼28.5 mag, of ∼0.5 arcmin−2 integrated to z ≈ 2. This survey depth is beyond the capability of HST but can be easily reached by JWST.
The Importance of the Upper Atmosphere to CO/O2 Runaway on Habitable Planets Orbiting Low-mass Stars
Authors: Ranjan Sukrit , Schwieterman Edward W. , Leung Michaela , Harman Chester E. , Hu Renyu
Published: November 2023

Efforts to spectrally characterize the atmospheric compositions of temperate terrestrial exoplanets orbiting M dwarf stars with JWST are now underway. Key molecular targets of such searches include O2 and CO, which are potential indicators of life. Recently, it was proposed that CO2 photolysis generates abundant (≳0.1 bar) abiotic O2 and CO in the atmospheres of habitable M dwarf planets with CO2-rich atmospheres, constituting a strong false positive for O2 as a biosignature and further complicating efforts to use CO as a diagnostic of surface biology. Importantly, this implied that TRAPPIST-1e and TRAPPIST-1f, now under observation with JWST, would abiotically accumulate abundant O2 and CO, if habitable. Here, we use a multi-model approach to reexamine photochemical O2 and CO accumulation on planets orbiting M dwarf stars. We show that photochemical O2 remains a trace gas on habitable CO2-rich M dwarf planets, with earlier predictions of abundant O2 and CO due to an atmospheric model top that was too low to accurately resolve the unusually high CO2 photolysis peak on such worlds. Our work strengthens the case for O2 as a biosignature gas, and affirms the importance of CO as a diagnostic of photochemical O2 production. However, observationally relevant false-positive potential remains, especially for O2's photochemical product O3, and further work is required to confidently understand O2 and O3 as biosignature gases on M dwarf planets.
Hidden Companions to Intermediate-mass Stars. XIV. Discovery of a 1.8 M
⊙, 0.3 au Companion to Ascella = Zeta Sagittarii A*
Authors: Waisberg Idel , Klein Ygal , Katz Boaz
Published: November 2023

Zeta Sagittarii is a nearby intermediate mass 13.2 au visual binary. Here we report on a VLTI/GRAVITY interferometric observation that revealed that ζ Sgr is actually a rather compact triple system: the visual primary Ascella (A) is a close equal mass ρ = 10.9 mas ↔ 0.3 au binary. Through isochrone fitting we find masses M
Aa = 1.83M
⊙, M
Ab = 1.81M
⊙ and M
B = 2.03M
⊙. The hierarchy of the triple is low enough to allow for possibly interesting dynamical effects and its ultimate outcome will be a double or triple white dwarf system. We estimate that about 1 Myr ago ζ Sgr passed within a minimum distance of the Sun of 11 pc, rather than 3 pc as previously reported.
A new small carder bee species from the eastern Canary Islands (Hymenoptera, Megachilidae, Anthidiini)
Authors: Vereecken Nicolas J. , Ruiz Carlos , Marshall Leon , Pérez-Gil Mónica , Molenberg Jean-Marc , Jacobi Bernhard , La Roche Francisco , Litman Jessica R.
Published: November 2023

Recent field surveys in the eastern Canary Islands (Spain), followed by contributions of new occurrence records through the citizen science platform iNaturalist.com and the social media photo repository Flickr.com have revealed the presence of an overlooked small carder bee species (genus Pseudoanthidium Friese (Megachilidae: Anthidiini)) on the islands of Lanzarote and Fuerteventura. Here, we combined morphology, DNA barcodes (mitochondrial cytochrome c oxidase subunit I, COI) and ecological data (distribution, altitudinal ranges and environmental niche classification) to describe this species as Pseudoanthidium (Pseudoanthidium) jacobiisp. nov. We provide an illustrated description along with diagnostic morphological characters to separate it from P. (P.) canariense (Mavromoustakis, 1954), the only other congeneric species known from the neighbouring islands of La Gomera, Tenerife and Gran Canaria and from which it is separated by a genetic distance of 2.7%. We also evaluated the extent of shared environmental niche space among the two Pseudoanthidium species, and our results show a significant difference in elevation range as well as a very small (less than 1%) overlap between the modelled climatic niche of P. jacobii and that of P. canariense. Given the extremely restricted geographic distribution and the fragile and isolated nature of the habitat and host plants of this new island endemic species, we assign it an IUCN conservation status of “EN” (endangered) and discuss avenues for future research on the ecology and conservation of wild bees in the Canary Islands and neighbouring regions.
Quel cadre pour penser la place du psychologue dans les prises en charge à domicile en psychopathologie périnatale ?
Authors: Briand Victoire , M’Bailara Katia
Published: November 2023

Cette étude explore les représentations des psychologues concernant les interventions de psychologue à domicile en psypérinatalité. Les 18 psychologues de psychiatrie périnatale inclus ont répondu à un entretien abordant d’une part les freins et leviers des interventions à domicile, et d’autre part les spécificités de la fonction contenante et de l’alliance thérapeutique à domicile. Les résultats issus de l’analyse de contenu thématique soulignent des représentations relatives à des questionnements éthiques transversaux à la pratique du psychologue – p. ex. cadre, posture, relation-. Cela encourage ainsi à penser la place du psychologue à domicile selon les intérêts, limites et enjeux associés tant déontologiques que thérapeutiques.
Qu’est-ce qu’une politique socialiste du travail ?
Authors: Fontaine Marion , Cazeneuve Nathan
Published: November 2023

Depuis plusieurs décennies, l’ambition d’une organisation démocratique du travail a presque disparu du débat public au profit de politiques de l’emploi, centrées sur la lutte contre le chômage, et portant sur des déterminations extérieures aux relations de travail (niveau des cotisations sociales, formation professionnelle). Face à des inégalités croissantes dans le partage de la valeur ajoutée, aux enjeux soulevés par la transformation écologique et aux phénomènes d’intensification du travail et de recomposition de certains secteurs, une politique socialiste du travail s’avère d’actualité. Elle invite à remettre au centre des luttes politiques le contenu du travail, son organisation démocratique et son importance en matière de santé publique.
Comment mieux rémunérerle travail ?
Authors: Askenazy Philippe , Cazeneuve Nathan
Published: November 2023

La part du travail dans la répartition de la valeur ajoutée diminue nettement depuis plusieurs décennies. L’économiste Philippe Askenazy revient sur les évolutions des mécanismes de formation des salaires et de structuration du marché du travail qui expliquent cette tendance qui se manifeste par une modération salariale. La désindexation des salaires, la fragmentation du marché du travail, et le pouvoir de monopsone des employeurs expliquent la pression à la baisse sur les salaires. Une politique salariée fondée sur la fin des allègements de cotisations sociales, une augmentation substantielle du SMIC et des négociations de branche permettrait d’inverser cette tendance.
La réforme de l’entreprise… impossible ?
Authors: Chatriot Alain
Published: November 2023

La réforme de l’entreprise a été au XX e  siècle au cœur d’un moment modernisateur qui permettait à des sensibilités différentes de se rencontrer sur un projet commun. Mais l’action de ces démocrates-chrétiens, technocrates, gaullistes ou syndicalistes minoritaires s’est heurtée à la fois à des confédérations de syndicats de salariés prises dans d’autres logiques et à un patronat organisé qui ne voulait pas se voir déposséder de son pouvoir. Pour autant, la question de la démocratie sociale reste dans l’entreprise et en France toujours posée.
Auto-entreprenariat : quels défis et quels modes de régulation ?
Authors: Abdelnour Sarah , Fontaine Marion
Published: November 2023

Depuis plusieurs années le statut d’auto-entrepreneur ne cesse de progresser au point d’avoir renversé la tendance d’une réduction du nombre des travailleurs indépendants. La sociologue Sarah Abdelnour revient sur les conséquences sociales de cette transformation, les dynamiques d’organisation qui s’y manifestent et l’ambivalence des aspirations à l’autonomie que recouvre l’auto-entreprenariat. Elle invite à une réflexion renouvelée, à partir des limites de l’auto-entreprenariat, sur la socialisation des salaires, la répartition de la valeur et la possession des moyens de production.
Télétravail, flexibilisation et inégalités
Authors: Le Gagneur Marianne
Published: November 2023

La progression de la pratique du télétravail est porteuse d’une dynamique ambivalente. Si elle concerne surtout les salariés qualifiés, elle permet également une réduction de certaines contraintes et notamment du temps de transport. Pour autant, celle-ci a accentué les inégalités de genre et a produit des effets d’intensification du travail ou de dégradation des conditions de travail par la pratique du flexoffice. Le télétravail présente ainsi le risque d’un travail intensifié qui pose la question tant de l’organisation du travail que de la frontière entre le travail et la vie domestique et familiale.
Les âges de Dante
Authors: Pinchard Bruno
Published: November 2023

Célébrer les anniversaires successifs de Dante peut apparaître comme un exercice académique dépourvu d’intérêt philosophique. Mais cette inscription de l’œuvre dans une succession de retours permet de rappeler la fonction de la circularité dans une construction mentale qui progresse depuis la conscience explicite de son incapacité à se constituer en cercle ( Vita nuova  XII, 4), jusqu’à la célébration ultime de l’amour comme cercle accompli ( Par.  XXXIII,143). En suivant cette voie d’inspiration géométrique et symbolique, il devient possible de se placer dans les pas de ceux qui ont célébré Dante en ses anniversaires, d’abord Victor Hugo et Saint-John Perse, pour tenter de prolonger leur effort de synthèse en un dialogue avec l’« éternel retour » selon Nietzsche et « La métamorphose des dieux » selon André Malraux.
La voix de l’abîme. L’herméneutique du mal dans Inf . III, 25-27
Authors: d’Onofrio Giulio
Published: November 2023

Dans les premiers chants de l’ Enfer , Dante déclare entre les lignes la tâche à laquelle il se sent appelé en tant que « poète chrétien » : d’un côté, il est invité à argumenter avec la rigueur du discours scientifique les vérités fondamentales de la religion ; de l’autre côté, il lui est confié la charge d’entraîner le lecteur dans une lecture anagogique de ces vérités en recourant aux fascinations allégoriques de la poésie. En accomplissant cette mission, Dante obtiendra, pour lui-même et pour les autres êtres humains, cette perfection anthropologique naturelle qui culmine, après la mort terrestre, par le retour aux conditions métaphysiques qui se seraient actualisées en la personne d’Adam s’il n’avait pas péché. Cette conception est déjà opérante dans certaines pages de la Vie nouvelle et du Banquet , mais c’est surtout dans La Divine Comédie que Dante en revient spontanément à ce genre de techniques sur un mode original et particulièrement efficace. On en a un exemple éclairant quand, au Chant III de l’ Enfer , la poésie décrit le tourbillon, apparemment disharmonieux et dépourvu de sens, des sons qui émergent de la cavité infernale, en se basant non seulement sur l’application évidente d’au moins deux artifices rhétoriques déterminés, mais surtout sur l’évocation formellement rigoureuse des règles de la dialectique (selon la terminologie en usage dans les écoles) : le succès de cette opération dépend de la capacité, de la part du lecteur, de retrouver la signification authentique de la terminologie scientifique mise en œuvre en poésie, utilisée pour illustrer les vérités de la foi et la nouvelle beauté de la synthèse entre art poétique et disciplines du Trivium .
Ternarité et Trinité
Authors: Pinchard Bruno
Published: November 2023

Par son lien insistant avec les formes de la ternarité, Béatrice est moins définie par une théologie trinitaire que par une théosophie du chiffre 9. Certes, Dante insiste sur la relation arithmétique entre le 3 et le 9, mais il souligne d’abord la destination de son aimée à la neuvième place dans l’ordre cosmique comme dans la poésie. Loin de réduire cet échange à un pur maniérisme, on peut se demander si c’est le 9 qui est dans le 3, ou le 3 dans le 9. Il en découle un système de relations entre le dogme trinitaire et la poétique du novénaire qui semble difficile à définir sans un détour par Virgile comme par différentes formes de spéculations apocalyptiques, où Joachim de Fiore est appelé à jouer un rôle essentiel.
Outrepasser l’humain. L’expression de l’ineffable dans le Paradis
Authors: Poirier Jean-Louis
Published: November 2023

Au Chant Premier du Paradis , Dante fait de la poésie un art de la subversion sinon de la transgression, en lui assignant la tâche de travailler la parole pour en contourner les limites : Outrepasser l’humain , c’est aller au-delà des limites du langage, prétendre aux formes angéliques de la communication. Les anges font une expérience heureuse de l’indicible et se comprennent en silence. C’est dans cet intervalle que la poésie doit se frayer son chemin et faire accéder l’impensable à l’expression, dire l’indicible. Elle doit signifier par des mots («  significar per verba  ») ce qui excède toute signification humaine. Nous retrouvons ici la théologie négative et son inventeur Denys l’Aréopagite : quand la théologie, confrontée à l’ineffable, aboutit au silence et à l’apophatisme, la poésie répond à l’appel pour assurer le passage de l’invisible à la figuration. Figuration également négative, qui fait exploser des images « bigarrées », faites de mots pour ainsi dire illisibles. En quoi la poésie a vocation à devenir non figurative.
Les mondes possibles de Malebranche et Leibniz
Authors: Pijaudier-Cabot Louis
Published: November 2023

Malebranche et Leibniz affirment que Dieu a créé le meilleur des mondes possibles. Mais ces mondes possibles remplissent des fonctions argumentatives sensiblement différentes dans leurs théodicées respectives. S’ils s’accordent tous deux pour définir l’ordre d’un monde par la généralité de volontés divines, ils ont toutefois des conceptions distinctes de son unité. Les mondes malebranchiens peuvent exister dans le même espace alors que la maximalité des mondes leibniziens empêche une telle possibilité. Ces deux modes de composition des mondes règlent différemment le choix divin. Ainsi, les mondes malebranchiens visent uniquement à prouver la perfection de ce choix, tandis que les mondes leibniziens permettent également d’en démontrer la liberté et la contingence.
Medication Adherence in Schizophrenia: Role of Opinion Makers
Authors: Kaur Ramandeep , Sidana Ajeet , Malhotra Nidhi , Tyagi Shikha
Published: November 2023

Background:

Nonadherence to treatment is a recognized problem and the most challenging aspect of treatment, particularly in first-episode schizophrenia (FES). We aimed to identify a set of individuals in the social milieu of patients as opinion makers who play significant role in influencing treatment-seeking behavior in patients with FES.

Materials and Methods:

Patients with a diagnosis of schizophrenia (Diagnostic and Statistical Manual of Mental Disorders, fifth edition), first episode, were administered with a 20 items semi-structured questionnaire to identify the individuals and their role in treatment-seeking behavior of patients with FES.

Results:

A total of 72 patients were enrolled in the study. The mean age of the sample was 29 years (standard deviation [SD] ±7.35), and the mean duration of illness was 9.2 (SD ± 0.58) months. Our study shows that apart from treating psychiatrists, patient's family members and relatives play a crucial role in influencing treatment-seeking behavior such as treatment commencement, drug dose, formulation, place of treatment, etc., A large number of patients went to faith healers on the advice of family members (34.7%) and also followed the advice of family members regarding the duration of treatment (63.3%) as well as discontinuing treatment (63.3%).

Conclusion:

The index study concludes the role of family members/relatives as opinion makers in the social milieu of patients with FES in influencing treatment-related decisions and affecting adherence to treatment.
Gender Differential in the Choice of Methods of Dying by Suicide in Southwest Nigeria
Authors: Adeyemo Sunday Oladotun , Olayinka-Aliu Damilola , Akindele-Oscar Abayomi , Aborishade Richard , Oyafunke-Omoniyi Comfort , Adeleke Oladele , Bawalla Oluwatoyin , Adenuga Ademolu
Published: November 2023

Background:

The choice of method of dying by suicide can determine the lethality of a suicide attempt, especially among males and females. However, a less attention has been paid to this area of research among Nigerian authors.

Objective:

The objectives of this study were to investigate the distribution of completed suicide across methods of suicide among decedents and to examine the odds ratio of males using hanging or poisoning methods.

Materials and Methods:

This retrospective chart-based study was conducted among those who died by suicide and whose cases were reported at the police stations. The data were collected by checking the files at the homicide and suicide departments at the police headquarters in southwest Nigeria. Ethical approval was obtained for the study. Descriptive statistics and logistic regressions were used to analyze the data.

Results:

The results revealed that 78.3% were male, while females were 21.7%. 53.7% of the sampled population died by hanging and 23.2% died by poisoning. 8.9% of the decedents died by self-harm suicide. Suicide choices traceable to mental illness and jumping/drowning were 6.4% and 6.4%, respectively, while suicide by gunshot (1.5%) was less prominent. Furthermore, the result showed that there was a 3% likelihood that a male would die by hanging.

Conclusion:

Males are 3% more likely to die by hanging and are less likely to die by poisoning.
Assessment of Psychological Distress and Perceived Social Support in the Patients of COVID-Associated Mucormycosis
Authors: Takwani Timirkant J. , Odedra Kunjal Maldebhai , Singh Priyam , Chandrani Kalpesh V.
Published: November 2023

Background/Objective:

Coronavirus disease (COVID) 2019-associated mucormycosis is an aggressive fungal infection with an unpredictable outcome and poor prognosis, including a permanent vision loss. It could potentially trigger and amplify mental health problems, and the social support has been known to buffer the negative impact of such a large-scale stressor on mental health. Therefore, the present study aimed to estimate the prevalence and severity of depression, anxiety, and stress with the level of perceived social support and correlation between them in patients with COVID-associated mucormycosis.

Materials and Methods:

This was a cross-sectional, observational study conducted on 100 patients of mucormycosis at a tertiary care hospital, and the patients were enrolled by a convenience sampling method on the basis of inclusion and exclusion criteria. Depression, anxiety, and Stress Scale-21 items, and Multidimensional Scale of Perceived Social Support with a self-constructed semi-structured pro-forma were used to collect the required data.

Results:

The prevalence of depression, anxiety, and stress was found to be 49%, 80%, and 56%, respectively. 8.0% perceived low, 65.0% perceived medium, and 27.0% perceived a high social support. No correlation between depression, anxiety, and stress with the perceived social support was found.

Conclusions:

Our study highlights the burden of psychological issues in mucormycosis patients. Psychiatric implications can be of paramount importance while dealing with pandemics, and therefore, a routine mental health assessment and timely psychological and social interventions can reduce the adverse impact on mental health outcomes.
An in vitro comparative evaluation of intraorifice barriers and bleaching agents on the fracture resistance of the endodontically treated anterior teeth
Authors: Mehrotra Arushi , Singh Shishir , Podar Rajesh Satyanarain , Shetty Roshan , Salgar Avinash , Kumar Mohan
Published: November 2023

Aim:

This study aimed to evaluate and compare the impact of different bleaching agents on the fracture resistance of endodontically treated teeth when using either GC Fuji type 2 glass ionomer cement (GIC) or Shofu Glass Ionomer RX EASE as intraorifice barriers (IOB).

Materials and Methods:

A total of 80 single-rooted human maxillary central incisors were prepared and obturated. Three millimeters of gutta-percha was then removed from the orifice. The specimens were divided into two primary groups based on the type of IOB material used: GC Fuji type 2 GIC and Shofu Glass Ionomer RX EASE (n = 40). Each group was further divided into four subgroups based on the bleaching agent used: Carbamide peroxide (CP) 37%, sodium perborate (SP), hydrogen peroxide (HP) 35%, and distilled water used as the control (n = 10). The teeth were subjected to fracture resistance testing.

Results:

The study found that the order of root fracture resistance was control > CP > SP > HP. There was no statistically significant difference in fracture resistance between GC Fuji type 2 GIC and Shofu Glass Ionomer RX EASE when used as IOB materials.

Conclusion:

The study concluded that the choice of bleaching agent significantly affects the fracture resistance of endodontically treated teeth. It was observed that fracture resistance is lowest with HP, followed by SP and CP. Both GC Fuji type 2 Glass Ionomer and Shofu Glass Ionomer RX EASE are effective as IOB.
Innovative ex vivo exploration: A comparative study of novel approaches of root canal filling material removal efficiency
Authors: Gupta Aakash , Showkat Rukhsar , Singh Tarun Kumar
Published: November 2023

Introduction:

Retention of the natural tooth without any symptoms in the oral cavity is one of the prime desires of endodontic treatment. Root canal therapy usually leads to failure when treatment is not up to the mark of acceptable standards. To address these deficiencies, non-surgical endodontic retreatment is the most accepted option with the success rate ranging from 65% to 83%. Forty-five single-rooted mandibular premolars with undeviated canals (as per Schneider’s criteria) were obtained and divided further into three groups with 15 specimens along with resin-based sealer solvent in each group: Group 1 - Retreatment rotary file system, Group 2 - Ultrasonics, and Group 3 - Diode laser. Specimens were then evaluated under a stereomicroscope at ×10 after cutting in two halves followed by evaluation of the remaining filling material using Hulsmann and Bluhm criteria.

Context:

Nonsurgical retreatment.

Aims:

The aim of the study was to evaluate and compare the efficacy of various retreatment techniques for the elimination of root canal filling material.

Settings and Design:

The sample size was determined using the formula n = (Zα/2)2 s2/d2. The design of the study is in vitro experimental study.

Subjects and Methods:

A sum of 45 single-rooted extracted human permanent mandibular premolars were included in this study. All teeth were biomechanically prepared and obturated followed by decoronating the samples. All specimens were randomly divided into 3 groups comprising 15 specimens along with solvent based on the technique for the filling material elimination from the root canal, i.e. Group I: retreatment rotary files, Group II: ultrasonics, and Group III: diode laser.

Statistical Analysis Used:

The Tukey’s post
hoc tests and one-way analysis of variance were used for comparison of the study parameters among the groups.

Results:

Results revealed that ultrasonics showed the least amount of remaining filling material within the root canal which had a significant difference from other groups, i.e. retreatment rotary files and diode laser.

Conclusions:

Ultrasonics with a resin-based sealer solvent can be considered a preferred option for nonsurgical retreatment. However, none of the groups shows complete elimination of filling material inside the root canal system.
Endodontic retreatment practice trends among dental surgeons: A survey-based research
Authors: Mandke Lalitagauri , Koparkar Tejas , Bhagwat Sumita , Vimala N. , Vandekar Mansi
Published: November 2023

Aim:

Root canal treatment procedures are considered “the bread and butter” for routine clinical practice. Although retreatments have been primarily performed by endodontists (ENs), many senior practitioners and dentists who are root canal enthusiasts do opt for undertaking endodontic retreatment procedures. This survey helps us understand the practice trends and attitude of dentists undertaking endodontic retreatment procedures in and around Mumbai city.

Materials and Methods:

Questionnaires pertaining to endodontic retreatment were randomly distributed (hard copy/soft copy) to 1000 practicing dentists in and around Mumbai city. The questionnaire survey was divided into Part A: involving basic details such as name, demographic information, and clinical experience of the dentist and Part B: a set of questions based on assessing the trends, techniques, materials, and opinions of dentists regarding endodontic retreatment. Only those dentists who treated endodontic retreatment patients were asked to fill the Part B form. A response rate of 60.2% was achieved.

Results:

Out of total 602 participants, 49% of dentists (295) reported to undertake endodontic retreatment cases. Among the 295 respondents, 46.11% were Endodontists (ENs) while 53.8% were BDS or MDS of other specialties (ODs). Most dentists preferred multi-visit retreatment and prescribed antibiotics only in specific cases. Radiovisiography was the most preferred imaging aid. Calcium hydroxide and 3% sodium hypochlorite were favored choices for intracanal medicament and irrigant, respectively. Cold lateral compaction obturation technique was most common. Advanced equipment such as microscopes, loupes, ultrasonics, retreatment files, and thermoplastic obturations were more prevalent among ENs as compared to ODs.

Conclusion:

This study found some differences in endodontic retreatment practice trends among ENs and other dentists. But overall, most clinicians followed the international norms and are updated in recent advances in materials and techniques used in endodontic retreatment.
A Spectrophotometric comparative evaluation of the sealing ability of various perforation repair materials with a novel eggshell modified GIC
Authors: Abraham Sathish , Chandwani Ekta Dharmendra , Nagmode Pradnya , Lokhande Nitin , Badgujar Manish Bhaskar , Diggikar Kshitija
Published: November 2023

Objectives:

The objective of this study was to evaluate and compare the sealing ability of mineral trioxide aggregate (MTA), Biodentine, glass ionomer cement, and glass ionomer cement modified with Chicken Eggshell Powder when used as furcation perforation repair material.

Materials and Methods:

In the present study, 80 human lower first molars were used. Collected teeth had no caries or restoration, and none had fused roots. Every molar had an endodontic access cavity made utilizing a high-speed, long-shank round bur for the initial entry and an Endo-Z for lateral extension and finishing the cavity walls. Each canal’s orifice was covered with a temporary filling material. The pulpal floor and cavity walls of every molar were thoroughly coated with two successive coats of clear nail polish. A significant perforation was made between the orifices to the furcation area using a high-speed long shank round bur #4. The perforation centered between the mesial and distal orifice. They were divided into four experimental groups: Group I: 20 molars were repaired using MTA, Group II: 20 molars with Biodentine, Group III: 20 molars were repaired with glass ionomer cement, and Group IV was repaired using glass ionomer cement modified with 7% chicken eggshell powder. Moist cotton pellets were placed over the repair materials, and molars were kept in 100% humidity for 24 h to allow materials to set. Then, according to each group, molars were put in Petri dishes. Methylene blue dye was applied inside the access cavity of all samples for 24 h. Molars were placed under running tap water for 30 min to remove all residues of methylene blue, and then varnish was removed with a Parker blade #15 and polishing discs. Molars were placed in vials containing 1 mL of concentrated (65 wt%) nitric acid for 3 days. Vials were centrifuged at 14,000 rpm for 5 min. The supernatant from each sample was transferred in a quantity of 200 L to a 96-well plate. Sample absorbance was read by an automatic microplate spectrophotometer at 550 nm using concentrated nitric acid as a blank. Statistical analysis was performed using one-way analysis of variance. When the analysis of variance test was significant, the pairwise comparison of the means was done using a Duncan post hoc test. The significance level was set at P < 0.05. Statistical analysis was performed with SPSS 14.0 (SPSS Inc., Chicago, IL, USA) for Windows (Microsoft, Redmond, WA, USA).

Results:

The highest dye absorbance was seen in Group III, followed by Groups IV, II, and I.

Conclusion:

Within the limitations of study it was concluded that maximum sealing ability was seen in Biodentine followed by MTA, Glass Ionomer Cement modified with 7% Chicken Eggshell powder and Glass Ionomer Cement.
Holistic management of complicated crown fracture: A case series
Authors: Patil Madhuri , Hegde Vivek , Khan Mehrosh , Kharbe Nain , Ghunawat Dhananjay
Published: November 2023

Coronal fractures of the anterior teeth give an agonizing experience for a young individual due to the physical disfigurement, and the psychological impact that is imposed on them. One of the options for managing complicated/uncomplicated crown fractures when the tooth fragment is available, and there is no or minimal violation of the biological width is the rebonding of the fractured segment. This treatment approach is promising, providing good and long-lasting esthetics as it helps in maintaining the tooth’s original anatomic form, hue, and surface texture. This article describes three case reports of successful reattachment of fractured tooth fragments. Following the root canal treatment procedures, prefabricated posts were cemented as intraradicular splint to reattach the fractured segments.
The effect of preparation design on fracture resistance of endodontically treated maxillary premolars restored with lithium disilicate computer-aided design/computer-aided manufacturing endocrowns: An in vitro study
Authors: Kazemi-Yazdi Haleh , Rezaei Sadaf , Seyedan Kaveh , Kazeminia Marjan , Rezaei Sina
Published: November 2023

Purpose:

This study aimed to assess the effect of preparation design on fracture resistance (FR) of endodontically treated maxillary premolars restored with lithium disilicate (LDS) endocrowns fabricated by the computer-aided design/computer-aided manufacturing (CAD/CAM) technology.

Materials and Methods:

In this in vitro, experimental study, 30 sound maxillary premolars were randomly assigned to three groups (n = 10) of control (no preparation), endocrown preparation with butt-joint design without ferrule, and endocrown preparation with ferrule (shoulder design with 1 mm height). After restoration fabrication and cementation, the teeth underwent thermocycling, were mounted with 45° angle, and subjected to compressive load in a universal testing machine to measure their FR. The mode of failure was also determined under a stereomicroscope. Data were analyzed using one-way ANOVA and Tukey’s test (α =0.05).

Results:

The shoulder group showed the highest FR (1768.98 ± 386.1 N). The difference in FR was statistically significant among the three groups (P < 0.05). Pairwise comparisons revealed that the shoulder group had significantly higher FR than the butt-joint (P = 0.001) and control (P = 0.009) groups. However, the difference in FR between the butt-joint and control groups was not significant (P = 0.75). The mode of failure was not significantly different among the three groups (P > 0.05).

Conclusions:

Preparation design had a significant effect on FR of endodontically treated maxillary premolars restored with LDS CAD/CAM Endocrowns, such that addition of a short axial wall in shoulder group significantly increased the FR of endocrowns.
Comparative clinical evaluation of two different formulated in-office newer desensitizing agents (Clinpro XT and Tokuyama Shield Force Plus) in reducing dentin hypersensitivity – A randomized clinical trial
Authors: Paramesh Yelloji , Durgabhavani Gondi , Suneelkumar Chinni , Gonapa Prasanthi , Rathod Ramawat Tejasree
Published: November 2023

Aim:

The aim of this study was to assess the effectiveness of two various in-office newer desensitizing agents in reducing dentinal hypersensitivity in patients with mild-to-moderate sensitivity for a 1-month follow-up.

Materials and Methods:

Forty subjects with cervical dentin hypersensitivity (otherwise healthy patients) were included. A split-mouth, randomized clinical trial was conducted. A Visual Analog Scale (VAS) was used to record the initial sensitivity levels at the baseline visit. Each individual has been exposed to thermal (ethyl chloride spray) and evaporative (air blast) stimuli to elicit sensitivity. A single application of two different in-office desensitizing agents, Clinpro XT Varnish (3M ESPE, Minnesota, USA) and Shield Force Plus (Tokuyama Dental, Tokyo, Japan), was done. The sensitivity scores were recorded after the application of the desensitizing agent immediately, after 1 week, and after 1 month using both air and cold stimuli in the same manner as initially.

Results:

Mean VAS scores represent teeth that were more sensitive to cold stimuli compared to air blasts in both groups. For both stimuli at all-time intervals except baseline, there is a significant difference between CXT and SFP, with low mean VAS scores for CXT. Post hoc analysis revealed that in the CXT group, there is a significant difference in mean VAS score between pre-and postintervention at all-time intervals except between immediate and 1-week time intervals (P < 0.001) but only at immediate and 1-week time intervals in SFP.

Conclusion:

Clinpro XT Varnish is more efficient compared to Shield Force Plus at all-time points irrespective of the stimuli after a 1-month follow-up.
Endodontic retreatment efficacy with and without solvents: A systematic review
Authors: Shah Tanvi , Ramesh Sindhu , Sugumaran Surendar , Choudhari Sahil
Published: November 2023

Introduction:

This systematic review investigates the crucial need for solvent use in root canal retreatment, as it effectively removes filling materials, reduces apical debris extrusion, and alleviates postoperative pain, ultimately enhancing treatment success. The review aims to assess the success rates, compare outcomes, explore benefits and drawbacks, and identify subgroups where solvent use may be more effective during root canal retreatment.

Materials and Methods:

The search was performed in PubMed Central, Scopus, Cochrane, LILAC, ScienceDirect, Google Search, Web of Science, and manually using the search items alone and in combination by means of PUBMED search builder. The studies were assessed for eligibility according to the eligibility criteria by two independent reviewers. Groups containing solvent with nonsolvent groups and randomized control trials were included and in vitro studies, retrospective studies, and animal studies were excluded from the study. Quality assessment was performed using the risk of bias (RoB) 2.0 tool.

Results:

Out of the 596 articles obtained, 14 were shortlisted for full-text reading and finally two articles were included in the study. The studies were assessed for quality, and data were extracted in a tabulated form. Overall RoB is low, but due to the lack of homogeneity, meta-analysis could not be conducted.

Conclusion:

The use of solvent does not cause any significant difference in the postoperative pain levels or analgesic intake for retrieval of gutta-percha in cases of root canal retreatment. Due to the limited number of studies available and the lack of clinician-related outcomes such as time taken to retrieve the gutta-percha, these results should be taken into consideration with caution.
The Perception and Practice of Routine Lingual Flap Retraction in Lower Third Molar Surgery among Oral and Maxillofacial Surgeons in Nigeria
Authors: Edetanlen Ekaniyere Benlance , Lawani Ufadime , Akinniyi Taofeek , Ayanere Esther , Okechi Uchenna C. , Fomete Benjamin , Osunde Otasowie , Aladelusi Timothy Olukunle
Published: November 2023

Background:

Lingual nerve injury is a known complication of mandibular third molar (M3M) surgery, and retraction of the lingual flap is reported to reduce the incidence of this complication. However, there is no global consensus on the routine retraction of lingual flap.

Aim:

The aim of the study was to assess the perception and practice of lingual flap retraction amongst oral and maxillofacial surgeons in Nigeria.

Materials and Methods:

This cross-sectional national survey was conducted amongst 122 oral and maxillofacial surgeons in Nigeria from January 2023 to March 2023 using a validated, structured, self-administered questionnaire. The questionnaire had three sections and 14-item questions. Section A consists of the sociodemographic questions, Section B comprises questions on perception towards lingual flap retraction, whereas Section C consists of questions on the practice of lingual flap retraction. These questionnaires were deployed as an online survey and as hard copies. Both qualitative and quantitative data were analysed. A critical probability level (P < 0.05) was used as the cut-off level for statistical significance.

Results:

Most of the participants (47.6%) belong to the age group of 31–40 years. The male-to-female ratio was 6:1. Only 12 (9.8%) participants had a positive perception towards routine lingual flap retractions following M3M surgery. Perception of lingual flap retraction was found not to be associated with the demographic variables of the participants (P > 0.05). A total of 95 participants (77.9%) did not raise nor retract the lingual flap during lower third molar surgery. The rate of practice of lingual flap retraction during third molar surgery was not influenced by any of the factors studied (P > 0.05).

Conclusion:

The majority of oral and maxillofacial surgeons in Nigeria do not agree that routine retraction of the lingual flap is necessary to reduce lingual nerve injury and majority, too, do not practice this in their management of impacted lower third molar.
Association between Periodontal Inflamed Surface Area and Systemic Inflammatory Biomarkers among Pre-dialysis Chronic Kidney Disease Patients
Authors: Onabanjo Olusoji Ayodele , Nwhator Solomon Olusegun , Arogundade Fatiu A.
Published: November 2023

Background:

Several studies have shown an association between chronic kidney disease (CKD) and periodontitis. However, only few studies have quantified the burden of periodontal inflammation in pre-dialysis CKD patients. The aim of this study was to determine the association between periodontal inflamed surface area (PISA) and systemic inflammatory biomarkers among pre-dialysis CKD patients.

Materials and Methods:

120 pre-dialysis CKD participants were recruited into this study. 60 participants constituted Group A (those with periodontitis) while 60 participants constituted Group B (those without periodontitis). Full periodontal examination was carried out in the participants for the estimation of PISA. Blood samples also collected to determine levels of high sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) in all participants. Independent t-test was used to compare means of PISA, hsCRP and IL-6 levels in the two groups. Pearson correlation analysis was used to determine association between PISA and (hsCRP and IL-6).

Results:

The mean value of hsCRP was significantly higher in Group A compared to Group B (3.41 mg/L vs. 2.18 mg/L). PISA moderately correlated with hsCRP (r = 0.4, P < 0.01) in both groups. hsCRP also moderately correlated with IL-6 (r = 0.6, P < 0.001) in both groups.

Conclusion:

This study demonstrates that there was an association between PISA and hsCRP. Increased hsCRP level in Group A revealed the inflammatory burden imposed by periodontitis.
Exploring Artificial Intelligence in the Nigerian Medical Educational Space: An Online Cross-sectional Study of Perceptions, Risks and Benefits among Students and Lecturers from Ten Universities
Authors: Oluwadiya Kehinde Sunday , Adeoti Adekunle Olatayo , Agodirin Sulaiman Olayide , Nottidge Timothy Eyo , Usman Mustapha Ibrahim , Gali Mtaku Bata , Onyemaechi Ndubuisi Onu , Ramat Ali Mohammed , Adedire Adejare , Zakari Lawal Ya’u
Published: November 2023

Background:

The impact of artificial intelligence (AI) has been compared to that of the Internet and printing, evoking both apprehension and anticipation in an uncertain world.

Objective:

This study aimed to explore the perceptions of medical students and faculty members from ten universities across Nigeria regarding AI.

Methods:

Using Google Forms and WhatsApp, a cross-sectional online survey was administered to clinical year medical students and their lecturers from ten medical schools representing all the six geopolitical zones of Nigeria.

Results:

The survey received 1003 responses, of which 708 (70.7%) were from students and 294 (29.3%) were from lecturers. Both groups displayed an average level of knowledge, with students (Median:4, range −5 to 12) significantly outperforming lecturers (Median:3, range −5 to 15). Social media (61.2%) was the most common form of first contact with AI. Participants demonstrated a favourable attitude towards AI, with a median score of 6.8 out of 10. Grammar checkers (62.3%) were the most commonly reported AI tool used, while ChatGPT (43.6%) was the most frequently mentioned dedicated AI tool. Students were significantly more likely than lecturers to have used AI tools in the past but <5% of both groups had received prior AI training. Excitement about the potential of AI slightly outweighed concerns regarding future risks. A significantly higher proportion of students compared to lecturers believed that AI could dehumanise health care (70.6% vs. 60.8%), render physicians redundant (57.6% vs. 34.7%), diminish physicians’ skills (79.3% vs. 71.3%) and ultimately harm patients (28.6% vs. 20.6%).

Conclusion:

The simultaneous fascination and apprehension with AI observed among both lecturers and students in our study mirrors the global trend. This finding was particularly evident in students who, despite possessing greater knowledge of AI compared to their lecturers, did not exhibit a corresponding reduction in their fear of AI.