Nonrenormalization of Flux Superpotentials in String Theory

Recent progress in understanding modulus stabilization in string theory relies on the existence of a non-renormalization theorem for the 4D compactifications of Type IIB supergravity which preserve N=1 supersymmetry. We provide a simple proof of this non-renormalization theorem for a broad class of Type IIB vacua using the known symmetries of these compactifications, thereby putting them on a similar footing as the better-known non-renormalization theorems of heterotic vacua without fluxes. The explicit dependence of the tree-level flux superpotential on the dilaton field makes the proof more subtle than in the absence of fluxes.Comment: 16 pages, no figures. Final version, to appear in JHEP. Arguments for validity of R-symmetry made more explicit. Minor extra comments and references adde

Retrograde filling material in periapical surgery: a systematic review

Background: Periapical surgery focuses on the treatment of teeth with persistent periapical lesions when orthograde root canal treatment fails. Although MTA® is the gold standard material for retrograde filling, Biodentine® - a tricalcium silicate-based cement - has been proposed in order to resolve several of its limitations. A systematic review has been carried out to compare the physicochemical properties of Biodentine® versus MTA® as root-end filling material in periapical surgery. Material and methods: An electronic search was conducted by two independent examiners during March 2020 in the Cochrane, PubMed-MEDLINE and Scopus databases. In addition, a manual search was made in specialized journals. Comparative human or in vitro studies that evaluated bond strength, the presence of marginal gap and sealing ability were included. No restriction on publication date was applied. Animal studies, clinical cases, cases series and expert opinions were excluded. Results: After analyzing 147 initially selected studies, 13 publications were included. Regarding bond strength, the studies seemed to evidence better performance of Biodentine® in both acidic and blood contaminated environments. In relation to the presence of marginal gap and sealing ability, the studies yielded contradictory results. According to some authors, the sealing ability of Biodentine® is greater than that of MTA® during the first 24 hours, though both materials prove equal after one week. Other authors recorded no significant differences. Conclusions: Considering the limitations and heterogeneity of the studies included, there is not sufficient evidence to confirm the clinical superiority of Biodentine® as a root-end filling material in periapical surgery

Presurgical diagnosis of diffuse gliomas in adults:Post-WHO 2021 practical perspectives from radiologists in neuro-oncology units

The 2021 World Health Organization classification of CNS tumours was greeted with enthusiasm as well as an initial potential overwhelm. However, with time and experience, our understanding of its key aspects has notably improved. Using our collective expertise gained in neuro-oncology units in hospitals in different countries, we have compiled a practical guide for radiologists that clarifies the classification criteria for diffuse gliomas in adults. Its format is clear and concise to facilitate its incorporation into everyday clinical practice. The document includes a historical overview of the classifications and highlights the most important recent additions. It describes the main types in detail with an emphasis on their appearance on imaging. The authors also address the most debated issues in recent years. It will better prepare radiologists to conduct accurate presurgical diagnoses and collaborate effectively in clinical decision making, thus impacting decisions on treatment, prognosis, and overall patient care.</p

Presurgical diagnosis of diffuse gliomas in adults:Post-WHO 2021 practical perspectives from radiologists in neuro-oncology units

The 2021 World Health Organization classification of CNS tumours was greeted with enthusiasm as well as an initial potential overwhelm. However, with time and experience, our understanding of its key aspects has notably improved. Using our collective expertise gained in neuro-oncology units in hospitals in different countries, we have compiled a practical guide for radiologists that clarifies the classification criteria for diffuse gliomas in adults. Its format is clear and concise to facilitate its incorporation into everyday clinical practice. The document includes a historical overview of the classifications and highlights the most important recent additions. It describes the main types in detail with an emphasis on their appearance on imaging. The authors also address the most debated issues in recent years. It will better prepare radiologists to conduct accurate presurgical diagnoses and collaborate effectively in clinical decision making, thus impacting decisions on treatment, prognosis, and overall patient care.</p

Las complicaciones de la resonancia magnética nuclear en la exploración de la articulación temporomandibular

La presencia de ciertos materiales ferromagnéticos , implantes y aparatos metálicos en el organismo se considera una contraindicación relativa para la práctica de una resonancia magnética nuclear, debido a los riesgos asociados al desplazamiento o dislocación de los mismos al ser atraídos en el campo magnético a que se les somete. Se presenta un resumen sobre los materiales con un riesgo potencial de complicaciones durante la práctica de la resonancia magnética nuclear de la articulación temporomandibular y se destaca la importancia de la detección previa de los mismos mediante la anamnesis y la exploración fisica de los pacientes que precisan dicha técnica. En algunos casos, se precisará asesoramiento especializado

Instanton effects and linear-chiral duality

We discuss duality between the linear and chiral dilaton formulations, in the presence of super-Yang-Mills instanton corrections to the effective action. In contrast to previous work on the subject, our approach appeals directly to explicit instanton calculations and does not rely on the introduction of an auxiliary Veneziano-Yankielowicz superfield. We discuss duality in the case of an axion that has a periodic scalar potential, and find that the bosonic fields of the dual linear multiplet have a modified interpretation. We note that symmetries of the axion potential manifest themselves as symmetries of the equations of motion for the linear multiplet. We also make some brief remarks regarding dilaton stabilization. We point out that corrections recently studied by Dijkgraaf and Vafa can be used to stabilize the axion in the case of a single super-Yang-Mills condensate.Comment: 1+18 pages, 1 figure, comments and references adde

Primary intraosseous squamous cell carcinoma arising in dentigerous cyst : report of 2 cases and review of the literature

Dentigerous cysts are one of the most common odontogenic cysts of the oral cavity. Odontogenic cysts can give rise to a variety of neoplasms. Carcinoma arising in a dentigerous cyst is extremely rare, with a review of literature showing near 30 cases. The present report describes 2 cases of primary intraosseous squamous cell carcinoma originated from a dentigerous cyst. The first one refers to a 57-year old female with a persistent lesion in the left retromolarregion and diagnosed with squamous cell carcinoma originated fromthe incomplete excision of the lower third molar follicle during its surgical extraction. The second case describes the case of an 18-year old male with an impacted upper canine with previous history of infection and swelling of the oral cavity. The histopathological study revealed the malignization of the follicle surrounding the dental crown. These two cases confirmed the importance of the histopathological study of all the tissue samples obtained from surgical procedures. Although the development of a malignant lesion from a dentigerous cyst is rare and its clinical-radiological features are apparently innocuous, this entity should be considered as a differential diagnosis

Cosmological Rescaling through Warped Space

We discuss a scenario where at least part of the homogeneity on a brane world can be directly related to the hierarchy problem through warped space. We study the dynamics of an anti-D3-brane moving toward the infrared cut-off of a warped background. After a region described by the DBI action, the self-energy of the anti-D3-brane will dominate over the background. Then the world-volume scale of the anti-D3-brane is no longer comoving with the background geometry. After it settles down in the infrared end, the world-volume inhomogeneity will appear, to a Poincare observer, to be stretched by an exponentially large ratio. This ratio is close to that of the hierarchy problem between the gravitational and electroweak scales.Comment: 12 pages, 2 figures; v2, PRD version, comments and references adde

Chronic neuropathic facial pain after intense pulsed light hair removal. Clinical features and pharmacological management

Intense Pulsed Light (IPL) photodepilation is usually performed as a hair removal method. The treatment is recommended to be indicated by a physician, depending on each patient and on its characteristics. However, the use of laser devices by medical laypersons is frequent and it can suppose a risk of damage for the patients. Most side effects associated to IPL photodepilation are transient, minimal and disappear without sequelae. However, permanent side effects can occur. Some of the complications are laser related but many of them are caused by an operator error or mismanagement. In this work, we report a clinical case of a patient that developed a chronic neuropathic facial pain following IPL hair removal for unwanted hair in the upper lip. The specific diagnosis was painful post-traumatic trigeminal neuropathy, reference 13.1.2.3 according to the International Headache Society (IHS)