Seventy years of pheochromocytomas and paragangliomas in Argentina. The FRENAR database.

Pheochromocytomas and paragangliomas (PPGL) are neuroendocrine tumors characterized by the excessive production of catecholamines. This study aims to describe the clinical characteristics of PPGL cases in Argentina over recent decades. A multicenter retrospective cross-sectional analysis was carried out using a database comprising both pediatric and adult patients with confirmed PPGL diagnoses based on pathological reports. A cohort of 486 patients with PPGL was recruited. Women represent 58.4% of the patients, with a mean age of 38.3 years old at the time of diagnosis and 15.2% of the patients were under the age of 18. Hypertension, as well as classic signs and symptoms, were present in 80.9% of the patients. The adrenal incidentaloma, as a mode of presentation, increased in the last two decades rising from 3.9% (1953-2000) to 21.8% (2001-2022), p<0.001. Most tumors were located within the adrenal glands, accounting 83.0% of the cases, with bilateral occurrences noted in 20.0%. The median tumor size was 4.8cm. Local recurrence and metastases were observed in 10.9% and 12.2%. Out of 412 patients, 87.0% exhibited urinary excretion elevation of catecholamines and/or their metabolites. Furthermore, 148 patients, representing 30.4% of the study population, displayed a distinct genetic profile indicative of hereditary syndromes. The distribution of hereditary syndromes revealed that MEN2, VHL, and PGL4 constituted the most prevalent syndromes. This population-based study, spanning seven decades, offers valuable insights into the demographic and clinical characteristics of PPGL patients in Argentina.

Regenerative endodontic treatment of an immature incisor tooth with a novel platelet-rich product: A five-year follow-up case report.

This case report presents a five-year follow-up and the management of a necrotic, immature incisor tooth treated by a novel platelet-rich plasma/platelet extract solution and platelet-rich fibrin (PRP-PES/PRF) and the restoration by using a stress-reduced direct composite restoration (SRDC) technique. The patient with a broken maxillary lateral tooth was referred to our clinic. Extra/intra-oral examinations were within normal limits. The nonvital tooth having an apical lesion and open-apical apex was treated with a regenerative endodontic treatment procedure (REP), and further root development with continued apical closure was shown in the follow-ups up to 60 months. In conclusion, the SRDC and PRP-PES/PRF combination can be an opportunity for the teeth requiring post-restoration. In contrast to the treatment strategy susceptible to weakening or fracturing the patient's tooth root, the REP approach may lead to a better prognosis for the patient's tooth.

Postoperative bleeding risk of direct oral anticoagulants after oral surgery procedures: a systematic review and meta-analysis.

Direct oral anticoagulants (dabigatran, rivaroxaban, apixaban and edoxaban; DOACs) have been introduced to improve safety and superior therapeutic value compared to their predecessors such as warfarin or enoxaparin. The aim of this systematic review and meta-analysis was to assess the postoperative bleeding risk of DOACs during oral surgery procedures. Systematic searches were performed in electronic databases including PubMed, Scopus, Web of Science and Cochrane Library. Thirteen studies were included in the qualitative synthesis: two retrospective case-control studies, five prospective case-control studies, three cross-sectional studies, two case series and a case report; while only six studies were statistically analysed. The risk ratio of postoperative bleeding in DOACs patients was significantly greater than in healthy patients (3.04; 95% confidence interval (CI)=1.31-7.04). This is especially true for rivaroxaban (4.13; 95% CI=1.25-13.69), and less so for dabigatran which presented a risk ratio similar to that of healthy patients (1.00; 95% CI=0.21-4.82). However, further research is required to support these results. Both apixaban and edoxaban were excluded from statistical analysis due to the lack of clinical studies.

The steroid response to human chorionic gonadotropin (hCG) stimulation in men with Klinefelter syndrome does not change using immunoassay or mass spectrometry.

PURPOSE: Liquid-chromatography tandem mass-spectrometry (LC-MS/MS) was developed in parallel to Immunoassays (IAs) and today is proposed as the "gold standard" for steroid assays. Leydig cells of men with Klinefelter syndrome (KS) are able to respond to human chorionic gonadotropin (hCG) stimulation, even if testosterone (T) production was impaired. The aim was to evaluate how results obtained by IAs and LC-MS/MS can differently impact on the outcome of a clinical research on gonadal steroidogenesis after hCG stimulation. METHODS: A longitudinal, prospective, case-control clinical trial. (clinicaltrial.gov NCT02788136) was carried out, enrolling KS men and healthy age-matched controls, stimulated by hCG administration. Serum steroids were evaluated at baseline and for 5 days after intramuscular injection of 5000 IU hCG using both IAs and LC-MS/MS. RESULTS: 13 KS patients (36 ± 9 years) not receiving T replacement therapy and 14 controls (32 ± 8 years) were enrolled. T, progesterone, cortisol, 17-hydroxy-progesterone (17OHP) and androstenedione, were significantly higher using IAs than LC-MS/MS. IAs and LC-MS/MS showed direct correlation for all five steroids, although the constant overestimation detected by IAs. Either methodology found the same 17OHP and T increasing profile after hCG stimulation, with equal areas under the curves (AUCs). CONCLUSIONS: Although a linearity between IA and LC-MS/MS is demonstrated, LC-MS/MS is more sensitive and accurate, whereas IA shows a constant overestimation of sex steroid levels. This result suggests the need of reference intervals built on the specific assay. This fundamental difference between these two methodologies opens a deep reconsideration of what is needed to improve the accuracy of steroid hormone assays.

Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago.

In the cold dark matter cosmology, the baryonic components of galaxies-stars and gas-are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius-a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high-redshift) Universe efficiently condensed at the centres of dark-matter haloes when gas fractions were high and dark matter was less concentrated.

Human chorionic gonadotropin stimulation gives evidence of differences in testicular steroidogenesis in Klinefelter syndrome, as assessed by liquid chromatography-tandem mass spectrometry.

BACKGROUND: Men with Klinefelter syndrome (KS) show hypergonadotropic hypogonadism, but the pathogenesis of hypotestosteronemia remains unclear. Testicular steroidogenesis in KS men was evaluated over three decades ago after human chorionic gonadotropin (hCG) stimulation, but inconclusive results were obtained. Intriguingly, some recent studies show increased intratesticular testosterone concentrations in men with KS. OBJECTIVE: To analyze serum steroid profile, as a proxy of testicular steroidogenesis, after hCG stimulation in KS compared with control men. DESIGN: A prospective, longitudinal, case-control, clinical trial. METHODS: Thirteen KS patients (36±9 years) not receiving testosterone (TS) replacement therapy and 12 eugonadic controls (32±8 years) were enrolled. Serum steroids were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) at baseline and for five consecutive days after intramuscular injection of 5000IU hCG. RESULTS: Progesterone (P), 17-hydroxyprogesterone (17OHP), TS, and estradiol (E2) showed a significant increase (P<0.001) after hCG stimulation in both groups. On the contrary, androstenedione (AS) and dehydroepiandrosterone did not increase after hCG stimulation. The 17OHP/P ratio increased in both groups (P<0.001), the TS/AS ratio (17ß-hydroxysteroid dehydrogenase type 3 (17ßHSD3) activity) did not increase after hCG in any group, and the E2/TS ratio (aromatase activity) increased significantly in both groups (P=0.009 in KS and P<0.001 in controls). Luteinizing hormone decreased after hCG in both groups (P=0.014 in KS and P<0.001 in controls), whereas follicle-stimulating hormone decreased only in control men (P<0.001). CONCLUSION: This study demonstrates for the first time using LC-MS/MS that Leydig cells of KS men are able to respond to hCG stimulation and that the first steps of steroidogenesis are fully functional. However, the TS production in KS men is impaired, possibly related to reduced hydroxysteroid deydrogenase activity due to an unfavorable intratesticular metabolic state.

Density functional theory for chiral nematic liquid crystals.

Even though chiral nematic phases were the first liquid crystals experimentally observed more than a century ago, the origin of the thermodynamic stability of cholesteric states is still unclear. In this Rapid Communication we address the problem by means of a density functional theory for the equilibrium pitch of chiral particles. When applied to right-handed hard helices, our theory predicts an entropy-driven cholesteric phase, which can be either right or left handed, depending not only on the particle shape but also on the thermodynamic state. We explain the origin of the chiral ordering as an interplay between local nematic alignment and excluded-volume differences between left- and right-handed particle pairs.

Results of modified Dufourmentel rhomboid flap in patients with extensive Sacrococcygeal pilonidal disease.

PURPOSE: The aim of our study was to assess our modified Dufourmentel flap outcomes in a standardized patient group (a symptom duration of equal to or greater than 60 months, presence of equal to or more than 3 sinus ostia or presence of sinus ostia fistulized equal to or greater than 2 cm laterally, and a normal body mass index) with extensive pilonidal sinus. METHODS: Patients who were diagnosed with chronic pilonidal sinus disease and gave consent to surgical repair with modified Dufourmentel flap were enrolled. Patients were assessed with respect to age, sex, body mass index, presenting symptom, symptom duration, number of previous operations, number of sinus ostia, length of flap rims, depth of intergluteal sulcus, distance of sinus from anus, duration of operation, time of drain removal, length of hospital stay, early postoperative complications, postoperative pain, loss of labor, length of follow-up, and recurrences. RESULTS: A total of 42 patients were enrolled. Average duration of presenting symptoms was 64.4 +/- 4.7 months and average length of follow-up was 29.4 +/- 3.6 months. Average length of hospital stay was 4.2 +/- 0.8 days, and time to return to work was 16.3 +/- 2.1 days. Two patients (4.7%) developed postoperative wound infection, one patient (2.4%) developed seroma, and three patients (7.1%) had wound dehiscence. There was no recurrence. CONCLUSION: Modified Dufourmentel flap application can be safely used in the treatment of extensive pilonidal sinus disease.

Effects of NaOCl, EDTA and MTAD when applied to dentine on stress distribution in post-restored roots with flared canals.

AIM: To evaluate the effect of NaOCl, EDTA and MTAD on the stress distribution and levels in roots with flared canals and three different aesthetic post systems using finite element stress analysis (FEA). METHODOLOGY: Three-dimensional (3D) FEA models simulating a maxillary incisor with excessive structural loss and flared root canals were created. The dentine of the first models of each post group was assumed as homogenous, whereas the others were deemed as having their elastic modulus affected up to 100 µm deep as a result of irrigation protocol (5.25 NaOCl, 17% EDTA and MTAD for 2 h). A sound incisor tooth model was used as the control. Restorations were created according to the post system used (pre-fabricated fibre post (PFP)), polyethylene fibre (Ribbond) post and core build-up (RBP), and one-piece milled zirconia post and core (ZP). Ceramic crowns were added to the models. A 300-N static load was applied at the centre of the palatal surface of the models to calculate the stress distributions. The SolidWorks/Cosmosworks structural analysis programmes were used for FEA analysis. Results were presented by considering von Mises criteria. RESULTS: The analysis of the von Mises stresses revealed that RBP created less stress in the remaining root dentine when compared to PFP and ZP. ZP maintained the stresses inside its body and reduced stress on the palatal surface of the root; however, it forwarded more stress towards the apical area. NaOCl-, EDTA- and MTAD-treated dentine increased the stresses within the root structure regardless of the effect of the post system used (11-15.4 MPa for PFP, 9.5-13.02 MPa for RBP and 14.2 MPa for ZP). Amongst the irrigation solutions used, EDTA and MTAD increased the stresses more than NaOCl in all models. All the irrigation solutions showed the same stress levels and distributions in the ZP model. CONCLUSION: NaOCl-, EDTA- and MTAD- treated dentine and a rigid post with high elastic modulus may increase fracture risk in roots with flared canals by increasing the stresses within root dentine. Therefore, solutions that alter the elastic modulus of dentine less (such as NaOCl) or an individually shaped post-core system constructed with a material that has an elastic modulus close to dentine (polyethylene fibre) should be used in weak roots.

Primary Intestinal-type Adenocarcinoma of the Nasal Cavity: A Case Report.

We report a rare case of sinonasal intestinal-type adenocarcinoma in the nasal cavity. A 31-year old man represented with headache and epistaxis. We identified a malignant tumour, which is a rare pathology, with detailed physical examination, anterior rhinoscopy, computed tomography scan, magnetic resonance imaging and histopathologic examination. Endoscopic excision of the tumour was performed. After three years of follow-up of the patient in our clinic, there was no sign of any recurrence.

A case report: primary melanoma of the nasal cavity / Un reporte de caso: melanoma primario de la cavidad nasal

We report a rare case of sinonasal mucosal malignant melanoma in the nasal cavity. The patient had respiratory difficulty, continuous epistaxis and nasal pain. We identified a malignant tumour which is a rare pathology with detailed physical examination, anterior rhinoscopy, computed tomography (CT) scan, magnetic resonance imaging (MRI) and histopathologic examination. The patient did not accept surgical procedures and was referred for chemotherapy or immunotherapy. Continued follow-up of this is necessary.

Reportamos un caso raro de melanoma maligno de la mucosa del tracto nasosinusal. El paciente tenía dificultad respiratoria, epistaxis continua, y dolor nasal. Identificamos un tumor maligno que es una patología, con examen físico detallado, rinoscopia anterior, tomografía computarizada (TC), resonancia magnética (MRI) y examen histopatológico. El paciente no aceptaba los procedimientos quirúrgicos y fue remitido para quimioterapia o inmunoterapia. Es necesario realizar un seguimiento continuo.

The response of cementoblasts to calcium phosphate resin-based and calcium silicate-based commercial sealers.

AIM: To investigate cell viability and gene expression of cementoblasts (OCCM.30) exposed to extractable components released by resin-based sealers with different chemical composition Hybrid Root Seal (HRS), SimpliSeal (SS), Real Seal (RS) and AH Plus (AH) and by a MTA-based sealers Tech Biosealer Endo (TBE). METHODOLOGY: Discs of all materials were prepared and allowed to set in humid conditions at 37° for 48 h. The discs were then incubated for 72 h at 37 °C to obtain material extracts (1/1) in DMEM. The extracts containing the components released by the sealers were filtered and other dilutions (1/2, 1/4) were prepared from the original solution (1/1). Original and diluted solutions were tested on the cementoblasts. Impedance-based real-time cell analysis (RTCA) was used to evaluate cell viability, quantitative real-time polymerase chain reaction (QRT-PCR) was used to examine the expression of mineralization-related genes (osteocalcin; OCN, Runt-related transcription factor-2; Runx2, collagen type 1; COL I, alkaline phosphatase; ALP). For statistical analysis, one-way analysis of variance (anova) and Tukey's honestly significant difference (HSD) tests were used. RESULTS: TBE (1/2), RS (1/2, 1/4), and HRS (1/2, 1/4) significantly decreased cell viability (P < 0.001). AH (1/2, 1/4) and SS (1/2, 1/4) had similar cell viability to the control at 30 h. All tested materials significantly decreased cell viability when compared to the control group except AH (1/2, 1/4) and SS (1/4) at 90 h. All of the tested sealers reduced COL I mRNA expressions when compared to the control. SS was associated with significant increases in OCN and Runx2 mRNA expressions when compared to the control (P < 0.001). Whereas all of the dilutions of TBE, RS and HRS significantly decreased BSP mRNA expressions (P < 0,001), 1/2 and 1/4 dilutions of SS increased BSP mRNA expression (P < 0,001). Except the 1/4 dilutions of AH and SS, all the sealer dilutions significantly reduced ALP mRNA expression in cementoblasts (P < 0,001). CONCLUSIONS: SimpliSeal and AH Plus resulted in more favourable response to cementoblasts because of their regulation potential on the mineralized tissue-associated protein's mRNA expressions.

A case report: primary melanoma of the nasal cavity.

We report a rare case of sinonasal mucosal malignant melanoma in the nasal cavity. The patient had respiratory difficulty, continuous epistaxis and nasal pain. We identified a malignant tumour which is a rare pathology with detailed physical examination, anterior rhinoscopy, computed tomography (CT) scan, magnetic resonance imaging (MRI) and histopathologic examination. The patient did not accept surgical procedures and was referred for chemotherapy orimmunotherapy. Continued follow-up of this is necessary.

Psychopathology and psychiatric co-morbidities in patients seeking rhinoplasty for cosmetic reasons.

AIM: The purpose of the study was to examine psychopathological traits and psychiatric co-morbidities in seekers of cosmetic rhinoplasty. SUBJECTS AND METHODS: Fifty persons seeking cosmetic rhinoplasty and 50 control subjects were admitted to the study. Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) and Symptom Checklist-90 [Revised] (SCL-90-R) were administered to people who requested cosmetic rhinoplasty and control subjects. All participants were also screened by the Structured Clinical Interview for DSM-IV-(SCIDI/CV, SCID-II). RESULTS: Thirteen cosmetic rhinoplasty seekers [CRS] (26%) and three control subjects (6%) had at least one psychiatric diagnosis. There was a significant difference between the two groups (p = 0.006). Beck depression inventory (p = 0.002) and BAI (p = 0.046) levels above the cut-off point were significantly higher in the CRS group than in the normal control. Somatoform disorders were statistically higher in the CRS than control group (p = 0.007). Nine CRS (18%) and two control subjects (4%) had at least one personality disorder. There were differences between the two groups (p = 0.025). The average of SCL-90-R was significantly higher in the CRS than in the control subjects (p < 0.001). The most prevalent somatoform disorders of the CRS were six with body dysmorphic disorder [BDD] (12%). The most prevalent personality disorders of the CRS were three with avoidant (6%) and three with narcissistic (6%) personality. CONCLUSION: Assessment of detailed psychopathological aspects and psychiatric co-morbidities could help to define the clinical profile of people requesting cosmetic rhinoplasty in cosmetic surgery settings. Research into these factors may be important as it is essential to detect crucial problems such as personality disorders and BDD before surgery.

Psychopathology and psychiatric co-morbidities in patients seeking rhinoplasty for cosmetic reasons / Psicopatología y comorbilidad psiquiátrica en pacientes que buscan rinoplastia por razones cosméticas

AIM: The purpose of the study was to examine psychopathological traits and psychiatric co-morbidities in seekers of cosmetic rhinoplasty. SUBJECTS AND METHOD: Fifty persons seeking cosmetic rhinoplasty and 50 control subjects were admitted to the study. Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) and Symptom Checklist - 90 [Revised] (SCL-90-R) were administered to people who requested cosmetic rhinoplasty and control subjects. All participants were also screened by the Structured Clinical Interview for DSM-IV-(SCIDI/ CV, SCID-II). RESULTS: Thirteen cosmetic rhinoplasty seekers [CRS] (26%) and three control subjects (6%) had at least one psychiatric diagnosis. There was a significant difference between the two groups (p = 0.006). Beck depression inventory (p = 0.002) and BAI (p = 0.046) levels above the cut-off point were significantly higher in the CRS group than in the normal control. Somatoform disorders were statistically higher in the CRS than control group (p = 0.007). Nine CRS (18%) and two control subjects (4%) had at least one personality disorder. There were differences between the two groups (p = 0.025). The average of SCL-90-R was significantly higher in the CRS than in the control subjects (p < 0.001). The most prevalent somatoform disorders of the CRS were six with body dysmorphic disorder [BDD] (12%). The most prevalent personality disorders of the CRS were three with avoidant (6%) and three with narcissistic (6%) personality. CONCLUSION: Assessment of detailed psychopathological aspects and psychiatric co-morbidities could help to define the clinical profile of people requesting cosmetic rhinoplasty in cosmetic surgery settings. Research into these factors may be important as it is essential to detect crucial problems such as personality disorders and BDD before surgery.

OBJETIVO: El propósito del estudio fue examinar los rasgos psicopatológicos y las comorbilidades psiquiátricas en los solicitantes de rinoplastia cosmética. SUJETOS Y MÉTODO: Cincuenta personas que buscaban rinoplastia cosmética, y 50 sujetos de control fueron registrados en el estudio. El Inventario de Depresión de Beck (BDI), el Inventario de Ansiedad de Beck (BAI), y el Listado de Síntomas 90 (Revisado) (SCL 90), fueron aplicados a las personas que solicitaron rinoplastia cosmética y a los sujetos del control. Todos los participantes fueron también sometidos a tamizaje mediante la Entrevista Clínica Estructurada para DSM - IV-(SCID-/ CV, SCIDII). RESULTADOS: Trece solicitantes de rinoplastia cosmética solicitantes (SRC) (26%) y tres sujetos de control (6%) tuvieron al menos un diagnóstico psiquiátrico. Hubo una diferencia significativa entre los dos grupos (p = 0.006). Los niveles de BDI (p = 0,002) y BAI (p = 0.046) por encima del valor límite, fueron significativamente más altos en el grupo de SRC que en el grupo control normal. Los trastornos somatoformes fueron estadísticamente más altos en el grupo SRC que en el grupo control (p = 0.007). Nueve SRC (18%) y dos sujetos de control (4%) tenían al menos un trastorno de personalidad. Hubo diferencias entre los dos grupos (p = 0. 025). El promedio de SCL-90-R fue significativamente más alto en el grupo de SRC que en los sujetos del grupo control (p < 0.001). Los trastornos somatoformes más prevalentes de SRC fueron seis con trastorno dismórfico corporal (TDC) (12%). Los trastornos de personalidad más prevalentes de SRC fueron: tres con trastorno de la personalidad por evitación (6%) y tres con personalidad narcisista (6%). CONCLUSIÓN: La evaluación de los aspectos psicopatológicos detallados y las comorbilidades psiquiátricas podrían ayudar a definir el perfil clínico de las personas que solicitan rinoplastia cosmética en los escenarios de cirugía cosmética. La investigación en estos factores puede ser importante, ya que es esencial para detectar problemas cruciales tales como los trastornos de personalidad y TDC antes de la cirugía.

Psychopathological evaluation of patients requesting cosmetic rhinoplasty: a review.

OBJECTIVE: The goal of this review is to discuss possible underlying psychopathological situations in patients requesting surgical cosmetic rhinoplasty operation and to examine potential problems that might arise. SUBJECTS AND METHODS: An extensive search was conducted through PubMed, Ambase and Psychlnfo by using related keywords in English, like "rhinoplasty and psychiatric comorbidities", "rhinoplasty and psychopathology". RESULTS: Patients who demand cosmetic rhinoplasty operation appealed to the surgeon since they wanted to feel better about themselves after the surgery. Indeed, some long-term studies determined that such a situation can take place at high rates. However, some studies reported the possibility of serious psychological disorders after such surgical operations. Studies relating to the analysis of psychopathologic symptoms are quite limited. Research has shown that psychopathologic evaluation conducted preoperatively is especially important to identify serious psychopathologies such as personality disorders and body dysmorphic disorder (BDD). CONCLUSIONS: Exclusion of patients possessing serious psychopathologies from operations provides better results in the long term. The lack of sufficient research in this area necessitates new and comprehensive studies.

Free minimization of the fundamental measure theory functional: Freezing of parallel hard squares and cubes.

Due to remarkable advances in colloid synthesis techniques, systems of squares and cubes, once an academic abstraction for theorists and simulators, are nowadays an experimental reality. By means of a free minimization of the free-energy functional, we apply fundamental measure theory to analyze the phase behavior of parallel hard squares and hard cubes. We compare our results with those obtained by the traditional approach based on the Gaussian parameterization, finding small deviations and good overall agreement between the two methods. For hard squares, our predictions feature at intermediate packing fraction a smectic phase, which is however expected to be unstable due to thermal fluctuations. Due to this inconsistency, we cannot determine unambiguously the prediction of the theory for the expected fluid-to-crystal transition of parallel hard squares, but we deduce two alternative scenarios: (i) a second-order transition with a coexisting vacancy-rich crystal or (ii) a higher-density first-order transition with a coexisting crystal characterized by a lower vacancy concentration. In accordance with previous studies, a second-order transition with a high vacancy concentration is predicted for hard cubes.

Depletion-induced biaxial nematic states of boardlike particles.

With the aim of investigating the stability conditions of biaxial nematic liquid crystals, we study the effect of adding a non-adsorbing ideal depletant on the phase behavior of colloidal hard boardlike particles. We take into account the presence of the depletant by introducing an effective depletion attraction between a pair of boardlike particles. At fixed depletant fugacity, the stable liquid-crystal phase is determined through a mean-field theory with restricted orientations. Interestingly, we predict that for slightly elongated boardlike particles a critical depletant density exists, where the system undergoes a direct transition from an isotropic liquid to a biaxial nematic phase. As a consequence, by tuning the depletant density, an easy experimental control parameter, one can stabilize states of high biaxial nematic order even when these states are unstable for pure systems of boardlike particles.

Psychopathological evaluation of patients requesting cosmetic rhinoplasty a review / Evaluación psicopatológica de pacientes que requieren rinoplastia cosmética una revisión

OBJECTIVE: The goal of this review is to discuss possible underlying psychopathological situations in patients requesting surgical cosmetic rhinoplasty operation and to examine potential problems that might arise. SUBJECTS AND METHODS: An extensive search was conducted through PubMed, Ambase and PsychInfo by using related keywords in English, like "rhinoplasty and psychiatric comorbidities ", "rhinoplasty and psychopathology". RESULTS: Patients who demand cosmetic rhinoplasty operation appealed to the surgeon since they wanted to feel better about themselves after the surgery. Indeed, some long-term studies determined that such a situation can take place at high rates. However, some studies reported the possibility of serious psychological disorders after such surgical operations. Studies relating to the analysis of psychopathologic symptoms are quite limited. Research has shown that psychopathologic evaluation conducted preoperatively is especially important to identify serious psychopathologies such as personality disorders and body dysmorphic disorder (BDD). CONCLUSIONS: Exclusion of patients possessing serious psychopathologies from operations provides better results in the long term. The lack of sufficient research in this area necessitates new and comprehensive studies.

OBJETIVO: El propósito de esta revisión es discutir las posibles situaciones psicopatológicas detrás de pacientes que solicitan la operación de rinoplastia quirúrgica cosmética, y examinar problemas potenciales que podrían suscitarse. SUJETOS Y MÉTODOS: Se llevó a cabo una búsqueda extensa a través de PubMed, Ambase y PsychInfo usando palabras claves en inglés, como "rinoplastia y comorbidades psiquiátricas " "rinoplastia y psicopatología ". RESULTADOS: Pacientes que solicitaban una operación de rinoplastia cosmética, apelaron al cirujano expresando que deseaban sentirse mejor luego de la cirugía. En realidad, algunos estudios a largo plazo determinaron que una situación semejantepuede tener una alta tasa de ocurrencia. Sin embargo, otros estudios reportan la posibilidad de trastornos psicológicos serios Los estudios que se refieren al análisis de síntomas psicopatológicos, son muy limitados. Las investigaciones han demostrado que realizar una evaluación psicopatológica antes de la operación, es en extremo importante [ara identificar serias psicopatologías tales como trastornos de la personalidad y Trastorno Dismórfico Corporal (TDC). CONCLUSIONES: El excluir a los pacientes con serias psicopatologías de las operaciones arroja mejores resultados a largo plazo. La insuficiente investigación en esta área apunta a la necesidad de que se realicen estudios nuevos y abarcadores.