Atmosphere injection of sea salts during large explosive submarine volcanic eruptions.

The 15 January 2022 submarine eruption at Hunga volcano was the most explosive volcanic eruption in 140 years. It involved exceptional magma and seawater interaction throughout the entire submarine caldera collapse. The submarine volcanic jet breached the sea surface and formed a subaerial eruptive plume that transported volcanic ash, gas, sea salts and seawater up to ~ 57 km, reaching into the mesosphere. We document high concentrations of sea salts in tephra (volcanic ash) collected shortly after deposition. We also discuss the potential climatic consequences of large-scale injection of salts into the upper atmosphere during submarine eruptions. Sodium chloride in these volcanic plumes can reach extreme concentrations, and dehalogenation of chlorides and bromides poses the risk of long-term atmospheric and weather impact. Salt content in rapidly collected tephra samples may also be used as a proxy to estimate the water:magma ratio during eruption, with implications for quantification of fragmentation efficiency in submarine breaching events. The balance between salt loading into the atmosphere versus deposition in ash aggregates is a key factor in understanding the atmospheric and climatic consequences of submarine eruptions.

Comparative analyses of holder pasteurization vs. HTST pasteurization for donor milk: a cost-minimization study applicable to human milk banks.

BACKGROUND: High-temperature short-time (HTST) pasteurization (72-75 °C, 15 s) is an alternative treatment to traditional Holder pasteurization (HoP) (62ºC, 30 min) for donor milk. HTST pasteurization guarantees the milk's microbiological safety and retains more of its biologically and nutritionally active compounds, but the cost of implementing this technology for a human milk bank is unknown. METHODS: A cost-minimization study was carried out on the facilities of a regional human milk bank in a public hospital. Total production costs (fixed plus variables) were quantified using HTST pasteurization and HoP in three hypothetical scenarios: (1) costs of the first 10 L of pasteurized milk in a newly opened milk bank; (2) costs of the first 10 L of pasteurized milk in an active milk bank; and (3) costs using the maximum production capacity of both technologies in the first two years of operation. The following costs were analyzed: health care professionals, equipment and software, external services, and consumables. RESULTS: In scenario 1, the total production costs were € 228,097.00 for the HTST method versus € 154,064.00 for the HoP method. In scenario 2, these costs were similar (€ 6,594.00 for HTST pasteurization versus € 5,912.00 for HoP). The cost of healthcare professionals was reduced by more than half when pasteurization was carried out by the HTST method versus the Holder method (€ 84.00 and € 191.00, respectively). In scenario 3, the unit cost of milk pasteurized by the HTST method decreased from the first to the second year by 43.5%, while for the HoP method, it decreased by 30%. CONCLUSIONS: HTST pasteurization requires a high initial investment in equipment; however, it provides a significant minimization of production costs in the long term, pasteurizes large quantities of donor milk per working day and achieves a more efficient management of the time of the health care professionals in charge of the bank's operation compared to HoP.

Modification at the C2'-O-Position with 2-Methylbenzothiophene Induces Unique Structural Changes and Thermal Transitions on Duplexes of RNA and DNA.

Oligonucleotides can be chemically modified for a variety of applications that include their use as biomaterials, in therapeutics, or as tools to understand biochemical processes, among others. This work focuses on the functionalization of oligonucleotides of RNA and DNA (12- or 14-nucleotides long) with methylbenzothiophene (BT), at the C2'-O-position, which led to unique structural features. Circular dichroism (CD) analyses showed that positioning the BT units on one strand led to significant thermal destabilization, while duplexes where each strand contained 4-BT rings formed a distinct arrangement with cooperativity/interactions among the modifications (evidenced from the appearance of a band with positive ellipticity at 235 nm). Interestingly, the structural arrays displayed increased duplex stabilization (>10 °C higher than the canonical analogue) as a function of [Na+] with an unexpected structural rearrangement at temperatures above 50 °C. Density functional theory-polarizable continuum model (DFT-PCM) calculations were carried out, and the analyses were in agreement with induced structural changes as a function of salt content. A model was proposed where the hydrophobic surface allows for an internal nucleobase rearrangement into a more thermodynamically stable structure, before undergoing full denaturation, with increased heat. While this behavior is not common, B- to Z-form duplex transitions can occur and are dependent on parameters that were probed in this work, i.e., temperature, nature of modification, or ionic content. To take advantage of this phenomenon, we probed the ability of the modified duplexes to be recognized by Zα (an RNA binding protein that targets Z-form RNA) via electrophoretic analysis and CD. Interestingly, the protein did not bind to canonical duplexes of DNA or RNA; however, it recognized the modified duplexes, in a [monovalent/divalent salt] dependent manner. Overall, the findings describe methodology to attain unique structural motifs of modified duplexes of DNA or RNA, and control their behavior as a function of salt concentration. While their affinity to RNA binding proteins, and the corresponding mechanism of action, requires further exploration, the tunable properties can be of potential use to study this, and other, types of modifications. The novel arrays that formed, under the conditions described herein, provide a useful way to explore the structure and behavior of modified oligonucleotides, in general.

Encuesta sobre las creencias de los implantes dentales en función de: salud bucodental, nivel educativo e ingresos económicos en un grupo de población / Survey on beliefs relating to dental implants according to: oral health, educational level and income in a population group

Introducción: En los comienzos de siglo, el asentamiento de cadenas dentales en el escenario de la odontología española produjo un aperturismo en el acceso al tratamiento implantológico, considerado hasta entonces como producto de lujo limitado por la capacidad económica del paciente. La financiación atrajo a cantidad de usuarios, creando una gran oferta que fomentó la aparición de publicidad dental invasiva que influye sobre las creencias y percepción de los pacientes para tomar decisiones. Se planteó como objetivo estudiar la influencia del nivel de ingresos, educación y salud bucodental en las creencias de la población en relación con los implantes dentales. Métodos: Sobre una encuesta de 48 preguntas a través de Google Formularios, abierta de marzo a junio de 2021, se tuvo acceso a un total de 535 usuarios no vinculados al sector odontoestomatológico. Los datos fueron secundariamente analizados mediante un análisis descriptivo. Resultados: El nivel de educación de los progenitores de los encuestados resultó ser más influyente en la salud bucodental de los encuestados que el nivel de ingresos o de educación de los propios encuestados. El nivel de ingresos no resultó influyente en relación con la elección del tipo de clínica dental, profesional o precio de los implantes, sino el nivel educativo intergeneracional. Conclusiones: El nivel educativo de los progenitores de los encuestados es el factor que más influyó en la muestra de este estudio, tanto en la salud bucodental, como en la toma de decisiones relacionadas con la implantología (AU)

Introduction: At the turn of the century, the establishment of dental chains on the Spanish dentistry scenario led to an opening up of access to implant treatments, which until then had been considered a luxury product limited by the patient’s financial capacity. Financing attracted a large number of users, creating a large supply that fostered the emergence of invasive dental advertising that influences patients’ beliefs and perceptions for decision making. The aim was to study the influence of income level, education and oral health on the beliefs of the population in relation to dental implants. Methods: A 48-question survey via Google Forms, opened from March to June 2021, provided access to a total of 535 users not linked to the dentistry sector. The data were secondarily analysed using an Excel spreadsheet. Results: The education level of the respondents’ parents was found to be more influential on the respondents’ oral health than the level of income or education of the respondents themselves. The level of income was not influential in relation to the choice of the type of dental clinic, professional or price of the implants, but rather the intergenerational educational level. Conclusions: The educational level of the respondents’ parents is the most influential factor in the sample of this study, both in terms of oral health and in decision-making related to implant dentistry (AU)

Analysis of the Effects of Lockdown on Staff and Students at Universities in Spain and Colombia Using Natural Language Processing Techniques.

The aim of this study is to analyze the effects of lockdown using natural language processing techniques, particularly sentiment analysis methods applied at large scale. Further, our work searches to analyze the impact of COVID-19 on the university community, jointly on staff and students, and with a multi-country perspective. The main findings of this work show that the most often related words were "family", "anxiety", "house", and "life". Besides this finding, we also have shown that staff have a slightly less negative perception of the consequences of COVID-19 in their daily life. We have used artificial intelligence models such as swivel embedding and a multilayer perceptron as classification algorithms. The performance that was reached in terms of accuracy metrics was 88.8% and 88.5% for students and staff, respectively. The main conclusion of our study is that higher education institutions and policymakers around the world may benefit from these findings while formulating policy recommendations and strategies to support students during this and any future pandemics.

Identification of RNA Fragments Resulting from Enzymatic Degradation using MALDI-TOF Mass Spectrometry.

RNA is a biopolymer present in all domains of life, and its interactions with other molecules and/or reactive species, e.g., DNA, proteins, ions, drugs, and free radicals, are ubiquitous. As a result, RNA undergoes various reactions that include its cleavage, degradation, or modification, leading to biologically relevant species with distinct functions and implications. One example is the oxidation of guanine to 7,8-dihydro-8-oxoguanine (8-oxoG), which may occur in the presence of reactive oxygen species (ROS). Overall, procedures that characterize such products and transformations are largely valuable to the scientific community. To this end, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry is a widely used method. The present protocol describes how to characterize RNA fragments formed after enzymatic treatment. The chosen model uses a reaction between RNA and the exoribonuclease Xrn-1, where enzymatic digestion is halted at oxidized sites. Two 20-nucleotide long RNA sequences [5'-CAU GAA ACA A(8-oxoG)G CUA AAA GU] and [5'-CAU GAA ACA A(8-oxoG)(8-oxoG) CUA AAA GU] were obtained via solid-phase synthesis, quantified by UV-vis spectroscopy, and characterized via MALDI-TOF. The obtained strands were then (1) 5'-phosphorylated and characterized via MALDI-TOF; (2) treated with Xrn-1; (3) filtered and desalted; (4) analyzed via MALDI-TOF. This experimental setup led to the unequivocal identification of the fragments associated with the stalling of Xrn-1: [5'-H2PO4-(8-oxoG)G CUA AAA GU], [5'-H2PO4-(8-oxoG)(8-oxoG) CUA AAA GU], and [5'-H2PO4-(8-oxoG) CUA AAA GU]. The described experiments were carried out with 200 picomols of RNA (20 pmol used for MALDI analyses); however, lower amounts may result in detectable peaks with spectrometers using laser sources with more power than the one used in this work. Importantly, the described methodology can be generalized and potentially extended to product identification for other processes involving RNA and DNA, and may aid in the characterization/elucidation of other biochemical pathways.

Processing of RNA Containing 8-Oxo-7,8-Dihydroguanosine (8-oxoG) by the Exoribonuclease Xrn-1.

Understanding how oxidatively damaged RNA is handled intracellularly is of relevance due to the link between oxidized RNA and the progression/development of some diseases as well as aging. Among the ribonucleases responsible for the decay of modified (chemically or naturally) RNA is the exonuclease Xrn-1, a processive enzyme that catalyzes the hydrolysis of 5'-phosphorylated RNA in a 5'→3' direction. We set out to explore the reactivity of this exonuclease towards oligonucleotides (ONs, 20-nt to 30-nt long) of RNA containing 8-oxo-7,8-dihydroguanosine (8-oxoG), obtained via solid-phase synthesis. The results show that Xrn-1 stalled at sites containing 8-oxoG, evidenced by the presence of a slower moving band (via electrophoretic analyses) than that observed for the canonical analogue. The observed fragment(s) were characterized via PAGE and MALDI-TOF to confirm that the oligonucleotide fragment(s) contained a 5'-phosphorylated 8-oxoG. Furthermore, the yields for this stalling varied from app. 5-30% with 8-oxoG located at different positions and in different sequences. To gain a better understanding of the decreased nuclease efficiency, we probed: 1) H-bonding and spatial constraints; 2) anti-syn conformational changes; 3) concentration of divalent cation; and 4) secondary structure. This was carried out by introducing methylated or brominated purines (m1G, m6,6A, or 8-BrG), probing varying [Mg2+], and using circular dichroism (CD) to explore the formation of structured RNA. It was determined that spatial constraints imposed by conformational changes around the glycosidic bond may be partially responsible for stalling, however, the results do not fully explain some of the observed higher stalling yields. We hypothesize that altered π-π stacking along with induced H-bonding interactions between 8-oxoG and residues within the binding site may also play a role in the decreased Xrn-1 efficiency. Overall, these observations suggest that other factors, yet to be discovered/established, are likely to contribute to the decay of oxidized RNA. In addition, Xrn-1 degraded RNA containing m1G, and stalled mildly at sites where it encountered m6,6A, or 8-BrG, which is of particular interest given that the former two are naturally occurring modifications.

Differentiation between normal and tumor mammary glands with depth-resolved attenuation coefficient from optical coherence tomography.

Optical coherence tomography (OCT) is a well-established imaging technology for high-resolution, cross-sectional imaging of biological tissues. Imaging processing and light attenuation coefficient estimation allows to further improve the OCT diagnostic capability. In this paper we use a commercial OCT system, Telesto II-1325LR from Thorlabs, and demonstrate its ability to differentiate normal and tumor mammary mouse glands with the OCT attenuation coefficient. Using several OCT images of normal and tumor mammary mouse glands (n = 26), a statistical analysis was performed. The attenuation coefficient was calculated in depth, considering a slope of 0.5 mm. The normal glands present a median attenuation coefficient of 0.403 mm-1, comparatively to 0.561 mm-1obtained for tumor mammary glands. This translates in an attenuation coefficient approximately 39% higher for tumor mammary glands when compared to normal mammary glands. The OCT attenuation coefficient estimation eliminates the subjective analysis provided by direct visualization of the OCT images.

Hospital and outpatient models for Hematopoietic Stem Cell Transplantation: A systematic review of comparative studies for health outcomes, experience of care and costs.

The number of Hematopoietic Stem Cell Transplantations has risen in the past 20 years. The practice of outpatient Hematopoietic Stem Cell Transplantation programs is increasing in an attempt to improve the quality of patient care and reduce the demand for hospital admission. A systematic review of 29 comparative studies between in-hospital and outpatient treatment of Hematopoietic Stem Cell Transplantation, with no restriction by outpatient regime was conducted. This study aims to analyse the current evidence on the effects of the outpatient model on patient-centred outcomes, comparing both in-hospital and outpatient models for autologous and allogeneic HSCT using the Triple Aim framework: health outcomes, costs and experience of care. We found evidence on improved health outcomes and quality of life, on enhanced safety and effectiveness and on reduced overall costs and hospital stays, with similar results on overall survival rates comparing both models for autologous and allogeneic patients. We also found that the outpatient Hematopoietic Stem Cell Transplantation is a safe practice as well as less costly, it requires fewer days of hospital stay both for autologous and allogeneic transplantations. Under a situation of an increasing number of transplants, rising healthcare costs and shortages of hospital capacity, incorporating outpatient models could improve the quality of care for people requiring Hematopoietic Stem Cell Transplantation programs.

Double-Layer Flexible Neural Probe With Closely Spaced Electrodes for High-Density in vivo Brain Recordings.

Flexible polymer neural probes are an attractive emerging approach for invasive brain recordings, given that they can minimize the risks of brain damage or glial scaring. However, densely packed electrode sites, which can facilitate neuronal data analysis, are not widely available in flexible probes. Here, we present a new flexible polyimide neural probe, based on standard and low-cost lithography processes, which has 32 closely spaced 10 µm diameter gold electrode sites at two different depths from the probe surface arranged in a matrix, with inter-site distances of only 5 µm. The double-layer design and fabrication approach implemented also provides additional stiffening just sufficient to prevent probe buckling during brain insertion. This approach avoids typical laborious augmentation strategies used to increase flexible probes' mechanical rigidity while allowing a small brain insertion footprint. Chemical composition analysis and metrology of structural, mechanical, and electrical properties demonstrated the viability of this fabrication approach. Finally, in vivo functional assessment tests in the mouse cortex were performed as well as histological assessment of the insertion footprint, validating the biological applicability of this flexible neural probe for acquiring high quality neuronal recordings with high signal to noise ratio (SNR) and reduced acute trauma.

The Impact of COVID 19 on University Staff and Students from Iberoamerica: Online Learning and Teaching Experience.

(1) Background: The COVID-19 pandemic has created a great impact on mental health in society. Considering the little attention paid by scientific studies to either students or university staff during lockdown, the current study has two aims: (a) to analyze the evolution of mental health and (b) to identify predictors of educational/professional experience and online learning/teaching experience. (2) Methods: 1084 university students and 554 staff in total from four different countries (Spain, Colombia, Chile and Nicaragua) participated in the study, affiliated with nine different universities, four of them Spanish and one of which was online. We used an online survey known as LockedDown, which consists of 82 items, analyzed with classical multiple regression analyses and machine learning techniques. (3) Results: Stress level and feelings of anxiety and depression of students and staff either increased or remained over the weeks. A better online learning experience for university students was associated with the age, perception of the experience as beneficial and support of the university. (4) Conclusions: The study has shown evidence of the emotional impact and quality of life for both students and staff. For students, the evolution of feelings of anxiety and depression, as well as the support offered by the university affected the educational experience and online learning. For staff who experienced a positive professional experience, with access to services and products, the quality-of-life levels were maintained.

Experimental and theoretical rationalization for the base pairing abilities of inosine, guanosine, adenosine, and their corresponding 8-oxo-7,8-dihydropurine, and 8-bromopurine analogues within A-form duplexes of RNA.

Inosine is an important RNA modification, furthermore RNA oxidation has gained interest due, in part, to its potential role in the development/progression of disease as well as on its impact on RNA structure and function. In this report we established the base pairing abilities of purine nucleobases G, I, A, as well as their corresponding, 8-oxo-7,8-dihydropurine (common products of oxidation at the C8-position of purines), and 8-bromopurine (as probes to explore conformational changes), derivatives, namely 8-oxoG, 8-oxoI, 8-oxoA, 8-BrG, and 8-BrI. Dodecamers of RNA were obtained using standard phosphoramidite chemistry via solid-phase synthesis, and used as models to establish the impact that each of these nucleobases have on the thermal stability of duplexes, when base pairing to canonical and noncanonical nucleobases. Thermal stabilities were obtained from thermal denaturation transition (Tm ) measurements, via circular dichroism (CD). The results were then rationalized using models of base pairs between two monomers, via density functional theory (DFT), that allowed us to better understand potential contributions from H-bonding patterns arising from distinct conformations. Overall, some of the important results indicate that: (a) an anti-I:syn-A base pair provides thermal stability, due to the absence of the exocyclic amine; (b) 8-oxoG base pairs like U, and does not induce destabilization within the duplex when compared to the pyrimidine ring; (c) a U:G wobble-pair is only stabilized by G; and (d) 8-oxoA displays an inherited base pairing promiscuity in this sequence context. Gaining a better understanding of how this oxidatively generated lesions potentially base pair with other nucleobases will be useful to predict various biological outcomes, as well as in the design of biomaterials and/or nucleotide derivatives with biological potential.

Translesion synthesis by AMV, HIV, and MMLVreverse transcriptases using RNA templates containing inosine, guanosine, and their 8-oxo-7,8-dihydropurine derivatives.

Inosine is ubiquitous and essential in many biological processes, including RNA-editing. In addition, oxidative stress on RNA has been a topic of increasing interest due, in part, to its potential role in the development/progression of disease. In this work we probed the ability of three reverse transcriptases (RTs) to catalyze the synthesis of cDNA in the presence of RNA templates containing inosine (I), 8-oxo-7,8-dihydroinosine (8oxo-I), guanosine (G), or 8-oxo-7,8-dihydroguanosine (8-oxoG), and explored the impact that these purine derivatives have as a function of position. To this end, we used 29-mers of RNA (as template) containing the modifications at position-18 and reverse transcribed DNA using 17-mers, 18-mers, or 19-mers (as primers). Generally reactivity of the viral RTs, AMV / HIV / MMLV, towards cDNA synthesis was similar for templates containing G or I as well as for those with 8-oxoG or 8-oxoI. Notable differences are: 1) the use of 18-mers of DNA (to explore cDNA synthesis past the lesion/modification) led to inhibition of DNA elongation in cases where a G:dA wobble pair was present, while the presence of I, 8-oxoI, or 8-oxoG led to full synthesis of the corresponding cDNA, with the latter two displaying a more efficient process; 2) HIV RT is more sensitive to modified base pairs in the vicinity of cDNA synthesis; and 3) the presence of a modification two positions away from transcription initiation has an adverse impact on the overall process. Steady-state kinetics were established using AMV RT to determine substrate specificities towards canonical dNTPs (N = G, C, T, A). Overall we found evidence that RNA templates containing inosine are likely to incorporate dC > dT > > dA, where reactivity in the presence of dA was found to be pH dependent (process abolished at pH 7.3); and that the absence of the C2-exocyclic amine, as displayed with templates containing 8-oxoI, leads to increased selectivity towards incorporation of dA over dC. The data will be useful in assessing the impact that the presence of inosine and/or oxidatively generated lesions have on viral processes and adds to previous reports where I codes exclusively like G. Similar results were obtained upon comparison of AMV and MMLV RTs.

7,8-Dihydro-8-oxoguanosine Lesions Inhibit the Theophylline Aptamer or Change Its Selectivity.

Aptamers are attractive constructs due to their high affinity/selectivity towards a target. Here 7,8-dihydro-8-oxoguanosine (8-oxoG) has been used, due in part to its unique H-bonding capabilities (Watson-Crick or Hoogsteen), to expand the "RNA alphabet". Its impact on the theophylline RNA aptamer was explored by modifying its binding pocket at positions G11, G25, or G26. Structural probing, with RNases A and T1 , showed that modification at G11 leads to a drastic structural change, whereas the G25-/G26-modified analogues exhibited cleavage patterns similar to that of the canonical construct. The recognition properties towards three xanthine derivatives were then explored through thermophoresis. Modifying the aptamer at position G11 led to binding inhibition. Modification at G25, however, changed the selectivity towards theobromine (Kd ≈160 µm), with a poor affinity for theophylline (Kd >1.5 mm) being observed. Overall, 8-oxoG can have an impact on the structures of aptamers in a position-dependent manner, leading to altered target selectivity.

Managing menopausal symptoms after cancer.

The joint burden of cancer and menopause impacts millions of women globally. This review provides an approach to management of menopausal symptoms after cancer in all settings. This includes an overview of current evidence for both hormonal and non-hormonal treatments for vasomotor symptoms and vaginal dryness after cancer. Systemic menopausal hormone therapy provides symptom control and may be used after most cancers but should be avoided after estrogen receptor-positive breast cancer and after some other estrogen-dependent cancers. Non-hormonal therapies have been minimally studied in women after a cancer diagnosis and, where they have been studied, it is usually in women with breast cancer. Non-hormonal methods to manage vasomotor symptoms include cognitive behavioral therapy, hypnosis, selective serotonin reuptake inhibitors, serotonin noradrenaline reuptake inhibitors, clonidine, and gabapentin. Vaginal estrogen may be useful to address vaginal dryness. However, safety data in breast cancer patients are still lacking and there is currently no consensus. Lubricants may also help with pain with sexual activity. Management of menopausal symptoms after cancer may be challenging and should include information about induced menopause and possible symptoms as well as available treatments. Management then requires a holistic and multidisciplinary approach with individualized care.

Photocycloaddition of S,S-Dioxo-benzothiophene-2-methanol, Reactivity in the Solid State and in Solution: Mechanistic Studies and Diastereoselective Formation of Cyclobutyl Rings.

The formation of cyclobutane rings is a promising strategy in the development of potential drugs and/or synthetic intermediates, typically challenging to obtain due to their constrained nature. In this work, the [2 + 2] photocycloaddition reaction of S,S-dioxobenzothiophene-2-methanol was explored in microcrystalline powders and its outcome was compared to that observed in solution. It was found that the molecular constraints inherited within the crystal lattice provide an optimal environment that leads to photodimer 4 as the major product in ca. 9.6:0.4 diastereomeric ratios with conversions >95%. The photoreaction was analyzed via X-ray, displaying a crystalline-to-amorphous transformation and showing that units of monomer 2 align to generate the corresponding dimer with a syn-head-to-tail regio- and diastereoselectivity. This result contrasted with that obtained in solution, where the diastereomeric ratio varied as a function of the excited state that is generated, to yield mixtures of dimers 4 and 5 (anti-head-to-tail), or exclusively 5 in the triplet-sensitized photoreaction, in the presence of benzophenone. Density functional theory was used to elucidate a plausible detailed mechanism for the phototransformation, which aided in justifying the results that led to the corresponding dimers. X-ray crystallography allowed us to establish the stereochemical assignment of the obtained cyclobutyl rings. Thus, the use of solid-state or solution photochemistry can be used to gain control of diastereo- and regioselectivities in the formation of this important moiety.

Surgically Managed Ovarian Masses at the Royal Children's Hospital, Melbourne -19 Year Experience.

BACKGROUND/PURPOSE: To describe the clinicopathological characteristics and management of surgically removed ovarian masses at the Royal Children's Hospital, Melbourne from 1993 to 2012. METHODS: Medical records were reviewed retrospectively. Data regarding clinical findings, imaging and surgical management were evaluated. RESULTS: There were 266 ovarian masses found in 258 surgeries (eight had bilateral masses). Most were benign (246/266, 92.5%), 2.3% (6/266) were borderline, and 5.3% (14/266) were malignant. The most common presenting symptom was abdominal pain for benign masses (169/246, 68.7%), and a palpable mass for borderline and malignant masses (12/20, 60.0%). Sensitivity and specificity of ultrasound for detection of malignancy was 64.7% and 52.9% respectively. Ovarian torsion occurred in 22.1% (n=57), none with malignancy, with seven cases diagnosed under one year of age. Sensitivity and specificity of ultrasound for ovarian torsion was 22.0% and 91.9%, respectively. The proportion undergoing ovarian cystectomy rather than oophorectomy has increased from 56.3% during 1993-1997 to 93.8% during 2008-2012 (p<0.005). Ovarian torsion was managed with ovarian conservation in 82.6% of cases between 2008-2012. CONCLUSION: The majority of pediatric and adolescent ovarian masses were benign. Sensitivity of ultrasound was fair for detection of malignancy, and poor for ovarian torsion. Conservative surgeries are increasingly common. LEVEL OF EVIDENCE: Level IV - case series with no comparison group TYPE OF STUDY: Retrospective Study.

Orthogonality Catastrophe in Dissipative Quantum Many-Body Systems.

We present an analog of the phenomenon of orthogonality catastrophe in quantum many-body systems subject to a local dissipative impurity. We show that the fidelity F(t), giving a measure for distance of the time-evolved state from the initial one, displays a universal scaling form F(t)∝t^{θ}e^{-γt}, when the system supports long-range correlations, in a fashion reminiscent of traditional instances of orthogonality catastrophe in condensed matter. An exponential falloff at rate γ signals the onset of environmental decoherence, which is critically slowed down by the additional algebraic contribution to the fidelity. This picture is derived within a second-order cumulant expansion suited for Liouvillian dynamics, and substantiated for the one-dimensional transverse field quantum Ising model subject to a local dephasing jump operator, as well as for XY and XX quantum spin chains, and for the two-dimensional Bose gas deep in the superfluid phase with local particle heating. Our results hint that local sources of dissipation can be used to inspect real-time correlations and to induce a delay of decoherence in open quantum many-body systems.