Comet Tail Research Articles

Resolving the Bow Shock and Tail of the Cannonball Pulsar PSR J0002+6216

We present X-ray and radio observations of the recently discovered bow-shock pulsar wind nebula (PWN) associated with PSR J0002+6216, characterizing the PWN morphology, which was unresolved in previous studies. The multifrequency, multiepoch Very Large Array (VLA) radio observations reveal a cometary tail trailing the pulsar and extending up to 5.′3, with multiple kinks along the emission. The presented radio continuum images from multiconfiguration broadband VLA observations are one of the first results from the application of multiterm multifrequency synthesis deconvolution in combination with the AWProject gridder implemented in the Common Astronomy Software Applications (CASA) package. The X-ray emission observed with Chandra extends to only 21″, fades quickly, and has some hot spots present along the extended radio emission. These kinks could indicate the presence of density variations in the local interstellar medium or turbulence. The bow-shock standoff distance estimates a small bow-shock region with a size of 0.003–0.009 pc, consistent with the pulsar spin-down power of = 1.51 × 1035 erg s−1 estimated from timing. The high-resolution radio image reveals the presence of an asymmetry in the bow-shock region, which is also present in the X-ray image. The broadband radio image shows an unusually steep spectrum along with a flat-spectrum sheath, which could indicate varying opacity or energy injection into the region. Spatially resolved X-ray spectra provide marginal evidence of synchrotron cooling along the extended tail. Our analysis of the X-ray data also shows that this pulsar has a low spin-down power and one of the lowest X-ray efficiencies observed in these objects.

Fetal Adenomyomatosis - A Case Report

With an average incidence rate of 0.07-1.15%, foetal adenomyomatosis is a rare discovery during a third- trimester ultrasound. We describe a case of foetal adenomyomatosis that occurred at 37 weeks' gestation and was diagnosed 4 days after delivery. Clinicians must be aware of the implications of this illness and how to treat it effectively. A degenerative and proliferative condition called gall bladder adenomyomatosis is characterised by excessive epithelial proliferation along with muscularis propria hypertrophy. This results in intramural diverticula known as Rokitansky- Aschoff sinuses, which are mucosal outpouchings into or beyond the muscle layer (RAS). These sinuses get clogged with cholesterol crystals, which cause the comet tail artefacts on USG that are indicative of adenomyomatosis and are caused by reverberation artefacts. Because it is benign, there is typically no need for therapy. The condition resolves on its own and ultrasonography follow-up is necessary. Surgery is required when the condition is not resolving or the patient is symptomatic.

New Active Asteroid 2015 VA108: A Citizen Science Discovery

We announce the discovery of activity, in the form of a distinct cometary tail, emerging from main-belt asteroid 2015 VA108. Activity was first identified by volunteers of the Citizen Science project Active Asteroids (a NASA Partner). We uncovered one additional image from the same observing run which also unambiguously shows 2015 VA108 with a tail oriented between the anti-solar and anti-motion vectors that are often correlated with activity orientation on sky. Both publicly available archival images were originally acquired UT 2015 October 11 with the Dark Energy Camera (DECam) on the Blanco 4 m telescope at the Cerro Tololo Inter-American Observatory (Chile) as part of the Dark Energy Camera Legacy Survey. Activity occurred near perihelion and, combined with its residence in the main asteroid belt, 2015 VA108 is a candidate main-belt comet, an active asteroid subset known for volatile sublimation.

Multiepoch Detections of the Extended Atmosphere and Transmission Spectra of KELT-9b with a 1.5 m Telescope

Irradiated Jovian atmospheres are complex and dynamic and can undergo temporal variations due to the close proximity of their parent stars. Of the Jovian planets that have been cataloged to date, KELT-9b is the hottest gas giant known, with an equilibrium temperature of 4050 K. We probe the temporal variability of transmission spectroscopic signatures from KELT-9b via a set of archival multiyear ground-based transit observations, performed with the TRES facility on the 1.5 m reflector at the Fred Lawrence Whipple Observatory. Our observations confirm past detections of Fe i, Fe ii, and Mg i over multiple epochs, in addition to excess absorption at Hα, which is an indicator for ongoing mass loss. From our multiyear data set, the Hα light curve consistently deviates from a standard transit and follows a “W” shape that is deeper near ingress and egress and shallower midtransit. To search for and quantify any seasonal variations that may be present, we parameterize a “cometary tail” model to fit for the Hα transit. We find no detectable variations between the different observed epochs. Though a “cometary tail” describes the Hα flux variations well, we note that such a scenario requires a high density of neutral hydrogen in the n = 2 excited state far beyond the planetary atmosphere. Other scenarios, such as center-to-limb variations larger than that expected from 1D atmosphere models, may also contribute to the observed Hα transit shape. These multiepoch observations highlight the capabilities of small telescopes to provide temporal monitoring of the dynamics of exoplanet atmospheres.

Dermoscopic Features of Perilesional Skin of Unstable Vitiligo: A Cross-Sectional Study

Objectives: Dermoscopy is a very useful tool in determining stability in vitiligo. Dermoscopic features of unstable vitiligo are trichrome appearance, comet tail appearance, star burst appearance, amoeboid pattern, nebular pattern, tapioca sago pattern and perifollicular hypopigmentation. Most studies are done on determining features of vitiligo lesions; however, there is lack of studies on dermoscopy in normal appearing perilesional skin. This would give an insight into the extent of the disease process, beyond the borders of skin lesions. We conducted a study on 100 unstable lesions of vitiligo and studied dermoscopic features in its perilesional skin. The objective of this study was to observe dermoscopic features of apparently normal perilesional skin in patients of unstable vitiligo. Materials and Methods: A cross-sectional study was conducted in a tertiary care centre in New Delhi. We evaluated perilesional skin of 100 unstable vitiligo lesions over a span of 1 year. The perilesional skin has been defined as area within 5 cm of the lesion. Dermoscopy was performed using DERMLITE 4 Dermoscope at 10X magnification with inbuilt white light and polarised light. Polarised light was used to study changes in the pigmentary network and other patterns. We looked for features such as pigment network, perifollicular pigmentation, presence of leukotrichia, microkoebner phenomenon and satellite lesions in the perilesional skin. Results: The study included a total of 100 unstable lesions. Majority of patients belonged to the age group of 18−30 years. Females outnumbered males (1.8:1). All cases had progressive disease and mean duration of disease was 12.07 ± 10. 85 years. Dermoscopic features of vitiligo were observed in 56% of patients even in normal appearing perilesional skin. The most common dermoscopic finding observed was reduced pigment network which was seen in 33% of cases. Perifollicular hypopigmentation and depigmentation were observed in 23 and two sites, respectively, while leukotrichia was seen at ten sites. Eight sites showed microkoebners phenomenon. Conclusion: The perilesional apparently normal skin also shows signs of disease activity in cases of unstable vitiligo. Hence, perilesional skin should also be examined carefully with the dermoscope and topical treatment and targeted phototherapy should aim at covering the normal looking perilesional skin as well, at least within 5 cm of the borders of the skin lesions. Importantly, the perilesional skin should also be examined before surgery.

Elucidation of the cytogenotoxic potential of vigabatrin and its in silico computer-assisted DNA interaction

Vigabatrin (VGB) is a gammaaminobutyric acid-ergic (GABA-ergic) antiepileptic drug (AED) and is one of 2 approved drugs available to treat infantile spasms (IS). The aim of this study is to elucidate conflicting data on the toxic effects of VGB and to obtain detailed information about its possible cytogenotoxic effects in human lymphocytes. For this purpose, in vitro Chromosomal Aberration (CA), Sister Chromatid Exchange (SCE), Micronucleus (MN) tests, and Comet Assay were performed to determine possible genotoxic and cytotoxic effects of VGB. In addition, the binding energy level of VGB to DNA was determined in silico by molecular docking. The highest concentration (80 μg/ml) of VGB increased the SCE, CA, MN and micronucleated binuclear cell (BNMN) frequency significantly compared to the control after 24 and 48 hours of treatment. In the tail density and tail length parameters, the dose-dependent increase was found to be statistically significant compared to the control. At the 40 and 80 μg/ml concentrations of VGB for 48 hours caused a statistically significant increase in both CA/Cell and AC percentages, while MI and NDI decreased only significantly at the highest concentration (80 µg/ml) causing. In the Comet Assay head density, tail density and tail length parameters, the dose-dependent increase was found to be statistically significant compared to the control. Also, the in silico molecular docking analysis showed that VGB interacts with B-DNA close to the threshold binding energy. The lowest negative free binding energy (ΔG binding) was found as −5.13 kcal/mol. In conclusion, all results are evaluated together, it has been determined that VGB has cytogenotoxic effects in vitro and binds to DNA in silico with significant free binding energy.

CT features of rounded atelectasis in chronic inflammatory pleural effusions in cats and dogs.

Rounded atelectasis is well described in human medicine as focal lung deformation and collapse secondary to inflammatory pleural effusions and pleuritis. Specific CT features (round to ovoid soft tissue pulmonary attenuations, creation of an acute angle with the adjoining visceral pleura, and the presence of perinodular comet tail signs) support the diagnosis of rounded atelectasis in humans so that further diagnostic workup is not necessary in defining the nodules. In this retrospective case series, we described the CT characteristics of rounded atelectasis in eight cats and three dogs diagnosed with restrictive pleuritis secondary to either a chylothorax or pyothorax. Thirty-six soft tissue attenuating pulmonary nodular lesions were identified on CT. Comet tail signs, consisting of bundles of bronchi and vessels coalescing into the pulmonary nodules, were associated with 92% of the nodules (33/36), and 92% of the nodules abutted and created an acute angle with the pleura (33/36). Other prevalent features included location in gravity-dependent regions of the lung lobes (33/36, 92%), blurred hilar margins with sharper pleural margins of the nodules (33/36, 92%), presence of air bronchograms (30/36, 83%), homogeneous contrast-enhancement (23/36, 64%), and volume loss of the affected lung lobe (22/36, 61%). Pulmonary malignant neoplasms were not found cytologically (6/11 patients) or histologically (5/11 patients). To avoid a misdiagnosis of neoplasia, veterinary radiologists should be aware of the CT features of rounded atelectasis and consider it as a differential for pulmonary nodular lesions in patients with concurrent inflammatory pleural effusion and pleuritis.

Myosin-I facilitates symmetry breaking and promotes the growth of actin 'comet tails'.

Myosin-Is are single-headed, membrane associated members of the myosin superfamily that participate in crucial cellular processes related to membrane morphology and trafficking. Recent studies show that myosin-I isoforms frequently concentrate on membranes in areas of Arp2/3 complex-mediated actin polymerization that affect membrane shape and dynamics. To investigate how myosin-Is affect actin assembly, we performed a “comet tail assay” where branched actin networks were nucleated by Arp2/3 complex from a bead surface coated with a nucleation promoting factor (NPF). Actin filaments first formed a cloud around the bead, which transitioned into a polarized comet tail after symmetry breaking. We site-specifically coupled a range of densities of myosin-Is to the bead surface and assessed their effects on actin polymerization, network architecture, and symmetry breaking. We found that high myosin densities prevented comet tail formation. Instead, an extremely sparse actin cloud was created surrounding the bead. Decreasing the myosin density resulted in an actin network that broke symmetry more rapidly and formed a polarized comet tail. This actin comet tail was able to elongate from the bead at a faster rate and frequently showed smooth, rather than pulsatile motion. Myosin also changed the architecture of actin networks in comet tails. Compared with the coherent actin networks from non-myosin-coated beads, actin networks emerging from myosin-coated beads were sparser and more disordered, which might be due to the gliding and rotating effect of myosin. Strikingly, under low capping protein concentrations, where bead was embedded in a highly-dense actin shell and symmetry breaking was completely inhibited, myosin-coated beads were able to overcome this inhibition to break symmetry and form a comet tail. These studies show synergy between myosin activity and actin polymerization to power morphological changes at the cell membrane.

Echogenic Content in the Fetal Gallbladder: Systematic Review of Ultrasound Features and Clinical Outcome.

It is rare to detect echogenic content in the fetal gallbladder. The etiology, natural course, and prognosis of this condition remain unclear. In addition to providing a systematic review of this topic, we suggest a plan for patient follow-up. From a total of 100 database entries identified in PubMed, EMBASE, and ICTRP reviews, we selected 34 studies in which we investigated the ultrasound features and outcome of this condition. There were 226 fetuses with gallbladder echogenic content identified. Seventy-two fetuses were found to have biliary sludge; thirty cases had a single hyperechogenic focus, and one hundred fetuses had multiple foci in the gallbladder. There were 16 cases of distal shadowing, 37 fetuses with comet tail and twinkling, and 26 cases with no acoustic artifacts. Nine cases of spontaneous resolution before birth have been documented; nine fetuses exhibited no echogenic content at birth, and 138 cases of resolution of echogenic content within the first year of life have been described. Typically, the condition resolves spontaneously during the postnatal period. After adequately reassuring the parents, the patients should be monitored for spontaneous resolution; medical or surgical intervention is not indicated. Asymptomatic patients can be managed with a wait-and-see strategy.

In vitro cytotoxicity of curcuminoids against head and neck cancer HNO97 cell line

Oral squamous cell carcinoma (OSCC) is a malignant tumour of Head and Neck Cancer (HNC). The recent therapeutic approaches used to treat cancer have adverse side effects. The natural agents exhibiting anticancer activities are generally considered to have a robust therapeutic potential. Curcuminoids, one of the major active compounds of the turmeric herb, are used as a therapeutic agent for several diseases including cancer. In this study, the cytotoxicity of curcuminoids was investigated against OSCC cell line HNO97. Our data showed that curcuminoids significantly inhibits the proliferation of HNO97 in a time and dose-dependent manner (IC50=35 μM). Cell cycle analysis demonstrated that curcuminoids increased the percentage of G2/M phase cell populations in the treated groups. Treating HNO97 cells with curcuminoids led to cell shrinking and increased detached cells, which are the typical appearance of apoptotic cells. Moreover, flow cytometry analysis revealed that curcuminoids significantly induced apoptosis in a time-dependent manner. Furthermore, as a response to curcuminoids treatment, comet tails were formed in cell nuclei due to the induction of DNA damage. Curcuminoids treatment reduced the colony formation capacity of HNO97 cells and induced morphological changes. Overall, these findings demonstrate that curcuminoids can in vitro inhibit HNC proliferation and metastasis and induce apoptosis.

Dear Girlhood

Dear Girlhood Mary Angelino (bio) 1. Anagrams for girls who don’t play in the sea My sleepyhead—all heeltapsand leash, all pleatedand petaled from playdates— ahead are steeplesof sea, pedestals of atlaselapsing. Don’t let girlhood drift, don’t dare it to drag—my eyelash, my sad little eel. So what? I’ll deal.I’m gloried, adored, she sings, haloed and splayed on the shore. (I’m all plea,no play.) Death an eyeshade,a pale lady, wades into the deep. [End Page 28] 2. Song for queer girls For catching pollywogs (those squirmycommas) with a net or hands or anychipped wayward old mug; for mud-cakedBarbie’s hair, for the cleft of plastic (like a comma, net, or hands)between her legs, for her shinyhair and her clefts of plasticbreasts and for Velcro’s easy rip-away between her legs; for my shiny,wooly strokes. For loving the neighbor girl’sbreasts and for Velcro’s easy rip-awaywhen I loved myself, for my pillow’s wooly strokes. For loving the neighbor girland her mother’s, Be back when the streetlightscome on. For loving myself, my pillow,and all the girls who stayed out past dark, after the streetlights came on, their voiceschipped wayward old mugs. For mud-cakedgirls who stayed out past dark.For Barbie’s hair. For the cleft of plastic. [End Page 29] 3. How girls are made She’s old enough to wonder how it’s done.Her thumbs slide across the screenand those little comet tails between the letterstrail, they clip made down to mad and dam and me,or stretch it to demons or demand—see howmaiden weaves herself in? Sometimesa cheerful mead, a willful dame. A willful dame, a cheerful mead—sometimes a maiden weaves herself in.See how it stretches to demons or demand,how dam and mad clips down to me?Between the letters, those little comet tailsslide across the screen; her thumbswonder how it’s done. She’s old enough. [End Page 30] 4. How the girl got thick skin First, she felt it thin and shrinklike a child caught in a lie,so she took it off and carried it.Please don’t ask how she looked underneath (like a child caught in a lie),splashing through the creek.Please don’t ask how she lookedwhen she hid, when a predator—mid-hunt— splashed through the creek. You want toknow how she stretched and toughenedthat hide when the predator was through,how it felt to slip back into her skin— its arguments stretched and toughened,outgrown. She took it off, carried it,turned it back into skin, and slipped in.Don’t ask how she looked. [End Page 31] Mary Angelino MARY ANGELINO’s publications include The Arkansas International, The Southern Review, Foglifter, Rattle, The Cincinnati Review, and The Southern Humanities Review, with work forthcoming in The New York Quarterly’s anthology Without a Doubt. She has been nominated for a Pushcart Prize and received an honorable mention for the 2019 Auburn Witness Poetry Prize. Her poetry has been anthologized in Best New Poets. She lives in Valencia, California, where she teaches composition and creative writing at College of the Canyons and serves on the Santa Clarita Art Council’s Sidewalk Poetry Project. Fairy tales were my first experience with the image. They taught me to see things in my mind’s eye: the Beast’s blood-red roses, Sleeping Beauty’s thorn-choked tower, the gnarled hand of the witch holding out the apple. In “Dear Girlhood” (a love letter of sorts), I let the images from my childhood haunt and pout and sing, tangle and untangle themselves through their forms—anagrams, pantoums, and the mirror poem. Copyright © 2023 Wayne State University Press

Use of lung ultrasound in the differential diagnosis of the causes of dyspnea

Background/Aim. The field of lung ultrasonography (US) is a fast-developing one, and it provides the medical community with numerous new diagnostic opportunities. The aim of this study was to examine the etiology of dyspnea on admission and assess the stage of heart failure (HF) according to the US examination of the heart and lungs. Methods. The cross-sectional study included a total of 110 patients treated for the symptoms of dyspnea. The study included all patients treated for any heart or pulmonary condition, as well as patients who reported the first episode of dyspnea with-out any previous illness. The most important diagnostic sign in the US of the lungs in patients with HF was the appearance of B-lines or ?comets? (ultrasound artifacts reminiscent of comet tails), which indicate the accumulation of fluid in the interstitium of the lungs. Results. The mean number of registered ?comets? in the total number of patients was 14.2 ? 7.4 (minimum 2, maximum 30). The mean number of ?comets? among patients with HF was 18.8 ? 5.9. The mean number of ?comets? among patients without HF was 8.0 ? 3.7 (p ? 0.001). Multivariate linear regression analyses showed the association between the number of ?comets? and HF (p ? 0.001). Conclusion. As the assessment of present ?comets? in pulmonary US examination is safe and non-invasive, it can easily be integrated into the daily clinical practice because it has been shown that the number of pulmonary ?comets? is significantly higher in patients with HF compared to those with dyspnea of other etiologies.

Image reconstruction algorithm for laser-induced ultrasonic imaging: The single sensor scanning synthetic aperture focusing technique.

This paper aims to implement a laser-induced ultrasound imaging reconstruction method based on the delay-and-sum beamforming through the synthetic aperture focusing technique (SAFT) for a circular scanning, performed with a tomograph that had one acoustic sensor and a system that rotates the sample around a fixed axis. The proposed method, called the Single-sensor Scanning Synthetic Aperture Focusing Technique, considers the size of the sensor and the detection procedure inside the SAFT's algebra. This image reconstruction method was evaluated numerically, using the Green function for the laser-induced ultrasound wave equation to generate a forward problem, and experimentally, using a solid object of polylactic acid, and a Sprague-Dawley rat heart located in a tissue-mimicking phantom. The resulting images were compared to those obtained from the time reversal and the conventional delay-and-sum reconstruction algorithms. The presented method removes the sidelobe artifacts and the comet tail sign, which produces a more distinguishable target on the image. In addition, the proposed method has a faster performance and lower computational load. The implementation of this method in photoacoustic microscopy techniques for image reconstruction is discussed.

Improving ultrasound-based brachytherapy needle conspicuity by applying an echogenic coating.

Applicator conspicuity in ultrasound-guided brachytherapy procedures is commonly impaired by imaging artifacts or non-ideal imaging geometry, which can slow down applicator position digitization and increase the geometric uncertainty of the delivered dose distribution. The purpose of this study was to improve the conspicuity of high-dose rate (HDR) brachytherapy needles under B-mode ultrasound imaging by applying an echogenic surface coating. Our hypothesis was that an echogenic coating would reduce artifacts and improve needle visualization within regions of signal degradation. In this study, 17-gauge, 25-cm long titanium HDR brachytherapy needles were coated with acoustically reflective microspheres over a 2.5cm region starting from the needle tip. Three coating thicknesses (27μm, 40μm, 64μm) were compared against an uncoated control needle. The coated and uncoated needles were imaged using B-mode ultrasound in a tissue-equivalent prostate phantom and in a cadaverous male pelvis using a transrectal probe. Needle conspicuity was assessed under multiple conditions: a single needle implant, an implant with multiple needles between the probe and the needle of interest, and an angled needle implant. All images were assessed qualitatively for needle conspicuity and the presence of artifacts and quantitatively using grey-scale image intensity values. The 64μm echogenic coating reduced the magnitude of reverberation artifacts by 31±14% and comet tail artifacts by 40%-70%. The echogenic coating also improved needle contrast, measured by the relative differences in signal intensity compared with the adjacent environment, when needles were angled up to 30° with respect to the transducer probe in the cadaver. The improvements in conspicuity and artifact reduction increased with increasing coating thickness. The performance of the needles coated with the 64μm thickness was qualitatively superior and yielded high-contrast, well-circumscribed signals in the cadaverous male pelvis, even under situations where a needle was acoustically shadowed by multiple other needles. An echogenic surface coating reduced imaging artifacts and improved needle conspicuity under realistic clinical conditions for ultrasound-based prostate or gynecological brachytherapy. The improved conspicuity has the potential to improve the efficiency of needle placement and the accuracy of needle position digitization during brachytherapy procedures.

One-Year Follow-Up Lung Ultrasound of Post-COVID Syndrome-A Pilot Study.

(1) Background: Millions of people worldwide were infected with COVID-19. After the acute phase of the disease, many suffer from prolonged symptoms, the post-COVID syndrome, especially the phenotype with lung residuals. Many open questions regarding lung ultrasound (LUS) have to be answered. One essential question is the means for optimal following-up of patients with post-COVID-19 residuals with LUS; (2) Methods: A retrospective data analysis of patients after acute COVID-19 infection diagnosed with post-COVID syndrome in the state hospital of Steyr and the rehabilitation center of Hochegg was performed. LUS examinations following a 12-zone scanning protocol were performed, and the LUS score quantified comet tail artifacts. A total of 16 patients were evaluated twice with LUS from May 2020 until June 2021. (3) Results: All patients’ reverberation artifacts were reduced over time. The initial LUS score of 17.75 (SD 4.84) points was decreased over the duration of the second rehabilitation to 8,2 (SD 5.94). The difference in the Wilcoxon test was significant (p < 0.001); (4) Conclusions: Lung ultrasound was a valuable tool in the follow-up of post-COVID-syndrome with lung residuals in the first wave of COVID-19. A reduction in reverberation artifacts was demonstrated. Further studies about the clinical significance have to follow.

Acute pericarditis as a major clinical manifestation of long COVID-19 syndrome

BackgroundThe long COVID-19 syndrome has been recently described and some reports have suggested that acute pericarditis represents important manifestation of long COVID-19 syndrome. The aim of this study was to identify the prevalence and clinical characteristics of patients with long COVID-19, presenting with acute pericarditis. MethodsWe retrospectively included 180 patients (median age 47 years, 62% female) previously diagnosed with COVID-19, exhibiting persistence or new-onset symptoms ≥12 weeks from a negative naso-pharyngeal SARS CoV2 swamp test. The original diagnosis of COVID-19 infection was determined by a positive swab. All patients had undergone a thorough physical examination. Patients with suspected heart involvement were referred to a complete cardiovascular evaluation. Echocardiography was performed based on clinical need and diagnosis of acute pericarditis was achieved according to current guidelines. ResultsAmong the study population, shortness of breath/fatigue was reported in 52%, chest pain/discomfort in 34% and heart palpitations/arrhythmias in 37%. Diagnosis of acute pericarditis was made in 39 patients (22%). Mild-to-moderate pericardial effusion was reported in 12, while thickened and bright pericardial layers with small effusions (< 5 mm) with or without comet tails arising from the pericardium (pericardial B-lines) in 27. Heart palpitations/arrhythmias (OR:3.748, p = 0.0030), and autoimmune disease and allergic disorders (OR:4.147, p = 0.0073) were independently related to the diagnosis of acute pericarditis, with a borderline contribution of less likelihood of hospitalization during COVID-19 (OR: 0.100, p = 0.0512). ConclusionOur findings suggest a high prevalence of acute pericarditis in patients with long COVID-19 syndrome. Autoimmune and allergic disorders, and palpitations/arrhythmias were frequently associated with pericardial disease.

The culprits of superoxide dismutase inactivation under size-dependent stress of ultrafine carbon black: Superoxide anion, genotoxicity and protein corona

As a critical component of atmospheric ultrafine particulates, ultrafine carbon black (UFCB) brings great exposure risk to organisms. At present, the action pathway and activity regulation mechanism of UFCB on functional proteins in vivo are not clear, and the size-dependent effects of UFCB during this process need to be elucidated. Superoxide dismutase (SOD), one of the most applied biomarkers to assess the environmental impact of pollutants, plays crucial roles in resistance to oxidative stress. Here, based on the inactivation of SOD (84.79 %, 86.81 % and 91.70 %) in primary mouse hepatocytes exposed to UFCB (13 nm, 50 nm and 95 nm), oxidative stress, genotoxicity and protein molecular studies were employed to elucidate the inactivation mechanisms. Results showed that inhibition of UFCB-mediated superoxide anion (O2−) contributed to a decrease in SOD activity. Furthermore, the significant increase in 8-hydroxy-2-deoxyguanosine content and the comet tail formation indicated the occurrence of DNA damage, supporting that concomitant aberrant transcriptional and protein translational under gene regulation should be responsible for SOD inactivation. At the molecular level, the constricted backbone, reduced content of α-helix and fluorescence sensitization all demonstrated that the attachment-type binding of SOD on UFCB to form the ‘protein corona’ disrupted protein structure. Enzyme activity assays indicated that SOD backbone tightening and helix decay resulted in decreased activity, which should be another reason for intracellular SOD inactivation. More importantly, the particle sizes of UFCB exert powerful influences on SOD inactivation mechanisms. Smaller UFCB (13 nm) induced more severe O2− inhibition and DNA damage, while UFCB50nm with the best dispersity bound more SOD and induced stronger molecular toxicity, which are their different strengths in stressing SOD inactivation in hepatocytes. Our findings provide novel insights for exploring functional proteins activity and underscore a potentially size-dependent risk of nanoparticles.

Targeted liver ultrasound performed by an expert is the pivotal imaging examination for low phospholipid-associated cholelithiasis.

Low phospholipid-associatedcholelithiasis (LPAC) is a clinical syndrome that can be associated with variants in the adenosinetriphosphate-binding cassette subfamily B, member 4 (ABCB4) transporter gene, in a proportion of patients. The diagnosis of LPAC is defined by clinical as well as imaging criteria of intrahepatic hyperechoic foci or microlithiasis and biliary sludge on ultrasound. The aim of the study was to assess the role of imaging in investigating patients presenting with clinical features suggesting a diagnosis of LPAC. Imaging findings in 51 patients with clinical LPAC were retrospectively reviewed. Most patients had been referred with difficult-to-manage biliary pain postcholecystectomy and some with intrahepatic dilated ducts and stones. The diagnosis of LPAC was made on clinical features. The patients were young with symptom onset at median age 24 years and were mainly female (75%). Ultrasound was performed by an expert in 48/51 and magnetic resonance cholangiopancreatography (MRCP) in 47/51 patients. Targeted liver ultrasound found small hyperechoic foci with comet tail artifacts or posterior acoustic shadowing typical of LPAC in 30/48 (63%) of examinations. However, ultrasound examinations performed before referral for investigation did not report these findings. Intrahepatic duct dilatation was seen in 26/51 (51%) of cases. MRCP did not reliably detect microlithiasis. Targeted liver ultrasound performed by an expert aware of the possible diagnosis is the pivotal investigation for patients with clinical features suggesting LPAC. The findings in ultrasound performed before referral suggest LPAC is under-recognized and under-diagnosed.

Influence of rapidly oscillating inspired O2 and N2 concentrations on pulmonary vascular function and lung fluid balance in healthy adults.

Introduction: Aircrew may experience rapidly oscillating inspired O2/N2 ratios owing to fluctuations in the on-board oxygen delivery systems (OBOG). Recent investigations suggest these oscillations may contribute to the constellation of physiologic events in aircrew of high-performance aircraft. Therefore, the purpose of this study was to determine whether these "operationally-relevant" environmental challenges may cause decrements in measures of pulmonary vascular physiology. Methods: Thirty healthy participants (Age: 29 ± 5years) were recruited and assigned to one of the three exposures. Participants were instrumented for physiologic monitoring and underwent baseline cardiopulmonary physiology testing (ground level) consisting of a rebreathe method for quantifying pulmonary blood flow (Qc), pulmonary capillary blood volume (Vc) and alveolar-capillary conductance (Dm). Ultrasound was used to quantify "comet tails" (measure of lung fluid balance). After baseline testing, the participants had two 45min exposures to an altitude of 8,000ft where they breathed from gas mixtures alternating between 80/20 and 30/70 O2/N2 ratios at the required frequency (30s, 60s, or 120s), separated by repeat baseline measure. Immediately and 45min after the second exposure, baseline measures were repeated. Results: We observed no changes in Qc, Dm or Vc during the 60s exposures. In response to the 30s oscillation exposure, there was a significantly reduced Qc and Vc at the post-testing period (p = 0.03). Additionally, exposure to the 120s oscillations resulted in a significant decrease in Vc at the recovery testing period and an increase in the Dm/Vc ratio at both the post and recovery period (p < 0.01). Additionally, we observed no changes in the number of comet tails. Conclusion: These data suggest "operationally-relevant" changes in inspired gas concentrations may cause an acute, albeit mild pulmonary vascular derecruitment, reduced distention and/or mild pulmonary-capillary vasoconstriction, without significant changes in lung fluid balance or respiratory gas exchange. The operational relevance remains less clear, particularly in the setting of additional environmental stressors common during flight (e.g., g forces).

On the Possibility of an Artificial Origin for 'Oumuamua.

The first large interstellar object discovered near Earth by the Pan STARRS telescope, 'Oumuamua, showed half a dozen anomalies relative to comets or asteroids in the solar system. All natural-origin interpretations of 'Oumuamua's anomalies contemplated objects of a type never seen before, such as a porous cloud of dust particles, a tidal disruption fragment or exotic icebergs made of pure hydrogen or pure nitrogen. Each of these natural-origin models has major quantitative shortcomings, and so the possibility of an artificial origin for 'Oumuamua must be considered. 'Oumuamua's anomalies suggest that it might have been a thin craft-with a large area per unit mass-pushed by the reflection of sunlight; sharing qualities with the thin artifact 2020 SO-launched by NASA in 1966 and discovered by Pan STARRS in 2020 to exhibit a push away from the Sun with no cometary tail. The Galileo Project aims to collect new data that will identify the nature of 'Oumuamua-like objects in the coming years.