The 2021 SIIM-FISABIO-RSNA Machine Learning COVID-19 Challenge: Annotation and Standard Exam Classification of COVID-19 Chest Radiographs.

We describe the curation, annotation methodology, and characteristics of the dataset used in an artificial intelligence challenge for detection and localization of COVID-19 on chest radiographs. The chest radiographs were annotated by an international group of radiologists into four mutually exclusive categories, including "typical," "indeterminate," and "atypical appearance" for COVID-19, or "negative for pneumonia," adapted from previously published guidelines, and bounding boxes were placed on airspace opacities. This dataset and respective annotations are available to researchers for academic and noncommercial use.

Extracellular ATP hydrolysis in Caco-2 human intestinal cell line.

Extracellular nucleotides and nucleosides activate signaling pathways that play major roles in the physiology and pathophysiology of the gastrointestinal tract. Ectonucleotidases hydrolyze extracellular nucleotides and thus regulate ligand exposure to purinergic receptors. In this study, we investigated the expression, localization and activities of ectonucleotidases using Caco-2 cells, a model of human intestinal epithelial cells. In addition, by studying ATP release and the rates of extracellular ATP (eATP) hydrolysis, we analyzed the contribution of these processes to the regulation of eATP in these cells. Results show that Caco-2 cells regulate the metabolism of eATP and by-products by ecto-nucleoside triphosphate diphosphohydrolase-1 and -2, a neutral ecto-phosphatase and ecto-5'-nucleotidase. All these ectoenzymes were kinetically characterized using intact cells, and their presence confirmed by denatured and native gels, western blot and cytoimmunofluorescence techniques. In addition, regulation of eATP was studied by monitoring the dynamic balance between intracellular ATP release and ectoATPase activity. Following mechanical and hypotonic stimuli, Caco-2 cells triggered a strong but transient release of intracellular ATP, with almost no energy cost, leading to a steep increase of eATP concentration, which was later reduced by ectoATPase activity. A data-driven algorithm allowed quantifying and predicting the rates of ATP release and ATP consumption contributing to the dynamic accumulation of ATP at the cell surface.

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm.

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{µ}≡(g_{µ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{µ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both µ^{+} and µ^{-}, the new experimental average of a_{µ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.

Excitonic hopping-pinning scenarios in lithium niobate based on atomistic models: different kinds of stretched exponential kinetics in the same system.

Based on a model of coupled processes with differently time-dependent decay kinetics we present a critical review on photoluminescence (PL) and transient absorption (TA) experiments in undoped and Mg or Fe-doped LiNbO3, together with a comprehensive interpretation of visible radiative and parallel non-radiative decay processes on timescales ranging from 50 ns up to minutes. Analogies and peculiarities of the kinetics of mobile self-trapped and pinned excitons are investigated and compared with those of hopping polarons in the same system. Exciton hopping with an activation energy of ≈0.18 eV is shown to govern the lifetime and quenching of the short PL component above 100 K. Strong interaction between excitons and dipolar pinning defects explains the exorbitant lifetimes and large depinning energies characterizing delayed TA components in doped LiNbO3, while restricted hopping of the pinned excitons is proposed to play a role in strongly delayed PL in LiNbO3:Mg exhibiting a narrowed emission band due to locally reduced electron-phonon coupling. Atomistic models of pinned excitons are proposed corresponding to charge-compensated dipolar defects predicted by theories of dopant incorporation in LiNbO3 and are systematically assigned to absorption bands observed near the UV edge. Excitation in these bands is shown to lead directly to pinned exciton states confirming also the previously proposed two-step exciton-decay scenario in LiNbO3:Fe. Weak intrinsic sub-80 ns luminescence in congruent LiNbO3 is explained as an opposite effect of enhanced electron-phonon coupling for excitons pinned on NbLi antisite defects. The comparison of the different observed stretching behaviors in the paradigmatic system LiNbO3 provides an intuitive picture of the underlying physical processes. The findings are relevant not only for holographic and non-linear optical applications of LiNbO3 but are of general interest also for the treatment of stretched exponential or other time-dependent kinetics in complex condensed systems ranging from nanocrystals and polymers to liquids and biophysical systems.

The role of self-trapped excitons in polaronic recombination processes in lithium niobate.

Transient absorption and photoluminescence are experimentally investigated in the polaronic reference system lithium niobate, LiNbO[Formula: see text] (LN), with the aim to refine the microscopic model of small polaron dynamics in materials with strong electron-phonon coupling. As a unique feature, our study is performed by using two different spectroscopic methods, in crystals with dopants enhancing photorefraction or damage resistance, and over a broad temperature range from 15-400 K. Although being self-consistent for particular experimental conditions, the hitherto used microscopic polaronic models reveal inconsistencies when applied to this larger data set. We show that comprehensive modeling is unlocked by the inclusion of an additional type of polaronic state with the following characteristics: (i) strongly temperature- and dopant-dependent relaxation times, (ii) an absorption feature in the blue-green spectral range, and (iii) a Kohlrausch-Williams-Watts decay shape with a temperature-dependent stretching factor [Formula: see text] showing a behavior contrary to that of small, strong-coupling polarons. The hypothesis of self-trapped excitons (STEs, i.e. bound electron-hole pairs strongly coupled to Nb[Formula: see text] and O[Formula: see text] within a niobium-oxygen octahedron) and their pinning on defects as the microscopic origin of these characteristics is supported by a spectroscopic linkage of photoluminescence at low (15 K) and elevated (300 K) temperatures and explains the long-lifetime components in transient absorption as due to pinned STEs.

Double-blind, placebo-controlled food challenges in Brazilian children: adaptation to clinical practice.

BACKGROUND: A double-blind, placebo-controlled food challenge (DBPCFC) is considered the gold standard for diagnosing food allergy, but because of methodological difficulties it is rarely conducted in clinical practice, especially in paediatric patients. The purpose of the study was to propose a DBPCFC protocol that is adapted to our conditions for the diagnosis of an IgE-mediated cow's milk allergy (CMA) in a Brazilian reference centre for paediatric allergies. METHODS: This study includes the experimental phase (choice of materials, adjustments made to protocols described in the literature) and the test execution phase. DBPCFCs were performed in 58 patients aged 1-15 years who were separated into two groups: Group 1 (n=39), sex 1.6 M:F, 5.3 years median age, suggestive history of IgE-mediated CMA; and Group 2 (n=19), sex 1.4 M:F, 8.3 years median age with symptoms not associated with milk ingestion and laboratory data not compatible with IgE-mediated CMA. RESULTS: The materials were standardised for testing: containers and disposable products, low-lactose cow's milk (CM) and vehicles, such as natural fruit juice, vegetable soup and soybean-based beverages. Each DBPCFC was performed in a single day with two blind, randomised phases with a 2-h interval between them. The milk doses were gradually increased and offered in regular intervals of 15-30 min. Following negative or inconclusive results, patients underwent an open oral challenge test with 200 mL of low-lactose CM. CONCLUSIONS: The proposed adaptation for the DBPCFC allowed to implement this important test for the diagnosis of IgE-mediated CMA in a reference centre for paediatric allergies. It was considered feasible and safe if performed in an appropriate setting with physician supervision.

Small-polaron based holograms in LiNbO3 in the visible spectrum.

Diffraction efficiency, relaxation behavior and dependence on pump-beam intensity of small-polaron based holograms are studied in thermally reduced, nominally undoped lithium niobate in the visible spectrum (λ = 488 nm). The pronounced phase gratings with diffraction efficiency up to η = (10.8 ± 1.0)% appeared upon irradiation by single ns-laser pulses (λ = 532 nm) and are comprehensively assigned to the optical formation of spatially modulated densities of small bound NbLi4+ electron polarons, NbLi4+:NbNb4+ electron bipolarons, and O⁻ hole polarons. A remarkable quadratic dependence on the pump-beam intensity is discovered for the recording configuration K || c-axis and can be explained by the electro-optic contribution of the optically generated small bound polarons. We discuss the build-up of local space-charge fields via small-polaron based bulk photovoltaic currents.

First measurement of kaonic helium-3 X-rays.

The first observation of the kaonic (3)He 3d→2p transition was made, using slow K- mesons stopped in a gaseous (3)He target. The kaonic atom X-rays were detected with large-area silicon drift detectors using the timing information of the K+K- pairs of ϕ-meson decays produced by the DAΦNE e+e- collider. The strong interaction shift of the kaonic (3)He 2p state was determined to be -2±2(stat)±4(syst) eV.

Characterization of a 2D soft x-ray tomography camera with discrimination in energy bands.

A gas detector with a 2D pixel readout is proposed for a future soft x-ray (SXR) tomography with discrimination in energy bands separately per pixel. The detector has three gas electron multiplier foils for the electron amplification and it offers the advantage, compared with the single stage, to be less sensitive to neutrons and gammas. The energy resolution and the detection efficiency of the detector have been accurately studied in the laboratory with continuous SXR spectra produced by an electronic tube and line emissions produced by fluorescence (K, Fe, and Mo) in the range of 3-17 keV. The front-end electronics, working in photon counting mode with a selectable threshold for pulse discrimination, is optimized for high rates. The distribution of the pulse amplitude has been indirectly derived by means of scans of the threshold. Scans in detector gain have also been performed to assess the capability of selecting different energy ranges.

Absorption cross sections and number densities of electron and hole polarons in congruently melting LiNbO(3).

The number densities and absorption cross sections of both optically generated and reduction-induced small electron and hole polarons in LiNbO(3) are determined by means of time-resolved pump-multiprobe spectroscopy. The data are obtained for free (Nb(Nb)(4+)) and bound (Nb(Li)(4+)) electron polarons, bound Nb(Li)(4+):Nb(Nb)(4+) electron bipolarons, and bound O(-) hole polarons. The peak absorption cross sections are in the range of σ(pol)≈(4-14) × 10(-22) m(2), comparable to that for Fe(2+). In all cases the ratio of occupied to unoccupied polaronic sites is less than 10(-2).

Pericarditis purulenta en paciente inmunocompetente con CIA / Purulent pericarditis in immunocompetent patient with interauricular communication

Paciente inmunocompetente quien presenta taponamiento cardíaco por pericarditis purulenta primaria asociado a CIA tipo ostium secundum. El ecocardiograma transesofágico y los hemocultivos fueron negativos para el diagnóstico de endocarditis. Queremos remarcar la utilidad del acceso quirúrgico subxifoideo, para el drenaje pericárdico

Pericarditis purulenta en paciente inmunocompetente con CIA / Purulent pericarditis in immunocompetent patient with interauricular communication

Paciente inmunocompetente quien presenta taponamiento cardíaco por pericarditis purulenta primaria asociado a CIA tipo ostium secundum. El ecocardiograma transesofágico y los hemocultivos fueron negativos para el diagnóstico de endocarditis. Queremos remarcar la utilidad del acceso quirúrgico subxifoideo, para el drenaje pericárdico (AU)

[Current viewpoints on the evaluation of testicular biopsy]. / A herebiopsiák értékelésének új szempontjai.

The aim of this study was to analize clinical diagnoses and histopathological reports in 185 cases of male infertility, investigated by testicular biopsies in the period 1993-1997. The classical objective of such investigations has been to clarify either obstructive, or so-called secretory lesions resulting in azoospermia. Histologically normal spermatogenesis was reported in 8 patients (4.3%). Hypospermatogenesis proved to be the most frequent pathologic lesion (69 cases, 37.3%), followed by maturation arrest (61 cases, 33%). Germ cell aplasia (Sertoli-cell-only syndrome) was found in 28 cases (15.1%). Tubular atrophy was the dominant lesion in 5 cases (2.7%). Inflammatory change without other histologic abnormalities was seen only in 1 biopsy (0.5%). Further 13 specimens (7%) showed miscellaneous lesions, including one intratubular germ cell neoplasia. Retrospective histopathologic analysis revealed the coexistence of different basic lesions in 43 of our cases (21.7%). According to the novel requirements, pathologists should always report the presence of germ cell forms in the specimen, which are potentially suitable for fertilization. This is essencial because the new methods of testicular spermium extraction and intracytoplasmatic spermium injection offer the chance of assisted fertilization, even for some patients with smaller testicles and slightly elevated FSH levels.

[Serum and salivary testosterone levels in erectile dysfunction]. / A szérum és nyál tesztoszteron szintje erectilis dysfunctióban.

In this study 66 male patients with erectile dysfunction were investigated. The authors measured the testosterone levels in serum and in saliva, which latter represent with good accuracy the serum levels of free testosterone. The mean serum total testosterone level was 17.6 nmol/L (confidence intervals: 15.5 and 20.2 nmol/L, normal range: 10-50 nmol/L). The mean salivary free testosterone level was 218.5 pmol/L (confidence intervals: 198.3 and 239.9 pmol/L, normal range: 200-1000 pmol/L). Low salivary (free) testosterone levels were found in 36.4% of patients, while only in 10.6% of patients had low serum testosterone levels (p = 0.01, by binomial test). Although there is a relationship between serum and salivary testosterone levels (r = 0.41, p < 0.001), the patients with low salivary (free) testosterone levels have in major part a normal serum total testosterone level. These data indicate that a considerable proportion of patients with erectile dysfunction have androgen deficiency. The serum total testosterone level is not a sensitive indicator to detection of hypogonadism. The androgen substitution therapy has a beneficial effect on erectile dysfunction in a significant part of patients. The measurement of free testosterone level in saliva may have an important role both in the diagnosis of diseases characterized by androgen deficiency and hyperandrogenic status.

Interlaboratory reproducibility in reporting inadequate cervical smears--a multicentre multinational study.

A set of 300 vaginal smears was interpreted by 13 cytologists from six European laboratories, who were requested to report inadequate and suboptimal smears. The set had been appropriately seeded to reach approximately 10% inadequate and 20% suboptimal smear frequency. According to the majority report, 230 smears were classified as adequate (76.7%), 43 as inadequate (14.3%), and 27 as suboptimal (9.0%). Agreement with the majority report ranged from 52% to 91% (average 78%). Kappa statistics for reporting inadequate smears showed a high level of agreement for five cytologists, and fair to good agreement for eight. In contrast, kappa statistics for reporting suboptimal smears showed fair to good agreement with the majority report only in five instances, whereas agreement was poor for eight cytologists. 'Inadequate smear' rates may be used to compare the quality of smears received in different laboratories, as there is a high level of agreement among cytologists as to what constitutes an inadequate smear. However, this is not true for "suboptimal smear" rates, and more precise reporting criteria must be defined and tested if an intermediate category is to be retained to report poor quality smears: more precise reporting criteria must be defined and tested if an intermediate category is to be retained to report poor quality smears.

Detection of Chlamydia trachomatis in the prostate by in-situ hybridization and by transmission electron microscopy.

Chlamydia trachomatis infection has been investigated in the prostate gland using in-situ DNA hybridization and transmission electron microscopy. Sixty-four samples of tissue removed by trans-urethral resection or by open surgery from men with benign prostatic hypertrophy (BPH), were examined histologically and 20 of the cases were found to be positive for mononuclear cell infiltration. Some samples were then investigated using in-situ hybridization and transmission electron microscopy. Out of 20 tissue samples with mononuclear cell infiltration, nine were found to be positive for C. trachomatis infection.

[Detection of Chlamydia trachomatis in chronic prostatitis by in situ hybridization (preliminary methodical report)]. / Chlamydia trachomatis kimutatása in situ hibridizációval krónikus prostatitisben (metodikai elözetes közlemény).

(Preliminary methodical report). In situ hybridization of Chlamydia trachomatis in formalin fixed, paraffin embedded specimens from the Urology Clinic were performed in 2nd Department of Pathology Semmelweis University of Medicine by a biotin labelled DNA probe. Chlamydia trachomatis is suspected to be responsible for the chronic abacterial inflammation of the prostate besides Ureaplasma urealyticum and Mycoplasmae. According to our retrospective study out of 79 biopsy specimens 34 had the diagnosis of chronic abacterial prostatitis. We examined 11 specimens of them. Bacteria were not identified. Three specimens were positive for Chlamydia trachomatis which were improved by transmission electron microscope. The age of patients was between 59 and 81 years. The detection of chlamydia infection rises the suspicion of a "healthy" career and especially at younger age could cause Chlamydia trachomatis associated genital disease. The undiagnosed and untreated diseases may lead to infertility.

Is seminal fluid a suitable specimen for detecting chlamydial infection in men?

As genital chlamydia infection is considered the most prevalent sexually transmitted bacterial disease worldwide, its correct diagnosis has a great clinical and epidemiological importance. Urethra is the recommended site for collecting specimen for detection of Chlamydia trachomatis in men, but urethral swabbing is very inconvenient for the patients. Testing of seminal fluid has two advantages: taking the sample is more convenient for the patient, and the ejaculate would provide more information on the possible infection of the upper genital tract. Three non-culture methods-enzyme immunoassay (EIA), DNA hybridization, and polymerase chain reaction (PCR)-were used for evaluation of suitability of seminal fluid as a sample for detection of Chlamydia in 4 patient groups comprising 259 symptomatic and asymptomatic, urology and andrology patients. The seminal fluids were tested parallel with the urethral samples. In one group of patients with typical prostatic complaints expressed prostatic secretion was examined parallel with urethral swab. C. trachomatis positivity rates were much higher in symptomatic (49.1%) than in asymptomatic patients (12.3%) in all kinds of sample. Seminal fluid was somewhat more frequently positive (7.9%) than urethral sample (6.2%). Simultaneous positivity was relatively rare (3.3%), it occurred most frequently in samples of patients with possible accessory gland infection tested by EIA. In a group of 17 patients with typical prostatic complaints the expressed prostatic secretion alone was positive in 7 cases, whereas only other two of the parallel urethral samples proved positive by PCR, simultaneous positivity occurred in one case. These findings suggest that testing of the ejaculate and/or the prostatic secretion parallel with the urethral sample would improve the sensitivity of detection of chlamydial infections.

[Effect of pyospermia on fertility. Studies by selective leukocyte staining, elastase determination and routine sperm parameters]. / A pyospermia hatása a fertilitásra. Vizsgálatok szelektív fehérvérsejt festéssel, elasztáz meghatározással és hagyományos ondóparaméterekkel.

The effect of cellular immune response on male fertility was investigated. 92 patients--attending the out patient practice of our Andrological department and 15 patients undergoing vasectomy for sterilisation purpose--were included in this study. For measuring the cellular immune response granulocyte concentration and PMN-elastase level were investigated in ejaculate, former according to WHO manual, and PMN-elastase concentration by ELISA technic. Elastase is a very sensitive non organ specific marker of inflammation. Pathological granulocyte concentration was present in 10.8%, slightly elevated level in 4.3% of cases, totally in 15.1%. Pathological elastase level was found in 17.4%, slightly elevated in 16.3%, totally in 33.7% of cases. High level of correlation was present between the two parameters of inflammation r = 0.695. The incidence of the two parameters in fertile and subfertile patients groups was not significant. Conventional spermaparameters (cell concentration/ml, motility %, intensive motility %, morphology %) were significantly different in the leucospermic and non leucospermic patient groups, except cell concentration. (P = 0.06, P = 0.04, P = 0.03, P = 0.001). The incidence of high elastase level was very similar P = 0.07, P = 0.005, P = 0.03, P = 0.005. As conclusion of our investigation we conclude that cellular response could have a negative influence on male fertility as "side-effect" of the cytotoxic influences of immune defense.

[Genital chlamydia infection in andrologic patients. Direct antigen detection and serologic screening]. / Genitalis chlamydia fertözés andrológiai betegekben. Vizsgálatok direkt antigénkimutatással és szerológiai módszerrel.

Authors investigated the frequency of genital chlamydial infection. 83 couples--complaining with infertility--were examined. Twenty patients were chlamydia positive by direct IF antigen detection. All chlamydia positive patients have elevated IgG antibody levels in sera. In 33 cases (18.1%) the antibody titers were significantly high above 1:128, in 58 cases (34.9%) antibody levels were slightly elevated between 1:16-1:64. Authors are analysing the questions of the humoral immune reactions and the results of the medical treatment.