Development of convolutional neural network models that recognize normal anatomic structures during real-time radial-array and linear-array EUS (with videos).

BACKGROUND AND AIMS: EUS is a high-skill technique that requires numerous procedures to achieve competence. However, training facilities are limited worldwide. Convolutional neural network (CNN) models have been previously implemented for object detection. We developed 2 EUS-based CNN models for normal anatomic structure recognition during real-time linear- and radial-array EUS evaluations. METHODS: The study was performed from February 2020 to June 2022. Consecutive patient videos of linear- and radial-array EUS videos were recorded. Expert endosonographers identified and labeled 20 normal anatomic structures within the videos for training and validation of the CNN models. Initial CNN models (CNNv1) were developed from 45 videos and the improved models (CNNv2) from an additional 102 videos. CNN model performance was compared with that of 2 expert endosonographers. RESULTS: CNNv1 used 45,034 linear-array EUS frames and 21,063 radial-array EUS frames. CNNv2 used 148,980 linear-array EUS frames and 128,871 radial-array EUS frames. Linear-array CNNv1 and radial-array CNNv1 achieved a 75.65% and 71.36% mean average precision (mAP) with a total loss of .19 and .18, respectively. Linear-array CNNv2 obtained an 88.7% mAP with a .06 total loss, whereas radial-array CNNv2 achieved an 83.5% mAP with a .07 total loss. CNNv2 accurately detected all studied normal anatomic structures with a >98% observed agreement during clinical validation. CONCLUSIONS: The proposed CNN models accurately recognize the normal anatomic structures in prerecorded videos and real-time EUS. Prospective trials are needed to evaluate the impact of these models on the learning curves of EUS trainees.

Artificial intelligence for diagnosing neoplasia on digital cholangioscopy: development and multicenter validation of a convolutional neural network model.

BACKGROUND: We aimed to develop a convolutional neural network (CNN) model for detecting neoplastic lesions during real-time digital single-operator cholangioscopy (DSOC) and to clinically validate the model through comparisons with DSOC expert and nonexpert endoscopists. METHODS: In this two-stage study, we first developed and validated CNN1. Then, we performed a multicenter diagnostic trial to compare four DSOC experts and nonexperts against an improved model (CNN2). Lesions were classified into neoplastic and non-neoplastic in accordance with Carlos Robles-Medranda (CRM) and Mendoza disaggregated criteria. The final diagnosis of neoplasia was based on histopathology and 12-month follow-up outcomes. RESULTS: In stage I, CNN2 achieved a mean average precision of 0.88, an intersection over the union value of 83.24 %, and a total loss of 0.0975. For clinical validation, a total of 170 videos from newly included patients were analyzed with the CNN2. Half of cases (50 %) had neoplastic lesions. This model achieved significant accuracy values for neoplastic diagnosis, with a 90.5 % sensitivity, 68.2 % specificity, and 74.0 % and 87.8 % positive and negative predictive values, respectively. The CNN2 model outperformed nonexpert #2 (area under the receiver operating characteristic curve [AUC]-CRM 0.657 vs. AUC-CNN2 0.794, P < 0.05; AUC-Mendoza 0.582 vs. AUC-CNN2 0.794, P < 0.05), nonexpert #4 (AUC-CRM 0.683 vs. AUC-CNN2 0.791, P < 0.05), and expert #4 (AUC-CRM 0.755 vs. AUC-CNN2 0.848, P < 0.05; AUC-Mendoza 0.753 vs. AUC-CNN2 0.848, P < 0.05). CONCLUSIONS: The proposed CNN model distinguished neoplastic bile duct lesions with good accuracy and outperformed two nonexpert and one expert endoscopist.

Assessing the Reactive Surface Area of Soils and the Association of Soil Organic Carbon with Natural Oxide Nanoparticles Using Ferrihydrite as Proxy.

Assessment of the surface reactivity of natural metal-(hydr)oxide nanoparticles is necessary for predicting ion adsorption phenomena in soils using surface complexation modeling. Here, we describe how the equilibrium concentrations of PO4, obtained with 0.5 M NaHCO3 extractions at different solution-to-soil ratios, can be interpreted with a state-of-the-art ion adsorption model for ferrihydrite to assess the reactive surface area (RSA) of agricultural top soils. Simultaneously, the method reveals the fraction of reversibly adsorbed soil PO4 (R-PO4). The applied ion-probing methodology shows that ferrihydrite is a better proxy than goethite for consistently assessing RSA and R-PO4. The R-PO4 pool agrees well with ammonium oxalate (AO)-extractable phosphorus, but only if measured as orthophosphate. The RSA varied between ∼2 and 20 m2/g soil. The corresponding specific surface area (SSA) of the natural metal-(hydr)oxide fraction is ∼350-1400 m2/g, illustrating that this property is highly variable and cannot be represented by a single value based on the AO-extractable oxide content. The soil organic carbon (SOC) content of our top soils increases linearly not only with the increase in RSA but remarkably also with the increase in mean particle size (1.5-5 nm). To explain these observations, we present a structural model for organo-mineral associations based on the coordination of SOC particles to metal-(hydr)oxide cores.

The fic domain: regulation of cell signaling by adenylylation.

We show that the secreted antigen, IbpA, of the respiratory pathogen Histophilus somni induces cytotoxicity in mammalian cells via its Fic domains. Fic domains are defined by a core HPFxxGNGR motif and are conserved from bacteria to humans. We demonstrate that the Fic domains of IbpA catalyze a unique reversible adenylylation event that uses ATP to add an adenosine monophosphate (AMP) moiety to a conserved tyrosine residue in the switch I region of Rho GTPases. This modification requires the conserved histidine of the Fic core motif and renders Rho GTPases inactive. We further demonstrate that the only human protein containing a Fic domain, huntingtin yeast-interacting protein E (HYPE), also adenylylates Rho GTPases in vitro. Thus, we classify Fic domain-containing proteins as a class of enzymes that mediate bacterial pathogenesis as well as a previously unrecognized eukaryotic posttranslational modification that may regulate key signaling events.

Usefulness of artificial intelligence-assisted digital single-operator cholangioscopy as a second-opinion consultation tool during interhospital assessment of an indeterminate biliary stricture: a case report.

Video 1Application of a novel digital single-operator cholangioscopy-based convolutional neuronal network to detect neoplastic lesions as a second-opinion consultation tool between 2 hospitals and biopsy sampling.

Effect of water storage on microtensile bond strength of a two-step self-etch adhesive and a two-step etch-and-rinse adhesive.

This study evaluated the effect of 24 h (1d) and one-year (1yr) water storage on the microtensile dentin bond strength of a two-step total-etch and a two-step self-etch adhesive system. Ten extracted human third molars were sectioned perpendicularly to their long axis to expose flat occlusal dentin surfaces. Teeth were divided into two groups (n=5) according to the adhesive used: a two-step etch-and-rinse adhesive (Adper Single Bond 2) and two-step self-etching adhesive (Adper Scotchbond SE). Composite resin (Z350) build-ups were incrementally constructed on the bonded surfaces. Specimens were sectioned into sticks (cross-sectional mean area 0.8 mm2) and after 1d and 1yr of storage in distilled water at 37 degrees C, the sticks were stressed to failure by microtensile test (1 mm/min). Interfacial observation of silver nanoleakage was performed using scanning electron microscopy (SEM). Data (MPa) were analyzed by two-way ANOVA and Bonferronis test (p = 0.05). SB2 showed the highest bond strength values after 1d of water storage. After 1yr, SB2 values significantly decreased and were similar to ASE, independently of water storage period. Both adhesives, independently of storage time, showed silver nitrate uptake within the hybrid layer and the adhesive layer One-year of water storage only affected the bond strength of the two-step etch-and-rinse adhesive.

Carbonate Adsorption to Ferrihydrite: Competitive Interaction with Phosphate for Use in Soil Systems.

Carbonate (CO3) interacts with Fe-(hydr)oxide nanoparticles, affecting the availability and geochemical cycle of other important oxyanions in nature. Here, we studied the carbonate-phosphate interaction in closed systems with freshly prepared ferrihydrite (Fh), using batch experiments that cover a wide range of pH values, ionic strength, and CO3 and PO4 concentrations. The surface speciation of CO3 has been assessed by interpreting the ion competition with the Charge Distribution (CD) model, using CD coefficients derived from MO/DTF optimized geometries. Adsorption of CO3 occurs predominately via formation of bidentate inner-sphere complexes, either (≡FeO)2CO or (≡FeO)2CO··Na+. The latter complex is electrostatically promoted at high pH and in the presence of adsorbed PO4. Additionally, a minor complex is present at high CO3 loadings. The CD model, solely parametrized by measuring the pH-dependent PO4 adsorption as a function of the CO3 concentration, successfully predicts the CO3 adsorption to Fh in single-ion systems. The adsorption affinity of CO3 to Fh is higher than to goethite, particularly at high pH and CO3 loadings due to the enhanced formation (≡FeO)2CO··Na+. The PO4 adsorption isotherm in 0.5 M NaHCO3 can be well described, being relevant for assessing the reactive surface area of the natural oxide fraction with soil extractions and CD modeling. Additionally, we have evaluated the enhanced Fh solubility due to Fe(III)-CO3 complex formation and resolved a new species (Fe(CO3)2(OH)2 3-(aq)), which is dominant in closed systems at high pH. The measured solubility of our Fh agrees with the size-dependent solubility predicted using the surface Gibbs free energy of Fh.

Influence of Tobacco Smoke Exposure on the Protein Expression of α7 and α4 Nicotinic Acetylcholine Receptors in Squamous Cell Carcinoma Tumors of the Upper Aerodigestive Tract (Out of the Larynx).

PURPOSE: To assess protein expression of α7 and α4 nicotinic acetylcholine receptors (nAChR) subtypes in squamous cell carcinoma of the upper aerodigestive track (out of the larynx) according to tobacco smoke exposure, considering the general characteristics of the patients. METHODS: The α7 and α4 nAChR subtypes were assessed by immunohistochemistry in tumor samples from 33 patients with novel diagnosis of squamous cell carcinoma of the upper aerodigestive tract (out of the larynx). RESULTS: Current smokers were middle-age men with alcohol consumption, whereas elderly women with no alcohol consumption prevailed among nonsmokers. Expression of α4 nAChR was high in all groups, with an influence of alcohol use, although expression of α7 nAChR was low in current smokers with alcohol use. Expression of α4 with no expression of α7 nAChR was associated with advanced disease. CONCLUSIONS: Squamous cell carcinoma tumors of the upper aerodigestive tract (out of the larynx) may show desensitization of α4 nAChR. Advanced disease at diagnosis might be associated with desensitization of α4 with decrease in α7 nAChR.

Effect of water storage on microtensile bond strenght of a two-step self-etch adhesive and a two-step etch-and-rinse adhesive

Este estudio evaluó el efecto del almacenamiento en agua por 24 hs. (1d) y un año (1a) sobre la resistencia de unión de un adhesivo de grabadoácido independiene de dos pasos y un adhesivo autoacodicionante de dos pasos. Diez terceros molares fueron cortados perpendiculares a su eje longitudinal para exponer superficiesplanas de dentina. Los dientes fueron divididos en dos grupos según el adhesivo a ser usado: uno de acondicionamiento ácido independiente de dos pasos (Adper Single Bond 2) y uno autoacondicionante de dos pasos (Adper Scotchbond SE). Incrementosen resina compuesta (Z350) fueron construidas sobre las superficies tratadas con adhesivo. Los especimenes fueron cortados para obtener probetas (área de sección transversal = 0,8 mm2) y después de 1d y 1a de almacenamiento en agua destiladaa 37° C, fueron sometidas a la prueba de microtracción (1 mm/min). La captación de nitrato de plata en las interfaces fue analizada con microscopia electrónica de barrido (MEB). Los datos (MPa) fueron analizados con ANOVA de dos factores y la prueba de Bonferroni (p = 0,05). Después de 1d de almacenamiento SB2 presento los mayores valores de resistencia deunión. No hubo diferencias entre los adhesivos después de 1a, y para ASE estos valores fueron similares al tiempo 1d. Independientemente del tiempo de almacenamiento, ambos adhesivospresentaron captación de nitrato de plata dentro de la capa híbrida y la capa de adhesivo. Un año de almacenamiento en agua solo afectó los valores de resistencia de unión del adhesivo de grabado ácido independiente de dos pasos.

Producción y purificación parcial de la hemolisina principal (Neumolisina) de Streptococcus pneumoniae / Production and partial purification of the main hemolysin (pneumolysin) of Streptococcus pneumoniae

The capacity of 36 Cuban strains of Streptococcus pneumoniae to produce pneumolysin was studied, and 94.4 of them were determined to be producers of that enzyme. One of the best producers was cultured at a great scale and the pneumolysin found in the supernatan was partially purified through an ion-exchange chromatography in mono-Q column. This method made it possible to recover the enzyme whose purity level increased by 4.39 with 100 output.

Presencia de Chlamydia pneumoniae en placas ateroscleróticas / Chlamydia pneumoniae presence in atherosclerotic plaques

Chlamydia pneumoniae es un patógeno mundialmente reconocido como causante de infecciones del tracto respiratorio en humanos, se caracteriza por ser un microorganismo intracelular obligado. Al presente, se ha comprobado su presencia en placas ateromatosas por múltiples técnicas como la inmunohistoquímica, la microscopía electrónica y la reacción en cadena de la polimerasa (PCR). La enfermedad aterosclerótica, es responsable de muchos de los accidentes cerebrovasculares y cardiovasculares. Sin embargo el papel patogénico de este microorganismo en dicha enfermedad aun no es claro. En este estudio, por medio de ka reacción en cadena de la polimerasa (PCR) se logró comprobar la presencia de C. pneumoniae en el 28 por ciento de 93 muestras de tejido vascular provenientes de pacientes que fueron sometidos a cirugía de revascularización quirúrgica. La presencia de este microorganismo en tejido vascular de pacientes con enfermedad coronaria podría considerarse como un factor de riesgo cardiovascular para el desarrollo de aterosclerosis y enfermedades cerebrovasculares