Influence of CBCT parameters on image quality and the diagnosis of vertical root fractures in teeth with metallic posts: an ex vivo study

Lagos de Melo Larissa Pereira,Queiroz Polyane Mazucatto,Moreira-Souza Larissa,Nadaes Mariana Rocha,Santaella Gustavo Machado,Oliveira Matheus Lima,Freitas Deborah Queiroz 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.2

Objectives The aim of this study was to evaluate the influence of peak kilovoltage (kVp) and a metal artifact reduction (MAR) tool on image quality and the diagnosis of vertical root fracture (VRF) in cone-beam computed tomography (CBCT). Materials and Methods Twenty single-rooted human teeth filled with an intracanal metal post were divided into 2 groups: control (n = 10) and VRF (n = 10). Each tooth was placed into the socket of a dry mandible, and CBCT scans were acquired using a Picasso Trio varying the kVp (70, 80, 90, or 99), and the use of MAR (with or without). The examinations were assessed by 5 examiners for the diagnosis of VRF using a 5-point scale. A subjective evaluation of the expression of artifacts was done by comparing random axial images of the studied protocols. The results of the diagnoses were analyzed using 2-way analysis of variance and the Tukey post hoc test, the subjective evaluations were compared using the Friedman test, and intra-examiner reproducibility was evaluated using the weighted kappa test (α = 5%). Results The kVp and MAR did not influence the diagnosis of VRF (p > 0.05). According to the subjective classification, the 99 kVp protocol with MAR demonstrated the least expression of artifacts, while the 70 kVp protocol without MAR led to the most artifacts. Conclusions Protocols with higher kVp combined with MAR improved the image quality of CBCT examinations. However, those factors did not lead to an improvement in the diagnosis of VRF. Objectives The aim of this study was to evaluate the influence of peak kilovoltage (kVp) and a metal artifact reduction (MAR) tool on image quality and the diagnosis of vertical root fracture (VRF) in cone-beam computed tomography (CBCT). Materials and Methods Twenty single-rooted human teeth filled with an intracanal metal post were divided into 2 groups: control (n = 10) and VRF (n = 10). Each tooth was placed into the socket of a dry mandible, and CBCT scans were acquired using a Picasso Trio varying the kVp (70, 80, 90, or 99), and the use of MAR (with or without). The examinations were assessed by 5 examiners for the diagnosis of VRF using a 5-point scale. A subjective evaluation of the expression of artifacts was done by comparing random axial images of the studied protocols. The results of the diagnoses were analyzed using 2-way analysis of variance and the Tukey post hoc test, the subjective evaluations were compared using the Friedman test, and intra-examiner reproducibility was evaluated using the weighted kappa test (α = 5%). Results The kVp and MAR did not influence the diagnosis of VRF (p > 0.05). According to the subjective classification, the 99 kVp protocol with MAR demonstrated the least expression of artifacts, while the 70 kVp protocol without MAR led to the most artifacts. Conclusions Protocols with higher kVp combined with MAR improved the image quality of CBCT examinations. However, those factors did not lead to an improvement in the diagnosis of VRF.

Seismic Performance of High-rise Concrete Buildings in Chile

Lagos, Rene,Kupfer, Marianne,Lindenberg, Jorge,Bonelli, Patricio,Saragoni, Rodolfo,Guendelman, Tomas,Massone, Leonardo,Boroschek, Ruben,Yanez, Fernando Council on Tall Building and Urban Habitat Korea 2012 International journal of high-rise buildings Vol.1 No.3

Chile is characterized by the largest seismicity in the world which produces strong earthquakes every $83{\pm}9years$ in the Central part of Chile, where it is located Santiago, the capital of Chile. The short interval between large earthquakes magnitude 8.5 has conditioned the Chilean seismic design practice to achieve almost operational performance level, despite the fact that the Chilean Code declares a scope of life safe performance level. Several Indexes have been widely used throughout the years in Chile to evaluate the structural characteristics of concrete buildings, with the intent to find a correlation between general structural conception and successful seismic performance. The Indexes presented are related only to global response of buildings under earthquake loads and not to the behavior or design of individual elements. A correlation between displacement demand and seismic structural damage is presented, using the index $H_o/T$ and the concrete compressive strain ${\varepsilon}_c$. Also the Chilean seismic design codes pre and post 2010 Maule earthquake are reviewed and the practice in seismic design vs Performance Based Design is presented. Performance Based Design procedures are not included in the Chilean seismic design code for buildings, nevertheless the earthquake experience has shown that the response of the Chilean buildings has been close to operational. This can be attributed to the fact that the drift of most engineered buildings designed in accordance with the Chilean practice falls below 0.5%. It is also known by experience that for frequent and even occasional earthquakes, buildings responded elastically and thus with "fully operational" performance. Taking the above into account, it can be said that, although the "basic objective" of the Chilean code is similar to the SEAOC VISION2000 criteria, the actual performance for normal buildings is closer to the "Essential/Hazardous objective".

Bacterial Community Structures in Rhizosphere Microsites of Lolium Perenne Var. Nui Grown in Chilean Andisol as Revealed by Pyroseque

Lorena Lagos,Milko Jorquera,Fumito Maruyama,David E. Crowley,M. Luz Mora 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Nonlinear analysis of heart rhythm in preeclampsia: a route for translational clinical applications in neuroinflammation

José Javier Reyes-Lagos,Eric Alonso Abarca-Castro 대한고혈압학회 2022 Clinical Hypertension Vol.28 No.1

Preeclampsia is a pregnancy-specific condition which gets detected through hypertension and excessive protein excretion in urine. While preeclampsia used to be regarded as a self-limiting maternal condition which resolved with the delivery of the placenta, it is nowadays considered a complex and multifactorial disease that affects the offspring. Unfortunately, the etiology and pathophysiology of this multifaceted disorder remain elusive. Recent findings have confirmed that an altered maternal autonomic function may play a vital role in developing preeclampsia in conjunction with an imbalanced maternal immune system. Additionally, further evidence supports the crucial role of an exacerbated immune response driven by a non-infectious trigger during preeclampsia. Therefore, as a sterile inflammation, the elucidation of the neuroinflammatory mechanisms of preeclampsia warrants obtaining relevant knowledge suitable for translational clinical applications.Heart rate variability (HRV) is an affordable and non-invasive method for indirectly assessing the autonomic nervous system and the cholinergic anti-inflammatory pathway (CAP). Notably, the nonlinear analysis of HRV offers novel indexes to explore the neuroimmune interactions in diverse preclinical and clinical settings of inflammation. Given that the dynamics of HRV is nonlinear in health, we hypothesized that a neuroinflammatory condition in preeclampsia might be associated with changes in nonlinear features of maternal and fetal HRV. Thus, the present review aims to present evidence of the potential changes in maternal-fetal HRV associated with neuroinflammatory modifications in preeclamptic women. We considered that there is still a need for assessing the nonlinear features of maternal and fetal HRV as complementary biomarkers of inflammation in this population in future studies, being a potential route for translational clinical applications.

Analytic ( 3+1 )-dimensional gauged Skyrmions, Heun, and Whittaker-Hill equations and resurgence

Canfora, Fabrizio,Lagos, Marcela,Oh, Seung Hun,Oliva, Julio,Vera, Aldo American Physical Society 2018 Physical Review D Vol.98 No.8

Arp 202: a TDG formed in a parent's extended dark matter halo?

Scott, T C,Lagos, P,Ramya, S,Sengupta, C,Paudel, S,Sahu, D K,Misra, K,Woo, J -H,Sohn, B W Oxford University Press 2018 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.475 No.1

<P>We report on H alpha+ [N II] imaging of the Arp 202 interacting pair and its tidal dwarf galaxy (TDG) candidate as well as a GMOS long slit spectrum from the TDG candidate, observed with the Gemini North telescope. Our H alpha + [N II] imaging reveals the TDG to have an elongated structure, similar to 1.9 kpc in length with the two principal star-forming knots at either end. Our observations also show the TDG candidate has a recessional V-H alpha similar to 3032km s(-1), within 100 km s(-1) of the parent pair's mean velocity and an oxygen abundance of 12+log(O/H) = 8.10 +/- 0.41. The TDG's oxygen abundance is in good agreement with that of a star-forming region in NGC 2719A, one of the parent galaxies, which has an estimated oxygen abundance of 12+log(O/H) = 8.05 +/- 0.41. The TDG's V-H alpha and oxygen abundance confirm previous results validating the candidate as a TDG. The absence of detectable emission from the TDG in Spitzer 3.6 and 4.5 vim images together with the lack of absorption lines and weak continuum in the spectrum is consistent with absence the of an old population (greater than or similar to 0.5 Gyr). The location of the TDG within the interaction debris and the absence of indicators of an old stellar population in the TDG is consistent with a scenario in which the TDG is formed from H I stripped from the parent galaxies and within the extended dark matter halo of one of the parents as proposed by Bournaud et al. and Duc et al.</P>

Predictive maintenance architecture development for nuclear infrastructure using machine learning

Gohel Hardik A.,Upadhyay Himanshu,Lagos Leonel,Cooper Kevin,Sanzetenea Andrew 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.7

Nuclear infrastructure systems play an important role in national security. The functions and missions of nuclear infrastructure systems are vital to government, businesses, society and citizen's lives. It is crucial to design nuclear infrastructure for scalability, reliability and robustness. To do this, we can use machine learning, which is a state of the art technology used in various fields ranging from voice recognition, Internet of Things (IoT) device management and autonomous vehicles. In this paper, we propose to design and develop a machine learning algorithm to perform predictive maintenance of nuclear infrastructure. Support vector machine and logistic regression algorithms will be used to perform the prediction. These machine learning techniques have been used to explore and compare rare events that could occur in nuclear infrastructure. As per our literature review, support vector machines provide better performance metrics. In this paper, we have performed parameter optimization for both algorithms mentioned. Existing research has been done in conditions with a great volume of data, but this paper presents a novel approach to correlate nuclear infrastructure data samples where the density of probability is very low. This paper also identifies the respective motivations and distinguishes between benefits and drawbacks of the selected machine learning algorithms.

Inhibition of cancer cell growth and migration by dihydroxynaphthyl aryl ketones

Julio Benites,Jaime A. Valderrama,David Ríos,Rosalba Lagos,Octavio Monasterio,Pedro Buc Calderon,Pedro Buc Calderon 대한독성 유전단백체 학회 2016 Molecular & cellular toxicology Vol.12 No.3

Dihydroxynaphthyl aryl ketones 1-5 exhibit activity as tubulin polymerization inhibitors by targeting the colchicine binding site of microtubules making them potential anticancer drugs. Therefore, analogues 1-5 have been evaluated for their cytotoxic activity against the cancer cell lines DU-145 (prostate), T24 (bladder) and MCF-7 (breast). Notable differences in biological activity were observed for compounds 1-5, most likely related to the nature of the aryl substituent bonded to the carbonyl group. Among the tested compounds, only compound 5 showed selectivity for cancer cells over healthy, non-transformed cells. T24 cancer cells treated with compound 5 presented a concentration-dependent decrease in cell proliferation and a loss of migration ability. The cytotoxicity of compounds 1-5 on the selected cell-based assays is discussed in terms of it lipophilicity and polarizability parameters.

Differences in clinical presentation and pregnancy outcomes in antepartum preeclampsia and new-onset postpartum preeclampsia: Are these the same disorder?

( Gustavo Vilchez ),( Luis R. Hoyos ),( Jocelyn Leon-peters ),( Moraima Lagos ),( Pedro Argoti ) 대한산부인과학회 2016 Obstetrics & Gynecology Science Vol.59 No.6

Objective New-onset postpartum preeclampsia is a poorly defined condition that accounts for a significant percentage of eclampsia cases. It is unclear whether new-onset postpartum preeclampsia is a different disorder from or belongs to the same spectrum of classic antepartum preeclampsia. The objective of this study was to compare the clinical presentation and pregnancy outcomes of antepartum preeclampsia and new-onset postpartum preeclampsia. Methods A retrospective study including 92 patients with antepartum preeclampsia and 92 patients with new-onset postpartum preeclampsia was performed. Clinical presentation and pregnancy outcomes were compared. Chi-square test was used to analyze categorical variables, and independent t-test and Mann-Whitney U-test for numerical variables. P-values of <0.05 were used to indicate statistical signifi cance. Results Patients with antepartum preeclampsia and new-onset postpartum preeclampsia differ significantly in profile, symptoms at presentation, laboratory markers and pregnancy outcomes. Conclusion New-onset postpartum preeclampsia has a distinct patient profile and clinical presentation than antepartum preeclampsia, suggesting they may represent different disorders. Characterization of a patient profile with increased risk of developing this condition will help clinicians to identify patients at risk and provide early and targeted interventions to decrease the morbidity associated with this condition.

Phenotypic Characteristics and Clonal Relationships of Stenotrophomonas maltophilia Isolates in Hospitalized Adults from a Private Center in Lima, Peru

Ortiz-Gómez Tamin,Toledano Paula,Gomez Andrea C.,López María,Alonso Carla Andrea,Ruiz Joaquim,Lagos José,Sáenz Yolanda 대한감염학회 2023 Infection and Chemotherapy Vol.55 No.2

Stenotrophomonas maltophilia is an opportunistic pathogen, often associated with nosocomial infections. Ten S. maltophilia were isolated from clinical samples during the period January 2021 and June 2022. Eight (80%) patients had cancer as a background disease and 2 patients had coronavirus disease 2019. A fatal outcome was recorded in 4 cases (40% of patients). All the isolates were susceptible to minocycline and levofloxacin. Trimethoprim/sulfamethoxazole and ceftazidime resistance rates were 20% and 40% respectively. Eight different patterns were observed by Pulsed-Field Gel Electrophoresis, only two isolates being clonally identical. The isolation of S. maltophilia in clinical settings requires the implementation of infection prevention measures.