Tangramrine : A Novel Graphical Recognition and Cued-recall based Password System

Steven Altamirano,Jesús Zanelli,Juan M. Gutiérrez Cárdenas,Daniela Bringas 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.8

Graphical passwords are an authentication user model that consists of the recall of pictures or graphics signs to gain access to a system. They have been proved to be a se-cure and reliable alternative to textual passwords; by giving a more robust schema against brute force and shoulder-surfing attacks. In this research paper we present an alternative to a graphical password based on a modification of the Tangram game. We believe our proposal accomplishes the features of being an easy recognition-based system password giving the user enough security against common threats such as brute force attacks by dictionary means or OCR types, as well as shoulder-surfing attacks.

Ambulatory hypertension diagnosed by 24-h mean ambulatory versus day and night ambulatory blood pressure thresholds in children: a cross-sectional study

Ajay P. Sharma,Luis Altamirano-Diaz,Mohamed Mohamed Ali,Katryna Stronks,Amrit Kirpalani,Guido Filler,Kambiz Norozi 대한고혈압학회 2022 Clinical Hypertension Vol.28 No.-

The agreement between the commonly used ambulatory blood pressure (ABP) thresholds to diagnose ambulatory hypertension in children (patient’s 24-h mean ABP classified by 24-h 95th ABP percentile threshold, American Heart Association [AHA] threshold, or patient’s day and night mean ABP classified by day-night 95th ABP percentile thresholds) is not known. We evaluated the agreement among 24-h ABP threshold, AHA threshold, and day-night ABP thresholds to diagnose ambulatory hypertension, white coat hypertension (WCH) and masked hypertension (MH).In a cross-sectional study design, we analyzed ABP recordings from 450 participants with suspected hypertension from a tertiary care outpatient hypertension clinic. The American Academy of Pediatrics thresholds were used to diagnose office hypertension. The 24-h ABP threshold and day-night ABP thresholds classified 19% ABP (95% confidence interval [CI], 0.15–0.23) differently into ambulatory normotension/hypertension (kappa [κ], 0.58; 95% CI, 0.51–0.66). Ambulatory hypertension diagnosed by 24-h ABP threshold in 27% participants (95% CI, 0.22–0.32) was significantly lower than that by day-night ABP thresholds in 44% participants (95% CI, 0.37–0.50; P < 0.001). The AHA threshold had a stronger agreement with 24-h ABP threshold than with day-night ABP thresholds for classifying ABP into ambulatory normotension/hypertension (k 0.94, 95% CI 0.91–0.98 vs. k 0.59, 95% CI 0.52–0.66). The diagnosis of ambulatory hypertension by the AHA threshold (26%; 95% CI, 0.21–0.31) was closer to that by 24-h ABP threshold (27%, P = 0.73) than by day-night ABP thresholds (44%, P < 0.001). Similar agreement pattern persisted among these ABP thresholds for diagnosing WCH and MH. The 24-h ABP threshold classifies a lower proportion of ABP as ambulatory hypertension than day-night ABP thresholds. The AHA threshold exhibits a stronger agreement with 24-h ABP than with day-night ABP thresholds for diagnosing ambulatory hypertension, WCH and MH. Our findings are relevant for a consistent interpretation of hypertension by these ABP thresholds in clinical practice.

Comparative Metabolic Analysis of Lactate for CHO Cells in Glucose and Galactose

Camila A. Wilkens,Claudia Altamirano,Ziomara P. Gerdtzen 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.4

t-PA producing CHO cells have been shown to undergo a metabolic shift when the culture medium is supplemented with a mixture of glucose and galactose. This metabolic change is characterized by the reincorporation of lactate and its use as an additional carbon source. The aim of this work is to understand lactate metabolism. To do so,Chinese hamster ovary cells were grown in batch cultures in four different conditions consisting in different combinations of glucose and galactose. In experiments supplemented with glucose, only lactate production was observed. Cultures with glucose and galactose consumed glucose first and produced lactate at the same time, after glucose depletion galactose consumption began and lactate uptake was observed. Comparison of the metabolic state of cells with and without the shift by metabolic flux analysis show that the metabolic fluxes distribution changes mostly in the reactions involving pyruvate metabolism. When not enough pyruvate is being produced for cells to support their energy requirements, lactate dehydrogenase complex changes the direction of the reaction yielding pyruvate to feed the TCA cycle. The slow change from high fluxes during glucose consumption to low fluxes in galactose consumption generates intracellular conditions that allow the influx of lactate. Lactate consumption is possible in cell cultures supplemented with glucose and galactose due to the low rates at which galactose is consumed. Evidence suggests that an excessive production and accumulation of pyruvate during glucose consumption leads to lactate production and accumulation inside the cell. Other internal conditions such as a decrease in internal pH, forces the flow of lactate outside the cell. After metabolic shift the intracellular pool of pyruvate, lactate and H+ drops permitting the reversal of the monocarboxylate transporter direction, therefore leading to lactate uptake. Metabolic analysis comparing glucose and galactose consumption indicates that after metabolic shift not enough pyruvate is produced to supply energy metabolism and lactate is used for pyruvate synthesis. In addition, MFA indicates that most carbon consumed during low carbon flux is directed towards maintaining energy metabolism.

Seven steps to deliver a low-cost, efficient, and high-impact online plastic surgery course during COVID-19 confinement: master series microsurgery for residents' experience

Santamaria, Eric,Nahas-Combina, Luciano,Altamirano-Arcos, Carlos,Vargas-Flores, Edgar Korean Society of Plastic and Reconstructive Surge 2021 Archives of Plastic Surgery Vol.48 No.4

Microstructural evolution and fracture toughness of Al₂O₃/Ti composites

M. Vázquez-Villar,M. Romero-Romo,A. Altamirano-Torres,E. Rocha-Rangel 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.3

The effect of different additions of a metal (Ti) on the microstructure and fracture toughness of Al2O3-based ceramics, as well as the establishment of a route for their processing was analyzed in this study. The samples were prepared by means of mechanical milling and pressureless sintering in an argon atmosphere. Due to the fact of working with very small sizes of powders of both the metal and ceramic, it was possible to reach in sintered products greater values of densification than 95% of their relative density. Measurements of fracture toughness (KIC) evaluated by the fracture indentation method, indicate that this mechanical property had improved with some additions of Ti in the composite, for example KIC for pure alumina processed under the conditions of this study was 3.0MPa·m1/2, whereas, KIC for the composite with 3 vol % Ti was 4.1MPa·m1/2. The microstructure observed in a scanning electron microscopy shows the formation of small and fine metallic interpenetrating networks in the ceramic matrix, that improve in their formation with an increases of Ti in the composite. The effect of different additions of a metal (Ti) on the microstructure and fracture toughness of Al2O3-based ceramics, as well as the establishment of a route for their processing was analyzed in this study. The samples were prepared by means of mechanical milling and pressureless sintering in an argon atmosphere. Due to the fact of working with very small sizes of powders of both the metal and ceramic, it was possible to reach in sintered products greater values of densification than 95% of their relative density. Measurements of fracture toughness (KIC) evaluated by the fracture indentation method, indicate that this mechanical property had improved with some additions of Ti in the composite, for example KIC for pure alumina processed under the conditions of this study was 3.0MPa·m1/2, whereas, KIC for the composite with 3 vol % Ti was 4.1MPa·m1/2. The microstructure observed in a scanning electron microscopy shows the formation of small and fine metallic interpenetrating networks in the ceramic matrix, that improve in their formation with an increases of Ti in the composite.

ESTIMATED S-N CURVE FOR NODULAR CAST IRON: A STEERING KNUCKLE CASE STUDY

M. JIMENEZ,J. MARTINEZ,U. FIGUEROA,L. ALTAMIRANO 한국자동차공학회 2014 International journal of automotive technology Vol.15 No.7

Durability assessment is performed to establish the damage applied by loads and the number of load cyclesversus S-N curves. This information is evaluated using a fatigue damage hypothesis. A new relationship is proposed toestimate the S-N curve of nodular cast iron, based on its ultimate strength, using a case study of a steering knuckle componentunder bending load. Finite element simulation was performed to obtain the maximum stresses in the component using PatranV2012.2 and Nastran V2008 software. Correction factors accounted for surface finish, type of load and level of reliability. Actual and proposed predictions were evaluated using experimental results. The main aim of this work was to design a fatiguetest, with a limited amount of information, through finite element simulation and tensile strength. The main advantage of thisrelationship over the other methods for estimating an S-N curve, is to improve life prediction at the boundary of low and highcycle fatigue with a simple relationship and without a series of tests to identify the S-N curve, thus simplifying durabilityassessment with a limited amount of information. The proposed relationship improved the life prediction by an average of10% in the case study.

Disease presentation and surgical treatment of patients with foreign-body granulomas and ASIA syndrome: case series

Lopez-Mendoza, Javier,Vargas-Flores, Edgar,Mouneu-Ornelas, Nicole,Altamirano-Arcos, Carlos Korean Society of Plastic and Reconstructive Surge 2021 Archives of Plastic Surgery Vol.48 No.4

Background The result of illicit polymer injection is chronic inflammation with foreign-body granuloma (FBG) formation. Treatment can be divided into medical and surgical. Some patients develop severe complications with need surgical treatment. This study aims to describe patients who underwent surgical removal of the FBGs and autoimmune/inflammatory syndrome induced by adjuvants (ASIA); additionally, we evaluated the quality of life after surgery. Methods In this retrospective single-center study, the authors examined data of patients who underwent surgical removal of FBG caused by illicit polymer injection for cosmetic purposes and confirmed ASIA from 2015 to 2020 by three different surgical approaches. Descriptive summary statistics were reported on patient demographics, presenting symptoms and clinical examination features, treatment strategies, histopathology reports and quality of life. Results The cohort included 11 female patients with FBGs and ASIA. The most affected anatomical zones were the combination of gluteal region, thighs and legs (40%); and thighs with legs (20%). Main presentation was: skin hyperpigmentation (90.9%), skin induration (63.6%), chronic fatigue (63.6%), and ulcers (36.4%). Surgical modalities consisted of: ultrasonic-assisted liposuction in four patients (36.4%); open en bloc excision and primary closure in four patients (36.4%); and open en bloc excision and microsurgical reconstruction in three patients (27.2%). The postoperative quality of life visual analog scale score was 83.9. Conclusions ASIA treatment represents a challenge for the plastic surgeon. Adequate surgical treatment emphasizing, when possible, the total or near-total resection of the FBG must be performed to improve ASIA evolution.

Synthesis of branched geminal zwitterionic liquids as wettability modifiers in enhanced oil recovery processes

J.F. Ramı´rez-Pe´ rez,R. Herna´ndez-Altamirano,J.M. Martı´nez-Magada´n,R. Cartas-Rosado,E. Soto-Castruita,R. Cisneros-Devora,L.A. Alca´ zar-Vara,R. Oviedo-Roa,V.Y. Mena-Cervantes,L.S. Zamudio-Rivera 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.45 No.-

A new class of branched geminal zwitterionic liquids (BGZLs) betaine base with a long alkyl chains witheither 8 (BGZL-ZW8) or 12 (BGZL-ZW12) carbons was synthesized and characterized by nuclearmagnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopic techniques. The BGZLsmolecules presents functionality as viscosity reducer and wettability modifier with application inenhanced oil recovery (EOR) processes with good oil recovery factors (ORF). The above is demonstratedby performing spontaneous imbibition tests on embedded limestone cores with light and heavy crudeoils in Amott cells at high temperature (90 8C) and different concentrations of BGZLs in presence ofconnate water with high salinity and hardness (36,275 ppm as NaCl and 6700 ppm hardness as CaCO3). The rheological behavior of BGZLs was also determined as viscosity reducers in heavy crude oil atconcentrations of 2000, 1000 and 500 ppm at temperatures of 25 and 40 8C, in the range of 36.11% to25 8C and 43.31% to 40 8C. To explain the mechanism through BGZLs act as viscosity reducers, werealized theoretical studies using the density functional theory (DFT), also as wettability modifierstaking BGZL-ZW8 and BGZL-ZW12 behavior, observed in the experimental part. The interaction energiesshow that BGZLs can disaggregate asphaltene (Asph) dimmer (Asph:Asph) by the formation ofsupramolecular sandwich complex (Asph:BGZL:Asph) among BGZLs and Asph:Asph, modifying theproperties of crude oil such as viscosity, is possible to support the fact of the BGZLs can desorbs Asphmolecules of the rock surface, modifying the calcite surface (Cs) wettability of oil-wet to water-wet. Theresults of this research show that it is feasible the use of zwitterionic liquids as viscosity and wettabilitymodifier in EOR process.

Experimental and theoretical study of lead sulfide nanocrystals attached to nitrogen‑doped carbon nanotubes

B. Rebollo‑Plata,M. P. Sampedro,M. G. G?mez‑Espinoza,M. Guzm?n‑Altamirano,J. G. Cabal‑Velarde,O. Portillo‑Moreno,A. Lobo‑Guerrero,M. L?pez‑Fuentes,Ra?l A. Morales‑Luckie 한국탄소학회 2023 Carbon Letters Vol.33 No.1

Lead sulfide ( PbS ) nanocrystals anchored on nitrogen-doped multiwalled carbon nanotubes ( CNx ) have been synthesized employing an environmentally friendly and inexpensive wet chemistry process. CNx?PbS composites have been examined by scanning electron microscopy, X-ray diffraction and Raman spectroscopy. Theorical ab initio calculations have been developed to determine the samples structural, morphological and optical properties to explain the experimental evidences. The PbS nanoparticles exhibit of 4 nm to 27 nm particle size with a face-centered cubic crystal structure and are homogeneously distributed along the carbon nanotubes. The nitrogen-doped CNTs acts as binding sites for the PbS clusters as ab initio theoretical study suggests.