Comparison of physicochemical properties of bio and commercial hydroxyapatite

A.L. Giraldo-Betancur,D.G. Espinosa-Arbelaez,A. del Real-López,B.M. Millan-Malo,E.M. Rivera-Muñoz,E. Gutierrez-Cortez,P. Pineda-Gomez,S. Jimenez-Sandoval,M.E. Rodriguez-García 한국물리학회 2013 Current Applied Physics Vol.13 No.7

This article reports a physicochemical comparison of synthetic and biological Hydroxyapatite (HAp). Eight samples were separated into two groups: bio and commercial hydroxyapatite (bio-HAp and commercial-HAp). The bio-HAp group containing defat, alkaline, and calcined samples taken from bovine bone were obtained by using three different treatments, in order to establish their effect on the final product quality. The commercial-HAp group, from different sources: NIST, sigma, apafill G, coralina, and biograft, were analyzed and compared with the bio-HAp results. Thermogravimetric analysis (TG) was used in order to establish thermal degradation of the samples; structural behavior was then analyzed by X-Ray Diffraction (XRD) to found the crystalline phases, as well as the crystalline quality. Fourier Transform Infrared Spectroscopy (FTIR) was performed in order to identify the corresponding HAp functional groups within the samples. The surface morphology was analyzed by Scanning Electron Microscopy (SEM) and the elemental composition was established by using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). It was found that the calcination process obtains HAp with comparable quality to the commercial samples. A crystallinity greater than 62% after the alkaline process was found. Additionally, the surface of the alkaline sample presents a transition behavior between dense and porous morphology.

Acute abdomen following COVID-19 vaccination: a systematic review

Cahuapaza-Gutierrez Nelson Luis,Pajuelo-Vasquez Renzo,Quiroz-Narvaez Cristina,Rioja-Torres Flavia,Quispe-Andahua María,Runzer-Colmenares Fernando M. 대한백신학회 2024 Clinical and Experimental Vaccine Research Vol.13 No.1

Purpose: Conduct a systematic review of case reports and case series regarding the development of acute abdomen following coronavirus disease 2019 (COVID-19) vaccination, to describe the possible association and the clinical and demographic characteristics in detail. Materials and Methods: This study included case report studies and case series that focused on the development of acute abdomen following COVID-19 vaccination. Systematic review studies, literature, letters to the editor, brief comments, and so forth were excluded. PubMed, Scopus, EMBASE, and Web of Science databases were searched until June 15, 2023. The Joanna Briggs Institute tool was used to assess the risk of bias and the quality of the study. Descriptive data were presented as frequency, median, mean, and standard deviation. Results: Seventeen clinical case studies were identified, evaluating 17 patients with acute abdomen associated with COVID-19 vaccination, which included acute appendicitis (n=3), acute pancreatitis (n=9), diverticulitis (n=1), cholecystitis (n=2), and colitis (n=2). The COVID-19 vaccine most commonly linked to acute abdomen was Pfizer-BioNTech (messenger RNA), accounting for 64.71% of cases. Acute abdomen predominantly occurred after the first vaccine dose (52.94%). All patients responded objectively to medical (88.34%) and surgical (11.76%) treatment and were discharged within a few weeks. No cases of death were reported. Conclusion: Acute abdomen is a rare complication of great interest in the medical and surgical practice of COVID-19 vaccination. Our study is based on a small sample of patients; therefore, it is recommended to conduct future observational studies to fully elucidate the underlying mechanisms of this association.

Evaluation of the Cell Growth of Mycobacteria Using Mycobacterium smegmatis mc2 155 as a Representative Species

Jorge A. Gonzalez-y-Merchand,Ruben Zaragoza-Contreras,Rosalina Guadarrama-Medina,Addy C. Helguera-Repetto,Sandra Rivera-Gutierrez,Jorge F. Cerna-Cortes,Leopoldo Santos-Argumedo,Robert A. Cox 한국미생물학회 2012 The journal of microbiology Vol.50 No.3

The study of the in vitro cell growth of mycobacteria still remains a fastidious, difficult, and time-consuming procedure. In addition, assessing mycobacterial growth in the laboratory is often complicated by cell aggregation and slow growth-rate. We now report that the use of a stainless steel spring in the culture led to an absence of large cell clumps, to a decrease of dead cells in the exponential phase and to growth of a more homogeneous population of large cells. We also report that flow cytometry is a rapid, simple and reliable approach to monitor mycobacterial cell growth and viability. Here, we monitored Mycobacterium smegmatis cellular growth by optical density, dry cell mass, and colony forming units; in addition, viability, cell size and granularity profiles were analyzed by flow cytometry, and cell morphology by electron microscopy. Cultures monitored by flow cytometry may lead to a better understanding of the physiology of mycobacteria. Moreover, this methodology may aid in characterizing the cell growth of other fastidious species of microorganisms.

Network Localization with Assisting Nodes

Carlos A. Gomez-Vega,Zhenyu Liu,Carlos A. Gutierrez,Andrea Conti,Moe Z. Win 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.2

Location awareness in wireless networks depends on propagation conditions, transmitting resources, and nodes deployment. A well designed node deployment strategy can enhance the localization performance significantly. In this paper, we present a near-optimal algorithm for deploying assisting nodes in localization networks with limited infrastructure. First, we formulate the node deployment task as an optimization problem to minimize the localization error of an agent. Then, we develop a node deployment algorithm based on this formulation. Finally, we present a case study to validate the proposed algorithm.

INVESTIGATION OF DRAG REDUCTION MECHANISM BY MICROBUBBLE INJECTION WITHIN A CHANNEL BOUNDARY LAYER USING PARTICLE TRACKING VELOCIMETRY

Hassan Yassin A.,Gutierrez-Torres C.C. Korean Nuclear Society 2006 Nuclear Engineering and Technology Vol.38 No.8

Injection of microbubbles within the turbulent boundary layer has been investigated for several years as a method to achieve drag reduction. However, the physical mechanism of this phenomenon is not yet fully understood. Experiments in a channel flow for single phase (water) and two phase (water and microbubbles) flows with various void fraction values are studied for a Reynolds number of 5128 based on the half height of the channel and bulk velocity. The state-of-the art Particle Tracking Velocimetry (PTV) measurement technique is used to measure the instantaneous full-field velocity components. Comparisons between turbulent statistical quantities with various values of local void fraction are presented to elucidate the influence of the microbubbles presence within the boundary layer. A decrease in the Reynolds stress distribution and turbulence production is obtained with the increase of microbubble concentration. The results obtained indicate a decorrelation of the streamwise and normal fluctuating velocities when microbubbles are injected within the boundary layer.

Perinatal/Postnatal Study of D-003, a Mixture of Long-Chain Fatty Acids, in Rats

M.D. Rodriguez,J.E. Gonzalez,E.F. Leon,A. Gutierrez,G. Marrero,R. Gamez,H Garcia,,E Goicochea,Y. Rodriguez,A. Gomez 한국식품영양과학회 2006 Journal of medicinal food Vol.9 No.2

D-003 is a mixture of long-chain fatty acids isolated and purified from sugar cane wax with cholesterol-low-ering and antiplatelet effects. In order to further characterize the developmental toxicity during the treatment period from lategestation up to weaning of the offspring, pregnant females received 0 (control), 500, and 1,000 mg/kg/day D-003 daily byoral gavage beginning at day 15 of pregnancy and through gestation until day 21 postpartum. Maternal clinical signs, bodyweight, and food intake were measured at regular intervals during gestation and lactation. Live pups were weighed, sexed,and examined for developmental signs. One female and male of each litter were randomly selected to evaluate the reproduc-tive potential. There were no spontaneous or dose-related maternal deaths during the course of this study. The general healthand behavioral condition of offspring was good in all groups. No significant differences among groups were found in com-parisons of litter size, survival through the weaning period, sex ratio, and male and female weights. This peri- and postnatalstudy conducted with D-003 in rats indicated that treatment of the dam during late gestation and lactation did not show ad-versely effects on reproductive performance or fetal development over two generations.

Optimal Dispatch Model for Demand Response Aggregators

Victor J. Gutierrez-Martinez,Enrique A. Zamora-Cardenas,Alejandro Pizano-Martinez,Jose M. Lozano-Garcia,Miguel A. Gomez-Martinez 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1

This paper proposes a new three-phase optimal dispatch model for multiple Demand Response (DR) aggregators. By means of the unbalanced distribution system modeling, DR involvement of single- and three-phase consumers is considered avoiding aggravating the asymmetric balancing between phases, as opposed to traditional positive-sequence DR approaches. Furthermore, this proposal can consider several DR service providers by means of the explicit inclusion of their characteristics, in the form of cost functions and capacity, in an optimal dispatch model for DR support at the distribution system level. Hence, this proposal helps to eliminate any possible uncertainty about the provision of DR services by improving the traditional hierarchical scheme adopted based on prices issued by the Independent System Operator (ISO). The model is implemented and solved combining the two state-of-the-art computational tools, Matlab® and OpenDSS. The former is used to solve the optimization problem, whereas the latter is used to perform numerical simulations of three-phase unbalanced power flow; both tools allow a straightforward model implementation resulting in a tool easily modified and updated. The effectiveness of the proposed approach is numerically demonstrated using the IEEE 13- and 123-node test feeders, in which undesirable operating scenarios are corrected by the implementation of the optimal dispatch of DR resources in very short computational times. Based on the results, it is shown how the ISO is capable to request DR considering several aggregators competing at the distribution system level. Finally, the loss reduction has been included in the objective function, showing that the proposal optimally dispatches the DR aggregators to conveniently minimize the ISO’s operational costs.

IgG4 Levels in Bile for Distinguishing IgG4-Associated Cholangiopathy from Other Biliary Disorders: A Single Blinded Pilot Study

Udayakumar Navaneethan,Norma G. Gutierrez,Ramprasad Jegadeesan,Preethi GK Venkatesh,Earl Poptic,Madhusudhan R. Sanaka,John J. Vargo,Mansour A. Parsi 대한소화기내시경학회 2014 Clinical Endoscopy Vol.47 No.6

Background/Aims: Immunoglobulin G4 (IgG4)-associated cholangiopathy (IAC) is an inflammatory disease and may mimic primary sclerosing cholangitis (PSC), cholangiocarcinoma (CCA), or pancreatic cancer on cholangiography. We investigated whether IgG4 levels in bile aspirated during endoscopic retrograde cholangiopancreatography (ERCP) can distinguish IAC from PSC, CCA, and pancreatic cancer. Methods: Bile was aspirated directly from the common bile duct during ERCP in patients with IAC prior to steroid therapy. For control purposes, bile was obtained from patients with PSC, CCA, pancreatic cancer, and benign biliary conditions (sphincter of oddi dysfunction/choledocholithiasis). Results: Biliary IgG4 levels were measured in 54 patients. The median bile IgG4 levels were markedly elevated in patients with IAC (5.5 mg/dL; interquartile range [IQR], 5.1 to 15.6) as compared to patients with benign biliary conditions (0 mg/dL; IQR, 0 to 0.1; p=0.003). The median biliary IgG4 levels in PSC, CCA, and pancreatic cancer were 1.2 (IQR, 0.2 to 3.8), 0.9 (IQR, 0.2 to 3.4), and 0.2 mg/dL (IQR, 0.1 to 0.8), respectively. A cutoff value of 3.8 mg/dL distinguished IAC from PSC and CCA patients with 100% and 76.9% sensitivity and specificity, respectively. Conclusions: The results of this pilot study suggest that measurement of biliary IgG4 levels may have clinical value in distinguishing patients with IAC from biliary disorders that can mimic IAC.

Affective Attachment to Ecological Consumer Products

( Alma Maria Jennifer A. Gutierrez ),( Rosemary R. Seva ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

There is an increase in the environmental conscience of consumers which results in the increased demand for green products an observation that a number of companies have taken advantage of by offering green products and services (Chan, 1999; J. Ottman, 1992; Peattie & Ratnayaka, 1992; Salzman, 1991; Vandermerwe & Oliff, 1990). The last decade has witnessed a drastic change in consumer preferences towards green products with the emergence of green consumers provoking market method for environmentally friendly organizations and new product innovations Ottman (1993). Integrating emotions into product has become a strategy for most manufacturers. As Marzano (1998) stated products have personality and can delight, infuriate and empower the consumer. This study aims to investigate the affective attachment of consumers to ecological products specifically on consumer based products. Aside from this, it wants to determine the type of emotions elicited by these kinds of consumer products. Buying eco products can elicit emotion in consumers. They elicit different kinds of emotional responses. These are normally positive responses making people attracted to these products and end up buying them (Schifferstein & Desmet, 2010).

One-dimensional ordered growth of magneto-crystalline and biocompatible cobalt ferrite nano-needles

Ravichandran, M.,Oza, G.,Velumani, S.,Ramirez, J.T.,Garcia-Sierra, F.,Andrade, N.B.,Garza-Navarro, M.A.,Garcia-Gutierrez, D.I.,Asomoza, R. North-Holland 2014 Materials letters Vol.135 No.-

<P>In this letter, we have reported a novel synthesis of CoFe2O4 nano-needles by a co-precipitation method using precursors of ferric chloride and cobalt nitrate at 80 degrees C. The structural and magnetic properties of as-grown needle-like CoFe2O4 nanostructures exhibit cubic spinel structure. CoFe2O4 nano-needles have an average diameter of 15 nm with an aspect ratio of 30:50, which was depicted by High-resolution transmission electron microscopy (HRTEM). Superconducting Quantum Interference Device (SQUID) confirmed the property of superparamagnetism. The magnetic measurement illustrated that the coercivity (Hc) of CoFe2O4 nano-needles increased from -145.84 Oe at 5 K to -25.38 Oe at 312 K. The cell viability studies of CoFe2O4 nano-needles were performed in the concentration range of 5-1000 mu g/ml on L6 (Skeletal muscle cell lines) and Hep-2 (Larynx carcinoma) cells using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. There was more than 50% cell viability for both the cell lines, but Hep-2 cells were more prone to killing as compared to L6 cells. Such biocompatible nanostructures can be used as drug-delivery systems for cancer therapeutics. (C) 2014 Elsevier B.V. All rights reserved.</P>