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.

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.

Heart Rate Variability and Psychometric Analysis in Patients with Hyperactive Heart Fire Syndrome

Oliverio Medina Martínez,Ruben Fossion,Yolanda García Piceno,Rosa E. Lopez-Gomez,Emma López-Espinosa,Ismael Jiménez-Estrada,Salvador Quiroz-González 사단법인약침학회 2021 Journal of Acupuncture & Meridian Studies Vol.14 No.4

Background: Hyperactive heart fire syndrome is characterized by anxiety, insomnia, dream-disturbed sleep, tongue ulcers, heat in the hands, and palpitations. However, syndrome differentiation is often subjective due to a lack of objective, quantifiable variables. Objectives: To identify changes in heart rate variability (HRV) and psychometric analysis in patients with hyperactive heart fire syndrome. Methods: Healthy controls (n = 33) were compared to patients with hyperactive heart fire syndrome (n = 48) from the Integrative University Clinic of the State University of Ecatepec Valley (CIU-UNEVE). Physiological outcome measures included heart rate (HR), the standard deviation of the normal-to-normal heartbeat intervals (SDNN), low (LF) and high frequency (HF) power, and the LF/HF ratio. Psychometric outcome measures included the Athens Insomnia Scale (AIS) and the Hamilton Anxiety Rating Scale (HARS). Results: Compared to controls, hyperactive heart fire patients had higher HR (9.6 ± 2.62%), LF (22 ± 4.21%) and LF/HF ratio (23 ± 3.14%), and lower SDNN (21 ± 2.33%) and HF (18 ± 4.61%). Patients showed increased anxiety, both with somatic (33 ± 11.2%) and psychic symptoms (39 ± 10.5%) with more difficulty falling asleep (47 ± 9.9%) and diurnal impact of sleep (31 ± 9.6%). Conclusion: Hyperactive heart fire patients may have a sympathovagal imbalance due to a reduced parasympathetic tone and/or adominant sympathetic tone, which may be at the origin of the observed symptoms of insomnia and anxiety.

Beta Decay Studies of Neutron Rich Nuclei Using Total Absorption Gamma-ray Spectroscopy and Delayed Neutron Measurements

J. L. Tain,A. Algora,E. Estevez,B. Rubio,E. Valencia,D. Jordan,J. Aysto,T. Eronen,A. Jokinen,I. Moore,H. Pentilla,J. Riisanen,L. Batist,M. Bowry,M. Bunce,W. Gelletly,R. Caballero,G. Cortes,B. Gomez-Ho 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

A complete characterisation of the β-decay of neutron-rich nuclei can be obtained from the measurement of β-delayed gamma rays and, whenever the process is energetically possible, β-delayed neutrons. The accurate determination of the β-intensity distribution and the β-delayed neutron emission probability is of great relevance in the fields of reactor technology and nuclear astrophysics. A programme for combined measurements using the total absorption gamma-ray spectroscopy technique and both neutron counters and neutron time-of-flight spectrometers is presented.

Combination of an Enzymatically Hydrolyzed Yeast and Yeast Culture with a Direct-fed Microbial in the Feeds of Broiler Chickens

Gomez, S.,Angeles, M.L.,Mojica, M.C.,Jalukar, S. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.5

A balance trial experiment was carried out to evaluate the potential relationship between an enzymatically hydrolyzed yeast (EHY) and yeast culture combined with a live Bacillus subtilis (Bs) on the productive parameters, ileal digestibility, retention of nutrient and energy and villus morphology in broilers. Seventy two 28 d old, Ross B308 male broilers were assigned to a factorial combination of 2 levels of EHY (0 and 1 kg/ton of feed) and 2 levels of Bs (0 and 125 g/ton of feed). The experiment lasted 2 weeks. Several treatment interactions were observed. EHY-fed broilers showed the lowest feed intake and feed conversion ratio whereas Bs-fed broilers showed the highest feed intake and intermediate feed conversion ratio (EHY and BS interaction, p<0.05). Also, EHY-fed broilers had greater ileal digestibility of dry matter (EHY and BS interaction, p<0.01) and energy (EHY and BS interaction, p<0.05) but these responses were counterbalanced by the combination of EHY and Bs. The thickness of the mucosa was similar between the control and EHY-fed broilers, but was lowest when Bs was added alone (EHY and BS interaction, p<0.01). The thickness of the villus was greater in EHY plus Bs-fed broilers, intermediate for the control and lower for Bs or EHY-fed broilers (EHY and BS interaction, p<0.05). The area of the villus was greater in the control and EHY plus Bs-fed broilers (EHY and BS interaction, p<0.05). In addition, EHY-fed broilers showed greater breast yield and nitrogen retention (p<0.01) and ashes digestibility (p<0.05). On the other hand, Bs-fed broilers had greater carcass and breast weight, nitrogen retention, energy excretion and villus height (p<0.05). In summary, EHY and Bs enhanced some growth, carcass and nutrient retention responses, but did not show any synergic relationship in these responses. Opposite to this, the results suggest that the positive effect of EHY on the feed conversion and digestibility of nutrients were counterbalanced by the addition of Bs.

Addition of a Worm Leachate as Source of Humic Substances in the Drinking Water of Broiler Chickens

Gomez-Rosales, S.,Angeles, M. De L. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.2

The objective of this research was to evaluate the growth performance, the apparent ileal digestibility of nitrogen and energy, the retention of nutrients and the apparent metabolizable energy corrected to zero nitrogen retention (AMEn) in broiler chickens supplemented with increasing doses of a worm leachate (WL) as a source of humic substances (HS) in the drinking water. In Exp. 1, 140 male broilers were penned individually and assigned to four WL levels (0%, 10%, 20%, and 30%) mixed in the drinking water from 21 to 49 days of age. Water was offered in plastic bottles tied to the cage. In Exp. 2, 600 male broilers from 21 to 49 days of age housed in floor pens were assigned to three levels of WL (0%, 10%, and 20%) mixed in the drinking water. The WL was mixed with tap water in plastic containers connected by plastic tubing to bell drinkers. The results of both experiments were subjected to analysis of variance and polynomial contrasts. In Exp. 1, the daily water consumption was similar among treatments but the consumption of humic, fulvic, and total humic acids increased linearly (p<0.01) as the WL increased in the drinking water. The feed conversion (p<0.01) and the ileal digestibility of energy, the excretion of dry matter and energy, the retention of dry matter, ash and nitrogen and the AMEn showed quadratic responses (p<0.05) relative to the WL levels in drinking water. In Exp. 2, the increasing level of WL in the drinking water had quadratic effects on the final body weight, daily weight gain and feed conversion ratio (p<0.05). The addition of WL as a source of HS in the drinking water had beneficial effects on the growth performance, ileal digestibility of energy, the retention of nutrients as well on the AMEn in broiler chickens; the best results were observed when the WL was mixed at levels of 20% to 30% in the drinking water.

Development of microporous-activated carbons derived from two renewable precursors for CO2 capture

Gomez-Delgado E.,Nunell G. V.,Cukierman A. L.,Bonelli P. R. 한국탄소학회 2020 Carbon Letters Vol.30 No.2

Wood sawdust from an invasive arboreal species, Parkinsonia aculeata, and seeds from a tropical fruit of massive consump�tion, Pouteria sapota, were used as precursors for the development of activated carbons (ACs) directed to CO2 adsorption. Chemical activation employing KOH as activating agent and pre-established experimental conditions was applied. Main physicochemical properties of the ACs in relation to their CO2 adsorption performance were examined. The ACs developed from the wood sawdust and the seeds presented specifc surfaces areas of 770 and 1000 m2 g−1, respectively, with their porosity development resulting essentially microporous (< 2 nm). They also showed a similar content of acidic surface groups, but basic functionalities of the former duplicated those of the latter. Maximum CO2 adsorbed at equilibrium (273 K and 100 kPa) was 5.0 mmol g−1 and 4.4 mmol g−1 for the samples derived from the sawdust and the seeds, respectively. On the other hand, CO2 adsorption capacities mimicking post-combustion conditions, as evaluated from thermogravimetric assays and breakthrough curves obtained in a packed-bed column, were approximately 1 mmol g−1, indicating a good CO2 adsorption performance for both ACs. Nevertheless, those derived from the wood sawdust with a notorious preeminence of micropores (~ 93%), narrower pore size distribution centered around 1 nm, and a higher content of basic functionalities than the ACs obtained from the seeds showed a relatively better performance. The CO2 removal capacity of the activated carbons was not noticeably afecte

Some properties of evolution algebras

L. M. Camacho,J. R. Gomez,B. A. Omirov,R. M. Turdibaev 대한수학회 2013 대한수학회보 Vol.50 No.5

The paper is devoted to the study of finite dimensional com- plex evolution algebras. The class of evolution algebras isomorphic to evolution algebras with Jordan form matrices is described. For finite dimensional complex evolution algebras the criterium of nilpotency is es- tablished in terms of the properties of corresponding matrices. Moreover, it is proved that for nilpotent n-dimensional complex evolution algebras the possible maximal nilpotency index is 1 + 2n−1.

Effects on the Proton Conduction Limiting Barriers and Trajectories in BaZr_0.875Y_0.125O₃ Due to the Presence of Other Protons

Gomez, Maria A.,Fry, Dana L.,Sweet, Marie E. The Korean Ceramic Society 2016 한국세라믹학회지 Vol.53 No.5

Kinetic Monte Carlo (KMC) and graph searches show that proton conduction limiting barriers and trajectories in $BaZr_{0.875}Y_{0.125}O_3$ are affected by the presence of other protons. At 1000 K, KMC limiting conduction barriers increase from 0.39 eV to 0.45 eV as the proton number is increased. The proton-proton radial distribution begins to rise at $2{\AA}$ and peaks at $4{\AA}$, which is half the distance expected, based on the proton concentration. Density functional theory (DFT) calculations find proton/proton distances of 2.60 and $2.16{\AA}$ in the lowest energy two-proton configurations. A simple average of the limiting barriers for 7-10 step periodic long range paths found via graph theory at 1100 K shows an increase in activation barrier from 0.32 eV to 0.37 eV when a proton is added. Both KMC and graph theory show that protons can affect each other's pathways and raise the overall conduction barriers.

ON A GENERALIZED INTEGRAL TRANSFORM

de Gomez Lopez, A.M.M.,Kalla, S.L. Department of Mathematics 1973 Kyungpook mathematical journal Vol.13 No.2