Fractional Radioactive Decay Law and Bateman equations

C.-A. Cruz-Lopez,G. Espinosa-Paredes 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1

The aim of this work is to develop the fractional Bateman equations, which can model memory effects insuccessive isotopes transformations. Such memory effects have been previously reported in the alpha decay,which exhibits a non-Markovian behavior. Since there are radioactive decay series with consecutive alphadecays, it is convenient to include the mentioned memory effects, developing the fractional Bateman Equations,which can reproduce the standard ones when the fractional order is equal to one. The proposed fractionalmodel preserves the mathematical shape and the symmetry of the standard equations, being the onlydifference the presence of the Mittag-Leffler function, instead of the exponential one. This last is a veryimportant result, because allows the implementation of the proposed fractional model in burnup and activationcodes in a straightforwardway.Numerical experiments showthat the proposed equations predict highdecay rates for small timevalues, in comparisonwith the standard equations,which have high decay rates forlarge times. This work represents a novelty approach to the theory of successive transformations, and opensthe possibility to study properties of the Bateman equation from a fractional approach

Super-stretchable Graphene Oxide Macroscopic Fibers with Outstanding Knotability Fabricated by Dry Film Scrolling

Cruz-Silva, Rodolfo,Morelos-Gomez, Aaron,Kim, Hyung-ick,Jang, Hong-kyu,Tristan, Ferdinando,Vega-Diaz, Sofia,Rajukumar, Lakshmy P.,Elí,as, Ana Laura,Perea-Lopez, Nestor,Suhr, Jonghwan,Endo, Morin American Chemical Society 2014 ACS NANO Vol.8 No.6

<P>Graphene oxide (GO) has recently become an attractive building block for fabricating graphene-based functional materials. GO films and fibers have been prepared mainly by vacuum filtration and wet spinning. These materials exhibit relatively high Young’s moduli but low toughness and a high tendency to tear or break. Here, we report an alternative method, using bar coating and drying of water/GO dispersions, for preparing large-area GO thin films (<I>e.g.</I>, 800–1200 cm<SUP>2</SUP> or larger) with an outstanding mechanical behavior and excellent tear resistance. These dried films were subsequently scrolled to prepare GO fibers with extremely large elongation to fracture (up to 76%), high toughness (up to 17 J/m<SUP>3</SUP>), and attractive macroscopic properties, such as uniform circular cross section, smooth surface, and great knotability. This method is simple, and after thermal reduction of the GO material, it can render highly electrically conducting graphene-based fibers with values up to 416 S/cm at room temperature. In this context, GO fibers annealed at 2000 °C were also successfully used as electron field emitters operating at low turn on voltages of <I>ca.</I> 0.48 V/μm and high current densities (5.3 A/cm<SUP>2</SUP>). Robust GO fibers and large-area films with fascinating architectures and outstanding mechanical and electrical properties were prepared with bar coating followed by dry film scrolling.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2014/ancac3.2014.8.issue-6/nn501098d/production/images/medium/nn-2014-01098d_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn501098d'>ACS Electronic Supporting Info</A></P>

Performance Analysis of Coordinated Cognitive Radio Networks under Fixed-Rate Traffic with Hard Delay Constraints

Castellanos-Lopez, S. Lirio,Cruz-Perez, Felipe A.,Rivero-Angeles, Mario E.,Hernandez-Valdez, Genaro The Korea Institute of Information and Commucation 2014 Journal of communications and networks Vol.16 No.2

Due to the unpredictable nature of channel availability, carrying delay-sensitive traffic in cognitive radio networks (CRNs) is very challenging. Spectrum leasing of radio resources has been proposed in the so called coordinated CRNs to improve the quality of service (QoS) experienced by secondary users (SUs). In this paper, the performance of coordinated CRNs under fixed-rate with hard-delay-constraints traffic is analyzed. For the adequate and fair performance comparison, call admission control strategies with fractional channel reservation to prioritize ongoing secondary calls over new ones are considered. Maximum Erlang capacity is obtained by optimizing the number of reserved channels. Numerical results reveal that system performance strongly depends on the value of the mean secondary service time relative to the mean primary service time. Additionally, numerical results show that, in CRNs without spectrum leasing, there exists a critical utilization factor of the primary resources from which it is not longer possible to guarantee the required QoS of SUs and, therefore, services with hard delay constraints cannot be even supported in CRNs. Thus, spectrum leasing can be essential for CRN operators to provide the QoS demanded by fixed-rate applications with hard delay constraints. Finally, the cost per capacity Erlang as function of both the utilization factor of the primary resources and the maximum allowed number of simultaneously rented channels is evaluated.

Novel Low-Power High-dB Range CMOS Pseudo-Exponential Cells

Carlos Aristoteles De La Cruz Blas,Antonio Lopez-Martin 한국전자통신연구원 2006 ETRI Journal Vol.28 No.6

In this paper, novel CMOS pseudo-exponential circuits operating in a class-AB mode are presented. The pseudoexponential approximation employed is based on second order equations. Such terms are derived in a straightforward way from the inherent nonlinear currents of class-AB transconductors. The cells are appropriate to be integrated in portable equipment due to their compactness and very low power consumption. Measurement results from a fabricated prototype in a 0.5 μm technology reveal a range of 45 dB with errors lower than ±0.5 dB, a power consumption of 100 μW, and an area of 0.01 mm2.

Synthesis and antitumor molecular mechanism of agents based on amino 2-(3',4',5'-trimethoxybenzoyl)benzo[b]furan: inhibition of tubulin and induction of apoptosis.

Romagnoli, Romeo,Baraldi, Pier Giovanni,Lopez-Cara, Carlota,Cruz-Lopez, Olga,Carrion, Maria Dora,Kimatrai Salvador, Maria,Bermejo, Jaime,Est?vez, Sara,Est?vez, Francisco,Balzarini, Jan,Brancale, Andre Wiley-VCH 2011 CHEMMEDCHEM Vol.6 No.10

<P>Induction of apoptosis is a promising strategy that could lead to the discovery of new molecules active in cancer chemotherapy. This property is generally observed when cells are treated with agents that target microtubules, dynamic structures that play a crucial role in cell division. Small molecules such as benzo[b]furans are attractive as inhibitors of tubulin polymerization. A new class of inhibitors of tubulin polymerization based on the 2-(3',4',5'-trimethoxybenzoyl)benzo[b]furan molecular skeleton, with the amino group placed at different positions on the benzene ring, were synthesized and evaluated for antiproliferative activity, inhibition of tubulin polymerization, and cell-cycle effects. The methoxy substitution pattern on the benzene portion of the benzo[b]furan moiety played an important role in affecting antiproliferative activity. In the series of 5-amino derivatives, the greatest inhibition of cell growth occurred if the methoxy substituent is placed at the C6 position, whereas C7 substitution decreases potency. The most promising compound in this series is 2-(3',4',5'-trimethoxybenzoyl)-3-methyl-5-amino-6-methoxybenzo[b]furan (3 h), which inhibits cancer cell growth at nanomolar concentrations (IC(50) =16-24 nM), and interacts strongly with tubulin by binding to the colchicine site. Sub-G(1) apoptotic cells in cultures of HL-60 and U937 cells were observed by flow cytometric analysis after treatment with 3 h in a concentration-dependent manner. We also show that compound 3 h induces apoptosis by activation of caspase-3, -8, and -9, and this is associated with cytochrome c release from mitochondria. The introduction of an α-bromoacryloyl group increased antiproliferative activity with respect to the parent amino derivatives.</P>

Consumption of Nopal Powder in Adult Women

Mayra Elisa Sanchez-Murillo,Edwyn Omar Cruz-Lopez,Marıa Julia Verde-Star,Catalina Rivas-Morales,Marıa Eufemia Morales-Rubio,Aurora de Jesus Garza-Juarez,Jorge Martın Llaca-Dıaz,Ma de Jesus Ibarra-Sala 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.9

Osteoporosis is a chronic disease in adult women caused by menopause and some other factors, which entails deficiency of calcium in diet. Natural products are the best source of nutriments to reduce the risk of chronic diseases. Nopal (Opuntia ficus-indica) is a plant characterized by its nutritional components and benefits to health. Its calcium content increases with maturation process that could be beneficial for consumers. Nopal powder (NP) was elaborated from nopal harvested within 16–24 weeks of maturation, and the nutritional content was determined. An experimental clinical trial was performed to evaluate the effect of NP. A total of 69 women between 40 and 60 years old participated in the study. During 24 weeks, experimental group (n = 56) consumed a daily dose of 5 g of NP and control group (n = 13) continue with habitual diet. Changes in bone mineral density (BMD), body mass index (BMI), body fat percentage and serum calcium were assessed. Between baseline and after 24 weeks of consumption, no significant changes were found in BMD P = .885 experimental group and P = .970 control group, BMI P = .865 experimental group and P = .984 control group, body fat P = .744 experimental group and P = .740 control group and serum calcium P = .282 experimental group and P = .959 control group. These results indicate that advanced maturation NP does not have influence in bone health, BMI, and body composition in adult women.

The influence of marine algae on iodine speciation in the coastal ocean

Carrano, Mary W.,Yarimizu, Kyoko,Gonzales, Jennifer L.,Cruz-Lopez, Ricardo,Edwards, Matthew S.,Tymon, Teresa M.,Kupper, Frithjof C.,Carrano, Carl J. The Korean Society of Phycology 2020 ALGAE Vol.35 No.2

Iodine exists as a trace element in seawater, with total iodine being generally constant at about 0.45-0.55 μM. Almost all of this iodine occurs in two main forms: iodate and iodide. Iodate is the thermodynamically stable form under normal seawater conditions, and thus should be the only iodine-containing species in the water column. However, iodate concentrations are found to vary considerably, being generally greater at depth and lower at the surface, while iodide concentrations follow the reverse pattern, being anomalously accumulated in the euphotic zone and decreasing with depth. The fact that iodide concentrations follow a depth dependence corresponding to the euphotic zone suggests that biological activity is the source of the reduced iodine. Nonetheless, the nature and source of iodate reduction activity remains controversial. Here, using a combination of field and laboratory studies, we examine some of the questions raised in our and other previous studies, and seek further correlations between changes in iodine speciation and the presence of marine macro- and microalgae. The present results indicate that microalgal growth per se does not seem to be responsible for the reduction of iodate to iodide. However, there is some support for the hypothesis that iodate reduction can occur due to release of cellular reducing agents that accompany cell senescence during phytoplankton bloom declines. In addition, support is given to the concept that macroalgal species such as giant kelp (Macrocystis pyrifera) can take up both iodide and iodate from seawater (albeit on a slower time scale). We propose a mechanism whereby iodate is reduced to iodide at the cell surface by cell surface reductases and is taken up directly as such without reentering the bulk solution.

Improved outcomes with implementation of an Enhanced Recovery After Surgery pathway for patients undergoing elective colorectal surgery in the Philippines

Mayou Martin T. Tampo,Mark Augustine S. Onglao,Marc Paul J. Lopez,Marie Dione P. Sacdalan,Ma. Concepcion L. Cruz,Rosielyn T. Apellido,Hermogenes J. Monroy III 대한대장항문학회 2022 Annals of Coloproctolgy Vol.38 No.2

Purpose: This study aims to evaluate surgical outcomes (i.e. length of stay [LOS], 30-day morbidity, mortality, reoperation, and readmission rates) with the use of the Enhanced Recovery After Surgery (ERAS) pathway, and determine its association with the rate of compliance to the different ERAS components. Methods: This was a prospective cohort of patients, who underwent the following elective procedures: stoma reversal (SR), colon resection (CR), and rectal resection (RR). The primary endpoint was to determine the association of compliance to an ERAS pathway and surgical outcomes. These were then retrospectively compared to outcomes prior to the implementation of ERAS. Results: A total of 267 patients were included in the study. The overall compliance to the ERAS component was 92.0% (SR, 91.8%; CR, 93.1%; RR, 90.7%). There was an associated decrease in morbidity rates across all types of surgery, as compliance to ERAS increased. The average total LOS decreased in all groups but was only found to have statistical significance in SR (12.1±6.7 days vs. 10.0±5.4 days, P=0.002) and RR (19.9±11.4 days vs. 16.9±10.5 days, P=0.04) groups. Decreased postoperative LOS was noted in all groups. Morbidity rates were significantly higher after ERAS implementation, but reoperation and mortality rates were found to be similar. Conclusion: Increased compliance to ERAS protocol is associated with a decrease in morbidity across all surgery types. The implementation of an ERAS protocol significantly decreased mean hospital LOS, without any increase in major surgical complications. Having your own hospital ERAS pathway improves documentation and accuracy of reporting surgical complications.

Phenolic Compounds of Potato Peel Extracts: Their Antioxidant Activity and Protection against Human Enteric Viruses

( Norma Patricia Silva-beltran ),( Cristobal Chaidez-quiroz ),( Osvaldo Lopez-cuevas ),( Saul Ruiz-cruz ),( Marco A. Lopez-mata ),( Carmen Lizette Del-toro-sanchez ),( Enrique Marquez-rios ),( Jose De 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.2

Potato peels (PP) contain several bioactive compounds. These compounds are known to provide human health benefits, including antioxidant and antimicrobial properties. In addition, these compounds could have effects on human enteric viruses that have not yet been reported. The objective of the present study was to evaluate the phenolic composition, antioxidant properties in the acidified ethanol extract (AEE) and water extract of PP, and the antiviral effects on the inhibition of Av-05 and MS2 bacteriophages, which were used as human enteric viral surrogates. The AEE showed the highest phenolic content and antioxidant activity. Chlorogenic and caffeic acids were the major phenolic acids. In vitro analysis indicated that PP had a strong antioxidant activity. A 3 h incubation with AEE at a concentration of 5 mg/ml was needed to reduce the PFU/ml (plaque-forming unit per unit volume) of Av-05 and MS2 by 2.8 and 3.9 log10, respectively, in a dose-dependent manner. Our data suggest that PP has potential to be a source of natural antioxidants against enteric viruses.

CYP3A4 Expression in Breast Cancer and its Association with Risk Factors in Mexican Women

Floriano-Sanchez, Esau,Rodriguez, Noemi Cardenas,Bandala, Cindy,Coballase-Urrutia, Elvia,Lopez-Cruz, Jaime Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Background: In Mexico, breast cancer (BCa) is the leading type of cancer in women. Cytochrome P450 (CYP450) is a superfamily of major oxidative enzymes that metabolize carcinogens and many antineoplastic drugs. In addition, these enzymes have influence on tumor development and tumor response to therapy. In this report, we analyzed the protein expression in patients with BCa and in healthy women. Links with some clinic-pathological characteristic were also assessed. Materials and Methods: Immunohistochemical analyses were conducted on 48 sets of human breast tumors and normal breast tissues enrolled in Hospital Militar de Especialidades de la Mujer y Neonatologia and Hospital Central Militar, respectively, during the time period from 2010 to 2011. Informed consent was obtained from all participants. Statistical analysis was performed using ${\chi}^2$ or Fisher exact tests to estimate associations and the Mann Whitney U test for comparison of group means. Results: We found a significant CYP3A4 overexpression in BCa stroma and gland regions in comparison with healthy tissue. A significant association between protein expression with smoking, alcoholism and hormonal contraceptives use was also observed. Additionally, we observed estrogen receptor (ER) and progesterone receptor (PR) positive association in BCa. Conclusions: We suggest that CYP3A4 expression promotes BCa development and can be used in the prediction of tumor response to different treatments. One therapeutic approach may thus be to block CYP3A4 function.