Artículos de revistas: "Ga-Free"

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Nazri, S. F. y Mohd Arif Anuar Mohd Salleh. "The Effects of Gallium Additions on the Microstructure of Lead-Free Solder Materials: A Short Review". Solid State Phenomena 280 (agosto de 2018): 187–93. http://dx.doi.org/10.4028/www.scientific.net/ssp.280.187.

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This paper reviews the results of gallium (Ga) additions on the properties of Lead (Pb)-free solder alloys in terms of the solderability, microstructure and mechanical properties. Throughout the review, it is proven that when 0.5% of Ga is added, the shear force is improved and the grain size of the solder has refined remarkably. Besides, the addition of Ga has significantly suppressed the interfacial intermetallic compounds (IMCs) formation at solder/Copper substrate interface. This is caused by the formation of the Cu2Ga phase around the joint surface during solidification which decrease the growth rate of the IMCs layer. In fact, the enhancement in the mechanical aspect can also be affiliated with the improvement of the IMCs of the solder due to the addition of Ga. Moreover, Ga element also added to act as solid solution strengthening in β-Sn matrix. Furthermore, the addition of Ga element definitely decreases the melting temperature of Pb-free solder in Sn-0.7Cu Pb-free solder. As Ga addition also improve the oxidation resistance and reduce the surface tension of the solder, thus the solderability of the Pb-free solder alloys is slightly improved.

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Fang, Shang-Ting, Shu-Hsiang Huang, Chin-Hao Yang, Jen-Wen Liou, Hemalatha Mani y Yi-Cheng Chen. "Effects of Calcium Ions on the Antimicrobial Activity of Gramicidin A". Biomolecules 12, n.º 12 (1 de diciembre de 2022): 1799. http://dx.doi.org/10.3390/biom12121799.

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Gramicidin A (gA) is a linear antimicrobial peptide that can form a channel and specifically conduct monovalent cations such as H+ across the lipid membrane. The antimicrobial activity of gA is associated with the formation of hydroxyl free radicals and the imbalance of NADH metabolism, possibly a consequence caused by the conductance of cations. The ion conductivity of gramicidin A can be blocked by Ca2+ ions. However, the effect of Ca2+ ions on the antimicrobial activity of gA is unclear. To unveil the role of Ca2+ ions, we examined the effect of Ca2+ ions on the antimicrobial activity of gramicidin A against Staphylococcus aureus (S. aureus). Results showed that the antimicrobial mechanism of gA and antimicrobial activity by Ca2+ ions are concentration-dependent. At the low gA concentration (≤1 μM), the antimicrobial mechanism of gA is mainly associated with the hydroxyl free radical formation and NADH metabolic imbalance. Under this mode, Ca2+ ions can significantly inhibit the hydroxyl free radical formation and NADH metabolic imbalance. On the other hand, at high gA concentration (≥5 μM), gramicidin A acts more likely as a detergent. Gramicidin A not only causes an increase in hydroxyl free radical levels and NAD+/NADH ratios but also induces the destruction of the lipid membrane composition. At this condition, Ca2+ ions can no longer reduce the gA antimicrobial activity but rather enhance the bacterial killing ability of gramicidin A.

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Skidchenko, E., M. V. Yakushev, L. Spasevski, P. R. Edwards, M. A. Sulimov y R. W. Martin. "Excitons in PL spectra of Cu(In, Ga)Se-=SUB=-2-=/SUB=- single crystal -=SUP=-*-=/SUP=-". Физика твердого тела 61, n.º 5 (2019): 1002. http://dx.doi.org/10.21883/ftt.2019.05.47609.39f.

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AbstractA photoluminescence (PL) study of Cu(In,Ga)Se_2 (CIGSe) single crystals, (grown by the vertical Bridgman technique) with the [Ga]/[Ga + In] ratio of 7 and 12% and the [Cu]/[In + Ga] ratio greater than unity, as measured by energy dispersive spectroscopy, is presented. Analysis of the excitation intensity and temperature dependence of the PL spectra suggested the excitonic nature of the observed near-band-edge emissions peaks. Free and bound excitons in CIGSe single crystals with both 7 and 12% Ga content are clearly observed, analyzed and identified. An activation energy of 19 meV is determined for the free exciton in the PL spectra of the sample with 12% Ga. The presence of the excitons demonstrated a high structural quality of the material.

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4

Burgette, J. M. y R. B. Quiñonez. "Cost-effectiveness of Treating Severe Childhood Caries under General Anesthesia versus Conscious Sedation". JDR Clinical & Translational Research 3, n.º 4 (4 de junio de 2018): 336–45. http://dx.doi.org/10.1177/2380084418780712.

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Background: Two common methods of treating pediatric dental patients with severe early childhood caries (S-ECC) are general anesthesia (GA) and conscious sedation (CS). We sought to first evaluate the cost-effectiveness of treating S-ECC with GA versus CS and then compare the cost-effectiveness at 2 time points: 2011 and 2015. Methods: We used a decision tree model to produce 2-y estimates of costs and outcomes from the Medicaid perspective. The model cohort consisted of healthy 3-y-olds with S-ECC in need of a theoretical set of dental treatments to be performed under either a single GA visit or 3 CS visits. Outcomes were measured in caries-free months. Costs were evaluated in 2015 US dollars. Costs, probabilities, and outcomes were estimated from published data, expert opinion, and Medicaid billing at an academic health center. One-way and probabilistic sensitivity analyses were performed. Results: As compared with CS, GA resulted in 4 additional caries-free months per child. The cost of a caries-free month for GA versus CS rose from $596 in 2011 to $881 in 2015. These findings were sensitive to loss to follow-up for subsequent CS visits and total cost of GA. Conclusions: Comprehensive S-ECC treatment had better outcomes when performed under GA versus CS. However, GA was not cost saving when compared with CS. While the cost of dental treatment increased for both GA and CS from 2011 to 2015, the cost rose faster for GA. These results have important implications due to the increasing cost to Medicaid insurance and the rising number of young children being treated for S-ECC under GA. Knowledge Transfer Statement: Medicaid policy makers can use the results of this study to evaluate the cost-effectiveness of dental treatment for young children with S-ECC at 2 time points: 2011 and 2015. Compared with CS, GA resulted in a longer amount of time during which children were free from dental caries but at a higher cost. The cost difference rose from 2011 to 2015.

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Aksela, S. y H. Aksela. "L2,3M4,5M4,5Auger spectra of free Ga and Ge atoms". Physical Review A 31, n.º 3 (1 de marzo de 1985): 1540–42. http://dx.doi.org/10.1103/physreva.31.1540.

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Suñol, J. J., L. Escoda, B. Hernando, W. O. Rosa, T. Sánchez, J. D. Santos, V. M. Prida y V. G. Shavrov. "Structure of rapidly quenched Ga-free Heusler alloys". physica status solidi (a) 208, n.º 10 (15 de junio de 2011): 2281–83. http://dx.doi.org/10.1002/pssa.201000743.

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7

Hsu, Po-Ya, Ting-Yu Hu, Selvaraj Rajesh Kumar, Kevin C. W. Wu y Shingjiang Jessie Lue. "Swelling-Resistant, Crosslinked Polyvinyl Alcohol Membranes with High ZIF-8 Nanofiller Loadings as Effective Solid Electrolytes for Alkaline Fuel Cells". Nanomaterials 12, n.º 5 (4 de marzo de 2022): 865. http://dx.doi.org/10.3390/nano12050865.

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The present work investigates the direct mixing of aqueous zeolitic imidazolate framework-8 (ZIF-8) suspension into a polyvinyl alcohol (PVA) and crosslinked with glutaraldehyde (GA) to form swelling-resistant, mechanically robust and conductivity retentive composite membranes. This drying-free nanofiller incorporation method enhances the homogeneous ZIF-8 distributions in the PVA/ZIF-8/GA composites to overcome the nanofiller aggregation problem in the mixed matrix membranes. Various ZIF-8 concentrations (25.4, 40.5 and 45.4 wt.%) are used to study the suitability of the resulting GA-crosslinked composites for direct alkaline methanol fuel cell (DAMFC). Surface morphological analysis confirmed homogeneous ZIF-8 particle distribution in the GA-crosslinked composites with a defect- and crack-free structure. The increased ionic conductivity (21% higher than the ZIF-free base material) and suppressed alcohol permeability (94% lower from the base material) of PVA/40.5%ZIF-8/GA resulted in the highest selectivity among the prepared composites. In addition, the GA-crosslinked composites’ selectivity increased to 1.5–2 times that of those without crosslink. Moreover, the ZIF-8 nanofillers improved the mechanical strength and alkaline stability of the composites. This was due to the negligible volume swelling ratio (<1.4%) of high (>40%) ZIF-8-loaded composites. After 168 h of alkaline treatment, the PVA/40.5%ZIF-8/GA composite had almost negligible ionic conductivity loss (0.19%) compared with the initial material. The maximum power density (Pmax) of PVA/40.5%ZIF-8/GA composite was 190.5 mW cm−2 at 60 °C, an increase of 181% from the PVA/GA membrane. Moreover, the Pmax of PVA/40.5%ZIF-8/GA was 10% higher than that without GA crosslinking. These swelling-resistant and stable solid electrolytes are promising in alkaline fuel cell applications.

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8

Jackson, Brian P. "Low level determination of gallium isotopes by ICP-QQQ". Journal of Analytical Atomic Spectrometry 33, n.º 5 (2018): 897–900. http://dx.doi.org/10.1039/c8ja00073e.

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9

Janicek, M., W. Kaplan, D. Neuberg, G. P. Canellos, L. N. Shulman y M. A. Shipp. "Early restaging gallium scans predict outcome in poor-prognosis patients with aggressive non-Hodgkin's lymphoma treated with high-dose CHOP chemotherapy." Journal of Clinical Oncology 15, n.º 4 (abril de 1997): 1631–37. http://dx.doi.org/10.1200/jco.1997.15.4.1631.

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PURPOSE This prospective study assessed the predictive value of early restaging gallium (Ga) and computed tomographic (CT) scans in poor-prognosis patients with aggressive non-Hodgkin's lymphoma (NHL) who were treated with high-dose cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy. PATIENTS AND METHODS Thirty newly diagnosed patients with bulky (> or = 10 cm) advanced-stage aggressive NHL were treated with a four-cycle high-dose CHOP regimen (22 patients at maximum-tolerated dose [MTD]: cyclophosphamide 4 g/m2, doxorubicin 70 mg/m2, vincristine 2 mg, and prednisone 100 mg orally for 5 days). All patients had chest/abdominal/pelvic CT scans and 10-mCi Ga scans at baseline and following two and four cycles of therapy. Scans were reviewed in a blinded manner for CT-documented rates of response and sizes of residual masses and Ga avidity of residual masses. The results of early (post-cycle 2) and final (post-cycle 4) restaging were subsequently associated with clinical outcome. RESULTS CT-documented rates of response and residual mass sizes were indistinguishable in complete responders who remained continuously disease-free (CR-Cont), complete responders who subsequently relapsed (CR-Rel), and partial responders who then progressed (PR/Prog). In marked contrast, early restaging (post-cycle 2) Ga scans accurately delineated these three categories of patients: CR-Cont 90% Ga-negative (18 of 20 patients) versus CR-Rel 25% Ga-negative (one of four patients) versus PR/Prog 0% Ga-negative (zero of six patients) (P = .000014). At a median follow-up duration of 31 months (range, 21 to 46), 94% of patients who had negative early restaging Ga scans remain free from progression (FFP), whereas only 18% of patients who had positive early restaging Ga scans remain FFP (P = .000007). Early restaging Ga scans were more predictive for FFP than final restaging Ga scans because patients who required four full cycles of therapy to become Ga-negative were more likely to develop recurrent disease. CONCLUSION Early restaging Ga scans delineate patients who are likely to have prolonged disease-free survival from those who fail to respond to intensive induction therapy. Patients whose tumors remain Ga-positive midway through high-dose CHOP therapy have a poor outcome and may be candidates for alternative treatment.

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Iarlori, C., D. Gambi, A. Lugaresi, A. Patruno, M. Felaco, M. Salvatore, L. Speranza y M. Reale. "Reduction of free radicals in multiple sclerosis: effect of glatiramer acetate (Copaxone®)". Multiple Sclerosis Journal 14, n.º 6 (julio de 2008): 739–48. http://dx.doi.org/10.1177/1352458508088918.

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Free radicals have been found in high concentrations within inflammatory multiple sclerosis (MS) lesions. The superoxide anion (O2–) reacts rapidly with nitric oxide (NO), producing peroxynitrite (ONOO–). Glatiramer acetate (GA) is a specific MS immunomodulator that induces the synthesis of Th2 cytokines, and reduces the frequency of relapses and the formation of active brain lesions. Proinflammatory cytokines could play a role in free radicals production in the peripheral immune system as well as in the central nervous system (CNS). The effect of GA on iNOS, superoxide radicals (O2–) and 3-nitrotyrosine production by peripheral blood adherent mononuclear cells (PBAMs) was assessed. Our findings demonstrate that in vitro GA reduced spontaneous and LPS-induced iNOS, 3-nitrotyrosine, NO and O2– production, and that similar inhibition can be demonstrated ex vivo in mononuclear cells obtained from GA-treated patients. The inhibition of the production of free radicals in PBAMs may represent a new therapeutic mechanism against inflammation during MS.

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Matsushita, M., Y. Sasaki y Y. Ikuta. "Investigation of a New Sn–Cu–Ga Alloy Solder". Defect and Diffusion Forum 312-315 (abril de 2011): 518–23. http://dx.doi.org/10.4028/www.scientific.net/ddf.312-315.518.

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Soldering processes involving the use of Pb have been known and practiced for more than 5000 years. In 2000, the European Union imposed a ban on the use of Pb because of the fact that Pb is poisonous to humans. Consequently, attempts are being made worldwide to develop a Pb-free solder. Among the various Pb-free solders, the Sn–0.75wt%Cu (Sn-0.75Cu) solder is the suitable one from the viewpoint of cost. Moreover, its acoustic properties are superior to those of the other Pb-free solders. However, the Sn-0.75Cu solder has a few disadvantages: its joining strength is lower than that of the other solders, and its melting temperature is higher than that of the Sn-37wt%Pb (Sn–Pb) solder. Therefore, we have attempted to decrease the melting temperature and improve the joining strength of Sn-0.75Cu to match those of the Sn–Pb solder. It is well known that when Ga is added to a Sn-based alloy, the melting temperature of the alloy decreases. Moreover, Ga has superior wettability. Therefore, we added Ga to the Sn-0.75Cu solder in order to improve the joining strength and decrease the melting temperature of the solder. We observed that the melting temperature of Sn95.3Cu0.7Ga4 reduced to less than that of the Sn–Pb solder. We also investigated the joining strength between the Ga-added solder and a Cu wire. We observed that the joining strength increased with an increase in Ga content, was the highest for Sn97.3Cu0.7Ga2, and then decreased with an increase in Ga content. The peak joining strength of the Ga-added solder was almost 1.5 times that of the Sn-0.75Cu solder. However, the brittleness of the solder increased with an increase in the Ga content. This is a disadvantage of the addition of Ga to Sn.

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Alfei, Silvana, Barbara Marengo, Guendalina Zuccari, Federica Turrini y Cinzia Domenicotti. "Dendrimer Nanodevices and Gallic Acid as Novel Strategies to Fight Chemoresistance in Neuroblastoma Cells". Nanomaterials 10, n.º 6 (26 de junio de 2020): 1243. http://dx.doi.org/10.3390/nano10061243.

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Human neuroblastoma (NB), a pediatric tumor inclined to relapse, after an initial response to therapy, usually develops resistance. Since several chemotherapeutics exert anticancer effect by increasing reactive oxygen species (ROS), NB cells overproduce antioxidant compounds becoming drugs-resistant. A strategy to sensitize NB cells to chemotherapy involves reducing their antioxidant defenses and inducing ROS overproduction. Concerning this, although affected by several issues that limit their clinical application, antioxidant/pro-oxidant polyphenols, such as gallic acid (GA), showed pro-oxidant anti-cancer effects and low toxicity for healthy cells, in several kind of tumors, not including NB. Herein, for the first time, free GA, two GA-dendrimers, and the dendrimer adopted as GA reservoir were tested on both sensitive and chemoresistant NB cells. The dendrimer device, administered at the dose previously found active versus sensitive NB cells, induced ROS-mediated death also in chemoresistant cells. Free GA proved a dose-dependent ROS-mediated cytotoxicity on both cell populations. Intriguingly, when administered in dendrimer formulations at a dose not cytotoxic for NB cells, GA nullified any pro-oxidant activity of dendrimer. Unfortunately, due to GA, nanoformulations were inactive on NB cells, but GA resized in nanoparticles showed considerable ability in counteracting, at low dose, ROS production and oxidative stress, herein induced by the dendrimer.

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Gafar, Sameh M. y Nehad M. Abdel-Kader. "Dosimetric characteristics and applications of cross-linking and degradation of a natural biopolymer Gum Acacia". Radiochimica Acta 108, n.º 3 (26 de marzo de 2020): 223–29. http://dx.doi.org/10.1515/ract-2019-3170.

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AbstractThe current study covers the effect of gamma rays on a natural biopolymer Gum Arabic (GA). Gum acacia has a very wide range applications in various fields, that a comparison between two dosimetry systems; the first system depends on the radiolysis of GA (mixing poly-vinyl alcohol) as a thin-film dosimeter. The second system depends on the same material GA as solutions dosimeter, which is more sensitive to γ-radiation due to free mobility of free radicals released by the action of gamma rays. The prepared GA/film/solutions have a considerable peak at 289 nm, which increases (cross-linking of GA polymer) upon irradiation until 28 and 6 kGy for two systems, respectively in case of the first step. However, upon increased the absorbed doses and the intensity of the signal decrease with increasing radiation dose (degradation of GA polymer) up to 80 and 15 kGy for film and solutions. Radiation chemical yield G-(value); dose-response function; gamma radiation sensitivity; also pre- and post-irradiation stability under various conditions were illustrated.

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Deng, Sui-Ping, Yi-Li Yang, Xing-Xing Cheng, Wen-Rong Li y Ji-Ye Cai. "Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity". International Journal of Molecular Sciences 20, n.º 4 (23 de febrero de 2019): 975. http://dx.doi.org/10.3390/ijms20040975.

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Kaempferol (Kae) is a natural flavonoid with potent antioxidant activity, but its therapeutic use is limited by its low aqueous solubility. Here, a series of Kae derivatives were synthesized to improve Kae dissolution property in water and antioxidant activity. These compounds included sulfonated Kae (Kae-SO3), gallium (Ga) complexes with Kae (Kae-Ga) and Kae-SO3 (Kae-SO3-Ga). The compound structures were characterized by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and thermal methods (TG/DSC). The results showed that a sulfonic group (-SO3) was successfully tethered on the C3’ of Kae to form Kae-SO3. And in the metal complexation, 4-CO and 3-OH of the ligand participated in the coordination with Ga(III). The metal-to-ligand ratio 1:2 was suggested for both complexes. Interestingly, Kae-SO3-Ga was obviously superior to other compounds in terms of overcoming the poor water-solubility of free Kae, and the solubility of Kae-SO3-Ga was about 300-fold higher than that of Kae-Ga. Furthermore, the evaluation of antioxidant activities in vitro was carried out for Kae derivatives by using α,α-diphenyl-β-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical scavenging. The results showed that Kae-SO3-Ga was also optimal for scavenging free radicals in a dose-dependent manner. These data demonstrate that sulfonate kaempferol-gallium complex has a promising future as a potential antioxidant and as a potential therapeutic agent for further biomedical studies.

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15

Sarney, W. L., S. P. Svensson, M. K. Yakes, Y. Xu, D. Donetsky y G. Belenky. "Ultra-short period Ga-free superlattice growth on GaSb". Journal of Applied Physics 124, n.º 3 (21 de julio de 2018): 035304. http://dx.doi.org/10.1063/1.5029328.

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Rud, V. Yu, Yu V. Rud, V. F. Gremenok y V. B. Zalesski. "Cd-free Cu(In,Ga)Se2/In2S3thin-film heterostructures". physica status solidi (c) 6, n.º 5 (mayo de 2009): 1269–72. http://dx.doi.org/10.1002/pssc.200881173.

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Svircevic, Vesna, Arno P. Nierich, Karel G. M. Moons, Jan C. Diephuis, Jacob J. Ennema, George J. Brandon Bravo Bruinsma, Cor J. Kalkman y Diederik van Dijk. "Thoracic Epidural Anesthesia for Cardiac Surgery: A Randomized Trial". Anesthesiology 114, n.º 2 (1 de febrero de 2011): 262–70. http://dx.doi.org/10.1097/aln.0b013e318201d2de.

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Background The addition of thoracic epidural anesthesia (TEA) to general anesthesia (GA) during cardiac surgery may have a beneficial effect on clinical outcomes. TEA in cardiac surgery, however, is controversial because the insertion of an epidural catheter in patients requiring full heparinization for cardiopulmonary bypass may lead to an epidural hematoma. The clinical effects of fast-track GA plus TEA were compared with those of with fast-track GA alone. Methods A randomized controlled trial was conducted in 654 elective cardiac surgical patients who were randomly assigned to combined GA and TEA versus GA alone. Follow-up was at 30 days and 1 yr after surgery. The primary endpoint was 30-day survival free from myocardial infarction, pulmonary complications, renal failure, and stroke. Results Thirty-day survival free from myocardial infarction, pulmonary complications, renal failure, and stroke was 85.2% in the TEA group and 89.7% in the GA group (P = 0.23). At 1 yr follow-up, survival free from myocardial infarction, pulmonary complications, renal failure, and stroke was 84.6% in the TEA group and 87.2% in the GA group (P = 0.42). Postoperative pain scores were low in both groups. Conclusions This study was unable to demonstrate a clinically relevant benefit of TEA on the frequency of major complications after elective cardiac surgery, compared with fast-track cardiac anesthesia without epidural anesthesia. Given the potentially devastating complications of an epidural hematoma after insertion of an epidural catheter, it is questionable whether this procedure should be applied routinely in cardiac surgical patients who require full heparinization.

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Saito, Tetsuji, Masahiro Tanaka y Daisuke Nishio-Hamane. "Production of Mn-Ga Magnets". Materials 17, n.º 4 (14 de febrero de 2024): 882. http://dx.doi.org/10.3390/ma17040882.

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Mn-based magnets are known to be a candidate for use as rare-earth-free magnets. In this study, Mn-Ga bulk magnets were successfully produced by hot pressing using the spark plasma sintering method on Mn-Ga powder prepared from rapidly solidified Mn-Ga melt-spun ribbons. When consolidated at 773 K and 873 K, the Mn-Ga bulk magnets had fine grains and exhibited high coercivity values. The origin of the high coercivity of the Mn-Ga bulk magnets was the existence of the D022 phase. The Mn-Ga bulk magnet consolidated at 873 K exhibited the highest coercivity of 6.40 kOe.

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Gajofatto, A., P. Bacchetti, B. Grimes, A. High y E. Waubant. "Switching first-line disease-modifying therapy after failure: impact on the course of relapsing–remitting multiple sclerosis". Multiple Sclerosis Journal 15, n.º 1 (enero de 2009): 50–58. http://dx.doi.org/10.1177/1352458508096687.

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Background Options for non-responders to relapsing–remitting multiple sclerosis (RRMS) first-line disease-modifying therapies (DMT) are limited. We explored whether switching first-line DMT is effective. Methods Patients with RRMS who first received interferon-beta (IFNB) or glatiramer acetate (GA) were classified in three categories: DMT change because of suboptimal response, DMT change because of other reasons, and no DMT change during follow-up. Outcomes included annualized relapse rate (ARR) and relapse-free proportions. Results We identified 597 patients who initiated first-line DMT. For patients who did not change DMT ( n = 240), pre-DMT and on-DMT median ARR were 0.50 and 0 ( P < 0.0001). At 24 months, 76% (95%CI = 69–81%) of patients who did not change DMT were relapse-free. Of the 155 who switched because of suboptimal response, 101 switched to another first-line DMT. Median ARR pre-DMT, on first DMT and second DMT were: 0.50, 0.55, and 0.25 for switchers from IFNB to GA (IFNB/GA, n = 12) (pre-DMT versus first DMT: P = 0.92; first versus second DMT: P = 0.31); 0.90, 0.50, and 0 for switchers from GA to IFNB (GA/IFNB, n = 18; P = 0.19; P = 0.01); 0.50, 0.68, and 0 for switchers from an IFNB to another IFNB (IFNB/IFNB’, n = 71; P = 0.34; P = 0.02). Estimated relapse-free proportion after 24 months of treatment was 42% (95%CI=15–66%) during the period on IFNB versus 53% (95%CI = 17–80%) on GA for IFNB/GA ( P = 0.21); 12% (95%CI = 0–40%) on GA versus 87% (95%CI = 59–97%) on IFNB for GA/IFNB ( P = 0.001); and 41% (95%CI = 29–52%) on initial IFNB versus 67% (95%CI = 53–79%) on subsequent IFNB for IFNB/IFNB’ ( P = 0.0001). Conclusions Switching first-line DMT in patients with RRMS failing initial therapy may be effective in many cases.

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Jiang, Bin, Xiaojing Wang, Linlin Wang, Shuang Wu, Dongmei Li, Chunhong Liu y Zhibiao Feng. "Study on the Preparation and Conjugation Mechanism of the Phosvitin-Gallic Acid Complex with an Antioxidant and Emulsifying Capability". Polymers 11, n.º 9 (7 de septiembre de 2019): 1464. http://dx.doi.org/10.3390/polym11091464.

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To develop a novel emulsifier with an antioxidant capacity, a phosvitin-gallic acid (Pv–GA) complex was prepared via a free-radical method. This emulsifier characterizes some key technologies. Changes in the molecular weight of the Pv–GA complex were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) and the matrix-assisted laser desorption/ionization time of light mass spectrometry (MALDI-TOF-MS). Fourier transform infrared spectroscopy (FTIR) indicated that C=O, C–N and N–H groups were also likely to be involved in the formation of the complex. A redshift was obtained in the fluorescence spectrogram, thereby proving that the covalent combination of Pv and GA was a free radical-forming complex. The results indicated that Pv and GA were successfully conjugated. Meanwhile, the secondary structure of Pv showed significant changes after conjugation with GA. The antioxidant activity and emulsifying properties of the Pv–GA complex were studied. The antioxidant activity of the Pv–GA complex proved to be much higher than that of the Pv, via assays of the scavenging activities of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals and because of their ability to reduce power. The emulsification activity of the Pv–GA complex was also slightly higher than that of Pv. To function with the most demanding antioxidant and emulsification activities, the optimum conjugation condition was Pv (5 mg/mL) conjugated 1.5 mg/mL GA. Furthermore, the mechanism of Pv–GA conjugation was studied. This study indicated that GA could quench the inner fluorescence of Pv, and this quenching was static. There was a strong interaction between GA and Pv, which was not obviously affected by the temperature. Furthermore, several binding sites were close to 1, indicating that there was an independent class of binding sites on Pv for GA at different temperatures. The conjugation reaction was a spontaneous reaction, and the interaction forces of GA and Pv were hydrogen bonds and van der Waals force.

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Klym, Halyna, A. Ingram, O. Shpotyuk, R. Szatanik, E. Petracovschi, L. Calvez y C. Lin. "Positron Annihilation in IR Transmitting GeS₂-Ga₂S₃ Glasses". Solid State Phenomena 230 (junio de 2015): 221–27. http://dx.doi.org/10.4028/www.scientific.net/ssp.230.221.

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Positron annihilation lifetime spectroscopy combined with Doppler broadening of annihilation radiation was applied to study free-volume entities in GeS2-Ga2S3glasses affected by Ga additions. It is shown that Ga-related void sub-system plays a decisive role in positron trapping process, while the overall density variation is defined mainly by Ge-related sub-system. These results serve as basis for new characterization route for inner free-volume structure of these glasses.

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Ervina Efzan, Mohd Noor y Mhd Nasir Nur Faziera. "Effects of Wetting Behavior on Gallium Addition in In-Zn Solder Alloy". Materials Science Forum 857 (mayo de 2016): 22–25. http://dx.doi.org/10.4028/www.scientific.net/msf.857.22.

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This paper reported the investigation on gallium, Ga addition into In-4.8Zn lead-free solder to improve its wettability performances. The effect of addition of Ga in In-4.8Zn solder alloy was studied. The results show with the addition of 0.5% Ga into the In-4.8Zn composition, the spreading area of In-4.8Zn-0.5Ga solder on copper increase between 35.71 and 43.75 %. Hence, as the spreading area increases, the contact angle decreased from between 22.09 to 39.71 %. Additionally, the addition of Ga as dopant increased the thickness of IMCs layer.

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23

Berangi, Mostafa, Andre Kuehne, Helmar Waiczies y Thoralf Niendorf. "MRI of Implantation Sites Using Parallel Transmission of an Optimized Radiofrequency Excitation Vector". Tomography 9, n.º 2 (8 de marzo de 2023): 603–20. http://dx.doi.org/10.3390/tomography9020049.

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Postoperative care of orthopedic implants is aided by imaging to assess the healing process and the implant status. MRI of implantation sites might be compromised by radiofrequency (RF) heating and RF transmission field (B1+) inhomogeneities induced by electrically conducting implants. This study examines the applicability of safe and B1+-distortion-free MRI of implantation sites using optimized parallel RF field transmission (pTx) based on a multi-objective genetic algorithm (GA). Electromagnetic field simulations were performed for eight eight-channel RF array configurations (f = 297.2 MHz), and the most efficient array was manufactured for phantom experiments at 7.0 T. Circular polarization (CP) and orthogonal projection (OP) algorithms were applied for benchmarking the GA-based shimming. B1+ mapping and MR thermometry and imaging were performed using phantoms mimicking muscle containing conductive implants. The local SAR10g of the entire phantom in GA was 12% and 43.8% less than the CP and OP, respectively. Experimental temperature mapping using the CP yielded ΔT = 2.5–3.0 K, whereas the GA induced no extra heating. GA-based shimming eliminated B1+ artefacts at implantation sites and enabled uniform gradient-echo MRI. To conclude, parallel RF transmission with GA-based excitation vectors provides a technical foundation en route to safe and B1+-distortion-free MRI of implantation sites.

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24

Pan, Hong Yu y Feng Qi Zhao. "Free polaron energy levels in AlyGa1−yN/AlxGa1−xN triangle quantum well structures". Modern Physics Letters B 31, n.º 17 (14 de junio de 2017): 1750187. http://dx.doi.org/10.1142/s0217984917501871.

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In this work, a variational method is used to examine the problems relevant to the free polaron energy spectrum in a wurtzite Al[Formula: see text]Ga[Formula: see text]N/Al[Formula: see text]Ga[Formula: see text]N triangle quantum well structure. The numerical calculations for the ground state energy, transition energy and polaron energy shifts as the functions of well-width [Formula: see text] and composition [Formula: see text] are carried out by considering the anisotropies of the parameters, such as the optical phonon frequency, dielectric constant and electron effective mass, as well as their observed changes with coordinate [Formula: see text] in this system. The research results show that the polaron energy shift caused by the electron–optical phonon interaction is large, and leads to an obvious energy decrease in the Al[Formula: see text]Ga[Formula: see text]N/Al[Formula: see text]Ga[Formula: see text]N triangular quantum well structure. The contribution of the confined phonon is found to increase with the increasing of the well-width and composition [Formula: see text], while that of the half space phonon is observed to decrease with the increasing of the well-width and composition [Formula: see text]. The total contribution of the phonon increases with the increasing composition [Formula: see text], while a minimum is found to occur to the total contribution of the phonon during the decreasing process with the well-width. As the [Formula: see text] increases, the free polaron energies and transition energies decrease. Meanwhile, with the increasing of the composition [Formula: see text], the energy and transition energy are found to be increased. In the Al[Formula: see text]Ga[Formula: see text]N/Al[Formula: see text]Ga[Formula: see text]N triangular quantum well structure, the trends of the free polaron energy, transition energy and polaron energy shifts with the well-width and composition [Formula: see text] are found to be similar to those in the GaN/Al[Formula: see text]Ga[Formula: see text]N square quantum well structure. However, the corresponding values in the triangular quantum well structure are obviously greater than those in the square quantum well structure.

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25

Hurter, Liezel, Stuart Fairclough, Zoe Knowles, Lorna Porcellato, Anna Cooper-Ryan y Lynne Boddy. "Establishing Raw Acceleration Thresholds to Classify Sedentary and Stationary Behaviour in Children". Children 5, n.º 12 (19 de diciembre de 2018): 172. http://dx.doi.org/10.3390/children5120172.

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This study aimed to: (1) compare acceleration output between ActiGraph (AG) hip and wrist monitors and GENEActiv (GA) wrist monitors; (2) identify raw acceleration sedentary and stationary thresholds for the two brands and placements; and (3) validate the thresholds during a free-living period. Twenty-seven from 9- to 10-year-old children wore AG accelerometers on the right hip, dominant- and non-dominant wrists, GA accelerometers on both wrists, and an activPAL on the thigh, while completing seven sedentary and light-intensity physical activities, followed by 10 minutes of school recess. In a subsequent study, 21 children wore AG and GA wrist monitors and activPAL for two days of free-living. The main effects of activity and brand and a significant activity × brand × placement interaction were observed (all p < 0.0001). Output from the AG hip was lower than the AG wrist monitors (both p < 0.0001). Receiver operating characteristic (ROC) curves established AG sedentary thresholds of 32.6 mg for the hip, 55.6 mg and 48.1 mg for dominant and non-dominant wrists respectively. GA wrist thresholds were 56.5 mg (dominant) and 51.6 mg (non-dominant). Similar thresholds were observed for stationary behaviours. The AG non-dominant threshold came closest to achieving equivalency with activPAL during free-living.

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26

Bell, Elizabeth A., Patrick Boehnke, T. Mark Harrison y Wendy L. Mao. "Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon". Proceedings of the National Academy of Sciences 112, n.º 47 (19 de octubre de 2015): 14518–21. http://dx.doi.org/10.1073/pnas.1517557112.

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Evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ∼3.5 billion years (Ga), the chemofossil record arguably to ∼3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ13CPDB of −24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ∼300 My earlier than has been previously proposed.

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27

Xu, Gang. "Deadlock-free scheduling method based on Petri net and GA". Chinese Journal of Mechanical Engineering (English Edition) 16, n.º 04 (2003): 371. http://dx.doi.org/10.3901/cjme.2003.04.371.

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28

Hua, Shijia y Wending Zhang. "Three-photon-induced free-carrier absorption in Ga-doped ZnO". Optics Letters 47, n.º 2 (6 de enero de 2022): 273. http://dx.doi.org/10.1364/ol.448167.

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29

Zoppi, L., M. Peressi y M. Tosolini. "Structural properties of free-standing (In,Ga)(As,N) alloys". IEE Proceedings - Optoelectronics 151, n.º 5 (1 de octubre de 2004): 263–66. http://dx.doi.org/10.1049/ip-opt:20040891.

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30

Schmitt, Mario, M. Ohtsuka y M. Kohl. "Electron beam lithography of Free-Standing Ni–Mn–Ga films". Physics Procedia 10 (2010): 174–81. http://dx.doi.org/10.1016/j.phpro.2010.11.095.

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31

Crespo, A., M. Bellott, K. Chabak, J. K. Gillespie, G. H. Jessen, M. Kossler, V. Trimble et al. "High frequency performance of Ga free barrier AlInN/GaN HEMT". physica status solidi (c) 7, n.º 10 (9 de julio de 2010): 2433–35. http://dx.doi.org/10.1002/pssc.200983886.

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32

Bouschet, Maxime, Vignesh Arounassalame, Anthony Ramiandrasoa, Isabelle Ribet-Mohamed, Jean-Philippe Perez, Nicolas Péré-Laperne y Philippe Christol. "Temperature Dependence Study of Electrical and Electro-Optical Performances of Midwave Infrared Ga-Free T2SL Barrier Photodetector". Applied Sciences 12, n.º 20 (14 de octubre de 2022): 10358. http://dx.doi.org/10.3390/app122010358.

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In this paper, we report on temperature dependence performances of a midwave infrared (MWIR) Ga-free InAs/InAsSb type-II superlattice (T2SL) barrier (XBn) photodetector grown by molecular beam epitaxy on n-type GaSb substrate. The T2SL structure, with a 3 µm thick active region, was processed in a mesa device in order to perform dark current measurements and spectral photoresponse as a function of temperature. Analyses of these temperature dependence characterizations help us to improve the design of Ga-free T2SL MWIR XBn detectors.

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33

Kan, Xuhui, Wangting Zhou, Weiqi Xu, Zhuqing Dai, Yamei Yan, Jia Mi, Yi Sun, Xiaoxiong Zeng, Youlong Cao y Lu Lu. "Zeaxanthin Dipalmitate-Enriched Emulsion Stabilized with Whey Protein Isolate-Gum Arabic Maillard Conjugate Improves Gut Microbiota and Inflammation of Colitis Mice". Foods 11, n.º 22 (16 de noviembre de 2022): 3670. http://dx.doi.org/10.3390/foods11223670.

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In the present study, protein-polysaccharide Maillard conjugates were used as novel emulsifiers and bioactive carriers. Effects and potential mechanisms of zeaxanthin dipalmitate (ZD)-enriched emulsion stabilized with whey protein isolate (WPI)-gum Arabic (GA) conjugate (WPI-GA-ZD) and ZD-free emulsion (WPI-GA) on gut microbiota and inflammation were investigated using a model of dextran sulfate sodium (DSS)-induced colitis in mice. As a result, supplementation with WPI-GA and WPI-GA-ZD improved the serum physiological and biochemical indicators, decreased the expression of pro-inflammatory cytokines and related mRNA, as well as increased the tight junction proteins to a certain extent. 16S rDNA sequencing analyses showed that supplementation with WPI-GA and WPI-GA-ZD presented differential modulation of gut microbiota and played regulatory roles in different metabolic pathways to promote health. Compared with WPI-GA, the relative abundances of Akkermansia, Lactobacillus and Clostridium_IV genera were enriched by the intervention of WPI-GA-ZD. Overall, the designed carotenoid-enriched emulsion stabilized with protein-polysaccharide conjugates showed potential roles in promoting health.

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34

Cardina, John y Barry J. Brecke. "Growth and Development of Florida Beggarweed (Desmodium tortuosum) Selections". Weed Science 37, n.º 2 (marzo de 1989): 207–10. http://dx.doi.org/10.1017/s0043174500071794.

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Florida beggarweed seeds were collected in Georgia, Florida, and South Carolina from plants differing in morphological characteristics. Seedlings were transplanted into peanut rows in field studies at Tifton, GA, and Jay, FL, in 1986 and 1987, and frequent observations of vegetative and reproductive characteristics were made. The competitiveness of the Florida beggarweed selections was evaluated by comparing pod weights from peanut plants grown in rows adjacent to the individual weed selections with pod weights of weed-free peanuts. There were significant differences among selections of Florida beggarweed in days to maximum height, maximum node formation, maximum branching, and initial flowering and fruiting at both locations. Selection GA-1 generally reached these growth stages earliest, was shorter, narrower, had fewer nodes, and produced less dry matter and fewer seeds than GA-2, which was generally the latest maturing selection. GA-4 produced fewer branches and smaller seeds than the other selections. Peanut pod weights adjacent to Florida beggarweed plants were reduced 12 to 18% in 1986 and 10 to 24% in 1987 compared to weed-free checks. Florida beggarweed selection GA-2 was the most competitive and GA-4 was among the least competitive both years. The variation of measured parameters among Florida beggarweed selections in this study may contribute to the survival and adaptability of this weed with changing environmental conditions, cultural practices, and control measures.

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Alvi, Sahir Sultan, Rabia Nabi, Mohd Shahnawaz Khan, Firoz Akhter, Saheem Ahmad y M. Salman Khan. "Glycyrrhizic Acid Scavenges Reactive Carbonyl Species and Attenuates Glycation-Induced Multiple Protein Modification: An In Vitro and In Silico Study". Oxidative Medicine and Cellular Longevity 2021 (11 de octubre de 2021): 1–14. http://dx.doi.org/10.1155/2021/7086951.

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The current study is aimed at studying the inhibitory effect of glycyrrhizic acid (GA) on D-ribose-mediated protein glycation via various physicochemical analyses and in silico approaches. Being a potent free radical scavenger and a triterpenoid saponin, GA plays a vital role in diminishing the oxidative stress and thus could be an effective inhibitor of the nonenzymatic glycation process. Our data showed that varying concentrations of GA inhibited the in vitro BSA-AGEs via inhibiting the formation of fructosamines, fluorescent AGEs, scavenging protein carbonyl and hydroxymethyl furfural (HMF) content, and protection against D-ribose-induced modification of BSA as evident by increased free Arg and Lys residues in GA-treated Gly-BSA samples. Moreover, GA also attenuated D-ribose-induced alterations in the secondary structure of BSA by protecting the α-helix and β-sheet conformers and amide-I band delocalization. In addition, GA attenuated the modification in β-cross amyloid structures of BSA and in silico molecular interaction study too showed strong binding of GA with higher number of Lys and Arg residues of BSA and binding energy (ΔG) of -8.8 Kcal/mol, when compared either to reference standard aminoguanidine (AG)-BSA complex (ΔG: -4.3 Kcal/mol) or D-ribose-BSA complex (ΔG: -5.2 Kcal/mol). Therefore, GA could be a new and favorable inhibitor of the nonenzymatic glycation process that ameliorates AGEs-related complications via attenuating the AGE formation and glycation-induced multiple protein modifications with a reduced risk of adverse effects on protein structure and functionality; hence, it could be investigated at further preclinical settings for the treatment and management of diabetes and age-associated complications.

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KAMAL, A. R. NADIRA BANU, S. THAMARAI SELVI y HENRY SELVARAJ. "ITERATION-FREE FRACTAL CODING FOR IMAGE COMPRESSION USING GENETIC ALGORITHM". International Journal of Computational Intelligence and Applications 07, n.º 04 (diciembre de 2008): 429–46. http://dx.doi.org/10.1142/s1469026808002399.

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An iteration-free fractal coding for image compression is proposed using genetic algorithm (GA) with elitist model. The proposed methodology reduces the coding process time by minimizing intensive computations. The proposed technique utilizes the GA, which greatly decreases the search space for finding the self-similarities in the given image. The performance of the proposed method is compared with the iteration-free fractal-based image coding using vector quantization method for both single block and Quad tree partition on benchmark images for parameters such as image quality and coding time. It is observed that the proposed method achieves excellent performance in image quality with reduction in computing time.

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Giordani, Barbara, Purusotam Basnet, Ekaterina Mishchenko, Barbara Luppi y Nataša Škalko-Basnet. "Utilizing Liposomal Quercetin and Gallic Acid in Localized Treatment of Vaginal Candida Infections". Pharmaceutics 12, n.º 1 (20 de diciembre de 2019): 9. http://dx.doi.org/10.3390/pharmaceutics12010009.

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Vulvovaginal candidiasis (VVC) is a widely spread fungal infection that causes itching, pain and inflammation at the vaginal site. Although common, currently available treatment suffers from limited efficacy and high recurrence. In addition, the growing problem of resistance to azole drugs used in current treatments emphasizes the need for superior treatment options. Antimicrobial polyphenols are an attractive approach offering multitargeting therapy. We aimed to develop novel liposomes for simultaneous delivery of two polyphenols (quercetin, Q, and gallic acid, GA) that, when released within the vaginal cavity, act in synergy to eradicate infection while alleviating the symptoms of VVC. Q was selected for its anti-itching and anti-inflammatory properties, while GA for its reported activity against Candida. Novel liposomes containing only Q (LP-Q), only GA (LP-GA) or both polyphenols (LP-Q+GA) were in the size range around 200 nm. Q was efficiently entrapped in both LP-Q and in LP-Q+GA (85%) while the entrapment of GA was higher in LP-Q+GA (30%) than in LP-GA (25%). Liposomes, especially LP-Q+GA, promoted sustained release of both polyphenols. Q and GA acted in synergy, increasing the antioxidant activities of a single polyphenol. Polyphenol-liposomes were not cytotoxic and displayed stronger anti-inflammatory effects than free polyphenols. Finally, LP-GA and LP-Q+GA considerably reduced C. albicans growth.

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38

Wu, Jie, Songbai Xue, Lu Liu, Peng Zhang y Qingcheng Luo. "Influence of Ga Content on the Microstructure and Mechanical Properties of Cadmium-Free Filler Metal". Metals 12, n.º 7 (6 de julio de 2022): 1151. http://dx.doi.org/10.3390/met12071151.

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The influence of Ga content on the melting temperature, wettability, microstructure, and mechanical properties of low-silver 12AgCuZnSn-2In-0.15Pr cadmium-free filler metal was investigated systematically by means of differential thermal analysis, X-ray diffractometer, scanning electron microscopy, energy-dispersive spectrometer, etc. The results showed that the addition of the Ga element reduced the solidus and liquidus temperatures of the novel low-silver filler metals, and effectively increased the spreading area of the filler metal on the copper and 304 stainless steel substrates. Furthermore, an appropriate amount of Ga element significantly optimized the interface morphology and improved the mechanical properties of the brazed joints. When the Ga content was 1wt.%, the shear strength of the brazed joints reached a peak value of 448 MPa, and the corresponding fracture morphology showed typical ductile characteristics with obvious dimples.

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39

Owczarek, Aleksandra, Monika Anna Olszewska y Jan Gudej. "Quantitative Determination of Ellagic Acid and Gallic Acid in Geum Rivale L. and G. Urbanum L." Acta Biologica Cracoviensia s. Botanica 56, n.º 2 (1 de marzo de 2015): 74–78. http://dx.doi.org/10.2478/abcsb-2014-0021.

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Abstract Hydrolyzable tannins and products of their hydrolysis, ellagic acid (EA) and gallic acid (GA), are important con-stituents of many medicinal plants and exhibit various biological activities. Geum rivale and G. urbanum are traditional herbal remedies rich in tannin compounds. The aim of the study was to quantitate free and total EA and GA in aerial and underground parts of G. rivale and G. urbanum. After optimization of extraction, both compounds were quantitated by reversed phase HPLC (RP-HPLC). EA was more abundant than GA in the inves-tigated material, and underground parts of G. rivale were the richest source of total EA and GA.

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40

SOBHI, Nour-El-Houda y Amel BOUKHOUIETE. "Corrosion inhibition of API5L X60 steel in sulfuric acid using gum arabic". Revue Roumaine de Chimie 68, n.º 1-2 (17 de enero de 2023): 17–25. http://dx.doi.org/10.33224/rrch.2023.68.1-2.02.

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The aim of this research is the evaluation of inhibitory efficiency of Gum Arabic (GA) against the corrosion of API5L X60 pipeline steel in H2SO4 (0.5M) media, using mass loss measurement and electrochemical methods. The results show that inhibition efficiency increases with inhibitor concentration to attain 83% at 4 g/L of GA. Polarization curves reveal that GA acts as a mixed-type inhibitor in sulfuric acid. The adsorption of GA on pipeline API 5L X60 steel surface obeyed the Langmuir adsorption isotherm. Gibbs free energy of adsorption indicated that the adsorption process is spontaneous and the molecules adsorbed on the metal surface by the process of physical adsorption.

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41

Yusoff, Marina y Anis Amalina Othman. "Genetic Algorithm with Elitist-Tournament for Clashes-Free Slots of Lecturer Timetabling Problem". Indonesian Journal of Electrical Engineering and Computer Science 12, n.º 1 (1 de octubre de 2018): 303. http://dx.doi.org/10.11591/ijeecs.v12.i1.pp303-309.

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<span>Genetic algorithm (GA) approach is one of an evolutionary optimization technique relies on natural selection. The employment of GA still popular and it was applied to many real-world problems, especially in many combinatorial optimization solutions. Lecturer Timetabling Problem (LTP) has been researched for a few decades and produced good solutions. Although, some of LTP offers good results, the criteria and constraints of each LTP however are different from other universities. The LTP appears to be a tiresome job to the scheduler that involves scheduling of students, classes, lecturers and rooms at specific time-slots while satisfying all the necessary requirements to build a feasible timetable. This paper addresses the employment and evaluation of GA to overcome the biggest challenge in LTP to find clashes-free slots for lecturer based on a case study in the Faculty of Computer and Mathematical Sciences, University Technologi MARA, Malaysia. Hence, the performance of the GA is evaluated based on selection, mutation and crossover using different number of population size. A comparison of performance between simple GA with Tournament Selection scheme combined with Elitism (TE) and a GA with Tournament (T) selection scheme. The findings demonstrate that the embedded penalty measures and elitism composition provide good performance that satisfies all the constraints in producing timetables to lecturers. </span>

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42

Aye, Nang Noon Shean, Pornsuda Maraming, Ratree Tavichakorntrakool, Attawut Chaibunruang, Patcharee Boonsiri, Sakda Daduang, Nattiya Teawtrakul, Prinya Prasongdee, Vittaya Amornkitbamrung y Jureerut Daduang. "A Simple Graphene Functionalized Electrochemical Aptasensor for the Sensitive and Selective Detection of Glycated Albumin". Applied Sciences 11, n.º 21 (3 de noviembre de 2021): 10315. http://dx.doi.org/10.3390/app112110315.

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Glycated albumin (GA) has been previously introduced as a promising biomarker for glycemic monitoring in diabetes patients with thalassemia. In this study, a label-free graphene oxide (GO)-modified aptasensor was developed for the rapid detection of GA. The fabrication of the aptasensor was dependent on the covalent interaction of the amine-functionalized GA-specific aptamer with the carboxylic groups of GO. Square wave voltammetry (SWV) analysis was carried out for the measurement of GA-aptamer binding to their specific proteins. The peak current changes before and after incubation with GA protein were directly proportional to the concentration. The developed aptasensor exhibited a broad linearity (1–10,000 µg mL−1), a low detection limit (LOD) of 0.031 µg mL−1, and high selectivity for GA detection. In addition, the aptasensor was successfully applied to detect GA in both spiked and clinical serum samples. The comparison of the developed method with a commercial assay validated the reliability of the aptasensor for clinical application. Therefore, the newly developed aptasensor is a promising tool for GA measurements in diabetic patients with underlying thalassemia.

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Akhtar, Muhammad Asim, Zoya Hadzhieva, Kanwal Ilyas, Muhammad Saad Ali, Wolfgang Peukert y Aldo R. Boccaccini. "Facile Synthesis of Gallium (III)-Chitosan Complexes as Antibacterial Biomaterial". Pharmaceutics 13, n.º 10 (15 de octubre de 2021): 1702. http://dx.doi.org/10.3390/pharmaceutics13101702.

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Even though antibiotic treatment remains one of the most common tools to handle bacterial infections, the excessive antibiotic concentration at the target site may lead to undesired effects. Aiming at the fabrication of antibiotic-free biomaterials for antibacterial applications, in this work, we propose the synthesis of gallium (III)—chitosan (Ga (III)-CS) complexes with six different gallium concentrations via an in situ precipitation method. Fourier Transform infrared spectroscopy indicated the chelation of chitosan with Ga (III) by peak shifts and changes in the relative absorbance of key spectral bands, while energy-dispersive X-ray spectroscopy indicated the homogenous distribution of the metal ions within the polymer matrix. Additionally, similar to CS, all Ga (III)-CS complexes showed hydrophobic behavior during static contact-angle measurements. The antibacterial property of the complexes against both Gram-negative and Gram-positive bacteria was positively correlated with the Ga (III) concentration. Moreover, cell studies confirmed the nontoxic behavior of the complexes against the human osteosarcoma cell line (MG-63 cells) and mouse embryonic fibroblasts cell line (MEFs). Based on the results of this study, new antibiotic-free antibacterial biomaterials based on Ga (III)-CS can be developed, expanding the scope of CS applications in the biomedical field.

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Li, Zhenhua, Jianyong Li, Yanzhi Dou, Lihua Wang y Shiping Song. "A Carbon-Based Antifouling Nano-Biosensing Interface for Label-Free POCT of HbA1c". Biosensors 11, n.º 4 (12 de abril de 2021): 118. http://dx.doi.org/10.3390/bios11040118.

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Electrochemical biosensing relies on electron transport on electrode surfaces. However, electrode inactivation and biofouling caused by a complex biological sample severely decrease the efficiency of electron transfer and the specificity of biosensing. Here, we designed a three-dimensional antifouling nano-biosensing interface to improve the efficiency of electron transfer by a layer of bovine serum albumin (BSA) and multi-walled carbon nanotubes (MWCNTs) cross-linked with glutaraldehyde (GA). The electrochemical properties of the BSA/MWCNTs/GA layer were investigated using both cyclic voltammetry and electrochemical impedance to demonstrate its high-efficiency antifouling nano-biosensing interface. The BSA/MWCNTs/GA layer kept 92% of the original signal in 1% BSA and 88% of that in unprocessed human serum after a 1-month exposure, respectively. Importantly, we functionalized the BSA/MWCNTs/GA layer with HbA1c antibody (anti-HbA1c) and 3-aminophenylboronic acid (APBA) for sensitive detection of glycated hemoglobin A (HbA1c). The label-free direct electrocatalytic oxidation of HbA1c was investigated by cyclic voltammetry (CV). The linear dynamic range of 2 to 15% of blood glycated hemoglobin A (HbA1c) in non-glycated hemoglobin (HbAo) was determined. The detection limit was 0.4%. This high degree of differentiation would facilitate a label-free POCT detection of HbA1c.

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45

Zhao, Z. D., E. C. Shang y Daniel Rouseff. "The Comparison of Bottom Parameter Inversion in Geoacoustic Space and in (P,Q) Space". Journal of Computational Acoustics 25, n.º 02 (25 de enero de 2017): 1750011. http://dx.doi.org/10.1142/s0218396x17500114.

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The acoustical properties of the sea-bottom can be described by geoacoustic (GA) parameters or by reflective parameters: [Formula: see text] (phase shift parameter) and [Formula: see text] (absorption parameter). Both in GA space and in ([Formula: see text], [Formula: see text]) space, the parameters are difficult to measure and are instead estimated by inversion methods such as matched field inversion (MFI). In GA space, an assumed model is needed to mount the GA parameters for inverting (model dependent), while the reflective parameters ([Formula: see text], [Formula: see text] are model-free. In this paper, the efficiency and quality of matched field processing (MFP) in GA space as well as in ([Formula: see text]) space are compared and the potential possibility of bottom sound-speed-profile estimation is discussed.

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46

Yi, Wenbin, Zhenya Lu, Xingyue Liu, Du Huang, Zhi Jia, Zhiwu Chen, Xin Wang y Huixiang Zhu. "Effects of Ga content on the structure and electrical performances of 0.69BiFe1-Ga O3-0.31BaTiO3 lead-free ceramics". Ceramics International 47, n.º 20 (octubre de 2021): 28455–59. http://dx.doi.org/10.1016/j.ceramint.2021.06.264.

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47

Marzano, Maria, Nicola Borbone, Felice Amato, Giorgia Oliviero, Pierpaolo Fucile, Teresa Russo y Filomena Sannino. "3D Chitosan-Gallic Acid Complexes: Assessment of the Chemical and Biological Properties". Gels 8, n.º 2 (15 de febrero de 2022): 124. http://dx.doi.org/10.3390/gels8020124.

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Three-dimensional chitosan-gallic acid complexes were proposed and prepared for the first time by a simple adsorption process of gallic acid (GA) on three-dimensional chitosan structures (3D chitosan). Highly porous 3D devices facilitate a high GA load, up to 2015 mmol/kg at pH 4.0. The preservation of the redox state of GA released from 3D chitosan was confirmed by spectroscopic analyses. The antioxidant activity of 3D chitosan-GA complexes was assessed using the DPPH radical scavenging assay and was found to be dramatically higher than that of free chitosan. The mechanical property of 3D chitosan–GA complexes was also evaluated using a compression test. Finally, 3D chitosan–GA complexes showed a significant antimicrobial capacity against E. coli and S. aureus, selected, respectively, as a model strain for Gram-negative and Gram-positive bacteria. Our study demonstrated a new, simple, and eco-friendly approach to prepare functional chitosan-based complexes for nutraceutical, cosmeceutical, and pharmaceutical applications.

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48

Dai, Longhai, Jiao Li, Jiangang Yang, Yan Men, Yan Zeng, Yi Cai y Yuanxia Sun. "Enzymatic Synthesis of Novel Glycyrrhizic Acid Glucosides Using a Promiscuous Bacillus Glycosyltransferase". Catalysts 8, n.º 12 (4 de diciembre de 2018): 615. http://dx.doi.org/10.3390/catal8120615.

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Glycyrrhetinic acid (GA) and glycyrrhizin (GA-3-O-[β-d-glucuronopyranosyl-(1→2)-β-d-glucuronopyranoside], GL) are the major bioactive components of Glycyrrhiza uralensis and possess multifarious notable biological activities. UDP-glycosyltransferase (UGT)–catalyzed glycosylation remarkably extends the structural and functional diversification of GA-glycoside derivatives. In this study, six glucosides (1–6) of GA and GL were synthesized using a Bacillus subtilis 168–originated flexible UDP-glycosyltransferase Bs-YjiC. Bs-YjiC could transfer a glucosyl moiety from UDP-glucose to the free C3 hydroxyl and/or C30 carboxyl groups of GA and GL and further elongate the C30 glucosyl chain via a β-1-2-glycosidic bond. Glycosylation significantly increased the water solubility of these novel glucosides by 4–90 folds. In vitro assays showed that GA monoglucosides (1 and 2) showed stronger antiproliferative activity against human liver cancer cells HepG2 and breast cancer cells MCF-7 than that of GL and GL glucosides. These findings provide significant insights into the important role of promiscuous UGTs for the enzymatic synthesis of novel bioactive GA derivatives.

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49

Welzel, Cindy, Ulla König, Anett Jannasch, Klaus Matschke, Sems-Malte Tugtekin, Claudia Dittfeld y Gerald Steiner. "Infrared Spectroscopic Verification of a α-Helical Collagen Structure in Glutaraldehyde-Free Crosslinked Bovine Pericardium for Cardiac Implants". Life 12, n.º 12 (6 de diciembre de 2022): 2035. http://dx.doi.org/10.3390/life12122035.

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The degeneration of heart valve bioprostheses due to calcification processes is caused by the intercalation of calciumhydroxyapatite in pericardium collagen bundles. Variations of the protein secondary structure of biomaterials according to preparation are relevant for this mineralization process and thus the structural characterization of innovative bioprostheses materials is of great importance. The gold standard for prostheses preparation is glutaraldehyde (GA)-fixation of bovine pericardium that adversely promotes calcification. The novel GA-free SULEEI-treatment of bovine pericardium includes decellularization, UV-crosslinking, and electron beam sterilization. The aim of this study is the structural characterization of SULEEI-treated and GA-fixed bovine pericardium. IR spectroscopic imaging combined with multivariate data and curve fit analysis was applied to investigate the amide I and amide II regions of SULEEI-treated and GA-fixed samples. The spectroscopic images of GA-fixed pericardial tissue exhibited a generally high content of amine groups and side chains providing nucleation points for calcification processes. In contrast, in SULEEI-treated tissue, the typical α-helical structure was retained and was supposed to be less prone to deterioration.

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50

Kitashima, Tomonrori, K. S. Suresh, Y. Yamabe-Mitarai y S. Iwasaki. "Tensile Strength and Impact Toughness of Gallium-Bearing Near-α Titanium Alloys". Materials Science Forum 783-786 (mayo de 2014): 619–23. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.619.

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The present study aims to quantify the properties of Ga-bearing near-titanium alloys in order to aid the future design of new compositions with Ga addition. The effect of different amounts of Sn and Ga, with an almost constant value in the Al equivalent without the formation of 2 phase, on microstructure, tensile strength and Charpy impact toughness was investigated at room temperature and 650°C. The microstructures after forging, hot rolling and heat treatment showed a bimodal structure. Increasing Ga decreased the 0.2% proof stress at 650°C. However, these alloys showed similar impact value at room temperature which was about 40 J/cm2. Increasing the amount of Ga increased the volume fraction of the equiaxed phase. The amount of Ga had only a minor effect on grain size, misorientation angles and grain aspect ratios of the alloy. However, Ga addition had a strong influence on the evolution of texture. Formation of <10-10> and <10-11> || normal direction (ND) fibers were observed in the Ga added samples, in addition to <0001> || ND fiber with a weak <10-11> || ND fiber. The Ga-free sample contained a strong <0001> || ND fiber. Other fibers were not observed.

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