Artículos de revistas: "Sodium phosphate buffer"

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Ali, Maysaa Adil. "Optimizing Extraction Conditions of Actinidin from Kiwifruit (Actinidia deliciosa)". Al-Mustansiriyah Journal of Science 28, n.º 3 (3 de julio de 2018): 61. http://dx.doi.org/10.23851/mjs.v28i3.57.

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Kiwifruit (Actinidia deliciosa) is one many fruits that is rich of enzymes like Actinidin. Actinidin is a member of cysteine protease. In this study, different parameters and conditions were tested for optimal Actinidin extraction from kiwifruit. The tested parameters are optimum buffers, pH, Molarity, time, and amounts (gm) of kiwifruit to volume (ml) of buffer ratio. The best buffer for Actinidin extraction from kiwifruit was Sodium phosphate because it gave high activity, with casein as a substrate. The next experiments used sodium phosphate as an optimal buffer for Actinidin extraction and casein as a substrate, detected the optimal Actinidin extraction conditions were carried out at pH 7.0, 0.1 M of sodium phosphate, 2.5 min of extraction time, 1:0.5 (gm of kiwifruit fruit/ v of sodium phosphate buffer) extraction percentage, and 30 min of incubation time. Also this study showed that the maximum enzyme activity for Actinidin extracted from kiwifruit was at pH 7and at 30 min of incubation with casein as substrate.

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Kim, Soo Hyun, Han Ju Yoo, Eun Ji Park y Dong Hee Na. "Nano Differential Scanning Fluorimetry-Based Thermal Stability Screening and Optimal Buffer Selection for Immunoglobulin G". Pharmaceuticals 15, n.º 1 (25 de diciembre de 2021): 29. http://dx.doi.org/10.3390/ph15010029.

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Nano differential scanning fluorimetry (nanoDSF) is a high-throughput protein stability screening technique that simultaneously monitors protein unfolding and aggregation properties. The thermal stability of immunoglobulin G (IgG) was investigated in three different buffers (sodium acetate, sodium citrate, and sodium phosphate) ranging from pH 4 to 8. In all three buffers, the midpoint temperature of thermal unfolding (Tm) showed a tendency to increase as the pH increased, but the aggregation propensity was different depending on the buffer species. The best stability against aggregation was obtained in the sodium acetate buffers below pH 4.6. On the other hand, IgG in the sodium citrate buffer had higher aggregation and viscosity than in the sodium acetate buffer at the same pH. Difference of aggregation between acetate and citrate buffers at the same pH could be explained by a protein–protein interaction study, performed with dynamic light scattering, which suggested that intermolecular interaction is attractive in citrate buffer but repulsive in acetate buffer. In conclusion, this study indicates that the sodium acetate buffer at pH 4.6 is suitable for IgG formulation, and the nanoDSF method is a powerful tool for thermal stability screening and optimal buffer selection in antibody formulations.

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Yuan, Zhiguo, Shanshan Duan, Jingsong Shen y Youzhi Liu. "Sulfur Capacity of Sodium Phosphate Buffer Solution". JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 52, n.º 2 (20 de febrero de 2019): 204–9. http://dx.doi.org/10.1252/jcej.18we018.

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Yu, A. W., C. B. Leung, P. K. T. Li, S. F. Lui y K. N. Lai. "Pain Perception following Subcutaneous Injections of Citrate-Buffered and Phosphate-Buffered Epoetin Alpha". International Journal of Artificial Organs 21, n.º 6 (junio de 1998): 341–43. http://dx.doi.org/10.1177/039139889802100612.

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Subcutaneous injection of citrate-buffered epoetin alpha (EPO-α) causes pain. Substitution of citrate buffer with a phosphate buffer in the EPO-α resulted in a significant reduction in duration and severity of pain. It is possible that sodium citrate which is present in the EPO-α may be the agent that causes discomfort in the patients.

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Suurkuusk, Malin y Dan Hallén. "Investigation of guanidine hydrochloride induced unfolding of apolipoprotein A-IMilano". Spectroscopy 16, n.º 3-4 (2002): 199–206. http://dx.doi.org/10.1155/2002/201073.

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A guanidine hydrochloride (GuHCl) induced unfolding study of apolipoprotein A-IMilano(apo A-IM) has been performed. The unfolding was followed by circular dichroism (CD) measurements at 222 nm and by isothermal titration (ITC) calorimetry at 25°C. In the ITC experiments enthalpies of transfer were determined for apo A-IMfrom aqueous sodium phosphate buffer solution into solutions of different concentrations of GuHCl. The CD data and the ITC data give complementary and consistent results of the complex unfolding process. Analytical ultracentrifugation experiments were made on apo A-IMin sodium phosphate buffer and in 0.6 M GuHCl, respectively. Analyses of the obtained sedimentation velocity data show that apo A-IMis highly aggregated in sodium phosphate buffer. The aggregates are almost completely dissociated in 0.6 M GuHCl. Aggregation of the protein in sodium phosphate buffer solution induces an increase in α-helical content. The loss of α-helical secondary structural element of the protein upon dissociation of the aggregates destabilises the protein resulting in a low GuHCl concentration of unfolding, [GuHCl]m=1.1 M. The unfolded protein has a significant α-helical content at the unfolded state. From ITC- and CD data we suggest that increased binding of GuHCl to the unfolded protein results in a disruption of the residual secondary structure.

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Spitsberg, Vitaly L., Liza Ivanov y Vladimir Shritz. "Recovery of milk fat globule membrane (MFGM) from buttermilk: effect of Ca-binding salts". Journal of Dairy Research 86, n.º 3 (agosto de 2019): 374–76. http://dx.doi.org/10.1017/s002202991900061x.

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AbstractIn this Research Communication we present a study of the effect of Ca-binding salts on the recovery of milk fat globule membrane (MFGM) from buttermilk. Sodium phosphate buffer was used for the purpose of MFGM recovery from buttermilk for the first time and we showed that 0.1 M buffer at pH 7.2 was the most effective for the recovery of MFGM. The fact of high efficacy of sodium phosphate buffer in recovery of MFGM from buttermilk allowed us to suggest that MFGM in buttermilk is present in association with casein through Ca- bridges formed between phospholipids of MFGM and phosphate groups of casein, primarily with k-casein as the peripheral protein of casein micelles.

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Okada, Toshihiko, Minoru Miyakoshi, Masao Inoue, Mayumi Miyanabe, Yasuko Ueno y Yasuko Nakabayashi. "Differential elution from a Sephadex G-15 column of sodium and phosphate ions of sodium phosphate with sodium or potassium phosphate buffer". Journal of Chromatography A 604, n.º 2 (julio de 1992): 219–24. http://dx.doi.org/10.1016/0021-9673(92)85131-c.

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Olmos, J. M., M. A. Lasunción y E. Herrera. "Dextran Sulfate Complexes with Potassium Phosphate to Interfere in Determinations of High-Density Lipoprotein Cholesterol". Clinical Chemistry 38, n.º 2 (1 de febrero de 1992): 233–37. http://dx.doi.org/10.1093/clinchem/38.2.233.

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Abstract The interference of dextran sulfate with the colorimetric determination of free cholesterol causes an increase in the absorbance that is proportional to the dextran sulfate concentration in the sample. This makes estimation of the free cholesterol concentration unreliable in high-density lipoprotein-containing supernates obtained after plasma precipitation with dextran sulfate/MgCl2. Analysis of the absorption spectrum demonstrated that the absorbance increase was due to turbidity. We observed this effect with colorimetric reagents based on potassium phosphate buffer but not with those based on sodium phosphate or Tris buffers. This effect is ascribed to dextran sulfate because neither the omission of Mg2+ ions nor their chelation with EDTA prevented turbidity, whereas precipitation of dextran sulfate with Ba2+ counteracted this effect. Therefore, potassium phosphate-buffered reagents appear unsuitable for colorimetric lipid determinations in samples containing dextran sulfate.

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Pinta Rizki Mala Hasibuan, Mitha Alviyulita y Farida Hanum. "PENGARUH PENAMBAHAN NATRIUM KLORIDA (NaCl) DAN WAKTU PERENDAMAN BUFFER FOSFAT TERHADAP PEROLEHAN CRUDE PAPAIN DARI DAUN PEPAYA (CARICA PAPAYA, L.)". Jurnal Teknik Kimia USU 3, n.º 3 (30 de septiembre de 2014): 39–44. http://dx.doi.org/10.32734/jtk.v3i3.1642.

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Papaya (Carica papaya L.) is one of the fruits of commodities internationally, either in the form of fresh fruit or as processed products. The leaves are green still not fully utilized. Papaya leaves contains papain enzyme which is a protease enzyme that very helpful for the industry. Papain is a protease enzyme contained in papaya latex, whether in fruit, stems and leaves, as an enzyme capable of solving the protein molecules, current papain into products that are beneficial to human life, either at home or industrial ladder. This study aims to determine the effect of the degree of saturation of sodium chloride and phosphate buffer to yield soaking rough papaya protease. This study varying the time of immersion phosphate buffer and saturation levels of sodium chloride. Analysis of protease activity was performed using UV-Vis spectrophotometer to measure the wavelength and absorbance values. The best research results obtained at 12 h immersion phosphate buffer with a concentration of sodium chloride 60% is 272.8222 unit / ml. In the analysis of the rendemen obtained by the best condition at the time of immersion phosphate buffer for 36 hours at a concentration of 90% is 43,5152%. In the analysis of moisture content obtained the best condition at the time of immersion of 36 hours at a concentration of 90% is 37.4266%.

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Sokołowska, Magdalena, Krystyna Pawlas y Wojciech Bal. "Effect of Common Buffers and Heterocyclic Ligands on the Binding of Cu(II) at the Multimetal Binding Site in Human Serum Albumin". Bioinorganic Chemistry and Applications 2010 (2010): 1–7. http://dx.doi.org/10.1155/2010/725153.

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Visible-range circular dichroism titrations were used to study Cu(II) binding properties of Multimetal Binding Site (MBS) of Human Serum Albumin (HSA). The formation of ternary MBS-Cu(II)-Buffer complexes at pH 7.4 was positively verified for sodium phosphate, Tris, and Hepes, the three most common biochemical buffers. The phosphate > Hepes > Tris order of affinities, together with strong spectral changes induced specifically by Tris, indicates the presence of both Buffer-Cu(II) and Buffer-HSA interactions. All complexes are strong enough to yield a nearly 100% ternary complex formation in 0.5 mM HSA dissolved in 100 mM solutions of respective buffers. The effects of warfarin and ibuprofen, specific ligands of hydrophobic pockets I and II in HSA on the Cu(II) binding to MBS were also investigated. The effects of ibuprofen were negligible, but warfarin diminished the MBS affinity for Cu(II) by a factor of 20, as a result of indirect conformational effects. These results indicate that metal binding properties of MBS can be modulated directly and indirectly by small molecules.

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Lorenc-Kubis, I. y B. Morawiecka. "Phosphatase activity of Poa pratensis seeds. I. Preliminary studies on acid phosphatase II". Acta Societatis Botanicorum Poloniae 42, n.º 3 (2015): 369–77. http://dx.doi.org/10.5586/asbp.1973.028.

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Acid phosphatase (EC 3.1.3.2) was extracted with 0.1 M sodium acetate buffer pH 5.1 from Poa pratensis seeds, and separated into three fractions by chromatography on DEAE cellulose. The highest activity was found in fraction Il-b (acid phosphatase II). The activity of the enzyme was optimal at pH 4.9. It hydrolyzed p-nitrophenyl phosphate most readily among the various phosphomonoesters examined. Acid phosphatase II showed also a high activity toward β-naphtyl phosphate and phenyl phosphate, very low activity towards β-glycero phosphate, 5'-GMP and no activity with glucose-1 phosphate. The enzyme was inhibited by Ca2+ and fluoride, but activated by Mg2+. EDTA had no influence on the activity of the enzyme.

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12

Sigamani, Santhosh, Sharmila Banu Vm, Hemalatha V, Venkatakrishnan V y Dhandapani R. "OPTIMIZATION STUDY ON EXTRACTION & PURIFICATION OF PHYCOERYTHRIN FROM RED ALGAE KAPPAPHYCUS ALVAREZII". Asian Journal of Pharmaceutical and Clinical Research 10, n.º 2 (1 de febrero de 2017): 297. http://dx.doi.org/10.22159/ajpcr.2017.v10i2.15598.

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Objective: The current study focuses on R-Phycoerythrin pigment production from Seaweed using different chemical and physical conditions. Methods: In the present study Seaweed was collected from Rameshwaram and identified by CS-MCRI Institute, Mandapam. The collected seaweed was then washed using distilled water for further processing. Using a sterile knife the seaweed was cut into small pieces. The chopped seaweeds were then weighed and subjected to different optimization procedures for pigment production. These equally weighed seaweeds were treated with three varying Buffers at different pH, the buffer showing better O.D value was subjected to different Cell disruption techniques and finally freeze thawed at different temperature stress.Results: The seaweeds were subjected to different chemical and physical stress conditions for R-phycoerythrin production. On optimizing the different buffer solutions for pigment production Sodium phosphate buffer showed maximum O.D of 0.215 when compared to other buffers whereas on providing different pH conditions the O.D value obtained was high at pH 7.2. Different cell disruption techniques were followed for pigment production using the sodium phosphate buffer at pH 7.2 and freeze thaw method was found suitable for the highest pigment production with O.D value of 0.441. Hence after optimization of different extraction procedures, cell disruption followed by freeze & thaw method (−20°C and 25°C) showed maximum R-phycoerythrin content. Conclusion: From the findings, it was also observed that the primary metabolites produced by these organisms may serve as potential bioactive compounds of interest in the Food industries as natural colourant and in cosmetic industries.Keywords: Seaweeds, Extraction, Phycoerythrin, Optimization, Cell disruption, Sonication.

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13

Haifeng, L., L. Yuwen, C. Xiaomin, W. Zhiyong y W. Cunxin. "Effects of sodium phosphate buffer on horseradish peroxidase thermal stability". Journal of Thermal Analysis and Calorimetry 93, n.º 2 (26 de enero de 2008): 569–74. http://dx.doi.org/10.1007/s10973-007-8407-y.

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Abdulkadir, Abdullahi, Adamu Yusuf Kabiru, Hadiza Lami Muhammad, Bala Alkali Mohammed y Tawakaltu Abdulrasheed-Adeleke. "Partial Purification of Phytocystatin from Moringa oleifera lam". AROC in Pharmaceutical and Biotechnology 2, n.º 1 (4 de febrero de 2022): 09–17. http://dx.doi.org/10.53858/arocpb02010917.

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Background: Phytocystatins are plants cysteine protease inhibitors (CPIs) that are known for their numerous uses in medicine and biotechnology. Methods: Different extraction media which include, Sodium Hydroxide, Hydrochloric acid, Sodium Chloride, Sodium phosphate buffer and distilled Water were used to evaluate flower, leave, root, latex, and stem bark of Moringa oleifera for inhibitory activity against cysteine protease (Papain enzyme). The phosphate buffer extract with higher protease inhibitory activity was concentrated by cold acetone precipitation and further subjected to partial purification using ammonium sulphate fractionation and Hydrophobic chromatography on Phenyl Sepharose column. The molecular weight of partially purified protein was estimated by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis. Results: The extracts of Sodium phosphate buffer from the seeds of Moringa oleifera showed higher CPI activity of 11.23 units/mg protein. Cold acetone precipitated extract gave high yield of 94.6% protein with 60% inhibition of protease. The partially purified protein showed a fifty percent inhibitory concentration (IC50) of 1.22±0.3 mg/ml protein against the enzyme with 63% inhibition. An estimated molecular weight of 13.5kDa was obtained from electrophoretic analysis of partially purified protein. Conclusion: Moringa oleifera seeds could be a good source of low molecular weight protein Inhibitor of Cysteine protease and might be useful in biotechnology of traditional medicinal plants, in transgenic crops to arrest the negative pathogenic over expressions of cysteine proteases

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Mutasher, Faisal K., Ghazi M. Aziz y Amani A. W. Abdul-Razzak. "Chemical detections of active compounds in Melilotus indica extracts". Journal of Biotechnology Research Center 3, n.º 1 (1 de enero de 2009): 130–40. http://dx.doi.org/10.24126/jobrc.2009.3.1.57.

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The crude extracts of the leaves of melilotus indica which collected in two dates (midFebruary, mid March) have been prepared by three solvents (Distilled water, ethanol 80% and chloroform) and three buffer solutions (Sodium acetate buffer, Sodium phosphate buffer and Tris-hydrochloric acid buffer), the greater percentage of crude extracts achieved by phosphate buffer which were 47.3% and 29.2% for second and first dates, respectively, while the lowest percentage of crude extracts achieved by chloroform extracts which were 13.2% and 10.0% for second and first dates, respectively. The qualitative chemical detections for active compounds in crude extracts revealed a positive results for the saponins, tannins, coumarins, flavones and glycosides, while the detections revealed a negative results for the alkaloids, resins and volatile oils. The active compounds in crude extracts prepared by solvents and buffer solutions were studied by thin layer chromatography (TLC), the solvent extracts were contains five compounds with relative flow (RF) 0.65, 0.4 for coumarin and umbelliferon, respectively, and 0.5, 0.27, 0.2 which belong to simple coumarins compounds in melilotus indica, while buffer solution extracts were contains two compounds with RF value 0.65 and 0.4 for coumarin and umbelliferon, respectively.

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FAGBEMI, Oluwole S. y Basil J. NORTHOVER. "Effect of sodium nitroprusside and L-arginine methyl ester on rat hearts stored at 4 °C for 24 h". Clinical Science 95, n.º 5 (1 de noviembre de 1998): 557–64. http://dx.doi.org/10.1042/cs0950557.

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1.This study examined the effects of altering nitric oxide levels with sodium nitroprusside or l-arginine in rat hearts stored hypothermically. 2.Hearts were microperfused at 4 ;°C for 24 ;h with a modified Krebs–Henseleit buffer (KHB) that contained either sodium nitroprusside, l-arginine, l-arginine methyl ester or dexamethasone. 3.After hypothermic storage, hearts were rewarmed to 37 ;°C with KHB alone or KHB containing sodium nitroprusside or l-arginine. Cardiac function was then assessed in either Langendorff mode or working heart mode. 4.Compared with values from fresh unstored hearts, hypothermic stored hearts showed a significant decrease in coronary flow and left ventricular developed pressure when the stored hearts were perfused in Langendorff mode. These hearts also produced less aortic flow and cardiac output when perfused in the working mode. 5.Hearts hypothermically microperfused with buffer containing either l-arginine or sodium nitroprusside and then reperfused in the Langendorff mode with untreated KHB buffer had the highest left ventricular developed pressure and coronary flow values. Aortic flow and cardiac output were also higher in these hearts. 6.In all groups of stored hearts, the concentrations of both ATP and creatine phosphate were significantly low, when compared with values from freshly isolated hearts. Addition of dexamethasone to the buffer either during storage or during reperfusion had no beneficial effect on high-energy phosphate loss or cardiac performance of stored hearts. 7.This study showed that the addition of nitric oxide donors to storage buffer significantly improves cardiac function on normothermic reperfusion. The improved functional recovery is unrelated to the high-energy phosphate content of these hearts.

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Brenan, M. y M. L. Bath. "Indoxyl-tetranitro blue tetrazolium method for detection of alkaline phosphatase in immunohistochemistry." Journal of Histochemistry & Cytochemistry 37, n.º 8 (agosto de 1989): 1299–301. http://dx.doi.org/10.1177/37.8.2474024.

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A sensitive method for detection of alkaline phosphatase in immunohistochemistry, using lymphoid cells, has been optimized. The conditions for staining are 0.23 mM 5-bromo-4-chloro-indoxyl phosphate, 0.55 mM tetranitro blue tetrazolium, 2.0 mM levamisole, 5.0 mM sodium azide, 10.0 mM magnesium chloride, and 0.15 mM 1-methoxyphenazine methosulfate dissolved in 100 mM Tris-HCl buffer, pH 9.5.

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TAYYAB, SAAD, TUAN NOR NAZIAN TUAN MAT y ADYANI AZIZAH ABD HALIM. "DIFFERENTIAL STABILIZING EFFECTS OF BUFFERS ON STRUCTURAL STABILITY OF BOVINE SERUM ALBUMIN AGAINST UREA DENATURATION". Latin American Applied Research - An international journal 52, n.º 1 (1 de enero de 2022): 7–13. http://dx.doi.org/10.52292/j.laar.2022.738.

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The conformational stability of bovine serum albumin (BSA) against urea denaturation was investigated in aqueous solutions both in the absence and presence of buffers. Various buffers differing in polar and nonpolar characters such as sodium phosphate, Tris-HCl, (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) HEPES and [3-(N-morpholino)propanesulfonic acid] MOPS buffers were used in this study. Urea-induced structural changes were analyzed using different probes, i.e., intrinsic fluorescence, ANS fluorescence and UV-difference spectral signal. Presence of different buffers in the incubation medium offered different degrees of resistance to the protein against urea-induced structural changes compared to those obtained in water (in the absence of buffers). A similar trend of buffer-induced structural resistance was noticed with three different probes. The stabilizing effect of these buffers followed the order: MOPS > HEPES > sodium phosphate > Tris-HCl > water. As found in MOPS and HEPES buffers, the highest stability of BSA can be attributed to the presence of morpholine and piperazine rings, respectively, in their structures. These groups might have produced a hydrophobic environment around the protein surface, thus stabilizing protein conformation against urea denaturation.

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Ferreira, Luisa A., Xiao Fan, Pedro P. Madeira, Lukasz Kurgan, Vladimir N. Uversky y Boris Y. Zaslavsky. "Analyzing the effects of protecting osmolytes on solute–water interactions by solvatochromic comparison method: II. Globular proteins". RSC Advances 5, n.º 73 (2015): 59780–91. http://dx.doi.org/10.1039/c5ra08612d.

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Adhikari, Anjan, Sangita Bhattacharya, Abhijit Chanda y Tapas Kumar Sur. "Assessment on antinociceptive actions of soluble fractions derived from edible mollusc (Bellamya bengalensis Lam.)". International Journal of Basic & Clinical Pharmacology 6, n.º 12 (23 de noviembre de 2017): 2916. http://dx.doi.org/10.18203/2319-2003.ijbcp20175218.

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Background: Bellamya bengalensis, an edible bivalve mollusc is traditionally used in the treatment of joint pain, bone fracture, jaundice and eye infections. Present study was designed to find out the most potent analgesic fractions derived from the body mass of Bellamya bengalensis.Methods: The test specimen was collected, identified and fractionated with solvent medium like, phosphate buffer saline (PB), ethyl acetate (EB), methanol (MB) and chloroform (CB). Protein concentration of each fraction was determined. The antinociceptive activities were measured either by thermal models like, hot plate and tail immersion (central analgesic action) or by chemical model like acetic acid induced writhing (peripheral analgesic action) in mice. Diclofenac sodium was used as analgesic standard.Results: Significant peripheral and central analgesic activity showed by phosphate buffer saline fraction at 100mg/kg, even better than diclofenac standard at 10mg/kg. In hot plate and tail immersion tests, phosphate buffer saline showed the highest activity followed by methanol, chloroform and ethyl acetate fraction respectively. However, in case of peripheral analgesic experiment, phosphate buffer fraction exhibited maximum writhing inhibitory properties and that was followed by chloroform, methanol and ethyl acetate fraction respectively.Conclusions: Phosphate buffer saline fraction of Bellamya bengalensis showed maximum potential central and peripheral analgesic activity than any other fractions.

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Zhou, Lan y Rodica Elena Ionescu. "Influence of Saline Buffers over the Stability of High-Annealed Gold Nanoparticles Formed on Coverslips for Biological and Chemosensing Applications". Bioengineering 7, n.º 3 (3 de julio de 2020): 68. http://dx.doi.org/10.3390/bioengineering7030068.

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Herein, coverslips were used as solid supports for the synthesis of gold nanoparticles (AuNPs) in three steps: (i) detergent cleaning, (ii) evaporation of 4 nm gold film and (iii) exposure at high annealing temperature (550 °C) for 3 h. Such active gold nanostructured supports were investigated for their stability performances in aqueous saline buffers for new assessments of chemical sensing. Two model buffers, namely saline-sodium phosphate-EDTA buffer (SSPE) and phosphate buffer saline (PBS), that are often used in the construction of (bio)sensors, are selected for the optical and microscopic investigations of their influence over the stability of annealed AuNPs on coverslips when using a dropping procedure under dry and wet media working conditions. A study over five weeks monitoring the evolution of the localized surface plasmon resonance (LSPR) chemosensing of 1,2-bis-(4-pyridyl)-ethene (BPE) is discussed. It is concluded that the optimal sensing configuration is based on annealed AuNPs exposed to saline buffers under wet media conditions (overnight at 4 °C) and functionalized with BPE concentrations (10−3–10−11 M) with the highest LSPR spectra after two weeks.

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Pastor, Ferenc T., Hana Dejmková, Jiří Zima y Jiří Barek. "Determination of chloramphenicol by differential pulse voltammetry at carbon paste electrodes – The use of sodium sulfite for removal of oxygen from electrode surface". Collection of Czechoslovak Chemical Communications 76, n.º 5 (2011): 383–97. http://dx.doi.org/10.1135/cccc2011011.

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The possibility of determination of chloramphenicol by differential pulse voltammetry at four different carbon paste electrodes, in the full pH range (2–12) of Britton–Robinson (BR) buffer was investigated. Electrodes were prepared by mixing spectroscopic graphite powder or glassy carbon microbeads with mineral oil (Nujol) or tricresyl phosphate. Under optimal conditions (BR buffer pH 12, the electrode prepared from glassy carbon microbeads and tricresyl phosphate), linear calibration graph was obtained only in 10–5 M chloramphenicol concentration range. Determination of lower concentrations of chloramphenicol was complicated by irreproducible peak of oxygen from the carbon paste which overlapped with peak of chloramphenicol. Addition of sodium sulfite removed the oxygen peak without influence on the peak of chloramphenicol. Under optimal conditions (electrode paste made from glassy carbon microbeads, BR buffer pH 10 and 0.5 M sodium sulfite), straight calibration line was obtained in the 10–6 and 10–5 M chloramphenicol concentration range. Limit of determination was 5 × 10–7 mol/l.

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Katakam, Prakash y Karanam R. Sireesha. "Simultaneous Determination of Ciprofloxacin Hydrochloride and Dexamethasone Sodium Phosphate in Eye Drops by HPLC". E-Journal of Chemistry 9, n.º 3 (2012): 1077–84. http://dx.doi.org/10.1155/2012/187824.

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A liquid chromatographic method was developed and validated for the simultaneous determination of ciprofloxacin hydrochloride and dexamethasone sodium phosphate in bulk and pharmaceutical formulations. Optimum separation was achieved in less than 5 min using a C18column (250 mmx4.6 mm i.d, 5μ particle size) by isocratic elution. The mobile phase consisting of a mixture of mixed phosphate buffer (pH 4) and acetonitrile (65:35, v/v) was used. Column effluents were monitored at 254 nm at a flow rate of 1ml/min. Retention times of ciprofloxacin hydrochloride and dexamethasone sodium phosphate were 2.0 and 3.16 min respectively. The linearity of ciprofloxacin hydrochloride and dexamethasone sodium phosphate was in the range of 3-18 μg/ml and 1-6 μg/ml respectively. Developed method was economical in terms of the time taken and amount of solvent consumed for each analysis. The method was validated and successfully applied to the simultaneous determination of ciprofloxacin hydrochloride and dexamethasone sodium phosphate in bulk and pharmaceutical formulations.

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Baharuddin, Maswati, Muh Rajib, Sappewali y Ummi Zahra. "Effect of combination of electrolyte and buffer on electrical production in fuel cell microbial system with Pseudomonas sp. in molasses substrate". E3S Web of Conferences 211 (2020): 03001. http://dx.doi.org/10.1051/e3sconf/202021103001.

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MFC is a bio-electrochemical system driving an electric current by using high-energy bacteria and oxidants. This research aimed to investigate the effect of electrolyte and buffer on electrical production using Pseudomonas sp. In Molasses substrate. The method in this research was the double compartment that consist of anode and cathode chambers. Both were related by salt bridge. This study showed that the addition of a combination of KMnO4 electrolyte solution with sodium phosphate buffer solution obtained a maximum potential difference of 0.67 V. The result also revealed that the combination of KMnO4 electrolyte solution with Potassium Phosphate Buffer solution produced a 1.44 mA maximum current with power density of 660.82 mW/m2.

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HEDDLESON, RONALD A., STEPHANIE DOORES, RAMASWAMY C. ANANTHESWARAN y GERALD D. KUHN. "Destruction of Salmonella Species Heated in Aqueous Salt Solutions by Microwave Energy". Journal of Food Protection 56, n.º 9 (1 de septiembre de 1993): 763–68. http://dx.doi.org/10.4315/0362-028x-56.9.763.

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Concentrations of 0.1, 0.5, 0.75, 1.0, and 1.25% wt/vol (0.017, 0.085, 0.13, 0.17, and 0.21 M, respectively) sodium chloride were added to 0.3 mM phosphate buffer, pH 6.8, and heated by microwave energy to study the relationship between salt concentration, temperatures achieved, and microbial destruction. Heating Salmonella spp. in saline solutions for a constant time (45 s) or to a constant final temperature (60°C) was also investigated. Fiberoptic thermometry was employed to obtain a temperature profile at specific sites within the solution. When heating for a constant time period, a minimum concentration of 0.75% wt/vol NaCl was necessary to afford Salmonella spp. significantly (P = 0.05) greater protection than the phosphate buffer control. Sodium, potassium, magnesium, and calcium chloride (1.0% wt/vol) in 0.3 mM phosphate buffer were also inoculated with a mixture of Salmonella spp. and heated by microwave energy. Of the salts examined, solutions containing NaCl consistently achieved the highest final surface temperature and largest temperature gradient from the surface to the bottom of the container. The amount of destruction of Salmonella spp. heated to a mixed mean final temperature of 60°C in buffer containing 1.0% wt/vol concentrations of NaCl, KCl, CaCl2, and MgCl2 was 56.4, 71.2, 72.8, and 88.7%, respectively. No relationship was found between the valency of the cation used and final temperatures achieved.

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AL-Sa'ady, Ali Jabbar Rashak y Lamees Mohammed Riuadh Abbas. "Effect of henna (lawsonia inermis) and juglans regia bark extract on some pathogenic microorganisms". Al Mustansiriyah Journal of Pharmaceutical Sciences 17, n.º 1 (13 de marzo de 2018): 13. http://dx.doi.org/10.32947/ajps.v17i1.54.

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Six types of extracts were prepared for henna leaves (Lawsonia inermis) and Juglans Regia bark, by using distilled water, 1 M phosphate buffer (pH 7.0), 1 M sodium acetate buffer (pH 6.0), 1 M Tris-HCl buffer (pH 8.0), ethanol and methanol alcohol. The antibacterial activities of the henna and J. regia extracts were determined using the agar disc diffusion on nutrient agar for each one of Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. The results of the phytochemical screening of henna extract revealed the presence of alkaloids, glycosides, terpens, anthraquinones, tannins and phenols, whilst flavonoids, saponins, steroids, resins and coumarines gave negative test, on the other hand, result indicate the presence of alkaloids, glycosides, flavonoids, tannins, saponins, phenols, steroids and anthraquinones, whereas the terpens, resins, and coumarines gave negative test in J. Regia bark extract. The highest antimicrobial activity was observed upon using 10 gm % (w:v) of henna extracted by 1M phosphate buffer (pH 7.0), and 10 gm % (w:v) of J. regia bark extracted with 1M sodium acetate buffer (pH 6.0), after mixing for 4 hours. The best concentration of henna and J. regia bark extract on discs that gave the high antimicrobial activity against the tested microorganisms was 10 mg/ml.

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27

Romano, Angela, Antonella Rosato, Stefano Bianchi, Giulio Zanaroli, Annamaria Celli, Grazia Totaro y Laura Sisti. "Triggering of Polymer-Degrading Enzymes from Layered Double Hydroxides for Recycling Strategies". International Journal of Molecular Sciences 24, n.º 1 (3 de enero de 2023): 831. http://dx.doi.org/10.3390/ijms24010831.

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The use of degrading enzymes in polymer formulation is a very attractive strategy to manage the end-of-life of plastics. However, high temperatures cause the denaturation of enzymes and the loss of their catalytic activity; therefore, protection strategies are necessary. Once protected, the enzyme needs to be released in appropriate media to exert its catalytic activity. A successful protection strategy involves the use of layered double hydroxides: cutinase, selected as a highly degrading polyester hydrolytic enzyme, is thermally protected by immobilization in Mg/Al layered double hydroxide structures. Different triggering media are here evaluated in order to find the best releasing conditions of cutinase from LDH. In detail, phosphate and citrate–phosphate buffers, potassium carbonate, sodium chloride, and sodium sulfate solutions are studied. After the comparison of all media in terms of protein release and activity retained, phosphate buffer is selected as the best candidate for the release of cutinase from LDH, and the effect of pH and concentration is also evaluated. The amount of the enzyme released is determined with the Lowry method. Activity tests are performed via spectrophotometry.

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B. Borse, Laxmikant, Atul R. Bendale, Sandhya L. Borse, Vaishali D. Naphade y Anil G. Jadhav. "Formulation and Evaluation of Mouth Dissolving Tablet Rivaroxaban and its Validation". Biosciences Biotechnology Research Asia 19, n.º 4 (20 de diciembre de 2022): 943–54. http://dx.doi.org/10.13005/bbra/3043.

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ABSTRACT: The foremost intention of present research was the preparation and assessment of mouth dissolving formulation Rivaroxaban and its validation. During present work, this tablet was formulated by straight compression technique by means of Cros-carmellose sodium and Sodium starch glycolate as super-disintegrants (concentration of 2, 4, 6%) and Avicel 102 as a binder. The formulated preparations were exposed to different consideration parameters like hardness test, friability test, disintegration test, release of drug and content of drug. The calibration curve of API using solvent phosphate buffer pH 6.8 was carried out. All prepared formulations exposed to different assessment parameters have shown the findings within prescribed limit. Due to the large concentration of super disintegrants in F8, disintegration time can reach 29±0.06 seconds. In used buffer, drug release was calculated at intervals of 0, 2, 4, 6, 8, 10, and 12 minutes. The F8 demonstrates 96.5±0.567 percent medication release. UV spectrophotometric validation was performed for the quantification of Rivaroxaban in bulk. Rivaroxaban was estimated at 247nm in phosphate buffer 6.8. The linearity range was observed 2–12µg/ml.

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29

Perez-Benito, Joaquin F., Driss Lamrhari y Conchita Arias. "Oxidation of DL-penicillamine by chromium(VI). Kinetics of formation of the thioester intermediate". Canadian Journal of Chemistry 72, n.º 7 (1 de julio de 1994): 1637–44. http://dx.doi.org/10.1139/v94-206.

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The kinetics of formation of the thioester involved as an intermediate in the reaction between chromium(VI) and DL-penicillamine in aqueous media (pH = 1–8) containing different buffers (acetate, citrate, and phosphate) has been studied by monitoring the disappearance of chromium(VI) at 370 nm and application of the initial-rates method. The initial rate is directly proportional to the initial concentrations of both oxidant and reductant, and the rate vs. pH plots show bell-shaped profiles. The reaction is catalyzed by the buffer present in the medium, the catalytic power of each buffer increasing in the order acetate < citrate < phosphate. This is explained in terms of a mechanism involving the formation of a complex between the acidic form of the buffer and HCrO4− previous to the formation of the thioester. Potassium chloride and sodium sulfate do not seem to have important specific effects on the reaction rate, their effect being that of an acceleration of the reaction as the ionic strength increases. On the contrary, the sulfates of magnesium, manganese(II), and zinc (the latter only in the presence of acetate buffer) have specific effects, indicating the probable formation of several complexes. The spectrophotometric detection of the thioester at 430 nm has allowed to confirm some of the conclusions extracted from the measurement of initial rates, and suggests that this intermediate might approach a steady-state behavior in the three buffers at pH > 6.25, and also that a bimolecular reaction with DL-penicillamine might be involved in its destruction.

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30

Massover, W. H. y N. J. Zaluzec. "Differential Mass Loss in Dried Sodium Phosphate Buffer Under Electron Beam Irradiation". Microscopy and Microanalysis 18, S2 (julio de 2012): 1144–45. http://dx.doi.org/10.1017/s143192761200757x.

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31

Pavani, Pannuru, Krishan Kumar, Anjeeta Rani, Pannuru Venkatesu y Ming-Jer Lee. "The influence of sodium phosphate buffer on the stability of various proteins: Insights into protein-buffer interactions". Journal of Molecular Liquids 331 (junio de 2021): 115753. http://dx.doi.org/10.1016/j.molliq.2021.115753.

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32

Partanen, Jaakko I. y Pentti O. Minkkinen. "Equations for calculation of the pH of buffer solutions containing sodium or potassium dihydrogen phosphate, sodium hydrogen phosphate, and sodium chloride at 25°C". Journal of Solution Chemistry 26, n.º 7 (julio de 1997): 709–27. http://dx.doi.org/10.1007/bf02767623.

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33

Ben Brahim, Raoua, Hasna Ellouzi, Khaoula Fouzai, Nedra Asses, Mohammed Neffati, Jean Marc Sabatier, Philippe Bulet y Imed Regaya. "Optimized Chemical Extraction Methods of Antimicrobial Peptides from Roots and Leaves of Extremophilic Plants: Anthyllis sericea and Astragalus armatus Collected from the Tunisian Desert". Antibiotics 11, n.º 10 (24 de septiembre de 2022): 1302. http://dx.doi.org/10.3390/antibiotics11101302.

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Extraction methods depend mainly on the chemical nature of the extracted molecule. For these reasons, the selection of the extraction medium is a vital part of obtaining these molecules. The extraction of antimicrobial peptides (AMPs) from extremophile plants is important because of its potential pharmaceutical applications. This work focused on the evaluation of several solvents for the extraction of AMPs from the following two extremophile plants: Astragalus armatus and Anthyllis sericea from southern Tunisia. In order to identify the most efficient solvents and extraction solutions, we used sulfuric acid, dichloromethane, phosphate buffer, acetic acid and sodium acetate, and we tested them on leaves and roots of both the studied plants. The extracts obtained using sulfuric acid, dichloromethane and phosphate buffer extraction did not show any antimicrobial activity, whereas the acetic acid and sodium acetate extracts led to growth inhibition of some of the tested bacterial strains. The extracts of leaves and roots of An. sericea and As. armatus obtained by acetic acid and sodium acetate were proven to be active against Gram-positive bacteria and Gram-negative bacteria. Therefore, the most appropriate solvents to use for antimicrobial peptide extraction from both plants are acetic acid and sodium acetate.

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34

Wang, Fanqiang, Shelby Kashket y Eva R. Kashket. "Maintenance of ΔpH by a butanol-tolerant mutant of Clostridium beijerinckii". Microbiology 151, n.º 2 (1 de febrero de 2005): 607–13. http://dx.doi.org/10.1099/mic.0.27587-0.

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The isolation of Clostridium beijerinckii mutants that are more tolerant of butanol than the wild-type offered the opportunity to investigate whether the membrane activities which are required for maintaining the transmembrane ΔpH (the difference in pH between the cellular interior and exterior) are sensitive targets of butanol toxicity. The ΔpH was measured by the accumulation of [14C]benzoate using late-exponential-phase cells which were suspended in citrate/phosphate buffer at pH 5 (to maximize the ΔpH component of the protonmotive force) and supplemented with glucose and Mg2+. The ΔpH of the butanol-tolerant tolerant mutant, strain BR54, of C. beijerinckii NCIMB 8052 was found to be significantly more tolerant of added butanol than the wild-type. Thus, in potassium citrate/phosphate buffer the mutant cells maintained a ΔpH of 1·4 when butanol was added to a concentration of 1·5 % (w/v), while the wild-type ΔpH was reduced to 0·1. The ΔpH of both strains was completely dissipated with 1·75 % butanol, an effect attributed to a chaotropic effect on the membrane phospholipids. Similar results were obtained in sodium citrate/phosphate buffer. In the absence of added Mg2+, the ΔpH of the mutant decreased in both sodium and potassium citrate/phosphate buffer, but more rapidly in the former. Interestingly, the addition of butanol at low concentrations (0·8 %) prevented this ΔpH dissipation, but only in cells suspended in sodium citrate/phosphate buffer, and not in potassium citrate/phosphate buffer. In wild-type cells the decrease in ΔpH occurred more slowly than in the mutant, and sparing of the ΔpH by 0·8 % butanol was less pronounced. The authors interpret these data to mean that the ΔpH is dissipated in the absence of Mg2+ by a Na+- or K+-linked process, possibly by a Na+/H+ or a K+/H+ antiporter, and that the former is inhibited by butanol. Apparently, butanol can selectively affect a membrane-associated function at concentrations lower than required for the complete dissipation of transmembrane ion gradients. Additionally, since the butanol-tolerant mutant BR54 is deficient in the ability to detoxify methylglyoxal (MG) and contains higher levels of MG than the wild-type, the higher Na+/H+ antiporter activity of the mutant may be due to the greater degree of protein glycation by MG in the mutant cells. The mechanism of butanol tolerance may be an indirect result of the elevated glycation of cell proteins in the mutant strain. Analysis of membrane protein fractions revealed that mutant cells contained significantly lower levels of unmodified arginine residues than those of the wild-type cells, and that unmodified arginine residues of the wild-type were decreased by exposure of the growing cells to added MG.

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Al-Sadoon, Taghreed H. "Nanoparticles Impression on Creatine Kinase Activity". NeuroQuantology 20, n.º 1 (4 de febrero de 2022): 1–10. http://dx.doi.org/10.14704/nq.2022.20.1.nq22001.

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Nanoparticles (NPs) are purchased from Sigma-Aldrich (730785). Sodium citrate as stabilizer comprises 10 nm particle size (TEM), dispersion (NPs), stabilizer Silver, and 0.02 mg/mL in aqueous buffer relative molecular mass (107.87). The concentration number (3.6×1012) packaging 25mL in a glass bottle. 10 nm diameter golden nanoparticles OD 1, stable 0.1 mM suspension is an aqueous salt solution that contains common salt, dihydrogen phosphate, and dilute phosphate-buffered saline (PBS). It also contains potassium dihydrogen phosphate and potassium chloride in certain formulations. While the pH rises, the role of the buffer is to regulate it. NPs, equipped with (Sigma-Aldrich752584) relative molecular mass (196.97). Structural and optical nanoparticles are studied. Findings show a nanoparticle size of approximately 10 nanometers. The silver and gold sources’ impact on healthy people’s creatine kinase (CK) activity within the blood was in vitro-studied. The results indicated that the nanoparticles of silver and gold had a dissimilar impact on serum CK activity. The gold particles tonic impacts serum CK activity and increases the activity of enzymes as the concentration of nanoparticles increases because it acts as an enzyme activator. At the same time, silver nanoscale has an inhibitory effect thereon.

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Krupa, S. y Murthy K. R. Siddalinga. "Phenolics, proteins, antioxidant activity and GC – MS analysis of Artocarpus heterophyllus Lam seeds". Research Journal of Biotechnology 17, n.º 3 (25 de febrero de 2022): 129–33. http://dx.doi.org/10.25303/1703rjbt129133.

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Artocarpus heterophyllus seeds are available in larger quantity and are good source for many phytochemicals. The seeds are rich in proteins and low in fat content. The present study was carried out to analyse the phenolics, proteins and antioxidant activity of A. heterophyllus seeds. Different aqueous solvents such as acetate buffer pH 5.0, phosphate buffer pH 7.0, tris buffer pH 8.5, different concentration of sodium hydroxide (0.05M, 0.1M, 0.2M, 0.3M, 0.4M, 0.5M), sodium chloride, water and organic solvents like ethanol, methanol and acetone were used for extraction. Sodium hydroxide (0.1M) showed maximum extraction efficiency. Among the organic solvents, ethanol showed maximum phytochemical extraction. Different concentrations of ethanol (20%, 40%, 60%, 80%) containing 0.1M NaOH were also used for extraction and maximum extraction was found in 40% ethanol containing 0.1M NaOH. GC – MS analysis was carried to identify various bioactive compounds present in the extracts (hexane, ethyl acetate, methanol and water) of the seeds.

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Journal, Baghdad Science. "Purification and Characterization of protease from Zahdi dates plam seeds (Phoenix dactylifera L.)". Baghdad Science Journal 6, n.º 4 (6 de diciembre de 2009): 633–39. http://dx.doi.org/10.21123/bsj.6.4.633-639.

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Proteinases (E.C.3.4.21) family are widely distributed in the nature; it was present in animals tissues , plants and microbial cell . Protease was purified from Zahdi seed (Phoenix dactylifera L.) by several steps included ammonium sulphite ppt (75%) saturation and dialyzed against the 80mM sodium phosphate buffer at pH 7.5 . The enzyme specific activity was 407.62 unit/mg protein. The obtained extract was purified by DEAE-Cellulose column followed by gel filtration through Sephacyl S-200 column .The enzyme specific activity ,yield and purification fold were 1873.49 unit/mg protein, 22.99 and 58.42% respectively. The results of protease characterization showed that the molecular weight was 25118 daltons as determined by gel filtration. The optimum temperature of the enzyme activity 35 C for 15 minutes and that for stability was 45 C for 15 minutes, using sodium phosphate buffer at pH 7.5, The optimum pH for the enzyme stability and activity were 8.5 for 15 minute and 7.5 respectively.

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Matsumoto, K., H. Kikuchi, S. Kano, H. Iri, H. Takahashi y M. Umino. "Automated determination of drugs in serum by liquid chromatography with column-switching. I. Separation of antiepileptic drugs and metabolites." Clinical Chemistry 34, n.º 1 (1 de enero de 1988): 141–44. http://dx.doi.org/10.1093/clinchem/34.1.141.

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Abstract This is a fully automated system for determining six common antiepileptic drugs and two principal metabolites of carbamazepine in serum. It is based on "high-performance" liquid chromatography (HPLC), with column switching. TSKprecolumn BSA-ODS and TSKgel ODS-120A (both from Toyo Soda) were used as the precolumn and analytical column, respectively. The former contains octadecylsilyl resins treated with bovine serum albumin (BSA), and does not adsorb macromolecules such as serum proteins but retains small lipophilic molecules such as antiepileptic drugs. Serum samples are directly injected onto the precolumn. After washing out the serum proteins from the precolumn with sodium phosphate buffer, we switch the column connections to introduce the retained substances onto the analytical column and elute with a step-gradient of acetonitrile/sodium phosphate buffer. The high analytical recovery (95-102%) and the reproducibilities (CV less than 5% within-run) indicate that this system is suitable for use in theraputic drug monitoring in clinical laboratories.

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39

Vachon, V., M. C. Delisle, R. Laprade y R. Béliveau. "Reconstitution of the renal brush-border membrane sodium/phosphate co-transporter". Biochemical Journal 278, n.º 2 (1 de septiembre de 1991): 543–48. http://dx.doi.org/10.1042/bj2780543.

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A simple and rapid procedure was developed for the reconstitution of Na(+)-dependent phosphate-transport activity from bovine kidney brush-border membranes. The phosphate transporter appears to be particularly sensitive to extraction conditions. To prevent its inactivation, the phosphate carrier was solubilized in a buffer containing its substrates, Na+ and phosphate, CHAPS, dithiothreitol, brush-border membrane lipids and glycerol. The uptake of phosphate by reconstituted vesicles was strongly stimulated by the presence of a transmembrane Na+ gradient. This stimulation was abolished when the Na+ gradient was dissipated by monensin. The affinity of the carrier for phosphate was similar in proteoliposomes and in brush-border membrane vesicles (apparent Kt = 40 microM). The transporter was also stimulated by the presence of a high concentration of phosphate on the trans side of the membrane. The reconstituted transport activity was inhibited by arsenate, a known inhibitor of phosphate transport. However, the bovine phosphate carrier, intact or reconstituted, was much less sensitive to inhibition by phosphonoformic and phosphonoacetic acids than were those of other species studied so far. SDS/PAGE revealed that only a small number of brush-border membrane proteins were incorporated into the proteoliposomes. This reconstitution procedure should be useful for the purification and identification of the carrier protein.

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40

Lai, Ka M., Harriet A. Burge y Melvin W. First. "Size and UV Germicidal Irradiation Susceptibility of Serratia marcescens when Aerosolized from Different Suspending Media". Applied and Environmental Microbiology 70, n.º 4 (abril de 2004): 2021–27. http://dx.doi.org/10.1128/aem.70.4.2021-2027.2004.

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ABSTRACT Experimental systems have been built in laboratories worldwide to investigate the influence of various environmental parameters on the efficacy of UV germicidal irradiation (UVGI) for deactivating airborne microorganisms. It is generally recognized that data from different laboratories might vary significantly due to differences in systems and experimental conditions. In this study we looked at the effect of the composition of the suspending medium on the size and UVGI susceptibility of Serratia marcescens in an experimental system built in our laboratory. S. marcescens was suspended in (i) distilled water, (ii) phosphate buffer, (iii) 10% fetal calf serum, (iv) phosphate-buffered saline (saline, 0.8% sodium chloride), and (v) synthetic saliva (phosphate-buffered saline with 10% fetal calf serum). At low humidity (36%), S. marcescens suspended in water-only medium was the most susceptible to UVGI, followed by those in serum-only medium. The count median diameters (CMDs) for culturable particles from water-only and serum-only media were 0.88 and 0.95 μm, respectively, with the measurements based on their aerodynamic behavior. The bacteria suspended in phosphate buffer, synthetic saliva, and phosphate-buffered saline had similar UVGI susceptibility and CMD at 1.0, 1.4, and 1.5 μm, respectively. At high humidity (68%) the CMD of the particles increased by 6 to 16%, and at the same time UVGI susceptibility decreased, with the magnitude of decrease related to the type of suspending medium. In conclusion, the choice of suspending medium influenced both size and UVGI susceptibility of S. marcescens. These data are valuable for making comparisons and deciding on the use of an appropriate medium for various applications.

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Tyunina, Elena Yu y Anna A. Kuritsyna. "HEAT CAPACITY PROPERTIES OF AQUEOUS BUFFER SOLUTIONS OF L-HISTIDINE IN A WIDE TEMPERATURE RANGE". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, n.º 11 (19 de noviembre de 2019): 78–84. http://dx.doi.org/10.6060/ivkkt.20196211.6082.

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The influence of temperature and concentration of L-histidine on the heat capacity properties of its aqueous buffer solutions was studied by differential scanning calorimetry. The investigations were carried out in aqueous buffer solutions (pH 7.4) containing monobasic sodium phosphate and dibasic sodium phosphate, which brings the environment closer to the conditions of real biological systems. The pH values of the solutions were fixed with a digital pH meter Mettler Toledo, model Five-Easy (Switzerland). The differential scanning microcalorimeter SCAL-1 (Biopribor, Pushchino, Russia) was used for measure the specific heat capacity of the system under study. It was equipped with Peltier thermoelectric elements, two measuring glass cells with an internal volume of 0.377 cm3, as well as a computer terminal and software for calculating heat capacity. The standard error of measurement of the specific heat for the studied solutions was within ±7·10-3 J·K-1·g-1. The experimental values of the specific heat of solutions of the amino acid in a phosphate buffer solvent in the temperature range (283.15 – 343.15) K were obtained. The concentration of histidine was varied from (0.00215 to 0.03648) mol·kg-1. All the studied solutions were prepared by the gravimetric method using Sartorius-ME215S scales (with a weighing accuracy of 1·10-5 g). The apparent molar heat capacities of L-histidine in the buffer solution, as well as its partial molar heat capacities at infinite dilution, were determined. The calculated molar parameters increase with an increase in both temperature and amino acid concentration. It was shown that the partial molar heat capacities transfers of L-histidine from water to the buffer solution have positive values in the temperature range studied. The results are discussed on base of the Gurney model.

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Visagaperumal, D., C. Mayuren, N. Anbalagan, Raghuveer P. Varma, B. Srinivas, V. B. Shanker Bontha y G. Ravikumar. "A FACILE SYNTHESIS OF MUTUAL PRODRUG OF DICLOFENAC SODIUM AND PARACETAMOL AND ITS PREFORMULATION STUDIES". INDIAN DRUGS 49, n.º 10 (28 de octubre de 2012): 29. http://dx.doi.org/10.53879/id.49.10.p0025.

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Mutual prodrug was synthesized by esterifying diclofenac with paracetamol. In vitro hydrolysis of prodrug in HCl buffer (pH 1.2) and phosphate buffer (pH 7.4) showed that the drug was released more in pH 7.4. The purity of the prodrug was confirmed by TLC and characterized on the basis of IR spectroscopy and 1H NMR spectroscopy. The physiochemical parameters were determined and the results showed that they are more lipophilic than the parent drug. The compound was also evaluated for anti-inflammatory and ulcerogenicity.

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Shu, Guowei, Xin Yang, Zhangteng Lei, Dan Huang y Yaling ZHAI. "Effects of Carbohydrates, Prebiotics and Salts on Survival of Saccharomyces boulardii During Freeze-Drying". Acta Universitatis Cibiniensis. Series E: Food Technology 22, n.º 2 (1 de diciembre de 2018): 59–66. http://dx.doi.org/10.2478/aucft-2018-0013.

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Abstract Saccharomyces boulardii, as a probiotic yeast, had been commonly used in food, medicine and feed to treat diarrhea in humans or livestock. However, there are few researches focusing on the preparation of its freeze-drying S.boulardii powder. In this study, the effect of carbohydrates (glucose, sucrose, maltose, fructose, lactose, mannose and trehalose), prebiotics (isomalto-oligosaccharide, xylo-oligosaccharide, raffinose, stachyose, inulin, galacto-oligosaccharide and fructo-oligosaccharide) and salts (NaHCO3, MgSO4, sodium glutamate, sodium ascorbate, and phosphate buffer) on the freeze-dried survival of S. boulardii were investigated to screen the cryoprotectant by using single factor experiments. As the result, trehalose and XOS had better protective effect, the survival rate was 23.72% and 20.70% respectively, the number of viable cells reached 0.91×1010 CFU/g and 0.85×1010 CFU/g respectively; the addition amount of NaHCO3 was 0.3%, the freeze-dried survival rate reached the maximum value of 12.92%. The phosphate buffer additive amount and the bacterial sludge weight were 0.8:1, the freeze-dried survival rate reached a maximum of 14.14%, the freeze-dried survival rate of sodium glutamate, sodium ascorbate and MgSO4 groups was increasing, reaching a maximum of 20.26%, 16.47% and 6.29% when the addition amount was 2%, 10%, 0.5%.

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Putra, Arief Yandra. "PERBANDINGAN KONDISI OPTIMUM PEMISAHAN NATRIUM SAKARIN, ASAM BENZOAT DAN KAFEIN DENGAN FASA GERAK METANOL-BUFFER FOSFAT DAN METANOL-BUFFER ASETAT MENGGUNAKAN HPLC". Jurnal Katalisator 2, n.º 2 (6 de octubre de 2017): 112. http://dx.doi.org/10.22216/jk.v2i2.2537.

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The development of food and beverage industry in Indonesia from year to year causes the production of food and soft drink circulating in community was increased. However, in food and soft drink were often added food additives such as sodium saccharin, benzoic acid, and caffeine that its level must be considered because it can caused negative effect on health. This study aims to compare optimum conditions of separation of sodium saccharin, benzoic acid and caffeine using methanol-phosphate buffer and methanol-acetate buffer as mobile phase using HPLC. The study was conducted by determining the wavelength, optimum pH of buffer and optimum composition of mobile phase. The optimum condition for the mobile phase of methanol-phosphate buffer were pH 4,5 with mobile phase composition of 12,5: 87,5 and UV detection system at 220 nm wavelength. The optimum condition for methanol-acetate buffer were pH 5,5 with mobile phase composition of 15:85 and the UV detection system at 230 nm wavelength. The composition of methanol-acetate buffer as mobile phase gives better result for the separation of sodium saccharin, benzoic acid and caffeine with shorter retention times. Perkembangan industri makanan dan minuman di Indonesia dari tahun ke tahun menyebabkan produksi makanan dan minuman ringan yang beredar di masyarakat semakin meningkat. Namun, di dalam makanan dan minuman ringan sering ditambahkan bahan tambahan pangan seperti natrium sakarin, asam benzoat, dan kafein yang kadarnya perlu diperhatikan karena dapat memberikan dampak negatif pada kesehatan. Penelitian ini bertujuan untuk membandingkan kondisi optimum pemisahan natrium sakarin, asam benzoat dan kafein menggunakan metanol-buffer fospat dan metanol-buffer asetat sebagai fasa gerak menggunakan HPLC. Penelitian dilakukan dengan menentukan panjang gelombang, pH buffer optimum dan komposisi fasa gerak optimum. Kondisi optimum untuk fasa gerak metanol-buffer fospat adalah pH 4,5 dengan komposisi fasa gerak 12,5:87,5 dan sistem pendeteksian UV pada panjang gelombang 220 nm. Kondisi optimum untuk fasa gerak metanol-buffer asetat adalah pH 5,5 dengan komposisi fasa gerak 15:85 dan sistem pendeteksian UV pada panjang gelombang 230 nm. Komposisi fasa gerak metanol-buffer asetat memberikan hasil yang lebih baik untuk pemisahan natrium sakarin, asam benzoat dan kafein dengan waktu retensi yang lebih pendek.

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Shinkar, Dattatraya M., Pooja S. Aher, Parag D. Kothawade y Avish D. Maru. "FORMULATION AND IN VITRO EVALUATION OF FAST DISSOLVING TABLET OF VERAPAMIL HYDROCHLORIDE". International Journal of Pharmacy and Pharmaceutical Sciences 10, n.º 10 (1 de octubre de 2018): 93. http://dx.doi.org/10.22159/ijpps.2018v10i10.28714.

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Objective: The main objective of this research work was to formulate and evaluate fast dissolving tablet of verapamil hydrochloride for the treatment of hypertension.Methods: In this study, fast dissolving tablet were prepared by wet granulation method by using croscarmellose sodium and sodium starch glycolate as superdisintegrants in the concentration of 2%, 4%, and 6%. Polyvinyl pyrollidone K30 is used as a binder. The designed tablets were subjected to various assessment parameters like friability test, hardness test, disintegration test, wetting time, in vitro drug release and drug content.Results: All the prepared formulations were subjected to various assessment parameters, and the findings obtain within the prescribed limit. The calibration curve of pure drug using various solvents like distilled water, phosphate buffer pH 6.8 was plotted. F1-F9 containing croscarmellose sodium and sodium starch glycolate in various concentration demonstrate the minimum disintegration time. Among all these formulations F8 shows disintegration time upto 19±0.06 seconds due to the high concentration of superdisintegrants. In vitro drug release was tested in phosphate buffer pH 6.8 at a time interval of 0, 1, 3,6,9,12,15 min. The F8 shows drug release 98.5±0.567%. Accelerated stability study of optimized formulation (F8) up to 2 mo showed there was no change in disintegration time and percentage drug release.Conclusion: The results obtained in the research work clearly showed a promising potential of fast dissolving tablets containing a specific ratio of crosscarmellose sodium and sodium starch glycolate as superdisintegrants for the effective treatment of hypertension.

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Zianni, M. R. "Immunogold labeling of phycobilisomes in a cyanobacterium". Proceedings, annual meeting, Electron Microscopy Society of America 47 (6 de agosto de 1989): 1044–45. http://dx.doi.org/10.1017/s0424820100157206.

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Phycobilisomes are pigment-protein complexes that act as the major light- harvesting antenna, in addition to chlorophyll, for photosynthesis in red algae and Cyanobacteria. In vivo, phycobilisomes transfer their energy mainly to the photosystem II reaction center to which they are assumed to be attached. This assumption will be tested by the use of gold labeling of antibodies raised against photosystem II reaction center components to localize the reaction centers and to compare the location of the antibodies with that of the phycobili- somes. In Cyanobacteria phycobi1isomes are difficult to fix particularly under conditions required for immunocytochemistry. Here, two methods for efficient fixation of phycobi1isomes are described, together with immunocytochemical results to confirm the identity of the phycobilisomes.For phycobilisome detection, Synechocvstis sp. PCC 6803 cells were either freeze substituted or fixed in a high molarity buffer followed by cryomicrotomy. For freeze substitution the cells were collected, subjected to ultra-rapid freezing with a slammer device and a copper block at liquid helium temperature, placed in 5% acrolein in ethanol at -85°C for 4 days, and embedded in LR White. For cryo- sectioning the cells were fixed with 1% glutaraldehyde in 0.75M sodium potassium phosphate buffer, pH 7.4, for 2 h, enrobed in 10% gelatin, infused with 1.6M sucrose in 0.1M sodium phosphate buffer,pH 7.2, for 3 h, and frozen in liquid freon. Cryosections were prepared with an RMC CR2000 cryoultramicrotomy unit on an MT-6000 ultramicrotome. In both procedures 0.05% Carnation nonfat dried milk in 0.1M sodium phosphate buffer was used to block nonspecific binding of the anti serum. Sections were treated with rod-phycocyanin (phycobilin protein) anti - serum followed by protein A conjugated to lOnm gold particles. Subsequently the plastic sections were stained with uranyl acetate and lead citrate. The cryosections were subsequently treated with 1% OSO4, 1% tannic acid, uranyl acetate, and alkaline bismuth, dehydrated in ethanol, and embedded in LR White. Sections were observed in a Philips EM201.

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47

Oguma, Kumiko, Kentaro Izaki y Hiroyuki Katayama. "Effects of salinity on photoreactivation of Escherichia coli after UV disinfection". Journal of Water and Health 11, n.º 3 (7 de junio de 2013): 457–64. http://dx.doi.org/10.2166/wh.2013.009.

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The effects of sodium chloride on photoreactivation of Escherichia coli were examined, assuming the discharge of ultraviolet (UV)-treated wastewater to water environment at different salinities. Suspensions of E. coli were first exposed to a low-pressure UV lamp in phosphate buffer to achieve 3 log inactivation, followed by an exposure to fluorescent light in NaCl solutions at the concentration of 1.0, 1.4, 1.9, 2.4 and 2.9 weight/volume %. When photoreactivation was completed in 3 h, survival ratio was recovered about 2 log in 1.0, 1.4, and 1.9% NaCl solutions, which was equivalent to the recovery observed in phosphate-buffered solution. Meanwhile, the recovery was suppressed to 0.8 log and −0.2 log in 2.4 and 2.9% NaCl solutions, respectively, which was significantly less than the recovery in phosphate buffer according to the t-test (p < 0.05). An endonuclease sensitive site assay demonstrated that the suppressed photoreactivation in 2.9% NaCl solution was due to the failure at repairing UV-induced pyrimidine dimers in the genome. In conclusion, photoreactivation of E. coli was significantly suppressed in NaCl solution at 2.4% or higher but not affected in NaCl solution at 1.9% or lower. This implies that photoreactivation of E. coli may potentially occur in brackish and coastal areas where salinity is rather low.

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48

Tynecka, Z. y A. Malm. "Energetics of Cd2+ efflux system in cadmium-resistant Staphylococcus aureus 17810R." Acta Biochimica Polonica 42, n.º 1 (31 de marzo de 1995): 119–23. http://dx.doi.org/10.18388/abp.1995_4678.

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Energetics of 109Cd efflux in resting cells of cadmium-resistant Staphylococcus aureus 17810R was assayed in 1 or 100 mM potassium/sodium phosphate buffer, pH7 (PB). Experiments with the use of inhibitors and ionophores showed that Cd2+ extrusion in this organism required ATP and either a pH gradient (delta pH) in 1 mM PB or membrane potential (delta psi) in 100 mM PB. The role of high phosphate ion concentration in delta psi-dependent Cd2+ efflux is discussed.

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49

Alemayehu, Saba, Daniel J. Fish, Greg P. Brewood, M. Todd Horne, Fidelis Manyanga, Rebekah Dickman, Ian Yates y Albert S. Benight. "Influence of Buffer Species on the Thermodynamics of Short DNA Duplex Melting: Sodium Phosphate versus Sodium Cacodylate†". Journal of Physical Chemistry B 113, n.º 9 (5 de marzo de 2009): 2578–86. http://dx.doi.org/10.1021/jp809310w.

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50

ORTA-RAMIREZ, ALICIA, JOHN E. MERRILL y DENISE M. SMITH. "Sucrose, Sodium Dodecyl Sulfate, Urea, and 2-Mercaptoethanol Affect the Thermal Inactivation of R-Phycoerythrin†". Journal of Food Protection 64, n.º 11 (1 de noviembre de 2001): 1806–11. http://dx.doi.org/10.4315/0362-028x-64.11.1806.

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Thermal inactivation kinetics (D- and z-values) of the algal protein, R-phycoerythrin (R-PE), were studied under different buffer conditions (pH 4.0, 7.0, and 10.0) and concentrations of sucrose, sodium dodecyl sulfate (SDS), urea, and 2-mercaptoethanol (ME). R-PE solutions were heated in capillary tubes at temperatures between 40 and 90°C depending on buffer conditions. Thermal inactivation parameters for R-PE, calculated on the basis of fluorescence loss, were modified by addition of chemicals. Overall, sucrose and ME had a thermostabilizing effect, while SDS and urea decreased thermal stability of R-PE. The z-values ranged from 5.9°C in 50 mM NaCl, 20 mM glycine buffer, pH 10.0, to 37.8°C in 60% sucrose, 50 mM NaCl, 20 mM phosphate buffer, pH 7.0. The z-values obtained for R-PE closely matched the z-values of some target microorganisms in food processes, suggesting R-PE might be used as a time-temperature integrator to verify thermal processing adequacy.

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