Displaying publications 321 - 340 of 1243 in total

Abstract:
Sort:
  1. Gazzali AM, Lobry M, Colombeau L, Acherar S, Azaïs H, Mordon S, et al.
    Eur J Pharm Sci, 2016 Oct 10;93:419-30.
    PMID: 27575880 DOI: 10.1016/j.ejps.2016.08.045
    Folic acid is a small molecule, also known as vitamin B9. It is an essential compound involved in important biochemical processes. It is widely used as a vector for targeted treatment and diagnosis especially in cancer therapeutics. Nevertheless, not many authors address the problem of folic acid degradation. Several researchers reported their observations concerning its denaturation, but they generally only took into account one parameter (pH, temperature, light or O2etc.). In this review, we will focus on five main parameters (assessed individually or in conjunction with one or several others) that have to be taken into account to avoid the degradation of folic acid: light, temperature, concentration, oxygen and pH, which are the most cited in the literature. Scrupulous bibliographic research enabled us to determine two additional degradation factors that are the influence of singlet oxygen and electron beam on folic acid stability, which are not considered as among the prime factors. Although these two factors are not commonly present as compared to the others, singlet oxygen and electron beams intervene in new therapeutic technologies and must be taken in consideration for further applications such photodynamic or X-rays therapies.
    Matched MeSH terms: Hydrogen-Ion Concentration
  2. Appan A
    Environ Monit Assess, 1991 Oct;19(1-3):361-72.
    PMID: 24233953 DOI: 10.1007/BF00401325
    In a case study involving preliminary investigations for the feasibility of a beach resort complex in the west coast of Sarawak, Malaysia, since the acceptable quality of recreational water quality had not been specified, existing international standards and practices were reviewed to arrive at acceptable microbiological and physicochemical parametric levels. Water samples were collected on a weekly basis in the proposed beach complex at Tanjong Batu Coastal Reserve and also along the nearby Sungei Batang Kemena and its estuary. It was ascertained that the swimming water quality was acceptable in terms of faecal Coliforms, temperature, pH and dissolved oxygen. However E. Coli counts did indicate a potential risk of 1.68% for gastrointestinal illness and the ubiquitous presence of faecal Streptococci pointed to recent pollution of human or animal origin. Besides, grease and oil contents exceeded the WHO Guideline values. It was hence recommended that an appropriate sanitation or pollution survey should be carried out in the adjacent coastal catchment area and the beach. Also routine water sampling should be undertaken. Such action will help to pinpoint sources of pollution and lead to antipollution measures, thus helping to upgrade swimming water quality and establish swimming water quality standards.
    Matched MeSH terms: Hydrogen-Ion Concentration
  3. Majidnia Z, Fulazzaky MA
    J Environ Manage, 2017 Apr 15;191:219-227.
    PMID: 28107756 DOI: 10.1016/j.jenvman.2017.01.019
    The presence of Cs(I) ions in nuclear wastewater becomes an important issue for the reason of its high toxicity. The development of adsorbent embedded metal-based catalysts that has sufficient adsorption capacity is expected for the removal of Cs(I) ions from contaminated water. This study tested the use of maghemite, titania and combined maghemite-titania polyvinyl alcohol (PVA)-alginate beads as an adsorbent to remove Cs(I) ions from aqueous solution with the variables of pH and initial concentration using batch experiments under sunlight. The results showed that the use of combined maghemite-titania PVA-alginate beads can have an efficiency of 93.1% better than the use of either maghemite PVA-alginate beads with an efficiency of 91.8% or titania PVA-alginate beads with an efficiency of 90.1%. The experimental data for adsorption of Cs(I) ions from aqueous solution with the initial concentrations of 50, 100 and 200 mg L(-1) on the surface of combined maghemite-titania PVA-alginate beads were well fit by the pseudo-second-order and Langmuir models. The optimal adsorption of Cs(I) ions from aqueous solution by combined maghemite-titania PVA-alginate beads under sunlight occurs at pH 8 with an initial Cs(I) ion concentration of 50 mg L(-1). The combined maghemite-titania PVA-alginate beads can be recycled at least five times with a slight loss of their original properties.
    Matched MeSH terms: Hydrogen-Ion Concentration
  4. Siddiquee S, Shafawati SN, Naher L
    Biotechnol Rep (Amst), 2017 Mar;13:1-7.
    PMID: 28352555 DOI: 10.1016/j.btre.2016.11.001
    Oil palm fibres are easy to degrade, eco-friendly in nature and once composted, they can be categorized under nutrient-enriched biocompost. Biocompost is not only a good biofertilizer but also a good biocontrol agent against soil-borne pathogens. In this research, experimental works on the composting of empty fruit bunches (EFB) from the oil palm industry were conducted using two potential Trichoderma strains. Analysis of pH initially found the soils to be slightly acidic. However, after composting, the soils were found to be alkaline. Trichoderma propagules increased by 72% in the soils compared to other fungi. Soil electrical conductivity was found to be 50.40 μS/cm for compost A, 42.10 μS/cm for compost B and 40.11 μS/cm for the control. The highest C:N ratio was obtained for compost A at 3.33, followed by compost B at 2.79, and then the control at 1.55. The highest percentages of nitrogen (N), phosphorus (P), and potassium (K) were found in compost A (0.91:2.13:6.68), which was followed by compost B (0.46:0.83:5.85) and then the control (0.32:0.26:5.76). Thus, the biocomposting of oil palm fibres shows great potential for enhancing soil micronutrient, plant growth performance, and crop yield production.
    Matched MeSH terms: Hydrogen-Ion Concentration
  5. Hafshejani MK, Ogugbue CJ, Morad N
    3 Biotech, 2014 Dec;4(6):605-619.
    PMID: 28324306 DOI: 10.1007/s13205-013-0192-7
    The decolorization and degradation of Direct Blue 71 were investigated using a mono culture of Pseudomonas aeruginosa. The bacterium was able to decolorize the dye medium to 70.43 % within 48 h under microaerophilic conditions. The medium was then aerated for 24 h to promote the biodegradation of the aromatic amines generated from azo bond cleavage. Reduction in total organic carbon in dye medium was 42.58 % in the microaerophilic stage and 78.39 % in the aerobic stage. The degradation metabolites formed were studied using UV-vis techniques, high performance liquid chromatography, Fourier transform infra red spectroscopy and nuclear magnetic resonance spectroscopy analysis. Data obtained provide evidence for the formation of aromatic amines and their subsequent oxidative biodegradation by a single strain of P. aeruginosa during successive microaerophilic/aerobic stages in the same flask. The influence of incubation temperature (20-45 °C), medium pH (5-10) and initial dye concentration (25-150 mg/L) on decolorization was evaluated to greatly influence decolorization extent. The optimal decolorization conditions were determined by response surface methodology based on three-variable central composite design to obtain maximum decolorization and to determine the significance and interaction effect of the variables on decolorization. The optimal conditions of response were found to be 35.15 °C, pH 8.01 and 49.95 mg/L dye concentration giving an experimental decolorization value of 84.80 %. Very high regression coefficient between the variables and the response (R(2) = 0.9624) indicated a good evaluation of experimental data by polynomial regression model.
    Matched MeSH terms: Hydrogen-Ion Concentration
  6. Affandi MMRMM, Tripathy M, Majeed ABA
    Curr Drug Deliv, 2018;15(1):77-86.
    PMID: 28322162 DOI: 10.2174/1567201814666170320144259
    BACKGROUND: Categorized as a Biopharmaceutics Classification System (BCS) Class II drugs, statin exhibit low aqueous solubility and bioavailability thus presenting an obstacle and great challenge to formulation researchers. This paper describes a de novo approach to enhance the aqueous solubility of one of the most commonly prescribed statins i.e., simvastatin (SMV) by forming a complex (SMV-ARG) with cosolute arginine (ARG).

    METHODS: The complex has been characterized for its apparent solubility and in vitro dissolution. The solid state characterization has been carried out using Fourier Transform Infra-Red (FTIR) Spectroscopy, Elemental Analysis, X-Ray Powder Diffraction (XRD), Differential Scanning Calorimetry (DSC) analysis, Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM).

    RESULTS: Simvastatin-Arginine (SMV-ARG) complex exhibited massive solubility enhancement by 12,000 fold and significant improvement in both acidic and alkaline dissolution media. A conversion of coherent crystalline to non-coherent pattern, and certain extent of amorphization in SMV-ARG complex, fully justifies the enhanced solubility, and hence the dissolution profile.

    CONCLUSION: The present study provides a significant evidence that ARG molecules are capable to form a complex with small molecules and increase their aqueous solubility which prove to be beneficial in drug formulation and development.

    Matched MeSH terms: Hydrogen-Ion Concentration
  7. Lambert DM
    J Hered, 1976 3 1;67(2):92-8.
    PMID: 5483
    The salivary chromosomes of four species of the nasuta complex of Drosophila, D. sulfurigaster albostrigata, D, kohkoa, D. albomicans, and D. kepulauana were studied and chromosome maps of each species are presented; the maps of the latter three species are based on the map of D. sulfurigaster albostrigata. Three of the species D. sulfurigaster albostrigata, D. albomicans, and D. kohkoa were shown to be highly polymorphic for chromosomal inversions while the available evidence indicated that D. kepulauana is much less polymorphic. These facts are correlated with the geographic distribution of the species. Transitional homoselection has not been complete in the evolution of three of the species since D. sulfurigaster albostrigata, D. kohkoa, and D. albomicans have a number of naturally occurring polymorphisms in common.
    Matched MeSH terms: Hydrogen-Ion Concentration
  8. Welch QB, Lie-Injo LE
    Hum Hered, 1972;22(5):503-7.
    PMID: 4670071
    Matched MeSH terms: Hydrogen-Ion Concentration
  9. Lie-Injo LE
    Med J Malaya, 1972 Dec;27(2):120-4.
    PMID: 4268037
    Matched MeSH terms: Hydrogen-Ion Concentration
  10. Latip W, Raja Abd Rahman RNZ, Chor Leow AT, Mohd Shariff F, Mohamad Ali MS
    PeerJ, 2016;4:e2420.
    PMID: 27781152 DOI: 10.7717/peerj.2420
    A gene encoding a thermotolerant lipase with broad pH was isolated from an Antarctic Pseudomonas strain AMS3. The recombinant lipase AMS3 was purified by single-step purification using affinity chromatography, yielding a purification fold of approximately 1.52 and a recovery of 50%. The molecular weight was approximately ∼60 kDa including the strep and affinity tags. Interestingly, the purified Antarctic AMS3 lipase exhibited broad temperature profile from 10-70 °C and stable over a broad pH range from 5.0 to pH 10.0. Various mono and divalent metal ions increased the activity of the AMS3 lipase, but Ni(2+) decreased its activity. The purified lipase exhibited the highest activity in the presence of sunflower oil. In addition, the enzyme activity in 25% v/v solvents at 50 °C particularly to n-hexane, DMSO and methanol could be useful for catalysis reaction in organic solvent and at broad temperature.
    Matched MeSH terms: Hydrogen-Ion Concentration
  11. Zainal MA, Ahmad A, Mohamed Ali MS
    Biomed Microdevices, 2017 Mar;19(1):8.
    PMID: 28124762 DOI: 10.1007/s10544-017-0148-5
    This paper reports the wireless Shape-Memory-Polymer actuator operated by external radio frequency magnetic fields and its application in a drug delivery device. The actuator is driven by a frequency-sensitive wireless resonant heater which is bonded directly to the Shape-Memory-Polymer and is activated only when the field frequency is tuned to the resonant frequency of heater. The heater is fabricated using a double-sided Cu-clad Polyimide with much simpler fabrication steps compared to previously reported methods. The actuation range of 140 μm as the tip opening distance is achieved at device temperature 44 °C in 30 s using 0.05 W RF power. A repeatability test shows that the actuator's average maximum displacement is 110 μm and standard deviation of 12 μm. An experiment is conducted to demonstrate drug release with 5 μL of an acidic solution loaded in the reservoir and the device is immersed in DI water. The actuator is successfully operated in water through wireless activation. The acidic solution is released and diffused in water with an average release rate of 0.172 μL/min.
    Matched MeSH terms: Hydrogen-Ion Concentration
  12. Prakash I, Markosyan A, Bunders C
    Foods, 2014 Feb 27;3(1):162-175.
    PMID: 28234311 DOI: 10.3390/foods3010162
    This work aims to review and showcase the unique properties of rebaudioside M as a natural non-caloric potential sweetener in food and beverage products. To determine the potential of rebaudioside M, isolated from Stevia rebaudiana Bertoni, as a high potency sweetener, we examined it with the Beidler Model. This model estimated that rebaudioside M is 200-350 times more potent than sucrose. Numerous sensory evaluations of rebaudioside M's taste attributes illustrated that this steviol glycoside possesses a clean, sweet taste with a slightly bitter or licorice aftertaste. The major reaction pathways in aqueous solutions (pH 2-8) for rebaudioside M are similar to rebaudioside A. Herein we demonstrate that rebaudioside M could be of great interest to the global food industry because it is well-suited for blending and is functional in a wide variety of food and beverage products.
    Matched MeSH terms: Hydrogen-Ion Concentration
  13. Ilowefah M, Chinma C, Bakar J, Ghazali HM, Muhammad K, Makeri M
    Foods, 2014 Feb 12;3(1):149-159.
    PMID: 28234309 DOI: 10.3390/foods3010149
    As fermentation could reduce the negative effects of bran on final cereal products, the utilization of whole-cereal flour is recommended, such as brown rice flour as a functional food ingredient. Therefore, this study aimed to investigate the effect of fermented brown rice flour on white rice flour, white rice batter and its steamed bread qualities. Brown rice batter was fermented using commercial baker's yeast (Eagle brand) according to the optimum conditions for moderate acidity (pH 5.5) to obtain fermented brown rice flour (FBRF). The FBRF was added to white rice flour at 0%, 10%, 20%, 30%, 40% and 50% levels to prepare steamed rice bread. Based on the sensory evaluation test, steamed rice bread containing 40% FBRF had the highest overall acceptability score. Thus, pasting properties of the composite rice flour, rheological properties of its batter, volume and texture properties of its steamed bread were determined. The results showed that peak viscosity of the rice flour containing 40% FBRF was significantly increased, whereas its breakdown, final viscosity and setback significantly decreased. Viscous, elastic and complex moduli of the batter having 40% FBRF were also significantly reduced. However, volume, specific volume, chewiness, resilience and cohesiveness of its steamed bread were significantly increased, while hardness and springiness significantly reduced in comparison to the control. These results established the effectiveness of yeast fermentation in reducing the detrimental effects of bran on the sensory properties of steamed white rice bread and encourage the usage of brown rice flour to enhance the quality of rice products.
    Matched MeSH terms: Hydrogen-Ion Concentration
  14. Aziz HA, Othman N, Yusuff MS, Basri DR, Ashaari FA, Adlan MN, et al.
    Environ Int, 2001 May;26(5-6):395-9.
    PMID: 11392757
    This paper discusses heavy metal removal from wastewater by batch study and filtration technique through low-cost coarse media. Batch study has indicated that more than 90% copper (Cu) with concentration up to 50 mg/l could be removed from the solution with limestone quantity above 20 ml (equivalent to 56 g), which indicates the importance of limestone media in the removal process. This indicates that the removal of Cu is influenced by the media and not solely by the pH. Batch experiments using limestone and activated carbon indicate that both limestone and activated carbon had similar metal-removal efficiency (about 95%). Results of the laboratory-scale filtration technique using limestone particles indicated that above 90% removal of Cu was achieved at retention time of 2.31 h, surface-loading rate of 4.07 m3/m2 per day and Cu loading of 0.02 kg/m3 per day. Analyses of the limestone media after filtration indicated that adsorption and absorption processes were among the mechanisms involved in the removal processes. This study indicated that limestone can be used as an alternative to replace activated carbon.
    Matched MeSH terms: Hydrogen-Ion Concentration
  15. Mashitah, Zulfadhly Z, Bhatia S
    Artif Cells Blood Substit Immobil Biotechnol, 1999 Sep-Nov;27(5-6):429-33.
    PMID: 10595444
    The equilibrium sorption capacity of a macro-fungi, Pycnoporus sanguineus biomass was studied using a single-metal system comprising copper ions. The rate and extent for the removal of copper were subjected to environmental parameters such as pH, biomass loading, temperature, and contact time. Results showed that the uptake of copper increased as the pH increased. However, as the biomass loading increased, the amount of metal uptake decreased. Instead, temperature does not have a significant effect on the metal uptake, especially between 30 to 40 degrees C. A maximum adsorption of copper ions was also observed within 15 minutes of reaction time for the entire sample tested. Furthermore, pre-treatment with sodium bicarbonate and boiling water significantly improved the sorption capacity of copper by Pycnoporus sanguineus.
    Matched MeSH terms: Hydrogen-Ion Concentration
  16. Mohd Suhaimi NI, Mat Ropi AA, Shaharuddin S
    Heliyon, 2021 Feb;7(2):e06279.
    PMID: 33681497 DOI: 10.1016/j.heliyon.2021.e06279
    The demand for fresh, safe, and healthy fruits by consumers has increased, which concurrently occurs with an increase in initiatives on reducing food wastage. Starfruit consists of good nutrition and valuable sensory attributes, but its shelf life is short and can only be preseved for a few days at ambient storage. This research was conducted to determine the effectiveness of synergistic edible coatings (pectin [Pe] and maltodextrin [M] and 100, 200, and 300 ppm of sodium chloride [SC]) on the quality and safety criterion of starfruits throughout a shelf life analysis of 14 days at ambient temperature. Consumer acceptability of the edible-coated starfruit was also evaluated. The coating process was performed using a dipping method. The uncoated (control) and coated samples were evaluated for the characteristics of weight, pH, total soluble solids (TSS), water activity, color, texture, microbial growth, FTIR, and sensory evaluation. From the results, the starfruit coated with Pe + M + 100 ppm SC had a significantly lower weight-loss trend compared to the other samples. On day 14, pH of the coated starfruits were 3.02, 3.14, and 3.31 for 100, 200, and 300 ppm of SC, respectively, were found to be significantly different (p < 0.05) from the control (pH 3.49). The control had a significantly higher value of total soluble solids (6.00 ⁰Brix) compared to the coated starfruits (6.00, 5.47, and 5.33 ⁰Brix, respectively). The coated samples have significantly higher values of firmness than control especially in initial days of storage. It was observed that Pe + M + 100 ppm SC could minimize the spoilage of fruits by reducing the growth of yeast and mold, as well as bacteria, up to 0.86 and 2.02 log CFU/ml, respectively. FTIR results confirmed the presence of the coating on the starfruit. In the sensory evaluation, no significance different (p > 0.05) were obtained for all the sensory attributes and overall acceptability for day 0 and 3. In conclusion, starfruit coated with synergistic Pe + M + 100 ppm SC appeared to be the best sample in extending its shelf life and maintaining the physicochemical characteristics of starfruits up to more than 14 days.
    Matched MeSH terms: Hydrogen-Ion Concentration
  17. Zainon SNM, Azmi WH
    Micromachines (Basel), 2021 Feb 11;12(2).
    PMID: 33670250 DOI: 10.3390/mi12020176
    Many studies have shown the remarkable enhancement of thermo-physical properties with the addition of a small quantity of nanoparticles into conventional fluids. However, the long-term stability of the nanofluids, which plays a significant role in enhancing these properties, is hard to achieve, thus limiting the performance of the heat transfer fluids in practical applications. The present paper attempts to highlight various approaches used by researchers in improving and evaluating the stability of thermal fluids and thoroughly explores various factors that contribute to the enhancement of the thermo-physical properties of mono, hybrid, and green nanofluids. There are various methods to maintain the stability of nanofluids, but this paper particularly focuses on the sonication process, pH modification, and the use of surfactant. In addition, the common techniques to evaluate the stability of nanofluids are undertaken by using visual observation, TEM, FESEM, XRD, zeta potential analysis, and UV-Vis spectroscopy. Prior investigations revealed that the type of nanoparticle, particle volume concentration, size and shape of particles, temperature, and base fluids highly influence the thermo-physical properties of nanofluids. In conclusion, this paper summarized the findings and strategies to enhance the stability and factors affecting the thermal conductivity and dynamic viscosity of mono and hybrid of nanofluids towards green nanofluids.
    Matched MeSH terms: Hydrogen-Ion Concentration
  18. Nawawi MH, Mohamad R, Tahir PM, Asa'ari AZ, Saad WZ
    Molecules, 2021 Jul 14;26(14).
    PMID: 34299554 DOI: 10.3390/molecules26144279
    The present work reports the biobleaching effect on OPEFB pulp upon utilisation of extracellular xylano-pectinolytic enzymes simultaneously yielded from Bacillus amyloliquefaciens ADI2. The impacts of different doses, retention times, pH, and temperatures required for the pulp biobleaching process were delineated accordingly. Here, the OPEFB pulp was subjected to pre-treatment with xylano-pectinolytic enzymes generated from the same alkalo-thermotolerant isolate that yielded those of higher quality. Remarkable enhanced outcomes were observed across varying pulp attributes: for example, enzyme-treated pulp treated to chemical bleaching sequence generated improved brightness of 11.25%. This resulted in 11.25% of less chlorine or chemical consumption required for obtaining pulp with optical attributes identical to those generated via typical chemical bleaching processes. Ultimately, the reduced consumption of chlorine would minimise the organochlorine compounds found in an effluent, resulting in a lowered environmental effect of paper-making processes overall as a consequence. This will undoubtedly facilitate such environmentally-friendly technology incorporation in the paper pulp industry of today.
    Matched MeSH terms: Hydrogen-Ion Concentration
  19. Sutirman ZA, Sanagi MM, Wan Aini WI
    Int J Biol Macromol, 2021 Mar 31;174:216-228.
    PMID: 33516856 DOI: 10.1016/j.ijbiomac.2021.01.150
    The presence of heavy metal and radionuclides in water bodies has been a long-lasting environmental problem which results in many undesirable consequences. In this framework, the biosorption process, which uses inexpensive and naturally produced material such as alginate, is an alternative technology in the environmental remediation. This review provides relevant and recent literature regarding the application of alginate and its derivatives on removal of various heavy metal ions and radionuclides. The effects of process variables such as solution pH, adsorbent dosage, metal ion concentration, contact time, temperature and co-existing ions used in batch studies in addition to kinetic, isothermal models as well as thermodynamic that fit the adsorption experimental data are critically discussed. This review also includes mechanisms involved during adsorption process. Furthermore, future research needs for the removal of contaminants by alginate-based materials with the aims of improving their adsorption performance and their practical applications are commented.
    Matched MeSH terms: Hydrogen-Ion Concentration
  20. Abdul Kadir NP, Ma ZF, Abdul Hafidz MI, Annamalai C, Jayaraman T, Hamid N, et al.
    Front Med (Lausanne), 2021;8:605647.
    PMID: 33659261 DOI: 10.3389/fmed.2021.605647
    Background: Non-cardiac chest pain is common with two-thirds due to gastroesophageal reflux disease (GERD). Objective: To evaluate the effectiveness and safety of guided vs. empirical therapy in non-cardiac chest pain. Methods: Adults with normal angiogram or stress test were randomized into either a guided or empirical group. In the guided group, after the ambulatory pH-impedance test, if GERD then dexlansoprazole 30 mg/day for 8 weeks, but if functional or hypersensitive chest pain, then theophylline SR 250 mg/day for 4 weeks. In the empirical group, dexlansoprazole 60 mg/day was given for 2 weeks. The primary outcome was global chest pain visual analog score (VAS) and secondary outcomes were Quality of Life in Reflux and Dyspepsia (QOLRAD), GERD questionnaire (GERDQ), and pH parameters, all determined at baseline, 2nd and 8th weeks. Results: Of 200 screened patients, 132 were excluded, and of 68 randomized per-protocol, 33 were in the guided group and 35 in the empirical group. For between-group analysis, mean global pain scores were better with guided vs. empirical group at 8th week (P = 0.005) but not GERDQ or QOLRAD or any of pH measures (all P > 0.05). For within-group analysis, mean QOLRAD improved earliest at 8th week vs. baseline (P = 0.006) in the guided group and 2nd week vs. baseline (P = 0.011) in the empirical group but no differences were seen in other secondary outcomes (P > 0.05). No serious adverse events were reported. Conclusions: Guided approach may be preferred over short-term empirical therapy in symptom response, however QOLRAD, acid-related symptoms, or pH measures are not significantly different (trial registration ID no. NCT03319121).
    Matched MeSH terms: Hydrogen-Ion Concentration
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links