Journal articles: 'Environmental pH'

1

KOBAYASHI, Hiroshi. "Bacterial Adaptation to Change in Environmental pH." Nippon Saikingaku Zasshi 51, no. 3 (1996): 745–53. http://dx.doi.org/10.3412/jsb.51.745.

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2

Gustafsson, T. K., and K. V. Waller. "Myths about pH and pH control." AIChE Journal 32, no. 2 (February 1986): 335–37. http://dx.doi.org/10.1002/aic.690320226.

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Tsai, Huei-Hsuan, and Wolfgang Schmidt. "The enigma of environmental pH sensing in plants." Nature Plants 7, no. 2 (February 2021): 106–15. http://dx.doi.org/10.1038/s41477-020-00831-8.

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Bila, T. A., E. V. Lyashenko, and O. V. Okhrimenko. "POTENTIOMETRIC METHOD OF NATURAL ENVIRONMENTAL WATERS PH DETERMINATION." Water bioresources and aquaculture, no. 1 (2021): 228–34. http://dx.doi.org/10.32851/wba.2021.1.17.

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Romanenko, Sergey, Timofey Radenkov, Egor Newsky, and Artur Kagirov. "Differential Sensor for PH Monitoring of Environmental Objects." MATEC Web of Conferences 79 (2016): 01008. http://dx.doi.org/10.1051/matecconf/20167901008.

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Barzaghi, C., T. W. K. Kok, S. F. Chew, J. M. Wilson, T. J. Lam, D. J. Randall, and Y. K. Ip. "Mudskippers detoxify ammonia externally by manipulating environmental pH." Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 126 (July 2000): S9. http://dx.doi.org/10.1016/s0305-0491(00)80017-6.

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Arayici, Semiha, Resat Apak, and Vildan Apak. "Equilibrium modeling of ph in environmental treatment processes." Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology 31, no. 5 (May 1996): 1127–34. http://dx.doi.org/10.1080/10934529609376412.

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Esquivel-Upshaw, Josephine F., Shu-Min Hsu, Fan Ren, Jenna Stephany, Xinyi Xia, Chan-Wen Chiu, Dan Neal, and John J. Mecholsky. "Fracture of Lithia Disilicate Ceramics under Different Environmental Conditions." Materials 15, no. 15 (July 29, 2022): 5261. http://dx.doi.org/10.3390/ma15155261.

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The objective of this research was to quantify the effect of surface degradation and abrasion separately and in combination on the flexural strength of lithia disilicate ceramics. Lithia disilicate disks were fabricated using the lost wax technique and pressing in vacuum. The eight groups in this pilot experiment were (i) reference, hydrated in distilled water for 24 h prior to fracture; (ii) reference, non-hydrated group; (iii) 28-day pH cycling group; (iv) 125K chewing cycle group; (v) combined pH cycling + 125K chewing cycle; (vi) constant pH 2 solution for 28 days; (vii) constant pH 7 solution for 28 days; and (viii) constant pH 10 solution for 28 days. pH cycling is a method that alternates between pH 2, 7 and 10 over 28 days. A total of 15 disks were used for each group. All the groups were tested using the biaxial piston and a three-ball flexural strength test to obtain their biaxial flexural strength. pH 2 constant immersion demonstrated the highest fracture strength and was significantly greater than all other groups (p < 0.0001). Chewing and pH cycling + chewing groups exhibited the lowest fracture strengths and were significantly lower than all other groups (p < 0.0001). The damage observed from the chewing simulator does not represent apparent clinical fractures.

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Okano, Kunihiro, Kazuya Shimizu, Yukio Kawauchi, Hideaki Maseda, Motoo Utsumi, Zhenya Zhang, Brett A. Neilan, and Norio Sugiura. "Characteristics of a Microcystin-Degrading Bacterium under Alkaline Environmental Conditions." Journal of Toxicology 2009 (2009): 1–8. http://dx.doi.org/10.1155/2009/954291.

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The pH of the water associated with toxic blooms of cyanobacteria is typically in the alkaline range; however, previously only microcystin-degrading bacteria growing in neutral pH conditions have been isolated. Therefore, we sought to isolate and characterize an alkali-tolerant microcystin-degrading bacterium from a water bloom using microcystin-LR. Analysis of the 16S rRNA gene sequence revealed that the isolated bacterium belonged to the genusSphingopyxis, and the strain was named C-1.Sphingopyxissp. C-1 can grow; at pH 11.0; however, the optimum pH for growth was pH 7.0. The microcystin degradation activity of the bacterium was the greatest between pH 6.52 and pH 8.45 but was also detected at pH 10.0. ThemlrAhomolog encoding the microcystin-degrading enzyme in the C-1 strain was conserved. We concluded that alkali-tolerant microcystin-degrading bacterium played a key role in triggering the rapid degradation of microcystin, leading to the disappearance of toxic water blooms in aquatic environments.

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Yang, Wu, Guang Fu Li, Hao Guo, Jian Jiang Zhou, Chun Bo Huang, and Jiasheng Bai. "Effects of Environmental Factors on Stress Corrosion Cracking of Pipeline Steels." Key Engineering Materials 297-300 (November 2005): 939–44. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.939.

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Effects of some environmental factors on stress corrosion cracking (SCC) of pipeline steel X-70 both in near-neutral pH environments, including NS4 solution and several solutions containing main types of soil in the eastern part of China, and in high pH solution were studied by means of electrochemical measurement and slow strain rate testing (SSRT). The anodic polarization curves showed different features in near-neutral pH and high pH solutions in terms of active-passive transition behavior. In near-neutral pH solutions, the cracking mode was transgranular with the feature of quasi-cleavage, the susceptibility to SCC increased with decreasing potential, pH and temperature as well as increasing CO2, indicating a dominant mechanism of hydrogen induced cracking (HIC). In high pH solutions, the cracking behavior was similar to that in near-neutral pH solutions when the specimens were polarized at cathodic potentials, but quite different at anodic potentials. A comparison of the electrochemical behavior with the SCC potential region indicated a dominant SCC mechanism associated with anodic dissolution (AD) of X70 in high pH solution at anodic potentials. A preliminary experimental potential (E)-pH-SCC diagram has been established for X70 in near-neutral pH environments.

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Li, Wenjie, Ying Zhou, Chunyu Shang, Hui Sang, and Hong Zhu. "Effects of Environmental pH on the Growth of Gastric Cancer Cells." Gastroenterology Research and Practice 2020 (March 9, 2020): 1–10. http://dx.doi.org/10.1155/2020/3245359.

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Background. Proton pump inhibitor (PPI) and other acid-suppressing drugs are widely used in the treatment of gastrointestinal ulcer, upper gastrointestinal bleeding, gastritis, and gastric cancer (GC). About 80% of GC patients receive acid suppression treatment. PPI suppresses the production of gastric acid by inhibiting the function of H+/K+-ATPase in gastric parietal cells and raises the pH value to achieve therapeutic purposes. Some studies have found that PPI had a certain antitumor effect in the proliferation and apoptosis of tumor cells. But the effects of environmental pH on the growth of GC cells and its mechanism are unknown. Therefore, we hoped to find the effects of culture medium pH on the biological behavior of GC cells by in vitro experiments and provide guidance for the use of acid-suppressing drugs in GC patients. Aims. We aimed to observe the effects of pH changes in GC cell culture medium on the cell biological behavior of cancer cells and to analyze the potential mechanisms. We hoped to find out the effect of acid suppression on the growth of GC cells. Methods. The GC cell lines (SGC-7901 and MKN45) were used as the research object. We adjusted the pH value in the cell culture medium to observe the changes in cell viability (MTT), apoptosis (flow cytometry), and invasion (Transwell) at pH 6, pH 7, and pH 8. qRT-PCR and western blot (WB) assays were used to determine the expression changes of genes and proteins (mTOR, AKT, Wnt, Glut, and HIF-1α) at pH 6, pH 7, and pH 8. Results. The results of MTT showed that the viability of SGC-7901 and MKN45 in the pH 8.0 group was significantly weaker than that in the pH 6.0 or pH 7.0 group (P<0.001). Flow cytometry results showed that the apoptosis of SGC-7901 and MKN45 in the pH 8.0 group was more obvious than that in the pH 6.0 or pH 7.0 group (P<0.001). The results of Transwell showed that the invasion ability of SGC-7901 and MKN45 in the pH 8.0 group was significantly weaker than that in the pH 6.0 or pH 7.0 group (P<0.001). As shown by PCR and WB results, with the increase of pH, the expression of mTOR, AKT, Wnt, Glut, and HIF-1α in SGC-7901 and MKN45 was downregulated (P<0.05). Conclusions. Compared with the microacid environment, the microalkaline environment inhibited the viability, invasion, and expression of genes and proteins (mTOR, AKT, Wnt, Glut, and HIF-1α) but promoted the apoptosis of GC cells and thus inhibited the growth of GC.

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Zhang, Liqiang, Fengyu Su, Xiangxing Kong, Fred Lee, Kevin Day, Weimin Gao, Mary E. Vecera, et al. "Ratiometric fluorescent pH-sensitive polymers for high-throughput monitoring of extracellular pH." RSC Advances 6, no. 52 (2016): 46134–42. http://dx.doi.org/10.1039/c6ra06468j.

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A polymeric water-soluble extracellular pH sensor is developed with fluorescence ratiometric and cell membrane impermeable characters. The pH sensor enables us to exclusively detect the environmental pH of cells in real time.

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Kataoka, Chihiro, Teppei Sugimoto, Shunta Shigemura, Kota Katayama, Satoshi P. Tsunoda, Keiichi Inoue, Oded Béjà, and Hideki Kandori. "TAT Rhodopsin Is an Ultraviolet-Dependent Environmental pH Sensor." Biochemistry 60, no. 12 (March 15, 2021): 899–907. http://dx.doi.org/10.1021/acs.biochem.0c00951.

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Wu, Hong, Yong Yin, Xiaobo Hu, Cheng Peng, Yong Liu, Qingxiang Li, Weidong Huang, and Qianli Huang. "Effects of Environmental pH on Macrophage Polarization and Osteoimmunomodulation." ACS Biomaterials Science & Engineering 5, no. 10 (September 24, 2019): 5548–57. http://dx.doi.org/10.1021/acsbiomaterials.9b01181.

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Du, Han, and Guanghua Huang. "Environmental pH adaption and morphological transitions in Candida albicans." Current Genetics 62, no. 2 (November 18, 2015): 283–86. http://dx.doi.org/10.1007/s00294-015-0540-8.

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Kang, Han Chang, Olga Samsonova, Sun-Woong Kang, and You Han Bae. "The effect of environmental pH on polymeric transfection efficiency." Biomaterials 33, no. 5 (February 2012): 1651–62. http://dx.doi.org/10.1016/j.biomaterials.2011.11.006.

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17

Grapentine, Lee C., and David M. Rosenberg. "Responses of the Freshwater Amphipod Hyalella azteca to Environmental Acidification." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 1 (January 1, 1992): 52–64. http://dx.doi.org/10.1139/f92-006.

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Effects of acidification on the freshwater amphipod Hyalella azteca were investigated by examining the role of pH on natural distribution of the species in 30 northwestern Ontario lakes and by determining its responses to acidification in a series of field and laboratory experiments. The amphipod was absent from all five lakes that had pH 5.03–5.40 or Ca concentration < 1.24 mg/L and was present in 23 of the 25 remaining lakes that had pH > 6.0 and Ca > 1.24 mg/L. In the field and laboratory experiments, amphipods transplanted to acidified lakes (pH 5.45, 5.66) or held in 500-L bags [Formula: see text] or 4-L aquaria [Formula: see text] showed lower survival than those held in corresponding neutral-pH, control treatments (P < 0.05). Neonate H. azteca were less tolerant of low pH than those in later life-history stages (P < 0.05). Populations of H. azteca will decline in habitats where the pH remains < 5.8, a condition extant in a substantial proportion of lakes in eastern North America.

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Boström, Marja Lena, and Olof Berglund. "Influence of pH-dependent aquatic toxicity of ionizable pharmaceuticals on risk assessments over environmental pH ranges." Water Research 72 (April 2015): 154–61. http://dx.doi.org/10.1016/j.watres.2014.08.040.

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Draffehn, Sören, and Michael U. Kumke. "Monitoring the Collapse of pH-Sensitive Liposomal Nanocarriers and Environmental pH Simultaneously: A Fluorescence-Based Approach." Molecular Pharmaceutics 13, no. 5 (April 14, 2016): 1608–17. http://dx.doi.org/10.1021/acs.molpharmaceut.6b00064.

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Mauro, Nicholas A., and Gregory W. Moore. "Effects of environmental pH on ammonia excretion, blood pH, and oxygen uptake in fresh water crustaceans." Comparative Biochemistry and Physiology Part C: Comparative Pharmacology 87, no. 1 (January 1987): 1–3. http://dx.doi.org/10.1016/0742-8413(87)90169-1.

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Smith, Eldon A., Susan L. Prues, and Frederick W. Oehme. "Environmental Degradation of Polyacrylamides. 1. Effects of Artificial Environmental Conditions: Temperature, Light, and pH." Ecotoxicology and Environmental Safety 35, no. 2 (November 1996): 121–35. http://dx.doi.org/10.1006/eesa.1996.0091.

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Kamel, Nariman H. M. "The Behaviour of134Cs,60Co, and85Sr Radionuclides in Marine Environmental Sediment." Scientific World JOURNAL 2 (2002): 1514–26. http://dx.doi.org/10.1100/tsw.2002.290.

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This work describes experimental investigations and modelling studies on the sorption of radionuclides134Cs,60Co, and85Sr by certain marine sediments within Egypt. The chemical composition of the marine sediments was determined. The soluble salts were measured for the sediments and the concentrations of the released cations, Al3+, Fe3+, and Si4+, were measured for the sediment materials in 0.1 M NaClO4aqueous solution at different hydrogen ion concentrations. The two main factors that control the uptake of the radionuclides onto the sediment are the pH and the exchangeable capacities of the sediment materials. Surface complex model was used to estimate the surface charge densities and the electric surface potential of the marine sediment materials. These two parameters were calculated at the surface capacity sites of the sediment materials. The desorption of the adsorbed cations was determined by means of selective consecutive extraction tests using different chemical reagents including (1) 1 M MgCl2(pH 7), (2) 1 M ammonium oxalate (pH 3-5), (3) 0.04 M NH2OH,HCl in 25% acetic acid (pH 3-4), (4) H2O2in 5% HNO3(pH 2-3), and (5) digestion with nitric acid followed by hydrofluoric and perchloric acids (pH 2).

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Nakata, T., W. Berard, E. Kogosov, and N. Alexander. "Cardiovascular change and hypothalamic norepinephrine release in response to environmental stress." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 264, no. 4 (April 1, 1993): R784—R789. http://dx.doi.org/10.1152/ajpregu.1993.264.4.r784.

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The major objective of this study was to compare the magnitude and duration of cardiovascular (CV) responses to acute environmental stresses with the associated patterns of noradrenergic activity in the paraventricular nucleus (PVN) and posterior nucleus (PH) of the hypothalamus. Simultaneous microdialysis samples of extracellular norepinephrine (NE) were collected at 5-min intervals from PVN and PH and the CV responses were recorded before, during, and for 15 min after acute shaker (cage oscillation) stress or inhalation of ether vapor in freely moving rats. Five minutes of shaker stress, 60 and 150 cycles/min, elicited pressor responses coupled with increases in dialysate NE from both PVN and PH in a frequency-dependent manner. Tachycardia occurred at 150 but not 60 cycles/min. Ten minutes after 60 cycles/min and 15 min after 150 cycles/min, NE efflux in PH was still increased, whereas in PVN it returned to control as had arterial pressure and heart rate. Ether vapor elicited a transient CV response but a continuing efflux of NE in PH and PVN. Urethan anesthesia raised baseline values of dialysate NE in PH and PVN but significantly attenuated cardiovascular and dialysate NE responses to shaker stress. We conclude that acute environmental stress simultaneously elicits CV responses and the efflux of NE from PVN and PH but, during or after stress, CV values may return to control levels while NE efflux remains elevated in PVN and/or PH.

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Li, Ang, and Li Na Sun. "The Change of Environmental in Sewage Sludge Compost." Applied Mechanics and Materials 733 (February 2015): 334–37. http://dx.doi.org/10.4028/www.scientific.net/amm.733.334.

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By aerobic composting bin type of sewage treatment plant sludge composting, through periodic sampling, research composting process temperature, moisture content, PH value changes and study the changes in compost maturity parameters of the DH. The results show that the compost temperature increased rapidly in the early rise in the first two days when fast to 50 degrees Celsius, in the tenth day decreased to room temperature; moisture content than the original sludge reduced by 40 percent to compost indicators; PH by reaction initial 6.2, and gradually becomes neutral and alkaline 7.8 biased. Experiments show that after aerobic sludge composting in temperature, moisture content, PH value terms have been reached sludge disposal requirements.

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Yanez-Pizana, A., D. Mota-Rojas, M. Castillo-Rivera, R. Rampirez-Necoechea, I. Guerrero-Legarreta, P. Mora-Medina, and M. Gonzalez-Lozano. "Effect of environmental enrichment on weaned piglets: physiological responses." Veterinární Medicína 64, No. 5 (May 28, 2019): 217–27. http://dx.doi.org/10.17221/104/2018-vetmed.

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The aim of this research consisted in assessing the effect of various kinds of environmental enrichment (EE) on the physiological responses of weaned piglets. The mean age of the 96 piglets that participated was 27 days. The piglets were weaned and then housed under two conditions: with no disruption of the social order (SO), and with disruption of the social order (DSO). After establishing the two experimental conditions, we proceeded to evaluate four different treatments; namely, control (C), suspended ropes (SR), aromatized bottles (AB) and pet toys and balls (PTB). The protocol required drawing three blood samples: at 30 (T30), 60 (T60) and 90 min (T90) after weaning. The DSO piglets had higher pH and haematocrit levels than those weaned in the SO condition (P < 0.05). Also, pCO2, potassium (K+) and base excess (BE) concentrations were higher in the SO animals than in those in the DSO group (P < 0.05). The control piglets, which did not receive any type of EE, showed higher pCO2 levels, but lower glucose and pH (P < 0.05) values, while the ones enriched with SR had increased lactate levels, but lower values for pH and HCO3– compared to the piglets in the other EE treatment regimens (P < 0.05). The SR-enriched piglets had higher lactate and haematocrit levels, but lower values for pH and bicarbonate (HCO3–) than the animals in the other EE groups (P < 0.005). The piglets subjected to sensorial EE with AB had higher plasma glucose than the ones in the other groups (P < 0.005). Finally, the PTB-enriched subjects showed higher Na+ levels than controls (P < 0.005). The alterations that were found to be related to the factor sampling time were more pronounced at T30 (P < 0.05) than T60 and T90. These results indicate that the conditions (SO, DSO) and EE (C, SR, AB, PTB) under which the piglets were weaned influenced the blood variables measured in the study.

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Kulkarni, Mukti. "PH 3.0." Journal of Public Health Management and Practice 23, no. 3 (2017): 331–33. http://dx.doi.org/10.1097/phh.0000000000000569.

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Sánchez-Clemente, Rubén, María Isabel Igeño, Ana G. Población, María Isabel Guijo, Faustino Merchán, and Rafael Blasco. "Study of pH Changes in Media during Bacterial Growth of Several Environmental Strains." Proceedings 2, no. 20 (October 22, 2018): 1297. http://dx.doi.org/10.3390/proceedings2201297.

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The effect of pH on bacterial cell-growth and the evolution of extracellular pH triggered by bacterial growth has been monitored for three bacterial strains, Escherichia coli ATCC 25922 and Pseudomonas putida KT2440 as reference strains, and Pseudomonas pseudoalcaligenes CECT 5344 because of its capacity to assimilate cyanide as the sole nitrogen source under alkaline conditions. In a first instance, the influence of the initial pH in the growth curve has been texted in LB-medium adjusted to pH 6, 7 and 8, for E. coli and P. putida, and 7.5, 8.25 and 9 for P. pseudoalcaligenes. Although the initial pH were different, the pH of the extracellular medium at the end of the stationary phase converged to a certain pH that is specific for each bacterium. Similar experiments were carried out in minimal medium with glucose as the carbon source. In this case, the pHs of the culture of both Pseudomonadaceae strains were almost constant, whereas it suddenly dropped during the exponential growth phase of E. coli. When the initial pH was 6 the extracellular pH fell sharply to 4.5, which irreversibly prevented further cellular growth. Nevertheless, at higher initial pH values subsequent cellular growth of E. coli restored the medium to the initial pHs values. Finally, in all cases the evolution of the pH has been shown to depend on the carbon source used. Among the sources used, cellular growth with glucose or glycerol did not affect the extracellular pH, whereas citrate caused the alkalinization of the media. This phenotype is in concordance with computational predictions, at least in the case of the genome-scale metabolic model of Pseudomonas putida KT2440.

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Lehmann, Anna, Kacper Nijakowski, Michalina Nowakowska, Patryk Woś, Maria Misiaszek, and Anna Surdacka. "Influence of Selected Restorative Materials on the Environmental pH: In Vitro Comparative Study." Applied Sciences 11, no. 24 (December 16, 2021): 11975. http://dx.doi.org/10.3390/app112411975.

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In dental caries treatment, it is worth using such restorative materials that may limit plaque accumulation. The pH of the filling seems to be an important factor affecting the potential bacterial colonisation. Our study aimed to assess how selected restorative materials influence the environmental pH. A total of 150 specimens (30 of each: Ketac Molar, Riva LC, Riva SC, Filtek Bulk Fill, and Evetric) were placed in 100 sterile hermetic polyethene containers with saline and stored in 37 °C. The pH of each sample was measured using the electrode Halo HI13302 (Hanna Instruments, Poland) at specific points in time for 15 days. The initial pH levels were significantly lower for glass ionomer cements (3.9–4.7) compared to composites (5.9–6.0). With time, the pH increased for samples with glass ionomer cements (by nearly 1.5), whereas it decreased for samples with composites (maximally by 0.8). In the end, all materials were in the pH range between 5.3 and 6.0. The highest final pH was obtained with Ketac Molar at about 5.9. Double samples had lower pH values than single samples, irrespective of the type of material. In conclusion, immediately after application, restorative materials decreased the environmental pH, especially light-cured glass ionomer cements. For glass ionomers, within two weeks, the pH increased to levels comparable with composites.

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Grisé, David, John E. Titus, and Daniel J. Wagner. "Environmental pH influences growth and tissue chemistry of the submersed macrophyte Vallisneria americana." Canadian Journal of Botany 64, no. 2 (February 1, 1986): 306–10. http://dx.doi.org/10.1139/b86-044.

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Wild celery (Vallisneria americana, Hydrocharitaceae) is a common submersed freshwater macrophyte rarely reported from lakes with pH below 6. Plants grown in a greenhouse on a uniform sediment within pH-controlled tanks all survived 60 days at pH 5 but showed reduced dry matter accumulation (by 76%), leaf area (by 79%), and rosette and winter bud production (by 44 and 63%, respectively) compared with plants grown at pH 7.5. The sensitivity of this plant to only moderate acidity did not differ for plants in water acidified to pH 5 by a combination of H2SO4 and HNO3 or by HCl, indicating that the former acids exerted no fertilizing effects to counter the detrimental influence of acidification. Tissue nitrogen and phosphorus levels were well above the critical concentrations previously reported for this species. Tissue calcium and manganese concentrations showed no clear relationship to treatment pH. Both aluminum and iron levels in tissues were twofold to threefold higher for the smaller plants grown at pH 5 (means of 1970 and 3090 μg/g, respectively), suggesting that metal toxicity may have caused growth reduction at low pH.

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Joshua Ong, Ee Xin, U.-Jin Adrian Yap, Azwatee Abdul Aziz, and Noor Azlin Yahya. "Effect of Oral Environmental pH on the Dynamic Characterization of Bioactive Restorative Materials." Sains Malaysiana 51, no. 9 (September 30, 2022): 2999–3008. http://dx.doi.org/10.17576/jsm-2022-5109-20.

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The objective of this study was to investigate the effects of oral environmental pH on the viscoelastic properties of bioactive restorative materials (BRMs) by using dynamic mechanical analysis. Stainless steel molds were used to fabricate 40 beam-shaped specimens (12 × 2 × 2 mm) for each material. The specimens were finished, measured, randomly divided into four groups (n = 10), and immersed in aqueous solutions of pH 3.0, 5.0, 6.8, and 10.0 at 37 °C for seven days. The specimens were then subjected to dynamic mechanical analysis with a 5 N load and frequency range of 0.1-10.0 Hz. Data were analyzed using one-way ANOVA/Dunnet T3’s test (α = 0.05). Mean elastic modulus spanned from 2.68 ± 0.17 to 6.49 ± 0.71 GPa, while viscous modulus ranged from 0.43 ± 0.03 to 0.62 ± 0.12 GPa. Loss tangent differed from 77.30 ± 4.90 to 164.50 ± 9.12. Significant differences among pH were discerned for (i) Elastic modulus: Cention N - pH 3.0, 5.0, 10.0 > 6.8; Activa Bioactive - pH 3.0, 6.8, 10.0 > 5.0, (ii) Viscous modulus: Cention N - pH 3.0, 5.0, 10.0 > 6.8, and (iii) Loss tangent: Activa Bioactive - pH 5.0 > 3.0, 6.8, 10.0. Significant differences in viscoelastic properties were noted among the BRMs with Activa Bioactive presenting the lowest elastic modulus for all pH. Immersion of all materials in pH 6.8 yielded the highest elastic modulus, except for Activa Bioactive. The effects of environmental pH on viscoelastic properties of BRMs are material-dependent.

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Carroll, James A., Claude F. Garon, and Tom G. Schwan. "Effects of Environmental pH on Membrane Proteins in Borrelia burgdorferi." Infection and Immunity 67, no. 7 (July 1, 1999): 3181–87. http://dx.doi.org/10.1128/iai.67.7.3181-3187.1999.

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ABSTRACT Borrelia burgdorferi, the causative agent of Lyme disease, alternates between the microenvironments of the tick vector,Ixodes scapularis, and a mammalian host. The environmental conditions the spirochete encounters during its infectious cycle are suspected to differ greatly in many aspects, including available nutrients, temperature, and pH. Here we identify alterations in the membrane protein profile, as determined by immunoblotting and two-dimensional nonequilibrium pH gradient gel electrophoresis (2D-NEPHGE), that occur in virulent B. burgdorferi B31 as the pH of the medium is altered. Initial comparisons of cultures incubated at pHs 6.0, 7.0, and 8.0 yielded alterations in the expression of seven membrane proteins as determined by probing with hyperimmune rabbit serum. Six of these membrane proteins (54, 45, 44, 43, 35, and 24 kDa) were either present in increased amounts in or solely expressed by cultures incubated at pHs 6.0 and 7.0. The 24-kDa protein that decreased in expression at pH 8.0 was identified as outer surface protein C (OspC). In addition, a 42-kDa membrane protein increased in amount in cultures incubated at pH 8.0. Similar changes were observed with serum from a mouse infected by tick bite, with the recognition of two additional bands (48 and 46 kDa) unique to pHs 6.0 and 7.0. When membrane fractions were analyzed by 2D-NEPHGE, at least 37 changes in the membrane protein profile between cells incubated at pHs 6.0, 7.0, and 8.0 were observed by immunoblotting and silver staining. Environmental cues such as pH may prove important in the regulation of virulence determinants and factors necessary for the adaptation of B. burgdorferi to the tick or mammalian microcosm.

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Lim, Diane S. W., Yuan Yuan, and Yugen Zhang. "pH-Degradable Polymers as Impermanent Antimicrobial Agents for Environmental Sustainability." ACS Applied Bio Materials 4, no. 2 (February 5, 2021): 1544–51. http://dx.doi.org/10.1021/acsabm.0c01402.

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Kullmann, T., I. Barta, B. Antus, M. Valyon, and I. Horvath. "Environmental temperature and relative humidity influence exhaled breath condensate pH." European Respiratory Journal 31, no. 2 (February 1, 2008): 474–75. http://dx.doi.org/10.1183/09031936.00128007.

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Popovic, A., and D. Djordjevic. "pH-Dependent Leaching of Dump Coal Ash—Retrospective Environmental Analysis." Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 31, no. 17 (October 9, 2009): 1553–60. http://dx.doi.org/10.1080/15567030802094003.

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Webb, Michael J., and Jack F. Loneragan. "Importance of Environmental pH during Root Development on Phosphate Absorption." Plant Physiology 79, no. 1 (September 1, 1985): 143–48. http://dx.doi.org/10.1104/pp.79.1.143.

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Azbar, N., H. Senel, and R. E. Speece. "Simultaneous Computer Control of pH in Multiple Environmental Laboratory Bioreactors." Environmental Technology 21, no. 9 (September 2000): 1007–11. http://dx.doi.org/10.1080/09593332208618048.

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Kao, Shih-Han, Kuo-Yen Huang, Hsin-Jung Li, S. -Ja Tseng, Zi-Xian Liao, and Ivan Kempson. "Environmental pH-sensitive polymeric nano-carriers for targeted tumor delivery." Journal of Controlled Release 213 (September 2015): e46-e47. http://dx.doi.org/10.1016/j.jconrel.2015.05.075.

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Garro, Marisa S., Laura Aguirre, and Graciela Savoy de Giori. "Biological activity of Bifidobacterium longum in response to environmental pH." Applied Microbiology and Biotechnology 70, no. 5 (August 9, 2005): 612–17. http://dx.doi.org/10.1007/s00253-005-0102-y.

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Peppler‐Lisbach, Cord. "Using species‐environmental amplitudes to predict pH values from vegetation." Journal of Vegetation Science 19, no. 4 (January 29, 2008): 437–44. http://dx.doi.org/10.3170/2008-8-18394.

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Wang, Xiao Yan, Adrian Yap U. Jin, and Hien C. Ngo. "Influence of environmental calcium/phosphate and pH on glass ionomers." European Journal of Oral Sciences 115, no. 3 (June 2007): 224–29. http://dx.doi.org/10.1111/j.1600-0722.2007.00443.x.

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Yang, Hong Yu, Xiu Mei Zhang, Li Jie Duan, Ming Yao Zhang, Guang Hui Gao, and Hui Xuan Zhang. "Environmental pH-responsive fluorescent PEG-polyurethane for potential optical imaging." Journal of Applied Polymer Science 129, no. 2 (December 19, 2012): 846–52. http://dx.doi.org/10.1002/app.38880.

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Sit, Izaac, Haibin Wu, and Vicki H. Grassian. "Environmental Aspects of Oxide Nanoparticles: Probing Oxide Nanoparticle Surface Processes Under Different Environmental Conditions." Annual Review of Analytical Chemistry 14, no. 1 (June 5, 2021): 489–514. http://dx.doi.org/10.1146/annurev-anchem-091420-092928.

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Surface chemistry affects the physiochemical properties of nanoparticles in a variety of ways. Therefore, there is great interest in understanding how nanoparticle surfaces evolve under different environmental conditions of pH and temperature. Here, we discuss the use of vibrational spectroscopy as a tool that allows for in situ observations of oxide nanoparticle surfaces and their evolution due to different surface processes. We highlight oxide nanoparticle surface chemistry, either engineered anthropogenic or naturally occurring geochemical nanoparticles, in complex media, with a focus on the impact of ( a) pH on adsorption, intermolecular interactions, and conformational changes; ( b) surface coatings and coadsorbates on protein adsorption kinetics and protein conformation; ( c) surface adsorption on the temperature dependence of protein structure phase changes; and ( d) the use of two-dimensional correlation spectroscopy to analyze spectroscopic results for complex systems. An outlook of the field and remaining challenges is also presented.

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Boron, Walter F. "Regulation of intracellular pH." Advances in Physiology Education 28, no. 4 (December 2004): 160–79. http://dx.doi.org/10.1152/advan.00045.2004.

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The approach that most animal cells employ to regulate intracellular pH (pHi) is not too different conceptually from the way a sophisticated system might regulate the temperature of a house. Just as the heat capacity (C) of a house minimizes sudden temperature (T) shifts caused by acute cold and heat loads, the buffering power (β) of a cell minimizes sudden pHi shifts caused by acute acid and alkali loads. However, increasing C (or β) only minimizes T (or pHi) changes; it does not eliminate the changes, return T (or pHi) to normal, or shift steady-state T (or pHi). Whereas a house may have a furnace to raise T, a cell generally has more than one acid-extruding transporter (which exports acid and/or imports alkali) to raise pHi. Whereas an air conditioner lowers T, a cell generally has more than one acid-loading transporter to lower pHi. Just as a house might respond to graded decreases (or increases) in T by producing graded increases in heat (or cold) output, cells respond to graded decreases (or increases) in pHi with graded increases (or decreases) in acid-extrusion (or acid-loading) rate. Steady-state T (or pHi) can change only in response to a change in chronic cold (or acid) loading or chronic heat (or alkali) loading as produced, for example, by a change in environmental T (or pH) or a change in the kinetics of the furnace (or acid extrudes) or air conditioner (or acid loaders). Finally, just as a temperature-control system might benefit from environmental sensors that provide clues about cold and heat loading, at least some cells seem to have extracellular CO2 or extracellular HCO3− sensors that modulate acid-base transport.

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Miranda Mugica, Monica, Kay Louise McGuinness, and Nathan Scott Lawrence. "Electropolymerised pH Insensitive Salicylic Acid Reference Systems: Utilization in a Novel pH Sensor for Food and Environmental Monitoring." Sensors 22, no. 2 (January 11, 2022): 555. http://dx.doi.org/10.3390/s22020555.

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This work summarizes the electrochemical response of a salicylic acid-based carbon electrode for use as a novel solid-state reference electrode in a redox-based pH sensor. This novel reference produces a pH insensitive response over a range of pH 3–10 in solutions with low buffer concentrations, different compositions, conductivities, and ionic strengths is produced. The pH of the local environment is shown to be determined by the chemistry and the electrochemical response of the redox active species on the surface of the electrode; the local pH can be controlled by the electropolymerized salicylic acid moieties due to the acid concentration on the surface, avoiding any perturbation in environmental pH and leading to a stable novel reference system. Sensitivities of −7.1 mV/pH unit, −2.4 mV/pH unit, −0.2 mV/pH unit, and 2.5 mV/pH units were obtained for different food medias, hydroponic solution, seawater, and cell-culture media, respectively, confirming its ability to control the local pH of the electrode. This reference system is paired with a new pH sensing element based on electropolymerized flavanone to provide a calibration free, pH sensitive sensor to effectively and accurately measure the pH of various media with high viscosity, low conductivity, low/high buffer concentration or cell-culture environment, presenting a maximum error of +/−0.03 pH units.

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Wong, D. H., K. Sivasithamparam, and M. J. Barbetti. "Influence of environmental factors on the growth and survival of Phytophthora clandestina." Canadian Journal of Microbiology 32, no. 7 (July 1, 1986): 553–56. http://dx.doi.org/10.1139/m86-103.

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The effects of temperature, pH, and osmotic water potential on the growth on lima bean agar and survival in soil of Phytophthora clandestina were investigated. On agar it grew over a wide pH range of 4–9 and growth increased as the pH of the initial medium rose from 4 to 6 at temperatures of 15, 20, and 25 °C. Growth was reduced by 58, 56, and 65% under acidic (pH 4) or by 54, 63, and 32% under alkaline (pH 9) conditions when compared with growth at pH 6 at 15, 20, and 25 °C, respectively. At 10, 15, 20, and 25 °C growth was reduced with increasing water stress. Generally growth increased with progressively increasing incubation temperatures up to 20 °C. Osmotic water potential of less than −12bars (1 bar = 100 kPa) prevented mycelial growth of P. clandestina. Maximum growth occurred on lima bean agar (0 bar) without KCl amendment at all temperatures. Survival of the pathogen within pasteurized soil was increased under cooler conditions (5–10 °C) at all water potentials tested (−0.01, −0.026, and −0.063 bars). At higher temperatures (15–32 °C) P. clandestina survived better under wetter soil conditions.

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Guenther, William B. "Reliable pH standards." Analyst 113, no. 4 (1988): 683. http://dx.doi.org/10.1039/an9881300683.

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Rao, Pin Hua, Wen Qi Zhang, Jie Zhao, and Xin Yu Dong. "Removal of Chromium(VI) by Zero Valent Iron: Effects of Environmental Factors." Advanced Materials Research 356-360 (October 2011): 1093–96. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.1093.

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The influences of various geochemical factors, such as pH, phosphate, bicarbonate, humic acid, permanganate, and dissolved oxygen, on hexavalent chromium(Cr(VI)) removal by zero-valent iron(Fe0) were investigated in a batch setting. Results showed that low pH environments were favorable to removal of Cr(VI) compared with high pH environments. Phosphate significantly inhibited removal of Cr(VI) possibly due to competition of adsorption sites on corrosion products. Humic acid introduced a marginal influence on Fe0reactivity toward Cr(VI) reduction, whereas bicarbonate enhanced Cr(VI) removal by maintaining the solution pH near neutral. Permanganate cumbered the removal of Cr(VI) due to its competition for electron from oxidation of Fe0. The removal efficiency of Cr(VI) was higher in oxic conditions than that in anoxic conditions.

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Jin, Mei, Ji Wei Hu, Xian Fei Huang, Li Ya Fu, Jin Luo, Miao Jia, Chun Liu, and Wei Shen. "Effects of Environmental Factors on Phosphorus Release in Sediment from Baihua Lake, China." Applied Mechanics and Materials 260-261 (December 2012): 912–16. http://dx.doi.org/10.4028/www.scientific.net/amm.260-261.912.

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This paper reports an investigation regarding the effects of temperature, pH, dissolved oxygen (DO) concentration and agitation on total phosphorus (TP) release in sediment form Baihua Lake. The results showed that an increase in the temperature led to a sharp increase in the TP release in the examined sediment. The TP release from the sediment decreased as the pH value increased until approximately pH = 7, and increased when pH > 7. There was phosphorus release in both aerobic and anoxic conditions, although the release quantities of TP were significantly higher in the anoxic condition than those in the aerobic condition. In addition, the TP release increased with agitation.

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Wang, Yanchun, Yongyan Wang, Chuanqi Su, and Jianguang Li. "Study of Influence of Environmental Factors on Deep Shale Creep Properties." Shock and Vibration 2018 (November 15, 2018): 1–8. http://dx.doi.org/10.1155/2018/9165238.

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In order to study the influence of environmental factors on creep properties of deep shale, a series of creep tests of deep black shales are performed under different environmental conditions, including stress deviation, temperature, and chemical pH value. The influence of these conditions on creep properties of deep shale is studied. The results show that the creep and creep rate of shale will grow with the increase of temperature, stress difference, and acidity-alkalinity. We get nonlinear creep model of deep shale when pH = 4 and T = 30°C. The critical stress difference of deep shale is no larger than 31.04 MPa when the chemical pH value is 4 and the temperature is 30°C. By scanning shale after corrosion, we know that the effects of chemical pH value on the creep characteristics are mainly determined by the feldspar dissolution and corrosion caused by chemical action. Our work has important theoretical significance and practical value for evaluating rock engineering stability.

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Vaca, H. Fabian, and Craig R. White. "Environmental modulation of metabolic allometry in ornate rainbowfish Rhadinocentrus ornatus." Biology Letters 6, no. 1 (September 23, 2009): 136–38. http://dx.doi.org/10.1098/rsbl.2009.0610.

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The nature of the relationship between the metabolic rate (MR) and body mass ( M ) of animals has been the source of controversy for over seven decades, with much of the focus on the value of the scaling exponent b , where MR is proportional to M b . While it is well known that MR does not generally scale isometrically (i.e. b is seldom equal to 1), the value of b remains the subject of heated debate. In the present study, we examine the influence of an ecologically relevant abiotic variable, pH, on the metabolic allometry of an Australian freshwater fish, Rhadinocentrus ornatus . We show that the value of b is lower for rainbowfish acclimated to acidic (pH 5.0) conditions compared to rainbowfish acclimated to alkaline conditions (pH 8.5), but that acute exposure to altered pH does not alter the value of b . This significant effect of an abiotic variable on metabolic allometry supports a growing body of evidence that there is no universal value of b and demonstrates that experimental manipulations of metabolic allometry represent powerful, and as yet underused, tools to understand the factors that constrain and influence the allometry of metabolic rate.

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Journal articles on the topic 'Environmental pH'

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