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71.
A fundamental difficulty in theoretical physics is the dual and apparently incompatible interpretations of radiation as showing both continuous and extensive wave properties but also those of discrete atomic or smaller individual particles. Some of these contradictions are outlined. The explanation offered is of a quantized nature of time; units to=h/moc2 for a particle at rest, and of similar interval unit so when in relative motion, with conventional relativistic corrections.
For many purposes this form of quantization replaces the need for a wave concept which then appears as a mathematical approach, chosen to avoid the physical concept of an intrinsicc time for any particle, just as we have for its intrinsic mass, spin and electrical charge. to and so are directly related to its frequency, energy and mass. The uncertainty principle and interference relations follow directly from this model, without any physical wave concept. 相似文献
72.
As copper(II) is a common ion in a variety of analytical samples, its effect on the stripping response of lead(II) at bismuth film screen-printed carbon electrode (BFSPCE) was investigated. The study was conducted using a screen-printed three-electrode system (working, counter and reference electrodes), with the carbon-working electrode plated in situ with bismuth film. Copper present at significant concentration level in samples was found to affect the sensitivity of the electrode by reducing the constant current stripping chronopotentiometric (CCSCP) response of lead(II). Recovery of the lead stripping response at the BFSPCE in the presence of copper was obtained when 0.1 mM ferricyanide was added to the test solution. The ferricyanide added circumvents the detrimental effect of copper(II) by selectively masking the copper ions by forming a complex. The analytical utility of the procedure is illustrated by the stripping chronopotentiometric determinations of lead(II) in soil extracts. 相似文献
73.
《Arabian Journal of Chemistry》2022,15(9):103970
Ethnopharmacological relevanceMetabolic syndrome is closely related to the intestinal microbiota and disturbances in the host metabolome. Hyperuricemia (HUA), a manifestation of metabolic syndrome, can induce various cardiovascular diseases and gout, seriously affecting a patient’s quality of life. Astragalus membranaceus has a long history as a commonly used traditional Chinese medicine to treat kidney disease in China and East Asia.Materials and methodsWe compared the therapeutic effect of benzbromarone and two different doses Astragalus membranaceus ultrafine powder (AMUP) in rats with HUA. Ultra-performance liquid chromatography-mass spectrometer was used to analyze the AMUP metabolism in the plasma, urine, and feces. Further, 16S ribosome RNA sequencing and feces metabolomic were performed to capture the variation of the gut microbiota and metabolites changes before and after drug administration.ResultsAMUP had a notable impact on reducing blood uric acid levels while protecting the liver and kidney. Drug metabolism analysis demonstrated that effective constituent flavonoids are distributed in the blood, whereas saponins remain in the intestine. Gut microbiota analysis showed that low-dose AMUP ameliorated HUA-induced gut dysbiosis by reducing the abundance of harmful bacteria and increasing that of some beneficial bacteria with anti-inflammatory properties, such as Clostridia, Lachnospiraceae, and Muribaculaceae. In addition, HUA-induced changes in metabolite contents in bile acid and adrenal hormone biosynthesis pathways were restored after treatment with AMUP.ConclusionLow-dose AMUP exerts remarkable therapeutic effects on HUA by regulating the gut microbiome and mediating gut metabolism pathways associated with uric acid excretion. 相似文献
74.
The m6A‐RNA modification is a dynamic and reversible process, which has emerged as a new RNA code for the regulation of gene expression. The functional network of methyltransferases (writers), demethylases (erasers), and binding proteins (readers) modulate the level of m6A modification. Dysfunction of RNA methylation has been associated with various fundamental biological processes and human diseases. Herein, we briefly introduce an understanding‐enabled manipulation on m6A‐RNA modification with an emphasis on the use of small‐molecule intervention. 相似文献
75.
The paper represents a further development of our hydrate hypothesis of simplest living matter origination (SLMO) from inorganic and simplest organic mineral substances. It is supposed that the sources of SLMO are simplest aliphatic hydrocarbons, niters, and phosphates. Thermodynamic calculations demonstrating a principal possibility for simultaneous syntheses of different nitrogen bases, d-ribose, and desoxy-d-ribose from these source substances are presented. The most probable principal mechanism of SLMO and the principal conditions necessary for realization of the proposed chemism of SLMO in the framework of the proposed mechanism are considered. A principal means for testing the hypothesis is proposed. 相似文献
76.
Removal of humic matter interference in the determination of Cr(VI) in soil extracts by the diphenylcarbazide method 总被引:1,自引:0,他引:1
Alkaline digestion of soil samples, which is recommended for minimizing Cr(III)–Cr(VI) interconversions during the extraction of Cr(VI), may also solubilize humic matter (HM). The latter is responsible for both positive and negative interference in the analysis of Cr(VI) in the extract by the diphenylcarbazide (DPC) method. Humic compounds indeed absorb light at 540 nm as the Cr-DPC product and are also able to rapidly reduce Cr(VI) under the pH conditions of the standard DPC method. To prevent any risk of interference and make the DPC method applicable to soil extracts, a new protocol is proposed. This consists of three successive steps: (1) extraction of Cr(VI) by the U.S.EPA method 3060A in the presence of Mg2+; (2) batch removal of solubilised HM by the XAD-7 sorbent at pH 3.0 ± 0.1 with 3–5 min contact time; (3) analysis of Cr(VI) with the DPC method at pH 3.0 ± 0.1. The application of this new protocol to the soil product SQC-012 Lot 4 certified by R.T. Corporation (RTC, USA) gave significantly lower Cr(VI) concentrations and smaller variability compared to certified values (46.5 ± 2.3 instead of 153 ± 32.6 mg/kg). The new protocol was validated by Cr(VI) and Cr(III) spikes either to the soil/extractant suspension or to the exctract. Cr(VI) results in the wide range of acceptance limits (104–202 mg/kg) reported by RTC were only obtained when the U.S.EPA method 3060A without the addition of Mg2+ and DPC analysis at pH 1.0 were applied. The latter procedure appears questionable since it leads to largely variable results which reflect the complex role played by humic matter in the determination of Cr(VI) and the instability of Cr(III) during the extraction. 相似文献
77.
ICP-AES中内标法的应用研究 Ⅲ.用内标法校正基体干扰 总被引:1,自引:0,他引:1
通过观测基体对分析元素发射强度的干扰情况,分析干扰机制,从而确定用来校正基体干扰的内标元素与分析元素的匹配条件。实验结果表明,只要选择合适的内标元素,可以校正基体干扰。 相似文献
78.
Iron interference in the spectrophotometric catalytic determination of molybdenum based on the iodide-hydrogen peroxide reaction can be corrected by using sulphosalicylic acid as masking and color-forming reagent. The catalytic influence of iron ions is circumvented to the extent of about 90% and correction of any remaining iron ions is possible by monitoring the colored iron(III)-salicylate complex at 490 nm. In this way, iron is also determined. With the proposed system, molybdenum can be determined in plant and food digests within the 0–100 μg Mo 1−1 range in the presence of up to 25 mg Fe 1−1, at a sampling rate of about 50 determinations h−1. The relative standard deviation of 10 consecutive measurements was estimated as < 2%. Results for samples were comparable with those obtained by graphite furnace atomic absorption spectrometry. In addition, recoveries within the range 94–100% were calculated. 相似文献
79.
80.