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Medium-temperature anaerobic digestion experiments lasting for 55 days were conducted using sulfamethoxazole (SMX)-containing chicken manure in sequential batch reactors added with nano-Fe2O3 at a concentration of 300 mg·kg−1·TS or nano-C60 at a concentration of 100 mg·kg−1·TS. The effects of nanoparticles on the anaerobic digestion properties of SMX-containing chicken manure were assessed by measuring the following indicators: biogas production by anaerobic digestion, chemical parameters, enzyme concentrations, and bacterial diversity and changes in antibiotic concentrations over time. The law of bacterial degradation of SMX was analyzed. The results showed that (1) adding either nano-Fe2O3 or nano-C60 promoted biogas production by anaerobic production from chicken manure containing different concentrations of SMX, and the cumulative biogas production in Fe2O3 and nano-C60 increased by 35.4% and 130.7%, respectively. The final cumulative biogas productions in different groups were as follows: 3,712(CK), 4,281(S1), 3,968(S2), 4,061(S3), 4,498(S4), and 4,639(S5) mL and the final concentration of SMX residues varied between 99.79% and 99.94%; (2) Bacterial abundance at the phylum level: on day 1, Firmicutes and Bacteroidota were the main dominant bacterial phyla, with relative abundances of 45.13–68.53% and 26.12–48.32%, respectively. The addition of nanoparticles increased the abundance of Bacteroidota in S4 and S5 significantly. The abundance of Bacteroidota was slightly higher in the group added with nanoparticles than in S2. On day 50, Firmicutes became the dominant bacterial phylum, and its relative abundance varied little across the groups, ranging from 90.87% to 94.54%; (3) At different stages, the bacterial community structure at the genus level was dramatically affected by substrates. As nutrients were being depleted, some bacterial communities lost their original competitive advantages. On day 5, the relative abundance of Prevotella increased. Especially, the relative abundances of Prevotella in S4 and S5 added with nanoparticles were lower than that in S2 by 8–10%. On day 15, the relative abundance of Prevotella in S2 decreased compared with the control group CK. A decrease was also observed in S4 and S5, although to a smaller extent than in S2.

Taking chicken manure containing antibiotic oxytetracycline (OTC) as the research object, nano-Fe2O3 with a concentration of 300 mg/kg TS and nano-C60 with a concentration of 100 mg/kg TS as carriers were used for a 55-day sequential batch mesophilic anaerobic digestion experiment. The gas production performance, chemical parameters, antibiotic content, enzyme concentration, and resistance gene changes during anaerobic digestion were analyzed to clarify the effect of nanoparticles on anaerobic systems containing antibiotic chicken manure and provide a reliable basis for pollution reduction capacity of livestock and poultry manure. The results showed that (1) adding nano-Fe2O3 and nano-C60 promoted anaerobic gas production in chicken manure with different concentrations of OTC. The cumulative gas production from days 1 to 10 was 2,234(T5) > 2,163(T4) > 1,445(T2) > 1,289(T3) > 1,220(T1) > 1,216(CK) mL. The cumulative gas production of T4 and T5 increased by 77.29 and 83.11%, respectively. The final cumulative gas production for each group was 3,712(CK), 3,993(T1), 4,344(T2), 4,447(T3), 4,671(T4), and 4,849(T5) mL. The final OTC residue concentrations were 15.25, 20.40, 56.56, 17.67, and 16.89 μg/L, with degradation rates of 98.31, 98.80, 98.29, 99.07, and 99.11% respectively; (2) antibiotic OTC increased the activities of dehydrogenase, amylase, protease, and urease, while adding nanoparticles increased the activities of dehydrogenase and amylase, with no significant impact on cellulase, urease, and protease activities; (3) antibiotic resistance gene (ARGs) of various types were found in groups T2, T4, and T5, with the multidrug resistance gene (ARGs)-Multidrug accounting for a high proportion of 33.54, 35.63, and 37.43%, respectively, while the proportions of the other four types MLS, tetracycline, glycopeptide, and peptide ranged from 8.18 to 12.98%.

Kitchen waste contains high contents of organic matter and moisture, and it is prone to biodegrade and decompose to give odors. If not collected and transported promptly or treated improperly, it is highly likely to pollute the environment and spread diseases. Because the lipid content in kitchen waste is high and a portion of organic matter is not subject to hydrolysis, the development of anaerobic digestion technology has been greatly limited. Kitchen waste was pretreated with NaOH, KOH, and Ca(OH)2 with different concentrations, and 50 days sequencing batch mesophilic anaerobic digestion experiments were conducted. This study sheds light on the pollution reduction and energy generation of kitchen waste. The results are as follows: (1) The lipid content of kitchen waste could be reduced, and the concentration of dissolved organic matter could be increased by pretreating with alkali. The degradation rate of kitchen waste lipid reached a maximum of 50.51%, if 3% NaOH was added, and the soluble chemical oxygen demand concentration was increased by 235.3%. (2) The cumulative methane (CH4) output and biogas production efficiency were improved in the anaerobic digestion process with kitchen waste pretreated with alkali. The maximum daily gas output of kitchen waste pretreated with NaOH and KOH took place on the 11th to 12th day, with the biogas production efficiency of 40.4 and 45.2 mL·g·VS−1. The cumulative CH4 output was increased from 370.2 mL·g·VS−1 (untreated) to 393.1 and 434.1 mL·g·VS−1, respectively. In addition, the concentration of CH4 in biogas was increased from 54.8% (untreated) to 59.1% and 61.7%, respectively. (3) The Chao1 and Ace values of bacteria were increased first and then decreased. On the 10th day, the diversity of bacteria reached the highest value, and on the 20th day, the diversity of archaea reached its maximum. Therefore, it was verified that the improvement in the hydrolysis acidification efficiency and degree was crucial for the rapid and complete anaerobic digestion reactions.

Water accounts for 70 % - 90 % of the total mass of food waste, and the contents of organic matter, oil, and salt in the waste are high. These conditions are highly suitable for the growth and reproduction of bacteria and other microorganisms. Therefore, anaerobic digestion is a common approach to treat food waste. Despite its long history, the research on anaerobic digestion has gradually developed with the progress in science and technology. This study aimed to explore the influence of temperature fluctuation on the anaerobic digestion characteristics of food waste by performing batch experiments; also, the characteristics were analysed from a microscopic perspective. The anaerobic digestion process was subjected to the interactions between various microorganisms and enzymes. The experimental results indicated that the activity of bacteria belonging to the phyla such as Proteobacteria and Chloroflexi was relatively high at a constant temperature. In contrast, the activity of the bacteria belonging to the phyla such as Bacteroidota and Acidobacteriota was relatively high at regulated temperatures. The activity of cellulase and lipase increased whereas that of protease decreased at a constant temperature. Regardless of the fluctuation mode of temperature, the activity of amylase did not obviously alter. These microorganisms with different responses to temperature fluctuation had unique functions in the anaerobic digestion process, and they participated in different anaerobic digestion stages. Therefore, based on the attribute of kitchen waste, an appropriate temperature mode can be selected to make anaerobic digestion more efficient. [ABSTRACT FROM AUTHOR]

Physiotherapeutic effects of infrared lasers have been proved in clinic. These infrared-based regulations of the bioelectrical activities can roughly be classified into enhancement and suppression of action potential (AP), which are described by sodium (Na) and potassium (K) transmembrane current equations, named as Hodgkin and Huxley (HH)-model. The enhancement effect is able to evoke or strengthen the AP when infrared light is applied. Its corresponding mechanism is commonly ascribed to the changes of the cell membrane capacitance, which is transiently increased in response to the infrared radiation. The distinctive feature of the suppression effect is to inhibit or reduce the AP by the designed protocols of infrared radiation. However, its mechanism presents more complexity than that in enhancement cases. HH-model describes how the Na current determines the initial phase of AP. So, the enhancement and suppression of AP can be also ascribed to the regulations of the corresponding Na currents. Here, a continuous infrared light at the wavelength of 980 nm (CIS-980) was employed to stimulate a freshly isolated hippocampal neuron in vitro and a suppression effect on the Na currents of the neuron cell was observed. Both Na and K currents, which are named as whole cell currents, were simultaneously recorded with the cell membrane capacitance current by using a patch clamp combined with infrared irradiation. The results demonstrated that the CIS-980 was able to reversibly increase the capacitance currents, completely suppressed Na currents, but little changed K currents, which forms the steady outward whole cell currents and plays a major role on the AP repolarization. A confirmation experiment was designed and carried out by synchronizing tens of milliseconds of infrared stimulation on the same kinds of hippocampal neuron cells. After the blocked K channel, a reduction of Na current amplitude was still recorded. This proved that infrared suppression of Na current was irrelevant to K channel. A membrane capacitance mediation process was preliminarily proposed to explain the Na channel suppression process. [ABSTRACT FROM AUTHOR]

Patch clamp is a technique that can measure weak current in the level of picoampere (pA). It has been widely used for cellular electrophysiological recording in fundamental medical researches, such as membrane potential and ion channel currents recording, etc. In order to obtain accurate measurement results, both the resistance and capacitance of the pipette are required to be compensated. Capacitance compensations are composed of slow and fast capacitance compensation. The slow compensation is determined by the lipid bilayer of cell membrane, and its magnitude usually ranges from a few picofarads (pF) to a few microfarads (μF), depending on the cell size. The fast capacitance is formed by the distributed capacitance of the glass pipette, wires and solution, mostly ranging in a few picofarads. After the pipette sucks the cells in the solution, the positions of the glass pipette and wire have been determined, and only taking once compensation for slow and fast capacitance will meet the recording requirements. However, when the study needs to deal with the temperature characteristics, it is still necessary to make a recognition on the temperature characteristic of the capacitance. We found that the time constant of fast capacitance discharge changed with increasing temperature of bath solution when we studied the photothermal effect on cell membrane by patch clamp. Based on this phenomenon, we proposed an equivalent circuit to calculate the temperature-dependent parameters. Experimental results showed that the fast capacitance increased in a positive rate of 0.04 pF/℃, while the pipette resistance decreased. The fine data analysis demonstrated that the temperature rises of bath solution determined the kinetics of the fast capacitance mainly by changing the inner solution resistance of the glass pipette. This result will provide a good reference for the fine temperature characteristic study related to cellular electrophysiology based on patch clamp technique.