Structure and function of the energy-converting system of mitochondria

The main energy source for all endergonic processes occurring in living organisms is the phosphate bond energy of nucleoside triphosphates, especially adenosine triphosphate (ATP). In aerobic organisms, as for instance in mammals, more than 90% of ATP is formed during the process called oxidative phosphorylation. In this process, similar to that of muscle contraction and nerve excitation, nature works with vectorial processes taking place at a membrane separating distinct spaces from each other. The present article deals with the operation of a set of water-insoluble membrane proteins and enzymes vectorially transporting electrons, protons and other ions, which finally leads to the formation of ATP. This machinery transforming substrate oxidation energy into chemical energy in the form of the phosphoric anhydride bond of ATP operates with a very high efficiency. The structure and function of the machinery of mitochondrial oxidative phosphorylation are described. It consists of the electron transfer chain, the ATP-synthetase, the adenine nucleotide translocase and the phosphate carrier. The electron transfer chain can be resolved into multiprotein complexes—at three of them energy conversion takes place—and into the electron carriers ubiquinone and cytochrome c. The substrate oxidation energy is converted into the chemical energy of ATP with an electrochemical proton gradient as intermediary form. The energetic aspects of the processes are analyzed by linear irreversible thermodynamics. Great success has been gained during the past few years on the structural characterization of the participating proteins. The function of the various systems is partially elucidated on the molecular level; this concerns especially the mechanism of proton and adenine nucleotide translocation, as well as ATP formation.     

Biomineralization of unicellular organisms: an unusual membrane biochemistry for the production of inorganic nano- and microstructures

With evolution, Nature has ingeniously succeeded in giving rise to an impressive variety of inorganic structures. Every organism that synthesizes biogenic minerals does so in a form that is unique to that species. This biomineralization is apparently biologically controlled. It is thus expected that both the synthesis and the form of every specific biogenic mineral is genetically determined and controlled. An investigation of the mechanism of biomineralization has only become possible with the development of modern methods in molecular biology. Unicellular organisms such as magnetic bacteria, calcareous algae, and diatoms, all of which are amongst the simplest forms of life, are particularly suited to be investigated by these methods. Crystals and composites of proteins and amorphous inorganic polymers are formed as complex structures within these organisms; these structures are not known in conventional inorganic chemistry.     

Methane production in a 100-L upflow bioreactor by anaerobic digestion of farm waste

Manure waste from dairy farms has been used for methane production for decades, however, problems such as digester failure are routine. The problem has been investigated in small scale (1–2 L) digesters in the laboratory; however, very little scale-up to intermediate scales are available. We report production of methane in a 100-L digester and the results of an investigation into the effect of partial mixing induced by gas upflow/recirculation in the digester. The digester was operated for a period of about 70 d (with 16-d hydraulic retention time) with and without the mixing induced by gas recirculation through an internal draft tube. The results show a clear effect of mixing on digester operation. Without any mixing, the digester performance deteriorated within 30–50 d, whereas with mixing continuous production of methane was observed. This study demonstrates the importance of mixing and its critical role in design of large scale anaerobic digesters.     

The Activation Strain Model in the Light of Real Space Energy Partitions

The distortion/interaction or activation strain model (ASM) of chemical reactivity is examined in real space through the interacting quantum atoms (IQA) approach. Attention is paid to the role that the geometrically constrained ASM structures of the fragments play in the chemical interpretation of the driving forces that lead to a given reaction channel. These fictitious intermediate states are necessary in the ASM, but IQA may or may not use them at will. Similarities and differences are highlighted by studying the endo/exo preference rules of simple [4+2] Diels–Alder cycloadditions. Although overall the agreement is reasonable, we warn about a blind use of the plain ASM if no further energy decomposition analyses of its interaction energy are done.     

Energy saving and environment-friendly element-transfer reactions with industrial application potential

Herein we wish to propose the concept of "element-transfer reaction",which may afford the access to elemental compounds by transferring certain elements from easily available resources efficiently,concisely and precisely.A good element-transfer reaction with industrial application potential shall not generate waste and is performed under energy-saving and environment-friendly conditions.During the past decade,we have developed a series of methods for the synthesis of fluorine-and seleniumcontaining compounds via the fluorine-and selenium-transfer reactions,while the redox reactions we re considered to be the oxygen-and hydrogen-transfer reactions as well and were also widely studied by our group for producing the high-value-added fine chemicals.Some of these technologies have been successfully industrialized.This review summarizes our staged research results on fluorine-,oxygen-,hydrogen-and selenium-transfer reactions and makes a prospect on the developing trend in the field.     

己内酰胺绿色生产技术

中国石化石油化工科学研究院历经20年,成功开发出己内酰胺绿色生产技术,建成3套20万t/a工业生产装置、多套工业装置正在建设中.己内酰胺绿色生产技术包括:钛硅分子筛与浆态床集成用于环己酮氨肟化合成环己酮肟;纯硅分子筛与移动床集成用于环己酮肟气相重排;非晶态合金催化剂与磁稳定床集成用于己内酰胺精制.工业实施后,装置投资下降70%、生产成本下降10%、原子利用率由60%提高到90%以上、三废排放是已有技术路线的1/200、无副产物硫酸铵.己内酰胺绿色生产技术产生了重大的经济效益和社会效益,践行了绿色化学的理念,是绿色化学的成功范例.     

能量最低原理在高分子化学教学中的应用探索

能量最低原理是自然界最普遍的规律之一,高分子化学中的许多现象都可以用它来加以解释。本文从聚合反应方向、自由基稳定性、聚合中的重排反应等几个方面阐述了能量最低原理在高分子化学中的具体体现,对用能量最低原理来解释高分子化学反应的规律和现象进行了初步探索。实践证明,在高分子化学教学中应用能量最低原理来讲解一些问题,会起到事半...     

厦门大学能源化学专业的创建与实践

Xiamen University established the world's first undergraduate program for energy chemistry in 2015. Herein, we introduced the energy chemistry course group which includes 11 courses. We also described the curriculum system and the teaching arrangement of the undergraduates, and summarized the experience in the construction of energy chemistry major, especially the ideas of science and technology integration and collaborative innovation. We expected our teaching experience would help the other universities to apply for the energy chemistry major and set up relevant courses.     

6-氨基青霉烷酸生产废水厌氧和深度处理实验研究

针对6-氨基青霉烷酸生产废水高污染物浓度,高硫酸根,难降解物质多的特点对废水经过硫酸根预处理,稀释3倍和6倍后,废水对厌氧污泥没有急毒性,厌氧污泥可以逐步适应废水环境。经过厌氧处理以及后续的Fenton深度处理,高浓度的6-氨基青霉烷酸生产废水COD_cr可由45450 mg/L 降到255 mg/L。出水COD_cr可达到污水三级排放标准。     

从能源产业发展和人才需求浅谈“能源化学”新工科改造

Based on building emerging engineering education of "energy chemistry", we investigated the state key petro-chemical enterprises according to the industrial development and the demand of professional talents. The research report summarizes, analyzes and discusses the current priority development fields of industry, the talent training status, curriculum structure and education program of the chemistry and chemical engineering in universities. The ideas on emerging engineering education of "energy chemistry" have been proposed, and it will be beneficial to building a novel education program for talents training, which integrates the principle of chemistry, energy conversion and information science, etc.     

“能源化学”本科专业建设建议

"Energy chemistry" was approved as one of the chemistry majors for undergraduate by the Ministry of Education in 2015. Based on the ideas and ways of emerging engineering education, this paper hereby proposed some of constructive suggestions on the training objectives, graduation requirements, curriculum system, teaching contents, teaching staff and conditions for development of "energy chemistry" major.     

High performance liquid chromatography method for the detection of released purinergic and biogenic amine signaling molecules from in vitro ileum tissue

Adenosine triphosphate (ATP) and serotonin (5‐HT) are known to play key roles in the function and activity of the gastrointestinal tract; however, no methods have been established for the monitoring of these signaling molecules within one assay. We have developed a simple chromatographic methodology using UV/visible detection for the analysis of purinergic and biogenic amine signaling molecules. The chromatographic separation was achieved in an isocratic mode, where the mobile phase consisted of 5% methanol and 95% ammonium phosphate buffer with 10 mM tetrabutylammonium bisulfate. Column temperature of 45°C provided the means to separate all analytes within 14.7 min. Good resolution and tailing factors were observed for all components within the separation. The LOD for ATP and 5‐HT was 30 and 317 nM, respectively, with a linear range from 10–0.02 μM. In vitro measurements were carried out by using aliquots from the buffer the tissue was stored in after 30 min to measure released molecules. In vitro assay of ileum tissue in the presence and absence of endogenous ATP was carried out. Results showed that ATP can elevate 5‐HT release. This method can be used to study alterations in these key signaling molecules with gastrointestinal disease.     

Raw Materials and Energy: A Challenge for Polymer Research

The substantial rapid growth of synthetic polymers—plastics, man-made fibers, films, rubbers, and coatings—which continued unabated over many years, suffered a severe setback for the first time in 1973–1974 followed by another in 1980. A major cause of these reverses was the changed situation with respect to raw materials and energy. For industrial polymer research, in particular, this presents a fresh challenge with considerably changed priorities. The individual ways of meeting this challenge are highlighted and illustrated by examples: the search for alternative raw material sources for monomers; the development of economic methods for production and processing of polymers; the recycling of polymers; and finally the development of new raw material-saving and energy-saving technologies based on the use of polymers. In the future, the applications of polymers to new technologies such as communication- and information-systems or biotechnology will join the traditional uses. But the efforts required in research and development to achieve this demand wide-ranging interdisciplinary cooperation on an even greater scale than hitherto.     

Dynamic simulation of pH in anaerobic processes

With the objective of contributing to the buildup of mathematical tools for anaerobic process simulation, an algorithm for the dynamic simulation of pH was developed. The dynamic simulation of the gaseous phase variables was also considered. The pH algorithm was validated for a watery system, obtaining good agreement between predicted and experimental data. The applied methodology provides a differential equation that allows the inclusion of pH as a state variable of the system that can be easily included in a general mathematical model of anaerobic digestion using matrix notation. This methodology also allows a noticeable decrease in computing time in simulations. A dynamic anaerobic digestion model of complex substrates taken from the literature was completed with the developed algorithms, and it was used to predict the response of an anaerobic reactor against overloading and against the presence of pH-dependent inhibitors with satisfactory results.     

Green chemistry of chromate cleaner production

Research topics and methods of green chemistry in chromate production are introduced in this paper . New original green chemical process of the heterogeneous reaction and separation system of liquid phase oxidation of chromite in molten salt of sodium hydroxide-one way separation in high concentration medium-metastable phase separation-carbonate recycle conversion has been developed. The green commercial process for comprehensive utilization of mineral resources-reactant recycle inside the process-zero emission was established .     

Determination of arsenic species in marine organisms by HPLC-ICP-OES and HPLC-HG-QFAAS

Separation and quantification of six arsenic species have been performed in cod, tuna and mussel samples by high performance liquid chromatography (HPLC) using inductively coupled plasma-optical emission spectrometry (ICP-OES) and hydride generation-quartz furnace atomic absorption spectrometry (HG-QFAAS) as detection techniques. It has been shown that arsenic extraction with a water-methanol (11) mixture is sufficiently quantitative for the cod and tuna, in which arsenic is mainly present as arsenobetaine (about 90% of total As extracted). In contrast, only 60% of the element is extracted from the mussels and the chromatograms obtained reveal the presence of an unknown compound. Detection limits are in the g ml^–1 range for the HPLC-ICP-OES technique (quantification of arsenobetaine and arsenocholine) and in the ng ml^–1 range for the HPLC-HG-QFAAS system (quantification of arsenite, arsenate, monomethylarsonic and dimethylarsinic acids).     

Thermodynamic analysis of the copper production step in a copper–chlorine cycle for hydrogen production

The hybrid copper–chlorine (Cu–Cl) thermo/electrochemical cycle for decomposing water into its constituents is a novel method for hydrogen production. The process involves a series of closed-loop chemical reactions. The cycle is assumed driven in an environmentally benign manner using nuclear energy. The cycle involves five steps of which three are thermally driven chemical reactions and one has an electrochemical reaction. In the present study, the electrochemical reaction, copper (Cu) production step, is described with its operational and environmental conditions, and analyzed thermodynamically. Various parametric studies are carried out on energetic and exergetic aspects of the step, considering variable reaction and reference-environment temperatures. At a reaction temperature of 45 °C, the reaction heat of the Cu production step is 140,450 kJ/kmol H₂. At a constant reaction temperature of 45 °C, the exergy destruction of the step varies between 50 kJ/kmol H₂ and 7000 kJ/kmol H₂ when the reference-environment temperature increases from 0 °C to 30 °C. At a reaction temperature of 45 °C and a reference-environment temperature of 25 °C, the exergy efficiency of this step is 99% and decreases with increasing reference-environment and/or reaction temperatures.     

Flow-based in vivo NMR spectroscopy of small aquatic organisms

NMR applied to living organisms is arguably the ultimate tool for understanding environmental stress responses and can provide desperately needed information on toxic mechanisms, synergistic effects, sublethal impacts, recovery, and biotransformation of xenobiotics. To perform in vivo NMR spectroscopy, a flow cell system is required to deliver oxygen and food to the organisms while maintaining optimal line shape for NMR spectroscopy. In this tutorial, two such flow cell systems and their constructions are discussed: (a) a single pump high-volume flow cell design is simple to build and ideal for organisms that do not require feeding (i.e., eggs) and (b) a more advanced low-volume double pump flow cell design that permits feeding, maintains optimal water height for water suppression, improves locking and shimming, and uses only a small recirculating volume, thus reducing the amount of xenobiotic required for testing. In addition, key experimental aspects including isotopic enrichment, water suppression, and 2D experiments for both ¹³C enriched and natural abundance organisms are discussed.     

Degradation and metabolism of imazapyr in soils under aerobic and anaerobic conditions

The degradation of imazapyr in four soils was investigated under laboratory aerobic and anaerobic conditions. Under aerobic conditions, imazapyr degraded faster in yellow–red soil than in other soils, and its persistence decreased depending on soil pH in the order coastal soil (pH 8.8)?>?silt-loamy paddy soil (pH 7.9)?>?fluvio-marine yellow loamy soil (pH 7.1)?>?Yellow–red soil (pH 5.3). However, soil pH did not affect imazapyr degradation under anaerobic conditions. The half-lives of imazapyr in soils under aerobic conditions were in the range of 26–44 days estimated by the first-order kinetics model, while 3–10 days calculated by two-stage model under anaerobic conditions. The preceding results demonstrated that anaerobic conditions contributed to imazapyr disappearance in soils. Based on the spectral data of APCI-MS, ¹H NMR and IR, structures of the following metabolites: 2,3-pyridinedicarboxamide, 2,3-pyridinedicarboxylic anhydride and 2,3-pyridinedicarboximide for aerobic treatments; 2,3-pyridinedicarboxylic anhydride and 2-(4-hydroxy-5-oxo-2-imdazolin-2-yl) nicotinic acid for anaerobic treatments, were identified. Degradation mechanism under the different conditions was also discussed.     

Engineering porous electrodes for next-generation redox flow batteries: recent progress and opportunities

Redox flow batteries are a promising electrochemical technology for energy-intensive grid storage applications, but further cost reductions are needed for universal adoption. As porous electrodes are responsible for functions within the flow cell that impact charge transfer, ohmics, and mass transport, improvements in electrode materials and design may yield significant performance and economic benefits. This mini-review summarizes recent developments in the design and characterization of porous electrodes with a focus on understanding and controlling both the microstructure and surface chemistry, which broadly align with mass transport and reaction kinetics. Key opportunities and challenges in the science and engineering of these materials are also presented with the goal of engaging the broader community and accelerating progress towards chemistry-specific flow battery electrodes.