Silencing the fatty acid elongase gene elovl6 induces reprogramming of nutrient metabolism in male Oreochromis niloticus.

Elongation of very long-chain fatty acids protein 6 (ELOVL6) plays a pivotal role in the synthesis of endogenous fatty acids, influencing energy balance and metabolic diseases. The primary objective of this study was to discover the molecular attributes and regulatory roles of ELOVL6 in male Nile tilapia, Oreochromis niloticus. The full-length cDNA of elovl6 was cloned from male Nile tilapia, and was determined to be 2255-bp long, including a 5'-untranslated region of 193 bp, a 3'-untranslated region of 1252 bp, and an open reading frame of 810 bp encoding 269 amino acids. The putative protein had typical features of ELOVL proteins. The transcript levels of elovl6 differed among various tissues and among fish fed with different dietary lipid sources. Knockdown of elovl6 in Nile tilapia using antisense RNA technology resulted in significant alterations in hepatic morphology, long-chain fatty acid synthesis, and fatty acid oxidation, and led to increased fat deposition in the liver and disrupted glucose/lipid metabolism. A comparative transcriptomic analysis (elovl6 knockdown vs. the negative control) identified 5877 differentially expressed genes with significant involvement in key signaling pathways including the peroxisome proliferator-activated receptor signaling pathway, fatty acid degradation, glycolysis/gluconeogenesis, and the insulin signaling pathway, all of which are crucial for lipid and glucose metabolism. qRT-PCR analyses verified the transcript levels of 13 differentially expressed genes within these pathways. Our findings indicate that elovl6 knockdown in male tilapia impedes oleic acid synthesis, culminating in aberrant nutrient metabolism.

Simulating chemical reaction dynamics on quantum computer.

The electronic energies of molecules have been successfully evaluated on quantum computers. However, more attention is paid to the dynamics simulation of molecules in practical applications. Based on the variational quantum eigensolver (VQE) algorithm, Fedorov et al. proposed a correlated sampling (CS) method and demonstrated the vibrational dynamics of H2 molecules [J. Chem. Phys. 154, 164103 (2021)]. In this study, we have developed a quantum approach by extending the CS method based on the VQE algorithm (labeled eCS-VQE) for simulating chemical reaction dynamics. First, the CS method is extended to the three-dimensional cases for calculation of first-order energy gradients, and then, it is further generalized to calculate the second-order gradients of energies. By calculating atomic forces and vibrational frequencies for H2, LiH, H+ + H2, and Cl- + CH3Cl systems, we have seen that the approach has achieved the CCSD level of accuracy. Thus, we have simulated dynamics processes for two typical chemical reactions, hydrogen exchange and chlorine substitution, and obtained high-precision reaction dynamics trajectories consistent with the classical methods. Our eCS-VQE approach, as measurement expectations and ground-state wave functions can be reused, is less demanding in quantum computing resources and is, therefore, a feasible means for the dynamics simulation of chemical reactions on the current noisy intermediate-scale quantum-era quantum devices.

Preparation and research of new black zirconia ceramics.

The existing black zirconia has problems such as uneven color development, poor stability, expensive raw materials, and harm to the human body and the environment. In order to solve the above problems, this paper intends to use NiAl2O4, NiTiO3, Fe2O3 as chromophore, zirconia as a matrix, and a solid-phase method is used to prepare high-performance black zirconia ceramics. The method avoids the introduction of toxic elements, and at the same time, it is more economical in the selection of color-developing pigments. The experimental results show that black zirconia ceramics with uniform color, continuous adjustment and high temperature stability can be obtained. When the sintering temperature is lower than 1450 °C and the color material mixing ratio is 10 wt.%, the mechanical properties and optical properties of the obtained samples optimum, the overall reflectance of the sample is less than 10 wt.%, which meets the conditions for market application. These black ceramics can be widely used in high-tech fields such as mobile phone backplanes, photovoltaic industry and high-end decorative materials, and have broad application prospects.

Ultrastructural, Antioxidant, and Metabolic Responses of Male Genetically Improved Farmed Tilapia (GIFT, Oreochromis niloticus) to Acute Hypoxia Stress.

Tilapia tolerate hypoxia; thus, they are an excellent model for the study of hypoxic adaptation. In this study, we determined the effect of acute hypoxia stress on the antioxidant capacity, metabolism, and gill/liver ultrastructure of male genetically improved farmed tilapia (GIFT, Oreochromis niloticus). Fish were kept under control (dissolved oxygen (DO): 6.5 mg/L) or hypoxic (DO: 1.0 mg/L) conditions for 72 h. After 2 h of hypoxia stress, antioxidant enzyme activities in the heart and gills decreased, while the malondialdehyde (MDA) content increased. In contrast, in the liver, antioxidant enzyme activities increased, and the MDA content decreased. From 4 to 24 h of hypoxia stress, the antioxidant enzyme activity increased in the heart but not in the liver and gills. Cytochrome oxidase activity was increased in the heart after 4 to 8 h of hypoxia stress, while that in the gills decreased during the later stages of hypoxia stress. Hypoxia stress resulted in increased Na+-K+-ATP activity in the heart, as well as hepatic vacuolization and gill lamella elongation. Under hypoxic conditions, male GIFT exhibit dynamic and complementary regulation of antioxidant systems and metabolism in the liver, gills, and heart, with coordinated responses to mitigate hypoxia-induced damage.

Single nucleotide polymorphism SNP19140160 A > C is a potential breeding locus for fast-growth largemouth bass (Micropterus salmoides).

BACKGROUND: Largemouth bass (Micropterus salmoides) has significant economic value as a high-yielding fish species in China's freshwater aquaculture industry. Determining the major genes related to growth traits and identifying molecular markers associated with these traits serve as the foundation for breeding strategies involving gene pyramiding. In this study, we screened restriction-site associated DNA sequencing (RAD-seq) data to identify single nucleotide polymorphism (SNP) loci potentially associated with extreme growth differences between fast-growth and slow-growth groups in the F1 generation of a largemouth bass population. RESULTS: We subsequently identified associations between these loci and specific candidate genes related to four key growth traits (body weight, body length, body height, and body thickness) based on SNP genotyping. In total, 4,196,486 high-quality SNPs were distributed across 23 chromosomes. Using a population-specific genotype frequency threshold of 0.7, we identified 30 potential SNPs associated with growth traits. Among the 30 SNPs, SNP19140160, SNP9639603, SNP9639605, and SNP23355498 showed significant associations; three of them (SNP9639603, SNP9639605, and SNP23355498) were significantly associated with one trait, body length, in the F1 generation, and one (SNP19140160) was significantly linked with four traits (body weight, height, length, and thickness) in the F1 generation. The markers SNP19140160 and SNP23355498 were located near two growth candidate genes, fam174b and ppip5k1b, respectively, and these candidate genes were closely linked with growth, development, and feeding. The average body weight of the group with four dominant genotypes at these SNP loci in the F1 generation population (703.86 g) was 19.63% higher than that of the group without dominant genotypes at these loci (588.36 g). CONCLUSIONS: Thus, these four markers could be used to construct a population with dominant genotypes at loci related to fast growth. These findings demonstrate how markers can be used to identify genes related to fast growth, and will be useful for molecular marker-assisted selection in the breeding of high-quality largemouth bass.

Optimal design of radial tire section layout based on thermal fatigue life improving.

The design of tire fatigue life was optimized by combining approximate model and finite element simulation, and compared with the tire endurance test results. The design variables are selected through sensitivity analysis of materials in various regions of the tire, and the thermal fatigue life of the tire is used as the objective function, and the approximate relationship between the design variables and the objective function is fitted based on the approximate model method, and the approximate model is optimized using genetic algorithm to find the optimal solution. The fatigue life of the tire is improved by about 25 %.

Transcriptional Knock-down of mstn Encoding Myostatin Improves Muscle Quality of Nile Tilapia (Oreochromis niloticus).

Myostatin (encoded by mstn) negatively regulates skeletal muscle mass and affects lipid metabolism. To explore the regulatory effects of mstn on muscle development and lipid metabolism in Nile tilapia (Oreochromis niloticus), we used antisense RNA to transcriptionally knock-down mstn. At 180 days, the body weight and body length were significantly higher in the mstn-knock-down group than in the control group (p < 0.05). Additionally, fish with mstn-knock-down exhibited myofiber hyperplasia but not hypertrophy. Oil red O staining revealed a remarkable increase in the area of lipid droplets in muscle in the mstn-knockdown group (p < 0.05). Nutrient composition analyses of muscle tissue showed that the crude fat content was significantly increased in the mstn-knock-down group (p < 0.05). The contents of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids were all significantly increased in the mstn-knock-down group (p < 0.05). Comparative transcriptome analyses revealed 2420 significant differentially expressed genes between the mstn-knock-down group and the control group. KEGG analysis indicates that disruptions to fatty acid degradation, glycerolipid metabolism, and the PPAR signaling pathway affect muscle development and lipid metabolism in mstn-knock-down Nile tilapia: acaa2, eci1, and lepr were remarkably up-regulated, and acadvl, lpl, foxo3, myod1, myog, and myf5 were significantly down-regulated (p < 0.05). These results show that knock-down of mstn results in abnormal lipid metabolism, acceleration of skeletal muscle development, and increased adipogenesis and weight gain in Nile tilapia.

Vitamin E Ameliorates Impaired Ovarian Development, Oxidative Stress, and Disrupted Lipid Metabolism in Oreochromis niloticus Fed with a Diet Containing Olive Oil Instead of Fish Oil.

Aquaculture feed containing olive oil (OO) instead of fish oil (FO) can cause oxidative stress and impair gonad development in fish. We determined the effect of dietary OO-induced oxidative stress on ovarian development, and explored whether vitamin E (VE) could mitigate negative effects. Female Nile tilapia (Oreochromis niloticus) were fed for 10 weeks with four diets: 5% OO + 70 mg/kg VE, 5% OO + 200 mg/kg VE, 5% FO + 70 mg/kg VE, or 5% FO + 200 mg/kg VE. Dietary OO reduced the specific growth rate and gonadosomatic index, inhibited superoxide dismutase and catalase, delayed ovarian development, decreased serum sex hormone levels, and reduced ovarian triglyceride and n-3 highly unsaturated fatty acid contents. The transcript levels of genes encoding sex hormone receptors (erα, fshr, lhr) and components of the lipid metabolism pathway (pparα, pparγ, hsl, accα, elovl6), the nrf2 signaling pathway (nrf2, keap1), and the nf-κb signaling pathway (nf-κb, tnfα, infγ, il1ß) differed between the 70VE/OO and 70VE/FO groups. Supplementation with 200 mg/kg VE mitigated the adverse effects of OO by improving antioxidant capacity and alleviating inflammation and abnormal lipid metabolism. This may be because VE is an antioxidant and it can regulate the nrf2-nf-κb signaling pathway.

Genomic comparison between two Inonotus hispidus strains isolated from growing in different tree species.

Inonotus hispidus mainly growing in broad-leaved trees, including Morus alba, Fraxinus mandshurica, and Ulmus macrocarpa etc. The fruiting body of I. hispidus growing in M. alba (hereafter as MA) is used as a traditional Chinese medicine "Sanghuang". However, differences between the genetic material basis of I. hispidus growing in other tree species have not been reported. Therefore, in this paper, the genomic comparison between MA and I. hispidus growing in F. mandshurica (hereafter as FM) were studied. The whole genome of MA monokaryon was sequenced by Illumina combined with Pac Bio platform. Next, genome assembly, genome component prediction and genome functional annotation were performed. Comparative genomics analysis was performed between FM monokaryon and MA monokaryon, using MA as the reference. The results showed that, MA had 24 contigs with a N50 length of 2.6 Mb. Specifically, 5,342, 6,564, 1,595, 383 and 123 genes were annotated from GO, KEGG, KOG, CAZymes and CYP450, respectively. Moreover, comparative genomics showed that, the coding genes and total number of genes annotated in different databases of FM were higher than that of MA. This study provides a foundation for the medicinal application of FM as MA from the perspective of genetic composition.

Study on the preparation and mechanical properties of purple ceramics.

This paper aims at preparing a smart wearable purple ceramic that meet the color requirements of purple smart wear in the market after using zirconate neodymium as a chromogenic agent. However, the mechanical performance of zirconate neodymium purple ceramic is not satisfactory, especially it has an extremely low fracture toughness. To solve this, a 3 mol% yttria-stabilized zirconia (3YSZ) is added to zirconate neodymium in the preparation of multiphase ceramics to improve its mechanical properties. In this experiment, a series of ceramic samples with addition of increasing amount of 3YSZ 0, 20, 40, 50, 60, 70 and 80% were prepared in the 1400-1500 °C sintering temperature range. It was found that at the same temperature, the mechanical properties of the ceramic samples gradually improved with the increase in the 3YSZ content. Moreover, with the same content, the mechanical properties of the ceramic samples gradually improved with the decrease in temperature. The results show that when 3YSZ has a mass fraction of 80% and is sintered at 1400 °C, the fracture toughness of the prepared ceramic samples reaches 8.15 MPa‧m1/2, which is nearly two times higher than that of the monolithic neodymium zirconate 2.57 MPa‧m1/2. The Vickers hardness of the prepared ceramic samples reached 12.93 GPa, which is nearly 88% higher than the undoped neodymium zirconate. This indicates that the samples can be applied in smart wearables, such as mobile phone backplane, with a certain practical significance for engineering toughening of zirconate ceramics.

Gut microbiota and hypertension: association, mechanisms and treatment.

OBJECTIVES: Hypertension is one of the most important risk factors for cardio-cerebral vascular diseases, which brings a heavy economic burden to society and becomes a major public health problem. At present, the pathogenesis of hypertension is unclear. Increasing evidence has proven that the pathogenesis of hypertension is closely related to the dysbiosis of gut microbiota. We briefly reviewed relevant literature on gut microbiota and hypertension to summarize the relationship between gut microbiota and hypertension, linked the antihypertension effects of drugs with their modulation on gut microbiota, and discussed the potential mechanisms of various gut microbes and their active metabolites to alleviate hypertension, thus providing new research ideas for the development of antihypertension drugs. METHODS: The relevant literature was collected systematically from scientific database, including Elsevier, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Baidu Scholar, as well as other literature sources, such as classic books of herbal medicine. RESULTS: Hypertension can lead to gut microbiota imbalance and gut barrier dysfunction, including increased harmful bacteria and hydrogen sulfide and lipopolysaccharide, decreased beneficial bacteria and short-chain fatty acids, decreased intestinal tight junction proteins and increased intestinal permeability. Gut microbiota imbalance is closely related to the occurrence and development of hypertension. At present, the main methods to regulate the gut microbiota include fecal microbiota transplantation, supplementation of probiotics, antibiotics, diet and exercise, antihypertensive drugs, and natural medicines. CONCLUSIONS: Gut microbiota is closely related to hypertension. Investigating the correlation between gut microbiota and hypertension may help to reveal the pathogenesis of hypertension from the perspective of gut microbiota, which is of great significance for the prevention and treatment of hypertension.

Whole Genome Sequencing of Brucella melitensis Isolated from Patients in Hohhot, China.

Brucellosis is a class B infectious disease that is spreading rapidly in Inner Mongolia, China. Investigating the genetics of this disease might provide insights into the mechanism by which the bacteria adapt to their hosts. Here, we report the genome sequence of Brucella melitensis strain BM6144, which was isolated from a human patient.

Transport Stress Induces Oxidative Stress and Immune Response in Juvenile Largemouth Bass (Micropterus salmoides): Analysis of Oxidative and Immunological Parameters and the Gut Microbiome.

Transport is essential in cross-regional culturing of juvenile fish. Largemouth bass (Micropterus salmoides) often exhibit decreased vitality and are susceptible to disease after transportation. To study the effects of transport stress on juvenile largemouth bass, juveniles (average length: 8.42 ± 0.44 cm, average weight 10.26 ± 0.32 g) were subjected to a 12 h simulated transport, then subsequently, allowed to recover for 5 d. Liver and intestinal tissues were collected at 0, 6 and 12 h after transport stress and after 5 d of recovery. Oxidative and immunological parameters and the gut microbiome were analyzed. Hepatocytic vacuolization and shortened intestinal villi in the bass indicated liver and intestinal damage due to transport stress. Superoxide dismutase, lysozyme and complement C3 activities were significantly increased during transport stress (p < 0.05), indicating that transport stress resulted in oxidative stress and altered innate immune responses in the bass. With the transport stress, the malondialdehyde content first increased, then significantly decreased (p < 0.05) and showed an increasing trend in the recovery group. 16S rDNA analysis revealed that transport stress strongly affected the gut microbial compositions, mainly among Proteobacteria, Firmicutes, Cyanobacteria and Spirochaetes. The Proteobacteria abundance increased significantly after transport. The Kyoto Encyclopedia of Genes and Genomes functional analysis revealed that most gut microbes played roles in membrane transport, cell replication and repair. Correlation analyses demonstrated that the dominant genera varied significantly and participated in the measured physiological parameter changes. With 5 days of recovery after 12 h of transport stress, the physiological parameters and gut microbiome differed significantly between the experimental and control groups. These results provide a reference and basis for studying transport-stress-induced oxidative and immune mechanisms in juvenile largemouth bass to help optimize juvenile largemouth bass transportation.

Gut microbiota combined with metabolites reveals unique features of acute myocardial infarction patients different from stable coronary artery disease.

INTRODUCTION: Acute myocardial infarction (AMI) accounts for the majority of deaths caused by coronary artery disease (CAD). Early warning of AMI, especially for patients with stable coronary artery disease (sCAD), is urgently needed. Our previous study showed that alterations in the gut microbiota were correlated with CAD severity. OBJECTIVES: Herein, we tried to discover accurate and convenient biomarkers for AMI by combination of gut microbiota and fecal/blood/urinary metabolomics. METHODS: We recruited 190 volunteers including 93 sCAD patients, 49 AMI patients, and 48 subjects with normal coronary artery (NCA), and measured their blood biochemical parameters, 16S rRNA-based gut microbiota and NMR-based fecal/blood/urinary metabolites. We further selected 20 subjects from each group and analyzed their gut microbiota by whole-metagenome shotgun sequencing. RESULTS: Multi-omic analyses revealed that AMI patients exhibited specific changes in gut microbiota and serum/urinary/fecal metabolites as compared to subjects with sCAD or NCA. Fourteen bacterial genera and 30 metabolites (11 in feces, 10 in blood, 9 in urine) were closely related to AMI phenotypes and could accurately distinguish AMI patients from sCAD patients. Some species belonging to Alistipes, Streptococcus, Ruminococcus, Lactobacillus and Faecalibacterium were effective to distinguish AMI from sCAD and their predictive ability was confirmed in an independent cohort of CAD patients. We further selected nine indicators including 4 bacterial genera, 3 fecal and 2 urinary metabolites as a noninvasive biomarker set which can distinguish AMI from sCAD with an AUC of 0.932. CONCLUSION: Combination of gut microbiota and fecal/urinary metabolites provided a set of potential useful and noninvasive predictive biomarker for AMI from sCAD.

A unified framework of transformations based on the Jordan-Wigner transformation.

Quantum simulation of chemical Hamiltonians enables the efficient calculation of chemical properties. Mapping is one of the essential steps in simulating fermionic systems on quantum computers. In this work, a unified framework of transformations mapping fermionic systems to qubit systems is presented and many existing transformations-such as Jordan-Wigner, Bravyi-Kitaev, and parity transformations-are included in this framework. Based on this framework, the Multilayer Segmented Parity (MSP) transformation is proposed. The MSP transformation is a general mapping with an adjustable parameter vector, which can be viewed as a generalization of the above-mentioned mappings. Furthermore, the MSP transformation can adjust flexibly when dealing with different systems. Applying these mappings to the electronic structure Hamiltonians of various molecules, the MSP transformation is found to perform better on a number of Pauli operators and gates needed in the circuit of Hamiltonian simulation. The MSP transformation will reduce the qubit gate requirement for Hamiltonian simulation on noisy intermediate-scale quantum devices, and it will provide a much wider choice of mappings for researchers.

Therapeutic effect of two methods on avulsion fracture of tibial insertion of anterior cruciate ligament.

BACKGROUND: The tibial stop of anterior cruciate ligament (ACL) is fan-shaped and attached to the medial groove in front of the intercondylar spine, which is located between the anterior horn of the medial and lateral meniscus. The incidence of this fracture is low previously reported, which is common in children and adolescents. With the increase of sports injury and traffic injury and the deepening of under-standing, it is found that the incidence of the disease is high at present. AIM: To explore the difference between open reduction and internal fixation with small incision and high-intensity non-absorbable suture under arthroscopy in the treatment of tibial avulsion fracture of ACL. METHODS: Seventy-six patients with tibial avulsion fracture of anterior cruciate ligament diagnosed and treated in Guanyun County People's Hospital from April 2018 to June 2020 were retrospectively analyzed. According to the surgical methods, they were divided into group A (40 cases) and group B (36 cases). Patients in group A were treated with arthroscopic high-strength non-absorbable suture, and patients in group B were treated with small incision open reduction and internal fixation. The operation time, fracture healing time, knee joint activity and functional score before and after operation, and surgical complications of the two groups were compared. RESULTS: The operation time of group A was higher than that of group B, and the difference was statistically significant (P < 0.05); the fracture healing time of group A was compared with that of group B, and the difference was not statistically significant (P > 0.05); The knee joint function activity was compared between two groups before operation, 3 mo and 6 mo after operation, and the difference was not statistically significant (P > 0.05); the knee joint function activity of group A and group B at 3 mo and 6 mo after operation was significantly higher than that before operation (P < 0.05); the limp, support, lock, instability, swelling, upstairs, squatting, pain and Lysholm score were compared between the two groups before and 6 mo after operation, and the difference was not statistically significant (P > 0.05); the scores of limp, support, lock, instability, swelling, upstairs, squatting, pain and Lysholm in group A and group B at 6 mo after operation were significantly higher than those before operation (P > 0.05); the surgical complication rate of group A was 2.63%, which was lower than 18.42% of group B, and the difference was statistically significant (P > 0.05). CONCLUSION: Both small incision open reduction and internal fixation and arthroscopic high-strength non-absorbable sutures can achieve good results in the treatment of anterior cruciate ligament tibial avulsion fractures. The operation time of arthroscopic high-strength non-absorbable sutures is slightly longer, but the complication rate is lower.

The berberine-enriched gut commensal Blautia producta ameliorates high-fat diet (HFD)-induced hyperlipidemia and stimulates liver LDLR expression.

Berberine (BBR) is an effective cholesterol-lowering drug. Although gut microbiota has been implicated in the pharmacological activities of BBR, little evidence exists on the specific species of gut microbiota involved in its therapeutic effects, nor on linking gut bacteria to its recognized hypercholesterolemia-alleviating mechanism-upregulation of the low-density lipoprotein receptor (LDLR) in the liver. The present study was performed to identify the specific species of gut microbiota involved in the anti-hyperlipdemic effect of BBR, and interpret its mechanism through linking the gut microbiota and LDLR. The BBR-enriched gut bacterial species were identified by whole genome shotgun sequencing. Pure cultured B. producta was orally administered to C57BL/6 mice to evaluate its anti-hyperlipdemic effect. The LDLR-upregulating effect of B. producta was evaluated both in vitro and in vivo. Orally administration of BBR (200 mg/kg) decreased serum and liver lipid levels in HFD-induced hyperlipidemic mice. Microbiome analysis indicated that Blautia was closely associated with BBR's lipid-modulating activities. Further analysis revealed that BBR selectively promoted the growth of Blautia producta. Orally treatment of HFD mice with live B. producta reduced obesity and alleviated hyperlipidemia. Notably, the B. producta significantly increased LDLR expression in the liver, and its spent culture supernatant upregulated the LDLR level and promoted LDL uptake by HepG2 cells. Simultaneously, B. producta also linked butyrate-producing and bile salt hydrolase (BSH)-inhibiting effect of BBR. The gut microbiota, especially B. producta, may confers the hypercholesterolemia-alleviating effects of berberine. B. producta represents a novel probiotic that may be used for the treatment of dyslipidemia.

Efficient Implementation of Block-Correlated Coupled Cluster Theory Based on the Generalized Valence Bond Reference for Strongly Correlated Systems.

An optimized implementation of block-correlated coupled cluster theory based on the generalized valence bond wave function (GVB-BCCC) for the singlet ground state of strongly correlated systems is presented. The GVB-BCCC method with two-pair correlation (GVB-BCCC2b) or up to three-pair correlation (GVB-BCCC3b) will be the focus of this work. Three major techniques have been adopted to dramatically accelerate GVB-BCCC2b and GVB-BCCC3b calculations. First, the GVB-BCCC2b and GVB-BCCC3b codes are noticeably optimized by removing redundant calculations. Second, independent amplitudes are identified by constraining excited configurations to be pure singlet states and only independent amplitudes need to be solved. Third, an incremental updating scheme for the amplitudes in solving the GVB-BCCC equations is adopted. With these techniques, accurate GVB-BCCC3b calculations are now accessible for systems with relatively large active spaces (50 electrons in 50 orbitals) and GVB-BCCC2b calculations are affordable for systems with much larger active spaces. We have applied GVB-BCCC methods to investigate three typical kinds of systems: polyacenes, pentaprismane, and [Cu2O2]2+ isomers. For polyacenes, we demonstrate that GVB-BCCC3b can capture more than 94% of the total correlation energy even for 12-acene with 50 π electrons. For the potential energy curve of simultaneously stretching 15 C-C bonds in pentaprismane, our calculations show that the GVB-BCCC3b results are quite close to the results from the density matrix renormalization group (DMRG) over the whole range. For two dinuclear copper oxide isomers, their relative energy predicted by GVB-BCCC3b is also in good accord with the DMRG result. All calculations show that the inclusion of three-pair correlation in GVB-BCCC is critical for accurate descriptions of strongly correlated systems.

Performance analysis of a half-batch multi-cell three-dimensional electrode reactor for drilling wastewater: COD removal, energy consumption and hydrodynamic characteristic.

Although a three-dimensional electrode system (3DES) has made remarkable achievements in improving the property of electrodes and investigating pollutant degradation mechanism, the design of an electrochemical reactor for application in drilling wastewater has not been reported yet. In this study, a novel half-batch multi-cell 3DES reactor was constructed by us to degrade organic compounds from drilling wastewater. The separate effect of electrolysis time, current density, the configuration of granular activated carbon (GAC) electrodes, aeration rate and volumetric recirculation flow on chemical oxygen demand (COD) removal and energy consumption of the half-batch reactor were analyzed, and further optimization via response surface methodology (RSM). Results showed that the optimal operation conditions for the reactor included electrolysis time of 100 min, a current density of 9.2 mA/cm2, GAC electrode vertical configuration, an aeration rate of 2.67 L/min and a volumetric recirculation flow of 100 mL/min. Under these conditions, the maximum percentage COD removal was found to be 97.39% with an energy consumption of 77.89 kWh(kg COD)-1. The residence time distribution (RTD) method was carried out in continuous flow pattern to investigate the hydrodynamic characteristics of the reactor. Results showed that flow rate was the most dominant factor for the flow pattern of the reactor, followed by the aeration rate and current density. The low dispersion number and the percentage of dead volume are 0.214 and 3.87% when the flow rate of 100 mL/min, respectively, which indicates that there is an intermediate flow pattern existing in between plug-flow ideal and complete mixing flow, furthermore, it is close to the plug-flow ideal.