Electron Transfer System Research Articles

Adipose Mitochondrial Respiratory Capacity in Obesity is Impaired Independently of Glycemic Status of Tissue Donors.

The study aimed to investigate how obesity and glycemic state affect mitochondrial respiration and ATP-generating pathways in mature human adipocytes. Subcutaneous (sc) and visceral (vc) adipocytes were isolated from patients undergoing abdominal surgery. Respiratory chain function was analyzed by high-resolution respirometry. Adipocyte ATP levels and lactate release were measured separately in the presence of either glycolysis (2-deoxy-D-glucose) or ATP synthase (oligomycin) inhibitors. A significant negative correlation between oxidative phosphorylation capacity and the BMI of tissue donors found in sc adipocytes (P<0.05). Furthermore, respirometry revealed an inverse relationship between BMI and the electron transfer system capacity of sc (P<0.05) but not vc adipocytes. In both depots, the respiratory capacity was not affected by the glycemic state. A positive correlation between BMI and adipocyte lactate release was measured independently of the tissue origin (sc: P=0.01; vc: P<0.05). Direct ATP measurements indicated that energy demands of adipocytes were predominantly fulfilled by glycolytic activity. The study's data suggest that obesity is the primary driver of impaired adipocyte mitochondrial respiration because the glycemic state did not further deteriorate this situation. The adipocytes' energy needs are covered primarily by the glycolytic pathway.

Establishment and application of an electronic transfer system for emergency surgery patients

Objective To explore the effects of the electronic transfer system on emergency surgery patients. Methods The electronic transfer system for emergency surgery patients were established. Totally 98 patients who were transferred from the emergency service into the Operation Room using the electronic surgery system were included into the observation group from January to December 2017, while 88 patients who were transferred from the emergency service into the Operation Room using oral and printed transfer records were included into the control group form January to December 2016. The success rate of transfer, patient's and nurse's satisfaction were compared between the two groups. Results The success rate of transfer using the electronic transfer system for emergency surgery patients was 95.92%, while that of the control group was 77.27% (χ2=14.343, P<0.05) . Patient's satisfaction of the observation group was 92.86%, while that of the control group was 59.09% (χ2=29.743, P<0.05) . The nurse's satisfaction of the observation group was 95.92%, while that of the control group was 87.50% (χ2=4.432, P<0.05) . Conclusions The establishment of the electronic transfer system for emergency surgery patients further clarifies the content of transfer, enhances nurses' responsibility and shortens the time of transfer, which plays a preventative and control role in risk management and safety management in emergency surgery patients. Key words: Emergency surgery; Electronic transfer system; Success rate of transfer; Nursing quality

Rational Design of Proton-Electron-Transfer System Based on Nickel Dithiolene Complexes with Pyrazine Skeletons.

To understand the effect of chemical modification on the stability and proton-electron coupling in neutral radical molecules with a proton-electron-transfer (PET) state, we investigate a nickel dithiolene complex with cyano-substituted pyrazine skeletons using experimental and theoretical methods. A Pourbaix diagram constructed from absorption spectroscopic and cyclic voltammetric measurements strongly suggests that the PET state of the complex is significantly more stable compared with that of the nonsubstituted complex. Theoretical calculations predicted that the introduction of electron-withdrawing groups leads to stabilization of the PET state mainly because of a greater delocalized electron distribution in the molecule. Crystallographic studies, with the support of theoretical calculations, revealed that the degree of coupling between protons and electrons varies depending on the Hammett σ value of the substituents; the electronic state of the nonsubstituted complex appears to be most sensitive to the protonated state mainly owing to the spatially confined π-electron system.

Anthracene-based azo dyes for photo-induced proton-coupled electron transfer.

Herein, we report a new donor-acceptor system for photo-induced proton-coupled electron transfer (PCET) that leverages an azo linkage as the proton-sensitive component and anthracene as a photo-trigger. Electrochemistry shows a change in the reduction potential with addition of acid. However, photochemistry is invariant to the absence or presence of acid. The anthracene and phenol/4-methoxyphenyl moieties of the azo dyes are highly conjugated, likely mitigating photo-induced charge transfer, despite sufficient driving force.

From paper to plastic: Understanding the impact of eWIC on WIC recipient behavior

Evidence shows that the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is underutilized. WIC enrolls 52.7% of eligible persons and participants claim a fraction of available benefits. Researchers suggest that people underutilize WIC because of the time needed to enroll in and use WIC and because participants may believe that, if others notice them participating in WIC, community members will stigmatize them. Recently enacted policies may reduce both time costs and potential for stigma associated with WIC. Congress mandated that, by 2020, all states disburse WIC benefits through an Electronic Benefits Transfer (eWIC) system. Given that eWIC reduces the time required for each transaction and and makes it more difficult to identify beneficiaries, we expect WIC redemptions to increase. In addition, eWIC might also increase the chance WIC recipients choose non-WIC foods for redemption increasing non-WIC expenditures. To measure the impact of eWIC on WIC redemptions and non-WIC food expenditures we analyze data on grocery expenditures of 11,887 WIC-participating households in one state over the period it implemented eWIC. We find that, after beneficiaries began redeeming WIC benefits through eWIC, spending on non-WIC eligible foods did not change but redemptions of WIC benefits increased.

Dopamine-functionalized upconversion nanoparticles as fluorescent sensors for organophosphorus pesticide analysis

Organophosphorus pesticide (OP) residues in agricultural products, herbal medicines and environment have attracted increasing concerns because they cause high healthy risk. Herein, a tyrosinase-mediated photoinduced electron transfer system was constructed for OPs analysis by using dopamine-functionalized upconversion nanoparticles (UCNPs) as fluorescent (FL) sensors. Dopamine quinone was produced by tyrosinase-mediated oxidation of dopamine on the surface of UCNPs, which acted as electron accepter to quench the FL emission of UCNPs. The FL quenching was inhibited by OP since it inhibited the activity of tyrosinase. Chlorpyrifos was used as a model analyte to investigate the feasibility of the FL sensor for the analysis of OPs. Under the optimal conditions, chlorpyrifos can be analysed in a wide range of 1.0 ‒ 1000 ng mL−1, with a detection limit of 0.38 ng mL−1 (3σ). Some other groups pesticides, including organonitrogen pesticide, organochlorine pesticide and chloronicotinyl insecticide all showed negligible interference. The proposed sensor was successfully used to analyse chlorpyrifos spiked in Balloonflower and Angelica with acceptable recovery values of 95.4–120.0%, demonstrating its application potential for real samples. It exhibits some advantages like low cost, high sensitivity and free of autofluorescent interference and photobleaching.

Selective ϖ-1 oxidation of fatty acids by CYP147G1 from Mycobacterium marinum

BackgroundCyp147G1 is one of 47 cytochrome P450 encoding genes in Mycobacterium marinum M, a pathogenic bacterium with a high degree of sequence similarity to Mycobacterium tuberculosis and Mycobacterium ulcerans. Cyp147G1 is one of only two of these cyp genes which are closely associated with a complete electron transfer system. MethodsThe substrate range of the enzyme was tested in vitro and the activity of CYP147G1 was reconstituted in vivo by co-producing the P450 with the ferredoxin and ferredoxin reductase. ResultsSubstrates of CYP147G1 include fatty acids ranging from octanoic to hexadecanoic acid. CYP147G1 catalysed the selective hydroxylation of linear and ω-2 methyl branched fatty acids at the ω-1 position (≥ 98%). Oxidation of ω-1 methyl branched fatty acids generated the ω and ω-1 hydroxylation products in almost equal proportions, indicating altered position of hydrogen abstraction. ConclusionsThis selectivity of fatty acid hydroxylation inferred that linear species must bind in the active site of the enzyme with the terminal methyl group sequestered so that abstraction at the CH bonds of the ω-1 position is favoured. With branched substrates, one of the methyl groups must be close to the compound I oxygen atom and enable hydroxylation at the terminal methyl group to compete with the reaction at the ω-1CH bond. General significanceHydroxy fatty acids are widely used for industrial, food and medical purposes. CYP147G1 demonstrates high regioselectivity for hydroxylation at a sub-terminal position on a broad range of linear fatty acids, not seen in other CYP enzymes.

Construct 3D Pd@MoS2-conjugated polypyrrole framworks Heterojunction with unprecedented photocatalytic activity for Tsuji-Trost reaction under visible light

Site-selective coupling of two photochemical system and one electron-transfer system to realize efficient charge separation and light absorption affords a promising route to enhance the photocatalytic efficiencies of semiconductors. To date, however, how to develop 3D porous multicomponent heterojunction systems for solar energy conversion in the visible and near-infrared (NIR) light region still remains a significant challenge. Here we report a simple technique for forming 3D Pd@MoS2-conjugated polypyrrole framworks (Pd@MoS2CPFs), in which two visible-light-active components (MoS2 nanosheets and polypyrrole) and the electron-transfer system (Pd) are spatially fixed, and the uniform Pd NPs are anchored in the MoS2CPFs. This 3D porous system exhibits good structural stability, high pore volume (0.31 cm3 g−1), high surface area (105.24 m2/g), improved light absorption, and a long living electron-hole pair at the Pd@MoS2CPFs interface. Unexpectedly, we first found that the formed Pd@MoS2CPFs exhibited excellent photocatalytic activity and long-term stability for the direct Tsuji-Trost reaction between allylalcohol and 1,3-dicarbonyl under visible light at room temperature, far exceeding those of the single- and two-component systems, as a result of vectorial electron transfer driven by the one-step excitation of polypyrrole and MoS2. These results provide a promising new avenue in the design and fabrication of unique 3D porous multicomponent heterojunction for visible-light-induced efficient artificial photosynthetic systems.

Mesoporous black TiO2 array employing sputtered Au cocatalyst exhibiting efficient charge separation and high H2 evolution activity

The separation and transfer of photogenerated carriers are the key issue in the design of high performance TiO2 photocatalysts. In order to overcome the kinetic limitations and achieve rapid charge transfer, TiO2-related multi-component catalysts have been extensively studied. Among all the TiO2 supports, the impressive black TiO2 (BT) with broad visible light absorption spectrum and oxygen vacancies are preferable, but still suffers from low quantum efficiency. Meanwhile, poor control of cocatalyst placement by conventional loading method can also severely impede photocatalytic efficiency. Herein a fast and simple metal magnetron sputter approach was used to place highly-uniformed Au nanoparticles cocatalyst on the top of the mesoporous TiO2–BT nanotube array fabricated by in situ electrochemical anodization approach on a Ti film. This confined plasmonic photocatalyst with highly uniformly distributed Au cocatalysts exhibited greatly enhanced charge-separation and charge-transfer behavior, and a remarkable 10 times enhancement of the photocatalytic H2 evolution reactivity over conventional TiO2 nanotube. The TiO2-BT-Au electron transfer cascade structure is proposed in which black TiO2 acts as a buffer layer for TiO2 conduction band electrons, allowing efficient photogenerated electrons to be transferred to Au nanoparticles and then into the TiO2 pores that suitable for H2 generation. Since the nanotube walls themselves are curved upwards, the short diffusion length allows electrons to be easily transferred to the cocatalyst, where recombination of photogenerated electron pairs is limited. The metal magnetron sputter technique for noble metal cocatalyst immobilization and the unique TiO2–BT–Au electron-transfer system are promising and can be extended to the design of other supported catalysts.

Mitochondrial functioning abnormalities observed in blood platelets of chronic smoke-exposed guinea pigs - a pilot study.

BackgroundCOPD represents a major global health issue, which is often accompanied by cardiovascular diseases. A considerable body of evidence suggests that cardiovascular risk is elevated by the activation of blood platelets, which in turn is exacerbated by inflammation. As reactive oxygen species are believed to be an important factor in platelet metabolism and functioning, the aim of our study was to perform a complex assessment of mitochondrial function in platelets in chronic smoke exposed animals with COPD-like lung lesions.Materials and methodsEight-week-old, male Dunkin Hartley guinea pigs (the study group) were exposed to the cigarette smoke from commercial unfiltered cigarettes (0.9 mg/cig of nicotine content) or to the air without cigarette smoke (control group), using the Candela Constructions® exposure system. The animals were exposed for 4 hours daily, 5 days a week, with 2×70 mL puff/minute, until signs of dyspnea were observed. The animals were bled, and isolated platelets were used to monitor blood platelet respiration. The mitochondrial respiratory parameters of the platelets were monitored in vitro based on continuous recording of oxygen consumption by high-resolution respirometry.ResultsAn elevated respiration trend was observed in the LEAK-state (adjusted for number of platelets) in the smoke-exposed animals: 6.75 (5.09) vs 2.53 (1.28) (pmol O2/[s ⋅ 1108 platelets]); bootstrap-boosted P1α=0.04. The study group also demonstrated lowered respiration in the ET-state (normalized for protein content): 12.31 (4.84) vs 16.48 (1.72) (pmol O2/[s ⋅ mg of protein]); bootstrap-boosted P1α=0.049.ConclusionOur results suggest increased proton and electron leak and decreased electron transfer system capacity in platelets from chronic smoke-exposed animals. These observations may also indicate that platelets play an important role in the pathobiology of COPD and its comorbidities and may serve as a background for possible therapeutic targeting. However, these preliminary outcomes should be further validated in studies based on larger samples.

Imaging of Mitochondria Metabolic Change after Radiation Treatment using Dynamic Nuclear Polarization (DNP)-MRI

In vivo dynamic nuclear polarization-magnetic resonance imaging (DNP-MRI) enables the anatomical distribution of free radical species to be monitored. DNP enhances the MRI signal from nuclei such as 1H by irradiating tissue at the electron paramagnetic resonance (EPR) frequency of the free radical, before applying the MRI pulse sequence, thus increasing the image intensity where free radicals are present. Low-molecular-weight, stable nitroxyl compounds, including carbamoyl-PROXYL (CmP), are organic free radicals that possess SOD-like activity, and they have been used as probes in a variety of biophysical and biochemical experiments. The reduction rate of the radical probe depends on the tissue redox environment, which is influenced by factors such as overproduction of ROS and decreased antioxidant defences. In this study, we evaluated the feasibility of mitochondrial redox metabolic imaging, assessed by DNP-MRI with CmP as a molecular imaging probe, for detecting the metabolic change after radiation treatment to the tissue homogenate solution. Redox imaging of mitochondrial metabolism was performed with a low magnetic field using an in vivo DNP-MRI system (Keller, Japan Redox Inc.). The external magnetic field (B0) for EPR irradiation and MRI was fixed at 15 mT, and the radiofrequencies for EPR irradiation and MRI were 455 MHz and 683 kHz, respectively. DNP-MRI images of liver homogenate solution with or without radiation (10 or 20 gray) were obtained at 3, 5, 10, 15, 20, 25, 30, 35 and 40 min after starting measurement. The redox map was obtained by the slope of the enhanced DNP image intensity of each pixel from four pharmacokinetic images using a custom Excel macro program. Phantom redox experiments were conducted to examine the ability of CmP to participate in the mitochondrial redox reaction, and time-dependent changes in image contrast were assessed using liver tissue homogenate and KCN, an inhibitor of mitochondrial electron transfer chain. The DNP images clearly showed the significant enhancement in tissue homogenate solution by CmP. The enhancement of DNP-image was gradually reduced by liver homogenate solution due to reduction of CmP and the reduction rate of CmP was increased by the treatment of radiation. Interestingly, reduction of CmP in both homogenates with or without radiation were completely inhibited by KCN treatment. It is suggested that enhancement of CmP reduction is related in mitochondrial electron transfer system. We demonstrated that the mitochondrial redox metabolic change in the electron transfer chain after radiotherapy could be monitored by DNP-MRI with CmP as a redox probe.

Ruthenium pyridyl thiocyanate complex increased the production of pro-inflammatory TNFα and IL1β cytokines by the LPS stimulated mammalian macrophages in vitro.

Every cell in our body depends on the electron transport processes in order to generate energy and function properly. Being able to regulate the metabolic activity of a cell would enable us altering its function and eventually lead us to a desired biological outcome at the cellular level and more desirably at a systemic level. Immunomodulatory or immunostimulatory molecules have been focus of the recent studies in order to regulate or boost the activities of the immune system cells and suppress or eliminate the disease conditions such as cancer, autoimmune reactions, inflammatory disorders as well as infections. In our study we used a ruthenium pyridyl thiocyanate complex, K330, to examine its effect on the activity of the innate immune system cells, macrophages in vitro. K330 was our candidate due to its application in the solar cells. Especially, due to its ability to get involved in electron transfer systems we hypothesized that it could change the activity of the immune system cells at cellular level, possibly by interfering the electron transfer reactions of the cells. Our results support our hypothesis since K330 lead to a significant increase in TNFα and IL1β cytokine production levels by LPS stimulated macrophages compared to only LPS treated control groups. Based on our in vitro results, K330 can also be utilized as an adjuvant candidate in vaccinations where the antigen itself is not sufficient to generate a proper immune response.

Quercetin preserves redox status and stimulates mitochondrial function in metabolically-stressed HepG2 cells

Hyperglycemia augments formation of intracellular reactive oxygen species (ROS) with associated mitochondrial damage and increased risk of insulin resistance in type 2 diabetes. We examined whether quercetin could reverse chronic high glucose-induced oxidative stress and mitochondrial dysfunction. Following long-term high glucose treatment, complex I activity was significantly decreased in isolated mitochondria from HepG2 cells. Quercetin dose-dependently recovered complex I activity and lowered cellular ROS generation under both high and normal glucose conditions. Respirometry studies showed that quercetin could counteract the detrimental increase in inner mitochondrial membrane proton leakage resulting from high glucose while it increased oxidative respiration, despite a decrease in electron transfer system (ETS) capacity, and lower non-ETS oxygen consumption. A quercetin-stimulated increase in cellular NAD+/NADH was evident within 2 h and a two-fold increase in PGC-1α mRNA within 6 h, in both normal and high glucose conditions. A similar pattern was also found for the mRNA expression of the repulsive guidance molecule b (RGMB) and its long non-coding RNA (lncRNA) RGMB-AS1 with quercetin, indicating a potential change of the glycolytic phenotype and suppression of aberrant cellular growth which is characteristic of the HepG2 cells. Direct effects of quercetin on PGC-1α activity were minimal, as quercetin only weakly enhanced PGC-1α binding to PPARα in vitro at higher concentrations. Our results suggest that quercetin may protect mitochondrial function from high glucose-induced stress by increasing cellular NAD+/NADH and activation of PGC-1α-mediated pathways. Lower ROS in combination with improved complex I activity and ETS coupling efficiency under conditions of amplified oxidative stress could reinforce mitochondrial integrity and improve redox status, beneficial in certain metabolic diseases.

Oxygen conserving mitochondrial adaptations in the skeletal muscles of breath hold divers.

BackgroundThe performance of elite breath hold divers (BHD) includes static breath hold for more than 11 minutes, swimming as far as 300 m, or going below 250 m in depth, all on a single breath of air. Diving mammals are adapted to sustain oxidative metabolism in hypoxic conditions through several metabolic adaptations, including improved capacity for oxygen transport and mitochondrial oxidative phosphorylation in skeletal muscle. It was hypothesized that similar adaptations characterized human BHD. Hence, the purpose of this study was to examine the capacity for oxidative metabolism in skeletal muscle of BHD compared to matched controls.MethodsBiopsies were obtained from the lateral vastus of the femoral muscle from 8 Danish BHD and 8 non-diving controls (Judo athletes) matched for morphometry and whole body VO2max. High resolution respirometry was used to determine mitochondrial respiratory capacity and leak respiration with simultaneous measurement of mitochondrial H2O2 emission. Maximal citrate synthase (CS) and 3-hydroxyacyl CoA dehydrogenase (HAD) activity were measured in muscle tissue homogenates. Western Blotting was used to determine protein contents of respiratory complex I-V subunits and myoglobin in muscle tissue lysates.ResultsMuscle biopsies of BHD revealed lower mitochondrial leak respiration and electron transfer system (ETS) capacity and higher H2O2 emission during leak respiration than controls, with no differences in enzyme activities (CS and HAD) or protein content of mitochondrial complex subunits myoglobin, myosin heavy chain isoforms, markers of glucose metabolism and antioxidant enzymes.ConclusionWe demonstrated for the first time in humans, that the skeletal muscles of BHD are characterized by lower mitochondrial oxygen consumption both during low leak and high (ETS) respiration than matched controls. This supports previous observations of diving mammals demonstrating a lower aerobic mitochondrial capacity of the skeletal muscles as an oxygen conserving adaptation during prolonged dives.

A novel electrochemical enzyme biosensor for detection of 17β-estradiol by mediated electron-transfer system

An extremely sensitive enzyme sensor for detection of 17β-estradiol based on electropolymerized L-lysine molecules on a glassy carbon electrode (GCE) modified with critic acid@graphene (CA-GR) and cross-linked with laccase enzyme has been developed in this work. As the laccase immobilization, glutaraldehyde was chosen as cross-linker through the groups reactions. The novel enzyme sensor could recognize and determinate 17β-estradiol effectively. The morphology of the enzyme modified electrode was characterized by transmission electron microscopy (TEM) and electron microscopy (SEM). The amino interaction between cross-linker and enzyme was characterized by Fourier transform infrared spectroscopy (FTIR). Under the optimal experimental conditions, good linear relationships were achieved in the range of 4 × 10–13 − 5.7 × 10–11 M and a limit of detection as low as 1.3 × 10–13 M. Moreover, the enzyme sensor exhibited good reproducibility, stability and high selectivity to 17β-estradiol. Excellent performance was showed in the human urine samples analysis, thus confirming great prospect for further application in clinic diagnosis and biological research.

Carbon export through zooplankton active flux in the Canary Current

Abstract Zooplankton vertical distribution, migrant biomass, and respiratory flux were studied in two transects performed in the Canary Current at 21°N and 26°N from the eu- and mesotrophic upwelling zone off Northwest Africa to the oligotrophic central gyre waters. Migrant biomass was estimated by sampling during day and night using a Longhurst-Hardy Plankton Recorder (LHPR) net in the 0–900 m depth water column. The electron transfer system (ETS) enzymatic activity was measured as a proxy for zooplankton respiration in the 0–900 m depth water column. Respiratory flux was obtained from the migrant biomass and the daytime respiration in the 200–800 m layer, assumed as the residence depth of migrant zooplankton. The southern transect at 21°N showed higher primary production, zooplankton biomass, migrant biomass, and lower passive flux. Zooplankton respiratory flux varied from 2.8 to 88.3% of the POC flux, being lower in the northern (5.3% ±2.7) than in the southern transect (46.1% ±32.9). Migrant biomass was significantly correlated to primary production (r2 = 0.570, p

Investigating the Composition and Metabolic Potential of Microbial Communities in Chocolate Pots Hot Springs.

Iron (Fe) redox-based metabolisms likely supported life on early Earth and may support life on other Fe-rich rocky planets such as Mars. Modern systems that support active Fe redox cycling such as Chocolate Pots (CP) hot springs provide insight into how life could have functioned in such environments. Previous research demonstrated that Fe- and Si-rich and slightly acidic to circumneutral-pH springs at CP host active dissimilatory Fe(III) reducing microorganisms. However, the abundance and distribution of Fe(III)-reducing communities at CP is not well-understood, especially as they exist in situ. In addition, the potential for direct Fe(II) oxidation by lithotrophs in CP springs is understudied, in particular when compared to indirect oxidation promoted by oxygen producing Cyanobacteria. Here, a culture-independent approach, including 16S rRNA gene amplicon and shotgun metagenomic sequencing, was used to determine the distribution of putative Fe cycling microorganisms in vent fluids and sediment cores collected along the outflow channel of CP. Metagenome-assembled genomes (MAGs) of organisms native to sediment and planktonic microbial communities were screened for extracellular electron transfer (EET) systems putatively involved in Fe redox cycling and for CO2 fixation pathways. Abundant MAGs containing putative EET systems were identified as part of the sediment community at locations where Fe(III) reduction activity has previously been documented. MAGs encoding both putative EET systems and CO2 fixation pathways, inferred to be FeOB, were also present, but were less abundant components of the communities. These results suggest that the majority of the Fe(III) oxides that support in situ Fe(III) reduction are derived from abiotic oxidation. This study provides new insights into the interplay between Fe redox cycling and CO2 fixation in sustaining chemotrophic communities in CP with attendant implications for other neutral-pH hot springs.

Sex-specific effects of maternal and postweaning high-fat diet on skeletal muscle mitochondrial respiration.

Exposure to maternal over-nutrition in utero is linked with developmental programming of obesity, metabolic syndrome and cardiovascular disease in offspring, which may be exacerbated by postnatal high-fat (HF) diet. Skeletal muscle mitochondrial function contributes to substrate metabolism and is impaired in metabolic disease. We examined muscle mitochondrial respiration in male and female mice exposed to maternal HF diet in utero, followed by postweaning HF diet until middle age. After in utero exposure to maternal control (Con) or HF diet (45% kcal fat; 39.4% lard, 5.5% soybean oil), offspring were weaned to Con or HF, creating four groups: Con/Con (male/female (m/f), n=8/8), Con/HF (m/f, n=7/4), HF/Con (m/f, n=9/6) and HF/HF (m/f, n=4/4). Oxidative phosphorylation (OXPHOS) and electron transfer system (ETS) capacity were measured in permeabilized gastrocnemius bundles. Maternal HF diet increased fasting glucose and lean body mass in males and body fat percentage in both sexes (P⩽0.05). Maximal adenosine diphosphate-stimulated respiration (complex I OXPHOS) was decreased by maternal HF diet in female offspring (-21%, P=0.053), but not in male (-0%, P&gt;0.05). Sexually divergent responses were exacerbated in offspring weaned to HF diet. In females, OXPHOS capacity was lower (-28%, P=0.041) when weaned to high-fat (HF/HF) v. control diet (HF/Con). In males, OXPHOS (+33%, P=0.009) and ETS (+42%, P=0.016) capacity increased. Our data suggest that maternal lard-based HF diet, rich in saturated fat, affects offspring skeletal muscle respiration in a sex-dependent manner, and these differences are exacerbated by HF diet in adulthood.

Double Effect Electron Transfer System in the AgBr/ZnO Composite with Enhanced Photocatalytic Degradation Performance against 3-Chlorophenol under Visible Light Irradiation.

Visible light-driven novel and highly efficient AgBr/ZnO photocatalysts were synthesized by a facile precipitation and dehydration methods. The synthesized samples were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS), and photoluminescence (PL) techniques. Within various combinations of AgBr and ZnO components in the composites, 1AgBr/ZnO showed higher photocatalytic activity against 3-chlorophenol (3-CP). UV-Vis DRS spectra showed that the absorbance of AgBr/ZnO was higher than pure ZnO in the visible light region. The PL results showed that efficient inhibition of the generated electron/hole pairs has occurred during the degradation process due to the formation of heterojunctions. The forming of metallic Ag0 by photogenerated electrons, which captures Ag+ ions, could act as an interfacial charge transmission bridge in the AgBr/ZnO composite. These results provided an important insight into the plasmonic Ag particles to obtain an efficient visible light-driven photocatalyst. In addition, the possible mechanism of charge transfers and separation of electron/hole pairs were also evaluated in detail.

Transposon Sequencing of Brucella abortus Uncovers Essential Genes for Growth In Vitro and Inside Macrophages.

Brucella abortus is a class III zoonotic bacterial pathogen able to survive and replicate inside host cells, including macrophages. Here we report a multidimensional transposon sequencing analysis to identify genes essential for Brucella abortus growth in rich medium and replication in RAW 264.7 macrophages. The construction of a dense transposon mutant library and mapping of 929,769 unique mini-Tn5 insertion sites in the genome allowed identification of 491 essential coding sequences and essential segments in the B. abortus genome. Chromosome II carries a lower proportion (5%) of essential genes than chromosome I (19%), supporting the hypothesis of a recent acquisition of a megaplasmid as the origin of chromosome II. Temporally resolved transposon sequencing analysis as a function of macrophage infection stages identified 79 genes with a specific attenuation phenotype in macrophages, at either 2, 5, or 24 h postinfection, and 86 genes for which the attenuated mutant phenotype correlated with a growth defect on plates. We identified 48 genes required for intracellular growth, including the virB operon, encoding the type IV secretion system, which supports the validity of the screen. The remaining genes encode amino acid and pyrimidine biosynthesis, electron transfer systems, transcriptional regulators, and transporters. In particular, we report the need of an intact pyrimidine nucleotide biosynthesis pathway in order for B. abortus to proliferate inside RAW 264.7 macrophages.