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A novel design method, which can transform the nonlinear circuits design to the impedance matching network (IMN) design, is proposed for wideband analog predistoter (APD) with the characteristics of frequency-dependent gain and phase conversions in this paper. First, the design method for the desired gain and phase conversions is introduced. The ABCD parameters of the IMN can be computed. To simplify the design, the obtained parameters are transformed to the IMN terminal impedance. Then we can only need to design the IMN terminal impedance to obtain the desired transfer characteristics. In the meanwhile, an APD with 4.5 dB gain conversion and 50° phase conversion is designed and simulated to validate the design method for specify gain and phase conversions. The simulated results show good effectiveness of the design method. Second, for wideband application, the complex gain and phase conversions surface design is transformed to the IMN terminal impendence curve versus frequency design. This gives the designers a well-defined strategy for wideband APD design focusing on frequency-dependent phase conversion as well as gain conversion. To validate the proposed method, a wideband APD operating at K-band (17-20 GHz) is designed, fabricated and measured. A linearized 100W K-band TWTA is shown to achieve a noise power ratio (NPR) >20 dB at 3 dB output power back-off, and phase change

PurposeObesity in children and in adolescents can lead to adult cardiovascular diseases, and the gut microbiota plays a crucial role in obesity pathophysiology. Exercise and diet interventions are typical approaches to improve physical condition and to alter the gut microbiota in individuals with obesity. However, whether central hemodynamic parameters including subendocardial viability ratio, the augmentation index standardized to a heart rate of 75/min (AIx75), resting heart rate, and blood pressure, correlate with gut microbiota changes associated with exercise and diet is unclear.MethodsAdolescents (n = 24, 12.88 ± 0.41 years) with obesity completed our 6-week program of endurance and strength exercises along with dietary restriction. Blood and fecal samples were collected, and physical parameters were measured before and 24 h after the last session of the intervention program. Pulse wave analysis using applanation tonometry provided the subendocardial viability ratio, a surrogate measure of microvascular myocardial perfusion, and AIx75, a measure of arterial stiffness and peripheral arteriolar resistance. Correlation analysis detected any associations of anthropometric or central hemodynamic parameters with gut microbiome composition.ResultsExercise and diet interventions significantly reduced body weight, body mass index, body fat, and waist-to-hip ratio, and lowered levels of fasting blood glucose, serum triglycerides, and high-density lipoprotein cholesterol. AIx75 and resting heart rate were also significantly reduced after the intervention without changes to systolic or diastolic blood pressure. The ratio of intestinal microbiota Firmicutes to Bacteroidetes displayed a marked increase after intervention. Interventional changes in gut microbiota members were significantly associated with anthropometric and metabolic parameters. Microbial changes were also significantly correlated with central hemodynamic parameters, including subendocardial viability ratio, AIx75, and resting heart rate.ConclusionExercise and diet interventions significantly improved measures of central hemodynamics, including subendocardial viability ratio, AIx75, and resting heart rate, which were correlated with altered gut microbiota in adolescents with obesity. Our findings shed light on the effects and mechanisms underlying exercise and diet interventions on obesity and suggest this approach for treating patients with both cardiovascular disease and obesity.

Petroleum pollution is a severe environmental issue. Comprehensively revealing the genetic backgrounds of hydrocarbon-degrading microorganisms contributes to developing effective methods for bioremediation of crude oil-polluted environments. Marine bacterium Achromobacter sp. HZ01 is capable of degrading hydrocarbons and producing biosurfactants. In this study, the draft genome (5.5 Mbp) of strain HZ01 has been obtained by Illumina sequencing, containing 5,162 predicted genes. Genome annotation shows that “amino acid metabolism” is the most abundant metabolic pathway. Strain HZ01 is not capable of using some common carbohydrates as the sole carbon sources, which is due to that it contains few genes associated with carbohydrate transport and lacks some important enzymes related to glycometabolism. It contains abundant proteins directly related to petroleum hydrocarbon degradation. AlkB hydroxylase and its homologs were not identified. It harbors a complete enzyme system of terminal oxidation pathway for n-alkane degradation, which may be initiated by cytochrome P450. The enzymes involved in the catechol pathway are relatively complete for the degradation of aromatic compounds. This bacterium lacks several essential enzymes for methane oxidation, and Baeyer-Villiger monooxygenase involved in the subterminal oxidation pathway and cycloalkane degradation was not identified. These results suggest that strain HZ01 degrades n-alkanes via the terminal oxidation pathway, degrades aromatic compounds primarily via the catechol pathway and cannot perform methane oxidation or cycloalkane degradation. Additionally, strain HZ01 possesses abundant genes related to the metabolism of secondary metabolites, including some genes involved in biosurfactant (such as glycolipids and lipopeptides) synthesis. The genome analysis also reveals its genetic basis for nitrogen metabolism, antibiotic resistance, regulatory responses to environmental changes, cell motility, and material transport. The obtained genome data provide us with a better understanding of hydrocarbon-degrading bacteria, which may contribute to the future design of rational strategies for bioremediation of petroleum-polluted marine environments.