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This paper presents a novel concept and design of a full monolithic integrated high-Tc superconducting (HTS) Josephson junction terahertz (THz) harmonic mixer coupled with a circularly polarized (CP) antenna. The fully on-chip mixer device is very compact in size and utilizes the CP antenna to enhance the polarization orientation flexibility in coupling THz radiation. Electromagnetic simulations are carried out to optimize the coupling efficiency and axial ratio of the THz CP antenna, and the signal transmission and isolation characteristics of the monolithic circuit. An equivalent circuit model of the HTS THz mixer is then established and simulation is performed based on our previously measured step-edge Josephson junction characteristics to evaluate the device performance and validate the concept of design. The results show that a superior performance could be achieved from such a monolithic HTS mixer device, which is significantly better than any HTS THz harmonic mixers reported to date. [ABSTRACT FROM AUTHOR]

This paper presents a wideband terahertz (THz) mixer based on a thin-film antenna-coupled high-temperature superconducting (HTS) YBa2Cu3O7−x (YBCO) step-edge Josephson junction. The HTS mixer enables the flexible harmonic mixing operation at multiple THz bands with the same microwave local oscillator (LO) source, and features very wide intermediate-frequency or instantaneous bandwidth. In order to optimize the frequency down-conversion performance of the mixer, systematic electromagnetic design and analysis have been carried out to improve the power coupling of THz radiation as well as wideband transmission of microwave signals. Experimental characterization of a fabricated device prototype has demonstrated that the mixer exhibits good performance at both the 200 GHz and 600 GHz bands. Detailed measurement results including the DC characteristics, LO pumping requirement, frequency response, mixing linearity and conversion gain are presented in this paper. [ABSTRACT FROM AUTHOR]

A high-temperature superconducting (HTS) terahertz (THz) frequency down-converter or mixer based on a thin-film ring-slot antenna coupled YBa2Cu3O7–x (YBCO)/MgO step-edge Josephson junction is reported. The frequency down-conversion was achieved using higher order harmonics of an applied lower frequency (19–40 GHz) local oscillator signal in the Josephson junction mixing with a THz signal of over 600 GHz, producing a 1–3 GHz intermediate frequency signal. Up to 31st order of harmonic mixing was obtained and the mixer operated stably at temperatures up to 77 K. The design details of the antenna, HTS Josephson junction mixer, the matching and isolation circuits, and the DC and RF performance evaluation are described in this paper. [ABSTRACT FROM AUTHOR]

We report modeling and simulation results for a Ka band high-temperature superconducting (HTS) monolithic microwave integrated circuit (MMIC) Josephson junction mixer. A Verilog-A model of a Josephson junction is established and imported into the system simulator to realize a full HTS MMIC circuit simulation containing the HTS passive circuit models. Impedance matching optimization between the junction and passive devices is investigated. Junction DC I–V characteristics, current and local oscillator bias conditions and mixing performance are simulated and compared with the experimental results. Good agreement is obtained between the simulation and measurement results. [ABSTRACT FROM AUTHOR]

As one of the key status of gas in shale reservoir, adsorption gas accounts for considerable percentage of total gas amount. Due to the complexity and nanostructure of shale gas reservoir, it is very challenging to represent adsorption gas through traditional methods. However, the integration of the fractal theory and molecular dynamics (MD) simulation may provide a new perspective of understanding such nanostructure and the micro-phenomenon happening in it. The key purpose of this paper is to investigate the adsorption phenomenon in shale kerogen. By using MD simulation and grand canonical Monte Carlo (GCMC) algorithm, the adsorption of methane in 2, 5 and 10nm slit-like pores is simulated for different temperature and pressure status. According to the results, the average gas density in smaller pores is higher than that in bigger pores, and multilayer adsorption presents on some areas of pore surfaces. Then, the simulation results are analyzed using the multilayer fractal adsorption model. The analysis indicates that the number of adsorption layer increases with pressure increase: four-layer adsorption presents in 10nm pores while three-layer adsorption shows up in 2nm and 5nm pores due to pore volume limit. Fractal dimension of pore wall surface generated in this study is in the range of 2.31-2.63. Moreover, high temperature could decrease the adsorption behavior in reservoir condition. [ABSTRACT FROM AUTHOR]

Studies have shown that phosphatase and tensin homolog deleted on chromosome ten (PTEN) participates in the regulation of cochlear hair cell survival. Bisperoxovanadium protects against neurodegeneration by inhibiting PTEN expression. However, whether bisperoxovanadium can protect against noise-induced hearing loss and the underlying mechanism remains unclear. In this study, we established a mouse model of noise-induced hearing loss by exposure to 105 dB sound for 2 hours. We found that PTEN expression was increased in the organ of Corti, including outer hair cells, inner hair cells, and lateral wall tissues. Intraperitoneal administration of bisperoxovanadium decreased the auditory threshold and the loss of cochlear hair cells and inner hair cell ribbons. In addition, noise exposure decreased p-PI3K and p-Akt levels. Bisperoxovanadium preconditioning or PTEN knockdown upregulated the activity of PI3K-Akt. Bisperoxovanadium also prevented H2O2-induced hair cell death by reducing mitochondrial reactive oxygen species generation in cochlear explants. These findings suggest that bisperoxovanadium reduces noise-induced hearing injury and reduces cochlear hair cell loss.

Two-dimensional J-resolved (2D JRES) nuclear magnetic resonance (NMR) experiments provide a simple and user-friendly spectral representation, in which J couplings and chemical shifts are separated into two orthogonal frequency dimensions. The 2D JRES experiments have attracted wide attention in fundamental pulse sequence developments and practical applications, since they were first proposed 40 years ago. In this paper, we review the recent advances in the development of novel 2D JRES pulse sequences and 2D J-edited methods for accurate measurements of J coupling, mainly focusing on pure shift based 2D orthogonal-pattern and phase-sensitive 2D JRES spectroscopy and their applications in overcoming strong coupling effects and field inhomogeneities.

IntroductionThe aim of this study was to investigate the associations of neck circumference (NC) and neck-to-height (NHR) with diabetic kidney disease (DKD) in Chinese patients with type 2 diabetes mellitus (T2DM).Materials and methodsA total of 2,615 patients with prevalent T2DM were enrolled. NHR was calculated through NC (cm) divided by height (cm), and prevalent DKD was defined as the urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g or the estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m2 in the absence of other primary kidney diseases.ResultsThe levels of NC and NHR were higher in DKD patients compared with non-DKD patients (38.22 vs. 37.71, P = 0.003; 0.232 vs. 0.227, P < 0.001, respectively). After full adjustments, individuals at the highest tertile of NHR had higher odds of DKD than those at the lowest tertile (multivariate-adjusted OR = 1.63, 95% CI: 1.22, 2.18), but this association was not pronounced with NC (multivariate-adjusted OR = 1.24, 95% CI: 0.87, 1.76). Individuals at the highest tertile of NHR had lower eGFR (β = -4.64, 95% CI: -6.55, -2.74) and higher UACR levels (β = 0.27, 95% CI: 0.10, 0.45) than those at the lowest tertile. The adverse association between NHR and prevalent DKD remained statistically significant among most of the subgroups analyzed and no interaction effects were observed.ConclusionThe increase in NHR was adversely and independently associated with DKD in this Chinese T2DM population.

• Determining the kinds of the organic acids in the pulp of Feizixiao litchi and observing the dynamic change characteristics of the different organic acids content. • Identifing the key biochemical pathways for the metabolism of the organic acids in the pulp of Feizixiao litchi through RNA-seq. • Confirming the key genes regulating the organic acids accumulation in the pulp of Feizixiao litchi and their expressions characteristics through RNA-seq. • Verifing the expression of the above key genes through real-time fluorescence quantitative PCR. To investigate the gene expression characteristics and patterns of organic acid synthesis and accumulation in the pulp of Litchi chinensis Sonn. cv. Feizixiao (FZX), 16-year-old Feizixiao litchi trees were used as the experimental material, and the dynamic changes in the main organic acids in the pulp were determined for two years. RNA sequencing was carried out when the total acids in the pulp changed drastically 35, 50 and 73 d after anthesis in 2020 to discover the molecular mechanism of the synthesis and accumulation of different organic acids in pulp. The results indicate that tartaric acid and malic acid were the main organic acids in pulp. The RNA-seq contained 165,886 transcripts, and 12 176, 19 835 and 5 048 DEGs were observed in the 35 d vs. 50 d, 35 d vs. 73 d and 50 d vs. 73 d groups, respectively. These expressed transcripts of organic acid metabolism were significantly enriched in correlated pathways, including glycolysis and gluconeogenesis, citric acid cycle (TCA cycle), and ascorbate and aldarate metabolism. In this paper, 75 genes of the enzymes related to organic acid metabolic pathways were screened, and these enzymes included PEPC, MDH, ME, CS, IDH and ACO. Ten unigenes were selected to confirm by real-time PCR, and the linear regression between the RNA-Seq results and real-time PCR data was significant (r = 0.8637). In addition, the expression of PEPC and ACO genes was consistent with the content of citric acid, the expression of the CS gene increased with time, and the change in expression of the MDH gene was similar to that of the malic acid content, while the expression of the ME gene showed an opposite trend. Therefore, it was possible to regulate acid accumulation in pulp by regulating the expression of key genes related to pathways such as the TCA cycle, and then the comprehensive fruit quality was regulated. [ABSTRACT FROM AUTHOR]

Abstract. Enhanced recovery after cesarean (ERAC) delivery is an evidence-based, multi-disciplinary approach throughout pre-, intra-, post-operative period. The ultimate goal of ERAC is to enhance recovery and improve the maternal and neonatal outcomes. This review highlights the role of anesthesiologist in ERAC protocols. This review provided a general introduction of ERAC including the purposes and the essential elements of ERAC protocols. The tool used for evaluating the quality of ERAC (ObsQoR-11) was discussed. The role of anesthesiologist in ERAC should cover the areas including management of peri-operative hypotension, prevention and treatment of intra- and post-operative nausea and vomiting, prevention of hypothermia and multi-modal peri-operative pain management, and active pre-operative management of unplanned conversion of labor analgesia to cesarean delivery anesthesia. Although some concerns still remain, ERAC implementation should not be delayed. Regular assessment and process improvement should be imbedded into the protocol. Further high-quality studies are warranted to demonstrate the effectiveness and efficacy of the ERAC protocol.

Abstract. Background:. The programmed intermittent epidural bolus (PIEB) technique is widely used in labor analgesia, but the parameter settings of PIEB have not yet been standardized. We designed a study to identify the optimal interval duration for PIEB using 10 mL of ropivacaine 0.08% and sufentanyl 0.3 μg/mL, a regimen commonly used to control labor pain in China, to provide effective analgesia in 90% of women during the first stage of labor without breakthrough pain. Methods:. We conducted a double-blind sequential allocation trial to obtain the effective interval 90% (EI90%) during the first stage of labor between April 2019 and May 2019. This study included the American Society of Anesthesiologists physical status II–III nulliparous parturients at term, who requested epidural analgesia. The bolus volume was fixed at 10 mL of ropivacaine 0.08% with sufentanyl 0.3 μg/mL. Participants were divided into four groups (groups 60, 50, 40, and 30) according to the PIEB intervals (60, 50, 40, and 30 min, respectively). The interval duration of the first parturient was set at 60 min and that of subsequent parturients varied according to a biased-coin design. The truncated Dixon and Mood method and the isotonic regression analysis method were used to estimate the EI90% and its 95% confidence intervals (CIs). Results:. Forty-four women were enrolled in this study. The estimated optimal interval was 44.1 min (95% CI 41.7–46.5 min) and 39.5 min (95% CI 32.5–50.0 min), using the truncated Dixon and Mood method and isotonic regression analysis, respectively. The maximum sensory block level above T6 was in nearly 20% of parturients in group 30; however, 5.3%, 0%, and 0% of the parturients presented with sensory block level above T6 in groups 40, 50, and 60, respectively. There were no cases of hypotension and only one parturient complained of motor block. Conclusion:. With a fixed 10 mL dose of ropivacaine 0.08% with sufentanyl 0.3 μg/mL, the optimal PIEB interval is about 42 min. Further studies are warranted to define the efficacy of this regimen throughout all stages of labor. Trial registration: Chinese Clinical Trial Registry, ChiCTR1900022199; http://www.chictr.org.cn/com/25/historyversionpuben.aspx?regno=ChiCTR1900022199.

Objective To study the effects of curcumine on renal tubular epithelial-mesenchymal transition (EMT) and its possible mechanisms. Methods The effect of curcumin on the morphology of human kidney cells (HKCs) in the presence of TGF-β1 alone or in combination with different concentration curcumine was observed by phase contrast microscopy. The expressions of E-cardhrin, keratin, vimentin, alpha smooth muscle actin (α-SMA),fibroblast-specific protein 1 (FSP1) and key proteins of AKT/mTOR pathway were analyzed by immunohistochemical stain and Western blot. Results HKC cells showed a classic cobblestone morphology. Exposure of HKCs to TGF-β1 for 72 h induced a complete conversion of the epithelial cell to myofibroblast. When HKCs were co-incubated with TGF-β1 and various concentrations of curcumin for 72 h, curcumine maintained the epithelial morphology in a dose-dependent manner (from 12.5 to 50 μg/mL), antagonizing TGF-β1-induced the down-regulation expression of E-cardhrin, keratin and the up-rgulation of FSP1, vimentin and α-SMA. Importantly. Curcumine effectively suppressed the activity of the Akt/mTOR pathway in HKCs as demonstrated by a remarkable reduction of the Akt, mTOR, p70S6K, 4E-BP1和eIF4E phosphorylation. Conclusions Curcumine is a potent inhibitor of TGF-β1-induced epithelial-mesenchymal transition (EMT) and antagonizes TGF-β1-driven fibrogenesis through inhibition of the activity of the Akt/mTOR pathway.

Cytosine methylation and demethylation play crucial roles in understanding the genomic DNA expression regulation. The epigenetic modification of cytosine and its continuous oxidative products are called the "new four bases of DNA" including 5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). However, compared to the abundant studies on the classical DNA bases, the photophysical and photochemical properties of those new bases have not yet aroused people's excessive attention. In this contribution, a systematic study on the nonradiative decay and photochemical pathways via excited states or conical intersections upon photoexcitation has been explored through high-level computational approaches such as the complete active space self-consistent field method, complete active space with second-order perturbation theory, and density functional theory. Pathways like the ring-distortion deactivation, hydrogen dissociation, hydrogen transfer, and also Norrish type I and II photochemical reactions have been investigated, and it was proposed that intersystem crossing from the S1 state to the T1 state is the most effective route for 5fC. For 5caC, ring-pucking and intramolecular isomerism are effective deactivation ways at both neutral and protonated forms. In the meantime, the influences of two important environmental factors, the solution and acidic environment (i.e., the protonated state), were also considered in this study. From the theoretical perspective, the initial properties of the photostability and photochemical reactivity for 5fC and 5caC have become a crucial aspect to facilitate a further comprehension of their potential role in gene regulation and transcription. [ABSTRACT FROM AUTHOR]

The aim of the present work was to evaluate the anaerobic ammonium oxidation (anammox) activity of simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm with different substrate concentrations and pH values. Kaldnes rings taken from the SNAD biofilm reactor were incubated in batch tests to determine the anammox activity. Haldane model was applied to investigate the ammonium inhibition on anammox process. As for nitrite inhibition, the NH4+-N removal rate of anammox process remained 87.4% of the maximum rate with the NO2--N concentration of 100 mg/L. Based on the results of Haldane model, no obvious difference in kinetic coefficients was observed under high or low free ammonia (FA) conditions, indicating that ammonium rather than FA was the true inhibitor for anammox process of SNAD biofilm. With the pH value of 7.0, the rmax, Ks and KI of ammonium were 0.209 kg NO2--N/kg VSS/day, 9.5 mg/L and 422 mg/L, respectively. The suitable pH ranges for anammox process were 5.0 to 9.0. These results indicate that the SNAD biofilm performs excellent tolerance to adverse conditions. [ABSTRACT FROM AUTHOR]

Cyanobacterial blooms in water supply sources in both central Indiana USA (CIN) and South Australia (SA) are a cause of great concerns for toxin production and water quality deterioration. Remote sensing provides an effective approach for quick assessment of cyanobacteria through quantification of phycocyanin (PC) concentration. In total, 363 samples spanning a large variation of optically active constituents (OACs) in CIN and SA waters were collected during 24 field surveys. Concurrently, remote sensing reflectance spectra (Rrs) were measured. A partial least squares-artificial neural network (PLS-ANN) model, artificial neural network (ANN) and three-band model (TBM) were developed or tuned by relating the Rrs with PC concentration. Our results indicate that the PLS-ANN model outperformed the ANN and TBM with both the original spectra and simulated ESA/Sentinel-3/Ocean and Land Color Instrument (OLCI) and EO-1/Hyperion spectra. The PLS-ANN model resulted in a high coefficient of determination (R²) for CIN dataset (R² = 0.92, R: 0.3-220.7 μg/L) and SA (R² = 0.98, R: 0.2-13.2 μg/L). In comparison, the TBM model yielded an R² = 0.77 and 0.94 for the CIN and SA datasets, respectively; while the ANN obtained an intermediate modeling accuracy (CIN: R² = 0.86; SA: R² = 0.95). Applying the simulated OLCI and Hyperion aggregated datasets, the PLS-ANN model still achieved good performance (OLCI: R² = 0.84; Hyperion: R² = 0.90); the TBM also presented acceptable performance for PC estimations (OLCI: R² = 0.65, Hyperion: R² = 0.70). Based on the results, the PLS-ANN is an effective modeling approach for the quantification of PC in productive water supplies based on its effectiveness in solving the non-linearity of PC with other OACs. Furthermore, our investigation indicates that the ratio of inorganic suspended matter (ISM) to PC concentration has close relationship to modeling relative errors (CIN: R² = 0.81; SA: R² = 0.92), indicating that ISM concentration exert significant impact on PC estimation accuracy. [ABSTRACT FROM AUTHOR]