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The modular multilevel matrix converter (M3C) is the high-power three-phase to three-phase AC/AC converter of the next generation. However, when the M3C is applied for power grid interconnection, with equal or close input and output frequency, the current distribution in its nine arms becomes significantly uneven. Furthermore, the current distribution pattern is directly influenced by the randomly changing input-output angle-difference, forcing each arm to be designed based on the highest-possible current, which significantly increases the required semiconductor rating and converter cost. To address this issue, a novel current reallocation is proposed to attenuate the highest-possible arm current of M3C. The equal-frequency operation of M3C is first modeled and analyzed, and the operation sweet-spot where each arm stays in natural energy balance is located. Then, the current reallocation is analytically derived for sweet-spot operation. By injecting proper circulating current, the highest-possible arm current is reduced by 13.4%, and the required circulating current component is analytically derived. The implementation method into the classic control structure of M3C is provided. Performance of the proposed strategy is validated by a simulation benchmark established in MATLAB/Simulink environment in the context of interconnection between two 220 kV/50 Hz power grids.

Offshore wind power has great development potential, of which operation and maintenance costs account for a large proportion in the full lifecycle cost. Power output control strategy plays a key role in wind turbine generator system (WTGS). Traditional control strategies, such as maximum power point tracking and unity power factor, which only uses current local information for decision-making, are not the optimal control method when considering the component fatigue. For the reason, this paper proposes a health-oriented power control strategy, which transforms control problem into an equivalent solution to an economic revenue model. The model aimed to maximize the economic revenue of the full lifecycle, and employed physics-of-failure methodology to quantify the remaining useful life, involving detailed mission profiles. Further, a receding horizon predictive controller is designed to flatten the junction temperature fluctuation and extend converter lifespan, for engineering application. A 1.2 MW WTGS is utilized as a benchmark to verify the proposed strategy performance, and the numerical results reveal the mechanism of the optimized control strategies for alleviating the fatigue and aging of the converters.

Hard carbon (HC) represents an attractive anode material for sodium-ion batteries. However, most HC materials deliver limited capacity and the sodium storage mechanisms in the slope and plateau regions are controversial. Herein, a series of hard carbon nanofibers (HCNFs) with tunable interlayer spacings are designed to understand the sodium storage manners in HC. The optimized HCNFs featuring short-range graphitic layers with sufficient interlayer spacings (0.37-0.40 nm) for Na+ intercalation deliver a high reversible capacity (388 mAh g-1 at 30 mA g-1 ) and good rate capability. In-situ X-ray diffraction and Raman characterizations reveal a revised adsorption/insertion-filling sodium storage mechanism. Combined with the density functional theory (DFT) calculation, the detailed relationship between pore-filling plateau capacity and interlayer spacing is disclosed. It is found that sufficient interlayer spacings (>0.37 nm) provide diffusion channels for Na+ to reach the pores for further filling. Additionally, the reason for plateau-region capacity degradation of the HCNFs is completely demonstrated. This contribution provides insights into the sodium storage mechanism and rational construction of high-performance HC anode materials.

Pichia pastoris is one of the most widely used recombinant protein expression systems. In this study, a novel method for rapid screening of P. pastoris strains capable of efficiently expressing recombinant proteins was developed. Firstly, the ability to express recombinant proteins of the modified strain GS115-E in which a functional Sec63-EGFP (Enhanced green fluorescent protein) fusion protein replaced the endogenous endoplasmic reticulum transmembrane protein Sec63 was tested. Next, the plasmids carrying different copy numbers of phytase (phy) gene or xylanase (xyn) gene were transformed into GS115-E to obtain recombinant strains with different expression levels of phytase or xylanase, and the expression levels of EGFP and recombinant proteins in different strains were tested. Finally, a flow cytometer sorter was used to separate a mixture of cells with different phytase expression levels into sub-populations according to green fluorescence intensity. A good linear correlation was found between the fluorescence intensities of EGFP and the expression levels of the recombinant proteins in the recombinant strains (0.8|R|1). By using the flow cytometer, high-yielding P. pastoris cells were efficiently screened from a mixture of cells. The expression level of phytase of the selected high-fluorescence strains was 4.09 times higher than that of the low-fluorescence strains after 120 h of methanol induction. By detecting the EGFP fluorescence intensity instead of detecting the expression level and activity of the recombinant proteins in the recombinant strains, the method developed by the present study possesses the greatly improved performance of convenience and versatility in screening high-yielding P. pastoris strains. Combining the method with high-throughput screening instruments and technologies, such as flow cytometer and droplet microfluidics, the speed and throughput of this method will be further increased. This method will provide a simple and rapid approach for screening and obtaining P. pastoris with high abilities to express recombinant proteins.毕赤酵母是当前应用最为广泛的重组蛋白表达系统之一，文中建立了一种快速筛选高效表达重组蛋白的毕赤酵母菌株的新方法。首先，对内质网转膜蛋白Sec63融合表达增强型绿色荧光蛋白EGFP的改造菌株GS115-E表达重组蛋白的能力进行检测；之后将携带不同拷贝数的植酸酶phy基因或木聚糖酶xyn基因的质粒转化进入GS115-E中，得到具有不同植酸酶或木聚糖酶表达水平的重组菌株，分别检测不同菌株的EGFP与重组蛋白的表达水平；最后，利用分选型流式细胞仪，根据绿色荧光值的高低对包含不同植酸酶表达水平的重组菌株的菌群进行分选。结果显示重组菌株中EGFP的荧光值与重组蛋白的活性表达水平之间具有良好的线性相关性(0.8|R|1)，且利用流式细胞仪可高效地从混合菌群中筛选得到高产菌株，所分选得到的高荧光菌株在摇瓶发酵120 h时植酸酶表达水平是低荧光菌株的4.09倍。本方法通过检测菌株的EGFP荧光值代替检测重组蛋白的表达水平和活性，从而实现高表达菌株的筛选，大大提高了其应用的便捷性及通用性。与流式细胞仪、液滴微流控等高通量筛选仪器或技术结合将进一步提高筛选的速度与通量，为筛选获得高效表达重组蛋白的毕赤酵母菌株提供了简便、快速的新途径。.

Qingjie Fuzheng granule (QFG) is a traditional Chinese medicinal formula used extensively as an alternative medicine for cancer treatment, including colorectal cancer (CRC). But its pathological mechanism in CRC is unclear. To study antitumor treatment effects and mechanisms of QFG, we established a CRC HCT-116 xenograft mouse model and assessed QFG on EMT and autophagy progression in vivo. The mice were randomly divided into 2 groups (n = 10 each group) and treated with intragastric administration of 1 g/kg of QFG or saline 6 days a week for 28 days (4 weeks). Body weight was measured every other day with electronic balance. At the end of the treatment, the tumor weight was measured. Immunohistochemical (IHC) and western blot (WB) assay were used to detect the expression level of E-cadherin, N-cadherin, vimentin, and TWIST1 to evaluate the effect of QFG on tumor cell EMT progression. IHC and WB assay were also used to detect the expression level of beclin-1, LC3-II, and p62 to evaluate the effect of QFG on tumor cell autophagy progression. Furthermore, the expression level of relative proteins in mTOR pathway was detected by WB assay to investigate the mechanism of QFG effect on CRC. We discovered that QFG inhibited the rise of tumor weight while it had no effect on mice body weight, which proved that QFG could inhibit CRC growth progression without significant side effects in vivo. In addition, QFG treatment inhibited EMT and induced autophagy progression in CRC tumor cells, including that QFG upregulated the expression of E-cadherin, beclin-1, and LC3-II, but downregulated the expression of N-cadherin, vimentin, TWIST1, and p62. And, QFG decreased the ratio of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR, but increased the ratio of p-AMPK/AMPK. All findings from this research proved that QFG can induce autophagy and inhibit EMT progression in CRC via regulating the mTOR signaling pathway.

Power converter is among the core components of the direct-drive wind turbines. The lifespan of semiconductor modules is essential for reliability evaluation of the power converter, but it is substantially influenced by output power fluctuation and intermittency of the turbine. This paper proposes a fast method for lifespan evaluation of semiconductor modules under various operation conditions. This method makes full use of wind speed and temperature information throughout the year, and considers the impact of low-frequency, fundamental-frequency, and ambient temperature fluctuations on the lifespan of the semiconductor module. By utilizing equivalent average model instead of the switching model for thermal effect calculation, the computation burden is significantly reduced, and satisfying calculation speed is guaranteed. A 1.2 MW wind turbine is utilized as a benchmark for lifespan evaluation, and the effectiveness of this method is validated.

A mild crystallization process was proposed to prepare chromium trioxide (CrO3) by reaction between K2Cr2O7 and HNO3 aqueous solutions. Through ICP, XRPD, SEM, and EDS analysis, key factors and mechanisms that influenced the preparation of CrO3 were studied. Large spherical particles of CrO3 (d50 ≥ 300 µm) with high purity (CrO3 ≥ 0.99 g/g, K ≤ 2 mg/g) were prepared when the initial concentration of K2Cr2O7 was kept at 80 g/100 mL HNO3, the acid feeding rate and the cooling rate were set at 1 mL · min−1 and 0.1 °C · min−1, respectively, and the direct recovery of Cr6+ was up to more than 95 %. Kinetic analysis indicated that low nucleation rate and high growth rate would favour the increase of CrO3 particle size in this process. As a high-valued byproduct, Cr(VI)-free KNO3 was further prepared with the designed crystallization steps. Additionally, green characteristics of the process were also discussed.

A chlorination roasting process was proposed to recover rubidium from the distinctive rubidium-containing kaolin ore. The rubidium ions which existed in the alumina octahedron of the phyllosilicates structure could be extracted effectively by using CaCl 2 as chlorinating reagent due to formation of Ca(Al 2 Si 2 O 8 ) phase in the chlorination process of kaolin ore, and the maximum extraction yield reached 96.95%. Additionally, the kinetics results of chlorination roasting of the kaolin ore showed that the extraction rate of rubidium was controlled by the chemical reaction, and the activation energy was found to be 40.13 kJ mol − 1 in the roasting temperature range of this study.

Emodin, an anthraquinone derivative from the root and rhizome of Rheum palmatum L., was found to have antitumor effects in different types of cancer by regulating multi-molecular targets. The aim of the present study was to explore the effect of emodin on the migration and invasion of MHCC-97H human hepatocellular carcinoma cells and the underlying molecular mechanisms. Firstly, it was demonstrated that emodin can inhibit cell proliferation and induce apoptosis of cells in a time- and dose-dependent manner, using a MTT assay and flow cytometry, respectively. However, when emodin concentration was

The Toll-like receptor 3 (TLR3) agonists as polyriboinosinic–polyribocytidylic acid (poly (I:C)) have been implicated as potential immunotherapy adjuvant for cancer whereas the exact roles of TLR3 agonists in hepatocellular carcinoma (HCC) treatment have not been clearly evaluated. In consistent with previous reports, we found that poly (I:C) triggering of TLR3 inhibited cell proliferation and induced apoptosis in HCC cells. However, poly (I:C), when used at lower concentration that cannot remarkably inhibit proliferation and induce apoptosis in HCC cells, enhanced the migration and invasion in vitro and the metastasis in vivo. More importantly, we found that bufalin, a prominent component of toad venom, could suppress poly (I:C)-inspired migration, invasion and metastasis of HCC cells despite that bufalin could not potentiate poly (I:C)-induced inhibition of proliferation and induction of apoptosis. In MHCC97 H cells, bufalin impaired poly (I:C)-induced activation of Tank-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3) pathway and NF-κB pathway. Inhibitor for TBK1 but not NF-κB suppressed poly (I:C)-inspired migration and invasion, which was further supported by using TBK1 deficient (Tbk1–/–) cells. In another model using poly (I:C) transfection, bufalin could also suppress the migration and invasion of HCC cells, which was not observed in Tbk1–/– MHCC97 H cells. Our data suggest that bufalin can suppress the metastasis of HCC cells in poly (I:C) therapy by impairing TBK1 activation, indicating that bufalin may be used in combination with poly (I:C) therapy in HCC treatment for the sake of reversing poly (I:C)-triggered metastasis of HCC cells.

Phase equilibria data for the KHSO4–H2SO4–H2O ternary system and the KHSO4–CrO3–H2SO4–H2O quaternary system at 313.15 K were measured, and the phase diagrams were constructed. Furthermore, analyses and discussions were made on the crystallization zones in the phase diagrams. All results can offer fundamental basis for preparation and purification of chromium trioxide by reacting potassium dichromate with sulfuric acid.

Supplemental Digital Content is available in the text, To evaluate the diagnostic accuracy of ultrasonic acoustic structure quantification (ASQ) for grading hepatic fibrosis/cirrhosis by comparing ultrasonographic features of regions of interest on ASQ images with the pathological characteristics of stage F0–F4 hepatic fibrosis cases. We retrospectively analyzed the medical records of 97 patients with chronic hepatitis who underwent ASQ evaluation at the Ultrasound Room of Dongfang Hepatobiliary Surgery Hospital (Shanghai, China) between July 2012 and October 2013. Regions of interest on stored ASQ images were analyzed to obtain cm2 values on modes, averages, and standard deviations. Correlation analysis, principal component analysis (PCA), and multivariate analysis of variance (MANOVA) of the mean cm2 values with hepatic fibrosis staging were performed. A receiver operating characteristic (ROC) curve was used to assess the diagnostic accuracy of ASQ. The mean cm2 of ASQ correlated with the pathological stage of hepatic fibrosis, with the best correlation coefficient (r = 0.81) in the right lobe below rib 2. The best cm2 average 1 and 2 values, which differed significantly among different hepatic fibrosis/cirrhosis stages, were also found in this area. The maximal area under the ROC curve (0.969) was for cm2average 1 for the F0 versus F1 to F4 group, with a low criterion (110), while the maximal criterion (145) was for cm2 average 2 for the F0–F3 versus F4 group, with a relatively small AUC (0.882). With objective and accurate results, ASQ analysis is a promising non-invasive method for grading hepatic fibrosis, although this should be verified in further studies.

A mesoporous boehmite (γ-AlOOH) synthesis and vanadate (V(V)) ion adsorption and desorption on the mesoporous γ-AlOOH were investigated. The synthesis and adsorption studies showed that the mesoporous γ-AlOOH with a BET surface of 442 m2 g−1 and a pore size of 2.75 nm possessed a maximum V(V) ion adsorption capacity of 3.28 mmol g−1. The adsorption mechanism results showed that the mesoporous γ-AlOOH liberated surface hydroxyls to form coordinatively unsaturated AlVI centres to adsorb V(V) ions which connected oxygen of the coordinatively unsaturated AlVI centres with mono-oxo, VO terminal double bonds. The desorption studies showed that the V(V) ions could be desorbed by NH3·H2O easily. In the cleaner production application of chromate, the mesoporous γ-AlOOH was synthesized in the Na2CrO4–NaAlO2–NaVO3–H2O solutions of the chromate production and then in situ adsorbed the V(V) ions. The results showed that the V(V) ions were removed effectively, so that the highly carcinogenic CaCrO4 containing Ca(VO3)2 residue which was obtained by the typical process of chromate production was eliminated. Therefore, green separation of V(V) ions to reduce waste pollution ensuring economy and feasibility could be expected.

Emodin is an active ingredient derived from root and rhizome of Rheum palmatum L and many studies have reported that it exhibits anticancer effects in a number of human tumors. However, there is little information demonstrating the possible effects of emodin on the proliferation and apoptosis of hepatocellular carcinoma (HCC). In the present study, we show that emodin may inhibit the proliferation of SMMC-7721 cells in a dose- and time-dependent manner and induced apoptosis of cells in a concentration-dependent manner after treatment for 24 h. Moreover, we further discovered that the possible molecular mechanisms involved may relate to the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT signaling pathways. Emodin may induce the phosphorylation of extracellular-signal-regulated kinase (ERK) and p38 while mildly suppressed the expression of p-c-Jun-N-terminal kinase (p-JNK). However, emodin did not affect the expression of the total (t)-ERK, t-p38 or t-JNK. Furthermore, emodin also suppressed the activation of p-AKT, but not the t-AKT. In vivo, we found that emodin suppressed tumor growth in experimental mice without an obvious change in body weight, which may work through the antiproliferation and apoptosis inducing effects. Moreover, emodin improves the liver and kidney function in mice, revealing that emodin may improve the life quality of the mice with implanted tumors. In conclusion, the above findings indicate that emodin may be a potentially effective and safe drug to induce apoptosis of HCC.