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The design and simulation of a terahertz high-order mode power coupler for sheet beam traveling wave amplifiers are presented in this paper. The proposed power coupler has functions of both the mode conversion and the beam wave convergence/separation. To improve the performance of this structure, some auxiliary structures are introduced, including a rectangular septum, a matching step and a pair of symmetric Bragg reflectors. The proposed power coupler has numerous competitive advantages, such as broad bandwidth, high transmission coefficient and high conversion efficiency, high port isolation, low port reflection, and high mode purity.

The preliminary design and analysis of a 0.3 THz extended interaction oscillator (EIO) driven by a sheet electron beam is presented in this paper. Its interaction circuit consists of a sheet electron beam tunnel with 17 gaps, two coupling cavities, a coupling waveguide, and a standard rectangular output waveguide. It was optimized to achieve good electrical performance by using the CST-Microwave Studio. The operating mode is the TM 11 -like $\mathrm{2}\pi$ mode and its corresponding resonant frequency is ∼294.32 GHz. Initial particle-in-cell simulations having considered the ohmic loss demonstrated that the designed EIO could provide a radiation power of 376 W at 294 GHz.

ObjectiveTo experimentally determine the involvement and mechanism of long non-coding RNA (lncRNA) HCP5 in the development of gastric cancer (GC).MethodsDetection of HCP5, miR-186-5p, and WNT5A expression in clinical GC tissues and adjacent healthy tissues was performed, followed by Pearson correlation analysis. BGC-823 and AGS cells, with interferences of HCP5, miR-186-5p, and WNT5A, were cultured under hypoxia. MTT, colony formation assay, Caspase-3 activity assay, and transwell assay were applied for the determination of cell proliferation, viability, apoptosis, and invasion, respectively. Expressions of WNT5A and protein markers of epithelial-mesenchymal transition (EMT) in cells were detected by western blotting. And the binding of HCP5 and WNT5A to miR-186-5p was validated using dual-luciferase reporter assay.ResultsIn GC tissues, an increase in HCP5 and WNT5A expressions and a reduction in miR-186-5p expression were found, and the negative correlation between miR-186-5p and HCP5/WNT5A was proven. Subsequently, under hypoxia, an increase in HCP5 and WNT5A expressions and a decrease in miR-186-5p expression in GC cells were confirmed. In addition, in GC cells under hypoxia, the inhibition of HCP5 suppressed cell biological activity and EMT, while the inhibition of miR-186-5p or the overexpression of WNT5A led to the opposite changes.ConclusionAn upregulation of WNT5A expression by HCP5 competitively binding to miR-186-5p promotes GC cell development.

One kind of G-band extended interaction oscillator (EIO) with rectangle cavity model which works on 220 GHz is simulated with CST Eigenmode Solver [1]. The influences of the structural parameters of the cavity on the electric field characteristics, including the gap length and the extension length of the coupling cavity, were simulated and analyzed. In addition, the field distribution, coupling impedance and beam-loaded conductance of the EIO are derived.

Objectives The aim of this study is to analyze the clinical and pathological features of HAS and investigate the factors affecting prognosis.Methods From January 2014 to May 2020, 31 patients were diagnosed as HAS in in the First Affiliated Hospital of Zhengzhou University. The clinicopathologic features and the relevant prognosis of these patients were analyzed.Results Of the 31 patients, 23 were male, with a median age of 62 years. And among the 31 patients, 22 patients underwent a radical gastrectomy and a D2 lymph node dissection. During the follow up period, 18 patients died of the disease. The median OS (mOS) was 28 months. The 1-year survival rate was 55%, the 3-year survival rate was 47%, and the 5-year survival rate was 34%. An elevated CA125 level, distant metastasis, and radical surgery were associated with the prognosis of HAS, and distant metastasis is an independent prognostic risk factor for survival. Conclusion HAS had a poor prognosis because of its frequent vascular involvement, and lymph node and liver metastasis. Aggressive multimodal treatment comprising radical gastrectomy and adjuvant chemotherapy is warranted.This article describes the Clinicopathological of Hepatoid Adenocarcinoma of the Stomach and through survival analysis, the factors affecting the patient’s prognosis were studied.

320 Background: Anti-PD-1 mAb treatment has been shown to be effective in the treatment of esophageal cancer. Anlotinib has been approved in China as a second-line treatment for advanced esophageal cancer because of its good tolerance and efficacy. In the treatment of esophageal cancer, antiangiogenic target therapy combined with immunotherapy has been preliminarily recognized internationally. The purpose of this study is to investigate the efficacy and safety of anlotinib in combination with PD-1 inhibitors in second-line or later therapy during the treatment of esophageal cancer in the real world setting.(A LOT-EC3, NCT04966611). Methods: This is a prospective, multicenter real-world study. The esophageal cancer patients who received anlotinib in combination with PD-1 inhibitors in second-line or later therapy were enrolled. The primary endpoint was PFS (progression-free survival), and secondary endpoints were ORR (objective response rate), DCR (disease control rate) and OS (overall survival). The response to treatment was evaluated according to RECIST version 1.1. In addition, adverse events were evaluated by CTCAE v5.0. Results: From Jul 2020 to Sep 2021, 40 patients with a median age of 65.5 (range: 48̃81) were enrolled, in which the metastasis of more than 1 organ occurred in 62.5% of the 40 patients; the metastasis of more than 2 organs occurred in 37.5% (15 patients). 26 (65.0%) and 14 (35.0%) patients received anlotinib combined with PD-1 inhibitors as second line and third & above line therapy, respectively. Among all patients, 1 patient achieved complete response (CR), 11 patients partial response (PR), 23 patients stable disease (SD), illustrating an ORR of 30.0% and a DCR of 87.5%. In the second line therapy, ORR was 30.8 %, DCR was 92.3%. In the third & above line, ORR with 28.6%, DCR with 78.6% was observed. Median PFS was not reached. For all the 40 patients, 27 of which were treated with Camrelizumab, 10 were treated with Sintilimab, other 3 patients were treated with other kinds of PD-1 inhibitors. There was no significant difference in DCR between different PD-1 inhibitors. Treatment related adverse events (trAEs) occurred in 22 (55%) patients. 4 patients had grade 3 or more trAEs. No patient died due to trAE. Conclusions: Anlotinib combined with PD-1 inhibitors is found to be a reasonable option in second-line or later therapy for the treatment of advanced esophageal cancer. To our best knowledge, this is the first summarized real-world study on anlotinib combined with PD-1 inhibitors in advanced esophageal cancer. The treatment effects are similar to the outcomes in comparable clinical trials, which support the further recommendation of anlotinib combined with PD-1 inhibitors in the treatment of esophageal cancer. Clinical trial information: NCT04966611.

A method aimed at improving the beam-wave interaction efficiency by changing the coupling slot configuration has been proposed in the study of extended interaction oscillators (EIOs). The dispersion characteristics, coupling coefficient and interaction impedance of the high-frequency structure based on different types of coupling slots have been investigated. Four types of coupled cavity structures with different layouts of the coupling slots have been compared to improve the beamwave interaction efficiency, so as to analyze the beam-wave interaction and practical applications. In order to determine the improvement of the coupling slot to a coupled cavity circuit in an EIO, we designed four nine-gap EIOs based on the coupled cavity structure with different coupling slot configurations. With different operating frequencies and voltages takes into consideration, beam voltages from 27 to 33 kV have been simulated to achieve the best beam-wave interaction efficiency so that the EIOs are able to work in the 2π mode. The influence of the Rb and the ds on the output power is also taken into consideration. The Rb is the radius of the electron beam, and the ds is the width of the coupling slot. The simulation results indicate that a single-slot-type EIO has the best beam-wave interaction efficiency. Its maximum output power is 2.8 kW and the efficiency is 18% when the operating voltage is 31 kV and electric current is 0.5 A. The output powers of these four EIOs that were designed for comparison are not less than 1.7 kW. The improved coupling-slot configurations enables the extended interaction oscillator to meet the different engineering requirements better.

A large amount of sulfur dioxide (SO2) will be released during rural household coal combustion, causing serious environmental pollution. Therefore, it is very urgent to develop a clean and efficient fuel to substitute rural household coal controlling SO2 emission. In this paper, a new strategy toward scattered coal combustion with remarkably reducing SO2 emission was proposed. Coal and compound additive of Al2O3 and CaCO3 were blended and then copyrolysis at 1050 °C was performed to produce clean coke. First, the sulfur content of clean coke was reduced, meanwhile, generating sulfur fixation precursor during pyrolysis. Then, clean coke is used for efficient sulfur fixation during the subsequent combustion process to reduce SO2 emissions. The effects of combustion temperature, Al/S molar ratio, and the mechanism of sulfur retention during clean coke combustion were studied in the tube furnace and muffle furnace. The mechanism can be attributed the following reason: (a) CaS produced during pyrolysis and CaO decomposed by complex additives were oxidized during combustion, and CaO captured the SO2 released from clean coke combustion, which formed CaSO4. (b) CaSO4 reacts with Al2O3 to produce calcium sulfoaluminate at high temperatures, which improves the sulfur fixation efficiency of clean coke combustion at high temperatures. In a word, this new strategy can greatly reduce the emission of SO2, thus helping to solve rural household coal pollution problems.

A W-band extended interaction oscillator (EIO) operating at two different types of $2\pi $ modes is presented. The modes and output characteristics were studied, and the circuit was optimized to ensure similar and efficient outputs of two standing-wave modes. For a cylindrical electron beam radius of 0.2 mm, voltage of 14 kV, and current of 0.5 A, particle-in-cell simulation predicts 616 W at 93.76 GHz for the $2\pi $ gap mode and 367 W at 94.22 GHz for the $2\pi $ cavity mode. In this paper, numerical simulations demonstrate the ability of the EIO circuit to be operated with two standing-wave modes in the millimeter-wave range.

Jie Yan,1,2 Pan Du,3 Yongxu Jia,2 Zhiwei Chang,2 Silin Gan,4 Xiaohan Xu,5 Yaohe Wang,3 Yanru Qin,2 Quancheng Kan1 1Department of Gastroenterology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China; 2Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China; 3National Center for International Research in Cell and Gene Therapy, Sino-British Research Centre for Molecular Oncology, Zhengzhou University, Zhengzhou, China; 4Department of Hematology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China; 5Department of Anesthesiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China Introduction: Minichromosome maintenance 10 (MCM10) is deregulated in several malignancies including cervical cancer and urothelial carcinoma. However, the expression and biologic role of MCM10 in esophageal squamous cell carcinoma (ESCC) is still unknown. Methods: In this study, we performed immunohistochemistry and real-time polymerase chain reaction (PCR) analysis to examine the expression of MCM10 in ESCC and adjacent normal esophageal tissues. The associations of MCM10 expression with clinicopathologic parameters of ESCC were analyzed. Ablation of MCM10 through the CRISPR/Cas9 technology was conducted and its impact on ESCC cell growth and migration was investigated. Results: The mRNA and protein expression levels of MCM10 were significantly greater in ESCC than in normal tissues (P

The applications of multiple beams in the extended-interaction oscillator (EIO) with coaxial structure permit a significant increase in the average output power at millimeter wavelength. The study of the TM mode in the coaxial structure shows it can operate in the base mode with a large diameter (relative to the operating wavelength). Through periodically connect the coaxial structure along the axis, the newly developed circuit is formed. The analysis of these circuits shows that the TM010 mode of the circuits with a large volume can interact with the multiple beams efficiently. To demonstrate this capability, a Ka-band EIO with coaxial structure has been designed. A five-beam with a total current of 6 A (evenly divided among five beams) at a voltage of 19 kV was used in this device. Simulations with a 3-D Particle-in-Cell-code computer simulation technology predict an output power up to 25 kW at 35.5 GHz; the efficiency is about 21.9%.

A low voltage (5 kV) ladder-type circuit is designed for the compact W-band extended interaction Klystron (EIK). Characteristics of the low voltage circuit are studied, synchronism relationship and electric field distribution are analyzed and optimized, and discussions on the circuit stability are embedded in the circuit design. In this paper, efficiency decline of the low voltage circuit is studied; two competing modes ( $2\pi $ cavity mode and upper $\pi /8$ mode) are observed, analyzed and suppressed. All of these efforts resulted in a low voltage W-band ladder-type EIK circuit with high stability and feasibility.

Purpose To investigate the therapeutic effects of concurrent preoperative β-elemene treatment in patients with esophageal squamous cell carcinoma who received concurrent chemoradiotherpay followed by surgery. Method The clinicopathological parameters and outcomes of 102 patients with esophageal squamous cell carcinoma were studied and compared between patients treated with and without β-elemene. Results β-elemene treatment could prolong the overall survival and progression-free survival. The 3-year overall survival rate was also increased by β-elemene treatment. β-elemene treatment was an independent prognostic factor for both overall survival and progression-free survival. Occurrence of toxicities associated with chemoradiotherapy was decreased by β-elemene treatment. Conclusions Findings in this study suggested that β-elemene treatment provided survival benefits and reduced chemoradiotherapy-associated toxicities in patients with esophageal squamous cell carcinoma.

The performance of electronic switching between multiple backward-wave modes is studied in a designed extended interaction oscillator (EIO) based on a ladder circuit with finite number of periods to overcome electronic tuning range limits of EIOs operated in standing-wave mode. The dispersion characteristic of the circuit with finite number of periods, which is constructed by a series of discrete modes, is investigated. The mode separation is analyzed and reduced to support continuous switching between multiple different modes by increasing the number of periods as compared with the standing-wave EIO approach. An output circuit is designed to extract the power of backward wave. The electronic switching between nine backward-wave modes has been achieved by changing the beam voltage from 4.1 to 10.5 kV, where the maximum output power over 58 W is obtained at 5.3 kV from the simulation prediction. The EIO can operate over an electronic tuning range of 3.53 GHz from 89.65 to 93.18 GHz in ensuring the output power no less than 20 W. This technique can be extensively applied to increase operating band for extended interaction klystrons (EIKs) and electronic tuning range for EIOs, making them more suitable for many potential applications.

BACKGROUND MicroRNAs (miRNAs) are a class of small non-coding RNAs that are strongly involved in various types of carcinogenesis, including hepatocellular carcinoma (HCC). This study aimed to clarify whether miR-4417 promotes HCC growth by targeting TRIM35 and regulating PKM2 phosphorylation. MATERIAL AND METHODS Online software, including TargetScan and miRanda, was used to predict the potential target of miR-4417. Real-Time PCR (qRT-PCR) and Western blot assays were performed to detect the expression levels of mRNA and protein, respectively. Cell proliferation was measured by MTT assay and apoptosis in A549 cells was examined by flow cytometry. RESULTS Bioinformatics reveal that TRIM35 mRNA contains 1 conserved target site of miR-4417. High level of miR-4417 and low levels of TRIM35 mRNA and protein were observed in HCC cells compared with a normal liver cell line. Biological function analysis showed that miR-4417 inhibitor inhibits cell proliferation and promotes apoptosis in HCC cells. Furthermore, we verified that TRIM35 is a functional target of miR-4417 by use of luciferase reporter assay, and TRIM35 overexpressing showed an elevation of proliferation and a reduction of apoptosis in HCC cells. We subsequently investigated whether miR-4417 and TRIM35 regulate HCC cell proliferation and apoptosis through PKM2 Y105 phosphorylation, and the results supported our speculation that miR-4417 targets TRIM35 and regulates the Y105 phosphorylation of PKM2 to promote hepatocarcinogenesis. CONCLUSIONS Our findings indicate that miR-4417 may function as an oncogene in HCC and is a potential alternative therapeutic target for this deadly disease.

Soy protein isolate (SPI) is a natural organic polymer, being used to prepare protective functional materials due to its sustainability, abundance, and easy processing. However, the protective effect of unmodified SPI films is significantly limited due to its poor mechanical properties, irreversible damage, and monotone functionality. Herein, high-flowability polyethyleneimine (PEI) was used to improve the dynamic properties of the protein matrix and cross-linking, and the phenolic hydrogen bonding of polydopamine (PDA) was used to develop a facile strategy for fabricating SPI-based films with satisfactory self-healing properties, high strength, excellent UV barrier performance, and remarkable fluorescence for the heavy metal detection. PEI disrupted the strong hydrogen bonds between protein molecules, causing them to be aggregated due to the PDA cross-linking. Thus, the phenols of PDA formed hydrogen bonds and constructed a reversible network, which endowed the SPI-PEI-PDA films with excellent self-healing properties. Because the hyperbranched PEI imparted the films with more cavities, the microcracks caused by external forces were blunted. Due to the further PDA crosslinking, the SPI-PEI-PDA films exhibited high mechanical strength. The SPI-PEI-PDA films also showed outstanding UV barrier performance and fluorescence properties for the heavy metal detection due to the bionic melanin-like characteristic of PDA and the Michael addition reaction between the reactants. Additionally, SPI-PEI-PDA films demonstrated the low toxicity in vitro and in vivo, as well as the favorable biodegradability. These films improved the adaptability and safety of protective materials and could greatly promote functional applications of other biopolymer-based materials.

The correlation between the expression of DNA methyltransferase-1 (DNMT1) and estrogen receptor α (ERα), as well as the methylation status of ERα, was analyzed to investigate the clinical significance of DNMT1 and ERα in breast cancer. Substance P immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were utilized to detect the protein and mRNA expression levels of DNMT1 and ERα in 112 breast cancer and 20 normal breast specimens. Methylation specific PCR was utilized to detect the methylation status of ERα in ERα-positive and -negative breast cancer specimens and 20 normal breast specimens. The results of the present study revealed that DNMT1 protein and mRNA levels were low in normal breast specimens (10.00 and 46.05%, respectively) and ERα-positive breast cancer specimens (15.00 and 48.68%, respectively), compared with increased levels in ERα-negative breast cancer specimens (81.11 and 88.89%, respectively; P0.05). The protein and mRNA expression levels of DNMT1 were negatively correlated with ERα expression (P

The theoretical analysis and the experiment of perturbation techniques to the quantitative measurement of electric field characteristics in a 94 GHz extended interaction resonant cavity (EIRC) are described. Parameters such as the observed reflection coefficient (S11) and resonant frequency at the disturbance point can be adopted to determine the Q-factor, relative electric field intensity, and distribution of the EIRC. In the experiment stage, the frequency deviation characteristics of the tested EIRC under the influence of the metallic sphere are consistent with the simulation results, and the relative error of the frequency deviation is 4.40%. This provides an effective solution for studies of the performance monitoring of millimeter–submillimeter-wave electronic devices and the exploration of high-frequency material science.

Background This study aims to clarify the underlying mechanism for the tumor suppressive function of lnc TUSC7 in chemotherapy resistance of esophageal squamous cell carcinoma (ESCC). Methods TUSC7, miR-224 and DESC1 expressions in ESCC tissues and cells were detected by qRT-PCR. Protein level of DESC1, EGFR and p-AKT were observed by Western blot. Overall survival was calculated using the Kaplan-Meier method. Dual-luciferase reporter gene assay and RIP assay were used to comfirm TUSC7 binding to miR-224, and miR-224 binding to DESC1. Cell proliferation, apoptosis, and colony formation was detected by MTT, Flow Cytometry and Colony formation assays. Results TUSC7 was downregulated in ESCC tissues and cells, and low TUSC7 indicated worse overall survival. The analysis of bioinformatics softwares showed that TUSC7 specifically bound to miR-224, and we proved miR-224 was upregulated in ESCC and negatively correlated with TUSC7 expression. Overexpression of TUSC7/inhibition of miR-224 suppressed cell proliferation, colony formation and chemotherapy resistance of ESCC cells, and promoted cell apoptosis. In addition, we confirmed that miR-224 specifically bound to DESC1, and negatively correlated with DESC1. TUSC7 suppressed the proliferation and chemotherapy resistance of ESCC cells by increasing DESC1 expression via inhibiting miR-224. We also confirmed DESC1 inhibited chemotherapy resistance of ESCC cells via EGFR/AKT. Finally, in vivo experiments demonstrated that overexpression of TUSC7 decreased tumor growth and chemotherapy resistance. Conclusion These findings suggested TUSC7 suppressed chemotherapy resistance of ESCC by downregulating miR-224 to modulate DESC1/EGFR/AKT pathway.

A study for designing a multi-purpose, miniature, multiple-beam electron optical system is presented in this paper. A matched magnetic circuit was also designed. We used pierce method to design the gun, 3D simulation software to optimize the optical system and magnetic circuit. A three-beam pierce electron optical system was designed to produce a total current of 3×0.87A divided equally among the three beams at an accelerating potential of 15kV, and the radius of beam tunnel is 1mm. It also consists of solenoid magnet structures to optimize the beam radius, which produce 0.52T magnetic field. This gun have vast prospect, which can be used for vacuum electronic devices, photonic crystals gyrotron and artificial electromagnetic new type medium.

Extended interaction oscillator (EIO) operated in the terahertz range puts greater demand on current density and brightness of electron beam. The pseudospark-sourced (PS) electron beam is an attractive candidate to drive such high frequency EIOs. The study of a THz EIO driven by a PS sheet electron beam is presented. This enables the advantages of a interaction circuit combined with the merits of a PS sheet electron beam, including large beam cross section, high current density and the fact that a PS electron beam does not require the use of an external focusing magnetic field. This paper presents the latest results that demonstrate the design and optimization of THz EIO driven by a 210 mA (500 A/cm2) PS-sourced electron beam. A peak power over 0.78 kW at 0.388 THz was achieved using a pseudospark-sourced sheet electron beam.

Extended interaction oscillator (EIO) operated in the terahertz range puts greater demand on current density and brightness of electron beam. The pseudospark (PS)-sourced electron beam is a good candidate to drive such high frequency EIOs as it has a very high combined beam current density and brightness. This paper presents the numerical studies of oscillation startup time in a G-band EIO based on a pseudospark-sourced electron beam. It was found that the G-band EIO circuit's oscillation startup time and efficiency are relative to the gap length of it with the same period. The authors also present the latest results that demonstrate the successful design and optimization of G-band EIO driven by a 402 mA (500 A/cm2) PS-sourced electron beam. A peak power over 1.27 kW at 184 GHz was achieved using an electron beam, which can be generated by PS discharge.

The applications of multiple-beam in the Extended Interaction Oscillator with coaxial structure permits a significant increase in the average output power at high frequencies. The EIO circuits suitable for the multiple-beam interaction are designed in a coaxial structure. The analysis of this newly developed circuits shows it can interaction with the multiple-beam efficiently. To demonstrate this capability, a Ka-band EIO with coaxial structure has been designed. A five-beam with a total current of 5 A (evenly divided among five beams) at a voltage of 25 kV was used in this device. Simulations with a 3-D PIC-code predict an output power up to 22 kW at 34.5 GHz, the efficiency is about 17.6%.

The aim of the present study was to determine the changes to the expression levels of fragile histidine triad (FHIT), breast cancer type 2 susceptibility protein (BRCA2), MutL homolog 1 (MLH1) and tumour protein 53 (p53) exhibited by families with a history of oesophageal cancer in a region that has a high incidence of oesophageal cancer, and to determine the association of these changes with the cancer history of the families. Immunohistochemistry was used to detect the protein expression of FHIT, p53, BRCA2, and MLH1 in the excised specimens of cancer tissues from 74 oesophageal cancer patients (positive family history of oesophageal cancer [OCFH +], n=33; negative family history of oesophageal cancer [OCFH −], n=41) from a region with a high incidence of oesophageal cancer. The positive expression rates of FHIT (61%; 45/74), BRCA2 (50%; 37/74) and MLH1 (27%; 9/33) in the oesophageal cancer tissues were significantly lower than those in the healthy tissues adjacent to the cancer (97% [29/30], 87% [26/30] and 73% [25/41], respectively). A significant difference was identified between the positive expression rates (P

Epigallocatechin‑3‑gallate (EGCG), a major catechin in green tea, has recently been reported to exhibit anticancer effects on a number of types of cancer cells in vitro; however, the molecular mechanisms of this anticancer effect remain poorly understood. In the current study, the effects of EGCG on the proliferation and migration of the OVCAR‑3 human ovarian carcinoma cell line were investigated. Cells were treated with EGCG and their proliferation rates were determined by an MTT assay. In addition, cell migration was detected by transwell assay. The activity of mitogen‑activated protein kinases (MAPKs) and the expression of matrix metalloproteinase‑2/9 (MMP‑2/9) were examined by western blotting. The results showed that EGCG significantly inhibited (P

A circuit design of sheet-beam extended interaction oscillator (SB-EIO) with an overmoded staggered grating array is embodied in theoretical analyses which combined with particle-in-cell (PIC) simulation. Mode and dispersion analyses on the design of the TM41-2π mode EIO demonstrated that the optimized cutoff frequency and the dimensions of the SWS noticeably suppress non-operating lower order modes. The overmoded structure only allowed the desired 4th order mode to propagate in the structure. In addition, this structure benefit from a mm-level transverse size structure, so that it can be a potential solution for the applications (such as communications and spectroscopy) lack in output power. The newly designed EIO is simulated with copper used as the background material, and the ∼0.375 THz radiation power of ∼105W is achieved when an electron beam with 1.3 A and 44.5 kV is injected. The designed circuit structure can be widely applied to sheet beam devices for THz RF generation.

The application of a TM31 mode scheme in extended interaction radiation sources permits the use of higher beam power and larger power capacity for power enhancement as compared with that of the conventional fundamental mode in the millimeter-wave band. To support this point, the effect of coupling cavities on the electromagnetic characteristics of the TM31 and fundamental modes is studied. This study shows that the TM31 mode can build up (1) a weaker TM11-like field in the gaps which has the same typical distribution pattern as that of a conventional fundamental mode at the same frequency and (2) two extra parts of field energy to support larger coupling cavities. To demonstrate this feature, we observe the field distribution and strength by injecting a certain wave power in two cavities, which are predicted to resonate in the TM31 and fundamental modes at the same frequency. The mode analysis and the beam-wave interaction are discussed to analyze the feasibility of the TM31 mode scheme. Through particle-in-cell simulations, the maximum output power over 26.3 kW is obtained at the desired frequency when the beam voltage and current are 61 kV and 3 A, respectively. The TM31 mode scheme could be a promising candidate for achieving high power in millimeter-wave extended interaction radiation sources.The application of a TM31 mode scheme in extended interaction radiation sources permits the use of higher beam power and larger power capacity for power enhancement as compared with that of the conventional fundamental mode in the millimeter-wave band. To support this point, the effect of coupling cavities on the electromagnetic characteristics of the TM31 and fundamental modes is studied. This study shows that the TM31 mode can build up (1) a weaker TM11-like field in the gaps which has the same typical distribution pattern as that of a conventional fundamental mode at the same frequency and (2) two extra parts of field energy to support larger coupling cavities. To demonstrate this feature, we observe the field distribution and strength by injecting a certain wave power in two cavities, which are predicted to resonate in the TM31 and fundamental modes at the same frequency. The mode analysis and the beam-wave interaction are discussed to analyze the feasibility of the TM31 mode scheme. Through particle-...

基于Born-Haber热力学循环理论, 利用多组态Dirac-Fock方法计算的超重元素Uus及其同族元素Cl, Br, I和At的离化势和亲和势及已有的标准电极电势的实验值,拟合得到了Uus的元素电势图. 结果表明: 在酸溶液中Uus的0价态能够稳定存在, 而1-, 1+和5+价态不能稳定存在; 在同族元素中, 随原子序数Z的增大, 0价态和1+态的稳定性逐渐增加, 1-价态的稳定性逐渐降低; 而5+价态的稳定性随原子序数变化并不是单调的. 对于这种稳定性随原子序数变化的规律, 我们从价电子能级的相对位置以及电子电离或亲和的过程作了定性的解释.

The mode-hopping phenomenon in extended interaction oscillator (EIO) based on the multiple-gap topology resonant system is studied to verify the remarkable advantage of the electronic tuning property for EIO. In contrast to the conventional EIO where electron beam interacts with the standing-wave mode in a narrow operating voltage range, the presented EIO can operate in a sequence of neighboring backward-wave modes by switching the beam voltage. According to particle-in-cell (PIC) simulation in CST, the mode-hopping effect has resulted in radiation power fluctuation. Simulation results demonstrate that the EIO is capable of electronic tuning in a relatively wide operating voltage range from 4.1 kV to 9.5 kV. An output power on the order of a few tens of watts is obtained. The study of the mode-hopping effect can show a promising way to operate the EIO in the backward-wave regime.

The circuit suitable for the hollow electron beam (HEB) interaction was formed by parallel connecting of the sheet beam extended interaction klystron circuit at the angular direction. The analysis of this newly developed circuit shows it can interacts with the distributed HEB. To demonstrate this capability, a W-band extended interaction oscillator (EIO) with distributed HEB has been designed. A DC distributed HEB with 27 keV energy and 8A current was injected into the interaction circuit, simulations with a 3-D Particle-in-cell (PIC) code predict an output power up to 6.6 kW at 99.7 GHz was obtained.

A compact three-cavity circuit with ladder type structure is designed for the pencil beam W-band extended interaction klystron (EIK). Circuit parameters such as coupling coefficient M, characteristic impedance R/Q and beam-loading conductance Ge are analyzed and optimized in the design procedure. The initial beam parameters are 18.1 kV, 0.2 A and 0.5 mm in diameter. Simulation predicts a saturation output power of 300 W is achieved at 94.5 GHz with an input power of 290 mW, corresponding to the gain of 30 dB and electronic efficiency of 8.3%.

A system of three dipole-coupled spins exhibits a surprisingly intricate relaxation behavior. Following Hubbard's pioneering 1958 study, many authors have investigated different aspects of this problem. Nevertheless, on revisiting this classic relaxation problem, we obtain several new results, some of which are at variance with conventional wisdom. Most notably from a fundamental point of view, we find that the odd-valued spectral density function influences longitudinal relaxation. We also show that the effective longitudinal relaxation rate for a non-isochronous three-spin system can exhibit an unusual inverted dispersion step. To clarify these and other issues, we present a comprehensive theoretical treatment of longitudinal relaxation in a three-spin system of arbitrary geometry and with arbitrary rotational dynamics. By using the Liouville-space formulation of Bloch-Wangsness-Redfield theory and a basis of irreducible spherical tensor operators, we show that the number of relaxation components in the different cases can be deduced from symmetry arguments. For the isochronous case, we present the relaxation matrix in analytical form, whereas, for the non-isochronous case, we employ a computationally efficient approach based on the stochastic Liouville equation.

Termites are worldwide pests causing considerable damage to agriculture, forestry and buildings. Although physical and chemical methods have been tried to eliminate termite populations, they have the limitations such as low effectiveness, high-toxicity residue, environmentally harmful and high cost. Therefore, it has attracted much attention to develop highly effective, low-toxic, long residual period, environmentally friendly and low-cost termiticidals. Here, we report the characterization and antitermitic activities of a new antitermitic compound-producing endophytic bacterium HUB-I-47 isolated from eastern red-cedar, Juniperus virginiana L. The morphological, physiochemical characteristics of strain HUB-I-47 and its 16S rDNA sequences, and the antitermitic compound were analyzed by gas chromatography-mass spectrometry were studied. We found that the morphology of HUB-I-47 was very similar to that of Bacillus subtilis but presented some differences in shape and cell size. Growth evaluation showed that the lowest, highest, and optimum growth temperatures of HUB-I-47 were 12, 47, and 31 degrees C, respectively, which were different from those of reference strains. The 16S rDNA sequence analysis revealed a high similarity of 99% to those of B. subtilis. Based on these analyses, we named strain HUB-I-47 as B. subtilis subsp. virginiana D. P. Zhou, K. Zhao, J. Liu et W. X. Ping, subsp. nov. This is the first report on the analysis of antitermitic compounds from endophytic bacteria. Our study identified a new resource of antitermitic compounds through endophytic bacteria fermentation.

This paper presents a theoretical study on a start current of a 0.378 THz sheet beam extended interaction oscillator (SB-EIO), and the design of this device driven by thermionic cathode stands a chance to realize a compact and powerful THz coherent continuous radiation sources. After theoretical study, the SB-EIO with eleven gaps is designed to operate at 2π mode. The coupling and interaction abilities are optimized to meet the synchronization conditions and thus improve the output power and efficiency. The start current analysis is preliminarily accomplished, and the advantages are: (1) At the operation frequency of 0.378 THz, the start current and current density of the device are optimized to 20 A/cm2 and 8.4 mA, and the output power is 14 W. (2) It works in the condition of smooth copper plane in simulation, and the output power is still about 20 W when an electron beam with 252 mA and 41 kV is injected. The research gives an estimation of up to 3.5 times decline in output power when the surface roughness emerges. (3) The results of the simulation show that a relatively high efficiency of ∼13% in particle-in-cell (PIC) was observed, and a stable output power range from 98 W to 234 W is found when the injected electron beam (0.35 mm × 0.12 mm) is 16.8–42 mA and 42 kV. Moreover, the reliability of PIC results is verified in this paper.

Highly overmoded structures of sheet beam EIK are barriers for the stable operation in RF circuit. In this paper, 3D simulations of an output cavity are presented followed by the calculations of RF parameters and mode competition analysis. Simulation results indicate that potential mode competition is feasible to be alleviated by systematic optimization while meeting the other performance requirements simultaneously.

Extended interaction oscillator (EIO) operation in the terahertz range puts greater demand on the current density and brightness of an electron beam. The pseudospark (PS)-sourced electron beam is a good candidate for driving such high frequency EIOs as it has a very high combined beam current density and brightness. However, the PS-sourced electron beam can have an inherent velocity spread unless some form of post acceleration is used. Before a new EIO device in the Y-band (220 GHz–325 GHz) based on a PS-sourced electron beam can be realized, it is first necessary to analyze the influence of the beam velocity spread on performance. This paper presents the numerical studies of the EIO performance with the inclusion of the beam velocity spread. It was found that the Y-band EIO circuit can operate in a relatively wide velocity spread range when a high beam current density is used. For an electron beam current density of 1 kA/cm2, the output power is not less than 0.9 times of the power obtained with an elect...

In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical exchange processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water (1)H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft-tissue contrast in clinical magnetic resonance imaging.

Objective: To explore the correlation between ROBO2 and RASSF2A gene methylations and gastric cancer family history. Materials and Methods: ROBO2 and RASSF2A gene methylations in gastric cancer tissues and peri.cancerous tissues were detected with methylation.specific PCR in 36. patients with gastric cancer family history and 33 without gastric cancer family history. The correlations of ROBO2 and RASSF2A gene methylations with family history, and clinical and pathological characteristics were analyzed. Results: ROBO2 and RASSF2A gene methylations were all significantly higher in gastric cancer tissues (30% and 26%) than in peri-cancerous tissues (0% and 0%) (all P < 0.05). ROBO2 gene methylation was significantly lower in the patients with gastric cancer family history (17%, 6/36) than in the patients without gastric cancer family history (41%, 15/33) (P < 0.05). Conclusion: ROBO2 and RASSF2A gene methylations may be related to gastric tumorigenesis, and ROBO2 gene methylation is associated with sporadic gastric cancer.