Search

Abstract To explore the related factors of turnover intention in clinical research coordinators (CRCs) and assess the mediating effects of professional identity on the association between job burnout and turnover intention. In China, CRC has become increasingly common among clinical trial teams in recent years. However, limited published research focused on the status of turnover intention in CRCs. We invited all the 220 CRCs currently working at Hunan Cancer Hospital located in Changsha city in the central south of China from March to June 2018. Participants were asked to complete structured questionnaires regarding basic demographic information, job burnout, professional identity and turnover intention. A total of 202 participants were included in this study, with a response rate of 91.82%. The main reason for turnover intention among CRCs was human resources, followed by communications, management and material resources (per item score in each dimension: 2.14 vs. 2.43 vs. 2.65 vs. 2.83). All the correlations among job burnout, professional identity and turnover intention were statistically significant, with coefficients ranging from −0.197 to 0.615. Multiple liner regression analysis showed that older age, longer workhours per week, and lower level of professional identity were associated with the prevalence of turnover intention among CRCs. Besides, the association between job burnout and turnover intention was fully mediated by professional identity. This study revealed the status and causes of turnover intention among Chinese CRCs. Effective measures on decreasing working time and improving professional identity should be taken in order to reduce CRCs’ turnover intention.

Mitochondria are semi-autonomous organelles in eukaryotic cells with their own genome. Plant mitogenomes differ from animal mitogenomes in size, structure, and repetitive DNA sequences. Despite larger sizes, plant mitogenomes do not have significantly more genes. They exhibit diverse structures due to variations in size, repetitive DNA, recombination frequencies, low gene densities, and reduced nucleotide substitution rates. In this study, we analyzed the mitochondrial genome of Stemona sessilifolia using Nanopore and Illumina sequencing. De-novo assembly and annotation were conducted using Unicycler, Geseq, tRNAscan-SE and BLASTN, followed by codon usage, repeat sequence, RNA-editing, synteny, and phylogenetic analyses. S. sessilifolia’s mitogenome consisted of one linear contig and six circular contigs totaling 724,751 bp. It had 39 protein-coding genes, 27 tRNA genes, and 3 rRNA genes. Transfer of chloroplast sequences accounted for 13.14% of the mitogenome. Various analyses provided insights into genetic characteristics, evolutionary dynamics, and phylogenetic placement. Further investigations can explore transferred genes’ functions and RNA-editing’s role in mitochondrial gene expression in S. sessilifolia.

In order to study the effect of magnesium salt (magnesium chloride hexahydrate + magnesium hydroxide) on the retarding characteristics of coal spontaneous combustion, the effects of inhibitor dosage and silane coupling agent on the characteristic temperature and thermal effect of coal spontaneous combustion were studied by synchronous thermal analysis and programmed heating-gas chromatography. The results of simultaneous thermal analysis showed that the inhibitory effect was relatively best when the magnesium salt inhibitor was added at 30%, the pyrolysis temperature T3 was delayed by 40 °C compared with the raw coal sample, and the total heat release was reduced by 165.14 J/mg. F@M30%·G resisted coal sample adding silane coupling agent mainly delayed the occurrence of coal pyrolysis and ignition, in which the pyrolysis temperature T3 was 49 °C higher than that of raw coal, and the ignition temperature T4 was increased by 26 °C. F@M30% inhibited coal samples can reduce the volume fraction of CO, and the effect of inhibiting spontaneous combustion of coal is gradually enhanced with the increase of temperature. After adding silane coupling agent, the volume fraction of CO of inhibited coal samples can be reduced by about 4×10-6. The inhibition rate of F@M30% inhibited coal samples is 30.87%, and that of F@M30%•G inhibited coal samples is as high as 91.57%.

Abstract In order to solve the security problems caused by malicious nodes in wireless sensor networks, a TS‐BRS reputation model based on time series analysis is proposed in this paper. By using the time series analysis method, the matching analysis of two time series is carried out to reduce the interference of channel conflicts on the reputation evaluation model and improve the accuracy of model recognition. In order to improve the adaptability of the evaluation model, the adaptive maintenance function μ is introduced into the update of credit value, which aggravates the influence of node behaviour on credit value at the present stage. The simulation results show that the new reputation evaluation model can effectively improve the detection rate and detection speed of malicious nodes in the network. After the introduction of maintenance function, the reputation value of the captured malicious nodes in the network has a faster convergence speed.

Given that more and more oil reservoirs are reaching the high water cut stage during water flooding, the construction of an advanced algorithmic model for identifying inter-well connectivity is crucial to improve oil recovery and extend the oilfield service life cycle. This study proposes a state variable-based dynamic capacitance (SV-DC) model that integrates artificial intelligence techniques with dynamic data and geological features to more accurately identify inter-well connectivity and its evolution. A comprehensive sensitivity analysis was performed on single-well pairs and multi-well groups regarding the permeability amplitude, the width of the high permeable channel, change, and lasting period of injection pressure. In addition, the production performance of multi-well groups, especially the development of ineffective circulation channels and their effects on reservoir development, are studied in-depth. The results show that higher permeability, wider permeable channels, and longer injection pressure maintenance can significantly enhance inter-well connectivity coefficients and reduce time-lag coefficients. Inter-well connectivity in multi-well systems is significantly affected by well-group configuration and inter-well interference effects. Based on the simulation results, the evaluation index of ineffective circulation channels is proposed and applied to dozens of well groups. These identified ineffective circulation channel changing patterns provide an important basis for optimizing oil fields’ injection and production strategies through data-driven insights and contribute to improving oil recovery. The integration of artificial intelligence enhances the ability to analyze complex datasets, allowing for more precise adjustments in field operations. This paper’s research ideas and findings can be confidently extended to other engineering scenarios, such as geothermal development and carbon dioxide storage, where AI-based models can further refine and optimize resource management and operational strategies.

Transradial access (TRA) is a safe and comfortable approach and the preferred access for percutaneous coronary intervention. However, TRA is not widely used for peripheral interventions. Currently, there is a lack of data on patient selection, appropriate medical devices, complication prevention, and TRA adoption. Therefore, the Chinese Society of Interventional Oncology of the China Anti-Cancer Association organized nationwide experts to establish a Working Group of China Expert Consensus on TRA in percutaneous peripheral interventions in 2022, and jointly formulated this consensus to better promote the application of TRA in peripheral interventions to guide clinicians on patient selection, technical recommendations, and physician training. This consensus mainly focuses on the current situation, advantages and limitations of TRA in peripheral interventions, anatomical characteristics of the radial artery, patient selection, technical aspects, prevention and management of complications, radiation dose, and learning curve. A consensus was reached through a literature evaluation and by referring to the opinions of the expert group.

PDR positioning is currently the core issue of autonomous positioning, there is a problem of high noise and interference in dynamic measurement using PDR (Pedestrian Dead Reckoning) MEMS (Micro-Electro-Mechanical System) device, which is often a low precision multi-source integration sensor. Two new models of improved spectral subtraction (ISS) and PDRS (PDR-Spectral subtraction) spectral subtraction are constructed in this paper according to the spectrum features of the periodic noise generated from personnel stepping in PDR positioning. It is proposed a two-stage noise reduction method of spectrum subtraction-Wiener filtering for obtaining the static magnetic sequence of personnel path and reducing the real-time noise in PDR positioning, which main mechanism is to use the step power spectrum as the background noise for primary noise reduction, secondary Wiener filtering noise reduction according to the correlation between the denoised signal and the reference signal. A self-made MEMS-based positioning device HBEQ-1 and a high-precision magnetometer FVM-400 were used to collect dynamic and static magnetic value from the test area, and a spectral subtraction-Wiener two-stage noise reduction test was carried out. The experimental results show that the improved ISS spectral subtraction and PDRS spectral subtraction are effective in denoising the dynamic magnetic measurement, but there is still a certain deviation between the peak value and the amplitude of the denoised signal. After secondary noise reduction by Wiener filtering, the signal morphology similarity of magnetic curve and the reference reached 0.7975, and the matched path values of the dynamic magnetic value reached around 12000–13000. It showed that the denoising effect is good and the waveform of denoised signal and the reference signal is similar, but there is spatial stretching of the overall magnetic sequence. It is shown that the spectral subtraction-Wiener noise reduction method cannot eliminate the inertial delay bias generated by personnel walking, the processing does not distort the magnetic signal, maintains spatial characteristics of the static magnetic sequence of personnel path, which is an excellent model for noise reduction of dynamic magnetic measurements in PDR positioning.

In order to clarify the adsorption pattern between coal and CO, CO2 and O2, the competition between CO and CO2 and O2 in coal is studied. Qianjiaying bituminous coal is used as the research object, and the molecular unit parameters are calculated by quantitative analysis method based on the experimental results of Fourier transform infrared spectroscopy (FTIR). The molecular cell structure of Qianjiaying bituminous coal is constructed (C1160H860O80N20). To verify the accuracy of the model, the infrared spectrum of molecules is simulated by quantum chemical calculation, and the calculated results are basically consistent with the experimental results. On this basis, the effects of pressure(0−16 MPa) and temperature(20−60 ℃) on the adsorption of CO, CO2 and O2 by coal are investigated by using the Grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) methods. From the experimental results, it can be concluded that the fitted isothermal adsorption curves conformed to the Langmuir equation. Under the same pressure, the adsorption capacity of CO, CO2 and O2 is weaker as the temperature increases. At the same temperature, there is a positive correlation trend between the burial pressure of coal seam and the adsorption amount. The magnitude of adsorption of single gases CO, CO2 and O2 is CO2 > O2 > CO, and CO2 can reach saturation adsorption state in the first. The competitive adsorption results of binary gases show that the adsorption selectivity of CO2/CO has obvious advantages in low-pressure or shallow buried coal seams. However, the adsorption selectivity of O2/CO did not change significantly with the change of pressure. The competitive adsorption capacity of CO2 is greater than that of CO, and the adsorption capacity of CO2 decreases with the increase of CO concentration; The competitive adsorption of O2 is greater than CO when the ratio of CO to O2 molar concentration is ≤ 1, but the adsorption of CO is greater than O2 when the molar concentration of CO is much greater than O2. Therefore, the molar concentration of CO is high, which inhibits the adsorption capacity of CO2 and O2. In other words, in bituminous coal seams with high abnormal CO concentration, the effect of using CO2 injection to control fire extinguishing is not significant, so the amount of air leakage from the working face should also be controlled to prevent CO from desorption to the coal body and to ensure that the CO concentration in the well is within the permissible range.

A numerical simulation method combining the detailed chemical reaction mechanism of methane deflagration with an approximate real tunnel structure was proposed to confirm whether the unevenness of the tunnel wall during a coal mine gas explosion can be ignored. The approximate real tunnel model and smooth wall tunnel model were developed using 3D modeling methods. The propagation and attenuation processes of shock waves in the two tunnel models, as well as the different dynamic responses of the two tunnel walls, were compared and analyzed. Research results show that the non-uniformity of the tunnel wall decreases the shock wave overpressure and propagation velocity. The peak overpressure reduction value of the shock wave reaches 81.91 kPa, and the shock wave overpressure reaches its peak at an extended maximum time of 7.4 ms. The stress distribution on the approximate real tunnel wall is discontinuous, the propagation speed of stress waves in the bend tunnel is slower, and the duration of high load is relatively low. The displacement of the approximate real tunnel after gas explosion is lower than that of tunnels with smooth walls, and the displacement of most measuring points on the tunnel on the right is only 1/3–1/2 that of the smooth tunnel.

To improve the accuracy of gas outburst early warning, this paper proposes a gas outburst risk warning model based on XGBoost–GR–stacking. The statistic is based on gas outburst data from 26 mines and establishes a data generation model based on XGBoost. The obtained virtual datasets are analyzed through visualization analysis and ROC curve analysis with respect to the original data. If the augmented data has an ROC area under the curve of 1, it indicates good predictive performance of the augmented data. Grey correlation analysis is used to calculate the grey correlation degrees between each indicator and the “gas emission”. The indicator groups with correlation degrees greater than 0.670 are selected as the main control factor groups based on the sorting of correlation degrees. In this study, SVM, RF, XGBoost, and GBDT are selected as the original models for stacking. The original data and virtual data with correlation degrees greater than 0.670 are used as inputs for SVM, RF, XGBoost, GBDT, and stacking fusion models. The results show that the stacking fusion model has an MAE, MSE, and R2 of 0.031, 0.031, and 0.981. Comparing the actual and predicted values for each model, the stacking fusion model achieves the highest accuracy in gas outburst prediction and the best model fitting effect.

In order to solve the defects of traditional coal spontaneous combustion prevention technology in a closed goaf, a strain of aerobic endogenous bacteria was isolated from coal and used as a blocking raw material. Based on the metabolic and reproductive characteristics of microorganisms, the experimental study on the inhibition of coal spontaneous combustion by microorganisms was carried out. The colonies were isolated and purified by the dilution concentration plate method and the scribing plate method. The growth morphology of microorganisms was analyzed, and the growth curve was determined. The strains were identified by seamless cloning technology for high-throughput sequencing. The surface morphology of coal was analyzed by SEM, the differences of oxidation characteristic temperature points were analyzed by TG–DTG–DSC images, a programmed heating experiment was used to analyze the concentration of the indicator gas CO, and the changes in microscopic groups before and after microbial action were analyzed by FTIR and XPS spectra. Therefore, the inhibition of coal oxidation by endogenous bacteria was verified from macroscopic and microscopic perspectives. The results show that the coal bacteria isolated from the coal is Lysinibacilus sp. After the culture of Lysinibacilus sp., the surface of the coal demonstrated less detritus, and was relatively smooth. In the early stage of low temperature oxidation of coal spontaneous combustion, the characteristic temperature point of coal oxidation and the reaction between coal and O2 could be delayed by Lysinibacilus sp., and the total heat release was reduced in the combustion process. Not only that, Lysinibacilus sp. could also reduce the CO concentration during coal heating. After the coal was decomposed by Lysinibacilus sp., the C=C thick ring skeleton structure had little effect; however, the aromatic substitution pattern changed. This bacterium had an effect on the C-O bond, reducing the percentage of -CH2- and increasing the percentage of -CH3. It might also use the crystalline water in coal for life activities. The carboxyl carbon in coal changed the most, with a decrease of 12.03%, so it might become the carbon source required for microbial growth. The reproductive metabolism of microorganisms also affected the form of nitrogen, and the percentage of pyridine nitrogen in coal was reduced. The ratio of single-bond carbon to double-bond carbon in raw coal was about 3:2, but after this bacterial action, the ratio of the two was about 1:1. The analytical conclusions of XPS and FTIR spectra were consistent, and the results supported each other.

Objective: This study aimed to assess the occurrence of chemotherapy-induced nausea and vomiting (CINV) in acute phase (24 h after chemotherapy) and delayed phase (2–5 days after chemotherapy) after standard antiemetic therapy and to explore the risk factors of CINV in the acute and delayed phases. Methods: This prospective and observational study analyzed the data of 400 breast cancer patients scheduled for chemotherapy in two hospitals. The self-report survey was developed to assess the occurrence of CINV and their associated factors. On day 2 and day 6 of chemotherapy, CINV was evaluated by the Multinational Association of Supportive Care in Cancer Antiemetic Tool (MAT). The incidence of acute and delayed CINV was expressed as frequency and percentage. Results: Among 400 patients, 29.8% and 23.5% experienced acute and delayed CINV, respectively. Logistic regression analysis showed that the risk factors associated with acute CINV included pain/insomnia, history of CINV, and highly emetogenic chemotherapy. The history of motion sickness (MS), history of CINV, number of chemotherapy cycles completed, and the incidence of acute CINV were significant risk factors for delayed CINV (all P < 0.05). Conclusions: The results of this study are helpful for nurses to identify high-risk patients with CINV, formulate effective treatment plans, and reduce the incidence of CINV.

To solve the bottleneck problem of low deep coal seam permeability and difficult coalbed methane (CBM) mining. Combining hydraulic splitting technology and directional drilling technology, a directional hydraulic splitting enhancement method of deep CBM mining was proposed. The selection equation for the directional hydraulic splitting of deep coalbed was constructed. The numerical simulation reveals the variation in coal fractures around different split angles. The split angle under the maximum coal damage effect was obtained. It was found that the combined effect of the double crack damage disturbance region led to reciprocal stress fluctuations during crack development and, eventually, the formation of a zigzag fracture. The larger the splitting angle, the larger the fissure development length and the larger the coal-damaged area. A double crack takes 25% less time to complete propagation than a single crack. When the splitting angle is 90°, the disturbed area occupies 2/3 of the area around the borehole, and the overall fracturing effect is the best. In the application process, the new directional hydraulic splitting technology can increase CBM mining by 5.08%, greatly improve CBM mining efficiency, and reduce the coal mining risk, which is of great significance to the project.

It is important that precise positioning and navigation of underground personnel for intelligent hedging and mine rescue in mine accidents or disasters. At present, there are many passive positioning methods such as RFID, Zigbee and other positioning products in the underground, which cannot work normally while there is power supply interruption or signal interruption in the underground. GRPM is a new active underground positioning method combining radio frequency identification and geomagnetic matching technology, which the positioning accuracy reach to the sub-meter level when the miner with the GRPM device in the underground. Geomagnetic matching algorithm is the core technology of GRPM, and its performance directly affects the accuracy of the geomagnetic positioning. For the MSD, MAD and PORD matching algorithms have low precision in geomagnetic matching localization; it is proposed a novel matching algorithm named MPMD to achieve underground geomagnetic precise positioning in this paper which is an optimal estimation of the eigenvector product of underground two magnetic variables. The matching test of underground geomagnetic positioning for the performance of MPMD algorithm was carried out in 9 tunnels about 150 meters long and 6 meters wide in mine. The geomagnetic data of the total magnetic field and the three axis component are measured with the portable FVM400 fluxgate magnetometer. MSD, MAD and MPMD algorithms were used to matching test for analyzed their effective matching length, positioning error, noise immunity. The test result shows that the MPMD algorithm has the advantages of minimum matching position error and better noise immunity than MSD, MAD matching algorithms under the same experimental conditions. It is suitable for the complications of underground geomagnetic spatial distribution, and meets the requirements of underground emergency refuge and navigation. However, matching process of MPMD algorithm is time-consuming, it can be further improved the search space and search strategy in later research.

Based on the statistical analysis of coal occurrence characteristics, and dynamic phenomena of coal and rock in Qianjiaying coal mine, China, an area–local outburst early warning system based on outburst key factors and early warning indicators was constructed. Statistical analysis of anomaly features of gas emission rate prior to outburst determined that the early warning index of the heading-face featured characteristic values of gas emission rate, including variance, peak difference, and fluctuation slope. Based on the entropy-weight method, the weight of indicators in the early warning process was determined, and the membership degree of each early warning grade under the synergistic effect of multiple indicators was calculated using Bayesian theory to determine the early warning grade. An outburst early warning model for Qianjiaying coal mine was constructed. The application client for an early warning system was developed, including a real-time gas data acquisition system and a visual early warning system. During the application of the early warning system in Qianjiaying Mine, it detected abnormal early warning indicators and issued early warning signals 6 hours in advance, avoiding casualties and equipment losses.

Hydration reactions of expansive materials are typically very safe, easy to induce, and low in cost, while the crushing of such materials is typically free from noise, dust, vibration, and toxic gases. In the present study, to realize the application of expansive materials in the prevention of coal seam gas disasters, the microstructure, heat release rate, and expansive pressure of expansive materials were investigated for different degrees of hydration based on temperature and pressure measurements and using a scanning electron microscope (SEM); fracture characteristics were determined based on fracture tests of coal-like materials. The results show that the expansive material with +30% water has the lowest hydration temperature (100°C). The expansive pressure of the steel tube was found to reach 57 MPa, which is deemed suitable for application in coal seams. The strain and displacement of coal-like materials were found to increase with time, with four main cracks appearing. Based on these results, it is feasible that hydration reactions of expansive materials could increase both gas drainage and permeability in coal seams, thus reducing the risk of rock burst around boreholes in coal seams.

Methane in coal seam is always under the dynamic process of adsorption and desorption. It has been demonstrated that the static blasting technology is an effective way to extract methane from coal. Although it is of great significance to understand the role of static blasting materials on methane extraction, the change of methane during static blasting is not well understood due to limited research studies. In this paper, we took the reaction pressure and heat from the hydration of the static blasting materials as the main factors. Microstructure changes in the static blasting materials and coal were analyzed by scanning electron microscopy, gas chromatography, infrared spectroscopy, and mercury injection. Changes of methane adsorption and adsorption rate before and after the static blasting were also measured. Our results demonstrated that the static blasting materials entered the microcracks of the coal body and the porosity of the coal was increased by heat expansion, improving methane migration. During the blasting process, methane began to desorb from the coal and its adsorption content was decreased. In contrast, the adsorption of methane was increased after the reaction. However, methane adsorption rate is higher than that of raw coal, indicating that the adsorbed methane is easier to convert into free methane, which is conducive to emission. This is of great significance to methane extraction and the safety of mines.

Karst cave collapse usually occurs during the process of drilling and reservoir development. Karst cave collapse increases drilling risk and seriously affects oil production. In order to reveal the collapse mechanism of karst caves in fractured-vuggy reservoirs in Tahe oil field, rock mechanic experiments and numerical simulation studies were conducted. In rock mechanic experiments, three types of rock mechanics tests (uniaxial compression, triaxial compression, and Brazilian splitting) were carried out to obtain the basic rock mechanics parameters. In numerical simulation studies, the collapse conditions of a single karst cave and a cave system were studied. Numerical simulation results indicate that for a single karst cave, the size and geometrical features of karst caves are the main factors influencing collapse condition. For a cave system, a combination pattern and distance between caves are two main factors affecting collapse condition. In order to facilitate the application of these research results, the authors present formulas for calculating the critical conditions of karst cave collapse by means of multivariate linear regression method. The calculation formulas and prediction chart were verified as consistent with actual field results. The research results in this paper have great theoretical and practical value for revealing the mechanism of karst cave collapse in fractured-vuggy carbonate reservoirs.

Coal seam gas pressure is one of the fundamental parameters used to assess coal seam gas occurrence and is an important index in assessing the risk of gas disaster. However, the geological characteristics of coal seams become increasingly complex with increasing mining degree, thus decreasing the accuracy and success rate of direct methods for measuring gas pressure. To address such issues, we have developed a new method for direct measurement of gas pressure in water-bearing coal seams. In particular, we developed a pressure measurement device based on theoretical analysis and quantified the basic parameters of the device based on well testing. Then, we verified the applicability of our method based on comparative analysis of the results of field experiments and indirect measurements. Our results demonstrate that this new method can resolve the effects of water pressure, coal slime, and other factors on the estimation of gas pressure. The performance of this new method is considerably better than that of traditional methods. In particular, field test results demonstrate that our method can accurately and efficiently measure gas pressure in water-bearing coal seams. These results will be of great significance in the prevention and control of coal seam gas disaster.

The technology of increasing coal seam permeability by high-pressure water jet has significant advantages in preventing and controlling gas disasters in low-permeability coal seam. The structural parameters of a nozzle are the key to its jet performance. The majority of the current studies take strike velocity as the evaluation index, and the influence of the interaction between the nozzle’s structural parameters on its jet performance is not fully considered. In practice, strike velocity and strike area will affect gas release in the process of coal breaking and punching. To further optimize the structural parameters of coal breaking and punching nozzle, and improve water jet performance, some crucial parameters such as the contraction angle, outlet divergence angle, and length-to-diameter ratio are selected. Meanwhile, the maximum X-axis velocity and effective Y-axis extension distance are used as evaluation indexes. The effect of each key factor on the water jet performance is analyzed by numerical simulation using the single factor method. The significance and importance effect of each factor and their interaction on the water jet performance are quantitatively analyzed using the orthogonal experiment method. Moreover, three optimal combinations are selected for experimental verification. Results show that with an increase in contraction angle, outlet divergence angle, and length-to-diameter ratio, the maximum X-axis velocity increases initially and decreases thereafter. The Y-direction expansion distance of the jet will be improved significantly with an increase in the outlet divergence angle. Through field experiments, the jet performance of the improved nozzle 3 is the best. After optimization, the coal breaking and punching diameter of the nozzle is increased by 118%, and the punching depth is increased by 17.46%.

Objectives: Iodine-125 (125I) irradiation has been widely applied in the treatment of advanced multiple malignant tumors. However, the underlying mechanism of 125I exerted an anti-tumor effect on hepatocellular carcinoma (HCC) was largely unknown. Methods: In both HCCLM3 and SMMC-7721 cells, the effect of 125I irradiation on the glycolysis was detected. The mRNA in HCC tissues and cell lines were detected by RT-qPCR. Cell proliferation, invasion and migration, and apoptosis were examined by CCK-8, Transwell, wound healing assay and flow cytometry assay, respectively. The interaction between miR-338 and PFKL (6-phosphofructokinase) were verified by dual-luciferase reporter gene assay. Western blotting was used to detect the expression of glycolysis-related proteins. We also evaluated the effect of 125I seed implantation on the tumor growth and Warburg effect in vivo. Results: 125I irradiation significantly decreased the Warburg effect, cell proliferation, invasion and migration, and induced apoptosis of HCCLM3 and SMMC-7721 cells. miR-338 was upregulated in HCC cells treated with 125I irradiation, which was a negative correlation with tumor size, tumor metastasis, and tumor development. Moreover, miR-338 directly interacted with PFKL and suppressed its expression. Mechanistically, 125I irradiation significantly decreased the Warburg effect and exhibited anti-tumorigenesis function through upregulating the inhibitory effect of miR-338 on PFKL expression. Conclusion: 125I irradiation upregulated the suppression of miR-338 on PFKL to downregulate the Warburg effect and anti-tumorigenesis in HCC and provided a new potential strategy for HCC clinical treatment.

Abstract Kanamycin B as the secondary metabolite of wild‐type Streptomyces kanamyceticus (S. kanamyceticus) ATCC12853 is often used for the synthesis of dibekacin and arbekacin. To construct the strain has the ability for kanamycin B production; the pSET152 derivatives from Escherichia coli ET12567 were introduced to S. kanamyceticus by intergeneric conjugal transfer. In this study, we established a reliable genetic manipulation system for S. kanamyceticus. The key factors of conjugal transfer were evaluated, including donor‐to‐recipient ratio, heat‐shock, and the overlaying time of antibiotics. When spores were used as recipient, the optimal conjugation frequency was up to 6.7 × 10−6. And mycelia were used as an alternative recipient for conjugation instead of spores; the most suitable donor‐to‐recipient ratio is 1:1 (107:107). After incubated for only 10–12 hr and overlaid with antibiotics subsequently, the conjugation frequency can reach to 6.2 × 10−5 which is sufficient for gene knockout and other genetic operation. Based on the optimized conjugal transfer condition, kanJ was knocked out successfully. The kanamycin B yield of kanJ‐disruption strain can reach to 543.18 ± 42 mg/L while the kanamycin B yield of wild‐type strain was only 46.57 ± 12 mg/L. The current work helps improve the content of kanamycin B in the fermentation broth of S. kanamyceticus effectively to ensure the supply for the synthesis of several critical semisynthetic antibiotics.

Based on airfoil curves that can effectively balance the rectification and drag reduction effects in flight hydrodynamics, we designed an internal streamline structure of jet nozzle for coalbed methane (CBM) mining. The three types of nozzles originating from three typical airfoil curves are compared with the conical nozzle. Results showed that the thin-type streamlined nozzle had the largest effective shock range and least radial divergence and was thus selected as the best nozzle. Moreover, the pressure distribution at the outlet of the nozzle was found to be related to the range and number of small-pressure fluctuations near the wall. A larger number of small-pressure fluctuations and a larger range caused faster pressure of the jet water column to decay along the axial direction. Rectification with a concentrated effect also slowed down the attenuation velocity of the jet-water-column pressure between the concentration point and the nozzle. The variation rule of shock pressure with range was further determined experimentally. We found that the shock pressure of jet water column initially increased within a short distance and then decreased rapidly. The effective shock range of the thin-type streamlined nozzle in air was 1.417 times that of the conical nozzle, and the effective reaming area was 1.104 times greater. Thus, the effect of reaming was effectively improved. The length of the water column at high pressure was larger than that of the conical nozzle, and the shock efficiency was relatively high.

A characteristic mode (CM) formulation is developed for the modal analysis of microstrip antennas. It is derived from the mixed-potential integral equation (MPIE) with spatial-domain Green’s functions for multilayered media, where spatial-domain Green’s functions take into account the effect of the multilayered media. The resultant characteristic currents and fields are orthogonal with each other among different orders of modes. Together with the eigenvalues and their deduced indicators, the CMs provide deep physical insights into the radiation mechanisms of microstrip antennas. Numerical results are presented to confirm CM formulation’s effectiveness and accuracy in determining the resonant frequencies, radiating mode currents, and modal fields of microstrip antennas. As opposed to the very popular CM formulation for conducting bodies, comparative studies are presented to show the quite different modal analysis results by considering the multilayered media.

The development of a peer-to-peer virtual instrumentation system for remote acquisition, analysis and transmission of data on low bandwidth networks is described. The objective of this system is to collect high frequency/high bandwidth data from multiple sensors placed at remote locations and adaptively adjust the resolution of this data so that it can be transmitted on bandwidth limited networks to a central monitoring and command center. This is achieved by adaptively re-sampling (decimating) the data from the sensors at the remote location before transmission. The decimation is adjusted to the available bandwidth of the communications network which is characterized in real-time. As a result, the system allows users at the remote command center to view high bandwidth data (at a lower resolution) with user-aware and minimized latency. This technique is applied to an eight hydrophone data acquisition system that requires a 25.6 Mbps connection for the transmission of the full data set using a wireless connection with 1 – 3.5 Mbps variable bandwidth. This technique can be used for applications that require monitoring of high bandwidth data from remote sensors in research and education fields such as remote scientific instruments and visually driven control applications.