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ObjectiveThe content of nitrogen (N) and potassium (K) in the soil directly affects crop yield, making it a crucial indicator in agricultural production processes. Insufficient levels of the two nutrients can impede crop growth and reduce yield, while excessive levels can result in environmental pollution. Rapidly quantifying the N and K content in soil is of great importance for agricultural production and environmental protection.MethodsA rapid and quantitative method was proposed for detecting N and K nutrient ions in soil based on polydimethylsiloxane (PDMS) microfluidic chip electrophoresis and capacitively coupled contactless conductivity detection (C4D). Microfluidic chip electrophoresis enables rapid separation of multiple ions in soil. The electrophoresis microfluidic chips have a cross-shaped channel layout and were fabricated using soft lithography technology. The sample was introduced into the microfluidic chip by applying the appropriate injection voltage at both ends of the injection channel. This simple and efficient procedure ensured an accurate sample introduction. Subsequently, an electrophoretic voltage was applied at both ends of the separation channel, creating a capillary zone electrophoresis that enables the rapid separation of different ions. This process offered high separation efficiency, required a short processing time, and had a small sample volume requirement. This enabled the rapid processing and analysis of many samples. C4D enabled precise measurement of changes in conductivity. The sensing electrodes were separated from the microfluidic chips and printed onto a printed circuit board (PCB) using an immersion gold process. The ions separated under the action of an electric field and sequentially reach the sensing electrodes. The detection circuit, connected to the sensing electrodes, received and regulated the conductivity signal to reflect the variance in conductivity between the sample and the buffer solution. The sensing electrodes were isolated from the sample solution to prevent interference from the high-voltage electric field used for electrophoresis.Results and DiscussionsThe voltage used for electrophoresis, as well as the operating frequency and excitation voltage of the excitation signal in the detection system, had a significant effect on separation and detection performance. Based on the response characteristics of the system output, the optimal operating frequency of 1 000 kHz, excitation voltage of 50 V, and electrophoresis voltage of 1.5 kV were determined. A peak overshoot was observed in the electrophoresis spectrum, which was associated with the operating frequency of the system. The total noise level of the system was approximately 0.091 mV. The detection limit (S/N = 3) for soil nutrient ions was determined by analyzing a series of standard sample solutions with varying concentrations. The detection limited for potassium (K+), ammonium (NH4+), and nitrate (NO3‒) standard solutions were 0.5, 0.1 and 0.4 mg/L, respectively. For the quantitative determination of soil nutrient ion concentration, the linear relationship between peak area and corresponding concentration was investigated under optimal experimental conditions. K+, NH4+, and NO3‒ exhibit a strong linear relationship in the range of 0.5~40 mg/L, with linear correlation coefficients (R2) of 0.994, 0.997, and 0.990, respectively, indicating that this method could accurately quantify N and K ions in soil. At the same time, to evaluate the repeatability of the system, peak height, peak area, and peak time were used as evaluation indicators in repeatability experiments. The relative standard deviation (RSD) was less than 4.4%, indicating that the method shows good repeatability. In addition, to assess the ability of the C4D microfluidic system to detect actual soil samples, four collected soil samples were tested using MES/His and PVP/PTAE as running buffers. K+, NH4+,Na+, Chloride (Cl‒), NO3‒, and sulfate (SO43‒) were separated sequentially within 1 min. The detection efficiency was significantly improved. To evaluate the accuracy of this method, spiked recovery experiments were performed on four soil samples. The recovery rates ranged from 81.74% to 127.76%, indicating the good accuracy of the method.ConclusionsThis study provides a simple and effective method for the rapid detection of N and K nutrient ions in soil. The method is highly accurate and reliable, and it can quickly and efficiently detect the contents of N and K nutrient ions in soil. This contactless measurement method reduced costs and improved economic efficiency while extending the service life of the sensing electrodes and reducing the frequency of maintenance and replacement. It provided strong support for long-term, continuous conductivity monitoring.

Objective To investigate the effect of circular RNA hsa_circ_0001922 on the proliferation, migration and invasion of prostate cancer cell PC-3 and its underlying molecular mechanism. Methods qRT-PCR and RNA FISH were used to detect the expression level and localization of hsa_circ_0001922 in PC-3 cells respectively. After hsa_circ_0001922 was targeted inhibited, clone formation, Transwell assay and scratch assay were used to detect the proliferation, migration and invasion abilities of PC-3 cells. qRT-PCR and Western blot were used to detect the expression levels of EMT pathway-related molecules after inhibiting hsa_circ_0001922. Results The expression of circular RNA hsa_circ_0001922 was increased in PC-3 cells (P < 0.01) and it existed in the cytoplasm and nucleus. The invasion, migration and invasion abilities were significantly weakened (P < 0.05) after inhibiting hsa_circ_0001922; the expression of E-cadherin mRNA increased (P < 0.05) while the mRNA level of Vimentin decreased (P < 0.05). The results of Western blot were consistent with the above (both P < 0.05). Conclusion The circular RNA hsa_circ_0001922 may promote the proliferation, migration and invasion of PC-3 cells through the EMT pathway.

Dendritic cells (DCs) have received considerable attention as potential targets for the development of novel cancer immunotherapies. However, the clinical efficacy of DC-based vaccines remains suboptimal, largely reflecting local and systemic immunosuppression at baseline. An autologous DC-based vaccine (DCVAC) has recently been shown to improve progression-free survival and overall survival in randomized clinical trials enrolling patients with lung cancer (SLU01, NCT02470468) or ovarian carcinoma (SOV01, NCT02107937), but not metastatic castration-resistant prostate cancer (SP005, NCT02111577), despite a good safety profile across all cohorts. We performed biomolecular and cytofluorometric analyses on peripheral blood samples collected prior to immunotherapy from 1000 patients enrolled in these trials, with the objective of identifying immunological biomarkers that may improve the clinical management of DCVAC-treated patients. Gene signatures reflecting adaptive immunity and T cell activation were associated with favorable disease outcomes and responses to DCVAC in patients with prostate and lung cancer, but not ovarian carcinoma. By contrast, the clinical benefits of DCVAC were more pronounced among patients with ovarian carcinoma exhibiting reduced expression of T cell-associated genes, especially those linked to TH2-like signature and immunosuppressive regulatory T (TREG) cells. Clinical responses to DCVAC were accompanied by signs of antitumor immunity in the peripheral blood. Our findings suggest that circulating signatures of antitumor immunity may provide a useful tool for monitoring the potency of autologous DC-based immunotherapy.

Water and fertilizer integration technology can effectively improve nutrient utilization efficiency. However, the existing water and fertilizer machines have some shortcomings, such as huge cost, single fertilizer injection, need for cleaning water and so on, which hinder the development of water and fertilizer integration technology. Aiming at the problems of precise and low-cost compounding of compound fertilizer at the local farm, the water and fertilizer integrated intelligent irrigation and fertilization system were taken as the research object. In this research, new concept of an intelligent sensing system was proposed， and accurate proportioning system of water and fertilizer concentration was constructed and implemented. Firstly, a fast on-line method of intelligent sensing model of water and fertilizer was established based on a series of concentration gradient compound fertilizer solutions. The conductivity values of these formulated solutions were tested by contactless conductivity detection electrodes. Subsequently, the data analysis algorithms were discussed and compared to fit regression model. Based on the intelligent sensing model of water and fertilizer , the framework structure of in-situ intelligent sensing and accurate proportioning system of water and fertilizer concentration was designed, and the working principle of the system was also explained. The system proposed includs a first-level water and fertilizer concentration intelligent perception model building subsystem and a second-level water and fertilizer accurate proportioning subsystem. The first-level subsystem was designed as a portable device, which mainly included a precise pump for quantitative dosing, a large-range online conductivity sensor, a plastic bucket and supporting control and model building software. The second-level subsystem was designed as a dynamic and precise fertilizer distribution device. The effectiveness of the system was verified by three types of water intelligent fertilizer application so as to guide the in-situ water and fertilizer concentration ratio. The testing results showed that the second-order polynomial fitting curve under regularization conditions was the best model to express the relationship between the conductivity and the concentration of water and fertilizer, and the correlation coefficients R2 was higher than 0.999. Combined with the proportion of each index of compound fertilizer, the concentration of each index of compound fertilizer that the user cares about can be obtained according to this model. The results of three types of water intelligent fertilizer application showed that the conductivity of natural water had an effect on the water and fertilizer system, and the relative deviation was more than 0.1. The online water and fertilizer perception and ratio system proposed in this research realized the elimination of the interference of the local water conductivity on the accuracy of the ratio of water and fertilizer, and the accurate calculation of compound fertilizer was achieved through model calculation. This system has a simple structure and accurate ratio, low cost， and can be easily combined with the existing water and fertilizer integrated machine or artificial fertilizer system. The system could be widely used in facility agriculture, orchard cultivation and field cash crop cultivation, et al.

Aiming at the problem that the uneven deformation of the tunnel surrounding rock in the deep inclined rock strata caused local instability, an innovative balanced-yielding support technology was proposed with the engineering background of the Shangping tunnel in Huafeng Mine. Based on the mechanism analysis of this technology, the specific implementing steps were proposed. It mainly included in situ stress analysis, the stress distribution of the tunnel surrounding rock with different sections, the design of the parameter of bolt-cable and yielding structure, and supporting effect evaluation. The results showed that (1) the stress concentration appeared at the top corners of the lower side and the bottom corner of the upper side of the rectangular and semicircular arched tunnel. (2) Compared with rectangle and vertical-wall semicircular arch tunnels, the trapezoidal tunnel could relieve the shearing effect of the inclined rock strata. (3) The length, prestress, spacing-row distance of the bolt, and the parameter of the yielding structure were all optimally designed to form the balanced-yielding support system. (4) In engineering application, the maximum deformations of the roof, right side and left side, were less than 80 mm. Compared with the original support system, the shallow separation of the trapezoidal tunnel supported by the balanced-yielding support system had been reduced by 147%.

Taking several tunnels under construction of a highway as the research object, the ultimate displacement of four buried depth sections of 0-50, 50-100, 100-300, 300-500 m in the surrounding rock of grade III, IV and V is numerically simulated by three-step and seven-step excavation method, middle-wall method, cross-middle-wall method and double-side-wall guide pit method for initial support of large-section highway tunnels. Through analysis, the deformation law of tunnel surrounding rock is obtained: under the same buried depth, the displacement ultimate displacement of the two-sided guide pit method and the cross-middle-wall method is the largest, the middle-wall method is the second, and the three-step seven-step excavation method is the smallest. Through the analysis and collation of the measured data obtained by monitoring and measurement of each construction method in the construction site, the surrounding rock deformation datum values of large-span and large-section tunnel under each construction method are obtained.

When the Xiaojiazhai tunnel is constructed by the double-wall method, different curvature radii have different effects on controlling the stability of the surrounding rock and speeding up the construction progress. By numerically simulating the tunnel excavation under different radius of curvature, it is concluded that R is adopted respectively. The deformation displacement of surrounding rock is =11.6m∠520 and R=5.76m∠1060. The maximum horizontal displacement and vertical displacement are smaller when R=5.76m∠1060 is selected. According to the analysis results, when R=5.76m∠1060 is selected, the deformation of surrounding rock can be controlled to ensure the safety of construction and provide reference for future construction.

According to the problem of deformation of surrounding rock when the double-wall method is adopted in the tunnel, the five tunnel monitoring points are set in the tunnel vault, arch waist and arch foot to simulate the tunnel excavation process. The surrounding rock is deformed, and the excavation of the middle guide hole makes the deformation of the surrounding rock reach 7.2mm. After the removal of the middle partition wall, the deformation reaches the maximum, which is 8.4mm. The horizontal displacement starts to increase rapidly, and the maximum is 5.3mm. According to the analysis results, the surrounding rock above the tunnel should be reinforced in time, and the deformation of the surrounding rock after the removal of the middle partition wall should be paid attention to ensure the construction safety and provide reference for future construction.

According to the surrounding rock conditions of Re Shuitang Tunnel NO.2, it is analyzed whether the CRD method is suitable for such surrounding rock conditions. By comparing and analyzing the distribution of plastic zone of surrounding rock during construction and the displacement deformation of tunnel monitoring point, the tunnel is constructed. The plastic zone of the middle arch and the arch is obviously changed, and should be reinforced. The settlement of the right vault and the side wall is larger than the left side, which is about 19.8% and 21.9%. According to the analysis results, the vault should be reinforced in advance during tunnel construction to prevent collapse and ensure construction safety, and provide reference for future construction.

Side-crossing residential buildings in tunnel construction may lead to building subsidence, structural damage by tension and affect the use of buildings. Aiming at the structural damage caused by the side-crossing structure of Re Shuitang Tunnel NO.1, by simulating the influence of tunnel construction on the building, it is concluded that the surrounding rock above the tunnel will be deformed when the tunnel crosses the building. The maximum horizontal displacement is 0.64 mm and the maximum vertical displacement is 4.43 mm. According to the analysis results, the surrounding rock above the tunnel should be strengthened in time, and attention should be paid to the impact of blasting on residential buildings, so as to ensure the safety of buildings and provide reference for future construction.

Based on the geological conditions of the fully weathered sandstone stratum in the expressway of the mountainous area, the Huizhou-Qingyuan section of the Yuzhan Expressway is used to analyze the mechanical parameters and creep characteristics of the surrounding rock of the tunnel through the indoor model test. It is concluded that: 1) The uniaxial compression deformation test measured the structural parameters of the fully weathered sandstone stratum structure, and obtained that the elastic modulus and internal friction angle φ of the fully weathered sandstone was 14.20°, and the cohesion c was 0.343Mpa. 2) The failure mode of fully weathered sandstone specimens was obtained by triaxial creep test. The creep curves of different weathered loads were analyzed and the Xiyuan rheological model was established. 3) The creep data was analyzed by MATLAB software, and the surrounding rock parameters under different surrounding rock were obtained.