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Natural environments play a crucial role in transmission of antimicrobial resistance (AMR). Development of methods to manage antibiotic resistance genes (ARGs) in natural environments are usually limited to the laboratory or field scale, partially due to the complex dynamics of transmission between different environmental compartments. Here, we conducted a nine-year longitudinal profiling of ARGs at a watershed scale, and provide evidence that restrictions on livestock farms near water bodies significantly reduced riverine ARG abundance. Substantial reductions were revealed in the relative abundance of genes conferring resistance to aminoglycosides (42%), MLSB (36%), multidrug (55%), tetracyclines (53%), and other gene categories (59%). Additionally, improvements in water quality were observed, with distinct changes in concentrations of dissolved reactive phosphorus, ammonium, nitrite, pH, and dissolved oxygen. Antibiotic residues and other pharmaceuticals and personal care products (PPCPs) maintain at a similarly low level. Microbial source tracking demonstrates a significant decrease in swine fecal indicators, while human fecal pollution remains unchanged. These results suggest that the reduction in ARGs was due to a substantial reduction in input of antibiotic resistant bacteria and genes from animal excreta. Our findings highlight the watershed as a living laboratory for understanding the dynamics of AMR, and for evaluating the efficacy of environmental regulations, with implications for reducing environmental risks associated with AMR on a global scale.

The interrupted-sampling repeater jamming (ISRJ) can cause false targets to the radio-frequency proximity sensors (RFPSs), resulting in a serious decline in the target detection capability of the RFPS. This article proposes a recognition method for RFPSs to identify the false targets caused by ISRJ. The proposed method is realized by assigning a unique identity (ID) to each RFPS, and each ID is a periodically and chaotically encrypted in every pulse period. The processing technique of the received signal is divided into ranging and ID decryption. In the ranging part, a high-resolution range profile (HRRP) can be obtained by performing pulse compression with the binary chaotic sequences. To suppress the noise, the singular value decomposition (SVD) is applied in the preprocessing. Regarding ID decryption, targets and ISRJ can be recognized through the encryption and decryption processes, which are controlled by random keys. An adaptability analysis conducted in terms of the peak-to-side lobe ratio (PSLR) and bit error rate (BER) indicates that the proposed method performs well within a 70-kHz Doppler shift. A simulation and experimental results show that the proposed method achieves extremely stable target and ISRJ recognition accuracies at different signal-to-noise ratios （SNRs） and jamming-to-signal ratios (JSRs).

Abstract Many methods are used to locate preoperative small pulmonary nodules. However, deficiencies of complications and success rates exist. We introduce a novel magnetic gel for small pulmonary nodules localization in rabbit model, and furtherly evaluate its safety and feasibility. Rabbits were used as the experimental objects. A magnetic gel was used as a tracer magnet, mixed as sodium alginate-Fe3O4 magnetic fluid and calcium gluconate solution. In short-term localization, a coaxial double-cavity puncture needle was applied to inject the gel into the lung after thoracotomy, and a pursuit magnet made of Nd-Fe-B permanent magnetic materials was used to attract the gel representing location of the nodule. In long-term localization, the gel was injected under X-ray guidance. Imaging changes to the lung were observed under X-ray daily. Thoracotomy was performed to excise tissue containing the gel, and hematoxylin–eosin staining was used to observe the tissue on postoperative days 1, 3, 5, and 7. Observe tissues morphology of heart, liver, spleen, and kidney in the same way. The gel was formed after injection and drew lung tissue to form a protrusion from the lung surface under the applied magnetic field. No complication was observed. The shape and position of the gel had not changed when viewed under X-ray. Pathological analysis showed the gel had a clear boundary without diffusion of magnetic fluid. All tissues retained good histologic morphology and no magnetic fluid was observed. Our study preliminarily suggested that the technique using sodium alginate-Fe3O4 magnetic gel to locate small pulmonary nodules with guidance of X-ray, and to search for them under an applied magnetic field during the operation is safe and feasible.

This paper considers the problem of target and jamming recognition for the pulse Doppler radar fuze (PDRF). To solve the problem, the matched filter outputs of the PDRF under the action of target and jamming are analyzed. Then, the frequency entropy and peak-to-peak ratio are extracted from the matched filter output of the PDRF, and the time-frequency joint feature is constructed. Based on the time-frequency joint feature, the naive Bayesian classifier (NBC) with minimal risk is established for target and jamming recognition. To improve the adaptability of the proposed method in complex environments, an online update process that adaptively modifies the classifier in the duration of the work of the PDRF is proposed. The experiments show that the PDRF can maintain high recognition accuracy when the signal-to-noise ratio (SNR) decreases and the jamming-to-signal ratio (JSR) increases. Moreover, the applicable analysis shows that he ONBCMR method has low computational complexity and can fully meet the real-time requirements of PDRF.

Abstract Background Programmed death- ligand 1 (PD-L1) seems to be associated with the immune escape of tumors, and immunotherapy may be a favorable treatment for PD-L1-positive patients. We evaluated intrahepatic cholangiocarcinoma (ICC) specimens for their expression of PD-L1, infiltration of CD8+ T cells, and the relationship between these factors and patient survival. Methods In total, 69 resections of ICC were stained by immunohistochemistry for PD-L1, programmed death factor-1 (PD-1), and CD8+ T cells. CD8+ T-cell densities were analyzed both within tumors and at the tumor-stromal interface. Patient survival was predicted based on the PD-L1 status and CD8+ T-cell density. Results The expression rate of PD-L1 was 12% in cancer cells and 51% in interstitial cells. The expression rate of PD-1 was 30%, and the number of CD8+ T-cells increased with the increase of PD-L1 expression (p

Pulse Doppler (PD) fuze is widely used in current battlefield. However, with the threat of repeater jamming, especially digital radio frequency memory technology, the deficiency in the anti-repeater jamming of a traditional PD fuze increasingly emerges. Therefore, a repeater jamming suppression method for a PD fuze based on identity (ID) recognition and chaotic encryption is proposed. Every fuze has its own ID which is encrypted with different chaotic binary sequences in every pulse period of the transmitted signal. The thumbtack-shaped ambiguity function shows a good resolution and distance cut-off characteristic. The ability of anti-repeater jamming is emphatically analyzed, and the results at different signal-to-noise ratio (SNR) show a strong anti-repeater jamming ability and range resolution that the proposed method possesses. Furthermore, the anti-repeater jamming ability is influenced by processing gain, bit error rate (BER) and correlation function. The simulation result validates the theoretical analysis, it shows the proposed method can significantly improve the anti-repeater jamming ability of a PD fuze.

Signal modulation is an essential design factor for proximity detectors and directly affects the system’s potential performance. In order to achieve the advantages of chaotic codes bi-phase modulation (CCBPM) and linear frequency modulation (LFM) simultaneously, this paper designed a waveform which combined chaotic codes bi-phase modulation and linear frequency modulation (CCBPM–LFM) for proximity detectors. The CCBPM–LFM waveform was analyzed in the aspect of time delay resolution (TDR) and Doppler tolerance (DT) based on ambiguity function (AF). Then, a ranging method, which we called instant correlation harmonic demodulation (ICHD), was presented for the detector using the CCBPM–LFM waveform. By combining time domain instant correlation with harmonic demodulation, the ICHD solved the problem caused by combination modulation and made the most of the linear frequency modulation (LFM) harmonics and the correlation of chaotic codes. Finally, a prototype was implemented and ranging experiments were carried out. From the theoretical analysis and experimental results, the proximity detector used the CCBPM–LFM waveform has an outstanding detection performance.

Pore pressure is essential data in drilling design, and its accurate prediction is necessary to ensure drilling safety and improve drilling efficiency. Traditional methods for predicting pore pressure are limited when forming particular structures and lithology. In this paper, a machine learning algorithm and effective stress theorem are used to establish the transformation model between rock physical parameters and pore pressure. This study collects data from three wells. Well 1 had 881 data sets for model training, and Wells 2 and 3 had 538 and 464 data sets for model testing. In this paper, support vector machine (SVM), random forest (RF), extreme gradient boosting (XGB), and multilayer perceptron (MLP) are selected as the machine learning algorithms for pore pressure modeling. In addition, this paper uses the grey wolf optimization (GWO) algorithm, particle swarm optimization (PSO) algorithm, sparrow search algorithm (SSA), and bat algorithm (BA) to establish a hybrid machine learning optimization algorithm, and proposes an improved grey wolf optimization (IGWO) algorithm. The IGWO-MLP model obtained the minimum root mean square error (RMSE) by using the 5-fold cross-validation method for the training data. For the pore pressure data inWell 2 andWell 3, the coefficients of determination (R²) of SVM, RF, XGB, and MLP are 0.9930 and 0.9446, 0.9943 and 0.9472, 0.9945 and 0.9488, 0.9949 and 0.9574. MLP achieves optimal performance on both training and test data, and the MLP model shows a high degree of generalization. It indicates that the IGWO-MLP is an excellent predictor of pore pressure and can be used to predict pore pressure. [ABSTRACT FROM AUTHOR]

As is well known, one can explain the current cosmic acceleration by considering an inhomogeneous and/or anisotropic universe (which violates the cosmological principle), without invoking dark energy or modified gravity. The well-known one of this kind of models is the so-called Lemaître–Tolman–Bondi (LTB) void model, in which the universe is spherically symmetric and radially inhomogeneous, and we are living in a locally underdense void centered nearby our location. In the present work, we test various LTB void models with some old high redshift objects (OHROs). Obviously, the universe cannot be younger than its constituents. We find that an unusually large r0 (characterizing the size of the void) is required to accommodate these OHROs in LTB void models. There is a serious tension between this unusually large r0 and the much smaller r0 inferred from other observations (e.g. SNIa, CMB and so on). However, if we instead consider the lowest limit 1.7 Gyr for the quasar APM 08279+5255 at redshift z=3.91, this tension could be greatly alleviated.

Objective To explore the clinical effect of posterior reduction and screw⁃rod (plate) internal fixation technique for the treatment of atlantoaxial dislocation in complex craniovertebral junction region malformation. Methods Clinical data of 18 patients suffered from atlantoaxial dislocation with complex craniovertebral junction region malformation were analysed retrospectively, including 15 cases of congenital atlantoaxial dislocation, 1 case with aggravated symptoms of cervico ⁃ occipital unstability after anterior odontoid process grinding, 2 cases with trauma ⁃ induced dislocation. All patients underwent posterior decompressive reduction and screw ⁃ rod internal fixation. During surgical procedure, senory evoked potential (SEP) and electromyography (EMG) monitorings were used. Japanese Orthopaedic Association (JOA) score and imaging were used to evaluate the surgical effect. Results Postoperative imaging examination showed that fixed system and atlantoaxial reduction were good in 16 cases and bad in 1 cases. The bony fusion was good in 16 cases and bad in 1 case. The patients' clinical symptoms were improved to different degree, but one patient suddenly occurred respiratory arrest and died. Patients were followed up for 3 to 28 months (mean 6.62 months). After operation the average JOA score was 11.62 ± 3.23, while before operation it was 7.51 ± 3.82. The difference was significant (t = ⁃ 5.476, P = 0.004). Conclusion Posterior decompressed reduction and screw ⁃ rod (plate) internal fixation for atlantoaxial dislocation with complex craniovertebral junction region malformation is save and effective. It will be widely used in the future. DOI：10.3969/j.issn.1672⁃6731.2012.04.010

The conventional Duffing oscillator weak signal detection method, which is based on a strong reference signal, has inherent deficiencies. To address these issues, the characteristics of the Duffing oscillatorʼs phase trajectory in a small-scale periodic state are analyzed by introducing the theory of stopping oscillation system. Based on this approach, a novel Duffing oscillator weak wide-band signal detection method is proposed. In this novel method, the reference signal is discarded, and the to-be-detected signal is directly used as a driving force. By calculating the cosine function of a phase space angle, a single Duffing oscillator can be used for weak wide-band signal detection instead of an array of uncoupled Duffing oscillators. Simulation results indicate that, compared with the conventional Duffing oscillator detection method, this approach performs better in frequency detection intervals, and reduces the signal-to-noise ratio detection threshold, while improving the real-time performance of the system. [ABSTRACT FROM AUTHOR]

Aim: To explore the anatomical feasibility of portacaval shunt using a magnetic compression technique (MCT) in cadavers., Methods: Computed tomography (CT) images of 30 portal hypertensive patients were obtained. The diameters of the portal vein (PV), the inferior vena cava (IVC), and distance between the two structures were measured. Similar measurements were performed on 20 adult corpses. The feasibility of portacaval shunt based on those measurements was analyzed. First stage of the extrahepatic portacaval shunt using MCT was performed on five cadavers. Specifically, the PV and IVC were exposed through an abdominal incision of the cadavers. The parent magnet was introduced from the femoral vein and was delivered into the IVC by an anchor wire and a 5F Cook catheter. The daughter magnet was introduced into the PV through the splenic vein using an interventional guide wire. When the daughter magnet met the parent magnet, they automatically clipped together and the first stage of the portacaval shunt was set up., Results: The average diameters of the PV and the IVC measured from the 30 CT image were 14.39 ± 2.36 mm and 18.59 ± 4.97 mm, respectively, and the maximum and minimum distances between the PV and the IVC were 9.79 ± 4.56 mm and 9.50 ± 4.79 mm, respectively. From 20 cadavers, the average diameters of the PV and the IVC were 14.48 ± 1.47 mm and 24.71 ± 2.64 mm, and the maximum and minimum distances between the PV and the IVC were 10.14 ± 1.70 mm and 8.93 ± 1.17 mm, respectively. The distances between the PV and the IVC from both the CT images and the cadavers were within the effective length of portacaval anastomosis using MCT (30.30 ± 4.19 mm). The PV and IVC are in close proximity to each other with no intervening tissues or structures in between. Simulated surgeries of the first stage using MCT on five cadavers was successfully performed., Conclusion: Anatomically, extrahepatic portacaval shunt employing MCT is highly feasible in humans.