Construction of an Integrated mCherry Red Fluorescent Protein Expression System for Labeling and Tracing in Lactiplantibacillus plantarum WCFS1

Thorough intestinal adhesion and colonization greatly promote the probiotic properties of lactic acid bacteria (LAB). Labeling and tracing with fluorescent proteins are effective and reliable for studying the in vivo physiological activities of LAB including localization, adhesion, and colonization. Lactiplantibacillus plantarum WCFS1 was successfully traced with a red fluorescent protein (RFP), which was expressed by the bacteria-carrying recombinant plasmids. In this study, we aimed to construct a stable RFP mCherry expression system, whose encoding gene was integrated into the bacterial chromosome via double-crossed homologous recombination, and use it for labeling WCFS1 with the goal of avoiding the potential loss of non-chromosomal plasmids along with intestinal growth. First, the constitutive expression of the mCherry protein was improved after adjusting the length of the spacer between the promoter and the gene start codon. Then, the optimized mCherry gene expression cassette was integrated into the chromosome of WCFS1. The resulting strain had normal unimpaired growth and strong fluorescent signals, even after 100 generations, indicating its stability. Furthermore, quantitative polymerase chain reaction (PCR) results revealed a strong positive correlation between the fluorescence intensity of the strain and the number of viable cells, demonstrating its potential usage for the quantification of in vivo WCFS1 cells. Finally, the increased adhesion ability of WCFS1 due to the recombinant expression of the bsh gene was visualized and evaluated using fluorescence intensity, the results of which were consistent with those obtained using the previously established quantification methods. These results suggest that the chromosomal-integrated mCherry labeling system can be extensively used to examine the distribution, colonization, and survival of LAB in vivo in order to determine the mechanism of its probiotic function

A Novel Active Noise Control Method Based on Variational Mode Decomposition and Gradient Boosting Decision Tree

Diversified noise sources pose great challenges in the engineering of an ANC (active noise control) system design. To solve this problem, this paper proposes an ANC method based on VMD (variational mode decomposition) and Ensemble Learning. VMD is used to extract IMFs (Intrinsic Model Functions) of different types of noise and obtain the approximate entropy of each IMF. Clustering analysis on the output of VMD is conducted based on the PCA (principal component analysis) dimension reduction method and k-means++ method to get classification results for different noises. On the basis of the clustering results, different GBDT (gradient boosting decision tree) regressors are constructed for different noise types, in order to create a high-performance ANC system for multiple noise sources. To verify the effectiveness of the proposed method, this paper designed four simulation schemes for the ANC: obstacle-free rectangular enclosed space, rectangular enclosed space with obstacle, obstacle-free trapezoidal enclosed space and trapezoidal enclosed space with obstacle. When machine gun noise is used as an example, noise attenuation by the proposed method in four simulation schemes is −23.27 dB, −21.6 dB, −19.08 dB and −15.48 dB respectively

Construction of an enteral nutrition evaluation system for critically ill patients based on the Delphi method

Background: This study aimed to construct an enteral nutrition evaluation system for critically ill patients using the Delphi method to direct the formulation of enteral nutrition support strategies and reduce interruption to enteral feeding. Methods: We used domestic and foreign databases to obtain and analyze the literature and form “The Whole-Proceeding Enteral Nutrition Evaluation System for Critically Ill Patients.” The Delphi method was used to conduct two rounds of expert opinion consultation, combined with the suggestions from the research group to finalize the nutrition evaluation content of the system. Results: After two rounds of expert consultation, a nutrition evaluation system was formed around three dimensions: before the start, during, and after the end of nutritional support. The effective recovery rates of the two rounds of expert consultation were 90.0% (18/20) and 100.0% (18/18), respectively. Authority coefficients were 0.865 and 0.908, while Kendall coordination coefficients were 0.108 (P < 0.05) and 0.115 (P < 0.001), respectively. Finally, the full enteral nutrition evaluation system for critically ill patients was constructed based on the Delphi method, including three primary items and seven secondary and 28 tertiary indicators. Conclusion: The established “Whole-Proceeding Enteral Nutrition Evaluation System for Critically Ill Patients” has high consistency from expert opinions and reliability, which can provide a practical evaluation tool for the process of enteral nutrition for severe patients

Deep eutectic solvents as highly active catalysts for the fast and mild glycolysis of poly(ethylene terephthalate)(PET)

Deep eutectic solvents (DESs) have attracted broad attention due to their low cost, easy preparation, low toxicity, good biological compatibility and similar characteristics to those of ionic liquids (ILs). In this study, we found that not only the glycolysis time is sharply shortened under mild reaction conditions, but also the high selectivity of monomer bis(hydroxyalkyl) terephthalate (BHET) is obtained when DESs were used as catalysts. Then, the influences of technological parameters on PET degradation were investigated and the optimization conditions were obtained. Under the optimization conditions of ethylene glycol (EG) (20 g), catalyst (n(urea)/n(ZnCl2) 4/1, 0.25 g), PET (5 g), and atmospheric pressure at 170 degrees C for 30 min, the conversion of PET and selectivity of BHET were 100% and 83%, respectively. This time is equal to that taken by a supercritical method under 15.3 MPa at 450 degrees C. In addition, the degradation mechanism of PET wastes catalyzed by DESs is proposed through the experiments and DFT calculations. The high catalytic activity is attributed to the synergetic catalysis of H-bonds and coordination bonds formed between the DES catalyst and EG

A New Proportionate Filtered-x RLS Algorithm for Active Noise Control System

The filtered-x recursive least square (FxRLS) algorithm is widely used in the active noise control system and has achieved great success in some complex de-noising environments, such as the cabin in vehicles and aircraft. However, its performance is sensitive to some user-defined parameters such as the forgetting factor and initial gain. Once these parameters are not selected properly, the de-noising effect of FxRLS will deteriorate. Moreover, the tracking performance of FxRLS for mutation is still restricted to a certain extent. To solve the above problems, this paper proposes a new proportional FxRLS (PFxRLS) algorithm. The forgetting factor and initial gain sensitivity are successfully reduced without introducing new turning parameters. The de-noising level and tracking performance have also been improved. Moreover, the momentum technique is introduced in PFxRLS to further improve its robustness and de-noising level. To ensure stability, its convergence condition is also discussed in this paper. The effectiveness of the proposed algorithms is illustrated by simulations and experiments with different user-defined parameters and time-varying noise environments

Winter wheat grain yield and its components in the North China Plain: irrigation management, cultivation, and climate

Irrigation has been identified as the main driving factor of groundwater drawdown in the North China Plain (NCP). In order to develop appropriate irrigation strategies for satisfactory yields of wheat ( Triticum aestivum L.), grain yield (GY), yield components, and water use efficiency (WUE) were studied. A field experiment was conducted with two types of winter wheat, &apos;Shimai15&apos; and &apos;Shixin733&apos;, and five irrigation treatments, including rainfed and four spring irrigation water applications, in four growing seasons (2005 to 2009). Results showed that maximum GY was achieved with three irrigation treatments in the 2005-2006 and 2008-2009 dry seasons and two irrigation treatments in the 2006-2007 normal season. However, in the 2007-2008 wet season, the four irrigation treatments, especially the additional irrigation event at the reviving stage (28), produced maximum GY. Grain yield was significantly related to seasonal full evapotranspiration (ET) and 410 to 530 mm of seasonal full ET, including 143 mm rainfall and 214 mm irrigation water, which led to maximum GY. The two types of cultivars responded differently to irrigation management in different rainfall years. The yield of the water-saving cv. &apos;Shimai 15&apos; was much higher in the dry seasons than in the other seasons. Variations of yield components were mainly caused by irrigation time and meteorological factors. The higher accumulated temperature during the sowing and tillering stages (24) and irrigation or precipitation at the reviving stage (28) significantly improved tiller growth. The lower average temperature in March and April greatly increased grain number per spike. Sunshine duration played a decisive role in improving grain weight. Our results provide very useful information about irrigation time and frequency of winter wheat in the NCP in order to obtain high yield but reduce the use of underground water

A surgical case of ciliated muconodular papillary tumor

Ciliated muconodular papillary tumor (CMPT) is a rare type of pulmonary tumor with mucoid features. Only a few cases confirmed by surgery have been reported worldwide. We report a case of CMPT following sublobectomy, with no recurrence detected in 10 months of follow‐up. The accumulation of similar cases is essential for pathologists and surgeons to improve their understanding of such tumors