In recent years, there have been many studies on the function of nitric oxide synthase (NOS) in experimental animals and humans. This review analyzes and explores the relationship between inducible ...nitric oxide synthase (iNOS) and T cells, macrophages, and dendritic cell et al. differentiation using data based on laboratory research, highlighting recent NOS laboratory research. Our insights into research prospects and directions are also presented.
Globally, since the outbreak of the Omicron variant in November 2021, the number of confirmed cases of COVID-19 has continued to increase, posing a tremendous challenge to the prevention and control ...of this infectious disease in many countries. The global daily confirmed cases of COVID-19 between November 1, 2021, and February 17, 2022, were used as a database for modeling, and the ARIMA, MLR, and Prophet models were developed and compared. The prediction performance was evaluated using mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean square error (RMSE). The study showed that ARIMA (7, 1, 0) was the optimum model, and the MAE, MAPE, and RMSE values were lower than those of the MLR and Prophet models in terms of fitting performance and forecasting performance. The ARIMA model had superior prediction performance compared to the MLR and Prophet models. In real-world research, an appropriate prediction model should be selected based on the characteristics of the data and the sample size, which is essential for obtaining more accurate predictions of infectious disease incidence.
This study aimed to construct a more accurate model to forecast the incidence of hand, foot, and mouth disease (HFMD) in mainland China from January 2008 to December 2019 and to provide a reference ...for the surveillance and early warning of HFMD.
We collected data on the incidence of HFMD in mainland China between January 2008 and December 2019. The SARIMA, SARIMA-BPNN, and SARIMA-PSO-BPNN hybrid models were used to predict the incidence of HFMD. The prediction performance was compared using the mean absolute error(MAE), mean squared error(MSE), root mean square error (RMSE), mean absolute percentage error (MAPE), and correlation analysis.
The incidence of HFMD in mainland China from January 2008 to December 2019 showed fluctuating downward trends with clear seasonality and periodicity. The optimal SARIMA model was SARIMA(1,0,1)(2,1,2)
, with Akaike information criterion (AIC) and Bayesian Schwarz information criterion (BIC) values of this model were 638.72, 661.02, respectively. The optimal SARIMA-BPNN hybrid model was a 3-layer BPNN neural network with nodes of 1, 10, and 1 in the input, hidden, and output layers, and the R-squared, MAE, and RMSE values were 0.78, 3.30, and 4.15, respectively. For the optimal SARIMA-PSO-BPNN hybrid model, the number of particles is 10, the acceleration coefficients c1 and c2 are both 1, the inertia weight is 1, the probability of change is 0.95, and the values of R-squared, MAE, and RMSE are 0.86, 2.89, and 3.57, respectively.
Compared with the SARIMA and SARIMA-BPNN hybrid models, the SARIMA-PSO-BPNN model can effectively forecast the change in observed HFMD incidence, which can serve as a reference for the prevention and control of HFMD.
Bottom-up design of functional device components based on nanometer-sized building blocks relies on accurate control of their self-assembly behavior. Atom-precise metal nanoclusters are ...well-characterizable building blocks for designing tunable nanomaterials, but it has been challenging to achieve directed assembly to macroscopic functional cluster-based materials with highly anisotropic properties. Here, we discover a solvent-mediated assembly of 34-atom intermetallic gold-silver clusters protected by 20 1-ethynyladamantanes into 1D polymers with Ag-Au-Ag bonds between neighboring clusters as shown directly by the atomic structure from single-crystal X-ray diffraction analysis. Density functional theory calculations predict that the single crystals of cluster polymers have a band gap of about 1.3 eV. Field-effect transistors fabricated with single crystals of cluster polymers feature highly anisotropic p-type semiconductor properties with ≈1800-fold conductivity in the direction of the polymer as compared to cross directions, hole mobility of ≈0.02 cm
V
s
, and an ON/OFF ratio up to ≈4000. This performance holds promise for further design of functional cluster-based materials with highly anisotropic semiconducting properties.
Duck hepatitis A virus type 1 (DHAV-1) can cause severe liver damage in infected ducklings and is a fatal and contagious pathogen that endangers the Chinese duck industry. The objective of this study ...was to explore the correlation mechanism of liver metabolism-gut microbiota in DHAV-1 infection. Briefly, liquid chromatography-mass spectrometry and 16S rDNA sequencing combined with multivariate statistical analysis were used to evaluate the effects of DHAV-1 infection on liver metabolism, gut microbiota regulation, and other potential mechanisms in ducklings. In DHAV-1-infected ducklings at 72 h postinfection, changes were found in metabolites associated with key metabolic pathways such as lipid metabolism, sugar metabolism, and nucleotide metabolism, which participated in signaling networks and ultimately affecting the function of the liver. The abundance and composition of gut microbiota were also changed, and gut microbiota is significantly involved in lipid metabolism in the liver. The evident correlation between gut microbiota and liver metabolites indicates that DHAV-host gut microbiome interactions play important roles in the development of duck viral hepatitis (DVH).
Aromatic polyketides have attractive biological activities and pharmacological properties. Different from other polyketides, aromatic polyketides are characterized by their polycyclic aromatic ...structure. The biosynthesis of aromatic polyketides is usually accomplished by the type II polyketide synthases (PKSs), which produce highly diverse polyketide chains by sequential condensation of the starter units with extender units, followed by reduction, cyclization, aromatization and tailoring reactions. Recently, significant progress has been made in characterization and engineering of type II PKSs to produce novel products and improve product titers. In this review, we briefly summarize the architectural organizations and genetic contributions of PKS genes to provide insight into the biosynthetic process. We then review the most recent progress in engineered biosynthesis of aromatic polyketides, with emphasis on generating novel molecular structures. We also discuss the current challenges and future perspectives in the rational engineering of type II PKSs for large scale production of aromatic polyketides.
Natural products are promising chemicals due to their structural diversity and bioactivities. Over the decades, a vast variety of gene clusters encoding natural products have been identified and ...overexpressed in microbes. Recently, the development of metabolic engineering, synthetic biology and bioinformatics strategies have facilitated target discovery and design. Microbial cells have been therefore constantly engineered for product accumulation. This review summarizes approaches of domesticating microbial hosts in producing major classes of natural products, with an emphasis on recent advances.
Tuberculosis (Tuberculosis, TB) is a public health problem in China, which not only endangers the population's health but also affects economic and social development. It requires an accurate ...prediction analysis to help to make policymakers with early warning and provide effective precautionary measures. In this study, ARIMA, GM(1,1), and LSTM models were constructed and compared, respectively. The results showed that the LSTM was the optimal model, which can be achieved satisfactory performance for TB cases predictions in mainland China.
The data of tuberculosis cases in mainland China were extracted from the National Health Commission of the People's Republic of China website. According to the TB data characteristics and the sample requirements, we created the ARIMA, GM(1,1), and LSTM models, which can make predictions for the prevalence trend of TB. The mean absolute error (MAE), root mean square error (RMSE), and mean absolute percentage error (MAPE) were applied to evaluate the effects of model fitting predicting accuracy.
There were 3,021,995 tuberculosis cases in mainland China from January 2018 to December 2020. And the overall TB cases in mainland China take on a downtrend trend. We established ARIMA, GM(1,1), and LSTM models, respectively. The optimal ARIMA model is the ARIMA (0,1,0) × (0,1,0)12. The equation for GM(1,1) model was X(k+1) = -10057053.55e(-0.01k) + 10153178.55 the Mean square deviation ratio C value was 0.49, and the Small probability of error P was 0.94. LSTM model consists of an input layer, a hidden layer and an output layer, the parameters of epochs, learning rating are 60, 0.01, respectively. The MAE, RMSE, and MAPE values of LSTM model were smaller than that of GM(1,1) and ARIMA models.
Our findings showed that the LSTM model was the optimal model, which has a higher accuracy performance than that of ARIMA and GM (1,1) models. Its prediction results can act as a predictive tool for TB prevention measures in mainland China.
Writing artificial logic and dynamic function into complex cellular background to achieve desired phenotypes or improved outputs calls for the development of new genetic tools as well as their ...innovative use. In this study, we present a sensor-regulator and RNAi-based bifunctional dynamic control network that can provide simultaneous upregulation and downregulation of cellular metabolism for engineered biosynthesis. The promoter-regulator-mediated upregulation function and its transduced downregulation function through RNAi are systematically verified and characterized. We apply this dynamic control network to regulate the phosphoenolpyruvate metabolic node in Escherichia coli and achieve autonomous distribution of carbon flux between its native metabolism and the engineered muconic acid biosynthetic pathway. This allows muconic acid biosynthesis to reach 1.8 g L
. This study also suggests the circumstances where dynamic control approaches are likely to take effects.
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•The oxide islands contain three types: hemispherical, disc-like and film-like.•EDS and SAED demonstrate the primary components of the oxide islands are amorphous SiO2, MnO, MnSiO3 ...and Mn2SiO4.•Surface diffusion and bulk diffusion dominate the geometry of the oxide islands.•Formation process of circular oxide nano-inclusions is discussed in detail.•An oxidation mechanism model is proposed based on experimental results.
The characterization of the oxide islands on the surface of the spatter contributes to a fundamental understanding of the formation and oxidation of spatter in laser powder bed fusion (LPBF). In the present study, the surface and cross-section characteristics of spatters with oxide islands are investigated using high resolution scanning electron microscopy combined with energy dispersive spectroscopy, scanning transmission electron microscopy and selected area electron diffraction. The oxide islands with different configurations on the spatter surface are divided into three main categories: hemispherical, disc-like and film-like. Moreover, the primary component of oxide islands is an amorphous SiO2, which may also contain MnO, MnSiO3, and Mn2SiO4. Furthermore, a transition layer (enriched in Si, Mn, and O) is found at the oxide islands || spatter substrate interface, and the width of which is 4 μm and 20 nm on the spatter surface and within the spatter cross-section, respectively. Besides, the composition and sources of the circular oxide nano-inclusions (50-600 nm) internal to the spatters are also discussed in detail. Eventually, the driving forces affecting the formation of oxide islands on the surface of spatters are summarized, and a schematic diagram of the formation procedure is developed.
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