Carbon dots promoted soybean photosynthesis and amino acid biosynthesis under drought stress: Reactive oxygen species scavenging and nitrogen metabolism

With global warming and water scarcity, improving the drought tolerance and quality of crops is critical for food security and human health. Here, foliar application of carbon dots (CDs, 5 mg·L^-1) could scavenge reactive oxygen species accumulation in soybean leaves under drought stress, thereby enhancing photosynthesis and carbohydrate transport. Moreover, CDs stimulated root secretion (e.g., amino acids, organic acids, and auxins) and recruited beneficial microorganisms (e.g., Actinobacteria, Ascomycota, Acidobacteria and Glomeromycota), which facilitate nitrogen (N) activation in the soil. Meanwhile, the expression of GmNRT, GmAMT, and GmAQP genes were up-regulated, indicating enhanced N and water uptake. The results demonstrated that CDs could promote nitrogen metabolism and enhance amino acid biosynthesis. Particularly, the N content in soybean shoots and roots increased significantly by 13.2 % and 30.5 %, respectively. The amino acids content in soybean shoots and roots increased by 257.5 % and 57.5 %, respectively. Consequently, soybean yields increased significantly by 21.5 %, and the protein content in soybean kernels improved by 3.7 %. Therefore, foliar application of CDs can support sustainable nano-enabled agriculture to combat climate change.

MOF-derived multicomponent Fe2P-Co2P-Ni2P hollow architectures for efficient hydrogen evolution

In this work, we introduce Fe and Ni into Co-MOF to construct a kind of multicomponent phosphide hollow architecture with walls assembled by nanosheets. The multicomponent nature can enhance the intrinsic catalytic activity, while the sheet-like surface and inter-sheet voids provide a large active area, which is beneficial for electrolyte penetration and gas generation. As expected, the optimized product has catalytic hydrogen evolution reaction (HER) overpotentials of 105 and 161 mV at current densities of 10 and 100 mA cm^-2, respectively, and maintained long-term stability for over 100 hours at 10 mA cm^-2 current densities.

Selenium nanomaterials improve the quality of lettuce (Lactuca sativa L.) by modulating root growth, nutrient availability, and photosynthesis

Macro- or micro-nutrients are essential for crop yield and nutritional quality. In this work, selenium engineering nanomaterials (Se ENMs, 0.5 mg‧kg-1) significantly increased the yield and nutritional quality of lettuce, which was better than that of selenite (Na2SeO3). Under the treatment of Se ENMs, macro-nutrients including nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were increased by 15.8%, 98.5%, 42.8%, 146.9%, and 62.5%, respectively, and micro-nutrients including manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn) were also increased by 87.4%, 78.0%, 61.1%, and 56.1%, respectively. As a result, the improved nutritional status of lettuce leaves increased photosynthesis (59.2%) and yield (37.6%). Root diameters and root tips of lettuce were increased by 23.9% and 18.6%, respectively, upon exposure to Se ENMs, which may be responsible for facilitating the absorption of macro and micro nutrients from the soil. These effects were significantly better than SeO32- treated group. Metabolome results indicated that Se ENMs could improve the shikimic acid, phenylalanine, and tyrosine pathway, resulting in an enhancement of the beneficial compounds, including quercetin, rutin, and coumarin, by 2.9, 2.7, and 2.4-fold, respectively. Besides, pyruvic acid and TCA cycle were also improved by Se ENMs. These results provide new insight into the positive effect of Se ENMs on crop yield and nutritional quality, which demonstrate that the Se ENMs-enabled agriculture practices have a promising prospect as a sustainable crop strategy.

Fe-Based Nanomaterial-Induced Root Nodulation Is Modulated by Flavonoids to Improve Soybean (Glycine max) Growth and Quality

Innovative technology to increase efficient nitrogen (N) use while avoiding environmental damages is needed because of the increasing food demand of the rapidly growing global population. Soybean (Glycine max) has evolved a complex symbiosis with N-fixing bacteria that forms nodules to fix N. Herein, foliar application of 10 mg L^-1 Fe₇(PO₄)₆ and Fe₃O₄ nanomaterials (NMs) (Fe-based NMs) promoted soybean growth and root nodulation, thus improving the yield and quality over that of the unexposed control, EDTA-control, and 1 and 5 mg L^-1 NMs. Mechanistically, flavonoids, key signaling molecules at the initial signaling steps in nodulation, were increased by more than 20% upon exposure to 10 mg L^-1 Fe-based NMs, due to enhanced key enzyme (phenylalanine ammonia-lyase, PAL) activity and up-regulation of flavonoid biosynthetic genes (GmPAL, GmC4H, Gm4CL, and GmCHS). Accumulated flavonoids were secreted to the rhizosphere, recruiting rhizobia for colonization. Fe₇(PO₄)₆ NMs increased Allorhizobium by 87.3%, and Fe₃O₄ NMs increased Allorhizobium and Mesorhizobium by 142.2% and 34.9%, leading to increased root nodules by 50.0% and 35.4% over the unexposed control, respectively. Leghemoglobin content was also noticeably improved by 8.2-46.5% upon Fe-based NMs. The higher levels of nodule number and leghemoglobin content resulted in enhanced N content by 15.5-181.2% during the whole growth period. Finally, the yield (pod number and grain biomass) and quality (flavonoids, soluble protein, and elemental nutrients) were significantly increased more than 14% by Fe-based NMs. Our study provides an effective nanoenabled strategy for inducing root nodules to increase N use efficiency, and then both yield and quality of soybean.

Meta-analysis of chitosan-mediated effects on plant defense against oxidative stress

Chitosan, as a natural non-toxic biomaterial, has been demonstrated to enhance plant defense against oxidative stress. However, the general pattern and mechanism of how chitosan application modifies the amelioration of oxidative stress in plants have not been elucidated yet. Herein, we performed a meta-analysis of 58 published articles up to January 2022 to fill this knowledge gap, and found that chitosan application significantly increased the antioxidant enzyme activity (by 40.6 %), antioxidant metabolites content (by 24.6 %), defense enzyme activity (by 77.9 %), defense-related genes expression (by 103.2 %), phytohormones (by 26.9 %), and osmotic regulators (by 23.2 %) under stress conditions, which in turn notably reduced oxidative stress (by 32.2 %), and increased plant biomass (by 28.1 %) and yield (by 15.7 %). Moreover, chitosan-mediated effects on the amelioration of oxidative stress depended on the properties and application methods of chitosan. Our findings provide a comprehensive understanding of the mechanism of chitosan-alleviated oxidative stress, which would promote the application of chitosan in plant protection in agriculture.

[Specification of statistical graphics in medical research]

Statistical graphics has a long history and is an important mean to present study design, analysis results and conclusions of medical research. A survey of statistical graphs of recent publications in Chinese and English academic journals shows that scientific and technical specifications of statistical graphics are still lacking. Based on the requirements of statistical graphics in prestigious medical journals (NEJM, Lancet, JAMA and The BMJ), this paper summarizes the technical requirements, key points of design of statistical graphs and practical conditions of common statistical graphs to provide reference for clinical researchers.

Prediction models on biomass and yield of rice affected by metal (oxide) nanoparticles using nano-specific descriptors

The use of in silico tools to investigate the interactions between metal (oxide) nanoparticles (NPs) and plant biological responses is preferred because it allows us to understand molecular mechanisms and improve prediction efficiency by saving time, labor, and cost. In this study, four models (C5.0 decision tree, discriminant function analysis, random forest, and stepwise multiple linear regression analysis) were applied to predict the effect of NPs on rice biomass and yield. Nano-specific descriptors (size-dependent molecular descriptors and image-based descriptors) were introduced to estimate the behavior of NPs in plants to appropriately represent the wide space of NPs. The results showed that size-dependent molecular descriptors (e.g., E-state and connectivity indices) and image-based descriptors (e.g., extension, area, and minimum ferret diameter) were associated with the behavior of NPs in rice. The performance of the constructed models was within acceptable ranges (correlation coefficient ranged from 0.752 to 0.847 for biomass and from 0.803 to 0.905 for yield, while the accuracy ranged from 64% to 77% for biomass and 81% to 89% for yield). The developed model can be used to quickly and efficiently evaluate the impact of NPs under a wide range of experimental conditions and sufficient training data.

RADIOMICS BASED ON TWO-DIMENSIONAL AND THREE-DIMENSIONAL ULTRASOUND FOR EXTRATHYROIDAL EXTENSION FEATURE PREDICTION IN PAPILLARY THYROID CARCINOMA

Aim

To evaluate the diagnostic performance of radiomics features of two-dimensional (2D) and three-dimensional (3D) ultrasound (US) in predicting extrathyroidal extension (ETE) status in papillary thyroid carcinoma (PTC).

Patients and Methods

2D and 3D thyroid ultrasound images of 72 PTC patients confirmed by pathology were retrospectively analyzed. The patients were assigned to ETE and non-ETE. The regions of interest (ROIs) were obtained manually. From these images, a larger number of radiomic features were automatically extracted. Lastly, the diagnostic abilities of the radiomics models and a radiologist were evaluated using receiver operating characteristic (ROC) analysis. We extracted 1693 texture features firstly.

Results

The area under the ROC curve (AUC) of the radiologist was 0.65. For 2D US, the mean AUC of the three classifiers separately were: 0.744 for logistic regression (LR), 0.694 for multilayer perceptron (MLP), 0.733 for support vector machines (SVM). For 3D US they were 0.876 for LR, 0.825 for MLP, 0.867 for SVM. The diagnostic efficiency of the radiomics was better than radiologist. The LR model had favorable discriminate performance with higher area under the curve.

Conclusion

Radiomics based on US image had the potential to preoperatively predict ETE. Radiomics based on 3D US images presented more advantages over radiomics based on 2D US images and radiologist.

[Altered dynamics of brain spontaneous activity in betel quid dependence chewers]

Objective: To investigate the dynamic characteristics of brain spontaneous activity in betel quid dependence (BQD) chewers and its relationship with clinical indexes. Method: This study was conducted in Hainan General Hospital from April to December 2019 and the data of 53 BQD chewers (37 males and 16 females, aged 20 to 58(38±11) years) and 37 healthy controls (HC) (24 males and 13 females, aged 23-57(42±12) years) were collected. All these subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI) scan. The dynamic characteristics of resting fMRI indexes, including dynamic amplitude of low-frequency fluctuations (ALFF), regional homogeneity (ReHo) and degree centrality (DC) of these subjects were calculated using the sliding time window method, parameters such as age and dynamic local consistency were analyzed and compared between the two groups. Pearson correlation was used to analyze the relationship between dynamic indexes, betel quid dependence score (BQDS) and disease duration in BQD group. Results: BQD chewers showed decreased dynamic ALFF in the left orbital prefrontal cortex (0.138±0.041 vs 0.171±0.070), the right temporal pole superior temporal gyrus (0.277±0.070 vs 0.319±0.086) and the right inferior parietal lobule (0.223±0.052 vs 0.259±0.088) than HC (all P<0.05). For regional homogeneity, BQD chewers showed a decrease dynamic ReHo in the right inferior temporal gyrus (0.055±0.008 vs 0.061±0.009), the orbital prefrontal cortex (0.058±0.005 vs 0.063±0.008), the right inferior frontal gyrus (0.081±0.006 vs 0.087±0.011), the right superior occipital gyrus (0.056±0.007 vs 0.062±0.008), the left precentral gyrus (0.068±0.008 vs 0.074±0.008), and the left superior frontal gyrus (0.058±0.008 vs 0.064±0.009) than HC (all P<0.05). BQD chewers showed an increase dynamic ReHo in the right precuneus (0.095±0.009 vs 0.089±0.008) (P<0.05). There was no significant difference in DC between the two groups (all P>0.05). The relationships between three dynamic ALFF and BQDS (r=-0.104, -0.015, -0.119), seven dynamic ReHo and BQDS (r=-0.099, -0.141, -0.055, -0.078, -0.027, -0.111, -0.090), three dynamic ALFF and disease duration (r=-0.122, -0.095, -0.171), and seven dynamic ReHo and disease duration (r=0.242, -0.252, 0.035, 0.056, 0.047, 0.081, 0.169) were not statistically significant (all P>0.05). Conclusions: BQD chewers showed a decrease dynamic ReHo and/or ALFF in multiple brain regions dominated by prefrontal cortex, and an increase dynamic ReHo in the right precuneus.

Nano-QSAR modeling for predicting the cytotoxicity of metallic and metal oxide nanoparticles: A review

Given the rapid development of nanotechnology, it is crucial to understand the effects of nanoparticles on living organisms. However, it is laborious to perform toxicological tests on a case-by-case basis. Quantitative structure-activity relationship (QSAR) is an effective computational technique because it saves time, costs, and animal sacrifice. Therefore, this review presents general procedures for the construction and application of nano-QSAR models of metal-based and metal-oxide nanoparticles (MBNPs and MONPs). We also provide an overview of available databases and common algorithms. The molecular descriptors and their roles in the toxicological interpretation of MBNPs and MONPs are systematically reviewed and the future of nano-QSAR is discussed. Finally, we address the growing demand for novel nano-specific descriptors, new computational strategies to address the data shortage, in situ data for regulatory concerns, a better understanding of the physicochemical properties of NPs with bioactivity, and, most importantly, the design of nano-QSAR for real-life environmental predictions rather than laboratory simulations.

Semen parameters and sex hormones as affected by SARS-CoV-2 infection: A systematic review

Background

Impaired semen quality and reproductive hormone levels were observed in patients during and after recovery from coronavirus disease 2019 (COVID-19), which raised concerns about negative effects on male fertility. Therefore, this study systematically reviews available data on semen parameters and sex hormones in patients with COVID-19.

Methods

Systematic search was performed on PubMed and Google Scholar until July 18th, 2022. We identified relevant articles that discussed the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on male fertility.

Results

A total number of 1,684 articles were identified by using a suitable keyword search strategy. After screening, 26 articles were considered eligible for inclusion in this study. These articles included a total of 1,960 controls and 2,106 patients. When all studies were considered, the results showed that the semen parameters and sex hormone levels of patients infected with SARS-CoV-2 exhibited some significant differences compared with controls. Fortunately, these differences gradually disappear as patients recover from COVID-19.

Conclusion

While present data show the negative effects of SARS-CoV-2 infection on male fertility, this does not appear to be long-term. Semen quality and hormone levels will gradually increase to normal as patients recover.

Selenium content and nutritional quality of Brassica chinensis L enhanced by selenium engineered nanomaterials: The role of surface charge

Selenium engineered nanomaterials (Se ENMs)-enabled agriculture has developed rapidly, however, the roles of surface charge in the bioavailability and enrichment efficiency of Se ENMs are still unknown. Herein, various Se ENMs of homogenous size (40-60 nm) and different surface charges (3.2 ± 0.7, -29.0 ± 0.4, and 45.5 ± 1.3 mV) were prepared to explore the Se content and nutritional quality in Brassica chinensis L. The results demonstrated that soil application of various Se ENMs (0.05 mg kg^-1) displayed different bio-availabilities via modulating the secretion of root exudates (e.g., tartaric, malic, and citric acids), microbial community composition (e.g., Flavobacterium, Pseudomonas, Paracoccus, Bacillus and Rhizobium) and root cell wall. Negatively charged Se ENMs (Se (-)) showed the highest Se content in the shoot of B. chinensis (3.7-folds). Se (-) also significantly increased yield (156.9%) and improved nutritional quality (e.g., ascorbic acid, amino acids, flavonoids, fatty acids, and tricarboxylic acid) of B. chinensis. Moreover, after harvest, the Se (-) did not lead to significant change in Se residue in soil, but the amount of Se residue in soil was increased by 5.5% after applying the traditional Se fertilizer (selenite). Therefore, this study provides useful information for producing Se-fortified agricultural products, while minimizing environmental risk.

[A deep learning segmentation model for detecting caries in molar teeth]

This study aimed to build a home use deep learning segmentation model to identify the scope of caries lesions. A total of 494 caries photographs of molars and premolars collected via endoscopy were selected. Subsequently, these photographs were labeled by physicians and underwent segmentation training by using DeepLabv3+, and then verification and evaluation were performed. The mean accuracy was 0.993, the sensitivity was 0.661, the specificity was 0.997, the Dice coefficient was 0.685, and the intersection over union (IoU) was 0.529. Therefore, the present deep learning segmentation model can identify and segment the scope of caries.

Carbon Dots Improve Nitrogen Bioavailability to Promote the Growth and Nutritional Quality of Soybeans under Drought Stress

The inefficient utilization of nitrogen (N) in soil and drought stress seriously threatens agricultural and food production. Herein, soil application of carbon dots (CDs, 5 mg kg^-1) promoted the growth and nutritional quality of soybeans by improving N bioavailability, which was beneficial to alleviate the economic losses caused by drought stress. Soil application of CDs enhanced the N-fixing ability of nodules, regulated rhizosphere processes, and ultimately enhanced N and water uptake in soybeans under drought stress. Compared to control (drought stress), the application of CDs under drought stress enhanced soybean nitrogenase activity by 8.6% and increased N content in soybean shoots and roots by 18.5% and 14.8%, respectively. CDs in soil promoted the secretion of root exudates (e.g., organic acids, fatty acids, and polyketides) and regulated beneficial microbial communities (e.g., Proteobacteria, Acidobacteria, Gemmatimonadetes, and Actinobacteria), thus enhancing the N release from soil. Besides, compared to control, the expression of GmNRT, GmAMT, GmLB, and GmAQP genes in roots were upregulated by 1.2-, 1.8-, 2.7-, and 2.3-fold respectively, implying enhanced N transport and water uptake. Furthermore, the proteins, fatty acids, and amino acids in soybean grains were improved by 3.4%, 6.9%, and 17.3%, respectively, as a result of improved N bioavailability. Therefore, CD-enabled agriculture is promising for improving the drought tolerance and quality of soybeans, which is of significance for food security in facing the crisis of global climate change.

[Relationship between etiology and morphological classification of benign central airway stenosis and its prognosis]

Objectives: To analyze the relationship between etiology and morphological classification of benign central airway stenosis and its prognosis. Methods: We performed a retrospective study of the medical records of 453 patients initially diagnosed with benign airway stenosis at Department of Respiratory Diseases in Beijing Tiantan Hospital affiliated to Capital Medical University from January 2003 to October 2019. Of 453 patients, 260 were male. The age of the study population was 12-86(44.0±24.5) years. Results: Among the 453 patients diagnosed with benign central airway stenosis, 161 case (35.5%, including 113 post-tracheostomy tracheal stenosis and 48 post-intubation tracheal stenosis) were iatrogenic; 88 cases were from benign tumors (19.4%), 77 cases from tracheal or bronchial tuberculosis (17.0%), 71 case from tracheal foreign bodies (15.7%). Disease causes varied among different gender or age groups. The main type of stenosis was structural stenosis, of which 241 cases (53.2%) were intra-luminal and 183 cases (40.4%) were scar contracture type. The site of stenosis showed a certain relationship with the causes of stenosis. The stenosis degree was mainly from grade 2 to grade 4 (76.4%), and the length was mainly within 3 cm (84.8%). Single factor analysis on the relationship between disease cause, morphological classification and prognosis of benign central airway stenosis showed statistically better prognosis in groups that were caused by benign tumor, intraductal stenosis or stenosis that were 3-4 in degree and 1-2 degree in length. Conclusion: The common causes of central airway stenosis included iatrogenic stenosis, benign tumor, tracheal or bronchial tuberculosis and tracheal foreign bodies. Benign airway stenosis with different disease causes and morphological classification had different prognosis after bronchoscopic interventional treatment. Clinicians should know the disease causes, morphological characterization and risk factors for benign airway stenosis for earlier diagnosis, treatment or prevention.

[Application of multiple post labeling delay time arterial spin labeling imaging in the quantitative blood flow analysis of brain subregions in healthy adults]

Objective: To explore the normal ranges of perfusion parameters between cerebral hemisphere, cerebellar hemisphere and brain anatomical subregions (56 pairs) in different gender and age groups with multiple post labeling delay time (Multi-PLD) arterial spin labeling (ASL) imaging. Methods: From November 2020 to December 2020, 42 healthy adult volunteers (Male 25, Female 17) were recruited to perform 7 PLD ASL imaging, including 21 young adults (15 males and 6 females, aged 23-35 years) and 21 seniors (10 males and 11 females, aged 36-74 years). The data was processed offline by Cereflow software to obtain arterial arrival time (ATT) and corrected cerebral blood flow (CBF) and cerebral blood volume (CBV) perfusion parameters. SimpleITK standardization function was used to standardize the calculated perfusion image according to the anatomical automatic labeling (AAL) template. Therefore, CBF, ATT, CBV perfusion values of brain subregions were obtained. Paired samples t test, Wilcoxon rank sum test, independent samples t test and Mann-Whitney U test were used to compare the differences of perfusion parameters in the cerebral hemisphere, the cerebellar hemisphere, brain subregions depending on side, gender and age. Pearson correlation analysis was used to compare the correlations of perfusion parameters with age. Results: CBF in 62.5% (35/56) subregions and CBV in 44.6% (25/56) subregions were higher in right side than those in left side. ATT in most brain anatomical subregions (16/56) were higher in left side. The CBF [(35.30±8.31) vs. (34.34±7.53) ml·100g^-1·min^-1, P=0.021], CBV [(0.47±0.11) vs. (0.45±0.09) ml/100g, P<0.001], ATT [(1.30±0.10) vs. (1.24±0.11) s, P<0.001] in left cerebellar hemisphere were higher than that of right side. The CBF (28/56) of cerebral hemisphere, cerebellar hemisphere and brain subregions was higher in females than that in males, while ATT in 83.9% (47/56) subregions was lower than that in males (all P<0.05). CBV in female subjects was higher only in 5 brain regions (superior occipital gyrus, middle occipital gyrus, inferior occipital gyrus, superior parietal gyrus and cerebelum_7b) (all P<0.05). In young subjects, CBF in 44.6% (25/56) subregions and CBV in 33.9% (19/56) subregions were higher than those in the senior group (all P<0.05). The ATT in most subregions in young group were lower than those in senior group, but the difference was statistically significant only in rectus gyrus (P=0.026) and paracentral lobule (P=0.006). The CBF (r=-0.430, P=0.005) and CBV (r=-0.327, P=0.035) of cerebral hemisphere were negatively correlated with age. The CBF (24/25, r range:-0.497 --0.343, all P<0.05) and CBV (16/19, r range:-0.474 --0.322, all P<0.05) in most subregions were negatively correlated with age, while ATT was positively correlated (gyrus rectus: r=0.311, P=0.045; paracentral lobule: r=0.392, P=0.010). Conclusions: Multi-PLD ASL imaging could be applied for quantitative analysis of brain perfusion. The perfusion parameters of anatomical subregions are different depending on side, gender, and age.

Metal-Organic Framework-Derived BiIn Bimetallic Oxide Nanoparticles Embedded in Carbon Networks for Efficient Electrochemical Reduction of CO2 to Formate

Bismuth-based catalysts exhibit excellent activity and selectivity for the electroreduction of carbon dioxide (CO₂). However, single-component bismuth-based catalysts are not satisfactory for the electrochemical reduction of CO₂ to formic acid, mainly due to their high hydrogen production, low electrical conductivity, and small catalytic current density. Herein, we used a coordination strategy to recombine Bi and In at the molecular level to form Bi/In bimetallic metal-organic frameworks (MOFs), which were then calcined to obtain MOF-derived Bi/In bimetallic oxide nanoparticles embedded in carbon networks. Thanks to the synergistic effect of bimetallic components, high specific surface area, suitable pore size distribution, and high electrical conductivity of the carbon network, the material exhibits excellent activity and selectivity for electroreduction of CO₂ to formate. In H-type electrolyzers, the formate Faradaic efficiency reaches 91% at -0.9 V (vs RHE) and does not decrease significantly within 48 h. In situ Fourier transform infrared spectroscopy confirms the reaction intermediates and reveals that CO₂ electroreduction is dominant by the *OCHO pathway.