Development of a spermine lipid for transient antibody expression.

Transient expression is the only way to quickly obtain a small scale of antibodies for biomedical research and therapeutic evaluation. The agents for transfecting the suspension cells, e.g. PEI or commercial agents, either lack efficiency or excessively expensive. Herein, a novel spermine-based lipid was developed and fabricated into a cationic liposome for antibody expression. This new transfection agent, designated as sperminoliposome, is feasible, cheap, and highly effective to produce antibodies. Compared to PEI, a 3 times higher yield of antibody was obtained by sperminoliposome during the transient expression of cetuximab in suspension 293F cells. Characterizations confirmed that the expressed antibody is fully functional and eligible for further research. Our study provides an effective tool for the rapid production of antibodies economically and feasibly.

[Effects of Straw Returning and Fertilizer Application on Soil Nutrients and Winter Wheat Yield].

In order to explore the effects of straw returning combined with fertilizer on soil nutrients and winter wheat yield in the Guanzhong area, an experimental split plot design was utilized. The main plot consisted of no straw returning (S0) and straw returning (S). The sub-regions consisted of no fertilizer (WF), nitrogen fertilizer (NF), and nitrogen and phosphate fertilizer (NPF). Ecological stoichiometry was used to study the relationship between soil carbon, nitrogen, phosphorus content, and yield under straw returning combined with nitrogen and phosphorus fertilizer conditions. The results showed that straw and fertilization interactions had significant effects on soil organic carbon, total nitrogen, and total phosphorus contents in the surface layer (0-20 cm) (P<0.05). Compared with that in the S0WF treatment, the SNPF treatment significantly increased soil organic carbon and total nitrogen contents in the surface layer (0-20 cm) (P<0.05). The interaction between straw and year had significant effects on soil total nitrogen content in the surface layer (0-20 cm) (P<0.05). With the increase in straw returning time, the total nitrogen content of soil 0-20 cm under the SWF treatment was significantly higher than that under the S0WF treatment (P<0.05). Straw and fertilization and their interaction had no significant effects on organic carbon and total nitrogen contents in the 20-40 cm soil layer (P>0.05). Straw and straw interaction with fertilization significantly affected total P content in 20-40 cm soil (P<0.05). Compared with that in the SWF treatment, the SNPF treatment significantly increased the total phosphorus content in the 20-40 cm soil layer (P<0.05). Straw returning combined with chemical fertilizer also had a significant effect on soil stoichiometry. Compared with that in the S0WF treatment, the S0NPF treatment decreased soil C:N in the surface layer (0-20 cm) and increased soil C:P and N:P in the surface layer (0-20 cm). Compared with that in the SWF treatment, the SNF treatment reduced soil C:N in the surface layer (0-20 cm). Straw returning combined with chemical fertilizer also had a significant effect on winter wheat yield. In 2020 and 2021, the SNPF treatment increased production by 24.23% and 28.9%, respectively, compared with that of the S0WF treatment. Correlation analysis showed that yield was significantly positively correlated with C:N (P<0.05) and C:P (P<0.01). At the same time, total nitrogen and N:P were positively correlated with treatment years (P<0.001). In conclusion, straw returning and that combined with nitrogen and phosphate fertilizer (SNPF) can improve soil nutrient characteristics, change soil stoichiometric characteristics, and increase yield in the Guanzhong area. Therefore, the results of this study indicate that straw returning combined with nitrogen and phosphate fertilizer (SNPF) is an effective way to optimize regional farmland nutrient management and improve grain production capacity.

[Effects of Straw Returning and Biochar Application on Summer Maize Yield and Soil N2O Emission in Guanzhong Plain].

Here, we investigated the effects of straw returning combined with biochar application on summer maize yield and soil nitrous oxide (N2O) emissions, based on a field location trial in the Guanzhong Plain from 2019 to 2020. The soil N2O emission rates were monitored using the static chamber-chromatography method. A comprehensive analysis of summer maize yields, soil N2O emissions, and soil labile nitrogen components was conducted to clarify the effects of straw returning combined with biochar application on improving soil fertility, increasing summer maize yield, and reducing greenhouse gas emissions. The three treatments were no straw returning (S0), straw returning (S), and straw returning combined with biochar application (SB). The results showed that the peak of N2O emissions from each treatment occurred 10 d after the straw return, and the rate of soil N2O emissions remained at a low level after 30 d of straw return. The rate of soil N2O emissions showed highly significant positive correlations (P<0.05) with ammonium nitrogen (NH4+-N), inorganic nitrogen (SIN), microbial nitrogen (MBN), and dissolved organic nitrogen (DON) contents. S significantly increased summer maize yield, cumulative N2O emissions, yield-scaled N2O intensity, and total nitrogen (TN) content by 7.4%-13%, 65.8%-132.2%, 54.6%-103%, and 27.8%-33%, respectively, compared to those in S0. Although the trend for SB to increase summer maize yield (2.5%-3.3%) compared to that in S was not significant (P>0.05), SB significantly reduced cumulative N2O emissions and yield-scaled N2O intensity by 24.0%-27.3% and 26.4%-29.2%, respectively, compared to that in S. SB significantly reduced the rate of soil N2O emissions by 45.1%-69.6% at the peak of N2O emissions compared to that in S. Biochar application mitigated soil N2O emissions induced by straw return and had a peak-shaving effect. SB significantly increased soil total N by 9.1%-12.2% compared to that in S. Combining summer maize yield, soil N2O emissions, and TN content, SB not only improved soil fertility and summer maize yield but also reduced yield-scaled N2O intensity, making it a suitable management practice that can be replicated to balance crop yield and environmental friendliness.

Disrupted Topological Organization of Resting-State Functional Brain Networks in Age-Related Hearing Loss.

Purpose: Age-related hearing loss (ARHL), associated with the function of speech perception decreases characterized by bilateral sensorineural hearing loss at high frequencies, has become an increasingly critical public health problem. This study aimed to investigate the topological features of the brain functional network and structural dysfunction of the central nervous system in ARHL using graph theory. Methods: Forty-six patients with ARHL and forty-five age, sex, and education-matched healthy controls were recruited to undergo a resting-state functional magnetic resonance imaging (fMRI) scan in this study. Graph theory was applied to analyze the topological properties of the functional connectomes by studying the local and global organization of neural networks. Results: Compared with healthy controls, the patient group showed increased local efficiency (Eloc) and clustering coefficient (Cp) of the small-world network. Besides, the degree centrality (Dc) and nodal efficiency (Ne) values of the left inferior occipital gyrus (IOG) in the patient group showed a decrease in contrast with the healthy control group. In addition, the intra-modular interaction of the occipital lobe module and the inter-modular interaction of the parietal occipital module decreased in the patient group, which was positively correlated with Dc and Ne. The intra-modular interaction of the occipital lobe module decreased in the patient group, which was negatively correlated with the Eloc. Conclusion: Based on fMRI and graph theory, we indicate the aberrant small-world network topology in ARHL and dysfunctional interaction of the occipital lobe and parietal lobe, emphasizing the importance of dysfunctional left IOG. These results suggest that early diagnosis and treatment of patients with ARHL is necessary, which can avoid the transformation of brain topology and decreased brain function.

Aberrant brain functional network strength related to cognitive impairment in age-related hearing loss.

Purpose: Age-related hearing loss (ARHL) is a major public issue that affects elderly adults. However, the neural substrates for the cognitive deficits in patients with ARHL need to be elucidated. This study aimed to explore the brain regions that show aberrant brain functional network strength related to cognitive impairment in patients with ARHL. Methods: A total of 27 patients with ARHL and 23 well-matched healthy controls were recruited for the present study. Each subject underwent pure-tone audiometry (PTA), MRI scanning, and cognition evaluation. We analyzed the functional network strength by using degree centrality (DC) characteristics and tried to recognize key nodes that contribute significantly. Subsequent functional connectivity (FC) was analyzed using significant DC nodes as seeds. Results: Compared with controls, patients with ARHL showed a deceased DC in the bilateral supramarginal gyrus (SMG). In addition, patients with ARHL showed enhanced DC in the left fusiform gyrus (FG) and right parahippocampal gyrus (PHG). Then, the bilateral SMGs were used as seeds for FC analysis. With the seed set at the left SMG, patients with ARHL showed decreased connectivity with the right superior temporal gyrus (STG). Moreover, the right SMG showed reduced connectivity with the right middle temporal gyrus (MTG) and increased connection with the left middle frontal gyrus (MFG) in patients with ARHL. The reduced DC in the left and right SMGs showed significant negative correlations with poorer TMT-B scores (r = -0.596, p = 0.002; r = -0.503, p = 0.012, respectively). Conclusion: These findings enriched our understanding of the neural mechanisms underlying cognitive impairment associated with ARHL and may serve as a potential brain network biomarker for investigating and predicting cognitive difficulties.

A study of cross-border E-commerce research trends: Based on knowledge mapping and literature analysis.

As a result of the trend toward economic globalization, the vigorous development of cross-border e-commerce has attracted many scholars to study this field, involving many related fields, such as consumer behavior, advertising, information systems, and supply chain management. Throughout the existing literature, it can be found that most of the research focuses on certain influencing factors of the development of cross-border e-commerce, and there is no systematic and macro- overview of the development trend of research in this field in recent years, nor the integration and analysis of keywords. Given that the research in the field of cross-border e-commerce is fragmented to a large extent, to effectively explore the research trend in this field, we must understand the current situation of cross-border e-commerce. Systematic bibliometric analysis can solve this problem by providing publishing trends and information on various topics. Therefore, based on the scientific database web, this study collected 198 references related to cross-border e-commerce from 2016 to 2021, briefly introduced the current situation and development trend of cross-border e-commerce, visually analyzed and refined the journals, authors, research institutions, countries, publication years, keywords, citations of academic publications in this field, and other key information, and summarized the development trend and path of CEBC in the existing research. It is helpful for researchers to solve the current research gap, understand the future research direction in this field, and help academia establish a strict knowledge system.