It is of great significance to study the effects of precipitation events on carbon exchange in the ecosystem for an accurate understanding of the carbon cycle. However, the response of net ecosystem ...CO
2
exchange (NEE) in the desert to precipitation events is elusive. In this study, the NEE in response to precipitation events of varying intensities in the Badain Jaran Desert (BJD) in China was continuously monitored using the eddy covariance (EC) technique. The following results were obtained: (1) The BJD ecosystem was a net CO
2
sink throughout the study period, with NEE values of -113.4, -130.7, and -175.4 g C m
-2
a
-1
in 2016, 2018, and 2019, respectively. The total precipitation yielded a higher carbon sequestration capacity in 2019 than in the other two years. In addition, the intensity, time, and frequency of precipitation had significant impacts on CO
2
; (2) the threshold value of the NEE response to precipitation was ~1.4 mm, indicating the extreme sensitivity of the BJD to precipitation events; (3) the variations in the NEE response to precipitation events conformed to a dual exponential model. The analytical results of the model indicate that precipitation intensity was positively correlated with the carbon sequestration capacity of the desert. The model revealed that the greater the precipitation intensity, the longer it takes the NEE to reach the maximum, and the lengthier the duration of the residual effects. With an increase in the total precipitation and frequency of extreme precipitation events under warm and humidification climates, the carbon sequestration capacity of the BJD will likely be enhanced. The results of this study are of great significance for revealing the carbon cycle mechanism of the desert ecosystem.
Cultural diffusion is one of the core issues among researchers in the field of cultural geography. This study aimed to examine the spatial diffusion patterns of the Qijia culture (QJC) to clarify the ...origin and formation process of Chinese field model-based cultural diffusion patterns (FM-CDP) and geographic information system (GIS) spatial analysis methods. It used the point data of Qijia cultural sites without time information and combined them with the relevant records of Qijia cultural and historical documents, as well as archaeological excavation materials. Starting with the spatial location information of cultural distribution, it comprehensively analysed the cultural hearth, regions, diffusion patterns, and diffusion paths. The results indicated the following. (1) The QJC’s heart is in the southeast of Gansu Province, where the Shizhaocun and Xishanping sites are distributed. (2) Five different levels of cultural regions were formed, which demonstrated different diffusion patterns at different regional scales. On a large regional scale, many cultural regions belong to relocation diffusion patterns. Meanwhile, at the small regional scale (in the Gansu–Qinghai region), there are two patterns of diffusion: expansion diffusion and relocation diffusion; however, the expansion diffusion pattern is the main one. (3) Based on the relationship between the QJC, altitude, and the water system, the culture also has the characteristics of diffusion to low altitude areas and a pattern of diffusion along water systems. (4) There is a circular structure of the core, periphery, and fringe regions of the QJC. Finally, (5) the dry and cold climate around 4000a B.P., the cultural exchange between Europe and the Asian continent (the introduction of barley, wheat, livestock and sheep, and copper smelting technology), and the war in the late Neolithic period were important factors affecting the diffusion of the QJC.
Mega-dunes in the lake group area of the Badain Jaran Sand Sea, China, are generally taller than dunes in the non-lake group area. This spatial distribution of dune heights may provide a new ...perspective on the controversy regarding the dunes’ formation mechanism. In this study, we calculated the relative heights and slopes of individual dunes based on a digital elevation model, and we confirmed the height distribution of abnormally tall dunes in the lake group area of the sand sea. It was also found that slopes of more than 10° in the lake group area are more common than those in the non-lake group area. Based on meteorological observations, coupled with the measurement of water content in the sand layers, we propose a conceptual model demonstrating that moisture exchange between the lakes and soil via non-rainfall water will humidify dune slopes and form a more favorable accumulation environment for aeolian sand, thus increasing dune heights. Although long-term observations are yet to be carried out, the present study can be used as evidence for understanding the basis of dune formation in the lake group area and assessing groundwater utilization in deserts.
It is of great significance to study the effects of precipitation events on carbon exchange in the ecosystem for an accurate understanding of the carbon cycle. However, the response of net ecosystem ...CO
exchange (NEE) in the desert to precipitation events is elusive. In this study, the NEE in response to precipitation events of varying intensities in the Badain Jaran Desert (BJD) in China was continuously monitored using the eddy covariance (EC) technique. The following results were obtained: (1) The BJD ecosystem was a net CO
sink throughout the study period, with NEE values of -113.4, -130.7, and -175.4 g C m
a
in 2016, 2018, and 2019, respectively. The total precipitation yielded a higher carbon sequestration capacity in 2019 than in the other two years. In addition, the intensity, time, and frequency of precipitation had significant impacts on CO
; (2) the threshold value of the NEE response to precipitation was ~1.4 mm, indicating the extreme sensitivity of the BJD to precipitation events; (3) the variations in the NEE response to precipitation events conformed to a dual exponential model. The analytical results of the model indicate that precipitation intensity was positively correlated with the carbon sequestration capacity of the desert. The model revealed that the greater the precipitation intensity, the longer it takes the NEE to reach the maximum, and the lengthier the duration of the residual effects. With an increase in the total precipitation and frequency of extreme precipitation events under warm and humidification climates, the carbon sequestration capacity of the BJD will likely be enhanced. The results of this study are of great significance for revealing the carbon cycle mechanism of the desert ecosystem.
Phlorizin exists in a number of fruits and foods and exhibits many bioactivities. The mechanism of its antidiabetic effect has been known as it can competitively inhibit sodium–glucose symporters ...(SGLTs). However, phlorizin has a wide range of two-phase metabolism in systemic circulation and shows poor oral bioavailability. An alternative mechanism may involve gut microbiota in intestine. Sixteen obese mice with type 2 diabetes (db/db) and eight age-matched control mice (db/+) were divided into three groups: diabetic group treated with phlorizin (DMT group), vehicle-treated diabetic group (DM group), and normal control group (CC group). Phlorizin was given in normal saline solution by intragastric administration for 10 weeks. After the last treatment course, body weight, energy intake, serum lipopolysaccharides (LPS), insulin resistance, and fecal short-chain fatty acids (SCFAs) were compared. 16S rRNA gene denaturing gradient gel electrophoresis (DGGE) and quantitative PCR were used to determine the changes in microbiome composition. Coadministration of phlorizin significantly prevented metabolic syndrome by decreasing weight gain, energy intake, serum lipopolysaccharides, and insulin resistance, and the fecal level of total SCFAs was dramatically increased, especially butyric acid. DGGE and quantitative PCR demonstrated that phlorizin coadministration increased the gut microbial diversity and the growth of Akkermansia muciniphila and Prevotella. Meanwhile, the gut microbiota structure of db/db mice after phlorizin treatment was improved and approached the normal group. The mechanism of the hypoglycemic action of phlorizin is associated with LPS decrease and gut microbiota changes; briefly, it acts in the intestine to modify gut microbial community structure, resulting in lower LPS load in the host and higher SCFAs producing beneficial bacteria.
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•Low electronegativity Se, P co-doping MnO2 nanorods have been favorably synthesized.•Doping Se, P impairs electrostatic interaction between H+/Zn2+ and MnO2.•Se, P co-doping MnO2 ...with medium adsorption energy balances adsorption–desorption.•Se, P co-doping MnO2 delivers exceptional high capacity with 232 mAh g−1 at 1 A g−1.
MnO2, a promising cathode material for aqueous zinc ion batteries (AZIBs), is vigorously developed. The development of MnO2 as the electrode for AZIBs is inevitably limited by low conductivity and slow reaction kinetics. Herein, Se, P co-doping MnO2 (Se, P-MnO2) nanorods are proposed as high-performance cathodes for AZIBs. Benefitting from the synthetic effect, the stability and reaction kinetics of Se, P-MnO2 cathode are significantly improved. The capacity of Se, P-MnO2 cathode is up to 295 mAh g−1 at 0.5 A g-1, surpassing that of MnO2 (126 mAh g−1), Se-MnO2 (216 mAh g−1) and P-MnO2 (250 mAh g−1). And Se, P-MnO2 cathode also displays stability with the capacity of 232 mAh g−1 at 1 A g-1 after 1000 cycles, and outstanding rate performance (122.4 mAh g−1 at 5.0 A g-1). Besides, the theoretical calculation verifies that doping Se and P with low electronegativity to replace O with high electronegativity can tune the inherent electronic structure of MnO2, equilibrate H+/Zn2+ adsorption–desorption, and impair the electrostatic interaction between MnO2 and H+/Zn2+, thus accelerating the reaction kinetics and endowing tremendous redox ability. This study indicates that Se and P co-doping is a successful tactic to upgrade the electrochemical performance of MnO2 cathode, which provides innovative viewpoints on the advance of suitable cathode materials for AZIBs, as well as fresh ideas for the logical design of electrode materials in alternative battery systems.
Mechanisms behind the impaired response of antigen-specific B cells to therapeutic vaccination in chronic hepatitis B virus (HBV) infection remain unclear. The development of vaccines or strategies ...to overcome this obstacle is vital for advancing the management of chronic hepatitis B.
A mouse model, denominated as E6F6-B, was engineered to feature a knock-in of a B-cell receptor (BCR) that specifically recognizes HBsAg. This model served as a valuable tool for investigating the temporal and spatial dynamics of humoral responses following therapeutic vaccination under continuous antigen exposure. Using a suite of immunological techniques, we elucidated the differentiation trajectory of HBsAg-specific B cells post-therapeutic vaccination in HBV carrier mice.
Utilizing the E6F6-B transfer model, we observed a marked decline in antibody-secreting cells 2 weeks after vaccination. A dysfunctional and atypical pre-plasma cell population (BLIMP-1+ IRF4+ CD40- CD138- BCMA-) emerged, manifested by sustained BCR signaling. By deploying an antibody to purge persistent HBsAg, we effectively prompted the therapeutic vaccine to provoke conventional plasma cell differentiation. This resulted in an enhanced anti-HBs antibody response and facilitated HBsAg clearance.
Sustained high levels of HBsAg limit the ability of therapeutic hepatitis B vaccines to induce the canonical plasma cell differentiation necessary for anti-HBs antibody production. Employing a strategy combining antibodies with vaccines can surmount this altered humoral response associated with atypical pre-plasma cells, leading to improved therapeutic efficacy in HBV carrier mice.
Therapeutic vaccines aimed at combatting HBV encounter suboptimal humoral responses in clinical settings, and the mechanisms impeding their effectiveness have remained obscure. Our research, utilizing the innovative E6F6-B mouse transfer model, reveals that the persistence of HBsAg can lead to the emergence of an atypical pre-plasma cell population, which proves to be relevant to the potency of therapeutic HBV vaccines. Targeting the aberrant differentiation process of these atypical pre-plasma cells stands out as a critical strategy to amplify the humoral response elicited by HBV therapeutic vaccines in carrier mouse models. This discovery suggests a compelling avenue for further study in the context of human chronic hepatitis B. Encouragingly, our findings indicate that synergistic therapy combining HBV-specific antibodies with vaccines offers a promising approach that could significantly advance the pursuit of a functional cure for HBV.
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•The HBsAg-specific BCR knock-in mouse was constructed to study the characteristics of B cells in chronic HBV infection.•An atypical pre-plasma cell population was identified post therapeutic vaccination in chronic HBV carrier mice.•Atypical pre-plasma cells display enhanced BCR signaling, ER stress and apoptosis-related gene expression.•Combination therapy (antibody + vaccine) partially overcame abnormal B-cell differentiation and led to superior HBsAg suppression.
Antitumor therapies based on adoptively transferred T cells or oncolytic viruses have made significant progress in recent years, but the limited efficiency of their infiltration into solid tumors ...makes it difficult to achieve desired antitumor effects when used alone. In this study, an oncolytic virus (rVSV-LCMVG) that is not prone to induce virus-neutralizing antibodies was designed and combined with adoptively transferred T cells. By transforming the immunosuppressive tumor microenvironment into an immunosensitive one, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy. This occurred whether the OV was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and recruited CD8
T cells to the TME to trigger antitumor immune responses. Pretreatment with adoptively transferred T cells and subsequent oncolytic virotherapy sensitizes refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD-1, and restoring effector T-cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells. The combination of OVs and mRNA vaccine also displays a significant reduction in tumor burden and prolonged survival. This study proposed a rational combination therapy of OVs with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.
Supervillin is an actin-associated protein that regulates actin dynamics by interacting with Myosin II, F-actin, and Cortactin to promote cell contractility and cell motility. Two splicing variants ...of human Supervillin (SV1 and SV4) have been reported in non-muscle cells; SV1 lacks 3 exons present in the larger isoform SV4. SV2, also called archvillin, is present in striated muscle; SV3, also called smooth muscle archvillin or SmAV, was cloned from smooth muscle. In the present study, we identify a novel splicing variant of Supervillin (SV5). SV5 contains a new splicing pattern. In the mouse tissues and cell lines examined, SV5 was predominantly expressed in skeletal and cardiac muscles and in proliferating cells, but was virtually undetectable in most normal tissues. Using RNAi and rescue experiments, we show here that SV5 displays altered functional properties in cancer cells, and regulates cell proliferation and cell migration.
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