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Green agriculture is a new sustainable agricultural development model that coordinates agricultural development with the environment which has been vigorously promoted in China in recent years. With the support of national policies, China has set up 130 pilot zones for green agricultural development. Taking these pilot zones as quasi-natural experimental areas, the difference-in-differences (DID) method and agricultural green total factor productivity are used to evaluate the effect of the policy in the pilot zones. The findings indicate that the pilot zones notably diminish non-point source agricultural pollution without affecting agricultural added value and improve agricultural green total factor productivity by improving technical efficiency. Heterogeneity analysis shows that the effectiveness of this policy varies regionally. The eastern region of China, the main agricultural producing areas, and the regions with higher initial environmental pollution levels and abundant educational resources experience more pronounced benefits. Based on the regional characteristics of different regions, this study considers the factors such as agricultural resource endowment and development basis and explores how the policy effects of agricultural green development in different regions, which has certain guiding significance for the continuous improvement in China's agricultural green development policies. [ABSTRACT FROM AUTHOR]

Background: Intrafibrillar remineralization within the hybrid layers (HLs) has recently attracted extensive attention in achieving durable resin-dentin bonds. The polyhydroxy-terminated poly(amidoamine) dendrimer (PAMAM-OH) at fourth generation becomes a desirable candidate to induce intrafibrillar remineralization to protect exposed collagen fibrils within HLs based on the size exclusion effect of fibrillar collagen. However, the remineralization process in vivo is time-consuming, during which the exposed collagen fibrils are vulnerable to enzymatic degradation, resulting in unsatisfactory remineralization. Thereby, if PAMAM-OH itself possesses concomitant anti-proteolytic activity during the induction of remineralization, it would be very beneficial to obtain satisfactory remineralization. Methods: Binding capacity tests using adsorption isotherm and confocal laser scanning microscopy (CLSM) were performed to assess if the PAMAM-OH had adsorption capacity on dentin. Anti-proteolytic testings were detected by MMPs assay kit, in-situ zymography and ICTP assay. Adhesive infiltration of resin-dentin interface and tensile bond strength before and after thermomechanical cycling were implemented to assess if the PAMAM-OH adversely affected resin-dentin bonds. Results: Anti-proteolytic testings performed using MMPs assay kit, in-situ zymography and ICTP assay indicated that PAMAM-OH inhibited exogenous soluble MMP-9 as well as had inhibitory effect on the endogenous proteases. Adhesive infiltration of resin-dentin interface and tensile bond strength before and after thermomechanical cycling were implemented to indicate that the PAMAM-OH pretreatment had no adverse effects on immediate dentin bonding and prolonged the durability of resin-dentin bonds. Conclusions: PAMAM-OH possesses anti-proteolytic activity and prevents exposed collagen fibrils within HLs from degradation, which lays the foundation for the satisfactory intrafibrillar remineralization induced by PAMAM-OH within HLs to achieve durable resin-dentin bonds in the next work. [ABSTRACT FROM AUTHOR]

To quantify the interaction between anthropogenic activities and the atmospheric environment in North China, spatiotemporal characteristics, transmission, source apportionment and a health risk assessment of the elements were analyzed in regional and background atmospheric research stations during a period of 2017. This study found that the concentration of PM2.5 and 16 elements in the regional station was 1.5 and 2.8 times higher, respectively, than that in the background station. Under the combined influence of human activities and the dusty weather in Spring, the concentration of 16 elements in the regional station was up to 3 times that in the background station. In terms of the transmission of PM2.5, the potential source regions of PM2.5 in North China were mainly the central and southern parts of Beijing-Tianjin-Hebei (BTH), as well as parts of northern Henan and western Shandong. The source apportionment of the elements proved that the elements in North China were mainly derived from soil dust (29.9–68.2%), followed by traffic (8.8–26.3%), with coal combustion and oil consumption accounting for 5.8–24.5% and 4.1–12.9%, respectively. Although the proportion was not the largest, traffic posed the highest health risk to people, which should draw the attention of the relevant authorities. [ABSTRACT FROM AUTHOR]

Objective: Secondary caries caused by oral microbiome dysbiosis and hybrid layer degradation are two important contributors to the poor resin–dentin bond durability. Cavity cleansers with long-term antimicrobial and anti-proteolytic activities are in demand for eliminating bacteria-induced secondary caries and preventing hybrid layers from degradation. The objectives of the present study were to examine the long-term antimicrobial effect and anti-proteolytic potential of poly(amidoamine) dendrimers with amino terminal groups (PAMAM-NH2) cavity cleanser. Methods: Adsorption tests by attenuated total reflectance–infrared (ATR-IR) spectroscopy and confocal laser scanning microscopy (CLSM) were first performed to evaluate whether the PAMAM-NH2 cavity cleanser had binding capacity to dentin surface to fulfill its relatively long-term antimicrobial and anti-proteolytic effects. For antibacterial testing, Streptococcus mutans , Actinomyces naeslundii , and Enterococcus faecalis were grown on dentin surfaces, prior to the application of cavity cleanser. Colony-forming unit (CFU) counts and live/dead bacterial staining were performed to assess antibacterial effects. Gelatinolytic activity within the hybrid layers was directly detected by in situ zymography. Adhesive permeability of bonded interface and microtensile bond strength were employed to assess whether the PAMAM-NH2 cavity cleanser adversely affected resin–dentin bonding. Finally, the cytotoxicity of PAMAM-NH2 was evaluated by the Cell Counting Kit-8 (CCK-8) assay. Results: Adsorption tests demonstrated that the binding capacity of PAMAM-NH2 on dentin surface was much stronger than that of 2% chlorhexidine (CHX) because its binding was strong enough to resist phosphate-buffered saline (PBS) washing. Antibacterial testing indicated that PAMAM-NH2 significantly inhibited bacteria grown on the dentin discs as compared with the control group (p < 0.05), which was comparable with the antibacterial activity of 2% CHX (p > 0.05). Hybrid layers conditioned with PAMAM-NH2 showed significant decrease in gelatin activity as compared with the control group. Furthermore, PAMAM-NH2 pretreatment did not adversely affect resin–dentin bonding because it did not decrease adhesive permeability and microtensile strength. CCK-8 assay showed that PAMAM-NH2 had low cytotoxicity on human dental pulp cells (HDPCs) and L929. Conclusions: PAMAM-NH2 cavity cleanser developed in this study could provide simultaneous long-term antimicrobial and anti-proteolytic activities for eliminating secondary caries that result from a dysbiosis in the oral microbiome and for preventing hybrid layers from degradation due to its good binding capacity to dentin collagen matrix, which are crucial for the maintenance of resin–dentin bond durability. [ABSTRACT FROM AUTHOR]

Immunotherapy utilizing natural killer cell-activated receptor natural-killer group-2 member D ligands (NKG2DLs) has had preclinical success in the treatment of small cell lung cancer. The present study aimed to investigate the association between NKG2Ls and chemoresistance. The mRNA expression of six NKG2DLs associated with progression-free survival time (PFS) and first-line chemotherapy were assessed in the present study. Major histocompatibility complex class I polypeptide-related sequence A (MICA)-overexpressing NCI-H446 cell line was constructed, and the mRNA expression levels of 11 genes associated with chemotherapy sensitivity were determined. The results demonstrated that MICA was positively and significantly associated with PFS. Furthermore, MICA expression was 1.6 times higher in patients with prolonged PFS compared with the rapid chemoresistance group. ATP binding cassette subfamily G member 2 (ABCG2) mRNA expression was associated with chemotherapy resistance and significantly downregulated in the cell line overexpressing MICA. Moreover, following addition of nicardipine (an ABCG2 inhibitor), chemotherapeutic sensitivity increased in the MICA-overexpressing cell line. Taken together, the results of the present study suggested that MICA may enhance the chemosensitivity of patients with extensive small cell lung cancer by downregulating ABCG2. [ABSTRACT FROM AUTHOR]

Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure 20 trace elements in PM2.5 from the Tangshan heavy industry areas. The variation characteristics, potential sources, and health risks of these trace elements were analyzed in great detail within the research area. The results showed that the annual total concentration of the 20 elements in the research area did not change significantly from 2016 to 2017, and the contributions of Na, Mg, Al, K, Ca, and Fe were very high, accounting for 89–96% of the total concentration. The concentrations of these elements were higher during the day than they were at night, and the concentrations in the spring and winter were higher than they were in the summer and autumn. Five potential sources were identified using the positive matrix factorization (PMF) model and enrichment factors (EFs). Traffic, dust source, oil combustion, coal combustion, and industrial sources contributed 17.80%, 12.2%, 8.8%, 7.7%, and 53.5% to the total trace elements, respectively. The contribution of each source was significantly different during different seasons. Industrial sources including steel industry and cement production were the largest source; nearly 70% of the total trace elements in the winter of 2017 were from industrial sources. The health risk assessment reflected that the cancer risks of Cr, Ni, and Cd to adults, and Cr to children were higher than the acceptable levels (1 × 10−6). Furthermore, Mn had a potential non-carcinogenic risk to children and adults, which should be given more attention by relevant departments. [ABSTRACT FROM AUTHOR]

Cellular retinoic acid binding protein 2 ( CRABP2) is essential for myoblast differentiation, however, little is known about its role in osteogenic differentiation. This study mainly aims to explore the biological functions and the underlying molecular mechanisms of CRABP2 in osteogenesis. Using quantitative polymerase chain reaction and western blot assays, we found that the expression of CRABP2 at both mRNA and protein levels were downregulated during osteogenesis. Furthermore, CRABP2 knockdown displayed significant changes in the cell phenotype and the actin filaments (F-actin) polymerization in C2C12 cells treated with BMP2. Moreover, the western blotting of osteogenic differentiation biomarkers, alkaline phosphatase ( ALP) staining and Alizarin red staining showed that CRABP2 dramatically inhibited osteogenic differentiation. The following investigation of molecular mechanisms implicated that CARBP2 specifically interacted with LIMK1, a key factor in acin cytoskeletal rearrangements in osteogenesis, to interrupt its activity and stability in an ubiquitin-proteasome pathway to prevent C2C12 cells from osteogenic differentiation in response to BMP2. Above all, our data suggest a novel function of CRABP2 in regulating actin remodeling and osteogenic differentiation via LIMK1, thus presenting a possible molecular target for promoting the osteogenic differentiation in bone degenerative diseases. [ABSTRACT FROM AUTHOR]