Ecological processes (e.g., nutrient cycling) in riparian zones are often affected by land-use type and flooding. The extent to which land-use types and flooding conditions affect soil microorganisms ...and their ecological functions in riparian zones is not well known. By using high-throughput sequencing and quantitative PCR (q-PCR), we tested the effects of three land-use types (i.e., forest, wetland, and grassland) and two flooding conditions (i.e., landward locations and waterward locations within the land-use types) on soil microbial communities and microbial functional genes in the riparian zones of a reservoir. Land-use type but not flooding significantly affected soil microbial community composition at the phylum level, while both land-use type and flooding significantly affected the orders Nitrosotaleales and Nitrososphaerales. Alpha diversity was higher in the wetland and forest regardless of flooding conditions. Functional gene abundance differed among the three land-use types. Archaeal
amoA
(AOA) and
nirS
genes were more abundant in the wetland than in the grassland or forest. Bacterial
amoA
(AOB),
nirK
,
nirS
, and
nosZ
genes were more abundant in the waterward location than in the landward location but only in the wetland. Soil pH, moisture, and concentrations of soil organic matter and total soil nitrogen were significantly associated with the composition of archaeal and bacterial communities as well as with their gene abundance. This study revealed that soil microorganisms putatively involved in nitrogen cycling in riparian zones were more affected by land-use type than flooding.
Pathogen infections and cancer are two major human health problems. Herein, we report the synthesis of an organic salt photosensitizer (PS), called 4TPA‐BQ, by a one‐step reaction. 4TPA‐BQ presents ...aggregation‐induced emission features. Owing to the aggregation‐induced reactive oxygen species generated and a sufficiently small ΔEST, 4TPA‐BQ shows a satisfactorily high 1O2 generation efficiency of 97.8 %. In vitro and in vivo experiments confirmed that 4TPA‐BQ exhibited potent photodynamic antibacterial performance against ampicillin‐resistant Escherichia coli with good biocompatibility in a short time (15 minutes). When the incubation duration persisted long enough (12 hours), cancer cells were ablated efficiently, leaving normal cells essentially unaffected. This is the first reported time‐dependent fluorescence‐guided photodynamic therapy in one individual PS, which achieves ordered and multiple targeting simply by varying the external conditions. 4TPA‐BQ reveals new design principles for the implementation of efficient PSs in clinical applications.
Millennium bug: A simple and highly efficient photosensitizer, called 4TPA‐BQ, operates by aggregation‐induced emission. A broad‐spectrum and potent antibacterial activity was attained after incubating 4TPA‐BQ with pathogens for 15 minutes. Upon lengthening of the incubation time to 12 hours, photodynamic therapy with 4TPA‐BQ targeted cancer cells and presented low toxicity to normal cells.
Using split Hopkinson pressure bar (SHPB) to carry out the Brazilian disk test, for the calculation of the splitting tensile strain rate of the specimen, the method in the existing literature only ...considers the influence of the tensile stress, while in the actual splitting tensile process, the combined effect of compressive stress and tensile stress leads to a large error between the calculated strain rate and the measured strain rate. Therefore, the calculation of splitting tensile strain rate by the existing method is not accurate. To solve this problem, a new analytical method considering the tension–compression coupling was proposed in this study. The true strain rate of specimens can be obtained using the classical three-wave method of SHPB test and the basic performance parameters of bars and specimens. The results of this method were verified by numerical calculation and experiment. The results show that the strain–time history curve calculated by this method is highly consistent with the numerical results in terms of numerical verification, and the error range of strain rate is 1.2–8.6%. However, the error range of strain rate obtained using the existing method is 34.4–41.2%. The rising stage of strain–time history curve calculated by this method is highly consistent with the experimental results in terms of experimental verification, and the error range of strain rate is 1.7–14.7%. While the error range of strain rate obtained using the existing method is 47.2–58.5%. The existing method of splitting tensile strain rate will overestimate the dynamic tensile strength of material and make engineering design in a dangerous state.
Circular RNA (circRNA) is a type of non-coding RNA that is widely expressed in mammals. It is highly conserved and abundantly expressed in the brain. Here, we report the regulatory role of circRNA ...derived from the pantothenate kinase 1 (Pank1) gene (circ-Pank1) in Parkinson's disease (PD). Circ-Pank1 is highly expressed in the substantia nigra (SN) of PD model mice treated with rotenone and in the MN9D cell model of dopaminergic neurons. The circ-Pank1 knockdown ameliorated dopaminergic neuron damage and locomotor dysfunction after the treatment with rotenone. We found that circ-Pank1 could adsorb miR-7a-5p and upregulate the expression of α-synuclein (α-syn), which is a molecular hallmark closely related to PD. The inhibition of miR-7a-5p reversed the circ-Pank1 knockdown-induced amelioration of dopaminergic neuron injury. In conclusion, circ-Pank1 is overexpressed in PD and enhances the locomotor dysfunction via the miR-7a-5p/α-syn signaling axis. We revealed the functional role of circRNAs in the progression of PD and provided a potential target for noncoding RNAs in delaying the progression of PD.
Considering the intrinsic poor self-healing capacity of meniscus, tissue engineering has become a new direction for the treatment of meniscus lesions. However, disturbed by mechanical stability and ...biocompatibility, most meniscus implants fail to relieve symptoms and prevent the development of osteoarthritis. The goal of this study was to develop a potential meniscal substitute for clinical application. Here, silk fibroin with good mechanical performance and biocompatibility, and strontium ion acting as bioactive factor, were incorporated with Ɛ-Polycaprolactone to fabricate a meniscus scaffold (SP-Sr). By the wet-electrospun method, the 3D SP-Sr provided suitable pore size (100–200 μm) and enough mechanical support (61.6 ± 2.9 MPa for tensile modulus and 0.11 ± 0.03 MPa for compressive modulus). Moreover, after addition of Sr2+, the SP-Sr seeded by rabbit adipose tissue-derived stromal cells (rADSCs) showed the highest secretion with 2.61- and 2.98-fold increase in collagen and aggrecan, respectively, compared with SF/PCL group. And the extracellular matrix related genes expression in SP-Sr also showed upregulation results. Particularly, the expression of the collagen II gene, which played a crucial role in the formation of meniscal inner avascular region, showed a 9-fold increase in SP-Sr compared with pure PCL group. Furthermore, the MRI results of SP-Sr implanted in rabbits with total meniscectomy for 6 months demonstrated effective prevention of meniscus extrusion and relieving joint space narrowing compared with meniscectomy group. And the effects of cartilage protection and delaying osteoarthritis development were confirmed by Pathological examination. Especially, after 6-month implantation, the neo-menisci showed similar structural constituent and mechanical performance.
Meniscus regeneration faces great challenge due to the meniscus having limited healing potential owing to its anisotropic structure, its hypocellularity and hypovascularity. The present tissue engineering solutions have failed to maintain the biological function for meniscus reconstruction in vivo because of fragile and poor biocompatible materials, leading to long-term joint degeneration. The goal of this study was to develop a meniscal substitute potential for clinical application. Here, silk fibroin and strontium were incorporated with Ɛ-Polycaprolactone by wet-electrospinning method to fabricate a meniscus scaffold (SP-Sr). The 6-month implantation results revealed that SP-Sr scaffold was effective in preventing meniscus extrusion, cartilage protection and delaying osteoarthritis development, and the regenerated menisci showed similar structural constituent and mechanical performance.
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Abstract A key challenge to the clinical implementation of decellularized scaffold-based tissue engineering lies in understanding the process of removing cells and immunogenic material from a donor ...tissue/organ while maintaining the biochemical and biophysical properties of the scaffold that will promote growth of newly seeded cells. Current criteria for evaluating whole organ decellularization are primarily based on nucleic acids, as they are easy to quantify and have been directly correlated to adverse host responses. However, numerous proteins cause immunogenic responses and thus should be measured directly to further understand and quantify the efficacy of decellularization. In addition, there has been increasing appreciation for the role of the various protein components of the extracellular matrix (ECM) in directing cell growth and regulating organ function. We performed in-depth proteomic analysis on four types of biological scaffolds and identified a large number of both remnant cellular and ECM proteins. Measurements of individual protein abundances during the decellularization process revealed significant removal of numerous cellular proteins, but preservation of most structural matrix proteins. The observation that decellularized scaffolds still contain many cellular proteins, although at decreased abundance, indicates that elimination of DNA does not assure adequate removal of all cellular material. Thus, proteomic analysis provides crucial characterization of the decellularization process to create biological scaffolds for future tissue/organ replacement therapies.
The exploitation of ultralong organic room temperature phosphorescence (UORTP) materials lags far behind the need because of the lack of general design strategies. Here we proposed a facile design ...strategy based on the structural control of intramolecular hydrogen bonding (IHB) and push-pull electron effects (PPEEs) to construct highly efficient UORTP materials. Two series of carbazole derivatives with different IHBs and PPEEs were designed accordingly. By enhancing the IHB interactions of the luminophores, the molecular planarity, intermolecular interactions and packing mode were effectively tuned, facilitating the intermolecular electron coupling. PPEEs, enhanced by introducing heteroatoms and heavy atoms, strengthened the intramolecular charge transfer states, which changed the orbital transition configuration of excited states, thus boosting the intersystem crossing (ISC) and spin-orbit coupling (SOC). Consequently, CzPM and CzPMBr with dual IHBs and the strongest PPEEs exhibited ultralong lifetimes (τ
P
) of 1.31 s and 233 ms with the highest phosphorescence quantum yields (
Φ
P
) of 1.7% and 48.6% in their series, respectively. Theoretical investigations revealed that the high-lying intersystem crossing (HISC) between excited singlet states (S
m
,
m
> 1) and triplet states (T
n
,
n
> 1) occurred and played a vital role in enhancing the
Φ
P
values of UORTP materials. Significantly, the SOC matrix elements between S
3
and T
7
(ξ(S
3
,T
7
)) of CzPMBr reached up to 39.95 cm
−1
. Finally, CzPMBr was successfully used as an anti-counterfeiting ink in calligraphy and painting due to its excellent RTP properties. The design strategy based on the structural control of IHBs and PPEEs will greatly widen the design platform of UORTP materials. Meanwhile, the discovery of the HISC process will also provide a new insight for the design of UORTP materials.
A facile design strategy based on the structural control of intramolecular hydrogen bonding and push-pull electron effects was proposed to construct highly efficient UORTP materials.
Prenatal exposure to diethylhexyl phthalate (DEHP) has been linked with a decline in testosterone levels in adult male rats, but the underlying mechanism remains unclear. We investigated the ...potential epigenetic regulation, particularly focusing on N6-methyladenosine (m6A) modification, as a possible mechanism. Dams were gavaged with DEHP (0, 10, 100, and 750 mg/kg/day) from gestational day 14 to day 21. The male offspring were examined at the age of 56 days. Prenatal DEHP administration at 750 mg/kg/day caused a decline in testosterone concentrations, an elevation in follicle-stimulating hormone, a downregulated expression of CYP11A1 HSD3B2, without affecting Leydig cell numbers. Interestingly, Methyltransferase Like 4 (METTL4), an m6A methyltransferase, was downregulated, while there were no changes in METTL3 and METTL14. Moreover, CYP11A1 showed m6A reduction in response to prenatal DEHP exposure. Additionally, METTL4 expression increased postnatally, peaking in adulthood. Knockdown of METTL4 resulted in the downregulation of CYP11A1 and HSD3B2 and an increase in SCARB1 expression. Furthermore, the increase in autophagy protection in adult Leydig cells induced by prenatal DEHP exposure was not affected by 3-methyladenosine (3MA) treatment, indicating a potential protective role of autophagy in response to DEHP exposure. In conclusion, prenatal DEHP exposure reduces testosterone by downregulating CYP11A1 and HSD3B2 via m6A epigenetic regulation and induction of autophagy protection in adult Leydig cells as a response to DEHP exposure.
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•Prenatal exposure to DEHP lowers testosterone levels in adult male rats.•Prenatal DEHP exposure downregulates the expression of METTL4 and CYP11A1.•METTL4 expression increased postnatally.•METTL4 knockdown is associated with steroid metabolism and autophagy.•DEHP reduces testosterone by downregulating CYP11A1 and HSD3B2 via m6A regulation.
Herein we report a linear ionic molecule that assembles into a supramolecular nano‐tunnel structure through synergy of trident‐type ionic interactions and π–π stacking interactions. The nano‐tunnel ...crystal exhibits anisotropic guest adsorption behavior. The material shows good thermal stability and undergoes multi‐stage single‐crystal‐to‐single‐crystal phase transformations to a nonporous structure on heating. The material exhibits a remarkable chemical stability under both acidic and basic conditions, which is rarely observed in supramolecular organic frameworks and is often related to structures with designed hydrogen‐bonding interactions. Because of the high polarity of the tunnels, this molecular crystal also shows a large CO2‐adsorption capacity while excluding other gases at ambient temperature, leading to high CO2/CH4 selectivity. Aggregation‐induced emission of the molecules gives the bulk crystals vapochromic properties.
A linear ionic molecule forms a stable framework with open pores through X‐aggregation packing, facilitated by a combination of trident‐type ionic interactions and π–π stacking. The nano‐tunnel exhibits anisotropic guest diffusion, excellent chemical stability, large CO2 uptake with high CO2/CH4 selectivity, and vapochrometric behavior.
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