In order to characterize the oxygen isotopic composition of internal phosphate and explore the possibility of using these data to identify phosphate sources, we measured oxygen isotopic compositions ...of phosphate（δ^18Op） in sediment pore water in Hongfeng Lake, a typical deep-water lake in a mountainous area. These data, in combination with δ^18Opin surface water samples and water column samples, were successfully used to identify phosphate sources. The δ^18Op value of sediment pore water ranged from 15.2% to 15.8%, with an average value of 15.5%—the δ^18Op value of internal phosphate. The δ^18Op values decreased gradually through the water column from 19.4% in surface water to 16.4% in deeper water, implying that internal phosphate had more negative δ^18Op values than external phosphate. This finding was substantiated by horizontal variations in δ^18Op values, which decreased with increasing distance from inflowing rivers. All collected evidence suggests that external and internal phosphate have distinctly different isotopic signatures and that these signatures have not been considerably altered by biological mediation in Hongfeng Lake. Therefore, δ^18Op can be used to distinguish phosphate sources. A two-endmember mixing model showed that internal phosphate had an average contribution of 40%, highlighting the influence of internal phosphorus loading on aqueous phosphate and eutrophication. This study illustrates the need to reduce the internal phosphorus load from sediment and provides guidance for nutrient management and in-lake restoration treatment in Hongfeng Lake. The data presented here are limited, but serve to highlight the great potential of δ^18Op as an effective tracer for identifying phosphate sources. Systematic investigations of the oxygen isotopic compositions of external phosphate, internal phosphate, and phosphate through the water column, in combination with in-lake P biogeochemical cycle study, would be desirable in further research.
Purpose
The water-level-fluctuating zone (WLFZ) is the buffer zone of energy and material exchange between terrestrial and aquatic ecosystems. Artificial vegetation restoration of WLFZ can improve ...the interception capacity of P pollution. The purpose of this study is to explore the effect of artificial vegetation restoration on the bioavailability of soil phosphorus (P) in the WLFZ.
Material and methods
Soil samples from different spatial locations (natural vegetation zone, artificial vegetation restoration zone) and different altitudes of the WLFZ were collected in the Three Gorges Reservoir (TGR) region, Chongqing, China. Soil P fraction, microbial biomass P (MBP), and phosphatase activity were measured.
Results and discussion
Artificial vegetation restoration changed the spatial distribution patterns of soil bioavailable P (Bio-P) in the WLFZ. The soil bioavailable inorganic P (Bio-P
i
) in the artificial vegetation restoration zone was significantly higher than those at the natural vegetation zone (
p
< 0.05) and its content decreased with the decrease of altitude. The content of bioavailable organic P (Bio-P
o
) in the two transects was not significantly different in general, but was different at different altitudes. Phosphodiesterase (PDE) activity was negatively correlated with Bio-P
o
in artificial vegetation restoration zone (
p
< 0.01,
R
2
= 0.21), but significantly positively correlated with in natural vegetation zone (
p
< 0.05,
R
2
= 0.17); this suggests that the relationship between Bio-P
o
and PDE activity was altered by vegetation restoration. Moreover, the factors controlling the bioavailability of P in the WLFZ are discussed.
Conclusion
Artificial vegetation restoration and altitude are the control factors of soil P fractions and bioavailability in WLFZ. Vegetation restoration can increase soil TP and Bio-P
i
in general but has little effect on Bio-P
o
.
In order to characterize the oxygen isotopic composition of internal phosphate and explore the possibility of using these data to identify phosphate sources, we measured oxygen isotopic compositions ...of phosphate(δ18Op) in sediment pore water in Hongfeng Lake, a typical deep-water lake in a mountainous area. These data, in combination with δ18Op in surface water samples and water column samples, were successfully used to identify phosphate sources. The δ18Op value of sediment pore water ranged from 15.2% to 15.8%, with an average value of 15.5%—the δ18Op value of internal phosphate. The δ18Op values decreased gradually through the water column from 19.4% in surface water to 16.4% in deeper water, implying that internal phosphate had more negative δ18Op values than external phosphate. This finding was substantiated by horizontal variations in δ18Op values, which decreased with increasing distance from inflowing rivers. All collected evidence suggests that external and internal phosphate have distinctly different isotopic signatures and that these signatures have not been considerably altered by biological mediation in Hongfeng Lake. Therefore, δ18Op can be used to distinguish phosphate sources. A two-endmember mixing model showed that internal phosphate had an average contribution of 40%, highlighting the influence of internal phosphorus loading on aqueous phosphate and eutrophication. This study illustrates the need to reduce the internal phosphorus load from sediment and provides guidance for nutrient management and in-lake restoration treatment in Hongfeng Lake. The data presented here are limited, but serve to highlight the great potential of δ18Op as an effective tracer for identifying phosphate sources. Systematic investigations of the oxygen isotopic compositions of external phosphate, internal phosphate, and phosphate through the water column, in combination with in-lake P biogeochemical cycle study, would be desirable in further research.
A novel mathematical model, entropy production diagnostic model (EPDM) with phase transition (EPDMS), was developed, which is practical to analyze the irreversible loss for cavitation flow in ...hydraulic machinery by including mass transfer and slip velocity. To model the corresponding flow, two-fluid model with main interphase forces was employed. Compared with the EPDM in homogeneous model, two extra contributions, diffusion and interface entropy production (DifE, IntE), are added in EPDMS. Then, EPDMS was validated by experiments of a pump-turbine in pump mode at three off-design conditions. The improved numerical model is more accurate in capturing the typical cavitation points, while the original one is obviously lower due to poor consideration of phase interaction. Therefore, the loss predicted by EPDMS is more rational. A detailed comparison among four overlapping items of EPDM and EPDMS was performed. It shows that these items merely interpret the accumulative effect of cavitation on the flow, while as a key part of EPDMS, IntE is closely related to the evolution of cavitation. Moreover, low-frequency excitation that caused by cavitation-induced vortex is captured by the probe at the edge of the cavity, which is consistent with the frequency-domain characteristics of IntE instead of other items.
•A two-fluid model with various interphase forces was established for cavitation.•The EPDMS considering mass transfer and slip velocity was firstly developed.•The global loss and the loss behind cavitation-induced instability were gotten.
Myocardial infarction is one of the most serious fatal diseases in the world, which is due to acute occlusion of coronary arteries. Grape seed proanthocyanidin extract (GSPE) is an active compound ...extracted from grape seeds that has anti-oxidative, anti-inflammatory and anti-tumor pharmacological effects. Natural products are cheap, easy to obtain, widely used and effective. It has been used to treat numerous diseases, such as cancer, brain injury and diabetes complications. However, there are limited studies on its role and associated mechanisms in myocardial infarction in mice. This study showed that GSPE treatment in mice significantly reduced cardiac dysfunction and improved the pathological changes due to MI injury.
, GSPE inhibited the apoptosis of H9C2 cells after hypoxia culture, resulting in the expression of Bax decreased and the expression of Bcl-2 increased. The high expression of p-PI3K and p-AKT was detected in MI model
and
. The use of the specific PI3K/AKT pathway inhibitor LY294002 regressed the cardio-protection of GSPE. Our results showed that GSPE could improve the cardiac dysfunction and remodeling induced by MI and inhibit cardiomyocytes apoptosis in hypoxic conditions through the PI3K/AKT signaling pathway.
The 'ethnodrug' Capparis spinosa L. has several pharmacological activities. First, it was found in previous experiments that an ethyl acetate extract of Capparis spinosa L. (CSE) exhibited ...antioxidant activity. In order to further research this finding, the present study investigate the blood biochemical indices, injury, energy metabolism, oxidative damage and mitochondrial membrane potential (Δψm) level of cardiac cells to study the effect of CSE on doxorubicin-induced cardiac toxicity. CSE had protective effects on the cardiac toxic effect of doxorubicin, and decreased the activity of lactic dehydrogenase (LDH) and creatine kinase (CK). CSE increased the ability of myocardial tissue to scavenge free radicals, inhibited lipid peroxidation, increased recovery activity of antioxidant enzymes, adjusted the energy metabolism of myocardial tissue, inhibited the generation of a large number of ROS in the cells, raised the level of Δψm, and improved the metabolism of free radicals. CSE demonstrated protective effects on doxorubicin-induced myocardial damage. Second, the quaternary ammonium hydroxide of Capparis spinosa L. (CSQAH) was found to possess antitumor activity, such as antiproliferative and apoptosis-induced effects on HepG2 cells. We investigated the regulatory mechanism of HepG2 apoptosis induced by CSQAH. Laser scanning confocal microscope and Fluo-3/AM staining were utilized to detect the Ca2+ concentration in the HepG2 cells. A microplate reader was used to measure the changes in Ca2+-Mg2+-ATP enzyme. Then, flow cytometry was applied to analyze the activity of ROS and the expression levels of Bcl-2 and Bax. As a result, different concentrations of CSQAH increased the concentration of Ca2+ in the cytoplasm in a dosage-dependent manner. CSQAH decreased the Ca2+-Mg2+-ATPase activity in the HepG2 cells. The levels of ROS in the CSQAH groups were significantly higher than the level in the control group. Flow cytometric analysis showed that the Bcl-2 expression levels in the CSQAH-treated groups were downregulated, while Bax expression levels were upregulated, and the effects were dosage-dependent. The regulatory mechanism of HepG2 cell apoptosis induced by CSQAH involved the increase in Ca2+ concentration and ROS levels, a decrease in Ca2+-Mg2+-ATPase activity in the HepG2 cells, and downregulation of anti-apoptotic Bcl-2 expression, and upregulation of apoptotic Bax expression. In summary, the present study demonstrated the antioxidant and antitumor activities of CSE which may suppress tumor growth and alleviate the side-effects of DOX, which may facilitate tumor treatment in a dual manner.
The prognosis for patients with metastatic bladder cancer (Bca) is poor, and has not been improved by current treatment methods. Long noncoding RNAs (lncRNAs) are involved in the pathology of various ...tumors, including bladder cancer. However, the role of zinc finger E-box-binding homeobox 1-antisense 1 (ZEB1-AS1) in BCa progression and metastasis remains unclear. The present study determined the expression level of ZEB1-AS1 in BCa and additionally investigated the functional role of ZEB1-AS1 in BCa metastasis. Reverse transcription quantitative polymerase chain reaction analysis showed that ZEB1-AS1 was upregulated in BCa cells compared with normal epithelial cells. Functionally, knockdown of ZEB1-AS1 suppressed BCa cell migration and invasion in vitro, and metastasis in vivo. Mechanistic investigations revealed that ZEB1-AS1 bound to heterogenous nuclear ribonucleoprotein d0 (AUF1), thereby activating the translation of ZEB1 mRNA without affecting its mRNA level. In addition, ZEB1-AS1 was significantly upregulated in BCa tissues and muscle-invasive Bca cases. ROc curve analysis demonstrated that ZEB1-AS1 expression was associated with metastasis in patients with Bca. In conclusion, the data from the present study demonstrated that ZEB1-AS1 induced BCa metastasis via an AUF1-mediated translation activation of ZEB1 mRNA mechanism. ZEB1-AS1 may serve as a promising target for clinical intervention in advanced Bca.
To demonstrate the feasibility of deintensification regimen in the light of the response to induction chemotherapy (IC) in human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma ...(OPSCC).
Patients with p16+ OPSCC, T1-2/N1-3M0 (excluding T1N1M0 with single and ≤3 cm lymph node) or T3-4N0-3M0 were enrolled between January 2019 and July 2021. All patients received 2 cycles of IC with docetaxel 75 mg/m2 dL and cisplatin 75 mg/m2 dL every 3 weeks. Those with major responses (≥50% decrease in both primary and lymph nodes) to IC entered the deintensification cohort (cohort D), in which intensity modulated radiation therapy alone was given to a reduced dose of 60 Gy/30 fractions. Those who failed to meet major responsesentered the concurrent chemoradiotherapy cohort (cohort C), where the dose was simultaneously integrated boosted to a standard 70 Gy/35 fractions to nonmajor response sites, concurrently with cisplatin 80 mg/m2 dL,22. Patient-reported swallow function was documented using the MD Anderson Dysphagia Inventory. The primary endpoint was 2-year progression-free survival (PFS) using Simon's 2 stage design.
A total of 26 of 48 (54.2%) participants met the criteria to enter cohort D and 22 of 48 (45.8%) patients entered cohort C. With a median follow-up time of 29.7 months (6.9-48.0 months), 2-year PFS and OS rates were 85.4% and 93.6%, respectively for all enrolled patients. In cohort D, 2-year PFS and OS rates were both 100%. Grade 3 and 4 IC-related toxicities included leukopenia/neutropenia occurring in 41.7% and hyponatremia in 4.2% of patients. A higher incidence of grade 3 and 4 mucositis (61.9% vs 23.1% P = .022) was observed in cohort C. Consistent decline in longitudinal MD Anderson Dysphagia Inventory scores were observed at month 3 after radiation therapy between cohorts and both were found to recover to baseline at month 12.
Selective radiation therapy dose reduction and concurrent chemotherapy removal based on IC response in HPV + OPSCC was feasible and promising. Further study of this strategy to balance efficacy and toxicity is warranted in a prospective controlled trial.
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