Carbon wet deposition flux and river carbon output in a forest watershed in permafrost region of the Da Xing'an Mountains.

Carbon wet deposition and river carbon output in river basins are important components of global carbon cycle. The assessment of both properties is of great significance for regional carbon budget. However, research on these topics in high-latitude permafrost regions in China is still lacking. We conducted dynamic monitoring of carbon wet deposition and carbon output in the river from May 28th to October 30th, 2022, in Laoyeling watershed, a typical forested watershed in the Da Xing'an Mountains permafrost region. We analyzed the variations of carbon component concentrations and fluxes in precipitation and river water, and estimated the contribution of carbon wet deposition to carbon output in the watershed. The results showed that wet deposition fluxes of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and total dissolved carbon (TDC) in the Laoyeling watershed were 1354.86, 684.59, and 2039.45 kg·km-2, respectively. The fluxes of DOC, DIC, TDC, particulate organic carbon (POC), particulate inorganic carbon (PIC), and total carbon (TC) in the river were 601.75, 1977.30, 2579.05, 125.13, 21.99, and 2726.17 kg·km-2, respectively. The contribution of TDC wet deposition to the river TDC output was 9941.89 kg, accounting for 17.6% of total output. The DIC concentration in the river showed significant seasonal differences, with increased runoff resulting from precipitation leading to a decrease in DIC concentration in the river and showing a clear dilution effect, while the concentrations of DOC, POC, and PIC increased, mainly due to erosion effect. In conclusion, carbon wet deposition flux in the Laoyeling watershed was mainly determined by precipitation, and its contribution to river carbon output was relatively small compared to other factor. Runoff was the dominant factor affecting river carbon output. The results would provide important insights into carbon cycling and carbon budget balance in permafrost regions under climate change.

The effect of Bletilla striata polysaccharide on the physical and healing properties of curdlan-based hydrogel for wound healing.

Bletilla striata polysaccharide (BSP) was added to curdlan to form a blend hydrogel through a simple heating-cooling procedure to improve the hydrophilicity and healing efficacy of curdlan-based hydrogel used in wound healing. We explored the interplay between BSP and curdlan, studied how BSP concentration affects the physical properties and microstructures of hydrogels, and examined the biocompatibility and healing properties of the blend hydrogel. It was proved that the hydrogel framework was primarily formed by ordered arranged curdlan molecules, with BSP uniformly dispersed and intertwined with curdlan through hydrogen bonding. This effectively improved its hydrophilicity and strengthened the microstructure. Curdlan was found to be compatible with BSP. The blend hydrogel B3Cd3 (containing 1.5% BSP and 1.5% curdlan, w/v) was identified as the optimal formulation based on its higher water adsorption, water retention, thermal stability and interconnected microstructure, and was thus selected for further research. In vitro experiments revealed the highest cell viability of L929 in B3Cd3 extracts compared to those extracts of single-component curdlan hydrogel (Cd). In vivo, animal studies indicated that the B3Cd3 accelerated wound healing compared to the control group by improving re-epithelialization and blood vessel regeneration. On Days 3 and 11, the therapeutic benefits of B3Cd3 exceeded those of the Cd group, and no significant differences were observed in wound healing rates between the B and B3Cd3 groups from Day 7. The study proves that BSP enhances the physical and healing properties, as well as cell proliferation, of the curdlan-based hydrogel. The blend hydrogel B3Cd3, with its exceptional properties, holds potential for future application as a material for non-infected wound healing.

Rock fragments significantly affect the carbon and nitrogen distribution in the surface soil - Evidences from large number samples of soil rock fragment interfaces in a boreal forest watershed.

Rock fragments are widely distributed in soils. The material cycling and the physico-chemical processes of soil ecosystems are both inevitably spatially affected by rock fragments. However, the effect of rock fragments on the spatial distribution characteristics of soil carbon and nitrogen is still not well studied and understood. We carried out a study on the effect of rock fragments on the spatial distribution of soil carbon and nitrogen by mass sampling at the interfaces of rock fragments in a boreal forest watershed ecosystem of northest China. We found that the carbon and nitrogen content of rock fragments interface soil (SRIS) was significantly lower than that of general soil (GS). The content of total soil carbon (TC) and total soil nitrogen (TN) in 0-20 cm SRIS accounted for 73 % and 43 % of those in the GS, respectively. The content of TN in 20-40 cm SRIS was about 43 % of that in the GS. The results of Random Forest Model and Pearson correlation analysis (P < 0.01) indicated that the soil water content (SWC) and soil machinery composition (SMC) contributed most to the variabilities of soil carbon and nitrogen. We also found significant differences in SMC between GS and SRIS. Such evidences suggested that the presence of rock fragments was expected to promote the loss of soil carbon and nitrogen，and consequently influence soil carbon and nitrogen distribution nearby them. Our findings help improve the understanding of the impact of rock fragments on soil carbon and nitrogen distribution and provide new insights into the participation of rock fragments in the material-energy cycle of ecosystems.

Characterization and evaluation of Bletilla striata polysaccharide/konjac glucomannan blend hydrogel for wound healing.

Bletilla striata polysaccharide (BSP) is effective for wound healing and has important applications in health care. A series of blend hydrogels was designed with BSP and konjac glucomannan (KGM) in this study to overcome the deficient mechanical performance caused by the excessive dissolution of BSP without affecting its physiological activity. The interplay between them, as well as the effects of KGM concentration on the physical properties and microstructures of hydrogels, were also explored. It was proved that the frame of the hydrogel was primarily formed by KGM. BSP was dispersed uniformly and linked to KGM through hydrogen bonding, which effectively improved the physical properties, such as increasing the water-holding capacity, improving the swelling degree, and enhancing the mechanical properties. Blend hydrogel BK2-2 (containing 1.0% BSP and 1.0% KGM, w/v) was found to be the optimal formulation based on the thermal stability and microstructure, which was used for further research. In vitro experiments revealed the L929 cell proliferative effects of the blend hydrogel, and no difference was found with BSP sponge extract after 72 h of exposure. In vivo animal studies indicated that the BK2-2 accelerated wound healing compared with the control group; however, no difference was found with dressings only made of BSP. These results demonstrated that KGM improved the physical properties of BSP-based material without negatively affecting its physiological properties. Also, the BSP/KGM blend hydrogel had good comprehensive properties and is expected to be used as a wound healing material in the future.

Characteristics and Factors Associated with Ability of Caregivers to Care for Hemodialysis Patients.

BACKGROUND The care ability of caregivers markedly impacts the patient' s quality of life and such ability may be influenced by various factors. This study aimed to explore the factors affected the care ability of caregivers for hemodialysis patients. MATERIAL AND METHODS This cross-sectional study involved 271 caregivers of hemodialysis patients. Various basic sociodemographic data of patients and caregivers were collected using questionnaires. The care abilities of caregivers were evaluated by the Caregiver Task Inventory (CTI). Univariate and multivariate linear regression analyses were used to identify the independent factors associated with the care ability of caregiver. The independent samples t test was used to further explore the impact of the independent factors on caregiver's care ability. RESULTS The mean age was 54.88±10.73 years for the patients and 44.68±15.22 years for the caregivers. Among the 271 hemodialysis patients, 59.04% were male. Multivariate regression analysis showed that female caregivers (standardized ß=-0.140, P=0.002), lived with patients (standardized ß=-0.381, P<0.001), high annual income of caregivers (standardized ß=-0.281, P<0.001), receiving caregiving training (standardized ß=-0.183, P<0.001), and patients without other chronic diseases (standardized ß=0.200, P<0.001) were associated with better care abilities of caregivers. CONCLUSIONS The gender and annual income of caregivers, receiving caregiving training, cohabitation with patient, and other concurrent chronic diseases of patients were the independent influencing factors for the care ability of caregivers for hemodialysis patients. Our study emphasized the necessity of implementing comprehensive socioeconomic and educational support to improve the care ability of caregivers.

[Characteristics of nitrogen wet deposition and flux with runoff during the spring freeze-thaw period in permafrost region watershed of Da Hinggan Mountains, Northeast China]. / å¤§å ´å®‰å²­å¤šå¹´å†»åœŸåŒºæµåŸŸæ˜¥å­£å†»èžæœŸæ°®æ¹¿æ²‰é™ä¸Žæ°´ä½“æ°®è¾“å‡ºç‰¹å¾.

Nitrogen (N) transport is an important component of a watershed's nutrient cycle, which has significant impacts on global nitrogen cycle. In this study, we measured precipitation and daily stream N concentrations during the spring freeze-thaw period (April 9-June 30, 2021) in a small forest watershed (Laoyeling) in the permafrost region of Da Hinggan Mountains to calculate wet N deposition and stream N flux. The results showed the wet deposition fluxes of ammonium, nitrate, and total N were 695.88, 448.72 and 1947.35 g·hm-2, respectively, while the stream N fluxes were 86.37, 186.87 and 1160.78 g·hm-2, respectively over the whole study period. Precipitation was the main influencing factor of wet N deposition. During the freeze-thaw cycle period (April 9 to 28), the stream N flux was dominated by runoff and was affected by soil temperature through its influence on runoff. During the melting period (April 29 to June 30), it was affected by both runoff and runoff N concentration. The stream total N flux accounted for 59.6% of wet deposition during the study period, which indicated that the watershed had a strong N fixation potential. These findings would have important implications for understanding the impact of climate change on N cycling in permafrost watersheds.

Impacts of permafrost thaw on streamflow recession in a discontinuous permafrost watershed of northeastern China.

Permafrost thaw due to climate change is altering terrestrial hydrological processes by increasing ground hydraulic conductivity and surface and subsurface hydrologic connectivity across the pan-Arctic. Understanding how runoff responds to changes in hydrologic processes and conditions induced by permafrost thaw is critical for water resources management in high-latitude and high-altitude regions. In this study, we analyzed streamflow recession characteristics for 1964-2016 for the Tahe watershed located at the southern margin of the permafrost region in Eurasia. Results reveal a link between streamflow recession and permafrost degradation as indicated by the statistical analyses of streamflow and the modeled ground warming and active layer thickening. The recession constant and the active layer temperatures at depths of 5, 40, 100, and 200 cm simulated by the backpropagation neural network model significantly increased during the study period from 1972 to 2020 due to intensified climate warming in northeastern China. The onset of seasonal active layer thaw was advanced by 10 days, and the modeled active layer thickness increased by 54 cm in this period. The average annual streamflow recession time increased by 11.5 days (+53 %) from the warming period (1972-1988) to the thawing period (1989-2016), with these periods determined from breakpoint analysis. These hydrologic changes arose from increased catchment storage and were correlated to increased active layer thickness and longer seasonal thawing periods. These results highlight that permafrost degradation can significantly extend the recession flow duration in a watershed underlain by discontinuous, sporadic, and isolated permafrost, and thereby alter flooding dynamics and water resources in the southern margin of the Eurasian permafrost region.

Recanalization of thrombosed aneurysmal hemodialysis arterovenous fistulas using a hybrid technique based on data from a single center.

OBJECTIVE: To explore the technical specifications and clinical outcomes of thrombosed aneurysmal haemodialysis arteriovenous fistula (AVF) treated with ultrasound-guided percutaneous transluminal angioplasty combined with minimal aneurysmotomy. METHODS: This case series study included 11 patients who had thrombosed aneurysmal AVF and underwent salvage procedures over a 13-month period. All procedures were performed under duplex guidance. Minimal aneurysmotomy was performed, along with manual thrombectomy and thrombolytic agent infusion, followed by angioplasty to macerate the thrombus and sufficiently dilate potential stenoses. A successful procedure was defined as immediate restoration of flow through the AVF. RESULTS: The 11 patients (four males and seven females) had a mean age of 49.6 years ± 11.9 years. Six patients (54.5%) had two or more aneurysms. The mean aneurysm maximal diameter was 21.5 mm (standard deviation: ± 5.0 mm), and the mean thrombus length was 12.9 cm (8-22 cm). Ten (83.3%) of the 12 procedures were technically successful. The mean duration of operation was 150.9 minutes (standard deviation: ± 34.2 minutes), and mean postoperative AVF blood flow was 728.6 ml/min (standard deviation: ± 53.7 mi/min). The resumption of hemodialysis was successful in all 11 cases, with a clinical success rate of 100%. The primary patency rates were 90.0% and 75.0% at three and four months over a mean follow-up time of 6.3 months (3-12 months). The secondary patency rates were 90.4% at three and four months. CONCLUSION: A hybrid approach combining ultrasound-guided percutaneous transluminal angioplasty and minimal aneurysmotomy might be a safe and effective method for thrombosed aneurysmal AVF salvage.

Transcriptional Comparison Investigating the Influence of the Addition of Unsaturated Fatty Acids on Aroma Compounds During Alcoholic Fermentation.

The levels of unsaturated fatty acids (UFAs) in grape must significantly influence yeast metabolism and the production of aroma compounds. In this work, cDNA microarray technology was applied to analyze the transcriptional discrepancies of wine yeast (commercial wine yeast Lalvin EC1118) fermenting in synthetic grape must supplemented with different concentrations of a mixture of UFAs (including linoleic acid, oleic acid, and α-linolenic acid). The results showed that the initial addition of a high level of UFAs can significantly enrich the intracellular UFAs when compared to a low addition of UFAs and further increase the cell population and most volatiles, including higher alcohols and esters, except for several fatty acids. Microarray analyses identified that 63 genes were upregulated, and 91 genes were downregulated during the different fermentation stages. The up-regulated genes were involved in yeast growth and proliferation, stress responses and amino acid transportation, while the repressed genes were associated with lipid and sterol biosynthesis, amino acid metabolism, TCA cycle regulation, mitochondrial respiration, and stress responses. Unexpectedly, the genes directly related to the biosynthesis of volatile compounds did not vary substantially between the fermentations with the high and low UFA additions. The beneficial aromatic function of the UFAs was ascribed to the increased biomass and amino acid transportation, considering that the incorporation of the additional UFAs in yeast cells maintains high membrane fluidity and increases the ability of the cells to resist deleterious conditions. Our results highlighted the importance of UFAs in the regulation of aroma biosynthesis during wine fermentation and suggested that the improvement of the resistance of yeast to extreme stresses during alcoholic fermentation is essential to effectively modulate and improve the production of aroma compounds. A potential way to achieve this goal could be the rational increase of the UFA contents in grape must.

Effect of training systems on fatty acids and their derived volatiles in Cabernet Sauvignon grapes and wines of the north foot of Mt. Tianshan.

C6 and C9 volatiles, originated from fatty acids, are important volatiles for 'Cabernet Sauvignon' grapes and wines. This study evaluated the influence of different training systems including Modified Vertical Shoot Positioned, (M-VSP); Fan training system with two trunks (F-TT); Fan training system with multiple trunks (F-MT) on these volatiles and the long-chain fatty acids (>C12) of grape berries and wines in the northwest of China. The expression profiles of genes from associated metabolic pathway were also analyzed. F-MT training resulted in lower vine vigor, larger yield, higher content of unsaturated fatty acids in grapes and lower C6 esters in wines in comparison with M-VSP and F-TT. M-VSP and F-TT enhanced C6 volatiles in grape berries. The concentrations of C6 volatiles were positively correlated with the expression of VvLOXA and VvHPL1. The results expanded the knowledge of the influence of training systems on fatty acids and their derived volatiles of grapes and wines.