Peripheral Arterial and Venous Response to Tilt Test after a 60-Day Bedrest with and without Countermeasures (ES-IBREP)

We quantified the impact of 60-day head-down bed rest (HDBR) with countermeasures on arterial and venous response to tilt. Methods: Twenty-one males: 7 control (Con), 7 resistive vibration exercise (RVE) and 7 Chinese herb (Herb) were assessed. Subjects were identified as finisher (F) or non-finishers (NF) at the post-HDBR 20-min tilt test. The cerebral (MCA), femoral (FEM) arterial flow velocity and leg vascular resistance (FRI), the portal vein section (PV), the flow redistribution ratios (MCA/FEM; MCA/PV), the tibial (Tib), gastrocnemius (Gast), and saphenous (Saph) vein sections were measured by echography and Doppler ultrasonography. Arterial and venous parameters were measured at 3-min pre-tilt in the supine position, and at 1 min before the end of the tilt. Results: At post-HDBR tilt, MCA decreased more compared with pre-HDBR tilt in the Con, RVE, and Herb groups, the MCA/FEM tended to decrease in the Con and Herb groups (not significant) but remained stable in the RVE gr. FRI dropped in the Con gr, but remained stable in the Herb gr and increased in the RVE gr. PV decreased less in the Con and Herb groups but remained unchanged in the RVE gr. MCA/PV decreased in the Con and Herb groups, but increased to a similar extent in the RVE gr. Gast section significantly increased more in the Con gr only, whereas Tib section increased more in the Con and Herb groups but not in the RVE gr. The percent change in Saph section was similar at pre- and post-HDBR tilt. Conclusion: In the Con gr, vasoconstriction was reduced in leg and splanchnic areas. RVE and Herb contributed to prevent the loss of vasoconstriction in both areas, but the effect of RVE was higher. RVE and Herb contributed to limit Gast distension whereas only RVE had a protective effect on the Tib

Classification of Alpine Grasslands in Cold and High Altitudes Based on Multispectral Landsat-8 Images: A Case Study in Sanjiangyuan National Park, China

Land-use–cover change (LUCC)/vegetation cover plays a critical role in Earth system science and is a reflection of human activities and environmental changes. LUCC will affect the structure and function of ecosystems and a series of other terrestrial surface processes, such as energy exchange, water circulation, biogeochemical circulation, and vegetation productivity. Therefore, accurate LUCC mapping and vegetation cover monitoring are the bases for simulating the global carbon and hydrological cycles, studying the interactions of the land surface and climate, and assessing land degradation. Based on field GPS surveys and UAV data, with cloud-free and snow/glacier algorithms and the SVM classifier to train and model alpine grassland, the alpine grassland and LUCC were extracted by using Landsat-8 OLI satellite images in Sanjiangyuan National Park in this paper. The latest datasets of vegetation types with 30 m × 30 m spatial resolution in the three parks were prepared and formed. The classification results show that the SVM classifier could better distinguish the major land-use types, and the overall classification accuracy was very high. However, in the alpine grassland subcategories, the classification accuracies of the four typical grasslands were relatively low, especially between desert steppes and alpine meadows, and desert steppes and alpine steppes. It manifests the limitations of Landsat-8 multispectral remote sensing imageries in finer-resolution grassland classifications of high-altitude alpine mountains. The method can be utilized for other multispectral satellite imageries with the same band matching, such as Landsat 7, Landsat 9, Sentinel-2, etc. The method described in this paper can rapidly and efficiently process annual alpine grassland maps of the source areas of the Yellow River, the Yangtze River, and the Lancang River. It can provide timely and high-spatial-resolution datasets for supporting scientific decisions for the sustainable management of Sanjiangyuan National Park

Reconsideration of the Detection and Fluorescence Mechanism of a Pyrene-Based Chemosensor for TNT

The rapid detection of chemical explosives is crucial for national security and public safety, and the investigation of sensing mechanisms is important for designing highly efficient chemosensors. This study theoretically investigates the detection and fluorescence mechanism of a newly synthesized pyrene-based chemosensor for the detection of trinitrotoluene (TNT) through density-functional-theory (DFT) and time-dependent density-functional-theory (TDDFT) methods and suggests a different interaction product of the probe and TNT from previously reported ones [Mosca et al. J. Am. Chem. Soc. 2015, 137, 7967]. Instead of forming Meisenheimer complexes, the energies of which are beyond those of the reactants, a low-energy product generated by a pi-pi-stacking interaction is more rational and favorable. The fluorescence-quenching property further confirms that the pi-pi-stacking product is the predicted one rather than luminescent Meisenheimer complexes. Frontier-molecular-orbital (FMO)-analysis results show that photoinduced electron transfer (PET) is the mechanism underlying the luminescence quenching of the probe upon exposure to TNT

Classification of Alpine Grasslands in Cold and High Altitudes Based on Multispectral Landsat-8 Images: A Case Study in Sanjiangyuan National Park, China

Land-use–cover change (LUCC)/vegetation cover plays a critical role in Earth system science and is a reflection of human activities and environmental changes. LUCC will affect the structure and function of ecosystems and a series of other terrestrial surface processes, such as energy exchange, water circulation, biogeochemical circulation, and vegetation productivity. Therefore, accurate LUCC mapping and vegetation cover monitoring are the bases for simulating the global carbon and hydrological cycles, studying the interactions of the land surface and climate, and assessing land degradation. Based on field GPS surveys and UAV data, with cloud-free and snow/glacier algorithms and the SVM classifier to train and model alpine grassland, the alpine grassland and LUCC were extracted by using Landsat-8 OLI satellite images in Sanjiangyuan National Park in this paper. The latest datasets of vegetation types with 30 m × 30 m spatial resolution in the three parks were prepared and formed. The classification results show that the SVM classifier could better distinguish the major land-use types, and the overall classification accuracy was very high. However, in the alpine grassland subcategories, the classification accuracies of the four typical grasslands were relatively low, especially between desert steppes and alpine meadows, and desert steppes and alpine steppes. It manifests the limitations of Landsat-8 multispectral remote sensing imageries in finer-resolution grassland classifications of high-altitude alpine mountains. The method can be utilized for other multispectral satellite imageries with the same band matching, such as Landsat 7, Landsat 9, Sentinel-2, etc. The method described in this paper can rapidly and efficiently process annual alpine grassland maps of the source areas of the Yellow River, the Yangtze River, and the Lancang River. It can provide timely and high-spatial-resolution datasets for supporting scientific decisions for the sustainable management of Sanjiangyuan National Park

Effects of Neuroticism on Differences in Symptom Structure of Life Satisfaction and Depression-Anxiety among College Students: A Network Analysis

Object: Numerous studies show that depression and anxiety have an adverse effect on life satisfaction among college students. Moreover, neuroticism affects depression, anxiety, and life satisfaction. Comparing the low-neuroticism and high-neuroticism groups, the current study used network analysis to examine the relationship between depression, anxiety, and life satisfaction among college students. Methods: A sample consisted of 1233 college students from China who completed the Big Five Inventory-2 (BFI-2), Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS), and Satisfaction With Life Scale (SWLS).All students were divided into two groups according to levels of neuroticism. Depression-anxiety symptom networks and flow networks were formed. Results: “Insomnia” (SAS19) and “Sleep disturbance” (SDS4) are bridge symptoms of groups with varying neuroticism. In addition, compared to the group with low levels of neuroticism, the group with high levels of neuroticism showed more depression symptoms in bridge symptoms and greater global strength. Many depression-anxiety symptoms are negatively associated with life satisfaction, and “Emptiness” (SDS18) is an important symptom in the high-neuroticism group’s flow network. Conclusion: This study contributes to our understanding of the connection between depression, anxiety, neuroticism, and life satisfaction. In addition, the current study identified the essential symptoms to target in depression and anxiety intervention and life satisfaction enhancement among college students

A Solid-Solid Phase Transformation of Triclabendazole at High Pressures

Triclabendazole is an effective medication to treat fascioliasis and paragonimiasis parasitic infections. We implemented a reliable quantum mechanical method which is density functional theory at the level of ωB97XD/6-31G* along with embedded fragments to elucidate stability and phase transition between two forms of triclabendazole. We calculated crystal structure parameters, volumes, Gibbs free energies, and vibrational spectra of two polymorphic forms of triclabendazole under different pressures and temperatures. We confirmed form I was more stable than form II at atmospheric pressure and room temperature. From high-pressure Gibbs free energy computations, we found a pressure-induced phase transformation between form I (triclinic unit cell) and form II (monoclinic unit cell). The phase transition between forms I and II was found at a pressure and temperature of 5.5 GPa and ≈350 K, respectively. In addition, we also studied the high-pressure polymorphic behavior of two forms of triclabendazole. At the pressure of 5.5 GPa and temperature from ≈350 K to 500 K, form II was more stable than form I. However, at temperatures lower than ≈350 K, form I was more stable than form II. We also studied the effects of pressures on volumes and Raman spectra. To the best of our knowledge, no such research has been conducted to determine the presence of phase transformation between two forms of triclabendazole. This is a case study that can be applied to various polymorphic crystals to study their structures, stabilities, spectra, and phase transformations. This research can assist scientists, chemists, and pharmacologists in selecting the desired polymorph and better drug design

Fine Root Production and Soil Available Nutrients in Rubber Monoculture versus Rubber–Flemingia macrophylla Agroforestry

In the present study, we examined fine root production and soil available nutrients (N, P and K) across different soil depths in rubber monoculture and rubber–Flemingia macrophylla agroforestry of different stand ages. We used the ingrowth cores method and sampled 360 soil cores over four growth intervals, representing one year of growth for the present study. The results showed that root production and macronutrient concentrations generally decreased with increasing soil depth. Total fine root production was comparatively high in the youngest stand age (12 years) rubber monoculture; a similar trend was observed for the soil available P and K, but available N was greater in older than younger stand ages. Root growth and soil available P and K were all lower in the agroforestry system than the monoculture. Significant differences in fine root production with stand ages, management system and seasons suggest that fine root responses to the soil available nutrients are vital to understanding the precise response of above- and belowground biomass to environmental changes

Fine Root Production and Soil Available Nutrients in Rubber Monoculture versus Rubber–<i>Flemingia macrophylla</i> Agroforestry

In the present study, we examined fine root production and soil available nutrients (N, P and K) across different soil depths in rubber monoculture and rubber–Flemingia macrophylla agroforestry of different stand ages. We used the ingrowth cores method and sampled 360 soil cores over four growth intervals, representing one year of growth for the present study. The results showed that root production and macronutrient concentrations generally decreased with increasing soil depth. Total fine root production was comparatively high in the youngest stand age (12 years) rubber monoculture; a similar trend was observed for the soil available P and K, but available N was greater in older than younger stand ages. Root growth and soil available P and K were all lower in the agroforestry system than the monoculture. Significant differences in fine root production with stand ages, management system and seasons suggest that fine root responses to the soil available nutrients are vital to understanding the precise response of above- and belowground biomass to environmental changes

The Temporal Relationship between Depressive Symptoms and Loneliness: The Moderating Role of Self-Compassion

Loneliness and depression are significant mental health challenges among college students; however, the intricate relationship between these phenomena remains unclear, particularly in the context of self-compassion. In this comprehensive study, we employ a cross-lagged panel network (CLPN) analysis to investigate the symptom-level association between depression and loneliness while exploring the potential moderating influence of self-compassion. Our sample consisted of 2785 college students, who were categorized into high- and low-self-compassion groups based on scores from the Self-Compassion Scale. Depressive symptoms were assessed using the Patient Health Questionnaire-9, while the UCLA Loneliness Scale-8 measured loneliness expressions. Our findings indicate that self-compassion plays a crucial role in the relationship between depression and loneliness. Specifically, we observed distinctive patterns within the high and low-self-compassion groups. In the low-self-compassion group, “energy” emerged as the most influential symptom, whereas “motor function” exhibited the highest influence in the high-self-compassion group. Furthermore, among individuals with high self-compassion, the pathway from depression to loneliness was characterized by “guilt—being alone when desired,” while the reverse path from loneliness to depression encompassed “left out—feeling sad” and “left out—anhedonia.” Conversely, in the low-self-compassion group, depression and loneliness demonstrated a more intricate mutual triggering relationship, suggesting that self-compassion effectively moderates the association between these variables. This study provides valuable insights into the underlying mechanisms driving the interplay between depression and loneliness, shedding light on the pivotal role of self-compassion in this intricate dynamic

Ecological characteristics and influencing factors of zooplankton community in Huangcun Reservoir and its connected water system,Lishui

A monthly survey on zooplankton (including rotifera,copepoda and cladocera) was conducted from April 2016 to March 2017 in Huangcun Reservoir and its connected watershed,Lishui,Zhejiang Province.The ecological characteristics of the community structure,spatiotemporal distribution difference of the community between in reservoirs and in connected rivers,and their key impact factors were analyzed in this study.The results showed that 37 species of zooplankton were recorded in the watershed,including 27 species of rotifers,5 species of copepods and of cladocerans respectively.Based on the community data,the zooplankton community was clustered into 4 types in the survey area:the Upstream Channel type,Dayang Reservoir type,Huangcun Reservoir type and the channel connecting two reservoirs type.The characteristics of zooplankton communities in the four types of water bodies were obvious respectively in specific composition,diversity,dominant species,biomass and endemic species.Water in Huangcun reservoir,Dayang reservoir and the connecting channel all comes from the upstream channel,while the structure of zooplankton communities varied in different degrees among the water bodies,which indicated that the structuring of zooplankton community was closely related to environmental (local species sorting) and spatial (dispersal limitation) factors