33 research outputs found
Effects of Xinwei granule on expression levels of cyclin D1 and its upstream genes in gastric intraepithelial neoplasia tissues
Purpose: To explore the effects of Xinwei granule (XWG) on low-grade gastric intraepithelial neoplasia (LGIN) and the underlying mechanisms.
Methods: To establish LGIN model, Wistar rats were treated with N-methyl-N'-nitrosoguanidine for 3 months. LGIN model rats were randomly grouped into five groups (n = 15), viz, negative control (NC), normal saline (NS) group, Xinwei granule (XWG) group, Weifuchun tablet (WFCT) group, and vatacoenayme tablet (VT) group. Normal rats (n = 17) served as negative control. Histological evaluation of gastric mucosa was undertaken using hematoxylin and eosin staining. Quantitative realtime polymerase chain reaction (qRT-PCR), western blot, and immunohistochemical assays were performed to determine mRNA expressions, protein expression, and the distribution of cyclin D1, kruppel-like factor 4 (KLF4), and p21-WAF1-CIP1, respectively.
Results: Compared with LGIN group, the body weight of the rats increased in XWG, WFCT, and VT groups. The pathological characteristics of LGIN group were alleviated by XWG, WFCT and VT treatments. The positive expression of cyclin D1 was enhanced in LGIN group, but reduced in XWG, WFCT and VT groups. The expression levels of KLF4 and p21-WAF1-CIP1, upstream regulators of cyclin D1 reduced in LGIN groups. However, administration of XWG, WFCT and VT strengthened the expressions of KLF4 and p21-WAF1-CIP1. More importantly, the protective effects of XWG against LGIN were superior to those of WFCT and VT.
Conclusion: Xinwei granules alleviate LGIN in vivo by inhibiting cyclin D1 expression and enhancing KLF4 and p21-WAF1-CIP1 expression
Morphological responses of root hairs to changes in soil and climate depend on plant life form
IntroductionRoot hairs increase the surface area of a plant’s root system that is in contact with the soil, thus facilitating plant water and nutrient uptake. However, little is known about the characteristics of the root hairs of herbaceous and woody plants and their specific response patterns to biotic and abiotic variables from the perspective of resource acquisition strategies in the context of global change.MethodsHere, we analyzed 74 published case studies with 1074 observations of root hair traits to identify patterns of root hair length, density and diameter in relation to soil (e.g., soil pH, nutrient levels), growing environments (e.g., greenhouse, field) and climatic factors (e.g., air temperature), as well as genome size and plant age.ResultsRoot hairs were longer, denser and thicker in woody plants compared with herbaceous plants, and the length and diameter of root hairs in herbaceous plants increased with genome size. With increasing plant age, woody plants had significantly longer and thicker root hairs, while root hair density and diameter declined significantly for herbaceous plants. Soil-cultured plants had longer root hairs than solution-cultured plants. The length and density of root hairs were greater in greenhouse-cultured plants than in field-grown plants, and the latter had thicker root hairs than the former. As soil pH increased, root hair length increased but diameter decreased in woody plants, while root hair density increased in herbaceous plants. Increased soil total nitrogen (N) and potassium (K) significantly increased root hair length, density and diameter in herbaceous plants, while soil total N significantly decreased root hair density in woody plants. Root hair length increased significantly, while root hair density decreased significantly, with higher mean annual temperature and greater precipitation seasonality, while the opposite pattern was true for a wider annual temperature range.DiscussionOur findings emphasize the life-form-specific responses of root hairs to soil and climatic variables. These findings will help deepen our understanding of resource acquisition strategies and their mechanisms in different plant forms under global climate change
Error calculation of large-amplitude internal solitary waves within the pycnocline introduced by the strong stratification approximation
At present, studies on large-amplitude internal solitary waves mostly adopt strong stratification models, such as the two-and three-layer Miyata—Choi—Camassa (MCC) internal wave models, which omit the pycnocline or treat it as another fluid layer with a constant density. Because the pycnocline exists in real oceans and cannot be omitted sometimes, the computational error of a large-amplitude internal solitary wave within the pycnocline introduced by the strong stratification approximation is unclear. In this study, the two- and three-layer MCC internal wave models are used to calculate the wave profile and wave speed of large-amplitude internal solitary waves. By comparing these results with the results provided by the Dubreil—Jacotin—Long (DJL) equation, which accurately describes large-amplitude internal solitary waves in a continuous density stratification, the computational errors of large-amplitude internal solitary waves at different pycnocline depths introduced by the strong stratification approximation are assessed. Although the pycnocline thicknesses are relatively large (accounting for 8%–10% of the total water depth), the error is much smaller under the three-layer approximation than under the two-layer approximation.</p
The Contrasting Responses of Mycorrhizal Fungal Mycelium Associated with Woody Plants to Multiple Environmental Factors
Research Highlights: Extraradical mycorrhizal fungal mycelium (MFM) plays critical roles in nutrient absorption and carbon cycling in forest ecosystems. However, it is often ignored or treated as a root uptake apparatus in existing biogeochemical models. Methods: We conducted a meta-analysis to reveal how MFM responds to various, coinciding environmental factors and their interactions. Results: Nitrogen (N) addition and N-phosphorus (P)-potassium (K) combination significantly decreased MFM. However, elevated CO2, organic matter addition, P addition, and CO2-N combination significantly increased MFM. In contrast, warming, K addition, N-P combination, and P-K combination did not affect MFM. Mycorrhizal fungal levels (individual vs. community), mycorrhizal type (ectomycorrhizal fungi vs. arbuscular mycorrhizal fungi), treatment time (<1 year vs. >1 year), and mycelium estimation/sampling method (biomarker vs. non-biomarker; ingrowth mesh bag vs. soil core) significantly affected the responses of MFM to elevated CO2 and N addition. The effect sizes of N addition significantly increased with mean annual precipitation, but decreased with soil pH and host tree age. The effect sizes of P addition significantly increased with N concentration in host plant leaves. Conclusions: The differential responses revealed emphasize the importance of incorporating MFM in existing biogeochemical models to precisely assess and predict the impacts of global changes on forest ecosystem functions
The Dynamics of Living and Dead Fine Roots of Forest Biomes across the Northern Hemisphere
Research Highlights: A detailed picture of the seasonality in fine root biomass (FRB), necromass (FRN), and the biomass/necromass ratio (FRBN) throughout the whole year is crucial to uncover profound effects of long-term environmental changes on fine root dynamics. Materials and Methods: We used meta-analysis to characterize the variability of FRB, FRN and FRBN, and determined their relations with climatic (monthly versus annual), edaphic and geomorphic factors for tropical, temperate and boreal forest biomes across the Northern Hemisphere. Results: Boreal forests exhibited the highest FRB and FRN, while tropical forests yielded the lowest FRN, and thus the greatest FRBN. FRB and FRN significantly decreased with sampling depth, but increased with soil organic carbon content and elevation, while an opposite pattern was found for FRBN. Temperature and precipitation at different time scales (monthly versus annual) and latitude had varying influences on fine roots. High FRB and FRN were observed during dry season for tropical forests, but in the late growing season for temperate forests. The three forest biomes exhibited the high root activity (measured as FRBN) in June or July. Conclusions: It is crucial to realize the universal and specific responses of fine roots to multiple environmental factors when attempting to incorporate these parameters into fine root monthly dynamic models in forest ecosystems. The biome-specific fluctuation of fine roots contributes to identify the influence factors on fine root seasonal patterns throughout the whole year. Our analysis is expected to improve the understanding of the key role of fine roots at monthly level in modeling and predicting carbon budget of various forest biomes under future climate change
RSC Adv.
We report the scalable synthesis of porous Si/C microspheres (PSCMs) by a spray drying process using carbon black (CB) or graphitized carbon black (GCB) nanoparticles as the primary carbon source, Si nanoparticles as the active additive, and sucrose as the binder, followed by a heat treatment at 900 degrees C. The samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption, thermogravimetric analysis, and Raman spectroscopy. It was found that the PSCMs have a particle size range of 5-20 mu m, and those composed of GCB and 5 wt% Si nanoparticles (named GCBSi5) display improved electrochemical performance. As can be observed, GCBSi5 delivered a reversible capacity of 483 mA h g(-1) at the current density of 50 mA g(-1) after 100 cycles, which is much higher than that of the commercial graphite microspheres (GMs; 344 mA h g(-1)). More importantly, GCBSi5 exhibited excellent rate performance, for example, its capacity is around 435 and 380 mA h g(-1) at the current densities of 500 and 1000 mA g(-1), respectively, which is much higher than those of GMs (200 and 100 mA h g(-1)). These enhanced electrochemical properties should correlate with its porous structure that can significantly suppress the aggregation and volume expansion/contraction of the Si nanoparticles and speed up Li ion diffusion. In addition, the introduction of GCB and carbon matrix interconnected with hard carbon derived from sucrose can enhance the electronic conductivity. This work demonstrates the feasibility of the large-scale and low-cost production of Si/C anode composites for Li-ion batteries.We report the scalable synthesis of porous Si/C microspheres (PSCMs) by a spray drying process using carbon black (CB) or graphitized carbon black (GCB) nanoparticles as the primary carbon source, Si nanoparticles as the active additive, and sucrose as the binder, followed by a heat treatment at 900 degrees C. The samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption, thermogravimetric analysis, and Raman spectroscopy. It was found that the PSCMs have a particle size range of 5-20 mu m, and those composed of GCB and 5 wt% Si nanoparticles (named GCBSi5) display improved electrochemical performance. As can be observed, GCBSi5 delivered a reversible capacity of 483 mA h g(-1) at the current density of 50 mA g(-1) after 100 cycles, which is much higher than that of the commercial graphite microspheres (GMs; 344 mA h g(-1)). More importantly, GCBSi5 exhibited excellent rate performance, for example, its capacity is around 435 and 380 mA h g(-1) at the current densities of 500 and 1000 mA g(-1), respectively, which is much higher than those of GMs (200 and 100 mA h g(-1)). These enhanced electrochemical properties should correlate with its porous structure that can significantly suppress the aggregation and volume expansion/contraction of the Si nanoparticles and speed up Li ion diffusion. In addition, the introduction of GCB and carbon matrix interconnected with hard carbon derived from sucrose can enhance the electronic conductivity. This work demonstrates the feasibility of the large-scale and low-cost production of Si/C anode composites for Li-ion batteries
RSC Adv.
We report in situ growth of amorphous silicon/carbon (Si/C) layers on graphitized carbon black (GCB) particles in porous microspheres (PMs) for formation of novel GCB@Si/C PMs as high performance anode materials. The preparation included spray drying, KOH activation and chemical vapor deposition at 900 degrees C, and used methyltrichlorosilane as both the Si and C precursor, which is a cheap byproduct in the organosilane industry. The obtained samples were characterized by X-ray diffraction, thermogravimetric analysis, nitrogen adsorption, transmission electron microscopy, and scanning electron microscopy. Compared with the bare GCB PMs, the GCB@Si/C PMs showed a significantly enhanced electrochemical performance with high lithium storage capacity and excellent cycling stability (the discharge capacity of GCB@Si/C-3 PMs and GCB@Si/C-6 PMs is maintained at 587.2 and 729.7 mA h g(-1) after 200 cycles at a current density of 100 mA g(-1)), because the unique interconnected porous structure within the microspheres could absorb a large portion of Si volume change during Li insertion and extraction reactions, promote the diffusion of Li-ion and electrolyte solution, hinder the cracking or crumbling of the electrode, and additionally, the GCB and amorphous C provide high conductive electron pathway. This work opens a new way for fabrication of Si/C nanocomposites as anode materials for Li-ion batteries.We report in situ growth of amorphous silicon/carbon (Si/C) layers on graphitized carbon black (GCB) particles in porous microspheres (PMs) for formation of novel GCB@Si/C PMs as high performance anode materials. The preparation included spray drying, KOH activation and chemical vapor deposition at 900 degrees C, and used methyltrichlorosilane as both the Si and C precursor, which is a cheap byproduct in the organosilane industry. The obtained samples were characterized by X-ray diffraction, thermogravimetric analysis, nitrogen adsorption, transmission electron microscopy, and scanning electron microscopy. Compared with the bare GCB PMs, the GCB@Si/C PMs showed a significantly enhanced electrochemical performance with high lithium storage capacity and excellent cycling stability (the discharge capacity of GCB@Si/C-3 PMs and GCB@Si/C-6 PMs is maintained at 587.2 and 729.7 mA h g(-1) after 200 cycles at a current density of 100 mA g(-1)), because the unique interconnected porous structure within the microspheres could absorb a large portion of Si volume change during Li insertion and extraction reactions, promote the diffusion of Li-ion and electrolyte solution, hinder the cracking or crumbling of the electrode, and additionally, the GCB and amorphous C provide high conductive electron pathway. This work opens a new way for fabrication of Si/C nanocomposites as anode materials for Li-ion batteries
Pitch-derived P-doped carbon/GeP3 composite via ball milling towards enhanced sodium-ion storage
GeP3 is a promising anode material for sodium ion battery due to better conductivity, relatively high theoretical capacity and improved mechanical endurance compared to phosphorus and other phosphides. However unsatisfied rate capability and cycling stability is still an annoying issue that hinders the application of GeP3. Here, GeP3 was hybridized with P doped carbon (PPC) derived from low-cost coal tar pitch to prepare composite electrode. Through ball-milling process, the GeP3 and PPC was homogenously mixed and form fused, secondary particles as confirmed by electron microscope. The formation of P-C and P-O-C bond between GeP3 and carbon matrix was evidenced by XPS, and prompted by P doping level and O content in PPC. The electrochemical performance of the composite electrodes was evaluated, demonstrated much enhanced properties compared to bare GeP3 and also GeP3/carbon black electrode. High reversible capacity of 781 mAh/g was achieved by GeP3/PPC-950 at 0.05 A/g. At higher current density of 2 A/g, the capacity can maintain at 360 mAh/g, 46% of the value that obtained at 0.05 A/g. The correlation between the structure of carbon and battery performance was discussed. The improvement in battery performance can be attributed to suppressed volume expansion and good conductive network of the GeP3/PPC composite, which affected by P doping level and O content of PPC