37 results on '"GUANGNAN CHEN"'
Search Results
2. Pyrolysis of wheat straw pellets in a pilot‐scale reactor: Effect of temperature and residence time
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Bidhan Nath, Guangnan Chen, Les Bowtell, and Thong Nguyen‐Huy
- Subjects
biochar ,gas ,pyrolysis ,reactor ,wheat straw pellet ,Technology ,Science - Abstract
Abstract Pyrolysis of two types of pellets (T1: 100% wheat straw, and T2: 70% wheat straw; 10% sawdust, 10% biochar, and 10% bentonite clay) was performed in a pilot‐scale reactor under a nitrogen environment at 20°C to 700°C. This was to investigate slow pyrolysis yields and gas composition as a function of temperature and residence time. The experimental data were obtained between 300°C and 600°C, with a residence time of 90 min, a nitrogen flow rate of 50 cm3/min, and a heating rate of 20°C/min. The results indicated that the maximum pyrolysis temperature is 605°C with a residence time of 55 min. The product analysis showed that the proportion of gas was higher than that of biochar and bio‐oil. The conversion efficiency increased with higher temperatures and varied between 66% and 76%. The results showed that carbon dioxide was the main component in the produced gas, and the maximum gas concentration was 63.6% at 300°C for T1. The higher temperature and longer residence time increased the syngas (CO + H2) composition for both T1 and T2 treatments. Nevertheless, the produced biochar had a high carbon content and retained a high calorific value, indicating slow pyrolysis is the ideal utilization route of wheat straw pellet biomass for biochar.
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- 2024
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3. Thermal decomposition of wheat straw pellets in a nitrogen environment: Characterization using thermogravimetric analyzer
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Bidhan Nath, Guangnan Chen, Les Bowtell, and Elizabeth Graham
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Thermogravimetric analyzer ,Pyrolysis ,Thermal behavior ,Thermal decomposition ,Wheat straw pellet ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
This experiment used a thermogravimetric (TG) analyzer within a nitrogen environment, investigating the thermal degradation patterns of wheat straw pellets (WSP) under temperatures ranging from 31 to 800 °C and varying heating rates (5, 10, and 20 °C/min). Two pellet types were considered: T1 (100 % wheat straw) and T2 (70 % wheat straw, 10 % sawdust, 10 % bentonite clay, and 10 % biochar). This study comprehensively analyzes WSP's thermal degradation, emphasizing model selection, composition effects, heating rate, and temperature. Results highlighted higher volatile matter content and calorific value in WSP. Model-free methods were applied to analyze TG/DTG profiles, revealing three distinct zones in WSP thermal decomposition: drying, devolatilization, and carbonization. Devolatilization, especially its 1st and 2nd steps, was extensively examined, with a significant mass loss (approx. 65 %) observed between 150 and 550 °C. Higher heating rates induced a shift in thermogravimetric profiles to elevated temperatures. Maximum mass loss rates during devolatilization ranged from 4.41 to 16.28 %/min for T1 and 4.0–15.9 % for T2 pellets. Temperature significantly influenced mass loss and reaction rates, whereas heating rates had a negligible impact. Thermodynamic properties indicated equilibrium reactions during pyrolysis for both T1 and T2 pellets. Additionally, increasing heating rates correlated with an upward trend in the reactivity index. The findings contribute valuable knowledge for optimizing biomass utilization in combustion and pyrolysis processes.
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- 2024
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4. An investigation of thermal decomposition behavior and combustion parameter of pellets from wheat straw and additive blends by thermogravimetric analysis
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Bidhan Nath, Guangnan Chen, Les Bowtell, and Elizabeth Graham
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Combustion parameters ,Wheat straw pellet ,Thermogravimetric analysis ,Derivative thermogravimetric analysis ,Thermal behavior ,Heat ,QC251-338.5 - Abstract
This study investigates the intricate thermal decomposition behavior and combustion characteristics of two distinct types of wheat straw pellets (WSP) represented as T1 (100 % wheat straw) and T5 (70 % wheat straw; 10 % sawdust, 10 % biochar; 10 % bentonite clay). Through a thermogravimetric analyzer (TGA) the pellets undergo combustion under varying heating rates (5, 10, and 20 °C/min) in an air atmosphere, ranging from 25 to 1200 °C. Differential thermogravimetric and thermogravimetric analyses reveal four distinct stages of decomposition in the biomass components. The results indicate that the optimal combustion heating rate is 20 °C/min, resulting in the highest reaction rate (∼50 %/min) and most substantial mass loss (∼55 %) for both T1 and T5 pellets. Notably, the T5 pellet demonstrates a lower ignition temperature (207 °C, at 20 °C/min) and higher burnout (457 °C at 10 °C/min) compared to the T1 pellet, indicating its superior suitability for combustion. The combustion efficiency ranges from 61.0 to 99 % within the temperature range of 300 to 700 °C, similar to coal combustion. Additionally, thermodynamic properties (Di, Db, C, and S) suggest the promising potential of WSP as a bioenergy feedstock. Furthermore, T1 pellets demonstrate higher ignition temperatures (Ti) than T5, indicative of rapid combustion and lower energy potential. burnout temperatures (Tb) revealed intricate results in both scenarios. These findings hold significance for the design of gasification or combustion reactors and the industrial utilization of WSP biomass. The insights gathered from this study offer valuable guidance for designing and enhancing bioenergy systems and fostering sustainable practices in utilizing agricultural residues for energy production.
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- 2024
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5. Pyrolytic Pathway of Wheat Straw Pellet by the Thermogravimetric Analyzer
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Bidhan Nath, Les Bowtell, Guangnan Chen, Elizabeth Graham, and Thong Nguyen-Huy
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activation energy ,model-based method ,pre-exponential factor ,pyrolysis ,thermokinetics ,wheat straw pellet ,Technology - Abstract
The study of the thermokinetics of two types of wheat straw pellets, T1 (100% wheat straw) and T2 (70% wheat straw, 10% each of bentonite clay, sawdust, and biochar), under a nitrogen atmosphere (31–800 °C and 5, 10, and 20 °C/min heating rates) using model-free and model-based approaches by TG/DTG data, revealed promising results. While model-free methods were not suitable, model-based reactions, particularly Fn (nth-order phase interfacial) and F2 (second-order) models, effectively described the three-phase consecutive thermal degradation pathway (A→B, C→D, and D→E). The activation energy (Eα) for phases 2 and 3 (Fn model) averaged 136.04 and 358.11 kJ/mol for T1 and 132.86 and 227.10 kJ/mol for T2, respectively. The pre-exponential factor (lnA) varied across heating rates and pellets (T2: 38.244–2.9 × 109 1/s; T1: 1.2 × 102–5.45 × 1014 1/s). Notably, pellets with additives (T2) exhibited a higher degradable fraction due to lower Eα. These findings suggest a promising potential for utilizing wheat straw pellet biomass as a bioenergy feedstock, highlighting the practical implications of this research.
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- 2024
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6. Research and Technologies to Reduce Grain Postharvest Losses: A Review
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Bidhan Nath, Guangnan Chen, Cherie M. O’Sullivan, and Dariush Zare
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postharvest losses ,grain ,technology ,supply chain ,value losses ,Chemical technology ,TP1-1185 - Abstract
Reducing postharvest losses offers a significant opportunity to enhance food availability without requiring extra production resources. A substantial portion of cereal grain goes to waste annually due to a lack of science-based knowledge, unconscious handling practices, suboptimal technical efficiency, and inadequate infrastructure. This article extensively reviews losses occurring during postharvest operations across various crops, examining diverse postharvest operations in different countries. Recent advancements in postharvest technology research are thoroughly discussed. The primary obstacles and challenges hindering the adoption and implementation of postharvest technologies are also explored. The appropriate postharvest technology relies on specific factors, including the kind of crops, production locales, seasons, and existing environmental and socioeconomic conditions.
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- 2024
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7. Exosome miR-4738-3p-mediated regulation of COL1A2 through the NF-κB and inflammation signaling pathway alleviates osteoarthritis low-grade inflammation symptoms
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Jun Xu, Kaifeng Zhou, Huijie Gu, Yiming Zhang, Liang Wu, Chong Bian, Zhongyue Huang, Guangnan Chen, Xiangyang Cheng, and Xiaofan Yin
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Exosome ,micro RNA (miR)-4739-3p ,collagen type I alpha 2 chain (COL1A2) ,nuclear factor kappa B (NF-κB) signaling pathway ,osteoarthritis (OA) ,Biology (General) ,QH301-705.5 - Abstract
This study aimed to elucidate the roles of microRNA (miR)-4738-3p and the collagen type I alpha 2 chain (COL1A2) gene in the pathogenesis of osteoarthritis (OA) through bioinformatics analysis and cellular assays. The GSE55235 dataset was analyzed using the weighted gene co-expression network analysis (WGCNA) method to identify gene modules associated with OA. Key overlapping genes were identified from these modules and the GSE55235-differential expressed genes (DEGs). The expression levels of selected genes were determined in C28/I2 cells using the quantitative real-time polymerase chain reaction (qRT-PCR). The interaction between miR-4738-3p and COL1A2 was examined in the context of interleukin 1 beta (IL-1β) induction. Exosome characterization was achieved through transmission electron microscopy (TEM), western blotting (WB), and other analyses. The study also investigated the functional relevance of miR-4738-3p in OA pathology through various molecular and cellular assays. Our findings revealed that the green module exhibited a strong correlation with the OA phenotype in the GSE55235 dataset, with COL1A2 emerging as a hub gene and miR-4738-3p as its key downstream target. IL-1β induction suggested that COL1A2 is involved in inflammation and apoptosis, while miR-4738-3p appeared to play an antagonistic role. The analysis of exosomes underscored the significance of miR-4738-3p in cellular communication, with an enhanced level of exo-miR-4738-3p antagonizing IL-1β-induced inflammation and promoting cell survival. Conversely, a reduction in exo-miR-4738-3p led to increased cell damage. This study established a clear regulatory relationship between miR-4738-3p and COL1A2, with the nuclear factor kappa B (NF-κB) signaling pathway playing a central role in this regulation. The miR-4738-3p significantly influences the OA-associated inflammation, primarily through modulation of COL1A2 and the NF-κB pathway. Therefore, targeting miR-4738-3p offers a potential therapeutic approach for OA, with exosome miR-4738-3p presenting a promising strategy.
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- 2023
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8. Kinetic mechanism of wheat straw pellets combustion process with a thermogravimetric analyser
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Bidhan Nath, Guangnan Chen, Les Bowtell, and Elizabeth Graham
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Combustion ,Wheat straw pellet ,Thermogravimetric analyser ,Derivative thermogravimetric analysis ,Heating rate ,Model-based methods ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
In this study, the combustion characteristics of two wheat straw pellets (WSP) (T1: 100% wheat straw and T5: 70% wheat straw; 10% sawdust, 10% biochar; 10% bentonite clay) were performed at a heating rate 20 °C/min under a temperature from 25 to 1200 °C in air atmosphere. A thermogravimetric analyser (TGA) was used to investigate the activation energy (Eα), pre-exponential factor (A), and thermodynamic parameters. The DTG/TG profile of WSP was evaluated by model-free and model-based methods and found the model-based method was suitable for WSP thermal characterisation. The result demonstrates that the thermal decomposition occurred in four stages, comprising four consecutive reaction steps. A→B→C→D→E→F. Further, the model-based techniques were best fitted with kinetic reaction models like Cn (nth-order reaction with auto-catalyst), Fn (reaction of nth order), F2 (second-order phase interfacial reaction) and D3 (diffusion control). The average Eα for Fn, Cn, D3 and F2 models were 164.723, 189.782, 273.88, and 45.0 kJ/mol, respectively, for the T1 pellets. Alternatively, for T5 pellets, the A was 1.17E+2, 1.76E+16, 5.5E+23, and 1.1E+3 (1/s) for F2, D3, Cn and Fn models. Overall, the thermodynamic properties showed that WSP thermokinetic reactions were complex and multi-point equilibrium, indicating a potentiality as a bioenergy feedstock.
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- 2023
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9. Assessment of densified fuel quality parameters: A case study for wheat straw pellet
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Bidhan Nath, Guangnan Chen, Les Bowtell, and Raid Ahmed Mahmood
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Biomass ,Wheat straw ,Pellet quality ,Properties relationship ,Additive/binding material ,Biochemistry ,QD415-436 - Abstract
An investigation was conducted to examine the impact of additive mixing with wheat straw (WS) for pellet making. This study manufactured seven types of pellets with different additive combinations to evaluate pellet quality characteristics and their relationships. A laboratory-type hammer mill and a pellet mill were used for feedstock preparation and pellet production. Experimental investigations showed that the lignin content increased from 7.0% to 13.1%, which was a primary need for pelletization. Also, the heating value rose from 17.02 to 20.36 MJ/kg. However, the ash content also increased from 7.09% to 16.2%. Results showed that dimension (length and diameter), durability, and tensile strength increased significantly with additives while the fines content decreased. The fines content had an inverse relationship with durability and strength. Wheat straw (60%), together with 10% sawdust (SD), 10% corn starch (CS), 10% bentonite clay (BC), and 10% biochar (BiC), was optimal with good pellet performance (T7). In addition, both the T5 pellets (70% WS, 10% SD, 10% BiC, and 10% BC) and the T6 pellets (70% WS, 10% SD, 10% BiC, and 10% CS) provide suitable quality according to EN plus 2015 standard requirements. The ash content of produced pellet was higher than the recommended value, which suggests that further research onto the alternative additive use for ash reduction is needed.
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- 2023
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10. Controlled traffic farming delivers improved agronomic performance of wheat as a result of enhanced rainfall and fertiliser nitrogen use efficiency
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Mahmood A. Hussein, Diogenes L. Antille, Shreevatsa Kodur, Guangnan Chen, and Jeff N. Tullberg
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enhanced efficiency fertilisers ,fertiliser nitrogen recovery ,random traffic ,surface runoff ,soil compaction ,water-use efficiency ,Plant culture ,SB1-1110 - Abstract
This study investigated the agronomic response and economic return of wheat grown in compacted and non-compacted soils to represent the conditions of non-controlled (non-CTF) and controlled traffic (CTF) systems, respectively. Yield-to-nitrogen responses were derived after application of urea, DMPP-treated urea, and UAN at rates between 0 and 300 kg ha−1 N. Soil properties were measured to guide parametrisation of APSIM, which was used to assess long-term (50 years) effects of CTF and non-CTF soil conditions on crop productivity, rainfall-use efficiency (RUE) and surface runoff. Grain yield and yield components were significantly higher in CTF compared with non-CTF. When N inputs were optimised, N use efficiency (NUE) was more than double in CTF (≈23%) compared with non-CTF (≈9%). RUE was about 15% higher in CTF, which concurrently reduced the amount of surface runoff compared with non-CTF. For years with average rainfall (240-mm in-crop), yield penalties of up 12% may be expected in non-CTF. APSIM simulations showed that increased productivity, and inter-annual yield stability, can increase gross margin of wheat by AUD30-50 ha−1 depending on in-crop rainfall and the tillage method used. In non-CTF systems, improvements in NUE and RUE are constrained by soil compaction. Enhanced efficiency fertilizers cannot compensate for other stresses caused by compaction and therefore cannot achieve the same NUE and RUE as the CTF system. Adoption of CTF in water-constrained environments improves profitability and resource-use efficiency.
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- 2021
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11. Expression Profile Analysis of Long Non-coding RNA in OVX Models-Derived BMSCs for Postmenopausal Osteoporosis by RNA Sequencing and Bioinformatics
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Huijie Gu, Zhongyue Huang, Kaifeng Zhou, Guangnan Chen, Chong Bian, Jun Xu, and Xiaofan Yin
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osteoporosis ,lncRNA ,BMSCs ,OVX model ,differentially expressed ,NONMMUT0961501 ,Biology (General) ,QH301-705.5 - Abstract
Osteoporosis (OP) has the characteristics of a systematically impaired bone mass, strength, and microstructure. Long non-coding RNAs (lncRNAs) are longer than 200 nt, and their functions in osteoporosis is yet not completely understood. We first harvested the bone marrow mesenchymal stem cells (BMSCs) from ovariectomy (OVX) and sham mice. Then, we systematically analyzed the differential expressions of lncRNAs and messenger RNAs (mRNAs) and constructed lncRNA–mRNA coexpression network in order to identify the function of lncRNA in osteoporosis. Totally, we screened 743 lncRNAs (461 upregulated lncRNAs and 282 downregulated lncRNAs) and 240 mRNAs (128 upregulated and 112 downregulated) with significantly differential expressions in OP compared to normal. We conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional analyses to investigate the functions and pathways of the differential expression of messenger RNAs (mRNAs), a coexpressed network of lncRNA/mRNA. Quantitative PCR (qPCR) validated that the expressions of NONMMUT096150.1, NONMMUT083450.1, and NONMMUT029743.2 were all downregulated, whereas NONMMUT026970.2, NONMMUT051734.2, NONMMUT003617.2, and NONMMUT034049.2 were all upregulated in the OVX group. NONMMUT096150.1, as a key lncRNA in OP, was identified to modulate the adipogenesis of BMSCs. Further analysis suggested that NONMMUT096150.1 might modulate the adipogenesis of BMSCs via the peroxisome proliferator-activated receptor (PPAR) signaling pathway, AMPK signaling pathway, and the lipolysis regulation in adipocyte and adipocytokine signaling pathway. Our study expands the understanding of lncRNA in the pathogenesis of OP.
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- 2021
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12. Controlled traffic farming effects on productivity of grain sorghum, rainfall and fertiliser nitrogen use efficiency
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Mahmood A. Hussein, Diogenes L. Antille, Shreevatsa Kodur, Guangnan Chen, and Jeff N. Tullberg
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Agronomic efficiency ,Enhanced efficiency fertilisers ,Fertiliser nitrogen recovery ,Random traffic ,Runoff ,Soil compaction ,Agriculture (General) ,S1-972 ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Controlled traffic farming (CTF) is a mechanisation system in which all machinery has the same (or modular) working and track width so that field traffic can be confined to the least possible area of permanent traffic lanes. CTF enables productivity of non-compacted crop beds to be optimised for given energy, fertiliser and water (rainfall) inputs. This study investigated the agronomic response and economic return of grain sorghum grown in compacted and non-compacted soils to represent the conditions of non-CTF and CTF systems, respectively. Yield-to-nitrogen (N) responses were derived following application of urea, 3,4-dimethyl pyrazole phosphate-treated urea (DMPP), and urea ammonium nitrate (UAN, 32% N) at rates between 0 and 300 kg ha−1 N. Selected soil properties were measured to guide parametrisation of the Agricultural Production Systems Simulator (APSIM), which was used to assess long-term (55 years) effects of CTF and non-CTF soil conditions on crop productivity, rainfall use efficiency (RUE) and develop rainfall-runoff relationships. Grain yield and yield components (harvest Index, grain thousand-grain weight, number of grains) were significantly higher in CTF compared with non-CTF. On average, the most economic N rates, and corresponding grain yields, were 144 and 3428 kg ha−1, and 100 and 1796 kg ha−1 for CTF and non-CTF, respectively. When N inputs were optimised, agronomic efficiency calculations showed 18% increase in CTF compared with non-CTF. Nitrogen use efficiency (NUE) was 1.75 times higher in CTF than in non-CTF. Rainfall-use efficiency was about 65% higher in CTF, which concurrently reduced the amount of runoff compared with non-CTF. Average rainfall season (330–450 mm in-crop) grain yield was 30% lower in non-CTF compared with CTF. For subtropical conditions of Australia, long-term APSIM simulations showed that increased productivity and inter-season yield stability can increase gross margin of grain sorghum by AUD74 ha−1 or greater depending on the adopted tillage system and in-crop rainfall. In non-CTF systems, improvements in NUE and RUE are constrained by soil compaction. Enhanced efficiency fertilisers, such as DMPP-treated urea, cannot compensate for other stresses caused by soil compaction and therefore cannot achieve the same NUE and RUE as the CTF system. Adoption of CTF delivers improved resource-use efficiency and profitability in rainfall-limited environments.
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- 2021
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13. MicroRNA-133a Inhibits Osteosarcoma Cells Proliferation and Invasion via Targeting IGF-1R
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Guangnan Chen, Tingting Fang, Zhongming Huang, Yiying Qi, Shaohua Du, Tuoyu Di, Zhong Lei, Xiangyu Zhang, and Weiqi Yan
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Osteosarcoma ,MicroRNA ,MicroRNA-133a ,IGF-1R ,ERK/AKT signaling pathway ,Physiology ,QP1-981 ,Biochemistry ,QD415-436 - Abstract
Background/Aims: MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression by repressing translation or cleaving RNA transcripts in a sequence-specific manner. Downregulated microRNAs and their roles in cancer development have attracted much attention. A growing body of evidence showed that microRNA-133a (miR-133a) has inhibitory effects on cell proliferation, migration, invasion, and metastasis of osteosarcoma. Methods: MiR-133a expression in human osteosarcoma cell lines and human normal osteoblastic cell line hFOB was investigated by real-time PCR (RT-PCR). The role of miR-133a in human osteosarcoma growth and invasion was assessed in cell lines in vitro and in vivo. Then, luciferase reporter assay validated IGF-1R as a downstream and functional target of miR-133a, and functional studies revealed that the anti-tumor effect of miR-133a was probably due to targeting and repressing of IGF-1R expression. Results: MiR-133a was lower expressed in human osteosarcoma cell lines than human normal osteoblastic cell line hFOB and its effect on inhibiting proliferation, invasion and metastasis is mediated by its direct interaction with the IGF-1R. Furthermore, the tumour-suppressive function of miR-133a probably contributed to inhibiting the activation AKT and ERK signaling pathway. Conclusion: MiR-133a suppresses osteosarcoma progression and metastasis by targeting IGF-1R in human osteosarcoma cells, providing a novel candidate prognostic factor and a potential anti-metastasis therapeutic target in osteosarcoma.
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- 2016
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14. Modeling of Stochastic Temperature and Heat Stress Directly Underneath Agrivoltaic Conditions with Orthosiphon Stamineus Crop Cultivation
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Noor Fadzlinda Othman, Mohammad Effendy Yaacob, Ahmad Suhaizi Mat Su, Juju Nakasha Jaafar, Hashim Hizam, Mohd Fairuz Shahidan, Ahmad Hakiim Jamaluddin, Guangnan Chen, and Adam Jalaludin
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transpiration ,PV heat conversion ,plant heat stress ,agrivoltaic system ,sustainable integration ,thermal analysis ,Agriculture - Abstract
This paper presents the field measured data of the ambient temperature profile and the heat stress occurrences directly underneath ground-mounted solar photovoltaic (PV) arrays (monocrystalline-based), focusing on different temperature levels. A previous study has shown that a 1 °C increase in PV cell temperature results in a reduction of 0.5% in energy conversion efficiency; thus, the temperature factor is critical, especially to solar farm operators. The transpiration process also plays an important role in the cooling of green plants where, on average, it could dissipate a significant amount of the total solar energy absorbed by the leaves, making it a good natural cooling mechanism. It was found from this work that the PV system’s bottom surface temperature was the main source of dissipated heat, as shown in the thermal images recorded at 5-min intervals at three sampling times. A statistical analysis further showed that the thermal correlation for the transpiration process and heat stress occurrences between the PV system’s bottom surface and plant height will be an important factor for large scale plant cultivation in agrivoltaic farms.
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- 2020
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15. An Assessment of Direct on-Farm Energy Use for High Value Grain Crops Grown under Different Farming Practices in Australia
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Tek Maraseni, Guangnan Chen, Thomas Banhazi, Jochen Bundschuh, and Talal Yusaf
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grain industry ,on-farm energy ,irrigation energy ,zero tillage ,conventional tillage ,Technology - Abstract
Several studies have quantified the energy consumption associated with crop production in various countries. However, these studies have not compared the energy consumption from a broad range of farming practices currently in practice, such as zero tillage, conventional tillage and irrigated farming systems. This study examines direct on-farm energy use for high value grain crops grown under different farming practices in Australia. Grain farming processes are identified and “typical” farming operation data are collected from several sources, including published and unpublished literature, as well as expert interviews. The direct on-farm energy uses are assessed for 27 scenarios, including three high value grain crops―wheat, barley and sorghum―for three regions (Northern, Southern and Western Australia) under three farming conditions with both dryland (both for conventional and zero-tillage) and irrigated conditions. It is found that energy requirement for farming operations is directly related to the intensity and frequency of farming operations, which in turn is related to tillage practices, soil types, irrigation systems, local climate, and crop types. Among the three studied regions, Western Australia requires less direct on-farm energy for each crop, mainly due to the easily workable sandy soils and adoption of zero tillage systems. In irrigated crops, irrigation energy remains a major contributor to the total on-farm energy demand, accounting for up to 85% of total energy use.
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- 2015
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16. Combined Use of Mesenchymal Stromal Cell Sheet Transplantation and Local Injection of SDF-1 for Bone Repair in a Rat Nonunion Model
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Guangnan Chen, Tingting Fang, Yiying Qi, Xiaofan Yin, Tuoyu Di, Gang Feng, Zhong Lei, Yuxiang Zhang, and Zhongming Huang
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Medicine - Abstract
Bone nonunion treatments pose a challenge in orthopedics. This study investigated the joint effects of using mesenchymal stem cell (MSC) sheets with local injection of stromal cell-derived factor-1 (SDF-1) on bone formation. In vitro, we found that migration of MSCs was mediated by SDF-1 in a dose-dependent manner. Moreover, stimulation with SDF-1 had no direct effect on the proliferation or osteogenic differentiation of MSCs. Furthermore, the results indicated elevated expression levels of bone morphogenetic protein 2, alkaline phosphatase, osteocalcin, and vascular endothelial growth factor in MSC sheets compared with MSCs cultured in medium. New bone formation in fractures was evaluated by X-ray, micro-computed tomography (micro-CT), hematoxylin and eosin (H&E) staining, Safranin-O staining, and immunohistochemistry in vivo. In the rat bone fracture model, the MSC sheets transplanted into the injured site along with injection of SDF-1 showed significantly more new bone formation within the gap. Moreover, at 8 weeks, complete bone union was obtained in this group. In contrast, the control group showed nonunion of the bone. Our study suggests a new strategy involving the use of MSC sheets with a local injection of SDF-1 for hard tissue reconstruction, such as the healing of nonunions and bone defects.
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- 2016
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17. Effects of UCP4 on the Proliferation and Apoptosis of Chondrocytes: Its Possible Involvement and Regulation in Osteoarthritis.
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Zhongming Huang, Junhua Li, Shaohua Du, Guangnan Chen, Yiying Qi, Ligang Huang, Luwei Xiao, and Peijian Tong
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Medicine ,Science - Abstract
Reactive oxygen species (ROS)-induced chondrocytes apoptosis plays a key role in osteoarthritis (OA) pathogenesis. Uncoupling protein 4 (UCP4) can protect cells against oxidative stress via reducing ROS production and cell apoptosis. Here, silencing of UCP4 in primary chondrocytes significantly inhibited cell survival, but induced ROS production and cell apoptosis. UCP4 mRNA of cartilage tissues was decreased in osteoarthritis patients, which was negatively correlated with synovial fluid (SF) leptin concentration. Moreover, leptin treatment (5, 10 and 20 ng/ml) of primary cultured chondrocytes significantly decreased mRNA and protein levels of UCP4, but increased ROS production and cell apoptosis in a dose-dependent manner. The effects of leptin treatment (20 ng/ml) on chondrocytes was partially reversed by ectopic expression of UCP4. More importantly, intraarticularly injection of UCP4 adenovirus remarkably alleviate OA progression and cell apoptosis in a rat OA model induced by anterior cruciate ligament transection (ACLT). In conclusion, UCP4, whose expression was suppressed by leptin, may be involved in the ROS production and apoptosis of chondrocytes, thus contributing to the OA pathogenesis.
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- 2016
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18. Exosome miR-4738-3p-mediated regulation of COL1A2 through the NF-κB and inflammation signaling pathway alleviates osteoarthritis low-grade inflammation symptoms.
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Jun Xu, Kaifeng Zhou, Huijie Gu, Yiming Zhang, Liang Wu, Chong Bian, Zhongyue Huang, Guangnan Chen, Xiangyang Cheng, and Xiaofan Yin
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- 2024
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19. Effect of Maturity Stages on Physical Properties of Cocoa (Theobroma cacao L.) Pods.
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Soyoye, Babatunde Oluwamayokun, Nawi, Nazmi Mat, Zulkifli, Mohamad Ariffin, Guangnan Chen, Madian, Nurfadzilah, Mokhtar, Ahmad Faiz, Adam, Siti Nooradzah, and Al Riza, Dimas Firmanda
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CACAO ,CACAO beans ,COCOA ,TROPICAL crops ,FRUIT processing ,MECHANIZATION - Abstract
Cocoa is one of the main plantation crops in Malaysia. Significant efforts have been made to modernise the industry using mechanisation and automation technologies. Thus, determination of the physical properties of cocoa pods at different maturity stages is paramount for an appropriate design and development of a post-harvest machinery system for pod breaking, sorting and grading. This study investigated the effect of five different maturity stages (unripe, under-ripe, ripe, very-ripe and over-ripe) on the physical properties of cocoa pods. A total of 80 cocoa pods (Clone PBC140) were used as samples, where 16 pods represented each maturity stage. For the unripe stage, the largest mean dimensional values were 172.45, 89.3 and 111.18 mm for the pods' length, diameter and geometric mean diameter, respectively. The highest mean values of 0.66 and 0.54 for the over-ripe stage were recorded for sphericity and aspect ratio, respectively. The geometric mean diameter, weight and firmness were found to be inversely proportional to the maturity stages. The advanced maturity stages experience greater colour intensity, as reflected in the chroma (C*) and higher L*, a* and b* values. This study has found that the colour and texture of the cocoa pods change throughout their maturity. In conclusion, the results reported in this study can be used as a reference for designing and developing a machinery system for post-harvest fruit processing. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Combination of computer vision and backscattering imaging for predicting the moisture content and colour changes of sweet potato (Ipomoea batatas L.) during drying.
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Daniel I. Onwude, Norhashila Hashim, Khalina Abdan, Rimfiel Janius, and Guangnan Chen
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- 2018
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21. Assessment of densified fuel quality parameters: A case study for wheat straw pellet.
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Nath, Bidhan, Guangnan Chen, Bowtell, Les, and Mahmood, Raid Ahmed
- Subjects
WHEAT straw ,WOOD pellets ,WOOD waste ,ADDITIVES ,LIGNINS - Abstract
An investigation was conducted to examine the impact of additive mixing with wheat straw (WS) for pellet making. This study manufactured seven types of pellets with different additive combinations to evaluate pellet quality characteristics and their relationships. A laboratory-type hammer mill and a pellet mill were used for feedstock preparation and pellet production. Experimental investigations showed that the lignin content increased from 7.0% to 13.1%, which was a primary need for pelletization. Also, the heating value rose from 17.02 to 20.36 MJ/kg. However, the ash content also increased from 7.09% to 16.2%. Results showed that dimension (length and diameter), durability, and tensile strength increased significantly with additives while the fines content decreased. The fines content had an inverse relationship with durability and strength. Wheat straw (60%), together with 10% sawdust (SD), 10% corn starch (CS), 10% bentonite clay (BC), and 10% biochar (BiC), was optimal with good pellet performance (T7). In addition, both the T5 pellets (70% WS, 10% SD, 10% BiC, and 10% BC) and the T6 pellets (70% WS, 10% SD, 10% BiC, and 10% CS) provide suitable quality according to EN plus 2015 standard requirements. The ash content of produced pellet was higher than the recommended value, which suggests that further research onto the alternative additive use for ash reduction is needed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. Effects of High-Pressure Carbon Dioxide on the Sensory and Chemical Properties of Dried Dates and Its Toxicity against Galleria mellonella (L.) and Plodia interpunctella (Hübner).
- Author
-
SADEGHI, REZA, HEIDARI, FERESHTEH, EBADOLLAHI, ASGAR, and GUANGNAN CHEN
- Abstract
The use of chemical pesticides can have many detrimental side effects, including environmental pollution, and be a threat to human health. Carbon dioxide (CO
2 ) treatment, a relatively new method for storage pest management, can replace harmful chemicals. Dates, an important food worldwide, contains many minerals, fiber, and a variety of vitamins and are an important dried fruit export from Iran annually. Thus, control of the pests of dried dates by using eco-friendly agents that do not affect quality features are critical. In this study, larval mortality of the Indian meal moth (Plodia interpunctella (Hübner)) and the greater wax moth (Galleria mellonella (L.)), two key pests of stored products, especially dried dates, was studied after exposure to different CO2 pressures within 24 h. Mortality percentages of the third-instar larvae of both pests were increased with an increase in CO2 pressure. Sensory tests on the qualitative characteristics of the dates revealed that CO2 pressures did not affect their aroma, color, sweetness, sourness, crispness, firmness, and overall acceptance. The highest tested pressure (33.4 mol%) of CO2 also had no significant effects on the chemical properties of the date samples, including moisture content, pH, acidity, Brix value, reducing sugar, and total sugar. We conclude that atmospheric CO2 gas can provide a cost-effective and environmentally friendly method for controlling the insect pests of dried dates in addition to preserving their sensory and quality properties. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
23. Convergence of linear multistep methods for two-parameter singular perturbation problems
- Author
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Aiguo, Xiao, Shoufu, Li, Hongyuan, Fu, and Guangnan, Chen
- Published
- 2001
- Full Text
- View/download PDF
24. Stability Analysis of Runge-Kutta Methods for Non-Linear Delay Differential Equations
- Author
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Chengming, Huang, Hongyuan, Fu, Shoufu, Li, and Guangnan, Chen
- Published
- 1999
- Full Text
- View/download PDF
25. Impact of cotton picker traffic on vertosol soil and yield in individual rows.
- Author
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Al-Shatib, Mohammed A. M., Bennett, John McL., Guangnan Chen, and Jensen, Troy A.
- Subjects
COTTON picking ,SOIL compaction ,SOIL moisture ,SOIL density ,SOILS ,COMPACTING - Abstract
This study investigated the impact of soil compaction owing to cotton picker traffic, and the impact of this compaction on cotton yield on a row-by-row basis across the field under both random traffic farming (RTF) and controlled traffic farming (CTF) systems. Measurements of soil water content, dry bulk density and soil penetration resistance were taken and compared with a depth of 80 cm both before and after traffic. It was found that the traffic of JD7760 round-bale cotton picker caused significant compaction in cotton rows and furrows located between, adjacent to, and in wheel tracks under both RTF and CTF systems, particularly for the top 30-cm depth. Because of the soil compaction, the yield was more significantly reduced (7~10% by the machine-pick method) in the rows between the dual-wheel than in those adjacent to the wheel track. Adopting CTF reduces the area of soil compaction and ensures the maintenance of soil characteristics of the cultivated portions of the farm, hence enhancing cotton yield. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
26. Network and pathway-based analyses of genes associated with osteoporosis.
- Author
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Huijie Gu, Zhongyue Huang, Guangnan Chen, Kaifeng Zhou, Yiming Zhang, Jiong Chen, Jun Xu, Xiaofan Yin, Gu, Huijie, Huang, Zhongyue, Chen, Guangnan, Zhou, Kaifeng, Zhang, Yiming, Chen, Jiong, Xu, Jun, and Yin, Xiaofan
- Published
- 2020
- Full Text
- View/download PDF
27. Differences in Characteristics and Clinical Outcomes Among Hispanic/Latino Men and Women Receiving HIV Medical Care - United States, 2013-2014.
- Author
-
Luna-Gierke, Ruth E., Shouse, R. Luke, Frazier, Emma, Beer, Linda, Qingwei Luo, Guangnan Chen, Luo, Qingwei, and Chen, Guangnan
- Abstract
The prevalence of diagnosed human immunodeficiency virus (HIV) infection among Hispanics/Latinos in the United States is approximately twice that of non-Hispanic whites (1). Barriers to, and experiences with, medical care have been found to vary by sex (2). Describing characteristics of Hispanics/Latinos in care by sex can help identify disparities and inform delivery of tailored services to this underserved population. Data from the 2013 and 2014 cycles of the Medical Monitoring Project (MMP) were analyzed to describe demographic, behavioral, and clinical characteristics among Hispanics/Latinos by sex. MMP is an annual cross-sectional, nationally representative surveillance system that, during 2013-2014, collected information about behaviors, medical care, and clinical outcomes among adults receiving outpatient HIV care. Hispanic/Latina women were significantly more likely than were men to live in poverty (78% versus 54%), report not speaking English well (38% versus 21%), and receive interpreter (27% versus 16%), transportation (35% versus 21%), and meal (44% versus 26%) services. There were no significant differences between Hispanic/Latino women and men in prescription of antiretroviral therapy (ART) (95% versus 96%) or sustained viral suppression (68% versus 73%). Although women faced greater socioeconomic and language-related challenges, the clinical outcomes among Hispanic/Latina women were similar to those among men, perhaps reflecting their higher use of ancillary services. Levels of viral suppression for Hispanics/Latinos are lower than those found among non-Hispanic whites (3) and lower than the national prevention goal of at least 80% of persons with diagnosed HIV infection. Providers should be cognizant of the challenges faced by Hispanics/Latinos with HIV infection in care and provide referrals to needed ancillary services. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
28. Effects of controlled traffic no-till system on soil chemical properties and crop yield in annual double-cropping area of the North China Plain.
- Author
-
Caiyun Lu, Hongwen Li, Jin He, Qingjie Wang, Sarker, Khokan Kumer, Wenying Li, Zhanyuan Lu, Rasaily, Rabi G., Hui Li, and Guangnan Chen
- Published
- 2016
- Full Text
- View/download PDF
29. Osteoarthritis prevention and meniscus regeneration induced by transplantation of mesenchymal stem cell sheet in a rat meniscal defect model.
- Author
-
YIYING QI, GUANGNAN CHEN, and GANG FENG
- Subjects
- *
MESENCHYMAL stem cells , *OSTEOARTHRITIS , *MENISCUS (Anatomy) , *CELL suspensions , *LABORATORY rats , *EXTRACELLULAR matrix , *TRANSPLANTATION of organs, tissues, etc. , *PREVENTION - Abstract
Transplantation of mesenchymal stem cells (MSCs) is a potential therapy for meniscus regeneration. However, when using single cell suspension injection, there is frequently a significant loss of cells, with only a small percentage of cells remaining at the target site. This issue may be solved with the use of MSC sheets. In the present study, we investigated whether the use of MSC sheets were able to regenerate the meniscus effectively in a rat meniscectomized model. The anterior half of the medial meniscus in 10 rats was excised and an MSC sheet was transplanted in the MSC sheet treatment group, while untreated rats served as the control. After 4 and 8 weeks, the knee joints were examined by gross and histological observation. Histological observation revealed that the anterior portion of meniscus was similar to the native tissue, showing typical fibrochondrocytes surrounded by richer extracellular matrix in the MSC sheet group. In addition, predominant collagen-rich matrix bridging the interface was observed and the neo-meniscus integrated well with its host meniscus. Furthermore, degenerative changes of tibial plateau and femoral condyle occurred in the two groups. MSC sheet transplantation alleviated the degenerative changes efficiently. In conclusion, transplantation of MSC sheets may efficiently promote meniscus regeneration, as well as inhibit the progression of osteoarthritis in knee joints. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
30. Application of the cell sheet technique in tissue engineering (Review).
- Author
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GUANGNAN CHEN, YIYING QI, LIE NIU, TUOYU DI, JINWEI ZHONG, TINGTING FANG, and WEIQI YAN
- Subjects
- *
CELL sheets (Biology) , *CELL culture , *CELL envelope (Biology) , *TISSUE engineering , *PHENOTYPES - Abstract
The development and application of the tissue engineering technique has shown a significant potential in regenerative medicine. However, the limitations of conventional tissue engineering methods (cell suspensions, scaffolds and/or growth factors) restrict its application in certain fields. The novel cell sheet technique can overcome such disadvantages. Cultured cells can be harvested as intact sheets without the use of proteolytic enzymes, such as trypsin or dispase, which can result in cell damage and loss of differentiated phenotypes. The cell sheet is a complete layer, which contains extracellular matrix, ion channel, growth factor receptors, nexin and other important cell surface proteins. Mesenchymal stem cells (MSCs), which have the potential for multiple differentiation, are promising candidate seed cells for tissue engineering. The MSC sheet technique may have potential in the fields of regenerative medicine and tissue engineering in general. Additionally, induced pluripotent stem cell and embryonic stem cell-derived cell sheets have been proposed for tissue regeneration. Currently, the application of cell sheet for tissue reconstruction includes: Direct recipient sites implantation, superposition of cell sheets to construct three-dimensional structure for implantation, or cell sheet combined with scaffolds. The present review discusses the progress in cell sheet techniques, particularly stem cell sheet techniques, in tissue engineering. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
31. An Assessment of Direct on-Farm Energy Use for High Value Grain Crops Grown under Different Farming Practices in Australia.
- Author
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Maraseni, Tek, Guangnan Chen, Banhazi, Thomas, Bundschuh, Jochen, and Yusaf, Talal
- Subjects
- *
GRAIN farming , *ENERGY consumption , *NO-tillage , *IRRIGATION farming , *FARMS - Abstract
Several studies have quantified the energy consumption associated with crop production in various countries. However, these studies have not compared the energy consumption from a broad range of farming practices currently in practice, such as zero tillage, conventional tillage and irrigated farming systems. This study examines direct on-farm energy use for high value grain crops grown under different farming practices in Australia. Grain farming processes are identified and "typical" farming operation data are collected from several sources, including published and unpublished literature, as well as expert interviews. The direct on-farm energy uses are assessed for 27 scenarios, including three high value grain crops--wheat, barley and sorghum--for three regions (Northern, Southern andWestern Australia) under three farming conditions with both dryland (both for conventional and zero-tillage) and irrigated conditions. It is found that energy requirement for farming operations is directly related to the intensity and frequency of farming operations, which in turn is related to tillage practices, soil types, irrigation systems, local climate, and crop types. Among the three studied regions, Western Australia requires less direct on-farm energy for each crop, mainly due to the easily workable sandy soils and adoption of zero tillage systems. In irrigated crops, irrigation energy remains a major contributor to the total on-farm energy demand, accounting for up to 85% of total energy use. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
32. Effectiveness of Ultrasound Guidance on Intraarticular and Periarticular Joint Injections.
- Author
-
Zhongming Huang, Shaohua Du, Yiying Qi, Guangnan Chen, and Weiqi Yan
- Published
- 2015
- Full Text
- View/download PDF
33. Prediction of Sugarcane Quality Parameters Using Visible-shortwave Near Infrared Spectroradiometer.
- Author
-
Mat, Nawi Nazmi, Rowshon, Kamal Md, Guangnan, Chen, and Troy, Jensen
- Abstract
This study was undertaken to explore the potential of spectroscopic method to predict sugarcane quality parameters by directly scanning the internode samples. Spectral data was collected from 125 internode using a visible-shortwave near infrared spectroradiometer (VNIRS). The spectral data was calibrated using Partial Least Square (PLS) method against the reference values of Brix, fibre content (FC) and moisture content (MC). The prediction results for Brix, FC and MC as represented by coefficient of determination ( R 2 ) were 0.88, 0.93 and 0.90, respectively. These results suggested that the spectroscopic method could be used to predict sugarcane quality parameters with good accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
34. Microstructural features of an iron-based laser coating.
- Author
-
Xiaolei Wu and Guangnan Chen
- Subjects
INDUSTRIAL lasers ,COATING processes ,MICROSTRUCTURE ,ELECTRON microscopy ,WINDOWLESS energy-dispersive X-ray analysis - Abstract
A high toughness wear resistant coating is produced by laser clad Fe-Cr-W-Ni-C alloys. The microstructural and compositional features of the laser-solidified microstructures and phase evolutions occurring during high temperature tempering at 963 K were investigated by using analytical electron microscopy with energy dispersive X-ray analysis. The clad coating possesses the hypereutectic microstructure consisted of M
7 C3 + (γ + M7 C3 ). During high temperature aging, the precipitation of M23 C6 and M2 C in austenite and in situ transformation of dendritic M7 C3 to M23 C6 and eutectic M7 C3 to M6 C occurred. The laser clad coating reveals an evident secondary hardening and superior impact wear resistance. [ABSTRACT FROM AUTHOR]- Published
- 1999
- Full Text
- View/download PDF
35. Spo0A-Dependent Activation of an Extended -10 Region Promoter in Bacillus subtilis.
- Author
-
Guangnan Chen, Kumar, Amrita, Wyman, Travis H., and Moran Jr., Charles P.
- Subjects
- *
BACILLUS subtilis , *DNA-binding proteins , *GENES , *CELLS , *GENETIC mutation - Abstract
At the onset of endospore formation in Bacillus subtilis the DNA-binding protein Spo0A directly activates transcription from promoters of about 40 genes. One of these promoters, Pskf, controls expression of an operon encoding a killing factor that acts on sibling cells. AbrB-mediated repression of Pskf provides one level of security ensuring that this promoter is not activated prematurely. However, Spo0A also appears to activate the promoter directly, since Spo0A is required for Pskf activity in a ΔabrB strain. Here we investigate the mechanism of Pskf activation. DNase I footprinting was used to determine the locations at which Spo0A bound to the promoter, and mutations in these sites were found to significantly reduce promoter activity. The sequence near the -10 region of the promoter was found to be similar to those of extended -10 region promoters, which contain a TRTGn motif. Mutational analysis showed that this extended -10 region, as well as other base pairs in the -10 region, is required for Spo0A-dependent activation of the promoter. We found that a substitution of the consensus base pair for the nonconsensus base pair at position -9 of Pskf produced a promoter that was active constitutively in both ΔabrB and Δspo0A ΔabrB strains. Therefore, the base pair at position -9 of Pskf makes its activity dependent on Spo0A binding, and the extended -10 region motif of the promoter contributes to its high level of activity. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
36. Roughening of the free surfaces of metallic sheets during stretch forming
- Author
-
Guangnan, Chen, Huan, Shen, Shiguang, Hu, and Baudelet, Bernard
- Published
- 1990
- Full Text
- View/download PDF
37. Distinct Roles of Ape1 Protein, an Enzyme Involved in DNA Repair, in High or Low Linear Energy Transfer Ionizing Radiation-induced Cell Killing.
- Author
-
Hongyan Wang, Xiang Wang, Guangnan Chen, Xiangming Zhang, Xiaobing Tang, Dongkyoo Park, Cucinotta, Francis A., Yu, David S., Xingming Deng, Dynan, William S., Doetsch, Paul W., and Ya Wang
- Subjects
- *
PROTEIN research , *ENZYMES , *DNA repair , *LINEAR energy transfer , *RADIOTHERAPY - Abstract
High linear energy transfer (LET) radiation from space heavy charged particles or a heavier ion radiotherapy machine kills more cells than low LET radiation, mainly because high LET radiation-induced DNA damage is more difficult to repair. Relative biological effectiveness (RBE) is the ratio of the effects generated by high LET radiation to low LET radiation. Previously, our group and others demonstrated that the cell-killing RBE is involved in the interference of high LET radiation with non-homologous end joining but not homologous recombination repair. This effect is attributable, in part, to the small DNA fragments (≤40 bp) directly produced by high LET radiation, the size of which prevents Ku protein from efficiently binding to the two ends of one fragment at the same time, thereby reducing non-homologous end joining efficiency. Here we demonstrate that Ape1, an enzyme required for processing apurinic/apyrimidinic (known as abasic) sites, is also involved in the generation of small DNA fragments during the repair of high LET radiation-induced base damage, which contributes to the higher RBE of high LET radiation-induced cell killing. This discovery opens a new direction to develop approaches for either protecting astronauts from exposure to space radiation or benefiting cancer patients by sensitizing tumor cells to high LET radiotherapy. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
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