Synthesis of reduced graphene oxide nanosheets from sugarcane dry leaves by two-stage pyrolysis for antibacterial activity

Oxidative-exfoliation methods were in vogue in the production of rGO from graphite.Processing of such synthetic graphite needs high temperatures(2500℃).Thus,such process is not cost-effective.The present study is made on the dry leaves of sugarcane(Saccharum officinarum)as an alternative raw material so as to be economical and environmentally benign.The dry leaves are subjected to two-step pyrolysis without any catalyst or reducing agent in far divergent temperatures to produce as prepared and acid treated rGOs.They were evaluated by UV–Vis.,FTIR,XRD,Raman spectroscopy,TGA/DTG,BET,FESEM-EDS and TEM.The as prepared rGO has few layers with irregular and folded architecture whereas acid-treated rGO has thinly stacked crumpled sheets with many wrinkles on its surface.The prepared rGOs have multilayered graphitic structure due to the unique ratio between G and D bands.Acid treated rGO has poor thermal stability as compared to that of as-prepared rGO at high temperatures due to the variation in the oxygen-containing functional groups.Acid treated rGO has low antibacterial activity as compared to that of the as-prepared rGO due to the paucity of the functional groups.

The effect of ensiled paulownia leaves in a high-forage diet on ruminal fermentation,methane production,fatty acid composition,and milk production performance of dairy cows

Background:The use of industrial by-products rich in bioactive compounds as animal feeds can reduce greenhouse gas production.Paulownia leaves silage(PLS)was supplemented to dairy cows'diet and evaluated in vitro(Exp.1;Rusitec)and in vivo(Exp.2,cannulated lactating dairy cows and Exp.3,non-cannulated lactating dairy cows).The study investigated the PLS effect on ruminal fermentation,microbial populations,methane production and concentration,dry matter intake(DMI),and fatty acid(FA)proportions in ruminal fluid and milk.Results:Several variables of the ruminal fluid were changed in response to the inclusion of PLS.In Exp.1,the p H increased linearly and quadratically,whereas ammonia and total volatile fatty acid(VFA)concentrations increased linearly and cubically.A linear,quadratic,and cubical decrease in methane concentration was observed with increasing dose of the PLS.Exp.2 revealed an increase in ruminal p H and ammonia concentrations,but no changes in total VFA concentration.Inclusion of PLS increased ruminal propionate(at 3 h and 6 h after feeding),isovalerate,and valerate concentrations.Addition of PLS also affected several populations of the analyzed microorganisms.The abundances of protozoa and bacteria were increased,whereas the abundance of archaea were decreased by PLS.Methane production decreased by 11%and 14%in PLS-fed cows compared to the control in Exp.2 and 3,respectively.Exp.3 revealed a reduction in the milk protein and lactose yield in the PLS-fed cows,but no effect on DMI and energy corrected milk yield.Also,the PLS diet affected the ruminal biohydrogenation process with an increased proportions of C18:3 cis-9 cis-12 cis-15,conjugated linoleic acid,C18:1 trans-11 FA,polyunsaturated fatty acids(PUFA),and reduced n6/n3 ratio and saturated fatty acids(SFA)proportion in milk.The relative transcript abundances of the 5 of 6 analyzed genes regulating FA metabolism increased.Conclusions:The dietary PLS replacing the alfalfa silage at 60 g/kg diet can reduce the methane emission and improve milk quality with greater proportions of PUFA,including conjugated linoleic acid,and C18:1 trans-11 along with reduction of SFA.

VG,encoding a thylakoid formation protein,regulates the formation of variegated leaves in tomato

Leaf-color mutations have been studied extensively in plants.However,to better understand the complex mechanisms underlying the formation of leaf color,it is essential to continue discover novel genes involved in the process of leaf color development.In this study,we identified a variegated-leaf(vg)mutant in tomato that exhibited defective phenotypes in thylakoids and photosynthesis.To clone the vg locus,an F2population was constructed from the cross between the vg mutant(Solanum lycopersicum)and the wild tomato LA1589(S.pimpinellifolium).Using the map-based cloning approach,the vg locus was mapped on chromosome 7 and narrowed down to a 128 kb region that contained 21 open reading frames(ORFs).The expression levels of ORF9,ORF10,and ORF13 were significantly lower in vg than in the wild-type plants,while the ORF11 transcript level was elevated in vg.We then mutagenized ORF9,ORF10,and ORF13 by the CRISPR/Cas9 system in the wild-type tomato background and found that only the ORF10 mutation reproduced the phenotype of variegated leaves,indicating that ORF10 represents VG and its down-regulated expression was responsible for the variegated leaf phenotype.ORF10 encodes a thylakoid formation protein and its mutant lines showed reduced levels of chlorophyll synthesis and photosynthesis.Taken together,these results suggest that VG is necessary for chloroplast development,chlorophyll synthesis,and photosynthesis in tomato.

Phytochemical Profile, Antioxidant, and Anti-Inflammatory Activities, Safety of Use and Spasmolytic Effects of Aqueous Decoction Extract of Diospyros mespiliformis Leaves Hochst. ex A. DC. (Ebenaceae) on the Isolated Duodenum of Rat

Diospyros mespiliformis Hochst. ex A. DC. (Ebenaceae) is a multi-use plant, including for therapeutic purposes. It is used in alternative medicine in Burkina Faso to treat conjunctivitis, menorrhagia, dysentery, and diarrhea. The aim of our study was to evaluate the chemical profile, antioxidant and anti-inflammatory activities, safety of use and spasmolytic effects of the aqueous decoction of Diospyros mespiliformis leaves. Phytochemical screening by HPTLC and assay of compounds of interest were carried out. Four methods were used to assess antioxidant activity. Inhibitory activity against 15-lipoxygenase and phospholipase A2 was assessed. Acute oral toxicity of the extract was tested on female mice (NMRI). Following these tests, the extract contained bioactive compounds of interest such as flavonoids, tannins, sterols, triterpenes, and saponosides. The total phenolic and flavonoid contents of the aqueous decoctate were 70.59 ± 3.20 mg EAT/g and 31.57 ± 0.78 mg EQ/g respectively. The extract was less active than Trolox with inhibitory concentrations of 50% (IC50) for the ABTS, DPPH, FRAP, and LPO tests of 7.53 ± 0.08 μg/mL, 29.47 ± 0.06 μg/mL, 1128.83 ± 4.82 mol EAA/g, and 32.30 ± 1.60 μg/mL respectively. The extract has an anti-inflammatory effect with inhibition of phospholipase A2 compared to betamethasone. In addition, the aqueous extract produced an antispasmodic effect with Emax of 70% and 80% respectively during contractions induced by BaCl2 and ACh. Finally, this study provided basic scientific data and could justify the use of D. mespiliformis leaves in the treatment of diarrhea.

Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in trees.One possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced leaves.However,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly documented.An experiment in a beech forest in Meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence period.The aim was to identify potential nutritional consequences of droughts for trees.Monitoring nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(i.e.resorption efficiency),thus reducing the K reserve in trees for the next growing season.This result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study site.Reduced foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(P)were also observed.In addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree nutrition.The calcium(Ca)negative resorption decreased,with no apparent consequence in our study site.Our results show that nutrient exchanges in the canopy and the partitioning of the green leaf pool can be modified by drought events,and may have consequences on tree nutrition.

Quantifying foliar trait variation and covariation in sun and shade leaves using leaf spectroscopy in eastern North America

Characterizing foliar trait variation in sun and shade leaves can provide insights into inter-and intra-species resource use strategies and plant response to environmental change.However,datasets with records of multiple foliar traits from the same individual and including shade leaves are sparse,which limits our ability to investigate trait-trait,trait-environment relationships and trait coordination in both sun and shade leaves.We presented a comprehensive dataset of 15 foliar traits from sun and shade leaves sampled with leaf spectroscopy,including 424 individuals of 110 plant species from 19 sites across eastern North America.We investigated trait variation,covariation,scaling relationships with leaf mass,and the effects of environment,canopy position,and taxonomy on trait expression.Generally,sun leaves had higher leaf mass per area,nonstructural carbohydrates and total phenolics,lower mass-based chlorophyll a+b,carotenoids,phosphorus,and potassium,but exhibited species-specific characteristics.Covariation between sun and shade leaf traits,and trait-environment relationships were overall consistent across species.The main dimensions of foliar trait variation in seed plants were revealed including leaf economics traits,photosynthetic pigments,defense,and structural traits.Taxonomy and canopy position collectively explained most of the foliar trait variation.This study highlights the importance of including intra-individual and intra-specific trait variation to improve our understanding of ecosystem functions.Our findings have implications for efficient field sampling,and trait mapping with remote sensing.

Influence of soaking Malus domeri(Bois)Chev.leaves on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,China

To investigate the effects of drinking the soaking of Malus domeri(Bois)Chev.leaves on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,China.It has been reported that longevity is closely related to metabolism and the gut microbiota.The 16S rRNA sequencing and liquid chromatography-mass spectrometry(LC-MS)were used to analysis fecal samples and explore the factors affecting longevity in the region.Interestingly,we discovered,that elderly individuals who had been drinking the soaking of M.domeri(Bois)Chev.leaves for a long time exhibited higher diversity of the gut microbiota than without drinking the soaking,notably.The proportions of Ruminococcaceae and Prevotella were decreased in those who did not drink this soaking.In addition,a total of 106 metabolites were characterized,and the people of long-lived people(>90 years old)and elderly people(<90 years old)who drinking soaking of M.domeri(Bois)Chev.leaves significantly altered the gut microbiota and upregulated levels of haplopine,farnesol,genipic acid,momordicinin,2-hydroxyestrone,hydroxyphenyllactic acid,caffeic acid,sophoraflavanone B,and soyasaponin I.We preliminarily determined that M.domeri(Bois)Chev.leaves consumption may be an important factor affecting longevity in this area.

Effects of Incorporating Mango (Mangifera indica), Avocado (Persea americana) and Guava (Psidium guajava) Leaves Powder in the Ration on Growth Characteristics in Rabbits

A study conducted on burgundy rabbits evaluated the effects of rations containing mango (Mangifera indica), avocado (Persea americana) and guava (Psidium guajava) powder. For this purpose, 36 rabbits (20 males and 16 females) aged 60 to 70 days with an average weight of 1012 ± 133 g were divided randomly into 4 equal groups (T0, T1, T2 and T3) of 9 animals each according to body weight (bw). The rabbits were divided throughout the trial, the animals were fed, those of group T0 (control) with a standard feed without any type of leaf powder, while those of groups 1, 2 and 3 received the standard feed supplemented with Mangifera indica, Persea americana and Psidium guajava leaves powder at the rate of 0.5% respectively. After two months of treatment, the animals were fasted for 12 hours (20 h - 8 h) and sacrificed to evaluate carcass and digestive organ weights. The results revealed that the values of feed intake, live weight and weight gain were non-significantly (p > 0.05) increased in all animals regardless of the ration in reference to the control. The different leaves powder induced an increase in carcass yield in rabbits but this increase was only significant (p M. indica leaf powder (51.03 ± 0.24) as compared to the control (48.63 ± 0.74). Gut length was significantly increased in animals fed rations containing Psidium guajava and Persea americana leaves powder compared to the control. A significant increase in gut weight was observed in animals fed the Persea americana leaf supplemented ration. In general, mango leaf powder performed better than other types of powders.

Effects of Different Exogenous Substances on Seed Germination of Isatis indigotica Under Drought Stress and Chemical Composition of Isatis indigotica leaves

This study was to investigate the effects of three exogenous substances on chemical constituents of Isatis indigotica leavesand their efficacy in alleviating drought stress, and explore the methods of applying exogenous substances to efficient cultivationof Isatis indigotica. Polyethylene glycol (PEG) was used to simulate drought stress to deal with seeds of Isatis indigotica at thegermination stage (concentration: 0, 10%, 15%, and 20%). Simultaneous operation of exogenous growth regulators [microbialinoculum (MI), γ-aminobutyric acid (GABA) and salicylic acid (SA)] and PEG were implemented in seeds of Isatis indigotica.The effects of drought stress and the mitigation of exogenous substances were observed by statistics of seed germination potential,germination rate, hypocotyl length, and radicle length of each treatment. The effects of exogenous substances on the content ofalkaloids, crude protein and free amino acids in the leaves of Isatis indigotica grown in a greenhouse were determined after sprayingexogenous substances on the plants. The differences of germination potential, germination rate, hypocotyl length, and radicle lengthamong 15% PEG stress treatment, 10% PEG stress treatment and the control were significant (P<0.05). According to the predesignedgermination standard, the seeds did not germinate under 20% PEG stress treatment. When the PEG concentration was 15%, the resultsof seed germination potential and germination rate after adding MI were significantly different from those under stress alone (P<0.05).When exposed to 10% PEG stress, the supplementation of GABA led to a notable increase in radicle length of Isatis indigotica seeds,showing significant differences compared to other three treatments. The application of MI and GABA under 15% PEG stress resultedin a significant increase in the radicle and hypocotyl length of Isatis indigotica seeds compared to other two treatments. The contentof the total alkaloids in leaves of Isatis indigotica was significantly increased after spraying GABA. Meanwhile, the contents of crudeprotein and the total free amino acids were kept constant after spraying exogenous substances. Application of MI and GABA couldalleviate drought stress of Isatis indigotica. The content of the total alkaloids in leaves of Isatis indigotica could significantly increaseafter spraying GABA.

Processing Effects on Selected Antioxidant Activities and Metabolizing Enzyme Inhibition of M. Koneigii (Curry Leaves) Extracts

Curry leaves, scientifically termed Murraya koenigii, are renowned in South Asian cuisine for their flavor enhancement and potential health benefits, including antioxidative, anti-inflammatory, and antidiabetic properties. This study aimed to evaluate the impact of thermal processing methods on curry leaves by analysing Total Phenolic Content (TPC), Total Flavonoid Content (TFC), antioxidant activity, and metabolizing enzyme inhibition. Fresh curry leaves were subjected to thermal treatments: Oven-dried at 60˚C and Air-dried at 25˚C for 2 weeks. Extracts were prepared using Ethanol and water solvents. Results indicated that Air-dried leaves exhibited significantly higher TPC (5132.65 mg GAE/100 g) and TFC (243.13 mg CE/100 g) compared to Fresh and Oven-dried leaves. Antioxidant assays show that oven-dried curry leaves at 60˚C displayed higher results in NORS, FRAP, and TEAC assays compared to Fresh and Air-dried leaves. Ethanol extracts showed better extraction of bioactive compounds than aqueous extracts. Moreover, Lipase inhibition activity was notably high, indicating potential health benefits. This study provides valuable insights into the effects of processing methods on curry leaf extracts, emphasizing the importance of solvent selection for optimal extraction of bioactive compounds.

Effects of Carrot (Daucus carota) Leaves Powder on Reproductive and Growth Characteristics of Rabbit (Oryctolagus cuniculus) Does

The present study was conducted to evaluate the effects of carrot leaf powder in the diet on reproductive and growth characteristics in rabbits. Thirty sexually matured rabbits does of 8 months old, 3.00 to 3.20 kg, were divided into three groups of 10 rabbits each, which were comparable in terms of body weight. Throughout the experiment, the rabbits of group 1 (control group) were fed ad libitum with a feed not containing carrot leaf powder (control ration), while those of groups 2 and 3 received the control ration supplemented with carrot leaf powder in concentrations of 0.5% and 1% respectively. Data was collected on feed intake, weight gain, receptivity, fertility, gestation length of does, litter size, weight, viability and sex ratio of the young rabbits till 5 weeks post-partum. There was no significant (P > 0.05) difference in the fertility rate, gestation duration and sex ratio of the kits with reference to the control. Litter size at birth was not significantly (P > 0.05) influenced in does fed diets containing carrot leaf powder compared to the control. However, the reversed effects were observed at five weeks post-partum. The live weight of weaned kits and weight gain of rabbit does at birth were significantly (P < 0.05) increased in treated rabbits compared to the control. The supplementation of carrot leaf powder in feed can improve production performance in female rabbits, through their antioxidant activities thanks to their various components, thus fighting against oxidative stress effects to which animals are exposed both from endogenous and environmental sources.

The Protective Effects of Flavonoids from Scutellaria Baicalensis Georgi Stems and Leaves on Oligodendrocyte Damage Induced by Aβ1-42

Aim: This study aimed to investigate the protective effects of flavonoids from the stem and leaves of Scutellaria baicalensis Georgi (SSFs) against Aβ1-42-induced oligodendrocytes (OL) damage. Methods: Immunofluorescence was used for the detection of myelin-associated glycoprotein (MAG), a characteristic protein of rat oligodendrocytes (OLN-93 cells). To evaluate the potential protective effects of SSFs on OLN-93 cells injured by Aβ1-42, an injury model was established by subjecting OLN-93 cells to Aβ1-42 exposed. Cell morphology was examined using an inverted microscope, while cell viability was assessed using the colorimetric method of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Additionally, lactate dehydrogenase (LDH) was measured using the pyruvic acid reduction assay. The Ginkgo biloba leaf extract (GBE) injection was used as a positive control. Results: A total of >95% of the MAG immunofluorescence-positive cells were identified as oligodendrocytes. Gradually increasing concentrations of SSFs impaired the cells, and the maximum nondetrimental dose for OLN-93 cells was 75 mg/L. This study assessed the effects of SSFs on OLN-93 cells damaged by Aβ1-42. The results indicated that SSFs significantly improved OLN-93 cell morphological abnormal changes, increased the OLN-93 cell survival rate, and reduced LDH release. Conclusion: SSFs can alleviate Aβ1-42-induced damage of OL.

Physicochemical Characterisation of Flours from Local Cereals and Powder from Cassava (Manihot esculenta Crantz) Leaves Varieties Cultivated in the Northern-Cameroon in Order to Supplement Infant Flours

The aim of the present study was to investigate on the inventory and determination of the nutritional value of cereals flour and cassava leaves powder in order to analyse their use in the production of infant flour. In this paper, a A survey to identify the cereals used in the preparation of infant porridge in the Northern Cameroon was done by using 447 mothers having children between 06 and 59 months from areas (Gbakoungue, Sassa-Mbersi, Sanguere-Ngal and Kotkong-Wouldata) with high rate on malnourished children. Flour was prepared from the most preponderant cereals and Cassava leaves powder from varieties identified by the Regional Centre of Agricultural Research (CRRA) of Wakwa and local population. Flour and powder samples obtained were subjected to chemical composition analysis. Parameters analysed were crude proteins, total carbohydrates, ash, total fats, total phenols, total tannins, total carotenoids, vitamin C or cyanide. Also Iron, calcium and zinc were determined. The results revealed that white maize (62%) was the main cereal used in the preparation of infant porridge followed respectively by red sorghum, white rice and muskwari. Ten cassava varieties were identified: three (03) by CRRA (TME, 96/1/14 and IRAD 4115) and seven (south, gambada, sweet, Benin, six months, M. glaziovii and grouna) by local population. Amongst cereals flour, those from white maize indicated high protein (10.09%), carbohydrates (84.46%) and total fat (7.46%) contents. The powder from 96/14/14 cassava variety showed high amount of iron (11.98 mg/100g), calcium (751.02 g/100g) and low cyanide content (1.21 ppm) amongst all the cassava leaves powder samples. The supplementation of white maize flour by cassava leaves powder from 96/14/14 variety could therefore be recommended for the preparation of infant flours.

Hypoglycemic Effect of Forsythia suspensa Leaves on Diabetic Mice

[Objective] This study aimed to investigate the hypoglycemic effect of Forsythia suspensa leaves in diabetic mice. [Method] The model of hyperglycemia mice were obtained by injecting streptozotocin intraperitoneally to study the effect of F. suspensa leaves on lowering blood sugar of hyperglycemia mice and normal ani- mals. [Result] F. suspensa leaves could antagonize the streptozotocin-reducing mice hyperglycemia and significantly reduce the fasting blood glucose level of diabetic mice. [Coaclusion] F. suspensa leaves exhibits a good therapeutic effect on diabetic mice and has a good development prospect.

Extracting Feature Bands for Damaged Rice Leaves by Planthoppers Using Multi-spectral Imaging Technology

[Objective] The aim of this study was to extract effective feature bands of damaged rice leaves by planthoppers to make identification and classification rapidly from great amounts of imaging spectral data. [Method] The experiment, using multi-spectral imaging system, acquired the multi-spectral images of damaged rice leaves from band 400 to 720 nm by interval of 5 nm. [Result] According to the principle of band index, it was calculated that the bands at 515, 510, 710, 555, 630, 535, 505, 530 and 595 nm were having high band index value with rich information and little correlation. Furthermore, the experiment used two classification methods and calcu-lated the classification accuracy higher than 90.00% for feature bands and ful bands of damaged rice leaves by planthoppers respectively. [Conclusion] It can be con-cluded that these bands can be considered as effective feature bands to identify damaged rice leaves by planthoppers quickly from a large scale of crops.

Viewing Asking for Leave from a Cultural Perspective

This thesis aims at investigating what the discourse patterns are in the asking-for-leave notes written by Chinese students and native English speakers respectively and what excuses are given by Chinese students and native English speakers.Role play and retrospective interview were employed as research methords.The results show that the Chinese students all use an inductive pattern,while all native English speakers write the note in a deductive way.Besides,the excuses presented by the two kinds of subjects are different due to their different cultural background.

Effect of dietary supplementation with mulberry(Morus alba L.) leaves on the growth performance,meat quality and antioxidative capacity of finishing pigs

The present study was conducted to evaluate the effect of dietary mulberry(Morus alba L.) leaves powder(MLP) supplementation on meat quality of finishing pigs.A total of 40 Duroc×Landrace×Yorkshire pigs(initial body weight of(40.5±0.63) kg) were randomly allotted into two treatments,fed either with control diet or 15% MLP diet for 85 d.The results showed that MLP diet decreased(P≤0.05) average daily gain(ADG) and increased(P<0.05) feed/gain ratio(F/G) in the finishing and whole period.MLP diet also decreased(P<0.05) carcass weight,dressing percentage,last rib and average backfat depth.However,MLP diet increased(P<0.05) intramuscular fat(IMF) content,decreased(P<0.05) shear force,cooking loss and drip loss.In addition,MLP diet increased(P<0.05) total antioxidative capacity,glutathione peroxidase and tended(P<0.10) to increase total superoxide dismutase in serum.In longissimus thoracis,myosin heavy chain(MyHC) I and IIa mRNA levels were increased(P≤0.05) for MLP diet.In conclusion,15% MLP supplementation reduced the growth performance and carcass traits,but improved meat quality of finishing pigs possibly through the change of myofiber characteristics,enhancement of antioxidative capacity and increase of IMF.

Automatic image segmentation method for cotton leaves with disease under natural environment

In order to improve the image segmentation performance of cotton leaves in natural environment, an automatic segmentation model of diseased leaf with active gradient and local information is proposed. Firstly, a segmented monotone decreasing edge composite function is proposed to accelerate the evolution of the level set curve in the gradient smooth region. Secondly, canny edge detection operator gradient is introduced into the model as the global information. In the process of the evolution of the level set function, the guidance information of the energy function is used to guide the curve evolution according to the local information of the image, and the smooth contour curve is obtained. And the main direction of the evolution of the level set curve is controlled according to the global gradient information, which effectively overcomes the local minima in the process of the evolution of the level set function. Finally, the Heaviside function is introduced into the energy function to smooth the contours of the motion and to increase the penalty function Φ(x) to calibrate the deviation of the level set function so that the level set is smooth and closed. The results showed that the model of cotton leaf edge profile curve could be obtained in the model of cotton leaf covered by bare soil, straw mulching and plastic film mulching, and the ideal edge of the ROI could be realized when the light was not uniform. In the complex background, the model can segment the leaves of the cotton with uneven illumination, shadow and weed background, and it is better to realize the ideal extraction of the edge of the blade. Compared with the Geodesic Active Contour(GAC) algorithm, Chan-Vese(C-V) algorithm and Local Binary Fitting(LBF) algorithm, it is found that the model has the advantages of segmentation accuracy and running time when processing seven kinds of cotton disease leaves images, including uneven lighting, leaf disease spot blur, adhesive diseased leaf, shadow, complex background, unclear diseased leaf edges, and staggered condition. This model can not only conduct image segmentation of cotton leaves under natural conditions, but also provide technical support for the accurate identification and diagnosis of cotton diseases.

In situ hyperspectral data analysis for pigment content estimation of rice leaves

Analyses of the correlation between hyperspectral reflectance and pigment content including chlorophyll a, chlorophyll b and carotenoid of leaves in different sites of rice were reported in this paper. The hyperspectral reflectance of late rice during the whole growing season was measured using a Spectroradiometer with spectral range of 350-1050 nm and resolution of 3 nm. The chlorophyll a, chlorophyll b and carotenoid contents in rice leaves in rice fields to which different levels of nitrogen were applied were measured. The chlorophyll a content of upper leaves was well correlated with the spectral variables. However, the correlation between both chlorophyll b and caroteniod and the spectral variables was far from that of chlorophyll a. The potential of hyperspectral reflectance measurement for estimating chlorophyll a of upper leaves was evaluated using univariate correlation and multivariate regression analysis methods with different types of predictors. This study showed that the most suitable estimated model of chlorophyll a of upper leaves was obtained by using some hyperspectral variables such as SD r, SD b and their integration.

Synthesis of activated carbon from spent tea leaves for aspirin removal

Adsorption capacity of activated carbon prepared from spent tea leaves （STL-AC） for the removal of aspirin from aqueous solution was investigated in this study. Preliminary studies have shown that treatment with phosphoric acid （H3PO4） increased removal efficiency of STL-AC. Characterizations on STL-AC revealed excellent textural properties （1200 m2.g-1, 51% mesoporosity）, as well as distinctive surface chemistry （1.08 mmol.g-1 and 0.54 mmol.g-1 for acidic and basic oxygenated groups, pHpzc = 2.02）. Maximum removal efficiency of aspirin observed was 94.28% after 60 rain when the initial concentration was 100 mg.L-1, 0.5 g of adsorbent used, pH 3 and at a temperature of 30 ℃. The adsorption data were well fitted to the Freundlich isotherm model and obeyed the pseudo-second order kinetics model. The adsorption of aspirin onto STL-AC was exothermic in nature （△H = - 13.808 kJ.mol-1） and had a negative entropy change, △S （-41.444 J.mol-1）. A negative Gibbs free energy, △G was obtained indicating feasibility and spontaneity of the adsorption process. The adsorp- tion capacity of △C-STL （178.57 mg.g-1） is considerably high compared to most adsorbents synthesized from various sources, due to the well-defined textural properties coupled with surface chemistry of STL-AC which fa- vors aspirin adsorption. The results demonstrate the potential of STL-AC as aspirin adsorbent.