[Objectives] The study aims to improve the ability of inspectors to recognize humoral morphology and provide data reference for the improvement of EQA work of humoral morphology by Guangxi Clinical Laboratory Center. ...[Objectives] The study aims to improve the ability of inspectors to recognize humoral morphology and provide data reference for the improvement of EQA work of humoral morphology by Guangxi Clinical Laboratory Center. [Methods] A retrospective analysis was made on the EQA of humoral morphology by Guangxi Clinical Laboratory Center from 2010 to 2022, and the number of participating laboratories, the rate of return, sample types and maps of EQA of humoral morphology such as urine sediment, vaginal secretions and so on(except feces), and the reasons for the high error rate of the results of the participating laboratories were analyzed. [Results] The number of laboratories participating in the assessment of humoral morphology increased from 98 in 2010 to 371 in 2022. Except for 2011(90.98%), the rate of return was more than 94%, and the highest rate of return was up to 100%. A total of 119 pictures of EQA of humoral morphology were studied, including 101 urine sediment smears, 13 vaginal secretions smears and 5 other smears. The types of specimens were relatively comprehensive. The distribution of the maps was basically reasonable. The urinary sediment was mainly composed of crystalline salts, followed by tubes, and cells and fungi ranked third. The coverage was relatively complete. The error rate of return results from high to low were bacteria(error rate was equal to 40%), tubes and crystalline salts(error rate was close to 29%), and cells and fungi(error rate was about 14%). The main cases with high error rate of return results are as follows: the difference between different tubes was not clear, and the diversity of crystal morphology was not understood enough;the phase division of cells in the same system was wrong. [Conclusions] The analysis and summary of the reasons for the high error rate of the data and results of Guangxi's EQA of humoral morphology is helpful for laboratory physicians to improve their awareness of morphological examination and identify clearly the error type and blurred concept, and lays a foundation for Guangxi Clinical Laboratory Center to carry out EQA of humoral morphology more specifically.展开更多
Allium is a complicated genus that includes approximately 1000 species.Although its morphology is well studied,the taxonomic importance of many morphological traits,including floral traits,are poorly understood.Here,w...Allium is a complicated genus that includes approximately 1000 species.Although its morphology is well studied,the taxonomic importance of many morphological traits,including floral traits,are poorly understood.Here,we examined and measured the floral characteristics of 87 accessions of 74 Allium taxa(belonging to 30 sections and nine subgenera)from Central to Eastern Asian countries.We then examined the taxonomic relationships between select flower characteristics and a phylogenetic tree based on ITS sequences.Our results confirm that floral morphology provides key taxonomic information to assess species delimitation in Allium.We found that perianth color is an important characteristic within the subg.Melanocrommyum,Polyprason,and Reticulatobulbosa.In subg.Allium,Cepa,and Rhizirideum,significant characteristics include ovary shape,perianth shape,and inner tepal apex.For species in subg.Angunium,the key taxonomic character is ovule number(only one ovule in per locule).In the subg.Allium,Cepa,Polyprason,and Reticulatobulbosa,which belong to the third evolutionary line of Allium,hood-like appendages occur in the ovary,although these do not occur in subg.Rhizirideum.Our results also indicated that the flower morphology of several species in some sections are not clearly distinguished,e.g.,sect.Sacculiferum(subg.Cepa)and sect.Tenuissima(subg.Rhizirideum).This study provides detailed photographs and descriptions of floral characteristics and information on general distributions,habitats,and phenology of the studied taxa.展开更多
From the environmental consideration,it would be very interesting to use natural fibers such as banana,jute or coir as reinforcement materials instead of artificial fibers or any kind of synthetic materials.Natural fi...From the environmental consideration,it would be very interesting to use natural fibers such as banana,jute or coir as reinforcement materials instead of artificial fibers or any kind of synthetic materials.Natural fibers have many advantages over synthetic ones.Polypropylene banana fiber composites(PPBC)are prepared using untreated and alkali-treated banana fibers at 10-25%by weight of the fiber loading.The thermal properties of polypropylene natural fiber composites are very important for technological uses.Thermogravimetric measurements show that the incorporation of banana fiber into PP enhances the thermal stability of composites containing treated fibers,in comparison with untreated fibers.A composite of biodegradable polypropylene(PP)reinforced with short banana natural fibers was prepared by melt blending followed by a hot press molding system.The thermal properties of matrix materials were studied using thermogravimetric analyzers TGA units.It is observed that the introduction of short banana fibers slightly improved the thermo oxidative stability of PP-banana composites.Physical and chemical changes occurred through dehydration,phase transition,molecular orientation,crystallinity disruption,oxidation and decomposition,and incorporation of several functional groups.Systematic investigations of the thermal behavior of polymers in gas,vacuum or inert atmosphere give the knowledge of how change takes place in polymers.To understand such changes thermogravimetric analysis(TGA)and thermal analysis(TG)were performed.It is observed reinforcement of short banana fiber leads to little improvement in the thermooxidative stability of PPBC.Due to the enhancement of thermo-mechanical properties,such composites may be used as building materials namely roof materials,selling materials and many other engineering applications.展开更多
Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers ar...Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers are renowned for their good mechanical properties,abundance,and short cycle growth.As beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic foundation.Three different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the thickness.The elastic properties of the composite are determined with the law of mixture.Employing Hamilton’s principle,the governing equations of motion are obtained.The generalized differential quadrature method(GDQM)is then applied to the equations to obtain the results.The achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam change.Furthermore,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber distribution.Eventually,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.展开更多
The particle morphology and surface texture play a major role in influencing mechanical and hydraulic behaviors of sandy soils. This paper presents the use of digital image analysis combined with fractal theory as a t...The particle morphology and surface texture play a major role in influencing mechanical and hydraulic behaviors of sandy soils. This paper presents the use of digital image analysis combined with fractal theory as a tool to quantify the particle morphology and surface texture of two types of quartz sands widely used in the region of Vitória, Espírito Santo, southeast of Brazil. The two investigated sands are sampled from different locations. The purpose of this paper is to present a simple, straightforward,reliable and reproducible methodology that can identify representative sandy soil texture parameters.The test results of the soil samples of the two sands separated by sieving into six size fractions are presented and discussed. The main advantages of the adopted methodology are its simplicity, reliability of the results, and relatively low cost. The results show that sands from the coastal spit(BS) have a greater degree of roundness and a smoother surface texture than river sands(RS). The values obtained in the test are statistically analyzed, and again it is confirmed that the BS sand has a slightly greater degree of sphericity than that of the RS sand. Moreover, the RS sand with rough surface texture has larger specific surface area values than the similar BS sand, which agree with the obtained roughness fractal dimensions. The consistent experimental results demonstrate that image analysis combined with fractal theory is an accurate and efficient method to quantify the differences in particle morphology and surface texture of quartz sands.展开更多
Machining damage occurs on the surface of carbon fiber reinforced polymer (CFRP) composites during processing. In the current simulation model of CFRP, the initial defects on the carbon fiber and the periodic random d...Machining damage occurs on the surface of carbon fiber reinforced polymer (CFRP) composites during processing. In the current simulation model of CFRP, the initial defects on the carbon fiber and the periodic random distribution of the reinforcement phase in the matrix are not considered in detail, which makes the characteristics of the cutting model significantly different from the actual processing conditions. In this paper, a novel three-phase model of carbon fiber/cyanate ester composites is proposed to simulate the machining damage of the composites. The periodic random distribution of the carbon fiber reinforced phase in the matrix was realized using a double perturbation algorithm. To achieve the stochastic distribution of the strength of a single carbon fiber, a novel method that combines the Weibull intensity distribution theory with the Monte Carlo method is presented. The mechanical properties of the cyanate matrix were characterized by fitting the stress-strain curves, and the cohesive zone model was employed to simulate the interface. Based on the model, the machining damage mechanism of the composites was revealed using finite element simulations and by conducting a theoretical analysis. Furthermore, the milling surfaces of the composites were observed using a scanning electron microscope, to verify the accuracy of the simulation results. In this study, the simulations and theoretical analysis of the carbon fiber/cyanate ester composite processing were carried out based on a novel three-phase model, which revealed the material failure and machining damage mechanism more accurately.展开更多
Natural fiber composites have been proved to have the ability to replace the synthetic fiber composites in many structural applications. Unprecedented growth in the field of computational techniques has opened the doo...Natural fiber composites have been proved to have the ability to replace the synthetic fiber composites in many structural applications. Unprecedented growth in the field of computational techniques has opened the doors of analysis and simulation of composite materials under various environment.Modelling and simulation using various available softwares saves a lot of time and resources. In the present work, an attempt has been made to analyze the tensile behavior of jute fiber reinforced epoxy based polymer composite materials using the student version of commercially available finite element code Siemens PLM NX 10.0. In most of the structural applications, materials are required to have enough stiffness to resist the shape deformation under normal loading conditions. Therefore, emphasis is given to the load-deformation behavior of the developed composites. A 3-dimensional model of the test specimen was developed using ply-stacking method and the strain-stress values were verified by the available literature. The model showed a good agreement between the experimental and software results. Effect of ply angle, fiber percentage, fiber type, number of layers and weft fiber angle on the stiffness of laminate have been studied.展开更多
A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter ...A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter steel tube.Twenty-four standard samples and a polynomial fitting method were used to establish calibration curve models.The R^2 factors of the calibration curves were all above 0.99,except for Cu,indicating the elements’ strong self-absorption effect.Five special steel materials were rapidly detected in the steel mill.The average absolute errors of Mn,Cr,Ni,V,Cu,and Mo in the special steel materials were 0.039,0.440,0.033,0.057,0.003,and0.07 wt%,respectively,and their average relative errors fluctuated from 2.9% to 15.7%.The results demonstrated that the performance of this mobile FO-LIBS prototype can be compared with that of most conventional LIBS systems,but the more robust and flexible characteristics of the FO-LIBS prototype provide a feasible approach for promoting LIBS from the laboratory to the industry.展开更多
AIM:To investigate the difference of retinal nerve fiber layer(RNFL) thickness between Alzheimer's disease patients and normal people,so as to provide clue for the early diagnosis of Alzheimer's disease.·...AIM:To investigate the difference of retinal nerve fiber layer(RNFL) thickness between Alzheimer's disease patients and normal people,so as to provide clue for the early diagnosis of Alzheimer's disease.· METHODS:The articles on the association of RNFL thickness and Alzheimer's disease were retrieved by searching international and national databases.The qualified articles were assessed by meta analysis with Stata11.0 software.The results were pooled using weighted mean difference(WMD) with a corresponding 95% confidence interval(CI).· RESULTS:Totally 7 studies enrolled 324 eyes were included in the meta-analysis.The results of meta analysis showed that in AD patients,there was a significant average RNFL thickness reduction compared with the control group [WMD=-17.561,95%CI:(-23.971,-11.151)].There were significant differences in superior,inferior,nasal and temporal RNFL thickness between the two groups.WMD with a 95%CI were [-18.829,95%CI:(-25.915,-11.743);P<0.05],[-25.775,95%CI:(-34.304,-17.247);P <0.05],[-16.877,95%CI:(-29.141,-4.613);P<0.001] and [-14.565,95%CI:(-28.002,-1.128);P<0.001] respectively.Begg's test and Egger's test did not show significant difference,funnel plot was basically symmetrical,indicating that there was no publication bias existed.· CONCLUSION:There are significant differences in the RNFL thickness in all quadrants between the two groups.RNFL thickness is reduced in AD patients compared with the control group.展开更多
One of the most successful techniques in planting trees is tree improvement in which trees with high qualities are selected for mass plantation. This study seeks to identify good properties of Eucalyptus camaldulensis...One of the most successful techniques in planting trees is tree improvement in which trees with high qualities are selected for mass plantation. This study seeks to identify good properties of Eucalyptus camaldulensis through selective phases. Sixty Eucalyptus camaldulensis trees (30 ten-year-old and 30 five-year-old) were randomly selected through stratified sampling from two plantation sites in Kurdistan region, North of Iraq. The trees were examined for fiber morphology and quality parameters such as height, number of branches, diameter and straightness. In the first phase of property selection, sixteen trees with high rank in growth properties and fiber morphology were selected. In the final phase of selection, the selected trees were re-examined according to the number of properties and fiber morphology features and seven trees with the highest number of good parameters were chosen. The 7 selected trees had higher qualities in growth characteristics and fiber morphology compared with the other trees in the sample. This article reports on a selection method for E. camaldulensis trees through tree improvement techniques. The results of the study indicates that high genotype qualities were identified among both 5- and 10-year-old E. camaldulensis trees as the final selection consisted of three 5-year-old trees and four 10-year-old trees.展开更多
Background:Nitrogen(N)is important for improving various morphological and physiological processes of cotton but their contribution to fiber quality is still lacking.Aims:The current study aimed to explore the relatio...Background:Nitrogen(N)is important for improving various morphological and physiological processes of cotton but their contribution to fiber quality is still lacking.Aims:The current study aimed to explore the relationship between root morphology,subtending leaf physiology,and fiber quality of contrasting N-efficient cotton genotypes in response to N.Methods:We analyzed the above parameters of CCRI 69(N-efficient)and Xinluzao-30(XLZ-30,N-inefficient)under control(2.5 mmol·L^(-1))and high N(5 mmol·L^(-1))conditions.Results:The results showed that root morphological traits were increased in CCRI-69 under control conditions than high N.Subtending leaf morphology,chlorophyll and carotenoid contents,free amino acids,and soluble proteins were higher under high N as compared with the control.However,soluble sugars,fructose,sucrose contents,and sucrose phosphate synthase were higher under control conditions than high N across the growth stages.Irrespective of the N conditions,all morphological and physiological traits of cotton subtending leaf were higher in CCRI-69 than XLZ-30.Except for fiber uniformity,fiber quality traits like fiber length,strength,micronaire,and elongation were improved under control conditions than high N.Between the genotypes,CCRI-69 had significantly higher fiber length,strength,micronaire,and elongation as compared with XLZ-30.Strong positive correlations were found between root morphology,soluble sugars,sucrose content,and sucrose phosphate synthase activity with fiber quality traits,respectively.Conclusions:These findings suggest that CCRI-69 performed better in terms of growth and fiber quality under relatively low N condition,which will help to reduce fertilizer use,the cost of production,and environmental pollution.展开更多
Composite felts reinforced by both SiC nano-fibers(SiC-NFs)and carbon fibers were prepared at 1 273 K using Ni granules as catalyzers with different deposition time.SiC-NFs were deposited on the surface of the carbon ...Composite felts reinforced by both SiC nano-fibers(SiC-NFs)and carbon fibers were prepared at 1 273 K using Ni granules as catalyzers with different deposition time.SiC-NFs were deposited on the surface of the carbon fibers in situ by catalytic chemical vapor deposition(CCVD).The phase,microstructure and morphology of the fibers after electroplating and deposition were characterized by XRD,SEM and TEM.The results show that the SiC-NFs produced by CCVD are composed of single crystal of β-SiC.It is found that smaller nano-granules are more active as catalyzers.The resulting SiC-NFs appear more spindle-like and have a more homogeneous dispersion.The mass change of the samples before and after deposition shows that using more Ni granules results in a faster growth velocity of SiC-NFs.With the same electroplating time,the growth velocity of the SiC-NFs first increases and then decreases.At around 4 h,it reaches the maximum growth velocity,and it becomes nearly constant at around 8 h.After 8 h, the stable growth velocity of the electroplated Ni samples is faster than that of the conventional sample produced without catalyzers, because the SiC-NFs can improve the specific surface area and the activity of the surface.展开更多
Sagittal otoliths morphology were compared to identify five Pampus species of the Chinese coast(Chinese pomfret Pampus chinensis, grey pomfret P. cinereus, southern lesser pomfret P. minor, plumage pomfret P.punctatis...Sagittal otoliths morphology were compared to identify five Pampus species of the Chinese coast(Chinese pomfret Pampus chinensis, grey pomfret P. cinereus, southern lesser pomfret P. minor, plumage pomfret P.punctatissmus, and Pampus sp.). Otoliths demonstrated species-specific characteristics with noticeable differences in overall shape, margin and anterior region among species. With species divergence, otoliths get thinner following further developed rostrum and anti-rostrum. Interspecies variation in otolith could associate with experienced different temperature and water column. The discriminant analysis presented a high classification accuracy of 96.6%, which confirms the inter-specific distinction of otolith shape and enable the species identification.展开更多
AIM:To investigate the effect of dietary fiber intake on constipation by a meta-analysis of randomized controlled trials(RCTs).METHODS:We searched Ovid MEDLINE(from 1946 to October 2011),Cochrane Library(2011),PubMed ...AIM:To investigate the effect of dietary fiber intake on constipation by a meta-analysis of randomized controlled trials(RCTs).METHODS:We searched Ovid MEDLINE(from 1946 to October 2011),Cochrane Library(2011),PubMed for articles on dietary fiber intake and constipation using the terms:constipation,fiber,cellulose,plant extracts,cereals,bran,psyllium,or plantago.References of important articles were searched manually for relevant studies.Articles were eligible for the meta-analysis if they were high-quality RCTs and reported data on stool frequency,stool consistency,treatment success,laxative use and gastrointestinal symptoms.The data were extracted independently by two researchers(Yang J and Wang HP) according to the described selection criteria.Review manager version 5 software was used for analysis and test.Weighted mean difference with 95%CI was used for quantitative data,odds ratio(OR)with 95%CI was used for dichotomous data.Both I2 statistic with a cut-off of ≥ 50% and the χ2 test with a P value < 0.10 were used to define a significant degree of heterogeneity.RESULTS:We searched 1322 potential relevant articles,19 of which were retrieved for further assessment,14 studies were excluded for various reasons,five studies were included in the analysis.Dietary fiber showed significant advantage over placebo in stool frequency(OR = 1.19;95%CI:0.58-1.80,P < 0.05).There was no significant difference in stool consistency,treatment success,laxative use and painful defecation between the two groups.Stool frequency were reported by five RCTs,all results showed either a trend or a significant difference in favor of the treatment group,number of stools per week increased in treatment group than in placebo group(OR = 1.19;95%CI:0.58-1.80,P < 0.05),with no significant heterogeneity among studies(I2= 0,P = 0.77).Four studies evaluated stool consistency,one of them presented outcome in terms of percentage of hard stool,which was different from others,so we included the other three studies for analysis.Two studies reported treatment success.There was significant heterogeneity between the studies(P < 0.1,I2 > 50%).Three studies reported laxative use,quantitative data was shown in one study,and the pooled analysis of the other two studies showed no significant difference between treatment and placebo groups in laxative use(OR = 1.07;95%CI 0.51-2.25),and no heterogeneity was found(P = 0.84,I2= 0).Three studies evaluated painful defecation:one study presented both quantitative and dichotomous data,the other two studies reported quantitative and dichotomous data separately.We used dichotomous data for analysis.CONCLUSION:Dietary fiber intake can obviously increase stool frequency in patients with constipation.It does not obviously improve stool consistency,treatment success,laxative use and painful defecation.展开更多
AIM: To evaluate the effects of dietary fiber (DF) as a part of enteral nutrition (EN) formula on diarrhea, infection, and length of hospital stay. METHODS: Following electronic databases were searched for randomized ...AIM: To evaluate the effects of dietary fiber (DF) as a part of enteral nutrition (EN) formula on diarrhea, infection, and length of hospital stay. METHODS: Following electronic databases were searched for randomized controlled trials about DF: Chinese Biomedicine Database (CBM), MEDLINE, EMBASE and Coohrane Controlled Trials Register. RevMan 4.1 was used for statistical analysis. RESULTS: Seven randomized controlled trials with 400 pat-ients were included. The supplement of DF in EN was compared with standard enteral formula in five trials. Combined analysis did not show a significant reduction in occurrence of diarrhea, but there were valuable results for non-critically ill patients. Combined analysis of two trials observing the infection also did not show any valid evidence that DF could decrease the infection rate, though the length of hospital stay was reduced significantly. CONCLUSION: Based on the current eligible randomized controlled trials, there is no evidence that the value of DF in the diarrhea can be proved. Though length of hospital stay was shortened by the use of DF, there is no available evidence in preventing infection by DF. Further studies are needed for evaluating the value of DF in EN.展开更多
A comparative proteomic analysis was performed to explore the mechanism of cell elongation in developing cotton fibers.The temporal changes of global proteomes at five representative
The morphology of polyvinyl chloride/polystyrene (PVC/PS) blend samples with different mass ratios, preparedby means of solution casting and melt mixing, have been successfully examined by electron microprobe analysis...The morphology of polyvinyl chloride/polystyrene (PVC/PS) blend samples with different mass ratios, preparedby means of solution casting and melt mixing, have been successfully examined by electron microprobe analysis (EMP). Thisexperiment was performed in a scanning electron microscope attached to an energy dispersive X-ray analyzer. Differentialscanning calorimetry was also used to investigate the phase separation of the blends. The results show that PVC and PS areincompatible and the blends have sea-islands phase structures. Blends prepared via melt mixing have finer phase-dispersionthan those prepared via solution casting.展开更多
The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 ye...The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 years for example, the fiber length at breast high grows faster than it does in the later years. But the standard deviation of distribution in fiber length at breast high in mature wood is larger than in the young tree. The technologically harvestable age of triploid clone of Populus tomentosa Carr., BL304 could be 4-7 year old to meet the requirement for paper industry. The distribution of fiber length become concentrated within an annual ring as the tree grows. The test results also show that the cloned poplar has a small Runkel ratio value (less than 0.4, generally about 0.3), and this ratio increases slightly with the tree grows.展开更多
基金Supported by the Scientific Research Project of Guangxi Health Commission (Z2014221)。
文摘[Objectives] The study aims to improve the ability of inspectors to recognize humoral morphology and provide data reference for the improvement of EQA work of humoral morphology by Guangxi Clinical Laboratory Center. [Methods] A retrospective analysis was made on the EQA of humoral morphology by Guangxi Clinical Laboratory Center from 2010 to 2022, and the number of participating laboratories, the rate of return, sample types and maps of EQA of humoral morphology such as urine sediment, vaginal secretions and so on(except feces), and the reasons for the high error rate of the results of the participating laboratories were analyzed. [Results] The number of laboratories participating in the assessment of humoral morphology increased from 98 in 2010 to 371 in 2022. Except for 2011(90.98%), the rate of return was more than 94%, and the highest rate of return was up to 100%. A total of 119 pictures of EQA of humoral morphology were studied, including 101 urine sediment smears, 13 vaginal secretions smears and 5 other smears. The types of specimens were relatively comprehensive. The distribution of the maps was basically reasonable. The urinary sediment was mainly composed of crystalline salts, followed by tubes, and cells and fungi ranked third. The coverage was relatively complete. The error rate of return results from high to low were bacteria(error rate was equal to 40%), tubes and crystalline salts(error rate was close to 29%), and cells and fungi(error rate was about 14%). The main cases with high error rate of return results are as follows: the difference between different tubes was not clear, and the diversity of crystal morphology was not understood enough;the phase division of cells in the same system was wrong. [Conclusions] The analysis and summary of the reasons for the high error rate of the data and results of Guangxi's EQA of humoral morphology is helpful for laboratory physicians to improve their awareness of morphological examination and identify clearly the error type and blurred concept, and lays a foundation for Guangxi Clinical Laboratory Center to carry out EQA of humoral morphology more specifically.
基金supported by research grants from the Korea National Arboretum (Grant No. KNA1-1-26, 20-1)the Mid-level professor Financial Program at Changwon National University in 2023
文摘Allium is a complicated genus that includes approximately 1000 species.Although its morphology is well studied,the taxonomic importance of many morphological traits,including floral traits,are poorly understood.Here,we examined and measured the floral characteristics of 87 accessions of 74 Allium taxa(belonging to 30 sections and nine subgenera)from Central to Eastern Asian countries.We then examined the taxonomic relationships between select flower characteristics and a phylogenetic tree based on ITS sequences.Our results confirm that floral morphology provides key taxonomic information to assess species delimitation in Allium.We found that perianth color is an important characteristic within the subg.Melanocrommyum,Polyprason,and Reticulatobulbosa.In subg.Allium,Cepa,and Rhizirideum,significant characteristics include ovary shape,perianth shape,and inner tepal apex.For species in subg.Angunium,the key taxonomic character is ovule number(only one ovule in per locule).In the subg.Allium,Cepa,Polyprason,and Reticulatobulbosa,which belong to the third evolutionary line of Allium,hood-like appendages occur in the ovary,although these do not occur in subg.Rhizirideum.Our results also indicated that the flower morphology of several species in some sections are not clearly distinguished,e.g.,sect.Sacculiferum(subg.Cepa)and sect.Tenuissima(subg.Rhizirideum).This study provides detailed photographs and descriptions of floral characteristics and information on general distributions,habitats,and phenology of the studied taxa.
文摘From the environmental consideration,it would be very interesting to use natural fibers such as banana,jute or coir as reinforcement materials instead of artificial fibers or any kind of synthetic materials.Natural fibers have many advantages over synthetic ones.Polypropylene banana fiber composites(PPBC)are prepared using untreated and alkali-treated banana fibers at 10-25%by weight of the fiber loading.The thermal properties of polypropylene natural fiber composites are very important for technological uses.Thermogravimetric measurements show that the incorporation of banana fiber into PP enhances the thermal stability of composites containing treated fibers,in comparison with untreated fibers.A composite of biodegradable polypropylene(PP)reinforced with short banana natural fibers was prepared by melt blending followed by a hot press molding system.The thermal properties of matrix materials were studied using thermogravimetric analyzers TGA units.It is observed that the introduction of short banana fibers slightly improved the thermo oxidative stability of PP-banana composites.Physical and chemical changes occurred through dehydration,phase transition,molecular orientation,crystallinity disruption,oxidation and decomposition,and incorporation of several functional groups.Systematic investigations of the thermal behavior of polymers in gas,vacuum or inert atmosphere give the knowledge of how change takes place in polymers.To understand such changes thermogravimetric analysis(TGA)and thermal analysis(TG)were performed.It is observed reinforcement of short banana fiber leads to little improvement in the thermooxidative stability of PPBC.Due to the enhancement of thermo-mechanical properties,such composites may be used as building materials namely roof materials,selling materials and many other engineering applications.
文摘Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers are renowned for their good mechanical properties,abundance,and short cycle growth.As beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic foundation.Three different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the thickness.The elastic properties of the composite are determined with the law of mixture.Employing Hamilton’s principle,the governing equations of motion are obtained.The generalized differential quadrature method(GDQM)is then applied to the equations to obtain the results.The achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam change.Furthermore,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber distribution.Eventually,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.
文摘The particle morphology and surface texture play a major role in influencing mechanical and hydraulic behaviors of sandy soils. This paper presents the use of digital image analysis combined with fractal theory as a tool to quantify the particle morphology and surface texture of two types of quartz sands widely used in the region of Vitória, Espírito Santo, southeast of Brazil. The two investigated sands are sampled from different locations. The purpose of this paper is to present a simple, straightforward,reliable and reproducible methodology that can identify representative sandy soil texture parameters.The test results of the soil samples of the two sands separated by sieving into six size fractions are presented and discussed. The main advantages of the adopted methodology are its simplicity, reliability of the results, and relatively low cost. The results show that sands from the coastal spit(BS) have a greater degree of roundness and a smoother surface texture than river sands(RS). The values obtained in the test are statistically analyzed, and again it is confirmed that the BS sand has a slightly greater degree of sphericity than that of the RS sand. Moreover, the RS sand with rough surface texture has larger specific surface area values than the similar BS sand, which agree with the obtained roughness fractal dimensions. The consistent experimental results demonstrate that image analysis combined with fractal theory is an accurate and efficient method to quantify the differences in particle morphology and surface texture of quartz sands.
基金Supported by Research Innovation Fund Project “Research on micro machining mechanism of fiber reinforced composites”(Grant No.HIT.NSRIF.2014055)of Harbin Institute of Technology,China
文摘Machining damage occurs on the surface of carbon fiber reinforced polymer (CFRP) composites during processing. In the current simulation model of CFRP, the initial defects on the carbon fiber and the periodic random distribution of the reinforcement phase in the matrix are not considered in detail, which makes the characteristics of the cutting model significantly different from the actual processing conditions. In this paper, a novel three-phase model of carbon fiber/cyanate ester composites is proposed to simulate the machining damage of the composites. The periodic random distribution of the carbon fiber reinforced phase in the matrix was realized using a double perturbation algorithm. To achieve the stochastic distribution of the strength of a single carbon fiber, a novel method that combines the Weibull intensity distribution theory with the Monte Carlo method is presented. The mechanical properties of the cyanate matrix were characterized by fitting the stress-strain curves, and the cohesive zone model was employed to simulate the interface. Based on the model, the machining damage mechanism of the composites was revealed using finite element simulations and by conducting a theoretical analysis. Furthermore, the milling surfaces of the composites were observed using a scanning electron microscope, to verify the accuracy of the simulation results. In this study, the simulations and theoretical analysis of the carbon fiber/cyanate ester composite processing were carried out based on a novel three-phase model, which revealed the material failure and machining damage mechanism more accurately.
文摘Natural fiber composites have been proved to have the ability to replace the synthetic fiber composites in many structural applications. Unprecedented growth in the field of computational techniques has opened the doors of analysis and simulation of composite materials under various environment.Modelling and simulation using various available softwares saves a lot of time and resources. In the present work, an attempt has been made to analyze the tensile behavior of jute fiber reinforced epoxy based polymer composite materials using the student version of commercially available finite element code Siemens PLM NX 10.0. In most of the structural applications, materials are required to have enough stiffness to resist the shape deformation under normal loading conditions. Therefore, emphasis is given to the load-deformation behavior of the developed composites. A 3-dimensional model of the test specimen was developed using ply-stacking method and the strain-stress values were verified by the available literature. The model showed a good agreement between the experimental and software results. Effect of ply angle, fiber percentage, fiber type, number of layers and weft fiber angle on the stiffness of laminate have been studied.
基金supported by National Natural Science Foundation of China(Nos.61705064,11647122)the Natural Science Foundation of Hubei Province(Nos.2018CFB773,2018CFB672)the Project of the Hubei Provincial Department of Education(No.T201617)。
文摘A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter steel tube.Twenty-four standard samples and a polynomial fitting method were used to establish calibration curve models.The R^2 factors of the calibration curves were all above 0.99,except for Cu,indicating the elements’ strong self-absorption effect.Five special steel materials were rapidly detected in the steel mill.The average absolute errors of Mn,Cr,Ni,V,Cu,and Mo in the special steel materials were 0.039,0.440,0.033,0.057,0.003,and0.07 wt%,respectively,and their average relative errors fluctuated from 2.9% to 15.7%.The results demonstrated that the performance of this mobile FO-LIBS prototype can be compared with that of most conventional LIBS systems,but the more robust and flexible characteristics of the FO-LIBS prototype provide a feasible approach for promoting LIBS from the laboratory to the industry.
文摘AIM:To investigate the difference of retinal nerve fiber layer(RNFL) thickness between Alzheimer's disease patients and normal people,so as to provide clue for the early diagnosis of Alzheimer's disease.· METHODS:The articles on the association of RNFL thickness and Alzheimer's disease were retrieved by searching international and national databases.The qualified articles were assessed by meta analysis with Stata11.0 software.The results were pooled using weighted mean difference(WMD) with a corresponding 95% confidence interval(CI).· RESULTS:Totally 7 studies enrolled 324 eyes were included in the meta-analysis.The results of meta analysis showed that in AD patients,there was a significant average RNFL thickness reduction compared with the control group [WMD=-17.561,95%CI:(-23.971,-11.151)].There were significant differences in superior,inferior,nasal and temporal RNFL thickness between the two groups.WMD with a 95%CI were [-18.829,95%CI:(-25.915,-11.743);P<0.05],[-25.775,95%CI:(-34.304,-17.247);P <0.05],[-16.877,95%CI:(-29.141,-4.613);P<0.001] and [-14.565,95%CI:(-28.002,-1.128);P<0.001] respectively.Begg's test and Egger's test did not show significant difference,funnel plot was basically symmetrical,indicating that there was no publication bias existed.· CONCLUSION:There are significant differences in the RNFL thickness in all quadrants between the two groups.RNFL thickness is reduced in AD patients compared with the control group.
文摘One of the most successful techniques in planting trees is tree improvement in which trees with high qualities are selected for mass plantation. This study seeks to identify good properties of Eucalyptus camaldulensis through selective phases. Sixty Eucalyptus camaldulensis trees (30 ten-year-old and 30 five-year-old) were randomly selected through stratified sampling from two plantation sites in Kurdistan region, North of Iraq. The trees were examined for fiber morphology and quality parameters such as height, number of branches, diameter and straightness. In the first phase of property selection, sixteen trees with high rank in growth properties and fiber morphology were selected. In the final phase of selection, the selected trees were re-examined according to the number of properties and fiber morphology features and seven trees with the highest number of good parameters were chosen. The 7 selected trees had higher qualities in growth characteristics and fiber morphology compared with the other trees in the sample. This article reports on a selection method for E. camaldulensis trees through tree improvement techniques. The results of the study indicates that high genotype qualities were identified among both 5- and 10-year-old E. camaldulensis trees as the final selection consisted of three 5-year-old trees and four 10-year-old trees.
基金the financial support from the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS),Cotton Research Institute,CAAS,Central Level Public Welfare Scientific Institutes Basic Research and Business Special Funding Project(Grant No.1610162021025)the State Key Laboratory of Cotton Biology,Institute of Cotton Research of CAAS(CB2021C10).
文摘Background:Nitrogen(N)is important for improving various morphological and physiological processes of cotton but their contribution to fiber quality is still lacking.Aims:The current study aimed to explore the relationship between root morphology,subtending leaf physiology,and fiber quality of contrasting N-efficient cotton genotypes in response to N.Methods:We analyzed the above parameters of CCRI 69(N-efficient)and Xinluzao-30(XLZ-30,N-inefficient)under control(2.5 mmol·L^(-1))and high N(5 mmol·L^(-1))conditions.Results:The results showed that root morphological traits were increased in CCRI-69 under control conditions than high N.Subtending leaf morphology,chlorophyll and carotenoid contents,free amino acids,and soluble proteins were higher under high N as compared with the control.However,soluble sugars,fructose,sucrose contents,and sucrose phosphate synthase were higher under control conditions than high N across the growth stages.Irrespective of the N conditions,all morphological and physiological traits of cotton subtending leaf were higher in CCRI-69 than XLZ-30.Except for fiber uniformity,fiber quality traits like fiber length,strength,micronaire,and elongation were improved under control conditions than high N.Between the genotypes,CCRI-69 had significantly higher fiber length,strength,micronaire,and elongation as compared with XLZ-30.Strong positive correlations were found between root morphology,soluble sugars,sucrose content,and sucrose phosphate synthase activity with fiber quality traits,respectively.Conclusions:These findings suggest that CCRI-69 performed better in terms of growth and fiber quality under relatively low N condition,which will help to reduce fertilizer use,the cost of production,and environmental pollution.
基金Project(2006CB600904)supported by the National Basic Research Program of China
文摘Composite felts reinforced by both SiC nano-fibers(SiC-NFs)and carbon fibers were prepared at 1 273 K using Ni granules as catalyzers with different deposition time.SiC-NFs were deposited on the surface of the carbon fibers in situ by catalytic chemical vapor deposition(CCVD).The phase,microstructure and morphology of the fibers after electroplating and deposition were characterized by XRD,SEM and TEM.The results show that the SiC-NFs produced by CCVD are composed of single crystal of β-SiC.It is found that smaller nano-granules are more active as catalyzers.The resulting SiC-NFs appear more spindle-like and have a more homogeneous dispersion.The mass change of the samples before and after deposition shows that using more Ni granules results in a faster growth velocity of SiC-NFs.With the same electroplating time,the growth velocity of the SiC-NFs first increases and then decreases.At around 4 h,it reaches the maximum growth velocity,and it becomes nearly constant at around 8 h.After 8 h, the stable growth velocity of the electroplated Ni samples is faster than that of the conventional sample produced without catalyzers, because the SiC-NFs can improve the specific surface area and the activity of the surface.
基金The Public Science and Technology Research Funds Projects of Ocean under contract No.201305030the Specialized Research Fund for the Doctoral Program of Higher Education under contract No.20120132130001the Fundamental Research Funds for the Central Universities under contract No.201262004
文摘Sagittal otoliths morphology were compared to identify five Pampus species of the Chinese coast(Chinese pomfret Pampus chinensis, grey pomfret P. cinereus, southern lesser pomfret P. minor, plumage pomfret P.punctatissmus, and Pampus sp.). Otoliths demonstrated species-specific characteristics with noticeable differences in overall shape, margin and anterior region among species. With species divergence, otoliths get thinner following further developed rostrum and anti-rostrum. Interspecies variation in otolith could associate with experienced different temperature and water column. The discriminant analysis presented a high classification accuracy of 96.6%, which confirms the inter-specific distinction of otolith shape and enable the species identification.
文摘AIM:To investigate the effect of dietary fiber intake on constipation by a meta-analysis of randomized controlled trials(RCTs).METHODS:We searched Ovid MEDLINE(from 1946 to October 2011),Cochrane Library(2011),PubMed for articles on dietary fiber intake and constipation using the terms:constipation,fiber,cellulose,plant extracts,cereals,bran,psyllium,or plantago.References of important articles were searched manually for relevant studies.Articles were eligible for the meta-analysis if they were high-quality RCTs and reported data on stool frequency,stool consistency,treatment success,laxative use and gastrointestinal symptoms.The data were extracted independently by two researchers(Yang J and Wang HP) according to the described selection criteria.Review manager version 5 software was used for analysis and test.Weighted mean difference with 95%CI was used for quantitative data,odds ratio(OR)with 95%CI was used for dichotomous data.Both I2 statistic with a cut-off of ≥ 50% and the χ2 test with a P value < 0.10 were used to define a significant degree of heterogeneity.RESULTS:We searched 1322 potential relevant articles,19 of which were retrieved for further assessment,14 studies were excluded for various reasons,five studies were included in the analysis.Dietary fiber showed significant advantage over placebo in stool frequency(OR = 1.19;95%CI:0.58-1.80,P < 0.05).There was no significant difference in stool consistency,treatment success,laxative use and painful defecation between the two groups.Stool frequency were reported by five RCTs,all results showed either a trend or a significant difference in favor of the treatment group,number of stools per week increased in treatment group than in placebo group(OR = 1.19;95%CI:0.58-1.80,P < 0.05),with no significant heterogeneity among studies(I2= 0,P = 0.77).Four studies evaluated stool consistency,one of them presented outcome in terms of percentage of hard stool,which was different from others,so we included the other three studies for analysis.Two studies reported treatment success.There was significant heterogeneity between the studies(P < 0.1,I2 > 50%).Three studies reported laxative use,quantitative data was shown in one study,and the pooled analysis of the other two studies showed no significant difference between treatment and placebo groups in laxative use(OR = 1.07;95%CI 0.51-2.25),and no heterogeneity was found(P = 0.84,I2= 0).Three studies evaluated painful defecation:one study presented both quantitative and dichotomous data,the other two studies reported quantitative and dichotomous data separately.We used dichotomous data for analysis.CONCLUSION:Dietary fiber intake can obviously increase stool frequency in patients with constipation.It does not obviously improve stool consistency,treatment success,laxative use and painful defecation.
文摘AIM: To evaluate the effects of dietary fiber (DF) as a part of enteral nutrition (EN) formula on diarrhea, infection, and length of hospital stay. METHODS: Following electronic databases were searched for randomized controlled trials about DF: Chinese Biomedicine Database (CBM), MEDLINE, EMBASE and Coohrane Controlled Trials Register. RevMan 4.1 was used for statistical analysis. RESULTS: Seven randomized controlled trials with 400 pat-ients were included. The supplement of DF in EN was compared with standard enteral formula in five trials. Combined analysis did not show a significant reduction in occurrence of diarrhea, but there were valuable results for non-critically ill patients. Combined analysis of two trials observing the infection also did not show any valid evidence that DF could decrease the infection rate, though the length of hospital stay was reduced significantly. CONCLUSION: Based on the current eligible randomized controlled trials, there is no evidence that the value of DF in the diarrhea can be proved. Though length of hospital stay was shortened by the use of DF, there is no available evidence in preventing infection by DF. Further studies are needed for evaluating the value of DF in EN.
文摘A comparative proteomic analysis was performed to explore the mechanism of cell elongation in developing cotton fibers.The temporal changes of global proteomes at five representative
基金This project is supported by National Natural Science Foundation of China (No. 59773024).
文摘The morphology of polyvinyl chloride/polystyrene (PVC/PS) blend samples with different mass ratios, preparedby means of solution casting and melt mixing, have been successfully examined by electron microprobe analysis (EMP). Thisexperiment was performed in a scanning electron microscope attached to an energy dispersive X-ray analyzer. Differentialscanning calorimetry was also used to investigate the phase separation of the blends. The results show that PVC and PS areincompatible and the blends have sea-islands phase structures. Blends prepared via melt mixing have finer phase-dispersionthan those prepared via solution casting.
文摘The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 years for example, the fiber length at breast high grows faster than it does in the later years. But the standard deviation of distribution in fiber length at breast high in mature wood is larger than in the young tree. The technologically harvestable age of triploid clone of Populus tomentosa Carr., BL304 could be 4-7 year old to meet the requirement for paper industry. The distribution of fiber length become concentrated within an annual ring as the tree grows. The test results also show that the cloned poplar has a small Runkel ratio value (less than 0.4, generally about 0.3), and this ratio increases slightly with the tree grows.
