RESUMO
Soil microbes play important roles in plant growth and in the biogeochemical cycling of earth's elements. However, the structure and functions of the microbial community associated with the growth of second-generation energy crops, such as Miscanthus, remain unclear. Thus, in this study, the composition and function of the bacterial and fungal communities associated with Miscanthus cultivation were analyzed by MiSeq sequencing combined with PICRUSt and FUNGUIld analyses. The results of community composition and diversity index analyses showed that Miscanthus cultivation significantly altered the bacterial and fungal community composition and reduced bacterial and fungal diversity. In addition, Miscanthus cultivation increased the soil organic matter (SOM) and total nitrogen (TN) contents. The correlation analysis between microbial community composition and environmental factors indicated that SOM and TN were the most important factors affecting bacterial and fungal communities. Miscanthus cultivation could enrich the abundances of Pseudomonas, Rhizobium, Luteibacter, Bradyrhizobium, Phenylobacterium and other common plant-promoting bacteria, while also increasing Cladophialophora, Hymenula, Magnaporthe, Mariannaea, etc., which predicted corresponded to the saprotrophic, plant pathogenic, and pathotrophic trophic modes. The PICRUSt predictive analysis indicated that Miscanthus cultivation altered the metabolic capabilities of bacterial communities, including the metabolism of carbon, nitrogen, and phosphorus cycle. In addition, FUNGUIld analysis indicated that Miscanthus cultivation altered the fungal trophic mode. The effects of Miscanthus on the communities and function of bacteria and fungi varied among Miscanthus species. Miscanthus specie Xiangdi NO 1 had the greatest impact on soil bacterial and fungal communities, whereas Miscanthus specie Wujiemang NO 1 had the greatest impact on soil bacteria and fungi functions. The results of this study provide a reference for the composition and function of microbial communities during the growth of Miscanthus.
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Bactérias/genética , Fungos/genética , Microbiota/fisiologia , Poaceae/crescimento & desenvolvimento , Poaceae/microbiologia , Rizosfera , Microbiologia do Solo , Agricultura , Sequenciamento de Nucleotídeos em Larga Escala , Solo/químicaRESUMO
BACKGROUND: Colorectal cancer is the 4th common cancer in China. Most colorectal cancers are due to modifiable lifestyle factors, but few studies have provided a systematic evidence-based assessment of the burden of colorectal cancer incidence and mortality attributable to the known risk factors in China. METHODS: We estimated the population attributable faction (PAF) for each selected risk factor in China, based on the prevalence of exposure around 2000 and relative risks from cohort studies and meta-analyses. RESULTS: Among 245,000 new cases and 139,000 deaths of colorectal cancer in China in 2012, we found that 115,578 incident cases and 63,102 deaths of colorectal cancer were attributable to smoking, alcohol drinking, overweight and obesity, physical inactivity and dietary factors. Low vegetable intake was the main risk factor for colorectal cancer with a PAF of 17.9%. Physical inactivity was responsible for 8.9% of colorectal cancer incidence and mortality. The remaining factors, including high red and processed meat intake, low fruit intake, alcohol drinking, overweight/obesity and smoking, accounted for 8.6%, 6.4%, 5.4%, 5.3% and 4.9% of colorectal cancer, respectively. Overall, 45.5% of colorectal cancer incidence and mortality were attributable to the joint effects of these seven risk factors. CONCLUSIONS: Tobacco smoking, alcohol drinking, overweight or obesity, physical inactivity, low vegetable intake, low fruit intake, and high red and processed meat intake were responsible for nearly 46% of colorectal cancer incidence and mortality in China in 2012. Our findings could provide a basis for developing guidelines of colorectal cancer prevention and control in China.
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Neoplasias Colorretais/epidemiologia , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Vigilância da População , Consumo de Bebidas Alcoólicas/efeitos adversos , China/epidemiologia , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Obesidade/complicações , Obesidade/mortalidade , Sobrepeso/complicações , Sobrepeso/mortalidade , Fatores de Risco , Fumar/efeitos adversosRESUMO
OBJECTIVE: To perform a systematic review between all-cause mortality and body mass index (BMI) in Asian adults. METHOD: Relevant prospective studies that reported the relative risks (RRs) of all-cause mortality for community-based adults in Asia were identified by a literature search.PubMed and CNKI electronic databases were searched from inception through September 30, 2014, with language restrictions of English and Chinese. Data were extracted by 1 reviewer and then reviewed by 3 independent reviewers. The overall effect of varied levels of BMI and all-cause mortality were then pooled and analyzed.Potential sources of heterogeneity were detected by stratification analyses and sensitivity analyses. Publication bias was detected by funnel plot, Egger's test and Begg's test. RESULTS: Seventeen studies met the inclusion criteria; these studies included 1 769 369 individuals with 104 888 deaths. Random-effects summary all-cause mortality RRs was calculated. With the use of a BMI (in kg/m²) of 18.5~22.9 as the reference, the summary RRs were 1.39(95% CI: 1.31~1.47) for BMI less than 18.5 kg/m² , 0.88 (95% CI: 0.85~0.92) for BMI of 23.0~29.9 kg/m² and 1.14 (95% CI: 1.05~1.23) for BMI more than 30.0 kg/m². The RRs tended to be higher when weight and height were self-reported rather than measured. The RRs were higher when papers were published before the year 2005 rather than after the year 2006. Also, the RRs were higher when the quality scores were higher. Potential sources of heterogeneity were gender, the method of obtaining weight and height, geography, publication year and quality scores. There was no publication bias (P>0.05) in this meta-analysis. CONCLUSION: There was an increased risk of all-cause mortality for those both at the lower and higher level of BMI in Asian adults.
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Índice de Massa Corporal , Mortalidade , Adulto , Povo Asiático , Humanos , Fatores de RiscoRESUMO
BACKGROUND: Low birth weight is strongly correlated with an increased risk of adult diseases. Additionally, low birth weight might be a risk factor for asthma later in life. METHODS: A systematic literature search of the PubMed database from 1966 to November 2013 was conducted. The criteria for inclusion of papers were as follows: case-control or cohort studies; the odds ratio (OR) or risk ratio (RR) estimates with the corresponding 95% confidence intervals (CIs) were presented, or there were sufficient data for calculation; and studies were published in English up to October 2013. Random-effect and fixed-effect meta-analyses, meta-regression, and cumulative meta-analysis were conducted. RESULTS: Thirteen cohort studies and 1,105,703 subjects were included. The overall pooled RRs (95% CIs) of asthma risk for low birth weight were 1.162 (fixed-effects model, 95% CI, 1.128-1.197) and 1.152 (random-effects model, 95% CI, 1.082-1.222). In stratified analyses, the effect of low birth weight on childhood asthma was strong, particularly in studies conducted in Europe, those with a small sample size, and those published recently. A meta-regression analysis did not find significant determinants. CONCLUSIONS: This meta-analysis shows that low birth weight significantly increases the risk of childhood asthma.
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Asma/fisiopatologia , Peso ao Nascer/fisiologia , Criança , Humanos , Recém-Nascido , Fatores de RiscoRESUMO
PURPOSE: To report a case of neurogenic dry eye (NDE) that developed after intravitreal ranibizumab injection (IVR). CASE REPORT: A 71-year-old woman had a history of cataract phacoemulsification and intraocular lens (IOL) implantation, Nd:YAG laser posterior capsulotomy and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). Aneurysmal dilatation of the inferior temporal retina was found in the left fundus, which was diagnosed as retinal aneurysm, and intravitreal ranibizumab injection was administered. Dry eye was found in the left eye after the first injection. After the second injection, the patient developed severe dry eye with left eye dryness, photophobia, irritation, and blurred vision. The tear film breakup time (TBUT) value was 3â s, the Schirmer test value was 2â mm/5â min, corneal fluorescein staining (CFS) showed diffuse patellar staining of the corneal epithelium with a staining area of >50% and irregular staining at the edge of the corneal flap, and the corneal touch threshold value in the filament length was 1.5â cm in the left eye. CONCLUSIONS: Patients with a history of intraocular lens implantation, Nd:YAG laser posterior capsulotomy, and femtosecond laser-assisted laser in situ keratomileusis surgery may have increased drug permeability due to an increased concentration of anti-VEGF drugs in the aqueous layer and thinning of the stromal layer of the cornea. The corneal subepithelial nerve repair mechanism was destroyed, causing neurogenic dry eye.
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Síndromes do Olho Seco , Ceratomileuse Assistida por Excimer Laser In Situ , Feminino , Humanos , Idoso , Injeções Intravítreas , Ranibizumab , Córnea , Síndromes do Olho Seco/induzido quimicamente , Síndromes do Olho Seco/diagnósticoRESUMO
PURPOSE: To explore the offset distribution of pupillary centres, the offset between the pupil centre and the coaxially sighted corneal light reflex (P-Dist) and their correlation in femtosecond laser combined with excimer laser in situ keratomileusis. METHODS: Randomly selected 194 patients (398 eyes) who underwent femtosecond-assisted laser in situ keratomileusis with preoperative use of WaveLight Allegro Topolyzer Corneal Topography (WaveLight Laser Technologies AG, Erlangen, Germany) to measure the pupil size and centre position. The P-Dist of the patients was recorded by the X and Y axis eyeball tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system. RESULTS: The P-Dist was 0.214â±â0.092âmm in the right eyes and 0.228â±â0.105âmm in the left eyes (Pâ=â.041). Under scotopic conditions, the pupil centre of left eye X-axis was -0.046â±â0.091âmm, the right eye was -0.152â±â0.084âmm, with significant differences (Pâ=â.015), and the Y-axis direction showed no significant changes (Pâ=â.062). The white to white was positively correlated with changes of pupil diameter (scotopic pupil diameter-photopic pupil diameter) (râ=â0.270, Pâ<â.001). The equivalent spherical mirror and measured centroid shift were negatively correlated (râ=â-0.214, Pâ=â.002). CONCLUSION: The angle kappa of the right eye is smaller than that of the left eye and from scotopic to photopic condition, the pupil centroid shift of both eyes to the nasal inferior side. If the cornea is too large, the low illumination environment should be maintained during the operation to improve the efficiency of pupil matching.
Assuntos
Ceratomileuse Assistida por Excimer Laser In Situ , Miopia , Córnea/cirurgia , Topografia da Córnea , Humanos , Lasers de Excimer , Miopia/cirurgia , Refração OcularRESUMO
To explore the mechanism by which the plant growth-promoting bacterium Brevibacillus sp. SR-9 improves sweet sorghum tolerance and enriches soil cadmium (Cd) under pot conditions, the effect of strain SR-9 inoculation on the microbial community of sorghum rhizosphere soil was analyzed by metagenomics. Gene expression in sweet sorghum roots was analyzed using transcriptomics. The results showed that strain SR-9 promoted the growth of sweet sorghum and improved the absorption and enrichment of Cd in the plants. Compared with the uninoculated treatment, the aboveground part and root dry weight in strain SR-9 inoculated with sorghum increased by 21.09% and 17.37%, respectively, and the accumulation of Cd increased by 135% and 53.41%, respectively. High-throughput sequencing showed that strain SR-9 inoculation altered the rhizosphere bacterial community, significantly increasing the relative abundance of Actinobacteria and Firmicutes. Metagenomic analysis showed that after inoculation with strain SR-9, the abundance of genes involved in amino acid transport metabolism, energy generation and conversion, and carbohydrate transport metabolism increased. KEGG functional classification showed that inoculation with strain SR-9 increased the abundance of genes involved in soil microbial metabolic pathways in the rhizosphere soil of sweet sorghum and the activity of soil bacteria. Transcriptome analysis identified 198 upregulated differentially expressed genes in sweet sorghum inoculated with strain SR-9, including those involved in genetic information processing, biological system, metabolism, environmental information processing, cellular process, and human disease. Most of the annotated differentially expressed genes were enriched in the metabolic category and were related to pathways such as signal transduction, carbohydrate metabolism, amino acid metabolism, and biosynthesis of other secondary metabolites. This study showed that plant growth-promoting bacteria can alter the rhizosphere bacterial community composition, increasing the activity of soil bacteria and upregulating gene expression in sweet sorghum roots. The findings enhance our understanding of the microbiological and botanical mechanisms by which plant growth-promoting bacterial inoculation improves the remediation of heavy metals by sorghum.
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Brevibacillus , Poluentes do Solo , Sorghum , Humanos , Cádmio/análise , Sorghum/metabolismo , Sorghum/microbiologia , Poluentes do Solo/análise , Brevibacillus/genética , Brevibacillus/metabolismo , Solo/química , Microbiologia do Solo , Perfilação da Expressão Gênica , Aminoácidos/metabolismo , Raízes de Plantas/metabolismo , Biodegradação AmbientalRESUMO
RATIONALE: Central retinal artery occlusion (CRAO) sparing the cilioretinal artery (CLRA) with severe subretinal fluid and non-characteristic cherry-red spot is uncommon. In the present case, the patient received an intravitreal injection of anti- vascular endothelial growth factor, which is very rare. PATIENT CONCERNS: A 59-year-old man underwent vitrectomy of the left eye for diabetic retinopathy and vitreous hemorrhage. Six months after the operation, the patient presented with sudden painless visual-acuity decline in his left eye and was diagnosed with CRAO; his best corrected visual acuity was weak light perception. Whole retinal edema was seen on the fundus, and macular gray retinal opacification was present without a characteristic cherry-red spot. Optical coherence tomography revealed subretinal fluid (SRF) in the papillomacular bundle and inner retinal thickening. Fundus fluorescein angiography confirmed that the central retinal artery was not filled at 40 seconds and that the CLRA supplied a part of the macular area. Eight months after the second intravitreal injection of ranibizumab, Optical coherence tomography showed a significant reduction in inner retinal hyperreflectivity and the thickness of the nasal macular retina. The SRF was clearly absorbed, and the visual acuity improved to 1.1 logMAR units. DIAGNOSIS: Atypical CRAO. INTERVENTIONS: The patient was treated with intravitreal injection of anti-VEGF in his left eye. The thickness of the nasal macular retina decreased. OUTCOMES: The SRF was clearly absorbed, and the patient's visual acuity significantly improved. LESSONS: When CRAO occurs in patients with diabetic retinopathy sparing the CLRA, the non-characteristic cherry-red spot may be due to macular inner retinal edema, SRF and other factors. According to the patient's condition, anti-vascular endothelial growth factor can be administered as appropriate to inhibit choroidal neovascularization, reduce SRF in the macular retina, and save some vision.
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Retinopatia Diabética , Edema Macular , Papiledema , Oclusão da Artéria Retiniana , Masculino , Humanos , Pessoa de Meia-Idade , Líquido Sub-Retiniano , Retinopatia Diabética/complicações , Retinopatia Diabética/tratamento farmacológico , Papiledema/complicações , Oclusão da Artéria Retiniana/etiologia , Artérias Ciliares , Inibidores da Angiogênese/uso terapêutico , Edema Macular/etiologia , Edema Macular/complicações , Fatores de Crescimento do Endotélio Vascular/uso terapêutico , Anticorpos Monoclonais/uso terapêuticoRESUMO
Miscanthus has good tolerance to heavy metals (HMs) and has received increasing attention in studies of HM-contaminated soil remediation. In this study, four Miscanthus cultivars (M. lutarioriparius Xiangnadi NO4, M. sinensis Xiangmang NO1, M. lutarioriparius × M. sinensis hybrid Xiangzamang NO1, and M. floridulus Wujiemang NO1) that grow in China were studied. Their tolerance and enrichment abilities in soils containing 50 mg kg-1 cadmium (Cd) and the structure and function of their rhizosphere bacterial communities during the remediation process were analyzed. The results exhibiting a tolerance index (TI) higher than 75 in roots and the aboveground parts (TI > 60, indicating highly tolerant plants) indicated that all four Miscanthus cultivars were tolerant to high Cd concentrations. Moreover, Cd was mainly enriched in roots, the translocation ability from roots to aboveground parts was weak, and the four cultivars exhibited phytostabilization ability in Cd-contaminated soils. High-throughput sequencing (HTS) analysis showed that the Miscanthus rhizosphere bacterial community comprised 33 phyla and 446 genera, including plant growth-promoting rhizobacteria (PGPRs), such as Bacillus, Sphingomonas, and Mesorhizobium. The addition of Cd affected the Miscanthus rhizosphere bacterial community and reduced community diversity. Phylogenetic molecular ecological networks (pMENs) indicated that Cd addition reduced interactions between Miscanthus rhizosphere bacteria and thereby led to a simpler network structure, increased the number of negative-correlation links, enhanced the competition between rhizosphere bacterial species, reduced the number of key bacteria, and changed the composition of those bacteria. PICRUSt functional predictive analysis indicated that Cd stress reduced soil bacterial functions in the Miscanthus rhizosphere. The results of this study provide a basis for the remediation of Cd-contaminated soils by Miscanthus and provide a reference for the subsequent regulation of Miscanthus remediation efficiency by PGPRs or key bacteria.
Assuntos
Cádmio , Poluentes do Solo , Bactérias , Biodegradação Ambiental , Cádmio/análise , Cádmio/toxicidade , Filogenia , Poaceae , Rizosfera , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidadeRESUMO
RATIONALE: Breast carcinoma is the most common primary source of choroidal metastasis (CM). In the present case, esophageal cancer was the primary tumour, brain metastasis occurred, and CM occurred later in the left eye with 2 retinal detachments, which is very rare. PATIENT CONCERNS: A 62-year-old man complained of a sudden decrease in visual acuity consisting of a small shadow in front of his left eye with a sensation of covered vision after 1 cycle of systemic chemotherapy and radiotherapy for resected esophageal cancer with brain metastasis. Fundus examination revealed exudative retinal detachment without retinal tears. CM with exudative retinal detachment was also considered. The patient refused further treatment. After the second cycle of chemotherapy, there were no significant changes in the retina and visual acuity improved. However, after craniocerebral surgery for brain metastasis, the visual acuity decreased again and showed 3 choroidal masses with macular involvement and retinal detachment but without retinal tears. DIAGNOSIS: The final diagnosis was CM with retinal detachment. INTERVENTIONS: The patient was advised to undergo enucleation of the left eye during the second retinal detachment, but he refused. OUTCOMES: Two months after the second retinal detachment, the patient died of systemic metastases. LESSONS: It is important to consider CM when the first retinal detachment and known cancer are diagnosed. At present, it is necessary to develop a standardised treatment plan as well as a multidisciplinary approach to early diagnosis, combined treatment, and timely intervention for such cases.
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Neoplasias Encefálicas/secundário , Neoplasias da Coroide/secundário , Neoplasias Esofágicas/patologia , Descolamento Retiniano/etiologia , Perfurações Retinianas/etiologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Neoplasias da Coroide/patologia , Terapia Combinada , Neoplasias Esofágicas/terapia , Evolução Fatal , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Pinus massoniana is a typical pioneer afforestation tree species widely distributed in southern China. It is crucial to study the ecological resilience of P. massoniana to disturbances under global warming, drying, and frequent pest infestation, which can shed lights on forest mana-gements. In this study, tree-ring samples collected from old-growth P. massoniana trees in Baisong Village, Xianyou County, Fujian Province, were used to develop the first standard chronology of P. massoniana ring width (1865-2014) in this region. The results showed that the low relative humidity from July to September and the extremely high temperature from May to September were the main limiting factors for tree growth. The extremely narrow years were identified in 1869, 1889, 1986, 1991 and 1993. These extremely narrow years were exacerbated after the persistently low values of the previously two years via the superposed epoch analysis (SEA). The insect infestations were more likely to happen in dry years. Insect outbreak exerted strongest effect on tree growth in 1889. The narrow tree-rings in 1986 and 1991 were affected by both insect infestation and drought. The other extremely narrow years were mainly affected by drought. The resistance of trees to insect infestation was weaker than that to drought event. The relative resilience of trees to insect infestation was higher than that to drought event, except for 1991. The relative resilience was the highest in 1889 and the lowest in 1991 under the influence of successive extreme events. Under the enhanced drying trend since 2000, more trees had died possibly due to the combined effects of insect infestation and drought.
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Pinus , Árvores , Animais , China , Mudança Climática , Secas , InsetosRESUMO
Planktonic fungi are important components of aquatic ecosystems, and analyses of their community composition and function have far-reaching significance for the ecological management and maintenance of the Danjiangkou reservoir. The composition and function of the planktonic fungal community in the surface water layer of the Danjiangkou Reservoir in October 2019 was investigated using Illumina MiSeq sequencing combined with FUNGuild analyses. According to the results, the reservoir community is primarily composed of 6 phyla 213 genera, with Ascomycota and Basidiomycota being the dominant phyla. The water quality monitoring results for the Danjiangkou Reservoir met the Grade â or â ¡ water quality standards for the Environmental Quality Standards for Surface Water (GB 38382-2002). A redundancy analysis (RDA) of the planktonic fungal community and environmental factors showed that TN, TP, T, ORP, and TLI are important factors influencing the distribution of planktonic fungi. The Spearman correlation analysis showed that Alternaria, Cladosporium, Penicillium, Lodderomyces, and Acremonium were significantly correlated with physical and chemical water quality parameters. FUNGuild was used to predict the nutritional and functional groups of planktonic fungi, and the results showed that pathotrophs, saprotrophs, and pathotroph-saprotrophs were the major components. The pathotroph composition analysis showed that the proportions of plant pathogens and animal pathogens in the Heijizui samples were significantly higher than those observed in the other monitoring sites. The community composition, function, and influencing factors of the planktonic fungi community in the Danjiangkou Reservoir were investigated and indicated that it is potentially at ecological risk and more attention needs to be paid to planktonic fungi in the biological monitoring of water quality.
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Micobioma , Plâncton , Animais , China , Ecossistema , Fungos/genética , Qualidade da ÁguaRESUMO
As a representative of second-generation bioenergy plants, Miscanthus has received increasing attention in the studies of heavy metal (HM)-contaminated soil remediation. Currently, few studies have examined the effects of using Miscanthus to remediate HM-contaminated soils on the composition and function of microbial communities. In this study, the Miscanthus cultivar M. saccariflorus was examined for its tolerance and enrichment abilities when grown in soils containing 100 mg ·kg-1 of cadmium (Cd). The structure, function, and co-occurrence network of their rhizosphere bacterial communities were analyzed during the remediation process. MiSeq sequencing showed that the Miscanthus rhizosphere bacterial community comprised 32 phyla and 425 genera, including plant growth-promoting rhizobacteria (PGPR), such as Sphingomonas, Bacillus, Gemmatimonas, and Streptomyces. The addition of Cd affected the Miscanthus rhizosphere bacterial community and reduced community diversity. Phylogenetic molecular ecological networks indicated that Cd addition reduced the interactions between Miscanthus rhizosphere bacteria to generate a simpler network structure, increased the number of negative-correlation links, enhanced the competition between rhizosphere bacterial species, and changed the composition of key bacteria. PICRUSt functional predictive analysis indicated that Cd stress reduced soil bacterial functions in the Miscanthus rhizosphere. The results of this study provide a reference for the subsequent regulation of efficient Miscanthus remediation by PGPRs or key bacteria.
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Rizosfera , Poluentes do Solo , Cádmio/análise , Cádmio/toxicidade , Filogenia , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidadeRESUMO
We sampled Pinus massoniana and Cunninghamia lanceolata in both plantation and natural forests in central and western Fujian Province, China. Using tree-ring width, tree-ring width index, and basal area increment, we reconstructed the annual growth of 109 conifer individuals from four sites for the 20-year period from 1993 to 2012. We then calculated resistance, recovery, and resilience indices of those trees in response to two consecutive extreme droughts (2003-2004 and 2011) and analyzed the differences in resistance and resilience between plantations and natural fore-sts. The results showed that there were temporal differences in moisture requirements between P. massoniana and C. lanceolata, which accounted for their inconsistent responses to drought in 2003-2004. For both species, drought induced a marked growth reduction, without any clear lag effect. The growth responses during and following the 2003-2004 drought were significantly stronger than that for the 2011 drought. Those results indicated that P. massoniana was more resilient to drought stress than C. lanceolata, and the natural forests were more sensitive than plantations, but with stronger capacity to recover. C. lanceolata plantations were more susceptible to frequent extreme drought events. To mitigate the vulnerability of plantation trees to more frequent droughts in the future, we suggested select trees from genetic provenances with strong drought resistance.
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Cunninghamia , Pinus , China , Secas , Florestas , HumanosRESUMO
The water-level fluctuation zone (WLFZ) is a transitional zone between terrestrial and aquatic ecosystems. Plant communities that are constructed artificially in the WLFZ can absorb and retain nutrients such as nitrogen (N) and phosphorus (P). However, the microbial community composition and function associated with this process have not been elucidated. In this study, four artificially constructed plant communities, including those of herbs (Cynodon dactylon and Chrysopogon zizanioides), trees (Metasequoia glyptostroboides), and shrubs (Salix matsudana) from the newly formed WLFZ of the Danjiangkou Reservoir were evaluated. The bacterial community compositions were analyzed by 16S rRNA gene sequencing using a MiSeq platform, and the functions of these communities were assessed via Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis. The results showed that the bacterial communities primarily comprised 362 genera from 24 phyla, such as Proteobacteria, Acidobacteria, Actinobacteria, and Gemmatimonadetes, showing the richness of the community composition. Planting altered the bacterial community composition, with varying effects observed among the different plant types. The bacterial community functional analysis revealed that these bacteria were primarily associated with six biological metabolic pathway categories (e.g., metabolism, genetic information processing, and environmental information processing) with 34 subfunctions, showing the richness of community functions. The planting of M. glyptostroboides, S. matsudana, and C. dactylon improved the metabolic capabilities of bacterial communities. N- and P-cycling gene analysis showed that planting altered the N- and P-cycling metabolic capacities of soil bacteria. The overall N- and P-metabolic capacity was highly similar between C. dactylon and C. zizanioides samples and between S. matsudana and M. glyptostroboides samples. The results of this study provide a preliminary analysis of soil bacterial community structure and function in the WLFZ of the Danjiangkou Reservoir and provides a reference for vegetation construction in this zone.
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Microbiota , Chuva , Rizosfera , Abastecimento de Água , Fenômenos Fisiológicos Bacterianos , China , Lagos , Estações do Ano , Microbiologia do SoloRESUMO
PURPOSE: To analyze the distribution of the offset between the pupil center and the coaxially sighted corneal light reflex (P-Dist), the effects of 50% and 100% angle kappa adjustments on refractive and visual quality in patients with moderate myopia were investigated. METHODS: A randomly selected 254 patients (254 eyes) with moderate myopia who underwent femtosecond laser-combined LASIK were examined. During the operation, the P-Dist of the patients was recorded by the x- and y-axis eyeball-tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system. Preoperatively and 3 months postoperatively, the WaveLight® ALLEGRO Topolyzer was used to measure the pupil size and center position, and the wavefront sensor was used to measure the wavefront aberrations. The visual function tester (OPTEC 6500) measured contrast sensitivity. RESULTS: The average P-Dist was 0.220 ± 0.102 mm. When the P-Dist >0.220 mm, the postoperative residual cylinder was 0.29 ± 0.34 D in the group with the 50% adjustment and 0.40 ± 0.32 D in the 100% group, which was significantly higher than the 50% group (P=0.036). The coma was 0.21 ± 0.17 µm in the 50% adjusted group and 0.34 ± 0.25 µm in the 100% group, which was significantly higher than that in the 50% group (P=0.021). At the 1.5 c/d spatial frequency, contrast sensitivity in the adjusted 100% group was significantly lower than that in the 50% group under visual glare conditions (P=0.039). CONCLUSION: The postoperative visual acuity and spherical equivalent were not affected in the two groups. However, when P-Dist >0.220 mm, the residual astigmatism and coma were lower in the 50% group. Individualized operations for those with moderate myopia and large-angle kappa in which 100% adjustment is chosen may not result in a better visual quality effect than 50%.
RESUMO
There are many types of bacteria in heavy metal-contaminated soils, including plant growth-promoting bacteria and heavy metal-immobilizing bacteria, which may potentially be used for the bioremediation of contaminated soil. In this study, the Cd-contaminated soil around a battery factory in Xinxiang City was collected and its bacterial community composition was analyzed using high-throughput sequencing (HTS) and the plate lineation separation method. The traditional culture method showed that bacteria isolated from contaminated soil belonged to four phyla (Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes) and 30 genera including Bacillus, Arthrobacter, and Rhizobium. HTS showed that the soil contained 25 phyla including Proteobacteria, Actinobacteria, and Acidobacteria and 400 genera. The HTS analysis revealed a greater diversity of the bacterial community than the traditional culture method. Network analysis was performed using the relative abundances of bacteria based on the phylogenetic molecular ecological network (pMEN) method. Network analysis showed that the key bacteria included Arthrobacter, Marmoricola, Nocardioides, Ferruginibacter, Flavitalea, Nitrospira, and Lysobacter. The Cd fixation and adsorption abilities of the 159 cultivable strains were determined. The results showed that 30 strains from 11 genera, including Aneurinibacillus, Arthrobacter, and Bacillus, were highly efficient. Six high-efficiency strains were shown to increase the biomass of pak choi (Brassica chinensis L.) and reduce the content of Cd in different pak choi tissues. This study provides candidate bacterial species for the remediation of heavy metal-contaminated soil in Xinxiang City and provides references for the bacterial community and its function in heavy metal-contaminated soil.
Assuntos
Brassica , Poluentes do Solo/análise , Bactérias , Bioacumulação , Cádmio/análise , Cidades , Filogenia , Solo , Microbiologia do SoloRESUMO
According to cold heading process with overloaded craft, high-impact dynamic real-time measurement requirements, this paper presents researches on dynamic characteristics and optimization of PVDF piezoelectric film force sensor for steel ball cold heading forming quality monitoring, through the combination method of mechanism analysis, mathematical modeling, numerical simulation and experimental validation. The motivation and strategic objectives are to breakthrough dynamic time-varying impacting load measuring fundamental technologies in steel ball forging process. The structure of piezoelectric film force sensor is proposed. The theoretical calculation formula of natural frequency is deduced and calculated by using MATLAB software. The mechanical performance analysis on dynamic model and structural optimization simulation by FEM is carried out. In order to study the validity of the proposed method, a prototype of the sensor is fabricated. The static and dynamic calibration devices are designed to realize calibration experiments on the fabricated PVDF piezoelectric film force sensor. The differences among experimental value, simulation value and the theoretical value are given. The nonlinear error of the fabricated sensor is 0.197%. The sensor's first order natural frequency value is 5238 Hz. It is proved that the PVDF piezoelectric film force sensor has superior dynamic performance and high accuracy for measuring deformation in steel ball. The paper will provide important scientific basis and technical foundation to achieve superior performance steel ball.
RESUMO
This paper presents a novel integrated piezoelectric six-dimensional force sensor which can realize dynamic measurement of multi-dimensional space load. Firstly, the composition of the sensor, the spatial layout of force-sensitive components, and measurement principle are analyzed and designed. There is no interference of piezoelectric six-dimensional force sensor in theoretical analysis. Based on the principle of actual work and deformation compatibility coherence, this paper deduces the parallel load sharing principle of the piezoelectric six-dimensional force sensor. The main effect factors which affect the load sharing ratio are obtained. The finite element model of the piezoelectric six-dimensional force sensor is established. In order to verify the load sharing principle of the sensor, a load sharing test device of piezoelectric force sensor is designed and fabricated. The load sharing experimental platform is set up. The experimental results are in accordance with the theoretical analysis and simulation results. The experiments show that the multi-dimensional and heavy force measurement can be realized by the parallel arrangement of the load sharing ring and the force sensitive element in the novel integrated piezoelectric six-dimensional force sensor. The ideal load sharing effect of the sensor can be achieved by appropriate size parameters. This paper has an important guide for the design of the force measuring device according to the load sharing mode.
RESUMO
To investigate wavefront aberrations in the entire eye and in the internal optics (lens) and retinal image qualities according to different lenticular opacity types and densities. Forty-one eyes with nuclear cataract, 33 eyes with cortical cataract, and 29 eyes with posterior subcapsular cataract were examined. In each group, wavefront aberrations in the entire eye and in the internal optics and retinal image quality were measured using a raytracing aberrometer. Eyes with cortical cataracts showed significantly higher coma-like aberrations compared to the other two groups in both entire eye and internal optic aberrations (P = 0.012 and P = 0.007, respectively). Eyes with nuclear cataract had lower spherical-like aberrations than the other two groups in both entire eye and internal optics aberrations (P < 0.001 and P < 0.001, respectively). In the nuclear cataract group, nuclear lens density was negatively correlated with internal spherical aberrations (r = -0.527, P = 0.005). Wavefront technology is useful for objective and quantitative analysis of retinal image quality deterioration in eyes with different early lenticular opacity types and densities. Understanding the wavefront optical properties of different crystalline lens opacities may help ophthalmic surgeons determine the optimal time to perform cataract surgery.