RESUMEN
When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure1-3, and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements3-5. Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements6-8 have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction.
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Antimicrobial resistance poses a serious threat to public health and is one of the major challenges worldwide. As global social, economic, and environmental changes lead to increased exposure of populations to antimicrobials, the antimicrobial resistance of pathogens has accelerated and resulted in weakened clinical infection treatment effects. This article reviews the main mechanisms and driving factors of the production and spread of antimicrobial resistance from the perspective of "One Health"and discusses methods and strategies for controlling antimicrobial resistance from multiple dimensions. It also looks forward to the prospects of research and prevention of drug resistance to explore antimicrobial resistance prevention and control strategies based on "One Health".
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Salud Única , Humanos , Salud Pública , Antibacterianos/farmacología , Farmacorresistencia BacterianaRESUMEN
Objective: To explore the effectiveness of Balint group on compassion fatigue among oncology nurses. Methods: From January to December 2016, 35 oncology nurses from one general hospital were enrolled. 18 cases were allocated in the observation group and 17 cases in the control group by computer randomization. Nurses in the observation group were received a total of 8 times Balint Group activities, with 2 times a month and 1.5 hours each time, which is aiming to discuss difficult cases encountered in the clinic to help nurses have a deeper experience and a better understanding of the emotions and behaviors, fantasies and needs between nurse-patient interaction. Nurses in the control group without intervention. All the Participants were requested to complete the survey of the Professional Quality of Life (ProQOL) , the Jefferson Scale of Empathy-Health Professionals (JSE-HP) , and the General Health Questionnaire (GHQ) at pre and post intervention. Results: Before intervention, two group of nurses in age, working years, marriage, and education were not statistically significant (P>0.05). There was no difference in the scores of empathy, compassion satisfaction, secondary traumatic stress, and General health (P>0.05). After intervention, the scores of JSE-HP and its three dimensions of perspective taking, emotional care, and trans-positional consideration in the observation group had significantly higher than the control group (P<0.05). The level of compassion satisfaction in the observation group was higher, and the general health status was lower (P<0.05). There was no statistically difference in the level of burnout and secondary traumatic stress between two groups (P>0.05) . Conclusion: Balint group has a positive role in promoting nurses'empathetic skills, compassion satisfaction and mental health.
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Agotamiento Profesional/psicología , Desgaste por Empatía/psicología , Enfermería Oncológica , Calidad de Vida/psicología , Empatía , Fatiga , Humanos , Satisfacción en el Trabajo , Recursos HumanosRESUMEN
Objective: To investigate the clinical value of ultrasound examination of carpal canal structure in patients with mild hand-arm vibration disease. Methods: A total of 29 patients (58 wrists) with mild hand-arm vibration disease who were treated in Shenzhen Prevention and Treatment Center for Occupational Diseases from May to December, 2015 were enrolled as observation group, and 20 healthy volunteers (40 wrists) were enrolled as the control group. Color Doppler ultrasound was used to observe the morphology and echo of the median nerve in the carpal canal and 9 muscle tendons and transverse carpal ligament. The thickness of transverse carpal ligament and diameter of the median nerve at the level of the hamulus of hamate bone were measured, as well as the cross-sectional area of the median nerve at the level of pisiform bone. Results: In the 29 patients with hand-arm vibration disease patients in the observation group, 8 experienced entrapment of the median nerve in the carpal canal, among whom 5 had entrapment in both wrists; there were 13 wrists (23%) with nerve entrapment and 45 wrists (77%) without nerve entrapment. Compared with the control group, the patients with hand-arm vibration disease and nerve entrapment in the observation group showed significant thickening of the transverse carpal ligament at the level of the hamulus of hamate bone and a significant increase in the cross-sectional area of the median nerve at the level of pisiform bone (P<0.05) , while there were no significant differences in the thickness of transverse carpal ligament at the level of the hamulus of hamate bone and the cross-sectional area of the median nerve at the level of pisiform bone (t=-9.397 and -4.385, both P>0.05) . Conclusion: Ultrasound examination can clearly show the radiological changes of carpal canal contents in patients with mild hand-arm vibration disease and has a certain diagnostic value in nerve damage in patients with hand-arm vibration disease.
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Síndrome del Túnel Carpiano/diagnóstico por imagen , Síndrome por Vibración de la Mano y el Brazo/diagnóstico por imagen , Nervio Mediano/diagnóstico por imagen , Brazo , Estudios de Casos y Controles , Síndrome por Vibración de la Mano y el Brazo/patología , Humanos , Ultrasonografía Doppler en Color , Vibración , MuñecaRESUMEN
Objective: To analyze the use of medicare antiviral drugs (ART) and related factors among HIV-infected people in Ningbo City. Methods: The retrospective data was collected related to infection and treatment of HIV-infected people in ART in Ningbo up to February 2023 through the National Infectious Disease Surveillance System. Binary logistic regression was used to analyze the factors related to medicare antiviral drug use in HIV-infected people. R 4.2.2 software was used for statistical analysis. Results: A total of 6 433 HIV-infected people with ART records were collected, among which 5 783 were in ART. The prevalence of medicare drugs use among people in ART was 24.8% (1 435/5 783, 95%CI: 23.7%-25.9%). Beilun District (8.7%, 43/497) and Fenghua District (5.7%, 14/247) had the lowest level in medicare drugs use. Among people in ART using medicare or out-of-pocket drugs, the prevalence of those who had at least one viral load test in the last year (84.9%, 1 352/1 593) was significantly lower than that of those using free drugs (91.4%, 3 829/4 190) (χ2=52.50, P<0.001). The results of multivariate logistic analysis showed that the factors influencing medicare drug use included low educational level (junior high school and below: aOR=0.24, 95%CI:0.17-0.34), farmer or worker (farmer: aOR=0.60, 95%CI: 0.39-0.91; worker: aOR=0.42, 95%CI: 0.27-0.64), low monthly income (<3 000 Yuan: aOR=0.29, 95%CI: 0.18-0.45), the longer interval time between diagnosis and treatment (≥21 days: aOR=0.47, 95%CI: 0.30-0.74). Conclusions: Significant regional differences on the prevalence of medicare antiviral drugs use in HIV-infected people exist in Ningbo City. Follow-up management program of patients should be improved to strengthen patient compliance to mobilize medicare drug promotion. Meanwhile, publicity of medicare drugs should be strengthened for farmers or workers with low education level and patients with delayed treatment.
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Infecciones por VIH , Trastornos Relacionados con Sustancias , Anciano , Estados Unidos/epidemiología , Humanos , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Infecciones por VIH/diagnóstico , Estudios Retrospectivos , Prevalencia , Medicare , Antivirales/uso terapéuticoRESUMEN
Rice and vegetables cultivated in naturally arsenic (As) endemic areas are the substantial source of As body loading for persons using safe drinking water. However, tracing As intake, particularly from rice and vegetables by biomarker analysis, has been poorly addressed. This field investigation was conducted to trace the As transfer pathway and measure health risk associated with consuming As enriched rice and vegetables. Purposively selected 100 farmers from five sub-districts of Chandpur, Bangladesh fulfilling specific requirements constituted the subjects of this study. A total of 100 Irrigation water, soils, rice, and vegetable samples were collected from those farmers' who donated scalp hair. Socio-demographic and food consumption data were collected face to face through questionnaire administration. The mean As level in irrigation water, soils, rice, vegetables, and scalp hairs exceeded the acceptable limit, while As content was significant at 0.1%, 5%, 0.1%, 1%, and 0.1% probability levels, respectively, in all five locations. Arsenic in scalp hair is significantly (p ≤ 0.01) correlated with that in rice and vegetables. The bioconcentration factor (BCF) for rice and vegetables is less than one and significant at a 1% probability level. The average daily intake (ADI) is higher than the RfD limit for As. Both grains and vegetables have an HQ (hazard quotient) > 1. Maximum incremental lifetime cancer risk (ILCR) showed 2.8 per 100 people and 1.6 per 1000 people are at considerable and threshold risk, respectively. However, proteinaceous and nutritious food consumption might have kept the participants asymptomatic. The PCA analysis showed that the first principle component (PC1) explains 91.1% of the total variance dominated by As in irrigation water, grain, and vegetables. The dendrogram shows greater variations in similarity in rice and vegetables As, while the latter has been found to contribute more to human body loading compared to grain As.
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Arsénico , Agua Potable , Oryza , Contaminantes del Suelo , Contaminantes Químicos del Agua , Arsénico/análisis , Agua Potable/análisis , Grano Comestible/química , Contaminación de Alimentos/análisis , Humanos , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisis , Verduras , Contaminantes Químicos del Agua/análisisRESUMEN
Polymer composites are gradually replacing traditional metal materials in the fields of aviation, aerospace, automotive and medicine due to their corrosion resistance, light weight and high strength. Moulding technology and organization morphology of polymer composite are key elements affecting the quality of products and their application, so a vacuum hot pressing process for graphenex/poly(ether ketone ketone) (PEKK) (x = 0%, 2%, 3%, 4%, 5%, 6%) composite powders is explored with particularly designed moulding parameters to achieve high conductive properties and good mechanical properties in graphene/PEKK composite sheet with thickness of 1.25 mm and diameter of 80 mm. The vacuum environment ensures that the graphene is not oxidized by air during hot pressing molding, which is essential for achieving conductive property in the graphene/PEKK composite; The hot pressing temperature of each graphene/PEKK composite powder is higher than glass transition temperature but lower than melting temperature, which ensures the graphene/PEKK composite powders is fully compacted and then graphene is fully lapped in the composite sheet. In addition, the graphene/PEKK composite sheet shows conductive property when the graphene content increases to 3wt%, and then the conductivity of the composites increases and then decreases with a peak value at 5wt% with increasing graphene content. By comparing the mechanical properties and microstructure morphology of the graphene/PEKK composite sheets, it was obtained that graphene content has an obvious effect on the mechanical properties of the composites, e.g., the mechanical properties will be increased as the graphene content increasing when graphene content is more than 3%. The graphene distribution law of the composite material with different graphene contents is analysed using a scanning electron microscope (SEM).
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Femtosecond-laser drilling may induce holes in HgCdTe with morphology similar to that induced by ion-milling in loophole technique. So-formed hole structures are proven to be pn junction diodes by the laser beam induced current characterization as well as the conductivity measurement. Transmission and photoluminescence spectral measurements on a n-type dominated hole-array structure give rise to different results from those of an ion-milled sample.
RESUMEN
Averrhoa carambola is a high-biomass tropical tree that has been identified as a Cd accumulator. In the present study, field survey, pot, and hydroponic experiments were conducted to investigate the variation of Cd tolerance and accumulation in cultivars of A. carambola as well as its potential for phytoextraction. In the field survey, it was found that concentrations of Cd in aerial tissues of A. carambola varied greatly among sites and cultivars. The Cd bioconcentration factors (BCFs) and Cd removals by the field-grown A. carambola differed significantly among sites but not among cultivars. Nonetheless, all four carambola cultivars investigated were able to accumulate considerably high concentrations of Cd in their shoots, which indicated that the 4-yr-old carambola stands could remove 0.3 to 51.8% of the total Cd content in the top 20-cm soil layer. When cultured in Cd-spiked soils, the carambola cultivar Hua-Di always showed higher Cd tolerance than the other cultivars; however, this tendency was not confirmed by hydroponic experiment. The Cd BCFs of cultivar Thailand grown in soils with 6 and 12 mg Cd kg(-1) were highest among cultivars, whereas this trend was reversed at 120 mg Cd kg(-1) treatment. Nevertheless, the pot- and hydroponics-grown carambola cultivars generally showed higher capacities to tolerate and accumulate Cd, compared with the control species. The present results indicate that a strong ability to tolerate and accumulate Cd seems to be a trait at the species level in A. carambola, although some degree of variances in both Cd tolerance and accumulation exists among cultivars.
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Cadmio/metabolismo , Restauración y Remediación Ambiental , Metales Pesados/metabolismo , Contaminantes del Suelo/metabolismo , Árboles/fisiología , Asia , Biomasa , Cadmio/toxicidad , Relación Dosis-Respuesta a Droga , Ecosistema , Metales Pesados/toxicidad , Contaminantes del Suelo/toxicidad , Árboles/clasificación , Clima TropicalRESUMEN
OBJECTIVE: This study aimed to explore the expression and clinical significance of LINC01197 in serum of patients with pancreatic cancer (PC). PATIENTS AND METHODS: Fifty PC patients (patient group) treated in our hospital from March 2012 to April 2014 were collected, and another 50 normal people (normal group) were collected for physical examination. The LINC01197 expression in serum of the two groups was detected by qRT-PCR method, and the CA 19.9 expression in serum was detected by Roche automatic biochemistry. The expression and diagnostic value of CA 19.9 and LINC01197 in PC were analyzed, and the relationship between LINC01197 and prognosis of PC patients was observed. RESULTS: The CA 19.9 expression in the patient group was significantly higher than that in the normal group (p<0.001). Their area under the curve was 0.791 and 0.944 respectively. The incidence of phases III+IV, lymphatic invasion, and distant metastasis in patients with low expression of LINC01197 is significantly higher than that in those with high expression, and has higher diagnostic value. With the progress of clinical staging, the TNM expression decreased gradually and there were differences between groups (p<0.001). Spearman's test analysis found that the decreased TNM staging of LINC01197 increased gradually (r=-0.816, p<0.001), and the area under the curve of LINC01197 distinguishing phase I and phase II+phase+III+phase IV was 0.930. The 1-year survival rate and 5-year survival rate of patients in low expression group were lower than those in high expression group (p1 year =0.037, p5 year =0.014). Distant metastasis is an independent prognostic factor for PC patients to survive for 1 to 5 years. Differentiation, TNM staging, and LINC01197 are independent prognostic factors for PC patients to survive for 5 years. CONCLUSIONS: The low expression of LINC01197 in PC patients indicates poor prognosis of patients and is expected to be a potential diagnostic and prognostic indicator of PC.
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Biomarcadores de Tumor/genética , Antígeno CA-19-9/genética , Neoplasias Pancreáticas/genética , ARN Largo no Codificante/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/diagnóstico , Pronóstico , Análisis de RegresiónRESUMEN
Objective: To explore the mediation mechanism of coronary artery lesion among both male and female Kawasaki disease (KD) children. Methods: Children with KD that hospitalized in the Wenzhou Medical University affiliated Yuying Children's Hospital from January 2009 to December 2014, were included in this study. Differences on demographical characteristics, clinical manifestations, laboratory indicators, regimen and time of treatment, results from pre/post echocardiography and treatment between male and female patients, were compared. The independent effect of gender on the risk of coronary artery lesions (CAL) was evaluated, and the mediating effect of BMI, visiting time and KD type on the association between gender and CAL were also studied. Results: The average BMI level of male patients was higher than that of female patients. The difference was statistically significant (P<0.001). The prevalence of overweight among male patients (20.9%) was higher than female (14.1%). The difference was statistically significant (P=0.011). Data from the multivariate logistic regression analysis confirmed that the incidence of CAL in male patients was higher than that in female patients (aOR=1.50, 95%CI: 1.06-2.12) but the CAL was mainly different before on the immunoglobulin therapy. Results from the mediation analysis showed that BMI was an important mediator in the association between gender and CAL, with the indirect effect as 1.05 (95%CI: 1.01- 1.10) and the proportion mediated as 13.0%. Conclusions: Male patients presented higher incidence of CAL but was mainly reflected in the difference of CAL before the treatment. BMI was probably an important mediator related to the association between gender and CAL.
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Enfermedad de la Arteria Coronaria , Síndrome Mucocutáneo Linfonodular , Niño , Enfermedad de la Arteria Coronaria/etiología , Enfermedad de la Arteria Coronaria/patología , Femenino , Humanos , Inmunoglobulinas Intravenosas , Incidencia , Masculino , Síndrome Mucocutáneo Linfonodular/complicaciones , Síndrome Mucocutáneo Linfonodular/terapiaAsunto(s)
Buceo/efectos adversos , Oxígeno/efectos adversos , Convulsiones/prevención & control , Animales , Encefalopatías/etiología , Encefalopatías/patología , Cardiomiopatías/etiología , Cardiomiopatías/patología , Buceo/fisiología , Humanos , Enfermedades Pulmonares/etiología , Enfermedades Pulmonares/patología , Oxígeno/toxicidad , Ratas , Convulsiones/fisiopatologíaRESUMEN
To investigate the effects of bacteria (Burkholderia cepacia) on metal uptake by the hyperaccumulating plant, Sedum alfredii, a hydroponic experiment with different concentrations of Cd and Zn was conducted. It was found that inoculation of bacteria on S. alfredii significantly enhanced plant growth (up to 110% with Zn treatment), P (up to 56.1% with Cd treatment), and metal uptake (up to 243% and 96.3% with Cd and Zn treatment, respectively) in shoots, tolerance index (up to 134% with Zn added treatment), and better translocation of metals (up to 296% and 135% with Cd and Zn treatment, respectively) from root to shoot. In the ampicillin added treatment with metal addition, stimulation of organic acid production (up to an increase of 133% of tartaric acid with Cd treatment) by roots of S. alfredii was observed. The secretion of organic acids appears to be a functional metal resistance mechanism that chelates the metal ions extracellularly, reducing their uptake and subsequent impacts on root physiological processes.
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Burkholderia cepacia/fisiología , Cadmio/metabolismo , Fósforo/metabolismo , Raíces de Plantas/microbiología , Sedum/microbiología , Zinc/metabolismo , Ampicilina , Antibacterianos , Biomasa , Carbono/análisis , Conductividad Eléctrica , Exudados y Transudados/química , Concentración de Iones de Hidrógeno , Hidroponía , Raíces de Plantas/fisiología , Sedum/crecimiento & desarrollo , Sedum/metabolismoRESUMEN
Cell wall hydroxyproline-rich glycoproteins (HRGPs) and glycine-rich proteins (GRPs) were examined at the protein and at the mRNA levels in developing soybean tissues by tissue print immunoblots and RNA blots. In young soybean stems, HRGPs are expressed most heavily in cambium cells, in a few layers of cortex cells surrounding primary phloem, and in some parenchyma cells around the primary xylem, whereas GRPs are highly expressed in the primary xylem and also in the primary phloem. In older soybean stems, HRGP genes are expressed exclusively in cambium cells and GRP genes are most heavily expressed in newly differentiated secondary xylem cells. Similar expression patterns of HRGPs and of GRPs were found in soybean petioles, seedcoats, and young hypocotyls, and also in bean petioles and stems. HRGPs and GRPs become insolubilized in soybean stem cell walls. Three major HRGP mRNAs and two major GRP mRNAs accumulate in soybean stems. Soluble HRGPs are abundant in young hypocotyl apical regions and young root apical regions, whereas in hypocotyl and root mature regions, soluble HRGPs are found only in a few layers of cortex cells surrounding the vascular bundles. GRPs are specifically localized in primary xylem cell walls of young root. These results show that the gene expression of HRGPs and GRPs is developmentally regulated in a tissue-specific manner. In soybean tissues, HRGPs are most heavily expressed in meristematic cells and in some of those cells that may be under stress, whereas GRPs are expressed in all cells that are or are going to be lignified.
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Using a yeast two-hybrid system, we identified a novel protein which interacts with ras p21. This protein shares 69% amino acid homology with ral guanine nucleotide dissociation stimulator (ralGDS), a GDP/GTP exchange protein for ral p24. We designated this protein RGL, for ralGDS-like. Using the yeast two-hybrid system, we found that an effector loop mutant of ras p21 was defective in interacting with the ras p21-interacting domain of RGL, suggesting that this domain binds to ras p21 through the effector loop of ras p21. Since ralGDS contained a region highly homologous with the ras p21-interacting domain of RGL, we examined whether ralGDS could interact with ras p21. In the yeast two-hybrid system, ralGDS failed to interact with an effector loop mutant of ras p21. In insect cells, ralGDS made a complex with v-ras p21 but not with a dominant negative mutant of ras p21. ralGDS interacted with the GTP-bound form of ras p21 but not with the GDP-bound form in vitro. ralGDS inhibited both the GTPase-activating activity of the neurofibromatosis gene product (NF1) for ras p21 and the interaction of Raf with ras p21 in vitro. These results demonstrate that ralGDS specifically interacts with the active form of ras p21 and that ralGDS can compete with NF1 and Raf for binding to the effector loop of ras p21. Therefore, ralGDS family members may be effector proteins of ras p21 or may inhibit interactions between ras p21 and its effectors.
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Proteínas Fúngicas/metabolismo , Proteínas de Unión al GTP/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Unión Competitiva , Línea Celular , Clonación Molecular , ADN de Hongos/genética , Proteínas Fúngicas/genética , Proteínas de Unión al GTP/genética , Ratones , Datos de Secuencia Molecular , Neurofibromina 1 , Unión Proteica , Proteínas/metabolismo , Ratas , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Homología de Secuencia de Aminoácido , Proteínas de Unión al GTP ral , Factor de Intercambio de Guanina Nucleótido ral , Proteínas de Unión al GTP rapRESUMEN
To investigate the variation of Zn and Cd accumulation and tolerance of Sedum alfredii (a newly reported Zn/Cd hyperaccumulator), field surveys and hydroponic experiments were conducted among three populations of this species: two originating from old Pb/Zn mines in Zhejiang (ZJ) and Hunan (HN) Provinces and one from a "clean" site in Guangdong (GD) Province, China. Under field conditions, up to 12,524 and 12,253 mg kg(-1) Zn, and 1400 and 97 mg kg(-1) Cd in shoots of ZJ and HN plants were recorded respectively. Under hydroponic conditions, ZJ and HN plants accumulated significantly higher Zn and Cd in their leaves and stems, and possessed significantly higher Zn and Cd tolerance than GD plants. Among the two contaminated populations, ZJ plants showed higher Cd tolerance and accumulation (in leaves) than HN plants. The present results indicate that significant differences in Zn and Cd accumulation and tolerance exist in populations of S. alfredii.
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Cadmio/análisis , Minería , Sedum/metabolismo , Contaminantes del Suelo/análisis , Zinc/análisis , Biomasa , Cadmio/farmacología , China , Monitoreo del Ambiente/métodos , Hidroponía/métodos , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/metabolismo , Tallos de la Planta/efectos de los fármacos , Tallos de la Planta/metabolismo , Sedum/efectos de los fármacos , Contaminantes del Suelo/farmacología , Zinc/farmacologíaRESUMEN
A field survey was conducted at a deserted arsenic (As) mine in Guangxi Province, China to explore new potential As hyperaccumulators. In addition, young plants of 11 Pteris taxa were grown in glasshouse conditions for 12 weeks on As-amended soils with 0, 50 and 200 mg As kg(-1). Results of the field survey showed that the fern Pteris fauriei accumulated over 1000 mg As kg(-1) in its fronds. Of the 11 Pteris taxa, Pteris aspericaulis, Pteris cretica var. nervosa, P. fauriei, Pteris multifida, P. multifida f. serrulata, and Pteris oshimensis were all found to hyperaccumulate As in addition to P. cretica 'Albo-Lineata' and Pteris vittata (already reported as As hyperaccumulators). However, Pteris ensiformis, Pteris semipinnata and Pteris setuloso-costulata showed no evidence of As hyperaccumulation. Results also revealed a constitutive property of As hyperaccumulation in different populations of P. cretica var. nervosa, P. multifida, P. oshimensis and P. vittata.
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Arsénico/farmacocinética , Pteris/metabolismo , Contaminantes del Suelo/farmacocinética , Agricultura , Arsénico/análisis , Biodegradación Ambiental , China , Monitoreo del Ambiente/métodos , Minería , Contaminantes del Suelo/análisisRESUMEN
A field survey of metal concentrations and arbuscular mycorrhizal (AM) components of plants growing on five mining sites was conducted in Chenzhou City, Hunan Province, Southern China and a control site in Hong Kong. Significant differences were observed in the average concentrations of total heavy metals (Pb, Zn, Cu, Cd) and one metalloid (As) in contaminated soils compared with the control site. Gramineae and Compositae were the dominant plant families growing on mine tailings, with Chrysanthemum moritolium (common chrysanthemum), Cynodon dactylon (Bermuda grass), Miscanthus florodulus (Sword grass) and Pteris vittata (Ladder brake fern) commonly found at all sites. AM fungal colonization was detected in most of the plants. Comparing the four common plant species, three components of mycorrhizal colonization (arbuscules, vesicles and coiled hyphae) were found in the roots of C. dactylon and P. vittata growing at Do Shun Long (DSL) mine site. Concentrations of As in fronds were 24-fold higher than in roots of P. vittata with the highest mycorrhizal colonization rate (73%) among all sampling sites. Extensive mycorrhizal colonization (85%) was also recorded in the roots of C. dactylon with As accumulation 57 times higher than in shoots. The four common plants found in metal contaminated sites had developed different strategies for survival in the contaminated sites with the aid of indigenous AM fungi.
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Metales Pesados/metabolismo , Micorrizas , Plantas/metabolismo , Plantas/microbiología , Contaminantes del Suelo/metabolismo , Arsénico/análisis , Arsénico/metabolismo , China , Hong Kong , Residuos Industriales , Metales Pesados/análisis , Minería , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Contaminantes del Suelo/análisisRESUMEN
Acidification of mine wastes can lead to a series of environmental problems, such as acid drainage, heavy metal mobilization, and ecosystem degradation. Prediction of acid-forming potential is one of the key steps in management of sulfide-bearing mine wastes. In this paper, the acid-forming potential of 180 mine waste samples collected from 17 mine sites in China were studied using a net acid generation (NAG) method. The samples contained different contents of total sulfur (ranging from 0.6 to 200 g kg(-1)), pyritic sulfur (ranging from 0 to 100 g kg(-1)), and acid neutralization capacity (ANC, ranging from -41 to 274 kg H2SO4 t(-1)). Samples with high acid-forming potential are generally due to their high sulfur content or low acid neutralization capacity. After the samples were oxidized by H2O2, the amounts of acid generation and the final NAG pH were measured. Results indicated that the final NAG pH gave a well-defined demarcation between acid-forming and non-acid-forming materials. Samples with final NAG pH >or= 5 could be classified as non-acid-forming materials, while those with NAG pH
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Ácidos/química , Monitoreo del Ambiente/métodos , Minería , Contaminación Química del Agua/prevención & control , Concentración de Iones de HidrógenoRESUMEN
The objective of this study is to evaluate the current status of heavy metal concentrations in constructed wetland, Shaoguan (Guangdong, China). Sediments, three wetland plants (Typha latifolia, Phragmites australis, and Cyperus malaccensis), and six freshwater fish species [Carassius auratus (Goldfish), Cirrhinus molitorella (Mud carp), Ctenopharyngodon idellus (Grass carp), Cyprinus carpio (Wild common carp), Nicholsicypris normalis (Mandarin fish), Sarcocheilichthys kiangsiensis (Minnows)] in a constructed wetland in Shaoguan were collected and analyzed for their heavy metal compositions. Levels of Pb, Zn, Cu, and Cd in sediments exceeded approximately 532, 285, 11, and 66 times of the Dutch Intervention value. From the current study, the concentrations of Pb and Zn in three plants were generally high, especially in root tissues. For fish, concentrations of all studied metals in whole body of N. mormalis were the highest among all the fishes investigated (Pb 113.4 mg/kg, dw; Zn 183.1 mg/kg, dw; Cu 19.41 mg/kg, dw; 0.846 mg/kg, dw). Heavy metal accumulation in different ecological compartments was analyzed by principle component analysis (PCA), and there is one majority of grouped heavy metals concentration as similar in composition of ecological compartment, with the Cd concentration quite dissimilar. In relation to future prospect, phytoremediation technology for enhanced heavy metal accumulation by constructed wetland is still in early stage and needs more attention in gene manipulation area.