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1.
J Coll Physicians Surg Pak ; 30(3): 276-281, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32169136

RESUMO

OBJECTIVE: To determine the regular changes of blood coagulation indices in twin pregnancy complicated with preeclampsia (PE). STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Fujian Provincial Maternity and Children Hospital from January 2014 to December 2017. METHODOLOGY: A total of 180 twin pregnancies were enrolled in this study, including 40 diagnosed as PE, 50 as severe PE (SPE), and 90 as normal twin pregnancies. The changes of coagulation parameters of twin pregnant women in different gestational states and periods were retrospectively analysed. RESULTS: During the middle and late pregnancies in all groups, the PT (prothrombin time) decreased, and D-Di (D-dimers) increased gradually compared to early pregnancy (p <0.05). When D-Di increased abnormally, adverse pregnancy outcomes increased. APTT (activated partial thromboplastin time) and TT (thromoplastin time) were shortened first and then significantly prolonged (p <0.05). In the normal twin group, FIB was increased gradually from early pregnancy to midlate pregnancy; in the PE group, FIB was increased and then decreased, especially in the sPE group (p <0.05). There was no significant difference in coagulation function in early pregnancy (p >0.05). FIB in sPE group was lower than that in other two groups in late pregnancy. TT in sPE group was higher than that in other two groups. D-Di and APTT in PE group and sPE group were higher than those in normal group (p <0.05). The TT sensitivity was 68.8% with specificity 72.4%, at cut-off value of 13.48 s (p <0.01). CONCLUSION: The regular changes of blood coagulation indices in twin pregnancy complicated with PE had great predictive and diagnostic value of preeclampsia.

2.
Anal Chem ; 92(5): 3581-3588, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-31916433

RESUMO

In situ monitoring of Sb speciation improves the understanding of Sb biogeochemistry and toxicity in ecosystems. Precise measurement of Sb is a challenge due to its instability of oxidation and ultratrace concentration. The development of simple and reliable methods specific to SbIII measurement is not only appealing but essential for implementing regulations. Here, we present an in situ speciation analysis method for SbIII, using the diffusive gradients in thin films (DGT) technique, combined with mercapto-functionalized SBA-15 mesoporous silica nanoparticles (MSBA). Laboratory performance tests confirmed MSBA-DGT uptake was independent of pH (4-9) and ionic strength (0.1-200 mmol L-1). DGT devices equipped with MSBA-based binding gels showed a theoretically linear accumulation of SbIII and exhibited a high capacity for SbIII at 65 µg/gel disc, with negligible accumulation of SbV over a 72 h deployment. Compared with commercial 3-mercaptopropyl-functionalized silica (MFS), the nanosized MSBA facilitate its even distribution in the binding gels. Furthermore, the good selectivity and high homogeneity of the MSBA gel enabled it to be applied in a rice rhizosphere in conjunction with AgI gel to investigate the effects of sulfur application on the SbIII solubility. In summary, the newly developed MSBA-DGT provides a selective measurement of SbIII, showing potential for environmental monitoring and further application in understanding the biogeochemical process of Sb.

3.
J Hazard Mater ; 383: 121196, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31539663

RESUMO

Lanthanum oxide nanoparticles (nano-La2O3) was used to develop a novel binding gel within an in situ passive sampler based on diffusive gradients in thin-films technique (NL-DGT) for measuring As(V), Sb(V), and V(V). Performance characteristics of NL-DGT were independent of pH (pH: 3.1-7.9 for As, 3.1-8.5 for V, and 3.1-6.5 for Sb) and ionic strength (0.1-500 mmol L-1 for As and V, and 0.1-200 mmol L-1 for Sb). No obvious competition effects among As, Sb, and V with different concentration ratios were found for NL-DGT measurement. Long term storage (8-188 d) of the nano-La2O3 gels in 0.01 mol L-1 NaNO3 at 4 °C did not affect their performance. During the field deployments in Yangtze and Jiuxiang River, NL-DGT measured concentrations of As and V were similar to those measured by the grab samples, while some differences were found for Sb between DGT and grab sampling because higher pH (∼8.0) in the studied rivers caused the performance deterioration of NL-DGT. Generally, the newly developed NL-DGT is suitable for monitoring As and V in freshwater from acidic to light alkaline and Sb in acidic and neutral water.

4.
J Matern Fetal Neonatal Med ; : 1-7, 2019 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-31588836

RESUMO

Objective: To explore the clinical characteristics, treatment and prognosis of fetal intracranial hemorrhage in pregnancy and to improve the level of diagnosis and treatment. Methods: We retrospectively analyzed the clinical data of eight cases of fetal intracranial hemorrhage in our hospital from 2014 to 2017, including the clinical manifestations, etiology, imaging features, treatment and prognosis. Results: All the cases were diagnosed by prenatal color ultrasound or magnetic resonance imaging (MRI); one of the cases had decreased fetal movements and abnormal fetal heart rate monitoring, and the remaining seven cases had no special clinical symptoms. No clear cause was found in all the cases. Two patients with grade I fetal intracranial hemorrhage and 1 patient with grade II had a cesarean delivery, and no neurological sequelae were found in these neonates after 6 months of follow-up. There was one patient with grade III and four patients with grade IV fetal intracranial hemorrhage; one of the patients with grade IV was stillborn at the time of the discovery, and cesarean section was selected due to scarring of the uterus; intra-amniotic injection of ethacridine lactate was selected to induce labor in three cases, and vaginal delivery was selected; one of the patients with grade IV chose vaginal delivery, and the neonatal cranial brain magnetic resonance imaging after delivery showed no increase in intracranial lesions but showed incomplete development of the remaining nervous system. Conclusion: Fetal intracranial hemorrhage can be diagnosed by prenatal color ultrasound and MRI, yet it is often impossible to determine the cause. The prognosis of fetal intracranial hemorrhage is related to grade, and the prognosis of cerebral hemorrhage in patients with grades III-IV is poor.

5.
J Phys Chem Lett ; 10(18): 5557-5562, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31475532

RESUMO

Mechanoresponsive luminescent (MRL) materials have attracted considerable attention because of their potential applications in mechanical sensors, memory chips, and security inks; MRL materials possessing high efficiency and multicolor emission qualities are especially interesting. In this Letter, we found 1,2,3,4-tetraphenyl-1,3-cyclopentadiene (TPC) crystal exhibited both pressure-induced emission enhancement (PIEE) and multicolor behavior. In addition, infrared spectroscopy analysis indicated that the ring-opening reaction of the phenyl ring occurred when pressure was beyond 24.7 GPa. The reaction was promoted from 24.7 to 35.9 GPa, which resulted in the redder irreversible color change for the sample released from 35.9 GPa than from 24.7 GPa. The results regarding the mechanoresponsive behavior of TPC offered a deep insight into PIEE and multicolor properties from the structural point of view and inspired the idea of capturing different colors by hydrostatic pressure, which will facilitate the design of and search for high-performance MRL materials.

6.
Environ Sci Technol ; 53(10): 5717-5724, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31009209

RESUMO

Although strong in vivo-in vitro correlations (IVIVCs) between relative bioavailability (RBA) and bioaccessibility of soil Pb were well reported, knowledge on the fractions of bioaccessible Pb in simulated gastrointestinal (GI) fluids that are available for absorption into the systemic circulation is limited. Here, Pb-RBA in 14 Pb-contaminated soils were assessed using an in vivo mouse bioassay and compared to Pb bioaccessibility by the gastrointestinal phase of the UBM (Unified Bioaccessibility research group of Europe (BARGE) Method) in vitro assay with and without 0.45 µm filtration of GI fluid. Results showed good IVIVC between Pb-RBA and Pb bioaccessibility without filtration ( r 2 = 0.62), while Pb bioaccessibility with filtration provided a poor correlation with Pb-RBA ( r 2 = 0.16). This suggested that besides dissolved Pb ions, Pb-complexes formed in the UBM gastrointestinal fluid might also contribute to bioavailable Pb. To ascertain this, DGT (diffusive gradients in thin-films) devices which can measure both Pb2+ ions and labile inorganic and organic Pb-complexes were introduced to the UBM fluids to measure Pb DGT-bioaccessibility, which showed strong correlation to Pb-RBA ( r 2 = 0.71). With increasing diffusive gel thickness which could enhance release of Pb ions from Pb-complexes, Pb DGT-bioaccessibility increased by 3.4-5.7 times, while inclusion of dialysis membrane within DGT devices significantly decreased Pb DGT-bioaccessibility by inhibiting diffusion of Pb complexes to binding gel. These results confirmed the contribution of Pb-complexes to Pb bioavailability, providing new insights to Pb bioavailability.


Assuntos
Poluentes do Solo , Animais , Bioensaio , Disponibilidade Biológica , Europa (Continente) , Camundongos , Diálise Renal , Solo
7.
Nature ; 565(7738): 218-221, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30626940

RESUMO

Laboratory measurements of sound velocities of high-pressure minerals provide crucial information on the composition and constitution of the deep mantle via comparisons with observed seismic velocities. Calcium silicate (CaSiO3) perovskite (CaPv) is a high-pressure phase that occurs at depths greater than about 560 kilometres in the mantle1 and in the subducting oceanic crust2. However, measurements of the sound velocity of CaPv under the pressure and temperature conditions that are present at such depths have not previously been performed, because this phase is unquenchable (that is, it cannot be physically recovered to room conditions) at atmospheric pressure and adequate samples for such measurements are unavailable. Here we report in situ X-ray diffraction and ultrasonic-interferometry sound-velocity measurements at pressures of up to 23 gigapascals and temperatures of up to 1,700 kelvin (similar to the conditions at the bottom of the mantle transition region) using sintered polycrystalline samples of cubic CaPv converted from bulk glass and a multianvil apparatus. We find that cubic CaPv has a shear modulus of 126 ± 1 gigapascals (uncertainty of one standard deviation), which is about 26 per cent lower than theoretical predictions3,4 (about 171 gigapascals). This value leads to substantially lower sound velocities of basaltic compositions than those predicted for the pressure and temperature conditions at depths between 660 and 770 kilometres. This suggests accumulation of basaltic crust in the uppermost lower mantle, which is consistent with the observation of low-seismic-velocity signatures below 660 kilometres5,6 and the discovery of CaPv in natural diamond of super-deep origin7. These results could contribute to our understanding of the existence and behaviour of subducted crust materials in the deep mantle.

8.
J Int Med Res ; 47(1): 206-214, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30465458

RESUMO

OBJECTIVES: To investigate the expression of ß-catenin in chorionic villi, and to explore its roles in placenta accreta and placenta previa. METHODS: We compared ß-catenin expression in the control group, placenta accreta group (lesion area and normal zones), and placenta previa group (placental central and placental edge zones) by immunohistochemistry, Western blotting, and RT-PCR techniques. RESULTS: Compared with the normal group, the placenta accreta group had a longer length of stay, greater bleeding volume, and lower newborn birth weight. Further, the expression of ß-catenin was lower in both placenta previa and placenta accreta groups than in the control group, as measured by immunohistochemistry. Compared with the control group, expression of ß-catenin was significantly lower in the placenta previa and placenta accreta groups by Western blotting and RT-PCR. Importantly, the level of placental ß-catenin was significantly different when compared between the lesion and normal zones of placenta. CONCLUSION: The expression of ß-catenin in placenta accreta might play an important role in the regulation of placental cell invasion; low expression of ß-catenin in placenta accreta might be responsible for excessive trophoblastic invasion.


Assuntos
Placenta Acreta/genética , Placenta Prévia/genética , Hemorragia Pós-Parto/genética , beta Catenina/genética , Adulto , Estudos de Casos e Controles , Vilosidades Coriônicas/metabolismo , Vilosidades Coriônicas/patologia , Feminino , Expressão Gênica , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Placenta Acreta/metabolismo , Placenta Acreta/patologia , Placenta Prévia/metabolismo , Placenta Prévia/patologia , Hemorragia Pós-Parto/metabolismo , Hemorragia Pós-Parto/patologia , Gravidez , Trofoblastos/metabolismo , Trofoblastos/patologia , beta Catenina/metabolismo
9.
Environ Sci Technol ; 52(24): 14140-14148, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30431268

RESUMO

The speciation of selenium (Se) controls its fate and behavior, determining both its biological and environmental activities. However, in situ monitoring of SeIV presents a significant challenge due to its sensitivity to redox change. A novel diffusive gradients in thin films (DGT) technique containing mercapto-, amino-bifunctionalized SBA15 mesoporous silica nanoparticles was developed and evaluated in a series of laboratory and field deployment tests. The SBA-DGT exhibited a linear accumulation of SeIV ( r2 > 0.997) over a 72 h deployment, with negligible accumulation of SeVI(<5%). Consistent prediction of SeIV occurred within ionic strength and pH ranges of 0.1-200 mmol L-1 and 3.6-8, respectively. Limits of detection of the SBA-DGT were 0.03 µg SeIV L-1, which is suitable for natural waters. Moreover, the properties of the bifunctionalized SBA15 enable it to be fabricated within ultrathin (0.05 mm) gel layers for use in conjunction with O2 planar optode imaging. This new sandwich sensor technology with SBA-DGT was validated by mapping the two-dimensional distribution of SeIV and oxygen simultaneously in rice rhizospheres. This study shows that SBA-DGT provides a selective measurement of SeIV in situ, demonstrating its potential for both environmental monitoring and as a research tool for improving our understanding of Se biogeochemical processes.


Assuntos
Nanopartículas , Selênio , Monitoramento Ambiental , Dióxido de Silício , Solo
10.
J Int Med Res ; 46(10): 4082-4091, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29963935

RESUMO

Objective To investigate the prognostic significance of and risk factors for solitary lymph node metastasis (SLNM) of patients with cervical carcinoma. Methods Clinical data from patients with International Federation of Gynecology and Obstetrics (FIGO) stages IA2 to IIA cervical carcinoma who underwent radical hysterectomy and pelvic lymphadenectomy between January 2003 and December 2010 were analysed retrospectively. Histopathological analysis was used to identify SLNM. Long-term survival and risk factors associated with SLNM were analysed. Results The study enrolled 302 patients with cervical cancer: 48 with SLNM (SLNM group) and 254 patients with no lymph node metastases (nLNM group). FIGO stage, tumour grade, depth of tumour invasion, uterine body involvement, parametrial involvement and lymphovascular invasion differed significantly between the two groups. Logistic regression analysis revealed that FIGO stage, depth of tumour invasion and lymphovascular invasion were independent factors associated with SLNM. The 5-year survival rates of the SLNM and nLNM groups were 54.2% and 87.8%, respectively. Multivariate analysis identified SLNM as an independent factor affecting survival. Conclusions The occurrence of just one solitary lymph node metastasis significantly worsened the prognosis in patients with cervical carcinoma compared with patients without lymph node metastases.


Assuntos
Linfonodos/patologia , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/patologia , Adulto , Sobreviventes de Câncer/estatística & dados numéricos , Feminino , Humanos , Histerectomia , Excisão de Linfonodo , Metástase Linfática , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Neoplasias do Colo do Útero/cirurgia
11.
Anal Chem ; 90(16): 10016-10023, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-30037218

RESUMO

Widespread use of organophosphorus flame retardants (OPFRs) and their ubiquity in water results in the need for a robust and reliable monitoring technique to better understand their fate and environmental impact. In situ passive sampling using the diffusive gradients in thin-films (DGT) technique provides time-integrated data and is developed for measuring OPFRs here. Ultrasonic extraction of binding gels in methanol provided reliable recoveries for all tested OPFRs. Diffusion coefficients of TCEP, TCPP, TDCPP, TPrP, TBP, and TBEP in the agarose diffusive gel (25 °C) were obtained. The capacity of an HLB binding gel for OPFRs was >115 µg per disc, and the binding performance did not deteriorate with time up to 131 days. DGT performance is independent of typical environmental ranges of pH (3.12-9.71), ionic strength (0.1-500 mmol L-1), and dissolved organic matter (0-20 mg L-1), and also of diffusive layer thickness (0.64-2.14 mm) and deployment time (3-168 h). Negligible competition effects between OPFRs was found. DGT-measured concentrations of OPFRs in a wastewater treatment plant (WWTP) effluent (12-16 days) were comparable to those obtained by grab sampling, further verifying DGT's reliability for measuring OPFRs in waters.

12.
Sci Rep ; 8(1): 6358, 2018 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-29679056

RESUMO

The 660-km seismic discontinuity, which is a significant structure in the Earth's mantle, is generally interpreted as the post-spinel transition, as indicated by the decomposition of ringwoodite to bridgmanite + ferropericlase. All precise high-pressure and high-temperature experiments nevertheless report 0.5-2 GPa lower transition pressures than those expected at the discontinuity depth (i.e. 23.4 GPa). These results are inconsistent with the post-spinel transition hypothesis and, therefore, do not support widely accepted models of mantle composition such as the pyrolite and CI chondrite models. Here, we present new experimental data showing post-spinel transition pressures in complete agreement with the 660-km discontinuity depth obtained by high-resolution in situ X-ray diffraction in a large-volume high-pressure apparatus with a tightly controlled sample pressure. These data affirm the applicability of the prevailing mantle models. We infer that the apparently lower pressures reported by previous studies are experimental artefacts due to the pressure drop upon heating. The present results indicate the necessity of reinvestigating the position of mantle mineral phase boundaries previously obtained by in situ X-ray diffraction in high-pressure-temperature apparatuses.

13.
Colloids Surf B Biointerfaces ; 162: 288-295, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29216516

RESUMO

The primary objective of this study was to determine the capacity and the mechanisms of adhesion of Bacillus subtilis onto variable- and constant-charge soil colloids. The adhesion process was investigated using in situ attenuated total reflectance (ATR)-Fourier transform infrared spectroscopy (FTIR), zeta potential, and batch adhesion experiments. The maximum adhesion capacity of B. subtilis on the colloids of Oxisol, Ultisol, and Alfisol reached 699.17, 462.56, and 258.82mgg-1, respectively. B. subtilis adhesion to all three soil colloids decreased as the suspension pH increased from 3 to 8. Saturation coverage and adhesion rate constant values were calculated with the pseudo-first-order kinetics equation using the absorbance at 1548cm-1. Both values were highest for Oxisol, followed by Ultisol, and lowest for Alfisol. These observations are consistent with the surface charges of these soil colloids. A larger positive charge on variable-charge soils (Oxisol and Ultisol) increased B. subtilis adhesion relative to that of constant-charge soil (Alfisol). This is in agreement with the interaction energy between B. subtilis and soil colloids, which was calculated using the Derjaguin-Landau-Verwey-Overbeek theory. As revealed by ATR-FTIR spectroscopy, chemical bonds formed by protein, phosphate, and COOH groups on B. subtilis, as well as iron and aluminum hydroxyl groups in soil, contributed to B. subtilis adhesion to soil colloids. Therefore, chemical bond formation and electrostatic interaction are two major mechanisms of B. subtilis adhesion onto soil colloids.


Assuntos
Alumínio/química , Bacillus subtilis/química , Proteínas de Bactérias/química , Ferro/química , Fosfatos/química , Solo/química , Adsorção , Aderência Bacteriana , Coloides , Concentração de Íons de Hidrogênio , Cinética , Eletricidade Estática , Termodinâmica
14.
Front Plant Sci ; 8: 1489, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28970841

RESUMO

This work was designed to understand the mechanisms of adsorption of copper (Cu) and cadmium (Cd) on roots of indica and japonica varieties of rice. Six varieties each of indica and japonica rice were grown in hydroponics and the chemical properties of the root surface were analyzed, including surface charges and functional groups (-COO- groups) as measured by the streaming potential and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Binding forms of heavy metals adsorbed on rice roots were identified using sequential extraction methods. In rice roots exposed to Cu and Cd solutions, Cu existed mainly in both exchangeable and complexed forms, whereas Cd existed mainly in the exchangeable form. The amounts of exchangeable Cu and Cd and total adsorbed metal cations on the roots of indica varieties were significantly greater than those on the roots of japonica varieties, and the higher negative charges and the larger number of functional groups on the roots of indica varieties were responsible for their higher adsorption capacity and greater binding strength for Cu and Cd. Surface charge and functional groups on roots play an important role in the adsorption of Cu and Cd on the rice roots.

15.
Environ Sci Pollut Res Int ; 24(30): 23598-23606, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28856587

RESUMO

The interaction between rice roots and Fe/Al oxide-coated quartz was investigated through zeta potential measurements and column leaching experiments in present study. The zeta potentials of rice roots, Fe/Al oxide-coated quartz, and the binary systems containing rice roots and Fe/Al oxide-coated quartz were measured by a specially constructed streaming potential apparatus. The interactions between rice roots and Fe/Al oxide-coated quartz particles were evaluated/deduced based on the differences of zeta potentials between the binary systems and the single system of rice roots. The zeta potentials of the binary systems moved in positive directions compared with that of rice roots, suggesting that there were overlapping of diffuse layers of electric double layers on positively charged Fe/Al oxide-coated quartz and negatively charged rice roots and neutralization of positive charge on Fe/Al oxide-coated quartz with negative charge on rice roots. The greater amount of positive charges on Al oxide led to the stronger interaction of Al oxide-coated quartz with rice roots and the more shift of zeta potential compared with Fe oxide. The overlapping of diffuse layers on Fe/Al oxide-coated quartz and rice roots was confirmed by column leaching experiments. The greater overlapping of diffuse layers on Al oxide and rice roots led to more simultaneous adsorptions of K+ and NO3- and greater reduction in leachate electric conductivity when the column containing Al oxide-coated quartz and rice roots was leached with KNO3 solution, compared with the columns containing rice roots and Fe oxide-coated quartz or quartz. When the KNO3 solution was replaced with deionized water to flush the columns, more K+ and NO3- were desorbed from the binary system containing Al oxide-coated quartz and rice roots than from other two binary systems, suggesting that the stronger electrostatic interaction between Al oxide and rice roots promoted the desorption of K+ and NO3- from the binary system and enhanced overlapping of diffuse layers on these oppositely charged surfaces compared with other two binary systems. In conclusion, the overlapping of diffuse layers occurred between positively charged Fe/Al oxides and rice roots, which led to neutralization of opposite charge and affected adsorption and desorption of ions onto and from the charged surfaces of Fe/Al oxides and rice roots.


Assuntos
Alumínio/química , Ferro/química , Oryza/química , Raízes de Plantas/química , Quartzo/química , Solo/química , Adsorção , Eletricidade , Oryza/crescimento & desenvolvimento , Óxidos , Raízes de Plantas/crescimento & desenvolvimento , Propriedades de Superfície
16.
Ecotoxicol Environ Saf ; 145: 207-213, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28735157

RESUMO

Iron (Fe) and aluminum (Al) hydroxides in variable charge soils attached to rice roots may affect surface-charge properties and subsequently the adsorption and uptake of nutrients and toxic metals by the roots. Adhesion of amorphous Fe and Al hydroxides onto rice roots and their effects on zeta potential of roots and adsorption of potassium (K+) and cadmium (Cd2+) by roots were investigated. Rice roots adsorbed more Al hydroxide than Fe hydroxide because of the greater positive charge on Al hydroxide. Adhesion of Fe and Al hydroxides decreased the negative charge on rice roots, and a greater effect of the Al hydroxide. Consequently, adhesion of Fe and Al hydroxides reduced the K+ and Cd2+ adsorption by rice roots. The results of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and desorption of K+ and Cd2+ from rice roots indicated that physical masking by Fe and Al hydroxides and diffuse-layer overlapping between the positively-charged hydroxides and negatively-charged roots were responsible for the reduction of negative charge on roots induced by adhesion of the hydroxides. Therefore, the interaction between Fe and Al hydroxides and rice roots reduced negative charge on roots and thus inhibited their adsorption of nutrient and toxic cations.


Assuntos
Hidróxido de Alumínio/química , Cádmio/metabolismo , Compostos Férricos/química , Oryza/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Potássio/metabolismo , Adesividade , Adsorção , Eletroquímica , Oryza/química , Oryza/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Solo/química , Propriedades de Superfície
17.
Environ Sci Pollut Res Int ; 24(7): 6698-6709, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28084598

RESUMO

The rapid increase in agricultural pollution demands judicious use of inputs and outputs for sustainable crop production. Crop straws were pyrolyzed under oxygen-limited conditions at 400 °C for 2 h to prepare peanut straw biochar (PB), canola straw biochar (CB), and wheat straw biochar (WB). Then, 300-g soils were incubated each with urea nitrogen (UN) and UN + biochars with or without dicyandiamide (DCD) for 60 days. During the incubations, soil acidification induced by urea was somewhat inhibited by biochars, but nitrification of hydrolyzed NH4+ produced much more acidity than the neutralization potential of the biochars. In single UN (200 mg/kg) treatment, soil pH decreased drastically and the final pH after incubation was lower than the control. Antagonistic to UN, all three biochars neutralized the soil acidity, which was consistent to their inherent alkalinity. DCD inhibited nitrification which was obvious throughout the incubations, as 30 mg/kg DCD + 200 mg/kg UN combined with 1  % PB, CB, and WB retained 0.94, 0.79, and 1.19 units higher pH, respectively, and significantly reduced exchangeable acidity over the treatments without DCD (P < 0.05). The treatments of UN + biochars with and without DCD had highly significant effects on soil pH, exchangeable Al3+, NH4+-N, (NO3-+NO2-)-N, and available P (P < 0.05). Amplified NH4+-N retentions at higher rates of PB referred increased negatively charged sites for nutrient adsorptions. Applied UN transformations varied among different treatments, and the maximum amounts of total mineral N recovered were 218.3, 218.5, and 223.8 mg/kg in the presence of DCD by PB, CB, and WB, compared to 198.2, 201.6, and 205.2 mg/kg, respectively, in no DCD treatments. Urea induced severe soil acidification and even lowered the ameliorative effects of applied biochars. Thus, ammonium-based fertilizers must include nitrification inhibitor (DCD) and, if used in combination with biochars will offer a suitable choice to reduce the acidity, improve base saturation and fertility of soil for sustainable agriculture.


Assuntos
Carvão Vegetal/química , Guanidinas/química , Poluentes do Solo/isolamento & purificação , Solo/química , Ureia/química , Agricultura , Compostos de Amônio/química , Arachis/química , Concentração de Íons de Hidrogênio , Componentes Aéreos da Planta/química , Poluentes do Solo/química , Triticum/química
18.
Sci Rep ; 6: 36373, 2016 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-27805020

RESUMO

Little information is available on chemical forms of heavy metals on integrate plant roots. KNO3 (1 M), 0.05M EDTA at pH6 and 0.01 M HCl were used sequentially to extract the exchangeable, complexed and precipitated forms of Cu(II) and Cd(II) from soybean roots and then to investigate chemical form distribution of Cu(II) and Cd(II) on soybean roots. Cu(II) and Cd(II) adsorbed on soybean roots were mainly exchangeable form, followed by complexed form, while their precipitated forms were very low under acidic conditions. Soybean roots had a higher adsorption affinity to Cu(II) than Cd(II), leading to higher toxic of Cu(II) than Cd(II). An increase in solution pH increased negative charge on soybean and thus increased exchangeable Cu(II) and Cd(II) on the roots. Ca2+, Mg2+ and NH4+ reduced exchangeable Cu(II) and Cd(II) levels on soybean roots and these cations showed greater effects on Cd(II) than Cu(II) due to greater adsorption affinity of the roots to Cu(II) than Cd(II). L-malic and citric acids decreased exchangeable and complexed Cu(II) on soybean roots. In conclusion, Cu(II) and Cd(II) mainly existed as exchangeable and complexed forms on soybean roots. Ca2+ and Mg2+ cations and citric and L-malic acids can potentially alleviate Cu(II) and Cd(II) toxicity to plants.

19.
J Chem Phys ; 145(12): 124319, 2016 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-27782680

RESUMO

We present a joint experimental and theoretical study on the high-pressure behavior of bromine confined in the one-dimensional (1D) nanochannels of zeolite AlPO4-5 (AFI) single crystals. Raman scattering experiments indicate that loading bromine into AFI single crystals can lead to the formation of bromine molecular chains inside the nanochannels of the crystals. High-pressure Raman and X-ray diffraction studies demonstrate that high pressure can increase the length of the confined bromine molecular chains and modify the inter- and intramolecular interactions of the molecules. The confined bromine shows a considerably different high-pressure behavior to that of bulk bromine. The pressure-elongated bromine molecular chains can be preserved when the pressure is reduced to ambient pressure. Theoretical simulations explain the experimental results obtained from the Raman spectroscopy and X-ray diffraction studies. Furthermore, we find that the intermolecular distance between confined bromine molecules gradually becomes comparable to the intramolecular bond length in bromine molecules upon compression. This may result in the dissociation of the bromine molecules and the formation of 1D bromine atomic chains at pressures above 24 GPa. Our study suggests that the unique nanoconfinement has a considerable effect on the high-pressure behavior of bromine, and the confined bromine species concomitantly enhance the structural stability of the host AFI single crystals.

20.
Exp Ther Med ; 12(6): 3767-3772, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28101166

RESUMO

Traumatic brain injury (TBI) is the predominant cause of mortality in young adults and children living in China. TBI induces inflammatory responses; in addition, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 are important pro-inflammatory cytokines. Considering the observation that Hsp-70 overexpression can exert neuroprotection, identifying a drug that is able to induce the upregulation of Hsp70 has the potential to be a promising therapy for the treatment of neurological diseases. Thus, the present study assessed the clinical effectiveness of an anticancer drug and Hsp70 activator, 17-allylamino-demethoxygeldanamycin (17-AAG), to evaluate its potential as a treatment for patients with TBI. The aim of present study was to determine the neuroprotective effects of 17-AAG following trauma and to investigate the underlying mechanisms of action. To establish rat models, rats were subjected to a controlled cortical impact injury and randomly divided into vehicle or 17-AAG groups. In the 17-AAG group, rats were administered with an intraperitoneal injection of 17-AAG (80 mg/kg) immediately following the establishment of TBI. The motor function was measured using Neurologic Severity Score, and neuronal death was evaluated using immunofluorescence. The expression levels of GLT-1, Bcl-2 and Hsp-70 were detected by western blot analysis and the expression levels of inflammatory cytokines were quantified using ELISA. The present study determined that 17-AAG significantly reduced brain edema and motor neurological deficits (P<0.05), in addition to increasing neuronal survival. The aforementioned findings are associated with a downregulation of the expression levels of pro-inflammatory cytokines TNF-α, IL-1ß and IL-6. Conversely, no significant changes of glutamate transporter-1 expression were observed. The present results suggest that 17-AAG treatment may provide a neuroprotective effect by reducing inflammation following TBI.

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