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1.
ACS Appl Mater Interfaces ; 16(7): 8772-8782, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38324765

RESUMEN

Olefin-linked covalent organic frameworks (COFs) have exhibited great potential in visible-light photocatalysis. In principle, expanding fully conjugated COFs can facilitate light absorption and charge transfer, leading to improved photocatalysis. Herein, three olefin-linked COFs with the same topology are synthesized by combining 2,4,6-trimethyl-1,3,5-triazine (TMT) with 1,3,5-triformylbenzene (TFB), 1,3,5-tris(4-formylphenyl)benzene (TFPB), and 1,3,5-tris(4-formylphenylethynyl)benzene (TFPEB), namely, TMT-TFB-COF, TMT-TFPB-COF, and TMT-TFPEB-COF, respectively. From TMT-TFB-COF to TMT-TFPB-COF, expanding phenyl rings provides only limited expansion for π-conjugation due to the steric effect of structural twisting. However, from TMT-TFPB-COF to TMT-TFPEB-COF, the insertion of acetylenes eliminates the steric effect and provides more delocalized π-electrons. As such, TMT-TFPEB-COF exhibits the best optoelectronic properties among these three olefin-linked COFs. Consequently, the photocatalytic performance of TMT-TFPEB-COF is much better than those of TMT-TFB-COF and TMT-TFPB-COF on the oxidation of organic sulfides into sulfoxides with oxygen. The desirable reusability and substrate compatibility of the TMT-TFPEB-COF photocatalyst are further confirmed. The selective formation of organic sulfoxides over TMT-TFPEB-COF under blue light irradiation proceeds via both electron- and energy-transfer pathways. This work highlights a rational design of expanding the π-conjugation of fully conjugated COFs toward selective visible-light photocatalysis.

2.
Aging Dis ; 15(1): 115-152, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37307828

RESUMEN

As a recently discovered waste removal system in the brain, cerebral lymphatic system is thought to play an important role in regulating the homeostasis of the central nervous system. Currently, more and more attention is being focused on the cerebral lymphatic system. Further understanding of the structural and functional characteristics of cerebral lymphatic system is essential to better understand the pathogenesis of diseases and to explore therapeutic approaches. In this review, we summarize the structural components and functional characteristics of cerebral lymphatic system. More importantly, it is closely associated with peripheral system diseases in the gastrointestinal tract, liver, and kidney. However, there is still a gap in the study of the cerebral lymphatic system. However, we believe that it is a critical mediator of the interactions between the central nervous system and the peripheral system.


Asunto(s)
Sistema Nervioso Central , Sistema Linfático , Encéfalo/fisiología , Homeostasis
3.
Int J Nanomedicine ; 18: 7559-7581, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38106446

RESUMEN

Dichloroacetate (DCA) is an investigational drug used to treat lactic acidosis and malignant tumours. It works by inhibiting pyruvate dehydrogenase kinase and increasing the rate of glucose oxidation. Some studies have documented the neuroprotective benefits of DCA. By reviewing these studies, this paper shows that DCA has multiple pharmacological activities, including regulating metabolism, ameliorating oxidative stress, attenuating neuroinflammation, inhibiting apoptosis, decreasing autophagy, protecting the blood‒brain barrier, improving the function of endothelial progenitor cells, improving mitochondrial dynamics, and decreasing amyloid ß-protein. In addition, DCA inhibits the enzyme that metabolizes it, which leads to peripheral neurotoxicity due to drug accumulation that may be solved by individualized drug delivery and nanovesicle delivery. In summary, in this review, we analyse the mechanisms of neuroprotection by DCA in different diseases and discuss the causes of and solutions to its adverse effects.


Asunto(s)
Enfermedades Metabólicas , Neoplasias , Enfermedades del Sistema Nervioso , Fármacos Neuroprotectores , Humanos , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Péptidos beta-Amiloides , Neoplasias/tratamiento farmacológico
4.
J Cancer Res Clin Oncol ; 149(11): 8923-8934, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37154927

RESUMEN

PURPOSE: To predict the risk of radiation pneumonitis (RP), a multiomics model was built to stratify lung cancer patients. Our study also investigated the impact of RP on survival. METHODS: This study retrospectively collected 100 RP and 99 matched non-RP lung cancer patients treated with radiotherapy from two independent centres. They were divided into training (n = 175) and validation cohorts (n = 24). The radiomics, dosiomics and clinical features were extracted from planning CT and electronic medical records and were analysed by LASSO Cox regression. A multiomics prediction model was developed by the optimal algorithm. Overall survival (OS) between the RP, non-RP, mild RP, and severe RP groups was analysed by the Kaplan‒Meier method. RESULTS: Sixteen radiomics features, two dosiomics features, and one clinical feature were selected to build the best multiomics model. The optimal performance for predicting RP was the area under the receiver operating characteristic curve (AUC) of the testing set (0.94) and validation set (0.92). The RP patients were divided into mild (≤ 2 grade) and severe (> 2 grade) RP groups. The median OS was 31 months for the non-RP group compared with 49 months for the RP group (HR = 0.53, p = 0.0022). Among the RP subgroup, the median OS was 57 months for the mild RP group and 25 months for the severe RP group (HR = 3.72, p < 0.0001). CONCLUSIONS: The multiomics model contributed to improving the accuracy of RP prediction. Compared with the non-RP patients, the RP patients displayed longer OS, especially the mild RP patients.


Asunto(s)
Neoplasias Pulmonares , Neumonitis por Radiación , Humanos , Neumonitis por Radiación/diagnóstico , Neumonitis por Radiación/etiología , Estudios Retrospectivos , Multiómica , Neoplasias Pulmonares/radioterapia , Factores de Riesgo
5.
Behav Neurol ; 2022: 3777351, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35126784

RESUMEN

The pathogenesis of sepsis-associated encephalopathy (SAE) involves many aspects, including intracellular peroxidative stress damage, mitochondrial dysfunction, and cell apoptosis. In this study, we mainly explored the influence of P2X7R on the cognitive function of SAE and its molecular mechanism. We established a sepsis model using lipopolysaccharide (LPS) stimulation, followed by an assessment of cognitive function using Morris water maze, and then Western Blot was used to analyze the expression of tight junction proteins ZO-1 and Occludin in the hippocampus of mice. TUNEL assay was used to analyze the apoptosis of brain cells in frozen brain slices of mice during sepsis. Human brain microvascular endothelial cells (HBMECs) were used to research the molecular mechanism of brain cell damage induced by P2X7R. The results showed that P2X7R inhibitors dramatically improved the survival rate of mice, relieved the cognitive dysfunction caused by LPS stimulation, and significantly reduced the brain cell apoptosis caused by LPS. In addition, the inhibition of P2X7R can also reduce the production and accumulation of reactive oxygen species (ROS) in HBMECs in vitro and inhibit the apoptosis signaling pathway associated with mitochondrial serine protease Omi/HtrA2 in HBMECs in vitro. These results suggest that P2X7R has strong value as a potential target for the treatment of SAE.


Asunto(s)
Encefalopatía Asociada a la Sepsis , Animales , Apoptosis , Células Endoteliales/metabolismo , Serina Peptidasa A2 que Requiere Temperaturas Altas/metabolismo , Humanos , Ratones , Receptores Purinérgicos P2X7 , Encefalopatía Asociada a la Sepsis/tratamiento farmacológico , Transducción de Señal
6.
Chinese Journal of School Health ; (12): 889-892, 2020.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-822534

RESUMEN

Objective@#To explore determinants of childhood trauma among college students with left-behind experience, and to provide a reference for effective intervention among students with left-behind experience.@*Methods@#A total of 2 468 students selected from 5 universities and 2 higher vocational colleges in tianjin by stratified cluster sampling method were investigated by self-compiled questionnaire and childhood trauma questionnaire.@*Results@#The scores in emotional abuse, sexual abuse, emotional neglect, physical neglect and childhood trauma of students with left-behind experience were significantly higher than those without left-behind experience(t=3.01,3.13,3.24,2.27,3.60,P<0.05);parental separation times and the frequency of parental return had significant interaction effect on the total score of childhood trauma of students with left-behind experience (F=2.37, P<0.05);the gender had a significant major effect on the total score of childhood trauma of students with left-behind experience under the interaction with the place of origin, age at first separation,the cumulative time of leftbehind experiences and the frequency of parents contacting (F=4.49,5.23,5.93,5.11,P<0.05);the age of subjects when parents going out under the interaction with the place of origin, the gender, if only-child,parental separation times and the frequency of parental return;as well as the frequency of parents contacting under the interaction with the place of origin,the household registration, the gender, if only-child and the cumulative time of left-behind experiences also had significantly main effect(F=3.88,4.25,3.32,2.86,3.45;3.82,4.02,2.64,3.29,P<0.05).@*Conclusion@#It is necessary to attach great importance to demographic and context information regarding left-behind experiences,which lead to more specific and effective prevention and intervention strategy for individual with left-behind experiences.

7.
Nat Commun ; 9(1): 3021, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-30069012

RESUMEN

Compositional engineering has been used to overcome difficulties in fabricating high-quality phase-pure formamidinium perovskite films together with its ambient instability. However, this comes alongside an undesirable increase in bandgap that sacrifices the device photocurrent. Here we report the fabrication of phase-pure formamidinium-lead tri-iodide perovskite films with excellent optoelectronic quality and stability. Incorporation of 1.67 mol% of 2D phenylethylammonium lead iodide into the precursor solution enables the formation of phase-pure formamidinium perovskite with an order of magnitude enhanced photoluminescence lifetime. The 2D perovskite spontaneously forms at grain boundaries to protect the formamidinium perovskite from moisture and suppress ion migration. A stabilized power conversion efficiency (PCE) of 20.64% (certified stabilized PCE of 19.77%) is achieved with a short-circuit current density exceeding 24 mA cm-2 and an open-circuit voltage of 1.130 V, corresponding to a loss-in-potential of 0.35 V, and significantly enhanced operational stability.

8.
Adv Mater ; 30(28): e1801501, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29782685

RESUMEN

Incorporating narrow-bandgap near-infrared absorbers as the third component in a donor/acceptor binary blend is a new strategy to improve the power conversion efficiency (PCE) of organic photovoltaics (OPV). However, there are two main restrictions: potential charge recombination in the narrow-gap material and miscompatibility between each component. The optimized design is to employ a third component (structurally similar to the donor or acceptor) with a lowest unoccupied molecular orbital (LUMO) energy level similar to the acceptor and a highest occupied molecular orbital (HOMO) energy level similar to the donor. In this design, enhanced absorption of the active layer and enhanced charge transfer can be realized without breaking the optimized morphology of the active layer. Herein, in order to realize this design, two new narrow-bandgap nonfullerene acceptors with suitable energy levels and chemical structures are designed, synthesized, and employed as the third component in the donor/acceptor binary blend, which boosts the PCE of OPV to 11.6%.

9.
Nano Lett ; 17(1): 269-275, 2017 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-27936782

RESUMEN

The ionic nature of perovskite photovoltaic materials makes it easy to form various chemical interactions with different functional groups. Here, we demonstrate that interfacial chemical interactions are a critical factor in determining the optoelectronic properties of perovskite solar cells. By depositing different self-assembled monolayers (SAMs), we introduce different functional groups onto the SnO2 surface to form various chemical interactions with the perovskite layer. It is observed that the perovskite solar cell device performance shows an opposite trend to that of the energy level alignment theory, which shows that chemical interactions are the predominant factor governing the interfacial optoelectronic properties. Further analysis verifies that proper interfacial interactions can significantly reduce trap state density and facilitate the interfacial charge transfer. Through use of the 4-pyridinecarboxylic acid SAM, the resulting perovskite solar cell exhibits striking improvements to the reach the highest efficiency of 18.8%, which constitutes an ∼10% enhancement compared to those without SAMs. Our work highlights the importance of chemical interactions at perovskite/electrode interfaces and paves the way for further optimizing performances of perovskite solar cells.

10.
Adv Mater ; 28(11): 2253-8, 2016 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-26790006

RESUMEN

5 mm-scale large FAPbI 3 single crystals and corresponding photoconductive properties are shown. The phase transition of FAPbI3 between the α-phase and δ-phase is studied. The carrier mobility is 4.4 cm(2) V(-1) s(-1) with a lifetime of 484 ns in the bulk of the single crystal. Finally, photodetectors based on single-crystal FAPbI3 are demonstrated.

11.
Genet Test Mol Biomarkers ; 19(10): 573-8, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26291893

RESUMEN

BACKGROUND: The disintegrin and metalloprotease domain containing protein 33 (ADAM33) is a novel susceptibility gene for asthma and airway hyperresponsiveness, particularly in the Asian population. We investigated the influence of ADAM33 polymorphisms on the serum levels of ADAM33 and the susceptibility to pediatric asthma in the Chinese Han population. METHODS: Polymerase chain reaction-restriction fragment length polymorphism analysis was employed to study the genotypic distribution of F+1, T1, and S2 in ADAM33 in a cohort of 120 pediatric asthma patients and 105 healthy controls. The serum levels of secreted ADAM33 protein were measured in all the study subjects using the enzyme-linked immunosorbent assay (ELISA). RESULTS: This case-control study showed that the distribution of F+1 and T1 genotypes of ADAM33 was not significantly different between pediatric asthma patients and healthy controls (p > 0.05); however, the genotype and allele frequencies of the S2 polymorphism were significantly different between asthmatic patients and healthy controls (both p < 0.05). In addition, the frequency of CGC and CGG haplotypes exhibited statistically significant differences, with lower CGC and higher CGG frequencies found in the case group compared to the control group. Finally, in comparison to healthy controls, the serum levels of ADAM33 protein were significantly lower in patients carrying the S2 polymorphism. CONCLUSION: Our results provide evidence that the ADAM33 S2 polymorphism is associated with increased susceptibility to pediatric asthma and that the CGG haplotype for the F+1, T1, and S2 polymorphisms is associated with an elevated risk of pediatric asthma in the Han population, whereas the CGC haplotype appears to confer a protective effect. Our results may prove useful for population-based screening to affect early intervention.


Asunto(s)
Proteínas ADAM/genética , Asma/genética , Proteínas ADAM/sangre , Pueblo Asiatico/genética , Estudios de Casos y Controles , Niño , Preescolar , China , Ensayo de Inmunoadsorción Enzimática , Etnicidad/genética , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Polimorfismo de Nucleótido Simple
12.
J Am Chem Soc ; 137(34): 11069-75, 2015 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-26281006

RESUMEN

Using Cu2ZnSn(S,Se)4 (CZTSSe) as a model system, we demonstrate the kinetic control of solid-gas reactions at nanoscale by manipulating the surface chemistry of both sol-gel nanoparticles (NPs) and colloidal nanocrystals (NCs). Specifically, we first identify that thiourea (commonly used as sulfur source in sol-gel processes for metal sulfides) can transform into melamine upon film formation, which serves as surface ligands for as-formed Cu2ZnSnS4 (CZTS) NPs. We further reveal that the presence of these surface ligands can significantly affect the outcome of the solid-gas reactions, which enables us to effectively control the selenization process during the fabrication of CZTSSe solar cells and achieve optimal film morphologies (continuous large grains) by fine-tuning the amount of surface ligands used. Such enhancement leads to better light absorption and allows us to achieve 6.5% efficiency from CZTSSe solar cells processed via a sol-gel process using nontoxic, low boiling point mixed solvents. We believe our discovery that the ligand of particulate precursors can significantly affect solid-gas reactions is universal to solid-state chemistry and will boost further research in both understanding the fundamentals of solid-state reactions at nanoscale and taking advantage of these reactions to fabricate crystalline thin film semiconductors with better morphologies and performances.

13.
Int J Dev Neurosci ; 41: 92-7, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25660944

RESUMEN

BACKGROUND: Neopterin, a pteridine mainly synthesized by activated macrophages, is a marker of inflammation, immune system activation and an active participant in Autism spectrum disorders (ASD). The aim of this study was to assess the clinical significance of plasma neopterin levels in ASD. METHODS: Eighty patients diagnosed with ASD and 80 sex and age matched typically developing children were assessed for plasma levels of neopterin at admission. Plasma neopterin levels were measured using a human ELISA kit and severity of ASD were evaluated with the Childhood Autism Rating Scale (CARS) score. RESULTS: We found that the mean plasma neopterin level was significantly (P<0.0001) higher in children with ASD as compared to controls. Plasma neopterin increased with increasing severity of ASD as defined by the CARS score. Based on the ROC curve, the optimal cutoff value of plasma neopterin level as an indicator for auxiliary diagnosis of ASD was projected to be 8.5nmol/L, which yielded a sensitivity of 84.2% and a specificity of 80.1%, with the area under the curve at 0.876 (95% CI, 0.825-0.928). Elevated neopterin (≥8.5nmol/L) was an independent diagnosis indicator of ASD with an adjusted OR of 12.11 (95% CI: 5.48-28.11; P<0.0001). CONCLUSIONS: These results indicated that autistic children had higher plasma levels of neopterin, and elevated plasma neopterin levels may be associated with severity of ASD among Chinese children.


Asunto(s)
Trastorno del Espectro Autista/sangre , Neopterin/sangre , Pueblo Asiatico , Estudios de Casos y Controles , Preescolar , Femenino , Humanos , Modelos Lineales , Masculino , Escalas de Valoración Psiquiátrica , Curva ROC
14.
Int J Dev Neurosci ; 40: 92-6, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25433158

RESUMEN

BACKGROUND: Oxidative stress increases serum thioredoxin (TRX), a redox-regulating protein with antioxidant activity recognized as an oxidative-stress marker. The aim of this study was to assess the clinical significance of serum TRX levels in Autism spectrum disorders (ASD). METHODS: Eighty patients diagnosed with ASD and 100 sex and age matched typically developing children were assessed for serum TRX content at admission. TRX were assayed with solid-phase sandwich ELISA, and severity of ASD was evaluated with the Childhood Autism Rating Scale (CARS) Score. RESULTS: The results indicated that the median serum TRX levels were significantly (P<0.0001) higher in children with ASD as compared to typically developing children [17.9(IQR: 10.7-25.8)ng/ml and 5.5(3.6-9.2)ng/ml, respectively]. Levels of TRX increased with increasing severity of ASD as defined by the CARS score. After adjusting for all other possible covariates, TRX still was an independent diagnosis marker of ASD with an adjusted OR of 1.454 (95% CI, 1.232-1.892; P<0.0001). Based on the receiver operating characteristic (ROC) curve, the optimal cut-off value of serum TRX levels as an indicator for auxiliary diagnosis of autism was projected to be 10.6ng/ml. Further, we found that an increased diagnosis of ASD was associated with TRX levels ≥10.6ng/ml (adjusted OR 15.31, 95% CI: 7.36-31.85) after adjusting for possible confounders. CONCLUSIONS: Our study demonstrated that serum TRX levels were associated with ASD, and elevated levels could be considered as a novel, independent diagnosis indicator of ASD.


Asunto(s)
Trastorno Autístico/sangre , Trastorno Autístico/diagnóstico , Tiorredoxinas/sangre , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Humanos , Masculino , Índice de Severidad de la Enfermedad , Estadística como Asunto
15.
Neural Regen Res ; 9(17): 1592-8, 2014 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-25368645

RESUMEN

Flavonoids from the stems and leaves of Scutellaria baicalensis Georgi, an antioxidant, markedly improve memory impairments and neuronal injuries. In the present study, primary cortical neurons of rats were exposed to potassium cyanide to establish a model of in vitro neural cell apoptosis. Inhibition of apoptosis by flavonoids from the stems and leaves of Scutellaria baicalensis Georgi at concentrations of 18.98, 37.36, and 75.92 µg/mL was detected using this model. These flavonoids dramatically increased cell survival, inhibited cell apoptosis and excessive production of malondialdehyde, and increased the activities of superoxide dismutase, glutathione peroxidase, and Na(+)-K(+)-ATPase in primary cortical neurons exposed to potassium cyanide. The flavonoids from the stems and leaves of Scutellaria baicalensis Georgi were originally found to have a polyhydric structure and to protect against cerebral hypoxia in in vitro and in vivo models, including hypoxia induced by potassium cyanide or cerebral ischemia. The present study suggests that flavonoids from the stems and leaves of Scutellaria baicalensis Georgi exert neuroprotective effects via modulation of oxidative stress, such as malondialdehyde, superoxide dismutase, glutathione peroxidase and Na(+)-K(+)-ATPase disorders induced by potassium cyanide.

16.
Chem Commun (Camb) ; 50(12): 1447-50, 2014 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-24352056

RESUMEN

Hybrid hydrogels based on electrostatic co-assembly of polyoxometalates and ABA triblock copolymers were readily prepared and exhibit excellent luminescence and self-healing performance.

17.
PLoS One ; 8(9): e73450, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24019923

RESUMEN

Appropriate tillage plays an important role in mitigating the emissions of greenhouse gases (GHG) in regions with higher crop yields, but the emission situations of some reduced tillage systems such as subsoiling, harrow tillage and rotary tillage are not comprehensively studied. The objective of this study was to evaluate the emission characteristics of GHG (CH4 and N2O) under four reduced tillage systems from October 2007 to August 2009 based on a 10-yr tillage experiment in the North China Plain, which included no-tillage (NT) and three reduced tillage systems of subsoil tillage (ST), harrow tillage (HT) and rotary tillage (RT), with the conventional tillage (CT) as the control. The soil under the five tillage systems was an absorption sink for CH4 and an emission source for N2O. The soil temperature positive impacted on the CH4 absorption by the soils of different tillage systems, while a significant negative correlation was observed between the absorption and soil moisture. The main driving factor for increased N2O emission was not the soil temperature but the soil moisture and the content of nitrate. In the two rotation cycle of wheat-maize system (10/2007-10/2008 and 10/2008-10/2009), averaged cumulative uptake fluxes of CH4 under CT, ST, HT, RT and NT systems were approximately 1.67, 1.72, 1.63, 1.77 and 1.17 t ha(-1) year(-1), respectively, and meanwhile, approximately 4.43, 4.38, 4.47, 4.30 and 4.61 t ha(-1) year(-1) of N2O were emitted from soil of these systems, respectively. Moreover, they also gained 33.73, 34.63, 32.62, 34.56 and 27.54 t ha(-1) yields during two crop-rotation periods, respectively. Based on these comparisons, the rotary tillage and subsoiling mitigated the emissions of CH4 and N2O as well as improving crop productivity of a wheat-maize cropping system.


Asunto(s)
Productos Agrícolas/crecimiento & desarrollo , Gases/análisis , Efecto Invernadero , Triticum/crecimiento & desarrollo , Zea mays/crecimiento & desarrollo , Metano/análisis , Óxidos de Nitrógeno/análisis , Estaciones del Año , Suelo , Temperatura , Agua
18.
Ying Yong Sheng Tai Xue Bao ; 24(5): 1374-80, 2013 May.
Artículo en Chino | MEDLINE | ID: mdl-24015558

RESUMEN

By using static chamber-TGC method, an in situ observation was conducted in a 10-year conservation tillage winter wheat field to study the effects of different maize straw-returning modes on the soil respiration. The soil respiration had a significant positive correlation with the stubble height of maize straw, and two peaks were observed in wheat growth period. Under no tillage and no straw-returning, the soil respiration was 72.5% of that under no tillage with all straw-returning, and the soil respiration under conventional tillage and no straw- returning was 76.5% of that under conventional tillage with all straw-returning. The soil respiration was significantly positively correlated with the soil temperature and soil organic carbon at 20 cm depth, but no significant correlation with the soil organic carbon at 40 cm depth. A correlation was also observed between the soil respiration and soil moisture. The diurnal soil respiration in the treatments of all straw-returning presented a single-peak curve, with the peak at 18:00. There was a similar variation trend of soil temperature and soil respiration at the depth of 20 cm. Among the treatments of different straw-returning amounts, straw-returning with the stubble of 1 m height could reduce the soil respiration significantly, being a reasonable straw-returning mode.


Asunto(s)
Agricultura/métodos , Tallos de la Planta/química , Suelo/química , Triticum/crecimiento & desarrollo , Zea mays/química , Carbono/análisis , Dióxido de Carbono/análisis , Eliminación de Residuos/métodos
19.
PLoS One ; 7(12): e51206, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23236456

RESUMEN

The objective of this study was to quantify soil methane (CH(4)) and nitrous oxide (N(2)O) emissions when converting from minimum and no-tillage systems to subsoiling (tilled soil to a depth of 40 cm to 45 cm) in the North China Plain. The relationships between CH(4) and N(2)O flux and soil temperature, moisture, NH(4) (+)-N, organic carbon (SOC) and pH were investigated over 18 months using a split-plot design. The soil absorption of CH(4) appeared to increase after conversion from no-tillage (NT) to subsoiling (NTS), from harrow tillage (HT) to subsoiling (HTS) and from rotary tillage (RT) to subsoiling (RTS). N(2)O emissions also increased after conversion. Furthermore, after conversion to subsoiling, the combined global warming potential (GWP) of CH(4) and N(2)O increased by approximately 0.05 kg CO(2) ha(-1) for HTS, 0.02 kg CO(2) ha(-1) for RTS and 0.23 kg CO(2) ha(-1) for NTS. Soil temperature, moisture, SOC, NH(4) (+)-N and pH also changed after conversion to subsoiling. These changes were correlated with CH(4) uptake and N(2)O emissions. However, there was no significant correlation between N(2)O emissions and soil temperature in this study. The grain yields of wheat improved after conversion to subsoiling. Under HTS, RTS and NTS, the average grain yield was elevated by approximately 42.5%, 27.8% and 60.3% respectively. Our findings indicate that RTS and HTS would be ideal rotation tillage systems to balance GWP decreases and grain yield improvements in the North China Plain region.


Asunto(s)
Agricultura/métodos , Efecto Invernadero , Metano/análisis , Óxido Nitroso/análisis , Suelo/análisis , Triticum/crecimiento & desarrollo , Biomasa , Carbono/análisis , China , Concentración de Iones de Hidrógeno , Temperatura , Agua/análisis
20.
J Transl Med ; 10: 176, 2012 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-22929614

RESUMEN

BACKGROUND: In China, high prevalence of HBV and HCV parallels with the growing epidemic of syphilis and HIV in the general population poses a great threat to blood safety. This study investigated the prevalence of serologic markers for transfusion transmissible infections (TTIs) among four Chinese blood centers. METHODS: We examined whole blood donations collected from January 2000 through December 2010 at four Chinese blood centers. Post-donation testing of TTIs (HIV, HBV, HCV and syphilis) were conducted using two different enzyme-linked immunosorbent assay kits for each seromarker. The prevalence of serologic markers for TTIs (%) was calculated and additional analysis was conducted to examine donor characteristics associated with positive TTIs serology. RESULTS: Of the 4,366,283 donations, 60% were from first-time donors and 40% were from repeated donors. The overall prevalence of HIV, HBsAg, HCV and syphilis was 0.08%, 0.86%, 0.51% and 0.47%, respectively. The prevalence profile of TTIs varied among different blood centers and appeared at relatively high levels. Overall, the prevalence of HBsAg and HCV demonstrated a decline trend among four blood centers, while the prevalence of HIV and syphilis displayed three different trends: constantly steady, continually increasing and declining among different centers. CONCLUSIONS: This study reflects the risk of TTIs has been greatly reduced in China, but blood transfusion remains an ongoing risk factor for the spread of blood-borne infections, and further work and improvements are needed to strengthen both safety and availability of blood in China.


Asunto(s)
Donantes de Sangre , Patógenos Transmitidos por la Sangre/aislamiento & purificación , Enfermedades Transmisibles/transmisión , Reacción a la Transfusión , Adolescente , Adulto , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Adulto Joven
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