Search

Cadmium (Cd) immobilization in the cell wall is responsible for Cd detoxification in Cd-accumulating cultivars. Lignin is the dominant constituent of the secondary cell wall (SCW), but its role in Cd compartmentalization is poorly understood. The mechanism of Cd compartmentalization by lignin was thus investigated herein. Lignin content and composition, as well as related genes and proteins, were analyzed in the Cd pollution-safe cultivar Brassica parachinensis L. ‘SJ19’. The lignin microstructural regions and Cd affinities were characterized by 2D-heteronuclear single quantum coherence nuclear magnetic resonance (HSQC NMR) and density functional theory (DFT). Lignin combined with 14.2% of the total Cd in SJ19, with a higher Cd distribution in acid-insoluble lignin (AIL). Additionally, the proportion of AIL increased under Cd treatment. The increase in the proportion of the lignin aromatic region syringyl (S) and decrease in the guaiacyl (G) proportion were in accordance with the significant up-regulation of peroxidase P7 and down-regulation of caffeoyl-CoA O-methyltransferase At1g67980 under Cd stress. Moreover, the Cd affinity associating with the lignin aromatic region ranked as S > G > H (p-hydroxyphenyl). Therefore, rather than lignin biosynthesis, the simultaneous elevation of AIL and S lignin was recognized as the preliminary strategy for lignin compartmentalization of Cd in SCW for the first time herein. This is beneficial for Cd detoxification in the Cd pollution-safe cultivar of B. parachinensis.

Underwater multimedia acoustic sensor networks will be widely used in many underwater applications such as image and video acquisition, multimedia undersea explorations, tactical surveillance and disaster prevention. However, due to the differences between terrestrial radio propagation and underwater acoustic propagation, it is essential to design energy efficient image transmission solution for underwater acoustic network. As the value of absorption coefficient in thermocline layer and deep water layer are quite different, how to find the optimal path with minimum energy consumption becomes a more challenge issue. In this paper, the transmission paths are divided into three types, the upward path, the straight path and the downward path. Because the energy consumption varies quite difference in different depth, the straight path with the shortest transmission distance may not be the optimal path with minimum energy consumption. In order to find the optimal path with minimum energy consumption from the source node to the sink, we evaluate the energy consumption of the three type path numerically and address how to gain the optimal path. The experimental results show that when the water depth is above about 2 km, the straight path has the least minimum energy consumption among the three paths, while the downward path that choice the correct parameters consumes the least energy when the water depth is below about 2 km.

CdS sensitized NiO electrode was used as the photoactive cathode in a photoelectrochemical cell for water splitting, avoiding the use of a sacrificial electron donor. Photocurrent increment under visible light irradiation was observed after integration of [Co(dmgH) 2 (4-Me-py)Cl] ( 1 ) to the photocathode, suggesting 1 could accept electrons from photoexcited CdS for water reduction and NiO could move the holes in the valence band of CdS to anode for water oxidation.

Visual stimulator is one of the key factors that affect the steady-state visual evoked potential (SSVEP). Research and development of brain-computer interface (BCI) system based on SSVEP have priority to consider the design and implementation of visual stimulation. Compare with visual stimulators for particular applications, this paper presents a visual stimulator that is portable and easy to modify apparatus, which is suitable for expanding the application of SSVEP based BCI system. This article induces a visual stimulator based on ARM microcontroller for BCI. The stimulator uses a common USB interface, achieving multiple selective stimulus methods. The system features include visual stimulation, parameter setting and display, the experimental results feedback display. Experimental data prove that this stimulator can be used for almost all types of brain-computer interface based on visual stimulation experiments, and have a portable operating mode, flexible parameter settings , and easy operation.

The effect of tartaric acid on the electrochemical behavior of K3[Fe(CN)6] was investigated on bare ITO electrodes, electrodes coated with multi-walled carbon nanotubes possessing carboxyl groups (MWNT-COOHs), and electrodes coated with cyclodextrin modified multi-walled carbon nanotubes (MWNT-CDs), respectively. It is found that the molecular chirality of tartaric acid can hardly influence the electrochemical behavior of K3[Fe(CN)6] on bare ITO electrodes. When the electrodes coated with MWNT-COOHs are used, the effect of the molecular chirality becomes distinguish. In the case of the electrodes coated with MWNT-CDs, the enhanced chiral discrimination between D-tartaric acid (D-TA) and L-tartaric acid (L-TA) can be observed. The control step in the electrochemical reaction of K3[Fe(CN)6] on the electrodes coated with MWNT-CDs is deduced to be different when D-TA or L-TA is introduced into the solution, respectively. Therefore, the enhanced chiral discrimination on the electrodes coated with MWNT-CDs is probably due to the change of the control step in the electrochemical reaction of K3[Fe(CN)6] caused by the chiral recognition of cyclodextrin moieties to D-TA and L-TA.

In the present work, the photocatalytic activity of La 2 Ti 2 O 7 for the photoreduction of Cr(VI) ions in water was investigated. The results indicated that La 2 Ti 2 O 7 is an efficient photocatalyst with 98% of reduction efficiency of Cr(VI) ions after 3 h ultraviolet (UV) irradiation. Meanwhile, the stability of La 2 Ti 2 O 7 in the photocatalysis was investigated by repeatedly performing Cr(VI) photoreducing experiments. It can be found that the photocatalytic activity of La 2 Ti 2 O 7 remained almost unchanged after nine successive cycles, and the reduction ratio of Cr(VI) ions was still up to 50% in the twentieth cycle. Furthermore, for practical purposes, the photocatalytic reduction of Cr(VI) ions was studied as functions of the solution pH, initial Cr(VI) concentration and additional salts.

To study the main risk factors of low back pain of workers ina foundry factory of the automobile company using cross sectional epidemiological investigation, and to provide scientific base for preventing the disorder.The low back pain and work loads of 1340 workers in a foundry factory of the automobile company were investigated using questionnaire, and logistic regression analysis was used to analyze the risk factors.The one-year morbidity of low back pain in workers was 58.9% the morbidities of low back pain in workers engaged in foundry, transportation and modeling were 64.6%, 64.6% and 62.5%, respectively. The lifting with squat postures, bending trunk heavily, bending trunk with twisting and moving the heavy objects were found to be the most dominant risk factors for low-back pain, the OR values were 2.085, 1.961, 1.967 and 1.956, respectively. The distributions of risk factors were different among the different jobs. The logistic regression analysis showed that moving the heavy objects, lifting with squat postures, bending trunk heavily, bending trunk with twisting existed simultaneously, also the work years and gender were the risk factors.The manual moving heavy objects, awkward working posture or both were the most important risk factors for low-back pain. The intervene ergonomic study should be performed in future to reduce the morbidity of low-back pain.

To understand the major causes of death in automobile foundry workers and investigate casting manipulations hazards to health.A cohort study of 3529 foundry workers registered in one big automobile factory in Shiyan city of China was performed. Standardized mortality ratios (SMRs) were calculated for the main causes of death by using Chinese national mortality rates as reference.The cohort mortality was traced from 1980 to the end of 2005 with an accumulation of 84 999 person-years, revealed 265 deaths. The results of this study showed that the standardized mortality ratio for all subjects was 0.96 (95% CI: 0.85 approximately 1.08), which was very close to that expected on the basis of the China national mortality rates. The SMR increased with age, the SMR became greater than 1 in all groups of age 50 and higher. The results showed that malignant neoplasm (3.43%), accidents (1.16%), cerebro-vascular diseases (1.08%), cardio-vascular diseases (0.79%) were the first four illnesses that threatened workers' life span. Statistically significant mortality of malignant neoplasm (SMR = 7.87), accidents (SMR = 2.70), cardio-vascular diseases (SMR = 2.68) and digestive diseases (SMR = 2.79) were found in the foundry workers. The relative risk of malignant neoplasm for first line workers to assistant workers was 1.99 (P0.05).The occupational hazards in foundry factory have harmful impact on the workers' health and life span.