A new strategy of using periphyton to simultaneously promote remediation of PAHs-contaminated soil and production of safer crops.

Contaminated farmland leads to serious problems for human health through biomagnification in the soil-crop-human chain. In this paper, we have established a new soil remediation strategy using periphyton for the production of safer rice. Four representative polycyclic aromatic hydrocarbons (PAHs), including phenanthrene (Phe), pyrene (Pyr), benzo[b]fluoranthene (BbF), and benzo[a]pyrene (BaP), were chosen to generate artificially contaminated soil. Pot experiments demonstrated that in comparison with rice cultivation in polluted soil with ΣPAHs (50 mg kg-1) but without periphyton, adding periphyton decreased ΣPAHs contents in both rice roots and shoots by 98.98% and 99.76%, respectively, and soil ΣPAHs removal reached 94.19%. Subsequently, risk assessment of ΣPAHs based on toxic equivalent concentration (TEQ), pollution load index (PLI), hazard index (HI), toxic unit for PAHs mixture (TUm), and incremental lifetime cancer risk (ILCR) indicated that periphyton lowered the ecological and carcinogenicity risks of PAHs. Besides, the role of periphyton in enhancing the rice productivity was revealed. The results indicated that periphyton alleviated the oxidative stress of PAHs on rice by reducing malondialdehyde (MDA) content and increasing total antioxidant capacity (T-AOC). Periphyton reduced the toxic stress of PAHs on the soil by promoting soil carbon cycling and metabolic activities as well. Periphyton also improved the soil's physicochemical properties, such as the percentage of soil aggregate, the contents of humic substances (HSs) and nutrients, which increased rice biomass. These findings confirmed that periphyton could improve rice productivity by enhancing soil quality and health. This study provides a new eco-friendly strategy for soil remediation and simultaneously enables the production of safe crops on contaminated land.

40 Hz auditory steady state response to linguistic features of stimuli during auditory hallucinations.

The auditory steady state response (ASSR) may reflect activity from different regions of the brain, depending on the modulation frequency used. In general, responses induced by low rates (≤40 Hz) emanate mostly from central structures of the brain, and responses from high rates (≥80 Hz) emanate mostly from the peripheral auditory nerve or brainstem structures. Besides, it was reported that the gamma band ASSR (30-90 Hz) played an important role in working memory, speech understanding and recognition. This paper investigated the 40 Hz ASSR evoked by modulated speech and reversed speech. The speech was Chinese phrase voice, and the noise-like reversed speech was obtained by temporally reversing the speech. Both auditory stimuli were modulated with a frequency of 40 Hz. Ten healthy subjects and 5 patients with hallucination symptom participated in the experiment. Results showed reduction in left auditory cortex response when healthy subjects listened to the reversed speech compared with the speech. In contrast, when the patients who experienced auditory hallucinations listened to the reversed speech, the auditory cortex of left hemispheric responded more actively. The ASSR results were consistent with the behavior results of patients. Therefore, the gamma band ASSR is expected to be helpful for rapid and objective diagnosis of hallucination in clinic.

Effects of polymorphisms in translesion DNA synthesis genes on lung cancer risk and prognosis in Chinese men.

PURPOSE: Translesion DNA synthesis (TLS) plays an important role in promoting replication through DNA lesions. Genetic polymorphisms in TLS genes may have potential roles in lung cancer development in humans. METHODS: We evaluated the association between genetic variants in six TLS genes and the risk and survival of lung cancer in a case-control study in China. Included in the study are 224 lung cancer patients and 448 healthy controls. RESULTS: Carriers of the G allele of POLκ rs5744724 had significantly reduced risk of lung cancer (odds ratio (OR)=0.62, 95% confidence interval (CI): 0.44-0.89), comparing with those carrying the C allele, and the AA genotype of PCNA rs25406 was also associated with significantly decreased cancer risk compared with the major homozygote alleles (OR=0.47, 95% CI: 0.25-0.86). Haplotype analysis showed that subjects with the POLκ C-G (rs5744533-rs5744724) haplotype had decreased risk of lung cancer (OR=0.69, 95% CI: 0.49-0.98), comparing with those carrying the C-C haplotype. Besides, the heterozygote of REV1 rs3087386 and rs3792136 were independent prognostic factors for lung cancer survival with hazard radio (HR) 1.54 (95% CI: 1.12-2.12) and 1.44 (95% CI: 1.06-1.97) respectively. CONCLUSIONS: Our findings suggested that genetic variants in POLκ and PCNA genes may play roles in the susceptibility of lung cancer, and REV1 gene may have roles in lung cancer survival in Chinese men.

Expressions of thermostable bacterial cellulases in tobacco plant.

An economical method for the conversion of lignocellulosic biomass is to use plants as bioreactors for cellulases production. Two bacterial thermostable cellulases (E2 and E3) and a E3-E2 fusion form were expressed in tobacco, driven by a double 35S promoter and 5' TEV-UTL. The enzymes were targeted to the apoplast and cytosol via 5' signal peptides and 3' retention signal peptides, respectively, and all showed functional activities. All transgenic plants exhibited normal growth compared to wild type. Transgenic plants that expressed apoplast-localized E2 had the highest average activity, about 1.5 and 3 times higher than those expressed ER-localized and cytosolic E2, respectively. Effect of subcellular compartment localization was due primarily to post-transcriptional modification, since mRNA abundances were similar despite the range of cellulase activities obtained. The recombinant cellulases exhibited good thermostability below 65 °C. After storing for 3 days at -20 and 28 °C, the enzymes lost nearly 20 and 80% of activity, respectively. The results suggested a potential application for heterologous expression of cellulases in plant for biomass conversion.

Phytase expression in transgenic soybeans: stable transformation with a vector-less construct.

A minimal linear gene cassette (35S-phytase gene-nos) with T-DNA borders was acquired by PCR and directly introduced into soybean through the pollen tube pathway. A total of 13% of T(1 )plants were positive for phyA by specific PCR. Southern blot analyses showed that phyA insertions were harbored stably in T(2) progeny. Phytase expression level increased 2.5-fold over a 6-week period; its highest activity was 150 U/mg protein, compared to 56 U/mg protein in untransformed controls. Activity of phytase increased to 125 FTU/kg in T(3) transgenic seeds as compared to 64 FTU/kg in wild-type plants.

[Neural engineering and neural prostheses].

The motivation of the brain-computer interface (BCI) research and its potential applications are introduced in this paper. Some of the problems in BCI-based medical device developments are also discussed.

Molecular cloning and characterization of betaine aldehyde dehydrogenase gene from Suaeda liaotungensis and its use in improved tolerance to salinity in transgenic tobacco.

cDNA encoding betaine aldehyde dehydrogenase (BADH) from the halophyte Suaeda liaotungensis has been cloned, sequenced and expressed in tobacco (Nictiana tabacum 89). The full-length cDNA is 1506 base pairs (bp) long and encodes a 502 amino-acid polypeptide. The cDNA fragment coding for the mature enzyme was cloned into vector pCAMBIA-1301 for expression in tobacco. Southern blotting analysis showed that that the Badh gene was integrated into the genome of tobacco. Tobacco expressing BADH survived on MS medium containing 200 mM NaCl, whereas the untransformed plants turned yellow after about 20 d and died.

[Rapid amplification of 3' cDNA end of Suaeda liaotungensis betaine aldehyde dehydrogenase using one-step PCR].

Based on part of a known cDNA sequence of Suaeda liaotungensis betaine aldehyde dehydrogenase, we successfully cloned the 3' cDNA end of S. lianotungensis betaine aldehyde dehydrogenase using one-step PCR with a gene-specific primer and universal primer. Compared with the typical 3' RACE, one-step PCR is rapid, simple and inexpensive. It is very rapid to amplify an unknown cDNA 3' end using this method.