High-throughput sequencing analysis of microRNAs in gills of red swamp crayfish, Procambarus clarkii infected with white spot syndrome virus.

MicroRNAs (miRNAs) are important posttranscriptional regulators. They play an important role in the antiviral innate immunity of invertebrates. In the present study, high-throughput small RNAs Illumina sequencing systems were carried out to identify differentially expressed miRNAs (DEMs) in the gills of Procambarus clarkii, which was challenged with white spot syndrome virus (WSSV). Our results identified 11,617 known and 6 novel miRNAs in normal group (NG) and WSSV-challenged group (WG) small RNA libraries. Additionally, 27 DEMs were shown to participate in the antiviral innate immunity of P. clarkii and were significantly upregulated or downregulated. In addition, the results of the KEGG pathway prediction of the DEMs target genes showed that putative target genes of these 27 DEMs were related mainly to the RNA transport pathway, tight junction pathway, mRNA surveillance pathway, regulation actin cytoskeleton pathway, focal adhesion pathway, and MAPK signaling pathway. These results provide important information for future studies about the antiviral innate immunity of crustaceans.

[Mineralogy and genesis of mixed-layer clay minerals in the Jiujiang net-like red soil].

Mineralogy and genesis were investigated using X-ray diffraction (XRD), Fourier infrared absorption spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) to understand the mineralogy and its genesis significance of mixed-layer clay minerals in Jiujiang red soil section. XRD and FTIR results show that the net-like red soil sediments are composed of illite, kaolinite, minor smectite and mixed-layer illite-smectite and minor mixed-layer kaolinite-smectite. HRTEM observation indicates that some smectite layers have transformed into kaolinite layers in net-like red soil. Mixed-layer illite-smectite is a transition phase of illite transforming into smectite, and mixed-layer kaolinite-smectite is a transitional product relative to kaolinite and smectite. The occurrence of two mixed-layer clay species suggests that the weathering sequence of clay minerals in net-like red soil traversed from illite to mixed-layer illite-smectite to smectite to mixed-layer kaolinite-smectite to kaolinite, which indicates that net-like red soil formed under a warm and humid climate with strengthening of weathering.

[Choice of internal fixation methods for posterior malleolus fracture in both biomechanics and clinical application].

OBJECTIVE: To study the biomechanical effects and the clinical outcome of different internal fixation methods in treating posterior malleolus fractures. METHODS: (1) Biomechaniccal study of 18 pairs of posterior malleolus fracture models was conducted, in which all the cases were divided into 3 groups as I, II and III (n=12), according to different fracture degrees that included specimens with 1/4, 1/3 and 1/2 of articular facets fractured respectively; Each group was further divided into 2 subgroups as group A and group B. Group A was fixed with 2 steel half-thread tensile screws whose diameter was 4.0 mm; and group B was fixed with "T-shaped" steel distal-radius plates and 4 screws. The uploading experiment was carried out by settling the specimen on an experiment machine at its neutral position, and the data were collected and managed. (2) Clinical Applications: 31 cases with closed trimalleolar fractures were treated from 2009.1-2010.12 in our hospital, in which 14 with posterior malleolus fractures ≤ 2 5% of the capital diameter of the tibial plafond were fixed with screws, and 17 with posterior malleolus fractures >25% of the capital diameter of the tibial plafond were fixed with steel plates. Prospective cohort study of these cases were carried out. The outcome was assessed using a Leeds Scoring System. RESULTS: The mechanical fixation strengths of the plates for 1/4, 1/3 and 1/2 facets of posterior malleolus fractures were all higher than those of the screw groups [(4.10 ± 0.13) kN vs. (4.6 0 ± 0.27)kN, (3.20 ± 0.12)kN vs. (4.12 ± 0.14)kN and (1.98 ± 0.18)kN vs. (3.72 ± 0.18)kN, respectively, P<0.05]. For the clinical study ,the mean follow-up period was 12 months (6-18 months), all the cases acquired bone union, and the mean time for healing was 10 weeks ( 8-12 weeks). In the evaluation of therapeutic effects, we found that 28 cases were excellent and 3 good, which was 100% satisfying. CONCLUSION: If only 1/4 of the posterior articular facet is involved, 2 screws are enough to supply the stability; but for the fractures involve more than 1/4 facet, the plate fixation supplies more stable fixation and is superior to simply screws.