[Dynesys and posterior decompression and fusion internal fixation for the treatment of lumbar degenerative diseases: a systematic review].

OBJECTIVE: Meta analysis was used to evaluate the efficacy and safety of Dynesys and posterior decompression and fusion internal fixation for lumbar degenerative diseases. METHODS: The computer was used to retrieve the Cochrane library, Medline, Embase, CNKI, Wanfang database and Chinese biomedical literature database; and the references and main Chinese and English Department of orthopedics journals were manually searched. All the prospective or retrospective comparative studies on the clinical efficacy and safety of Dynesys and posterior decompression and fusion internal fixation were collected, so as to evaluate the methodological quality of the study and to extract the data. The RevMan 5.2 software provided by Cochrane collaboration was used for systematic evaluation. RESULTS: A total of 9 clinical studies were included, including 3 prospective randomized controlled trials(RCT) and 6 retrospective controlled observational studies, which included 692 patients, with 336 cases in Dynesys group, and 356 cases in posterior decompression and fusion internal fixation (PLIF) group. The results showed that compared with PLIF, Dynesys system significantly decreased operation time(P<0.01), intraoperative blood loss (P<0.01). Both Dynesys and PLIF groups experienced improved ODI and back/leg pain VAS scores at final follow-up, and no statistically significant difference was noted according to the two surgical procedures(P>0.05). Dynesys could remain the range of motion (ROM) of surgical segments with less increased ROM of adjacent segments compared with that of PLIF group(P<0.01). Regarding the disc height of surgical segments, no statistically significant difference was noted according to the two groups(P>0.05), but postoperative complications incidence rate in PLIF group was higher than that in Dynesys group (P<0.05). CONCLUSIONS: Both Dynesys system and PLIF can improve clinical outcomes of lumbar degenerative diseases effectively. Compared with PLIF, Dynesys could remain the range of motion(ROM) of surgical segments with less increased ROM of adjacent segments and lower complication incidence rate. But the ability to prevent adjacent segments degeneration needs more RCTs with long-term follow-up to confirm.

Complete mitochondrial genome sequence of the Rattus norvegicus SILN strain with central nervous system disorder.

The Rattus norvegicus SILN strain is a common used model for nervous system disorder disease study. We sequenced this R. norvegicus strain SILN mitochondrial genome for the first time (GenBank Accession No. KM114606). Its mitogenome was 16,311 bp and coding 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes.

[Characteristics of coarse woody debris in Huzhong area of Great Xing' an Mountains].

An investigation was made on the coarse woody debris (CWD) in burned forestlands in Huzhong area of Great Xing' an Mountains. The loading capacity of CWD in the burned forestlands was 24.9-181.0 m3 x hm(-2), among which, snag and log occupied 24.3%-85.9% and 14.0%-75.7%, being 6.0-93.9 m3 x hm(-2) and 15.3-138.4 m3 x hm(-2), respectively. Significant differences were observed among burned forestlands and among years. The predominant DBH class of snag and log was 2.5-20 cm and 1.5-15 m, and the height of most snags and logs was 2.5-15 m and 5-20 cm, respectively. The loading capacity of CWD had no obvious change with the recovery of forest vegetation. The characteristics of CWD had a close relationship with pre-fire forest stand conditions and burn intensity.

[Spatial pattern of land surface dead combustible fuel load in Huzhong forest area in Great Xing'an Mountains].

By using geo-statistics and based on time-lag classification standard, a comparative study was made on the land surface dead combustible fuels in Huzhong forest area in Great Xing'an Mountains. The results indicated that the first level land surface dead combustible fuel, i. e., 1 h time-lag dead fuel, presented stronger spatial auto-correlation, with an average of 762.35 g x m(-2) and contributing to 55.54% of the total load. Its determining factors were species composition and stand age. The second and third levels land surface dead combustible fuel, i. e., 10 h and 100 h time-lag dead fuels, had a sum of 610.26 g x m(-2), and presented weaker spatial auto-correlation than 1 h time-lag dead fuel. Their determining factor was the disturbance history of forest stand. The complexity and heterogeneity of the factors determining the quality and quantity of forest land surface dead combustible fuels were the main reasons for the relatively inaccurate interpolation. However, the utilization of field survey data coupled with geo-statistics could easily and accurately interpolate the spatial pattern of forest land surface dead combustible fuel loads, and indirectly provide a practical basis for forest management.