BACKGROUND:The surgical treatment of severe lumbar fractures is mainly based on posterior short-segment fixation,and different pedicle screw fixation methods have differences in biomechanical properties.OBJECTIVE:To simulate three different screw fixation techniques in the treatment of severe L1 vertebral fractures using three-dimensional finite element technology,and to compare and analyze the biomechanical characteristics of the upper and lower intervertebral discs,fractured vertebrae,and internal fixation devices during the simulated spinal movement.METHODS:A three-dimensional model of the T11-L3 spine was established to simulate severely unstable fracture of the lumbar 1 vertebral body using the designed three pedicle screw fixation methods:Model A with 4 traditional pedicle screws(2 in each T12 and L2),model B with 4 Universal Spine System pedicle screws(2 in each T12 and L2),and Model C were bilateral intermediate fixation with 6 pedicle screws(2 in each of T12,L1,and L2).Restraint and load were applied to simulate the maximum stress and maximum displacement of the internal fixation,the displacement of the L1 vertebral body,and stress on the intervertebral discs superior and inferior to the injured vertebra during the anterior flexion,posterior extension,left-sided bending,right-sided bending and left-right rotation of the lumbar spine.RESULTS AND CONCLUSION:(1)The maximum displacement and motion range of the lumbar 1 vertebra with Model C in flexion and extension,left bending,right bending,left rotation,and right rotation were lowest in the tested motion states;the maximum stress of the screws and connecting rods was the smallest;and the maximum stress of intervertebral discs superior and inferior to the injured vertebra was the smallest.This was followed by the Model B,while the maximum displacement and motion range of the lumbar 1 vertebra and the stress and displacement of the screw connecting rod in the Model A were highest,but it showed the worst biomechanical stability and was more prone to adjacent segment degeneration.(2)These results show that bilateral intermediate fixation with six pedicle screws during the treatment of severe lumbar fractures is more dispersed in internal fixator stress and exhibits the least displacement and motion range of the vertebral pedicle screws and rods compared with four universal spinal system pedicle screws and four traditional pedicle screws.Thus,it can effectively reduce the occurrence of internal fixation failure and the adjacent segment degeneration.

BACKGROUND:The surgical treatment of severe lumbar fractures is mainly based on posterior short-segment fixation,and different pedicle screw fixation methods have differences in biomechanical properties.OBJECTIVE:To simulate three different screw fixation techniques in the treatment of severe L1 vertebral fractures using three-dimensional finite element technology,and to compare and analyze the biomechanical characteristics of the upper and lower intervertebral discs,fractured vertebrae,and internal fixation devices during the simulated spinal movement.METHODS:A three-dimensional model of the T11-L3 spine was established to simulate severely unstable fracture of the lumbar 1 vertebral body using the designed three pedicle screw fixation methods:Model A with 4 traditional pedicle screws(2 in each T12 and L2),model B with 4 Universal Spine System pedicle screws(2 in each T12 and L2),and Model C were bilateral intermediate fixation with 6 pedicle screws(2 in each of T12,L1,and L2).Restraint and load were applied to simulate the maximum stress and maximum displacement of the internal fixation,the displacement of the L1 vertebral body,and stress on the intervertebral discs superior and inferior to the injured vertebra during the anterior flexion,posterior extension,left-sided bending,right-sided bending and left-right rotation of the lumbar spine.RESULTS AND CONCLUSION:(1)The maximum displacement and motion range of the lumbar 1 vertebra with Model C in flexion and extension,left bending,right bending,left rotation,and right rotation were lowest in the tested motion states;the maximum stress of the screws and connecting rods was the smallest;and the maximum stress of intervertebral discs superior and inferior to the injured vertebra was the smallest.This was followed by the Model B,while the maximum displacement and motion range of the lumbar 1 vertebra and the stress and displacement of the screw connecting rod in the Model A were highest,but it showed the worst biomechanical stability and was more prone to adjacent segment degeneration.(2)These results show that bilateral intermediate fixation with six pedicle screws during the treatment of severe lumbar fractures is more dispersed in internal fixator stress and exhibits the least displacement and motion range of the vertebral pedicle screws and rods compared with four universal spinal system pedicle screws and four traditional pedicle screws.Thus,it can effectively reduce the occurrence of internal fixation failure and the adjacent segment degeneration.

In order to mine candidate vaccine antigens against ticks and to control ticks safely and effectively,the aim of this study was to immunize rabbits with purified aquaporins(AQPs)rD-mAQP1,rDmAQP2 and rDmAQP3 of Dermacentor marginatus.Blood collections for Western blot and ELISA tests were performed.The anti-tick challenge was conducted.The optimal expression conditions of rDmAQP1,rDmAQP2 and rDmAQP3 were screened by SDS-PAGE gel electrophore-sis.The three recombinant proteins were purified by HisSepNi-NTA6FF purification column.Rab-bits were divided into four groups of three rabbits each,including a control group and three immu-nized groups.The three purified recombinant proteins were separately immunized to three groups of rabbits,and the rabbits were immunized once on the 0th,14th and 21st day.Blood samples were collected every 7 days to prepare polyclonal antibodies.The reactivity was detected by Western blot and the antibody titer was detected by ELISA.Tick challenge test was carried out after the anti-body titer increased.The results showed that the optimal expression conditions for rDmAQP1 were induced for 8 h at IPTG concentration of 1.0 mmol/L and 37 ℃;the optimal expression conditions for rDmAQP2 were induced for 7 h at IPTG concentration of 1.0 mmol/L and 37 ℃;and the opti-mal expression conditions for rDmAQP3 were induced for 5 h at IPTG concentration of 1.0 mmol/L and 37 ℃.Western blot results showed that rDmAQP1,rDmAQP2 and rDmAQP3 all had certain reactivity.The ELISA results showed that the antibody titers of rabbits immunized with rD-mAQP1,rDmAQP2 and rDmAQP3 were as follows:the total anti-tick effect of rDmAQP1 protein was 79.74％,and the inhibition rates on average full-blooded tick weight,average egg weight and average egg hatching rate were 9.43％,25.17％and 63.81％,respectively.The total anti-tick effect of rDmAQP2 protein was 78.78％,and the inhibition rates of average full-blooded tick weight,av-erage egg weight and average egg hatching rate of Dermacentor marginatus were 8.30％,20.14％and 68.26％,respectively.The total anti-tick effect of rDmAQP3 protein was 87.91％,and the inhi-bition rates of average full-blooded tick weight,average egg weight and average egg hatching rate were 3.23％,22.47％and 80.5％,respectively.Through serological test and anti-tick test,it has been found that rDmAQP1,rDmAQP2 and rDmAQP3 all have the potential of candidate antigens against ticks,among which rDmAQP3 has the best immune effect,which lays a foundation for the study of the function of rDmAQP1,rDmAQP2 and rDmAQP3.

The importance of structural variants(SVs)for human phenotypes and diseases is now recognized.Although a variety of SV detection platforms and strategies that vary in sensitivity and specificity have been developed,few benchmarking procedures are available to confidently assess their performances in biological and clinical research.To facilitate the validation and application of these SV detection approaches,we established an Asian reference material by characterizing the genome of an Epstein-Barr virus(EBV)-immortalized B lymphocyte line along with identified benchmark regions and high-confidence SV calls.We established a high-confidence SV callset with 8938 SVs by integrating four alignment-based SV callers,including 109x Pacific Biosciences(PacBio)continuous long reads(CLRs),22 x PacBio circular consensus sequencing(CCS)reads,104x Oxford Nanopore Technologies(ONT)long reads,and 114×Bionano optical mapping plat-form,and one de novo assembly-based SV caller using CCS reads.A total of 544 randomly selected SVs were validated by PCR amplification and Sanger sequencing,demonstrating the robustness of our SV calls.Combining trio-binning-based haplotype assemblies,we established an SV benchmark for identifying false negatives and false positives by constructing the continuous high-confidence regions(CHCRs),which covered 1.46 gigabase pairs(Gb)and 6882 SVs supported by at least one diploid haplotype assembly.Establishing high-confidence SV calls for a benchmark sample that has been characterized by multiple technologies provides a valuable resource for investigating SVs in human biology,disease,and clinical research.

Tung tree (Vernicia fordii) is an economically important woody oil plant that produces tung oil rich in eleostearic acid. Here, we report a high-quality chromosome-scale genome sequence of tung tree. The genome sequence was assembled by combining Illumina short reads, Pacific Bio-sciences single-molecule real-time long reads, and Hi-C sequencing data. The size of tung tree gen-ome is 1.12 Gb, with 28,422 predicted genes and over 73％ repeat sequences. The V. fordii underwent an ancient genome triplication event shared by core eudicots but no further whole-genome duplication in the subsequent ca. 34.55 million years of evolutionary history of the tung tree lineage. Insertion time analysis revealed that repeat-driven genome expansion might have arisen as a result of long-standing long terminal repeat retrotransposon bursts and lack of efficient DNA deletion mechanisms. The genome harbors 88 resistance genes encoding nucleotide-binding sites;17 of these genes may be involved in early-infection stage of Fusarium wilt resistance. Further, 651 oil-related genes were identified, 88 of which are predicted to be directly involved in tung oil biosynthesis. Relatively few phosphoenolpyruvate carboxykinase genes, and synergistic effectsbetween transcription factors and oil biosynthesis-related genes might contribute to the high oil content of tung seed. The tung tree genome constitutes a valuable resource for understanding genome evolution, as well as for molecular breeding and genetic improvements for oil production.

Objective To investigate the incidence of motor system disorders or symptoms that occurred among naval afloat personnel onboard a certain naval surface ship after a prolonged distant voyage.Methods In the year of 2015,a randomized questionnaire survey was carried out among the naval afloat personnel,who experienced a prolonged ocean-going voyage greater than 5 months with a total distance as far as 32 500 nautical miles,covering 4 continents and crossing 2 great oceans.All the subjects finished the questionnaire survey independently and all the questionnaire survey forms were recovered on site and statistical analyses were made by Excel and SPSS 13.0 software.Results Totally,109 copies of questionnaire were issued and 95 copies were recovered,and 90 copies were confirmed valid,with a total valid rate of 94.7％.The average age of the subjects (11 females and 79 males) was (25.12 ± 4.63) years.There were 22 naval afloat personnel with past motor system chronic diseases,accounting for 24.4％.Before prolong distant voyage,52 people complained of motor system disorders (52/90),accounting for 58％,but after prolonged distant voyage,58 people complained of motor system disorders (58/90),accounting for 65.2％.Before prolonged distant voyage,in the ship crew who lived in the relatively dry cabins,22 people complained of motor system disorders (22/33),accounting for 66.7％,but after prolonged distant voyage,21 people complained of motor system disorders (21/33),accounting for 63.6％.However,Before prolonged distant voyage,in the ship crew who lived in the relatively humid cabins,25 people complained of motor system disorders (25/46),accounting for 54.3％,but after prolonged distant voyage,34 people complained of motor system disorders (34/46),accounting for 73.9％.Conclusions Various environmental factors during prolonged distant voyage,particularly humidity in living cabins,exerted negative effects on musculoskeletal system.More strict prophylactic countermeasures should be applied.Due to high incidence of musculoskeletal system disorders,poor knowledge of the naval ship crew about the prevention and treatment of the disorders and their urgent desire to obtain required necessary consultation on the disorders,corresponding medical service should be provided in accordance with the above-mentioned features.

Objective To investigate the incidence of motor system disorders or symptoms that occurred among naval afloat personnel onboard a certain naval surface ship after a prolonged distant voyage.Methods In the year of 2015,a randomized questionnaire survey was carried out among the naval afloat personnel,who experienced a prolonged ocean-going voyage greater than 5 months with a total distance as far as 32 500 nautical miles,covering 4 continents and crossing 2 great oceans.All the subjects finished the questionnaire survey independently and all the questionnaire survey forms were recovered on site and statistical analyses were made by Excel and SPSS 13.0 software.Results Totally,109 copies of questionnaire were issued and 95 copies were recovered,and 90 copies were confirmed valid,with a total valid rate of 94.7％.The average age of the subjects (11 females and 79 males) was (25.12 ± 4.63) years.There were 22 naval afloat personnel with past motor system chronic diseases,accounting for 24.4％.Before prolong distant voyage,52 people complained of motor system disorders (52/90),accounting for 58％,but after prolonged distant voyage,58 people complained of motor system disorders (58/90),accounting for 65.2％.Before prolonged distant voyage,in the ship crew who lived in the relatively dry cabins,22 people complained of motor system disorders (22/33),accounting for 66.7％,but after prolonged distant voyage,21 people complained of motor system disorders (21/33),accounting for 63.6％.However,Before prolonged distant voyage,in the ship crew who lived in the relatively humid cabins,25 people complained of motor system disorders (25/46),accounting for 54.3％,but after prolonged distant voyage,34 people complained of motor system disorders (34/46),accounting for 73.9％.Conclusions Various environmental factors during prolonged distant voyage,particularly humidity in living cabins,exerted negative effects on musculoskeletal system.More strict prophylactic countermeasures should be applied.Due to high incidence of musculoskeletal system disorders,poor knowledge of the naval ship crew about the prevention and treatment of the disorders and their urgent desire to obtain required necessary consultation on the disorders,corresponding medical service should be provided in accordance with the above-mentioned features.

Objective To explore relationship of the anesthetic risks and intraoperative complications.Methods Preoperative anesthetic risks were assessed with Hussman's method from May 2015 to May 2016 in 2 494 surgical patients, including 1 462 males and 1 032 females.Intraoperative data and complications were tracked and recorded.Results Three hundred and thirty-six intraoperative complications occurred, accounting for 13.47% of total patients.The cardiovascular complications were a major intraoperative complications, accounting for 80.7%.2 494 patients were graded respectively into risk grade 1 with 1 540 (61.75%), grade 2 with 660 (26.46%), grade 3 with 202 (8.10%), grade 4 with 80 (3.21%) and grade 5 with 12 (0.48%).The incidence of complications were 112 (7.28%), 82 (12.42%), 82 (40.59%), 50 (62.50%) and 10 (83.33%) respectively.The sensitivity of prediction was 33.33%, 24.40%, 24.40%, 14.88% and 2.78%;the specificity 33.76%, 73.26%, 94.44%, 98.61% and 99.91%;and the accuracy 33.76%, 66.64%, 85.01%, 87.33% and 86.85%, respectively, in patients with risk grade 1, 2, 3, 4 and 5.Conclusion Hussman's method of anesthetic risks well predicts the intraoperative complications.

Objective To evaluate the role of several imaging technology in the diagnosis of patients with mitochondrial encephalomyopathy.Methods Clinical and image findings of 11 cases of mitochondrial encephalomyopathy were retrospectively analyzed.9 patients were studied with MR,2 patients with MRA and DSA,3 patients with CT plain scan,and 1 patient with positron emission tomography (PET).Results CT and MR imaging showed multiple or migrating infarct-like lesions in 9 cases,mainly involving the posterior temporal and occipital regions which crossed vascular boundaries.Lesions were distributed in the temporo- occipital and parietal lobes in 7 cases,bilateral thalamus in 1 case,the brainstem,cerebellum,and the deep cerebral white matter in 1 case.Other lesions demonstrated as cerebellum atrophy in 1 case,syringomyelia in thoracic spinal cord in 1 case.PET showed the metabolic rate of glucose was elevated early in the acute phase and reduced in the recovery phase.Conclusion The examination combined with several imaging methods will help to improve the imaging diagnosis.