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To investigate the response mechanisms of soil bacterial and fungal communities to the changes of preci-pitation in a desert steppe of Ningxia, we conducted a three-year precipitation control experiment following completely randomized design. There were five treatments, natural precipitation (T0), 50% less in precipitation (T1), 25% less in precipitation (T2), 25% more in precipitation (T3) and 50% more in precipitation (T4). By using Illumina high-throughput sequencing and bioinformatics analysis, we investigated the effects of increased and decreased precipitation on soil bacterial and fungal communities, and examined the correlations between soil physicochemical properties, plant communities and soil bacterial and fungal communities. The result showed that the richness of soil bacteria and fungi was highest in the T4 treatment. In addition, the relative abundance of Chloroflexi, the predominant phyla of soil bacteria was more sensitive to precipitation change. However, the relative abundance of only Ascomycota, a rare fungal taxon, responded to precipitation changes. Results of redundancy analysis showed that the first two axes accounted for 92.8% and 87.4% of the total variance for soil bacterial and fungal community composition, respectively. Precipitation and soil pH were the most important environmental factors driving changes in soil bacterial diversity and community composition. On the one hand, precipitation had a direct positive effect on bacterial diversity and community composition. On the other hand, precipitation changed pH by affecting soil moisture, which in turn had a significant indirect effect on bacterial diversity and community composition. Plant community biomass, plant species richness, and soil pH were the most influential environmental factors affecting fungal diversity and community composition. Precipitation had no direct effect on soil fungal community, but had a significant indirect effect by changing plant community richness and soil pH. The response mechanisms of bacterial and fungal communities in soil differed significantly under different precipitation regimes in the desert grasslands of Ningxia.

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Reasonable rotation is of great significance to grassland management. We examined the distribution characteristics, stability, organic carbon content and contribution rate of 0-30 cm soil aggregates in the forbidding grazing, continuous grazing, and rotation in the two-paddock, four-paddock and six-paddock rotational districts in a desert steppe in Ningxia. The results showed that except for the forbidding grazing grassland that was dominated by mechanically stable large aggrega-tes, other water-stable aggregates were mainly composed of microaggregates. Increasing the rotational grazing zoning was conducive to maintain the content of water-stable aggregates in the surface soil and increase the content of large aggregates. The mechanical stability aggregate fractal dimension was the largest in continuous grazing, increased the fractal dimension of the rotation and shepherd partition to reduce the trend, but the fractal dimension of water-stable aggregates did not change. The average weight diameter (MWD) and geometric mean diameter (GMD) of the aggregates were the largest in the pastoral grassland and increased with the increases of the rotational grassland partition. MWD and GMD were negatively correlated with the microaggregate content. The organic carbon content in water-stable large aggregate was higher in the six-paddock rotational district and forbidding grazing, and the two-paddock rotational grazing and continuous grazing were lower. The contribution rate of micro-aggregates organic carbon to soil organic carbon content was higher in this region. In the 0-20 cm soil layer, the contribution rate of organic carbon in large aggregates increased with the increases of rotation. Considering the characteristics of soil aggregates and their organic carbon, the rotation of six-paddock was the most suitable method for rotational grazing in the desert steppe of the study area.

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Objective To investigate the preoperative evaluation methods of multi-channel cochlear implantation in prelinguistic deaf patients with central nervous system diseases,and explore the outcomes of speech rehabilitation.Methods Multi-channel cochlear implantation was conducted in 23 prelinguistic deaf patients with central nervous system diseases,admitted to our hospital from January 1996 to January 2009.Of the 23 patients,13 had white matter abnormalities,4 pallium dysplasia,2 hydrocephalus,2 congenital temporal lobe cyst,1 Tourette syndrome and 1 Down's syndrome.Another 30 prelinguistic deaf patients without central nervous diseases and performed cochlear implantation at the same period were chosen as control group.Preoperative hearing and imaging data,developmental assessments,implantation methods and postoperative outcomes of patients from these two groups were compared.Results These 23 patients were reconstructed hearing successfully after cochlear implantation without serious complications; postoperative mean thresholds in sound field 6 months after the surgery were (42.89±3.5) dBHL,which were significantly higher than those in control group ([32.4±4.5] dBHL,P＜0.05); the mean value of speech discrimination rate in close-set word list one year after the surgery was (65.18 ±3.1)％,which was significantly lower than that in control group ([81.63±3.7]％,P＜0.05).Outcomes of hearing-speech rehabilitation were good,but the patients with serious white matter abnormalities and pallium dysplasia had a lower hearing-speech rehabilitation rate than the other patients.Conclusion Cochlear implantation can be performed safely and effectively in patients with central nervous diseases after comprehensive pre-operative imaging and audiological evaluation are performed;type and severity of the central diseases can affect postoperative rehabilitation.

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<p><b>OBJECTIVE</b>To investigate the outcomes of prelingually deafened adolescents and young adults receiving cochlear implantation (CI).</p><p><b>METHODS</b>Thirty-three patients with prelingual deafness aged 7-33 years at the time of CI were followed up for 4 years. The Speech Discrimination Score (SDS) was tested using disyllabic words and short sentences with close-set and open-set, respectively.</p><p><b>RESULTS</b>After appropriate mapping, sound field audiometry with warble tone showed that the warble tone threshold average (WTA) of the patients reached 25-41 dBHL, with a mean threshold of 28.62∓2.37 dBHL. At 1 year after the operation, the mean value of SDS was 70.03% in close-set word list with lip-reading and 61.18% without lip-reading, and was improved to 82.12% and 72.67% at 4 years, respectively. In open-set word list, the mean value of SDS was 77.94% with lip-reading and 67.85% without lip-reading. The safety and the benefits-cost evaluation of CI for prelingually deafened school age children and adolescents had been recognized by 90.9% of the families involved.</p><p><b>CONCLUSION</b>These patients can obtain appropriate speech discrimination scores with improved quality of life after CI.</p>

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<p><b>OBJECTIVE</b>To construct a modified and enhanced thymidine kinase (TK) vector regulated by human telomerase catalytic subunit promoter (hTERT) promoter and cytomegalovirus (CMV) enhancer and its killing effect on nasopharyngeal carcinoma in vitro and in vivo and its safety in vivo.</p><p><b>METHODS</b>The pGL3-basic, as basic vector template, was linked and constructed into TK vector regulated by hTERT promoter and CMV enhancer with mono-promoter vector as control. Enhanced TK expression was confirmed by fluorescent microscopy and real time fluorescent quantitative PCR. Telomerase activity was measured by stretch PCR. Tumour killing effects were examined by MTT and Boyden areola. The effects of enhanced TK on the invasiveness of tumor cell NPC 5-8F and the growth of xenograft implanted in nude mice were investigated.</p><p><b>RESULTS</b>Compared with non-enhanced vector, TK expressed by the enhanced vector significantly increased in NPC 5-8F and MCF-7 cells, telomerase activity was positive in human in NPC 5-8F cells and breast cancer MCF-7 cells and negative in control human blood vessel endothelium ECV-304 cells. After ganciclovir(GCV) treatment, NPC 5-8F cell survival rate and invasiveness decreased and tumor progress of NPC xenograft implanted in nude mice was inhibited, without obvious toxicity effects on mouse liver and kidney.</p><p><b>CONCLUSIONS</b>The enhanced TK vector regulated by hTERT promoter and CMV enhancer can obviously and specifically inhibit and kill nasopharyngeal carcinoma cells in culture and nasopharyngeal carcinoma xenograft in nude mice in vivo, without obviously toxic side effects on nude mice. The targeted and enhanced TK gene vector with high performance may be a new tumour targeted gene therapy strategy clinically to aim directly at most malignant tumours including nasopharyngeal carcinoma, with more extensive anti-cancer spectrum.</p>

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<p><b>OBJECTIVE</b>To investigate the physical characteristic of Chinese Mandarin Monosyllabic word phonemes by the time-frequency analysis.</p><p><b>METHODS</b>Manufactured and study the three-dimensional speech chart which was on the basic of information of the time-frequency analysis in 40 monosyllabic words with the SigmaPlot 9.0 and Matlab 7.0 software.</p><p><b>RESULTS</b>The mean value of basic frequency in 40 monosyllabic words was between 220 to 320 Hz area, and the mean value of four groups has significant difference by t-test. It is indicated by time-frequency analysis that the characteristics vary according to the tone of monosyllabic words. With the change of time, the various frequencies and its intensity of tone first remain basically unchanged, the curve is horizontal type; the different frequencies of tone second gradually tend to high-frequency direction, the graph is upward-type, additionally, the intensity of some tone drops little; the divers frequencies of tone third firstly deflect to low-frequency areas, then increasingly deviate to high-frequency direction of bias after maintaining a period of time, the figure is v-type, intensity changes are concave-shaped; The various frequencies of tone fourth deviate from high-frequency to low-frequency areas, and its intensity drops sharply, the graph is decreased type.</p><p><b>CONCLUSION</b>Through time-frequency analysis and three-dimensional speech chart observation, we consider that the physical characteristic of Chinese Mandarin Monosyllabic word phonemes mainly reflects the frequencies and intensity change with time.</p>

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<p><b>OBJECTIVE</b>To summarize the clinical experience with multi-channel cochlear implantation in patients with inner ear malformations and evaluate and the outcomes of speech rehabilitation.</p><p><b>METHODS</b>A retrospective study was conducted in 295 patients receiving cochlear implantation from 1998 to 2007, including 25 patients with large vestibular aqueduct syndrome (LVAS), 9 with Modini malformation, and 5 with common cavity deformity. All the patients received the Nucleus24 cochlear implants. In LVAS cases, 4 had Nucleus 24R (ST) implants, 8 had Contuor implants, 10 had Contuor Advance, and the remaining cases used Nucleus24(M) straight-electrode implants.</p><p><b>RESULTS</b>Severe gusher appeared in 3 cases of LVAS, and perilymph fluctuation were seen in other 15 cases. Four patients with Mondini malformation and 2 with common cavity malformation also experienced severe gusher, but the electrodes were inserted smoothly in all the patients without postoperative facial paralysis or cerebrospinal fluid leakage. The hearing threshold in these patients was similar to that in patients with normal cochlear structure. After speech rehabilitation for over 6 months, the abilities of speech discrimination and spoken language improved in all the cases in comparison with the preoperative lingual functions.</p><p><b>CONCLUSION</b>Multi-channel cochlear implantation can be performed in patients with inner ear malformation, but should not be attempted in patients with poor cochlear and cochlear nerve development. A comprehensive pre-operative radiographic and audiological evaluation is essential.</p>

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<p><b>OBJECTIVE</b>To evaluate the hearing and speech recognition in patients with large vestibular aqueduct syndrome undergoing multi-channel cochlear implantation.</p><p><b>METHODS</b>From 2005 to 2008, multi-channel cochlear implantation surgeries were performed in 22 patients with large vestibular aqueduct syndrome. All the patients received multi-channel cochlear implantation through transmastoid facial recess approach. The postoperative outcomes of the patients were compared with those of 22 patients with non-malformed cochlear.</p><p><b>RESULTS</b>Severe gusher occurred in 3 cases during the implantation, and perilymph fluctuation was found in another 15 cases, with a rate of anomalies of 81.8%. All the electrodes were totally inserted into the cochlear, and no facial paralysis or cerebrospinal fluid leakage occurred after the operation. The hearing threshold in these patients was similar to that in patients with normal cochlear receiving the implantation. After speech rehabilitation for over 6 months, all the patients showed improved hearing and verbal ability.</p><p><b>CONCLUSION</b>Multi-channel cochlear implantation can be performed in patients with large vestibular aqueduct syndrome, but preoperative hearing assessment and radiographic examinations should be performed.</p>

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<p><b>OBJECTIVE</b>To compare the influences of stapedectomy and small fenestra stapedotomy on the hearing of guinea pigs.</p><p><b>METHODS</b>Twenty-four (48 ears) guinea pigs were randomized equally into two groups, and the left ears were subjected to stapedectomy and total stapes replacement with a prosthesis, or sham operation (12 ears) to expose the footplate of the stapes and the round window. Each guinea pig was tested by ABR perioperatively. Four guinea pigs were chosen randomly from each group and decapitated for morphological examination by light microscopy and scanning electron microscopy after ABR test.</p><p><b>RESULTS</b>In the sham operation group, the post-operative latencies of each wave, the intervals and the hearing threshold exhibited no significant changes other than prolonged latency of wave I. In stapedectomy group, the hearing threshold increased to 23.75-/+3.77 dBSPL 1 h after operation with significantly prolonged post-operative latencies of all the waves and intervals but for III-IV interval, which was shortened. The latencies of each wave (especially waves I and III) in the stapedectomy group were increased by a greater magnitude than those in the sham operation group, but the intervals were comparable between the two groups. No significant difference was noted in the parameters of ABR either 1 h or 1 day after the operation between the two groups, in which the architecture of cochleas remained intact with similar number of spiral ganglion cells. The stereocilia of the outer hearing cells (OHC) were normal in the sham operation group while in stapedectomy group, slight stereocilia disorder occurred but became normal 1 day after operation. No obvious changes were found in the stereocilia of the inner hearing cell (IHC) in either groups.</p><p><b>CONCLUSION</b>Stapedectomy can induce mild hearing loss without seriously damaging the function of the cochlea in guinea pigs.</p>

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<p><b>OBJECTIVE</b>To observe the alterations of auditory brainstem response (ABR) in guinea pigs with gentamicin-induced hearing loss under awake and anesthetic conditions.</p><p><b>METHODS</b>We recorded the ABR in 20 normal guinea pigs and 20 with gentamicin-induced hearing loss before and after anesthesia for statistical analysis.</p><p><b>RESULTS</b>No significant difference was observed in the waveform, response threshold (RT), I and III peak latencies (PL), I-III interpeak latencies (IPL) of ABR between awake and anesthetic conditions in normal guinea pigs (P>0.05), nor did gentamicin-induced hearing loss showed obvious impact on the ABR parameters (P>0.05).</p><p><b>CONCLUSION</b>No significant ABR alterations occur under awake and anesthetic conditions in either normal guinea pigs or those with hearing loss, therefore ABR test can be performed without anesthesia to ensure the success and error minimization of the experiment.</p>

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