Metal vapor vacuum arc (MEVVA) source ion implantation is a new technology used for achieving long range ion impantation.It is very important for research and application of the ion beammodification of materials. The ...Metal vapor vacuum arc (MEVVA) source ion implantation is a new technology used for achieving long range ion impantation.It is very important for research and application of the ion beammodification of materials. The results showthat the implanted atom diffusion coefficient increases in Mo implanted Al with high ion flux andhigh dose. The implanted depth is 311.6 times greater than that ofthe corresponding ion range. The ionspecies, doses and ion fluxes play an important part in the long-range implantation. Especially,thermal atom chemistry have specific effect on the long-range implantation during high ion fluximplantation at transient high target temperature.展开更多
Background Microarray and microdissection techniques were being used for many applications to study the carcinogenesis of some human tumors. But seldom studies had hitherto combined these two techniques to study carci...Background Microarray and microdissection techniques were being used for many applications to study the carcinogenesis of some human tumors. But seldom studies had hitherto combined these two techniques to study carcinogenesis mechanism of nasopharyngeal carcinoma （NPC）. To identify a set of genes involved in the carcinogenesis and development of NPC, we used the microdissected homogeneous NPC tissue cells and the pure normal epithelium pillar cells to construct the whole human genome expression profiles. Methods We preserved the tissue samples from nasopharynx of 18 patients （including 13 samples of NPC and 5 samples of normal or inflammatory mucous tissue samples from nasopharynx） in RNAlater Stabilization Reagent. The tissue samples were microdissected to harvest the homogeneous tissue cells, then total RNA was isolated from them. The sufficient antisense RNA （aRNA） was amplified from these total RNA. HG-U133.Plus.2.0 GeneChip was used to construct the human whole genome expression profiling of each sample. Differential patterns of expression of genes correlated with the carcinogenesis, classification and progression of NPC were identified with comparing the expression profiling data respectively in leave one out cross-validation analysis. Correlation between aRNA expression measured by the microarrays and semi-quantitative reverse transcription polymerase chain reaction （sqRT-PCR） were also ascertained, and found that hybridization results were validated in all of the 18 patients. Results Differential patterns of expression of 127 genes correlated with the carcinogenesis （A P value less than 0.001 with the 2-fold differentiated expression between case group and control group） of the NPC were filtered. The top most up-regulated and down-regulated 8 genes by the way of permutation test were also selected and listed in the paper. Expression of genes E2F6 and TSPAN-1 was identified using aRNA by sqRT-PCR and showed that there was significant difference between the average value of case groups and that of control group respectively （t=2.170, df=16, P=-0.045 and t=-2.946, df=16, P=0.009）. Conclusions We had identified some genes which could be the molecular marker during the carcinogenesis and the development of the NPC. The genes which selected from the different subgroups seemed to be implicated for the diagnosis,classification, and progression of NPC, and provided important insights into their underlying biology.展开更多
Background Ascorbic acid （AA） represents one of the most important enzyme co-factors, antioxidants and neuromodulators and plays an important role in the cerebral system. Increasing evidence has suggested that AA co...Background Ascorbic acid （AA） represents one of the most important enzyme co-factors, antioxidants and neuromodulators and plays an important role in the cerebral system. Increasing evidence has suggested that AA could treat certain kinds of vertigo diseases such as Meniere＇s disease. To elucidate the neurochemical functions associated with AA in vertigo, the change of extracellular AA in the brain cortex following caloric vestibular stimulation （CVS） was evaluated.Methods An on-line electrochemical detection was coupled with in vivo microdialysis to continuously monitor the change of extracellular AA in the primary somatosensory （SI） area of guinea pigs following a caloric vestibular stimulation. Sixteen guinea pigs were divided into three groups, i.e., experimental group with irrigation of the ear canal with ice water （0℃） （n=-8）, and two control groups, one with irrigation of the ear canal with warm water （38℃） （n=-4） and the other with irrigation of the auricle with ice water （n=-4）.Results In the experimental group, the ice water irrigation of the left external ear canal induced a horizontal nystagmus towards the right side lasting about 45 seconds. No nystagmus was induced by warm water irrigation of the external ear canal or by ice water irrigation of the auricle. The extracellular AA concentration significantly increased following the ice water vestibular stimulation, reaching a maximum of （130±20）% （n=8） of the basal dialysate level （2.61±0.92） μmol/L （n=8）, lasting at least for an hour. AA level did not change distinctly after the irrigation of the left external ear canal with warm water or the irriclation of the auricle with ice water.Conclusions The concentration of extracellular AA in the brain cortex of the SI area increased following the ice water vestibular stimulation. This demonstration may be useful for the investigation of the neurochemical processes associated with AA in the process of vertigo.展开更多
Background Anatomic and electrophysiological studies have revealed that the neurons located in the media vestibular nuclei （MVN） receive most of the sensory vestibular input coming from the ipsilateral labyrinth and...Background Anatomic and electrophysiological studies have revealed that the neurons located in the media vestibular nuclei （MVN） receive most of the sensory vestibular input coming from the ipsilateral labyrinth and the responses of MVN neurons to caloric stimulation directly reflect changes in primary vestibular afferent activity. The aim of this study was to clarify the intrinsic characteristics of serotonin （5-hydroxytryptamine, 5-HT） release in the MVN during the period of vertigo induced by caloric stimulation. Methods We used an in vivo microdialysis technique to examine the effects of caloric stimulation on the serotoninergic system in MVN. Twenty four guinea pigs were randomly divided into the groups of irrigation of the ear canal with hot water （n=6）, ice water （n=6） and 37℃ water （n=4）, and the groups of irrigation of the auricle with hot water （n=-4） and ice water （n=4）, according to different caloric vestibular stimulation. We examined the animal＇s caloric nystagmus with a two-channel electronystagmographic recorder （ENG）, and meanwhile examine serotonin （5-hydroxytryptamine, 5-HT） level in the MVN with microdialysis technique after caloric stimulation. Results In the caloric test the hot water （44℃） irrigation of the right external auditory canal induced horizontal nystagmus towards the right side lasting about 60 seconds and the ice water irrigation of the right external auditory canal induced it towards the left side lasting for about 90 seconds. No nystagmus was induced by 37℃ water irrigation of the external ear canal. Therefore, it was used as a negative control stimulation to the middle ear. The MVN 5-HT levels significantly increased in the first 5-minute collecting interval and increased to 254% and 189% of the control group in the second collecting interval in response to caloric vestibular stimulation with ice water and hot water respectively. The serotonin release was not distinctly changed by the irrigation of the auricle with ice water or hot water. Conclusions Neither somato-sensory stimulation of the middle ear nor nonspecific cold or hot stress affects the serotonin release. The rise of 5-HT in MVN may be involved in the mechanism of vertigo induced by caloric stimulation.展开更多
基金The National Natural Science Foundation (Nos.59671051 and 59871003), and tile 863High Technology Program (863-715-023-02-01)
文摘Metal vapor vacuum arc (MEVVA) source ion implantation is a new technology used for achieving long range ion impantation.It is very important for research and application of the ion beammodification of materials. The results showthat the implanted atom diffusion coefficient increases in Mo implanted Al with high ion flux andhigh dose. The implanted depth is 311.6 times greater than that ofthe corresponding ion range. The ionspecies, doses and ion fluxes play an important part in the long-range implantation. Especially,thermal atom chemistry have specific effect on the long-range implantation during high ion fluximplantation at transient high target temperature.
文摘Background Microarray and microdissection techniques were being used for many applications to study the carcinogenesis of some human tumors. But seldom studies had hitherto combined these two techniques to study carcinogenesis mechanism of nasopharyngeal carcinoma （NPC）. To identify a set of genes involved in the carcinogenesis and development of NPC, we used the microdissected homogeneous NPC tissue cells and the pure normal epithelium pillar cells to construct the whole human genome expression profiles. Methods We preserved the tissue samples from nasopharynx of 18 patients （including 13 samples of NPC and 5 samples of normal or inflammatory mucous tissue samples from nasopharynx） in RNAlater Stabilization Reagent. The tissue samples were microdissected to harvest the homogeneous tissue cells, then total RNA was isolated from them. The sufficient antisense RNA （aRNA） was amplified from these total RNA. HG-U133.Plus.2.0 GeneChip was used to construct the human whole genome expression profiling of each sample. Differential patterns of expression of genes correlated with the carcinogenesis, classification and progression of NPC were identified with comparing the expression profiling data respectively in leave one out cross-validation analysis. Correlation between aRNA expression measured by the microarrays and semi-quantitative reverse transcription polymerase chain reaction （sqRT-PCR） were also ascertained, and found that hybridization results were validated in all of the 18 patients. Results Differential patterns of expression of 127 genes correlated with the carcinogenesis （A P value less than 0.001 with the 2-fold differentiated expression between case group and control group） of the NPC were filtered. The top most up-regulated and down-regulated 8 genes by the way of permutation test were also selected and listed in the paper. Expression of genes E2F6 and TSPAN-1 was identified using aRNA by sqRT-PCR and showed that there was significant difference between the average value of case groups and that of control group respectively （t=2.170, df=16, P=-0.045 and t=-2.946, df=16, P=0.009）. Conclusions We had identified some genes which could be the molecular marker during the carcinogenesis and the development of the NPC. The genes which selected from the different subgroups seemed to be implicated for the diagnosis,classification, and progression of NPC, and provided important insights into their underlying biology.
文摘Background Ascorbic acid （AA） represents one of the most important enzyme co-factors, antioxidants and neuromodulators and plays an important role in the cerebral system. Increasing evidence has suggested that AA could treat certain kinds of vertigo diseases such as Meniere＇s disease. To elucidate the neurochemical functions associated with AA in vertigo, the change of extracellular AA in the brain cortex following caloric vestibular stimulation （CVS） was evaluated.Methods An on-line electrochemical detection was coupled with in vivo microdialysis to continuously monitor the change of extracellular AA in the primary somatosensory （SI） area of guinea pigs following a caloric vestibular stimulation. Sixteen guinea pigs were divided into three groups, i.e., experimental group with irrigation of the ear canal with ice water （0℃） （n=-8）, and two control groups, one with irrigation of the ear canal with warm water （38℃） （n=-4） and the other with irrigation of the auricle with ice water （n=-4）.Results In the experimental group, the ice water irrigation of the left external ear canal induced a horizontal nystagmus towards the right side lasting about 45 seconds. No nystagmus was induced by warm water irrigation of the external ear canal or by ice water irrigation of the auricle. The extracellular AA concentration significantly increased following the ice water vestibular stimulation, reaching a maximum of （130±20）% （n=8） of the basal dialysate level （2.61±0.92） μmol/L （n=8）, lasting at least for an hour. AA level did not change distinctly after the irrigation of the left external ear canal with warm water or the irriclation of the auricle with ice water.Conclusions The concentration of extracellular AA in the brain cortex of the SI area increased following the ice water vestibular stimulation. This demonstration may be useful for the investigation of the neurochemical processes associated with AA in the process of vertigo.
基金a grant from National Science Foundation of China(No.30500556)
文摘Background Anatomic and electrophysiological studies have revealed that the neurons located in the media vestibular nuclei （MVN） receive most of the sensory vestibular input coming from the ipsilateral labyrinth and the responses of MVN neurons to caloric stimulation directly reflect changes in primary vestibular afferent activity. The aim of this study was to clarify the intrinsic characteristics of serotonin （5-hydroxytryptamine, 5-HT） release in the MVN during the period of vertigo induced by caloric stimulation. Methods We used an in vivo microdialysis technique to examine the effects of caloric stimulation on the serotoninergic system in MVN. Twenty four guinea pigs were randomly divided into the groups of irrigation of the ear canal with hot water （n=6）, ice water （n=6） and 37℃ water （n=4）, and the groups of irrigation of the auricle with hot water （n=-4） and ice water （n=4）, according to different caloric vestibular stimulation. We examined the animal＇s caloric nystagmus with a two-channel electronystagmographic recorder （ENG）, and meanwhile examine serotonin （5-hydroxytryptamine, 5-HT） level in the MVN with microdialysis technique after caloric stimulation. Results In the caloric test the hot water （44℃） irrigation of the right external auditory canal induced horizontal nystagmus towards the right side lasting about 60 seconds and the ice water irrigation of the right external auditory canal induced it towards the left side lasting for about 90 seconds. No nystagmus was induced by 37℃ water irrigation of the external ear canal. Therefore, it was used as a negative control stimulation to the middle ear. The MVN 5-HT levels significantly increased in the first 5-minute collecting interval and increased to 254% and 189% of the control group in the second collecting interval in response to caloric vestibular stimulation with ice water and hot water respectively. The serotonin release was not distinctly changed by the irrigation of the auricle with ice water or hot water. Conclusions Neither somato-sensory stimulation of the middle ear nor nonspecific cold or hot stress affects the serotonin release. The rise of 5-HT in MVN may be involved in the mechanism of vertigo induced by caloric stimulation.
