Biomedical subjects

Yongchang Liu

Publications and source records attributed to Yongchang Liu.

3 recordsLinked to original sources

PubMed2005

Spider's microstructure for sensing.

The spider is well known for sensing the movements of air and preys. Bionics of the spider based on this principle is being paid great attention by many researchers. Here, this paper presents some detailed organs of the spider to make an attempt to clarify the sensing mechanism of the spider from the point view of physical structure by scanning electron microscopy. And behavior characteristics concerning sensing action are observed by optical microscopy. Compared with structures, some novel features of sense movements in micro- and nano-scale size and corresponding possible models are presented. At the same time, simple structure analysis is made to explain and prove this hypothesis.

Animals↗

PubMed2003

Brain glucose metabolism and neuropsychological test in patients with mild cognitive impairment.

OBJECTIVE: To investigate the features of regional cerebral metabolic rate of glucose (rCMRglc) in patients with mild cognitive impairment (MCI) by positron emission-tomography and its relationship with neuropsychological test. METHODS: Positron emission tomography, mini-mental state examination and Wechsler memory scale were applied in 10 patients with MCI and 10 healthy volunteers as the control group. RESULTS: Scores of mini-mental state examination and Wechsler memory scale in MCI patients were lower than those in the control group (P < 0.01). rCMRglc of the left orbital gyrus, right middle temporal gyrus and right putamen was lower in the MCI group than in the control group (P < 0.05). Correlation analysis in the MCI group indicated that rCMRglc of many brain regions such as the orbital gyrus, putamen, left hippocampus and parahippocampal gyrus, cingulate gyrus, left amygdaloid body, precentral gyrus, postcentral gyrus, and medial occipitotemporal gyrus in MCI patients, were correlated negatively with age; while the rCMRglc of many parts of the brain such as the left putamen, temporal lobe, anterior cingulate gyrus, left insular lobe, amygdaloid body, precentral gyrus, postcentral gyrus and medial occipitotemporal gyrus were correlated positively with mini-mental state examination; and rCMRglc of the left putamen, temporal lobe, left insular lobe, precentral gyrus and postcentral gyrus were correlated positively with Wechsler memory scale. The right putamen, the right inferior temporal gyrus, precentral gyrus, and left postcentral gyrus were correlated positively with the length of education. However, only rCMRglc of the left amygdaloid body were correlated positively with gender. CONCLUSION: The rCMRglc was lower in the orbital gyrus and putamen of MCI patients. Their rCMRglc were correlated with their cognitive impairment severity, age, length of education and sex.

Aged↗

PubMed2002

[The comparison of the regional cerebral metabolism rate of glucose in Alzheimer's disease with mild cognitive impairment].

OBJECTIVE: To study the feature of regional cerebral metabolism rate of glucose (rCMRglc) of Alzheimer's disease (AD) and mild cognitive impairment (MCI) by positron emission tomography (PET) and the relationship between MCI and AD. METHODS: 13 AD patients, 10 MCI patients and 10 health volunteers as a control group (HC) were underwent 18F-fluoro deoxyglucose (18F-FDG)-PET scanning. RESULTS: (1) There was lightly decreasing of radioactivity of temporal lobe and parietal lobe in HC group, a little severer decrease in MCI group, markedly decrease of radioactivity of temporal lobe, parietal lobe and frontal lobe in AD group examined by naked-eye. (2) The rCMRglc of many parts of brain such as frontal lobe, including superior, middle and inferior frontal gyrus, orbital gyrus and rectus gyrus, temporal lobe, including superior, middle and inferior temporal gyrus, parietal lobe, including superior parietal lobe, supramarginal gyrus and angular gyrus, limbic system, including anterior cingulate gyrus, insular lobe, basal ganglions, including thalamus, caudate nucleus and amygdaloid nucleus decreased significantly in AD group, compared to MCI and HC groups (p < 0.05 to p < 0.001). (3) The rCMRglc of many parts of brain such as frontal lobe, temporal lobe, parietal lobe, limbic system, and basal ganglions in MCI group was lower than that in HC group, but not significantly (p > 0.05). Only that of the left caudate nucleus in MCI decreased significantly compared to that in HC group (p < 0.05). CONCLUSION: Decreasing of rCMRglc of parietal lobe is sensitive in evaluating cognitive function, next one is temporal lobe, and then frontal lobe. The rCMRglc of frontal lobe, temporal lobe, parietal lobe, limbic system, and basal ganglions decreasing markedly indicates that global function decayed in AD patients. While the rCMRglc of those parts in MCI patients' brain decreases mildly. This indicates that MCI is the middle state of AD and HC. Decreasing of rCMRglc of the left caudate nucleus has a certain role in diagnosis of MCI.

Aged↗