Objective To investigate the formaldehyde emission rate of wood-based materials sold in Hangzhou and to ana-lyze its emission characteristics.Methods Four kinds of wood-based materials were selected and the formaldehyde emission rates were determined by applying the balancing concentration method of small environmental test chamber and the emission rates of different kinds of the materials were compared.Results A-level wood-based materials were of40%,B-level50%and C-level10%of the whole.The formaldehyde emission rates of these different kind of wood-based materials were significantly different (0.01

BACKGROUND: Patients with Alzheimer disease (AD) usually have visuospatial dysfunction at an early stage and most patients with AD were evolved from mild cognitive impairment (MCI).OBJECTIVE: To detect whether a patient with MCI has a visuospatial dysfunction similar to AD. To compare the cerebral activation with ferromagnetic resonance between the healthy people and the patients with mild cognitive disorder.DESIGN: A case controlled observationSETTING: The Department of Neurology of the First Hospital of Peking University.PARTICIPANTS: Nine inpatients with mild cognitive disorder hospitalized at the Department of Neurology of the First Hospital of Peking University from April 2000 to March 2003 were involved and other 9 healthy people matching in age, gender and the educational level were also involved.METHODS: The subjects had the task of discriminating the different finger positions on the clockface. They could see the mission clearly showed on the cloth through refractor, and they were supposed to give the corresponding reaction to different cognitive tasks with left and right hands pressing the keys according to visual sign generated by the computer.Block design was adopted in the cognitive task. Stimulus block and baseline block appeared in turn. Baseline block displayed "+" mapped in the center of the image and was kept for 21s. Stimulus block displayed 10 pictures successively. The finger position of the two clockfaces among three clockfaces was the same in one picture. The absolute value of the rotated angles of the different clockfaces in each image on the same stimulus block was the same. The angles formed by six stimulus block fingers arranged randomly were 300, 450, 1800. The two clockfaces had the same finger positions, and the subjects were requested to discriminate the finger position of these two clockfaces. It was carried out on a 1.5 T GEMRTWIN magnetic resonance scanning apparatus. Then t test was performed to work out the right reaction time and proper rate with Excel software between the patients with mild Alzheimer's disease and the healthy persons. Pretreatment and statistical analyses were performed with analysis of functional neuroimages software used internationally.MAIN OUTCOME MEASURES: Comparison of the reaction time and proper rate between the two groups.parison of the reaction time between the two groups: The reaction time for distinguishing the change of 300, 450, 1800 was longer than that in the control group, and there was significant difference in distinguishing the change of 300, 450, 1800 for the patients [(1 776.7±570.2), (1 646.3±432.7)ms;of the proper rate between the two groups: The proper rate for distinguishing the change of 300, 450, 1800 was significantly lower than that in the control group (62.8±21.4)%, (82.8±15.8)% ;(76.7±17.0)%, (95.0±8.7)%; (69.4vation: the activation density at the bilateral parietal lobe, bilateral temporooccipital borderline and bilateral lateral striate cortex in patients was weaker than that in the control group (P ＜ 0.05).CONCLUSION: Neural network activation related with visual space in patients with MCI was weaker than that in the healthy people indicating that visuospatial impairment exists in the patients with mild cognitive impairment.

Objective To assess the value of 18F-FDG PET/CT in clinical classification,monitoring of chemotherapeutic response and surveillance of histopathological transformation of Castleman's disease (CD).Methods Fourteen pathologically diagnosed CD patients (7 males,7 females; mean age:(45.64±14.30) years) were retrospectively reviewed.18F-FDG PET/CT was performed before chemotherapy in all patients and 4 of 14 patients were reexamined after the treatment.The study parameters included histopathological results,sites,number and highest SUVmax of the lesions.Mann-Whitney and Kruskal-Wallis tests were used for data analysis.Results Of all the 12 patients without histopathological transformation,one or more enlarged and metabolically active lymph nodes were found in each patient (SUVmax =3.94± 1.44,range:1.9-6.8),including 2 unicentric CD (UCD) and 10 multicentric CD (MCD).There was no statistically significant difference of SUVmam between UCD and MCD (4.55±3.18 vs 3.82±1.14; Z=0.22,P＞0.05).There was also no significant difference of SUVmax among different pathological types (hyaline-vascular CD (4/12):3.56±0.96,plasma cell CD (6/12):4.73±1.41,mixed CD (2/12):2.30±0.57; x2 =4.74,P＞0.05).For the 4 patients with follow-up PET/CT after chemotherapy,the lesion activity was normalized in 3 patients and clearly reduced in 1 patient.The SUVmax of 2 patients with histopathological transformation (10.85±2.05) was significantly higher than that without transformation (3.94± 1.44; Z=-2.19,P＜0.05).Conclusion 18F-FDG PET/CT may play an important role in clinical classification,monitoring of chemotherapeutic response and surveillance of histopathological transformation of CD.

ObjectiveTo explore the early diagnosis of Alzheimer's disease (AD),the arithmetic calculation ability in the patients with mild cognitive impairment (MCI) was detected under the functional magnetic resonance imaging (fMRI),combined with the neuropsychological test.Methods8 patients with MCI and 9 controls matched for the age, gender, level of education and handedness performed the subtraction of two digits presented visually while the MR machine was scanning. The raw data of the fMRI were processed with the software AFNI. The reaction time and correct ratio were analyzed with the statistical software Excel.ResultsCompared with the controls, the patients manifested longer reaction time and lower correct ratio. The patients' brain activation showed significant decrease in the inferior frontal lobe,temporal neocortex and inferior parietal area mainly in the left hemisphere. On the contrary, the activation intensity and extension in the right inferior frontal lobe were increased as compensation.ConclusionsThe patients with MCI have the deficit in calculation ability. The examination of the calculation by means of the cognitive neuropsychology and fMRI test can offer a powerful reference for the early diagnosis of AD.

Objective To investigate the underlying neural mechanism of left hemiparalexia and left hemialexia in reading Chinese characters. Methods A patient with reading disorders caused by brain infarctions at the left ventralis medialis occipitotemporal lobe and the splenium of the corpus callosum was studied. A series of neuropsychological tests, such as reading Chinese characters presented in the central foveal field or in the left and right half of the foveal field, were conducted with the patient, and neuroimaging techniques including high spatial resolution 3D-MRI and diffusion tensor tractography (DTT) were used to examine whether or not there were lesions of the neural pathway. Results The patient showed left hemiparalexia, which was characterized by making substitution or omission mistakes, mostly in the left parts of Chinese characters, and also left hemialexia(alexia for characters presented in left visual field). 3D-MRI demonstrated infarctions in the left ventral mesial occipitotemporal area and in the left side of the splenium of the corpus callosum. The left lateral mid-fusiform cortex, which has been identified as the visual word form area(VWFA), was almost intact. DTT indicated the major forceps fibers running through the splenium were all disconnected due to the infarction of the left splenium. Conclusion As a result of disruption of the splemium-major forceps pathway, visual character information in the left visual field which is initially projected to the right occipital cortex cannot be transferred from the right visual cortex to the left VWFA. This mechanism of left hemiparalexia and left hemialexia in reading Chinese characters is similar to that in reading English words.

BACKGROUND:The establishment of a safe, reliable and easily repeatable mouse model of nonalcoholic fatty liver disease is the prerequisite for the study of the diagnosis and treatment of the disease.
OBJECTIVE:To establish a C57BL/6 mouse model of nonalcoholic fatty liver disease and observe changes of biochemical indicators, which can provide a theoretical basis for its pathogenesis and drug treatment.
METHODS:Sixty healthy male C57BL/6 mice were randomly divided into a control group of 30 cases (normal diet), and a model group of 30 cases (high fat diet). Models of nonalcoholic fatty liver were established. At 8 weeks, body mass, liver index, and homogenate superoxide dismutase activity in the liver were detected. Changes in serum alanine aminotransferase, aspartate aminotransferase, triglyceride glycerol, cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol were observed. Pathological examination was performed.
RESULTS AND CONCLUSION:(1) Pathological sections showed that large droplets and smal lipid droplets in the mouse liver and spread the whole liver. Swel ing of the liver cel s, visible cytoplasmic vacuoles and obviously inflammatory changes in liver cel s were observed in the model group. (2) Body weight and liver index were significantly higher in the model group than in the control group (P<0.05). Superoxide dismutase activity was significantly reduced in the liver (P<0.05). (3) Triglycerides, cholesterol, and low-density lipoprotein cholesterol levels were significantly higher, but high-density lipoprotein cholesterol levels were significantly lower in the model group than in the control group (P<0.05). (4) Nonalcoholic fatty liver mouse model is ideal for high-fat diet-induced animal model. The method is simple, repetitive, and can provide a stable animal model for the study on the mechanism of nonalcoholic fatty liver disease and drug treatment.

Objective To investigate the levels of blood pressure, blood lipid, blood glucose, body mass index (BMI) as well as the epidemiological characteristics of dyslipidemia, hyperglycemia, hypertension and metabolic syndrome of Hangzhou citizens. Methods A total of 28 990 citizens in Hangzhou city who underwent health checkup were recruited in this study, including 10 179 males and 18 811 females. The average age of subjects was 65.05 years. Subjects were asked to complete questionnaires regarding personal characteristics. The physical examination emphasized measurement of height, waist and blood pressure. Blood samples were collected and subjected to serum glucose, TC, HDL-C, LDL-C and TG measurements. The values of the examinations was described as xˉ± s . The ratios were compared with chi-square test. The trend analysis was conducted by linear correlation test. Results The prevalence of hypertension and metabolic syndrome was 17.1% and 11.2% respectively. And the prevalence of overweight/obesity and hyperglycemia was 36.3%,8.1%,16.4%respectively. It was indicated that the men had higher prevalence of hyperglycemia, hypertension, metabolic syndrome and overweight compared with women. However, as to the dyslipidemia, men and women were totally different. Women were more prone to suffer from hypercholesterolemia and elevation of low-density lipoprotein cholesterol. Men were apt to suffer from hypertriglyceridemia and reduction of high-density lipoprotein cholesterol. Divided the subjects by age into three groups, it was suggested that the rates of dyslipidemia, hyperglycemia, hypertension and overweight/obesity increased along with the increment of age in women. Although the rates of metabolic disorders were higher in the group of men, the trend of increase with age was not as significant as in women. It could be seen in men that dyslipidemia and overweight/obesity were reduced with the increase of age. Conclusion The metabolic disorders in Hangzhou citizens showed their own characteristics. It is suggested that multiple strategies targeting at different sexes and age-groups should be formulated to prevent and control the occurrence of metabolic diseases.

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Objective: To evaluate the diagnostic value of fluorine-18 fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography ( PET/CT) in fever of unknown origin ( FUO) in a Chinese hospital .Methods:The records of 51 patients with FUO (32 men and 19 women;mean age 54 years with a range between 3 and 81 years) were analyzed retrospectively .All the patients were examined by 18 F-FDG PET/CT scan and the results were compared with the final diagnosis which was established by additional procedures including pathology , laboratory examination , and clinical follow-up for more than 3 months.The t test was used for statistical analysis .Results: A final diagnosis was established for 48 patients , including 32 patients with infectious diseases , 9 with malignancies , and 7 with non-infectious inflammatory diseases .By FDG PET scan alone , the rates of true positive , false positive , false negative, and true negative were 52.9%, 27.5%, 17.6%, and 2.0%, respectively.By FDG PET/CT scan, the rates of true positive, false positive, false negative, and true negative were 70.6%, 27.5%, 2.0%, and 0, respectively.18F-PET/CT had a sensitivity of 97.3%(36/37), specificity of 0 (0/14), and accuracy of 70.6%(36/51) in FUO, especially a high sensitivity and accuracy of 100%(9/9) in the diagnosis of malignant tumor .Moreover , the maximum standardized uptake value ( SUVmax ) in tumor was significant higher than that in infection (3.7 ±2.7 vs.7.7 ±3.5, P=0.001, t=3.6), which implied that SUVmax might be useful in differential diagnosis in FUO .Conclusion:FDG PET/CT is a valuable imaging tool for the identification and location of the potential lesion in FUO and is helpful for the etiological diagnosis , especially in the diagnosis of malignant lesions .