Objective: To explore the therapeutic effects of ginseng total saponins (GTSs) on cognitive impairments in astronauts caused by prolonged exposure to microgravity environment. Methods: Fifty specific pathogen-free (SPF) male Wistar rats were randomized into control, hindlimb suspension (HLS), Huperzine A (HLS-Hup A 0.1 mg/kg), low-dose GTSs (HLS-GTSs 100 mg/kg), and high-dose GTSs (HLS-GTSs 200 mg/kg) groups, based on the completion time of reward-directed conditioning tasks. Except for rats in the control group, the others were subjected to HLS and treated with drugs (day 20 – 58), received reflex test under the condition of rewarding, and underwent Nissl body staining and Western blot detection on hippocampal. Results: After modeling, rats in HLS group exhibited a reduction in the number of lever presses and an increase in the completion time of the reward-directed operant conditioning task Ⅰ (P < 0.05) when compared with the control group, which were not substantially altered in the HLS-GTSs 100 and 200 mg/kg groups (P > 0.05). In the reward-directed operant conditioning task Ⅱ, the HLS group rats demonstrated a marked decrease in the number of lever presses (P < 0.05) and nose pokes (P < 0.01) when compared with the control group rats; the HLS-GTSs 100 mg/kg showed a significant increase in the number of lever presses and nose pokes (P < 0.05), while the HLS-GTSs 200 mg/kg demonstrated a significant reduction in completion time and an elevation in the number of lever presses (P < 0.05) when compared with the HLS group rats. In visual signal discrimination task, compared with the control group rats, the HLS group rats showed decrease in the indexes of the visual signal discrimination(P < 0.01), while HLS-GTSs 100 and 200 mg/kg groups exhibited manifest increase in it (P < 0.01). In reward extinction experiment, the number of lever presses in HLS rats significantly increased when compared with the control group (P < 0.01); compared with the HLS group, HLS-GTSs 100 and 200 mg/kg groups demonstrated a marked descrease (P < 0.05). The expressions of N-methyl-D-aspartic acid receptor 1 (NR1) and phosophorylated N-methyl-Daspartic acid receptor 2B (p-NR2B) proteins were markedly decreased in rats in the HLS group (P < 0.05 and P < 0.01, respectively), while that of NR2B protein maintained the same (P > 0.05). GTSs increased the expression levels of p-NR2B (P < 0.01). Conclusion GTSs improved the learning and memory ability of complex operations by regulating the NR1/NR2B phosphorylation pathways in rats.

Objective In view of the controversy over radiotherapy target volume for patients with limited-stage small cell lung cancer ( SCLC), a prospective randomized controlled trial was conducted to compare the impact of different radiotherapy target volumes on prognosis. Methods After 2 cycles of EP chemotherapy,patients without progressive disease were randomly assigned to receive thoracic radiotherapy (TRT) to either the post-or pre-chemotherapy primary tumour extent as study arm or control. Involved field radiotherapy (IFRT) to the entire metastatic lymph node regions was applied for both arms. TRT consisted of 45 Gy/30Fx/19 d administered concurrently with cycle 3 chemotherapy. Prophylactic cranial irradiation was administered to patients achieved complete or partial remission. Kaplan-Meier method was used for survival analysis. Results Between June 2002 and December 2017,159 and 150 patients were randomly assigned to study arm and control respectively. The 1-,2-,and 5-year local/regional control rates were 79. 4%,61. 5% and 60. 1% respectively in the study arm versus 79. 8%,66. 5%,and 57. 3% in the control arm (P=0. 73). The median OS time was 22. 1 months in the study arm (95%CI,18. 2-26. 0 months) and 26. 9 months (95%CI,23. 5-30. 3 months) in the control arm,the 1-,3-,5-,and 7-year OS rates were 81. 1%,31. 6%, 23. 9% and 22. 2% respectively in the study arm versus 85. 3%,36. 6%,26. 1% and 20. 0% in the control arm (P=0. 51).Grade 2-3 acute esophagitis was developed in 32. 9% and 43. 2% of patients respectively in study arm and control arm (P=0. 01),while grade 2-3 pulmonary fibrosis was observed in 2. 0% and 10. 9% of patients ( P= 0. 01 ) respectively. Conclusions For patients with limited-stage SCLC who received induction chemotherapy,thoracic radiotherapy can be limited to post-chemotherapy tumour extent and IFRT can be routinely applied.

Objective To investigate the neural representations of long-term digital memory in human brain by functional magnetic resonance imaging (fMRI) technique. Methods 22 right-handed normal volunteers were recruited to participate in a test of long-term digital memory while the fMRI data were recorded. Control tasks were performed for the block-design. SPM 99 was used to analyze the data and to obtain the activated brain regions.Numbers of activated voxels were used to calculate lateralization index (LI). Results When the threshold was set as P＜0. 0001 ,using a one-sample t -test,the middle gyrus of the left frontal lobe(t=9.68) and the right cerebellum ( t = 9.85 ) were activated remarkably during the memory task. The subcortical structures including the thalamus (t=6.72) and the caudate (t=6.58) were also obviously activated during the memory task. LI of the numbers of activated voxels was 0.51. Conclusions The subcortical structures and the cerebellum as well as the cerebral cortex are collaborative to contribute to long-term digital memory function in human brain. The results also reveal that the functional areas of long-term digital memory in human brain are localized with the functional lateralization in the left hemisphere.

Objective To examine whether the marginal division of the striatum(MrD)is involved in the associative learning and memory function of human brain with the help of functional magnetic resonance imaging(fMRI)technique.Methods Sixteen right-handed normal volunteers participated in a test of paired-word associative learning and memory,while the fMRI data were recorded.Control tasks were performed for the block-design.Statistcs parameter mapping 99 was used to analyze the data and to obtain the activated brain regions.Results When the threshold was set as P＜0.005.using a one-sample T-test,the left occipital lobe and the superior and middle gyrus of the left frontal lobe were activated remarkably during the encoding process of the paired-word associative learning and memory task,with the maximum intensity T value being 13.87 and 9.36.respectively.The left MrD was also obviously activated during this stage(T value was 5.46).But during the retrieval process,the left parietal lobe was prominently activated(T value was 8.73).Conclusion The resuhs of this study reveal that the subcortical structures such as MrD as well as the cerebral cortex are involved in the associative learning and memory of paired-word in human brain.

BACKGROUND: The physical property of porcelain fused to metal (PFM) differs from those of its constituents, which nake impacts on PFM,and the mechanical property of most composites can be estimated with mixture rule. However, there are various factors influencing the mechanical property of PFM and great differences found in the estimations, thus it is necessary to combine the theoretical analysis of mechanical property and mechanics of materials by matbematical models, and provide guidances for PFM' s application.OBJECTIVE: To explore the experiment and computing methods of mechanical analysis on PFM repair materials, and analyze its correlativity and internal relation.DESIGN: Three-point bending experiment and mixture rule of the composites were applied to measure and calculate the intensity and modulus of materials, and then the experimental results and computations were compared.SETTING: Repair Department of Stomatology, West China Stomatological College.MATERIALS: According to the different metal-porcelain ratios, 15 PFM test pieces of 26 mm×4 mm×1.5 mm were divided into 5 groups, with 3 in each.METHODS: Three-point bending experiment was used to detect the bending level and elastic modulus of PFM, whose changing rule was observed,and then was compared with theoretical computed value as well as study the correlation.MAIN OUTCOME MEASURES: PFM experimental result, theoretical computation and the comparison of the two,RESULTS: There were obvious correlations between the experimental measurement and theoretical results, which indicated that the mechanical property of PFM could be predicted by the revised formula.CONCLUSION: The mechanical property of PFM has regular relations with the geometrical morphous parameter and mechanical parameter of PFM constituents, and can be predicted and improved by revised theoretical formula.

BACKGROUND: Hippocampal structure in brain is the division related to learning and memory, generally it is closely relevant to spatial cognitive activity. Marginal division of striatum is a latest discovered subdivision related to learning and memory function of brain, whether is its learning and memory function different from that in hippocampus?OBJECTIVE: To compare the difference, function and importance in learning and memory function between marginal division of striatum and hippocampus in brain and observe the difference in escape learning and memory between marginal division of striatum and hippocampus.DESIGN: Completely randomized controlled experiment.SETTING: Institute of Neuroscience in Zhujiang Hospital Affiliated to First Military Medical University of Chinese PLA.MATERIALS: The experiment was performed in Institute of Neuroscience in Zhujiang Hospital Affiliated to First Military Medical University of Chinese PLA from March 2002 to July 2003. Totally 109 normal male adult SD rats were employed and 75 rats of them were screened as the qualified animals by twice Y-maze test. Randomly, 25 rats were divided into damaged marginal division of striatum group (DMD group), 10 rats were into bilateral fimbria-fornix transection group (FFT group), 30 rats were into the control of marginal division of striatum (MD control) and 10 rats were into the control of bilateral fimbria-fornix group (FF control). After 24 hours training in Y-maze,In DMD group, 10 g/L kainic acid 0.1 to 0.2 μL was used to damage bilateral marginal division of striatum of rats. In MD control, physiological saline of minim dose was injected in bilateral marginal division of striatum of rats. In FFT group, bilateral fimbria-fornix was transectioned. In FF control, the cortical tissue of the superficial layer of bilateral fimbria-fornix was transectioned. The operation was done on the second day after the 2nd screening. The behavior of rats in learning and memory was observed in Y-maze on the 5th day after operation (during 30 times of maze test, if success frequency ≥ 15,normal capacity of learning and memory was identified.).MAIN OUTCOME MEASURES: Success frequency of rats in different groups in Y-maze learning before and after operation.RESULTS: Of 109 normal male adult SD rats, 75 rats were screened to be qualified after twice Y-maze test. During the experiment, 3 rats were died and other 32 rats fell into disuse for the drug or physiological saline was not injected accurately to the marginal division of striatum. Terminally, 40 rats entered the analysis in total, of which, 11 rats were in DMD group, 9 rats in MD quency in Y-maze learning of rats in DMD group after operation was lower than MD control, FFT group and FF control [(9.27±4.29) times, (22.56±4.25)frequency in Y-maze learning of rats in DMD group after operation was also significantly lower than that before operation [(9.27±4.29) time, (18.27±3.07)FFT group was basically same as FF control and MD control (P=0.660 and P=0.489) and it was basically same to the success frequency in Y-maze learning before operation (P=0.700).CONCLUSION: The learning of Y-maze in rats with damaged marginal division of striatum was remarkably reduced and there was no obvious change in learning and memory between the rats with fimbria-fornix transaction and without transaction. It is verified that marginal division of striatum can reflex complex learning and memory behavior in electric Y-maze test, which cannot be achieved in hippocampus. It is further explained the difference of the two divisions in controlling learning and memory in cerebrum, the marginal division of striatum is able to control hippocampus in learning and memory function.

BACKGROUND: The marginal division, a new sub-region in rat brain striatum discovered in recent decades, has been found to closely relate to learning and memory function of the brain. The immediate-early genes such as c-fos and c-jun participate in the signal transduction of learning and memory in the marginal division. But what other intermediate events are initiated in the marginal division in the process of learning and memory?Cyclic adenosine monophosphate (cAMP) response element-binding protein (CREBP) is an molecule essential for the formation of long-term memory,and investigation of the expression and distribution of phosphorylated CREBP in the striatum may help understand the signal transduction mechanism in the striatum during learning and memory at the molecular level.OBJECTIVE: To investigate the expression of phosphorylated CREBP in rat brain stratum during learning and memory process.DESIGN: Completely randomized controlled study.SETTING: Institute of Neurosciences, Zhujiang Hospital of the First Military Medical University of Chinese PLA.MATERIALS: This experiment was conducted in the Institute of Neurosciences, Zhujiang Hospital of the First Military Medical University of Chinese PLA between April and August 2003. Totally 48 normal male adult SD rats were provided from the Experimental Animal Center of First Military Medical University, and after two Y-maze tests, 40 rats were selected for this study (MG-2 type, Sanshengxing electricity company).METHODS: The 40 SD rats were randomized into 4 equal groups. The rats in the first group were subjected to training to acquire dark avoidance reflex in a Y maze, those in the second group underwent sham training with only light stimulation in the Y maze without electricity on the floor.The rats in the third group were trained in the Y maze with electricity on the floor but not light stimulations, with the rest 10 rats serving as the control group subjected to sham training in the Y maze without either electric or light stimulations. After the training in the Y maze, the rats were sacrificed immunohistochemical detection of phosphorylated CREBP expression in the brain striatum.MAIN OUTCOME MEASURES: Expression of phosphorylated CREBPin rat brain striatum.RESULTS: All the 40 rats enrolled in this study were examined for phosphorylated CREBP expression. Positive expression of phosphorylated CREBP was observed in the medial marginal division of the brain striatum after the rats were trained in the Y maze with electric stimulation, but no obvious expression was seen in rats in the sham training or control groups.Massive expression of phosphorylated CREBP could be observed, typically,in the hippocampus, front prefrontal lobe cortex and cingulate gyrus of the rat brain.CONCLUSION: The transcriptional factor phosphorylated CREBP in the marginal division of the striatum participates in the signal transduction for learning and memory in rats receiving Y maze training to acquire dark avoidance reflex.

In this study we compare the experimental and mathematical analyses of mechanical properties of PFM and analyze their correlation levels and inner links. Fifteen PFM specimens with different thickness ratio of metal to porcelain are made , with the shape of 26mm x 4mm x 1.5mm, and are divided into 5 groups, the metal thickness increases with 0.05mm change each among every group from 0.25mm to 0.45mm, the porcelain thickness decreases accordingly. The three-point-fracture test is used to measure their bending strength and elastic modulus, exhibit their changing laws, and disclose their inner relationships. When the whole thickness of the specimen is determined, the fracture load, bending strength and elastic modulus increase according to the increase of the metal thickness. The experimental mechanical properties of PFM are significantly influenced by the thickness ratio of metal to porcelain, and are the same as the theoretical ones calculated by the mixed law formula of compound material. There is significant correlation between the experimental analysis and mathematical analysis of mechanical properties of PFM. The regression coefficients can be obtained to describe this relationship. Further more, they can be used as the corrected parameters of the theoretical formula. The corrected mathematical formula is helpful to predicting and improving the mechanical properties of PFM.
Compressive Strength ; Dental Bonding ; Dental Porcelain ; Dental Stress Analysis ; Elasticity ; Materials Testing ; Metal Ceramic Alloys ; Models, Theoretical ; Tensile Strength

With its excellent character , Holmium:Yag laser had been used in more and more areas of medicine. It's growing success is a result of its excellent performance as both a lithotriptor and a surgical laser on soft tissues. The low level laser power is a good stimulator to the growth of biological tissue and the metabolism of cells.

The short chain fatty acids inplatelet concentrate (PC) and serumwere determined by means of gaschromatography.The short chainfatty acids determined includeacetic,propionic,butyric,isobuty-ric,valeric,isovaleric,lactic,pyruvic and succinic acids.Therewere acetic,lactic,pyruvic andsuceinic acids in PC;their relativecontents were 1.14,13.50,1.41 and9.54,respectively.The serum cont-ained acetic,lactic and pyruvic aci-ds;their relative contents were0.98,4.33 and 1.88,respectively.Succinic acid wasn't found in theserum,suggesting that the succinicacid in PC is the content of platelets.There was a positive correlationbetween the platelet count and lacticacid content of PC.Fresh PC wascompared with the PC of same volumepreserved for 0,24,48,72 hours atroom temperature.The lactic acidcontent of PC increased with thetime of preservation.