Temporal contrast enhancement of picosecond pulses based on phase-conjugate wave generation

A practical technique based on the phase-conjugate wave (PCW) generation is proposed to improve the temporal contrast of the picosecond pulses. Our theory predicts the temporal contrast of the picosecond pulses can be enhanced to about the cube of the temporal contrast of the input pulse via the PCW generation, in which the conversion efficiency from the incident pulse to the PCW is about 25%. In a proof-of-principle experiment, the temporal contrast of picosecond pulses was enhanced from 1.7×10(3) to 8.6×10(8) with the conversion efficiency of 10%. This technique is promising to effectively eliminate the background of the ultrashort and ultraintense laser pulses in the future.

Application of natural and amplification-created restriction sites in prenatal and preimplantation diagnosis of beta-thalassemia

We attempted the strategy of natural and amplification-created restriction sites for early prenatal and preimplantation diagnosis of Chinese beta-thalassemia. Mutagenesis primers were designed for 11 mutations reported for the Chinese population. The diagnosis was established after polymerase chain reaction and digestion of products by specific enzymes. The results were confirmed by direct sequencing of enzymatically amplified double-stranded DNA. The beta-globin gene was amplified from triploid embryos and isolated blastomeres using mismatched primers. The mutant and normal alleles can be distinguished clearly by this new method. Early prenatal diagnosis was successfully achieved in 9 cases. The beta-globin gene was successfully amplified from single blastomeres and tripronuclear embryos with mismatched primers. Natural and amplification-created restriction sites are a reliable method for rapid prenatal diagnosis of beta-thalassemia. Furthermore, the strategy provides a possible approach for the preimplantation diagnosis of beta-thalassemia.

Molecular diagnosis of thalassemia in Taiwan

Thalassemia is an autosomal recessive disease characterized by absent or decreased synthesis of the globin chain. This disease is very common in Taiwan area. It mainly consists of alpha- and beta-thalassemia. The diagnosis of these entities depends on hemoglobin electrophoresis, mean corpuscular volume (MCV), or mean hemoglobin concentration of red blood cell and excludes the disease of iron deficiency anemia. However, these tests are not reliable. The definite diagnosis is to check the hemoglobin genes directly. In recent years, we have developed several molecular techniques to solve these problems. This review focuses on the techniques which are used recently in Taiwan area.

[Increased serum C-C chemokine ligand 19 levels correlated with B cell abnormalities in systemic lupus erythematosus]

OBJECTIVE

To detect the levels of serum C-C chemokine ligand 19 (CCL19) in patients with systemic lupus erythematosus (SLE) and to evaluate the correlation between CCL19 expression and clinical features and laboratory parameters, trying to reveal the possible role of CCL19 in the pathogenesis of systemic lupus erythematosus.

METHODS

The levels of serum CCL19 were measured by enzyme linked immunosorbent assay (ELISA) in 90 patients with SLE and 30 healthy controls. These SLE patients included 75 patients who received treatment with glucocorticoids and disease-modifying anti-rheumatic drug (DMARD) and 15 patients without therapy. The frequencies of peripheral blood B cells and the B cell subsets were assessed in the patients with SLE by flow cytometry. The correlation between the clinical data, laboratory parameters, B cell subset frequencies and serum CCL19 levels were analyzed. Indepen-dent samples t test, paired t test, Pearson and Spearman correlation were used for statistical analyses.

RESULTS

The levels of CCL19 were markedly higher in the SLE patients without therapy and the patients with therapy than in the health controls[(596.25±409.19) ng/L and (422.90±395.84) ng/L vs. (157.79±125.23) ng/L, all P<0.001]. Serum CCL19 levels in the SLE patients without therapy were higher than the SLE patients who accepted glucocorticoids and DMARD treatment (P<0.05). The levels of serum CCL19 were positively correlated with anti-double stranded deoxyribonucleic acid (dsDNA), anti-nucleosome antibody (AnuA), IgA, IgG and IgM (r=0.38, P=0.007; r=0.332, P=0.029; r=0.519, P=0.007; r=0.461, P=0.018, respectively). Serum CCL19 levels in the SLE patients with photosensitivity, arthritis and secondary Sjögren's syndrome were higher than the SLE patients without photosensitivity, arthritis and secondary Sjögren's syndrome, respectively [(562.25±399.12) ng/L, (565.6±435.24) ng/L and (694.9±531.02) ng/L vs. (394.7±281.42) ng/L, (385.90±325.33) ng/L and (424.8±305.46) ng/L, all P<0.05]. The levels of serum CCL19 were positively correlated with the percentage of CD27-B cells and CD27-IgD-double-negative memory B cells (r=0.519, P=0.007; r=0.461, P=0.018, respectively). However, the levels of serum CCL19 were negatively correlated with the percentage of CD27⁺ memory B cells and CD27⁺IgD^- switched memory B cells (r=-0.433, P=0.027; r=-0.616, P=0.001, respectively).

CONCLUSION

The increased serum CCL19 levels in SLE patients were associated with the production of autoantibodies, and CCL19 might be involved in the pathogenesis of SLE by disturbing the homeostasis of B cell subsets.

Shear stress-induced MMP1 and PDE2A expressions in coronary atherosclerosis

AIM

Biomechanical stress plays an essential role in coronary atherosclerosis (CAS), however, inter-relations between mechanical conditions and gene expressions remain unclear.

METHODS

We constructed finite element model of CAS to map human wall shear stress (WSS). Biopsy aortic tissue samples were obtained from 3 CAS patients. Gene expression pattern in CAS was analyzed by GEO datasets. Immunofluorescence staining and western blot confirmed protein expression and localization.

RESULTS

Peak WSS was significantly increased in the vessel stenosis of CAS at 0.25 s (mean 55.1 Pa). Analyses results of GSE76275 showed matrix metalloproteinases1 (MMP1) and phosphodiesterase-2A (PDE2A) up-regulation in endothelial shear responsiveness, which was further validated and localized in vascular endothelial cells, smooth muscle cells and other cells by double immunofluorescence staining. Western blotting assay demonstrated up-regulation of MMP1 and PDE2A expression dependent on the WSS.

CONCLUSIONS

MMP1 and PDE2A up-regulations rely on increased WSS in development and risk of CAS, suggesting that their elevation may be potential target for diagnosis and treatment (Fig. 3, Ref. 28).

Altitude convulsion threshold and time to altitude convulsion in gold thioglucose obese mice

Gold thioglucose-induced hypothalamic obesity caused a higher altitude convulsion threshold and a decrease in the time to altitude convulsion. The average altitude convulsion threshold for the obese mice was 151 torr (38,500 ft). In contrast, the average value for the controls was 131 torr (41,500 ft). It was also observed that at 206 torr (32,000 ft), the average time until altitude convulsion of the obese mice was 69 s; at 179 torr (35,000 ft), 27 s; at 141 torr (40,000 ft), 17 s; at 111 torr (45,000 ft), 10 s; at 87 torr (50,000 ft), 9 s; and at 69 torr (55,000 ft), 8 s. On the other hand, the average control time until altitude convulsion at the above-mentioned altitudes was 97, 37, 26, 11, 9, and 8 s, respectively. Moreover, the average accumulation of fat between pleura and lungs in obese mice was 154 (Table I) or 181 mg (Table II), while the value of the control group was only 72 to 67 mg. Such an increase of fat accumulation in the thoracic cage could decrease the tidal volume. The altitude convulsion threshold and the time until altitude convulsion might thus be changed. The time until altitude convulsion may be regarded as a convenient objective measure of altitude tolerance in mice.

Expression of HSP70 gene in rat brain after exposures to repeated +Gz

OBJECTIVE

To study the changes of mRNA expression of heat shock protein 70 (HSP70) in the rat brain exposed to repeated +Gz.

METHOD

The mRNA expression levels of HSP70 in rat brain were measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).

RESULT

The HSP70 mRNA expression levels in rat brains taken 30 min and 6 h after repeated +Gz exposures were significantly higher than those in control group, while the difference between the levels of control group and those of experimental rat brains taken 24 h after +Gz exposure was not significant.

CONCLUSION

It is suggested that HSP70 mRNA expression in rat brain can be induced by repeated +Gz exposures and the increased HSP70 mRNA expression may play an important role in self-protection against brain damage induced by +Gz exposures.

[Transthoracic implantation of dual-chamber pacemaker for synchronous treatment of cardiac dysfunction due to idiopathic complete left bundle branch block in children]

Objective: To investigate the efficacy and feasibility of transthoracic implantation of permanent left atrial and left ventricular dual-chamber pacemaker for synchronous treatment of cardiac dysfunction due to idiopathic complete left bundle branch block (CLBBB) in children. Methods: The clinical data of five children with cardiac dysfunction due to idiopathic CLBBB and accepting implantation of permanent left atrial and left ventricular epicardial dual chamber pacemaker from January 2015 to July 2019 at the Pediatric Cardiologic Department of the First Hospital of Tsinghua University were analyzed retrospectively. The effects of pacemaker implantation on patients' cardiac function and cardiac synchrony were evaluated by echocardiogram. Results: Among 5 patients, 2 were males and 3 females. At the time of pacemaker implantation, the age of these patients was 0.5-5.7 years, the left ventricle ejection fraction (LVEF) was 29%-46%, the left ventricle end stage of diastolic diameter was 30-53 mm and the mean Z score was 4.0-34.0. Pacemaker was successfully implanted for all the patients. After the implantation, medications that can suppress atrioventricular node conduction were used and sensed atrioventricular delay (SAV) parameters were modulated until patients' QRS duration became shortest and the percentage of left ventricular pacing increased to and maintained at 97% to 100%. Patients' QRS duration was 120-160 ms before implantation and 90-120 ms after implantation. Patients' cardiac function began to improve 1 day to 1 month after implantation. Patients' cardiac function normalized after a mean of 1-12 months. LVEF increased from 29%-46% to 55%-67%. During the follow-up, interventricular mechanical delay, septal-to-posterior wall motion delay, and left ventricular systolic dyssynchrony index decreased significantly: IVMD decreased from 31-62 ms to 26-50 ms; SPWMD decreased from 40-63 ms to 10-50 ms and Ts-SD decreased from 34.3-50.3 ms to 16.3-31.4 ms. The global longitudinal strain of left ventricle decreased from -7.7%--13.8% to -13.5%--20.3%. Conclusion: Cardiac dysfunction due to CLBBB in children can be treated with transthoracic implantation of permanent epicardial left atrial and left ventricular dual chamber pacemaker which can substitute three chamber pacemaker to achieve the effects of synchronous therapy that lead to reversion and normalization of cardiac function.

In situ detection of reovirus in formalin-fixed, paraffin-embedded chicken tissues using a digoxigenin-labeled cDNA probe

An in situ hybridization (ISH) technique using a digoxigenin (DIG)-labeled cDNA probe detected avian reovirus (ARV) RNA in formalin-fixed, paraffin-embedded chicken tissues. Tissues were collected 3 and 10 days following inoculation with the R-2 or the S1133 strain of ARV. The cDNA clone HJp1, located on the S1 gene segment of the ARV S1133 strain, was used to prepare a nonradioactive probe. The ISH assay localized ARV RNA in infected tissues including heart, liver, intestine, pancreas, and tendon. No positive-stained cells occurred in sections from uninfected chickens.

Photodegradation of alpha-naphthaleneacetic acid in aqueous solution

Kinetic processes of alpha-naphthaleneacetic acid (NAA) photolysis were studied under different conditions. The results showed that the ultraviolet light was more effective than fluorescent light in promoting degradation, and the degradation of NAA under ultraviolet light followed the first order kinetics with the photolysis rate constant of 1.15 x 10(-2) min-1 and half-life time (t1/2) of 60 min. Further, it was proved that the photolysis rate was higher in the presence of oxygen, titanium dioxide (TiO2), and low pH (acidic solution). At last, two photolysis intermediates were identified by GC-MS and possible photolysis pathways were proposed.

[Experimental studies of the protective effects of basic fibroblast growth factor and Radix Salviae Miltiorrhizae on brain injury in rats caused by repeated exposures to +Gz]

Objective. To investigate the preventive and theralseutive (therapeutic) effects of basic fibroblast growth factor (bFGF) and Radix Salviae Miltiorrhizae (RSM) on brain injury caused by repeated +Gz exposures. Method. bFGF and RSM were injected intraperitoneally into SD rats before and after repeated +Gz exposures. The contents of excitatory amino acids (EAAs), nitric oxide (NO) and the number of cell apoptosis in the brain were measured, and were compared to those of the control group and normal saline (NS) group. Result. The contents of EAAs, NO and the number of cell apoptosis were significantly higher in repeated +Gz exposures group than those in control group. The values were markedly lower in bFGF and RSM group than those in repeated +Gz exposures group and NS group. Conclusion. bFGF and RSM showed distinct preventive and therapeutic effect on the brain injury induced by repeated +Gz exposures.

[Effect of WW-domain transcription regulator 1 on aging regulation of human dental pulp stem cells]

Objective: Investigating the changes of phenotype and moleculars associated with aging with the increase of passage times of human dental pulp stem cells (hDPSC), to explore the role of WW-containing transcriptional regulator 1 (WWTR1) in the aging mechanism. Methods: hDPSCs were cultured by tissue block method, and were divided into 4 groups according to the age, algebra, cell knockdown and overexpression of WWTR1 in hDPSCs. Group Ⅰ: hDPSCs from human teeth were further divided into youth group (15-25 years old) and group middle-aged group (40-50 years old) according to different ages. Group Ⅱ: according to different passage, hDPSCs were divided into young cells group (hDPSCs were transmitted to P3 generation), and old cells group (hDPSCs were transmitted to P10 generation). Group Ⅲ: hDPSCs were knocked down of WWTR1, which were further divided into knockdown group and knockdown carrier group. Group Ⅳ: hDPSCs were overexpressed of WWTR1, which were further divided into overexpression group and overexpression carrier group. Real-time fluorescence quantitative PCR (RT-qPCR) was used to detect the changes of WWTR1 expression in groups Ⅰ and Ⅱ, and cell counting kit-8 (CCK-8) was used for groups Ⅱ, Ⅲ, and Ⅳ. Cell proliferation capacity was detected by CCK-8 assay. The ability of osteogenic differentiation was detected by alizarin red staining. Cell senescence positive rate was detected by age-related β-galactosidase staining. The expression levels of age-related genes p53 and p21 were detected by RT-qPCR. Results: The proportion of senescent cells increased gradually with continuous culture. The proliferation and osteogenic differentiation of hDPSCs in the old group were significantly lower than those in the young group (P<0.001). The expression levels of senescence related genes p53 (2.09±0.24) and p21 (4.91±0.54) in old cell group were higher than those in young cell group respectively [p53: (1.08±0.09) and p21: (1.09±0.08)] (P<0.01, P<0.001). The WWTR1 expression levels of hDPSCs in middle-aged group and old cells group were both decreased compared with those in young group and young cells group (P<0.01). The proportion of senescent cells in knockdown group (44.50±2.42) was higher than that in knockdown carrier group (22.27±0.56) (P<0.001). After knocking down WWTR1 in hDPSCs, the expression levels of age-related genes p53 and p21 were up-regulated (P<0.001), and the abilities of proliferation and osteogenic differentiation in the knockdown group were lower than those in the knockdown carrier group (P<0.001). The proportion of senescent cells in overexpression empty carrier group (20.40±0.79) was higher than that in overexpression group (10.07±0.61) (P<0.001). After WWTR1 overexpression ins hDPSCs, the expression levels of age-related genes p53 and p21 were down-regulated, and the proliferation and osteogenic differentiation ability in overexpression group were higher than those in overexpression carrier group (P<0.001). Conclusions: WWTR1 can inhibit the expression levels of age-related genes p53 and p21, thus delaying the aging process as well as promoting the proliferation and osteogenic differentiation of hDPSCs.

[A cohort study on the epidemiological characteristics of HBeAg sero-clearance in HBeAg positive chronic hepatitis B patients in Jiangsu province from 2012 to 2014]

Objective: To understand the epidemiological characteristics and influencing factors related to HBeAg sero-clearance in chronic hepatitis B patients so as to provide evidence for regular management on chronic HBV patients. Methods: From 2012 to 2014, a cohort study was conducted among HBeAg positive chronic HBV patients in Jiangsu province. Association between the characteristics and incidence of HBeAg sero-clearance was analyzed by Cox regression method. The changing trend on HBV DNA between patients with HBeAg sero-clearance and those with persistent HBeAg positive status was compared by repeated measure data variance analysis method. Results: In 2012, there were 721 HBeAg positive hepatitis B patients aged (45.2 ± 14.2) years enrolled in this study. By 2014, the follow-up observation period was 1 058 person-years, and 393 cases had lost their HBeAg status, with the rate as 37.2/100 person-years. The HBeAg sero-clearance rate was 32.4/100 person-years in hepatitis B patients who received antiviral treatment. The probability of HBeAg clearance in HBeAg positive hepatitis B patients aged ≥60 year (62.0/100 person-years) was higher than those of aged <20 year (7.0/100 person-years). The rate of HBeAg sero-clearance in HBeAg positive patients with HBV DNA <20 000 IU/ml (75.8/100 person-years) was higher than those whose HBV DNA were ≥200 000 IU/ml (16.1/100 person-years). By Cox regression analysis, the HBV DNA level was an important influencing factor on the progress of HBeAg sero-clearance. Patients with HBV DNA levle as ≥200 000 IU/ml, had a lower HBeAg clearance rate (HR=0.18, 95%CI: 0.13-0.23, P<0.001). Compared to the persistent HBeAg positive group, HBV DNA showed a more dramatic fall in the HBeAg-lost group (P<0.001). Conclusion: The rate of HBeAg sero-clearance among HBeAg positive hepatitis B patients was correlated with age and HBV DNA status of the patients that called for comprehensive management and intervention programs to develop for the HBeAg positive hepatitis B patients with different characteristics.

Effects of L-glutamic acid on acid secretion and mucosal blood flow in the rat stomach

The effect of intravenous administration of L-glutamic acid (L-Glu) on gastric acid secretion and gastric mucosal blood flow (GMBF) in anesthetized rats were investigated. Infusion with synthetic L-Glu alone had no effect on spontaneous acid secretion. However, L-Glu reduced histamine- (2 mg/kg/hr) or oxotremorine- (1 microg/kg/hr) stimulated acid secretion, whereas L-Glu had no effect on acid secretion induced by pentagastrin (8 microg/kg/hr). Furthermore, this inhibitory effect of L-Glu on histamine- or oxotremorine-stimulated acid secretion was blocked by 6,7-dinitroquinoxaline-2,3-dione (DNQX), a non-NMDA receptor antagonist. The effect of L-Glu on gastric mucosal microcirculation in the anesthetized rats was evaluated by using Laser Doppler Flowmetry (LDF). The results showed that L-Glu did not significantly reduce both mucosal and serosal blood flow in stomach. No significant modulatory effect on histamine- or oxotremorine-stimulated increase in GMBF was noted after infusion with L-Glu. It is concluded that L-glutamic acid is capable of the modulating of gastric acid secretion via ionotropic non-NMDA receptors, but do not affect on GMBF. However, L-glutamic acid showed no effect on acid secretion by itself.

Involvement of nitric oxide and N-methyl-D-aspartate in acute hypoxic altitude convulsion in mice

BACKGROUND

Altitude convulsion is a rather specific form of experimental convulsion which is induced by acute exposure to a hypobaric hypoxic condition. Several neurotransmitters have been shown to be involved in the mechanisms of altitude convulsions. However, their roles and interaction were not clear.

HYPOTHESIS

The novel neurotransmitter nitric oxide (NO) may be involved in the mechanisms of altitude convulsion through its neuronal signalling roles in relation to the NMDA receptor.

METHODS

There were 177 mice intraperitoneally administrated (i.p.) with several drugs. The altitude convulsion threshold (ACT) was used as an index to evaluate the acute hypoxic tolerance.

RESULTS

NO synthesis precursor, L-arginine (20, 40, 200, 800 mg/kg), resulted in a dose-dependent decrease in the ACT in mice, while the NO synthase (NOS) inhibitor, NG-nitro-L-arginine-methyl ester (L-NAME, 1.25, 2.50, 5.00 mg/kg, i.p.) increased the ACT. Pretreatment with L-NAME (5.0 mg/kg) prior to L-arginine (200 mg/kg) administration prevented the effect of decreasing ACT caused by L-arginine. Similarly, N-methyl-D-aspartate (NMDA, 2.5, 10.0, 20.0 mg/kg, i.p.) yielded a decrease in the ACT in mice and this decrease in hypoxic tolerance caused by NMDA can be prevented by pretreatment with either NMDA receptor antagonist 2-amino-5-phosphovalerate (AP-5, 20.0 mg/kg, i.p.) or NOS inhibitor L-NAME (5.0 mg/kg, i.p.).

CONCLUSIONS

These findings suggest an important signalling role for nitric oxide and NMDA in the development of altitude convulsion and further support the hypothesized relationship between NMDA-receptor mediated neurotoxicity and nitric oxide.

Decolorization of reactive bright red K2G dye: electrochemical process catalyzed by manganese mineral

This paper presents the results of the decolorization of azo dye K2G by the electrochemical process catalyzed by manganese mineral. It is proved that the MnOOH(s), main component of the manganese mineral, can catalyze the electrochemical process and enhance the decolorization efficiency. X-ray powder diffraction spectrum shows that the content of MnOOH(s) has not been changed at the end of the reaction. The effects of initial pH value, current density, concentration of electrolyte on the decolorization efficiency of the dye were investigated in detail. The initial pH effect on the decolorization efficiency of K2G dye is found not to be significant. The optimum current density is 0.26 A/dm2. In addition, a proposed catalyzing mechanism of manganese mineral is discussed in this paper.

[Influencing factors of visual hallucinations in patients with Parkinson's disease and its relationship with sleep disorders]

OBJECTIVE

To investigate the prevalence and influencing factors of visual hallucinations in patients with Parkinson's disease(PD), and to analyze the relationship between visual hallucinations and sleep disorders.

METHODS

We recruited 187 patients with PD(H-Y Ⅰ-Ⅲ) from outpatient department in Beijing Hospital. The patients were investigated for general information and the use of medicine. The patients were divided into visual hallucination(VH) group and non-hallucination(non-VH) group. A comparison study was conducted between two groups. We investigated the sleep disorders of PD patients according to Non Motor Symptom Quest(NMSquest) and Parkinson's disease sleep scale(PDSS). Logistic stepwise multiple regression procedures were used to determine the best predictive model of visual hallucinations in patients with PD.

RESULTS

(1) 42 cases(22.5%) of PD patients were accompanied by visual hallucinations; (2) the VH group and non-VH group had no difference in age, sex, duration of illness, the scores of Minimum Mental State Examination(MMSE) and levodopa equivalent doses (LED). The scores of Unified Parkinson's Disease Rating Scale(UPDRS) Ⅰ, the Hamilton Rating Scale for Anxiety(HAMA) and the Hamilton Rating Scale for Depression(HAMD) in VH group were significantly higher than those in non-VH group[3.5(2, 5) vs 2 (1, 3); 10(6.75, 15) vs 8(5, 11); 11(7.75, 17) vs 9(5, 13); P<0.05]; (3) the incidences of vivid dreams and REM sleep behavior disorder(RBD) in VH group were significantly higher than those in non-VH group(61.9% vs 40.7%, 71.4% vs 47.6%, P<0.05). There were no significant differences in incidences of excessive daytime sleepiness and restless legs between two groups(P>0.05). The score of PDSS in VH group was significantly lower than that in non-VH group[111(92.75, 128.25) vs 123(109, 135), P<0.05]; (4) the Logistic stepwise multiple regression revealed that vivid dreams(P=0.045) and the score of PDSS(P=0.006) were the independent influencing factors for VH in PD patients.

CONCLUSIONS

The incidence of VH in PD with H-Y staging Ⅰ-Ⅱ is 22.5%. The presence of vivid dreams and severe sleep disorder are independently associated with VH in PD.

[Prevalence and 5-year mortality of dementia and association with geriatric syndromes in elderly population in Beijing]

Objective: To investigate the prevalence and mortality of dementia and assess the impact of geriatric syndromes (GS) on the risk for dementia and death in elderly population in Beijing. Methods: A cross-sectional survey was conducted in the elderly population aged ≥65 years and selected by a multi-stage sampling in Beijing during 2013-2015. Cognitive function was screened using the Chinese Revised Version of the Mini-Mental State Examination (MMSE). Then, neurological examination and psychiatric assessment were performed for those with the MMSE score lower than the cut-off value. The information about GS prevalence was also collected. The study also collected death records for all individuals from baseline until December 31, 2019. Based on the age and gender distribution from Beijing data of the 2010 Sixth National Population Census, the dementia prevalence in the study population was directly standardized. Logistic regression analysis was used to evaluate the association of different forms of dementia with GS, and Cox proportional hazards regression model was used to estimate the hazard ratio (HR) and 95%CI of death. Results: During 2013-2015, a total of 2 935 individuals completed dementia assessments, of which 167 were diagnosed with dementia. The standardized prevalence of dementia was 5.9% (95%CI: 5.0%-17.4%). The individuals with Alzheimer's disease (AD) and vascular dementia (VaD) accounted for 58.7% and 28.1% of total individuals with dementia, respectively. Aging, lower education level, urinary incontinence, and fall were risk factors for AD, while disability of activity of daily life dependence, hypertension, and stroke were found to be risk factors for VaD. After a median follow-up of 5.44 person-years, 399 deaths were recorded. The 5-year mortality risk was 2.87 (95%CI: 1.92-4.17) times and 4.93 (95%CI: 3.23-7.53) times higher for the elderly individuals with AD and VaD, respectively, compared to non-demented individuals. After adjusting for demographic, GS, and cardiovascular risk factors, the mortality risk in the elderly individuals with AD showed no significant difference compared with non-demented individuals (HR=1.32, 95%CI: 0.89-1.97), while the mortality risk in those with VaD was 2.46 (95%CI: 1.49-4.05) times higher than that in non-demented individuals. Conclusions: The prevalence of dementia in Beijing increased significantly in the context of population aging, especially the prevalence of AD. The presence of GS increased the risks for AD and VaD, as well as the risk for death. Close attention needs to be paid to GS management in dementia prevention in elderly population.

Strong interlayer coupling in two-dimensional PbSe with high thermoelectric performance

It was generally believed that weak van der Waals interactions exist between neighboring layers in the two-dimensional group-IV chalcogenides. Using PbSe as a prototypal example, we find additional strong coupling between the Pb-Pb layers, as evidenced by detailed analysis of the differential charge density plot. The coupling is covalent-like and can be fine-tuned to obviously reduce the phonon thermal conductivity but slightly change the electronic transport of PbSe layer. As a consequence, a maximumZTvalue of 2.5 can be realized at 900 K for thep-type system. Our work also offers an effective and feasible design strategy to enhance the thermoelectric performance of similar layered structures.

Pharmacologic studies of the central action of zopiclone: effects on locomotor activity and brain monoamines in rats

To investigate the effects of zopiclone on the central nervous system, we examined the effects of zopiclone on brain monoamines such as dopamine (DA), noradrenaline (NA) and serotonin (5-HT) and their metabolites such as homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA), as well as locomotor activity in comparison with those of nitrazepam and flurazepam. Zopiclone in a dose of 10 mg/kg (p.o.) significantly reduced it (p less than 0.01) in 30 min and the reduced locomotor activity persisted until 180 min. The reducing effect on locomotor activity by zopiclone was similar to that of nitrazepam and more potent than flurazepam. The effects of zopiclone on brain monoamines (MA) were examined. No significant changes in DA, NA and 5-HT were observed, but HVA and 5-HIAA were reduced. A fluorescent-histochemical study conducted simultaneously revealed almost the same results as the biochemical test results. From the facts that zopiclone inhibited locomotor activity in rats, and inhibited brain DA and 5-HT turnover, the mechanism of action of zopiclone in brain MA neurons seems to be similar to that of benzodiazepine derivatives.

Theoretical study of alkali atom doped outside 4 angstroms carbon nanotubes

Using first-principles calculations, we study the doping of alkali atoms on the outer surface of 4 angstroms single-walled carbon nanotubes. It is found that the exterior doping at the "center" site is more favorable than the interior doping along tube axis. The calculated binding energies show a strong chirality dependence, and the alkali atoms tend to be bound strongest with the (5, 0) tube. The change of band structure upon doping is studied and the charge transfer between tube and alkali atom is shown. Our calculations indicate that the Li storage capacity can be reached to a maximum of LiC2.5, which suggests that the 4 angstroms nanotube could be a plausible candidate for Li-ion battery applications.

Manganese silicide nanowires on Si(001)

A method for promoting the growth of manganese silicide nanowires on Si(001) at 450 °C is described. The anisotropic surface stress generated by bismuth nanolines blocks the formation of embedded structures and stabilizes the nucleation of manganese silicide islands which grow in a preferred direction, forming nanowires with a band gap of approximately 0.6 eV, matching the reported band gap of MnSi(1.7). This method may also provide a means to form silicide nanowires of other metals where they do not otherwise form.