The development of the high intensity electron cyclotron resonance ion source at China Institute of Atomic Energy

High-current microwave ion source has been under development over 15 years for accelerator driven sub-critical system research at China Institute of Atomic Energy, and the beam intensity higher than 140 mA proton beam is produced by this ion source with long lifetime and high reliability. The emittance of high intensity continue-wave and pulse beam is measured on a test-bench in the laboratory. Based on the good performance of this proton ion source, a new 120 mA deuterium ion source is proposed for a high intensity neutron generator. The ion source details and status will be presented.

Observation of a charged (DD*)± mass peak in e+ e- → πDD* at sqrt[s] = 4.26 GeV

We report on a study of the process e+ e- → π± (DD*)∓ at sqrt[s] = 4.26  GeV using a 525 pb(-1) data sample collected with the BESIII detector at the BEPCII storage ring. A distinct charged structure is observed in the (DD*)∓ invariant mass distribution. When fitted to a mass-dependent-width Breit-Wigner line shape, the pole mass and width are determined to be Mpole = (3883.9±1.5(stat)±4.2(syst))  MeV/c2 and Γpole = (24.8±3.3(stat)±11.0(syst))  MeV. The mass and width of the structure, which we refer to as Zc(3885), are 2σ and 1σ, respectively, below those of the Zc(3900) → π± J/ψ peak observed by BESIII and Belle in π+ π- J/ψ final states produced at the same center-of-mass energy. The angular distribution of the πZc(3885) system favors a JP = 1+ quantum number assignment for the structure and disfavors 1- or 0-. The Born cross section times the DD* branching fraction of the Zc(3885) is measured to be σ(e+ e- → π± Zc(3885)∓)×B(Zc(3885)∓ → (DD*)∓) = (83.5±6.6(stat)±22.0(syst))   pb. Assuming the Zc(3885) → DD* signal reported here and the Zc(3900) → πJ/ψ signal are from the same source, the partial width ratio (Γ(Zc(3885) → DD*)/Γ(Zc(3900) → πJ/ψ)) = 6.2±1.1(stat)±2.7(syst) is determined.

Observation of a charged charmoniumlike structure Zc(4020) and search for the Zc(3900) in e+e-→π+π-hc

We study e+e-→π+π-hc at center-of-mass energies from 3.90 to 4.42 GeV by using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross sections are measured at 13 energies and are found to be of the same order of magnitude as those of e+e-→π+π-J/ψ but with a different line shape. In the π±hc mass spectrum, a distinct structure, referred to as Zc(4020), is observed at 4.02  GeV/c2. The Zc(4020) carries an electric charge and couples to charmonium. A fit to the π±hc invariant mass spectrum, neglecting possible interferences, results in a mass of (4022.9±0.8±2.7)  MeV/c2 and a width of (7.9±2.7±2.6)  MeV for the Zc(4020), where the first errors are statistical and the second systematic. The difference between the parameters of this structure and the Zc(4025) observed in the D*D[over ¯]* final state is within 1.5σ, but whether they are the same state needs further investigation. No significant Zc(3900) signal is observed, and upper limits on the Zc(3900) production cross sections in π±hc at center-of-mass energies of 4.23 and 4.26 GeV are set.

Silencing of survivin using YM155 induces apoptosis and chemosensitization in neuroblastomas cells

OBJECTIVES

Aggressive cell growth and chemoresistance are notorious obstacles in neuroblastoma therapy. Accumulating evidence suggests that survivin is preferentially expressed in cancer cells and plays a crucial role in cell division and apoptosis dysfunction. Thus, in the present study, we investigated whether silencing of survivin, using a novel small-molecule survivin suppressant, YM155 could suppress the proliferation and induce chemosensitization of neuroblastoma cells.

MATERIALS AND METHODS

SH-SY5Y human neuroblastomas cells were treated with YM155 (10 to 500 mM) and/or chemotherapeutic agent cisplatin for 72 hours, and cell viability, apoptosis, mRNA and protein expression level were then evaluated. Furthermore, the efficacy of YM155 combined with cisplatin was further examined in established xenograft models.

RESULTS

YM155 suppressed expression of survivin, inhibited the proliferation and induced apoptosis in SH-SY5Y cells in a concentration-dependent manner. Reduced levels of survivin sensitized SH-SY5Y to the chemotherapeutic agent cisplatin. YM155 showed antiproliferative effects and induced tumor regression and apoptosis in established SH-SY5Y xenograft models. Cisplatin showed antitumor activity against SH-SY5Y cells, it did not induce survivin upregulation. Combination treatment of YM155 and cisplatin induced a greater rate of apoptosis than the sum of the single-treatment rates and promoted tumor regression without enhanced body weight loss in the SH-SY5Y xenograft models.

CONCLUSIONS

The concomitant combination of YM155 with cisplatin induced more intense apoptosis compared with each single treatment in vivo and in vitro. YM155 in combination with cisplatin is well tolerated and shows greater efficacy than either agent alone in mouse xenograft models.

Membrane microdomain determines the specificity of receptor-mediated modulation of Kv7/M potassium currents

The Kv7/M current is one of the major mechanisms controlling neuronal excitability, which can be modulated by activation of the G protein-coupled receptor (GPCR) via distinct signaling pathways. Membrane microdomains known as lipid rafts have been implicated in the specificity of various cell signaling pathways. The aim of this study was to understand the role of lipid rafts in the specificity of Kv7/M current modulation by activation of GPCR. Methyl-β-cyclodextrin (MβCD), often used to disrupt the integrity of lipid rafts, significantly reduced the bradykinin receptor (B2R)-induced but not muscarinic receptor (M1R)-induced inhibition of the Kv7/M current. B2R and related signaling molecules but not M1R were found in caveolin-containing raft fractions of the rat superior cervical ganglia. Furthermore, activation of B2R resulted in translocation of additional B2R into the lipid rafts, which was not observed for the activation of M1R. The increase of B2R-induced intracellular Ca(2+) was also greatly reduced after MβCD treatment. Finally, B2R but not M1R was found to interact with the IP3 receptor. In conclusion, the present study implicates an important role for lipid rafts in mediating specificity for GPCR-mediated inhibition of the Kv7/M current.

Factors associated with acceptability of circumcision among male drug users in western China: a cross-sectional study

This study is aimed to investigate whether male circumcision (MC) is feasible among IDUs in China. 1304 drug users who attended methadone maintenance therapy clinics in Guangxi, Chongqing and Xinjiang were selected for participation by using convenience sampling, and completed a self-administered questionnaire. The factors associated with the acceptability of MC were examined via multiple logistic regression models. 45.2% (589/1304) of the participants reported an acceptance of MC. Many of the participants who were initially not willing to accept MC (715/1304) had changed their mind when they were informed that MC would reduce the risk of HIV and STDs (43.4%; 310/715), that MC is associated with few surgery-related complications (23.1%; 165/715), that the surgical procedure could be arranged free of charge (20.1%, 144/715). In the multivariate analysis, higher acceptability of MC was associated with knowledge of the hazards of phimosis (OR=2.22), the presence of phimosis (OR=14.87), and knowledge that MC can prevent AIDS and STDs (OR=1.49); while lower acceptability was associated with residing in Chongqing province (OR=0.41) and an educational level of junior (OR=0.64) and senior high (OR=0.63) school. The MC policy targeting IDUs in China should take into account these factors associated with MC acceptability.

Observation of a charged charmoniumlike structure in e+ e- → π+ π- J/ψ at sqrt[s] = 4.26 GeV

We study the process ee+ e- → π+ π- J/ψ at a center-of-mass energy of 4.260 GeV using a 525  pb(-1) data sample collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross section is measured to be (62.9±1.9±3.7)  pb, consistent with the production of the Y(4260). We observe a structure at around 3.9  GeV/c2 in the π(±)J/ψ mass spectrum, which we refer to as the Z(c)(3900). If interpreted as a new particle, it is unusual in that it carries an electric charge and couples to charmonium. A fit to the π(±)J/ψ invariant mass spectrum, neglecting interference, results in a mass of (3899.0±3.6±4.9)  MeV/c2 and a width of (46±10±20)  MeV. Its production ratio is measured to be R = (σ(e+ e- → π(±)Z(c)(3900)(∓) → π+ π- J/ψ)/σ(e+ e- → π+ π- J/ψ)) = (21.5±3.3±7.5)%. In all measurements the first errors are statistical and the second are systematic.

Impaired natural killer cell-induced antibody-dependent cell-mediated cytotoxicity is associated with human immunodeficiency virus-1 disease progression

This study evaluates the correlation between natural killer (NK) cell function and human immunodeficiency virus (HIV)-1 disease progression in 133 untreated HIV-1 positive Chinese subjects, including 41 former plasma donors (FPDs) and 92 men who have sex with men, and 35 HIV-negative controls. Flow cytometry was used to determine the abundance of NK cell subsets, the expression levels of receptor species, human leucocyte antigen (HLA) genotyping and the antibody-dependent cell-mediated cytotoxicity (ADCC) responses of NK cells. We observed a decreased expression of CD56(dim) CD16(+) NK cell subsets and an increased expression of CD56(-) CD16(+) with HIV-1 infection. As well, the expression of activating and inhibitory receptors increased significantly in NK cells, but CD16 receptor levels and the NKG2A/NKG2C ratio were down-regulated with HIV-1 infection. ADCC responses were higher in elite controllers than in all other groups, and were correlated inversely with HIV-1 viral load but correlated positively with CD4 count only in FPDs. Furthermore, individuals infected for < 1 year have lower ADCC responses than those infected for > 1 year. We also observed a negative association between ADCC responses and viral load in those who carry the HLA-A*30/B*13/Cw*06 haplotype. The positive correlation between CD16 expression and ADCC responses and a negative correlation trend between CD158a and ADCC responses were also observed (P = 0·058). Our results showed that the ADCC response is associated with patients' disease status, receptor expression levels, infection time and specific HLA alleles, which indicates that ADCC may offer protective effects against HIV-1 infection.

Exome sequencing-driven discovery of coding polymorphisms associated with common metabolic phenotypes

AIMS/HYPOTHESIS

Human complex metabolic traits are in part regulated by genetic determinants. Here we applied exome sequencing to identify novel associations of coding polymorphisms at minor allele frequencies (MAFs) >1% with common metabolic phenotypes.

METHODS

The study comprised three stages. We performed medium-depth (8×) whole exome sequencing in 1,000 cases with type 2 diabetes, BMI >27.5 kg/m(2) and hypertension and in 1,000 controls (stage 1). We selected 16,192 polymorphisms nominally associated (p < 0.05) with case-control status, from four selected annotation categories or from loci reported to associate with metabolic traits. These variants were genotyped in 15,989 Danes to search for association with 12 metabolic phenotypes (stage 2). In stage 3, polymorphisms showing potential associations were genotyped in a further 63,896 Europeans.

RESULTS

Exome sequencing identified 70,182 polymorphisms with MAF >1%. In stage 2 we identified 51 potential associations with one or more of eight metabolic phenotypes covered by 45 unique polymorphisms. In meta-analyses of stage 2 and stage 3 results, we demonstrated robust associations for coding polymorphisms in CD300LG (fasting HDL-cholesterol: MAF 3.5%, p = 8.5 × 10(-14)), COBLL1 (type 2 diabetes: MAF 12.5%, OR 0.88, p = 1.2 × 10(-11)) and MACF1 (type 2 diabetes: MAF 23.4%, OR 1.10, p = 8.2 × 10(-10)).

CONCLUSIONS/INTERPRETATION

We applied exome sequencing as a basis for finding genetic determinants of metabolic traits and show the existence of low-frequency and common coding polymorphisms with impact on common metabolic traits. Based on our study, coding polymorphisms with MAF above 1% do not seem to have particularly high effect sizes on the measured metabolic traits.

Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

In-silico prediction of blood-brain barrier permeability

The ability of penetration of the blood-brain barrier is one of the significant properties of a drug or drug-like compound for the central nervous system (CNS), which is commonly expressed by log BB (log BB = log (C (brain)/C (blood))). In this work, a dataset of 320 compounds with log BB values was split into a training set including 198 compounds and a test set including 122 compounds according to their structure properties by a Kohonen's self-organizing map (SOM). Each molecule was represented by global and shape descriptors, 2D autocorrelation descriptors and RDF descriptors calculated by ADRIANA.Code. Several quantitative models for prediction of log BB were built by a multilinear regression (MLR), a support vector machine (SVM) and an artificial neural network (ANN) analysis. The models show good prediction performance on the test set compounds.

Temperature-sensitive poly(N-isopropylacrylamide-co-butyl methylacrylate) nanogel as an embolic agent: distribution, durability of vascular occlusion, and inflammatory reactions in the renal artery of rabbits

BACKGROUND AND PURPOSE

We have developed a new thermosensitive liquid embolic agent, PIB nanogel, that can be solidified at body temperature. We thus further investigated the distribution, durability of vascular occlusion, and inflammatory reactions of PIB in embolization of the renal artery of rabbits.

MATERIALS AND METHODS

The bilateral renal arteries of 9 rabbits were first embolized with PIB at different injection rates. The distribution pattern of PIB was investigated by contact radiography and histology 1 hour after embolization. The right renal arteries of 20 rabbits were then embolized with PIB at the proper injection rate. Angiography and pathologic examination of the kidneys were performed at 1 week and 1, 2, and 3 months after embolization to evaluate the long-term outcomes.

RESULTS

With the injection rate increasing, PIB could reach the more distal branch of the renal artery. The proper injection rate was chosen as 0.10 mL/s due to the homogeneous distribution of PIB from the main renal artery to the precapillary level at this rate. During a 3-month follow-up observation period, no angiographic recanalization was observed. Histologically, we found no disruption of the vessel wall or subintimal bleeding, no extravasation of PIB, and no evidence of neovascularization. Moreover, there was only a mild inflammatory response, manifested by few lymphocytic and monocellular infiltration, without foreign body granuloma formation.

CONCLUSIONS

Embolization of the renal artery with PIB was easy and controllable, which could lead to a homogeneous and persistent occlusion without severe inflammatory changes. PIB might be a suitable material for intravascular embolization.

Attributable causes of cancer in China

BACKGROUND

Most cancers are due to modifiable lifestyle and environmental risk factors, and are potentially preventable. No studies have provided a systematic quantitative assessment of the burden of cancer mortality and incidence attributable to known risk factors in China.

METHODS

We calculated the proportions of cancer deaths and new cases attributable to known risk factors in China, based on the prevalence of exposure around 1990 and national data on cancer mortality and incidence for the year 2005.

RESULTS

Chronic infection is the main risk factor for cancer in China, accounting for 29.4% of cancer deaths (31.7% in men and 25.3% in women), followed by tobacco smoking (22.6% with 32.7% in men and 5.0% in women), low fruit intake (13.0%), alcohol drinking (4.4%), low vegetable intake (3.6%) and occupational exposures (2.7%). The remaining factors, including environmental agents, physical inactivity, the use of exogenous hormones and reproductive factors are each responsible for <1.0%.

CONCLUSIONS

Modifiable risk factors explain nearly 60% of cancer deaths in China, with a predominant role of chronic infection and tobacco smoking. Our findings could provide a basis for cancer prevention and control programs aimed at reducing cancer risk in other developing countries.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

Investigation of space-time clusters and geospatial hot spots for the occurrence of tuberculosis in Beijing

OBJECTIVE

To characterise the geographic and spatiotemporal distribution of confirmed tuberculosis (TB) cases in Beijing between 2005 and 2009.

DESIGN

The yearly notification rate maps were used to describe the distribution of confirmed adult TB patients. Spatial autocorrelation (Moran's I) and hot-spot analysis were adopted to detect the clusters and hot spots of TB.

RESULTS

The TB incidence rate (cases per 100,000 population) in Beijing increased from 29.8 in 2005 to 35.0 in 2009. The incidence rate was significantly higher in the Urban Development New District and the Ecologic Reservation Development District (>30/100,000) than in the other districts. There was a significant spatial autocorrelation throughout the city (u = 2.58, P = 0.01). Evident clusters were observed in the Capital Functional Core District and the Urban Function Extension District (G(i)* > 1).

CONCLUSION

Spatial autocorrelation and hot-spot analysis may serve as efficient tools to detect space-time clusters and geospatial hot spots of TB incidence. Between 2005 and 2009, TB incidence in Beijing showed population density and mobility-dependent and eco-social status-dependent space-time clusters and geospatial hot spots.