Occupational metal exposures, smoking and risk of diabetes and prediabetes

BACKGROUND

Metal exposure and tobacco smoking have been independently associated with diabetes, but no study has been conducted to investigate the interaction between them on the risk of diabetes.

AIMS

To investigate the effect of occupational exposure to metals, and potential effect modification by smoking, on the risk of diabetes and prediabetes in a cohort of Chinese male workers.

METHODS

We assessed metal exposure and tobacco smoking at baseline in the Jinchang Cohort of male workers. We used Poisson regression analyses to estimate the interaction between smoking and metal exposures based on occupations, which we grouped according to the measured urinary metal levels.

RESULTS

Among the 26008 study subjects, compared with non-smokers, the adjusted prevalence ratio (PR) for diabetes was 1.8 [95% confidence interval (CI) 1.3-2.4] for smokers of >40 pack-years. The adjusted PRs were 1.2 (95% CI 1.1-1.4) among mining/production workers and 2.7 (95% CI 2.4-3.0) among smelting/refining workers, both compared with office workers. There was significant effect modification under the additive model between smoking and metal exposure on the prevalence of diabetes (Pinteraction = 0.001), with an adjusted PR of 3.6 (95% CI 2.4-5.4) for those with >40 pack-years of smoking who had the highest metal exposures, whereas no significant interaction was observed for prediabetes.

CONCLUSIONS

Both exposure to metals and heavy smoking were associated with an increased prevalence of diabetes in this large cohort of male workers. There was also strong interaction between these two exposures in affecting diabetes risk that should be confirmed in future studies.

[Natural history of breast cancer: a systematic review of worldwide randomized controlled trials of mammography screening]

Objective: To parameterize the 1-year transition probabilities between different health status of the natural history of breast cancer based on the data of randomized controlled trial of X-ray mammography screening worldwide. Methods: Based on the breast cancer screening randomized controlled trials defined by a mammography screening review from the Cochrane 2013 and the International Agency for Research on Cancer, a systematic review was initiated in PubMed by searching names of the key investigators of the trials, combined with the diseases, screening intervention and outcome indicators. If applicable, all the original cumulative incidence rates were converted into one-year transition rate, using the life-table approach considering time length of follow-up. Results: A total of 23 reports from 9 RCTs were included. The data on transition rate between the healthy status to precancerous lesions was absent. The 1-year transition rate from health to carcinoma in situ was 17.78 to 50.21 per 100 000 persons in the intervention group and 9.16 to 26.84 per 100 000 persons in the control group. Correspondingly, the 1-year transition rate from health to breast cancer (including carcinoma in situ and invasive cancer) were estimated as 143.75 to 316.97 per 100 000 persons in the intervention group, and 141.45 to 288.84 per 100 000 persons in the control group. Furthermore, the transition rate from the healthy status to invasive breast cancer was 159.79 to 264.60 per 100 000 persons in intervention group and 170.12 to 255.33 per 100 000 persons in control group. The transition rate from carcinoma in situ to invasive breast cancer varied among different pathological types. Conclusions: The most common natural history states of reported by the included trials involved the full healthy status, carcinoma in situ and invasive breast cancer. The findings of transition rates between different health statuses will be informative for future model development of natural history studies of breast cancer. Information in relation to breast precancerous lesions still limited and needs to be further addressed.

[Disease burden of famale breast cancer in China]

OBJECTIVE

To analyze the data on burden of female breast cancer in China.

METHODS

The data from Chinese Cancer Registry Annual Report 2012, three national death cause surveys in China, Disease Surveillance Points system(DSP), China Health Statistics Yearbook, GLOBOCAN 2012, Cancer Incidence in Five Continents(CI5), WHO Mortality Database and Global Burden of Disease(GBD)2013 were used to extract the incidence, mortality and disability-adjusted life years(DALY)of female breast cancer and analyze related trends in China.

RESULTS

The data from three national death cause surveys showed that the crude mortality of breast cancer doubled from year 1973-1975 to year 2004-2005, the increase was higher in urban area(127.4%)than in rural area(75.2%). WHO Mortality Database showed that average annual percentage change(AAPC)of breast cancer crude mortality increased by 3.1%(P<0.05)from 1987 to 2000, and China Health Statistics Yearbook showed that the AAPC in urban females increased by 2.7% from 2002 to 2013(P<0.05), whereas the AAPC in rural females showed no significant change(P>0.05). It was estimated by GLOBOCAN 2012 that in 2012 the age-standardized incidence and age-standardized mortality of breast cancer in China was 22.1 per 100 000 and 5.4 per 100 000, respectively. The age-specific incidence began to increase obviously at age of 40 years and peaked at age 45-59 years(GLOBOCAN 2012). Chinese Cancer Registry Annual Report 2012 showed that breast cancer incidence and mortality were 2-fold and 1.5-fold higher in urban females than in rural females in 2009. It was estimated that the breast cancer case number and death number in females in China would increase to 251 600 and 75 900, respectively, more increose in age group ≥65 years. Only GBD 2013 reported DALY, the DALY caused by breast cancer in China was 1 666.0 thousand in 2013, accounting for 12.7% of global DALY, and increased by 56.7% from 1990(1 062.6 thousand), the peak age-specific DALY rate was at 50 to 59 years, and national average ratio of years lived with disability(YLD)was 8.7%(ranging from 8.1% to 9.0% at provincial level).

CONCLUSIONS

Burden of disease caused by female breast cancer is becoming increasingly severe in China, especially in urban areas. It is necessary to strengthen the population-based prevention and control programs and further studies may focus on DALY.

[A prospective follow-up study on the association between serum level of C-reactive protein and risk of digestive system cancers in Chinese women]

Objective: It has been reported by some prospective studies that C-reactive protein (CRP) is associated with cancer risk. However, the correlation between CRP and digestive system cancers has not been evaluated in Chinese females. We conducted a large population-based cohort study to investigate whether elevated level of CRP in serum is associated with an increased risk of digestive system cancers in Chinese women. Methods: From the Chinese Kailuan Female Cohort, 19, 437 women were enrolled in this study in July 2006, and all of the subjects were followed up through 2014. At the baseline investigation, the serum levels of high-sensitivity CRP (hsCRP) were tested for all subjects, and demographic information and risk factor data were collected. Multivariable Cox proportional hazards regression model was used to calculate the hazard ratios (HR) and 95% confidence intervals (95% CI) for the baseline levels of hsCRP after adjusting for age, marital status, smoking, drinking, body mass index (BMI), diabetes and physical activity, and risk of digestive system tumors (including colorectal cancer, stomach cancer, pancreas cancer, liver and gallbladder cancer, and other cancers). Results: By Dec 31, 2014, a total of 100 incident cancer cases were observed, including 47 colorectal cancers, 17 stomach cancers, and altogether 29 pancreas, liver and gallbladder cancers. All the subjects investigated were divided into three groups according to the level of hsCRP (<1 mg/L, 1-3 mg/L and >3 mg/L). The 8-year cumulative incidence of digestive system cancers were 405/100 000, 520/100 000 and 787/100 000 in these 3 groups, respectively (Log rank test χ² = 8.37, P=0.015). Compared to those with lower hsCRP levels (<1 mg/L), the women with higher hsCRP (>3 mg/L) had a significantly increased risk of pancreas, liver and gallbladder cancers (HR = 2.70, 95% CI = 1.06-6.91; P_trend = 0.036). Conclusions: Elevated levels of hsCRP at baseline may be associated with increased risk of certain digestive system cancers.

Neonatal Kisspeptin is Steroid-Independently Required for Defeminisation and Peripubertal Kisspeptin-Induced Testosterone is Required for Masculinisation of the Brain: A Behavioural Study Using Kiss1 Knockout Rats

Rodents show apparent sex differences in their sexual behaviours. The present study used Kiss1 knockout (KO) rats to evaluate the role of kisspeptin in the defeminisation/masculinisation of the brain mechanism that controls sexual behaviours. Castrated adult Kiss1 KO males treated with testosterone showed no male sexual behaviours but demonstrated the oestrogen-induced lordosis behaviours found in wild-type females. The sizes of some of the sexual dimorphic nuclei of Kiss1 KO male rats are similar to those of females. Plasma testosterone levels at embryonic day 18 and postnatal day 0 (PND0) in Kiss1 KO males were high, similar to wild-type males, indicating that perinatal testosterone is secreted in a kisspeptin-independent manner. Long-term exposure to testosterone from peripubertal to adult periods restored mounts and intromissions in KO males, suggesting that kisspeptin-dependent peripubertal testosterone secretion is required to masculinise the brain mechanism. This long-term testosterone treatment failed to abolish lordosis behaviours in KO males, whereas kisspeptin replacement at PND0 reduced lordosis quotients in Kiss1 KO males but not in KO females. These results suggest that kisspeptin itself is required to defeminise behaviour in the perinatal period, in cooperation with testosterone. Oestradiol benzoate treatment at PND0 suppressed lordosis quotients in Kiss1 KO rats, indicating that the mechanisms downstream of oestradiol work properly in the absence of kisspeptin. There was no significant difference in aromatase gene expression in the whole hypothalamus between Kiss1 KO and wild-type male rats at PND0. Taken together, the present study demonstrates that both perinatal kisspeptin and kisspeptin-independent testosterone are required for defeminisation of the brain, whereas kisspeptin-dependent testosterone during peripuberty to adulthood is needed for masculinisation of the brain in male rats.

[Association between body mass index and risk of lung cancer in non-smoking males: a prospective cohort study]

Objective: To assess the association between baseline body mass index (BMI) and risk of lung cancer in non-smoking males. Methods: A dynamic non-smoking male cohort was established on May, 2006. Baseline information on demography, lifestyle, such as smoking status and alcohol consumption, anthropometry, such as body height and weight, were collected during the baseline interview, and the information of newly-diagnosed lung cancer cases were also collected during the follow-up period. Multivariable Cox proportional-hazards regression model was used to analyze the association between baseline BMI and lung cancer in non-smoking males. Results: By December 31, 2011, a total of 48 799 male non-smokers had been assessed in the study and there were 214 620.18 person-years of follow-up and 4.40 years of average follow-up period. During follow-up, 198 lung cancer cases were identified among the 48 799 non-smoking males. Compared with those with normal BMI (kg/m²) (18.5≤BMI<24.0), the hazard ratio (95%CI) of lung cancer were 1.14(0.53-2.45), 0.57(0.41-0.78) and 0.61(0.38-0.97) for underweight (BMI<18.5), overweight (24.0≤BMI<28.0) and obese males (≥28.0), respectively, after adjustment for potential confounding factors, including age, education level, alcohol consumption, physical activity, history of diabetes and work environment. Baseline BMI was negatively associated with the risk of lung cancer in non-smoking males and the risk would be reduced by 22% (HR=0.78, 95% CI: 0.64-0.95) for per 5 kg/m² BMI increase. The negative association between BMI and risk of lung cancer was significant among non-smoking males who aged ≥50 years, and in those who had physical exercise <4 times/week, never drunk and worked above the coal mine, and for per 5 kg/m² BMI increase, the risk of lung cancer would be reduced by 26%(HR=0.74, 95%CI: 0.60-0.92), 24%(HR=0.76, 95%CI: 0.62-0.95), 20% (HR=0.80, 95%CI: 0.65-1.00) and 23% (HR=0.77, 95%CI: 0.61-0.97), respectively. The result was similar after excluding the cancer patients newly diagnose within 1-year and their contribution person years. Conclusion: Baseline BMI might be negatively associated with risk of lung cancer in non-smoking males.

[The accuracy of mammography screening for breast cancer: a Meta-analysis]

Objective: To estimate the accuracy of mammography for population-based breast cancer screening. Methods: Studies of screening mammography performance were systematically reviewed in the Medline, Embase, Cochrane and China National Knowledge Infrastructure (CNKI) literature databases. The retrieval was performed by using related key words, including disease name, screening and intervention indicators and study type. A total of 1 167 records were retrieved by June 4, 2015 and those studies met the inclusion criteria were included for the current analysis. The numbers of true-positive, false-positive, false-negative and true-negative were originally extracted and calculated from each individual study. A QUADAS checklist was used to assess the quality of the studies. A curve of summary receiver operating characteristic (SROC) was applied as a comprehensive assessment of diagnosed accuracy. The pooled effect size of both sensitivity and specificity was quantitatively synthesized in both total population and subgroup with dense breast using the bivariate mixed-effects models. We conducted a sensitivity analysis in the studies with sample size over 100 000. Heterogeneity between studies was measured by the Q test and I² statistic, and publication bias was evaluated by a funnel plot and the linear regression test. Results: A total of 48 publications with 8 551 873 individuals were identified for the final qualitative synthesis, most of them were from Europe area and American (38 studies), 8 were from Asia area, and 2 were from Oceania area. The studies were conducted during period of 1975-2013, and the age of study women ranged mostly from 40 to 75 years. The area under the SROC curve (AUC) was 0.95 (95%CI: 0.93-0.97). It was estimated that the pooled sensitivity and specificity were 0.81 (95%CI: 0.77-0.84) and 0.96 (95%CI: 0.94-0.96), respectively. The results were indicated stable and robust in sensitivity analysis. In the subgroup with dense breast, the sensitivity and specificity were 0.74 (95% CI: 0.61-0.83) and 0.93 (95% CI: 0.89-0.96), respectively. Funnel plot and test results showed there was no significant publication bias among the included studies. Conclusion: The accuracy of mammography is high for population-based breast cancer screening in women, although the sensitivity is lower in women with dense breast.

Association of single-nucleotide polymorphisms, rs2235371 and rs2013162, in the IRF6 gene with non-syndromic cleft palate in northeast China

The aim of this study was to determine the association between two SNPs (rs2235371 and rs2013162) in the interferon regulatory factor 6 (IRF6) gene and non-syndromic cleft palate (NSCP) in northeast China. We genotyped these two SNPs in 104 NSCP cases, as well as in 178 parents and 300 controls. Case-control and case-parent analyses were performed using χ2 tests and family-based association tests (FBAT). Results indicated that there were significant differences in both genotypic and allelic distributions between patients and controls at rs2235371 and rs2013162 in the IRF6 gene. Case-parent analysis revealed over-transmission of the C allele in rs2235371 and the A allele in rs2013162. Lastly, FBAT showed over-transmission of the CA haplotype. This study demonstrated that the two SNPs, rs2235371 and rs2013162, are strongly associated with NSCP in the northeast Chinese population.

[Body mass index and the risk of lung cancer incidence in smokers: a prospective cohort study]

OBJECTIVE

To investigate the effect of baseline body mass index (BMI) on the risk of lung cancer incidence in male smokers.

METHODS

All the male employees and retirees of the Kailuan Group were recruited in the Chinese Kailuan Male Cohort Study, and they had been experienced routine physical examinations every two years since May, 2006. Up to 31st December 2011, a total of 3 rounds physical examinations had been completed. A total of 42 718 male smokers candidates from the Chinese Kailuan Male Cohort Study were enrolled in the present study. The date of entering this study was defined as that of taking first check-up, and the date of end-of-observation was defined as that of cancer diagnosis, death or end of follow-up (31 December 2011). Information on demographics, lifestyle such as smoking, alcohol consumption, anthropometries such as height and weight, as well as the information of newly-diagnosed cancer cases, were collected at the baseline investigation. Multivariable Cox proportional hazards regression models were used to investigate the association between levels of the baseline BMI and risk of lung cancer.

RESULTS

Of the 42 718 male smokers, there were 181 998.09 person-years of follow-up, taking 4.26 years of average follow-up period. During follow-up, 234 new lung cancer cases were identified among the 42 718 male smokers and the crude incidence density was 128.57/100 000. After the factors adjustment for age, education level, alcohol consumption, physical activity, work environment and cumulative smoking levels (pack-years), compared with subjects of normal BMI group, hazard ratio and 95% confidence intervals of lung cancer for subjects of underweight, overweight, and obesity were 1.63 (0.79-3.37), 0.79 (0.57-1.09) and 0.50 (0.27-0.91), respectively. After the facotors adjustment for age, education level, alcohol consumption, physical activity, work environment and cumulative smoking levels (pack-years), compared with subjects of normal BMI, hazard ratio and 95% confidence intervals of lung cancer for subjects of obesity among subjects who aged 50 years or above, smoked more than 20 pack-years, and exercised less than 4 times per week were 0.33 (0.15-0.71), 0.27 (0.10-0.75), and 0.44 (0.20-0.96), respectively. Obesity subjects who worked above the well had decreased risk of lung cancer (HR=0.38, 95% CI: 0.15-0.96) compared with normal BMI ones who worked above the well.

CONCLUSION

BMI was negatively correlated with the risk of lung cancer in male smokers. As for male smokers, one of the most effective approaches to prevent and control the lung cancer has been shown to quit smoking and keep fit.

High precision relative attitude measurement for inner payload of new photoelectric platform

A new method for measuring the relative attitude of a load on an airborne photoelectric platform supported by three-axis universal joint structure is proposed. The mathematical model for angle measurement is established, based on which the linear relation between the angle and distance is derived by using the eccentric method. Furthermore, the relative attitude measurement method for a load rotating along the yaw and pitch directions is also proposed based on a unique eccentric structure. Finally, to validate the proposed new method, a comprehensive experiment for measurement angle from -5° to +5° in increments of 0.5° was performed by using the angular capacitive sensor. The experimental results show that the precision of the angular measurement is better than 15″ with maximum 1.24 kHz bandwidth, which meets the relative attitude measurement requirements of the internal load on the airborne photoelectric platform.

Evaluation of left atrial function by speckle tracking echocardiography in patients with systemic lupus erythematosus

Left atrial (LA) function plays a key role in maintaining optimal cardiac output. Left ventricular diastolic dysfunction (LVDD) has been reported in systemic lupus erythematosus (SLE), but whether LA functional abnormalities also occur in patients with SLE is unknown. Toward this aim we evaluated left atrial function and volume by strain and strain rate derived from speckle tracking echocardiography (STE) and their associations with LVDD. Sixty SLE patients were compared with age- and gender-matched normal controls. The LA strain (S) and strain rate (SR) during systole, early diastole and late diastole (SRs, SRe and SRa, respectively) were measured by STE. The LA volume index (LAVI), traditional parameters of LA and left ventricular diastolic function also were analysed. Global strain and positive SRe were significantly reduced in the SLE group compared with the control group (26.2% ± 9.5% vs 32.5% ± 9.8% and −2.4 ± 1.0 s−1 vs −3.1 ± 1.2 s−1, both p < 0.05). The SRs in the SLE and control groups were not significantly different (2.1 ± 0.7 s−1 vs 2.4 ± 0.8 s−1, p = 0.2). The positive SRa was increased in the SLE group compared with the control group (−2.1 ± 0.8 s−1 vs −1.6 ± 0.5 s−1, p < 0.05) and the LAVI was larger in the SLE group than in the control group (32.4 ± 8.0 vs 25.8 ± 7.1 ml/m2, p < 0.001). Patients with SLE exhibiting varying grades of LVDD displayed significant differences in LA parameters, including LAVI, SRs, SRe and SRa (all p < 0.05). Multivariate linear analysis additionally revealed that SLICC/ACR damage index (SDI) was independently and inversely associated with global strain, SRs and positive SRe. LA functions were changed in SLE patients, demonstrating impairment in conduit function, decrease in storage function and increase in pump function. Meanwhile, the magnitude of this impairment was predictively associated with the severity of LVDD. The results from this study demonstrate that STE is capable of detecting various aspects of LA functional impairment during SLE progression, and should be further explored as a diagnostic tool for improving the outcomes of SLE patients.

Identification of Campylobacter jejuni and determination of point mutations associated with macrolide resistance using a multiplex TaqMan MGB real-time PCR

AIMS

The aim of the study was to develop a multiplex real-time PCR method to identify Campylobacter jejuni containing mutations commonly associated with macrolide resistance.

METHODS AND RESULTS

A multiplex fluorescence real-time PCR assay was developed based on TaqMan minor groove binder (MGB) probes. The VS1-MGB probe was designed based on the VS1 gene and was used to identify Camp. jejuni. The 23S rDNA-MGB probe was designed to distinguish macrolide resistance mutations in 23S rDNA, while 57D-MGB and 74D-MGB were designed to detect resistance mutations in ribosomal protein L4. The specificity and accuracy of our method were identical to the conventional biochemical tests, mapA PCR, minimum inhibitory concentration (MIC) determination and DNA sequencing. The linear detection limit of the method was 0·03 ng genomic DNA and three colony formation unit (CFU) per reaction. In 6 of 18 cases, the nature of Erythromycin resistance could be correctly determined from natural isolates; absence of the tested mutations was demonstrated in the remaining four resistant isolates.

CONCLUSIONS

A multiplex TaqMan MGB real-time PCR assay with high specificity and accuracy was developed to simultaneously identify Camp. jejuni and detect the gene mutations associated with macrolide resistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This multiplex method can potentially simplify the identification of Camp. jejuni and determine macrolide resistance due to mutations in 23S rDNA or ribosomal protein L4. This method has a potential for application in different research areas and molecular surveillance.

Precision Measurement of the (e^{+}+e^{-}) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

Electron and positron fluxes in primary cosmic rays measured with the alpha magnetic spectrometer on the international space station

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30  GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200  GeV the positron fraction no longer exhibits an increase with energy.

Structural changes in dermal collagen and oxidative stress levels in the skin of Japanese overweight males

OBJECTIVE

It has been reported that obese people have poorly organized dermal collagen structure because of the degradation of collagen fibers, which is caused by an increase in oxidative stress levels associated with the hypertrophy of subcutaneous adipose cells. However, it is unclear whether an increase in oxidative stress levels caused by the accumulation of subcutaneous adipose tissue and a change in the dermal structure also occur in overweight and obese Japanese people. The objectives of this study are to identify structural changes that occur in the dermis and to measure the levels of oxidative stress in Japanese overweight males.

METHODS

The overweight group included 43 Japanese male volunteers aged between 25 and 64 years and with a body mass index (BMI) of ≥25 and <30. The control group included 47 male volunteers aged between 22 and 64 years and with BMI of <25. The 20-MHz Dermascan C® ultrasound scanner with software for image analyses was used. Echogenicity of the upper and lower dermis was measured. The mRNA expression level of heme oxygenase-1 (HMOX1) in hair follicles was quantitatively analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) and was used as a marker of oxidative stress. Ultrasonographic imaging and collection of hair follicles were performed at the same site on the thigh, abdomen, and upper arm.

RESULTS

The HMOX1 mRNA expression level in the abdomen and thigh was significantly lower in the overweight group than in the control group. Moreover, the echogenicity of the upper dermis of the abdomen and the lower dermis of the abdomen and thigh was significantly lower in the overweight group than in the control group.

CONCLUSION

We detected an increase in oxidative stress levels and a decrease in the density of dermal collagen at the same site on the thigh, abdomen, and upper arm of Japanese overweight males. These findings suggest the fragility of the dermis of Japanese overweight males, which might have been caused by the accumulation of subcutaneous adipose tissue.

Concurrent optical parametric down-conversion in χ(2) nonlinear photonic crystals

We experimentally investigated concurrent parametric downconversion processes in a two-dimensional hexagonally poled lithium tantalate crystal. The substantial enhancement of parametric gain was observed when concurrent processes shared a common parametric beam. Both degenerate and nondegenerate concurrent parametric downconversion processes were studied. Analyses of the spatial forms and output angles showed a strong dependence on the working temperature, during which a well-defined beamlike parametric output was observed. Our results will stimulate the design for coherent high-gain generation of multiple parametric beams and also shed light on the compact engineering of path-entanglement with specific spatial forms based on concurrent spontaneous parametric downconversion processes.

First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV

A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

Energy depletion of bovine mammary epithelial cells activates AMPK and suppresses protein synthesis through inhibition of mTORC1 signaling

The molecular mechanisms by which cellular energy status regulates global protein synthesis in mammary epithelial cells have not been characterized. The objective of this study was to examine the effect of AMP-activated protein kinase (AMPK) activation by 2-deoxyglucose on protein synthesis and the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway in bovine mammary epithelial cells. Phosphorylation of AMPK at Thr172 increased by 1.4-fold within 5 min, and remained elevated throughout a 30-min time course, in response to 2-deoxyglucose. Global rates of protein synthesis declined by 78% of control values. The decline in protein synthesis was associated with repression of mTORC1 signaling, as indicated by reduced phosphorylation of ribosomal protein S6 kinase 1 and eIF4E binding protein-1 (4E-BP1). Phosphorylation of ER-stress marker eIF2α was also increased but only at 30 min of 2-deoxyglucose exposure. 2-Deoxyglucose increased phosphorylation of tuberous sclerosis complex 2 (TSC2) on AMPK consensus sites but did not change the amount of TSC1 bound to TSC2. Activation of AMPK did not result in changes in the amount of raptor bound to mTOR. The inhibitory effects of AMPK activation on mTORC1 signaling were associated with a marked increase in Ser792 phosphorylation on raptor. Collectively, the results suggest that activation of AMPK represses global protein synthesis in mammary epithelial cells through inhibition of mTORC1 signaling.

Identification of a novel HLA-A allele, A*02:357, in a Chinese individual

Human leukocyte antigen (HLA)-A*02:357 differs from A*02:01:01:01 by a single nucleotide at position 840 from A to T exon 4, leading to amino acid substitution from Arg to Ser.

European guidelines for quality assurance in colorectal cancer screening and diagnosis: overview and introduction to the full supplement publication

Population-based screening for early detection and treatment of colorectal cancer (CRC) and precursor lesions, using evidence-based methods, can be effective in populations with a significant burden of the disease provided the services are of high quality. Multidisciplinary, evidence-based guidelines for quality assurance in CRC screening and diagnosis have been developed by experts in a project co-financed by the European Union. The 450-page guidelines were published in book format by the European Commission in 2010.  They include 10 chapters and over 250 recommendations, individually graded according to the strength of the recommendation and the supporting evidence. Adoption of the recommendations can improve and maintain the quality and effectiveness of an entire screening process, including identification and invitation of the target population, diagnosis and management of the disease and appropriate surveillance in people with detected lesions. To make the principles, recommendations and standards in the guidelines known to a wider professional and scientific community and to facilitate their use in the scientific literature, the original content is presented in journal format in an open-access Supplement of Endoscopy. The editors have prepared the present overview to inform readers of the comprehensive scope and content of the guidelines.