To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
It has not been well established whether dietary folate intake reduces the risk of diabetes development. We aimed to clarify the prospective association between dietary folate intake and type 2 diabetes (T2D) risk among 7333 Korean adults aged 40 years or older who were included in the Multi-Rural Communities Cohort. Dietary folate intake was estimated from all 106 food items listed on a FFQ, not including folate intake from supplements. Two different measurements of dietary folate intake were used: the baseline consumption and the average consumption from baseline until just before the end of follow-up. The association between folate intake and T2D risk was determined through a modified Poisson regression model with a robust error estimator controlling for potential confounders. For 29 745 person years, 319 cases of diabetes were ascertained. In multivariable analyses, dietary folate intake was inversely associated with risk of T2D for women, not for men. For women, the incidence rate ratio of diabetes in the third tertile compared with the first tertile was 0·57 (95 % CI 0·38–0·87, Pfor trend=0·0085) in the baseline consumption model and 0·64 (95 % CI 0·43–0·95, Pfor trend=0·0244) in the average consumption model. These inverse associations was found in both normal fasting blood glucose group and impaired fasting glucose group among women. Among non-users of multinutrients and vitamin supplements, the significant inverse association remained. Thus, higher dietary intake of folate is prospectively associated with lower risk of diabetes for women.
The purpose of this study was to investigate whether significant difference exists on radiation dose delivered to organs at risks in megavoltage computed tomography (MVCT) verification using three predefined scanning modes, namely fine (2 mm), normal (4 mm) and coarse (6 mm). This will provide information for the imaging protocol of tomotherapy for the left breast.
Materials and methods
Organ doses were measured using thermoluminescent dosimeters (TLD-100) placed within a female Rando phantom for MVCT imaging. Kruskal–Wallis test was conducted with p<0·05 to evaluate the significant difference between the three MVCT scanning modes.
Statistically significant difference existed in organ absorbed dose between different scan mode selections (p<0·001). Relative to the normal scan selection (4 mm), the absorbed dose to the organs of interests can be scaled down by 0·7 and scaled up by 2·1 for coarse (6 mm) and fine scans (2 mm) respectively.
Optimisation of imaging protocols is of paramount importance to keep the radiation exposure ‘as low as reasonably achievable’. The recommendation of undergoing daily coarse mode for MVCT verification in breast tomotherapy not only mitigates the radiation exposure to normal tissues, but also trims the scan-acquisition time.
Δ14C values of leaves of deciduous trees provide a means to map the regional-scale fossil fuel ratio in the atmosphere. We collected a batch of ginkgo (Ginkgo biloba Linnaeus, a deciduous tree) leaf samples from across Korea in the month of July in both 2010 and 2011 to obtain the regional distribution of Δ14C. The Δ14C values of the samples were measured using accelerator mass spectrometry (AMS) at the Korea Institute of Geoscience and Mineral Resources (KIGAM). The average of the Δ14C values from clean air sites in Korea in 2011 measured slightly lower than the average of Δ14C values in 2010. Distribution maps of Δ14C of 2011 and 2010 in Korea were made based on a series of Δ14C values of ginkgo leaf samples from Korea using the Geostatistical and Spatial analyst tools in ESRI's ArcMap software. The distribution maps of Δ14C showed that Δ14C values in the western part of Korea are lower than those in the eastern part of Korea. This is because the western part of Korea is densely populated and contains many industrial complexes, and also because westerly winds from China, containing CO2 from fossil fuel use, blow into Korea. We compared the distribution maps of 2010 and 2011 and tried to find traces of the Fukushima power plant accident in Japan.
People living with HIV (PLWH) experience greater psychological distress than the general population. Evidence from high-incomes countries suggests that psychological interventions for PLWH can improve mental health symptoms, quality of life, and HIV care engagement. However, little is known about the effectiveness of mental health interventions for PLWH in low- and middle-income countries (LMICs), where the large majority of PLWH reside. This systematized review aims to synthesize findings from mental health intervention trials with PLWH in LMICs to inform the delivery of mental health services in these settings. A systematic search strategy was undertaken to identify peer-reviewed published papers of intervention trials addressing negative psychological states or disorders (e.g. depression, anxiety) among PLWH in LMIC settings. Search results were assessed against pre-established inclusion and exclusion criteria. Data from papers meeting criteria were extracted for synthesis. Twenty-six papers, published between 2000 and 2014, describing 22 unique interventions were identified. Trials were implemented in sub-Saharan Africa (n = 13), Asia (n = 7), and the Middle East (n = 2), and addressed mental health using a variety of approaches, including cognitive-behavioral (n = 18), family-level (n = 2), and pharmacological (n = 2) treatments. Four randomized controlled trials reported significant intervention effects in mental health outcomes, and 11 preliminary studies demonstrated promising findings. Among the limited mental health intervention trials with PLWH in LMICs, few demonstrated efficacy. Mental health interventions for PLWH in LMICs must be further developed and adapted for resource-limited settings to improve effectiveness.
Specific roles of individual CDPKs vary, but in general they mediate essential biological functions necessary for parasite survival. A comparative analysis of the structure-activity relationships (SAR) of Neospora caninum, Eimeria tenella and Babesia bovis calcium-dependent protein kinases (CDPKs) together with those of Plasmodium falciparum, Cryptosporidium parvum and Toxoplasma gondii was performed by screening against 333 bumped kinase inhibitors (BKIs). Structural modelling and experimental data revealed that residues other than the gatekeeper influence compound–protein interactions resulting in distinct sensitivity profiles. We subsequently defined potential amino-acid structural influences within the ATP-binding cavity for each orthologue necessary for consideration in the development of broad-spectrum apicomplexan CDPK inhibitors. Although the BKI library was developed for specific inhibition of glycine gatekeeper CDPKs combined with low inhibition of threonine gatekeeper human SRC kinase, some library compounds exhibit activity against serine- or threonine-containing CDPKs. Divergent BKI sensitivity of CDPK homologues could be explained on the basis of differences in the size and orientation of the hydrophobic pocket and specific variation at other amino-acid positions within the ATP-binding cavity. In particular, BbCDPK4 and PfCDPK1 are sensitive to a larger fraction of compounds than EtCDPK1 despite the presence of a threonine gatekeeper in all three CDPKs.
In February 2012, an outbreak of gastroenteritis was reported in school A; a successive outbreak was reported at school B. A retrospective cohort study conducted in school A showed that seasoned green seaweed with radishes (relative risk 7·9, 95% confidence interval 1·1–56·2) was significantly associated with illness. Similarly, a case-control study of students at school B showed that cases were 5·1 (95% confidence interval 1·1–24·8) times more likely to have eaten seasoned green seaweed with pears. Multiple norovirus genotypes were detected in samples from students in schools A and B. Norovirus GII.6 isolated from schools A and B were phylogenetically indistinguishable. Green seaweed was supplied by company X, and norovirus GII.4 was isolated from samples of green seaweed. Green seaweed was assumed to be linked to these outbreaks. To our knowledge, this is the first reported norovirus outbreak associated with green seaweed.
Individuals with borderline personality disorder (BPD) frequently display co-morbid mental disorders. These disorders include ‘internalizing’ disorders (such as major depressive disorder and anxiety disorders) and ‘externalizing’ disorders (such as substance use disorders and antisocial personality disorder). It is hypothesized that these disorders may arise from latent ‘internalizing’ and ‘externalizing’ liability factors. Factor analytic studies suggest that internalizing and externalizing factors both contribute to BPD, but the extent to which such contributions are familial is unknown.
Participants were 368 probands (132 with BPD; 134 without BPD; and 102 with major depressive disorder) and 885 siblings and parents of probands. Participants were administered the Diagnostic Interview for DSM-IV Personality Disorders, the Revised Diagnostic Interview for Borderlines, and the Structured Clinical Interview for DSM-IV.
On confirmatory factor analysis of within-person associations of disorders, BPD loaded moderately on internalizing (factor loading 0.53, s.e. = 0.10, p < 0.001) and externalizing latent variables (0.48, s.e. = 0.10, p < 0.001). Within-family associations were assessed using structural equation models of familial and non-familial factors for BPD, internalizing disorders, and externalizing disorders. In a Cholesky decomposition model, 84% (s.e. = 17%, p < 0.001) of the association of BPD with internalizing and externalizing factors was accounted for by familial contributions.
Familial internalizing and externalizing liability factors are both associated with, and therefore may mutually contribute to, BPD. These familial contributions account largely for the pattern of co-morbidity between BPD and internalizing and externalizing disorders.
The Slewing Mirror Telescope (SMT) is the UV/optical telescope of UFFO-pathfinder. The
SMT optical system is a Ritchey-Chrétien (RC) telescope of 100 mm diameter pointed by
means of a gimbal-mounted flat mirror in front of the telescope. The RC telescope has a
17 × 17arcmin2 in Field of View and 4.3 arcsec resolution (full width half
maximum of the point spread function) The beam-steering mirror enables the SMT to access a
35 × 35degree region and point and settle within 1 sec. All mirrors were fabricated to
about 0.02 wavelengths RMS in wave front error (WFE) and 84.7% average reflectivity over
200 nm ~ 650 nm. The RC telescope was aligned to 0.05 wavelengths RMS in WFE (test
wavelength 632.8 nm). In this paper, the technical details of the RC telescope and slewing
mirror system assembly, integration, and testing are given shortly, and performance tests
of the full SMT optical system are reported.
We report on mid-infrared (600 – 4000 cm-1), refection-type optical-Hall effect measurements on epitaxial graphene grown on C-face silicon carbide and present Landau-level transition features detected at 1.5 K as a function of magnetic field up to 8 Tesla. The Landau-level transitions are detected in reflection configuration at oblique incidence for wavenumbers below, across and above the silicon carbide reststrahlen range. Small Landau-level transition features are enhanced across the silicon carbide reststrahlen range due to surface-guided wave coupling with the electronic Landau-level transitions in the graphene layer. We analyze the spectral and magnetic-field dependencies of the coupled resonances, and compare our findings with previously reported Landau-level transitions measured in transmission configuration [4,5,6]. Additional features resemble transitions previously assigned to bilayer inclusion , as well as graphite . We discuss a model description to account for the electromagnetic polarizability of the graphene layers, and which is sufficient for quantitative model calculation of the optical-Hall effect data.
Imprinting control regions (ICRs) play a fundamental role in establishing and maintaining the non-random monoallelic expression of certain genes, via common regulatory elements such as non-coding RNAs and differentially methylated regions (DMRs) of DNA. We recently surveyed DNA methylation levels within four ICRs (H19-ICR, IGF2-DMR, KvDMR, and NESPAS-ICR) in whole-blood genomic DNA from 128 monozygotic (MZ) and 128 dizygotic (DZ) human twin pairs. Our analyses revealed high individual variation and intra-domain covariation in methylation levels across CpGs and emphasized the interaction between epigenetic variation and the underlying genetic sequence in a parent-of-origin fashion. Here, we extend our analysis to conduct two genome-wide screenings of single nucleotide polymorphisms (SNPs) underlying either intra-domain covariation or parent-of-origin-dependent association with methylation status at individual CpG sites located within ICRs. Although genome-wide significance was not surpassed due to sample size limitations, the most significantly associated SNPs found through multiple-trait genome-wide association (MQFAM) included the previously described rs10732516, which is located in the vicinity of the H19-ICR. Similarly, we identified an association between rs965808 and methylation status within the NESPAS-ICR. This SNP is positioned within an intronic region of the overlapping genes GNAS and GNAS-AS1, which are imprinted genes regulated by the NESPAS-ICR. Sixteen other SNPs located in regions apart from the analyzed regions displayed suggestive association with intra-domain methylation. Additionally, we identified 13 SNPs displaying parent-of-origin association with individual methylation sites through family-based association testing. In this exploratory study, we show the value and feasibility of using alternative GWAS approaches in the study of the interaction between epigenetic state and genetic sequence within imprinting regulatory domains. Despite the relatively small sample size, we identified a number of SNPs displaying suggestive association either in a domain-wide or in a parent-of-origin fashion. Nevertheless, these associations will require future experimental validation or replication in larger and independent samples.
Carbon nanofibers (CNFs) have been thoroughly investigated as potential anode materials in Li-ion battery owing to their exceptional properties such as the higher surface area to mass ratio, electrical conductivity and mechanical toughness. However, one of the major limitations of nano carbon materials is lower mass loading density. To address this issue, we have developed a novel anode system composed of CNFs directly grown on 3D Cu mesh current collector (hereafter mentioned as 3D CNFs) using a thermal catalytic chemical vapor deposition (CVD) method. Compared to CNF-based anodes on 2D Cu current collector, active The active material loading amount of the 3D CNFs has been found to be 400 % higher while comparing with 2D CNF. Owing to an increase of the active surface area, 3D CNFs demonstrated enhanced electrochemical performance of Li-ion battery in terms of charge capacity (50% improvement), rate capability and cycling life. Interfacial contact between the CNFs and Cu could play a crucial role in promoting the electrochemical properties. The intermediate TiC thin layer, formed at high temperature 750°C, could function as an efficient electric conducting pathway and a strong bonding bridge between the CNFs and Cu. In order to improve the pristine 3D CNF redox reactions, the amorphous Si (a-Si)/3D CNF has been sputter deposited to produce Si wrapped 3D CNF hybrid anode material. It has been found that the electrochemical properties of the a-Si/3D CNF yields superior specific capacity (Cdis 549 mAhg-1, LiC4.1) and cycling stability than that of pristine 3D CNF (461 mAhg-1, LiC4.8).
We report an increase in superconducting temperature of magnesium diboride (MgB2) by minute single-wall carbon nanotubes (SWCNT) inclusions. The SWCNTs concentration was varied from 0.1wt% to 1.0wt%. The temperature dependence resistivity of sintered MgB2- SWCNTs composites containing 0.1wt%, 0.5wt% and 1.0wt% were measured and compared with that of the pure MgB2. The superconducting critical temperature (Tc) of the MgB2 increased from 40 K to as high as 42.4 K for the MgB2 containing 0.5wt% of SWCNTs. The room temperature resistivity ratio (RRR) shows dependence on the sample composition. The temperature width (ΔT) decreases with increasing SWCNT content from 0.1wt% to 1.0wt%. The normal state resistivity data were fitted with the generalized Block-Grüneisen function obtaining a Debye temperature of ∼ 900K.
Well ordered arrays of carbon nanotubes (CNTs) are of interest for a broad range of potential applications including energy storage and as catalyst supports. On some substrates such as copper and nickel, CNTs do not grow well or at all. We have previously shown that mesoporous silica thin films can be deposited onto metal substrates including copper and nickel, and that, after removal of the templating surfactant, the mesoporous silica film can be used as template for the electrodeposition of metals to give metal nanostructures.[Campbell et. al., Micro. Meso. Mater., 97, 114-121 (2006)] The size of the metal nanostructures makes them attractive as seeds for growth of CNTs. We have found that under appropriate conditions nickel deposited into mesoporous silica can act as catalyst for CNT growth on a number of different substrates including copper coated silicon wafers, and nickel foam. Using three different furnaces and different feed streams it was found that the growth is sensitive to carbon source; acetylene and ethylene both produced CNTs whereas attempts to produce CNTs using xylene have so far been unsuccessful.
Well ordered mesoporous silica thin films could potentially give arrays of nanorod seeds, leading to well ordered arrays of CNTs, SEM images of some of our samples show dense CNT arrays, but do not indicate significant ordering.
Hemin immobilized reduced graphene(HGN) has been investigated to be an outstanding enzymatic catalysis in detection important molecular recently. In this work, two "clean" methods to prepare HGN through π-π stack were charactered by UV-vis spectra, TEM images, and δ-potential. The enzymatic catalysis of both materials was compared by catalytic hydrogen peroxide to oxidize pyrogallol. The colorimetric result shows HGN attached before reduction has stronger catalytic ability than the one after reduction. The optimized HGN was then used as an electrochemical biosensor to determine L-tyrosine levels. The cyclic voltammetry (CV) tests were carried out for the bare glass carbon electrode (GCE), and the optimized hemin-reduced graphene electrode (HGN1/GCE). The HGN1/GCE based biosensor exhibits a Tyrosine detection linear range from 5×10-7 M to 4×10-5 M with a detection limitation of 7.5×10-8 M at signal noise ratio (S/N) of 3. In comparison with other biosensor, electrochemical biosensors are easy-fabricated, easy-controlled, and cost-effective. Compared with other materials, the hemin-reduced graphene based biosensors demonstrate higher stability, a broader detection linear range, and better detection sensitivity. The study of oxidation scheme reveals that reduced graphene enhanced the electron transfer between electrode and hemin. Meanwhile, the hemin groups effectively electrocatalyzed the oxidation of tyrosine. This study contributes to a widespread clinical application of nanomaterial based biosensor devices with a broader detection linear range, improved stability, enhanced sensitivity, and reduced costs.
In this paper we demonstrate that graphene is one of the best materials for new types of terahertz lasers as optical and/or injection pumping of graphene can exhibit negative-dynamic conductivity in the terahertz spectral range. We analyze the formation of nonequilibrium states in optically pumped graphene layers and in forward-biased graphene structures with lateral p-i-n junctions and consider the conditions of population inversion and lasing. The latter provides a significant advantage of the injection pumping in realization of graphene terahertz lasers. We benchmark graphene as a prospective material for injection-type terahertz lasers.
Amorphous carbon (a-C) films have a growing interest in the biological and medical field, as a coating material, due to their biocompatibility and antibacterial property. However, a-C films deposited directly on polymers often show adhesion failure.
In this paper, two types of a-C films, amorphous hydrogenated carbon (a-C:H) film and hydrogen-free a-C (H-free a-C) film were deposited on polytetrafluoroethylene (PTFE) using a plasma deposition method. Prior to a-C film coating, the PTFE substrates were treated with Ar and O2 plasma and an appropriate interlayer was chosen to enhance the adhesion strength. The effect of the plasma pretreatment on the chemical composition of the PTFE was investigated by X-ray photoelectron spectroscopy (XPS). A T-peel test was carried out to evaluate the adhesion strength of the a-C coated PTFE. In the T-peel test, Ar plasma pretreatment improved the adhesion strength more effectively than that of O2 plasma pretreatment, because of the substantial defluorination and oxygen bonding occurred by Ar plasma pretreatment. Moreover, H-free a-C film reduced the numbers of Escherichia coli (E. coli) colonies dramatically, compared with original PTFE and a-C:H coated PTFE. Consequently, H-free a-C film coating can be a promising method to inhibit the increase of bacteria.
Carbon/carbon composites (C/C composites) possess superior characteristics of low density, high strength, extremely low coefficient of thermal expansion, high fatigue resistance. In carbonization process, the high temperature pyrolysis made of carbon, hydrogen, oxygen and other elements, results in a lot of voids and cavities generated in the interior of C/C composites. Therefore, the C/C composites are densified to fill the void by using repeated impregnation. But densification is a time-wasting and complex process, which increases production costs in the manufacturing process.
In this study, the Multi-Wall Carbon Nanotubes (MWNTs) were adopted as reinforcement material for C/C composites to reduce the existence of voids or cavities and enhance the mechanical properties of C/C composites under environment aging effects. Three different temperature with high moisture conditions are used to be tested, including high temperature (150°C/ 90%RH), room temperature (25°C/90%RH), and low temperature (-15°C/90%RH) to analyze the mechanical properties of C/C composites, such as flexural and Interlaminar Shear Strength (ILSS).