Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

Optimal assessment of lymph node status in gallbladder cancer

BACKGROUND

Lymph node (LN) metastasis is an important prognostic factor in gallbladder cancer (GBCA). LN status has been adopted as a critical element of staging systems. However, the influence of total lymph node count (TLNC) remains unclear. We determined the optimal minimum TLNC and compared the prognostic significance of LN status indices in GBCA.

METHODS

We retrospectively reviewed medical records of 128 patients with T2 or greater GBCA who underwent LN dissection. We analyzed overall survival (OS) and relevance of the number of metastatic LNs, ratio of metastatic LNs to retrieved LNs (LNR), and TLNC in predicting OS.

RESULTS

The median OS durations were 120, 35, and 18 months in T2, T3, and T4 GBCA. Five-year OS rates were 73%, 43%, and 0% in T2, T3, and T4 GBCA. LN status did not significantly impact OS in T2 or T4 GBCA. However, all LN indices were significantly correlated with OS in T3 GBCA. Furthermore, multivariate analysis revealed that a metastatic LN count of more than four and a TLNC of more than eight were independent prognostic factors of OS in T3 GBCA.

CONCLUSIONS

TLNC and the number of positive LNs may be more important prognostic factors than LNR in T3 GBCA. Additionally, accurate staging may not be achieved in cases of T3 GBCA if the total number of retrieved LNs is less than eight. Thus, to ensure proper staging, we recommend that surgeons harvest more than eight LNs in patients with T3 GBCA.

3D reconstruction based on compressed-sensing (CS)-based framework by using a dental panoramic detector

In this work, we propose a practical method that can combine the two functionalities of dental panoramic and cone-beam CT (CBCT) features in one by using a single panoramic detector. We implemented a CS-based reconstruction algorithm for the proposed method and performed a systematic simulation to demonstrate its viability for 3D dental X-ray imaging. We successfully reconstructed volumetric images of considerably high accuracy by using a panoramic detector having an active area of 198.4 mm × 6.4 mm and evaluated the reconstruction quality as a function of the pitch (p) and the angle step (Δθ). Our simulation results indicate that the CS-based reconstruction almost completely recovered the phantom structures, as in CBCT, for p≤2.0 and θ≤6°, indicating that it seems very promising for accurate image reconstruction even for large-pitch and few-view data. We expect the proposed method to be applicable to developing a cost-effective, volumetric dental X-ray imaging system.

Characterizing the pathotype of neonatal meningitis causing Escherichia coli (NMEC)

Background

Neonatal meningitis-causing Escherichia coli (NMEC) is the predominant Gram-negative bacterial pathogen associated with meningitis in newborn infants. High levels of heterogeneity and diversity have been observed in the repertoire of virulence traits and other characteristics among strains of NMEC making it difficult to define the NMEC pathotype. The objective of the present study was to identify genotypic and phenotypic characteristics of NMEC that can be used to distinguish them from commensal E. coli.

Methods

A total of 53 isolates of NMEC obtained from neonates with meningitis and 48 isolates of fecal E. coli obtained from healthy individuals (HFEC) were comparatively evaluated using five phenotypic (serotyping, serum bactericidal assay, biofilm assay, antimicorbial susceptibility testing, and in vitro cell invasion assay) and three genotypic (phylogrouping, virulence genotyping, and pulsed-field gel electrophoresis) methods.

Results

A majority (67.92 %) of NMEC belonged to B2 phylogenetic group whereas 59 % of HFEC belonged to groups A and D. Serotyping revealed that the most common O and H types present in NMEC tested were O1 (15 %), O8 (11.3 %), O18 (13.2 %), and H7 (25.3 %). In contrast, none of the HFEC tested belonged to O1 or O18 serogroups. The most common serogroup identified in HFEC was O8 (6.25 %). The virulence genotyping reflected that more than 70 % of NMEC carried kpsII, K1, neuC, iucC, sitA, and vat genes with only less than 27 % of HFEC possessing these genes. All NMEC and 79 % of HFEC tested were able to invade human cerebral microvascular endothelial cells. No statistically significant difference was observed in the serum resistance phenotype between NMEC and HFEC. The NMEC strains demonstrated a greater ability to form biofilms in Luria Bertani broth medium than did HFEC (79.2 % vs 39.9 %).

Conclusion

The results of our study demonstrated that virulence genotyping and phylogrouping may assist in defining the potential NMEC pathotype.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-015-0547-9) contains supplementary material, which is available to authorized users.

Photodynamic therapy of melanoma skin cancer using carbon dot - chlorin e6 - hyaluronate conjugate

Despite wide application of photodynamic therapy (PDT) for the treatment of melanoma skin cancers, there are strong biomedical unmet needs for the effective generation of singlet oxygen after targeted delivery of photosensitizers. Here, we investigated a facile PDT of melanoma skin cancer using transdermal carbon dot - chlorine e6 - hyaluronate (Cdot-Ce6-HA) conjugates. The Cdot-Ce6-HA conjugate was synthesized by the coupling reaction of diaminohexane modified HA (DAH-HA) with the carboxylic group of Ce6. The singlet oxygen generation of Cdot-Ce6-HA conjugates in aqueous solution was more significant than that of free Ce6. The enhanced transdermal and intracellular delivery of Cdot-Ce6-HA conjugates to B16F10 melanoma cells in tumor model mice were corroborated by confocal microscopy and two-photon microscopy. The laser irradiation after topical treatment with Cdot-Ce6-HA conjugates resulted in complete suppression of melanoma skin cancers. The antitumor effect was confirmed by histological analysis with H&E staining and TUNEL assay for tumor apoptosis. Taken together, we could confirm the feasibility of Cdot-Ce6-HA conjugate for transdermal PDT of melanoma skin cancers.

STATEMENT OF SIGNIFICANCE

To our knowledge, this is the first report on a facile transdermal photodynamic therapy (PDT) of melanoma skin cancer using carbon dot - chlorine e6 - hyaluronate (Cdot-Ce6-HA) conjugates. We found that the singlet oxygen generation of Cdot-Ce6-HA conjugates in aqueous solution was more significant than that of free Ce6. Confocal microscopy and two-photon microscopy clearly confirmed the enhanced transdermal and intracellular delivery of Cdot-Ce6-HA conjugates to B16F10 melanoma cells in tumor model mice. Taken together, we could confirm the feasibility of Cdot-Ce6-HA conjugate for transdermal PDT of melanoma skin cancers.

Bioimaging of Hyaluronate-Interferon α Conjugates Using a Non-Interfering Zwitterionic Fluorophore

We conducted real-time bioimaging of the hyaluronate-interferon α (HA-IFNα) conjugate using a biologically inert zwitterionic fluorophore of ZW800-1 for the treatment of hepatitis C virus (HCV) infection. ZW800-1 was labeled on the IFNα molecule of the HA-IFNα conjugate to investigate its biodistribution and clearance without altering its physicochemical and targeting characteristics. Confocal microscopy clearly visualized the effective in vitro cellular uptake of the HA-IFNα conjugate to HepG2 cells. After verifying the biological activity in Daudi cells, we conducted the pharmacokinetic analysis of the HA-IFNα conjugate, which confirmed its target-specific delivery to the liver with a prolonged residence time longer than that of PEGylated IFNα. In vivo and ex vivo bioimaging of the ZW800-1-labeled HA-IFNα conjugate directly showed real-time biodistribution and clearance of the conjugate that are consistent with the biological behaviors analyzed by an enzyme-linked immunosorbent assay. Furthermore, the elevated level of OAS1 mRNA in the liver confirmed in vivo antiviral activity of HA-IFNα conjugates. With the data taken together, we could confirm the feasibility of ZW800-1 as a biologically inert fluorophore and target-specific HA-IFNα conjugate for the treatment of HCV infection.

Oral administration of Lactobacillus casei variety rhamnosus partially alleviates TMA-induced atopic dermatitis in mice through improving intestinal microbiota

AIMS

The purpose of this study was to investigate the effect of Lactobacillus casei variety rhamnosus (LCR35) on Atopic dermatitis (AD)-like symptoms in mice.

METHODS AND RESULTS

AD-like skin lesions in BALB/C mice were induced by sensitization and subsequent repeated challenges with trimellitic anhydride (TMA) for 10 days. LCR35 was orally administered to the mice once daily throughout the study. In the TMA-induced AD model, orally administered LCR35 suppressed significantly irritant-related scratching behaviour and skin dehydration as well as apparent severity of AD. LCR35 also significantly decreased serum levels of IgE and IL-4, but not IFN-γ, implying the restoration of TMA-induced disruption of Th1/Th2 balance. Quantitative real-time PCR targeting hypervariable regions of 16S rDNA gene of faecal microbiota indicated that the LCR35 treatment increased the population of Bifidobacterium, Lactobacilli, Enterococcus and Bacteroides fragilis group, but decreased those of Clostridium coccoides group.

CONCLUSIONS

LCR35 has the ability to suppress the development of AD in mice, possibly through the modulation of Th1/Th2 balance and gut microbiota.

SIGNIFICANCE AND IMPACT OF THE STUDY

LCR35 has a strong potential as a probiotic for preventing AD.

Evaluation of a commercial orthopaedic metal artefact reduction tool in radiation therapy of patients with head and neck cancer

OBJECTIVE

To assess the image quality and dosimetric effects of the Philips orthopaedic metal artefact reduction (OMAR) (Philips Healthcare System, Cleveland, OH) function for reducing metal artefacts on CT images of head and neck (H&N) patients.

METHODS

11 patients and a custom-built phantom with metal bead inserts (alumina, titanium, zirconia and chrome) were scanned. The image was reconstructed in two ways: with and without OMAR (OMAR and non-OMAR image). The mean and standard deviation values of CT Hounsfield unit (HU) for selected regions of interest of each case were investigated for both images. Volumetric modulated arc therapy plans were generated for all cases. Gamma analysis of each dose distribution pair in the patient (1%/1 mm criteria) and phantom (2%/2 mm and 3%/3 mm criteria) images was performed. The film measurements in phantom for two metal beads were conducted for evaluating the calculated dose on both OMAR and non-OMAR images.

RESULTS

In the OMAR images, noise values were generally reduced, and the mean HU became closer to the reference value (measured from patients without metal implants) in both patient and phantom cases. Although dosimetric difference was insignificant for the eight closed-mouth patients (γ = 99.4 ± 0.5%), there was a large discrepancy in dosimetric calculation between OMAR and non-OMAR images for the three opened-mouth patients (γ = 91.1%, 94.8% and 96.6%). Moreover, the calculated dose on the OMAR image is closer to the real delivered dose on a radiochromic film than was the dose from the non-OMAR image.

CONCLUSION

The OMAR algorithm increases the accuracy of CT HU and reduces the noise such that the entire radiation treatment planning process can be improved, especially for contouring and segmentation.

ADVANCES IN KNOWLEDGE

OMAR reconstruction is appropriate for the radiotherapy planning process of H&N patients, particularly of patients who use a bite block.

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

Seed dormancy and germination in Jeffersonia dubia (Berberidaceae) as affected by temperature and gibberellic acid

The genus Jeffersonia, which contains only two species, has a trans-Atlantic disjunct distribution. The aims of this study were to determine the requirements for breaking dormancy and germination of J. dubia seeds and to compare its dormancy characteristics with those of the congener in eastern North America. Ripe seeds of J. dubia contain an underdeveloped embryo and were permeable to water. In nature, seeds were dispersed in May, while embryos began to grow in September, and were fully elongated by late November. Germination started in March of the next year, and seeds emerged as seedlings soon after germination. In laboratory experiments, incubation at high temperatures (25 °C, 25/15 °C) for at least 8 weeks was required to initiate embryo growth, while a transfer to moderate temperatures (20/10 °C, 15/6 °C) was needed for the completion of embryo growth. At least 8 weeks at 5 °C was effective in overcoming physiological dormancy and for germination in seeds after the embryos had fully elongated. Thus, both high and low temperatures were essential to break dormancy. Gibberellic acid (GA3 ) treatment could substitute for the high temperature requirement, but not for the low temperature requirement. Based on the dormancy-breaking requirements, it is confirmed that the seeds have deep simple morphophysiological dormancy. This dormancy type is similar to that of seeds of the eastern North American species J. diphylla. Although seeds require 10-11 months from seed dispersal to germination in nature, under controlled conditions they required only 3 months after treatment with 1000 mg·l(-1) GA3 , followed by incubation at 15/6 °C. This represents practical knowledge for propagation of these plants from seed.

Quantification of the placental epigenetic signature of the SERPINB5 gene in maternal plasma of pregnancies complicated by small for gestational age

INTRODUCTION

To investigate the association between pregnancies with small for gestational age (SGA) neonates and the concentration of cell-free fetal DNA or cell-free total DNA in maternal plasma during the first and second trimesters using tissue-specific epigenetic characteristics of the SERPINB5 gene.

METHODS

A nested case-control study was conducted with maternal plasma collected at 11 to 26 gestational weeks from 51 women with SGA neonates and 102 controls. We performed a real-time quantitative methylation-specific PCR to quantify concentrations of unmethylated-SERPINB5 (U-SERPINB5) as a cell-free fetal DNA marker and methylated-SERPINB5 (M-SERPINB5) as a cell-free total DNA marker.

RESULTS

A positive correlation was observed between U-SERPINB5 and M-SERPINB5 concentrations in both control (r = 0.363, p < 0.001) and SGA groups (r = 0.548, p < 0.001). Moreover, the concentration of U-SERPINB5 or M-SERPINB5 was significantly positive correlated with gestational age at sampling in both controls (U-SERPINB5: r = 0.397, p < 0.001; M-SERPINB5: r = 0.275, p = 0.005) and SGA (U-SERPINB5: r = 0.274, p = 0.052; M-SERPINB5: r = 0.439, p = 0.001). However, the concentration of U-SERPINB5 or M-SERPINB5 was not correlated with birthweight. At 11-14 weeks, U-SERPINB5 and M-SERPINB5 concentrations in SGA did not differ significantly from those of controls. There were also no statistically significant differences in the concentrations of U-SERPINB5 and M-SERPINB5 between SGA and controls at 15-26 weeks of gestation.

DISCUSSION

Our findings suggest that U-SERPINB5 and M-SERPINB5 concentrations in maternal plasma during early pregnancy are not associated with pregnancies who delivered SGA neonates.

Hearing among male firefighters: a comparison with hearing data from screened and unscreened male population

We investigated whether hearing loss is associated with firefighting. We conducted cross-sectional study comparing hearing threshold levels (HTLs) of 912 male firefighters with two hearing databases obtained from an otologically normal male Korean population (KONP) and a non-industrial noise-exposed male Korean population (KNINEP), considering age and the main roles of firefighters. Firefighters' age-adjusted HTLs were significantly worse than those of KONP (prevalence ratio (PR)=5.29, P<0.001)but not different from those of KNINEP (PR=0.99, P=0.550). Rescuers (PR=1.005, P<0.001) had worse hearing than the KNINEP after age adjustment. Comparison of firefighters' HTLs (50th and 90th percentiles) with those of KONP and KNINEP by age and frequency showed that firefighters' HTLs had significant increases (poorer hearing) across most age groups and frequencies compared with KONP. Compared with KNINEP, firefighters' HTLs were worse in the younger age groups (<45 years) but not different in the older age groups (>45 years). In conclusion, the hearing thresholds of younger firefighters and rescuers were worse than expected by normal aging alone. Future research should include longitudinal studies to consider variable risk factors, such as military service, smoking, and so on.

Hyaluronate–Flt1 peptide conjugate/epirubicin micelles for theranostic application to liver cancers

We successfully developed hyaluronate–Flt1 peptide conjugate/epirubicin micelles for theranostic applications to the treatment of liver cancer.

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).

Angle-resolved photoemission spectroscopy of tetragonal CuO: evidence for intralayer coupling between cupratelike sublattices

We investigate by angle-resolved photoemission the electronic structure of in situ grown tetragonal CuO, a synthetic quasi-two-dimensional edge-sharing cuprate. We show that, in spite of the very different nature of the copper oxide layers, with twice as many Cu in the CuO layers of tetragonal CuO as compared to the CuO(2) layers of the high-T(c) cuprates, the low-energy electronic excitations are surprisingly similar, with a Zhang-Rice singlet dispersing on weakly coupled cupratelike sublattices. This system should thus be considered as a member of the high-T(c) cuprate family, with, however, interesting differences due to the intralayer coupling between the cupratelike sublattices.

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.

A numerical study on the charge transport in TPD/Alq3-based organic light emitting diodes

We report our simulation study on the charge transport characteristic of the multi-layer structure for organic light emitting diodes (OLEDs). We performed a numerical simulation on a multilayer structure comprising a hole transport layer (HTL), an emission layer (EML), and an electron transport layer (ETL) between both electrodes. The material of the HTL is TPD (N,N'-Bis (3-methylphenyl)-N,N'-bis(phenyl) benzidine), and the ETL includes Alq3 (Tris (8-hyroxyquinolinato) aluminium). Here, we investigated the parameters such as recombination rates which influence the efficiency of the charge transport between layers in bilayer OLEDs. We also analyzed a transient response during the turn on/off period and the carrier transport in accordance with the variation of the injection barrier and applied voltage. In addition, our numerical simulation revealed that the insertion of the EML affects the photonic characteristics in bilayer structure and also the efficiency due to the difference in the internal barrier height.

The impact of group B Streptococcus prophylaxis on early onset neonatal infections

OBJECTIVE

To determine if changes have occurred in the causative pathogens and/or antibiotic susceptibility profiles in early onset neonatal infections since initiation of group B Streptococcus (GBS) prophylaxis and to determine risk factors for ampicillin/penicillin resistant microorganisms.

STUDY DESIGN

Data on 220 infants with positive blood, urine, or cerebrospinal fluid cultures for bacteria or fungi at ≤seven days of age from 1990-2007 were examined and divided into three epochs, based on intrapartum antibiotic prophylactic (IAP) practices. Pathogens and antibiotic resistance were compared among epochs.

RESULTS

A significant decrease in the incidence of GBS infections occurred over time, with no change in the incidence of other pathogens or the emergence of antibiotic resistance, including the very low-birthweight population. In regression analysis, ampicillin resistance was associated with male gender (OR 3.096).

CONCLUSIONS

No emergence of antibiotic resistant pathogens was found following IAP use. Changing microorganisms and increasing antibiotic resistance found in prior studies are likely multifactorial. Further study is needed to continue to reduce the rates of common early onset pathogens.

Impact of internal spermatic artery preservation during laparoscopic varicocelectomy on recurrence and the catch-up growth rate in adolescents

OBJECTIVE

To investigate the effectiveness of laparoscopic varicocelectomy (LV) in adolescents with varicocele and analyze the impact of internal spermatic artery (ISA) preservation on surgical outcomes.

MATERIALS AND METHODS

Data on 92 adolescents with left varicocele who underwent LV between December 1998 and January 2011 were retrospectively analyzed. The mean age of the patients was 13.2 ± 2.1 years. Age, grade of disease, number of ligation veins, recurrence rates, and catch-up growth were analyzed in patients who underwent ISA preservation and ligation. The median duration of the follow-up was 21 months.

RESULTS

ISA preservation was performed on 50 patients (54%). There were no significant inter-group differences in terms of age, varicocele grade, number of ligation veins, and catch-up growth (93% vs. 90%). The patients who received artery preservation demonstrated a higher recurrence rate (22%) than those who received artery ligation (5%; p = 0.032). Among 13 patients who had persistent or recurrent varicocele, nine were treated with embolization and one was treated with magnification-assisted subinguinal varicocelectomy. None of these 10 patients demonstrated recurrence or testicular atrophy.

CONCLUSIONS

LV with ISA ligation can reduce the recurrence rate and results in the same catch-up growth rate in comparison with LV with ISA preservation.

Hyaluronate-gold nanoparticle/tocilizumab complex for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory immune disease causing the inflammation of synovial membrane and the articular cartilage destruction. In this work, hyaluronate-gold nanoparticle/Tocilizumab (HA-AuNP/TCZ) complex was prepared for the treatment of RA. AuNP was used as a drug carrier with antiangiogenic effect. TCZ is a humanized monoclonal antibody against the interleukin-6 (IL-6) receptor and used as an immunosuppressive drug by interfering IL-6 in the pathogenesis of RA. HA is known to have cartilage-protective and lubricant effects. HA was modified with cystamine via reductive amination, which was reduced with dithiothreitol (DTT) to prepare end-group thiolated HA (HA-SH). AuNP was chemically modified with HA-SH and physically modified with TCZ. The formation of HA-AuNP/TCZ complex was corroborated by UV-vis spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The therapeutic effect of HA-AuNP/TCZ complex on RA was confirmed in collagen-induced arthritis (CIA) model mice by ELISA, histological, and Western blot analyses.