Dissociative ionization and Coulomb explosion of CH4 in two-color asymmetric intense laser fields.

Directional fragment ejection from a tetrahedral molecule CH4 in linearly polarized two-color (ω and 2ω) asymmetric intense laser fields (50 fs, 1.4 × 1014 W cm-2, 800 nm and 400 nm) has been studied by three-dimensional ion coincidence momentum imaging. The H+ fragment produced from dissociative ionization, CH4 → H+ + CH3 + e-, is preferentially ejected on the larger amplitude side of the laser electric fields. Comparison with theoretical predictions by weak-field asymptotic theory shows that the observed asymmetry can be understood by the orientation selective tunneling ionization from the triply degenerated highest occupied molecular orbital (1t2) of CH4. A similar directional ejection of H+ was also observed for the low kinetic energy components of the two-body Coulomb explosion, CH4 → H+ + CH3+ + 2e-. On the other hand, the fragment ejection in the opposite direction were observed for the high energy component, as well as H2+ produced from the Coulomb explosion CH4 → H2+ + CH2+ + 2e-. Possible origins of the characteristic fragmentation are discussed.

Helicity-dependent dissociative tunneling ionization of CF4 in multicycle circularly polarized intense laser fields.

Dissociative tunneling ionization of tetrafluoromethane (CF4) in circularly polarized ultrashort intense laser fields (35 fs, 0.8 × 1014 W cm-2, 1035 nm), CF4 → CF4+ + e- → CF3+ + F + e-, has been studied by three-dimensional electron-ion coincidence momentum imaging. The photoelectron angular distribution in the recoil frame revealed that the dissociative tunneling ionization occurs efficiently when the laser electric field points from F to C. The obtained results are qualitatively consistent with the theoretical predictions by the weak-field asymptotic theory (WFAT) for tunneling ionization from the highest and next-highest occupied molecular orbitals, HOMO (1t1), and HOMO-1 (4t2), respectively. On the other hand, the angular distribution shows clear dependences on the polarization helicity, indicating that the breaking of the C-F bonds is sensitive to the helicity of the multicycle circularly polarized laser fields.

Enhancement of Above Threshold Ionization in Resonantly Excited Helium Nanodroplets.

Clusters and nanodroplets hold the promise of enhancing high-order nonlinear optical effects due to their high local density. However, only moderate enhancement has been demonstrated to date. Here, we report the observation of energetic electrons generated by above-threshold ionization (ATI) of helium (He) nanodroplets which are resonantly excited by ultrashort extreme ultraviolet (XUV) free-electron laser pulses and subsequently ionized by near-infrared (NIR) or near-ultraviolet (UV) pulses. The electron emission due to high-order ATI is enhanced by several orders of magnitude compared with He atoms. The crucial dependence of the ATI intensities with the number of excitations in the droplets suggests a local collective enhancement effect.

Factors affecting patient adherence to publicly funded colorectal cancer screening programmes: a systematic review.

OBJECTIVES: Colorectal cancer (CRC) is the third most common cancer. Many countries in Europe have already implemented systematic screening programmes as per the recommendations by the European Union. The impact of screening is highly dependent on participation rates. The aim of the study was to identify barriers, facilitators and modifiers to participation in systematised, stool sample-based, publicly financed CRC screening programmes. STUDY DESIGN: Systematic review. METHODS: A systematic search in PubMed, Embase, MEDLINE, CINAHL, Cochrane CENTRAL, Google Scholar and PsycINFO was undertaken. We included both qualitative and quantitative studies reporting on barriers and facilitators (excluding sociodemographic variables) to participation in stool sample-based CRC screening. Barriers and facilitators to participation were summarised and analysed. RESULTS: The inclusion criteria were met in 21 studies. Reported barriers and facilitators were categorised into the following seven themes (examples): psychology (fear of cancer), religion (believing cancer is the will of God), logistics (not knowing how to conduct the test), health-related factors (mental health), knowledge and awareness (lack of knowledge about the test), role of the general practitioner (being supported in taking the test by the general practitioner), and environmental factors (knowing someone who has participated in a screening programme). Six studies reported that non-participation was not due to a negative attitude towards screening for CRC. CONCLUSION: Many barriers to screening were found. It is important to work with peoples' fear of screening. Moreover, this review suggests that it might be possible to increase participation rates, if the population-wide awareness and knowledge of potential health benefits of CRC screening are increased and proper logistical support is provided.

Reduction in myocardial strain is evident in adolescents and young adults with obesity and type 2 diabetes.

AIMS/HYPOTHESIS: Heart failure is a complication of type 2 diabetes (T2DM). Echocardiography can identify subclinical systolic dysfunction in adults with T2DM. We hypothesized that reduced systolic strain was present in youth with T2DM. METHODS: Global longitudinal strain (GLS) was measured in 151 subjects with T2DM matched to lean (L = 146), and obese (O = 162) subjects (23.0 ± 4.0 years, 35% male, 63% African American). Anthropometrics, BP, HR, labs, and echocardiograms were obtained. ANOVA was performed to compare differences among groups, and ANCOVA to determine if T2DM remained an independent predictor after corrections. RESULTS: BP, lipid levels, and metabolic control worsened and GLS was reduced from L to O to T2DM. BMI was lower in L than O or T2DM. Global longitudinal strain rate (GLSR) was lower and LVM/ht2.7 was higher in O and T2DM as compared to L (all P ≤ .05). Presence of T2DM was an independent determinant of GLS and GLSR adjusted for most CV risk factors, but lost significance when BMI was added to the model. GLS = -21.6-age*0.088 - male*1.8 + 0.12*BMI + 0.045*DBP + 0.058*HR - 0.023*HDL (R2 = 0.38, P ≤ .0001); GLSR = -1.20-male*0.093 + WHR*0.48 + DBP*0.0029 (R2 = 0.23, P ≤ .0001). CONCLUSION: Both adiposity and T2DM have a deleterious effect on systolic cardiac function. Treatment of obesity in youth is necessary for prevention of future heart failure.

Molecular Symmetry-Mixed Dichroism in Double Photoionization of H_{2}.

Dichroism in double photoionization of H_{2} molecules by elliptically polarized extreme ultraviolet pulses is formulated analytically as a sum of atomiclike dichroism (AD) and molecular symmetry-mixed dichroism (MSMD) terms. The MSMD originates from an interplay of ^{1}Σ_{u}^{+} and ^{1}Π_{u}^{+} continuum molecular ionization amplitudes. For detection geometries in which the AD vanishes, numerical results for the sixfold differential probabilities for opposite pulse helicities show that the MSMD is significant in the electron momentum and angular distributions and is controllable by the ellipticity.

A randomized controlled trial of working memory and processing speed training in schizophrenia.

BACKGROUND: Although prior research has shown that cognitive training may improve cognition for schizophrenia patients, it is currently unclear which domains of cognition should be targeted in training. One suggestion is to target low- or mid-level cognitive processes. In particular, working memory (WM) and processing speed (PS) have been named as two key areas of impairment in schizophrenia, and two domains of cognition that are linked to higher-order cognition and daily functioning. This study aimed to investigate the near-transfer (transfer of gains to related contexts), far-transfer (transfer of gains to unrelated contexts), and real-world gains associated with WM and PS training in schizophrenia. METHODS: Eighty-three participants with schizophrenia were recruited and randomly assigned to computerized WM training, PS training, or a no-training control group. Outcome measures included WM, PS, fluid intelligence, executive functioning, social cognition, and daily functioning and symptoms. RESULTS: PS training led to significant gains in untrained PS tasks, as well as gains in far-transfer tasks that required speed of processing. WM training did not lead to gains in untrained WM tasks and showed inconsistent effects on some far-transfer tasks. CONCLUSIONS: These results suggest some benefit of domain-specific cognitive training, specifically PS training, in schizophrenia. Far-transfer of gains to other cognitive domains and to real-world functioning may not occur after targeted WM or PS training, though non-specific effects (e.g. through behavioral activation, increased motivation) may lead to improvements in some tasks. Future studies should continue to investigate the mechanisms by which cognitive training may enhance cognition and functioning in schizophrenia.

Diabetic retinopathy in people with Type 2 diabetes and obesity treated by Roux-en-Y gastric bypass compared with non-operated controls: with focus on the role of diabetes remission in a cross-sectional and a 6-year follow-up study.

AIM: Whether or not Roux-en-Y gastric bypass (RYGB) and the derived metabolic improvements are beneficial to diabetic retinopathy is controversial. We aimed to determine the presence and development of retinopathy in individuals with obesity and Type 2 diabetes treated by RYGB compared with non-operated controls, and to determine the role of diabetes remission. METHODS: We graded fundus photography using the Wisconsin Epidemiologic Study of Diabetic Retinopathy in 96 individuals with obesity and Type 2 diabetes treated by RYGB 6 years after surgery compared with 48 non-operated controls. In a subsample, we investigated the development of retinopathy over time. In the secondary analysis, we divided the RYGB group according to diabetes remission. RESULTS: RYGB surgery was not statistically associated with less retinopathy [relative risk (RR) 0.82, 95% CI 0.59 to 1.14], when adjusted for diabetes duration, sex, age and BMI. During 5.9 years of follow-up, retinopathy grading in the RYGB group was unchanged, whereas the control group displayed worse grading by 0.69 steps (95% CI 0.18 to 1.19). The RYGB group with diabetes remission (52%) showed a trend towards less retinopathy [adjusted RR (aRR) 0.45; 95% CI 0.19 to 1.06] than controls, and less retinopathy (aRR 0.33; 95% CI 0.11 to 0.94) than the RYGB group without remission in the cross-sectional data. CONCLUSIONS: In a cross-sectional setting, individuals with Type 2 diabetes treated by RYGB showed a tendency towards less retinopathy than non-operated controls, in particular diabetes remission following RYGB was associated with less retinopathy. Moreover after 5.9 years, retinopathy in the RYGB group had progressed less than in the control group. (Clinical Trial Registry No: NCT02625649).

Hepatocellular carcinoma in patients with chronic hepatitis C and cirrhosis in Denmark: A nationwide cohort study.

Cirrhosis in patients with chronic hepatitis C increases the risk of hepatocellular carcinoma (HCC), and surveillance with ultrasound (US) and alpha-fetoprotein (AFP) is recommended. This study aimed to estimate changes in the HCC incidence rate (IR) over time, HCC stage and prognosis, and AFP and US performed in patients with hepatitis C and cirrhosis. Eligible patients were identified in the Danish Database for Hepatitis B and C, and data from national health registries and patient charts were obtained. Tumour stage was based on Barcelona-Clinic Liver Cancer stage, TNM classification and size and number of lesions combined into stages 0-3. We included 1075 patients with hepatitis C and cirrhosis, free of HCC and liver transplant at baseline. During 4988 person years (PY), 115 HCC cases were diagnosed. The HCC incidence rate increased from 0.8/100 PY [CI95% 0.4-1.5] in 2002-2003 to 2.9/100 PY [2.4-3.4] in 2012-2013. One-year cumulative incidence of at least one AFP or US was 53% among all patients. The positive predictive value of an AFP ≥ 20 ng mL-1 was 17%. Twenty-three (21%) patients were diagnosed with early-stage HCC (stage 0/1) and 84 (79%) with late stage. Median survival after HCC for early-stage HCC disease was 30.1 months and 7.4 months for advanced HCC (stage 2/3). The incidence rate of HCC increased over time among patients with hepatitis C and cirrhosis in Denmark. Application of AFP and US was suboptimal, and most patients were diagnosed with advanced HCC with a poor prognosis.

Induction of lipogenesis in white fat during cold exposure in mice: link to lean phenotype.

This corrects the article DOI: 10.1038/ijo.2016.228.

Induction of lipogenesis in white fat during cold exposure in mice: link to lean phenotype.

BACKGROUND/OBJECTIVE: Futile substrate cycling based on lipolytic release of fatty acids (FA) from intracellular triacylglycerols (TAG) and their re-esterification (TAG/FA cycling), as well as de novo FA synthesis (de novo lipogenesis (DNL)), represent the core energy-consuming biochemical activities of white adipose tissue (WAT). We aimed to characterize their roles in cold-induced thermogenesis and energy homeostasis. METHODS: Male obesity-resistant A/J and obesity-prone C57BL/6J mice maintained at 30 °C were exposed to 6 °C for 2 or 7 days. In epididymal WAT (eWAT), TAG synthesis and DNL were determined using in vivo 2H incorporation from 2H2O into tissue TAG and nuclear magnetic resonance spectroscopy. Quantitative real-time-PCR and/or immunohistochemistry and western blotting were used to determine the expression of selected genes and proteins in WAT and liver. RESULTS: The mass of WAT depots declined during cold exposure (CE). Plasma levels of TAG and non-esterified FA were decreased by day 2 but tended to normalize by day 7 of CE. TAG synthesis (reflecting TAG/FA cycle activity) gradually increased during CE. DNL decreased by day 2 of CE but increased several fold over the control values by day 7. Expression of genes involved in lipolysis, glyceroneogenesis, FA re-esterification, FA oxidation and mitochondrial biogenesis in eWAT was induced during CE. All these changes were more pronounced in obesity-resistant A/J than in B6 mice and occurred in the absence of uncoupling protein 1 in eWAT. Expression of markers of glyceroneogenesis in eWAT correlated negatively with hepatic FA synthesis by day 7 in both strains. Leptin and fibroblast growth factor 21 plasma levels were differentially affected by CE in the two mouse strains. CONCLUSIONS: Our results indicate integrated involvement of (i) TAG/FA cycling and DNL in WAT, and (ii) hepatic very-low-density lipoprotein-TAG synthesis in the control of blood lipid levels and provision of FA fuels for thermogenesis in cold. They suggest that lipogenesis in WAT contributes to a lean phenotype.

Endobronchial ultrasound-guided transbronchial needle aspiration: performance of biomedical scientists on rapid on-site evaluation and preliminary diagnosis.

OBJECTIVES: Rapid on-site evaluation (ROSE) of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) followed by a subsequent preliminary adequacy assessment and a preliminary diagnosis, was performed at Aarhus University Hospital by biomedical scientists (BMS). The aim of this study was to evaluate the BMS accuracy of ROSE adequacy assessment, the preliminary adequacy assessment and the preliminary diagnosis as compared with the cytopathologist-rendered final adequacy assessment and final diagnosis. METHODS: The BMS-rendered assessments for 717 sites from 319 consecutive patients over a 4-month period were compared with the cytopathologist-rendered assessments. Comparisons of adequacy and preliminary diagnoses were based on inter-observer Cohen's Kappa coefficient with a 95% confidence interval (CI). RESULTS: Strong correlations between ROSE and final adequacy assessments [Kappa coefficient of 0.90 (CI: 0.85-0.96)] and between the preliminary and final adequacy assessments [Kappa coefficient of 0.93 (CI: 0.87-0.99)] were found. As for the correlation between the preliminary and final diagnoses, the Kappa coefficient was 0.99 (CI: 0.98-1). CONCLUSION: Both ROSE and preliminary adequacy assessments as well as preliminary diagnoses, all performed by BMS, were highly accurate when compared with the final assessment by the cytopathologist.

Electron vortices in photoionization by circularly polarized attosecond pulses.

Single ionization of He by two oppositely circularly polarized, time-delayed attosecond pulses is shown to produce photoelectron momentum distributions in the polarization plane having helical vortex structures sensitive to the time delay between the pulses, their relative phase, and their handedness. Results are obtained by both ab initio numerical solution of the two-electron time-dependent Schrödinger equation and by a lowest-order perturbation theory analysis. The energy, bandwidth, and temporal duration of attosecond pulses are ideal for observing these vortex patterns.

Weight cycling promotes fat gain and altered clock gene expression in adipose tissue in C57BL/6J mice.

Repeated attempts to lose weight by temporary dieting may result in weight cycling, eventually further gain of body fat, and possible metabolic adaptation. We tested this with a controlled experiment in C57BL/6J mice subjected to four weight cycles (WC), continuous hypercaloric feeding (HF), or low-fat feeding (LF). To search for genes involved in an adaptive mechanism to former weight cycling and avoid acute effects of the last cycle, the last hypercaloric feeding period was prolonged by an additional 2 wk before euthanization. Total energy intake was identical in WC and HF. However, compared with HF, the WC mice gained significantly more total body mass and fat mass and showed increased levels of circulating leptin and lipids in liver. Both the HF and WC groups showed increased adipocyte size and insulin resistance. Despite these effects, we also observed an interesting maintenance of circulating adiponectin and free fatty acid levels after WC, whereas changes in these parameters were observed in HF mice. Global gene expression was analyzed by microarrays. Weight-cycled mice were characterized by a downregulation of several clock genes (Dbp, Tef, Per1, Per2, Per3, and Nr1d2) in adipose tissues, which was confirmed by quantitative PCR. In 3T3-L1 cells, we found reduced expression of Dbp and Tef early in adipogenic differentiation, which was mediated via cAMP-dependent signaling. Our data suggest that clock genes in adipose tissue may play a role in metabolic adaptation to weight cycling.

Low-energy photoelectrons in strong-field ionization by laser pulses with large ellipticity.

The 3D photoelectron momentum distributions created by the strong-field ionization of argon atoms and naphthalene molecules with intense, large ellipticity (∼0.7) femtosecond laser pulses are studied. The experiment reveals the presence of low-energy electrons for randomly oriented naphthalene, but not for argon. Our theory shows that the induced dipole part of the cationic potential facilitates the creation of the low-energy electrons. We establish the conditions in terms of laser pulse parameters and molecular properties for which this type of low-energy electrons can be observed and point to applications thereof.

Nonlinear Dichroism in Back-to-Back Double Ionization of He by an Intense Elliptically Polarized Few-Cycle Extreme Ultraviolet Pulse.

Control of double ionization of He by means of the polarization and carrier-envelope phase (CEP) of an intense, few-cycle extreme ultraviolet (XUV) pulse is demonstrated numerically by solving the six-dimensional two-electron, time-dependent Schrödinger equation for He interacting with an elliptically polarized XUV pulse. Guided by perturbation theory (PT), we predict the existence of a nonlinear dichroic effect (∝I^{3/2}) that is sensitive to the CEP, ellipticity, peak intensity I, and temporal duration of the pulse. This dichroic effect (i.e., the difference of the two-electron angular distributions for opposite helicities of the ionizing XUV pulse) originates from interference of first- and second-order PT amplitudes, allowing one to probe and control S- and D-wave channels of the two-electron continuum. We show that the back-to-back in-plane geometry with unequal energy sharing is an ideal one for observing this dichroic effect that occurs only for an elliptically polarized, few-cycle attosecond pulse.

Electron-nuclear energy sharing in above-threshold multiphoton dissociative ionization of H2.

We report experimental observation of the energy sharing between electron and nuclei in above-threshold multiphoton dissociative ionization of H2 by strong laser fields. The absorbed photon energy is shared between the ejected electron and nuclei in a correlated fashion, resulting in multiple diagonal lines in their joint energy spectrum governed by the energy conservation of all fragment particles.

Estimating open population site occupancy from presence-absence data lacking the robust design.

Many animal monitoring studies seek to estimate the proportion of a study area occupied by a target population. The study area is divided into spatially distinct sites where the detected presence or absence of the population is recorded, and this is repeated in time for multiple seasons. However, when occupied sites are detected with probability p < 1, the lack of a detection does not imply lack of occupancy. MacKenzie et al. (2003, Ecology 84, 2200-2207) developed a multiseason model for estimating seasonal site occupancy (ψt ) while accounting for unknown p. Their model performs well when observations are collected according to the robust design, where multiple sampling occasions occur during each season; the repeated sampling aids in the estimation p. However, their model does not perform as well when the robust design is lacking. In this paper, we propose an alternative likelihood model that yields improved seasonal estimates of p and Ψt in the absence of the robust design. We construct the marginal likelihood of the observed data by conditioning on, and summing out, the latent number of occupied sites during each season. A simulation study shows that in cases without the robust design, the proposed model estimates p with less bias than the MacKenzie et al. model and hence improves the estimates of Ψt . We apply both models to a data set consisting of repeated presence-absence observations of American robins (Turdus migratorius) with yearly survey periods. The two models are compared to a third estimator available when the repeated counts (from the same study) are considered, with the proposed model yielding estimates of Ψt closest to estimates from the point count model.

Ultrasound evaluation of Cesarean scar after single- and double-layer uterotomy closure: a cohort study.

OBJECTIVES: To compare residual myometrial thickness (RMT) and size of the Cesarean scar defect after single- and double-layer uterotomy closure following first elective Cesarean section. METHODS: A retrospective cohort study was conducted in 149 women at least 6 months after an uncomplicated, elective Cesarean delivery. Two-dimensional transvaginal ultrasonographic measures of RMT, scar defect depth, width and length and myometrial thickness adjacent to the scar were compared in 68 women with single-layer and 81 women with double-layer closure delivered before and after, respectively, a change in the surgical procedure. Outcomes between the two groups were compared. RESULTS: Median RMT was 5.8 (interquartile range (IQR), 4.1-7.8) mm in women with double-layer closure vs 4.6 (IQR, 3.4-6.5) mm in those with single-layer closure (P = 0.04). Scar defect length was greater in women with single-layer closure (median, 6.8 (IQR, 4.4-8.5) mm) than in those with double-layer closure (median, 5.6 (IQR, 3.9-6.8) mm) (P = 0.01). Measurements of defect depth and width, and the proportion of scars with RMT < 2.3 mm were similar in the two groups. CONCLUSIONS: RMT was greater and defect length, but not defect depth and width, was smaller following double-layer compared with single-layer closure, which may indicate some limited benefit of double-layer closure following first elective Cesarean section.

Potential role of the porcine superoxide dismutase 1 (SOD1) gene in pig reproduction.

In a recent study we confirmed that QTL regions on pig chromosomes 11, 13, and 15 are associated with reproduction traits in the pig. Within these regions the genetic variation was largest on chromosome 13. The QTL region on this chromosome was therefore studied further to identify genes known to contribute to litter size. The superoxide dismutase (SOD1) gene localized at around 200 Mb in the pig (Sscrofa10) was the most obvious candidate gene. In the present study, we have cloned and sequenced the porcine SOD1 gene. The SOD1 amino acid sequence is highly conserved between human, mouse, rat, and pig. Expression studies by quantitative PCR showed differential levels of the SOD1 transcript in all tissues investigated. Sequence comparison between sows with high and low estimated breeding value (EBV) for litter size, revealed a total of eight single nucleotide polymorphisms (SNPs) in the noncoding sequence and no SNPs in the coding region. One of the intronic SNPs was genotyped in 248 sows with high and low EBV for litter size. Allele frequency differed significantly between the two group of sows indicating that polymorphism in the chromosome 13 locus has an impact on litter size. The sows homozygous for the A/A genotype conceive three piglets more compared to the A/T genotype, making this SNP a possible marker for litter size. However, this genotype was negatively correlated with other important traits under selection in the Danish pig production.