Self-Similar Structure and Experimental Signatures of Suprathermal Ion Distribution in Inertial Confinement Fusion Implosions.

The distribution function of suprathermal ions is found to be self-similar under conditions relevant to inertial confinement fusion hot spots. By utilizing this feature, interference between the hydrodynamic instabilities and kinetic effects is for the first time assessed quantitatively to find that the instabilities substantially aggravate the fusion reactivity reduction. The ion tail depletion is also shown to lower the experimentally inferred ion temperature, a novel kinetic effect that may explain the discrepancy between the exploding pusher experiments and rad-hydro simulations and contribute to the observation that temperature inferred from DD reaction products is lower than from DT at the National Ignition Facility.

Machine learning based unfolding of x-ray spectra from filter stack spectrometer data.

We demonstrate the application of neural networks to perform x-ray spectra unfolding from data collected by filter stack spectrometers. A filter stack spectrometer consists of a series of filter-detector pairs, where the detectors behind each filter measure the energy deposition through each layer as photo-stimulated luminescence (PSL). The network is trained on synthetic data, assuming x-rays of energies <1 MeV and of two different distribution functions (Maxwellian and Gaussian) and the corresponding measured PSL values obtained from five different filter stack spectrometer designs. Predicted unfolds of single distributions are near identical reproductions of the ground truth spectra, with differences in the values lower than 20% at the higher energy end in some cases. The neural network has also demonstrated robustness to experimental measurement errors of <5% and some capability of performing unfolds for linear combinations of the two distributions without previous training. The network can perform unfolds at rates >1 Hz, ideal for application to some high-repetition-rate systems.

Reduced-order model to approximate response matrices for filter stack spectrometers.

We present a reduced-order model to calculate response matrices rapidly for filter stack spectrometers (FSSs). The reduced-order model allows response matrices to be built modularly from a set of pre-computed photon and electron transport and scattering calculations through various filter and detector materials. While these modular response matrices are not appropriate for high-fidelity analysis of experimental data, they encode sufficient physics to be used as a forward model in design optimization studies of FSSs, particularly for machine learning approaches that require sampling and testing a large number of FSS designs.

Robust unfolding of MeV x-ray spectra from filter stack spectrometer data.

We present an inversion method capable of robustly unfolding MeV x-ray spectra from filter stack spectrometer (FSS) data without requiring an a priori specification of a spectral shape or arbitrary termination of the algorithm. Our inversion method is based upon the perturbative minimization (PM) algorithm, which has previously been shown to be capable of unfolding x-ray transmission data, albeit for a limited regime in which the x-ray mass attenuation coefficient of the filter material increases monotonically with x-ray energy. Our inversion method improves upon the PM algorithm through regular smoothing of the candidate spectrum and by adding stochasticity to the search. With these additions, the inversion method does not require a physics model for an initial guess, fitting, or user-selected termination of the search. Instead, the only assumption made by the inversion method is that the x-ray spectrum should be near a smooth curve. Testing with synthetic data shows that the inversion method can successfully recover the primary large-scale features of MeV x-ray spectra, including the number of x-rays in energy bins of several-MeV widths to within 10%. Fine-scale features, however, are more difficult to recover accurately. Examples of unfolding experimental FSS data obtained at the Texas Petawatt Laser Facility and the OMEGA EP laser facility are also presented.

Effects of ultraviolet germicidal irradiation and swirling motion on airborne Staphylococcus aureus, Pseudomonas aeruginosa and Legionella pneumophila under various relative humidities.

UNLABELLED: Staphylococcus aureus, Pseudomonas aeruginosa, and Legionella pneumophila have been detected in indoor air and linked to human infection. It is essential to adopt control methods to inactivate airborne pathogens. By passing bioaerosols horizontally into a UV device at two flow rates (Qs) and moving cells around a central UVC lamp at relative humidity (RH) of 12.7-16.7%, 58.7-59.6%, and 87.3-90%, the effects of swirling motion and 254-nm ultraviolet germicidal irradiation (UVGI) against bioaerosols were assessed under UV-off and UV-on settings, respectively. An inverse relationship between RH and UVGI effectiveness was observed for every test bioaerosol (r = -0.74 ∼ -0.81, P < 0.0001). Increased UV resistance with RH is likely associated with the hygroscopicity of bioaerosols, evident by increased aerodynamic diameters at high RH (P < 0.05). UVGI effectiveness was significantly increased with decreasing Q (P < 0.0001). Moreover, P. aeruginosa was the most susceptible to UVGI, while the greatest UV resistance occurred in L. pneumophila at low RH and S. aureus at medium and high RH (P < 0.05). Results of UV off show P. aeruginosa and L. pneumophila were more sensitive to air-swirling motion than S. aureus (P < 0.05). Overall, test bioaerosols were reduced by 1.7-4.9 and 0.2-1.7 log units because of the UVGI and swirling movement, respectively. PRACTICAL IMPLICATIONS: The studied UV device, with a combination of swirling motion and UVGI, is effective to inactivate airborne S. aureus, P. aeruginosa, and L. pneumophila. This study also explores the factors governing the UVGI and swirling motion against infectious bioaerosols. With understanding the environmental and operational parameters, the studied UV device has the potential to be installed indoors where people are simultaneously present, for example, hospital wards and nursing homes, to prevent the humans from acquiring infectious diseases.

High Fat Diet Mediated Alterations in Serum Sphingolipid Profiles in An Experimental Mouse Model Measured by Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry.

Non-alcoholic fatty liver disease (NAFLD) is associated with hepatic steatosis, a benign condition caused by accumulation of lipids in hepatocytes, which may progress to steatohepatitis and cirrhosis. Recent studies suggest that sphingolipids are involved in the development and severity of NAFLD. The goal of this study is to identify the circulating sphingolipid species that are altered by chronic high fat diet (HFD) feeding and correlate these abnormalities with hepatic sphingolipids. We utilized a previously established experimental model of NAFLD generated by HFD feeding of 8-week-old male mice for 16 weeks. Lipids were extracted from serum samples by Folch method and analyzed with matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) in the positive and negative ion modes. MALDI-TOF detected a total of 47 serum sphingolipids including sphingomyelins, sulfatides, ceramides, phosphosphingolipids, and glycosphingolipids within the mass range of 600-2000 Da. Principle component analysis demonstrated clear separation of hepatic sphingolipids from low fat diet (LFD) and HFD groups and partial overlap of serum sphingolipids with a variance of 53.5% and 15.1%, and 11.7% in PC1, PC2, and PC3, respectively. Chronic HFD feeding significantly increased expression of SM (40:0), SM(42:2), ST(42:2), Hex(6)-Cer (40:1), and Hex(4)-HexNAc (2)-Cer (34:1) in both serum and liver. In addition, HFD mediated percent changes in hepatic sphingolipids correlate linearly with the percent changes in serum sphingolipids as determined by Pearson correlation (P = 0.0002). Elevated levels of serum and hepatic sphingomyelins and glycoceramides are key factors mediating NAFLD development and may serve as peripheral markers of hepatic steatosis.

Efficiency enhancement of silicon solar cells using a nano-scale honeycomb broadband anti-reflection structure.

This experiment demonstrates the process for manufacturing a ZnO honeycomb sub-wavelength structure using nanosphere lithography technology exhibiting excellent anti-reflection properties from the UV to NIR wavelength regions. This honeycomb nanostructure, combined with commercially available crystalline Si solar cells, show substantially improved conversion efficiency from 15.6% to 16.6% using optimized honeycomb sizes and precursor concentrations of ZnO. The present work develops an unsophisticated and economical technique suitable for industrial applications in producing a uniform and low-reflective texture.

Vacuum laser acceleration of super-ponderomotive electrons using relativistic transparency injection.

Intense lasers can accelerate electrons to very high energy over a short distance. Such compact accelerators have several potential applications including fast ignition, high energy physics, and radiography. Among the various schemes of laser-based electron acceleration, vacuum laser acceleration has the merits of super-high acceleration gradient and great simplicity. Yet its realization has been difficult because injecting free electrons into the fast-oscillating laser field is not trivial. Here we demonstrate free-electron injection and subsequent vacuum laser acceleration of electrons up to 20 MeV using the relativistic transparency effect. When a high-contrast intense laser drives a thin solid foil, electrons from the dense opaque plasma are first accelerated to near-light speed by the standing laser wave in front of the solid foil and subsequently injected into the transmitted laser field as the opaque plasma becomes relativistically transparent. It is possible to further optimize the electron injection/acceleration by manipulating the laser polarization, incident angle, and temporal pulse shaping. Our result also sheds light on the fundamental relativistic transparency process, crucial for producing secondary particle and light sources.

Biomimetic nanostructured antireflection coating and its application on crystalline silicon solar cells.

In this report, we demonstrate the implementation of biomimetic nanostructured antireflection coatings with polymethyl methacrylate (PMMA) layer on the micro-textured surface of silicon crystalline solar cells. To reduce cost, the process combines colloidal lithography, cast molding method, and reversal nanoimprint lithography. The technique is simple, low cost, and does not cause damage to the thin and brittle conventional crystalline solar cells. The antireflection properties of this biomimetic nanostructure coating are considered as effective as those of a conventional single-layer SiNx thin film. The resultant structures alone could reduce the average reflectance of solar cell from 13.2% to 7.8% and enhance power conversion efficiency from 12.85% to 14.2%.

Association of primary cutaneous amyloidosis with atopic dermatitis: a nationwide population-based study in Taiwan.

BACKGROUND: Primary cutaneous amyloidosis (PCA) is a pruritic skin disorder most commonly seen in Southeast Asia and South America. Association of PCA with atopic dermatitis (AD) has been reported in the literature. However, no large-scale epidemiological study of PCA and its associations with other diseases has been conducted so far. OBJECTIVES: We aimed to provide overall demographic data and comorbidities of patients with PCA based on a nationwide database in Taiwan. METHODS: Cases of PCA were collected from records of National Health Insurance claims from 2000 to 2007. We analysed patients' gender, age when the diagnosis was first made, and the overall 8-year prevalence. We also investigated comorbidities. RESULTS: The overall 8-year prevalence of PCA was 7·87 per 10,000 persons. Although there was no significant gender difference in the prevalence of PCA, men and women showed a different peak age (men, 71-80 years; women, 41-50 years) and a different age distribution at diagnosis. The mean age at diagnosis of PCA was significantly younger for women than for men. Men sought medical assistance for PCA more frequently than women. There was a higher disease activity from May to September than during other months. PCA was strongly associated with AD (odds ratio 7·18). Patients with PCA had a higher comorbidity of hyperlipidaemia and diabetes mellitus. CONCLUSIONS: This is the first nationwide population-based epidemiological study of PCA. We demonstrate that PCA can be associated with other disorders, especially AD.

Prospective study of health-related quality of life after Roux-en-Y bypass surgery for morbid obesity.

BACKGROUND: The aim of this study was to evaluate the effects of Roux-en-Y gastric bypass for morbid obesity on health-related quality of life (QOL) during the first year of follow-up. METHODS: The World Health Organization Quality of Life-Brief (WHOQOL-BREF) was administered 1 month before operation, and at 1, 3, 6 and 12 months after surgery. Body mass index, co-morbidities and operation-related complications were measured at these times. A mixed-effect model was constructed to analyse repeated measurements and determine the relationships between body mass index, WHOQOL-BREF scores and other variables. RESULTS: A total of 102 patients were enrolled. The mixed-effect model showed that the physical, psychological and social domains improved after bariatric surgery, with simultaneous reduction in weight and improvement in co-morbidities. There was a dip in scores in physical and psychological domains 3-6 months after surgery, significantly related to complications. All patients gradually improved between 6 and 12 months after surgery, reaching levels similar to those of healthy subjects. CONCLUSION: Health-related QOL improved dramatically after bariatric surgery, dipped slightly between 3 and 6 months, and improved again up to the end of the first year.

Risk factors for extra-pulmonary tuberculosis compared to pulmonary tuberculosis.

BACKGROUND: Tuberculosis (TB) continues to be a major global health problem. Extra-pulmonary TB (EPTB) manifests with protean symptoms, and establishing a diagnosis is more difficult than pulmonary TB (PTB). SETTING: A university-affiliated hospital in southern Taiwan. OBJECTIVE: To analyse the risk factors for EPTB compared with PTB. DESIGN: This retrospective study compared patients with EPTB and PTB in southern Taiwan by analysing their demographic data and clinical underlying diseases. Risk factors for EPTB were further analysed. RESULTS: A total of 766 TB patients were enrolled in this study, with 102 (13.3%) EPTB and 664 (86.7%) PTB cases. Of the 766 patients, 3% of PTB patients had EPTB, while 19.6% of EPTB patients also had PTB. The most frequently involved EPTB site was the bone and joints (24.5%). The incidence of EPTB vs. PTB decreased significantly for each decade increase in patient age. Multivariate logistic regression analysis showed that being female, not being diabetic, having end-stage renal disease and not smoking were independent risk factors for EPTB. CONCLUSION: This study defines the risk factors for EPTB compared with PTB. Awareness of these factors is essential for physicians to have a high index of suspicion for accurate and timely diagnosis.

An introductory study using impedance spectroscopy technique with polarizable microelectrode for amino acids characterization.

Portable, low power, yet ultra-sensitive life detection instrumentations are vital to future astrobiology flight programs at NASA. In this study, initial attempts to characterize amino acids in an aqueous environment by electrochemical impedance spectroscopy (EIS) using polarizable (blocking) electrodes in order to establish a means of detection via their electrical properties. Seven amino acids were chosen due to their scientific importance in demonstrating sensitivity levels in the range of part per billion concentration. Albeit more challenging in real systems of analyst mixtures, we found individual amino acids in aqueous environment do exhibit some degree of chemical and physical uniqueness to warrant characterization by EIS. The polar amino acids (Asp, Glu, and His) exhibited higher electrochemical activity than the non-polar amino acids (Ala, Gly, Val, and Leu). The non-polar amino acids (Gly and Ala) also exhibited unique electrical properties which appeared to be more dependent on physical characteristics such as molecular weight and structure. At concentrations above 1 mM where the amino acids play a more dominant transport role within the water, the conductivity was found to be more sensitive to concentrations. At lower concentrations <1 mM, however, the polar amino acid solution conductivity remained constant, suggesting poor chemical activity with water. As revealed by equivalent circuit modeling, the relaxation times showed a 1-2 order of magnitude difference between polar and non-polar amino acids. The pseudo-capacitance from EIS measurements on sample mixtures containing salt water and individual amino acids revealed the possibility for improvement in amino acid selectivity using gold nanoporous surface enhanced electrodes. This work establishes important methodologies for characterizing amino acids using EIS combined with microscale electrodes, supporting the case for instrumentation development for life detection and origin of life programs.

Clinical outcomes associated with anti-coagulant therapy in patients with renal infarction.

Background: Patients with renal infarction are vulnerable to thromboembolic complications with poor outcomes. There is limited report concerning the effect of anti-coagulant therapy in this population. Aim: To assess the impact of anti-coagulant therapy on outcomes in patients with renal infarction. Design: A retrospective cohort study of 101 renal infarction patients was conducted. Methods: The association between anti-coagulant therapy, all-cause mortality, thromboembolic complications and renal outcome was evaluated. Demographic data and comorbidities were collected for analysis. Anti-coagulant therapy was treated as a time-dependent variable. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multi-variate Cox proportional hazards models. Results: Fifty-seven (56.4%) patients with renal infarction received anti-coagulant therapy during the study period. The all-cause mortality rate was 7.56 per 100 patient-years. Age (HR 1.05, 95% CI 1.02-1.08) was a risk factor for all-cause mortality and anti-coagulant therapy was associated with a 92% improved survival (HR 0.08, 95% CI 0.02-0.34). Twelve (11.9%) thromboembolic events occurred following renal infarction. Current smoking (HR 10.37, 95% CI 1.60-67.43) had an adverse effect and anti-coagulant therapy (HR 0.14, 95% CI 0.03-0.73) had a significant protective impact on thromboembolic complications. There was no significant association between anti-coagulant therapy and long-term renal outcome in renal infarction patients including the monthly change in the estimated glomerular filtration rate (eGFR), the incidence of eGFR reduction of more than 50% and end-stage renal disease. Conclusion: Anti-coagulant therapy in patients with renal infarction was associated with better survival and reduced thromboembolic complications.

Central venous catheter-related Stenotrophomonas maltophilia bacteraemia and associated relapsing bacteraemia in haematology and oncology patients.

This retrospective study investigated the clinical significance and impact of Stenotrophomonas maltophilia bacteraemia in 49 haematology and oncology patients at a tertiary referral medical centre in Taipei between July 1999 and December 2003. Sixteen patients had 24 episodes of central venous catheter (CVC)-related bacteraemia, with the main clinical characteristics being a nosocomial bacteraemia (100%), preceding antibiotic therapy (94%), bacteraemia developed in a general ward (87%), immunosuppressive therapy (75%), in-situ CVC-related bacteraemia (75%), and neutropenia (63%). Only four (25%) patients had inflammatory signs at the CVC site following diagnosis of bacteraemia. Five patients had recurrent bacteraemia, with risk-factors being long-lasting (>10 days) neutropenia (p 0.036) and an initial failure to remove the CVC (p 0.001). These cases did not involve re-infection, as the same S. maltophilia strain was identified following random amplified polymorphic DNA (RAPD) analysis of the initial and subsequent isolates. However, relapses could occur after long latency periods (maximum, 200 days). Most patients were cured after removal of the CVC, even without appropriate antibiotic treatment. Physicians should have a high index of suspicion for CVC-related bacteraemia with haematology and oncology patients with CVCs and S. maltophilia bacteraemia. In addition to appropriate antibiotic therapy, removal of the CVC is crucial for successful treatment of CVC-related S. maltophilia bacteraemia and prevention of relapses.

Endogenous substrates for cyclic AMP-dependent and calcium-dependent protein phosphorylation in rabbit peritoneal neutrophils.

As in other cells, cAMP-dependent (protein kinase A) and calcium-dependent protein kinases are present in the rabbit peritoneal neutrophil. The major substrates for protein kinase A in the cytosol of rabbit peritoneal neutrophil is a 43 kDa protein which appears to be actin (pI 5.7). The other substrates for protein kinase A in the cytosol are very acidic proteins with molecular weights of 135000 (pI 4.6) and 130 000 (pI 4.8). Two classes of calcium-dependent protein kinases are present in the rabbit peritoneal neutrophil: one is calcium, calmodulin-dependent, the other is calcium, phosphatidylserine-dependent. Phosphatidylserine appears to be much more effective than calmodulin in stimulating calcium-dependent protein kinase activity. The phospholipid-sensitive, calcium-dependent protein kinase (protein kinase C), present only in the cytosol fraction, exhibits much higher activity than the cAMP-dependent protein kinase from the same source. At least four substrates (Mr 130 000 (pI 4.6) 43 000 (pI 4.8), 41 000 (pI 6.3) and 34 000) of the protein kinase C in the cytosol were identified. Trifluoperazine, a compound which inhibits the degranulation, aggregation and stimulated oxygen consumption of rabbit peritoneal neutrophils. (Alobaidi, T., Naccache, P.H. and Sha'afi, R.I. (1981) Biochim. Biophys. Acta 675, 316-321), also inhibits the activity of protein kinase C. The possible role of cAMP-dependent and calcium-dependent phosphorylation system in neutrophil function is discussed.

cAMP, not Ca2+/calmodulin, regulates the phosphorylation of acetylcholine receptor in Torpedo californica electroplax.

The regulation of the phosphorylation of the acetylcholine receptor in electroplax membranes from Torpedo californica and of purified acetylcholine receptor was investigated. The phosphorylation of the membrane-bound acetylcholine receptor was not stimulated by Ca2+/calmodulin, nor was it inhibited by EGTA, but it was stimulated by the catalytic subunit of cAMP-dependent protein kinase, and was blocked by the protein inhibitor of cAMP-dependent protein kinase. Purified acetylcholine receptor was not phosphorylated by Ca2+/calmodulin-dependent protein kinase activity in electroplax membranes, nor by partially purified Ca2+/calmodulin-dependent protein kinases from soluble or particulate fractions from the electroplax. Of the four acetylcholine receptor subunits, termed alpha, beta, gamma and delta, only the gamma- and delta-subunits were phosphorylated by the cAMP-dependent protein kinase (+ cAMP), or by its purified catalytic subunits.

Roles of PI3K in neutrophil function.

Neutrophils are terminally differentiated cells that play a vital role in host defense. It has recently become evident that phospholipid regulation plays an import role in many neutrophil functions. We review the regulation of neutrophil functions such as chemotaxis, superoxide production, and phagocytosis by phosphatidylinositol-3,4,5-trisphosphate (PIP3), which is generated in neutrophils by PI3K(gamma). Several lines of evidence are presented demonstrating the importance of this kinase in regulating chemotaxis, in particular the directionality of chemotactic migration. Evidence suggesting that this kinase is important for phagocytosis, especially during engulfment and the internalization of large particles, is also reviewed. Finally, it is suggested that PI3K is important for superoxide production and neutrophil priming. The common link between these seemingly diverse functions is that PI3K(gamma), via its phospholipid products, appears to be providing spatial-temporal cues for the binding of actin-organizing proteins.

Partial purification and characterization of formylpeptide receptor from rabbit peritoneal neutrophils.

The formylpeptide receptors from 40 X 10(9) cells of rabbit peritoneal neutrophils have been solubilized with digitonin and partially purified by sequential fMet-Leu-Phe-Sepharose affinity and wheat-germ agglutinin agarose affinity chromatography. The binding activity of the receptor toward [3H]fNle-Leu-Phe is difficult to restore fully after elution of the receptor from the fMet-Leu-Phe-Sepharose affinity column. A 2,000-fold purification of the receptor from the particulate fraction is achieved with a yield of about 23%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Coomasie blue or silver staining of purified receptor preparations reveal a major polypeptide with an apparent Mr (50,000-70,000) and isoelectric points (pl 6.0-6.5) that coincides with the polypeptide labeled by the specific affinity cross-linking probe for formylpeptide receptor (125I-hexapeptide). The receptor has an apparent Stokes radius of 47 A when analyzed by gel filtration chromatography. Using synthetic peptides poly(Glu-Tyr) (4:1) as the substrates, a membrane-associated tyrosine protein kinase activity is detected and can be solubilized by digitonin. Subsequent analysis indicates that the tyrosine kinase activity is not derived from the receptor.

Partial characterization of protein kinase C and inhibitor activity of protein kinase C in rabbit peritoneal neutrophils.

Analysis of the cytosol fraction containing protein kinase C activity from rabbit peritoneal neutrophils by DEAE-cellulose chromatography identified protein kinase C activity in the fractions eluted with 0.08 M-0.14 M NaCl and protein kinase C inhibitor activity in the fraction eluted with 0.16 M-0.5 M NaCl. On further analysis by Sephadex G-150 gel filtration, one peak of protein kinase C and two peaks of inhibitor activity were identified. The peak of protein kinase C and two peaks of inhibitor activity were identified. The peak of protein kinase C activity eluted at Ve/Vo 1.6 corresponding to a Stokes radius of 35 A. The first peak of the inhibitor activity eluted at Ve/Vo 1.4 and the second peak of the inhibitor activity eluted at Ve/Vo 2.5. The peak of phosphoprotein phosphatase activity does not coincide with the peaks of inhibitor activity of protein kinase C.