Stabilized Radiation Pressure Acceleration and Neutron Generation in Ultrathin Deuterated Foils.

Premature relativistic transparency of ultrathin, laser-irradiated targets is recognized as an obstacle to achieving a stable radiation pressure acceleration in the "light sail" (LS) mode. Experimental data, corroborated by 2D PIC simulations, show that a few-nm thick overcoat surface layer of high Z material significantly improves ion bunching at high energies during the acceleration. This is diagnosed by simultaneous ion and neutron spectroscopy following irradiation of deuterated plastic targets. In particular, copious and directional neutron production (significantly larger than for other in-target schemes) arises, under optimal parameters, as a signature of plasma layer integrity during the acceleration.

Effect of COVID-19 driven lockdown on social contact pattern in Puducherry, India: A longitudinal study.

Objective: This study was undertaken to assess the change in social contact and transmission dynamics among adults in the Puducherry district during the different phases of country-wide lockdown. Methods: Adults aged 18-69 years in Puducherry were assessed for frequency and duration of contacts in the following time points: prior to lockdown (March 2020), during lockdown, immediate post-lockdown (April, June 2020), and seven months post-lockdown (February 2021). Adjusted incidence rate ratios (aIRR) were obtained using a generalized estimating equation. We also assessed the exponential trajectory of the time-varying reproduction number (Rt) during and after lockdown. Results: Compared to pre-lockdown phase, frequency of social contacts during 1st week, 4th week of lockdown, and immediate post-lockdown were reduced by 89% (aIRR = 0.11; 95% CI: 0.09-0.13), 40% (aIRR = 0.60; 95% CI: 0.52-0.69) and 91% (aIRR = 0.09; 95% CI: 0.07-0.10) respectively. However, the decline was not statistically significant at seven months post-lockdown. Correspondingly, we observed an initial spike in Rt during the lockdown phase followed by a gradual decline during the immediate post-lockdown phase. However, seven months post-lockdown, Rt has increased again. Conclusion: The study showed high compliance to the lockdown measures in Puducherry during the lockdown and immediate post-lockdown periods. However, as the lockdown measures were relaxed, the contact rate returned to the pre-lockdown state.

Is the rural population of Puducherry district healthy in terms of the burden of non-communicable diseases? Findings from a cross-sectional analytical survey.

INTRODUCTION: Epidemiological transition remains a key contributor to the rising prevalence of non-communicable diseases (NCDs) across developing nations. Population-specific NCD risk factors estimates derived using World Health Organization (WHO) 'STEP-wise approach' are crucial for devising evidence-based public health interventions to combat NCDs. OBJECTIVE: To estimate the prevalence of behavioral and biological risk factors for NCDs among the rural adult population of Puducherry district in India. METHODOLOGY: STEPS survey was conducted by following all three steps (behavioral, physical measurements and biochemical risk factors) of NCD risk factor assessment. A total of 790 participants were selected from 50 villages through multistage cluster sampling method. STEPS instrument was used to assess behavioral risk factors, physical measurements and biochemical (fasting blood glucose and total cholesterol) risk factors. RESULTS: Tobacco use and alcohol consumption were present among 11.3% (95% Confidence Interval (CI): 9-13.6%) and 19.2% (95% CI: 16.5-22.4%) of the population, respectively. Low physical activity, inadequate intake of fruits and vegetables, overweight and obesity were observed among 29.3% (95% CI: 26.2-32.7%), 89.8% (95% CI: 87.6-92%), 15.6% (95% CI: 13.1-18.3%) and 38.9% (95% CI: 35.4-42.2%), respectively. About 28.2% (95% CI: 25.2-31.6%) had hypertension and 24.4% (95% CI: 20-29%) had diabetes mellitus. Abdominal obesity was twice highly prevalent among women. Tobacco and alcohol use were more common among men, whereas low physical activity, obesity and hypercholesterolemia were higher among women. CONCLUSION: Public health interventions to promote healthy lifestyle need to be initiated especially to increase physical activity, intake for fruits and vegetables, and quitting of tobacco and alcohol consumption in the rural population of Puducherry.

Selective Ion Acceleration by Intense Radiation Pressure.

We report on the selective acceleration of carbon ions during the interaction of ultrashort, circularly polarized and contrast-enhanced laser pulses, at a peak intensity of 5.5×10^{20} W/cm^{2}, with ultrathin carbon foils. Under optimized conditions, energies per nucleon of the bulk carbon ions reached significantly higher values than the energies of contaminant protons (33 MeV/nucleon vs 18 MeV), unlike what is typically observed in laser-foil acceleration experiments. Experimental data, and supporting simulations, emphasize different dominant acceleration mechanisms for the two ion species and highlight an (intensity dependent) optimum thickness for radiation pressure acceleration; it is suggested that the preceding laser energy reaching the target before the main pulse arrives plays a key role in a preferential acceleration of the heavier ion species.

Significance of cytosolic cathepsin D in Alzheimer's disease pathology: Protective cellular effects of PLGA nanoparticles against ß-amyloid-toxicity.

BACKGROUND: Evidence suggests that amyloid ß (Aß) peptides play an important role in the degeneration of neurons during the development of Alzheimer's disease (AD), the prevalent cause of dementia affecting the elderly. The endosomal-lysosomal system, which acts as a major site for Aß metabolism, has been shown to exhibit abnormalities in vulnerable neurons of the AD brain, reflected by enhanced levels/expression of lysosomal enzymes including cathepsin D (CatD). At present, the implication of CatD in selective neuronal vulnerability in AD pathology remains unclear. METHODS: We evaluated the role of CatD in the degeneration of neurons in Aß-treated cultures, transgenic AD mouse model (that is 5xFAD) and post mortem AD brain samples. RESULTS: Our results showed that Aß1-42 -induced toxicity in cortical cultured neurons is associated with impaired lysosomal integrity, enhanced levels of carbonylated proteins and tau phosphorylation. The cellular and cytosolic levels/activity of CatD are also elevated in cultured neurons following exposure to Aß peptide. Additionally, we observed that CatD cellular and subcellular levels/activity are increased in the affected cortex, but not in the unaffected cerebellum, of 5xFAD mice and post mortem AD brains. Interestingly, treatment of cultured neurons with nanoparticles PLGA, which targets lysosomal system, attenuated Aß toxicity by reducing the levels of carbonylated proteins, tau phosphorylation and the level/distribution/activity of CatD. CONCLUSION: Our study reveals that increased cytosolic level/activity of CatD play an important role in determining neuronal vulnerability in AD. Additionally, native PLGA can protect neurons against Aß toxicity by restoring lysosomal membrane integrity, thus signifying its implication in attenuating AD.

Willingness to quit tobacco and its correlates among Indian tobacco users-Findings from the Global Adult Tobacco Survey India, 2016-17.

BACKGROUND: Willingness to quit in a tobacco user forms the basis for future quit attempts and quitting successfully. OBJECTIVE: To determine the prevalence and correlates of willingness to quit among tobacco users in India using the Global Adult Tobacco Survey (GATS), India, 2016-2017. METHODS: GATS, 2016-17 was a multistage geographically clustered sample survey done among 74,037 individuals aged 15 years and above across all the states and two of the Union Territories of India. Data of all those reported using any form of tobacco were studied for past attempts to quit tobacco, advised to quit by a health care provider, and exposure to anti-tobacco messages delivered through various media and the correlation of these with the willingness to quit using multivariate analysis. RESULTS: Of the 21,085 current tobacco users in the survey, 11,679 (52.2%), were willing to quit all forms of tobacco. Multivariate analysis showed that those in younger age groups (OR: 1.39 [1.23-1.56]), higher education levels (OR 1.15 [1.05-1.18]), time of first tobacco use in the day being more than 60 min after waking up in the morning (OR 1.11 [1.03-1.2]), history of attempts to quit in the past 12 months (OR 1.78 [1.69-1.87]), those advised to quit by health care provider in the past 12 months (OR 1.11 [1.06-1.17]), those using single form of tobacco (OR 1.1 [1.05-1.17]), those exposed to anti-tobacco messages in newspapers/magazines (OR 1.1 [1.05-1.17]), and cinemas (1.14 [1.08-1.20]) were more willing to quit compared to their counterparts. CONCLUSION: Enhanced publicizing of anti-tobacco messages through the currently employed media, and ensuring that doctors give a brief advice to quit during any contact with a tobacco user could improve the willingness to quit and the consequent quit rate, especially among those tobacco users who are in younger age groups and who have attempted to quit earlier.

Effect of metformin on thyroid function tests in patients with subclinical hypothyroidism: an open-label randomised controlled trial.

PURPOSE: Though most of the observational studies have shown that metformin can reduce serum thyroid stimulating hormone (TSH) level in patients of hypothyroidism with diabetes or polycystic ovarian disease, randomised controlled trials are sparse. The primary objective of this study was to evaluate the effect of metformin on thyroid function tests (TSH, free T4, and free T3) in patients with subclinical hypothyroidism (SCH). METHODOLOGY: In this open label, parallel arm, randomised controlled trial, 60 patients of SCH (TSH 5.5-10 mIU/L) were randomised to either metformin group (1500 mg/day) or control group. RESULT: A total of 46 patients (23 in each group) completed the study and no significant difference in serum TSH, free T4 or free T3 was found in between the 2 groups. Neither there was any significant change in serum TSH, free T4 or free T3 (pre and post 6 months) within the individual groups. However, the rate of normalisation of serum TSH in patients with negative thyroid antibody was significantly higher than patients with positive thyroid antibody (71.4% vs. 18.8%; P = 0.026) in metformin group in post hoc analysis. Fasting plasma glucose, serum high-density lipoprotein and indices of insulin sensitivity significantly improved in metformin group. Four patients (17%) had mild gastrointestinal adverse effects in the metformin group. CONCLUSION: We did not find any significant change in thyroid function test in patients with SCH with metformin therapy.

Unconditional probability of dying and age-specific mortality rate because of major non-communicable diseases in India: Time trends from 2001 to 2013.

Background: Unconditional probability of dying because of four major non-communicable diseases (NCDs) between 30 and 70 years of age is the selected global indicator to measure the impact of NCD prevention and control programs. Objective: To calculate the unconditional probability of dying and age-specific mortality rate because of major NCDs in India from 2001 to 2013. Methods: This study used multiple data sources that are available in the public domain-Census 2001 and 2011, Sample Registration System, causes of death reports in 2001-03, 2004-06, and 2010-13. Unconditional probability of dying between ages 30 and 70 years during 2001, 2006, and 2013 was calculated by the formula suggested by the World Health Organization. Line graphs were used to depict time trends in age-specific mortality rates over the years in four major NCDs (cardiovascular diseases, cancer, diabetes, and chronic respiratory diseases). Results: The age-specific mortality rate because of four NCDs showed a decrease of 51 deaths per 100,000 population from 2001 to 2013. Of the four NCDs, age-specific mortality rate was highest in cardiovascular diseases (238.2/100,000 population) and least in diabetes mellitus (21.9/100,000 population); it was 76.3 and 58.2/100,000 population for cancer and chronic respiratory diseases, respectively. The probability of dying was very less and was almost the same from 30 to 44 years of life and increased steeply after that till 70 years of life; and it was more in males (24%) compared with females (17.4%). Conclusion: Although India has shown a decreasing trend in premature mortality because of NCDs in the past decade, the rate of decrease is not on par to achieve the global "25 × 25" target.

Numerical analysis of an enhanced cooling rate cryopreservation process in a biological tissue.

Cryopreservation is the method of preservation of biological tissues for future references without causing significant damages to their physical and functional properties. This can be done by exposing them to very low cryogenic temperature that involves a greater heat removal rate. A two dimensional numerical model is developed to study the temperature distribution, cooling rate attained and movement of the freezing front during the cryopreservation process. The Pennes Bio-heat model is used for current study. The Finite Volume Method is employed for discretization of the governing differential equations while the Tri-Diagonal Matrix Algorithm is used to solve the discretized algebraic equations to find temperature distribution inside the domain. The Enthalpy-Porosity method is used to track the solid-liquid interfaces during the freezing process. The current model is first validated with the result of the existing literature. In the present work, freezing of tissue is done from one and two sides in two separate cases and the resulting temperature distribution inside the tissue and cooling rate in the two cases are compared. It is found that the freezing rate of tissue is enhanced about two times when it is freezed from two sides as compared to freezing from single side. Further, it is observed that a lower value of blood perfusion rate causes a lower value of the final temperature of the tissue after freezing. Thus, it can be concluded that the tissue with high blood perfusion rate is to be freezed in a lower cooling medium temperature. In the present condition, metabolic heat generation plays no significant role in the temperature distribution inside the healthy tissue.

Dual Ion Species Plasma Expansion from Isotopically Layered Cryogenic Targets.

A dual ion species plasma expansion scheme from a novel target structure is introduced, in which a nanometer-thick layer of pure deuterium exists as a buffer species at the target-vacuum interface of a hydrogen plasma. Modeling shows that by controlling the deuterium layer thickness, a composite H^{+}/D^{+} ion beam can be produced by target normal sheath acceleration (TNSA), with an adjustable ratio of ion densities, as high energy proton acceleration is suppressed by the acceleration of a spectrally peaked deuteron beam. Particle in cell modeling shows that a (4.3±0.7) MeV per nucleon deuteron beam is accelerated, in a directional cone of half angle 9°. Experimentally, this was investigated using state of the art cryogenic targetry and a spectrally peaked deuteron beam of (3.4±0.7) MeV per nucleon was measured in a cone of half angle 7°-9°, while maintaining a significant TNSA proton component.

Effect of cabergoline monotherapy in Cushing's disease: an individual participant data meta-analysis.

CONTEXT: The primary treatment of choice for Cushing's disease (CD) is the removal of the pituitary adenoma by transsphenoidal surgery (TSS). The surgical failure is seen in up to 75% of cases depending on the experience of the surgeon in different studies. Medical therapy is one of the options for the treatment of recurrent or persistent CD. METHODOLOGY: The primary outcome of this meta-analysis was to find the proportion of patients achieving normalisation of 24-h urinary free cortisol (remission of CD) following cabergoline monotherapy. Literature search was conducted in January 2018 in PubMed/MEDLINE database from its date of inception to 31st December 2017. The search strategy used was "[(cushing) OR Cushing's] AND cabergoline". Individual participant data were extracted from the included studies and risk of bias was analysed by review checklist proposed by MOOSE. RESULTS: The individual participant data of 124 patients from six observational studies were included in this meta-analysis. 92 patients (74.2%) had past pituitary surgery. The proportion of patients achieving remission of Cushing's disease (CD) with cabergoline monotherapy was 34% (95% confidence interval 0.26­0.43; P = 0.001) [corrected]. The previous surgery [odds ratio (OR) 28.4], duration of cabergoline monotherapy (OR 1.31) and maximum cabergoline dose (OR 0.19) were predictors for remission of CD. Mild and severe side effects were reported in 37.3% and 5.6% of patients, respectively, during cabergoline monotherapy. CONCLUSIONS: This meta-analysis shows that cabergoline monotherapy is a reasonable alternative for subjects with persistent or recurrent CD after TSS. It can also be used in CD patients either as a bridge therapy while waiting for surgery or in those unwilling for surgery or have contraindication to it.

Epidemiology of mental disability using Indian Disability Evaluation Assessment Scale among general population in an urban area of Puducherry, India.

BACKGROUND: There is paucity of information on epidemiology of mental disability in India. OBJECTIVE: The objective of this study was to assess mental disability, and to study the association between sociodemographic and comorbid chronic conditions with mental disability. MATERIALS AND METHODS: This community-based cross-sectional study was conducted among ≥5 years age group in an urban area attached to a Tertiary Care Medical Institute in Puducherry, India. Mental disability was assessed using Indian Disability Evaluation and Assessment Scale. Chronic morbid conditions and other associated factors were collected using pretested questionnaire. STATISTICAL ANALYSIS: Univariate and multiple logistic regression analysis. RESULTS: About 2537 subjects were covered with a response rate of 94.1%. Overall, the prevalence of mental disability was found to be 7.1% (181/2537). Among them, majority had mild mental disability (151, 83.4%), followed by moderate (21, 11.6%), severe (8, 4.4%), and profound (1, 0.6%) mental disability. Univariate analysis showed that age group status, marital status, education level, occupation, family type, religion, hypertension, joint pain, backache, current smoking, current alcohol use, and conflicts were associated with mental disability (P < 0.05). Multiple logistic regression analysis showed that male gender (adjusted odds ratio [AOR] =2.064), widowed status (AOR = 27.022), separated/divorced status (AOR = 16.674), currently married status (AOR = 18.487), being illiterate (AOR = 4.352), having 1st-10th standard education (AOR = 2.531), being in an unskilled (AOR = 0.287) or semiskilled/skilled occupation (AOR = 0.025), belonging to a nuclear family (AOR = 1.816), and absence of family conflicts (AOR = 0.259) were significantly associated with mental disability compared to their counterparts. CONCLUSION: Mental disability is more common in this area. Males, lesser education level, skilled or unskilled occupation, nuclear family, and conflicts were associated with mental disability after adjusting other variables. Multicentric cross-sectional analytical studies will explore the mental disability burden and its associated factors at regional or country level.

Infant feeding patterns and eczema in children in the first 6 years of life.

BACKGROUND: Modes of infant feeding such as direct and indirect breastfeeding, and formula feeding, and their combinations may play a role in child health. OBJECTIVE: The aim was to investigate which feeding patterns in the first 6 months pose risks of eczema/skin allergy in children up to 6 years compared to direct breastfeeding for at least 3 months. METHODS: The Infant Feeding Practices Study II in the United States and its 6-year follow-up provided data on feeding modes in infancy and doctor's diagnosed eczema/skin allergy in the first 6 years of life (1387 infants), based on parental reports. Different feeding patterns were identified. Log-linear models were used to estimate prevalence ratios (PRs) of feeding patterns for doctor's diagnosed eczema/skin allergy in the first 6 years of life, adjusting for confounders. RESULTS: Compared to "direct breastfeeding for at least 3 months" (DBF3m), the combination of "direct feeding at the breast (DBF), pumping and feeding breast milk (BM), and formula (FF) in the first months" (DBF/BM/FF) showed a statistically significant higher risk of eczema/skin allergy in the first 6 years of life (PR = 1.46), adjusting for confounders. DBF combined with BM for the first 3 months followed by mixed feeding also had an increased risk (PR = 1.26), although not statistically significant. Formula feeding introduced since birth had no effect on eczema. Among the confounders, paternal eczema and race/ethnicity (Hispanic vs White) were associated with a higher risk of eczema/skin allergy. CONCLUSIONS & CLINICAL RELEVANCE: Mixed infant feeding may carry a higher risk of eczema/skin allergy compared to direct feeding at the breast. The recent epidemic of pumping and feeding in the United States and the use of mixed infant feeding modes requires additional studies to provide appropriate and renewed assessments of the risks of feeding modes for the future development of allergies.

Polarization Dependence of Bulk Ion Acceleration from Ultrathin Foils Irradiated by High-Intensity Ultrashort Laser Pulses.

The acceleration of ions from ultrathin (10-100 nm) carbon foils has been investigated using intense (∼6×10^{20} W cm^{-2}) ultrashort (45 fs) laser pulses, highlighting a strong dependence of the ion beam parameters on the laser polarization, with circularly polarized (CP) pulses producing the highest energies for both protons and carbons (25-30 MeV/nucleon); in particular, carbon ion energies obtained employing CP pulses were significantly higher (∼2.5 times) than for irradiations employing linearly polarized pulses. Particle-in-cell simulations indicate that radiation pressure acceleration becomes the dominant mechanism for the thinnest targets and CP pulses.

Achieving Stable Radiation Pressure Acceleration of Heavy Ions via Successive Electron Replenishment from Ionization of a High-Z Material Coating.

A method to achieve stable radiation pressure acceleration (RPA) of heavy ions from laser-irradiated ultrathin foils is proposed, where a high-Z material coating in front is used. The coated high-Z material, acting as a moving electron repository, continuously replenishes the accelerating heavy ion foil with comoving electrons in the light-sail acceleration stage due to its successive ionization under laser fields with Gaussian temporal profile. As a result, the detrimental effects such as foil deformation and electron loss induced by the Rayleigh-Taylor-like and other instabilities in RPA are significantly offset and suppressed so that stable acceleration of heavy ions are maintained. Particle-in-cell simulations show that a monoenergetic Al^{13+} beam with peak energy 3.8 GeV and particle number 10^{10} (charge >20 nC) can be obtained at intensity 10^{22} W/cm^{2}.

Is rule of halves still an occurrence in South India: Findings from community-based survey in a selected urban area of Puducherry.

BACKGROUND: The objective of the present study was to assess the applicability of the rule of halves in an urban population of Puducherry, South India. We also aimed to find the correlates associated with undiagnosed hypertension to facilitate targeted screening. METHODOLOGY: We derive our observation from a community-based cross-sectional study conducted using the World Health Organization STEPwise approach to surveillance in urban slum of Puducherry during 2014-15. Blood pressure (BP) was measured for all the study subjects (n = 2399), and the subjects were classified as hypertensive using Joint National Committee 8 criteria, systolic BP (SBP) ≥140 mm Hg and/or diastolic BP (DBP) ≥90 mmHg and/or known hypertensives and/or treatment with antihypertensive drugs. Controlled hypertension was defined as SBP <140 mmHg and DBP <90 mmHg. RESULTS: Of 2399, 799 (33.3%; 95% confidence interval [CI]: 31.4%-35.2%) adults were found to have raised BP by any means (known and unknown hypertensives). Of the 799, 367 (15.3%; 95%CI: 13.9%-16.8%) of study participants were known hypertensives. Of the known hypertensives, 74.7% (274/367) were put on treatment (drugs and or lifestyle modification), and 80% (218/274) were on regular treatment. Higher proportions of men were found to have undiagnosed hypertension compared to women (26.1 vs. 19.8%, P < 0.001). Similarly, adult from below poverty line (23.8 vs. 20%, P < 0.001), unskilled laborer (26.6 vs. 20%, P < 0.001), and literacy less than middle school (12.3 vs. 23%, P < 0.001) had more undiagnosed hypertension. CONCLUSION: In the selected urban area of Puducherry around one-third of the adult populations are having hypertension, including the 54% of undiagnosed hypertension. Adults from the vulnerable subgroups such as lower level of literacy, below poverty line, and unskilled work are found to have higher proportions of undiagnosed hypertension.

Synthesis and characterization of Cu/Ag nanoparticle loaded mullite nanocomposite system: A potential candidate for antimicrobial and therapeutic applications.

BACKGROUND: Microbial resistance to antibiotics has triggered the development of nanoscale materials as an alternative strategy. To stabilize these particles an inert support is needed. METHOD: Porous nanomullite developed by sol-gel route is loaded with copper and silver nanoparticle by simple adsorption method. These nanocomposites are characterized using XRD, FTIR, TEM, SEM, EDAX and UV-visible spectrophotometer. Antibacterial activity of these nanocomposites against Gram positive and Gram negative bacteria are performed by bactericidal kinetics, flow cytometry and MTT assay. The underlying mechanisms behind the antimicrobial property and cell death are also investigated by EPR spectroscopy, intracellular ROS measurement and ß-galactosidase assay. The cytocompatibility of the nanocomposites is investigated by cell viability (MTT), proliferation (Alamar blue) and wound healing assay of mammalian fibroblast cell line. RESULTS: Nanocomposites show a fairly uniform distribution of metal nanoparticle within mullite matrix. They show excellent antibacterial activity. Metal ions/nanoparticle is found to be released from the materials (CM and SM). Treated cells manifested high intracellular oxidative stress and ß-galactosidase activity in the growth medium. The effect of nanocomposites on mammalian cell line depends on exposure time and concentration. The scratch assay shows normal cell migration with respect to control. CONCLUSION: The fabricated nanoparticles possess diverse antimicrobial mechanism and exhibit good cytocompatibility along with wound healing characteristics in mouse fibroblast cell line (L929). GENERAL SIGNIFICANCE: The newly synthesized materials are promising candidates for the development of antimicrobial ceramic coatings for biomedical devices and therapeutic applications.

Expression of microRNA-155 correlates positively with the expression of Toll-like receptor 7 and modulates hepatitis B virus via C/EBP-ß in hepatocytes.

Effective recognition of viral infection and successive activation of antiviral innate immune responses are vital for host antiviral defence, which largely depends on multiple regulators, including Toll-like receptors (TLRs) and microRNAs. Several early reports suggest that specific TLR-mediated immune responses can control hepatitis B virus (HBV) replication and express differentially with disease outcome. Considering the versatile function of miR-155 in the TLR-mediated innate immune response, we aimed to study the association between miR-155 and TLRs and their subsequent impact on HBV replication using both a HBV-replicating stable cell line (HepG2.2.15) and HBV-infected liver biopsy and serum samples. Our results showed that miR-155 was suppressed during HBV infection and a subsequent positive correlation of miR-155 with TLR7 activation was noted. Further, ectopic expression of miR-155 in vitro reduced HBV load as evidenced from reduced viral DNA, mRNA and subsequently reduced level of secreted viral antigens (HBsAg and HBeAg). Our results further suggested that CCAAT/enhancer-binding protein-ß (C/EBP-ß), a positive regulator of HBV transcription, was inhibited by miR-155. Taken together, our study established a correlation between miR-155 and TLR7 during HBV infection and also demonstrated in vitro that increased miR-155 level could help to reduce HBV viral load by targeting C/EBP-ß.

Temporal Narrowing of Neutrons Produced by High-Intensity Short-Pulse Lasers.

The production of neutron beams having short temporal duration is studied using ultraintense laser pulses. Laser-accelerated protons are spectrally filtered using a laser-triggered microlens to produce a short duration neutron pulse via nuclear reactions induced in a converter material (LiF). This produces a ∼3 ns duration neutron pulse with 10(4) n/MeV/sr/shot at 0.56 m from the laser-irradiated proton source. The large spatial separation between the neutron production and the proton source allows for shielding from the copious and undesirable radiation resulting from the laser-plasma interaction. This neutron pulse compares favorably to the duration of conventional accelerator sources and should scale up with, present and future, higher energy laser facilities to produce brighter and shorter neutron beams for ultrafast probing of dense materials.