Towards building a trustworthy pipeline integrating Neuroscience Gateway and Open Science Chain

When the scientific dataset evolves or is reused in workflows creating derived datasets, the integrity of the dataset with its metadata information, including provenance, needs to be securely preserved while providing assurances that they are not accidentally or maliciously altered during the process. Providing a secure method to efficiently share and verify the data as well as metadata is essential for the reuse of the scientific data. The National Science Foundation (NSF) funded Open Science Chain (OSC) utilizes consortium blockchain to provide a cyberinfrastructure solution to maintain integrity of the provenance metadata for published datasets and provides a way to perform independent verification of the dataset while promoting reuse and reproducibility. The NSF- and National Institutes of Health (NIH)-funded Neuroscience Gateway (NSG) provides a freely available web portal that allows neuroscience researchers to execute computational data analysis pipeline on high performance computing resources. Combined, the OSC and NSG platforms form an efficient, integrated framework to automatically and securely preserve and verify the integrity of the artifacts used in research workflows while using the NSG platform. This paper presents the results of the first study that integrates OSC-NSG frameworks to track the provenance of neurophysiological signal data analysis to study brain network dynamics using the Neuro-Integrative Connectivity tool, which is deployed in the NSG platform. Database URL: https://www.opensciencechain.org.

Geospatial mapping of distribution grid with machine learning and publicly-accessible multi-modal data

Detailed and location-aware distribution grid information is a prerequisite for various power system applications such as renewable energy integration, wildfire risk assessment, and infrastructure planning. However, a generalizable and scalable approach to obtain such information is still lacking. In this work, we develop a machine-learning-based framework to map both overhead and underground distribution grids using widely-available multi-modal data including street view images, road networks, and building maps. Benchmarked against the utility-owned distribution grid map in California, our framework achieves > 80% precision and recall on average in the geospatial mapping of grids. The framework developed with the California data can be transferred to Sub-Saharan Africa and maintain the same level of precision without fine-tuning, demonstrating its generalizability. Furthermore, our framework achieves a R2 of 0.63 in measuring the fraction of underground power lines at the aggregate level for estimating grid exposure to wildfires. We offer the framework as an open tool for mapping and analyzing distribution grids solely based on publicly-accessible data to support the construction and maintenance of reliable and clean energy systems around the world.

Imaging the electron charge density in monolayer MoS2 at the Ångstrom scale

Four-dimensional scanning transmission electron microscopy (4D-STEM) has recently gained widespread attention for its ability to image atomic electric fields with sub-Ångstrom spatial resolution. These electric field maps represent the integrated effect of the nucleus, core electrons and valence electrons, and separating their contributions is non-trivial. In this paper, we utilized simultaneously acquired 4D-STEM center of mass (CoM) images and annular dark field (ADF) images to determine the projected electron charge density in monolayer MoS2. We evaluate the contributions of both the core electrons and the valence electrons to the derived electron charge density; however, due to blurring by the probe shape, the valence electron contribution forms a nearly featureless background while most of the spatial modulation comes from the core electrons. Our findings highlight the importance of probe shape in interpreting charge densities derived from 4D-STEM and the need for smaller electron probes.

Fluids and Electrolytes under Confinement in Single-Digit Nanopores

Confined fluids and electrolyte solutions in nanopores exhibit rich and surprising physics and chemistry that impact the mass transport and energy efficiency in many important natural systems and industrial applications. Existing theories often fail to predict the exotic effects observed in the narrowest of such pores, called single-digit nanopores (SDNs), which have diameters or conduit widths of less than 10 nm, and have only recently become accessible for experimental measurements. What SDNs reveal has been surprising, including a rapidly increasing number of examples such as extraordinarily fast water transport, distorted fluid-phase boundaries, strong ion-correlation and quantum effects, and dielectric anomalies that are not observed in larger pores. Exploiting these effects presents myriad opportunities in both basic and applied research that stand to impact a host of new technologies at the water-energy nexus, from new membranes for precise separations and water purification to new gas permeable materials for water electrolyzers and energy-storage devices. SDNs also present unique opportunities to achieve ultrasensitive and selective chemical sensing at the single-ion and single-molecule limit. In this review article, we summarize the progress on nanofluidics of SDNs, with a focus on the confinement effects that arise in these extremely narrow nanopores. The recent development of precision model systems, transformative experimental tools, and multiscale theories that have played enabling roles in advancing this frontier are reviewed. We also identify new knowledge gaps in our understanding of nanofluidic transport and provide an outlook for the future challenges and opportunities at this rapidly advancing frontier.

Transport Mediating Core-Shell Photocatalyst Architecture for Selective Alkane Oxidation

The high activation barrier of the C-H bond in methane, combined with the high propensity of methanol and other liquid oxygenates toward overoxidation to CO₂, have historically posed significant scientific and industrial challenges to the selective and direct conversion of methane to energy-dense fuels and chemical feedstocks. Here, we report a unique core-shell nanostructured photocatalyst, silica encapsulated TiO₂ decorated with AuPd nanoparticles (TiO₂@SiO₂-AuPd), that prevents methanol overoxidation on its surface and possesses high selectivity and yield of oxygenates even at high UV intensity. This room-temperature approach achieves high selectivity for oxygenates (94.5%) with a total oxygenate yield of 15.4 mmol/g_cat·h at 9.65 bar total pressure of CH₄ and O₂. The working principles of this core-shell photocatalyst were also systematically investigated. This design concept was further demonstrated to be generalizable for the selective oxidation of other alkanes.

The impact of signposting and group support pathways on a community-based physical activity intervention grounded in motivational interviewing

BACKGROUND

Brief advice is recommended to increase physical activity (PA) within primary care. This study assessed change in PA levels and mental well-being after a motivational interviewing (MI) community-based PA intervention and the impact of signposting (SP) and social action (SA) (i.e. weekly group support) pathways.

METHODS

Participants (n = 2084) took part in a community-based, primary care PA programme using MI techniques. Self-reported PA and mental well-being data were collected at baseline (following an initial 30-min MI appointment), 12 weeks, 6 months and 12 months. Participants were assigned based upon the surgery they attended to the SP or SA pathway. Multilevel models derived point estimates and 95% confidence intervals for outcomes at each time point and change scores.

RESULTS

Participants increased PA and mental well-being at each follow-up time point through both participant pathways and with little difference between pathways. Retention was similar between pathways at 12 weeks, but the SP pathway retained more participants at 6 and 12 months.

CONCLUSIONS

Both pathways produced similar improvements in PA and mental well-being; however, the addition of a control would have provided further insight as to the effectiveness. Due to lower resources yet similar effects, the SP pathway could be incorporated to support PA in primary care settings.

The impact of signposting and group support pathways on a community-based physical activity intervention grounded in motivational interviewing

BACKGROUND

Brief advice is recommended to increase physical activity (PA) within primary care. This study assessed change in PA levels and mental well-being after a motivational interviewing (MI) community-based PA intervention and the impact of signposting (SP) and social action (SA) (i.e. weekly group support) pathways.

METHODS

Participants (n = 2084) took part in a community-based, primary care PA programme using MI techniques. Self-reported PA and mental well-being data were collected at baseline (following an initial 30-min MI appointment), 12 weeks, 6 months and 12 months. Participants were assigned based upon the surgery they attended to the SP or SA pathway. Multilevel models derived point estimates and 95% confidence intervals for outcomes at each time point and change scores.

RESULTS

Participants increased PA and mental well-being at each follow-up time point through both participant pathways and with little difference between pathways. Retention was similar between pathways at 12 weeks, but the SP pathway retained more participants at 6 and 12 months.

CONCLUSIONS

Both pathways produced similar improvements in PA and mental well-being; however, the addition of a control would have provided further insight as to the effectiveness. Due to lower resources yet similar effects, the SP pathway could be incorporated to support PA in primary care settings.

Photoabsorption Imaging at Nanometer Scales Using Secondary Electron Analysis

Optical imaging with nanometer resolution offers fundamental insights into light-matter interactions. Traditional optical techniques are diffraction limited with a spatial resolution >100 nm. Optical super-resolution and cathodoluminescence techniques have higher spatial resolutions, but these approaches require the sample to fluoresce, which many materials lack. Here, we introduce photoabsorption microscopy using electron analysis, which involves spectrally specific photoabsorption that is locally probed using a scanning electron microscope, whereby a photoabsorption-induced surface photovoltage modulates the secondary electron emission. We demonstrate spectrally specific photoabsorption imaging with sub-20 nm spatial resolution using silicon, germanium, and gold nanoparticles. Theoretical analysis and Monte Carlo simulations are used to explain the basic trends of the photoabsorption-induced secondary electron signal. Based on our current experiments and this analysis, we expect that the spatial resolution can be further improved to a few nanometers, thereby offering a general approach for nanometer-scale optical spectroscopic imaging and material characterization.

Practical consensus recommendations on fertility preservation in patients with breast cancer

Young women diagnosed with cancer today have a greater chance of long-term survival than ever before. Successful survivorship for this group of patients includes maintaining a high quality of life after a cancer diagnosis and treatment; however, lifesaving treatments such as chemotherapy, radiation, and surgery can impact survivors by impairing reproductive and endocrine health. Expert oncologists along with reproductive medicine specialists discuss fertility preservation options in this chapter since fertility preservation is becoming a priority for young women with breast cancer. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at these practical consensus recommendations for the benefit of community oncologists.

Imaging Arrangements of Discrete Ions at Liquid-Solid Interfaces

The individual and collective behavior of ions near electrically charged interfaces is foundational to a variety of electrochemical phenomena encountered in biology, energy, and the environment. While many theories have been developed to predict the interfacial arrangements of counterions, direct experimental observations and validations have remained elusive. Utilizing cryo-electron microscopy, here we directly visualize individual counterions and reveal their discrete interfacial layering. Comparison with simulations suggests the strong effects of finite ionic size and electrostatic interactions. We also uncover correlated ionic structures under extreme confinement, with the channel widths approaching the ionic diameter (∼1 nm). Our work reveals the roles of ionic size, valency, and confinement in determining the structures of liquid-solid interfaces and opens up new opportunities to study such systems at the single-ion level.

Study of 3He(n,p)3H reaction at cosmological energies with trojan horse method

In the network of reactions present in the Big Bang nucleosynthesis, the 3He(n, p)3H has an important role which impacts the final 7Li abundance. The Trojan Horse Method (THM) has been applied to the 3He(d, pt)H reaction in order to extract the astrophysical S(E)-factor of the 3He(n, p)3H in the Gamow energy range. The experiment will be described in the present work together with the first preliminary results.

Use of a chalazion clamp for intraoral biopsies: a technical note

Oral biopsies are common diagnostic and therapeutic procedures in oral and maxillofacial surgical (OMFS) outpatient departments. The chalazion clamp is similar to a pair of forceps. One extension has a flat, solid, oval plate, the other, a ring-like structure that is used to clamp and retract soft tissues. We highlight the benefits of using this simple, widely-available tool during oral biopsies. We find that the clamp increases effectiveness and efficiency for the clinician and assistant. We recommend its use in daily OMFS practice.

Tuberculosis-diabetes screening: how well are we doing? A mixed-methods study from North India

Setting

Public health care facilities in Sonipat District, Haryana State, India.

Objectives

To assess 1) the proportion of tuberculosis (TB) patients screened for diabetes mellitus (DM) and vice versa, 2) factors associated with screening, and 3) the enablers, barriers and solutions related to screening.

Design

A mixed-methods study with quantitative (cohort study involving record reviews of patients registered between November 2016 and April 2017) and qualitative (interviews of patients, health care providers [HCPs] and key district-level staff) components.

Results

Screening for TB among DM patients was not implemented, despite documents indicating that it had been. Of 562 TB patients, only 137 (24%) were screened for DM. TB patients registered at tertiary and secondary health centres were more likely to be screened than primary health centres. Low patient awareness, poor knowledge of guidelines among HCPs, lack of staff and inadequate training were barriers to screening. Enablers were the positive attitude of HCPs and programme staff. The key solutions suggested were to improve awareness of HCPs and patients regarding the need for screening, training of HCPs and wider availability of DM testing facilities.

Conclusion

The implementation of bidirectional screening was poor. Adequate staffing, regular training, continuous laboratory supplies for DM diagnosis and widespread publicity should be ensured.

Phenotype of CNTNAP1: a study of patients demonstrating a specific severe congenital hypomyelinating neuropathy with survival beyond infancy

CHN is genetically heterogeneous and its genetic basis is difficult to determine on features alone. CNTNAP1 encodes CASPR, integral in the paranodal junction high molecular mass complex. Nineteen individuals with biallelic variants have been described in association with severe congenital hypomyelinating neuropathy, respiratory compromise, profound intellectual disability and death within the first year. We report 7 additional patients ascertained through exome sequencing. We identified 9 novel CNTNAP1 variants in 6 families: three missense variants, four nonsense variants, one frameshift variant and one splice site variant. Significant polyhydramnios occurred in 6/7 pregnancies. Severe respiratory compromise was seen in 6/7 (tracheostomy in 5). A complex neurological phenotype was seen in all patients who had marked brain hypomyelination/demyelination and profound developmental delay. Additional neurological findings included cranial nerve compromise: orobulbar dysfunction in 5/7, facial nerve weakness in 4/7 and vocal cord paresis in 5/7. Dystonia occurred in 2/7 patients and limb contractures in 5/7. All had severe gastroesophageal reflux, and a gastrostomy was required in 5/7. In contrast to most previous reports, only one patient died in the first year of life. Protein modelling was performed for all detected CNTNAP1 variants. We propose a genotype-phenotype correlation, whereby hypomorphic missense variants partially ameliorate the phenotype, prolonging survival. This study suggests that biallelic variants in CNTNAP1 cause a distinct recognisable syndrome, which is not caused by other genes associated with CHN. Neonates presenting with this phenotype will benefit from early genetic definition to inform clinical management and enable essential genetic counselling for their families.

A dual-mode textile for human body radiative heating and cooling

Maintaining human body temperature is one of the most basic needs for living, which often consumes a huge amount of energy to keep the ambient temperature constant. To expand the ambient temperature range while maintaining human thermal comfort, the concept of personal thermal management has been recently demonstrated in heating and cooling textiles separately through human body infrared radiation control. Realizing these two opposite functions within the same textile would represent an exciting scientific challenge and a significant technological advancement. We demonstrate a dual-mode textile that can perform both passive radiative heating and cooling using the same piece of textile without any energy input. The dual-mode textile is composed of a bilayer emitter embedded inside an infrared-transparent nanoporous polyethylene (nanoPE) layer. We demonstrate that the asymmetrical characteristics of both emissivity and nanoPE thickness can result in two different heat transfer coefficients and achieve heating when the low-emissivity layer is facing outside and cooling by wearing the textile inside out when the high-emissivity layer is facing outside. This can expand the thermal comfort zone by 6.5°C. Numerical fitting of the data further predicts 14.7°C of comfort zone expansion for dual-mode textiles with large emissivity contrast.

Heterodyne x-ray diffuse scattering from coherent phonons

Here, we report Fourier-transform inelastic x-ray scattering measurements of photoexcited GaAs with embedded ErAs nanoparticles. We observe temporal oscillations in the x-ray scattering intensity, which we attribute to inelastic scattering from coherent acoustic phonons. Unlike in thermal equilibrium, where inelastic x-ray scattering is proportional to the phonon occupation, we show that the scattering is proportional to the phonon amplitude for coherent states. The wavevectors of the observed phonons extend beyond the excitation wavevector. The nanoparticles break the discrete translational symmetry of the lattice, enabling the generation of large wavevector coherent phonons. Elastic scattering of x-ray photons from the nanoparticles provides a reference for heterodyne mixing, yielding signals proportional to the phonon amplitude.

Caregiver's perception of epilepsy treatment, quality of life and comorbidities in an international cohort of CDKL5 patients

OBJECTIVE

CDKL5 is a genetic condition associated with drug-resistant epilepsy and intellectual disability. There is limited information on its natural history. We investigated the natural history, complications, and the effectiveness of current treatment strategies.

METHODS

This study was conducted in conjunction with the CDKL5-UK Charity, with patients recruited from the USA and Europe. Online questionnaires were completed by parents/carers and included information relating to demographics, growth, development, epilepsy, comorbid conditions, and efficacy and side effects of antiepileptic treatments.

RESULTS

Thirty-nine of the 44 patients were female. Median age was five years (range five months to 31 years), and all had a history of epilepsy. All patients had developmental delay, with 4/21 able to run and 4/22 able to climb. Gastrointestinal problems were reported in 31/43. Cardiac arrhythmia was seen in 11/29. Over one-quarter of the patients had tried ten or more antiepileptic medications. Vigabatrin was reportedly the most effective AED (antiepileptic drug) in 12/23; clobazam (most effective in 6/14); sodium valproate (most effective in 5/27), and levetiracetam (most effective in 3/27). VNS (Vagal Nerve Stimulator) was reported to be effective in 9/12. One year after VNS insertion, 9/12 reported improved (QoL), and there were improvements in mood, school achievement and concentration in (9/11). The ketogenic diet was considered effective and to have improved QoL in (12/23).

CONCLUSION

Vigabatrin appears to be more effective than other AEDs. VNS and ketogenic diet are also relatively effective. Gastrointestinal and cardiovascular system complications are common. The results may help to guide management of epilepsy in CDKL5. It highlights a possible link between CDKL5 and potentially treatable life-threatening complications such as cardiac arrhythmia. More research in this area may help us develop a more systematic approach to treating these patients. HIPPOKRATIA 2017, 21(3): 130-135.

An evaluation of the feasibility and validity of a patient-administered malnutrition universal screening tool ('MUST') compared to healthcare professional screening in an inflammatory bowel disease (IBD) outpatient clinic

BACKGROUND

Malnutrition is common in inflammatory bowel disease (IBD) and is associated with poor health outcomes. Despite this, screening for malnutrition in the outpatient-setting is not routine and research in the area is limited. The present study aimed to evaluate whether agreement between malnutrition screening completed by patients and healthcare professionals (HCPs) could be achieved by comparing patient self-administered 'MUST' ('MUST'-P) with HCP administered 'MUST' ('MUST'-HCP) in a single tertiary IBD outpatient clinic.

METHODS

We conducted a feasibility and validity study on adult outpatients with IBD. We collected anthropometric, nutritional and clinical data from patients. All patients completed 'MUST'-P using a self-administered questionnaire, followed by 'MUST'-HCP. 'MUST'-P was timed and feedback on ease-of-use was obtained. The risk of malnutrition was classified as low (score = 0), medium (score = 1) and high (score ≥ 2) and agreement was tested using kappa statistics (κ).

RESULTS

Eighty patients were recruited (Crohn's disease: n = 49, ulcerative colitis: n = 29, unclassified: n = 2), with a mean (SD) age of 39.9 (15.1) years (51.2% were males). Seventy-one (92%) of patients found 'MUST'-P either easy or very easy. The mean (SD) time to complete 'MUST'-P was 3.1  (1.8) min (range 1-10 min). Sixty-eight (85%) of patients were at low risk of malnutrition when screened by the HCP. There was moderate agreement (κ = 0.486, P < 0.001) between 'MUST'-P and 'MUST'-HCP, with 100% agreement in scoring for medium- and high-risk categories.

CONCLUSIONS

The results of the present study suggests that self-screening using 'MUST' could be effectively used in an IBD outpatient clinic to identify those at medium and high risk of malnutrition. The patient friendly version of 'MUST' ('MUST'-P) was considered quick and easy to use by patients. Implementation of self-screening with 'MUST' could improve the nutritional management of IBD patients.

Evolutionary algorithm optimization of biological learning parameters in a biomimetic neuroprosthesis

Biomimetic simulation permits neuroscientists to better understand the complex neuronal dynamics of the brain. Embedding a biomimetic simulation in a closed-loop neuroprosthesis, which can read and write signals from the brain, will permit applications for amelioration of motor, psychiatric, and memory-related brain disorders. Biomimetic neuroprostheses require real-time adaptation to changes in the external environment, thus constituting an example of a dynamic data-driven application system. As model fidelity increases, so does the number of parameters and the complexity of finding appropriate parameter configurations. Instead of adapting synaptic weights via machine learning, we employed major biological learning methods: spike-timing dependent plasticity and reinforcement learning. We optimized the learning metaparameters using evolutionary algorithms, which were implemented in parallel and which used an island model approach to obtain sufficient speed. We employed these methods to train a cortical spiking model to utilize macaque brain activity, indicating a selected target, to drive a virtual musculoskeletal arm with realistic anatomical and biomechanical properties to reach to that target. The optimized system was able to reproduce macaque data from a comparable experimental motor task. These techniques can be used to efficiently tune the parameters of multiscale systems, linking realistic neuronal dynamics to behavior, and thus providing a useful tool for neuroscience and neuroprosthetics.

Functionalization of silica particles to tune the impact resistance of shear thickening fluid treated aramid fabrics

Kevlar fabrics treated with MTMS modified silica based STF showed better impact energy absorption as compared to APTES modified and control silica based STF treated fabrics, attributed to changes in interactions between fabrics and silica particles.

Assessment of health-related quality of life and its determinants in patients with chronic kidney disease

Health-related quality of life is an important, yet neglected aspect of chronic kidney disease (CKD) care. We evaluated the quality of life and its determinants across CKD 3 to 5D using a kidney disease specific tool (Kidney Disease Quality of Life-SF™) in an underprivileged, predominantly rural population with high rates of illiteracy and unemployment. The scores of individual domains were summarized to three composite scores – physical composite summary (PCS), mental composite summary (MCS), and kidney disease component summary score (KDCS)^. A total number of 204 participants were recruited from nephrology outpatient clinics. About 68.1% of participants were males. The mean age of the study population was 49.14 ± 13.63 years. There was a high proportion of illiteracy (36.3%) and unemployment (80.9%). KDCS showed a significant decline (P = 0.01) from CKD 3 to CKD 5D whereas MCS and PCS showed a nonsignificant decrease. There was no difference in KDCS, PCS, or MCS scores between patients treated by hemodialysis and CAPD. Illiteracy and unemployment were associated with significantly lower KDCS, PCS, and MCS scores. Age ≥50 years was associated with poor PCS (29.49 ± 8.20 vs. 34.17 ± 9.99; P < 0.001). Hemoglobin <10 g/dL was associated with poor KDCS (58.93 ± 13.09 vs. 65.55 ± 13.38; P < 0.001) and PCS (29.56 ± 8.13 vs. 33.37 ± 9.82; P < 0.001). The presence of comorbidities such as diabetes and hypertension had no impact on the composite scores. KDCS, MCS, or PCS scores did not vary among patients having high serum phosphorus (≥4.5 mg/dL), low albumin (<3.5 g/dL), and elevated parathyroid hormone (≥150 pg/ml). On multiple linear regression analysis, the predictors of KDCS were unemployment (P < 0.001) and illiteracy (P = 0.03). Unemployment (P < 0.001) and age (P < 0.001) were predictors of PCS whereas literacy level (P < 0.001) was predictive of MCS.

Mononuclear bis(dithiolene) Mo(iv) and W(iv) complexes with P,P; S,S; O,S and O,O donor ligands: a comparative reactivity study

Comparative redox reactions of eight Mo^IV/W^IVcomplexes with P,P; S,S; S,O and O,O donor ligands are presented.

Using a Microcantilever Array for Detecting Phase Transitions and Stability of DNA

We report the extension of the microcantilever platform to study the thermal phase transition of biomolecules as they are heated. Microcantilever-based sensors directly translate changes in Gibbs free energy due to macromolecular interactions into mechanical responses. We observe surface stress changes in response to thermal dehybridization of double-stranded DNA oligonucleotides that are attached onto one side of a microcantilever. Once the cantilever is heated, the DNA undergoes a transition as the complementary strand melts, which results in changes in the cantilever deflection. This deflection is due to changes in the electrostatic, ionic, and hydration interaction forces between the remaining immobilized DNA strands. This new technique has allowed us to probe DNA melting dynamics and leads to a better understanding of the stability of DNA complexes on surfaces. (JALA 2006;11:222–6)

Evaluation of a Silicon 90Sr Betavoltaic Power Source

Betavoltaic energy converters (i.e., β-batteries) are attractive power sources because of their potential for high energy densities (>200 MWh/kg) and long duration continuous discharge (>1 year). However, conversion efficiencies have been historically low (<3%). High efficiency devices can be achieved by matching β-radiation transport length scales with the device physics length scales. In this work, the efficiency of c-Si devices using high-energy (>1 MeV) electrons emitted from ⁹⁰Sr as a power source is investigated. We propose a design for a >10% efficient betavoltaic device, which generates 1 W of power. A Varian Clinac iX is used to simulate the high-energy electrons emitted from ⁹⁰Sr, and a high efficiency c-Si photovoltaic cell is used as the converter. The measured conversion efficiency is 16%. This relatively high value is attributed to proper length scale matching and the generation of secondary electrons in c-Si by the primary β-particles.

Resveratrol and pterostilbene attenuated smokeless tobacco induced cardiovascular aberrations in estrogen deficient female rats

This study evaluated the impact of resveratrol (RSV) and pterostilbene (PT) on the aqueous extract of smokeless tobacco (AEST) induced cardiovascular aberrations in estrogen deficient female Sprague-Dawley rats. Exposure to 4-vinylcyclohexene diepoxide (VCD) (80 mg kg-1, i.p.) for 30 days induces estrogen deficiency. The rats were administered AEST alone or AEST along with resveratrol and/or pterostilbene. Several markers of cardiovascular health were estimated to evaluate the repercussion of the exposures. RSV and PT per se and in combination significantly reversed the derangements caused by AEST. RSV decreased the atherogenic index and systolic blood pressure and normalized ECG. RSV and PT treatment markedly decreased aortic collagen, cardiac-carbonylated proteins, serum creatine-kinase, cholesterol, LDH, LDL, VLDL, CRP and TNF-α levels. Conversely, they increased serum nitrate-nitrite and HDL levels. The drugs improved the gene expression of SIRT1, PGC-1α, PPAR-α, TFAM, NRF-1 and mtDNA in the cardiac tissue. However, the expression of SIRT1 was not modified by PT. These favorable effects were comparable to those of estradiol therapy. Histopathological outcomes also corroborated these benefits. Thus, resveratrol and pterostilbene abrogated the deleterious effects of AEST on cardiovascular parameters in estrogen deficient female rats.

Label-Free Electrical Detection of Enzymatic Reactions in Nanochannels

We report label-free electrical detection of enzymatic reactions using 2-D nanofluidic channels and investigate reaction kinetics of enzymatic reactions on immobilized substrates in nanoscale-confined spaces. Trypsin proteolysis is chosen for demonstration of the detection scheme. When trypsin cleaves poly-l-lysine coated on the surface of silica nanochannels, the resulting change of surface charge density can be detected by monitoring the ionic conductance of the nanochannels. Our results show that detection of such surface enzymatic reactions is faster than detection of surface binding reactions in nanochannels for low-concentration analytes. Furthermore, the nanochannel sensor has a sensitivity down to 5 ng/mL, which statistically corresponds to a single enzyme per nanochannel. Our results also suggest that enzyme kinetics in nanochannels is fundamentally different from that in bulk solutions or plain surfaces. Such enzymatic reactions form two clear self-propagating reaction fronts inside the nanochannels, and the reaction fronts follow square-root time dependences at high enzyme concentrations due to significant nonspecific adsorption. However, at low enzyme concentrations when nonspecific adsorption is negligible, the reaction fronts propagate linearly with time, and the corresponding propagation speed is related to the channel geometry, enzyme concentration, catalytic reaction constant, diffusion coefficient, and substrate surface density. Optimization of this nanochannel sensor could lead to a quick-response, highly sensitive, and label-free sensor for enzyme assay and kinetic studies.

Systematic review: current concepts and challenges for the direct-acting antiviral era in hepatitis C cirrhosis

BACKGROUND

The burden of HCV cirrhosis is high and projected to increase significantly over the next decade. While interferon therapy is problematic in HCV cirrhosis, the era of direct-acting anti-viral (DAA) therapy provides effective treatment for patients with cirrhosis.

AIM

To systematically review the results of DAA therapy to date in patients with HCV cirrhosis, and highlight the ongoing challenges for DAA therapy in this population.

METHODS

A structured Medline search was conducted to obtain phase II and III HCV trials in patients with cirrhosis. Citations from review articles were cross-referenced and conference abstracts from EASL and AASLD liver meetings for the preceding 3 years were reviewed manually. Keywords used included hepatitis C, cirrhosis and the DAA's: sofosbuvir, ledipasvir, velpatasvir, grazoprevir, elbasvir, daclatasvir, beclabuvir, asunaprevir, simeprevir, paritaprevir, ombitasvir and dasabuvir.

RESULTS

Successful direct-acting anti-viral treatment is now possible in patients with HCV-related cirrhosis including those with liver decompensation with several regimens now offering sustained virological response (SVR) of 90-95%. Overall success rates in GT1 cirrhosis are excellent while GT3-infected patients with cirrhosis remain hard to cure. The pangenotypic combination of sofosbuvir and velpatasvir holds promise for GT3 cirrhosis achieving SVR of ~90%.

CONCLUSIONS

Potent DAA therapies provide much needed, safe and highly effective treatment options for persons with HCV cirrhosis including those previously deemed unsuitable for treatment. Combination therapy with two or more classes of drug is essential to achieve high efficacy and minimise viral resistance, with the role of ribavirin still under evaluation. However, several challenges remain including the hard-to-cure groups of GT3 cirrhosis and direct-acting anti-viral failures, and managing drug-drug interactions.