bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on the Leakage and Rotordynamic Coefficients of a Long Smooth Seal at Laminar Flow Conditions
Authors: Zhang Min , Childs Dara W.
Published: January 2019

This paper experimentally investigates the performance of a long smooth seal (length-diameter ratio L/D = 0.65 and radial clearance Cr = 0.140 mm) under laminar flow conditions. Tests are carried out at shaft speeds ω up to 10 krpm, pressure drops PD up to 48.3 bars, exit pressure Pe = 6.9 bars, and inlet temperature Ti = 39.4 °C. The seal is centered. Since there is no validated friction formula published for a liquid seal in the transitional regime, this paper uses San Andrés’s bulk-flow model with laminar-flow friction formula to produce predictions. Test results show that under laminar flow conditions, increasing ω decreases measured direct stiffness K, increases measured cross-coupled stiffness k, barely changes measured direct damping C, and generally increases measured cross-coupled damping c. The model correctly predicts these trends, and the predictions of K, k, C, and c are reasonably close to test results. Measured direct virtual-mass M values are normally larger than predictions.

This paper also judges two cases with high PD or high ω to be in the transitional regime. For these cases, the predictions of K, k, C, and c based on the laminar-flow friction formula are significantly different from test results. This discrepancy further strengthens the judgment that the flow in these cases is transitional.

For all test cases, measured leakage mass flow rate ṁ and measured effective damping Ceff are not sensitive to changes in ω, but increase as PD increases. The model with the laminar-flow friction formula adequately predicts ṁ and Ceff even when the flow within the seal annulus is at the start of the transitional flow regime. Also, Ceff predictions are lower than test results, allowing a safe margin for the pump design.
Induction of Inflammatory Responses in Splenocytes by Exosomes Released from Intestinal Epithelial Cells followingCryptosporidium parvumInfection
Authors: Wang Yang , Shen Yujuan , Liu Hua , Yin Jianhai , Zhang Xin-Tian , Gong Ai-Yu , Chen Xiqiang , Chen Siyi , Mathy Nicholas W. , Cao Jianping , Chen Xian-Ming
Published: January 2019

Cryptosporidium, a protozoan parasite that infects the gastrointestinal epithelium and other mucosal surfaces in humans and animals, is an important opportunistic pathogen in AIDS patients and one of the most common enteric pathogens affecting young children in developing regions. This parasite is referred to as a “minimally invasive” mucosal pathogen, and epithelial cells play a central role in activating and orchestrating host immune responses.
Yersinia pestis Exploits Early Activation of MyD88 for Growth in the Lungs during Pneumonic Plague
Authors: Olson Rachel M. , Dhariwala Miqdad O. , Mitchell William J. , Anderson Deborah M.
Published: January 2019

Yersinia pestis
causes bubonic, pneumonic, and septicemic plague. Although no longer responsible for pandemic outbreaks, pneumonic plague continues to be a challenge for medical treatment and has been classified as a reemerging disease in some parts of the world.
Artificial Selection for Pathogenicity Mutations in
Staphylococcus aureus
Identifies Novel Factors Relevant to Chronic Infection
Authors: McLean Kathryn , Holmes Elizabeth A. , Penewit Kelsi , Lee Duankun K. , Hardy Samantha R. , Ren Mingxin , Krist Maxwell P. , Huang Kevin , Waalkes Adam , Salipante Stephen J.
Published: January 2019

Adaptation of
Staphylococcus aureus
to host microenvironments during chronic infection involves spontaneous mutations, yet changes underlying adaptive phenotypes remain incompletely explored. Here, we employed artificial selection and whole-genome sequencing to better characterize spontaneous chromosomal mutations that alter two pathogenicity phenotypes relevant to chronic infection in
S. aureus
: intracellular invasiveness and intracellular cytotoxicity.
Purification of a Crenarchaeal ATP Synthase in the Light of the Unique Bioenergetics of
Ignicoccus
Species
Authors: Kreuter Lydia J. , Weinfurtner Andrea , Ziegler Alexander , Weigl Julia , Hoffmann Jan , Morgner Nina , Müller Volker , Huber Harald
Published: January 2019

The
Crenarchaeota
represent one of the major phyla within the
Archaea
domain. This study describes the successful purification of a crenarchaeal ATP synthase. To date, all information about A-type ATP synthases is from euryarchaeal enzymes. The fact that it has not been possible to purify this enzyme complex from a member of the
Crenarchaeota
until now points to significant differences in stability, possibly caused by structural alterations. Furthermore, the study subject
I. hospitalis
has a particular importance among crenarchaeotes, since it is the only known host of
N. equitans
. The energy metabolism in this system is still poorly understood, and our results can help elucidate the unique relationship between these two microbes.
Impact of Gastrointestinal Panel Implementation on Health Care Utilization and Outcomes
Authors: Axelrad Jordan E. , Freedberg Daniel E. , Whittier Susan , Greendyke William , Lebwohl Benjamin , Green Daniel A.
Published: January 2019

PCR-based multiplex gastrointestinal (GI) pathogen panels have started to replace stool culture and ova and parasite exam as a rapid and accurate means of diagnosing acute gastroenteritis. However, there are limited data on the impact of panel testing on patient outcomes.
Can unsuccessful treatment in primary medical institutions influence patients’ choice? A retrospective cluster sample study from China
Authors: Niu Yadong , Zhang Liang , Ye Ting , Yan Yan , Zhang Yan
Published: January 2019

Objective

China has been attempting to control the patients’ choice of high-level medical institutions through series measures of first point of contact at primary medical institutions, but the outcome is considered poor. We aim to analyse whether unsuccessful treatment in primary medical institutions can lead to the patients’ choice of high-level medical institutions.

Design

A retrospective cluster sample study.

Setting

The study setting was in Macheng city, Hubei province.

Participants

The respondents are township–county (TC) patients (patients who first went to township hospitals and then county hospitals within 30 days for the same disease) who experienced unsuccessful treatment in primary medical institutions. A total of 2090 TC patients were screened out based on the New Rural Cooperative Medical System database in 2013.

Main outcome measures

The choice of patients between township hospitals (primary medical institutions) and county hospitals was observed. We compared TC patients’ ratio of choosing county hospitals (RoCC) before TC experience with after TC experience. Thereafter, we compared RoCC of TC patients and non-TC patients (patients who did not experience TC) based on coarsened exact matching.

Results

The ratio of TC for outpatient in township hospitals is 0.68% and that of TC for inpatient in township hospitals is 3.37%. RoCC for TC disease increased from 20.8% to 35.5% (p<0.001), RoCC for other disease increased from 35% to 37.3% (p=0.01). TC patients had significantly higher RoCC than non-TC patients (p<0.001).

Conclusions

Patients’ choice of high-level medical institutions is highly associated with the experience of unsuccessful treatment in primary medical institutions. Moreover, people likely select high-level medical institutions thereafter regardless of conditions in rural China. Unsuccessful treatment in primary medical institutions is inevitable for patients. Thus, additional measures should be considered in lowering the potential risks for patients when treatments fail.

Trial registration number

ChiCTR-OOR-14005563.
Lunar cycle in homicides: a population-based time series study in Finland
Authors: Näyhä Simo
Published: January 2019

Objective

To test whether homicides in Finland vary according to moon phases.

Design

A time series study.

Setting

Finland.

Participants

6808 homicides committed in 1961–2014.

Outcome

Daily numbers of homicides.

Method

The daily numbers of homicides were related to eight moon phases and the illuminated percentage of the moon disc using negative binomial regression. To identify lunar patterns, piecewise linear terms of lunar days were used, together with changes from one moon phase to another. Homicides were similarly regressed on quintiles of the illuminated percentage of the moon disc. A periodic term of length 29.53 days was included to detect cyclic patterns. The results were adjusted for sex, age, secular trend, distance from the moon, seasons, weekday, major holidays and temperature.

Results

During the full moon, 15% less homicides were committed than during the new moon (RR 0.85; 95% CI 0.77 to 0.94) and 86% less during the lightest quintile of illumination compared with the darkest quintile (RR 0.14; 95% CI 0.04 to 0.50). Adjustments did not change the results. Piecewise linear regressions showed a significant decline in homicides at the full moon and a rise thereafter. The full moon drop in homicides was directionally similar for seasons, weekdays, sex, age and time periods, and it was particularly pronounced in the early part of period studied (1961–1974). Periodic regression showed a regular cyclic pattern of length 29.53 days (p~0.035).

Conclusions

Contrary to current scientific opinion, an association exists between moon phases and homicides, and contrary to what has been previously assumed, homicides declined during the full moon, especially in earlier decades. However, the causality of the association remains elusive.
Clinical and pathological factors of renal anaemia in patients with IgA nephropathy in Chinese adults: a cross-sectional study
Authors: Wang Yang , Wei Ri-bao , Su Ting-yu , Huang Meng-jie , Li Ping , Chen Xiang-mei
Published: January 2019

Objective

Few studies with large sample populations concerning renal anaemia and IgA nephropathy have been reported worldwide. The purpose of this cross-sectional study was to examine the clinical and pathological characteristics and influencing factors associated with renal anaemia in patients with IgA nephropathy, which is the most common aetiology of chronic kidney disease.

Methods

A total of 462 hospitalised patients with IgA nephropathy confirmed by renal biopsy who met the inclusion criteria were consecutively recruited from January 2014 to January 2016. Their general information, routine blood test results, blood chemistries, estimated glomerular filtration rates (eGFRs) and renal pathologies were collected. The Oxford classification was used to characterise the renal pathologies. Univariable and multivariate logistic regression models were used to analyse the influencing factors of anaemia associated with IgA nephropathy.

Results

The incidence of renal anaemia was 28.5% (132/462 patients) in our study (21.3% in males and 38.9% in females). The anaemia type was primarily normocytic and normochromic. The rate of anaemia in patients with eGFR values of 30–59 mL/min/1.73 m2was higher than that in patients with an eGFR >60 mL/min/1.73 m2(42.9% vs 17.8%, p<0.001). Notably, in the group with eGFR values <15 mL/min/1.73 m2, the anaemia rate was 100%. Logistic regression analysis showed that factors affecting anaemia in patients with IgA nephropathy included being female (OR 3.02, 95% CI 1.76 to 5.17), low albumin levels (OR 0.87, 95% CI 0.82 to 0.93), reduced eGFR values (OR 0.98, 95% CI 0.97 to 0.99) and renal tubulointerstitial lesions >50% (OR 2.57, 95% CI 1.22 to 5.40).

Conclusions

The female sex, hypoalbuminaemia, reduced eGFR levels and severe renal tubulointerstitial lesions were correlated with renal anaemia in patients with IgA nephropathy. These results provide new insight into our understanding of anaemia in IgA nephropathy and may improve the management and treatment of clinical renal anaemia.
Protocol for a scoping review to understand how interorganisational electronic health records affect hospital physician and pharmacist decisions
Authors: Scott Philip , Nakkas Haythem , Roderick Paul
Published: January 2019

Introduction

Patient records are often fragmented across organisations and departments in UK health and care services, often due to substandard information technology. However, although government policy in the UK and internationally is strongly pushing ‘digital transformation’, the evidence for the positive impact of electronic information systems on cost, quality and safety of healthcare is far from clear. In particular, the mechanisms by which information availability is translated into better decision-making are not well understood. We do not know when a full interorganisational record is more useful than a key information summary or an institutional record. In this paper, we describe our scoping review of how interorganisational electronic health records affect decision-making by hospital physicians and pharmacists.

Methods and analysis

This scoping review will follow the Arksey and O’Malley (2005) methodology. The review has adopted sociotechnical systems thinking and the notion of distributed cognition as its guiding conceptual models. The UK National Institute for Health and Care Excellence Healthcare Databases Advanced Search will be used, as it incorporates key sources including PubMed, Medline, Embase, HMIC and Health Business Elite. A hand search will be conducted using the reference lists of included studies to identify additional relevant articles. A two-part study selection process will be used: (1) a title and abstract review and (2) full text review. During the first step, two researchers separately will review the citations yielded from the search to determine eligibility based on the defined inclusion and exclusion criteria. Related articles will be included if they are empirical studies that address how interorganisational records affect decision-making by hospital physicians and pharmacists.

Ethics and dissemination

The results will be disseminated through stakeholder meetings, conference presentations and peer-reviewed publication. The data used are from publicly available secondary sources, so this study does not require ethical review.
Pros and cons of gastric bypass surgery in individuals with obesity and type 2 diabetes: nationwide, matched, observational cohort study
Authors: Liakopoulos Vasileios , Franzén Stefan , Svensson Ann-Marie , Miftaraj Mervete , Ottosson Johan , Näslund Ingmar , Gudbjörnsdottir Soffia , Eliasson Björn
Published: January 2019

Objectives

Long-term effects of gastric bypass (GBP) surgery have been presented in observational and randomised studies, but there are only limited data for persons with obesity and type 2 diabetes mellitus (T2DM) regarding postoperative complications.

Design

This is a nationwide observational study based on two quality registers in Sweden (National Diabetes Register, NDR and Scandinavian Obesity Surgery Register, SOReg) and other national databases.

Setting

After merging the data, we matched individuals with T2DM who had undergone GBP with those not surgically treated for obesity on propensity score, based on sex, age, body mass index (BMI) and calendar time. The risks of postoperative outcomes (rehospitalisations) were assessed using Cox regression models.

Participants

We identified 5321 patients with T2DM in the SOReg and 5321 matched controls in the NDR, aged 18–65 years, with BMI >27.5 kg/m² and followed for up to 9 years.

Primary and secondary outcome measures

We assessed risks for all-cause mortality and hospitalisations for cardiovascular disease, severe kidney disease, along with surgical and other medical conditions.

Results

The results agree with the previously suggested lower risks of all-cause mortality (49%) and cardiovascular disease (34%), and we also found positive effects for severe kidney disease but significantly increased risks (twofold to ninefold) of several short-term complications after GBP, such as abdominal pain and gastrointestinal conditions, frequently requiring surgical procedures, apart from reconstructive plastic surgery. Long-term, the risk of anaemia was 92% higher, malnutrition developed approximately three times as often, psychiatric diagnoses were 33% more frequent and alcohol abuse was three times as great as in the control group.

Conclusions

This nationwide study confirms the benefits and describes the panorama of adverse events after bariatric surgery in persons with obesity and T2DM. Long-term postoperative monitoring and support, as better selection of patients by appropriate specialists in interdisciplinary settings, should be provided to optimise the outcomes.
Longitudinal associations of gross motor development, motor milestone achievement and weight-for-length z score in a racially diverse cohort of US infants
Authors: Shoaibi Azza , Neelon Brian , Østbye Truls , Benjamin-Neelon Sara E
Published: January 2019

Objectives

To investigate longitudinal associations between gross motor development, motor milestone achievement and weight-for-length z scores in a sample of infants. In a secondary aim, we explored potential bidirectional relationships, as higher weight-for-length z scores may impede motor development, and poor motor development may lead to obesity.

Design

The design was an observational birth cohort.

Setting

We used data from the Nurture study, a birth cohort of predominately black women and their infants residing in the Southeastern USA.

Participants

666 women enrolled their infants in Nurture. We excluded infants with missing data on exposure, outcome or main covariates, leaving a total analytic sample of 425 infants.

Primary outcome

The outcome was weight-for-length z score, measured when infants were 3, 6, 9 12 months.

Results

Among infants, 64.7% were black, 18.8% were white and 16.9% were other/multiple race. Mean (SD) breastfeeding duration was 17.6 (19.7) weeks. Just over one-third (38.5%) had an annual household income of < $20 000. After adjusting for potential confounders, higher motor development score was associated with lower weight-for-length z score (−0.004; 95% CI −0.001 to –0.007; p=0.01), mainly driven by associations among boys (−0.007; 95% CI −0.014 to –0.001; p=0.03) and not girls (0.001; 95% CI −0.005 to 0.008; p=0.62). Earlier crawling was the only milestone associated with a lower weight-for-length z score at 12 months (−0.328; 95% CI −0.585 to 0.072; p=0.012). However, this association appeared to be driven by male infants only (−0.461; 95% CI −0.825 to −0.096; p=0.01). Weight-for-length z score was unrelated to subsequent motor development score and was thus not bidirectional in our sample.

Conclusions

Higher motor development score and earlier crawling were associated with lower subsequent weight-for-length z score. However, this was primary true for male infants only. These findings contribute to the growing body of evidence suggesting that delayed motor development may be associated with later obesity.
Prevalence and correlates of ‘sexual competence’ at first heterosexual intercourse among young people in Britain
Authors: Palmer Melissa J , Clarke Lynda , Ploubidis George B , Wellings Kaye
Published: January 2019

Background

A greater understanding of the circumstances of first sexual intercourse, as opposed to an exclusive focus on age at occurrence, is required in order that sexual health and well-being can be promoted from the onset of sexual activity.

Methods

We used data from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) conducted in Britain. Participants were categorised as ‘sexually competent’ at first heterosexual intercourse if the following self-reported criteria applied to the event: contraceptive use, autonomy of decision, both partners ‘equally willing’, and occurrence at the perceived ‘right time’. We examined the prevalence of ‘sexual competence’, and its component parts, by age at first intercourse among 17–24-year-olds. Using multivariable logistic regression, we explored associations between sexual competence and potential explanatory factors.

Results

Variation in ‘sexual competence’ and its component parts was associated with, but not fully explained by, age at first sex: 22.4% and 36.2% of men and women who had first sex at age 13–14 years were categorised as ‘sexually competent’, rising to 63.7% and 60.4% among those aged ≥18 years at first intercourse. Lack of sexual competence was independently associated with: first intercourse before the age of 16 years, area-level deprivation (men only), lower educational level, black ethnicity (women only), reporting ‘friends’ as main source of learning about sex (women only), non-’steady’ relationship at first sex, and uncertainty of first partner’s virginity status.

Conclusions

A substantial proportion of young people in Britain transition into sexual activity under circumstances incompatible with positive sexual health. Social inequalities in sexual health are reflected in the context of first intercourse.
Microfluidic encapsulation of SN-38 in block copolymer nanoparticles: effect of hydrophobic block composition on loading and release properties
Authors: Jensen Danica , Cao Yimeng , Lu Changhai , Wulff Jeremy E. , Moffitt Matthew G.
Published: January 2019

A gas–liquid microfluidic reactor was used to prepare polymer nanoparticles (PNPs) containing the drug 7-ethyl-10-hydroxy camptothecin (SN-38) from a series of poly(methyl caprolactone-co-caprolactone)-b-poly(ethylene oxide) (P(MCL-co-CL)-b-PEO) amphiphilic block copolymers with variable MCL content in the hydrophobic block. All three copolymers formed spheres with ∼20 nm core diameters by TEM, although some rigid rod-like aggregates were also formed by the PMCL-50 and PMCL-75 copolymers. SN-38 encapsulation efficiencies (EE = 2.7%–3.0%) and loading levels (DL = 2.0%–2.9%) were similar for the three copolymers. In vitro release kinetics became significantly slower as the MCL content increased, with release half times increasing monotonically from 3.4 to 6.2 h as the MCL content of the hydrophobic block increased from 50% to 100%. The ability to systematically tune release half times via controlled variation in the hydrophobic block composition, while maintaining constant PNP size and loading levels, represents an intriguing chemical handle for the optimization of SN-38 nanomedicines.
Mesozoic C-cycle perturbations and climate: evidence for increased resilience of the Cretaceous biosphere to greenhouse pulses
Authors: Weissert Helmut
Published: January 2019

The Mesozoic C-isotope record traces the history of the global carbon cycle. Major perturbations of the carbon cycle triggered by extraordinary volcanic activity are recorded in negative spikes coupled with positive C-isotope excursions. Prominent examples are the C-isotope anomaly events at the Permian–Triassic boundary and at the Triassic–Jurassic boundary, in the Toarcian or in the Aptian. While the major volcanic pulses at the Permian–Triassic and Triassic–Jurassic boundaries are considered as the main trigger of mass extinctions, carbon cycle perturbations in the Jurassic and Cretaceous were not accompanied by comparable extreme changes in marine or terrestrial biota. The data suggest either that changes in degassing of large igneous provinces explain the difference in the biota’s response to perturbation or (and) that the resilience of the Mesozoic biosphere to volcanic pulses changed through time. It is hypothesized that two factors contributed to the increased resilience of the biosphere in the Late Mesozoic: (1) starting in the Middle Jurassic, pelagic carbonate developed into an important sink of CO2in the long-term carbon cycle, contributing to increased resilience of the carbon cycle to perturbations, and (2) increasing fragmentation of Pangea resulted in the establishment of a transequatorial current system coupled with equatorial upwelling. This circulation pattern was intensified during greenhouse pulses. Increased marine productivity and widespread basinal anoxia favoured burial of organic carbon. Increased resilience of the Cretaceous biosphere against volcanic activity may explain why Deccan Trap volcanism was no longer sufficient as a trigger of a mass extinction at the Cretaceous–Paleogene boundary.
How Far can Neural Correlations Reduce Uncertainty? Comparison of Information Transmission Rates for Markov and Bernoulli Processes
Authors: Pregowska Agnieszka , Kaplan Ehud , Szczepanski Janusz
Published: January 2019

The nature of neural codes is central to neuroscience. Do neurons encode information through relatively slow changes in the firing rates of individual spikes (rate code) or by the precise timing of every spike (temporal code)? Here we compare the loss of information due to correlations for these two possible neural codes. The essence of Shannon’s definition of information is to combine information with uncertainty: the higher the uncertainty of a given event, the more information is conveyed by that event. Correlations can reduce uncertainty or the amount of information, but by how much? In this paper we address this question by a direct comparison of the information per symbol conveyed by the words coming from a binary Markov source (temporal code) with the information per symbol coming from the corresponding Bernoulli source (uncorrelated, rate code). In a previous paper we found that a crucial role in the relation between information transmission rates (ITRs) and firing rates is played by a parameter [Formula: see text], which is the sum of transition probabilities from the no-spike state to the spike state and vice versa. We found that in this case too a crucial role is played by the same parameter [Formula: see text]. We calculated the maximal and minimal bounds of the quotient of ITRs for these sources. Next, making use of the entropy grouping axiom, we determined the loss of information in a Markov source compared with the information in the corresponding Bernoulli source for a given word length. Our results show that in the case of correlated signals the loss of information is relatively small, and thus temporal codes, which are more energetically efficient, can replace rate codes effectively. These results were confirmed by experiments.
On the effects of the Lorentz symmetry violation in a magnetic medium at a low energy scenario
Authors: Bakke K. , Salvador C. , Belich H.
Published: January 2019

It is analyzed the influence of a fixed background that breaks the Lorentz symmetry on the scalar field in the nonrelativistic regime. It is considered a medium with a nonuniform magnetization and the presence of an induced electric field. Then, due to the effects of the Lorentz symmetry violation, it is shown that the interaction of the scalar field with the magnetic field (produced by the nonuniform magnetization) and the induced electric field yields an effective potential analogous to the double anharmonic oscillator. Thereby, a discrete spectrum of energy can stem from the effects of the violation of the Lorentz symmetry on the scalar field.
Trembling motion of the wave packet in armchair graphene nanoribbons (AGNRs)
Authors: Majid M. J. , Alaa M. H.
Published: January 2019

A treatment of the trembling motion or Zitterbewegung (ZB) phenomena in the armchair graphene nanoribbons (AGNRs) by using long-wave approximation is presented theoretically. We are first interested to study the time dependence of the average values for the current density in AGNR. The longitudinal and transversal components of the current density operator are derived analytically in the Heisenberg representation. The wave packet in a Gaussian distribution is considered with half-width d and a carrier wave vector in the longitudinal orientation k[Formula: see text]. The average values of the current density which represent the current induced by the motion of the electrons along the nanoribbon are calculated numerically. The interference between two energy branches, or the corresponding upper and lower energy states, leads to the trembling motion in the armchair graphene nanoribbon, and hence, our results emphasized that the phenomena of ZB has an aperiodic and nontransient oscillation in the longitudinal and transversal direction, respectively. The average values for the current density for AGNRs are calculated with extremely large value of N and compared with infinite pristine graphene.
Compact, Programmable, Two-Stage Configuration for Implantable Biopotential Recording Amplifiers
Authors: Maghami Mohammad Hossein , Sodagar Amir Masoud
Published: January 2019

This paper proposes an area-efficient CMOS amplifier for neural recording applications. The proposed neural amplifier takes advantage of indirect negative feedback to realize a rather low upper [Formula: see text]3-dB cutoff frequency. As a result, the capacitance needed to realize the cutoff frequency is so small that can be easily implemented on-chip. Moreover, the proposed circuit also employs attenuators in the same feedback loop in order to further reduce the silicon area consumed by the capacitors and at the same time to increase the input impedance of the circuit. Designed based on a two-stage configuration, the amplifier provides tunable lower cutoff frequency and digitally-programmable upper cutoff frequency and voltage gain. The circuit is designed in a 0.18-[Formula: see text]m technology, and consumes 0.022[Formula: see text]mm2 and 0.27[Formula: see text]mm2 of chip areas for single- and eight-channel designs, respectively. Operated with a supply voltage of 1.8[Formula: see text]V, power consumption of the proposed amplifier is 36.7[Formula: see text][Formula: see text]W with the simulated input-referred noise of 4[Formula: see text][Formula: see text] over 1[Formula: see text]Hz–10[Formula: see text]kHz for each channel. The amplifier also provides an output swing of 0.95 Vpp with a total harmonic distortion of [Formula: see text]50[Formula: see text]dB at the frequency of 1[Formula: see text]kHz.
An Electronically Controllable Voltage-Mode MOSFET-Only Single-Input Dual-Output Filter
Authors: Yesil Abdullah , Ozenli Deniz , Arslan Emre , Kacar Fırat
Published: January 2019

A new design of voltage mode (VM), single-input dual-output MOSFET-only filter which has electronic tunability property is presented without using passive circuit elements like resistors and capacitors. The filter topology is able to realize low-pass (LP) and band-pass (BP) filter functions with using the same circuit configuration. The proposed filter is laid-out in the Cadence environment using 0.18-[Formula: see text]m TSMC CMOS technology parameters. The layout area is only 344.4[Formula: see text][Formula: see text]m2 and the power consumption is about 170[Formula: see text][Formula: see text]W. Furthermore, variations in the center frequency of the BP filter are presented performing Monte Carlo (MC) analysis to reinforce the filter results. Also, the noise performance of the proposed filter is investigated and it is shown that the theoretical and simulation results are in very good agreement.
Efficient PSoC Implementation of Modular Multiplication and Exponentiation Based on Serial-Parallel Combination
Authors: Issad M. , Boudraa B. , Anane M. , Bellemou A. M.
Published: January 2019

This paper presents an FPGA implementation of the most critical operations of Public Key Cryptography (PKC), namely the Modular Exponentiation (ME) and the Modular Multiplication (MM). Both operations are integrated as Programmable System on Chip (PSoC) where the processor Microblaze of Xilinx is used for flexibility. Our objective is to achieve a best trade-off between time execution, occupied area and flexibility. The implementation of these operations on such environment requires taking into account several criteria. Indeed, the Hardware (HW) architectures data bus should be smaller than the input data length. The design must be scalable to support different security levels. The implementation achieves optimums execution time and HW resources number. In order to satisfy these constraints, Montgomery Power Ladder (MPL) and Montgomery Modular Multiplication (MMM) algorithms are utilized for the ME and the MM implementations as HW accelerators, respectively. Our implementation approach is based on the digit-serial method for performing the basic arithmetic operations. Efficient parallel and pipeline strategies are developed at the digit level for the optimization of the execution times. The application for 1024-bits data length shows that the MMM run in 6.24[Formula: see text][Formula: see text]s and requires 647 slices. The ME is executed in 6.75[Formula: see text]ms using 2881 slices.
Distributed Amplifier Based on Monolayer Graphene Field Effect Transistor
Authors: Safari Ali , Dousti Massoud , Tavakoli Mohammad Bagher
Published: January 2019

Due to the ultra-high carrier mobility and ultralow resistivity of Graphene channel, a Graphene field effect transistor (GFET) is an interesting candidate for future RF and microwave electronics. In this paper, the introduction and review of existing compact circuit-level model of GFETs are presented. A compact GFET model based on drift-diffusion transport theory is then implemented in Verilog-A for RF/microwave circuit analysis. Finally, the GFET model is used to design a GFET-based distributed amplifier (DA) using advanced design system (ADS) tools. The simulation results demonstrate a gain of 8[Formula: see text]dB, an input/output return loss less than [Formula: see text]10[Formula: see text]dB, [Formula: see text]3[Formula: see text]dB bandwidth from DC up to 5[Formula: see text]GHz and a dissipation of about 60.45[Formula: see text]mW for a 1.5[Formula: see text]V power supply. The main performance characteristics of the distributed amplifier are compared with 0.18[Formula: see text][Formula: see text]m CMOS technology.
Dynamic Energy Reduction in TCAM Match-Line Sensing Using Charge-Sharing and Positive Feedback
Authors: Ali Syed Iftekhar , Hakim Safayat Bin
Published: January 2019

Network routers use ternary content addressable memory (TCAM) for high-speed table look-up. A match-line (ML) sensing scheme for TCAM combining charge-sharing and positive feedback is presented. The objective is to simplify the ML sense amplifier (MLSA) of existing charge-sharing scheme while reducing ML energy consumption during look-up. The look-up has been performed in two steps. In the first step, a segment of each TCAM word is compared with the search key to detect large percentage of the mismatched words. The detected mismatched words are deactivated in the second step to reduce energy consumption. In the second step, the charge stored in a matched ML first segment is shared with second ML segment. Use of positive feedback in this step makes the MLSA circuit simple. Post-layout simulations implemented using 180[Formula: see text]nm 1.8[Formula: see text]V CMOS logic have been performed. In addition to lower scheme complexity and 16.5% reduction in circuit area, the proposed scheme provides dynamic energy saving up to 5.5% and peak power reduction of 52% compared to existing state-of-the-art charge-sharing technique.
Expediting Binary Fuzzing with Symbolic Analysis
Authors: Xu Luhang , Yin Liangze , Dong Wei , Jia Weixi , Li Yongjun
Published: January 2019

Fuzzing is an important method for binary vulnerability mining. It can analyze binary programs without their source codes, which is not easy to do by other technologies. But due to the blindness of input generation, binary fuzzing often falls into traps for a long time when the new mutated inputs cannot generate unexplored paths. In this paper, we propose an efficient and flexible fuzzing framework named Tinker. It defines the growth rate of path coverage to measure the current state of fuzzing. If the fuzzing falls into low-speed or blocked states, a symbolic analysis procedure is invoked to generate a new input which can help the fuzzing jump out of the trap. In the symbolic analysis procedure, we employ dynamic execution to track the traversed nodes. The untraversed branches are then identified according to the recorded data of American Fuzzy Lop (AFL) [M. Zalewski, American Fuzzy Lop (2014), http://lcamtuf.coredump.cx/afl/ ]. At last, we employ control flow graph (CFG) to construct complete paths to these branches and a new input is generated using symbolic execution. Moreover, to expedite the detection of vulnerabilities, we generate inputs which trigger more high-risk system calls first, such that the possibility of finding vulnerabilities can be improved. Tinker has been implemented and the experiments on DARPA CGC benchmark show that Tinker is more efficient in vulnerability mining than state-of-the-art binary vulnerability mining tools.
Recursive axiomatizations for representable posets
Authors: Egrot Rob
Published: January 2019

We use model theoretic techniques and games to construct explicit first-order axiomatizations for the classes of posets that can be represented as systems of sets, where the order relation is given by inclusion, and existing meets and joins of specified countable cardinalities correspond to intersections and unions, respectively.
Theoretical study on nanostructural modifications of the Si(111) surface
Authors: Dong Yue-Hang , Liu Xiao-Hui , Su Wan-Sheng , Zhao Li-Zhen , Zang Qing-Jun , Lu Wen-Cai
Published: January 2019

Modified Si(111) surface with designed nanostructural modifications including grown pits, nanobars and nanoislands as well as deposited hill-, diamond- and cage-like nanoclusters were studied using density-functional theory (DFT) calculations. The thermal stabilities, electronic structures and optical properties of these various nanostructural modifications of the Si(111) surface were calculated and discussed. The results indicate that the optical absorption of the modified Si(111) surface can be enhanced by these surface modifications especially when depositing diamond-like nanoclusters on the surface.
Validation of Multi-Physics Integrated Procedure for the HCPB Breeding Blanket
Authors: Favetti R. , Chiovaro P. , Di Maio P. A. , Spagnuolo G. A.
Published: January 2019

The wide range of requirements and constraints involved in the design of nuclear components for fusion reactors makes the development of multi-physics analysis procedures of utmost importance. In the framework of the European DEMO project, the Karlsruhe Institute of Technology (KIT) is dedicating several efforts to the development of a multi-physics analysis tool allowing the characterization of breeding blanket design points which are consistent from the neutronic, thermal-hydraulic and thermal-mechanical points of view. In particular, a procedure developed at KIT is characterized by the implementation of analysis software only. A preliminary step for the validation of such a procedure has been accomplished using a dedicated model of the DEMO Helium Cooled Pebble Bed Blanket 4th outboard module. A global model representative of nuclear irradiation in DEMO and two local models have been set up. Nuclear power deposition and the spatial distribution of its volumetric density have been calculated using Monte Carlo N-Particle transport code for the aforementioned models and compared in order to validate the procedure set up. The outcomes of this comparative study are herein presented and critically discussed.
On Natural Frequency of Finite Element Modeled Geometrically Imperfect Shear Deformable Functionally Gradient Sandwich Arches in Thermal Environment
Authors: Ali Vakkar , Alklaibi A. M. , Talha Mohammad
Published: January 2019

In the present study, the natural frequency of finite element modeled geometrically imperfect shear deformable functionally gradient (FG) sandwich arches in the thermal environment has been studied. The formulation is based on the higher-order shear deformation theory. The upper layer of the sandwich arch is considered to be ceramics, whereas the lower layer is made of metal. The core of the sandwich arch is made of gradient materials. The material properties of the sandwich arches are varying continuously in the thickness direction only by a simple power-law distribution in terms of volume fractions of the constituents. Comparison and convergence studies have been performed to validate the present formulation with the limited available literature. Parametric studies have been performed to study the effect of various influencing parameters on the frequency of the FG sandwich arches, i.e., volume fraction index, thickness-to-length ratio, imperfection amplitude, and opening angle. New results are presented which can be treated as benchmark solutions for future researches.
Nonlinear Static and Dynamic Thermal Buckling Analysis of Spiral Stiffened Functionally Graded Cylindrical Shells with Elastic Foundation
Authors: Shaterzadeh Alireza , Foroutan Kamran , Ahmadi Habib
Published: January 2019

In this paper, an analytical method is used to study the nonlinear static and dynamic thermal buckling analysis of imperfect spiral stiffened functionally graded (SSFG) cylindrical shells. The SSFG cylindrical shell is surrounded by a linear and nonlinear elastic foundation. The proposed linear model is based on the two-parameter elastic foundation (Winkler and Pasternak). A three-parameter elastic foundation with hardening/softening cubic nonlinearity is used for nonlinear model. The material properties are temperature dependent and assumed to be continuously graded in the thickness direction. Also, for thermal buckling analysis, the uniform and linear temperature distribution in thickness direction is considered. The SSFG cylindrical shells are considered with various angles for spiral stiffeners. The strain–displacement relations are obtained based on the von Kármán nonlinear equations and the classical plate theory of shells. The smeared stiffener technique and the Galerkin method are applied to solve the nonlinear problem. In order to find the nonlinear dynamic thermal buckling responses, the fourth-order Runge–Kutta method is used. To validate the results, comparisons are made with those available in literature and good agreements are shown. The effects of various geometrical and material parameters are investigated on the nonlinear static and dynamic thermal buckling response of SSFG cylindrical shells.
Stable Perovskite Solar Cells with Improved Hydrophobicity Based on BHT Additive
Authors: Jin Lifen , Huang Yuelong , Ma Zhu , Mao Hanying , Li Yuepeng , Yu Hua , Peng Changtao
Published: January 2019

Remarkable progress has been achieved in organometallic halide perovskite solar cells (PSCs). However, poor environmental stability of PSCs has been proved to be challenging and needs further improvement. Here, a strategy of butylated hydroxytoluene (BHT) antioxidant additive with hydrophobic tert butyl and hydrophilic hydroxyl is developed to enhance the hydrophobicity, control nucleation rate and passivate the defect states of perovskite. The tert butyl group effectively prevents the penetration of moisture, as well as the formed hydrogen bond between hydroxyl group and iodine controls the assembly process of BHT and perovskite. By optimizing weight ratio of BHT and MAPbI3 in precursor solution, the power conversion efficiency of PSCs increased from 14.93% to 18.28% and greatly enhanced device stability compared with control device. We believe that our tactic of BHT additive can be applied to various perovskite films and will facilitate the realization of stable perovskite optoelectronics.
Bioinspired Fabrication and Evaluation of Molecularly Imprinted Nanocomposite Membranes with Inorganic/Organic Multilevel Structure for the Selective Separation of Emodin
Authors: Yu Chao , Lu Jian , Zhang Qi , Fan Hougang , Meng Minjia , Zhou Shi , Jiang Yinhua , Yan Yongsheng , Wu Yilin , Li Chunxiang
Published: January 2019

High purity emodin is in great demand with the development of medical treatment. Molecularly imprinted membranes (MIMs) have gained wide attention for selective separation of emodin due to its preferable selectivity. In this work, we describe a simple two-step method for developing emodin-imprinted TiO2@CA (ETMIMs) and emodin-imprinted SiO2@CA (ESMIMs) based on organic–inorganic nanoparticle (SiO2/TiO2) modified cellulose acetate membranes at room temperature. SiO2/TiO2 is used to improve the structural stability and roughness of membranes, and dopamine is used as the functional monomer and crosslinker. Importantly, the as-prepared membranes not only exhibited enhanced rebinding capacity ([Formula: see text] and [Formula: see text]) but also possessed superior rebinding selectivity (2.76 and 2.99 for physcion and 2.42 and 3.30 for aloe emodin onto ETMIMs and ESMIMs) as well as permselectivity (7.59 and 6.69 for physcion and 5.94 and 5.78 for aloe emodin onto ETMIMs and ESMIMs). The regeneration ability of ETMIMs and ESMIMs still maintained 90.4% and 89.2% of the original rebinding capacity after 10 cycling steps, respectively. The ETMIMs and ESMIMs obtained in this work show potential applications for selective separation and purification of emodin from analogs.
Delayed information induces oscillations in a dynamical model for infectious disease
Authors: Kumar Anuj , Srivastava Prashant K , Yadav Anuradha
Published: January 2019

During disease outbreak, it has been observed that information about the disease prevalence induces the individual’s behavioral changes. This information is usually assumed to be generated by the density of infective individuals and active mass media. The delay in reporting of these infective individuals may have its impact on generated information. Hence, to study the impact of delay on information generation, and therefore on the disease dynamics, a delay differential equation model is proposed and analyzed. The dynamics of information with delay effect is also modeled by a separate rate equation. Model analysis is performed and a unique infected equilibrium is obtained when the basic reproduction number ([Formula: see text]) is greater than one, whereas the disease free equilibrium always exists. When [Formula: see text], the disease free equilibrium is found to be locally stable independent of delay effect. The unique infected equilibrium is found to be locally stable till delay reaches a threshold value. The global stability of the unique infected equilibrium is also established under some parametric conditions by constructing a suitable Lyapunov function. The occurrence of Hopf bifurcation is observed when the delay in information crosses the threshold value. Analytically, the direction and stability of bifurcating periodic solutions is established. Further, we observed the occurrence of Hopf-Hopf bifurcation at two different delays. At first delay threshold, the endemic equilibrium loses its stability and produces periodic oscillations via Hopf bifurcation. It further regains its stability at second delay threshold via another Hopf bifurcation. Hence, the delay effect on information shows possibility of stability switches. Numerical experiments are carried out to support the obtained analytical results. Our study infers that the disease will show persistent oscillations if there is a significant time lag in reporting of infective after the disease outbreak. Thus, the delay in dissemination of information shows rich and complex dynamics in the model and provides important insights. We also observe numerically that the saturation in information plays a significant role on stability of infected equilibrium in presence of delay.