bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimized mid-infrared thermal emitters for applications in aircraft countermeasures
Authors: Lorenzo Simón G. , You Chenglong , Granier Christopher H. , Veronis Georgios , Dowling Jonathan P.
Published: December 2017

We introduce an optimized aperiodic multilayer structure capable of broad angle and high temperature thermal emission over the 3 μm to 5 μm atmospheric transmission band. This aperiodic multilayer structure composed of alternating layers of silicon carbide and graphite on top of a tungsten substrate exhibits near maximal emittance in a 2 μm wavelength range centered in the mid-wavelength infrared band traditionally utilized for atmospheric transmission. We optimize the layer thicknesses using a hybrid optimization algorithm coupled to a transfer matrix code to maximize the power emitted in this mid-infrared range normal to the structure’s surface. We investigate possible applications for these structures in mimicking 800–1000 K aircraft engine thermal emission signatures and in improving countermeasure effectiveness against hyperspectral imagers. We find these structures capable of matching the Planck blackbody curve in the selected infrared range with relatively sharp cutoffs on either side, leading to increased overall efficiency of the structures. Appropriately optimized multilayer structures with this design could lead to matching a variety of mid-infrared thermal emissions. For aircraft countermeasure applications, this method could yield a flare design capable of mimicking engine spectra and breaking the lock of hyperspectral imaging systems.
Robust plasmonic hot-spots in a metamaterial lattice for enhanced sensitivity of infrared molecular detection
Authors: Ishikawa Atsushi , Hara Shuhei , Tanaka Takuo , Zhang Xiang , Tsuruta Kenji
Published: December 2017

High-density and long-lived plasmonic hot-spots are an ideal system for high-sensitive surface-enhanced infrared absorption (SEIRA), but these conditions are usually incompatible due to unwanted near-field coupling between the adjacent unit structures. Here, by fully controlling plasmonic interference in a metamaterial lattice, we experimentally demonstrate densely packed long-lived quadrupole plasmons for high-sensitive SEIRA. The metamaterial consists of a strongly coupled array of super- and sub-radiant plasmonic elements to exhibit an electromagnetic transparency mode at 1730 cm−1, which spectrally overlaps with the C=O vibrational mode. In the SEIRA measurement, the C=O mode of poly(methyl methacrylate) molecules is clearly observed as a distinct dip within a transmission peak of the metamaterial. The corresponding numerical simulations reveal that constructive interference uniformly forms coherent quadrupole plasmons over the metamaterial lattice, leading to a stronger molecular signal from the system. Our metamaterial approach provides a robust way to construct ideal hot-spots over the sample, paving the way toward a reliable sensing platform of advanced infrared inspection technologies.
Core losses of a permanent magnet synchronous motor with an amorphous stator core under inverter and sinusoidal excitations
Authors: Yao Atsushi , Sugimoto Takaya , Odawara Shunya , Fujisaki Keisuke
Published: December 2017

We report core loss properties of permanent magnet synchronous motors (PMSM) with amorphous magnetic materials (AMM) core under inverter and sinusoidal excitations. To discuss the core loss properties of AMM core, a comparison with non-oriented (NO) core is also performed. In addition, based on both experiments and numerical simulations, we estimate higher (time and space) harmonic components of the core losses under inverter and sinusoidal excitations. The core losses of PMSM are reduced by about 59% using AMM stator core instead of NO core under sinusoidal excitation. We show that the average decrease obtained by using AMM instead of NO in the stator core is about 94% in time harmonic components.
Percolating transport in superconducting nanoparticle films
Authors: Fostner Shawn , Nande Amol , Smith Alex , Martinez Gazoni Rodrigo , Grigg Jack , Temst Kristiaan , Van Bael Margriet J. , Brown Simon A.
Published: December 2017

Nanostructured and disordered superconductors exhibit many exotic fundamental phenomena, and also have many possible applications. We show here that films of superconducting lead nanoparticles with a wide range of particle coverages, exhibit non-linear V(I) characteristics that are consistent with percolation theory. Specifically, it is found that V∝(I−Ic)a, where a = 2.1 ± 0.2, independent of both temperature and particle coverage, and that the measured critical currents (Ic) are also consistent with percolation models. For samples with low normal state resistances, this behaviour is observable only in pulsed current measurements, which suppress heating effects. We show that the present results are not explained by vortex unbinding [Berezinskii-Kosterlitz-Thouless] physics, which is expected in such samples, but which gives rise to a different power law behaviour. Finally, we compare our results to previous calculations and simulations, and conclude that further theoretical developments are required to explain the high level of consistency in the measured exponents a.
Note: Ultraviolet photodissociation dynamics of o-bromofluorobenzene in 234–267 nm
Authors: Chen Min , He Chao , Bai Xilin , Zhao Dongfeng , Chen Yang
Published: December 2017

Photodissociation dynamics of o-bromofluorobenzene in the 234–267 nm range has been experimentally investigated using the DC-slice velocity map imaging technique. It is found that Br(2P3/2) atoms produced from repulsive singlet state surfaces via excitation of one or more 1ππ* excited states dominate the Br photofragments. The quantum yield of spin-orbit excited Br(2P1/2) atoms was found to be only ∼0.02, indicating weak spin-orbit couplings in the low-lying electronic states of o-bromofluorobenzene.
Thermodynamic properties of Heusler Fe2VSi
Authors: Ito Masakazu , Kai Keita , Furuta Tatsuya , Manaka Hirotaka , Terada Norio , Hiroi Masahiko , Kondo Akihiro , Kindo Koichi
Published: December 2017

We investigated temperature, T, dependence of magnetization, M(T), electrical resistivity, ρ(T), and specific heat, Cp(T), for the Heusler compound Fe2VSi. M(T) shows anomalies at TN1 ∼ 115 K and at TN2 ∼ 35 K. The anomaly at TN1 is caused by the magnetic transition with a crystal structural change. On the other hand, ρ(T) and Cp(T) show only anomaly at TN1, and no trace of anomaly at TN2 is observed. Because of the irreversibility of M(T), which is the characteristic of spin-glass freezing, appears below TN2, a spin-glass freezing may occur at TN2. From the analogy of the Heusler compound (Fe1−xVx)3Si with the cubic D03 crystal structure, (0 ≤ x ≤ 0.2), we suggested that the atomic disorder of V site by the Fe atoms gives rise to the magnetic frustration. This could be cause for the spin-glass freezing. By the Clausius-Clapeyron relation, pressure, P, derivative of TN1, (dTN1dP), is estimated to be ∼−10 K/Gpa.
The use of pulsed magnetic fields to increase the uptake of iron oxide nanoparticles by living cells
Authors: Uzhytchak M. , Lynnyk A. , Zablotskii V. , Dempsey N. M. , Dias A. L. , Bonfim M. , Lunova M. , Jirsa M. , Kubinová Š. , Lunov O. , Dejneka A.
Published: December 2017

Remote control of the interaction of magnetic nanoparticles with cells is fundamental to any potential downstream applications of magnetic nanoparticles such as gene and drug delivery vehicles and magnetic cell labeling. Thus, approaches based on the application of external magnetic fields to increase the efficiency of magnetic cell labeling are desirable. Here, we report a simple approach that enhances magnetic cell labeling using pulsed magnetic fields. The rate of uptake of superparamagnetic iron oxide nanoparticles (SPIONs) and transport across the cell membrane were enhanced upon application of a high intensity (7 T) short pulse width (∼15 μs) magnetic field. We present a quantitative analysis and mechanistic explanation of how a pulsed magnetic field influences the uptake of SPIONs by cells. Our findings offer insights into the mechanics of how pulsed magnetic fields can be effectively used to optimize magnetic cell labeling, which can provide a basis for better controlled biomedical applications of SPIONs.
Non-destructive spatial characterization of buried interfaces in multilayer stacks via two color picosecond acoustics
Authors: Faria Jorge C. D. , Garnier Philippe , Devos Arnaud
Published: December 2017

We demonstrate the ability to construct wide-area spatial mappings of buried interfaces in thin film stacks in a non-destructive manner using two color picosecond acoustics. Along with the extraction of layer thicknesses and sound velocities from acoustic signals, the morphological information presented is a powerful demonstration of phonon imaging as a metrological tool. For a series of heterogeneous (polymer, metal, and semiconductor) thin film stacks that have been treated with a chemical procedure known to alter layer properties, the spatial mappings reveal changes to interior thicknesses and chemically modified surface features without the need to remove uppermost layers. These results compare well to atomic force microscopy scans showing that the technique provides a significant advantage to current characterization methods for industrially important device stacks.
Study for optimizing the design of optical temperature sensor
Authors: Li Panpan , Sun Zhen , Shi Ruixin , Liu Guofeng , Fu Zuoling , Wei Yanling
Published: December 2017

The correlations between temperature sensitivity (relative sensitivity Sr and absolute sensitivity Sa) and thermally coupled level gaps (ΔE) are vital but less-studied for potential applications in scientific research, industrial production, clinical medicine, and so on. We take YbPO4:Ln3+ (Ln = Tm3+, Ho3+, and Er3+) up-conversion phosphors as a case to study the relationships between temperature sensitivity (Sr, Sa) and ΔE. The results of various discussions, including the experimental data of temperature sensitivity based on YbPO4:Ln3+ (Ln = Tm3+, Ho3+, and Er3+) and theoretical derivation from original formulas, show that Sr and ΔE are linearly positive correlation, which is invalid for Sa. Noticeably, YbPO4:Tm3+ nanoparticles display intense near infrared red emission within the biological window, leading to great potential application in biological sensing and biological imaging. All the research studies would benefit the design of optical temperature sensing.
Current flow instability and nonlinear structures in dissipative two-fluid plasmas
Authors: Koshkarov O. , Smolyakov A. I. , Romadanov I. V. , Chapurin O. , Umansky M. V. , Raitses Y. , Kaganovich I. D.
Published: December 2017

The current flow in two-fluid plasma is inherently unstable if plasma components (e.g., electrons and ions) are in different collisionality regimes. A typical example is a partially magnetized E×B plasma discharge supported by the energy released from the dissipation of the current in the direction of the applied electric field (perpendicular to the magnetic field). Ions are not magnetized so they respond to the fluctuations of the electric field ballistically on the inertial time scale. In contrast, the electron current in the direction of the applied electric field is dissipatively supported either by classical collisions or anomalous processes. The instability occurs due to a positive feedback between the electron and ion current coupled by the quasi-neutrality condition. The theory of this instability is further developed taking into account the electron inertia, finite Larmor radius and nonlinear effects. It is shown that this instability results in highly nonlinear quasi-coherent structures resembling breathing mode oscillations in Hall thrusters.
What’s the Point of Ceteris Paribus? or, How to Understand Supply and Demand Curves
Authors: Jhun Jennifer S.
Published: December 2017

Philosophers sometimes claim that economics, and the idealizing strategies it employs, is ultimately unable to provide genuine laws of nature. Therefore, unlike physics, it does not qualify as an actual science. Careful consideration of thermodynamics, a well-developed physical theory, reveals substantial parallels with economic methodology. The corrective account of scientific understanding I offer appreciates these parallels: understanding in terms of efficient performance.
A high-fidelity weather time series generator using the Markov Chain process on a piecewise level
Authors: Hersvik K , Endrerud O-E V
Published: December 2017

A method is developed for generating a set of unique weather time-series based on an existing weather series. The method allows statistically valid weather variations to take place within repeated simulations of offshore operations. The numerous generated time series need to share the same statistical qualities as the original time series. Statistical qualities here refer mainly to the distribution of weather windows available for work, including durations and frequencies of such weather windows, and seasonal characteristics. The method is based on the Markov chain process. The core new development lies in how the Markov Process is used, specifically by joining small pieces of random length time series together rather than joining individual weather states, each from a single time step, which is a common solution found in the literature. This new Markov model shows favorable characteristics with respect to the requirements set forth and all aspects of the validation performed.
Health Benefits of the Mediterranean Diet: Metabolic and Molecular Mechanisms
Authors: Tosti Valeria , Bertozzi Beatrice , Fontana Luigi
Published: December 2017

Consuming a Mediterranean diet rich in minimally processed plant foods has been associated with a reduced risk of developing multiple chronic diseases and increased life expectancy. Data from several randomized clinic trials have demonstrated a beneficial effect in the primary and secondary prevention of cardiovascular disease, type 2 diabetes, atrial fibrillation, and breast cancer. The exact mechanism by which an increased adherence to the traditional Mediterranean diet exerts its favorable effects is not known. However, accumulating evidence indicates that the five most important adaptations induced by the Mediterranean dietary pattern are: (a) lipid-lowering effect, (b) protection against oxidative stress, inflammation and platelet aggregation, (c) modification of hormones and growth factors involved in the pathogenesis of cancer, (d) inhibition of nutrient sensing pathways by specific amino acid restriction, and (e) gut microbiota-mediated production of metabolites influencing metabolic health. More studies are needed to understand how single modifications of nutrients typical of the Mediterranean diet interact with energy intake, energy expenditure, and the microbiome in modulating the key mechanisms that promote cellular, tissue, and organ health during aging.
Peer supporters’ experiences on an Australian perinatal mental health helpline
Authors: Biggs Laura J , McLachlan Helen L , Shafiei Touran , Small Rhonda , Forster Della A
Published: December 2017

Perinatal mental health is an important public health issue, and peer support is a potentially important strategy for emotional well-being in the perinatal period. PANDA Perinatal Anxiety & Depression Australia provides support to individuals impacted by perinatal mental health issues via the National Perinatal Anxiety & Depression Helpline. Callers receive peer support from volunteers and counselling from paid professional staff. The views and experiences of PANDA peer support volunteers have not previously been studied. We conducted two focus groups and an online survey to explore the experiences of women providing volunteer peer support on the Helpline. Data collection took place in October and November 2013. Two social theories were used in framing and addressing the study aims and in interpreting our findings: the Empathy–Altruism Hypothesis, and the Helper Therapy Principle. All PANDA volunteers were invited to participate (n = 40). Eight volunteers attended a focus group, and 11 survey responses were received. Descriptive statistics were used to analyse quantitative data. All survey respondents ‘strongly agreed’ that they felt positive about being part of PANDA. Thematic analysis of data from focus groups and open-ended survey responses identified the following themes: motivated to help others, supported to support callers, helping to make a difference and emotional impacts for volunteers. Respondents described a strong desire to support others experiencing emotional distress as a motivator to volunteer. Although perinatal peer support services are designed to benefit those who receive support, this study suggests volunteers may also experience personal benefits from the role.
Smoking status and attractiveness among exemplar and prototypical identical twins discordant for smoking
Authors: Skinner Andrew L. , Woods Andy , Stone Christopher J. , Penton-Voak Ian , Munafò Marcus R.
Published: December 2017

Smoking is associated with negative health of skin and increased signs of facial ageing. We aimed to address two questions about smoking and appearance: (1) does facial appearance alone provide an indication of smoking status, and (2) how does smoking affect the attractiveness of faces? We used faces of identical twins discordant for smoking, and prototypes made by averaging the faces of the twins. In Task 1, we presented exemplar twin sets and same sex prototypes side-by-side and participants (
n
 = 590) indicated which face was the smoker. Participants were blind to smoking status. In Task 2 a separate sample (
n
 = 580) indicated which face was more attractive. For the exemplar twin sets, there was inconclusive evidence participants selected the smoking twin as the smoker more often, or selected the non-smoking twin as the more attractive more often. For the prototypes, however, participants clearly selected the smoking prototypes as the smoker more often, and the non-smoking prototypes as the more attractive. Prototypical faces of smokers are judged more attractive and correctly identified as smokers more often than prototypical faces of matched non-smokers. We discuss the possible use of these findings in smoking behaviour change interventions.
Semisynthesis and insecticidal activity of some novel fraxinellone-based thioethers containing 1,3,4-oxadiazole moiety
Authors: Guo Yong , Wang Xiaoguang , Fan Jiangping , Zhang Qian , Wang Yi , Zhao Yi , Huang Mengxing , Ding Ming , Zhang Yanbing
Published: December 2017

Two series of novel fraxinellone-based thioethers containing 1,3,4-oxadiazole moiety were prepared as insecticidal agents against the oriental armyworm,
Mythimna separata
Walker. The structural assignment was based on the spectroscopic and X-ray analysis data. Among all the target compounds, compounds
4b
,
4k
,
5b
,
5j
and
5k
exhibited more potent insecticidal activity with final mortality rates (FMRs) of more than 65%, especially
4k
with the FMR of 75.9%, when compared with toosendanin. Some interesting results of structure–activity relationships are also discussed.
A brittle star-like robot capable of immediately adapting to unexpected physical damage
Authors: Kano Takeshi , Sato Eiki , Ono Tatsuya , Aonuma Hitoshi , Matsuzaka Yoshiya , Ishiguro Akio
Published: December 2017

A major challenge in robotic design is enabling robots to immediately adapt to unexpected physical damage. However, conventional robots require considerable time (more than several tens of seconds) for adaptation because the process entails high computational costs. To overcome this problem, we focus on a brittle star—a primitive creature with expendable body parts. Brittle stars, most of which have five flexible arms, occasionally lose some of them and promptly coordinate the remaining arms to escape from predators. We adopted a synthetic approach to elucidate the essential mechanism underlying this resilient locomotion. Specifically, based on behavioural experiments involving brittle stars whose arms were amputated in various ways, we inferred the decentralized control mechanism that self-coordinates the arm motions by constructing a simple mathematical model. We implemented this mechanism in a brittle star-like robot and demonstrated that it adapts to unexpected physical damage within a few seconds by automatically coordinating its undamaged arms similar to brittle stars. Through the above-mentioned process, we found that physical interaction between arms plays an essential role for the resilient inter-arm coordination of brittle stars. This finding will help develop resilient robots that can work in inhospitable environments. Further, it provides insights into the essential mechanism of resilient coordinated motions characteristic of animal locomotion.
Buckling of a stiff thin film on an elastic graded compliant substrate
Authors: Chen Zhou , Chen Weiqiu , Song Jizhou
Published: December 2017

The buckling of a stiff film on a compliant substrate has attracted much attention due to its wide applications such as thin-film metrology, surface patterning and stretchable electronics. An analytical model is established for the buckling of a stiff thin film on a semi-infinite elastic graded compliant substrate subjected to in-plane compression. The critical compressive strain and buckling wavelength for the sinusoidal mode are obtained analytically for the case with the substrate modulus decaying exponentially. The rigorous finite element analysis (FEA) is performed to validate the analytical model and investigate the postbuckling behaviour of the system. The critical buckling strain for the period-doubling mode is obtained numerically. The influences of various material parameters on the results are investigated. These results are helpful to provide physical insights on the buckling of elastic graded substrate-supported thin film.
MicroRNAs regulate the sesquiterpenoid hormonal pathway inDrosophilaand other arthropods
Authors: Qu Zhe , Bendena William G. , Nong Wenyan , Siggens Kenneth W. , Noriega Fernando G. , Kai Zhen-peng , Zang Yang-yang , Koon Alex C. , Chan Ho Yin Edwin , Chan Ting Fung , Chu Ka Hou , Lam Hon Ming , Akam Michael , Tobe Stephen S. , Lam Hui Jerome Ho
Published: December 2017

Arthropods comprise the majority of all described animal species, and understanding their evolution is a central question in biology. Their developmental processes are under the precise control of distinct hormonal regulators, including the sesquiterpenoids juvenile hormone (JH) and methyl farnesoate. The control of the synthesis and mode of action of these hormones played important roles in the evolution of arthropods and their adaptation to diverse habitats. However, the precise roles of non-coding RNAs, such as microRNAs (miRNAs), controlling arthropod hormonal pathways are unknown. Here, we investigated the miRNA regulation of the expression of the juvenile hormone acid methyltransferase gene (JHAMT), which encodes a rate-determining sesquiterpenoid biosynthetic enzyme. Loss of function of the miRNAbantamin the flyDrosophila melanogasterincreasedJHAMTexpression, while overexpression of thebantamrepressedJHAMTexpression and resulted in pupal lethality. The male genital organs of the pupae were malformed, and exogenous sesquiterpenoid application partially rescued the genital deformities. The role of thebantamin the regulation of sesquiterpenoid biosynthesis was validated by transcriptomic, qPCR and hormone titre (JHB3 and JH III) analyses. In addition, we found a conserved set of miRNAs that interacted withJHAMT, and the sesquiterpenoid receptor methoprene-tolerant (Met) in different arthropod lineages, including insects (fly, mosquito and beetle), crustaceans (water flea and shrimp), myriapod (centipede) and chelicerate (horseshoe crab). This suggests that these miRNAs might have conserved roles in the post-transcriptional regulation of genes in sesquiterpenoid pathways across the Panarthropoda. Some of the identified lineage-specific miRNAs are potential targets for the development of new strategies in aquaculture and agricultural pest control.
The behavioural response of migrating humpback whales to a full seismic airgun array
Authors: Dunlop Rebecca A. , Noad Michael J. , McCauley Robert D. , Kniest Eric , Slade Robert , Paton David , Cato Douglas H.
Published: December 2017

Despite concerns on the effects of noise from seismic survey airguns on marine organisms, there remains uncertainty as to the biological significance of any response. This study quantifies and interprets the response of migrating humpback whales (
Megaptera novaeangliae
) to a 3130 in
3
(51.3l) commercial airgun array. We compare the behavioural responses to
active
trials (array operational;
n
= 34 whale groups), with responses to
control
trials (source vessel towing the array while silent;
n
= 33) and
baseline
studies of normal behaviour in the absence of the vessel (
n
= 85). No abnormal behaviours were recorded during the trials. However, in response to the
active
seismic array and the
controls
, the whales displayed changes in behaviour. Changes in respiration rate were of a similar magnitude to changes in
baseline
groups being joined by other animals suggesting any change group energetics was within their behavioural repertoire. However, the reduced progression southwards in response to the
active
treatments, for some cohorts, was below typical migratory speeds. This response was more likely to occur within 4 km from the array at received levels over 135 dB re 1 µPa
2
.s.
A conserved tad pilus promotes Vibrio vulnificus oyster colonization
Authors: Pu Meng , Duriez Patrick , Arazi Mattan , Rowe‐Magnus Dean A.
Published: December 2017

Vibrio vulnificus has the highest death rate (>35%) and per‐case economic burden ($3.3 million) of any foodborne pathogen in the United States. Infections occur via open wounds or following ingestion of contaminated seafood, most infamously oysters. We isolated a 1000th generation descendant, designated NT that exhibited increased biofilm and aggregate formation relative to its parent. We identified two significant causal changes underlying these phenotypes. First, the entire 24‐kb capsular polysaccharide biosynthesis locus, which is essential for virulence but inhibits biofilm formation, had been purged from the genome. However, NT formed more extensive biofilms and aggregates than a defined cps mutant, suggesting that additional factor(s) contributed to its phenotypes. Second, the expression of a tight adherence (tad) pilus locus was elevated in NT. Deletion of the associated pilin (flp) decreased NT biofilm and aggregate formation. Furthermore, NTΔflp strains were deficient relative to NT in an oyster colonization model, demonstrating a positive correlation between the biofilm and aggregation phenotypes associated with Tad pilus production and efficient bacterial retention by feeding oysters. Despite being widely distributed in the Vibrionaceae, this is the first demonstration of a bona fide physiological role for a Tad pilus in this bacterial family.
Review article: Best practice management of common ankle and foot injuries in the emergency department (part 2 of the musculoskeletal injuries rapid review series)
Authors: Strudwick Kirsten , McPhee Megan , Bell Anthony , Martin‐Khan Melinda , Russell Trevor
Published: December 2017

Ankle and foot injuries are the most common musculoskeletal injuries presenting to Australian EDs and are associated with a large societal and economic impact. The quality of ED care provided to patients with ankle and foot fractures or soft tissue injuries is critical to ensure the best possible outcomes for the patient. This rapid review investigated best practice for the assessment and management of common ankle and foot injuries in the ED. Databases including PubMed, CINAHL, EMBASE, TRIP and the grey literature, including relevant organisational websites, were searched in 2017. Primary studies, systematic reviews and guidelines were considered for inclusion. English language articles published in the last 12 years that addressed the acute assessment, management or prognosis in the ED were included. Data extraction of included articles was conducted, followed by quality appraisal to rate the level of evidence where possible. The search revealed 1242 articles, of which 71 were included in the review (n = 22 primary articles, n = 35 systematic reviews and n = 14 guidelines). This rapid review provides clinicians managing fractures and soft tissue injuries of the ankle and foot in the ED a summary of the best available evidence to enhance the quality of care for optimal patient outcomes. Following a thorough history and physical examination, including the application of the Ottawa ankle rules, ED clinicians should not only provide a diagnosis, but rate the severity of soft tissue injuries, or stability of fractures and dislocations, which are the pivotal decision points in guiding ED treatment, specialist referral and the follow‐up plan.
Sex hormone‐binding globulin is associated with androgen deficiency features independently of total testosterone
Authors: Rastrelli Giulia , Corona Giovanni , Cipriani Sarah , Mannucci Edoardo , Maggi Mario
Published: December 2017

Objective

It is recognized that total testosterone (TT) does not sufficiently describe androgen status when sex hormone‐binding globulin (SHBG) is altered. However, in humans, evidence supporting the existence of a hypogonadism due to low T bioactivity is scanty. The aim of the study was to assess whether changes in SHBG levels, independently of TT, are associated with subjective and objective androgen‐dependent parameters.

Design

Cross‐sectional observation.

Patients

Two thousand six hundred and twenty‐two men (aged 51.1 ± 13.5 years) attending a Sexual Medicine and Andrology Outpatient Clinic for sexual dysfunctions.

Measurements

All patients underwent a standardized diagnostic protocol before starting any treatment. Clinical and biochemical parameters have been collected. Higher ANDROTEST score has been used as a comprehensive marker of more severe hypogonadal symptoms. Prostate‐specific antigen (PSA) and haematocrit have been used as objective surrogate markers of T bioactivity.

Results

After adjusting for TT and lifestyle, SHBG showed a significant positive association with ANDROTEST score (B = 0.79 [0.61; 0.96], P < .0001). Conversely, higher SHBG, independently of TT, was negatively related to PSA (B = −0.86 [−0.83; −0.89]; P < .0001) and haematocrit (B = −0.64 [−0.88; −0.40]; P < .0001), after adjustment for the aforementioned confounders along with age and body mass index. Furthermore, a relationship between SHBG and lipids or blood pressure was found, with lower SHBG levels associated with a worse metabolic profile, independently of TT.

Conclusions

Higher SHBG, independently of TT, is associated with either subjective or objective androgen deficiency features. This indicates that besides a hypogonadism due to an impaired T production, a hypogonadism due to a lower biological activity of T does exist.
Relationships of serum 25‐hydroxyvitamin D, ionized calcium and parathyroid hormone after obesity surgery
Authors: Hewitt Stephen , Aasheim Erlend Tuseth , Søvik Torgeir Thorson , Jahnsen Jørgen , Kristinsson Jon , Eriksen Erik Fink , Mala Tom
Published: December 2017

Objective

The high prevalence of secondary hyperparathyroidism (SHPT) after obesity surgery is a concern for long‐term bone health. Limited knowledge exists about optimal vitamin D and suppression of parathyroid hormone (PTH) after these procedures. The aim of this study was to investigate the prevalence of SHPT and its relation to vitamin D status.

Design

A cross‐sectional study at Oslo University Hospital, Norway.

Patients

A total of 502 consecutive patients, age 22‐64 years, attending 2‐year follow‐up after Roux‐en‐Y gastric bypass.

Measurements

A serum intact PTH >7.0 pmol/L in the absence of elevated serum ionized calcium (iCa) was considered as SHPT. Vitamin D status was defined by serum concentrations of 25‐hydroxyvitamin D (S‐25(OH)D).

Results

Altogether, 171 patients (34%) had SHPT. The prevalence of SHPT varied across the range of S‐25(OH)D (P < 0.001), being highest (71%) with S‐25(OH)D < 25 nmol/L. Compared with S‐25(OH)D < 50 nmol/L, the prevalence of SHPT was lower with S‐25(OH)D ≥ 50 nmol/L (29.0%; RR = 0.64 (95%‐CI:0.50‐0.81)) and S‐25(OH)D ≥ 75 nmol/L (27.7%; RR = 0.61 (95%‐CI:0.44‐0.84)). S‐25(OH)D ≥ 100 nmol/L was associated with the lowest PTH and the lowest prevalence of SHPT (16.0%; RR = 0.35 (95%‐CI:0.14‐0.88) compared with S‐25(OH)D < 50 nmol/L) and the most normal calcium distribution. These associations were most pronounced with iCa in the lower range. A synergistic association was found for S‐25(OH)D and iCa on SHPT.

Conclusions

Vitamin D deficient patients had the highest prevalence of SHPT 2 years after gastric bypass. PTH and the prevalence of SHPT were notably lower with S‐25(OH)D ≥ 100 nmol/L, compared with lower target levels.
Sex steroid hormones and brain function:PETimaging as a tool for research
Authors: Moraga‐Amaro R. , van Waarde A. , Doorduin J. , de Vries E. F. J.
Published: December 2017

Sex steroid hormones are major regulators of sexual characteristic among species. These hormones, however, are also produced in the brain. Steroidal hormone‐mediated signalling via the corresponding hormone receptors can influence brain function at the cellular level and thus affect behaviour and higher brain functions. Altered steroid hormone signalling has been associated with psychiatric disorders, such as anxiety and depression. Neurosteroids are also considered to have a neuroprotective effect in neurodegenerative diseases. So far, the role of steroid hormone receptors in physiological and pathological conditions has mainly been investigated post mortem on animal or human brain tissues. To study the dynamic interplay between sex steroids, their receptors, brain function and behaviour in psychiatric and neurological disorders in a longitudinal manner, however, non‐invasive techniques are needed. Positron emission tomography (PET) is a non‐invasive imaging tool that is used to quantitatively investigate a variety of physiological and biochemical parameters in vivo. PET uses radiotracers aimed at a specific target (eg, receptor, enzyme, transporter) to visualise the processes of interest. In this review, we discuss the current status of the use of PET imaging for studying sex steroid hormones in the brain. So far, PET has mainly been investigated as a tool to measure (changes in) sex hormone receptor expression in the brain, to measure a key enzyme in the steroid synthesis pathway (aromatase) and to evaluate the effects of hormonal treatment by imaging specific downstream processes in the brain. Although validated radiotracers for a number of targets are still warranted, PET can already be a useful technique for steroid hormone research and facilitate the translation of interesting findings in animal studies to clinical trials in patients.
Anatomical map of the cranial vasculature and sensory ganglia
Authors: Taberner Laura , Bañón Aitor , Alsina Berta
Published: December 2017

There is growing evidence of a direct influence of vasculature on the development of neurons in the brain. The development of the cranial vasculature has been well described in zebrafish but its anatomical relationship with the adjacent developing sensory ganglia has not been addressed. Here, by 3D imaging of fluorescently labelled blood vessels and sensory ganglia, we describe for the first time the spatial organization of the cranial vasculature in relation to the cranial ganglia during zebrafish development. We show that from 24 h post‐fertilization (hpf) onwards, the statoacoustic ganglion (SAG) develops in direct contact with two main blood vessels, the primordial hindbrain channel and the lateral dorsal aortae (LDA). At 48 hpf, the LDA is displaced medially, losing direct contact with the SAG. The relationship of the other cranial ganglia with the vasculature is evident for the medial lateral line ganglion and for the vagal ganglia that grow along the primary head sinus (PHS). We also observed that the innervation of the anterior macula runs over the PHS vessel. Our spatiotemporal anatomical map of the cranial ganglia and the head vasculature indicates physical interactions between both systems and suggests a possible functional interaction during development.
Structure analysis and conditions of formation of akimotoite in the Tenham chondrite
Authors: Tschauner O. , Ma C. , Prescher C. , Prakapenka V. B.
Published: December 2017

Akimotoite (Mg,Fe)SiO3 is one of the most common mineralogical indicators for high‐level shock metamorphism in meteorites. First described 1997, its occurrence has been amply confirmed in a number of highly shocked chondrites. Yet, a thorough structure analysis of natural akimotoite has remained extant. Here we report accurate cell parameters, fractional atomic coordinates, and site occupancies for natural akimotoite from the holotype specimen based on synchrotron microdiffraction. The variation of unit cell shape and volume with Fe content define mixing volumes. Based on the mixing volume relation for akimotoite and hemleyite, we constrain the unit cell volume of endmember hemleyite to 273.8 ± 1.0 Å3. We show that mixing is nearly ideal for low Fe content but evolves to positive excess volume toward the Fe endmember. Based on this finding and the actual composition of akimotoite in Tenham, we show that this mineral has formed by solid–solid transformation prograde from enstatite, not by crystallization from melt.
Type IV secretion in Gram‐negative and Gram‐positive bacteria
Authors: Grohmann Elisabeth , Christie Peter J. , Waksman Gabriel , Backert Steffen
Published: December 2017

Type IV secretion systems (T4SSs) are versatile multiprotein nanomachines spanning the entire cell envelope in Gram‐negative and Gram‐positive bacteria. They play important roles through the contact‐dependent secretion of effector molecules into eukaryotic hosts and conjugative transfer of mobile DNA elements as well as contact‐independent exchange of DNA with the extracellular milieu. In the last few years, many details on the molecular mechanisms of T4SSs have been elucidated. Exciting structures of T4SS complexes from Escherichia coli plasmids R388 and pKM101, Helicobacter pylori and Legionella pneumophila have been solved. The structure of the F‐pilus was also reported and surprisingly revealed a filament composed of pilin subunits in 1:1 stoichiometry with phospholipid molecules. Many new T4SSs have been identified and characterized, underscoring the structural and functional diversity of this secretion superfamily. Complex regulatory circuits also have been shown to control T4SS machine production in response to host cell physiological status or a quorum of bacterial recipient cells in the vicinity. Here, we summarize recent advances in our knowledge of ‘paradigmatic’ and emerging systems, and further explore how new basic insights are aiding in the design of strategies aimed at suppressing T4SS functions in bacterial infections and spread of antimicrobial resistances.
‘Holding on to life’: An ethnographic study of living well at home in old age
Authors: Bjornsdottir Kristin
Published: December 2017

In recent years, much attention has been paid to how older people living at home can remain independent and manage their illness themselves, while less attention has been given to those who have become frail and need assistance with challenges of everyday life. In this article, I drew on Latimer's formulation of care for frail older people as relational and world‐making and on Foucault's work related to the care of the self in developing an understanding of how frail older persons manage to live well at home in the final years of their lives. I use data from an ethnographic study of home care nursing in the homes of 15 frail older people to develop an understanding of how their care at home can be developed. The participants were holding on to life, which reflected their vitality and vulnerability as well as agency in continuing to explore ways to preserve and build their world at home. With declining ability and stamina relations with material things, relatives and official care workers become of central importance in holding on to life. Home care services can be thought of as part of life, as world‐forming, where workers contribute to daily activities that support living well at home.
Post‐transfusion changes in serum hepcidin and iron parameters in preterm infants
Authors: Stripeli Fotini , Kapetanakis John , Gourgiotis Dimitris , Drakatos Antonis , Tsolia Maria , Kossiva Lydia
Published: December 2017

Background

Packed red blood cell transfusion is common in preterm neonates. Hepcidin acts as a negative feedback iron regulator. Iron parameters such as immature reticulocyte fraction (IRF) and high‐light‐scatter reticulocytes (HLR) are used to clarify iron metabolism. Very little is known about the regulation of hepcidin in preterm infants because most reports have evaluated prohepcidin. The aim of this study was therefore to evaluate serum hepcidin and establish hematological parameters in preterm infants after transfusion.

Methods

The subjects consisted of 19 newborns (10 boys) with mean gestational age 29.1 ± 2.0 weeks, who had been transfused at the chronological age of 44.84 ± 19.61 days. Blood sample was collected before the transfusion and thereafter at 5 days and at 1 month. Serum hepcidin and other iron parameters were evaluated.

Results

Mean serum hepcidin before and 5 days after transfusion was significantly different (5.5 ± 5.1 vs 10 ± 7.9 ng/mLrespectively,P= 0.005).IRFand %HLRwere also decreased significantly, 5 days after transfusion (0.4 ± 0.2 vs 0.2 ± 0.1,P= 0.009; 1.4 ± 1.5% vs 0.5 ± 0.4%,P= 0.012, respectively). Changes in hepcidin 5 days after transfusion were correlated significantly with changes in mean corpuscular hemoglobin (β, 0.13;SE, 0.05;P= 0.017), total iron binding capacity (β, 3.74;SE, 1.56;P= 0.016) and transferrin (β, 2.9,SE, 1.4;P= 0.039).

Conclusions

Serum hepcidin concentration, along withIRFandHLR, are potentially useful in estimating pre‐ and post‐transfusion iron status. Larger studies are needed to evaluate the sensitivity and specificity of hepcidin compared with ordinary iron parameters in premature infants.
A diaper bank and home visiting partnership: Initial exploration of research and policy questions
Authors: Sadler Lois S. , Condon Eileen M. , Deng Shirley Z. , Ordway Monica Roosa , Marchesseault Crista , Miller Andrea , Alfano Janet Stolfi , Weir Alison M.
Published: December 2017

Objectives

The cost of diapering an infant can place a significant financial strain on families living in poverty. Partnerships between diaper banks and home visiting programs for young families may offer an innovative solution to expanding the reach and impact of diaper banks in low‐income communities. The purpose of this pilot study was to uncover preliminary information about the functions of diaper distribution through home visiting programs, and to inform future research and policy questions regarding diaper distribution to families in need.

Design and Sample

In this descriptive qualitative pilot study, semi‐structured interviews were conducted with 6 home visitors from Minding the Baby® (MTB), a home visiting intervention for young parents. MTB clinicians routinely distribute diapers in partnership with The Diaper Bank in Connecticut. We used directed content analysis to code and analyze interview transcripts.

Results/Conclusion

These preliminary findings indicate that partnerships between home visiting programs and diaper banks may benefit families by improving diaper access, reducing stigma, and fostering trusting relationships with home visitors. Home visiting program benefits including engagement or re‐engagement with families may need to be balanced with potential effects on clinical and therapeutic relationships. Recommendations for next steps in research and related policy questions are discussed.
The effect of Cyanidin‐3‐o‐glucoside on UVA‐induced damage in human dermal fibroblasts
Authors: Wu Shi , Hu Yunfeng , Li Zhen , Bai Weibin , Zhao Jiayi , Huang Cuiqin , Li Qin , Fan Chongzhu , Deng Liehua , Lu Daxiang
Published: December 2017

Background/purpose

Ultraviolet‐A (UVA) radiation can induce photoaging and skin cancer, but means to prevent or treat UVA‐induced skin damage require further study. We investigated the effects of cyanidin‐3‐o‐glucoside (C3G), a monomer of anthocyanin, on UVA‐induced damage in primary human dermal fibroblasts (HDFs), and we identify possible mechanisms underlying the protective effects of this compound.

Methods

Primary HDFs were pretreated with 80 μmol/L C3G for 2 hours and UVA irradiated at 12 J/cm2. The cells were then incubated with 80 μmol/L C3G for 12 hours after irradiation. HDFs were randomly divided into control, UVA treatment, C3G, and UVA treatment plus C3G pretreatment groups.

Results

C3G increased the cell viability of primary HDFs and decreased UVA‐induced ROS production and apoptosis rate. Compared to the UVA group, the UVA plus pretreatment with C3G group displayed increased Bcl‐2 expression and Bcl‐2/Bax ratio, decreased cleaved caspase‐3 and p‐P38 levels, and increased ERK phosphorylation; no significant effect on p‐JNK levels was observed.

Conclusion

C3G reduced UVA‐induced HDF oxidative damage and apoptosis, likely be related to the down‐regulation of p‐P38, up‐regulation of ERK protein phosphorylation.
The Physcomitrella patens chromosome‐scale assembly reveals moss genome structure and evolution
Authors: Lang Daniel , Ullrich Kristian K. , Murat Florent , Fuchs Jörg , Jenkins Jerry , Haas Fabian B. , Piednoel Mathieu , Gundlach Heidrun , Van Bel Michiel , Meyberg Rabea , Vives Cristina , Morata Jordi , Symeonidi Aikaterini , Hiss Manuel , Muchero Wellington , Kamisugi Yasuko , Saleh Omar , Blanc Guillaume , Decker Eva L. , van Gessel Nico , Grimwood Jane , Hayes Richard D. , Graham Sean W. , Gunter Lee E. , McDaniel Stuart F. , Hoernstein Sebastian N.W. , Larsson Anders , Li Fay‐Wei , Perroud Pierre‐François , Phillips Jeremy , Ranjan Priya , Rokshar Daniel S. , Rothfels Carl J. , Schneider Lucas , Shu Shengqiang , Stevenson Dennis W. , Thümmler Fritz , Tillich Michael , Villarreal Aguilar Juan C. , Widiez Thomas , Wong Gane Ka‐Shu , Wymore Ann , Zhang Yong , Zimmer Andreas D. , Quatrano Ralph S. , Mayer Klaus F.X. , Goodstein David , Casacuberta Josep M. , Vandepoele Klaas , Reski Ralf , Cuming Andrew C. , Tuskan Gerald A. , Maumus Florian , Salse Jérome , Schmutz Jeremy , Rensing Stefan A.
Published: December 2017

The draft genome of the moss model, Physcomitrella patens, comprised approximately 2000 unordered scaffolds. In order to enable analyses of genome structure and evolution we generated a chromosome‐scale genome assembly using genetic linkage as well as (end) sequencing of long DNA fragments. We find that 57% of the genome comprises transposable elements (TEs), some of which may be actively transposing during the life cycle. Unlike in flowering plant genomes, gene‐ and TE‐rich regions show an overall even distribution along the chromosomes. However, the chromosomes are mono‐centric with peaks of a class of Copia elements potentially coinciding with centromeres. Gene body methylation is evident in 5.7% of the protein‐coding genes, typically coinciding with low GC and low expression. Some giant virus insertions are transcriptionally active and might protect gametes from viral infection via siRNA mediated silencing. Structure‐based detection methods show that the genome evolved via two rounds of whole genome duplications (WGDs), apparently common in mosses but not in liverworts and hornworts. Several hundred genes are present in colinear regions conserved since the last common ancestor of plants. These syntenic regions are enriched for functions related to plant‐specific cell growth and tissue organization. The P. patens genome lacks the TE‐rich pericentromeric and gene‐rich distal regions typical for most flowering plant genomes. More non‐seed plant genomes are needed to unravel how plant genomes evolve, and to understand whether the P. patens genome structure is typical for mosses or bryophytes.