bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drag reduction in turbulent flows along a cylinder by streamwise-travelling waves of circumferential wall velocity
Authors: Zhao Ming-Xiang , Huang Wei-Xi , Xu Chun-Xiao 
Published: January 2019

Drag reduction at the external surface of a cylinder in turbulent flows along the axial direction by circumferential wall motion is studied by direct numerical simulations. The circumferential wall oscillation can lead to drag reduction due to the formation of a Stokes layer, but it may also result in centrifugal instability, which can enhance turbulence and increase drag. In the present work, the Reynolds number based on the reference friction velocity and the nominal thickness of the boundary layer is 272. A map describing the relationship between the drag-reduction rate and the control parameters, namely, the angular frequency $\unicode[STIX]{x1D714}^{+}=\unicode[STIX]{x1D714}\unicode[STIX]{x1D708}/u_{\unicode[STIX]{x1D70F}0}^{2}$ and the streamwise wavenumber $k_{x}^{+}=k_{x}\unicode[STIX]{x1D708}/u_{\unicode[STIX]{x1D70F}0}$, is obtained at the oscillation amplitude of ${A^{+}=A/u}_{\unicode[STIX]{x1D70F}0}=16$, where $u_{\unicode[STIX]{x1D70F}0}$ is the friction velocity of the uncontrolled flow and $\unicode[STIX]{x1D708}$ is the kinematic viscosity of the fluid. The maximum drag-reduction rate and the maximum drag-increase rate are both approximately 48 %, which are respectively attained at $(\unicode[STIX]{x1D714}^{+},k_{x}^{+})=$ (0.0126, 0.0148) and (0.0246, 0.0018). The drag-reduction rate can be scaled well with the help of the effective thickness of the Stokes layer. The drag increase is observed in a narrow triangular region in the frequency–wavenumber plane. The vortices induced by the centrifugal instability become the primary coherent structure in the near-wall region, and they are closely correlated with the high skin friction. In these drag-increase cases, the effective control frequency or wavenumber is crucial in scaling the drag-increase rate. As the wall curvature normalised by the boundary layer thickness becomes larger, the drag-increase region in the $(\unicode[STIX]{x1D714}^{+},k_{x}^{+})$ plane as well as the maximum drag-increase rate also become larger. Net energy saving with a considerable drag-reduction rate is possible when reducing the oscillation amplitude. At $A^{+}=4$, a net energy saving of 18 % can be achieved with a drag-reduction rate of 25 % if only the power dissipation due to viscous stress is taken into account in an ideal actuation system.
Trichomonas vaginalisandMycoplasma hominis: new tales of two old friends
Authors: Dessì Daniele , Margarita Valentina , Cocco Anna Rita , Marongiu Alessandra , Fiori Pier Luigi , Rappelli Paola 
Published: January 2019

AbstractTrichomonas vaginalisis an anaerobic protist, responsible for the most prevalent non-viral sexually transmitted infection in humans. One of the most intriguing aspects ofT. vaginalispathobiology is the complex relationship with intracellular microbial symbionts: a group of dsRNA viruses belonging to family ofTotiviridae(T. vaginalisvirus), and eubacteria belonging to theMycoplasmagenus, in particularMycoplasma hominis. Both microorganisms seem to strongly influence the lifestyle ofT. vaginalis, suggesting a role of the symbiosis in the high variability of clinical presentation and sequelae during trichomoniasis. In the last few years many aspects of this unique symbiotic relationship have been investigated:M. hominisresides and replicates in the protozoan cell, andT. vaginalisis able to pass the bacterial infection to both mycoplasma-free protozoan isolates and human epithelial cells;M. hominissynergistically upregulates the proinflammatory response of human monocytes toT. vaginalis. Furthermore, the influence ofM. hominisoverT. vaginalismetabolism and physiology has been characterized. The identification of a novel species belonging to the class ofMollicutes(CandidatusMycoplasma girerdii) exclusively associated toT. vaginalisopens new perspectives in the research of the complex series of events taking place in the multifaceted world of the vaginal microbiota, both under normal and pathological conditions.
Allometric scaling of weight to height and resulting body mass index thresholds in two Asian populations
Authors: Hood Karoline , Ashcraft Jacob , Watts Krista , Hong Sangmo , Choi Woong , Heymsfield Steven B. , Gautam Rajesh K. , Thomas Diana 
Published: January 2019

Abstract
Background
Body mass index (BMI) represents a normalization of weight to height and is used to classify adiposity. While the capacity of BMI as an adiposity index has been experimentally validated in Caucasians, but there has been little testing Asian populations.

Methods
To determine whether weight scales to height squared in Asian Indians across the general population and in Asian Indian tribes an allometric analysis on the power law model, W = αHβ, where W is weight (kg) and H is height (m) was performed on cross-sectional weight and height data from India (N = 43,880) collected through the Anthropological Survey of India. The database contained males 18–84 years of age spanning 161 districts of 14 states and including 33 different tribes (N = 5,549). Models were developed that were unadjusted and adjusted for tribe membership. The Korean National Health and Nutrition Examination Survey (KNHANES) was used to compare to height–weight data from the Anthropological Survey of India and to calculate BMI thresholds for obesity status using a receiver operating characteristic.

Results
The unadjusted power was β = 2.08 (s = 0.02). The power for the general population (non-tribal) was β = 2.11 (s = 0.02). Powers when adjusted for tribe ranged from 1.87 to 2.35 with 24 of the 33 tribes resulting in statistically significant (p < 0.05) differences in powers from the general population. The coefficients of the adjusted terms ranged from −0.22 to 0.26 and therefore the scaling exponent does not deviate far from 2. Thresholds for BMI classification of overweight in the KNHANES database were BMI = 21 kg/m2 (AUC = 0.89) for males 18 kg/m2 (AUC = 0.97) for females. Obesity classification was calculated as BMI = 26 kg/m2 (AUC = 0.81) and 23 kg/m2 (AUC = 0.83) for females.

Conclusions
Our study confirms that weight scales to height squared in Asian Indian males even after adjusting for tribe membership. We also demonstrate that optimal BMI thresholds are lower in a Korean population in comparison to currently used BMI thresholds. These results support the application of BMI in Asian populations with potentially lower thresholds.
Flat acoustics with soft gradient-index metasurfaces
Authors: Jin Yabin , Kumar Raj , Poncelet Olivier , Mondain-Monval Olivier , Brunet Thomas 
Published: January 2019

AbstractRecently, metasurfaces have been proven to be effective and compact devices for the design of arbitrary wavefronts. Metasurfaces are planar metamaterials with a subwavelength thickness that allows wavefront shaping by introducing in-plane variations, namely, gradients, in the spatial wave response of these flat structures. Here we report a new class of acoustic gradient-index (GRIN) metasurfaces engineered from soft graded-porous silicone rubber with a high acoustic index for broadband ultrasonic three-dimensional wavefront shaping in water. The functionalities of these soft flat lenses are illustrated through various experiments, which demonstrate beam steering and beam focusing, as well as vortex beam generation in free space. These new GRIN metasurfaces may have important applications in various domains using designed ultrasonic fields (biomedical imaging, industrial non-destructive testing, contactless particle manipulation), since their fabrication is very straightforward with common polymer science engineering.
Excitation to defect-bound band edge states in two-dimensional semiconductors and its effect on carrier transport
Authors: Wang Dan , Han Dong , West Damien , Chen Nian-Ke , Xie Sheng-Yi , Tian Wei Quan , Meunier Vincent , Zhang Shengbai , Li Xian-Bin 
Published: January 2019

AbstractThe ionization of dopants is a crucial process for electronics, yet it can be unexpectedly difficult in two-dimensional materials due to reduced screening and dimensionality. Using first-principles calculations, here we propose a dopant ionization process for two-dimensional semiconductors where charge carriers are only excited to a set of defect-bound band edge states, rather than to the true band edge states, as is the case in three-dimensions. These defect-bound states have small enough ionization energies but large enough spatial delocalization. With a modest defect density, carriers can transport through band by such states.
Biodiversity in remnants of natural mountain forests under conservation-oriented management
Authors: Horák Jakub , Materna Jan , Halda Josef P. , Mladenović Strahinja , Bogusch Petr , Pech Pavel 
Published: January 2019

AbstractThe structure of forests is an important stabilizing factor regarding ongoing global climate and land use change. Biodiverse mountain forests with natural structure are one of the ecosystems most endangered by these problems. We focused on the mountain forest islands of European beech (Fagus sylvatica) and their role in the natural distribution of organisms. The study area was situated in the oldest Czech national park, Krkonoše (385 km2), which is the highest mountain ridge in the country. We studied multi-taxa (lichens, beetles and hymenopterans) responses to three hierarchical spatial levels of the environment: the topography was described by the elevation gradient; the patch structure was described by canopy openness, dead wood amounts, and Norway spruce (Picea abies) cover; and the tree level was described by species of the sampled tree and its diameter. Lichens preferred higher elevations, while insect groups responded conversely. Furthermore, insect groups were mainly influenced by the inner patch structure of beech islands. Lichens may be jeopardized due to the predicted future increase in temperatures, since they would need to shift toward higher altitudes. Insects may be mainly threatened in the future by land use changes (i.e., forest management) – as indicated by an interconnection of canopy openness and the amount of dead wood.
SOX2 participates in spermatogenesis of Zhikong scallop Chlamys farreri
Authors: Liang Shaoshuai , Liu Danwen , Li Xixi , Wei Maokai , Yu Xiaohan , Li Qi , Ma Huixin , Zhang Zhifeng , Qin Zhenkui 
Published: January 2019

AbstractAs an important transcription factor, SOX2 involves in embryogenesis, maintenance of stem cells and proliferation of primordial germ cell (PGC). However, little was known about its function in mature gonads. Herein, we investigated theSOX2gene profiles in testis of scallop,Chlamys farreri. The level ofC.farreri SOX2(Cf-SOX2) mRNA increased gradually along with gonadal development and reached the peak at mature stage, and was located in all germ cells, including spermatogonia, spermatocytes, spermatids and spermatozoa. Knockdown ofCf-SOX2using RNAi leaded to a mass of germ cells lost, and only a few spermatogonia retained in the nearly empty testicular acini after 21 days. TUNEL assay showed that apoptosis occurred in spermatocytes. Furthermore, transcriptome profiles of the testes were compared betweenCf-SOX2knockdown and normal scallops, 131,340 unigenes were obtained and 2,067 differential expression genes (DEGs) were identified. GO and KEGG analysis showed that most DEGs were related to cell apoptosis (casp2,casp3,casp8), cell proliferation (samd9,crebzf,iqsec1) and spermatogenesis (htt,tusc3,zmynd10,nipbl,mfge8), and enriched in p53, TNF and apoptosis pathways. Our study revealedCf-SOX2is essential in spermatogenesis and testis development ofC.farreriand provided important clues for better understanding ofSOX2regulatory mechanisms in bivalve testis.
Deducing Mucosal Pharmacokinetics and Pharmacodynamics of the Anti-HIV Molecule Tenofovir from Measurements in Blood
Authors: Govil Sachin , Katz David F. 
Published: January 2019

AbstractMicrobicide pharmacokinetic (PK) studies typically sample drug in luminal fluid, mucosal tissue, and blood. Blood measurements can be conducted most frequently, serially within subjects. Antiretroviral drugs, however, act against HIV in mucosal tissue/cells. We computationally modeled the extent measurements in blood can predict concentrations in tissue, focusing on the antiretroviral drug tenofovir delivered by a vaginal gel. Deterministic PK models input host and product factors and output spatiotemporal drug concentrations in luminal fluid, epithelium, stroma/host cells, and blood. Pharmacodynamic (PD) analysis referenced stroma/host cell concentrations to prophylactic values; summary metrics were time from product insertion to protection (tlag) and degree of protection (PPmax). Results incorporated host factors characteristic of population variability. Neural nets (NN) linked simulated blood PK metrics (Cmax, tmax, AUC, C24) to mucosal PK/PD metrics. The NNs delivered high-performance mapping of these multiparametric relationships. Given multi-log variability typical of biopsy data for tenofovir and other topical microbicides, results suggest downstream but higher fidelity measurements in blood could help improve determination of PK and create inferences about PD. Analysis here is for a tenofovir gel, but this approach offers promise for application to other microbicide modalities and to topical drug delivery to vaginal mucosa more generally.
Behaviors of Glioblastoma Cells in in Vitro Microenvironments
Authors: Diao Wenwen , Tong Xuezhi , Yang Cheng , Zhang Fengrong , Bao Chun , Chen Hao , Liu Liyu , Li Ming , Ye Fangfu , Fan Qihui , Wang Jiangfei , Ou-Yang Zhong-Can 
Published: January 2019

AbstractGlioblastoma (GBM) is the most malignant and highly aggressive brain tumor. In this study, four types of typical GBM cell lines (LN229, SNB19, U87, U251) were cultured in a microfabricated 3-D model to study their in vitro behaviors. The 3-D in vitro model provides hollow micro-chamber arrays containing a natural collagen interface and thus allows the GBM cells to grow in the 3-D chambers. The GBM cells in this model showed specific properties on the aspects of cell morphology, proliferation, migration, and invasion, some of which were rarely observed before. Furthermore, how the cells invaded into the surrounding ECM and the corresponding specific invasion patterns were observed in details, implying that the four types of cells have different features during their development in cancer. This complex in vitro model, if applied to patient derived cells, possesses the potential of becoming a clinically relevant predictive model.
Functional and morphologic study of retinal hypoperfusion injury induced by bilateral common carotid artery occlusion in rats
Authors: Qin Yali , Ji Meiqi , Deng Tingting , Luo Dan , Zi Yingxin , Pan Lin , Wang Zhijun , Jin Ming 
Published: January 2019

AbstractRetinal hypoperfusion injury is the pathophysiologic basis of ocular ischemic syndrome (OIS) which often leads to severe visual loss. In this study, we aimed to establish a rat model of retinal chronic hypoperfusion by bilateral common carotid artery occlusion (BCCAO) and observe changes in the retinal function and morphology. We found that model rats showed retinal arteriosclerosis, slight dilated retinal vein, small hemangiomas, hemorrhages, vascular segmental filling, and nonperfused areas after 2 weeks of BCCAO. In the model rats, the retinal circulation time was significantly prolonged by fluorescein fundus angiography (FFA), the latency of a and b waves was delayed and the amplitude was decreased significantly at each time point by electroretinogram (ERG), and the perfusion of the eyes continued to reduced. Morphologic and ultrastructural changes covered that the retinal ganglion cells (RGCs) presented obvious apoptosis and the thickness in the retinal layers were significantly thinner. Collectively, these findings suggested that BCCAO induced retinal hypoperfusion injury in the model rats, thus providing an ideal animal model for the study of OIS.
Memory effect of arsenic-induced cellular response and its influences on toxicity of titanium dioxide nanoparticle
Authors: Liu Su , Wu Bing , Yu Yue , Shen Zhuoyan 
Published: January 2019

AbstractToxicity of arsenic (As) has been widely characterized. However, few studies focus on whether cell responses induced by As at nontoxic concentration could be inherited and further change cell tolerance to another pollutant. In this study, human A549 and HeLa cells were exposed to As at nontoxic concentrations for 10 or 15 passages, then the cells were recovered in the cell medium without As. At 25th passage, residual As in both type of cells was completely removed through the recovery process. And no abnormity in cell viability was identified in both type of cells between control and As-treated groups. Above results indicated that As exposure-recovery treatment had limited influence on phenotype of the cells. However, gene expression profiles determined by high-throughput sequencing showed that As exposure-recovery treatment induced similar expression modification of genes related to inflammation, oxidative stress and epigenetic modulation in the A549 and HeLa cells after recovery of 10 or 15 passages, indicating that As-induced cellular responses have been partially memorized at transcriptional level. The memory effect might play key roles in increased tolerance of the A549 and HeLa cells to adverse effects (cell viability, intracellular reactive oxygen species (ROS) generation and plasma membrane damage) induced by titanium dioxide nanoparticles (as representative pollutant). This study shed new lights on toxic effects induced by As at nontoxic concentration, which is useful for risk assessment of combined effects of As and other pollutants.
Astrocytoma progression scoring system based on the WHO 2016 criteria
Authors: Li Zhen-Hang , Guan Yan-Lei , Liu Qiang , Wang Yao , Cui Run , Wang Yun-Jie 
Published: January 2019

AbstractDiffuse astrocytoma (including glioblastoma) is morbid with a worse prognosis than other types of glioma. Therefore, we sought to build a progression-associated score to improve malignancy and prognostic predictions for astrocytoma. The astrocytoma progression (AP) score was constructed through bioinformatics analyses of the training cohort (TCGA RNA-seq) and included 18 genes representing distinct aspects of regulation during astrocytoma progression. This classifier could successfully discriminate patients with distinct prognoses in the training and validation (REMBRANDT, GSE16011 and TCGA-GBM Microarray) cohorts (P < 0.05 in all cohorts) and in different clinicopathological subgroups. Distinct patterns of somatic mutations and copy number variation were also observed. The bioinformatics analyses suggested that genes associated with a higher AP score were significantly involved in cancer progression-related biological processes, such as the cell cycle and immune/inflammatory responses, whereas genes associated with a lower AP score were associated with relatively normal nervous system biological processes. The analyses indicated that the AP score was a robust predictor of patient survival, and its ability to predict astrocytoma malignancy was well elucidated. Therefore, this bioinformatics-based scoring system suggested that astrocytoma progression could distinguish patients with different underlying biological processes and clinical outcomes, facilitate more precise tumour grading and possibly shed light on future classification strategies and therapeutics for astrocytoma patients.
In vivo effects of single or combined topical neuroprotective and regenerative agents on degeneration of retinal ganglion cells in rat optic nerve crush model
Authors: Kitamura Yuta , Bikbova Guzel , Baba Takayuki , Yamamoto Shuichi , Oshitari Toshiyuki 
Published: January 2019

AbstractTo determine the effectiveness of a single or a combination of topical neurotrophic factors (NFs) in protecting retinal ganglion cells (RGCs) in the rat optic nerve crush (ONC) model, the left ONC was performed to induce the death of the RGCs in adult Sprague-Dawley rats. The NFs studied were tauroursodeoxycholic acid (TUDCA), citicoline, neurotrophin-4 (NT-4), combined TUDCA/citicoline (Doublet-1), combined TUDCA/NT-4 (Doublet-2), combined TUDCA/citicoline/NT-4 (Triplet), and PBS. After 2 weeks, the number of RGCs was determined by Brn3a immunostaining. The optic nerves were immunostained for anti-Growth Associated Protein-43(GAP-43) and -200kD neurofilament heavy antibody to study optic nerve regeneration. Two weeks after the ONC, the densities of RGCs in all treated eyes were significantly higher than that of the PBS treated eyes. In the Triplet group, the number of RGC axons after ONC was significantly higher than that in all of the single treatment groups and the number of TUNEL positive cells was significantly reduced and the number of GAP-43 immunopositive axons was significantly greater than those in the PBS group. Neovascularization was observed only in the Doublet-1 group. We conclude that the combination of the three NFs was the most effective way to protect RGCs after the ONC.