bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling and Parametric Analysis of In-Plane Free Vibration of a Floating Cable-Stayed Bridge with Transfer Matrix Method
Authors: Su Xiaoyang , Kang Houjun , Guo Tieding , Cong Yunyue
Published: September 2019

As a classic bridge type, cable-stayed bridge is widely used because of its superior spanning capacity. Based on the mechanical characteristics of stay cable supporting deck, we propose a novel mechanical model aiming to evaluate the vertical bending stiffness of a floating cable-stayed bridge, namely, multi-beam model with discrete springs. First, a single-tower cable-stayed bridge is modeled as a triple-beam model with discrete springs in order to introduce the novel method easily. In this model, the stay cables are simplified as springs without mass and the single tower is regarded as an Euler–Bernoulli beam with consideration of the effect of axial force. At the same time, the bridge deck has been cut into two Euler–Bernoulli beams at the intersection of a deck and a tower. Then equations governing vibrations of the beam and tower are derived according to Hamilton’s principle for dynamic problems in elastic body under equilibrium state. The program is established by transfer matrix method to solve the eigenvalues of the system along with its boundary and matching conditions. Thus, the vertical bending stiffness of the floating cable-stayed bridge can be evaluated based on the frequency. In addition, the influences of the cables’ material, location, stiffness and number on vertical bending stiffness are analyzed in detail when the steel cables are replaced with CFRP cables. Lastly, the same method is directly extended to modeling the floating multi-tower cable-stayed bridge. The results, which are validated by commercial finite element software, demonstrate that the proposed mechanical model and method are both valuable and significant not only in theoretical research and calculation but also in design of engineering.
Abelian endoregular modules
Authors: Medina-Bárcenas Mauricio , Sim Hanna
Published: September 2019

In this paper, we introduce the notion of abelian endoregular modules as those modules whose endomorphism rings are abelian von Neumann regular. We characterize an abelian endoregular module [Formula: see text] in terms of its [Formula: see text]-generated submodules. We prove that if [Formula: see text] is an abelian endoregular module then so is every [Formula: see text]-generated submodule of [Formula: see text]. Also, the case when the (quasi-)injective hull of a module as well as the case when a direct sum of modules is abelian endoregular are presented. At the end, we study abelian endoregular modules as subdirect products of simple modules.
Single-Channel EEG-Based Machine Learning Method for Prescreening Major Depressive Disorder
Authors: Wan Zhijiang , Zhang Hao , Huang Jiajin , Zhou Haiyan , Yang Jie , Zhong Ning
Published: September 2019

Many studies developed the machine learning method for discriminating Major Depressive Disorder (MDD) and normal control based on multi-channel electroencephalogram (EEG) data, less concerned about using single channel EEG collected from forehead scalp to discriminate the MDD. The EEG dataset is collected by the Fp1 and Fp2 electrode of a 32-channel EEG system. The result demonstrates that the classification performance based on the EEG of Fp1 location exceeds the performance based on the EEG of Fp2 location, and shows that single-channel EEG analysis can provide discrimination of MDD at the level of multi-channel EEG analysis. Furthermore, a portable EEG device collecting the signal from Fp1 location is used to collect the second dataset. The Classification and Regression Tree combining genetic algorithm (GA) achieves the highest accuracy of 86.67% based on leave-one-participant-out cross validation, which shows that the single-channel EEG-based machine learning method is promising to support MDD prescreening application.
Additive matrix convolutions of Pólya ensembles and polynomial ensembles
Authors: Kieburg Mario
Published: September 2019

Recently, subclasses of polynomial ensembles for additive and multiplicative matrix convolutions were identified which were called Pólya ensembles (or polynomial ensembles of derivative type). Those ensembles are closed under the respective convolutions and, thus, build a semi-group when adding by hand a unit element. They even have a semi-group action on the polynomial ensembles. Moreover, in several works transformations of the bi-orthogonal functions and kernels of a given polynomial ensemble were derived when performing an additive or multiplicative matrix convolution with particular Pólya ensembles. For the multiplicative matrix convolution on the complex square matrices the transformations were even done for general Pólya ensembles. In the present work, we generalize these results to the additive convolution on Hermitian matrices, on Hermitian anti-symmetric matrices, on Hermitian anti-self-dual matrices and on rectangular complex matrices. For this purpose, we derive the bi-orthogonal functions and the corresponding kernel for a general Pólya ensemble which was not done before. With the help of these results, we find transformation formulas for the convolution with a fixed matrix or a random matrix drawn from a general polynomial ensemble. As an example, we consider Pólya ensembles with an associated weight which is a Pólya frequency function of infinite order. But we also explicitly evaluate the Gaussian unitary ensemble as well as the complex Laguerre (aka Wishart, Ginibre or chiral Gaussian unitary) ensemble. All results hold for finite matrix dimension. Furthermore, we derive a recursive relation between Toeplitz determinants which appears as a by-product of our results.
Future assistive devices: What's at stake for you or me?
Authors: Oestreicher Lars
Published: September 2019

In the future, small portable devices will be available for all kinds of purposes, not least as a support for people with different kinds of impairments. But is this purely a good development or are there possible dangers? In the latter case, how can we find a proper balance?
Lighting the way to wireless efficiency
Authors: Carver Charles J. , Li Tianxing , Zhou Xia
Published: September 2019

The ubiquity of light makes it an attractive option for both illumination and wireless communication. We explore the future of visible light communication, including next-generation devices, groundbreaking applications, and open challenges.
Row reduction process for matrices of scalar operators
Authors: Abramov Sergei A. , Barkatou Moulay A.
Published: September 2019

It is well known that if the leading matrix of a linear ordinary differential or difference system is nonsingular, then the determinant of this matrix contains some useful information on solutions of the system. We investigate a kind of non-arithmetic complexity of known algorithms for transforming a matrix of scalar operators to an equivalent matrix which has non-singular frontal, or, leading matrix. In the algorithms under consideration, the differentiation in the differential case and the shift in the difference case play a significant role. We give some analysis of the complexity measured as the number of differentiations or, resp., shifts in the worst case. We not only offer estimates of the complexity written using the
O
-notation, but we also show that some estimates are sharp and can not be improved.
Learning from Criminals: Active Offender Research for Criminology
Authors: Topalli Volkan , Dickinson Timothy , Jacques Scott
Published: September 2019

Active offender research relies on the collection of data from noninstitutionalized criminals and has made significant contributions to our understanding of the etiology of serious crime. This review covers its history as well as its methodological, scientific, and ethical pitfalls and advantages. Because study subjects are currently and freely engaging in crime at the time of data collection, their memories, attitudes, and feelings about their criminality and specific criminal events are rich, detailed, and accurate. Contemporary approaches to active offender research employ systematized formats for data collection and analysis that improve the validity of findings and help illuminate the foreground of crime. Although active offender research has traditionally relied on qualitative techniques, we outline the potential for it to make contributions via mixed methods, experiments, and emerging computational and technological approaches, such as virtual reality simulation studies and agent-based modeling.
Upwelling Bays: How Coastal Upwelling Controls Circulation, Habitat, and Productivity in Bays
Authors: Largier John L.
Published: September 2019

Bays in coastal upwelling regions are physically driven and biochemically fueled by their interaction with open coastal waters. Wind-driven flow over the shelf imposes a circulation in the bay, which is also influenced by local wind stress and thermal bay–ocean density differences. Three types of bays are recognized based on the degree of exposure to coastal currents and winds (wide-open bays, square bays, and elongated bays), and the characteristic circulation and stratification patterns of each type are described. Retention of upwelled waters in bays allows for dense phytoplankton blooms that support productive bay ecosystems. Retention is also important for the accumulation of larvae, which accounts for high recruitment in bays. In addition, bays are coupled to the shelf ecosystem through export of plankton-rich waters during relaxation events. Ocean acidification and deoxygenation are a concern in bays because local extrema can develop beneath strong stratification.
Cellular and extracellular matrix of bone, with principles of synthesis and dependency of mineral deposition on cell membrane transport
Authors: Schlesinger Paul H. , Blair Harry C. , Beer Stolz Donna , Riazanski Vladimir , Ray Evan C. , Tourkova Irina L. , Nelson Deborah J.
Published: September 2019

Bone differs from other connective tissues; it is isolated by a layer of osteoblasts that are connected by tight and gap junctions. This allows bone to create dense lamellar type I collagen, control pH, mineral deposition, and regulate water content forming a compact and strong structure. New woven bone formed after degradation of mineralized cartilage is rapidly degraded and resynthesized to impart structural order for local bone strength. Ossification is regulated by thickness of bone units and by patterning via bone morphogenetic receptors including activin, other bone morphogenetic protein receptors, transforming growth factor-β receptors, all part of a receptor superfamily. This superfamily interacts with receptors for additional signals in bone differentiation. Important features of the osteoblast environment were established using recent tools including osteoblast differentiation in vitro. Osteoblasts deposit matrix protein, over 90% type I collagen, in lamellae with orientation alternating parallel or orthogonal to the main stress axis of the bone. Into this organic matrix, mineral is deposited as hydroxyapatite. Mineral matrix matures from amorphous to crystalline hydroxyapatite. This process includes at least two-phase changes of the calcium–phosphate mineral as well as intermediates involving tropocollagen fibrils to form the bone composite. Beginning with initiation of mineral deposition, there is uncertainty regarding cardinal processes, but the driving force is not merely exceeding the calcium-phosphate solubility product. It occurs behind a epithelial-like layer of osteoblasts, which generate phosphate and remove protons liberated during calcium-phosphate salt deposition. The forming bone matrix is discontinuous from the general extracellular fluid. Required adjustment of ionic concentrations and water removal from bone matrix are important details remaining to be addressed.
Electrical stimulation prevents doxorubicin-induced atrophy and mitochondrial loss in cultured myotubes
Authors: Guigni Blas A. , Fix Dennis K. , Bivona Joseph J. , Palmer Bradley M. , Carson James A. , Toth Michael J.
Published: September 2019

Muscle contraction may protect against the effects of chemotherapy to cause skeletal muscle atrophy, but the mechanisms underlying these benefits are unclear. To address this question, we utilized in vitro modeling of contraction and mechanotransduction in C2C12 myotubes treated with doxorubicin (DOX; 0.2 μM for 3 days). Myotubes expressed contractile proteins and organized these into functional myofilaments, as electrical field stimulation (STIM) induced intracellular calcium (Ca2+) transients and contractions, both of which were prevented by inhibition of membrane depolarization. DOX treatment reduced myotube myosin content, protein synthesis, and Akt (S308) and forkhead box O3a (FoxO3a; S253) phosphorylation and increased muscle RING finger 1 (MuRF1) expression. STIM (1 h/day) prevented DOX-induced reductions in myotube myosin content and Akt and FoxO3a phosphorylation, as well as increases in MuRF1 expression, but did not prevent DOX-induced reductions in protein synthesis. Inhibition of myosin-actin interaction during STIM prevented contraction and the antiatrophic effects of STIM without affecting Ca2+ cycling, suggesting that the beneficial effect of STIM derives from mechanotransductive pathways. Further supporting this conclusion, mechanical stretch of myotubes recapitulated the effects of STIM to prevent DOX suppression of FoxO3a phosphorylation and upregulation of MuRF1. DOX also increased reactive oxygen species (ROS) production, which led to a decrease in mitochondrial content. Although STIM did not alter DOX-induced ROS production, peroxisome proliferator-activated receptor-γ coactivator-1α and antioxidant enzyme expression were upregulated, and mitochondrial loss was prevented. Our results suggest that the activation of mechanotransductive pathways that downregulate proteolysis and preserve mitochondrial content protects against the atrophic effects of chemotherapeutics.
A myosin-based mechanism for stretch activation and its possible role revealed by varying phosphate concentration in fast and slow mouse skeletal muscle fibers
Authors: Straight Chad R. , Bell Kaylyn M. , Slosberg Jared N. , Miller Mark S. , Swank Douglas M.
Published: September 2019

Stretch activation (SA) is a delayed increase in force following a rapid muscle length increase. SA is best known for its role in asynchronous insect flight muscle, where it has replaced calcium’s typical role of modulating muscle force levels during a contraction cycle. SA also occurs in mammalian skeletal muscle but has previously been thought to be too low in magnitude, relative to calcium-activated (CA) force, to be a significant contributor to force generation during locomotion. To test this supposition, we compared SA and CA force at different Pi concentrations (0–16 mM) in skinned mouse soleus (slow-twitch) and extensor digitorum longus (EDL; fast-twitch) muscle fibers. CA isometric force decreased similarly in both muscles with increasing Pi, as expected. SA force decreased with Pi in EDL (40%), leaving the SA to CA force ratio relatively constant across Pi concentrations (17–25%). In contrast, SA force increased in soleus (42%), causing a quadrupling of the SA to CA force ratio, from 11% at 0 mM Pi to 43% at 16 mM Pi, showing that SA is a significant force modulator in slow-twitch mammalian fibers. This modulation would be most prominent during prolonged muscle use, which increases Pi concentration and impairs calcium cycling. Based upon our previous Drosophila myosin isoform studies and this work, we propose that in slow-twitch fibers a rapid stretch in the presence of Pi reverses myosin’s power stroke, enabling quick rebinding to actin and enhanced force production, while in fast-twitch fibers, stretch and Pi cause myosin to detach from actin.
Burn-induced reductions in mitochondrial abundance and efficiency are more pronounced with small volumes of colloids in swine
Authors: Chao Tony , Gómez Belinda I. , Heard Tiffany C. , Smith Brian W. , Dubick Michael A. , Burmeister David M.
Published: September 2019

Severe burn injury results in systemic disruption of metabolic regulations and impaired cardiac function. Restoration of hemodynamic homeostasis utilizing intravenous (IV) fluids is critical for acute care of the burn victim. However, the effects of burns and resuscitation on cardiomyocyte mitochondria are currently unknown. The purpose of this study is to determine cardiac mitochondrial function in a swine burn model with subsequent resuscitation using either crystalloids or colloids. Anesthetized Yorkshire swine ( n = 23) sustained 40% total body surface area burns and received IV crystalloids ( n = 11) or colloids ( n = 12) after recovery from anesthesia. Non-burned swine served as controls ( n = 9). After euthanasia at 48 h, heart tissues were harvested, permeabilized, and analyzed by high-resolution respirometry. Citrate synthase (CS) activity was measured, and Western blots were performed to quantify proteins associated with mitochondrial fusion (OPA1), fission (FIS1), and mitophagy (PINK1). There were no differences in state 2 respiration or maximal oxidative phosphorylation. Coupled complex 1 respiration decreased, while uncoupled state 4O and complex II increased significantly due to burn injury, particularly in animals receiving colloids ( P < 0.05). CS activity and electron transfer coupling efficiency were significantly lower in burned animals, particularly with colloid treatment ( P < 0.05). Protein analysis revealed increased FIS1 but no differences in mitophagy in cardiac tissue from colloid-treated compared with crystalloid-treated swine. Taken together, severe burns alter mitochondrial respiration in heart tissue, which may be exacerbated by early IV resuscitation with colloids. Early IV burn resuscitation with colloids may require close hemodynamic observation. Mitochondrial stabilizing agents incorporated into resuscitation fluids may help the hemodynamic response to burn injury.
Slc26a6 is an apical membrane anion exchanger that drives HCO3−-dependent fluid secretion in murine pancreatic acinar cells
Authors: Munemasa Takashi , Mukaibo Taro , Melvin James E.
Published: September 2019

The nonselective anion exchanger Slc26a6, also known as putative anion transporter 1 and chloride/formate exchanger, is thought to play a major role in [Formula: see text] transport in exocrine glands. In this study, Slc26a6 null mice were used to explore the function of Slc26a6 in the exocrine pancreas. Slc26a6 primarily localized to the apical membrane of pancreatic exocrine acinar cells. The volume of stimulated juice secretion by the ex vivo pancreas was significantly reduced ~35% in Slc26a6−/− mice, but no changes occurred in the gross structure or gland weights of Slc26a6 null mice. The secretion of pancreatic juice by Slc26a6+/+ mice was dependent on [Formula: see text] while, in contrast, fluid secretion by Slc26a6 −/− mice was independent of [Formula: see text], suggesting that Slc26a6 mediates the [Formula: see text]-dependent component of fluid secretion. Consistent with these observations, disruption of Slc26a6 also significantly reduced [Formula: see text] secretion by the pancreas ~35%. Taken together, these results demonstrate that the apical Slc26a6 anion exchanger in acinar cells is involved in [Formula: see text]-dependent fluid secretion but that another major [Formula: see text]-independent pathway is the primary driver of the fluid secretion process in the mouse pancreas.
Positive expiratory pressure improves arterial and cerebral oxygenation in acute normobaric and hypobaric hypoxia
Authors: Rupp Thomas , Saugy Jonas J. , Bourdillon Nicolas , Verges Samuel , Millet Grégoire P.
Published: September 2019

Positive expiratory pressure (PEP) has been shown to limit hypoxia-induced reduction in arterial oxygen saturation, but its effectiveness on systemic and cerebral adaptations, depending on the type of hypoxic exposure [normobaric (NH) versus hypobaric (HH)], remains unknown. Thirteen healthy volunteers completed three randomized sessions consisting of 24-h exposure to either normobaric normoxia (NN), NH (inspiratory oxygen fraction, [Formula: see text] = 13.6%; barometric pressure, BP = 716 mmHg; inspired oxygen partial pressure, [Formula: see text] = 90.9 ± 1.0 mmHg), or HH (3,450 m, [Formula: see text] = 20.9%, BP = 482 mmHg, [Formula: see text] = 91.0 ± 0.6 mmHg). After the 6th and the 22nd hours, participants breathed quietly through a facemask with a 10-cmH2O PEP for 2 × 5 min interspaced with 5 min of free breathing. Arterial ([Formula: see text], pulse oximetry), quadriceps, and cerebral (near-infrared spectroscopy) oxygenation, middle cerebral artery blood velocity (MCAv; transcranial Doppler), ventilation, and cardiovascular responses were recorded continuously. [Formula: see text]without PEP was significantly lower in HH (87 ± 4% on average for both time points, P < 0.001) compared with NH (91 ± 3%) and NN (97 ± 1%). PEP breathing did not change [Formula: see text] in NN but increased it similarly in NH and HH (+4.3 ± 2.5 and +4.7 ± 4.1% after 6h; +3.5 ± 2.2 and +4.1 ± 2.9% after 22h, both P < 0.001). Although MCAv was reduced by PEP (in all sessions and at all time points, −6.0 ± 4.2 cm/s on average, P < 0.001), the cerebral oxygenation was significantly improved ( P < 0.05) with PEP in both NH and HH, with no difference between conditions. These data indicate that PEP could be an attractive nonpharmacological means to improve arterial and cerebral oxygenation under both normobaric and hypobaric mild hypoxic conditions in healthy participants.
Chronic effects of repeated low-dose cisplatin treatment in mouse kidneys and renal tubular cells
Authors: Fu Ying , Cai Juan , Li Fanghua , Liu Zhiwen , Shu Shaoqun , Wang Ying , Liu Yuxue , Tang Chengyuan , Dong Zheng
Published: September 2019

Cisplatin is a commonly used chemotherapeutic drug for cancer treatment, but its nephrotoxicity may lead to the deterioration of renal function. Previous work has been focused on cisplatin-induced acute kidney disease, whereas the mechanism of chronic kidney disease after cisplatin chemotherapy is largely unknown. In the present study, we have characterized the mouse model of chronic kidney defects induced by repeated low-dose cisplatin treatment. We have also established a relevant cell culture model. In the animal model, C57 mice were given weekly injection of 8 mg/kg cisplatin for 4 wk. This led to a sustained decline of kidney function. These mice showed loss of kidney mass, interstitial fibrosis, continued activation of inflammatory cytokines, and appearance of atubular glomeruli. In the cell model, the BUMPT mouse proximal tubular cell line was treated four times with 1–2 μM cisplatin, resulting in low levels of apoptosis and the expression of fibrosis proteins and profibrotic factors. These data suggest that repeated treatment with low-dose cisplatin causes long-term renal pathologies with characteristics of chronic kidney disease.
Sensorimotor integration in the whisker somatosensory brain stem trigeminal loop
Authors: Tsur Omer , Khrapunsky Yana , Azouz Rony
Published: September 2019

The rodent’s vibrissal system is a useful model system for studying sensorimotor integration in perception. This integration determines the way in which sensory information is acquired by sensory organs and the motor commands that control them. The initial instance of sensorimotor integration in the whisker somatosensory system is implemented in the brain stem loop and may be essential to the way rodents explore and sense their environment. To examine the nature of these sensorimotor interactions, we recorded from lightly anesthetized rats in vivo and brain stem slices in vitro and isolated specific parts of this loop. We found that motor feedback to the vibrissal pad serves as a dynamic gain controller that controls the response of first-order sensory neurons by increasing and decreasing sensitivity to lower and higher tactile stimulus magnitudes, respectively. This delicate mechanism is mediated through tactile stimulus magnitude-dependent motor feedback. Conversely, tactile inputs affect the motor whisking output through influences on the rhythmic whisking circuitry, thus changing whisking kinetics. Similarly, tactile influences also modify the whisking amplitude through synaptic and intrinsic neuronal interaction in the facial nucleus, resulting in facilitation or suppression of whisking amplitude. These results point to the vast range of mechanisms underlying sensorimotor integration in the brain stem loop.

NEW & NOTEWORTHY Sensorimotor integration is a process in which sensory and motor information is combined to control the flow of sensory information, as well as to adjust the motor system output. We found in the rodent’s whisker somatosensory system mutual influences between tactile inputs and motor output, in which motor neurons control the flow of sensory information depending on their magnitude. Conversely, sensory information can control the magnitude and kinetics of whisker movement.
Estimates of persistent inward current in human motor neurons during postural sway
Authors: Foley Ryan C. A. , Kalmar Jayne M.
Published: September 2019

Persistent inward current (PIC) plays a critical role in setting the gain of spinal motor neurons. In humans, most estimates of PIC are made from plantarflexor or dorsiflexor motor units in a seated position. This seated and static posture negates the task-dependent nature of the monoaminergic drive and afferent inhibition that modulate PIC activation. Our purpose was to estimate PIC during both the conventional seated posture and in a more functionally relevant anterior postural sway. We hypothesized that paired motor unit estimates of PIC would be greater when during standing compared with sitting. Soleus motor neuron PIC was estimated via the paired motor unit (PMU) technique. For each motor unit pair, difference in reference unit firing frequency (ΔF) estimates of PIC were made during isometric ramps in plantarflexion force during sitting (conventional approach) and during standing anterior postural sway (new approach). Baseline reciprocal inhibition (RI) was also measured in each posture using the poststimulus time histogram technique. ΔF estimates during standing postural sway were not different [2.64 ± 0.95 pulses/s (pps), P = 0.098] from seated PIC estimates (3.15 ± 1.45 pps) measured from the same motor unit pair. Similarly, reciprocal inhibition at the onset of each task was the same in standing (−0.60 ± 0.32, P = 0.301) and seated (−0.86 ± 0.82) postures. PMU recordings made during standing postural sway met all assumptions that underlay the PMU technique, including rate modulation ≥0.5 pps (3.11 ± 1.90 pps), rate-rate correlation r ≥ 0.7 (0.84 ± 0.13), and time between reference and test unit recruitment ≥1 s (1.83 ± 0.81 s). This study presents a novel, functionally relevant standing method for investigating PIC in humans.

NEW & NOTEWORTHY Paired motor unit (PMU) estimates of persistent inward current (PIC) in human soleus motor units are typically made in seated posture. Our study demonstrates that these estimates can be made during standing forward sway, a task that more accurately reflects the postural role of human soleus muscle. PMU recordings made during standing postural sway were validated using all previously published criteria used to test the assumptions of the PMU technique. Standing estimates of PIC did not differ from seated estimates made from the same motor unit pairs.
Acceptability Indexes for Portfolio Vectors
Authors: Zeng Xianfu , Chen Yanhong , Hu Yijun
Published: September 2019

In this paper, we introduce two new classes of acceptability indexes, named quasi‐concave acceptability indexes and coherent acceptability indexes, for portfolio vectors. We establish the one‐to‐one correspondence between quasi‐concave (coherent, resp.) acceptability indexes and convex (coherent, resp.) risk measures for portfolio vectors. We derive the representation results for coherent and convex risk measures. Finally, based on these results, we derive the representation results for quasi‐concave acceptability indexes and coherent acceptability indexes for portfolio vectors. These new acceptability indexes can be considered as a kind of multivariate extension of univariate coherent and quasi‐concave acceptability indexes introduced by Cherny and Madan (2009) and Rosazza Gianin and Sgarra (2013), respectively.
Effect of Temperature and Accelerator on Gel Time and Compressive Strength of Resin Anchoring Agent
Authors: Liu Xiaohu , Yao Zhishu , Xue Weipei , Li Xiang
Published: September 2019

In this study, we examined the effects of different temperatures and accelerators on the gelation (gel) time and compressive strength of a Polyethylene Terephthalate (PET)-type unsaturated polyester resin anchorage agent. First, the formation temperature of 20–70°C was simulated using self-made test equipment. N,N-Dimethylaniline (DMA), N,N-dimethylp-toluidine (DMT), and hydroquinone were selected as accelerators to determine gel time and heat release peak. The gel time of an anchorage agent is strongly influenced by accelerant and temperature. When DMT, DMA, and hydroquinone were added at the same temperature, the gelation time increased; with increasing ambient temperature, the gelation time of the anchorage agent decreased. The peak exothermic value of the curing reaction was less affected by the accelerator, and the peak exothermic value of the anchoring agent increased with the increase in ambient temperature. Then, the compressive strength of the anchorage agent, maintained at 20, 50, and 80°C for 1.5, 6, 12, and 24 h, was measured. We found that the compressive strength of resin anchorage agent decreased significantly with the increase in temperature, and the addition of DMT can improve the compressive strength of resin anchorage agent slightly at the same temperature conditions. Finally, through Fourier transform infrared scanning analysis, we determined the intrinsic causes of the influence of temperature and accelerator on the gelation time and compressive strength of the anchorage agent. Through SPSS fitting analysis, an empirical formula for predicting gelation time based on ambient temperature is proposed. Our findings provide a basis for reasonable mixing time and support design optimization of anchorage support in deep stratum in high-temperature geothermal environments.
The Relationship between First Trimester 25-Hydroxyvitamin D3 Levels and Second Trimester Femur Length and Their Effects on Birth Weight and Length at Birth: A Preliminary Study
Authors: Aydeniz Elif Ganime , Sari Umut , Tekin Isil , Dilek Talat Umut Kutlu
Published: September 2019

Objective. The main goal of our study was to assess relationships between first trimester 25-hydroxyvitamin D3 levels and infant birthweight and length at birth. Materials and Methods. We conducted a study over our medical records of 154 live-term births at Acibadem Atakent Hospital, Istanbul, Turkey. Subjects were classified into five independent groups. Results. We retrospectively reviewed a total of 154 live birth records. They took vitamin D3 supplement 1000 U/day. We classified the serum vitamin D levels into 5 groups by concentration. Group 1 comprised serum vitamin D levels <10 ng/ml (n = 41); group 2 comprised serum Vitamin D levels between >10–16 ng/ml (n = 33); group 3 comprised serum vitamin D levels >16–20 ng/ml (n = 26); group 4 vitamin D level between >20–30 ng/ml (n = 33) and group 5 comprised vitamin D levels >30 ng/ml. The femurs of infants were found to be longer between the groups, although the differences were not significant (p=0.054). There was also a statistically significant difference in the neonatal birth weight (p=0.048). Conclusion. We observed associations between low and high maternal 25-hydroxyvitamin D3 levels and fetal growth at birth weight but no difference in birth length. We conclude that we always need to conduct further research to be able to predict the effects of vitamin D deficiency.
A Repeatable Motion Scheme for Kinematic Control of Redundant Manipulators
Authors: Ying Kong , Qingqing Tang , Ruiyang Zhang , Lv Ye
Published: September 2019

To achieve closed trajectory motion planning of redundant manipulators, each joint angle has to be returned to its initial position. Most of the repeatable motion schemes have been proposed to solve kinematic problems considering only the initial desired position of each joint at first. Actually, it is very difficult for various joint angles of the robot arms to be positioned in the expected trajectory before moving. To construct an effective kinematic model, a novel optimal programming index based on a recurrent neural network is designed and analyzed in this paper. The repetitiveness and timeliness are presented and analyzed. Combining the kinematic equation constraint of manipulators, a repeatable motion scheme is formulated. In addition, the Lagrange multiplier theorem is introduced to prove that such a repeatable motion scheme can be converted into a time-varying linear equation. A finite-time neural network solver is constructed for the solution of the motion scheme. Simulation results for two different trajectories illustrate the accuracy and timeliness of the proposed motion scheme. Finally, two different repetitive schemes are compared and verified the optimal time for the novelty of the proposed kinematic scheme.
Prognostic Models for Predicting Overall Survival in Patients with Primary Gastric Cancer: A Systematic Review
Authors: Feng Qi , May Margaret T. , Ingle Suzanne , Lu Ming , Yang Zuyao , Tang Jinling
Published: September 2019

Background. This study was designed to review the methodology and reporting of gastric cancer prognostic models and identify potential problems in model development. Methods. This systematic review was conducted following the CHARMS checklist. MEDLINE and EMBASE were searched. Information on patient characteristics, methodological details, and models’ performance was extracted. Descriptive statistics was used to summarize the methodological and reporting quality. Results. In total, 101 model developments and 32 external validations were included. The median (range) of training sample size, number of death, and number of final predictors were 360 (29 to 15320), 193 (14 to 9560), and 5 (2 to 53), respectively. Ninety-one models were developed from routine clinical data. Statistical assumptions were reported to be checked in only nine models. Most model developments (94/101) used complete-case analysis. Discrimination and calibration were not reported in 33 and 55 models, respectively. The majority of models (81/101) have never been externally validated. None of the models have been evaluated regarding clinical impact. Conclusions. Many prognostic models have been developed, but their usefulness in clinical practice remains uncertain due to methodological shortcomings, insufficient reporting, and lack of external validation and impact studies. Impact. Future research should improve methodological and reporting quality and emphasize more on external validation and impact assessment.
Face Stability Analysis of Shield Tunnel Using Slip Line Method
Authors: Liu Weiping , Wan Shaofeng , Song Xinqiang , Fu Mingfu , Hu Lina
Published: September 2019

The sufficient support pressure is essential to guarantee the safe construction of shield tunnel. Thus, it is necessary to analyze the stability and assess the limit support pressure of the tunnel face. The main methods for face stability analysis mostly focused on finite element method, limit equilibrium method, and numerical simulation method. In this paper, the slip line method is applied to analyze the stability of the tunnel face. The soil is supposed as ideal isotropic, homogeneous, and incompressible continuous material, which obeys the Mohr–Coulomb yield criterion. A mathematical model of the limit equilibrium boundary value problem is established. The slip line method is used to solve the slip line field and stress field of the soil behind the tunnel face. Limit support pressure and failure mechanism of the tunnel face are then obtained. In addition, comparisons between the results of this study and those of existing approach are performed, and the influence factors are also discussed. The results show that the slip line method is proven to be reliable for the evaluation of limit support pressure of the tunnel face stability.
Lenvatinib Administered via Nasogastric Tube in Poorly Differentiated Thyroid Cancer
Authors: Molinaro Eleonora , Viola David , Viola Nicola , Falcetta Pierpaolo , Orsolini Francesca , Torregrossa Liborio , Vagli Paola , Ribechini Alessandro , Materazzi Gabriele , Vitti Paolo , Elisei Rossella
Published: September 2019

Background. The tyrosine kinase inhibitors (TKIs) are indicated for the treatment of locally advanced or metastatic progressive thyroid carcinoma (CDT), refractory to radioactive iodine. The following report describes the efficacy of lenvatinib administered through a nose-gastric tube (SNG) in a patient affected with a poorly differentiated thyroid carcinoma (PDTC) which determined a stenosis of the esophagus. Material and Methods. A patient was followed up for papillary thyroid carcinoma follicular variant (T3NxMx), subjected to total thyroidectomy and treated with iodine-131 radio metabolic therapy. Two years after surgery, following the onset of dysphonia and dysphagia, patient was submitted to a computed tomography (CT) scan of the neck that showed the presence of a lesion of 6 × 2.5 × 3.5 cm, which determined trachea deviation and cervical esophagus compression. The biopsy indicated the presence of PDTC, triggering tracheal lumen reduction and sub-stenosis of the cervical esophagus for an ab-extrinsic compression. A nose-gastric tube (SNG) was placed and lenvatinib was started at a dose of 20 mg/day, administered via this probe after opening the capsules and diluting the drug in 10 ml of saline solution. Results. One month later, CT showed a significant cervical lesion reduction. Bronchoscopy confirmed tracheal infiltration, but the residual caliber was improved from 50% to 75%. At the esophagogastroduodenoscopy (EGDS), the sub stenosis of the cervical esophagus was no longer appreciated; however, a double perforation of the esophagus was found, without fistula. Conclusion. Lenvatinib therapy is effective also when administered via SNG. Our result is of particular relevance in the management of thyroid cancer patients, especially in the presence of subjects unable to swallow. Further studies are needed to validate the administration of lenvatinib by SNG, in order to extend the indications to this alternative administration way, beside the oral one.
A Sliding Mode Control with Nonlinear Fractional Order PID Sliding Surface for the Speed Operation of Surface‐Mounted PMSM Drives Based on an Extended State Observer
Authors: Gao Peng , Zhang Guangming , Ouyang Huimin , Mei Lei
Published: September 2019

A novel sliding mode controller (SMC) with nonlinear fractional order PID sliding surface based on a novel extended state observer for the speed operation of a surface‐mounted permanent magnet synchronous motor (SPMSM) is proposed in this paper. First, a new smooth and derivable nonlinear function with improved continuity and derivative is designed to replace the traditional nonderivable nonlinear function of the nonlinear state error feedback control law. Then, a nonlinear fractional order PID sliding mode controller is proposed on the basis of the fractional order PID sliding surface with the combination of the novel nonlinear state error feedback control law to improve dynamic performance, static performance, and robustness of the system. Furthermore, a novel extended state observer is designed based on the new nonlinear function to achieve dynamic feedback compensation for external disturbances. Stability of the system is proved based on the Lyapunov stability theorem. The corresponding comparative simulation results demonstrate that the proposed composite control algorithm displays good stability, dynamic properties, and strong robustness against external disturbances.
Electroacupuncture Improves Synaptic Function in SAMP8 Mice Probably via Inhibition of the AMPK/eEF2K/eEF2 Signaling Pathway
Authors: Dong Weiguo , Yang Wendan , Li Feifei , Guo Wanqing , Qian Changhui , Wang Feng , Li Changzhen , Lin Lan , Lin Ruhui
Published: September 2019

Synaptic loss and dysfunction is associated with cognitive impairment in Alzheimer’s disease (AD). Recent evidence indicates that the AMP-activated protein kinase (AMPK)/eukaryotic elongation factor-2 kinase (eEF2K)/eukaryotic elongation factor-2 (eEF2) pathway was implicated in synaptic plasticity in AD. Therapeutic strategies for AD treatment are currently limited. Here, we investigate the effects of electroacupuncture (EA) on synaptic function and the AMPK/eEF2K/eEF2 signaling pathway in male senescence-accelerated mouse-prone 8 (SAMP8) mice. Male 7-month-old SAMP8 and SAMR1 mice (senescence-accelerated mouse resistant 1) were randomly divided into 3 groups: SAMR1 control group (Rc), SAMP8 control group (Pc), and SAMP8 electroacupuncture group (Pe). The Pe group was treated with EA for 30 days. Transmission electron microscopy (TEM) was used to observe the structure of synapse. The protein and mRNA expression of synaptophysin (SYN) and postsynaptic density 95 (PSD95) was examined by immunohistochemistry, western blot, and real-time RT-PCR. The activity of AMPK and eEF2K was studied by western blot. Our results showed that EA ameliorated synaptic loss, increased the expression of SYN and PSD95, and inhibited AMPK activation and eEF2K activity. Collectively, these findings suggested that the mechanisms of EA improving synaptic function in AD may be associated with the inhibition of the AMPK/eEF2K/eEF2 signaling pathway.
The Influence of Metabolic Syndrome on the Risk of Hepatocellular Carcinoma in Patients with Chronic Hepatitis B Infection in Mainland China
Authors: Tan Yifei , Zhang Xiaoyun , Zhang Wei , Tang Li , Yang Hanwei , Yan Ke , Jiang Li , Yang Jian , Li Chuan , Yang Jiayin , Wen Tianfu , Tang Huairong , Yan Lunan
Published: September 2019

Background:

The association between metabolic syndrome (MS), both in terms of its components and as a whole, and the risk of hepatocellular carcinoma (HCC) in subjects with hepatitis B virus (HBV) infection remains unclear, especially in mainland China.

Methods:

We prospectively included 6,564 individuals with HBV infection from an initial cohort of 105,397 civil servants. The multivariate-adjusted HR and 95% confidence interval (95% CI) were evaluated using Cox proportional hazards models to explore the potential connection between HCC risk and MS. Cumulative incidences were plotted using Kaplan–Meier curves.

Results:

After a 45,668.0 person-year follow-up (76.0 ± 30.8 months) of 6,564 subjects who were seropositive for hepatitis B surface antigen, 89 incident HCC cases were identified. MS as a whole was independently associated with a 2-fold increased HCC risk (HR, 2.25; 95% CI, 1.41–3.60) after adjusting for age (in 1-year increments), gender, cigarette smoking, alcohol consumption, liver cirrhosis, and elevated aspartate aminotransferase levels (≥40 U/L). Subjects with three or more factors and those with one or two factors had adjusted increased HCC risks of 2.12-fold (95% CI, 1.16–3.89) and 1.28-fold (95% CI, 0.74–2.22), respectively, in comparison with those without any metabolic factors. Central obesity and type 2 diabetes were associated with significantly increased HCC risk, whereas this association was not observed in obese subjects (body mass index ≥30 kg/m2; 95% CI, 0.73–3.44).

Conclusions:

MS as a whole, central obesity, and type 2 diabetes were independently associated with increased HCC risk in a population with HBV infection in mainland China.

Impact:

MS may be a risk factor for HCC.
A Novel Scoring System for Pivotal Autophagy-Related Genes Predicts Outcomes after Chemotherapy in Advanced Ovarian Cancer Patients
Authors: Niu Yuequn , Sun Wenjie , Chen Kelie , Fu Zhiqin , Chen Yaqing , Zhu Jianqing , Chen Hanwen , Shi Yu , Zhang Honghe , Wang Liming , Shen Han-Ming , Xia Dajing , Wu Yihua
Published: September 2019

Background:

In the clinical practice of ovarian cancer, the application of autophagy, an important regulator of carcinogenesis and chemoresistance, is still limited. This study aimed to establish a scoring system based on expression profiles of pivotal autophagy-related (ATG) genes in patients with stage III/IV ovarian cancer who received chemotherapy.

Methods:

Data of ovarian serous cystadenocarcinoma in The Cancer Genome Atlas (TCGA-OV) were used as training dataset. Two validation datasets comprised patients in a Chinese local database and a dataset from the Gene Expression Omnibus (GEO). ATG genes significantly (P < 0.1) associated with overall survival (OS) were selected and aggregated into an ATG scoring scale, of which the abilities to predict OS and recurrence-free survival (RFS) were examined.

Results:

Forty-three ATG genes were selected to develop the ATG score. In TCGA-OV, patients with lower ATG scores had better OS [HR = 0.41; 95% confidence interval (CI), 0.26–0.65; P < 0.001] and RFS [HR = 0.47; 95% CI, 0.27–0.82; P = 0.007]. After complete or partial remission to primary therapy, the rate of recurrence was 47.2% in the low-score group and 68.3% in the high-score group (odds ratio = 0.42; 95% CI, 0.18–0.92; P = 0.03). Such findings were verified in the two validation datasets.

Conclusions:

We established a novel scoring system based on pivotal ATG genes, which accurately predicts the outcomes of patients with advanced ovarian cancer after chemotherapy.

Impact:

The present ATG scoring system may provide a novel perspective and a promising tool for the development of personalized therapy in the future.
Postdiagnosis Loss of Skeletal Muscle, but Not Adipose Tissue, Is Associated with Shorter Survival of Patients with Advanced Pancreatic Cancer
Authors: Babic Ana , Rosenthal Michael H. , Bamlet William R. , Takahashi Naoki , Sugimoto Motokazu , Danai Laura V. , Morales-Oyarvide Vicente , Khalaf Natalia , Dunne Richard F. , Brais Lauren K. , Welch Marisa W. , Zellers Caitlin L. , Dennis Courtney , Rifai Nader , Prado Carla M. , Caan Bette , Sundaresan Tilak K. , Meyerhardt Jeffrey A. , Kulke Matthew H. , Clish Clary B. , Ng Kimmie , Vander Heiden Matthew G. , Petersen Gloria M. , Wolpin Brian M.
Published: September 2019

Background:

Pancreatic cancer is associated with development of cachexia, a wasting syndrome thought to limit survival. Few studies have longitudinally quantified peripheral tissues or identified biomarkers predictive of future tissue wasting.

Methods:

Adipose and muscle tissue were measured by computed tomography (CT) at diagnosis and 50 to 120 days later in 164 patients with advanced pancreatic cancer. Tissue changes and survival were evaluated by Cox proportional hazards regression. Baseline levels of circulating markers were examined in relation to future tissue wasting.

Results:

Compared with patients in the bottom quartile of muscle change per 30 days (average gain of 0.8 ± 2.0 cm2), those in the top quartile (average loss of 12.9 ± 4.9 cm2) had a hazard ratio (HR) for death of 2.01 [95% confidence interval (CI), 1.12–3.62]. Patients in the top quartile of muscle attenuation change (average decrease of 4.9 ± 2.4 Hounsfield units) had an HR of 2.19 (95% CI, 1.18–4.04) compared with those in the bottom quartile (average increase of 2.4 ± 1.6 Hounsfield units). Changes in adipose tissue were not associated with survival. Higher plasma branched chain amino acids (BCAA; P = 0.004) and lower monocyte chemoattractant protein-1 (MCP-1; P = 0.005) at diagnosis were associated with greater future muscle loss.

Conclusions:

In patients with advanced pancreatic cancer, muscle loss and decrease in muscle density in 2 to 4 months after diagnosis were associated with reduced survival. BCAAs and MCP-1 levels at diagnosis were associated with subsequent muscle loss.

Impact:

BCAAs and MCP-1 levels at diagnosis could identify a high-risk group for future tissue wasting.