bluuebunny/crossref_metadata_2025 huggingface dataset:
Progressive Disruption of Dynamic Functional Network Connectivity in Patients With Hepatitis B Virus‐related cirrhosis
Authors: Lin Shiwei , Li Jing , Chen Shengli , Lin Xiaoshan , Ye Min , Qiu Yingwei
Published: May 2021

Background

The diseased‐related dynamic functional network connectivity (dFNC) disruption and its relationship with cognitive impairment in hepatitis B virus‐related cirrhosis (HBV‐RC) patients with minimal hepatic encephalopathy (MHE) and no MHE (NMHE) remain unknown. This knowledge would help identify MHE pathophysiology and monitor disease progression in HBV‐RC patients.

Purpose

To investigate the dFNC in patients with NMHE and MHE and the relationship between dFNC indices with the psychometric hepatic encephalopathy score (PHES).

Study type

Prospective.

Population

Thirty HBV‐RC patients (including 17 NMHE and 13 MHE) and 38 healthy controls (HC).

Field strength/sequence

A 1.5 T MRI and gradient‐echo echo‐planar imaging and fast field echo three‐dimensional T1‐weighted imaging.

Assessment

The independent components, dFNC matrix and dFNC indices (mean dwell times [DT], number of states, number of transitions, and fraction time in each state), were obtained through GIFT package. Cognitive measurement and patients grouping were based on PHES tests.

Statistical Tests

One‐way ANOVA, chi‐square test, two‐sample t‐test, Kruskal–Wallis test, spearman's correlation analysis and the false discovery rate. Significance level: P < 0.05.

Results

Compared to HC (21.1 ± 4.02), the DT of state 1 decreased in NMHE (9.0 ± 3.04, P = 0.062, 95% confidence interval [CI] is −0.65 to 24.88) and significantly in MHE stage (1.2 ± 1.01) and was significantly correlated with PHES (r = 0.5) for all patients. The DT of state 2 increased gradually in NMHE (75.2 ± 13.10, P = 0.052, 95% CI, −54.23 to 0.28) and significantly in MHE stage (94.6 ± 15.61) when compared to HC (48.2 ± 6.97). Moreover, the connectivity between cognitive control network (CCN) and visual network (VIS) in state 1 (0.7 ± 0.79) and between default mode (DMN) and VIS in state 2 (−0.2 ± 0.29) decreased significantly in MHE when compared to HC (0.1 ± 0.68 for CCN‐VIS in state 1 and 0.1 ± 0.17 for DMN‐VIS for state 2).

Data Conclusion

dFNC exhibited progressive impairment as the disease advances in patients with HBV‐RC.

Evidence Level

2

Technical Efficacy

Stage 2
Fully Automated MR Detection and Segmentation of Brain Metastases in Non‐small Cell Lung Cancer Using Deep Learning
Authors: Jünger Stephanie T. , Hoyer Ulrike Cornelia Isabel , Schaufler Diana , Laukamp Kai Roman , Goertz Lukas , Thiele Frank , Grunz Jan‐Peter , Schlamann Marc , Perkuhn Michael , Kabbasch Christoph , Persigehl Thorsten , Grau Stefan , Borggrefe Jan , Scheffler Matthias , Shahzad Rahil , Pennig Lenhard
Published: May 2021

Background

Non‐small cell lung cancer (NSCLC) is the most common tumor entity spreading to the brain and up to 50% of patients develop brain metastases (BMs). Detection of BMs on MRI is challenging with an inherent risk of missed diagnosis.

Purpose

To train and evaluate a deep learning model (DLM) for fully automated detection and 3D segmentation of BMs in NSCLC on clinical routine MRI.

Study Type

Retrospective.

Population

Ninety‐eight NSCLC patients with 315 BMs on pretreatment MRI, divided into training (66 patients, 248 BMs) and independent test (17 patients, 67 BMs) and control (15 patients, 0 BMs) cohorts.

Field Strength/Sequence

T1‐/T2‐weighted, T1‐weighted contrast‐enhanced (T1CE; gradient‐echo and spin‐echo sequences), and FLAIR at 1.0, 1.5, and 3.0 T from various vendors and study centers.

Assessment

A 3D convolutional neural network (DeepMedic) was trained on the training cohort using 5‐fold cross‐validation and evaluated on the independent test and control sets. Three‐dimensional voxel‐wise manual segmentations of BMs by a neurosurgeon and a radiologist on T1CE served as the reference standard.

Statistical Tests

Sensitivity (recall) and false positive (FP) findings per scan, dice similarity coefficient (DSC) to compare the spatial overlap between manual and automated segmentations, Pearson's correlation coefficient (r) to evaluate the relationship between quantitative volumetric measurements of segmentations, and Wilcoxon rank‐sum test to compare the volumes of BMs. A P value <0.05 was considered statistically significant.

Results

In the test set, the DLM detected 57 of the 67 BMs (mean volume: 0.99 ± 4.24 cm3), resulting in a sensitivity of 85.1%, while FP findings of 1.5 per scan were observed. Missed BMs had a significantly smaller volume (0.05 ± 0.04 cm3) than detected BMs (0.96 ± 2.4 cm3). Compared with the reference standard, automated segmentations achieved a median DSC of 0.72 and a good volumetric correlation (r = 0.95). In the control set, 1.8 FPs/scan were observed.

Data Conclusion

Deep learning provided a high detection sensitivity and good segmentation performance for BMs in NSCLC on heterogeneous scanner data while yielding a low number of FP findings.

Level of Evidence

3

Technical Efficacy Stage

2
Change in Susceptibility Values in Knee Cartilage After Marathon Running Measured Using Quantitative Susceptibility Mapping
Authors: Zhang Ming , Li Yufei , Feng Ruimin , Wang Zhongzheng , Wang Wenjin , Zheng Nan , Wang Shaobai , Yan Fuhua , Lu Yong , Tsai Tsung‐Yuan , Wei Hongjiang
Published: May 2021

Background

Quantitative susceptibility mapping (QSM) has been used to study the magnetic susceptibility properties of collagen fibers in articular cartilage; however, it is unclear whether QSM is sensitive to changes due to degradation caused by long‐distance running. It is clinically important to understand the link between long‐distance running and microstructural changes in knee cartilage.

Purpose

To investigate the ability of QSM to assess microstructural changes within cartilage after repetitive loading.

Study Type

Prospective.

Population

Thirteen recreational, male long‐distance runners.

Field Strength/Sequence

Three‐dimensional gradient recalled echo acquired at 3 T.

Assessment

Magnetic resonance imaging (MRI) and 3D kinematics (translations and rotations during treadmill walking and running) of the knee joint were collected before and after marathon running. The compartments for analysis included the patella, trochlea, and subregions of femoral and tibial cartilage. Changes in regional susceptibility and cartilage thickness were calculated after marathon running. A susceptibility profile was obtained by fitting susceptibility as a function of the normalized depth of cartilage from the superficial to deep layers.

Statistical Tests

Paired t‐test or Wilcoxon signed‐rank test, 95% confidence interval (CI) of the depth‐wise susceptibility profile, Pearson correlation or Spearman correlation.

Results

There was a statistically significant increase in susceptibility value in the weight‐bearing region of central medial femoral cartilage (cMF‐c) after marathon running (pre‐marathon: −0.0219 ± 0.0151 ppm, post‐marathon: −0.0070 ± 0.0213 ppm, P < 0.05), while the cartilage thickness did not show significant changes in any regions (P‐value range: 0.068–0.963). Significant susceptibility elevations occurred in the middle and deep layers of cMF‐c (95% CIs did not overlap). A trend toward a positive correlation was found between the changes in susceptibility value in cMF‐c and proximal–distal translation of the knee joint during walking (r = 0.55, P = 0.101) and running (r = 0.57, P = 0.089).

Data Conclusion

Localized magnetic susceptibility alterations were observed within knee cartilage in the weight‐bearing area after repetitive loading without any morphologic changes.

Level of Evidence

2

Technical Efficacy

Stage 2
Design of substrate integrated waveguides based on nanowires: Numerical guidelines
Authors: Van Kerckhoven Vivien , Piraux Luc , Huynen Isabelle
Published: May 2021

A thorough study of the parameters influencing the operation of devices based on nanowired alumina substrate is presented. The basic structures are realized by growing metallic nanowires inside alumina porous substrate. The control of the areas wherein growth occurs allows building of various microwave devices supported on the filled template. The performances of these devices depend on the material parameters and topology/geometry in presence. These devices have the particularity to combine nanoscale, through the use of nanowires, and millimeter scale that is characteristic of microwave devices and their associated operating wavelength. The gap between the two‐scale ranges implies that analytical models and numerical simulation tools have to be combined to modelize and design performant microwave devices, such as Nanowired Substrate Integrated Waveguides (NSIWs) devices that are the subject of the paper. A deep parametric analysis of the properties and operation of the basic NSIW is presented and is followed by the illustration of two designs: a simple NSIW line, and an EBG NSIW filter.
Design of a reconfigurable antenna based on graphene for terahertz communication
Authors: Zhang Xingyun , Cunjun Ruan , Dai Jun , Ding Yikun , Ullah Shahid , Kosar Fahad Ayesha
Published: May 2021

A broadband, high radiation efficiency graphene‐based reconfigurable square spiral antenna for terahertz communication is proposed. The main part of the antenna is the graphene‐based square spiral microstrip patch. The proposed antenna is built and simulated using high‐frequency structure simulator (HFSS). By applying different combinations of chemical potentials on the graphene layer, the operating frequency of the antenna can be varied from 0.1 to 2 THz. The tuning range of frequency and beam direction with same and different chemical potentials applied to the two graphene sheets are also studied. When the antenna is applied with different chemical potentials, the required bias voltages are much lower to achieve the same frequency tuning range, and the tuning range of beam direction is about 2.5 times that of same chemical potentials. The realized beam reconfiguration of the proposed antenna is over a wide range up to 74°, and the calculated maximum radiation efficiency of the proposed antenna at 1.48 THz is 85.06%. Therefore, the proposed reconfigurable antenna makes it extremely promising for terahertz communication system.
The in vitro efficacy of biofilm removal from titanium surfaces using Er:YAG laser: Comparison of treatment protocols and ablation parameters
Authors: Polak David , Shani‐Kdoshim Sharon , Alias Mary , Shapira Lior , Stabholz Ayala
Published: May 2021

Background

The aims of the present study were to compare the antibacterial effect of Er:YAG laser with other acceptable decontamination methods and to single out the optimal laser device parameters for effective bacterial elimination.

Methods

A multispecies biofilm which was composed of Streptococcus sanguis, Actinomyces naeslundii, Porphyromonas gingivalis, and Fusobacterium nucleatum was grown on sandblasted and acid‐etched (SLA, homogeneous moderately microrough, and nanosmooth surface) titanium disks. The biofilm was removed from the coated disks by hand curets, ultrasonic device, nylon brush (dental polishing prophy cup), or Er:YAG. Additionally, different parameter combinations of the laser machine were examined to reach an optimal lasing power for bacterial elimination/reduction. Residual biofilm samples were stained with bacterial live/dead staining and quantified using a fluorescent microscope.

Results

A multispecies biofilm was accumulated on the SLA titanium surfaces exhibiting cluster distribution next to bacteria‐poor areas. Hand curets, nylon brushes, and the ultrasonic device showed limited capability to effectively remove the biofilm from the SLA surfaces as opposed to the Er:YAG which displayed a superior ability to remove the biofilm. All Er:YAG parameter combinations that were evaluated as well as the tested “tip to target” distances showed similar excellent anti‐biofilm effects. Furthermore, we observed that the Er:YAG capability of biofilm removal is not only due to its light emission, but depends on its water irrigation as well.

Conclusions

Er:YAG laser has an excellent biofilm removal capability compared with hand curets, ultrasonic devices, or nylon brushes even when low energy parameters and low power settings are used. Additionally, an excellent antibacterial effect can be reached using a non‐contact mode of 1 to 5 mm “tip to target” distance.
Human occupation continuity in southern Italy towards the end of the Middle Palaeolithic: a palaeoenvironmental perspective from Apulia
Authors: Boschin Francesco , Columbu Andrea , Spagnolo Vincenzo , Crezzini Jacopo , Bahain Jean‐Jacques , FalguèRes Christophe , Benazzi Stefano , Boscato Paolo , Ronchitelli Annamaria , Moroni Adriana , Martini Ivan
Published: May 2021

After the last interglacial [Marine Isotope Stage (MIS) 5e] Europe was affected by several harsh climatic oscillations. In this context southern Italy acted, like the rest of peninsular Mediterranean Europe, as a ‘glacial refugium’, allowing the survival of various species, and was involved in the spread of ‘cold taxa’ (e.g. woolly mammoth and woolly rhino) only during the coldest phases (MIS 4 and MIS 2). Both late Mousterian and early Upper Palaeolithic sites testify to a human occupation continuity in southern Italy and especially in Apulia in this time span. Here we present a focus on three key Apulian Palaeolithic sequences (Grotta di Santa Croce, Riparo L'Oscurusciuto and Grotta del Cavallo – layers F‐E) jointly spanning from the late MIS 4 to the demise of Neanderthals around 43 ka. Novel chronological, sedimentological and zooarchaeological data are discussed for the first time in the light of the palaeoenvironmental information provided by recent analyses carried out on a speleothem from Pozzo Cucù cave (Bari) and the results of the magnetic susceptibility analysis from Riparo L'Oscurusciuto. This integrated reading allows a better understanding of the role played by the Apulian region as both a refugium for late Neaderthals and a suitable habitat for the early settling of modern humans.
Airway and Swallowing Outcomes Following Laryngotracheoplasty With Posterior Grafting in Children
Authors: Kou Yann‐Fuu , Redmann Andrew , Tabangin Meredith E. , Wilcox Lyndy , Miller Claire K. , Smith Matthew , Myer Charles , Hart Catherine K. , Rutter Michael J. , de Alarcon Alessandro
Published: May 2021

Objectives/Hypothesis

Evaluate swallowing and airway outcomes following laryngotracheoplasty with posterior grafting (LTP PCCG).

Methods

Retrospective review of pediatric patients undergoing LTP PCCG from 2016 to 2019 at a tertiary care pediatric hospital. We included demographics, indications, approach, and revision status. We evaluated preoperative and postoperative instrumental and functional swallow evaluations, and we also gathered information on airway outcomes.

Results

Thirty‐one patients were included in the study. Median (interquartile range [IQR]) age was 4.0 (2.0, 7.0) years old. Primary indication for surgery was bilateral vocal cord immobility (BVCI) in 11 (35.5%) and posterior glottic stenosis (PGS) in 20 (64.5%). Mean (standard deviation) length of follow‐up was 11.0 (8.3) months. Twelve patients had gastrostomy tubes (GT) before surgery, and no patients required placement of GT after surgery. Of the remaining 19 patients, 6 required nasogastric feeding for >4 weeks (average length 1.8 months, longest 3.5 months). At last follow‐up, 25 (80.6%) patients were primarily orally fed. Eighteen patients had tracheotomies prior to surgery. No patients without a tracheostomy required placement of tracheostomy before or after surgery and only 1 patient had a tracheostomy at last follow‐up. Average time to decannulation was 3.7 months, with surgery‐specific success of 87.1% and overall success of 96.8%. Four (12.9%) patients required a major intervention to achieve decannulation.

Conclusion

LTP PCCG is an effective surgical technique to address PGS and BVCI with high decannulation rates. It may cause temporary swallowing dysfunction, but in this series a majority of children were orally fed at last follow‐up.

Level of Evidence

4 Laryngoscope, 131:2798–2804, 2021
Nanoparticles Composed of PEGylated Alternating Copolymer‐Combretastatin A4 Conjugate for Cancer Therapy
Authors: Zhang Yu , Liu Xinming , Wang Xueping , He Pan , Xiao Chunsheng , Yu Haiyang , Chen Xuesi
Published: May 2021

Chemotherapy using vascular targeting agents is an emerging new approach for cancer therapy. Combretastatin A4 (CA4) is a leading vascular‐disrupting agent that targets the tumor blood vasculature for clinical tumor elimination. However, the extremely poor water solubility of CA4 hinders its biomedical applications. In this study, nanoparticles composed of novel PEGylated alternating copolymer‐CA4 conjugates are designed to improve the therapeutic efficiency of CA4. First, an alternating copolymer with an alkene‐pendant is synthesized by mPEG‐OH‐initiated ring‐opening copolymerization. Then, side carboxyl groups are introduced by a thio‐ene “click” chemical reaction, followed with CA4 conjugation through the Yamaguchi‐reaction, resulting in the target copolymer, mPEG‐b‐P(PA‐alt‐GCA4). Interestingly, the polymer‐drug conjugates can self‐assemble into nanoparticles with an average diameter of 55.6 nm. The in vitro drug release and cytotoxicity of the obtained CA4‐NPs toward 4T1 cells are investigated. Finally, the antitumor efficiency is evaluated in a 4T1‐tumor bearing murine model. The in vivo test results demonstrate that CA4‐NPs inhibited tumor growth much more efficiently at doses of 30 and 60 mg kg−1, compared with the control group.
Characteristic of solutions for non‐local fractional p(x)‐Laplacian with multi‐valued nonlinear perturbations
Authors: Cheng Yi , O'Regan Donal
Published: May 2021

In this paper, we establish a new abstract functional space where K is a uncertain weighted function and p is a variable exponent. Based on the properties of this space, we consider the existence and regularity of weak solutions for non‐local fractional differential inclusion with homogeneous Dirichlet boundary conditions. Under a suplinear growth condition we obtain the existence of weak solutions, the compactness and Hölder regularity of the solution set using set‐valued analysis and the surjectivity principle of pseudomonotonicity. Furthermore, the existence of extremal solutions and a relaxation result is discussed.
Non‐isocyanate Polyurethanes from 1,1′‐Carbonyldiimidazole: A Polycondensation Approach
Authors: Wolfgang Josh D. , White B. Tyler , Long Timothy E.
Published: May 2021

1,1′‐Carbonyldiimidazole (CDI) provides a platform to generate high molecular weight polyurethanes from industrially relevant diols and diamines. CDI, which is described in the literature for its use in amidation and functionalization reactions, enables the production of well‐defined and stable polyurethane precursors, thus eliminating the need for isocyanates. Herein, the functionalization of 1,4‐butanediol with CDI yields an electrophilic biscarbamate, bis‐carbonylimidazolide (BCI), which is suitable for further step‐growth polymerization in the presence of amines. Elevated reaction temperatures enable the solvent‐, catalyst‐, and isocyanate‐free polycondensation reaction between the BCI monomer and various diamines. The thermoplastic polyurethanes produced from this reaction demonstrate high thermal stability, tunable glass transition temperatures based on incorporation of flexible polyether segments, and mechanically ductile thin films. CDI functionalized diols will allow the preparation of diverse polyurethanes without the use of isocyanate‐containing monomers.
Comparison of rainfall microphysics characteristics derived by numerical weather prediction modelling and dual‐frequency precipitation radar
Authors: Zhu Jingxuan , Zhang Shuliang , Yang Qiqi , Shen Qi , Zhuo Lu , Dai Qiang
Published: May 2021

The understanding of large‐scale rainfall microphysical characteristics plays a significant role in meteorology, hydrology and natural hazards managements. Traditional instruments for estimating raindrop size distribution (DSD), including disdrometers and ground dual‐polarization radars, are available only in limited areas. However, the development of space‐based radars and mesoscale numerical weather prediction models would allow for DSD estimation on a large scale. This study investigated the performance of the weather research and forecasting (WRF) model and the global precipitation measurement mission (GPM) dual‐frequency precipitation radar for DSD retrieval under different conditions. The DSD parameters (Dm and Nw), rain rate (R), rainfall kinetic energy (KE) and radar reflectivity (Z) were estimated in Chilbolton, United Kingdom, by using long‐term disdrometer observations for validation. The rainfall kinetic energy–rain rate (KE–R) and radar reflectivity–rain rate (Z–R) relationships were explored using a disdrometer, the WRF model and GPM. It was found that the DSD parameter distribution trends of the three approaches are similar although the WRF model has larger Dm and smaller Nw values. In terms of the rainfall microphysical relationship, GPM performs better when both Ku‐ and Ka‐band precipitation radars (KuPR and KaPR) observe precipitation simultaneously (R > 0.5 mm h−1), while the WRF model shows high accuracy in light rain (R < 0.5 mm h−1). The fusion of GPM and WRF model is recommended for the improved understanding of rainfall microphysical characteristics in ungauged areas.
COVID‐19 in patients with myasthenia gravis: Epidemiology and disease course
Authors: Businaro Pietro , Vaghi Gloria , Marchioni Enrico , Diamanti Luca , Arceri Sebastiano , Bini Paola , Colombo Elena , Cosentino Giuseppe , Alfonsi Enrico , Costa Alfredo , Ravaglia Sabrina , Mallucci Giulia , Ballante Elena , Franciotta Diego , Gastaldi Matteo
Published: May 2021

Introduction/Aims

Coronavirus disease 2019 (COVID‐19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, has become a global pandemic. Patients with myasthenia gravis (MG), often treated with immunosuppressants, might be at higher risk of developing COVID‐19 and of demonstrating a severe disease course. We aimed to study prevalence and describe features of COVID‐19 in MG patients.

Methods

In May 2020, we conducted telephonic interviews with MG patients followed at our referral center. We collected structured data regarding MG and COVID‐19, which was diagnosed as probable or confirmed according to the European Centre for Disease Prevention and Control case definition. We compared confirmed‐COVID‐19 prevalence calculated from the beginning of the pandemic in MG patients with that of the overall Pavia district.

Results

We interviewed 162 MG patients (median age, 66 y; interquartile range 41‐77; males 59.9%), 88 from the Pavia district. Three patients had SARS‐CoV‐2‐confirmed by polymerase chain reaction and eight had probable‐COVID‐19. In the Pavia district, the prevalence of confirmed‐COVID‐19 among MG patients (1/88, 1.14%) and overall population (4777/546 515, 0.87%) did not differ (P = .538). Higher Myasthenia Gravis Foundation of America clinicalclass and the need for recent rescue treatment, but not ongoing immunosuppressive treatments, were associated with COVID‐19 risk. Of 11 MG patients with probable/confirmed‐COVID‐19, 3 required ventilator support, and 2 elderly patients died of COVID‐19 respiratory insufficiency. Only 1 of11 patients experienced worsening MG symptoms, which improved after increasing their steroid dose.

Discussion

The risk of COVID‐19 in MG patients seems to be no higher than that of the general population, regardless of immunosuppressive therapies. In our cohort, COVID‐19 barely affected MG course.
Adhesion and proliferation of living cell on surface functionalized with glycine nanostructures
Authors: Rahman Aminur , Roy Kumar Jyotirmoy , Rahman K. M. Ashikur , Aktar Mst. Khudishta , Kafi Md. Abdul , Islam Md. Shafiqul , Rahman Md. Bahanur , Islam Md. Rafiqul , Hossain Khandker Saadat , Rahman Md. Mizanur , Heidari Hadi
Published: May 2021

This research presents the application of glycine amino acid for establishing firm cell‐substrate interaction instead of expensive adhesion proteins, peptides and peptide derivatives. The glycine amino acid is chemically functionalized on the coverslip to achieve self‐assembled nanostructure. Glycine self‐assembly on NaCl treated coverslips is initiated with SiONa+:COO−linkage while their nanostructure is achieved with formation of glycine chain through NH3+:COO−covalent linkage between the adjacent molecules. The functionalization steps are confirmed by Fourier‐transform infrared spectroscopy (FTIR) investigation. The atomic force microscopy (AFM) and scanning electron microscopy (SEM) investigations reveal that glycine growth initiates at 4 Hours (H) post‐treatment while maximum growth appears after 8H‐10H. Both the vertical and horizontal growth of nanostructures show dependence on functionalization periods. Various levels of glycine functionalized surface show different levels of baby hamster kidney (BHK‐21) cell adhesion and proliferation efficiency with maximum performance for 10H functionalized surface. The adhesion and proliferation performance of 10H glycine functionalized surface shows negligible difference when compared with glycine‐aspartic acid (RGD) functionalized surface. Finally, growth curves obtained from both glycine and RGD functionalized surface reveal exponential growth phage up to 48H followed by stationary phage between 48H and 72H while death of many cells appears from 72H to 96H. Thus, this research concluded that glycine functionalized surface is equally effective for cell adhesion and proliferation.
Photocatalytic reduction of Cr(VI) within mesoporous TiO2 templated and confined with chlorophyll
Authors: Yang Haiyan , Yang Yepeng , Jiang Liang , Wang Yuanfeng , Chen Yongjuan , He Jiao , Wang Wei , Wang Jiaqiang
Published: May 2021

Biomimetic light‐harvesting architecture has been proposed as an alternative for existing solar conversion systems. Chlorophyll‐sensitized TiO2 have been identified as promising catalyst for photocatalytic reduction system, but it is largely limited to complicated process for purification of chlorophyll and adding extra hole scavenger in system. In sharp contrast to conventional photosensitization methods in which the organic dyes were often adsorbed after photosensitization, herein mesoporous TiO2 incorporated with chlorophyll extract was synthesized in situ (TiO2/Chl). Interestingly, TiO2 incorporated with chlorophyll exhibited two distinct absorption bands around 407 and 668 nm which are closed to the characteristic absorption peak of chlorophyll. TiO2 incorporated with chlorophyll kept at 185°C for 1.5 hours (TiO2/Chl‐185) achieved a high photoreduction rate of 86.1% for the photocatalytic reduction of Cr(VI), which was approximately 29 and 20 times higher than that of TiO2 and TiO2 adsorbing chlorophyll (TiO2/ads Chl), respectively. The significant enhancement was due to the confinement of chlorophyll. This demonstrates that mesoporous TiO2 templated and confined with chlorophyll could offer a new approach for synergistic photoreduction of Cr(VI).
Geometrically exact shell with drilling rotations formulated on the special Euclidean group SE(3)
Authors: Zhang Teng , Liu Cheng , Tang Huiying
Published: May 2021

Based on the local frame approach, a new geometrically exact shell with drilling rotations is proposed in the SE(3) framework when dealing with the finite deformation and rotation issues. To eliminate the geometric nonlinearity of rigid‐body motion, a drilling rotation formulation is applied to the 5‐DoF shell presented in advance. As expected, the shell with drilling rotations completely eliminates the geometric nonlinearity of rigid‐body motion, which results in the invariance of the Jacobian matrices of inertial and internal forces under any rigid‐body motion, while the shell without drilling rotations does not. Therefore, the updates times of Jacobian matrices decreases sharply and the computational costs can be significantly reduced during dynamic analysis. By removing the rigid‐body motion of the reference point, the objectivity of the discretized strain measures is guaranteed by interpolating the relative motion. To maintain second‐order convergence, the expressions of the inertial and internal forces are strictly derived by linearizing the discrete weak form of the equilibrium equations. Furthermore, locking alleviation techniques are employed to alleviate shear and membrane locking. For dynamic analysis, the generalized‐α method on Lie group is used to solve dynamic equilibrium equations. Finally, numerical examples are presented to illustrate the versatility and robustness of the present formulation.
Bayesian EWMA control chart with measurement error under different loss functions
Authors: Noor‐ul‐Amin Muhammad , Noor Surria
Published: May 2021

This paper presents the Bayesian EWMA control chart under two different loss functions (i) squared error loss function (SELF) and (ii) linex loss function (LLF) in the presence of measurement error (ME). We take posterior and posterior predictive distribution under the conjugate prior. We used a linear covariate model in the existence of ME to evaluate the control chart. We also studied the effects of multiple measurements and linear increasing variance methods in the existence of the ME. The average run length and standard deviation of run length are used to measure the performance of the Bayesian EWMA control chart with ME. We conducted the Monte Carlo simulation study to evaluate the performance of Bayesian EWMA control chart with ME. A real‐life data example is also presented to demonstrate the application of the control chart.
Finite‐time self‐triggered model predictive control of discrete‐time Markov jump linear systems
Authors: He Peng , Wen Jiwei , Luan Xiaoli , Liu Fei
Published: May 2021

In the present study, a self‐triggered model predictive control (MPC) strategy is proposed for a class of discrete‐time Markov jump linear systems (MJLSs) to achieve the desired control performance in a finite‐time interval and simultaneously save the computational resources. Obtained results show that with eminent optimization performance and low computational complexity of tube‐based MPC algorithm, it guarantees stochastic finite‐time boundedness of MJLSs. Meanwhile, a self‐triggered scheme is proposed to reduce unnecessary sampling when the system state satisfies the control target. Furthermore, the cost function of the MPC algorithm and the error‐based self‐triggered scheme are adjusted to keep the state trajectories within prespecified bounds over a given time interval. Finally, the effectiveness of the proposed strategy is numerically evaluated from different aspects, including the overall performance and resource‐saving capability.
Dynamic event‐triggering based design of sliding mode control
Authors: Yesmin Asifa , Behera Abhisek K. , Bera Manas K. , Bandyopadhyay Bijnan
Published: May 2021

This article presents a new event‐triggering based design of sliding mode control (SMC) for the control of a dynamical system against external perturbations. This triggering mechanism aims to generate a sparser sampling pattern than the existing one while achieving the minimum resource utilization. The triggering mechanism employs scalar dynamics, hence it is called the dynamic event‐triggering mechanism, which acts as a filter for the triggering condition. The output of this dynamics is used in the event condition in addition to a constant threshold while the part of the event function is fed as an input to this filter. The existing design algorithms for event‐triggered SMC may not guarantee an increase in the inter event time for the dynamic event‐triggering strategy. An alternative approach to this is proposed for the design of dynamic triggering based SMC where we partially relax the dependency of SMC gain on the event parameter without affecting the steady‐state performance for the closed‐loop system. It is shown that the proposed design achieves a larger inter event time leading to a sparser triggering sequence. We guarantee the stability by showing the convergence of state trajectories of the closed‐loop system within any desired bound around the origin for the proposed triggering mechanism, and also the absence of the Zeno phenomenon in the triggering sequence is established. Finally, an illustration of the proposed scheme is presented in a simulation study for a mass‐spring‐damper system.
Predicting defoliator abundance and defoliation measurements using Landsat‐based condition scores
Authors: Pasquarella Valerie J. , Mickley James G. , Barker Plotkin Audrey , MacLean Richard G. , Anderson Riley M. , Brown Leone M. , Wagner David L. , Singer Michael S. , Bagchi Robert
Published: May 2021

Remote sensing imagery can provide critical information on the magnitude and extent of damage caused by forest pests and pathogens. However, monitoring short‐term changes in deciduous forest condition caused by defoliating insects is challenging and requires approaches that directly account for seasonal vegetation dynamics. We implemented a previously published harmonic modeling approach for forest condition monitoring in Google Earth Engine and systematically assessed the relative ability of condition change products generated using various model parameterizations for predicting pest abundances and defoliation during the 2016–2018 gypsy moth (Lymantria dispar) outbreak in southern New England. Our comparisons revealed that most models made reasonable predictions of changes in canopy condition and egg and larval abundances of L. dispar, indicating a strong correlation between our harmonic‐based estimates of condition change and defoliator activity. The greatest differences in predictive ability were in the spectral domain, with assessments based on Tasseled Cap Greenness, Simple Ratio, and the Enhanced Vegetation Index ranking among the top models, and the commonly used Normalized Difference Vegetation Index consistently exhibiting poorer performance. We also observed notable differences in the magnitude of scores for different baseline periods. Additionally, we found that Landsat‐based condition scores better explained larval abundance than egg mass counts, which have historically been used as a proxy for later‐season larval abundance, indicating that our remote sensing approach may be more accurate and cost‐effective for generating consistent retrospective assessments of L. dispar population abundance in addition to estimates of canopy damage. These findings provide important linkages between spectral changes detected using a harmonic modeling approach and biophysical aspects of defoliator activity, with potential to extend monitoring and prediction to regional or even continental scales.
Vitreum Etching‐Assisted Fabrication of Porous Hollow Carbon Architectures for Enhanced Capacitive Sodium and Potassium‐Ion Storage
Authors: Zhou Kaiqiang , Qiu Ruoxue , Zhen Yichao , Huang Zhigao , Mathur Sanjay , Hong Zhensheng
Published: May 2021

Carbonaceous materials exhibit promising application in electrochemical energy storage especially for hollow or porous structure due to the fascinating and outstanding properties. Although there has been achieved good progress, controllable synthesis of hollow or porous carbons with uniform morphology by a green and easy way is still a challenge. Herein, a new artful and green approach is designed to controllably prepare hollow porous carbon materials with the assistance of boron oxide vitreum under a relatively low temperature of 500 °C. The vitreous B2O3 provides a flowing carbonization environment and acts as etching agent accompanying with boron doping. By this general strategy, hollow and porous carbon architectures with various morphology of spheres and hollow polyhedrons are successfully fabricated by metal organic framework (MOF) precursors. Furthermore, such hollow carbon materials exhibit considerably excellent Na+/K+ storage properties through enhanced capacitive behavior due to due to the highly porous structure and large surface area. It is notable that hollow carbon spheres display nearly 90% initial Coulombic efficiency, outstanding rate capability with 130 mAh g‐1 at 30 A g‐1 and long cycling life for sodium ion storage.
Delivery of siHIF‐1α to Reconstruct Tumor Normoxic Microenvironment for Effective Chemotherapeutic and Photodynamic Anticancer Treatments
Authors: Chen Xiaobing , Jin Rongrong , Jiang Qian , Bi Qunjie , He Ting , Song Xu , Barz Matthias , Ai Hua , Shuai Xintao , Nie Yu
Published: May 2021

The tumor hypoxic microenvironment not only induces genetic and epigenetic changes in tumor cells, immature vessels formation for oxygen demand, but also compromises the efficiency of therapeutic interventions. On the other hand, conventional therapeutic approaches which kill tumor cells or destroy tumor blood vessels to block nutrition and oxygen supply usually facilitate even harsher microenvironment. Thus, simultaneously relieving the strained response of tumor cells and blood vessels represents a promising strategy to reverse the adverse tumor hypoxic microenvironment. In the present study, an integrated amphiphilic system (RSCD) is designed based on Angiotensin II receptor blocker candesartan for siRNA delivery against the hypoxia‐inducible factor‐1 alpha (HIF‐1α), aiming at both vascular and cellular “relaxation” to reconstruct a tumor normoxic microenvironment. Both in vitro and in vivo studies have confirmed that the hypoxia‐inducible HIF‐1α expression is down‐regulated by 70% and vascular growth is inhibited by 60%. The “relaxation” therapy enables neovascularization with more complete and organized structures to obviously increase the oxygen level inside tumor, which results in a 50% growth inhibition. Moreover, reconstruction of tumor microenvironment enhances tumor‐targeted drug delivery, and significantly improves the chemotherapeutic and photodynamic anticancer treatments.
An Effective Strategy of Combining Surface Passivation and Secondary Grain Growth for Highly Efficient and Stable Perovskite Solar Cells
Authors: Ma Dongyu , Li Wenlang , Chen Xiaojie , Yang Zhan , Zhao Juan , Yang Zhiyong , Zhang Yi , Chi Zhenguo
Published: May 2021

Interfacial engineering methods have been developed to solve defect issues of perovskite solar cells (PSCs). However, traditional surface passivation has limited effects on eliminating defect‐forming residuals, while secondary grain growth (SGG) is restricted by limited choices of additives and intrinsic properties of perovskites. Here, a pincer strategy of taking advantages of surface passivation and SGG is proposed to modify both exterior and interior of CH3NH3PbI3 (MAPbI3) perovskite, by employing cyanoacetate‐containing donor‐acceptor compounds (CA‐D‐A) including 2‐cyano‐3‐(3,4,5‐trimethoxyphenyl)acrylic acid (CA), methanaminium 2‐cyano‐3‐(3,4,5‐trimethoxyphenyl)acrylate (CAMA), and aminomethaniminium (Z)‐2‐cyano‐3‐(3,4,5‐trimethoxyphenyl)acrylate (CAFA). In comparison to untreated perovskite, CA‐D‐A treated perovskites present better crystallinity because of SGG, lower trap densities due to the synergistic effect of surface passivation and SGG, and tuned energy levels induced by CA‐D‐A. Accordingly, the CA‐D‐A treated MAPbI3‐based PSCs exhibit higher open‐circuit voltage and fill factor than the control PSC without any treatment, leading to improved power conversion efficiency (PCE) and enhanced device stability, especially the CAMA treated PSCs with an average PCE promoted from 17.77 (control PSCs) to 18.71%, and importantly an excellent PCE of 19.71% through further optimization. This work provides an effective strategy for developing highly efficient and stable PSCs with the assistance of both surface passivation and SGG.
Dissolution of 2D Molybdenum Disulfide Generates Differential Toxicity among Liver Cell Types Compared to Non‐Toxic 2D Boron Nitride Effects
Authors: Li Jiulong , Guiney Linda M. , Downing Julia R. , Wang Xiang , Chang Chong Hyun , Jiang Jinhong , Liu Qi , Liu Xiangsheng , Mei Kuo‐Ching , Liao Yu‐Pei , Ma Tiancong , Meng Huan , Hersam Mark C. , Nel André E. , Xia Tian
Published: May 2021

2D boron nitride (BN) and molybdenum disulfide (MoS2) materials are increasingly being used for applications due to novel chemical, electronic, and optical properties. Although generally considered biocompatible, recent data have shown that BN and MoS2 could potentially be hazardous under some biological conditions, for example, during, biodistribution of drug carriers or imaging agents to the liver. However, the effects of these 2D materials on liver cells such as Kupffer cells (KCs), liver sinusoidal endothelial cells, and hepatocytes, are unknown. Here, the toxicity of BN and MoS2, dispersed in Pluronic F87 (designated BN‐PF and MoS2‐PF) is compared with aggregated forms of these materials (BN‐Agg and MoS2‐Agg) in liver cells. MoS2 induces dose‐dependent cytotoxicity in KCs, but not other cell types, while the BN derivatives are non‐toxic. The effect of MoS2 could be ascribed to nanosheet dissolution and the release of hexavalent Mo, capable of inducing mitochondrial reactive oxygen species generation and caspases 3/7‐mediated apoptosis in KUP5 cells. In addition, the phagocytosis of MoS2‐Agg triggers an independent response pathway involving lysosomal damage, NLRP3 inflammasome activation, caspase‐1 activation, IL‐1β, and IL‐18 production. These findings demonstrate the importance of Mo release and the state of dispersion of MoS2 in impacting KC viability.
Hydrogen‐Bonding Crosslinking MXene to Highly Robust and Ultralight Aerogels for Strengthening Lithium Metal Anode
Authors: Meng Xiangyu , Sun Yufeng , Yu Mengzhou , Wang Zhiyu , Qiu Jieshan
Published: May 2021

Li metal batteries offer the ultimate choice of high‐energy power source, but suffer the performance decay and safety risk originated from notorious dendrite problem and infinite volume change of Li metal anode. Herein, it is reported to strengthen the Li metal anode by ultralight but highly robust MXene aerogels (ULRMA) with build‐in strain‐resistant and molecular‐level lithiophilic properties. A hydrogen‐bonding crosslinking strategy is developed for rapidly assembling 2D MXene to ULRMA at ambient conditions with less sacrifice of intrinsic properties of MXene. The ULRMA with an ultralow density below 10 mg cm−3 are favorable to maximize the merit of Li metal in gravimetric energy density while offering exceptional stability of porous frameworks against mechanical strain of long‐term Li plating/stripping. The lithiophilic architecture with high conductivity and hierarchical porosity further largely reduces the potential polarization and guides the pattern of Li deposition. Uptaking Li metal into ULRMA leads to a stable Li metal anode with an ultralong lifetime of 1600 h with a high‐rate response up to 20 mA cm−2 and high coulombic efficiency. It yields a highly robust Li metal anode with high effectiveness in engineering stable Li‐ion and Li–S batteries even paring with commercial LiFePO4 or sulfur cathode without nanostructuring.
Conservation of Sage‐grouse Critical Habitat and Implications for Prairie Songbirds
Authors: Rose Phillip K. , Brigham R. Mark , Davis Stephen K.
Published: May 2021

A popular approach for conserving multiple organisms in a given region is to identify one or more umbrella species. Identifying and managing for species that have a high degree of overlap in their habitat requirements with a broader suite of organisms is expected to enhance the effectiveness of conservation actions when resources are limited. The greater sage‐grouse (Centrocercus urophasianus) has received considerable attention as a potential umbrella species for shrub‐steppe flora and fauna in the core of its range. However, the extent to which conserving sage‐grouse habitat benefits mixed‐grass prairie songbirds in the northern portion of its range is unclear. We compared abundance of grassland songbirds within grasslands designated as sage‐grouse critical habitat by the Canadian federal government, and within a 1.6‐km buffer of adjacent habitat in southwestern Saskatchewan, Canada in 2016 and 2017. We also quantified relationships between bird abundance and gradients of vegetation structure. Lark bunting (Calamospiza melanocorys) abundance was 3 times greater within sage‐grouse critical habitat, whereas chestnut‐collared longspur (Calcarius ornatus), Baird's sparrow (Centronyx bairdii), and Sprague's pipit (Anthus spragueii) abundance was 1.6–1.8 times greater outside of these areas. The abundance of grassland specialists was negatively associated with total shrub and silver sagebrush (Artemisia cana) cover, both of which characterize sage‐grouse critical habitat in Canada at both landscape and local scales. Furthermore, characteristics of vegetation structure associated with grassland generalists overlapped with characteristics of vegetation structure that defined greater sage‐grouse critical habitat. Conservation of greater sage‐grouse critical habitat in Canada is likely to have a positive influence on shrub‐dependent or shrub‐tolerant species, such as lark bunting. The conservation of open, native grasslands within greater sage‐grouse critical habitat could benefit grassland specialists, however, any changes in the current management that increases the cover of exotic species, silver sagebrush, and other shrubs will negatively affect grassland specialists. We recommend that protection and management activities be targeted towards greater sage‐grouse, Sprague's pipit, and chestnut‐collared longspur to maximize the conservation of mixed‐grass prairie songbirds and minimize the number of focal umbrella species required. © 2021 The Wildlife Society.
Ensiling of maple leaves and its use in winter nutrition of mantled guereza (Colobus guereza)
Authors: Lasek Olga , Rajtar Patrycja , Malec Andrzej , Bielatowicz Wojciech , Przybyło Marcin
Published: May 2021

Young leaves are favored by mantled guereza (Colobus guereza) and the gastrointestinal tract of this species is well adapted to such a high fiber diet. Fresh maple leaves are often used in the diets for guereza in captivity but their use in winter feeding time is limited. The aim of the study was to evaluate the effect of additives on chemical composition and fermentation parameters of maple leaf silage, as well as inclusion of maple leaf silage in the diet for mantled guereza on feed and nutrient intake. Maple leaves were ensiled without additives (MLS), with a mixture of bacterial inoculants (MLS + BI) and with carrot additives (MLS + C). The chemical composition and fermentation parameters were determined in fresh and ensiled material. A group of seven mantled guerezas were fed a standard diet, and afterwards shifted to a diet with maple leaf silage (contained 20% of MLS; as fed). Each diet was fed for 7 days when the feed and nutrient intake were measured. The ensiling process did not change the concentration of most nutrients compared to the fresh material. The inclusion of leaf silage increased dry matter intake by guereza (125.3 vs. 163.3 g dry matter/day). Therefore, higher nutrient intake (crude protein, NDF, ADF) was observed when maple leaf silage was included in the diet. In conclusion, the ensiling process (even without additives) proved to be a good conservation method for maple leaves. Furthermore, inclusion of maple leaf silage in the winter diets for guereza, and possibly other folivorous primates, may increase dry matter and nutrients (particularly fiber) intake.