bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain connectivity–based prediction of real-life creativity is mediated by semantic memory structure
Authors: Ovando-Tellez Marcela , Kenett Yoed N. , Benedek Mathias , Bernard Matthieu , Belo Joan , Beranger Benoit , Bieth Theophile , Volle Emmanuelle
Published: February 2022

Associative theories of creativity argue that creative cognition involves the abilities to generate remote associations and make useful connections between unrelated concepts in one’s semantic memory. Yet, whether and how real-life creative behavior relies on semantic memory structure and its neural substrates remains unclear. We acquired multi-echo functional magnetic resonance imaging data while participants underwent a semantic relatedness judgment task. These ratings were used to estimate their individual semantic memory networks, whose properties significantly predicted their real-life creativity. Using a connectome predictive modeling approach, we identified patterns of task-based functional connectivity that predicted creativity-related semantic memory network properties. Furthermore, these properties mediated the relationship between functional connectivity and real-life creativity. These results provide new insights into how brain connectivity patterns support real-life creative behavior via the structure of semantic memory. We also show how computational network science can be used to couple behavioral, cognitive, and neural levels of analysis.
Nutrient regulation of biological nitrogen fixation across the tropical western North Pacific
Authors: Wen Zuozhu , Browning Thomas J. , Cai Yihua , Dai Rongbo , Zhang Ruifeng , Du Chuanjun , Jiang Ruotong , Lin Wenfang , Liu Xin , Cao Zhimian , Hong Haizheng , Dai Minhan , Shi Dalin
Published: February 2022

Nitrogen fixation is critical for the biological productivity of the ocean, but clear mechanistic controls on this process remain elusive. Here, we investigate the abundance, activity, and drivers of nitrogen-fixing diazotrophs across the tropical western North Pacific. We find a basin-scale coherence of diazotroph abundances and N
2
fixation rates with the supply ratio of iron:nitrogen to the upper ocean. Across a threshold of increasing supply ratios, the abundance of
nifH
genes and N
2
fixation rates increased, phosphate concentrations decreased, and bioassay experiments demonstrated evidence for N
2
fixation switching from iron to phosphate limitation. In the northern South China Sea, supply ratios were hypothesized to fall around this critical threshold and bioassay experiments suggested colimitation by both iron and phosphate. Our results provide evidence for iron:nitrogen supply ratios being the most important factor in regulating the distribution of N
2
fixation across the tropical ocean.
Drift-dominant exciton funneling and trion conversion in 2D semiconductors on the nanogap
Authors: Lee Hyeongwoo , Koo Yeonjeong , Choi Jinseong , Kumar Shailabh , Lee Hyoung-Taek , Ji Gangseon , Choi Soo Ho , Kang Mingu , Kim Ki Kang , Park Hyeong-Ryeol , Choo Hyuck , Park Kyoung-Duck
Published: February 2022

Understanding and controlling the nanoscale transport of excitonic quasiparticles in atomically thin two-dimensional (2D) semiconductors are crucial to produce highly efficient nano-excitonic devices. Here, we present a nanogap device to selectively confine excitons or trions of 2D transition metal dichalcogenides at the nanoscale, facilitated by the drift-dominant exciton funneling into the strain-induced local spot. We investigate the spatiospectral characteristics of the funneled excitons in a WSe
2
monolayer (ML) and converted trions in a MoS
2
ML using hyperspectral tip-enhanced photoluminescence imaging with <15-nm spatial resolution. In addition, we dynamically control the exciton funneling and trion conversion rate by the gigapascal-scale tip pressure engineering. Through a drift-diffusion model, we confirm an exciton funneling efficiency of ∼25% with a significantly low strain threshold (∼0.1%), which sufficiently exceeds the efficiency of ∼3% in previous studies. This work provides a previously unexplored strategy to facilitate efficient exciton transport and trion conversion of 2D semiconductor devices.
T
H
17 cells in multiple sclerosis dislodge another brick in the wall
Authors: Pillai Shiv
Published: February 2022

DICAM is an adhesion molecule on T
H
17 cells and inflamed brain endothelial cells that may have potential as a therapeutic target in multiple sclerosis.
Euphoric effect induced by zolpidem: a case study of magnetoencephalography
Authors: Lyu Xuechan , Hu Yegang , Zhao Yan , Wang Haihong , Du Jiang , Wang Jijun , Jiang Haifeng
Published: February 2022

Initially, zolpidem, a non-benzodiazepine hypnotic agent, was considered to have fewer adverse reactions than traditional benzodiazepines. However, after zolpidem was approved for medical use, an increasing number of case reports have described abuse or dependence complications. We were especially interested in the cases of dependence that presented a paradoxical ‘euphoric’ effect of zolpidem. This article reports the case of a female zolpidem-dependent patient who presented with 6 years of daily use of 400–1400 mg of zolpidem. She reported subjective effects of euphoria, intense craving and the inability to stop drug ingestion. Her diagnoses were zolpidem dependence and a depressive episode induced by substance abuse. To explore the neural mechanisms of the euphoric effect caused by high-dose zolpidem, we performed repeated magnetoencephalography (MEG) recordings. Before undergoing detoxification, her MEG results indicated that cerebellar electrical signal activation increased when taking high zolpidem doses. However, the prefrontal and parietal lobes’ electrical signal activity showed a tendency to recover to a normal state as the withdrawal time progressed to completion. This case suggests that the cerebellum plays a role in the euphoria induced by high zolpidem doses and provides clues for further research.
Human papillomavirus (HPV) and cervical dysplasia in adult female cystic fibrosis (CF) lung transplant recipients
Authors: Thornton Christina , Somayaji Ranjani , Chu Angel , Parkins Michael D
Published: February 2022

Human papillomavirus (HPV) is the principal risk factor for cervical cancer. Transplant recipients are at a disproportionate risk of HPV complications. We conducted a single-centre, retrospective study of adult female cystic fibrosis (CF) lung transplant recipients between 2008 and 2021. We observed 12 of 34 (35.3%) with ≥1 abnormal pap smear (median age: 26.7 years). Complications included refractory anogenital warts (n=3), vulvectomy (n=2) and cervical cancer (n=4), with two deaths from metastatic disease. None with HPV morbidity was vaccinated. Lung transplant recipients had greater odds of cervical dysplasia relative to controls (OR, 3.98; 95% CI 1.17 to 11.82). CF care providers must prioritise HPV vaccination to attenuate potential future morbidity and mortality.
A catastrophic coal mine spill in the Athabasca River watershed induces isotopic niche shifts in stream biota including an endangered rainbow trout ecotype
Authors: Medinski Nathan A. , Maitland Bryan M. , Jardine Timothy D. , Drake D. Andrew R. , Poesch Mark S.
Published: February 2022

Freshwater biodiversity is declining from impacts associated with anthropogenic stressors. Here, we use carbon (δ13C) and nitrogen (δ15N) stable isotopes to assess food web effects following a coal mine spill that displaced biota and altered biophysical stream characteristics. We compared isotopic niche metrics of benthic macroinvertebrates and the fish community, including non-native brook trout (Salvelinus fontinalis) and endangered Athabasca rainbow trout (Oncorhynchus mykiss), to infer spatial differences in site-specific resource use along a habitat disturbance gradient. Predatory benthic macroinvertebrate trophic position was elevated where impacts from the spill were most pronounced. Autochthonous carbon contribution to consumer diets was lowest in biota sampled at the most highly impacted site from the mine spill, leading to an unexpected expansion of the isotopic niche size of rainbow trout and the aquatic invertebrate community. Collectively, our results suggest variation in trophic resource assimilation across multiple levels of the food web, fueled by the allochthonous energy pathway in highly impacted study sites. We conclude this reflects a biotic response to altered basal aquatic resources following a major industrial disturbance.
Scalarized non-topological neutron stars in multi-scalar Gauss–Bonnet gravity
Authors: Staykov Kalin V. , Zheleva Radostina Z.
Published: February 2022

In the present paper we construct novel non-topological, spontaneously scalarized neutron stars in multi-scalar Gauss–Bonnet gravity with maximally symmetric target space, and nontrivial map $$\varphi :spacetime \rightarrow target\ space$$

φ
:
s
p
a
c
e
t
i
m
e
→
t
a
r
g
e
t

s
p
a
c
e

. The theory is characterized by the fact that for some classes of coupling functions the field equations allow solutions with trivial scalar field, which coincide with the general relativistic ones. For a certain range of parameters those solutions lose stability and new branches of solutions with nontrivial scalar field bifurcate from the trivial branch. For a given set of parameters, those branches are characterized by the number of zeros of the scalar field, and they are energetically more favorable than the general relativistic ones.
Evidence for the maximally entangled low x proton in Deep Inelastic Scattering from H1 data
Authors: Hentschinski Martin , Kutak Krzysztof
Published: February 2022

We investigate the proposal by Kharzeev and Levin of a maximally entangled proton wave function in Deep Inelastic Scattering at low x and the proposed relation between parton number and final state hadron multiplicity. Contrary to the original formulation we determine partonic entropy from the sum of gluon and quark distribution functions at low x, which we obtain from an unintegrated gluon distribution subject to next-to-leading order Balitsky–Fadin–Kuraev–Lipatov evolution. We find for this framework very good agreement with H1 data. We furthermore provide a comparison based on NNPDF parton distribution functions at both next-to-next-to-leading order and next-to-next-to-leading with small x resummation, where the latter provides an acceptable description of data.
Notoginsenoside R1, An Active Compound from Panax notoginseng, Inhibits Hepatic Stellate Cell Activation and Liver Fibrosis via MAPK Signaling Pathway
Authors: Gong Xu , Shan Linlin , Cao Sisi , Li Kaitao , Wu Yanli , Zhang Qing
Published: February 2022

Activation of the hepatic stellate cell is implicated in pathological vascularization during development of liver fibrosis. MAPK signaling is involved in the activation of hepatic stellate cell. Oxidative stress and inflammation are also involved in the pathogenesis of liver fibrosis. Notoginsenoside R1 is an effective saponin isolated from the roots of Panax notoginseng (Burk) F. H. Chen and exerts anti-oxidant, anti-inflammatory and anti-fibrotic roles in various diseases. However, the role of Notoginsenoside R1 in liver fibrosis has not been investigated yet. First, a rat model with liver fibrosis was established through oral gavage administration with carbon tetrachloride. Data from hematoxylin and eosin (H&E) and Masson’s trichrome stainings showed that carbon tetrachloride induced severe hepatic damages, including inflammatory cell infiltration, lipid droplets deposition in hepatocytes and liver centrilobular necrosis. Meanwhile, the rats were also intraperitoneal injected with different concentrations of Notoginsenoside R1. Results demonstrated that Notoginsenoside R1 treatment suppressed the pathological changes in the livers with enhanced levels of ALB and TP, and reduced levels of ALP, AST and ALT. Second, Notoginsenoside R1 also significantly attenuated carbon tetrachloride-induced decrease in PPAR-[Formula: see text] and increase in Coll-a1, [Formula: see text]-SMA and TIMP1 in liver tissues ([Formula: see text][Formula: see text] 0.001). Third, the decrease in GSH, SOD and GST and increase in MDA, IL-1[Formula: see text], IL-6 and TNF-[Formula: see text] induced by carbon tetrachloride were markedly restored by Notoginsenoside R1 ([Formula: see text][Formula: see text] 0.001). Lastly, Notoginsenoside R1 counteracted with the promotive effects of carbon tetrachloride on levels of proteins involved in MAPK signaling, including phosphorylated p65 (p-p65), p-ERK, p-JNK and p-p38. In conclusion, Notoginsenoside R1 suppressed the activation of hepatic stellate cells and exerted anti- oxidant and anti-inflammatory to attenuate carbon tetrachloride-induced liver fibrosis through inactivation of NF-[Formula: see text]B and MAPK signaling.
Comprehensive analysis of thermally radiative transport of Sisko fluid over a porous stretchable curved surface with gold nanoparticles
Authors: Naqvi Syed Muhammad Raza Shah , Farooq Umar , Aiyashi M. A. , Waqas Hassan
Published: February 2022

Nanofluid and magnetic field impacts are significant in bioengineering and medical treatment. The effectiveness of gold particles in blood flow (Sisko fluid flow) with nonlinear thermal radiation and heat source over a curved surface is investigated in this work. The partial slip influence is utilized to explore the characteristics of nanofluid flow in depth. The Sisko model’s first-order partial differential equations (PDEs) are simplified to ordinary differential equations (ODEs) by employing suitable variables. The findings are displayed by using the bvp4c (shooting approach) in MATLAB. When compared to earlier reports, the accuracy is found to be satisfactory. In addition to the influence of a magnetic field and radiation, although both are useful in therapeutic hyperthermia, the magnetic field reduces the velocity distribution. The velocity profile is boomed for the estimations of slip parameter while declined for the suction parameter. The thermal profile is boosted up for the higher magnitude of temperature ratio parameter and Biot number. The thermal profile is decreased for the greater values of the suction parameter while increases for the heat source parameter.
Architectural Design of a Fast Search Algorithm and Implementation to Intra-Mode Decision Block of Still Image Coding
Authors: Cekli Serap , Akman Ali
Published: February 2022

As a requirement of many modern image compression standards faced today, a computational complexity is observed due to the best mode selection in the intra-prediction stage. This computational complexity is tried to be reduced by various techniques without affecting the performance criteria of the image. In this study, a fast search algorithm, which simplifies the mode selection process of the intra-prediction algorithm and provides calculation with less number of modes is proposed. The hardware architecture of this proposed algorithm is implemented for realization. There are two main sections of the intra-prediction algorithm in image compression, namely the image prediction process and the mode selection process. In this study, main objective is to reduce the process time of the mode selection and the simplification of the hardware design. Sum of absolute difference (SAD) is a frequently used criterion to simplify hardware design. The algorithm searches for the most suitable mode in a single step, where the decision is based on the SAD criterion preferred for the simplicity. The proposed algorithm and related hardware architecture is tested by using various experiments. The number of the modes calculated is reduced effectively, while the process is kept within the acceptable limits in terms of peak signal to noise ratio (PSNR) and compression rate (CR) performance criteria. Therefore, the number of clock cycles observed is considerably reduced. The designed architecture is synthesized for the field programmable gate arrays (FPGA) board and the obtained results are given. In addition, these results are compared with the HM reference software where the corresponding results are in accordance with the reference software.
Analysis-aware defeaturing: Problem setting and a posteriori estimation
Authors: Buffa Annalisa , Chanon Ondine , Vázquez Rafael
Published: February 2022

Defeaturing consists in simplifying geometrical models by removing the geometrical features that are considered not relevant for a given simulation. Feature removal and simplification of computer-aided design models enables faster simulations for engineering analysis problems, and simplifies the meshing problem that is otherwise often unfeasible. The effects of defeaturing on the analysis are then neglected and as of today, there are basically very few strategies to quantitatively evaluate such an impact. Understanding well the effects of this process is an important step for automatic integration of design and analysis. We formalize the process of defeaturing by understanding its effect on the solution of Poisson equation defined on the geometrical model of interest containing a single feature, with Neumann boundary conditions on the feature itself. We derive an a posteriori estimator of the energy error between the solutions of the exact and the defeatured geometries in [Formula: see text], [Formula: see text], that is simple, reliable and efficient up to oscillations. The dependence of the estimator upon the size of the features is explicit.
THERMOELECTRIC EFFECTS IN SELF-SIMILAR MULTIBARRIER STRUCTURE BASED ON MONOLAYER GRAPHENE
Authors: MINIYA M. , OUBRAM O. , REYNAUD-MORALES A. G. , RODRÍGUEZ-VARGAS I. , GAGGERO-SAGER L. M.
Published: February 2022

Thermoelectric effects have attracted wide attention in recent years from physicists and engineers. In this work, we explore the self-similar patterns in the thermoelectric effects of monolayer graphene-based structures, by using the quantum relativistic Dirac equation. The transfer matrix method has been used to calculate the transmission coefficient. The Landauer–Büttiker formalism and the Cutler–Mott formula were used to calculate the conductance, the Seebeck coefficient, and the power factor. We find self-similar behavior and the scale factors between generations in transport and thermoelectric properties. Furthermore, we implement these scale invariances as general scaling rules. We present a new analytical demonstration of self-similarity in the Seebeck coefficient. These findings can open outstanding perspectives for experimentalists to develop thermoelectric devices.
The Schreier property and the composite semigroup ring A + B[Γ*]
Authors: Boulayat B. , El Baghdadi S. , Izelgue L.
Published: February 2022

Let [Formula: see text] be an extension of integral domains and [Formula: see text] a commutative, additive, cancellative torsion-free monoid. Let [Formula: see text] be the semigroup ring of [Formula: see text] over [Formula: see text] and set [Formula: see text]. Suppose that [Formula: see text]. Then [Formula: see text] is a subring of [Formula: see text]. In this paper, we study primal elements in [Formula: see text] domains. As an application, we characterize when the construction [Formula: see text] is a (pre-)Schreier domain.
Emerging hyperbolic spaces and some considerations in AdS cosmology
Authors: Pigazzini Alexander , Pincak Richard , Jafari Saeid , Özel Cenap
Published: February 2022

Recently, PNDP-manifolds have been introduced, and these have shown to be useful in applicative aspects especially in the field of cosmology, introducing a new geometric/topological approach to the concept of “emerging space”. However, the applications considered so far concern only trivial and flat PNDP-manifolds. Therefore, we show the existence of non-Ricci-flat solutions for PNDP-manifolds with positive “virtual” dimension which have hyperbolic [Formula: see text]-manifold. Based on this, we have advanced an applicative hypothesis, accompanied by some open considerations, in the context of [Formula: see text] cosmology.
Comparative study on Photobiomodulation between 630 nm and 810 nm LED in diabetic wound healing both in vitro and in vivo
Authors: Zhao Hongyou , Ji Tengda , Sun Tianzhen , Liu Haolin , Liu Yidi , Chen Defu , Wang Ying , Tan Yizhou , Zeng Jing , Qiu Haixia , Gu Ying
Published: February 2022

Photobiomodulation (PBM) promoting wound healing has been demonstrated by many studies. Currently, 630 nm and 810 nm light-emitting diodes (LEDs), as light sources, are frequently used in the treatment of diabetic foot ulcers (DFUs) in clinics. However, the dose–effect relationship of LED-mediated PBM is not fully understood. Furthermore, among the 630[Formula: see text]nm and 810[Formula: see text]nm LEDs, which one gets a better effect on accelerating the wound healing of diabetic ulcers is not clear. The aim of this study is to evaluate and compare the effects of 630[Formula: see text]nm and 810[Formula: see text]nm LED-mediated PBM in wound healing both in vitro and in vivo. Our results showed that both 630[Formula: see text]nm and 810[Formula: see text]nm LED irradiation significantly promoted the proliferation of mouse fibroblast cells (L929) at different light irradiances (1, 5, and 10[Formula: see text]mW/cm[Formula: see text]. The cell proliferation rate increased with the extension of irradiation time (100, 200, and 500[Formula: see text]s), but it decreased when the irradiation time was over 500[Formula: see text]s. Both 630[Formula: see text]nm and 810[Formula: see text]nm LED irradiation (5[Formula: see text]mW/cm[Formula: see text] significantly improved the migration capability of L929 cells. No difference between 630[Formula: see text]nm and 810[Formula: see text]nm LED-mediated PBM in promoting cell proliferation and migration was detected. In vivo results presented that both 630[Formula: see text]nm and 810[Formula: see text]nm LED irradiation promoted the wound healing and the expression of the vascular endothelial growth factor (VEGF) and transforming growth factor (TGF) in the wounded skin of type 2 diabetic mice. Overall, these results suggested that LED-mediated PBM promotes wound healing of diabetic mice through promoting fibroblast cell proliferation, migration, and the expression of growth factors in the wounded skin. LEDs (630[Formula: see text]nm and 810[Formula: see text]nm) have a similar outcome in promoting wound healing of type 2 diabetic mice.
China-U.S. Strategic Collaboration: Four Cases and Their Lessons
Authors: Dongxiao Chen , Liuqiang Su , Guoxing Wang , Yu Ye , Yanliang Li
Published: February 2022

The China-U.S. relationship has entered a new phase of “competition.” A fundamental shift in Washington’s China policy under President Trump’s watch intensified strategic competition to the extent of nearly eliminating any possibility of cooperation. As Washington resorts to a policy of “containment and suppression,” competition will be the defining feature of the bilateral relationship for the foreseeable future and the focus of China-U.S. diplomacy should be on risk control, crisis stability, and getting around the Thucydides Trap. Even if growing strategic competition seems inescapable, there are plenty of shared interests and common concerns that warrant closer coordination between the two superpowers. The most pressing issue is how to restart the engine of cooperation under the Biden presidency after almost all the available avenues of coordination have been shut down by the Trump administration. Beijing and Washington may have calibrated their strategic objectives and developed new perceptions of each other as they find themselves in a new balance of power and profoundly changed circumstances, but some of the success stories of bilateral strategic collaboration over the past forty years since normalization still hold important lessons, and a world of growing uncertainty has rendered those lessons even more relevant for today’s bilateral relationship.
Mechanical properties and energy absorption of AlSi10Mg Gyroid lattice structures fabricated by selective laser melting
Authors: Wu Siqi , Yang Lei , Yang Xiao , Chen Peng , Su Jin , Wu Hongzhi , Liu Zhufeng , Wang Haoze , Wang Changshun , Yan Chunze , Shi Yusheng
Published: February 2022

Aluminium alloy lattice structures are prospective candidates for high-value engineering applications due to their excellent comprehensive properties. Selective laser melting (SLM), a promising additive manufacturing (AM) process, enables the fabrication of metallic periodic lattices with complex and controllable internal design. In this paper, finite element (FE) analysis with the Johnson–Cook model was employed to investigate the compressive plastic deformation and the fracture mechanisms of AlSi10Mg Gyroid lattice structures (GLSs). The simulated accuracy was then validated by the compression test of GLS samples with various volume fractions fabricated via SLM. The results revealed that FE simulations were in conformity with the experimental testing with most prediction errors less than 25% and could be utilised to estimate and characterise the mechanical properties for AlSi10Mg GLSs. Finally, the discussion about the energy absorption of GLSs during the elastic and yield stage demonstrated that the FE data were comparable with the experimental results, and the rise in volume fraction contributed to the increase of energy absorption capability from 1.33 J/mm3 to 9.61 J/mm3 and improved the ability to resist the decline of absorption efficiency. This study provides a deeper understanding and guidance based on FE analysis for the optimal design and AM of Al alloy lattice structures.
Threat-modeling-guided Trust-based Task Offloading for Resource-constrained Internet of Things
Authors: Bradbury Matthew , Jhumka Arshad , Watson Tim , Flores Denys , Burton Jonathan , Butler Matthew
Published: February 2022

There is an increasing demand for Internet of Things (IoT) networks consisting of resource-constrained devices executing increasingly complex applications. Due to these resource constraints, IoT devices will not be able to execute expensive tasks. One solution is to offload expensive tasks to resource-rich edge nodes, which requires a framework that facilitates the selection of suitable edge nodes to perform task offloading. Therefore, in this article, we present a novel
trust-model-driven system architecture
, based on
behavioral evidence
, that is suitable for resource-constrained IoT devices and supports computation offloading. We demonstrate the viability of the proposed architecture with an example deployment of the Beta Reputation System trust model on real hardware to capture node behaviors. The open environment of edge-based IoT networks means that threats against edge nodes can lead to deviation from expected behavior. Hence, we perform a
threat modeling
to identify such threats. The proposed system architecture includes threat handling mechanisms that provide security properties such as confidentiality, authentication, and non-repudiation of messages in required scenarios and operate within the resource constraints. We evaluate the efficacy of the threat handling mechanisms and identify future work for the standards used.
Photophysics of Two-Dimensional Semiconducting Organic–Inorganic Metal-Halide Perovskites
Authors: Straus Daniel B. , Kagan Cherie R.
Published: February 2022

Two-dimensional organic–inorganic hybrid perovskites (2DHPs) consist of alternating anionic metal-halide and cationic organic layers. They have widely tunable structural and optical properties. We review the role of the organic cation in defining the structural and optical properties of 2DHPs through the example of lead iodide 2DHPs. Even though excitons reside in the metal-halide layers, the organic and inorganic frameworks cannot be separated—they must be considered as a single unit to fully understand the photophysics of 2DHPs. We correlate cation-induced distortion and disorder in the inorganic lattice with the resulting optical properties. We also discuss the role of the cation in creating and altering the discrete excitonic structure that appears at cryogenic temperatures in some 2DHPs, including the cation-dependent presence of hot-exciton photoluminescence. We conclude our review with an outlook for 2DHPs, highlighting existing gaps in fundamental knowledge as well as potential future applications.
Functionalized Silica Facilitated Proton Coupled Electron Transfer in Electrochemical CO2 Reduction on Pd
Authors: Fang Yuxin , Flake John
Published: February 2022

Electrochemical reduction of CO2 holds promise for renewable energy storage and electrolytic fuel generation. Previous studies have surveyed multiple aspects for engineering selective and efficient catalysts (such as size scale1, composite material2 and electrolyte co-catalysis3, etc.). Along with the density functional theory based simulation, the selectivity descriptors for the most common products CO and HCOOH are *COOH and *HCOO, respectively.4 The fact that CO reduction yields similar hydrocarbon products distribution suggests that CO is the ideal intermediate for further hydrogenated products.5 So far, only Cu-based catalysts yield energy-dense liquid hydrocarbon products6 (ie. CH3OH and C2H5OH, etc.), this can be attributed to the unique binding energies of CO* and COH*.7

Inspired by enzyme chemistry that leverage metal nanoclusters with ligands in photosynthesis8, we explored the possibility using engineered metal-ligand electrocatalyst to yield the hydrocarbon liquid products. Our previous study on thiolate-Au system has proved ligands facilitate the proton coupled electron transfer (PCET) with mild acidic pKa.9 In the present work, we considered functional ligands supported by silica facilitates the PCET in CO2 reduction on Pd nanoparticle tripled that yield of the CH3OH production. Ligand facilitated PCET with metal center that favor CO production and adsorption may be a promising strategy for selective electrochemical CO2 reduction.

REFERENCE

W. Zhu, R. Michalsky, Ö. Metin, H. Lv, S. Guo, C. J. Wright, X. Sun, A. A. Peterson and S. Sun, J. Am. Chem. Soc., 135, 16833 (2013).

M. Watanabe, M. Shibata, A. Kato, M. Azuma and T. Sakata, J. Electrochem. Soc., 138, 3382 (1991).

M. R. Thorson, K. I. Siil and P. J. A. Kenis, J. Electrochem. Soc., 160, F69 (2013).

J. T. Feaster, C. Shi, E. R. Cave, T. Hatsukade, D. N. Abram, K. P. Kuhl, C. Hahn, J. K. Nørskov and T. F. Jaramillo, ACS Catalysis, 7, 4822 (2017).

Y. Hori, A. Murata, R. Takahashi and S. Suzuki, J. Am. Chem. Soc., 109, 5022 (1987).

Y. Hori, A. Murata and R. Takahashi, J. Chem. Soc., Faraday Trans. 1, 85, 2309 (1989).

C. Shi, H. A. Hansen, A. C. Lausche and J. K. Norskov, Phys. Chem. Chem. Phys., 16, 4720 (2014).

B. El-Zahab, D. Donnelly and P. Wang, Biotechnol. Bioeng., 99, 508 (2008).

Y. Fang and J. C. Flake, J. Am. Chem. Soc., 139, 3399 (2017).
(Invited) Integrating Ab-Initio Simulations and Experimental Characterization Methods: Towards Accelerated Chalcopyrite Materials Development for Hydrogen Production
Authors: Ogitsu Tadashi , Varley Joel , DeAngelis Alexander D , Horsley Kimberly , Gaillard Nicolas
Published: February 2022

Recent development of ab-initio simulation and experimental characterization techniques enabled us to obtain information that is crucial for accelerated materials development for sustainable energy solutions. In this presentation, we will particularly focus on some of the most complex problems currently facing hydrogen production technology and how these ab-initio simulations can be used to gain insights about them. Taking what we know from ab-initio simulations we can then validate multiple and independent experimental results to provide a theoretically grounded interpretation. This cross-validation between theory and experiment is one of the capabilities that the new HydroGEN consortium (h2awsm.org), established under DOE EERE, provides to scientific community. As the use examples, we will discuss about an effective use of ab-initio simulations for development of high performance materials for a photoelectrochemical hydrogen production device. We emphasize an importance on the comprehensive use of ab-initio simulations on multiple aspects of materials developments, such as usable synthesis conditions, detrimental defect formation for a given synthesis condition, and the consequential saturation of open circuit voltage. We emphasize that systematic comparisons between the multiple aspects of theory and experiment are important for rapid materials development procedure via effective identification of the roadblocks.

This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and funded by the U. S. Department of Energy, Office of Energy Efficiency & Renewable Energy (EERE).
(Invited) Efficient Hot Electron Transfer By Plasmon Induced Interfacial Charge Transfer Transitio
Authors: Lian Tianquan
Published: February 2022

Surface plasmon resonance in metal nanostructures has been widely used to enhance the efficiency of semiconductors and/or molecular chromophore based solar energy conversion devices by increasing absorption or energy transfer rates through the enhanced local field strength. In more recent years, it has been shown that excitation of plasmons in metal nanostructures can also lead to the injection of hot electrons into semiconductors and enhanced photochemistry. This novel mechanism suggests that plasmonic nanostructures can potentially function as a new class of widely tunable and robust light harvesting materials for solar energy conversion. More importantly, it provide a novel approach to access highly energetic and reactive states of metals that is difficult to utilize with thermal chemistry. However, plasmon-induced hot electron injections from metal to semiconductor or molecules are still inefficient because of the competing ultrafast hot electron relaxation processes within the metallic domain.

In this talk, I will discuss a recent study on the key factors that limit the efficiency of plasmon induced hot electron transfer in colloidal quantum-confined semiconductor-gold nanorod heterostructures. These heterostructures provide a well-defined and systematically tunable model system for studying the mechanism of hot electron transfer. In CdSe NRs with Au tips, the distinct plasmon band of the Au nanoparticles was completely damped due to strong interaction with the CdSe domain. Using transient absorption spectroscopy, we show that optical excitation of plasmons in the Au tip leads to efficient hot electron injection into the semiconductor nanorod. In the presence of sacrificial electron donors, this plasmon induced hot electron transfer process can be utilized to drive photoreduction reactions under continuous illumination. We propose that the strong metal/semiconductor coupling in CdSe/Au hetersostructures leads to a new pathway for this surprising efficient hot electron transfer. In this plasmon induced interfacial charge transfer transition (PICTT) the a plasmon decay by direct excitation of an electron from the metal to semiconductor, bypassing the competition with hot electron transfer in metal. Ongoing studies are examining the generality of this mechanism and exploring possible approaches for improving its efficiency through controlling the size and shape of the plasmonic and excitonic domains.

Reference

[1]. Kaifeng Wu, Jinquan Chen, James R. McBride, Tianquan Lian, “Efficient hot-electron transfer by a plasmon-induced interfacial charge-transfer transition”, Science (2015), 349 (6248): 632. DOI: 10.1126/science.aac5443

[2]. Kaifeng Wu, William E. Rodríguez-Córdoba, Ye Yang, and Tianquan Lian, “Plasmon-Induced Hot Electron Transfer from the Au Tip to CdS Rod in CdS-Au Nanoheterostructures”, Nano Lett. (2013), 13(11), 5255-5263. DOI: 10.1021/nl402730m
Sexual dimorphism in testosterone programming of cardiomyocyte development in sheep
Authors: Ghnenis Adel , Padmanabhan Vasantha , Vyas Arpita
Published: February 2022

The present study demonstrates sex-specific effects of gestational T excess between days 30 and 90 of gestation on the cardiac phenotype. Furthermore, the sex-specific programming is likely secondary to perturbation in both estrogen and insulin signaling pathways collectively. These findings are supportive of the role of androgen excess to serve as early biomarkers of CVD and could be critical in identifying therapeutic targets for LV hypertrophy and predict long-term CVD.
On the Graphs of Minimum Degree At Least 3 Having Minimum Sum‐Connectivity Index
Authors: Mohammed Wael W. , Ahmed Shahzad , Raza Zahid , Liu Jia-Bao , Ahmad Farooq , Elsayed Elsayed M.
Published: February 2022

For a graph G, its sum‐connectivity index is denoted by χ(G) and is defined as the sum of the numbers (d(u) + d(v))−1/2 over all edges uv of G, where d(w) denotes the degree of a vertex w ∈ V(G). In this study, we find a sharp lower bound on the sum‐connectivity index of graphs having minimum degree of at least 3 under certain constraints and characterize the corresponding extremal graphs.
Bioactivities of the Green Synthesized Silver Nanoparticles Reduced Using Allium cepa L Aqueous Extracts Induced Apoptosis in Colorectal Cancer Cell Lines
Authors: Abdellatif Ahmed A. H. , Mahmood Amer , Alsharidah Mansour , Mohammed Hamdoon A. , Alenize Salman Khalaf , Bouazzaoui Abdellatif , Al Rugaie Osamah , Alnuqaydan Abdullah M. , Ahmad Rehan , Vaali-Mohammad Mansoor-Ali , Alfayez Musaad , Traiki Thamer Bin , Al-Regaiey Khalid A. , Ali Asmaa T. , Hassan Yasser A. H. , Abdulla Maha-Hamadien
Published: February 2022

Allium cepa L (A. cepa) extract is frequently used as an adjuvant food in cancer treatment. We hypothesized that it contains a source of anticancer activity. There is a need to synthesize the silver nanoparticles (AgNPs) using an environment‐friendly green synthesis reduction method using an aqueous extract of A. cepa. The AgNPs‐CEPA were prepared by reduction method using the aqueous extract of A. cepa. The formed AgNPs‐CEPA were characterized for their sizes and charge distribution. The AgNP‐CEPA was investigated for its antioxidant and anticancer properties. Cell viability was evaluated by MTT assay. Gene expression was evaluated by real‐time polymerase chain reaction (RT‐PCR), and apoptosis measurement was carried out by flow cytometry in AgNP‐CEPA‐treated cells. The results showed a uniform size for AgNPs‐CEPA of 155 ± 2.1 nm with a zeta potential of −37.3 ± (−2.92) mv. The produced AgNPs‐CEPA are biocompatible with anticancer action and a moderate level of antioxidant reactivity. AgNPs‐CEPA showed better reducing activity for A. cepa extract compared to the AgNPs‐CEPA. AgNP‐CEPA treatment of human colorectal cancer cell lines (HT‐29 and SW620) inhibited cell proliferation and altered Bcl2 family gene expression. Moreover, exposure of cell lines to AgNPs‐CEPA resulted in the significant induction of apoptosis compared to A. cepa and AgNO3. These findings indicate that AgNP‐CEPA induces apoptosis by inhibiting Bcl2 family gene expression, suggesting that this formula is a promising anticancer agent for treating colorectal cancer.
Analgesic Effect of Ropivacaine Combined with Hydromorphone following Surgery for Mixed Hemorrhoids: A Pilot Study
Authors: Luo Xuejing , Xia Yanfei , Gu Mengting , Yao Jin
Published: February 2022

Background. Postoperative pain is a major adverse effect of surgery for mixed hemorrhoids. We evaluated whether spinal anesthesia with ropivacaine and hydromorphone provided safe and effective analgesia after surgery for mixed hemorrhoids. Methods. This single-center, double-blind pilot study included patients with mixed hemorrhoids who underwent a procedure for prolapse and hemorrhoids (PPH) and external hemorrhoidectomy under spinal anesthesia at Zhejiang Hospital, China (October 2020 to December 2020). Patients were randomized to a hydromorphone group (spinal anesthesia with 0.5% ropivacaine and 75 μg hydromorphone) or morphine group (spinal anesthesia with 0.5% ropivacaine and 150 μg morphine). Pain scores (numerical rating scale), incidences of vomiting and itching, and length of hospital stay (LoS) were recorded at 6, 12, 18, and 24 hours after surgery. Results. The analysis included 40 patients in each group. Median (interquartile range) pain score in the hydromorphone group was higher than that in the morphine group at 12 hours (1 (0–2] vs. 0 (0–2),

p
=
0.044

) but not significantly different between groups at 6 hours (0 (0–1) vs. 0 (0-0)

p
=
0.228

), 18 hours (2 (2–3) vs. 2 (1–3)

p
=
0.060

) or 24 hours (2 (2–3) vs. 2 (1–3)

p
=
0.081

). The hydromorphone group had a lower incidence of pruritus than the morphine group (47.5% vs. 67.5%,

p
=
0.018

). There were no significant differences between groups in vomiting incidence or LoS. Conclusion. In patients with mixed hemorrhoids, spinal anesthesia with ropivacaine/hydromorphone has a comparable analgesic effect and a lower incidence of pruritus during the first 24 hours after surgery than spinal anesthesia with ropivacaine/morphine.
Papaver Plants: Current Insights on Phytochemical and Nutritional Composition Along with Biotechnological Applications
Authors: Butnariu Monica , Quispe Cristina , Herrera-Bravo Jesús , Pentea Marius , Sarac Ioan , Küşümler Aylin Seylam , Özçelik Beraat , Painuli Sakshi , Semwal Prabhakar , Imran Muhammad , Gondal Tanweer Aslam , Emamzadeh-Yazdi Simin , Lapava Natallia , Yousaf Zubaida , Kumar Manoj , Eid Ali Hussein , Al-Dhaheri Yusra , Suleria Hafiz Ansar Rasul , del Mar Contreras María , Sharifi-Rad Javad , Cho William C.
Published: February 2022

The genus Papaver is highly esteemed in the pharmacy industry, in the culinary field, and as ornamental plants. These plants are also valued in traditional medicine. Among all Papaver species, Papaver somniferum L. (opium poppy) is the most important species in supplying phytochemicals for the formulation of drugs, mainly alkaloids like morphine, codeine, rhoeadine, thebaine, and papaverine. In addition, Papaver plants present other types of phytochemicals, which altogether are responsible for its biological activities. Therefore, this review covers the phytochemical composition of Papaver plants, including alkaloids, phenolic compounds, and essential oils. The traditional uses are reviewed along with their pharmacological activities. Moreover, safety aspects are reported to provide a deep overview of the pharmacology potential of this genus. An updated search was carried out in databases such as Google Scholar, ScienceDirect, and PubMed to retrieve the information. Overall, this genus is a rich source of alkaloids of different types and also contains interesting phenolic compounds, such as anthocyanins, flavonols, and the characteristic indole derivatives nudicaulins. Among other pharmacological properties, numerous preclinical studies have been published about the analgesic, anticancer, antimicrobial, antioxidant, and antidiabetic activities of Papaver plants. Although it highlights the significant impact of this genus for the treatment of a variety of diseases and conditions, as a future prospect, characterization works accompanying preclinical studies are required along with clinical and toxicology studies to establish a correlation between the scientific and traditional knowledge.
Bioactive Cellulose Acetate Electrospun Mats as Scaffolds for Bone Tissue Regeneration
Authors: Laboy-López Simara , Méndez Fernández Pedro O. , Padilla-Zayas Jorge G. , Nicolau Eduardo
Published: February 2022

In the last decades, cell-based approaches for bone tissue engineering (BTE) have relied on using models that cannot replicate the complexity of the bone microenvironment. There is an ongoing amount of research on scaffold development responding to the need for feasible materials that can mimic the bone extracellular matrix (ECM) and aid bone tissue regeneration (BTR). In this work, a porous cellulose acetate (CA) fiber mat was developed using the electrospinning technique and the mats were chemically modified to bioactivate their surface and promote osteoconduction and osteoinduction. The mats were characterized using FTIR and SEM/EDS to validate the chemical modifications and assess their structural integrity. By coupling adhesive peptides KRSR, RGD, and growth factor BMP-2, the fiber mats were bioactivated, and their induced biological responses were evaluated by employing immunocytochemical (ICC) techniques to study the adhesion, proliferation, and differentiation of premature osteoblast cells (hFOB 1.19). The biological assessment revealed that at short culturing periods of 48 hours and 7 days, the presence of the peptides was significant for proliferation and adhesion, whereas at longer culture times of 14 days, it had no significant effect on differentiation and maturation of the osteogenic progenitor cells. Based on the obtained results, it is thus concluded that the CA porous fiber mats provide a promising surface morphology that is both biocompatible and can be rendered bioactive upon the addition of osteogenic peptides to favor osteoconduction leading to new tissue formation.
Factors Associated with Linkage to Care following Community-Level Identification of HIV-Positive Clients in Lira District
Authors: Adwar Claire , Puleh Steven Sean , Ochaba Isaac , Ogweng Isaac , Benyumiza Deo , Amusu Kosta , Achola Brenda , Ocen Francis , Abolo Lydia , Kumakech Edward , Obua Celestino
Published: February 2022

Background. Community HIV testing helps to increase access to high-risk groups who are less likely to visit a clinic for a test. A large proportion of people identified with HIV following community-based testing are not easily linked to care compared to facility-based identified cases. There is a paucity of literature on linkage to HIV care and its predictors particularly following community-based testing in a rural setting. We assessed the level of linkage to the care of HIV-positive individuals and associated factors following community-level identification in Lira district. Method. A cross-sectional survey was conducted in Lira district employing mixed methods among HIV-positive adults identified in the communities. Quantitative data were collected from 329 randomly selected study participants using interviewer-administered questionnaires. Key informant interview guide was used to collect qualitative data. The data were double entered, cleaned, and analyzed using SPSS version 23. Odds ratios and confidence intervals were used to assess the association between predictors of linkage with HIV care. Qualitative data were analyzed using thematic content analysis. Results. The respondents were aged between 18 and 85 years with a mean age of 42.9 (SD = 11.6). The level of linkage to HIV care following community-level identification of HIV testing in Lira district was 98% (95% CI 96.07–99.33). Clients who self-initiated the HIV testing were more likely to link to HIV care than their counterparts (AOR = 9.03; 95% CI 1.271–64.218,

p
=
0.028

). Key informants identified factors influencing linkage to care as health education, counseling, follow-up, and family support. Fear of stigma, disclosure, denial, and distance to facility were reported as barriers to linkage. Conclusion/Recommendation. The level of linkage to HIV care following community identification was found to be excellent (98%). Predictors to linkage to care included self-initiated testing, positive perception of distance, and waiting time at health facilities. We recommend health education, counseling, follow-up, and family support as interventions to strengthen successfully linking to care.