bluuebunny/crossref_metadata_2025 huggingface dataset:
Trans Z‐source‐based half‐bridge inverter: A method for achieving high voltage gain
Authors: Aalami Mohammadamin , Babaei Ebrahim , Ghassem Zadeh Saeid , Iqbal Atif
Published: August 2022

This article offers a modified trans Z‐source‐based half‐bridge inverter topology. A suitable pulse width modulation (PWM)‐based control method is applied on the proposed inverter. Regarding this control technique, the state of switches in each of the operational states is obtained, and their equivalent control circuits are demonstrated and examined in depth. With the help of the results of these analyses, the boost factor for the proposed structure can be calculated. Additionally, the necessary equations for designing the passive components, as well as the power ratings of the active components, are found. Then, in order to evaluate the advantages and disadvantages of the proposed topology, a comparative study is conducted in several aspects, including the boost factor, the voltage stresses on capacitors, and the voltage stresses on passive devices. This comparison demonstrates that the proposed topology provides a high boost factor while minimizing voltage stresses on the devices, resulting in a smaller volume and size and a lower cost. Once the proposed topology has been thoroughly analyzed, the total power losses and the percentages of power losses consumed by each component device are calculated to obtain efficiency. Finally, an experimental prototype based on the equations for passive and active components is developed. Experiments are used to verify the validity of the proposed topology and the accuracy of the equations.
A novel generalized fractional‐order memristor model with fully explicit memory description
Authors: Banchuin Rawid
Published: August 2022

In this work, a novel generalized mathematical model of fractional‐order memristor with fully explicit memory description has been proposed. For obtaining such full explicit memory description, the Atangana‐Baleanu fractional derivative in Liouville‐Caputo sense, which employs a nonsingular kernel, has been adopted as the mathematical basis. The proposed model has been derived without regarding to any specific conventional memristor. A comparison with the singular kernel fractional derivative‐based model has been made. The behavioral analysis of the fractional‐order memristor based on the proposed model has been performed, where both DC and AC stimuli have been considered. In addition, its application to the practical fractional‐order memristor‐based circuit and its extension to the fractional‐order memreactance have also been shown. Unlike the singular kernel fractional derivative‐based model, a fully explicit memory description can be obtained by ours. Many other interesting results that are contradict to the previous singular kernel fractional derivative‐based ones, e.g., the fractional‐order memristor that can be locally active, have been demonstrated. The abovementioned extension can be conveniently performed. In summary, this is the first time that a nonsingular kernel fractional derivative has been applied to the fractional‐order memristor modeling and the resulting model with a fully explicit memory description has been proposed. The proposed model is also highly generic, applicable to the practical circuit, and extendable to the fractional‐order memreactance.
Celastrol: A lead compound that inhibits SARS‐CoV‐2 replication, the activity of viral and human cysteine proteases, and virus‐induced IL‐6 secretion
Authors: Fuzo Carlos A. , Martins Ronaldo B. , Fraga‐Silva Thais F. C. , Amstalden Martin K. , Canassa De Leo Thais , Souza Juliano P. , Lima Thais M. , Faccioli Lucia H. , Okamoto Débora Noma , Juliano Maria Aparecida , França Suzelei C. , Juliano Luiz , Bonato Vania L. D. , Arruda Eurico , Dias‐Baruffi Marcelo
Published: August 2022

The global emergence of coronavirus disease 2019 (COVID‐19) has caused substantial human casualties. Clinical manifestations of this disease vary from asymptomatic to lethal, and the symptomatic form can be associated with cytokine storm and hyperinflammation. In face of the urgent demand for effective drugs to treat COVID‐19, we have searched for candidate compounds using in silico approach followed by experimental validation. Here we identified celastrol, a pentacyclic triterpene isolated from Tripterygium wilfordii Hook F, as one of the best compounds out of 39 drug candidates. Celastrol reverted the gene expression signature from severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2)‐infected cells and irreversibly inhibited the recombinant forms of the viral and human cysteine proteases involved in virus invasion, such as Mpro (main protease), PLpro (papain‐like protease), and recombinant human cathepsin L. Celastrol suppressed SARS‐CoV‐2 replication in human and monkey cell lines and decreased interleukin‐6 (IL‐6) secretion in the SARS‐CoV‐2‐infected human cell line. Celastrol acted in a concentration‐dependent manner, with undetectable signs of cytotoxicity, and inhibited in vitro replication of the parental and SARS‐CoV‐2 variant. Therefore, celastrol is a promising lead compound to develop new drug candidates to face COVID‐19 due to its ability to suppress SARS‐CoV‐2 replication and IL‐6 production in infected cells.
Laser‐induced graphene‐based flexible interdigital electrode realizing micro supercapacitor sustainable in different temperatures
Authors: Awasthi Himanshi , Renuka H , Srivastava Alok Kumar , Goel Sanket
Published: August 2022

Electronic components for energy storage need to be mechanically conformable to ensure maximum wearer comfort, flexibility, and good thermal stability in different environments. Hence, the development of supercapacitors (SCs) as an alternative to micro‐batteries for use in microelectronics applications is currently receiving much scientific attention. This work presents an adaptable, cost‐effective, and efficient method to fabricate flexible laser‐induced graphene (LIG) supercapacitor electrodes using a CO2 laser. LIG formation and morphology have been studied and confirmed through energy dispersive X‐ray (EDX) spectroscopy and scanning electron microscopy (SEM) techniques. The interdigital laser‐induced graphene electrodes are fabricated and optimized for SCs on a flexible substrate. These SCs have the advantages of charge‐discharge cycles, capacitive performance, high power density as well as long cyclic life. For LIG electrodes, the suitable electrolyte is optimized to control the electrochemical properties of supercapacitors, such as charge transfer, flexibility, and stability. Hence, a supercapacitor composed of 3D porous laser‐induced graphene with PVA‐KOH gel electrolyte is fabricated, with 83.33 mF/cm2 areal capacitance at a constant current density of 0.5 mA/cm2. The energy density 4.62 μWh/cm2 and power density 0.2 mW/cm2 are observed at a 0.5 mA/cm2 constant current density. The capacitance of the proposed SC increases with an increase in certain temperatures and shows excellent performance. This flexible SC could be a high potential for use in energy storage and wearable device applications.
An Intelligent Routing for Internet of Things Mesh Networks
Authors: Chakraborty Ishita , Das Prodipto , Pradhan Buddhadeb
Published: August 2022

Internet of Things (IoT) is gaining popularity due to its complex network architecture, formed by the tremendous connection of objects. Sensors used in different IoT applications are installed in unfavorable terrains and conditions. Since each sensor node can sense, compute, and promote wireless communication, a novel intelligent routing algorithm is required, as the traditional ones do not fulfill the current network requirements. Reinforcement learning models can help overcome the wireless network's challenges faced during routing due to its dynamicity by selecting and adapting weights that optimize the paths based on the requirement of the applications and operating conditions. In this article, a routing agent with Q‐learning is proposed that adjusts the routing policy of a network based on local information to converge toward an optimal solution by maintaining the overall balance between latency and the network's lifetime. A reward is given to an agent that increases the network lifetime and reduces the average network latency. The evaluation of the proposed model was done using network simulators (NS‐2) on different network scenarios that showed improved results in terms of network lifetime compared to centralized minimum angle and distributed minimum angle.
Abolition in the Clutch: Shifting through the Gears with Anthropology
Authors: Shange Savannah
Published: August 2022

Abolition is not a metaphor, and it is essential that our notion of “abolition” not get defanged and deracinated within the self‐evident boundaries of a discipline or even the academy. Amidst the tangle of complicity that is anthropology, there are also parts of the disciplinary toolkit that are useful for worldmaking: listening deeply, bearing witness, challenging the inevitability of the state, and building deep transnational and cross‐diasporic relation. In particular as surveillance, policing, and imprisonment become globalized as techniques of repression, anthropology can help disrupt US‐centrism while cultivating thicker solidarities. In this essay, I draw on Chela Sandoval's theory of differential political consciousness to roughly sketch five interlocking ideology‐praxes – five gears of abolition that at times are complementary, and at times contradictory. Within each gear, I lift up organizers and scholars whose work is shaping the theory and practice of abolition. Following the lead of activists, artists and movement builders, I invite academics to bring abolition home by contributing to ongoing campaigns happening on their campuses and in their neighborhoods.
Onde Mundoand pseudo‐Aristotle, a geoarchaeological analysis
Authors: Stiros Stathis C.
Published: August 2022

“De Mundo” (“On the Cosmos”), an influential ancient anonymous treatise (manuscript) covering natural phenomena and philosophical ideas, is assigned by the majority of investigators to pseudo‐Aristotle, an unknown philosopher of Roman times mimicking Aristotle. This article focuses on differences in the geological content between “Meteorologica” (“Meteorology”), the famous work of Aristotle on Natural Sciences, and “de Mundo.” Four themes are examined: the evolution of the legend of the 373 BC earthquake and tsunami at Helike and Boura (Gulf of Corinth, Greece) based on new geoarchaeological and archaeological evidence, volcanic eruptions of the Aeolian Islands and Etna, but not of Vesuvius (Italy), neurotoxic effects of gas seepage, mostly in oracles, and the style of referencing to geological information. The new geoarchaeological evidence permits the dating of “de Mundo” in the first century AD, thereby refining previous interpretations, and implies no evidence of change in Aristotle's philosophical and geographical ideas at the end of his life. The overall analysis provides an explanation for the legend of the catastrophe of Helike, and it highlights the potential of geoarchaeological methods to provide new insights even into literary, philosophical, and geographical issues, and the dating of various ancient manuscripts.
A wider‐aperture lens for global strategic management: The multinational enterprise in a bifurcated global economy
Authors: Teece David J.
Published: August 2022

Research Summary

The growth of China and President Xi's policies have transformed the global economy in ways that global strategy and international business (IB) scholars have yet to reflect fully in their research. The global economy is increasingly bifurcated between a China‐centered authoritarian system and a market‐oriented democratic system, generating complications and perils largely unknown since the end of the Cold War. The global business environment now bears faint resemblance to existing models in IB. To properly analyze the new reality, global strategy and IB scholars need to adopt a wider‐aperture, systems‐theoretic view that will require the cross‐fertilization of ideas and collaboration with other disciplines such as international political economy. This engagement will allow the development of more broadly based frameworks, theories, and models that can assist decision makers in the private and public sectors.

Managerial Summary

Strategic rivalry between China and the West requires managers to face a new reckoning. China remains the world's factory, but it has a tenuous relationship to even‐handed rules of law, both domestically and internationally. China leverages access to its market and has aligned with other autocratic countries to reshape the world order. Many firms have straddled the divide and tried to play by two sets of rules. This is not viable longer term. The strategic decisions of Western firms, particularly those involved with advanced and, especially, dual‐use technologies, are consequential to the future of democracy. A systemic view of the long‐term health of the enterprise may reveal the need to choose. Choosing democracy means, at minimum, guarding intellectual property, enhancing organizational capabilities, coordinating with peers, and protecting national security.
Reproductive Embryo Editing: Attending to Justice
Authors: De Melo‐Martín Inmaculada
Published: August 2022

The use of embryonic genome editing tools is often touted as a way to ensure the birth of healthy and genetically related children. Many would agree that this is a worthy goal. Yet the purpose of this article is to argue that, if we are concerned with justice, accepting such a goal as morally appropriate commits one to rejecting the use of social resources for further development of embryo editing for reproductive purposes. This is so because there are safer and more effective means that can allow many more prospective parents to achieve the same valued goal and that can offer additional benefits.
The Microethics of Communication in Health Care: A New Framework for the Fast Thinking of Everyday Clinical Encounters
Authors: Sisk Bryan , Dubois James M.
Published: August 2022

In almost every clinical interaction, clinicians must navigate interpersonal challenges with near‐instantaneous responses to patients. Yet medical ethics has largely overlooked these small, interpersonal exchanges, instead focusing on “big” ethical problems, such as euthanasia, brain death, or genetic modification. In 1995, Paul Komesaroff proposed the concept of microethics as a nonprinciplist approach to ethics that focuses on “what happens in every interaction between every doctor and every patient.” We aim to develop a microethics framework to guide everyday clinical encounters, with a special focus on communication with patients and family members. We will advance three core insights: First, communication is an ethical act in ways seldom considered. Second, microethics is an essential lens through which to view the ethics of communication. Third, virtue can bridge reflective and automatic processes. Our intuitionist framework for microethics is thus based on this understanding of the role of virtue, and we propose six virtues that contribute to the goal of healing communication.
Rethinking Theory in Bioethics
Authors: Blumenthal‐Barby Jennifer
Published: August 2022

This book review essay points to some of the more novel and controversial contributions of A Theory of Bioethics, by Joseph Millum and David DeGrazia (Cambridge University Press, 2021), such as their account of moral status. With a remarkable breadth of topics, the book is characterized by philosophical care and nuance and by spelling out the implications of the authors’ theorizing for real‐world, pressing questions, for instance, about the implications of Millum and DeGrazia's theoretical work on moral status for embryo research, animal research with mice and apes, and human‐brain organoids.
Genetic predisposition to porto‐sinusoidal vascular disorder: A functional genomic‐based, multigenerational family study
Authors: Shan Jingxuan , Megarbane André , Chouchane Aziz , Karthik Deepak , Temanni Ramzi , Romero Atilio Reyes , Hua Huiying , Pan Chun , Chen Xixi , Subramanian Murugan , Saad Chadi , Mbarek Hamdi , Mehawej Cybel , Chouery Eliane , Abuaqel Sirin W. , Dömling Alexander , Remadi Sami , Yaghi Cesar , Li Pu , Chouchane Lotfi
Published: August 2022

Background and Aims:

Porto‐sinusoidal vascular disorder (PSVD) is a group of liver vascular diseases featuring lesions encompassing the portal venules and sinusoids unaccompanied by cirrhosis, irrespective of the presence/absence of portal hypertension. It can occur secondary to coagulation disorders or insult by toxic agents. However, the cause of PSVD remains unknown in most cases. Hereditary cases of PSVD are exceptionally rare, but they are of particular interest and may unveil genetic alterations and molecular mechanisms associated with the disease.

Approach and Results:

We performed genome sequencing of four patients and two healthy individuals of a large multigenerational Lebanese family with PSVD and identified a heterozygous deleterious variant (c.547C>T, p.R183W) of FCH and double SH3 domains 1 (FCHSD1), an uncharacterized gene, in patients. This variant segregated with the disease, and its pattern of inheritance was suggestive of autosomal dominant with variable expressivity. RNA structural modelling of human FCHSD1 suggests that the C‐to‐T substitution at position 547, corresponding to FCHSD1

R183W
, may increase both messenger RNA (mRNA) and protein stability and its interaction with MTOR‐associated protein, LST8 homolog, a key protein of the mechanistic target of rapamycin (mTOR pathway). These predictions were substantiated by biochemical analyses, which showed that FCHSD1

R183W
induced high FCHSD1 mRNA stability, overexpression of FCHSD1 protein, and an increase in mTORC1 activation. This human FCHSD1 variant was introduced into mice through CRISPR/Cas9 genome editing. Nine out of the 15 mice carrying the human FCHSD1

R183W
variant mimicked the phenotype of human PSVD, including splenomegaly and enlarged portal vein.

Conclusions:

Aberrant FCHSD1 structure and function leads to mTOR pathway overactivation and may cause PSVD.
miR‐125a‐3p aggravates ox‐LDL‐induced HUVEC injury through BAMBI
Authors: Xia Feng , Zeng Qingrong
Published: August 2022

Atherosclerosis (AS) is a chronic inflammatory disease characterized by the formation of atherosclerotic plaque in the intima of arteries. Among the known regulators of atherosclerosis, microRNAs (miRNAs) have been reported to play critical roles in lipoprotein homeostasis and plaque formation. But the roles of microRNA‐125a‐3p (miR‐125a‐3p) in the pathogenesis of AS remain unknown. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low‐density lipoprotein (ox‐LDL) to construct the vascular injury model of AS pathogenesis in vitro. miR‐125a‐3p and BMP and activin membrane‐bound inhibitor (BAMBI) expression levels in HUVECs were then measured by quantitative real‐time polymerase chain reaction and western blot. The viability and apoptosis of HUVECs were analyzed by Cell Counting Kit‐8 assay, TUNEL assay, and flow cytometry, respectively. The relationship between BAMBI 3′‐untranslated region and miR‐125a‐3p was validated by dual luciferase reporter gene assay. miR‐125a‐3p expression was raised in HUVECs induced with ox‐LDL. In HUVECs, miR‐125a‐3p enhanced the effects of ox‐LDL treatment on repressing the viability and promoting the apoptosis of cells. Additionally, BAMBI was confirmed as a direct target of miR‐125a‐3p and BAMBI overexpression reversed the effects of miR‐125a‐3p on HUVECs. miR‐125a‐3p aggravates the dysfunction of HUVECs induced by ox‐LDL via BAMBI, which implies that miR‐125a‐3p is involved in the pathogenesis of AS.
Serum non‐coding RNAs for diagnosis and stage of liver fibrosis
Authors: Liu Chao , Hou Xueyun , Mo Kaixin , Li Nannan , An Cheng , Liu Guijian , Pan Zongdai
Published: August 2022

Background

All chronic liver diseases could lead to liver fibrosis. Accurate diagnosis and stage of fibrosis were important for the medical determination, management, and therapy. Liver biopsy was considered to be the gold criteria of fibrosis diagnosis. However, liver biopsy was an invasive method with some drawbacks. Non‐invasive tests for liver fibrosis included radiologic method and serum‐based test. Radiologic examination was influenced by obesity, cost, and availability. Serum‐based test was widely used in the screening and diagnostic of liver fibrosis. However, the accuracy was still needed to be improved.

Methods

Recent studies showed serum non‐coding RNAs: microRNA, long non‐coding RNA(lncRNA), and circular RNA(circRNA), which have the potentiality to be non‐invasive markers for liver fibrosis. The recent progress was summarized in this review.

Results

These studies showed serum non‐coding RNAs exerted a good diagnostic performance for liver fibrosis. A panel that included several non‐coding RNAs could increase the accuracy of single marker.

Conclusions

Serum microRNAs, lncRNAs, and circRNAs could be potential non‐invasive markers for diagnosis and stage of liver fibrosis. More high‐quality clinical study is needed for further research.
Circular RNAs as prognostic and diagnostic biomarkers in renal cell carcinoma
Authors: Rashedi Sina , Mardani Mahta , Rafati Ali , Khavandi Mohammad Mahdi , Mohammadi Fatemeh , Javanshir Salar , Sarallah Rojin , Dolatshahi Mahsa , Sabahi Mohammadmahdi , Azadnajafabad Sina , Tavolinejad Hamed , Rezaei Nima
Published: August 2022

Background

Circular RNAs (circRNAs) play pivotal roles in proliferation, apoptosis, migration, and invasion of renal cell carcinoma (RCC) cells. This study is aimed to systematically summarize the current evidence regarding the clinical implications of circRNAs in RCC patients.

Methods

A systematic search in PubMed, Embase, and Web of Science was performed until January 1, 2022. The correlation between the expression of circRNAs and clinicopathological, prognostic, and diagnostic features of RCC was evaluated using the meta‐analysis.

Results

Ultimately, 41 studies with 3485 RCC patients were included in this study: 26 studies for clinicopathological features, 31 studies for prognosis, and eight studies for diagnosis. Altered expression of circRNAs was significantly associated with clinicopathological characteristics of RCC, including tumor size, tumor stage, lymph node metastasis, distant metastasis, and TNM stage. The tumor promoter circRNAs were associated with reduced overall survival (OS) (Hazard Ratio (HR) = 1.98, 95% confidence interval [CI] 1.68–2.34) and disease/progression/recurrence‐free survival (DFS/PFS/RFS) (HR = 2.34, 95% CI 1.85–2.97). Contrarily, the tumor suppressor circRNAs were linked with better OS (HR = 0.49, 95% CI 0.40–0.60) and DFS/PFS/RFS (HR = 0.40, 95% CI 0.28–0.59). The pooled sensitivity and specificity of circRNAs for RCC diagnosis in tissue samples were both 0.84. These results in fluid samples (serum and urine) were 0.78 and 0.69, respectively.

Conclusion

CircRNAs can serve as promising diagnostic and prognostic biomarkers for RCC.
“Lymphocyte * Neutrophil” count decreased in SARS‐CoV‐2 Omicron patients in Shanghai with no significant change in CRP and SAA
Authors: Chang Huanhuan , Li Jiao
Published: August 2022

Background

At present, there is a new variant Omicron BA.2 of SARS‐CoV‐2. In some previous studies, it was found that CBC, NLR, CRP, SAA, etc. in patients with SARS‐CoV‐2 had a series of changes, which were significantly correlated with the diagnosis and prognosis of patients. Therefore, in order to find specific diagnostic indicators, we explore the changes in these blood indicators and inflammatory indicators in patients with the SARS‐CoV‐2 Omicron.

Methods

A total of 127 Omicron confirmed patients who had visited fever clinic was selected as the positive group, and 75 Omicron excluded patients were selected as the negative group. We collected and analyzed the CBC, CRP, SAA test data, and clinical data of all subjects for analysis and statistics.

Results

WBC, NEU, LYM, EOS, PLT, PCT, LYM * NEU count compared with the negative group were significantly lower (p < 0.05); on the contrary, CNR were significantly higher (p < 0.05); The levels of CRP and SAA were not significantly different from those of the negative group (p > 0.05); the AUC of 0.781 for the diagnosis of LYM * NEU with an optimal cutoff value of 5.79, with a sensitivity and specificity of 68% and 73%, respectively, Youden index of 0.41, giving the best diagnostic performance.

Conclusion

The decreased LYM * NEU count can be used as the early, rapid, and accurate diagnostic indicator for Omicron. While due to the attenuated toxicity of BA.2 sublineage, CRP and SAA had no significance in the differential diagnosis of confirmed patients.
Evaluating dental students’ perspectives on the concurrent teaching of didactic and case‐based courses
Authors: Parikh Neha , Risinger Dane , Holland Julian N , Molony Donald A , van der Hoeven Dharini
Published: August 2022

Purpose

To evaluate student perception of integrating biomedical and clinical sciences based on survey of dental students on the concurrent teaching of a didactic systems‐based course and a case‐based course.

Methods

First‐year to fourth‐year students (DS1–DS4) students were surveyed for their experiences in concurrent teaching. Student response rate for the survey was 55% (229/420). Pearson's Chi‐squared tests and Kruskal‐Wallis rank sum tests were used to assess statistical significance (p < 0.05).

Results

Of the students surveyed, 83% strongly agreed or agreed that concurrent teaching of the didactic and case‐based courses helped them better understand the biomedical science background and the clinical ramifications (p < 0.001). On average, 75% percent strongly agreed or agreed that concurrent teaching kept them engaged, motivated, think critically, apply the course content and prepare for clinical practice (p < 0.001). Of the students surveyed, 69% support expanding concurrent teaching to all four years (p < 0.001). Mean responses from DS1 and DS4 students differed for questions relating to understanding of biomedical sciences, critical thinking and application to clinic (p < 0.01). Qualitative data showed that students enjoyed the reinforcement of concepts and application to clinical scenarios.

Conclusions

Concurrent teaching of didactic and case‐based learning courses, thus showing clinical relevance of biomedical sciences in the first year of dental curriculum, is perceived by students as an effective method of educating dental students. Such integrative learning process with horizontal and vertical integration and concurrent curriculum is even more relevant with the implementation of the integrated national board dental examination.
Guillain–Barré syndrome with unilateral peripheral facial paralysis in a Chinese child
Authors: Xue Jiao , Song Zhenfeng , Li Fei , Yi Zhi , Yang Chengqing , Liu Kaixuan , Zhang Ying
Published: August 2022

Background

Guillain–Barré syndrome (GBS) is an immune‐mediated polyradiculoneuropathy with the classic presentation of acute onset neurological symptoms preceded by an infective illness, followed by progressive limb weakness. Unilateral facial paralysis is rarely seen in GBS.

Case presentation

We reported a child presented with unilateral facial paralysis, limited outward movement of one eye and unilateral lower limb weakness, who was later diagnosed to have GBS. Through reviewing the patients with similar presentation reported previously, we found that the onset time of unilateral facial weakness in relation to other presentations of GBS seemed to be variable, which could be later or earlier than other symptoms, or concomitant. Most of the patients had a relatively good outcome within 2 weeks to 12 months of follow‐up.

Conclusions

Unilateral facial paralysis may be a feature of GBS, albeit a rare thing. Recognising the clinical patterns of such atypical variants of GBS allows for more timely and accurate diagnosis, and for treatment to be initiated without delay.
Reproducibility and Optimal Arterial Input Function Selection in Dynamic Contrast‐Enhanced Perfusion MRI in the Healthy Brain
Authors: Cramer Stig P. , Larsson Henrik B. W. , Knudsen Maria H. , Simonsen Helle J. , Vestergaard Mark B. , Lindberg Ulrich
Published: August 2022

Background

Dynamic contrast‐enhanced MRI (DCE‐MRI) has seen increasing use for quantification of low level of blood–brain barrier (BBB) leakage in various pathological disease states and correlations with clinical outcomes. However, currently there exists limited studies on reproducibility in healthy controls, which is important for the establishment of a normality threshold for future research.

Purpose

To investigate the reproducibility of DCE‐MRI and to evaluate the effect of arterial input function (AIF) selection and manual region of interests (ROI) delineation vs. automated global segmentation.

Study Type

Prospective.

Population

A total of 16 healthy controls; 11 females; mean age 28.7 years (SD 10.1).

Field Strength/Sequence

A 3T; GE DCE; 3D TFE T1WI. 2D TSE T2.

Assessment

The influx constant Ki, a measure of BBB permeability, and Vp, the blood plasma volume, was calculated using the Patlak model. Cerebral blood flow (CBF) was calculated using Tikhonov model free deconvolution. Manual tissue ROIs, drawn by H.J.S. (30+ years of experience), were compared to automatic tissue segmentation.

Statistical Tests

Intraclass correlation coefficient (ICC) and repeatability coefficient (RC) was used to assess reproducibility. Bland–Altman plots were used to evaluate agreement between measurements day 1 vs. day 2, and manual vs. segmentation method.

Results

Ki showed excellent reproducibility in both white and gray matter with an ICC between 0.79 and 0.82 and excellent agreement between manual ROI and automatic segmentation, with an ICC of 0.89 for Ki in WM. Furthermore, Ki values in gray and white matter conforms with histological tissue characteristics, where gray matter generally has a 2‐fold higher vessel density. The highest reproducibility measures of Ki (ICC = 0.83), CBF (ICC = 0.77) and Vd (ICC = 0.83) was obtained with the AIF sampled in the internal carotid artery (ICA).

Data Conclusion

DCE‐MRI shows excellent reproducibility of pharmacokinetic variables derived from healthy controls.

Evidence Level

2

Technical Efficacy

Stage 2
The impact of governmental COVID‐19 measures on manufacturers' stock market valuations: The role of labor intensity and operational slack
Authors: Chen Lujie , Li Taiyu , Jia Fu , Schoenherr Tobias
Published: August 2022

This study investigates the impact of the Chinese government's Level I emergency response policy on manufacturers' stock market values. We empirically examine the roles of human resource dependence (labor intensity) and operational slack within the context of supply chain resilience. Through an event study of 1357 Chinese manufacturing companies, we find that the government's emergency response policy triggered statistically significant positive abnormal returns for manufacturers. However, we also find that there exists a negative impact on abnormal returns for manufacturers that are labor‐intensive, giving rise to arguments based in resource dependence theory. In addition, the results indicate the positive role played by operational slack (e.g., financial and inventory slack) in helping manufacturers maintain operations and business continuity, effectively mitigating risks and adding to the manufacturers' resilience. With these findings, we contribute to operations and supply chain management by calling attention to the importance of human resource redundancy while at the same time identifying financial slack and inventory as supply chain resilience strategies that were able to mitigate pandemic‐related risks.
Quality evaluation of the classical prescription, Danggui Jianzhong decoction, using ultra‐high‐performance liquid chromatography fingerprint, chemical pattern recognition, and network pharmacology
Authors: Feng Yu , Hu Jingnan , Wang Fengxia , Li Baolin , Qian Qi , Wang Xinguo , Niu Liying
Published: August 2022

Danggui Jianzhong decoction is a classical prescription that has been widely used for thousands of years. However, the quality of this formula is difficult to control owing to its complex chemical component system. In this study, a simple and efficient method comprising ultra‐high‐performance liquid chromatography fingerprint, chemical pattern recognition, and network pharmacology was established to evaluate the quality of this decoction. A total of 20 common peaks were obtained by fingerprint analysis and 19 chemicals were identified. The fingerprint similarity of 15 batch samples ranged from 0.963 to 0.991. Chemical pattern recognition analysis could clearly classify 15 batches of Danggui Jianzhong decoction into three groups. Further, seven chemical markers were screened out. A herbs‐active components‐targets‐disease network was constructed and enrichment analyses were performed, which indicated that these 19 chemical components are the medicinal substances of Danggui Jianzhong decoction. Further, the mechanism employed by this formula to treat primary dysmenorrhea may be related to the regulation of inflammatory response. In conclusion, this combination approach enables accurate evaluation and prediction of the quality of Danggui Jianzhong decoction, and lays the foundation for studies on the material basis and exploration of the mechanism of Danggui Jianzhong decoction in the treatment of primary dysmenorrhea.
Extraction and Purification of Phycocyanin from Arthrophira platensis Microalgae Using a Green Solid‐Liquid Extraction Technology (RSLDE)
Authors: Naviglio Daniele , Montesano Domenico , Ciaravolo Martina , Savastano Alessandro , Nebbioso Viviana , Piccirillo Anna Maria , Gallo Monica
Published: August 2022

Spirulina is a blue alga belonging to the class of Cyanobacteria. This alga is characterized by a high content of phycocyanin (PC), a blue photosynthetic pigment belonging to the phycobiliprotein family. As natural dye, PC has a lot of industrial applications, in several fields such as the cosmetic, food, and textile sectors. It is also used in the biomedical field as a fluorescent marker. Anti‐inflammatory, nephroprotective, and hepatoprotective properties are also reported, probably related to its antioxidant activity. However, the extraction of phycobiliproteins from cyanobacteria is a very complicated procedure due to the extreme resistance of the wall of the cellular aggregates that make up spirulina. In literature, several procedures have been used to cause rupture of cell envelopes, through cycles of freezing/thawing, sonication, and rupture of the cell wall with lysozyme. However, all these methods do not guarantee a high quality of the extract, due to the complexity of the mixture obtained. In order to improve the yield of PC and to reduce the extraction process time, in this work, the conventional extraction by sonication is compared with a green innovative extraction technique, the rapid solid liquid dynamic extraction (RSLDE). This technique can generate a pressure and a consequent depression on the matrix to be extracted. The final extract was immediately frozen at −20°C and then lyophilized. UV–Vis spectrophotometric analysis and acrylamide gel electrophoresis are performed to evaluate the extraction efficiency and purity of PC.
High‐Resolution Ultrasonic Visualization of the Micromechanical Behavior of Reinforced Composites with Fine Fiber Microstructure
Authors: Morokov Egor , Levin Vadim
Published: August 2022

In the work, the first results of in situ ultrasound observation of microstructure changes in the volume of carbon fiber reinforced composites under tension are presented. The results depict the mechanical behavior of the laminate with stacking sequences of [−45°/0°/+45°/90°/+45°/0°/−45°]. Ultrasound visualization of volume microstructure is carried out with a controlled stepwise increase in deformation of the loaded specimens. Data of ultrasound investigation are compared with optical microphotograph and strain–stress curves of controlled and tested specimens. This approach makes it possible to visualize in dynamics the processes of appearance, growth, and transformation of microstructural damages in the volume with a resolution of tenth microns.
Influence of the Addition of Waste Glass and Microbiological Performance of Metakaolin‐Based Geopolymers Cement
Authors: Catauro Michelina , D'Angelo Antonio , Piccolella Simona , Leonelli Cristina , Dal Poggetto Giovanni
Published: August 2022

Glass recycling reduces the amount of waste to be treated or disposed in landfills, allowing both to limit environmental damage and to save on the costs of transportation and disposal of waste. In this paper, an advantageous method for recycling glass containers (bottles, jars, jars for food, glasses, and cans for drinks, etc.) is presented. The glass is crushed and without being washed or separated from any foreign bodies it is safely incorporated into a metakaolin (MK)‐based geopolymeric matrix. Pure MK and mixtures obtained by adding different percentages (30–50 wt%) of glass cullet are consolidated via alkali activation at 50°C. Infrared spectroscopy is able to reveal the formation of bonds in the mixtures between the geopolymeric matrix and the glass. Leaching tests are carried out to evaluate the eventual release of toxic metals, while the antibacterial tests complete the environmental evaluation of the final consolidated products that show how the mechanical performance are modified by adding different amount of glass cullet.
Exploiting Design Intent to Produce Fail‐Safe Extrusion‐Based Additive Manufacturing Parts
Authors: Bailas Konstantinos , Louka Eleftheria‐Sotiria , Papanikos Paraskevas
Published: August 2022

Additive manufacturing (AM) technology is an innovated production process mostly in the field of customization parts that gained the interest of many academics and industries over the last 20 years. The extrusion‐based technique and a wide variety of constantly developed polymer materials that AM technology uses, integrates multiple functions and mechanical properties to parts, and provides a flexibility in fabrication of complicated shapes, making products attractive to a wide range of applications. The quality and durability of those parts are controlled by numerous of building features that need to be set before building through specialized software that accompanies AM machines. A very crucial building feature that determines the inner structure of parts is lattice structure which is proved to determine the strength‐to‐weight ratio, the minimization of the material, the building time, and the energy absorption of the produced parts. However, lattice structures can be applied only to the entire geometry of a part because the software that accompanies AM machines have limited capabilities regarding the inner geometry of products since they cannot define different shell thickness values to the inner surfaces as well as multiple geometry lattice pattern to specific areas of the part. The current study proposes a new methodology of controlling the internal geometry and fatigue limits of extrusion‐based parts, bypassing the low capabilities of AM software using the meaning of design intent to insert lattice structures on specific areas of a part to produce AM products applicable to the field of fail‐safe in industry.
Synthesis and UV Cross‐Linking of Methacrylated Linear and Star‐Shaped Lactide Oligomers as Potential Biodegradable Resins for Stereolithography
Authors: Sedush Nikita , Kalinin Kirill , Puchkov Alexander , Chvalun Sergei
Published: August 2022

Stereolithography and DLP printing attract a lot of attention in medical field as techniques for fabrication of personalized implants and various medical devices. However, there is a lack of photo‐curable resins for fabrication of biodegradable tissue engineering constructs and implants. In this work biodegradable UV‐curable d,l‐lactide oligomers are presented, which can be good candidates as resins for SLA and DLP 3D printing. Linear and star‐shaped (3‐ and 6‐arm) methacrylated d,l‐lactide oligomers with different molecular weight are synthesized and cross‐linked in various conditions. UV‐curing is performed at elevated temperatures in the absence of any diluents and revealed formation of gel fraction, which has achieved 99%. The cross‐linked materials demonstrate high tensile modulus (up to 1.8 GPa), suggesting the resins are perspective for fabrication of load‐bearing implants.
Influence of Mixed Sulfur and Peroxide Curing Systems on Cross‐Linking and Properties of Rubber Compounds Based on EPDM
Authors: Kruželák Ján , Kvasničáková Andrea , Hložeková Klaudia , Gregorová Jana , Džuganová Michaela
Published: August 2022

In this work, sulfur vulcanization system, peroxide vulcanization system, and combined sulfur and peroxide curing systems are applied for cross‐linking of rubber compounds based on ethylene propylene diene monomer rubber. The goal is to investigate the influence of curing system composition on cross‐linking and properties of rubber formulations. The combination of both vulcanization systems in cross‐linking of rubbers combines the pattern of carbon–carbon linkages and sulfidic bridges, which gives the real presumption to modify physical–mechanical properties of final vulcanizates. The results reveal that the combination of vulcanization systems affects the curing characteristics, cross‐link density as well as physical–mechanical properties of tested materials. In comparison with vulcanizates cured only with sulfur or peroxide system, rubber compounds cross‐linked with mixed sulfur and peroxide curing systems exhibite higher tensile strength and elongation at break.
Chitosan‐Based Porous Composites for Bone Tissue Engineering
Authors: Sharikova N.A. , Antipova K.G. , Lukanina K.I. , Stolyarova D.Y. , Vdovichenko A.Y. , Malakhov S.N. , Krasheninnikov S.V. , Kulikova O. R. , Khramtsova E.A. , Chvalun S.N. , Grigoriev T.E.
Published: August 2022

This paper highlights the idea of creating highly porous composite materials for osteogenesis purposes based on chitosan with various functional fillers: reduced graphene oxide (rGO) and tricalcium phosphate (TCP). RGO filler is a carbon based electrical conductor with a high aspect ratio, therefore it is preferred for growth of osteoblasts populations with concomitant electrical stimulation. TCP is the main building block of bone tissue; hence composites filled with it can be used to accelerate the process of osteosynthesis. This paper considers the aspects of the functional agents influence on the morphological, electrically conductive, and mechanical characteristics of composites based on chitosan.
Determining the Influencing Factors on the Cooling of a 3D Printed Thermoforming Mould
Authors: Boca Marius‐Andrei , Sover Alexandru , Slătineanu Laurențiu
Published: August 2022

Using a mould for thermoforming produced by fused filament fabrication implies several limitations, such as thermal damage due to the low thermal conductivity properties of the plastic material. For the cooling of the plastic mould, many different approaches and influencing factors can be considered. This paper identifies those factors, and based on statistical DOE, adequate experiments have been conducted to analyze the influence of process variables. The results reveal that by using the Voronoi pattern performs an optimum, uniform, and effective cooling. By using the PLA material, the lowest temperatures are obtained in the case of moulds with Conformal Cooling channels.
Sodium Alginate Biopolymer: An Efficient, Recyclable Green Catalyst for the Synthesis of Chalcone Derivatives under Mild Conditions
Authors: Bora Manisha A.
Published: August 2022

One‐pot chemical synthesis of highly pure chalcone under mild conditions using biocompatible Na‐alginate biopolymer is reported. Several chalcone derivatives are prepared by magnetic stirring the equimolar quantities of the appropriate methyl ketone and aryl aldehyde with sodium alginate in ethanol under neutral conditions at room temperature. It is observed that in the presence of recyclable sodium alginate biocatalyst, highly pure chalcone with excellent yields in a very short time are obtained. The chalcone derivatives obtained are well characterized by UVDRS and FTIR techniques. The easily separable Na‐alginate biocatalyst acts as a Bronsted acid and may be reused up to five cycles.
A Survey on the Integration between Additive Manufacturing and Maintenance
Authors: Abbate Raffaele , Manco Pasquale , Macchiaroli Roberto , Lambiase Alfredo
Published: August 2022

Industry 4.0 (I4.0) is an emerging paradigm that is affecting several industrial fields. Many innovations have been introduced to optimize and improve the production efficiency by means of new technologies. Additive manufacturing (AM) is an enabling technology of I4.0 that is leading to innovations related to the production systems, but companies are looking to AM also for maintenance purposes. The aim of this study is to find the existing innovations that link AM and maintenance and to discuss on their benefits and feasibility. A systematic literature review (SLR) approach has been used to this purpose. The outcome of the SLR highlights that there are three main fields in which AM technologies can be very useful for maintenance purposes.
Blockchain and Its Application to Manage the Covid‐19 Pandemic: A Literature Review
Authors: Turino Maria Antonietta , Rinaldi Marta , Macchiaroli Roberto
Published: August 2022

At the end of 2019, a severe respiratory syndrome named COVID‐19 is started to be transmitted in the world and it has rapidly spread to a global pandemic. Every day, a series of data are collected for real‐time monitoring of the development of this pandemic. The data validation and the verification are becoming very important to manage the pandemic and give recommendations to the people. Nevertheless, sometimes, it is not possible to guarantee the truthfulness of such data and some information may be lost during collection. Due to its characteristics, the Blockchain technology can become an important support to face the COVID‐19 pandemic. In this regard, the aim of this research is to propose a literature review to understand how the blockchain technology has been used for health care and supply chain management to guarantee an efficient tracing, tracking, and monitoring solution, ensure a transparent and safe data transmission, and to delineate the emerging future research directions.
A Feasibility Study on Innovative Reinforced Modular Frames for Automotive Applications
Authors: Acanfora Valerio , Sellitto Andrea , Fittipaldi Francesco , Riccio Aniello
Published: August 2022

Vehicle frames can be considered the main stiffening component being, at the same time, functional hubs for all the other components assembly. Frames’ main goal is to absorb the static and dynamic loads acting on the vehicle, ensuring passengers’ safety. In this paper a feasibility study on an innovative modular frame concept is presented. An attempt has been made to design a modular frame by using customized additive manufacturable steel joints. Actually, standard frame structures are manufactured by welding separated tubes, making access to some internal areas of the vehicle very difficult where not impossible. Consequently, some maintenance operations become also challenging. The modular configuration solves these maintenance problems enabling, at the same time, to start thinking about multi‐purposes vehicle configurations, which can be switched by simply changing the modules connected to a central cell. Reinforced panels have been, also, integrated into the modular frame, which contribute to torsional stiffness with an overall mass reduction. The concept of a modular frame with collaborating reinforced panels, has been preliminary demonstrated by means of numerical simulations within the ABAQUS FEM environment. Certification torsional loads have been applied to the modular reinforced frame and the obtained numerical results contributed to prove the feasibility and the effectiveness of the proposed design.