bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective Synthesis of Diverse Heterocycles via Metal‐Free Oxidative Coupling of beta‐Tetralone and Nitrogen Nucleophiles
Authors: Wang Shuowen , Li Rong , Jiang Shuxin , Huang Huawen , Shao Wen , Deng Guo‐Jun
Published: March 2022

A mild procedure for the selective preparation of diverse heterocycles (such as quinoxaline, phenazine, phenothiazine, etc.) from beta‐tetralones and nitrogen nucleophiles under metal‐free conditions has been developed. The iodine reagents played an important role in the selectivity control of condensation and dehydrogenative aromatization cascade processes. These reaction conditions tolerate a wide range of functional groups and apply to oxidation‐sensitive nitrogen nucleophiles.

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Effect of H2, H2O, and CO2 on the deNOx characteristics of a combined passive NOx adsorber and NOx reduction catalyst
Authors: Khatri Prateek , Bhatia Divesh
Published: March 2022

The effect of H2, H2O, and CO2 on the NOx removal characteristics of a non‐PGM material (Ag/MgO/γ‐Al2O3) is investigated, which is shown to be active for both NOx adsorption and reduction. H2O facilitates NOx adsorption at early times but inhibits it at longer times. The inhibiting effect of CO2 is observed at low temperatures and is proposed to be due to bicarbonates. However, the inhibiting effect of both H2O and CO2 decreases at higher temperatures. The formation of NO2 at low temperatures is attributed to NO oxidation, and the contribution of stored NOx to NO2 formation increases with temperature. H2O inhibits NH3 oxidation at high temperatures as well as NOx reduction by NH3‐SCR at low temperatures. However, the NOx reduction activity is not affected by CO2. H2 significantly promotes the NH3‐SCR reactions, which is attributed to the facilitation of NOx spillover from the reduced Ag sites to the support.
Strategies for monitoring mentoring relationship quality to predict early program dropout
Authors: Lyons Michael D. , Edwards Kelly D.
Published: March 2022

We examined data from a nationally implemented mentoring program over a 4‐year period, to identify demographic and relationship characteristics associated with premature termination. Data were drawn from a sample of 82,224 mentor and mentees. We found matches who reported shared racial or ethnic identities were associated with lower likelihood of premature termination as was mentee's positive feelings of the relationship. We also found that, if data were used as a screening tool, the data were suboptimal for accuracy classifying premature closure with sensitivity and specificity values equal to 0.43 and 0.75. As programs and policymakers consider ways to improve the impact of mentoring programs, these results suggest programs consider the types of data being collected to improve impact of care.
Re‐imagining mental health services for American Indian communities: Centering Indigenous perspectives
Authors: Gone Joseph P.
Published: March 2022

The Indigenous peoples of North America are heirs to the shattering legacy of European colonization. These brutal histories of land dispossession, military conquest, forced settlement, religious repression, and coercive assimilation have robbed American Indian communities of their economies, lifeways, and sources of meaning and significance in the world. The predictable consequence has been an epidemic of “mental health” problems such as demoralization, substance abuse, violence, and suicide within these communities. One apparent solution would seem to be the initiation or expansion of mental health services to better reach American Indian clients. And yet, conventional mental health services such as counseling and psychotherapy depend on assumptions and aspirations that may not fit well with American Indian cultural sensibilities. For example, counseling practices draw on the presumed value for clients of introspective and expressive “self talk,” whereas Indigenous community norms may emphasize communicative caution outside of interactions with intimate kin, leading to marked reticence rather than candid disclosure. Moreover, given community sensitivities to salient histories of colonization, such differences have the potential to further alienate American Indian community members from the very services and providers designated to help them. In this article, I review a postcolonial predicament that bedevils American Indian community mental health services and trace a program of research that has sought to harness American Indian cultural and spiritual traditions for reimagining helping services in a manner that truly centers Indigenous perspectives.
A Nepalese bipolar case amidst risk and protective factors during COVID‐19 pandemic
Authors: Shakya Dhana Ratna , Upadhaya Sandesh Raj
Published: March 2022

Bipolar disorder is a chronic and recurring psychiatric illness. Emphasis on enhancing key protective factors like social support systems and promoting this to minimize risk factors like non‐compliance is one of the key strategies tied to enhance overall psychological, intellectual, and emotional health for symptoms remission and relapse prevention even during adverse situations like the COVID‐19 crisis. We intend here to point out implication of the dynamics of the protective and risk factors for bipolar mood through a 23‐year patient from eastern Nepal, which is largely harmonious in its multi‐ethnic, multilingual and multicultural social composition. This attribute of social cohesiveness and compassion is evident in this case report. When disturbed and ill, neighbors from native semi‐urban Nepalese society did support even in the times of crisis of COVID‐19 pandemic. The support of other people including neighbors is a key factor for the short‐term and long‐term management of bipolar mood.
Flow Patterns of Multiple Axial‐Radial Impellers for Potential Use in Aerated Stirred Tanks
Authors: Posadas-Navarro David , Palacios Carlos , Blancas-Cabrera Abel , Trujillo-Roldán Mauricio A. , Salinas-Vázquez Martín , Ascanio Gabriel
Published: March 2022

The hydrodynamics of a stirred tank equipped with multiple hybrid impellers was experimentally characterized. They were coaxially placed to agitate a viscous Newtonian fluid under gassed conditions. Experiments were performed by using the particle image velocimetry technique, and flow fields were reported in terms of the velocity magnitude, vertical currents, turbulent intensity, and strain rates. For comparison purposes, impellers providing radial flow (Rushton turbines) and axial flow (pitched blade turbines) were also tested. The results showed that hybrid impellers provided a uniform flow distribution throughout the tank at moderate strain rates, which make them an attractive alternative for fermentation processes with shear‐sensitive cultures and viscous liquids.
Composite Correlated Molecular Orbital Theory Calculations of Ring Strain for Use in Predicting Polymerization Reactions
Authors: Confer Matthew P. , Qu Taoguang , Rupar Paul A. , Dixon David A.
Published: March 2022

Strained ring systems play an important role in synthesis and can be characterized by the ring strain energy (RSE). The RSE of 3, 4, 5, and 6 membered saturated and unsaturated ring systems containing N, O, P, and S heteroatoms and H, F, SiMe3, and SO2Me substituents were calculated at the G3(MP2) composite correlated molecular orbital theory level using up to 5 models to predict the RSE. Generally, the RSE decreased as ring size increased with a substantial decrease from 4 to 5 membered rings. Replacement of a ring CH2 with P or S reduced the RSE, consistent with less angle strain. The RSE for unsaturated systems were generally greater than for saturated systems due to increased angle strain. No general trends were found with respect to substituent effects. The RSE values suggest that 3‐pyrroline and 2‐pyrroline and their derivatives may be able to support ring opening metathesis polymerization and warrant further study.
Comparison of ad libitum snack consumption and acquisition between adolescents living with food security and food insecurity: A stage 1 registered report
Authors: Stadterman Jill , Karvay Yvette G. , Feuerstahler Leah , Burke Natasha L.
Published: March 2022

Objective

Approximately 11% of the U.S. population experiences food insecurity (FI; insufficient access to healthy food due to financial constraints). FI is associated with detrimental health outcomes, including the development of eating disorders (EDs). However, additional studies are needed, particularly in adolescence when EDs are likely to emerge. The current study will utilize an experimental ad libitum snack paradigm to investigate snack consumption, acquisition (i.e., taking snacks home), and associated disordered eating behaviors among racially, ethnically, and financially diverse adolescents living with FI and food security (FS).

Method

Sixty‐four adolescents will be recruited and randomized into one of two conditions: prior knowledge condition (i.e., participants will know prior to snacking that they can take any remaining food home) and no prior knowledge condition (i.e., participants will not know ahead of time that they can take snacks home).

Results

We expect youth with FI to show increased eating and acquisition behaviors compared to youth with FS across both conditions.

Discussion

This study, utilizing a novel experimental design, is an important step in understanding how FI impacts adolescent eating behaviors among youth from marginalized backgrounds, who have historically been excluded from research.
HP‐SPC algorithm with dynamic partially connected structure for mmWave MIMO systems
Authors: Du Ruiyan , Liu Huajing , Guan Zhiqing , Liu Fulai
Published: March 2022

This article proposes a low complexity hybrid precoding algorithm for the switch network‐based dynamic partially connected (SPC) structure, that is, named as HP‐SPC algorithm. First, via a new defined effective optimal precoding matrix, the analog switch precoding matrix optimization problem is transformed into a sparse representation problem. Thus, invoking that the key characteristic of only one nonzero entry in each row of the analog dynamic switch precoding matrix, the analog dynamic switch precoding matrix can be accurately and effectively solved. Second, the digital precoding matrix optimization problem is modeled as a dictionary update problem by the defined effective optimal precoding matrix and the combining matrix. Further, the digital precoding matrix is easily optimized based on the defined effective optimal precoding matrix, since the measurement vectors are sparsely represented by a single dictionary atom. Third, the analog phase shifter precoding matrix is given by the phase rotation method. Finally, the precoding matrices are alternant updated until convergence, a near optimal solution of the precoding matrix is obtained. Compared with the previous works, the proposed HP‐SPC algorithm provides better hybrid precoding performance, for examples: (1) it avoids complexity computation such as matrix inversion and singular value decomposition, so that it presents a low computational complexity; (2) it has a favorable property of convergence since a stable point can be reached with about 10 loop iterations. Based on the simulation results, the effectiveness of HP‐SPC algorithm is further demonstrated.
The curvilinear effect of perceived overqualification on constructive voice: The moderating role of leader consultation and the mediating role of work engagement
Authors: Duan Jinyun , Xia Ying , Xu Yue , Wu Chia‐Huei
Published: March 2022

Drawing on the social cognitive theory of self‐regulation, we proposed a model considering an inverted U‐shaped relationship between perceived overqualification and constructive voice. We reasoned from the theory that this curvilinear effect would be moderated by leader consultation, which could intensify the upward curvilinear trend and neutralize the downward curvilinear trend, and be mediated by work engagement. We conducted two studies to test our model. In Study 1, based on a three‐wave time‐lagged sample of 293 employees and 120 supervisors, we found an inverted U‐shaped relationship between perceived overqualification and constructive voice, which was moderated by leader consultation. In Study 2, we examined the proposed mediated moderation model using a sample of 231 matched leader–subordinate dyads. We found that, at lower levels, perceived overqualification has a positive association with constructive voice, which is mediated by work engagement, especially at higher leader consultation. At higher levels, perceived overqualification has a negative association with work engagement and thus constructive voice, especially at lower levels of leader consultation. The implications of our research are discussed.
Light‐induced high‐efficient cellular production of immune functional extracellular vesicles
Authors: Ruan Shaobo , Erwin Nina , He Mei
Published: March 2022

Extracellular vesicle (EV)‐based therapies and vaccines are emerging. However, employment at the scale for population‐based dose development is always a huge bottleneck. In order to overcome such a roadblock, we introduce a simple and straightforward approach for promoting cellular production of dendritic cell derived EVs (DEVs) by leveraging phototherapy based light induction. Under the optimization of light wavelengths, intensities, and exposure times, we achieved more than 13‐fold enhancement in DEV production rate, while maintaining good integral quality and immune function from produced EVs. The LED light at 365 nm is optimal to reliably trigger enhanced cellular production of EVs no matter cell line types. Our observation and other reported studies support longer near UV wavelength does not impair cell growth. We conducted a series of investigations in terms of size, zeta potential, morphology, immune surface markers and cytokines, biocompatibility, cellular uptake behaviour, and immune‐modulation ability on eliciting cellular responses in vitro. We also validated the biodistribution, immunogenicity, and administration safety using light‐promoted DEVs in mice models from both male and female genders. Overall data supports that light promoted DEVs are highly immune functional with great biocompatibility for serving as good therapeutic platforms. The in vivo animal study also demonstrated light‐promoted DEVs are as well tolerated as native DEVs, with no safety concerns. Taken together, the data supports that light promoted DEVs are in excellent quality, high biocompatibility, in vivo tolerant, and viable for serving as an ideal therapeutic platform in scalable production.
Staphylococcus aureus nasal colonization increases the risk of cedar pollinosis
Authors: Morizane Atsushi , Uehara Yoshio , Kitamura Satoko , Komori Masahiro , Matsushita Masahide , Takeuchi Seisho , Seo Hiromi
Published: March 2022

Background

One‐third of the people in Japan are colonized with Staphylococcus aureus (S. aureus) and suffer from virulence factor‐mediated subclinical inflammation of the nares. We investigated whether subclinical inflammation contributed to cedar pollinosis affecting 20 million people annually.

Methods

The study participants were 814 inhabitants of the A or B prefectures. We compared the colonization rate and population structure of S. aureus, in association with the prevalence of cedar pollinosis, between participants in these two areas.

Results

A prefecture had twice the annual amount of airborne cedar pollen compared with B. The prevalence of cedar pollinosis was significantly higher in A (23.5%) than in B (13.1%) (p = 0.0004). Moreover, the prevalence of cedar pollinosis was higher in female participants (23.3%) than in male participants (14.7%) (p = 0.003). In addition, the prevalence of cedar pollinosis was higher in S. aureus carriers (24.2%) than in S. aureus noncarriers (17.9%) (p = 0.03). The isolation rate of clonal complex (CC) 508 was higher in the A group (21%) than in the B group (7%) (p = 0.015).

Conclusion

Nasal colonization of S. aureus is a major risk factor for cedar pollinosis. However, the direct mechanism of this risk is currently unknown.
No human respiratory syncytial virus but SARS‐CoV‐2 found in children under 5 years old referred to Children Medical Center in 2021, Tehran, Iran
Authors: Letafati Arash , Aghamirmohammadali Fahimeh Sadat , Rahimi‐Foroushani Abbas , Hasani Seyed Abbas , Mokhtari‐Azad Talat , Yavarian Jila
Published: March 2022

Acute respiratory infections (ARIs) are one of the leading causes of illness and death among community members worldwide. Viral infections are the most common agents estimated to be involved in these patients. This study aimed to investigate the prevalence of human respiratory syncytial virus (hRSV) and severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) among children with ARIs. This study evaluated the presence of SARS‐CoV‐2 and hRSV in 168 throat and nasopharyngeal swab samples using real‐time RT‐PCR. All samples were collected from children under 5 years old with ARIs who attended Children's Medical Center, Tehran, Iran, and sent to the Iranian National Influenza Center with appropriate conditions in 2021. Chi‐square and Fisher's exact tests were used for comparison of the data of the prevalence of hRSV and SARS‐CoV‐2 infections among children. Of 168 patients examined, 95 (57%) were male and 73 (43%) female. Out of them, 47 (28%) cases were younger than 1 year old and 121 cases (72%) were 1–5 years old. The most common clinical manifestations of patients were cough (78%), nausea (31%), diarrhea (27%), and fever (18%). Among 168 patients, no hRSV was detected, while the SARS‐CoV‐2 genome was identified in 16 (9.5%) patients. Among 16 positive cases of SARS‐CoV‐2, 8 (50%) were under 1 year old and 8 positive cases were 1–5 years old. This study was performed at cold months of the year but due to the coronavirus disease 2019 pandemic and adherence to health protocols, school closures, and virtual classes, no cases of hRSV infections were identified.
Effects of different carbon sources on metabolic profiles of carbohydrates in Streptococcus thermophilus during fermentation
Authors: Song Xin , Hou Chengjie , Yang Yong , Ai Liangzhong , Xia Yongjun , Wang Guangqiang , Yi Huaxi , Xiong Zhiqiang
Published: March 2022

BACKGROUND

Streptococcus thermophilus is a major starter used in the dairy industry and it could improve the flavor of fermented products. It is necessary to improve biomass of S. thermophilus for its application and industrialization. The utilization of carbon sources directly affects the biomass of S. thermophilus. Therefore, the carbohydrate metabolism of S. thermophilus should be investigated.

RESULTS

In the present study, metabolic parameters and gene expression of S. thermophilus S‐3 with different carbon sources were investigated. The physicochemical results showed that S. thermophilus S‐3 had high lactose utilization. Transcriptome analysis found that approximately 104 genes were annotated onto 15 carbohydrate metabolic pathways, of which 15 unigenes were involved in the phosphotransferase system and 75 were involved in the ATP‐binding cassette transporter system. In addition, 171 differentially expressed genes related to carbohydrate metabolism were identified. Expression of the galactose metabolism genes lacSZ and galKTEM increased significantly from the lag phase to the mid‐exponential growth phase as a result of the global regulator protein, catabolite control protein A (CcpA). The high expression of galK in the mid‐ to late‐ phases indicated that the metabolite galactose is re‐transported for intracellular utilization. CcpA regulation may also induce high expressions of glycolytic pathway regulated‐genes related to lactose utilization, including ldh, fba, eno, pfkA, bglA, pgi, pgm and pyk, producing optimal glycolytic flux and S. thermophilus S‐3 growth.

CONCLUSION

The present study provides new insights into the carbon metabolism regulation and provide theoretical support for high‐density fermentation of S. thermophilus S‐3. © 2022 Society of Chemical Industry.
Corporate social responsibility focusing on consumer surplus and endogenous competition structure: A case of managerial delegation
Authors: Nakamura Yasuhiko
Published: March 2022

We suppose that firms care about corporate social responsibility (CSR) and revisit the endogenous choice between price and quantity. We consider that each owner can delegate the decision on market competition to their manager. We express the objective of each firm's owner as the weighted sum of their profit and consumer surplus. We find that the two types of symmetric competitions are observed in equilibrium regardless of the degree of importance of CSR within each firm. In contrast, which of their two competitions is chosen based on the risk domination strikingly depends on the degree of importance of CSR.
Application of the modified Fourier series method and the genetic algorithm for calibration of small‐scale parameters in the nonlocal strain gradient nanobeams
Authors: Mohammadian Mostafa
Published: March 2022

In recent years, nonlocal strain gradient theory (NSGT) has been widely applied by researchers for the analysis of nanostructures. In this theory, the appropriate selection of small‐scale parameters and the type of high‐order boundary conditions is of great importance. In the current paper, free vibrations of carbon nanotubes are studied using a nonlocal strain gradient Timoshenko beam model, and the small‐scale parameters are calibrated based on the molecular dynamics (MD) results. The calibration process is conducted by defining an optimization problem, and the genetic algorithm is applied for obtaining the best values of the small‐scale parameters. The governing equations are derived based on Hamilton's principle and solved analytically using the modified Fourier series method. The variational consistent high‐order boundary conditions are obtained applying the weighted residual approach. The small‐scale parameters are calibrated for the first three natural frequencies considering two different boundary conditions. Moreover, the type of high‐order boundary conditions that is more consistent with the MD results is determined. The outcomes of this paper provide an appropriate reference for researchers who are using the NSGT for the analysis of micro/nanobeams.
Unternehmen: Wege in die Zukunft
Authors: Ehrensberger Christian
Published: March 2022

In der Chemie‐ und Pharmaindustrie sind die Ausgaben für Forschung und Entwicklung im Jahr 2020 gesunken. Gleichzeitig zeigt sich langfristig ein Abwärtstrend bei der Forschungsproduktivität in Unternehmen, also dem Verhältnis von Output zu investierten Mitteln. Dem lässt sich entgegenwirken.
Synthese im Blickpunkt: Organische Elektronik flexibler und weicher machen
Authors: Lissel Franziska
Published: March 2022

Die organische Elektronik findet sich in Anwendungen von Flachbildschirmen bis zu Solarzellen. Kohlenstoffbasierte Materialien sind zwar weniger leistungsstark als klassische siliciumbasierte Elektronik, aber durch entsprechende Polymere lassen sich dehnbare Bauteile herstellen und so an die menschliche Haut anpassen. Eine Übersicht über Materialien und Eigenschaften der genutzten Polymere.
Nachruf auf Reiner Ellmer (1927–2021) und Gudrun Ellmer (1941–2021)
Authors: Guggolz Ernst
Published: March 2022

Die Zeitschrift CLB mit ihrer Zielgruppe nichtakademische Chemiker und Chemikerinnen war das Lebenswerk der Ellmers.
Zwischen Amor und Atira: Erdnahe Asteroiden
Authors: Meier Matthias
Published: March 2022

Vor 50 Jahren waren noch relativ wenige erdnahe Asteroiden bekannt. Heute hat sich das geändert.
Geschüttelt oder gerührt? – Geschleudert!
Authors: Vogt Patrik , Kasper Lutz
Published: March 2022

Ein zu gut eingeschenktes Glas führt beim Tragen schnell zum Überschwappen des edlen Tropfens. Es gibt aber eine sportliche Lösung des Problems.
Effect of freeze–thaw cycles on the performance of cast‐in‐place piles in permafrost regions: Working state and action effect sharing
Authors: Shi Rui , Wen Zhi , Li Desheng , Gao Qiang , Wei Yanjing
Published: March 2022

Owing to a minor thermal disturbance to the permafrost environment, cast‐in‐place piles are widely used for building and bridge foundations in permafrost regions. However, because of the dynamic and cyclic variation in frozen ground affected by the atmosphere, the load transfer mechanism is not yet clear, and the current design is economically insufficient. To illustrate the bearing pattern of cast‐in‐place piles subjected to freeze–thaw cycles, a systematic in situ investigation was carried out. Results show that the load from the superstructure has a marginal action effect, while freeze–thaw cycles have a more significant action effect. Freeze–thaw cycles have a decisive effect on the dynamic variations of the pile's working state and action effect sharing while the mechanisms are quite different, which vary with depths. Action effect sharing of the pile shaft and tip experiences a cyclic variation and is affected by the long‐term effect of freeze–thaw cycles. The shaft takes an increasing sharing proportion gradually and has a 19% rise after two freeze–thaw cycles, while the pile tip goes the opposite way. Two years after the building is completed, the bearing capacity is almost entirely provided by shaft resistance and mainly by the upper one‐third of the pile. This research clarifies several essential issues about the bearing pattern and provides solid scientific support and novel opinions for the pile design in permafrost regions.
Myricetin reverses epithelial–endothelial transition and inhibits vasculogenic mimicry and angiogenesis of hepatocellular carcinoma by directly targeting PAR1
Authors: Wang Ming , Ren Shanfa , Bi Zhun , Zhang Liang , Cui Mengqi , Sun Ronghao , Bao Jiali , Gao Dandi , Yang Bo , Li Xiaoping , Li Mingjiang , Xiao Ting , Zhou Hong‐gang , Yang Cheng
Published: March 2022

Most antiangiogenic inhibitors targeting endothelium‐dependent vessels cannot inhibit tumor growth but promote tumor invasion and metastasis in some patients. Vasculogenic mimicry (VM) employs mechanisms that differ from those used to construct endothelium‐dependent vessels. Inhibiting VM may be a novel antiangiogenic strategy against alternative tumor vascularization. In this paper, myricetin was selected from among several flavonoid compounds as an effective PAR1 antagonist. In two different hepatocellular carcinoma (HCC) cell lines high‐expressed PAR1, myricetin inhibited cell migration, invasion and VM formation and reversed the expression of epithelial–endothelial transition (EET) markers by inhibiting PAR1 activation. Knockout of PAR1 inhibited HCC cell invasion and metastasis and weakened the inhibitory effect of myricetin on HCC cells. The migration, invasion and tube formation ability of PLC‐PRF‐5 cells were enhanced after PAR1 overexpression, and the inhibitory effect of myricetin was enhanced. A docking assay revealed that myricetin binds to Leu258 and Thr261 in the PAR1 activity pocket. Mutation of Leu258 and Thr261 inhibited the antitumor effect of myricetin in vitro and in vivo. In summary, myricetin reverses PAR1‐mediated EET and inhibits HCC cell invasion, metastasis, VM formation and angiogenesis by targeting PAR1, and Leu258 and Thr261 of PAR1 participate in VM and angiogenesis in HCC tissues.
Optimal distinctiveness across revenue models: Performance effects of differentiation of paid and free products in a mobile app market
Authors: van Angeren Joey , Vroom Govert , McCann Brian T. , Podoynitsyna Ksenia , Langerak Fred
Published: March 2022

Research Summary

The optimal distinctiveness literature highlights a fundamental trade‐off in product positioning within market categories: Products should be distinct to minimize competition, but similar to build legitimacy. Most recently, this research has focused on understanding sources of variance in the distinctiveness–performance relationship. We extend this literature with an examination of digital products and argue that the relationship depends on products' revenue models: We theorize the relationship is inverted U‐shaped for paid products but U‐shaped for free products, owing to heightened privacy concerns of free product customers. We further argue that this latter relationship becomes flatter for free products that provide greater monetization transparency by publishing a privacy statement or adopting a freemium revenue approach. Hypotheses are tested using a sample of 250,000‐plus Apple App Store apps.

Managerial Summary

How should firms in the digital space position their products for optimal performance? We study this question in the Apple App Store, and suggest that the optimal positioning of digital products depends on their revenue model. Paid products should be moderately differentiated from competing products. By contrast, free products benefit most from very low or very high levels of differentiation. We attribute the different performance effects of differentiation to customers' privacy concerns over free products. Firms can partially ameliorate those privacy concerns by providing greater monetization transparency by publishing a privacy statement or by adopting a freemium revenue approach, making moderate levels of differentiation more viable. Our findings help managers align choices of positioning and revenue model, two critical aspects of the firm's business model.
Single‐Crystalline Cathodes for Advanced Li‐Ion Batteries: Progress and Challenges
Authors: Han Yongkang , Lei Yike , Ni Jie , Zhang Yingchuan , Geng Zhen , Ming Pingwen , Zhang Cunman , Tian Xiaorui , Shi Ji‐Lei , Guo Yu‐Guo , Xiao Qiangfeng
Published: March 2022

Single‐crystalline cathodes are the most promising candidates for high‐energy‐density lithium‐ion batteries (LIBs). Compared to their polycrystalline counterparts, single‐crystalline cathodes have advantages over liquid‐electrolyte‐based LIBs in terms of cycle life, structural stability, thermal stability, safety, and storage but also have a potential application in solid‐state LIBs. In this review, the development history and recent progress of single‐crystalline cathodes are reviewed, focusing on properties, synthesis, challenges, solutions, and characterization. Synthesis of single‐crystalline cathodes usually involves preparing precursors and subsequent calcination, which are summarized in the details. In the following sections, the development issues of single‐crystalline cathodes, including kinetic limitations, interfacial side reactions, safety issues, reversible planar gliding and micro‐cracking, and particle size distribution and agglomeration, are systematically analyzed, followed by current solutions and characterization techniques. Finally, this review is concluded with proposed research thrusts for the future development of single‐crystalline cathodes.
3D Bioprinted GelMA‐Nanoclay Hydrogels Induce Colorectal Cancer Stem Cells Through Activating Wnt/β‐Catenin Signaling
Authors: Zhang Yanmei , Wang Zixuan , Hu Qifan , Luo Hao , Lu Bingchuan , Gao Yunhe , Qiao Zhi , Zhou Yongsen , Fang Yongcong , Gu Jin , Zhang Ting , Xiong Zhuo
Published: March 2022

Cancer stem cells (CSCs) are a rare cell population in tumors that are responsible for tumor recurrence and metastasis. They are a priority as therapeutic targets, however, assays targeting CSCs have been limited by expanding and maintaining CSCs in vitro. Here, the authors find that gelatin methacryloyl (GelMA)‐nanoclay hybrid hydrogels can induce and enrich colorectal CSCs assisted by three‐dimensional (3D) bioprinting. The presence of the nanoclay increases the printability, Young's modulus, pore size, and cytocompatibility of the hydrogels. Bioprinted GelMA‐nanoclay hydrogels promote the formation of spheroids expressing elevated levels of the stemness markers LGR5, CD133, CD26, and SOX2. Cancer cells grown in GelMA‐nanoclay hydrogel possess higher self‐renewal and differentiation capacity in vitro and higher tumorigenic capacity in vivo. GelMA‐nanoclay hydrogels induce CSCs by stimulating the activation of the Wnt/β‐catenin signaling pathway. Further studies demonstrate that spheroids from GelMA‐nanoclay hydrogels possess increased stemness, higher consistency, yield, and sensitivity to the anti‐CSC compounds compared to the classic CSC‐enrichment model. Collectively, this study may provide a valuable biomaterial and method for inducing and enriching CSCs, to facilitate the effective CSC‐targeting drug screening.
Financial lessons for student services at community colleges and regional public institutions
Authors: Trentacoste Peter J. , Ward Molly C. , Aluso Salome , Copeland Olivia C. , Nguyen David J.
Published: March 2022

This article reflects on how financial operations, especially at community colleges and regional public institutions, were adversely affected by the pandemic and considers what institutions could do moving forward and for the future.
A perspective on high‐entropy two‐dimensional materials
Authors: Cui Yanglansen , Zhang Yongzheng , Cao Zhenjiang , Gu Jianan , Du Zhiguo , Li Bin , Yang Shubin
Published: March 2022

In past decades, high‐entropy (HE) materials, containing five or more elements with approximately equal atomic ratio, are extensively investigated due to their desirable properties in a series of applications. Recently, HE two‐dimensional (2D) materials have become promising materials, which not only endow the advantages from their bulk form but also exhibit unusual properties due to their 2D features. So far, the HE 2D transition metal carbides (MXenes), dichalcogenides (TMDs), hydrotalcites (LDHs), and oxides have been successfully synthesized and performed well in different electrochemical reactions, which is originated from the synergistic effect of multicomponents and atomic thin characteristics. Here, the challenges on processing, characterization, and property predictions of HE 2D materials are emphasized. Finally, viable strategies, advanced processing, fundamental understanding, in‐depth characterization of new HE 2D materials are proposed.
Exome sequencing as first‐tier test for fetuses with severe central nervous system structural anomalies
Authors: Yaron Y. , Ofen Glassner V. , Mory A. , Zunz Henig N. , Kurolap A. , Bar Shira A. , Brabbing Goldstein D. , Marom D. , Ben Sira L. , Baris Feldman H. , Malinger G. , Krajden Haratz K. , Reches A.
Published: March 2022

Objective

Prenatally detected central nervous system (CNS) anomalies present a diagnostic challenge. In this study, we compared the diagnostic yield of exome sequencing (ES) and chromosomal microarray analysis (CMA) in fetuses with a major CNS anomaly.

Methods

This was a retrospective study of 114 cases referred for genetic evaluation following termination of pregnancy (TOP) due to a major CNS anomaly detected on prenatal ultrasound. All fetuses were first analyzed by CMA. All CMA‐negative cases were offered ES. CMA‐positive cases were reanalyzed using ES to assess its ability to detect copy‐number variants (CNVs).

Results

CMA identified a pathogenic or likely pathogenic (P/LP) CNV in 11/114 (10%) cases. Eighty‐six CMA‐negative cases were analyzed using ES, which detected P/LP sequence variants in 38/86 (44%). Among recurrent cases (i.e. cases with a previously affected pregnancy), the incidence of P/LP sequence variants was non‐significantly higher compared with non‐recurrent ones (12/19 (63%) vs 26/67 (39%); P = 0.06). Among the 38 cases with an ES diagnosis, 20 (53%) were inherited and carried a significant risk of recurrence. Reanalysis of 10 CMA‐positive cases by ES demonstrated that the bioinformatics pipeline used for sequence variant analysis also detected all P/LP CNVs, as well as three previously known non‐causative CNVs.

Conclusions

In our study, ES provided a high diagnostic yield (> 50%) in fetuses with severe CNS structural anomalies, which may have been partly due to the highly selected case series that included post‐TOP cases from a specialist referral center. These data suggest that ES may be considered as a first‐tier test for the prenatal diagnosis of major fetal CNS anomalies, detecting both P/LP sequence variants and CNVs. This is of particular importance given the time constraints of an ongoing pregnancy and the risk of recurrence in future pregnancies. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Perinatal outcomes of fetoscopic laser surgery for twin–twin transfusion syndrome in triplet pregnancy: cohort study, systematic review and meta‐analysis
Authors: Mustafa H. J. , Javinani A. , Krispin E. , Tadbiri H. , Shamshirsaz A. A. , Espinoza J. , Nassr A. A. , Donepudi R. , Belfort M. A. , Sanz Cortes M. , Harman C. , Turan O. M.
Published: March 2022

Objectives

The aims of this study were to investigate the perinatal outcome of dichorionic triamniotic (DCTA) and monochorionic triamniotic (MCTA) triplet pregnancies complicated by twin–twin transfusion syndrome (TTTS) treated with fetoscopic laser photocoagulation (FLP) in two academic fetal centers, and to conduct a systematic review of previously published data to investigate perinatal survival in this targeted population.

Methods

The first part of the study was a retrospective cohort study of prospectively collected data of consecutive triplet pregnancies with TTTS that underwent FLP at two fetal treatment centers between 2012 and 2020. Demographic, preoperative and operative variables and postoperative outcome were collected. Perinatal outcomes were investigated. The second part of the study was a systematic review and meta‐analysis of studies evaluating the outcome of DCTA and/or MCTA triplet pregnancies, including our cohort study. PubMed, Web of Science and Scopus were searched from inception to September 2020. Primary outcomes were fetal survival (survival to birth), neonatal survival (survival to 28 days of age) and gestational age (GA) at birth.

Results

A total of 31 sets of triplets with TTTS managed with FLP were included in the cohort study. Of these, 24 were DCTA and seven were MCTA. There were no significant differences in preoperative and operative variables between the two groups. There were also no significant differences between groups in GA at delivery or perinatal survival rate, including fetal and neonatal survival of at least one triplet, at least two triplets and all three triplets. Nine studies, including our cohort study, were included in the systematic review (156 DCTA and 37 MCTA triplet pregnancies treated with FLP). The overall fetal and neonatal survival was 79% (95% CI, 75–83%) and 75% (95% CI, 71–79%), respectively, in DCTA cases and 74% (95% CI, 52–92%) and 71% (95% CI, 49–89%), respectively, in MCTA cases. The rate of preterm birth before 28 weeks and before 32 weeks' gestation was 14% (95% CI, 4–29%) and 61% (95% CI, 50–72%), respectively, in DCTA triplets and 21% (95% CI, 3–45%) and 82% (95% CI, 62–96%), respectively, in MCTA triplets.

Conclusions

Triplet pregnancies with TTTS are at high risk of adverse perinatal outcome and preterm birth, regardless of chorionicity. The rate of survival after FLP in MCTA triplets was higher in our study than that reported in previous studies and is currently comparable with survival in DCTA triplets, which could be due to improved surgical skills. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Entfernung (kurzkettiger) PFAS mit einem neuen Ansatz aus Aktivkohle und Ionenaustauscher
Authors: Riegel Marcel
Published: March 2022

Zur Entfernung von poly‐ und perfluorierten Alkylverbindungen (PFAS) wurde ein zweistufiges Verfahrenskonzept getestet, bei dem die langkettigen PFAS mittels Aktivkohlefiltration und die kurzkettigen PFAS in einer anschließenden Behandlung mittels Ionenaustauscher entfernt werden. Der Betrieb des Ionenaustauschers erfolgt hierbei zyklisch durch Beladung und Regeneration mit Natronlauge. Die im basischen Regenerat vorliegenden kurzkettigen PFAS sollen anschließend elektrochemisch mineralisiert werden. Beim Betrieb des Ionenaustauschers wurden über 14 Zyklen aus Beladung und Regeneration Entfernungsraten der beiden Substanzen PFBA und PFPeA von 80 bis > 95 % ermittelt. Ferner konnten sehr hohe Ausbeuten hinsichtlich behandelter Wassermenge und anfallendem, PFAS‐haltigem Regenerat zwischen 99 und 99,5 % erzielt werden. Dadurch resultiert ein sehr geringes Wasservolumen, das anschließend energieintensiv zur PFAS‐Zerstörung behandelt werden muss.
Light bending from eikonal in worldline quantum field theory
Authors: Bastianelli Fiorenzo , Comberiati Francesco , de la Cruz Leonardo
Published: March 2022

Abstract

Using the worldline quantum field theory (WQFT) formalism for classical scattering, we study the deflection of light by a heavy massive spinless/spinning object. WQFT requires the use of the worldline dressed propagator of a photon in a gravitational background, which we construct from first principles. The action required to set up the worldline path integral is constructed using auxiliary variables, which describe dynamically the spin degrees of freedom of the photon and take care of path ordering. We test the fully regulated path integral by recovering the photon-photon-graviton vertex. With the dressed propagator at hand, we follow the WQFT procedure by setting up the partition function and deriving the Feynman rules which can be used to evaluate it perturbatively. These rules depend on the auxiliary variables. The latter ultimately do not contribute in the geometric-optics regime, which realizes the equivalence between the scattering of a photon and a massive scalar with that of a massless and a massive scalar. Then, the calculation of the eikonal phase and the deflection angle simplifies considerably. Using the eikonal phase defined in terms of the partition function, we calculate explicitly the deflection angle at NLO in the spinless case, and at LO in the spinning case up to quadratic order in spin.
Prevalence and molecular identification of zoonotic Anisakis and Pseudoterranova species in fish destined to human consumption in Chile
Authors: Muñoz-Caro Tamara , Machuca Alvaro , Morales Pamela , Verdugo Javiera , Reyes Rodrigo , García Macarena , Rutaihwa Liliana , Schindler Tobias , Poppert Sven , Taubert Anja , Hermosilla Carlos
Published: March 2022

Zoonotic larvae of the family Anisakidae found in several fish species represent a serious risk in public health since they may cause food-borne anisakidosis in humans. Chile has culinary preferences including eating raw fish in many traditional preparations. In the present study, a total of 180 fish specimens representing three different fish species, i.e., Chilean hake (Merluccius gayi), snoek (Thyrsites atun), and sea bream (Brama australis), were caught at central coast of Chile. Parasitological examination was performed on musculature and abdominal cavity for subsequent extraction and quantification of anisakid larvae. Estimation of infection parameters, such as prevalence, was performed indicating 100% (CI: 0.94–1.0) prevalence of anisakid L3 in Chilean hakes and snoeks. Moreover, sea breams reached a prevalence of 35% (CI: 0.23–0.48). Prevalence of anisakid larvae in muscle was also analyzed showing values of 18.6% (CI: 0.097–0.309) in Chilean hakes, 15% (CI: 0.07–0.26) in snoeks, and 1.7% (CI: 0–0.089) in sea breams. Meanwhile, prevalence of anisakid larvae in internal organs showed highest values for peritoneum (100% and 83.3%) for snoeks and Chilean hakes, respectively, for liver (96.7%) and gonads (86.6%) in Chilean hakes, and for intestine (98.3%) in snoeks. Molecular analysis of collected anisakid L3 unveiled presence of two potentially zoonotic nematode species, i.e., Pseudoterranova cattani and Anisakis pegreffii. P. cattani was found in Chilean hakes and snoeks being the first molecular host species report for Chilean snoeks. Besides, A. pegreffii was also identified in these species being the first molecular report on this regard. These findings are relevant for better understanding of epidemiology of anisakiasis in Chilean coasts and for public health issues considering potential risk of human population due to its culinary preferences in eating raw fish.
Can statistical remote sensing aid in predicting the potential productivity of inland lakes? Case study: Lake Qaroun, Egypt
Authors: Mohamed Hagar Mahmoud , Khalil Magdy Tawfik , El-Kafrawy Sameh Bakr , El-Zeiny Ahmed Mohamed , Khalifa Nehad , Emam Wiame Waheed Mahmoud
Published: March 2022

This study aimed at creating a sustainable and inexpensive Landsat-based electrical conductivity model that can easily notify fisheries managers of changes in electrical conductivity and hence the potential fish yield of Lake Qaroun in Egypt. The study integrated geospatial technology, field measurements, mathematical computations, and fish yield empirical model into the adopted methodology. Seventeen sampling sites covering the entire study area were selected to measure the electrical conductivity (EC; mS/cm) and water depths (D; m) of Lake Qaroun, Egypt, during November 2018. Spatial analysis tools within ArcGIS were used to extract EC data from non-surveyed sites. A high-resolution Sentinel-2B MSI and a cloud-free medium-resolution Landsat-8 OLI scenes for Lake Qaroun were used for morphometric and regression analyses, respectively. For regression, 75% of the dataset was used to build up the regression model, while the remaining 25% was used for validation. The study selected Landsat band ratios that correlated with the highest certainty (R > 0.80) with the examined EC. Stepwise regression model was then developed to predict EC from Landsat-8 data. In choosing the best regression model, the study selected the significant model (P < 0.05) with the highest coefficient of determination (R2) and the least error metrics. Finally, the developed model was applied in calculating the potential yield of Lake Qaroun. The innovative EC model derived in the current study using Landsat-8 OLI for Lake Qaroun showed a very good performance in estimating 95% of EC values significantly with high acceptable accuracy. In closure, the model can be used very efficiently as a decision support tool in assisting managers not only in monitoring the lake’s electrical conductivity regularly, during the month of November, but also in making preliminary estimates of the lake’s potential yield.
Fear of childbirth postpartum and its correlation with post-traumatic stress symptoms and quality of life among women with birth complications — a cross-sectional study
Authors: Grundström Hanna , Malmquist Anna , Ivarsson Alice , Torbjörnsson Elin , Walz Malin , Nieminen Katri
Published: March 2022

The primary aim of the study was to analyze differences in post-traumatic stress symptoms (PTSS) and quality of life (QoL) between women with and without severe fear of childbirth postpartum (PP FOC). The secondary aims were to analyze the correlation between PP FOC and PTSS, and PP FOC and QoL, in women undergoing complicated childbirth. This cross-sectional study was conducted in South-East Sweden. Women aged ≥ 18 years who had undergone complicated childbirth (i.e., acute or emergency cesarean section, vacuum extraction, child in need of neonatal care, manual placenta removal, sphincter rupture, shoulder dystocia, or hemorrhage ≥ 1000 ml) were invited. Seventy-six women answered demographic questions and three validated instruments measuring PP FOC, PTSS, and QoL. The study population was divided into two sub groups: severe PP FOC or no severe PP FOC. Statistical analyses were conducted using Mann–Whitney U-test, chi-square test or Fisher’s exact test, and Spearman’s rank-order correlation. Severe PP FOC was reported by 29% of the women, and 18% reported PTSS indicating post-traumatic stress disorder. Women with severe PP FOC reported significantly higher levels of PTSS, and significantly lower QoL in five dimensions: physical role functioning, emotional role functioning, energy/fatigue, emotional well-being, and social functioning. There was a positive significant correlation between level of PP FOC and PTSS. There were also significant negative correlations between level of PP FOC and most of the QoL dimensions. In conclusion, almost one-third of the women with complicated childbirth reported severe PP FOC, and almost one-fifth reported PTSS indicating post-traumatic stress disorder. PP FOC correlated with PTSS and deteriorated QoL.