bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrosynthesis of Stable Betulin‐Derived Nitrile Oxides and their Application in Synthesis of Cytostatic Lupane‐Type Triterpenoid‐Isoxazole Conjugates
Authors: Lugiņina Jevgeņija , Linden Martin , Bazulis Māris , Kumpiņš Viktors , Mishnev Anatoly , Popov Sergey A. , Golubeva Tatiana S. , Waldvogel Siegfried R. , Shults Elvira E. , Turks Māris
Published: April 2021

Novel lupane‐type triterpenoid‐isoxazole conjugates were designed by direct placing of isoxazole linker at C(17) of triterpenoid. The suggested synthetic sequence demonstrates successful combination of electro‐organic synthesis and conventional approaches. TEMPO‐mediated electrooxidation of betulin to betulinal was developed and optimized at boron‐doped diamond anodes with potassium acetate as inexpensive supporting electrolyte. Betulinal‐derived oxime was further selectively electro‐oxidized at a graphite anode to nitrile oxide, which proved to be stable and isolable species. The same reaction sequence was performed with 3β‐lupane‐3,28‐diol. Nitrile oxides were characterized by 15N NMR and X‐ray crystallography. The isolable nitrile oxides allowed creation of isoxazole library by 1,3‐dipolar cycloaddition reactions with various alkynes. Some of the title conjugates exhibit cytostatic properties against breast cancer cell line MCF7, glioblastoma multiform cell line U‐87 MG and lung carcinoma cell line A549 with growth inhibition (GI50) concentrations up to 11 μm, while being harmless to immortalized human fibroblasts hTERT (GI50 >100 μm).
Sequential Formal [4+1]‐Cycloaddition, C−H Functionalization and Suzuki–Miyaura Cross‐Coupling for the Synthesis of Trisubstituted Isoxazolines
Authors: Ushakov Pavel Yu. , Sukhorukov Alexey Yu. , Ioffe Sema L. , Tabolin Andrey A.
Published: April 2021

Suzuki–Miyaura cross‐coupling reaction of 3‐bromomethyl isoxazolines with arylboronic acids was suggested as final C−C bond forming step in convenient diastereoselective route to trisubstituted isoxazolines. The required bromides were readily available from nitroalkenes and sulfonium ylides through an efficient sequence of formal [4+1]‐cycloaddition and C−H functionalization of intermediate isoxazoline N‐oxides. The synthetic utility of the obtained isoxazolines was demonstrated by their conversion into valuable products such as hydroxy ketone, pyrrolidinone, etc.
Visualisation of Chemical Shielding Tensors (VIST) to Elucidate Aromaticity and Antiaromaticity**
Authors: Plasser Felix , Glöcklhofer Florian
Published: April 2021

Aromaticity is a central concept in chemistry, pervading areas from biochemistry to materials science. Recently, chemists also started to exploit intricate phenomena such as the interplay of local and global (anti)aromaticity or aromaticity in non‐planar systems and three dimensions. These phenomena pose new challenges in terms of our fundamental understanding and the practical visualisation of aromaticity. To overcome these challenges, a method for the visualisation of chemical shielding tensors (VIST) is developed here that allows for a 3D visualisation with quantitative information about the local variations and anisotropy of the chemical shielding. After exemplifying the method in different planar hydrocarbons, we study two non‐planar macrocycles to show the unique benefits of the VIST method for molecules with competing π‐conjugated systems and conclude with a norcorrole dimer showing clear evidence of through‐space aromaticity. We believe that the VIST method will be a highly valuable addition to the computational toolbox.
Brazilian green propolis promotes TNFR2 expression on regulatory T cells
Authors: Mikami Norihisa , Tani Hiroko , Kawakami Ryoji , Sugimoto Atsushi , Sakaguchi Shimon , Ikuta Tomoki
Published: April 2021

FoxP3+ regulatory T cells (Tregs) are needed to suppress inflammatory diseases and maintain immune homeostasis. The suppressive function of Tregs can be used to control autoimmune or inflammatory diseases; therefore, it is well studied how Tregs can be artificially up‐ or downregulated in vitro and in vivo, by using antibodies, chemical compounds, foods, and natural resources. Propolis is a famous functional food that has an anti‐inflammatory effect. However, the influences of propolis on Treg function have not been fully evaluated so far. Here, we demonstrated that Brazilian green propolis increases TNFR2 expression in Tregs via the IRF4/cMyc axis, and artepillin C was a major effective component of propolis on Tregs. These results indicate that propolis and artepillin C have the potential as Treg activators via TNFR2 expression and may be useful for the prevention and/or therapy of autoimmune or inflammatory diseases.
A brachiopod fauna from latest Permian to Induan of northern Guizhou, South China and its evolutionary pattern
Authors: Wu Hui‐Ting , Zhang Yang , Sun Yuan‐Lin
Published: April 2021

A new brachiopod fauna is reported from the Bozhou section spanning the latest Permian and Early Induan in Zunyi, northern Guizhou, South China. The brachiopods were collected from the Changhsingian Changhsing Formation and the Lower Induan Yelang Formation. The Changhsing Formation is composed of limestone and bioclastic limestone. The lower part of the Yelang Formation is composed of calcareous mudstone and argillaceous limestone intercalated with clay, and the upper part of the Yelang Formation comprises limestone intercalated with calcareous mudstone. After applying cluster analysis on the occurrence data of brachiopod species, three communities are recognized. FAS community mainly includes Fusichonetes, Acosarina, Spinomarginifera, and Araxathyris individuals. LP community mainly contains several Permian holdovers including Paracrurithyris, Orbicoelia, and Araxathyris, and disaster taxa like Lingularia. AP community is composed of Abrekia?, Paracrurithyris, and Prelissorhynchia. Shift of brachiopods from FAS community to LP community represents the extinction stage. LP community represents the survival stage. AP community is in the survival‐initial recovery stage. In the extinction stage, global brachiopod faunas showed similar patterns in that most brachiopod species and genera disappeared. In the survival stage, Lingularia quickly occupied the vacant ecospace and dominated the brachiopod community in the shallow‐water environment with soft substrate. In the survival‐initial recovery stage, Mesozoic‐type brachiopods appeared and were sporadically found in various environments.
Delayed access to conscious processing in multiple sclerosis: Reduced cortical activation and impaired structural connectivity
Authors: Has Silemek Arzu C. , Ranjeva Jean‐Philippe , Audoin Bertrand , Heesen Christoph , Gold Stefan M. , Kühn Simone , Weygandt Martin , Stellmann Jan‐Patrick
Published: April 2021

Although multiple sclerosis (MS) is frequently accompanied by visuo‐cognitive impairment, especially functional brain mechanisms underlying this impairment are still not well understood. Consequently, we used a functional MRI (fMRI) backward masking task to study visual information processing stratifying unconscious and conscious in MS. Specifically, 30 persons with MS (pwMS) and 34 healthy controls (HC) were shown target stimuli followed by a mask presented 8–150 ms later and had to compare the target to a reference stimulus. Retinal integrity (via optical coherence tomography), optic tract integrity (visual evoked potential; VEP) and whole brain structural connectivity (probabilistic tractography) were assessed as complementary structural brain integrity markers. On a psychophysical level, pwMS reached conscious access later than HC (50 vs. 16 ms, p < .001). The delay increased with disease duration (p < .001, β = .37) and disability (p < .001, β = .24), but did not correlate with conscious information processing speed (Symbol digit modality test, β = .07, p = .817). No association was found for VEP and retinal integrity markers. Moreover, pwMS were characterized by decreased brain activation during unconscious processing compared with HC. No group differences were found during conscious processing. Finally, a complementary structural brain integrity analysis showed that a reduced fractional anisotropy in corpus callosum and an impaired connection between right insula and primary visual areas was related to delayed conscious access in pwMS. Our study revealed slowed conscious access to visual stimulus material in MS and a complex pattern of functional and structural alterations coupled to unconscious processing of/delayed conscious access to visual stimulus material in MS.
HBV/Pregenomic RNA Increases the Stemness and Promotes the Development of HBV‐Related HCC Through Reciprocal Regulation With Insulin‐Like Growth Factor 2 mRNA‐Binding Protein 3
Authors: Ding Wen‐bin , Wang Meng‐chao , Yu Jian , Huang Gang , Sun Da‐peng , Liu Lei , Zhang Jia‐ning , Yang Yuan , Liu Hui , Zhou Wei‐ping , Yang Fu , Yuan Sheng‐xian
Published: April 2021

Background and Aims

HBV‐pgRNA (pregenomic RNA) has been proposed for predicting the response of nucleos(t)ide analogue (NA) treatment, guiding discontinuation of NA therapy and monitoring the emergence of viral mutations. However, the contributions of HBV‐pgRNA to HCC remain open for study.

Approach and Results

Double‐center cohorts of serum samples with undetectable serum HBV‐DNA (below the lower limit of detection) were obtained from long‐term NA‐treated (≥48 weeks) HBV‐related HCC patients. The correlation between serum pgRNA concentration and the prognosis of HCC were analyzed. The role pgRNA played in HCC development was assessed both in vitro and in vivo. Our findings revealed that for patients who underwent long‐term NA therapy with undetectable serum HBV‐DNA, patients with high serum pgRNA expression had a poorer overall survival rate and higher cumulative recurrence rate after hepatectomy. Experiments demonstrated that pgRNA promotes proliferation, stemness, and tumorigenicity of HCC cells. Mechanistically, we found that pgRNA could up‐regulate the expression of insulin‐like growth factor 2 mRNA‐binding protein 3 (IGF2BP3), a well‐proven oncoprotein, at the posttranscriptional level. Furthermore, interferon (IFN)‐α‐2a could degrade the stability of pgRNA through increasing its N6‐methyladenosine (m6A) RNA modification. Collectively, our findings uncover that serum pgRNA could serve as a potential biomarker for predicting the prognosis and recurrence of HCC in patients who received long‐term NA therapy with undetectable serum HBV‐DNA; and the pgRNA‐IGF2BP3 axis plays an important role in the development of HBV‐related HCC. Moreover, IFN‐α‐2a could reduce the stability of pgRNA by increasing its m6A RNA modification level, thereby suppressing the development of HBV‐related HCC.

Conclusions

In conclusion, our studies reveal a significance and mechanism of HBV‐pgRNA in increasing stemness features and offer a potential prognostic marker and a therapeutic target for HBV‐related HCC.
The technology acceptance scale: Its Bayesian psychometrics assessed in a factor analysis via Markov chain Monte Carlo models
Authors: Schmid Daniela
Published: April 2021

The technology acceptance scale (TAS) by van der Laan, Heino, and De Waard (1997) measures the psychological construct of the same term as a sum of attitudes of an operator toward a specific complex sociotechnical system. The TAS has been claimed to comprise two subscales, usefulness and satisfaction. However, recent empirical work has found evidence for only one underlying factor. To provide further insight into the factor structure of the TAS, this study adopts a Bayesian exploratory factor analysis (BEFA) to analyse the data of a flight simulation study regarding single pilot operations. A series of Markov chain Monte Carlo (MCMC) models is used to assess the latent factor structure of the TAS for the two different crewing conditions and their corresponding workstation and cockpit setups of the copilot. A reliable step‐by‐step data analysis of the MCMC models provides evidence for a one‐factor solution of the scale. The divergence to the previous studies which claim two factors can be due to the different applications as well as due to different statistical paradigms and methodological issues in exploratory factor analysis.
Organic Spacers in 2D Perovskites: General Trends and Structure‐Property Relationships from Computational Studies
Authors: Jahanbakhshi Farzaneh , Mladenović Marko , Dankl Mathias , Boziki Ariadni , Ahlawat Paramvir , Rothlisberger Ursula
Published: April 2021

Addition of large organic molecules to halide perovskites has been shown to provoke dimensionality reduction and formation of two‐dimensional phases that demonstrate improved long‐term stabilities. Optoelectronic properties of the resulting 2D layered perovskites are strongly influenced by the chemical nature of the additive molecules, which opens immense possibilities for preparation of materials with tailored properties. However, given the huge chemical space of possible organic spacers, a systematic and exhaustive search for optimal compounds is impossible and general structure–property relationships that could guide a rational design are still largely absent. Here, we provide an overview of a series of recent computational studies from our group on different types of spacers. We first develop a simplified universal monovalent cation model to map out approximate structural stability maps as a function of the van der Waals radius and the magnitude of dispersion interactions to monitor the possible emergence of 2D phases. We further provide structural and photophysical insights from classical and first‐principles molecular dynamics simulations and density functional theory calculations on 2D hybrid perovskites based on a wide range of spacers with different chemical nature and varying conformational properties. Our computational predictions are validated through comparison with powder diffraction, conductivity and optical measurements. Such comparative study allows for providing some general structure–property correlations, which can serve as design guidelines in the search for optimal 2D and mixed 2D/3D perovskite photovoltaic materials.
The San Dimas experimental forest: Hydrologic research in semiarid steepland terrain
Authors: Wohlgemuth Peter M.
Published: April 2021

The San Dimas Experimental Forest (SDEF) is located in southern California and is representative of the chaparral shrublands of the Southwest USA. Chaparral – including genera of Ceanothus, Adenostoma, Quercus, Salvia and Arctostaphylos – is a dense, drought‐tolerant vegetation assemblage with a closed canopy 3–5 m in height. Chaparral is a fire‐prone ecosystem and wildfires have burned the SDEF about every 40 years. The SDEF was established in 1933 to quantify the water cycle in a steep, semiarid landscape. Study catchments range in size from 15 to 1160 ha and measurements of stream runoff are made in a nested weir and flume arrangement to account for the very flashy flows. Apart from native chaparral vegetation, streamflow measurements in these study watersheds have also quantified the hydrologic response of vegetation type‐conversion and fire. Innovations in hydrologic monitoring developed on the SDEF include a critical depth flume (the San Dimas flume) and tilted rain gages to better sample precipitation in mountainous terrain. Subsurface runoff and plant water relations have been measured in a large lysimeter complex. Water quality monitoring shows that stream water in the SDEF has very high levels of nitrate, derived from atmospheric deposition of chronic air pollution, that approach the Federal EPA standard of 10.0 mg L−1 for nitrate‐N. Spreadsheets of rainfall and streamflow (from 1938 to 2015) – the San Dimas Experimental Forest hydrologic database – may be found at the right‐hand side of the web page at https://www.fs.fed.us/psw/ef/san_dimas/index.shtml. Hard copy charts, tables and other records associated with the foregoing data streams are available from the USDA Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, California, 92501 USA or at pete.wohlgemuth@usda.gov.
Green Chemistry as a Driver for Innovation in the Pharmaceutical Industry
Authors: Beaver Matthew G. , Caille Seb , Içten Elçin , Michalak Sharon E. , St‐Pierre Gabrielle , Thiel Oliver R.
Published: April 2021

The application of green chemistry principles is foundational in the route section and route development for active pharmaceutical ingredients at Amgen. In this perspective we present several examples where the application of concepts like atom economy, solvent minimization, reagent optimization, synthetic convergence, reduced energy use, real‐time analysis and strong safety focus have contributed to the development of processes that are significantly greener and more environmentally friendly that the corresponding starting points. The selected examples span different levels of molecular complexity, and many of the presented examples have been reduced to practice on significant scale.
Being an accountant, cook, entertainer and teacher—all at the same time: Changes in employees' work and work‐related well‐being during the coronavirus (COVID‐19) pandemic
Authors: Syrek Christine , Kühnel Jana , Vahle‐Hinz Tim , de Bloom Jessica
Published: April 2021

In March 2020, the world was hit by the coronavirus disease (COVID‐19) pandemic which led to all‐embracing measures to contain its spread. Most employees were forced to work from home and take care of their children because schools and daycares were closed. We present data from a research project in a large multinational organisation in the Netherlands with monthly quantitative measurements from January to May 2020 (N = 253–516), enriched with qualitative data from participants' comments before and after telework had started. Growth curve modelling showed major changes in employees' work‐related well‐being reflected in decreasing work engagement and increasing job satisfaction. For work‐non‐work balance, workload and autonomy, cubic trends over time were found, reflecting initial declines during crisis onset (March/April) and recovery in May. Participants' additional remarks exemplify that employees struggled with fulfilling different roles simultaneously, developing new routines and managing boundaries between life domains. Moderation analyses demonstrated that demographic variables shaped time trends. The diverging trends in well‐being indicators raise intriguing questions and show that close monitoring and fine‐grained analyses are needed to arrive at a better understanding of the impact of the crisis across time and among different groups of employees.
Behavioural effects of early‐life exposure to parabens in zebrafish larvae
Authors: Merola Carmine , Lucon‐Xiccato Tyrone , Bertolucci Cristiano , Perugini Monia
Published: April 2021

Parabens are classified as endocrine disrupting chemicals due to their ability to activate several nuclear receptors causing changes in hormones‐dependent signalling pathways. Central nervous system of developing organisms is particularly vulnerable to changes in hormonal pathways, which could lead to altered brain function, abnormal behaviour and even diseases later in life. The aim of the present study was to investigate the effects of exposure to butylparaben (BuP), ethylparaben (EtP) and methylparaben (MeP) during early development on nervous system using zebrafish larvae's behavioural models. Zebrafish were exposed until 4 days post fertilization (dpf) to three concentrations of each paraben chosen considering the environmentally realistic concentrations of human exposure and the benchmark‐dose lower bound calculated for zebrafish larvae (BuP: 5, 50 and 500 μg/L; EtP: 50, 500 and 5000 μg/L; MeP: 100, 1000 and 10,000 μg/L). Activity in novel and in familiar environment, thigmotaxis, visual startle response and photic synchronization of the behavioural circadian rhythms were analysed at 4, 5 and 6 dpf. Zebrafish larvae exposed to BuP 500 μg/L and EtP 5000 μg/L revealed increased anxiety‐like behaviour in novel environment. Larvae treated with 500 μg/L of BuP showed reduced activity in familiar and marginally in unfamiliar environment, and larvae exposed to 5000 μg/L of EtP exhibited hyperactivity in familiar environment. Parabens exposure did not influence the visual startle response and the photic synchronization of circadian rhythms in zebrafish larvae. This research highlighted as the exposure to parabens has the potential to interfere with behavioural development of zebrafish.
The Effects of Type 1 Diabetes and Diabetic Peripheral Neuropathy on the Musculoskeletal System: A Case–Control Study
Authors: Vilaca Tatiane , Paggiosi Margaret , Walsh Jennifer S , Selvarajah Dinesh , Eastell Richard
Published: April 2021

Fracture risk is increased in type 1 diabetes (T1D). Diabetic neuropathy might contribute to this increased risk directly through effects on bone turnover and indirectly through effects on balance, muscle strength, and gait. We compared patients with T1D with (T1DN+, n = 20) and without (T1DN−, n = 20) distal symmetric sensorimotor polyneuropathy and controls (n = 20). We assessed areal bone mineral density (aBMD) and appendicular muscle mass by dual-energy X-ray absorptiometry, microarchitecture by high-resolution peripheral quantitative tomography at the standard ultra-distal site and at an exploratory 14% bone length site at the tibia and radius, bone turnover markers, and muscle strength, gait, and balance by Short Physical Performance Battery (SPPB). At the standard ultra-distal site, tibial cortical porosity was 56% higher in T1DN+ compared with T1DN− (p = .009) and correlated positively with the severity of neuropathy (Toronto Clinical Neuropathy Score; r = 0.347, p = .028) and negatively with nerve conduction amplitude and velocity (r = −0.386, p = .015 and r = −0.358, p = .025, respectively). Similar negative correlations were also observed at the radius (r = −0.484, p = .006 and r = −0.446, p = .012, respectively). At the exploratory 14% offset site (less distal), we found higher trabecular volumetric BMD (tibia 25%, p = .024; radius 46%, p = .017), trabecular bone volume (tibia 25%, p = .023; radius 46%, p = .017), and trabecular number (tibia 22%, p = .014; radius 30%, p = .010) in T1DN– compared with controls. Both CTX and PINP were lower in participants with TD1 compared with controls. No difference was found in aBMD and appendicular muscle mass. T1DN+ had worse performance in the SPPB compared with T1DN– and control. In summary, neuropathy was associated with cortical porosity and worse performance in physical tests. Our findings suggest that bone structure does not fully explain the rate of fractures in T1D. We conclude that the increase in the risk of fractures in T1D is multifactorial with both skeletal and non-skeletal contributions. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
Transition‐metal‐catalyzed dehydrogenative coupling of alcohols and amines: A novel and atom‐economical access to amides
Authors: Heravi Mohammad Reza Poor , Hosseinian Akram , Rahmani Zahra , Ebadi Abdolghaffar , Vessally Esmail
Published: April 2021

The catalytic synthesis of amides directly from primary alcohols and amines represents an atom‐economical and environmentally benign methodology, which produces H2as the sole by‐product. Over the past few years, several highly efficient metal‐based catalytic systems have been developed for this green and sustainable synthetic procedure. This review will focus on the recent advancements and discoveries in this promising and hot research field which may allow possible new insights into catalyst improvement.
Development of novel quality control material based on CRISPR/Cas9 editing and xenografts for MLH1 protein deficiency testing
Authors: Li Rui , Zhang Runling , Tan Ping , Wang Meng , Chen Yuqing , Zhang Jiawei , Han Dongsheng , Han Yanxi , Li Jinming , Zhang Rui
Published: April 2021

Background

Mismatch repair deficiency (dMMR) status induced by MLH1 protein deficiency plays a pivotal role in therapeutic decision‐making for cancer patients. Appropriate quality control (QC) materials are necessary for monitoring the accuracy of MLH1 protein deficiency assays used in clinical laboratories.

Methods

CRISPR/Cas9 technology was used to edit the MLH1 gene of GM12878Cas9 cells to establish MLH1 protein‐deficient cell lines. The positive cell lines were screened and validated by Sanger sequencing, Western blot (WB), and next‐generation sequencing (NGS) and were then used to prepare formalin‐fixed, paraffin‐embedded (FFPE) samples through xenografting. These FFPE samples were tested by hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) for suitability as novel QC materials for MLH1 protein deficiency testing.

Results

We successfully cultured 358 monoclonal cells, with a survival rate of 37.3% (358/960) of the sorted monoclonal cells. Through Sanger sequencing, cell lines with MLH1 gene mutation were identified. Subsequently, two cell lines with MLH1 protein deficiency were identified by WB and named as GM12878Cas9_6 and GM12878Cas9_10. The NGS results further confirmed that the MLH1 gene mutation in these two cell lines would cause the formation of stop codons and terminate the expression of the MLH1 protein. The H&E staining and IHC results also verified the deficiency of the MLH1 protein, and FFPE samples from xenografts proved their similarity and consistency with clinical samples.

Conclusions

We successfully established MLH1 protein‐deficient cell lines. Followed by xenografting, we developed novel FFPE QC materials with homogenous, sustainable, and typical histological structures advantages that are suitable for the standardization of clinical IHC methods.
Adaptive e‐learning platforms can improve student performance and engagement in dental education
Authors: Yakin Muhammed , Linden Kelly
Published: April 2021

Purpose

Knowledge of normal tissue architecture is essential for one of the vitally important graduate competencies in dentistry, which is the recognition and appropriate referral of patients with oral mucosal and jawbone abnormalities for timely management and improved outcomes. The aim of this study was to examine the effect of online adaptive lessons on improving perceived and measured student performance, motivation, and student perceptions in dental education.

Methods

This mixed‐method study was conducted on year 1 and year 3 undergraduate dental students. Adaptive lessons supplementing a number of histology topics were designed and made available. Adaptive lesson scores and analytics, exam scores on topics that were supplemented by adaptive lessons (Experimental Questions), and those that were not (Control Questions) were compared among the year 1 students (n = 43). A validated questionnaire including Likert‐type scales about the student attitudes and perceptions toward adaptive lessons followed by open‐ended questions was administered to year 1 and 3 students (n = 57).

Results

Students obtained significantly higher scores in experimental exam questions than control exam questions (p = 0.01). A significantly larger number of students perceived that the adaptive lessons improved their knowledge of the subject (p < 0.001).

Conclusions

The adaptive lessons employed in this study showed significant potential to improve student engagement, motivation, perceived knowledge, and measured exam performance. These are particularly important findings especially amid the COVID‐19 pandemic as institutions transitioned to online education in lieu of face‐to‐face classes to comply with recommendations from Health Authorities.
Diversity, equity, and inclusion interventions to support admissions have had little benefit to Black students over past 20 years
Authors: Nalliah Romesh P. , Timothé Peggy , Reddy Michael S.
Published: April 2021

The United States has a history of systemic racism and violence toward minority communities. Unfortunately, the last year has demonstrated that systemic racism, and its consequences, persist. The dental profession has also failed to adequately resolve known issues of racial inequity and systemic racism, with persistent disparities in oral health outcomes for Black Americans compared to all other Americans, underrepresentation of minorities in the profession, and barriers to entry. However, dental education has the opportunity to address these issues. Current accreditation standards do not specifically address racial diversity among the student body, yet it is clear that representation of a population matters and the lack of representation may exacerbate race and racism as public health issues in dentistry.

To explore the issue, we curated American Dental Education Association (ADEA) data on the race of students admitted and enrolled into dental programs across the United States. We used data visualization techniques to present the data and study trends.

While the number of Black and African American (BAA) enrollees in dental schools has increased between 2000 and 2019, this population continues to make up a disproportionately small percentage of all enrollees, relative to the BAA percentage in the U.S. population. Much of the increase in BAA enrollment is attributable to increased places (due to the opening of new schools and increased class size in established schools) and the rate of acceptance of BAA students has had limited improvement.

Very little progress has been accomplished in growing the enrollment of BAA applicants to dental school in 20 years. As a profession, we also fail to grow interest among our graduates in careers that may support historically underrepresented and marginalized racial groups—public health, rural practice, population research, academia, and health policy. This may be a contributing factor to the oral health disparities faced by Black Americans and have implications for dental education.
CO2 and N2O emissions and microbial community structure from fields that include salt‐affected soils
Authors: Fiedler Douglas J. , Clay David E. , Joshi Deepak R. , Engel Andrew , Marzano Shin‐Yi , Jakubowski Duncan , Bhattarai Dwarika , Reese Cheryl L. , Bruggeman Stephanie A. , Clay Sharon A.
Published: April 2021

Although salinity and sodicity are worldwide problems, information on greenhouse gas (GHG) emissions from agricultural salt‐affected soils is scarce. The CO2–C and N2O–N emissions were quantified from three zones intertwined within a single U.S. northern Great Plains field: a highly productive zone (electrical conductivity with 1:1 soil/water mass ratio [EC1:1] = 0.4 dS m–1; sodium adsorption ratio [SAR] = 1.8), a transition zone (moderately salt‐affected; EC1:1 = 1.6 dS m–1; SAR = 4.99), and a saline/sodic zone (EC1:1 = 3.9 dS m–1; SAR = 22). In each zone, emissions were measured every 4 h for 7 d in four randomly placed chambers that were treated with two N rates (0 and 224 kg N ha–1). The experiment was conducted in 2018 and 2019 during similar seasonal periods. Soil samples taken from treatments after GHG measurement were analyzed for soil inorganic N, and microbial biomass from different communities was quantified using phospholipid fatty acid analysis. Real‐time polymerase chain reaction was used to quantify the number of copies of some specific denitrification functional genes. The productive zone had the highest CO2–C, the lowest N2O–N emissions, and the greatest microbial biomass, whereas the saline/sodic zone had the lowest CO2–C, the highest N2O–N emissions, and the lowest microbial biomass. Within a zone, urea application did not influence CO2–C emissions; however, N2O–N emissions from the urea‐treated saline/sodic zone were 84 and 57% higher than from the urea‐treated productive zone in 2018 and 2019, respectively. The copy number of the nitrite reductase gene, nirS, was 42‐fold higher in the saline/sodic zone than in the productive soil, suggesting that the saline/sodic soil had a high potential for denitrification. These findings suggest N2O–N emissions could be reduced by not applying N to saline/sodic zones.
Professional Identity Development and Multicultural Identity Among International Counselor Education Doctoral Students
Authors: Kuo Patty , Washington Ahmad , Woo Hongryun
Published: April 2021

This qualitative study examined the professional and multicultural identities among 13 international counselor education doctoral students. Participants identified cultural identities and difficulties with studying abroad, and their influence on their professional development. Implications and recommendations for counselor education programs are discussed.

Este estudio cualitativo examinó las identidades profesionales y multiculturales de 13 estudiantes internacionales en programas de doctorado en educación de consejeros. Los participantes identificaron identidades culturales y dificultades relacionadas con el hecho de estudiar en un país extranjero, así como la influencia de estas en su desarrollo profesional. Se discuten las implicaciones y recomendación para programas de educación de consejeros.
Effects of Vicarious Racism Exposure via the Media on College Students of Color: Exploring Affect and Substance Use
Authors: Giordano Amanda L. , Prosek Elizabeth A. , Henson Robin K. , Silveus Sarah , Beijan Lisa , Reyes Ana , Molina Citlali , Agarwal Sarah M.
Published: April 2021

Given the potential negative effects of vicarious racism, we sought to examine the impact of vicarious racism via the media on college students of color. Using a sample of 217 college students of color, we analyzed positive and negative affect and craving for alcohol and marijuana before and after exposure to media stimuli. Split‐plot analysis of variance results revealed a statistically significant interaction effect between time and group for negative affect, but not cravings for substances.
Mental Health in the Transition to College: Experiences of Six Low‐Income, High‐Achieving Students
Authors: Sabaner Can , Arnold Karen D.
Published: April 2021

This study examined the mental health issues of low‐income, high‐achieving undergraduate students, a largely overlooked population in mental health research. Study participants provided in‐depth reports across their first semester of college through interviews and semiweekly audio‐diary transcripts. Factors related to race, community, money, and access to counseling services were the major determinants of students' college experiences and mental health. Intensive case studies of six students raise implications for student affairs and counseling centers.
Predictors of Help‐Seeking Attitudes in College Student Service Members and Veterans
Authors: Noble Melissa A. , Platt Lisa F. , Leppma Monica
Published: April 2021

We explored predictors of attitudes toward psychological help seeking among 103 student service members and veterans (SSM/V). Results showed that self‐stigma, public stigma, and gender significantly predicted attitudes toward psychological help seeking. A test of mediation revealed that self‐stigma fully mediated the relationship between public stigma and attitudes toward psychological help seeking. Implications for college counseling professionals who serve SSM/V are discussed.
Responses of soil erosion to land‐use changes in the largest tableland of the Loess Plateau
Authors: Zhang Jianxiang , Wang Naiang , Wang Yafeng , Wang Linhua , Hu Aiping , Zhang Duoyong , Su Xianbao , Chen Junhe
Published: April 2021

Soil erosion is a global environmental problem, and land‐use changes have significantly altered soil erosion processes. However, soil erosion processes and their major influencing factors vary among different landforms. Dongzhiyuan (DZY), that is, the largest tableland in the Loess Plateau (LP), has experienced significant land‐use changes in previous decades. However, little is known about impacts of land‐use changes on soil erosion across different landforms in the DZY tableland. LANDSAT images from 1987, 1997, 2007, and 2017 were used to extract information on the land‐use changes in DZY. The decreases of farmland amount to 2.57 × 104 ha from 1987 to 1997, forest by 1.30 × 104 ha from 1997 to 2007, and grassland by 2.74 × 104 ha from 2007 to 2017. Urban areas increased by 1.41 × 104 ha from 1987 to 2017. The soil erosion estimated by the revised universal soil loss equation (RUSLE) and Chinese soil loss equation (CSLE) was 11.3 and 5.8 t ha−1 yr−1, respectively. The conversion from urban areas to farmland and grassland increased soil erosion. Changes from farmland to grassland and forest to grassland, intensified soil erosion; the severity of soil erosion depended on the intensity of the land‐use changes. Urban expansion caused a smaller decrease in soil erosion in the loess tableland, whereas vegetation restoration, to a large extent, decreased soil erosion in the loess gully area. Anthropogenic activity accelerated soil erosion before 1997, but slowed its influence after 1997. This study provides a reference for land‐use planning and soil water conservation in the LP.
Seasonal shifts of microbial methane oxidation in Arctic shelf waters above gas seeps
Authors: Gründger Friederike , Probandt David , Knittel Katrin , Carrier Vincent , Kalenitchenko Dimitri , Silyakova Anna , Serov Pavel , Ferré Bénédicte , Svenning Mette M. , Niemann Helge
Published: April 2021

The Arctic Ocean subseabed holds vast reservoirs of the potent greenhouse gas methane (CH4), often seeping into the ocean water column. In a continuously warming ocean as a result of climate change an increase of CH4 seepage from the seabed is hypothesized. Today, CH4 is largely retained in the water column due to the activity of methane‐oxidizing bacteria (MOB) that thrive there. Predicted future oceanographic changes, bottom water warming and increasing CH4 release may alter efficacy of this microbially mediated CH4 sink. Here we investigate the composition and principle controls on abundance and activity of the MOB communities at the shallow continental shelf west of Svalbard, which is subject to strong seasonal changes in oceanographic conditions. Covering a large area (364 km2), we measured vertical distribution of microbial methane oxidation (MOx) rates, MOB community composition, dissolved CH4 concentrations, temperature and salinity four times throughout spring and summer during three consecutive years. Sequencing analyses of the pmoA gene revealed a small, relatively uniform community mainly composed of type‐Ia methanotrophs (deep‐sea 3 clade). We found highest MOx rates (7 nM d−1) in summer in bathymetric depressions filled with stagnant Atlantic Water containing moderate concentrations of dissolved CH4 (< 100 nM). MOx rates in these depressions during spring were much lower (< 0.5 nM d−1) due to lower temperatures and mixing of Transformed Atlantic Water flushing MOB with the Atlantic Water out of the depressions. Our results show that MOB and MOx in CH4‐rich bottom waters are highly affected by geomorphology and seasonal conditions.
Development and validation of 3‐CpG methylation prognostic signature based on different survival indicators for colorectal cancer
Authors: Huang Hao , Zhang Lei , Fu Jinming , Tian Tian , Liu Xinyan , Liu Yupeng , Sun Hongru , Li Dapeng , Zhu Lin , Xu Jing , Zheng Ting , Jia Chenyang , Zhao Yashuang
Published: April 2021

Abnormal DNA methylation is considered a vital hallmark to regulate gene expression and influence the development and progression of colorectal cancer (CRC). Although CRC‐related methylation prognostic models have been developed, their clinical application is limited due to the lack of external validation and extension to other survival evaluation indicators. Therefore, this study aimed to develop and validate novel methylation prognostic models correlated with different survival indicators for individualized prognosis prediction for CRC patients. The prognostic‐related CpG sites of methylation‐driven genes screened by the MethylMix algorithm were identified and validated in The Cancer Genome Atlas (TCGA) CRC methylation data and our methylation data. The prognostic models correlated with different survival evaluation indicators (overall survival [OS] and disease‐free survival [DFS]) were developed and validated in the TCGA CRC dataset (N = 376) and our independent CRC dataset (N = 227). We utilized the combination of selected 3‐CpG methylation sites in three genes (DAPP1, FAM3D, and PIGR) to construct a prognostic risk‐score model. In the training dataset, Kaplan–Meier survival analysis demonstrated that high‐risk patients had significantly poorer survival than low‐risk patients (pOS = .0014; pDFS < .001). Then, the 3‐CpG methylation signature was successfully validated as an independent predictor in the testing data set (pOS = .016; pDFS = .016). A prognostic nomogram was constructed and validated. Additionally, mediation analysis revealed the direct effect of the methylation signature on CRC prognosis (pOS = 9.149e−06; pDFS = .001). In summary, our study revealed that the 3‐CpG methylation signature might be a potential prognostic indicator to facilitate individualized survival prediction for CRC patients.
The Neurophysiology of Sleep in Parkinson's Disease
Authors: Zahed Hengameh , Zuzuarregui Jose Rafael Pantoja , Gilron Ro'ee , Denison Timothy , Starr Philip A. , Little Simon
Published: April 2021

Sleep disturbances are among the most common nonmotor complications of Parkinson's disease (PD), can present in prodromal stages, and progress with advancing disease. In addition to being a symptom of neurodegeneration, sleep disturbances may also contribute to disease progression. Currently, limited options exist to modulate sleep disturbances in PD. Studying the neurophysiological changes that affect sleep in PD at the cortical and subcortical level may yield new insights into mechanisms for reversal of sleep disruption. In this article, we review cortical and subcortical recording studies of sleep in PD with a particular focus on dissecting reported electrophysiological changes. These studies show that slow‐wave sleep and rapid eye movement sleep are both notably disrupted in PD. We further explore the impact of these electrophysiological changes and discuss the potential for targeting sleep via stimulation therapy to modify PD‐related motor and nonmotor symptoms. © 2021 International Parkinson and Movement Disorder Society
Artificial neural networking (ANN) analysis for heat and entropy generation in flow of non‐Newtonian fluid between two rotating disks
Authors: Zhao Tie‐Hong , Khan M. Ijaz , Chu Yu‐Ming
Published: April 2021

Mixed convection is a mechanism of heat transport in a thermodynamic system in which the motion of fluid particles is produced by gravity as well as external forces like fans, pumps, or any other devices. Such type of heat transport has a fruitful application in daily life due to reliable maintenance. In this regard, numerous researchers and analyst have focused on the importance of mixed convective flow to explore its different aspects, and frequent research articles are published in this area. In this work, mixed convective entropy optimized nanomaterial magnetohydrodynamics (MHD) flow of Ree‐Eyring fluid is discussed between two rotating disks. The effects of porosity and velocity slip are considered. Both the disks are rotating with different angular frequency and stretching rates. Modeling is performed for the energy equation subject to heat generation/absorption, dissipation, radiative heat flux, and Joule heating. Four types of irreversibilities are discussed, and total entropy rate is calculated. The obtained results are compared with past studies and found good agreement with them. The physical curiosity like skin friction and Sherwood and Nusselt numbers are numerically calculated. Series solutions are computed via homotopy method. Our obtained outcomes show that the velocity and temperature fields show contrast behavior against larger magnetic parameter. It is also noticed that the entropy rate and Bejan number have opposite behaviors against higher values of Weissenberg number. The entropy rate increases for higher Weissenberg number while Bejan number decays.
Substantial, tempered, and shifted fractional derivatives: Three faces of a tetrahedron
Authors: Ortigueira Manuel D. , Bengochea Gabriel , Machado J. Tenreiro
Published: April 2021

The substantial, tempered, and shifted fractional derivatives, useful in medium range systems, are reviewed and highlighted in a unified framework. Their historical evolution is described and their properties studied. Moreover, they are characterized and assessed under the light of the strict sense criterion for the definition of derivatives. The relationship between these derivatives and several formulations developed in fractional calculus are explored. Additionally, the interpretations in the time and frequency domains are included. In the scope of the framework, new tempered linear systems and transfer functions are introduced. As particular applications, several systems for compensation and control purposes are revisited.
Motion of general non‐null curve in Minkowski 3‐spaces associated with Landau‐Lifshitz equation
Authors: Kelleci Akbay Alev , Yüzbaşi Zühal Küçükarslan , Cavlak Aslan Ebru
Published: April 2021

In that paper, firstly, we get two additional different non‐null space curve evolutions in Minkowski 3‐space by considering Landau–Lifshitz (LL) equation where we identify the spin vector with the binormal vector and the normal vector of these curves, respectively. Then, we obtain some links for constructing the moving non‐null space curves by using the integrable LL equation. Finally, we give as an application the exact solution of the moving non‐null curve evolutions obtained by taking the spin vector, the normal vector of the curve, and we showed graphically that these solutions are wave solutions.
Long‐term evolution of the chemical and structural stability of graphene oxide after storage as solid and as aqueous dispersion
Authors: Méndez‐Romero Ulises Antonio , Velasco‐Soto Miguel Angel , Licea‐Jiménez Liliana , González‐Hernández Jesús , Pérez‐García Sergio Alfonso
Published: April 2021

Nanomaterials are intended for industrial applications, for that purpose scalability needs to be addressed, therefore an important issue comes to the picture: storage. Graphene oxide (GO) is of great interest for practical applications in optoelectronics, chemical sensors, supercapacitor electrodes, among others. GO properties are related to its O/C ratio and its precise control allows fine tuning of properties such as conductivity, chemical reactivity and band gap. Nevertheless, GO has a critical storage restriction, due to its chemical self‐reduction, that is, the oxygen loss not only alters its properties, but also promotes aggregation through time. In this work, the impact of storage conditions on GO properties was studied by comparing two systems: a solid sample and a liquid dispersion, which were analyzed during the course of 3 years. For this purpose, stability, O/C ratio and optical band‐gap of the stored samples were analyzed through time by means of zeta potential, X‐ray photoelectron spectroscopy (XPS) and UV‐Vis. Results show the difference in stability between the samples due to oxygen loss in the GO structure, confirmed by XPS. Moreover, optical band‐gap shows that the solid sample decreases its value around 64% compared to the liquid dispersion.
Cyanotoxin Response Leads to Successful Resilience Planning
Authors: Johnson Christopher , Davis Jason , Sherman Timothy
Published: April 2021

Although Salem, Ore., had a well‐designed monitoring and treatment process in place, an algal bloom with historic consequences led the city to implement immediate mitigation measures and establish a long‐term strategy for meeting future water quality challenges.