bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman 18O‐labeling of bacteria in visible and deep UV‐ranges
Authors: Azemtsop Matanfack Georgette , Pistiki Aikaterini , Rösch Petra , Popp Jürgen 
Published: March 2021

AbstractRaman stable isotope labeling with 2H, 13C or 15N has been reported as an elegant approach to investigate cellular metabolic activity, which is of great importance to reveal the functions of microorganisms in native environments. A new strategy termed Raman 18O‐labeling was developed to probe the metabolic activity of bacteria. Raman 18O‐labeling refers to the combination of Raman microspectroscopy with 18O‐labeling using H218O. At an excitation wavelength of 532 nm, the incorporation of 18O into the amide I group of proteins and DNA/RNA bases was observed in Escherichia coli cells, while for an excitation wavelength electronically resonant with DNA or aromatic amino acid absorption at 244 nm 18O assimilation was detected using chemometric tools rather than visual inspection. Raman 18O‐labeling at 532 nm combined with 2D correlation analysis confirmed the assimilation of 18O in proteins and nucleic acids and revealed the growth strategy of E. coli cells; they underwent protein synthesis followed by nucleic acid synthesis. Independent cultural replicates at different incubation times corroborated the reproducibility of these results. The variations in spectral features of 18O‐labeled cells revealed changes in physiological information of cells. Hence, Raman 18O‐labeling could provide a powerful tool to identify metabolically active bacterial cells.
Enhancing the soft‐tissue integration of dental implant abutments—in vitro study to reveal an optimized microgroove surface design to maximize spreading and alignment of human gingival fibroblasts
Authors: Doll Patrick W. , Husari Ayman , Ahrens Ralf , Spindler Bruno , Guber Andreas E. , Steinberg Thorsten 
Published: March 2021

AbstractWithin this work, we demonstrate the influences of different microgrooved surface topographies on the alignment and spreading of human gingival fibroblast (HGF) cells and present the optimal parameters for an improved soft‐tissue integration design for dental implant abutments for the first time. Microgrooves with lateral widths from 2.5 to 75 μm were fabricated by UV‐lithography and wet etching on bulk Ti6Al4V ELI material. The microstructured surfaces were compared to polished and ground surfaces as current state of the art. The resulting microtopographies were analyzed using vertical scanning interferometry and scanning electron microscopy. Samples loaded with HGF cells were incubated for 8 and 72 hr and cell orientation, spreading, resulting area, and relative gene expression were analyzed. The effect of contact guidance occurred on all microstructured surfaces yet there is a clear preferable range for the lateral widths of the microgrooves between approx. 11.5 and 13.9 μm and depths between 1.6 and 2.4 μm for an abutment surface design, where cell orientation and spreading maximizes. For structures larger than 30 μm, cell orientation, spreading and even gene expression of intercellular adhesion molecule‐1 and yes‐associated protein decrease.
COVID‐19 pandemic and its impact on dental students: A multi‐institutional survey
Authors: Klaassen Hannah , Ashida Sato , Comnick Carissa L. , Xie Xian Jin , Smith Becky M. , Tabrizi Maryam , Arsenault Karin , Capin Oriana R. , Scully Allison C. , da Mata Cristiane , Soto Annetty P. , Dias Ribeiro Ana Paula , Prince David , Christensen Angela , Giner‐Tarrida Lluís , Satorres Nieto Marta , León Soraya , Gambetta‐Tessini Karla , Santos Mateus B. F. , Dias da Silva Marco Antonio , Pereira Andresa C. , Dias do Carmo Elaine , Aurora Stabile Gonnelli Fernanda , Carvalho Fabíola G. , Collares Kaue , Bervian Juliane , Sarkis‐Onofre Rafael , Jerfeson dos Santos Gonçalves Francisco , Bueno‐Silva Bruno , Estela Haddad Ana , Gurgel Bruno César de Vasconcelos , Alves Polliana M. , Shigli Kamal , Nayak Sushma S. , Nayak Prajna P. , Murugaboopathy Vikneshan , Savitha PN , Murthy Varsha , Deshpande Saee , Marchini Leonardo 
Published: March 2021

AbstractPurpose/objectivesTo investigate dental students’ perceptions and concerns regarding the COVID‐19 pandemic, their coping strategies and support resources, and their perceived stress levels.MethodsA customized 19‐item survey and the perceived stress scale (PSS) were applied to undergraduate dental students from the US, Spain, Ireland, Chile, India, and Brazil between April 10 and July 5, 2020. Linear modeling and mediation analysis were used to explore the relationships among demographics, stressors, coping mechanisms, social support, and stressResultsA total of 4475 students responded to the survey. The majority (72.4%) were women, and 52.3% had no COVID‐19 training at the time of the survey. The students reported that they had to accommodate to changes in patient care (96.6%) and didactic learning (95.2%) activities, while 88.5% of the respondents indicated at least one of their courses moved online. Transition to online courses went “smoothly with some troubles” for 51.8% of the respondents, and 48.3% perceived the faculty as prepared for the online transition; however, 45.9% reported feeling extremely concerned about the impact of COVID‐19 on their education. The average PSS score was 21.9 of 40 (moderate stress). Multivariate models were built for participants with full data (n = 3899). Being male, having completed more dental coursework, and perceiving a smoother transition were associated with lower PSS scores; more concern about academic progress was associated with higher PSS. Faculty support mediated the relationship between a smoothness of transition and concern about academic progress and PSS scoresConclusionStress caused by the pandemic may be alleviated by smoother transition and good faculty support.
Striped catfish (Pangasianodon hypophthalmus) use air‐breathing and aquatic surface respiration when exposed to severe aquatic hypercarbia
Authors: Morgan Rachael , Tunnah Louise , Tuong Dang D. , Hjelmstedt Per , Nhu Pham N. , Stiller Kevin T. , Phuong Nguyen Thanh , Huong Do Thi Thanh , Bayley Mark , Wang Tobias , Milsom William K. 
Published: March 2021

AbstractWe investigated the extent to which the facultative air‐breathing fish, the striped catfish (Pangasianodon hypophthalmus), uses air‐breathing to cope with aquatic hypercarbia, and how air‐breathing is influenced by the experimental exposure protocol and level of hypercarbia. We exposed individuals to severe aquatic hypercarbia (up to PwCO2 = 81 mmHg) using step‐wise and progressive exposure protocols while measuring gill ventilation rate, heart rate, mean arterial blood pressure, and air‐breathing frequency, as well as arterial blood pH and PCO2. We confirm that P. hypophthalmus is tolerant of hypercarbia. Under both protocols gill ventilation rate, heart rate, and mean arterial blood pressure were maintained near control levels even at very high CO2 levels. We observed a marked amount of individual variation in the PwCO2 at which air‐breathing was elicited, with some individuals not responding at all. The experimental protocol also influenced the onset of air‐breathing. Air‐breathing began at lower PwCO2 in the step‐wise protocol (23 ± 4.1 mmHg) compared with the progressive protocol (46 ± 7.8 mmHg). Air‐breathing was often followed by aquatic surface respiration, at higher PCO2 (71 ± 5.2 mmHg) levels. On average, the blood PCO2 was approximately 43% lower (46 ± 2.5 mmHg) than water PwCO2 (~81 mmHg) at our highest tested CO2 level. While this suggests that aerial CO2 elimination is an effective, and perhaps critical, respiratory strategy used by P. hypophthalmus to cope with severe hypercarbia, this observation may also be explained by a long lag time required for equilibration.
Effects of change in temperature on the cardiac contractility of broad‐snouted caiman (Caiman latirostris) during digestion
Authors: Lopes André G. , Monteiro Diana A. , Kalinin Ana L. 
Published: March 2021

AbstractIn many reptiles, digestion has been associated with the selection of higher body temperatures, the so‐called post‐prandial thermophilic response. This study aimed to investigate the excitation–contraction (E–C) coupling in postprandial broad‐snouted caimans (Caiman latirostris) in response to acute warming within a preferred body temperature range of crocodiles. Isometric preparations subjected to a temperature transition from 25°C to 30°C were used to investigate myocardial contractility of postprandial caimans, that is, 48 h after the animals ingested a rodent meal corresponding to 15% of body mass. The caiman heart exhibits a negative force–frequency relationship that is independent of the temperature. At 25°C, cardiac muscle was able to maintain a constant force up to 36 bpm, above which it decreased significantly, reaching minimum values at the highest frequency of 84 bpm. Moreover, E–C coupling is predominantly dependent on transsarcolemmal Ca2+ transport denoted by the lack of significant ryanodine effects on force generation. On the contrary, ventricular strips at 30°C were able to sustain the cardiac contractility at higher pacing frequencies (from 12 to 144 bpm) due to an important role of Na+/Ca2+ exchanger in Ca2+ cycling, as indicated by the decay of the post‐rest contraction, and a significant contribution of the sarcoplasmic reticulum above 72 bpm. Our results demonstrated that the myocardium of postprandial caimans exhibits a significant degree of thermal plasticity of E–C coupling during acute warming. Therefore, myocardial contractility can be maximized when postprandial broad‐snouted caimans select higher body temperatures (preferred temperature zone) following feeding.
Nrf2 activates antioxidant enzymes in the anoxia‐tolerant red‐eared slider turtle, Trachemys scripta elegans
Authors: Breedon Sarah A. , Hadj‐Moussa Hanane , Storey Kenneth B. 
Published: March 2021

AbstractThe freshwater red‐eared slider turtle, Trachemys scripta elegans, experiences weeks to months of anoxia at the bottom of ice‐locked bodies of water in the winter. While this introduces anoxia‐reoxygenation cycles similar to the ischemia‐reperfusion events that mammals experience, T. s. elegans does not suffer any apparent tissue damage. To survive prolonged anoxia and prevent cellular damage associated with reactive oxygen species, these turtles have developed numerous adaptions, including highly effective antioxidant defenses. Herein, we examined the subcellular localization and protein expression of nuclear factor erythroid‐2‐related factor 2 (Nrf2), a central transcription factor responsible for modulating cellular antioxidant responses, that was found to be upregulated and localized to the nucleus in anoxic turtles. Additionally, we examined protein levels of glutathione S‐transferases (GSTs) and manganese superoxide dismutase (MnSOD) antioxidant enzymes in anoxic liver, kidney, heart, and skeletal muscle tissues. MnSOD levels were significantly higher in heart and muscle during anoxia, and the four GST isozymes (GSTK1, GSTT1, GSTP1, and GSTM3) were elevated in a tissue‐specific manner during anoxia and/or aerobic recovery. Together, these results indicate that Nrf2 is likely involved in activating downstream antioxidant genes in response to anoxic stress. These results provide a possible Nrf2‐mediated transcriptional mechanism that supports existing findings of enhanced antioxidant defenses that allow T. s. elegans to cope with anoxia‐reoxygenation cycles, and subsequent oxidative stress.
On the sequence heterochrony of cranial ossification of bats in light of Haeckel's recapitulation theory
Authors: Nojiri Taro , Tu Vuong Tan , Sohn Joon Hyuk , Koyabu Daisuke 
Published: March 2021

AbstractHaeckel's recapitulation theory has been a controversial topic in evolutionary biology. However, we have seen some recent cases applying Haeckel's view to interpret the interspecific variation of prenatal ontogeny. To revisit the validity of Haeckel's recapitulation theory, we take bats that have undergone drastic morphological changes and possess a characteristic ecology as a case study. All members of Rhinolophoidea and Yangochiroptera can generate an ultrasonic pulse from the larynx to interpret surrounding objects (laryngeal echolocation) whereas Pteropodidae lacks such ability. It is known that the petrosal bone is particularly derived in shape and expanded in laryngeal echolocators. If Haeckel's recapitulation theory holds, the formation of this derived trait should occur later than those of other bones. Therefore, we compared the prenatal ossification timing of the petrosal in 15 bat species and five outgroup species. We found that the ossification of the petrosal is accelerated in laryngeal echolocators while it is the last bone to ossify in non‐laryngeal echolocating bats and non‐volant mammals, which runs counter to the prediction generated by Haeckel's recapitulation theory. We point out the evolutionarily labile nature of trait developmental timing and emphasize that Haeckel's recapitulation theory does not hold in many cases. We caution that generating predictions on ancestral conditions and evolutionary history leading from Haeckel's recapitulation theory is not well supported.
Validation of the liver traffic light test as a predictive model for survival and development of liver‐related events
Authors: Sylvester Rochelle , Hydes Theresa J , Hales Alan , Williams Roger , Sheron Nick 
Published: March 2021

AbstractBackground and AimLiver disease mortality rates continue to rise due to late diagnosis. We need noninvasive tests to be made available in the community that can identify patients at risk from a serious liver‐related event (SLE). We examine the performance of a blood test, the liver traffic light test (LTLT), with regard to its ability to predict survival and SLEs.MethodsUsing routinely gathered clinical data, sequential LTLT test results from 4854 individuals with suspected liver disease were prospectively analyzed (median follow‐up 41 months). An SLE was defined as the development of cirrhosis, liver failure, ascites, or varices. Patients were graded as follows: red (high risk), amber (intermediate risk), and green (low risk).ResultsOverall, 565 individuals experienced an SLE (11.6%). The area under the curve (AUC) for the continuous LTLT variable was 0.87 (95% confidence interval 0.85–0.89) for prediction of an SLE and 0.81 (0.78–0.84) for mortality. When categorized into red/amber/green grades, a red LTLT result predicted an SLE with negative and positive predictive values of 0.97 and 0.29, respectively. A red LTLT score predicted mortality with negative and positive predictive values of 0.98 and 0.18, respectively. Kaplan–Meier plots demonstrated increased mortality and SLEs in the red group versus the green and amber groups (P < 0.001) and an increase in SLEs in the amber versus green group (P < 0.001).ConclusionHere, the LTLT is further validated for the prediction of survival and SLE development. The LTLT could aid primary care risk management and referral pathways with the aim of detecting and treating liver disease earlier in the general population.
High prevalence of anal high‐risk HPV infection among transwomen: estimates from a Brazilian RDS study
Authors: Jalil Emilia M , Wilson Erin C , Monteiro Laylla , de Velasque Luciane S , Ferreira Ana Cristina G , Nazer Sandro C , Friedman Ruth K , Veloso Valdilea G , Levi José Eduardo , Grinsztejn Beatriz 
Published: March 2021

AbstractIntroductionAs the leading sexually transmitted infection worldwide, human papillomavirus (HPV) may disproportionately affect transwomen. We aimed to estimate anal HPV prevalence, especially focusing on high‐risk (hr)‐HPV types and evaluate their associated factors among transwomen living in Rio de Janeiro, Brazil.MethodsTranswomen enrolled in a respondent‐driven sampling (RDS)‐based survey conducted between August 2015 and January 2016 self‐collected anal samples, which were promptly stored at minus 80°C. After DNA extraction, HPV detection and genotyping were performed using the PapilloCheck test. We estimated HPV prevalences and evaluated the correlates of anal hr‐HPV infection using a regression logistic model.ResultsOut of 345 transwomen, 272 (78.8%) were included in this analysis (122 [44.9%] HIV‐positive). No participant had ever received HPV vaccination. Among participants enrolled, 212 (77.9%) were positive for any anal HPV type and 165 (60.7%) for hr‐HPV. Most common hr‐HPV were as follows: HPV16 (17.6%), HPV68 (14.7%), HPV39 (14.3%), HPV56 (12.5%), HPV51 (11.4%) and HPV52 (11.0%). HIV‐positive transwomen had three times the odds of having an hr‐HPV compared to HIV‐negative transwomen. Participants who had a current rectal Neisseria gonorrhoeae infection had 3.7 times the odds of being coinfected with hr‐HPV. Among HIV‐positive transwomen, neither antiretroviral therapy use, undetectable viral load, current and nadir CD4 counts were associated with anal hr‐HPV infection.ConclusionsBrazilian transwomen in our study exhibit some of the highest population‐specific rates of HPV and hr‐HPV. There is an urgent need to elucidate the burden of HPV infection, prevalence of HPV‐related diseases and access to and uptake of HPV vaccination among transwomen, especially from low‐ and middle‐income settings.
Do demographics influence workforce agility score of tax professionals in Bangalore, India?
Authors: Thayyib P. V. , Khan Mohd Asif 
Published: March 2021

AbstractHandling an unpredictable and ever‐changing environment has become a pressing issue for the tax consulting industry, which has experienced unprecedented changes in technology and working practices in recent years. To respond, tax consulting firms need to become more agile. Prior research has focused on workforce agility at the organizational level, paying little attention to agility at the individual level; here we set out to examine the influence of demographic factors on workforce agility. The study is based on data from 220 full‐time tax professionals in Bangalore, India, and validates a workforce agility score developed by combining seven attributes of workforce agility. It looks at the influence of age, professional qualifications, employer type, service type, and job level on agility level. The results show that workforce agility varies significantly across four out of these five dimensions (except service type) and both confirms and challenges previous work. This research also offers managers insights into the key demographics, skills, and attributes required to achieve workforce agility in technology‐driven environments such as tax consulting.
Aspects of Talc Grinding in the Presence of Sodium Dodecyl Sulfonate
Authors: Farag Reham M. , El‐Midany Ayman A. 
Published: March 2021

AbstractIn this study, the effect of sodium dodecyl sulfonate (SDS), as a well‐known flotation collector, on talc grinding was investigated using a statistical design in terms of solids%, pH, grinding time, and SDS dosage taking the d80 of the ground product as a response. The results indicated that the factors under study significance order were grinding time > solids% > SDS dosage > pH. In addition, the interactions between solids % and the grinding time and between the solids% and SDS dosage significantly affected the product d80. More interestingly, the presence of SDS not only improves the grinding process at short grinding times but also it enhances the grinding at higher pH values. The optimum conditions for talc grinding are similar in the absence or presence of SDS in terms of factors under study, except for solids%. The vital role of SDS, as a grinding aid, is the production of particles with the same fineness or even finer at higher solids % which leads to an increase in the mill throughput. The smallest d80 was obtained at 60% solids, 60 min, pH 4, and 2 kg t−1 of SDS.
Surface and Biocidal Properties of Gemini Cationic Surfactants Based on Propoxylated 1,6‐Diaminohexane and Alkyl Bromides
Authors: Rahimov Ravan A. , Ahmadova Gulnara A. , Hashimzade Seyid‐Zeynab F. , Imanov Elmar , Khasiyev Hajibala G. , Karimova Nazani K. , Zubkov Fedor I. 
Published: March 2021

AbstractTwo new classes of gemini cationic surfactants—hexanediyl‐1,6‐bis[(isopropylol) alkylammonium] dibromide {in the abbreviation form: CnC6Cn[iPr‐OH] and CnC6Cn[iPr‐OH]2; alkyl: CnH2n + 1 with n = 9, 10, 12 and 14}—have been synthesized by interaction of alkyl bromides with N,N′‐di‐(isopropylol)‐1,6‐diaminohexane and N,N,N′,N′‐tetra‐(isopropylol)‐1,6‐diaminohexane. The surface tension, electrical conductivity, and dynamic light scattering (DLS) techniques were used to investigate the aggregation properties of the gemini cationic surfactants in aqueous solution. The formation of critical aggregates at two concentrations in an aqueous solution from obtained gemini cationic surfactants were determined via the tensiometric method. Thus, these gemini cationic surfactants start to form aggregates at concentrations well below their critical micelle concentrations (CMC). The surface properties and the binding degree (β) of the opposite ion were tested against the length of the surfactant hydrocarbon chain and the number of the isopropylol groups in the head group. By applying the DLS technique, it was explored that how the number of isopropylol groups in gemini cationic surfactants with C12H25 chain affects the sizes of micelles at concentrations greater than CMC. It was discovered that the obtained gemini cationic surfactants have a biocidal character.
Interactions between Anionic Polyacrylamide and Cationic Gemini/Conventional Surfactants
Authors: Nishat Afreen , Azum Naved , Asiri Abdullah M. , Sardar Najam 
Published: March 2021

AbstractThe interaction of anionic polymer polyacrylamide and cationic Gemini surfactants, namely: α,ω‐bis(hexadecyldimethylammonium)alkane dibromides, (16‐s‐16), s = 5, 6 and their conventional counterpart cetyltrimethylammonium bromide (CTAB) has been investigated by electrical conductivity, rheology, and scanning electron microscopy (SEM) techniques. Stronger interaction of Gemini surfactants in comparison to their conventional counterpart CTAB was observed from conductivity studies, while viscosity studies show that the interaction is quite significant with Gemini surfactants. The thermodynamic parameters for interactions show feasibility of interaction between the polymer and surfactant. SEM results support the viscosity data.
Aberration‐free pupil steering Maxwellian display with wide‐view broadband polarization converters
Authors: Xiong Jianghao , Li Yannanqi , Li Kun , Wu Shin‐Tson 
Published: March 2021

AbstractA see‐through Maxwellian display with aberration‐free pupil steering is proposed and experimentally demonstrated. The system uses a polarization‐dependent off‐axis lens coupler set fabricated with cholesteric liquid crystal. Electrically addressable polarization converters are used to switch among pupils. A wide‐view broadband polarization converter is designed accordingly.