bluuebunny/crossref_metadata_2025 huggingface dataset:
Tatar influence upon the formation of the Russian postal (yamskaya) system: historiography of the problem
Authors: Hu Weiyang
Published: April 2021

Yamskaya mail delivery as the postal communication system played an important role for the Russian State. The word “yam” is of Turkic origin. The Tatar post stations were known as “yamy”. In order to understand the degree of influence of the Golden Horde on the Russian lands, it is crucial to understand what influence the Tatar (yamskaya) postal system had upon the formation of the Russian postal (yamskaya) service. This question has the scholars’ attention; however, there is yet no uniform opinion. The subject of this research is the factor of the Tatar influence upon establishment of the Russian postal (yamskaya) system. The object is the scientific works of pre-revolutionary, Soviet, and modern Russian scholars on the topic. The studies are demonstrated in chronological order. The article employs the traditional methods of historiographical research: historical-narrative and historical-comparative. As a result, the author determines the three groups of researchers: 1) Scholars, who recognize the considerable influence of the conquerors upon the formation of the Russian postal (yamskaya) service. Their conclusions indicate direct participation of Tatars in establishment of the Russian postal system, or taking the Mongolian system as an example; 2) Historians who denied the influence of the Tatar postal (yamskaya) system upon the formation of the Russian postal service. 3) Researchers who believe that the influence of the conquerors was significant, however not determinant for the Russian postal service. The experts underline the borrowing of terminology and introduction of the new postal tax.
Soviet Church diplomacy in the SFRY in 1948-1953 in the context of the international situation of the USSR
Authors: Pashkov Nikodim Olegovich , Novikov Oleg Alekssevich
Published: April 2021

The subject of this article is a historical and political study of the key vectors of the state-confessional policy of the USSR in the countries of "people's democracy", which received their practical embodiment within the framework of prevailing legal practices. Special attention is paid to the study of the intervention of Soviet diplomacy in state-confessional relations on the territory of socialist Yugoslavia. After the end of World War II, one of the largest religious organizations of the Yugoslav state, the Serbian Orthodox Church, faced numerous historical challenges. The course of the historical process pushed this religious organization into opposition to the political elite of Yugoslavia. Numerous external "players" sought to take advantage of this situation, including the Soviet Union, whose relations with Yugoslavia significantly worsened during the period under study. The main method used in the preparation of the article was comparative historical. The novelty of the research lies in the study of the relationship of political and ideological discourses of state-confessional relations of the mid-twentieth century with modern practices of state confessional policy of the Russian Federation. The study of the genesis and practical implementation of the main vectors of "confessional diplomacy" of the Soviet Union is primarily connected with the practical implementation of Marxist political and legal ideas, in the field of "political compromise" with the "capitalist world". The key conclusion of the article: in the international "confessional diplomacy" of the Soviet Union, the Russian Orthodox Church has historically served as its instrument and an expression of the interests of the ruling political regime in the USSR, which influenced both the international position of the ROC and its internal state.
Reception of the novel “What is to be Done?” by N. G. Chernyshevsky: “new people” in the Soviet dramaturgy of the 1920s – 1930s
Authors: Romanova Ekaterina , Gubina Nina
Published: April 2021

The goal of this research is to reveal the peculiarities of reception of the novel “What is to be Done?” by N. G. Chernyshevsky in the Soviet dramaturgy of the 1920s – 1930s. These texts fully reflect the concept of state order, the pursuance of “socialist realist” normatization, and thus, most vividly demonstrate the specificity of functionality of the fundamental mythological concepts in semantic field of the Soviet literature. Particular attention is given to the plays by V. N. Bill-Belocerkovskij and A. Glebov. The article also employs the works of A. Neverov, V. Vishnevsky, A. Afinogenov, who largely determined the dramaturgical image of their time. The work is conducted within the framework of the mythopoetic approach, using structural-semiotic and intertextual methods. The relevance is substantiated by the need for a more comprehensive examination of the literary discourse of the 1920s – 1930s. The scientific novelty consists in attraction of an array of little studied texts of the “official” Soviet dramaturgy for identification of the cultural and literary sources of the image of “new people”, which determined the functionality of this mythologem in the literary discourse of the 1920s – 1930s. The conducted research demonstrated that in the period of post-revolutionary culture, the novel “What is to be Done?” by N. G. Chernyshevsky acquires the status of a sacred text, becomes the focus of intertextual overlap of dramaturgical texts, as well as one of the foundations for the formation of the Communist myth of the “new people” common to literature of that time. The works of the official Soviet playwrights are characterized by the declaration of continuity with regards to the novel, which in their works is demonstrated on the level of plot, themes, ideas, particular images, and separated details.
“Own” and “alien” space in the novel “Dead Men Walking” by Steve Lyons
Authors: Vasil'ev Evgenii Vadimovich
Published: April 2021

The subject of this research is the peculiarities of organization of space in the novel “Dead Men Walking” by Steve Lyons from the perspective opposition “own – alien”. The research employs the cultural-historical method and comparative analysis. The article examines the peculiarities of perception of space in the novel. The basic conflict is association with intervention of the alien civilization on the planet of people. Emphasis is placed on the fact that the war erases the boundaries of “own” and “alien”, each of parties to the conflict has reason to believe that the planet is “their own”. The characters of the novel are divided into “living” and “dead”, which complicates the conflict and organization of space even more. Space in the literary text is the subject of multiple scientific articles. However, the works dedicated to examination of space in S. Lyons’ novel are not featured in modern literary studies, which defines the scientific novelty of this research. The conclusion is drawn that  for humanity and for alien civilization space is simultaneously “own” and “alien”, since other civilization existed on the planet for a long time prior to the arrival of humans. Moreover, the organization of space is complicated by the arrival of human forces of rom other planet, who were unfamiliar with the concept of “own” space at all, which affects the course of war and determines the fate of the characters in the novel. Such approach demonstrates that the concept of “own” and “alien” in the novel is vague due to the fact that it is impossible to unambiguously attribute the planet neither to “own” nor “alien” space.
“Unfathomable Event of the Fatal Time” or the Russian theme in the novella “Vision” by in E. T. A. Hoffmann
Authors: Il'chenko Natal'ya Mikhailovna
Published: April 2021

The relevance of this research is defined by the scientific significance of the problem of Germany-Russia relations as an important factor of cross-cultural interaction. Dresden has imprinted hundreds of Russian names. This found reflection in the novel “Vision” by E. T. A. Hoffmannn, inspired by the experiences during his life in Dresden. The German romanticist appeared to be in the center of anti-Napoleonic War for a few month in 1813. Hoffmann also expressed his emotions in letters, diary notes, and publicistic texts. The “Unfathomable Event” of the novella “Vision” allowed avoiding unambiguity of explanation of the “fatal, difficult, and turbulent time”, as well as preserving the magic of the fantastic. It is noted that E. T. A. Hoffmann described in the novel and related texts the situations borrowed from life, reminiscences of the parlous Dresden days. At the same time, he highlighted the liberation mission of the Russian troops. Special attention is given to application of the so-called Serapiontic principle, which implies the transformation of reality in the consciousness of the imaginative nature. The novelty of this research consists in observation that the fantastic event described in the novel, turned Hoffmann into the “translator” of the meaning of feat of the Russian participants of the Liberation wars in the language of images. Such approach presented the peculiarities of development of the Russian theme and Russian literary images in the works of the German romanticist in the historical perspective.
Middle Eastern Chronotope in the prose of S. S. Kondurushkin of the turn of the XIX-XX centuries: to articulation of the problem
Authors: Vladimirova Svetlana Mikhailovna , Dubrovskaya Svetlana Anatol'evna , Dubrovskaya Dina Andreevna
Published: April 2021

The object of this research is the early prose of S. S. Kondurushkin (1874-1919), journalist and writer, who served five years as a teacher in the schools of the Middle East, an active participant in Russia’s literary-social life, an employee of the newspaper “Rech”, war correspondent, author of several compilations dedicated to the Middle East, Russian Volga Region, Novaya Zemlya, and Siberia. The subject of this research is the techniques and approaches of creating the Middle East in the essays and stories, which were published for the first time in the journals “Russian Wealth”, “Russian Thought”, and “History Herald”. Reference of the Russian writer to the problems of the Middle East at the turn of the XIX – XX centuries, development of artistic techniques, reconstruction of the flavor and the corresponding elements of the narrative require indicating the methodology used in the article. Along with the traditional for academic literary studies comparative-historical, historical-cultural, imageological and biographical methods, the author turns to the colonial/postcolonial, as well as imperial/post-imperial formats of research, micro-history approach, “deliberate” and "distant” reading, as well as holistic analysis. The article is first to examine the artistic peculiarities of the early prose of S. S. Kondurushkin in the context of his interest in problems of the Middle East. Special attention is given to analysis of the essay “Damascus” (1903) that demonstrates that everyday life of the religion serves for the writer as a part of the Middle Eastern chronotope, within the structure of which there are not only historical time with its transformations, not only historical space and its modern modifications, but also the current events. Such articulation of the problem defines the novelty of this research and outlines its  prospects in further examination of the Middle Eastern chronotope of Russian literature of the turn of the XIX – XX centuries, and academic pursuits dedicated to the creative path of S. S. Kondurushkin
Childhood apraxia of speech evaluation in autism spectrum disorders: three clinical cases report
Authors: Martins Fernanda Cristina Reis Merli , Machado Fernanda Prada , Silva Caroline Santos Rodrigues da , Palladino Ruth Ramalho Ruivo
Published: April 2021

Introduction: Among the communication impairments found in subjects with Autism Spectrum Disorders (ASD), recently the literature has suggested a comorbid relationship with childhood apraxia of speech (CAS). The aim of the present study was to report the CAS assessment of 3 children diagnosed with ASD. Report: The subjects were three children aged 4 to 6 years, with a medical diagnosis of ASD. The language development assessment (LDA) was performed in the subjects, as well as the ABFW vocabulary evaluation and oral praxis (verbal, orofacial, a sequence of movements, and parallel movements) and evaluation of vocal, prosodic, and speech characteristics. All subjects had moderate language delay with better performance in the receptive area. Difficulties in oral praxis tasks were more evident in one of the subjects. Vocal, prosodic and speech features of all the cases were compatible with CAS. Conclusion: In the 3 cases reported, CAS signs were identified with impaired oral motor skills, prosody, and oral praxis, as well as inconsistent speech sound production.
Primary headache and factors associated in university students: a cross sectional study
Authors: Vitta Alberto de , Biancon Rangel dal Bello , Cornélio Guilherme Porfírio , Bento Thiago Paulo Frascareli , Maciel Nicoly Machado , Perrucini Priscila de Oliveira
Published: April 2021

Introduction: Primary headaches, defined as disorders in themselves caused by independent pathomechanisms and not by other disorders, are prevalent in university students and considered one important health problems in the world. Objective: To investigate the prevalence of primary headaches and analyze associations with sociodemographic characteristics and the use of electronic devices by university students. Methods: A cross-sectional observational study analysis was carried out with a sample of 1,143 students of both genders who responded to the questionnaire on demographic, socioeconomic aspects, use of electronic devices, and on the primary headaches. Descriptive analysis, bivariate analysis, and Poisson regression were performed. Results: The overall prevalence of primary headache of 60.7%, being that, in relation to the type, 33.2% presented tension-type headache, 54.3% migraine, and 12.3% other types of headache. Regression analysis showed that female gender and income of up to two minimum wages were associated with primary headache and migraine type. The primary headache was associated with subjects of the white race; watching television and playing video games for more than 3 hours per day, for example. The sitting posture, semi-lying down, and distance from the eyes to the mobile phone and tablet longer than 20 cm were associated with primary headache and the three types of headaches. Conclusion: The results allow us to conclude that there is a high prevalence of primary headaches in college students and that socioeconomic factors related to the use of electronic devices are associated with the presence of primary headaches.
COVID-19 and the incidence of neglected tropical diseases: reflections from pandemic times
Authors: Santos Gessi Carvalho de Araújo , Mariano Sandra Maria Botelho , Silva José Bruno Nunes Ferreira
Published: April 2021

not applicable
Stimulus-dependent relationships between behavioral choice and sensory neural responses
Authors: Chicharro Daniel , Panzeri Stefano , Haefner Ralf M
Published: April 2021

Understanding perceptual decision-making requires linking sensory neural responses to behavioral choices. In two-choice tasks, activity-choice covariations are commonly quantified with a single measure of choice probability (CP), without characterizing their changes across stimulus levels. We provide theoretical conditions for stimulus dependencies of activity-choice covariations. Assuming a general decision-threshold model, which comprises both feedforward and feedback processing and allows for a stimulus-modulated neural population covariance, we analytically predict a very general and previously unreported stimulus dependence of CPs. We develop new tools, including refined analyses of CPs and generalized linear models with stimulus-choice interactions, which accurately assess the stimulus- or choice-driven signals of each neuron, characterizing stimulus-dependent patterns of choice-related signals. With these tools, we analyze CPs of macaque MT neurons during a motion discrimination task. Our analysis provides preliminary empirical evidence for the promise of studying stimulus dependencies of choice-related signals, encouraging further assessment in wider data sets.
Membrane transporter dimerization driven by differential lipid solvation energetics of dissociated and associated states
Authors: Chadda Rahul , Bernhardt Nathan , Kelley Elizabeth G , Teixeira Susana CM , Griffith Kacie , Gil-Ley Alejandro , Öztürk Tuğba N , Hughes Lauren E , Forsythe Ana , Krishnamani Venkatramanan , Faraldo-Gómez José D , Robertson Janice L
Published: April 2021

Over two-thirds of integral membrane proteins of known structure assemble into oligomers. Yet, the forces that drive the association of these proteins remain to be delineated, as the lipid bilayer is a solvent environment that is both structurally and chemically complex. In this study, we reveal how the lipid solvent defines the dimerization equilibrium of the CLC-ec1 Cl-/H+ antiporter. Integrating experimental and computational approaches, we show that monomers associate to avoid a thinned-membrane defect formed by hydrophobic mismatch at their exposed dimerization interfaces. In this defect, lipids are strongly tilted and less densely packed than in the bulk, with a larger degree of entanglement between opposing leaflets and greater water penetration into the bilayer interior. Dimerization restores the membrane to a near-native state and therefore, appears to be driven by the larger free-energy cost of lipid solvation of the dissociated protomers. Supporting this theory, we demonstrate that addition of short-chain lipids strongly shifts the dimerization equilibrium toward the monomeric state, and show that the cause of this effect is that these lipids preferentially solvate the defect. Importantly, we show that this shift requires only minimal quantities of short-chain lipids, with no measurable impact on either the macroscopic physical state of the membrane or the protein's biological function. Based on these observations, we posit that free-energy differentials for local lipid solvation define membrane-protein association equilibria. With this, we argue that preferential lipid solvation is a plausible cellular mechanism for lipid regulation of oligomerization processes, as it can occur at low concentrations and does not require global changes in membrane properties.
Language mechanisms of building the ironic texts and ways of their linguistic research (linguistic pragmatic aspect)
Authors: Chernyshova Tatiana Vladimirovna
Published: April 2021

The article is devoted to the study of means and ways of modeling the comic effect in contemporary ironic media texts as well as to characterizing the method of their linguistic description in the linguistic pragmatic aspect. Special attention is paid to the ways of linguistic analysis of the conflict in ironic media text, which is the object of a court case. Within the complex linguistic analysis, including the semantic analysis to reveal the “semantic aspects,” and on the material of the editions Kommersant and Moskovsky Komsomolets, the authors described the signals of irony as language play and as a socially marked way of communication, defining their stylistic variety. On the example of ironic media text which is the object of a court case, it is established that the basic way to model the comic (ironic) subtext in contemporary media texts is the contrast used both at textual and subtextual levels. The article draws the conclusion that the comic form of presentation of the ironic text content cannot be the object of a court case because it is connected with the evaluation and expression of the author’s own opinion.
Humour and satire in everyday life in 1920s Soviet society
Authors: Ryabova Galina Nikolaevna
Published: April 2021

In the Soviet society of the 1920s, humour and satire existed on two levels: official and unofficial. They have rather diverse forms. At the official level, there were, first of all, satirical articles, humoresques, and cartoons in the newspapers. Newspapers were an integral part of Soviet everyday life. Secondly, there were the performances of propaganda teams (the «Blue Blouse» in particular). These performances took place at any venues: in working clubs and village halls, on the factory floors, in different offices. The repertoire of propaganda teams always included satirical couplets directed against «internal and external enemies». At the unofficial level, there were witty-ditties, funny couplets, and anecdotes. They have various contents: from everyday and romantic issues to political problems. Therefore, at this level humour and satire expressed a critical attitude to the government and popular protest. At each level, humour and satire had their own goals and fulfilled various functions: from ideological to relaxational.
Classification model for accuracy and intrusion detection using machine learning approach
Authors: Agarwal Arushi , Sharma Purushottam , Alshehri Mohammed , Mohamed Ahmed A. , Alfarraj Osama
Published: April 2021

In today’s cyber world, the demand for the internet is increasing day by day, increasing the concern of network security. The aim of an Intrusion Detection System (IDS) is to provide approaches against many fast-growing network attacks (e.g., DDoS attack, Ransomware attack, Botnet attack, etc.), as it blocks the harmful activities occurring in the network system. In this work, three different classification machine learning algorithms—Naïve Bayes (NB), Support Vector Machine (SVM), and K-nearest neighbor (KNN)—were used to detect the accuracy and reducing the processing time of an algorithm on the UNSW-NB15 dataset and to find the best-suited algorithm which can efficiently learn the pattern of the suspicious network activities. The data gathered from the feature set comparison was then applied as input to IDS as data feeds to train the system for future intrusion behavior prediction and analysis using the best-fit algorithm chosen from the above three algorithms based on the performance metrics found. Also, the classification reports (Precision, Recall, and F1-score) and confusion matrix were generated and compared to finalize the support-validation status found throughout the testing phase of the model used in this approach.
Deterministic clustering based compressive sensing scheme for fog-supported heterogeneous wireless sensor networks
Authors: Osamy Walid , Aziz Ahmed , M Khedr Ahmed
Published: April 2021

Data acquisition problem in large-scale distributed Wireless Sensor Networks (WSNs) is one of the main issues that hinder the evolution of Internet of Things (IoT) technology. Recently, combination of Compressive Sensing (CS) and routing protocols has attracted much attention. An open question in this approach is how to integrate these techniques effectively for specific tasks. In this paper, we introduce an effective deterministic clustering based CS scheme (DCCS) for fog-supported heterogeneous WSNs to handle the data acquisition problem. DCCS employs the concept of fog computing, reduces total overhead and computational cost needed to self-organize sensor network by using a simple approach, and then uses CS at each sensor node to minimize the overall energy expenditure and prolong the IoT network lifetime. Additionally, the proposed scheme includes an effective algorithm for CS reconstruction called Random Selection Matching Pursuit (RSMP) to enhance the recovery process at the base station (BS) side with a complete scenario using CS. RSMP adds random selection process during the forward step to give opportunity for more columns to be selected as an estimated solution in each iteration. The results of simulation prove that the proposed technique succeeds to minimize the overall network power expenditure, prolong the network lifetime and provide better performance in CS data reconstruction.
Potentially toxic metal(loid) distribution and migration in the bottom weathering profile of indigenous zinc smelting slag pile in clastic rock region
Authors: Peng Yishu , Yang Ruidong , Jin Tao , Chen Jun , Zhang Jian
Published: April 2021

Background

There are contaminated by potentially toxic metal(loid)s (PTMs) that the surface soil and the weathering profiles around the indigenous zinc smelting slag piles or smelters in the smelting area. However, few systematic studies are currently focusing on the PTM distribution and migration among the slag and its bottom weathering profile.

Methods

This research determined the concentrations of PTMs and pH values. And we analyzed PTM distribution in the two weathering profiles (slag-covered and slag-absent) with a small horizontal distance in the clastic rock region in the smelting area.

Results

The soil As and Pb contents, respectively, within the 30 and 50 cm depth in the slag-covered section were higher than those in the slag-absent profile. All soil Cd and Zn contents of the slag-covered core were significantly higher than those in the slag-absent weathering section.

Conclusions

Compared with the slag-absent weathering section, some PTMs (i.e., As, Cd, Pb and Zn) in the bottom weathering profile were polluted by these elements in the covered slag in the clastic rock region, and their depths were influenced by the slag to varying degrees. Additionally, with time, some PTMs (especially Cd and Zn) of the slag might finally contaminate the groundwater by leaching and infiltration through its bottom weathering profile in the clastic rock region.
Diversity structure of the microbial communities in the guts of four neotropical termite species
Authors: Vikram Surendra , Arneodo Joel D. , Calcagno Javier , Ortiz Maximiliano , Mon Maria Laura , Etcheverry Clara , Cowan Don A. , Talia Paola
Published: April 2021

The termite gut microbiome is dominated by lignocellulose degrading microorganisms. This study describes the intestinal microbiota of four Argentinian higher termite species with different feeding habits: Microcerotermes strunckii (hardwood), Nasutitermes corniger (softwood), Termes riograndensis (soil organic matter/grass) and Cornitermes cumulans (grass) by deep sequencing of amplified 16S rRNA and ITS genes. In addition, we have performed a taxonomic and gut community structure comparison incorporating into the analysis the previously reported microbiomes of additional termite species with varied diets. The bacterial phylum Spirochaetes was dominant in the guts of M. strunckii, N. corniger and C. cumulans, whereas Firmicutes predominated in the T. riograndensis gut microbiome. A single bacterial genus, Treponema (Spirochaetes), was dominant in all termite species, except for T. riograndensis. Both in our own sequenced samples and in the broader comparison, prokaryotic α-diversity was higher in the soil/grass feeders than in the wood feeders. Meanwhile, the β-diversity of prokaryotes and fungi was highly dissimilar among strict wood-feeders, whereas that of soil- and grass-feeders grouped more closely. Ascomycota and Basidiomycota were the only fungal phyla that could be identified in all gut samples, because of the lack of reference sequences in public databases. In summary, higher microbial diversity was recorded in termites with more versatile feeding sources, providing further evidence that diet, along with other factors (e.g., host taxonomy), influences the microbial community assembly in the termite gut.
Audiometry Analysis for the Assessment of Hearing Deficit in Patients with Oral Submucous Fibrosis
Authors: Desai Ashwini , Diwaan Nikkhiel , Sapkal Rashmi , Shenoy Siddesh , Desai Niranjan , Supnekar Shraddha , Devi Shweta , Deshpande Narayani
Published: April 2021

Introduction: Oral Submucous Fibrosis (OSMF) is a slowly progressive chronic fibrotic disease of the oral cavity extending to pharynx. Function and patency of eustachian tube gets altered when the palatal and paratubal muscles which regulate the patency of pharyngeal orifice gets affected. This leads to pain in ear along with mild to moderate conductive loss of hearing. Aim: To evaluate hearing deficit in OSMF patients and to correlate clinical stages of OSMF with degree of hearing deficits in patients. Materials and Methods: It was a cross-sectional study. The study comprised of a total of 50 subjects (100 ears). Forty patients diagnosed with OSMF who reported to Department of Oral Medicine and Radiology constituted the study group. Ten normal individuals with no deleterious habits and without any previously diagnosed ear disorders constituted the control group. Pure Tone Audiometry (PTA) was used for evaluating all the subjects for air conduction and bone conduction hearing loss. Values on qualitative characteristics were shown as n (% prevalence) across five study groups. Values on quantitative variables were shown as Mean±SD across five study groups. Inter group comparison for qualitative and quantitative variables was done using chi-square test and analysis of variance (ANOVA) test respectively with Post-Hoc Bonferroni’s correction for multiple group comparisons. Results: The OSMF group showed a marked degree of hearing loss compared to the control group. The distribution of mean PTA in quantitative assessment was significantly higher in group D compared to group A and group B (p-value<0.05 for both) and also the distribution of qualitative hearing loss was significantly higher in group C and group D (p-value<0.05). Conclusion: There was a significant association between OSMF and hearing deficit in this study. Fibrosis of the oropharynx and palatal/paratubal muscles which are affected in OSMF and theses muscles are attached to eustachian tube, the patency of the eustachian tube gets affected. As a result, patients with mainly advanced cases of OSMF should be assessed for hearing deficit.
Remineralising Potential of Marine Skeletal Species-Perna viridis Powder Extract on Human Teeth Enamel: An In-vitro Study
Authors: Revankar Vanita Dattatraya , Saranyan R , Chakravarthy Yadav , Manivannan E , Rajmohan M
Published: April 2021

Introduction: Biomineralisation is a dynamic, complex, constant mechanism by which living organisms manage precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Realising the mechanism of mineral deposition is crucial for the progress of treatments for mineralisation associated diseases and also for the innovation and development of scaffolds. Aim: To measure the remineralisation capacity of enamel surface lesion using marine skeletal species-Perna viridis (mussel shell) powder extract on human tooth enamel. Materials and Methods: The in vitro quantitative observational research study conducted from June 20th, 2020 to July 20th, 2020, included five freshly extracted un-erupted third molars decoronated at Cemento-Enamel Junction (CEJ). The coronal portion of single tooth was sectioned into 4 samples of enamel blocks in order to receive 20 blocks which were subjected to demineralisation process and divided as: Group A(Experimental group)-subsurface demineralisation + mussel shell powder extract and Group B (Control group)- subsurface demineralisation + clinpro application being placed in artificial saliva solution for thirty days. The specimens were tested for X-ray fluorescence spectroscopy analysis, microhardness testing and atomic analyses using Energy dispersive X-ray spectroscopy. Statistical analysis was done using unpaired t-test to check differences at the level of p≤0.05 between groups which were considered as statistically significant. Results: X-ray fluorescence spectroscopy showed calcium concentration in mussel shell of 95% and concentration of Phosphate as 0.31%. Group B (Clinpro) presented statistically significantly higher (p-value 0.028) potential in enhancing the remineralisation than Group A: Mussel Shell Powder Extract (MSPE). The results of atomic analyses exhibited that quantitative amounts of Ca weight % and P weight % is statistically insignificant between both the groups. Group B (Clinpro) showed greatest ability in promoting remineralisation than Group A (mussel shell extract). Conclusion: Marine shells with 95% of calcium concentration can remineralise enamel surface lesion.
Use of Diode Lasers to Enhance Aesthetics of Anterior Implant Supported Prosthesis: A Report of Two Cases
Authors: Dhiman Mohit , Pruthi Gunjan , Shastry Tejomaya D , Bhandari Sudhir
Published: April 2021

Diode lasers have been used for multiple applications in dentistry; however, its use for soft tissue management around dental implants has not been reported much. The role of symmetrical gingival tissue with properly positioned zenith is paramount to achieving aesthetics. The gingival zenith can be described as the most apical point on the marginal gingiva; its ideal placement should be at the crest of the curvature of the gingival margin for the central incisors, canines, and premolars, this should be ideally located slightly distal to the middle of the long axis on these teeth. This produces a slight inclination of the distal root which plays a vital role in the foundation of a beautiful smile. If this gingival complex is malpositioned in maxillary anterior region, it may result in an unaesthetic appearance even if the artificial teeth are perfectly aligned. Here, authors are presenting two patients with missing anterior teeth, who were not satisfied with the final aesthetic outcome of their implant supported prostheses. Due to history of trauma and painful course of treatment, patients were not comfortable with one more exposure to injectable anaesthesia, use of scalpel, or long healing process when they were almost nearing completion of their treatment. So, Diode laser was used for soft tissue excision around implants followed by gingival contouring in pontic region to achieve the desired gingival zenith and contour. The procedure was painless, blood free, followed by quick healing and effective in achieving optimal aesthetic outcome for both the patients.
Stress and Depressive Symptoms among Undergraduate Medical Students of Different Professional Years at a Medical College in Northern India- A Cross-sectional Study
Authors: Pandey Abhinav , Pandey Achyut Kumar , Sureka Pankaj , Singh Amit , Gupta Sanjay
Published: April 2021

Introduction: Medical students are exposed to tremendous pressure, leading to stress, depression and other psychiatric disorder at increasingly higher rates. The stress and depression can affect their learning and can lead to poor quality of life. The students of different professional year may have differing reasons for being under stress and in depression. Assessing stress and depression in students of different professional years may provide better insights, and help policy makers plan appropriate interventions. Aim: To measure and compare the prevalence and severity of stress, various aspects of life affected by stress and depressive symptoms among medical students of various professional years. Materials and Methods: A cross-sectional study was conducted from February 2018 to January 2019; on 150 undergraduate medical students (50 each from 1st, 2nd and 3rd professional year) of a medical institute in Northern part of India. Mini International Neuropsychiatric Interview (MINI version 5) was used to screen for depression, Student’s Stress Dimension Questionnaire (SSDQ) was used to assess for stress prevalence and severity and to find the various aspects of life affected by stress and Hamilton Depression Rating Scale (HAM-D) was used to measure the severity of depressive symptoms. Chi-square test and one-way Analysis of Variance (ANOVA) was used to make the group comparisons. Results: Overall stress and depressive symptoms were present in 66.67% and 52% of the participants, respectively. The three groups also differed significantly in the total score of SSDQ (H=13.664, p<0.05) and HAM-D (H=11.352, p<0.05) with first professional year students having higher scores than second and third professional year students. Domain wise comparison of SSDQ also showed higher prevalence and severity of impaired domains in first professional year students. Conclusion: Special care must be taken of the medical students. Interventions addressing stress and depression should be initiated from first professional year students itself.
Ultrasound Diagnosed Disorders of Subacromial Shoulder Pain Patients: A Retrospective Study at a Tertiary Care Rural Hospital, Mewat, Haryana
Authors: Kaur Depinder , Madan Harnam , Kumar Surendra , Anand Saurabh , Dhanda Manjeet
Published: April 2021

Introduction: Shoulder pain is leading cause of disability and pain among musculoskeletal pain patients. Ultrasound is coming in a bigger way for diagnosis and management of subacromial pain due to its low cost, easy availability and accuracy in detecting soft tissues pathologies and for planning further treatment. Aim: To assess the role of diagnostic Ultrasound (US) in subacromial shoulder pathologies evaluation in shoulder pain patients. Materials and Methods: This was a retrospective observational study conducted on 98 patients who presented with subacromial shoulder pain. Diagnostic ultrasound examination was done and patients were categorised based upon underlying pathology and analysed in terms of frequency. Results: Most common ultrasound findings in subacromial shoulder pain patients were subacromial bursopathy 46 (46.93%) followed by Rotator cuff pathology including tear 38 (38.77%), mixed pathology 9 (9.18%) and Acromioclavicular (AC) joint pathology 5 (5.10%). Isolated biceps pathology was not seen in our study rather biceps pathology along with other tendon and joint involvement was observed. Conclusion: The findings in the present study imply that diagnostic ultrasound of shoulder pain patients helps to stratify them into different categories for better understanding of underlying pathology and targeted treatment approach. Ultrasound shall be used as an outpatient primary diagnostic modality for evaluation of subacromial shoulder pain patients.
Solvent‐Dependent Chemoselective and Stereoselective Approach to Synthesis of Spiro‐γ‐Lactams with Potent Anticancer Activity
Authors: Lei Jie , He Liu‐Jun , Tang Dian‐Yong , Wen Jingyuan , Yan Wei , Li Hong‐yu , Chen Zhong‐Zhu , Xu Zhi‐Gang
Published: April 2021

Chemoselective approaches were developed for derivatizing diastereoselective chromanone spiro‐γ‐lactams through the Michael‐type addition by using amide as a weak nucleophile to construct the spiro‐carbon center under basic conditions. To expand the scope of this post‐Ugi cascade reaction, a new series of oxidized chromone derivatives was synthesized by altering solvent from EtOH to DMF. Compounds 7 a and 7 b which could be synthesized in one day, demonstrated comparable anticancer activities with legendary anticancer drug paclitaxel in the PANC and U87 cell lines. This methodology offers a new approach to construct spiro‐carbon centers with functionalized chromanones or chromones under mild reaction conditions.

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Visible‐Light‐Induced Manganese‐Catalyzed Reactions: Present Approach and Future Prospects
Authors: Jamatia Ramen , Mondal Avijit , Srimani Dipankar
Published: April 2021

Visible‐light‐induced reactions have allowed researchers to attain unorthodox bond formation and elusive chemical processes under mild and inherently safe reaction conditions. However, these methods have relied heavily on Ru‐ and Ir‐based complexes or metal‐free chromophores. While the heavy transition metal complexes are limited by their high cost, toxicity, and adverse environmental effects. Metal‐free photo‐redox catalysts are restricted due to their poorer photo‐stability. In order to overcome these shortcomings, extensive research aimed towards utilizing 3d‐transition metals has come to the forefront. Manganese, in this regard, holds great promise as a versatile and economically sustainable 3d‐transition metal catalyst. Hence, it is not surprising that recent years have witnessed several advances in visible‐light‐mediated manganese catalysis in areas of organic, polymer, and materials chemistry. Manganese‐based heterogeneous systems have also been utilized to effect dimerization and oxygenation reactions showcasing the versatility of manganese. Moreover, manganese has enabled late‐stage functionalization of valuable medicinal compounds and natural products, which are all important from the viewpoint of medicinal and pharmaceutical chemistry. In the present review, comprehensive discussions on the advances, significance, approaches, and mechanistic aspects have been added for each photochemical reaction process. Further, the reaction scope, limitations, and future prospects of visible‐light‐induced manganese catalysis have also been reviewed.

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Critical Assembly and Test Procedures Driven by Mechanical Constriction Principle for Advanced Performances of Solid‐State Batteries
Authors: Li Xin
Published: April 2021

The perspective aims to articulate the fundamental aspect of the unique mechanical constriction effect that is implied in some widely used experimental procedures in solid‐state battery assembly and test. The effect is important to battery performances in terms of the voltage stability with high voltage cathodes and Li metal anode, the fast‐charging ability using Li metal anode, and the cycling stability. The physical picture of the mechanical constriction effect under the constrained ensemble is first described. Theoretical and computational approaches to implement such a physical picture are then introduced to make concrete metastability and kinetic stability predictions that can be compared with experiments from various measurable aspects. Future directions are discussed in the end regarding a synergistic mechanical constriction design by simultaneously considering battery materials, assembly procedures, and device designs for advanced battery performances and the compatibility with practical considerations of interest to industries. It can be envisioned that fully unlocking the potential of the mechanical constriction design principle will greatly speed up the development of solid‐state batteries.
Total Synthesis and Structural Characterization of Caveolin‐1
Authors: Hojo Hironobu , Takei Toshiki , Asahina Yuya , Okumura Nobuaki , Takao Toshifumi , So Masatomo , Suetake Isao , Sato Takeshi , Kawamoto Akihiro , Hirabayashi Yoshio
Published: April 2021

Caveolin‐1, which is an essential protein for caveola formation, was chemically synthesized. It is composed of 177 amino acid residues, is triply palmitoylated at the C‐terminal region, and is inserted into the lipid bilayer to form a V‐shaped structure in the middle of the polypeptide chain. The entire sequence was divided into five peptide segments, each of which was synthesized by the solid‐phase method. To improve the solubility of the C‐terminal region, O‐acyl isopeptide structures were incorporated. After ligation by the thioester method and the introduction of the palmitoyl groups, all the protecting groups were removed and the isopeptide structures were converted into the native peptide bond. Finally, the obtained polypeptide was successfully inserted into bicelles, thus showing the success of the synthesis.
Ruthenium‐Catalyzed Enantioselective Propargylic Phosphinylation of Propargylic Alcohols with Phosphine Oxides
Authors: Liu Shiyao , Tanabe Yoshiaki , Kuriyama Shogo , Sakata Ken , Nishibayashi Yoshiaki
Published: April 2021

The development of transition metal‐catalyzed enantioselective propargylic substitution reactions has gained much progress in recent years, however, no successful example with phosphorus‐centered nucleophiles has yet been reported until now. Herein, we report the first successful example of ruthenium‐catalyzed enantioselective propargylic substitution reactions of propargylic alcohols with diarylphosphine oxides as phosphorus‐centered nucleophiles. This synthetic approach provides a new method to prepare chiral phosphorus‐containing organic compounds.
(2‐Ethylhexyl)sodium: A Hexane‐Soluble Reagent for Br/Na‐Exchanges and Directed Metalations in Continuous Flow
Authors: Harenberg Johannes H. , Weidmann Niels , Wiegand Alexander J. , Hoefer Carla A. , Annapureddy Rajasekar Reddy , Knochel Paul
Published: April 2021

We report the on‐demand generation of hexane‐soluble (2‐ethylhexyl)sodium (1) from 3‐(chloromethyl)heptane (2) using a sodium‐packed‐bed reactor under continuous flow conditions. Thus, the resulting solution of 1 is free of elemental sodium and therefore suited for a range of synthetic applications. This new procedure avoids the storage of an alkylsodium and limits the handling of metallic sodium to a minimum. (2‐Ethylhexyl)sodium (1) proved to be a very useful reagent and undergoes in‐line Br/Na‐exchanges as well as directed sodiations. The resulting arylsodium intermediates are subsequently trapped in batch with various electrophiles such as ketones, aldehydes, Weinreb‐amides, imines, allyl bromides, disulfides and alkyl iodides. A reaction scale‐up of the Br/Na‐exchange using an in‐line electrophile quench was also reported.
Correlation between Oxygen Vacancies and Oxygen Evolution Reaction Activity for a Model Electrode: PrBaCo2O5+δ
Authors: Marelli Elena , Gazquez Jaume , Poghosyan Emiliya , Müller Elisabeth , Gawryluk Dariusz J. , Pomjakushina Ekaterina , Sheptyakov Denis , Piamonteze Cinthia , Aegerter Dino , Schmidt Thomas J. , Medarde Marisa , Fabbri Emiliana
Published: April 2021

The role of the perovskite lattice oxygen in the oxygen evolution reaction (OER) is systematically studied in the PrBaCo2O5+δ family. The reduced number of physical/chemical variables combined with in‐depth characterizations such as neutron dif‐fraction, O K‐edge X‐ray absorption spectroscopy (XAS), electron energy loss spectroscopy (EELS), magnetization and scanning transmission electron microscopy (STEM) studies, helps investigating the complex correlation between OER activity and a single perovskite property, such as the oxygen content. Larger amount of oxygen vacancies appears to facilitate the OER, possibly contributing to the mechanism involving the oxidation of lattice oxygen, i.e., the lattice oxygen evolution reaction (LOER). Furthermore, not only the number of vacancies but also their local arrangement in the perovskite lattice influences the OER activity, with a clear drop for the more stable, ordered stoichiometry.
Simultaneous Broadening and Enhancement of Cr3+Photoluminescence in LiIn2SbO6by Chemical Unit Cosubstitution: Night‐Vision and Near‐Infrared Spectroscopy Detection Applications
Authors: Liu Dongjie , Li Guogang , Dang Peipei , Zhang Qianqian , Wei Yi , Lian Hongzhou , Shang Mengmeng , Lin Chun Che , Lin Jun
Published: April 2021

Near‐infrared (NIR)‐emitting phosphor materials have been extensively developed for optoelectronic and biomedical applications. Although Cr3+‐activated phosphors have been widely reported, it is challenging to achieve ultra‐broad and tunable NIR emission. Here, a new ultra‐broadband NIR‐emitting LiIn2SbO6:Cr3+phosphor with emission peak at 965 nm and a full‐width at half maximum of 217 nm is reported. Controllable emission tuning from 965 to 892 nm is achieved by chemical unit cosubstitution of [Zn2+–Zn2+] for [Li+–In3+], which can be ascribed to the upshift of4T2genergy level due to the strengthened crystal field. Moreover, the emission is greatly enhanced, and the FWHM reaches 235 nm. The as‐prepared luminescent tunable NIR‐emitting phosphors have demonstrated the potential in night‐vision and NIR spectroscopy techniques. This work proves the feasibility of chemical unit cosubstitution strategy in emission tuning of Cr3+‐doped phosphors, which can stimulate further studies on the emission‐tunable NIR‐emitting phosphor materials.