bluuebunny/crossref_metadata_2025 huggingface dataset:
Hubungan antara Kualitas Tidur dengan Daya Konsentrasi Belajar pada Mahasiswa Kepaniteraan Klinik Fakultas Kedokteran Universitas Andalas
Authors: Fitri Nadhila Shafira , Syah Nur Afrainin , Asterina Asterina
Published: November 2020

Setiap orang memerlukan kadar tidur yang cukup agar tubuh dapat berfungsi normal. Kurangnya kebutuhan tidur akan berdampak pada menurunnya kemampuan untuk berkonsentrasi, membuat keputusan, dan berpartisipasi dalam aktivitas sehari-hari. Dewasa muda banyak yang mengalami hambatan dalam proses belajar yang disebabkan oleh rasa mengantuk dan lelah akibat kurang tidur. Mahasiswa kedokteran adalah salah satu subkelompok dari populasi yang sangat rentan terhadap kualitas tidur yang buruk. Hal ini diduga karena tuntutan akademis yang tinggi, tugas klinis, pilihan gaya hidup, sampai pekerjaan yang menantang secara emosional. Penelitian ini bertujuan untuk mengetahui hubungan kualitas tidur terhadap konsentrasi belajar mahasiswa kepaniteraan klinik FK Unand. Jenis penelitian yang digunakan adalah secara analitik dengan metode cross sectional. Teknik pengambilan sampel dilakukan secara stratified random sampling dengan total sampel didapatkan sebanyak 222 orang. Dengan menggunakan kuesioner PSQI dan kuesioner konsentrasi belajar yang kemudian hasilnya dianalisis secara univariat dan bivariat menggunakan uji Chi-Square, didapatkan sebanyak 65,32% mahasiswa mengalami gangguan tidur dan 77,48% mahasiswa memiliki tingkat konsentrasi yang tergolong kurang. Dari hasil uji Chi-Square (p=0,000) dapat disimpulkan bahwa terdapat bermakna antara kualitas tidur dengan tingkat konsentrasi belajar mahasiswa.
Kata kunci:  kualitas tidur, konsentrasi belajar, mahasiswa kepaniteraan klinik, koas
 
Everyone needs enough sleep so the body can function normally. Lack of sleep will result in decreased ability to concentrate, make decisions, and participate in daily activities. Most of the difficulties young adults experience in their learning process are caused by drowsiness and fatigue due to lack of sleep. Medical students are a subgroup of the population who are vulnerable to poor sleep quality. This is thought to be due to high academic demands, clinical assignments, lifestyle choices, and emotionally challenging work. This study aims to determine the relationship between sleep quality and the concentration level of clinical clerkship students from Faculty of Medicine, Andalas University. This is a cross-sectional study. The sampling technique was carried out by stratified random sampling with a total sample of 222 people. By using the PSQI questionnaire and the learning concentration questionnaire which were then analyzed univariately and bivariately using the Chi-Square test, the results obtained were as many as 65.32% of students experiencing sleep disturbances and 77.48% of students had relatively poor concentration levels. From the Chi-Square test results (p=0,000) it can be concluded that there is a significant correlation between the quality of sleep and the students’ concentration level.
Keyword: sleep quality, concentration level, clinical clerkship students
Los efectos de la inseguridad ciudadana sobre el emprendimiento: un freno al desarrollo de Latinoamérica
Authors: Pinazo-Dallenbach Pablo
Published: November 2020

En este trabajo de revisión teórica, a pesar de la escasa literatura existente, se identifican, agrupan y categorizan los posibles efectos de la inseguridad ciudadana sobre el emprendimiento en Latinoamérica, entendiendo estos como un freno al desarrollo económico y social de la región. Los principales resultados reflejan que altas tasas de inseguridad ciudadana afectan de manera directa a la actividad emprendedora en forma de aumento de costes y gastos extraordinarios, disminución de la productividad de empresas y trabajadores y disminución de la actitud emprendedora innovadora. De la misma manera, se identifican efectos indirectos sobre el emprendimiento derivados del coste de oportunidad que supone dedicar fondos públicos y privados a paliar los efectos de la inseguridad, y de la disminución de la demanda.
Stone Industries of Baraba “Flat-Bottomed Neolithic” Settlements
Authors: Yurakova Alena Yu. , Marochkin Alexey G.
Published: November 2020

Purpose. The article presents the results of a study of technological and morphological characteristics of stone tool collections from the Early Neolithic settlement assemblages of Barabinsk forest-steppe containing flat-bottomed ware – Avtodrom-2, Avtodrom-2/2, Staryi Moskovsky Trakt-5 settlements. The results of a mineralogical study of the raw materials has been used. The objects of all considered collections have been proven to be identical (lithic cores, flakes, blades, perforators, sandstone abrasives, polished axes; in the absence of primary flakes and arrow points). Similarities of three sites have been found in preferable raw material (silty sandstone and other metamorphic rocks, flint, opal) in primary technology (prismatic lithic core), big amount of microblades, predominance of regular end-scrapers made from flakes, big abrasives.
Results. A difference in the predominant retouch location in a special work of blades: ventral (Avtodrom-2/2, SMT-5 – up to 60 %) and dorsal (Avtodrom-1 – 61 %). The specifics of the stone industries in Baraba Neolithic settlements with flat-bottomed ceramic ware can be clearly seen in comparison with local assemblages of Artynskaya culture (late Neolithic). In comparison with considered industries, Artynsksya culture (Avtodrom-2/1 settlement) preferred another type of raw material (gray silicified sandstone), bigger role of counterstrike knapping, larger blades, clear predominance of dorsal retouch in treatment of blade tools, and differences in object classification (series of arrow points, scrapers of occasional forms, knives on large blades, stone club knobs).
Conclusion. The obtained results do not contradict the idea of cultural and chronological unity of all settlements in Barabinsk forest-steppe with flat-bottomed Neolithic ware. Comparative and typological analysis of stone industries of all Neolithic assemblages with flat-bottomed ceramic ware in the Ural-West Siberian region is still advantageous, yet an undeveloped approach taking into account their polemical cultural and chronological attribution.
The Chronological Positions of the Boborykino and Koshkino Complexes in the Lower Ishim River Region (Based on Materials of the Mergen-6 Settlement)
Authors: Enshin Dmitry N.
Published: November 2020

Purpose. The article is devoted to one of the most debatable problems for the Trans-Ural Neolithic – the chronological correlation of the Boborykino and Koshkino complexes. From the excavations of the settlement Mergen-6 (Lower Ishim River Region), groups of these ceramic vessels from the ditches of dwellings were obtained. This allowed a spatial and chronological comparison.
Results. Planographic, stratigraphic analysis of the location of the dwellings and the application of the “ties” method in assessing the spatial distribution of vascular fragments revealed a number of patterns. Morphological features of the in-depth part of buildings, interior details and the general relative position of structures (13 objects) indicate a unified architectural strategy and the presence of signs of the spatial organization of the settlement in antiquity – a layout loosely resembling a circular shape. This indicates the synchronization of the functioning of the dwellings. Ceramic vessels of both types lay in the same structures, at the same depths. Also, parts from the same vessels were found in different dwellings (fragments of 40 items). This is another confirmation of the synchronism of buildings and ceramic complexes in them. A comparison of the information with the dates (21 units) obtained from these structures on bone, horn, ceramics, and сharred crust on pottery confirmed these findings.
Conclusion. The presented materials testify to the coexistence of the bearers of the Boborykino and Koshkino cultural traditions on the territory of the Lower Ishim River Region in the early Neolithic (the last quarter of the 7th millennium BC).
New Interpretation of the Lithic Assemblage Location in Sai Djanurpa (Eastern Caspian)
Authors: Alisher kyzy Saltanat , Shnaider Svetlana V. , Yanina Tamara A.
Published: November 2020

The central geographical position of the Caspian region plays a key role in understanding the historical processes which took place in the territory of Central Asia. One of the important geological factors that influenced the processes of settlement in this region by ancient populations is the transgressive-regressive variability of the Caspian sea level and access to fresh water. There are dozens of Early Holocene sites on the Krasnovodsk Peninsula (Eastern Caspian), most of them being surface complexes. The interpretation of these complexes has so far been controversial due to the lack of stratigraphic context and absolute dating.
Purpose. This paper analyzes the techno-typological characteristics of lithic tool assemblages assigned to Early Holocene industries from Eastern Caspian site Sai Djanurpa. The article also discusses the links of how the dynamics of the ancient shores of the Caspian influenced settlement dynamics in the region.
Results. The conducted detailed techno-typological analysis of the lithic collection of Sai Djanurpa allowed to discern two distinct complexes. The two complexes defined by different technological and typological characteristics: types of chips, types of tools and metric indicators. The first complex is characterized by the exploitation of chalcedony flint for the production of blades by soft hammer percussion, by borer, end-scraper and retouched flakes in the toolkit. The second complex is associated with the use of chalcedony, sandstone and flint for the production of microbladelets by the pressure technique, from conical and frontal cores. The toolkit of the second set of complexes is characterized by bifacial narrow points, burins, ventral retouched microblades and micro-scrapers.
Conclusion. Based on the analysis of the lithic assemblages, the geomorphological position of the site and the paleogeographic condition of the Caspian region, the authors assume that two different populations with two different material cultures inhabited the Sai Djanurpa site during the final Pleistocene – early Holocene and the middle Holocene.
Use of Infrared Imaging in Contemporary Source Studies
Authors: Kalashnikova Angelina A.
Published: November 2020

The paper gives a brief overview of infrared (IR) imaging techniques and the cases of their applying to the study of ancient manuscripts and objects of cultural heritage. The method of IR reflectography is used in fine art research, which allows the visualization of details hidden by the paint layers with the help of a scanner. There are also the cases, when IR reflectography is implemented into papyrology with the purpose to make ancient papyri, that turned dark-brown, more legible. Thermography is also used both in studies of cultural heritage and written documents, such as research of bookbinding and supports. Multispectral analysis is a well-proven method of text visualization and digital restoration of ancient manuscripts, which usually is applied in palimpsest decipher. Then the paper considers the method that includes part of IR spectrum is hyperspectral analysis. It is also used in papyrology. Finally, the author observed method of near-infrared imaging (NIRI) and its use for different purposes of the source studies. The paper concludes by arguing the relevance of near-infrared analysis of paper-based historical documents as a key-element of source study. NIRI allows researchers to obtain digital copies of watermarks and investigate corrections of the text made with different inks. The paper provides reader with the technical recommendations on basic NIRI equipment. To sum up, the author declares that there is a possibility for NIRI to become an everyday routine practice for researchers in near future due to its ability to provide a basic analysis of paper, watermarks and ink.
Integrating the Values of Moderate Islam in Social Science Learning: A Qualitaive Study at Islamic Junior High School (MTs) Darul A’mal Metro
Authors: Jusmirah Jusmirah
Published: November 2020

The purpose of the article describing social studies learning integrated with moderate Islamic ideology is able to ward off religious ideology (theology) with characteristics: First, escapist radicalism, trying to release worldly life, ascetic life, freeing themselves from worldly pleasures that are considered poisonous and virtual. Second, theological-ideological radicalism, building an exclusive community, as an anti-group identity the surrounding world that is considered to be like the devil's world must be eradicated. The method of data collection is done by observation and interviews obtained from the staff of 8 MTs educators and 4 students who were analyzed using a quantitative approach. From the stages of the research conducted found several main components in counteracting radical ideology through the integration of social studies learning namely 1). Formulating competency achievements, 2). Formulating the description of the subjects in the lesson plan based on moderate Islamic values, 3). Implementing learning by instilling an attitude ( tassamuh, tawasud, tawazun ). Conclusion of the changes made, first through the achievement of competence, secondly formulating a description of each social studies subject integrated with the Islamic concept of  Rahmatan lil 'alamin  , thirdly learning strategies are integrated with the concept of wasaton, fourth in evaluating the portion of the attitude assessment component. The resulting impact: 1). Islam rahmatan lil 'alamin , build tolerance, harmony, and peace without violence. 2). Islam will continue to synergize with culture, in search of the relevance of universal values ​​of religion in responding to life's problems.
Nickel-Catalyzed Site- and Stereoselective Reductive Alkylalkynylation of Alkynes
Authors: Jiang Yi , Pan Jiaoting , Yang Tao , Lim Joel Jun Han , Zhao Yu , Koh Ming Joo
Published: November 2020

Development of a catalytic multicomponent reaction by orthogonal activation of readily available substrates for the streamlined difunctionalization of alkynes is a compelling objective in organic chemistry. Alkyne carboalkynylation, in particular, offers a direct entry to valuable 1,3-enynes with different substitution patterns. Here, we show that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides and redox-active N-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to 89% yield as single regio- and E isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable to further elaboration to synthetically useful building blocks. With olefin-tethered N-(acyloxy)phthalimides, a cascade radical addition/cyclization/alkynylation process can be implemented to obtain 1,5-enynes. The present study underscores the crucial role of redox-active esters as superior alkyl group donors compared to haloalkanes in reductive alkyne dicarbofunctionalizations.
Clusteroluminescence from Cluster Excitons in Small Heterocyclics Free of Aromatic Rings
Authors: He Benzhao , Zhang Jing , Zhang Jianyu , Zhang Haoke , Wu Xiuying , Chen Xu , Kei Konnie H. S. , Qin Anjun , Sung Herman H.-Y. , Lam Jacky W. Y. , Tang Ben Zhong
Published: November 2020

The study on non-conventional luminescence is important for revealing the luminescence of natural systems and has gradually drawn the attention of researchers in recent years. However, the underlying mechanism is still inexplicable. Herein, the luminescence behaviors of two series of simple, heteroatom-containing small molecules without aromatic rings, i.e. maleimide and succinimide derivatives, are studied to gain further mechanistic insight into the non-conventional luminescence process. It has been unveiled that all the molecules exhibit bright and visible luminescence in concentrated solution and solid state and the formation of clusters is the root cause for such behaviors, which can effectively increase the possibility of both the non-radiative n-π* and favorable π-π* transitions and stabilize the excitons formed in the excited state. The distinctive luminescent phenomena and intriguing mechanism presented in this work will be significant for understanding the mechanism of clusteroluminescence and provide new strategies for the rational design of novel luminescent materials.
Rapid Screening of Diverse Biotransformations for Enzyme Evolution
Authors: Kempa Emily , Galman James L. , Parmeggiani Fabio , Marshall James , Malassis Julien , Fontenelle Clement , Vendeville Jean-Baptiste , Linclau Bruno , Charnock Simon J. , Flitsch Sabine , Turner Nicholas , Barran Perdita
Published: November 2020

The lack of label-free high-throughput screening technologies presents a major bottleneck in the identification of active and selective biocatalysts, with the number of variants often exceeding the capacity of traditional analytical platforms to assess their activity in a practical timescale. Here we show the application of direct infusion mass spectrometry (DiBT-MS) screening to a variety of enzymes, in different formats, achieving sample throughputs equivalent to ~40 seconds per sample. The heat-map output allows rapid selection of active enzymes within 96-well plates facilitating identification of industrially relevant biocatalysts. This DiBT-MS screening workflow has been applied to the directed evolution of a phenylalanine ammonia lyase (PAL), enhancing its activity towards electron-rich cinnamic acid derivatives which are relevant to lignocellulosic biomass degradation. Additional benefits of the screening platform include the discovery of biocatalysts (kinases, imine reductases) with novel activities and the incorporation of ion mobility technology for the identification of product hits with increased confidence.
Ab Initio Molecular Dynamics Simulation of Zinc metalloproteins with Enhanced Self-Organizing Incremental High Dimensional Neural Network
Authors: Xu Mingyuan , Zhu Tong , Zhang John ZH
Published: November 2020

Artificial neural network provides the possibility to develop molecular potentials with both the efficiency of the classical molecular mechanics and the accuracy of the quantum chemical methods. In this work, we developed ab initio based neural network potential (NN/MM-RESP-MBG) to perform molecular dynamics study for metalloproteins. The interaction energy, atomic forces, and atomic charges of metal binding group in NN/MM-RESP-MBG are described by a neural network potential trained with energies and forces generated from density functional calculations. Here, we used our recently proposed E-SOI-HDNN model to achieve the automatic construction of reference dataset of metalloproteins and the active learning of neural network potential functions. The predicted energies and atomic forces from the NN potential show excellent agreement with the quantum chemistry calculations. Using this approach, we can perform long time AIMD simulations and structure refinement MD simulation for metalloproteins. In 1 ns AIMD simulation of four common coordination mode of zinc-containing metalloproteins, the statistical average structure is in good agreement with statistic value of PDB Bank database. The neural network approach used in this study can be applied to construct potentials to metalloproteinase catalysis, ligand binding and other important biochemical processes and its salient features can shed light on the development of more accurate molecular potentials for metal ions in other biomacromolecule system.
Hydrogen from Wood Gasification with CCS - a Technoenvironmental Analysis of Production and Use as Transport Fuel
Authors: Antonini Cristina , Treyer Karin , Moioli Emanuele , bauer christian , Mazzotti Marco
Published: November 2020

In the presented work, we performed an integrated techno-environmental assessment of hydrogen production from woody biomass gasification, combined with CO2 capture and storage (CCS). We have included three different types of gasification technologies for syngas production. CO2 is captured from the syngas with conventional amine-based technology. Based on our integrated approach linking detailed process simulation with Life Cycle Assessment, we are able to quantify benefits and potential trade-offs of a wide range of process configurations from both technical and environmental perspectives in a consistent way. We have also performed a comparative evaluation of hydrogen use in fuel cell electric vehicles (passenger cars and freight trucks), to investigate the role of hydrogen in decarbonizing the transport sector.
Improving Robustness of LCA Results Through Stakeholder Engagement: A Case Study of Emerging Oil Sands Technologies
Authors: Sleep Sylvia , Dadashi Zainab , chen yuanlei , Brandt Adam R. , MacLean Heather L. , Bergerson Joule A.
Published: November 2020

Life cycle assessments can help to inform decision-making about greenhouse gas (GHG) emission reduction opportunities but are often not embraced by stakeholders associated with industries where study results are highly scrutinized and often contentious. This project was motivated by stakeholder interest in understanding open source life cycle models (the Oil Production Greenhouse Gas Emissions Estimator, OPGEE, and the Petroleum Refinery Life Cycle Inventory Model, PRELIM) and how accurately they can estimate emissions for existing oil sands projects and emerging technologies. We evaluate the robustness of these models and improve them using data from three existing oil sands projects (mining + upgrading, mining + dilution, and steam assisted gravity drainage, SAGD, + dilution). The models are then applied to estimate the GHG emissions reduction potential for two emerging in situ oil sands technologies. We find that, when boundaries are aligned, OPGEE can generate upstream GHG emissions estimates for the projects modeled within 1-4% of company reported GHG emissions data. Extending the boundary to include indirect (life cycle) emissions can lead to a doubling in upstream GHG emissions intensity. The two emerging technologies evaluated in the study can reduce upstream emissions by 14-19% compared to a SAGD project operating at the same reservoir, or 1.4-1.9% on a well-to-wheel basis. This work contributes a revised process of conducting LCAs that includes stakeholder input throughout and results in more robust and transparent estimations of emissions from deploying existing and emerging technologies.
A Tailored Phosphoaspartate Probe Unravels CprR as a Response Regulator in Pseudomonas Aeruginosa Interkingdom Signaling
Authors: Allihn Patrick , Hackl Mathias W. , Ludwig Christina , Hacker Stephan M. , A. Sieber Stephan
Published: November 2020

Pseudomonas aeruginosa is a difficult-to-treat Gram-negative bacterial pathogen causing life-threatening infections. Adaptive resistance (AR) to cationic peptide antibiotics such as polymyxin B impairs the therapeutic success. This self-protection is mediated by two component systems (TCS) consisting of a membrane-bound histidine kinase and an intracellular response regulator (RR). As phosphorylation of the key RR aspartate residue is transient during signaling and hydrolytically unstable, the study of these systems is challenging. Therefore, we applied a tailored reverse polarity chemical proteomic strategy to capture this transient modification and read-out RR phosphorylation in complex proteomes using a nucleophilic probe. An ideal trapping methodology was developed with a recombinant RR demonstrating the importance of fine-tuned acidic pH values to facilitate the attack on the aspartate carbonyl C-atom and prevent unproductive hydrolysis. Analysis of Bacillus subtilis and P. aeruginosa proteomes revealed the detection of multiple phosphoaspartate sites, which closely resembled the conserved RR sequence motif. With this validated strategy we dissected the signaling of dynorphin A, a human peptide stress hormone, which is sensed by P. aeruginosa to mediate AR. Intriguingly, our methodology identified CprR as an unprecedented RR in dynorphin A interkingdom signaling.
Site-Specific Electronic Properties of [Ag25(SR)18]- Nanoclusters by X-Ray Spectroscopy
Authors: Chen Ziyi , Walsh Andrew , wei xiao , Zhu Manzhou , Zhang Peng
Published: November 2020

We present the site-specific electronic properties of Ag25(SR)18 and Au25(SR)18 using X-ray spectroscopy experiments and quantum simulations. To overcome the final state effect observed in X-ray photoelectron spectroscopy (XPS), a unique method was developed to reliably analyze the charge transfer behavior of the NCs. Density functional theory calculations were combined with XPS to provide more insight into the electronic properties of the NCs. The differences in the XPS valence bands of these two NCs were further compared and interpreted using the relativistic effect. The first derivative of the X-ray absorption near-edge structure (XANES) spectrum was further used as a tool to sensitively probe the bonding properties of Ag25(SR)18. By combining the experimental XANES data and their site-specific quantum simulations, the large impact of the staple motif on the bonding properties of the NC was demonstrated. These findings highlight the unique electronic properties of each atomic site in Ag25(SR)18; the effective X-ray analysis techniques developed here can offer new opportunities for the site-specific study of other NCs.
Ab Initio Molecular Dynamics Simulations of the Interaction between Organic Phosphates and Goethite
Authors: Ganta Prasanth Babu , Kühn Oliver , Ahmed Ashour A.
Published: November 2020

Today's fertilizers rely heavily on mining phosphorus (P) rocks. These rocks are known to become exhausted in near future and hence, effective P use is crucial to avoid food shortage. A substantial amount of P from fertilizers gets adsorbed onto soil minerals to become unavailable to plants. Understanding P interaction with these minerals would help efforts that improve P efficiency. To this end we performed a molecular level analysis of the interaction of common organic P compounds (glycerolphosphate [GP] & inositol hexaphosphate [IHP]) with the abundant soil mineral (goethite) in presence of water. Molecular dynamics simulations are performed for goethite-IHP/GP-water complexes using the multiscale quantum mechanics/molecular mechanics method. Results show that GP forms monodentate (M) and bidentate mononuclear (B) motifs with B being more stable than M. IHP interacts through multiple phosphate groups with the \textbf{3M} motif being most stable. The order of goethite-IHP/GP interaction energies is: GP M < GP B < IHP M < IHP 3M. Water is important in these interactions as multiple proton transfers occur and hydrogen bonds are formed between goethite--IHP/GP complexes and water. We also present theoretically calculated infrared spectra which match reasonably well with frequencies reported in literature.
Identifying Molecules as Biosignatures with Assembly Theory and Mass Spectrometry
Authors: Marshall stuart , Mathis Cole , Carrick Emma , Keenan Graham , Cooper Geoffrey , Graham Heather , Bame Jessica , Craven Matthew , Bell Nicola , Gromski Piotr S. , Swart Marcel , Moore Douglas G. , Walker Sara , Cronin Leroy
Published: November 2020

The search for evidence of life elsewhere in the universe is hard because it is not obvious what signatures are unique to life. Here we postulate that complex molecules found in high abundance are universal biosignatures as they cannot form by chance. To explore this, we developed the first intrinsic measure of molecular complexity that can be experimentally determined, and this is based upon a new approach called assembly theory which gives the molecular assembly number (MA) of a given molecule. MA allows us to compare the intrinsic complexity of molecules using the minimum number of steps required to construct the molecular graph starting from basic objects, and a probabilistic model shows how the probability of any given molecule forming randomly drops dramatically as its MA increases. To map chemical space, we calculated the MA of ca. 2.5 million compounds, and collected data which showed the complexity of a molecule can be experimentally determined by using three independent techniques including infra-red spectroscopy, nuclear magnetic resonance, and by fragmentation in a mass spectrometer, and this data has an excellent corelation with the values predicted from our assembly theory. We then set out to see if this approach could allow us to identify molecular biosignatures with a set of diverse samples from around the world, outer space, and the laboratory including prebiotic soups. The results show that there is a non-living to living threshold in MA complexity and the higher the MA for a given molecule, the more likely that it had to be produced by a biological process. This work demonstrates it is possible to use this approach to build a life detection instrument that could be deployed on missions to extra-terrestrial locations to detect biosignatures, map the extent of life on Earth, and be used as a molecular complexity scale to quantify the constraints needed to direct prebiotically plausible processes in the laboratory. Such an approach is vital if we are going to find new life elsewhere in the universe or create de-novo life in the lab.
Ab Initio Effective One-Electron Potential Operators:Applications for Charge-Transfer Energy in Effective Fragment Potentials
Authors: Blasiak Bartosz , Bednarska Joanna D. , Chołuj Marta , Góra Robert , Bartkowiak Wojciech
Published: November 2020

The concept of effective one-electron potentials (EOP) has proven to be extremely useful in efficient description of electronic structure of chemical systems, especially extended molecular aggregates such as

interacting molecules in condensed phases. Here, a general method for EOP-based elimination of electron

repulsion integrals (ERIs) is presented, that is tuned towards the fragment-based calculation methodologies

such as the second generation of the effective fragment potentials (EFP2) method. Two general types of the

EOP operator matrix elements are distinguished and treated either via the distributed multipole expansion or

the extended density fitting schemes developed in this work. The EOP technique is then applied to reduce

the high computational costs of the effective fragment charge-transfer (CT) terms being the bottleneck of

EFP2 potentials. The alternative EOP-based CT energy model is proposed, derived within the framework of

intermolecular perturbation theory with Hartree–Fock non-interacting reference wavefunctions, compatible

with the original EFP2 formulation. It is found that the computational cost of the EFP2 total interaction

energy calculation can be reduced by up to 38 times when using the EOP-based formulation of CT energy,

as compared to the original EFP2 scheme, without compromising the accuracy for a wide range of weakly

interacting neutral and ionic molecular fragments. The proposed model can thus be used routinely within

the EFP2 framework.
Mechanistic Investigations of Metallo-β-Lactamase Inhibitors: Strong Zinc Binding Is Not Required for Potent Enzyme Inhibition
Authors: Wade Nicola , Tehrani Kamaleddin , Brüchle Nora , J. van Haren Matthijs , Mashayekhi Vida , Martin Nathaniel
Published: November 2020

Metallo-β-lactamases (MBLs) are zinc-dependent bacterial resistance enzymes that can inactivate essentially all classes of β-lactam antibiotics. Infections due to multi-drug-resistant pathogens that express MBLs are difficult to treat and carry high mortality rates. At present there are no clinically approved MBL inhibitors underscoring the urgent need for pharmaceutical agents capable of counteracting the action of these enzymes. In order to develop effective MBL inhibitors it is essential to understand their inhibitory mechanisms. We here describe a comprehensive mechanistic study on a panel of structurally distinct MBL inhibitors drawn from the diverse collection of compounds reported to date in both the scientific and patent literature. Specifically, we determined the half-maximal inhibitory concentration value (IC50) for each inhibitor against purified NDM-1 and IMP-1 revealing clear differences in inhibitory potency among the compounds tested. Additional mechanistic insights into metal binding were also obtained by means of isothermal titration calorimetry (ITC) which was used to assess the affinity of the MBL inhibitors for Zn2+, Ca2+ and Mg2+. These investigations revealed clear differences in metal binding among the MBL inhibitors evaluated. In addition, we directly compared the ability of these compounds to resensitize an NDM-1-expressing E. coli strain to the last resort carbapenem antibiotic meropenem. Notably, indole carboxylate 12 proved to be the most potent inhibitor tested in its ability to synergize with meropenem and with IC50 values in the low nanomolar range against both enzymes. Interestingly, while compound 12 was found the most active MBL inhibitor, it exhibited no appreciable binding to any of the metals tested. These findings provide valuable insights into differences in mechanism and potency for the various classes of MBL inhibitors reported to date.
Great Location: About Effects of Surface Bound Neighboring Groups for Passive and Active Fine-Tuning of CO2 Adsorption Properties in Carbon Capture Materials
Authors: Klinkenberg Nele , Kraft Sophia , Polarz Sebastian
Published: November 2020

Better carbon capture materials are crucial for managing today’s and the future CO2 level in the atmosphere. The past focus was on increasing adsorption capacities. One knows by now that controlling the heat of adsorption (DHads) is equally important. Is it too low, CO2 uptake takes place at unfavorable conditions far from ambient and with insufficient selectivity. Is it too high, chemisorption occurs, and the materials can hardly be regenerated. The conventional approach for influencing DHads is the modification of the adsorbing center. This paper proposes an alternative strategy. The hypothesis is that fine-tuning of the molecular environment in direct vicinity to the adsorbing center (primary amines) is a powerful tool for the adjustment of CO2-binding properties. Via click chemistry, any desired neighboring group (NG) can be incorporated on the surfaces of the resulting bifunctional, nanoporous organosilica materials. Passive NGs induce a change of the polarity of the surface, whereas active NGs are capable of a direct interaction with the active-center/ CO2pair. The effects on DHads and also on the selectivity are studied in detail. A situation can be realized on the surface which resembles frustrated Lewis acid-base pairs, and the investigation of the binding-species by 13C solid-state NMR indicate that the push-pull effects could play an essential role not only for CO2 adsorption but also for its activation.
Computational Modeling Predicts the Stability of Both Pd+ and Pd2+ Ion-Exchanged into H-CHA
Authors: Van der Mynsbrugge Jeroen , Head-Gordon Martin , Bell Alexis T.
Published: November 2020

Passive NOx adsorbers (PNA) using Pd/zeolites have emerged as a promising solution for the reduction of cold-start emissions from vehicle exhaust. However, the nature of the active sites and the mechanisms underlying NOx adsorption in Pd/zeolites remain a subject of ongoing investigation. In this study, we employ quantum chemical simulations to investigate the structure of Pd species in cation-exchange sites at isolated Al and Al pairs in the 6-ring and 8-ring of the CHA framework, before the introduction of NOx. Our calculations show that the speciation of Pd in these exchange sites strongly depends on the precise Al arrangement within the framework, as well as the operating conditions. Ionically dispersed Pd is found to be the most favorable species over a wide range of oxidizing and reducing conditions. Small oligomers of PdO and metallic Pd do not appear to be competitive at either isolated Al or Al pairs. Notably, our calculations show that ion exchange sites other than next-next-nearest neighbor Al pairs in the 6-ring will be preferentially occupied by Pd+ instead of Pd2+. The stability of Pd+ in the zeolite environment is an interesting contrast with its rareness in molecular Pd compounds. Nonetheless, a detailed analysis of the electronic structure shows that predicted Pd oxidation states are consistent with chemical intuition for all complexes investigated in this study. We also discuss the potential ambiguity in Pd characterization provided by typical experimental techniques such as XANES, EXAFS and UV-VIS, and highlight the need for additional EPR spectroscopy studies to further elucidate the initial Pd speciation in zeolites for PNA applications.
How Natural Materials Remove Heavy Metals from Water: Mechanistic Insights from Molecular Dynamics Simulations
Authors: Pietrucci Fabio , Boero Mauro , Andreoni Wanda
Published: November 2020

Heavy metals are captured by hemicellulose from water: modeling and simulations. Classical and ab initio molecular dynamics aided by metadynamics. Relevant to the understanding of removal of heavy metals from water sources with natural materials, e.g. spent coffee grains.
Dynamics of Ion Locking in Doubly Polymerized Ionic Liquids
Authors: Arora Swati , Rozon Julisa , Laaser Jennifer
Published: November 2020

In this work, we investigate the dynamics of ion motion in “doubly-polymerized” ionic liquids (DPILs) in which both charged species of an ionic liquid are covalently linked to the same polymer chains. Broadband dielectric spectroscopy is used to characterize these materials over a broad frequency and temperature range, and their behavior is compared to that of conventional “singly-polymerized” ionic liquids (SPILs) in which only one of the charged species is attached to the polymer chains. Polymerization of the DPIL decreases the bulk ionic conductivity by four orders of magnitude relative to both SPILs. The timescales for local ionic rearrangement are similarly found to be approximately four orders of magnitude slower in the DPILs than in the SPILs, and the DPILs also have a lower static dielectric constant. These results suggest that copolymerization of the ionic monomers affects ion motion on both the bulk and the local scales, with ion pairs serving to form strong physical crosslinks between the polymer chains. This study provides quantitative insight into the energetics and timescales of ion motion that drive the phenomenon of “ion locking” currently under investigation for new classes of organic electronics.
Intersecting Dalit and Cultural Studies: De-brahmanising the Disciplinary Space
Authors: Ingole Prashant
Published: November 2020

The paper begins with the context in which Dalit culture and resistance emerges and the way brahmanical social order tries to maintain their status quo through established cultural inequalities with the dominance of power and knowledge. By invoking different claims of dominant epistemologies re-articulated by Dalit intellectuals and locating the cultural past of Dalit humiliation, this paper examines the anti-caste discourse and the Dalit cultural resistance from the colonial and postcolonial time. With an attempt to bring in the intersections of Dalit and cultural studies, the paper argues that by challenging brahmanical cultural knowledge production, Dalits can reclaim power and knowledge in relation with the ‘politics of difference’. The Dalit aesthetic decenters the cultural production and circulation of the hitherto grand narratives. Further, it attempts to de-brahmanize the established disciplinary space by bringing the discourse of Dalit experience of caste and humiliation into mainstream academia. Lastly, drawing from the interdisciplinary context, the paper has elaborated the possibility of the making of a field of Dalit Cultural Studies as a step forward- a newer way for the cultural resistance of the oppressed.
Dalit Counterpublic and Social Space on Indian Campuses
Authors: Garalyte Kristina
Published: November 2020

This article discusses three different university campuses in India (Jawaharlal Nehru University, Osmania University, and the English and Foreign Languages University) and their political and social environments with a particular focus on Dalit student activism from March to June, 2013, and from January to March, 2014 when this ethnographic research was conducted. It questions what place Dalit student activism, constituting the ‘counterpublic’ (Fraser, 1990; Warner, 2002), occupied in these campuses; how Dalit student activists interacted with other student political groups; what characteristic features the Dalit student activism had on each campus. This article discusses the changing power relations in Indian universities and the role of ‘social space’ (Bourdieu, 2018) in negotiating social statuses. Dalit student activists actively engaged in appropriating social space by installing Dalit symbolic icons on the university campuses, bringing up caste issues to public attention and thus temporarily turning certain campuses into ‘political strongholds’ (Jaoul, 2012) of the Dalit movement. Contributing to the recent scholarship on student politics in South Asia this article argues for the understanding of interactive relation between campus space and student politics, showing how Dalit students changed the campus space through symbolic appropriation and, conversely, how historically constituted campus spaces affected the nature of Dalit student activism in each of the discussed localities.
Leisure, Festival, Revolution: Ambedkarite Productions of Space
Authors: Crowley Thomas
Published: November 2020

This article analyzes the town of Mahad in the state of Maharashtra, using it as a lens to examine protests and commemorations that are inseparable from Ambedkarite and Neo-Buddhist transformations of space. A key site of anti-caste struggle, Mahad witnessed two major protests led by Dr. B.R. Ambedkar in 1927: the claiming of water from Chavdar Tale, a tank located in a upper caste neighbourhood; and the burning of the Manusmriti. These events are commemorated every year with large-scale festivities. The article analyzes the ways that these protests and festivities have worked to produce a distinctly Ambedkarite space, one that is radically counterposed to hierarchical, Brahminical productions of space. Exploring the writings of Ambedkar and more recent Ambedkarite scholars, and putting these texts into dialogue with the spatial theories of Henri Lefebvre, the article contributes to a growing international literature on the spatiality of caste. The Navayana Buddhism pioneered by Ambedkar has been analyzed in terms of its ideology, its pragmatism, and its politics, but rarely in terms of its spatiality. Drawing on Lefebvre helps flesh out this spatial analysis while a serious engagement with neo-Buddhist practices helps to expand, critique and globalize some of Lefebvre’s key claims.
Key words: Ambedkar, Lefebvre, Mahad, neo-Buddhism, festival, revolution
Dysosmia: a very unpleasant symptom causing severe anorexia and breathing problems in COVID-19: a case report
Authors:   1Early detection childhood disabilities centre, Otolaryngology Department, Duhok, Iraq. 2Rheumatology Section, Department of Rheumatology, Hamad Medical Institute, Doha, Qatar.
Published: November 2020

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new coronavirus that is highly contagious and responsible for the ongoing pandemic disease; coronavirus disease (COVID-19). The disease was first identified in December 2019, and the World Health Organization declared the pandemic on the 11th of March 2020. Although individuals infected with SARS-CoV-2 may be asymptomatic, the disease can present as an upper respiratory tract illness. In the majority of the cases, it is of a mild type, however, some patients experience severe viral pneumonia that leads to respiratory failure, and, in some cases to death. A COVID-19 diagnosis is confirmed by viral RNA detection in nasopharyngeal swab specimens; nonetheless, in some countries, COVID-19 tests are not available for screening and are only used to diagnose severe cases. Since 31 December 2019 and as of 17 October 2020 and in accordance with the applied case definitions and testing strategies in the affected countries 39 400 032 cases of COVID-19 have been reported, including 1 105 353 deaths [1]. The main way to control the spread of COVID-19 is to prevent human-to-human transmission, which can be achieved through a combination of public health measures, including the rapid identification and isolation of infected people [1]. Diagnostic suspicion is based on nonspecific symptoms, such as fever, odynophagia, head- ache, and dry cough which are present in almost all acute respiratory virus cases [2]. Anosmia, which may be associated with the loss of taste, has been initially observed in European cases and seems to be a more specific symptom of COVID-19. Thus, during the pandemic, individuals with these symptoms should be tested for COVID-19; when tests are not available, isolation of the patient is indicated [3]. It should also be noted that olfactory dysfunction significantly influences the physical well-being, quality of life, safety, and nutritional status of those affected. And it becomes a greater problem when it becomes permanent. Yet, very little is known about olfactory dysfunction in COVID-19. Through our case report and review of the subject of the olfactory dysfunction, we would like to contribute to the existing knowledge and clinical evolution and to reinforce the importance of this manifestation from the patient prospected, and in the diagnosis and control of the disease from Otolaryngological point of view. We, self-reported an Anosmia turned to Dysosmia (in Otolaryngeal senior consultant) and in one of his patient with anosmia which was followed by Dysosmia as well. This occurred in August 2020 and September 2020 in Duhok, Iraq.