bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complexation in situ of 1‐methylpiperidine, 1,2‐dimethylpyrrolidin, and 1,2‐dimethylpiperidine with rhodium(II) tetracarboxylates: Nuclear magnetic resonance spectroscopy, chiral recognition, and density functional theory studies
Authors: Sadlej Agnieszka , Jaźwiński Jarosław 
Published: August 2021

AbstractComplexation in situ of 1‐methylpiperidine, racemic 1,2‐dimethylpyrrolidin, and racemic 1,2‐dimethylpiperidine with rhodium(II) tetracarboxylates in chloroform was studied by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) methods. As substrates, three dirhodium(II) compounds were applied, tetraacetate, tetrakistrifluoroacetate, and a derivative of optically pure Mosher's acid. Due to conformational flexibility, free and complexed ligands can adopt potentially various conformations. The NMR titration experiments revealed the subsequent formation of 1:1 and 1:2 complexes, depending on the molar ratio of substrate to ligand. Conformations of free and complexed ligands were examined by the comparison of experimental and DFT gauge‐independent atomic orbital (GIAO) calculated chemical shifts and by the analysis of the internal energy of the compounds. For some ligand and substrate combinations, a mixture of complexes differing in ligand conformations was formed. Complexes of Mosher's acid derivative of rhodium(II) with racemic 1,2‐dimethylpyrrolidin and 1,2‐dimethylpiperidine exhibited NMR chiral recognition phenomenon, manifested by splitting of signals in 13C NMR and 1H,13C HSQC spectra.
Primary breast cancer biomarkers based on glycosylation and extracellular vesicles detected from human serum
Authors: Terävä Joonas , Verhassel Alejandra , Botti Orsola , Islam Md. Khirul , Leivo Janne , Wittfooth Saara , Härkönen Pirkko , Pettersson Kim , Gidwani Kamlesh 
Published: August 2021

AbstractBackgroundBreast cancer is a very common cancer that can be severe if not discovered early. The current tools to detect breast cancer need improvement. Cancer has a universal tendency to affect glycosylation. The glycosylation of circulating extracellular vesicle‐associated glycoproteins, and mucins may offer targets for detection methods and have been only explored in a limited capacity.AimOur aim was to develop an approach to detect the aberrant glycosylation of mucins and extracellular vesicle‐associated glycoproteins from human sera using fluorescent nanoparticles, and preliminarily evaluate this approach for the differential diagnosis of breast cancer.Methods and resultsThe assay involved immobilizing glycosylated antigens using monoclonal antibodies and then probing their glycosylation by using lectins and glycan‐specific antibodies coated on Eu+3‐doped nanoparticles. Detection of mucin 1 and mucin 16 glycosylation with wheat germ agglutinin, and detection of the extracellular vesicle‐associated CD63 were found to have better diagnostic ability for localized breast cancer than the conventional assays for mucin 1 and mucin 16 based tumor markers when the receiver operating characteristics were compared.ConclusionsThese results indicate that successful differential diagnosis of primary breast cancer may be aided by detecting cancer‐associated glycosylation of mucin 1 and mucin 16, and total concentration of CD63, in human serum.
Defect Passivation for Perovskite Solar Cells: from Molecule Design to Device Performance
Authors: Wu Tianhao , Li Xing , Qi Yabing , Zhang Yiqiang , Han Liyuan 
Published: August 2021

AbstractPerovskite solar cells (PSCs) are a promising third‐generation photovoltaic (PV) technology developed rapidly in recent years. Further improvement of their power conversion efficiency is focusing on reducing the non‐radiative charge recombination induced by the defects in metal halide perovskites. So far, defect passivation by the organic small molecule has been considered as a promising approach for boosting the PSC performance owing to their large structure flexibility adapting to passivating variable kinds of defect states and perovskite compositions. Here, the recent progress of defect passivation toward efficient and stable PSCs was reviewed from the viewpoint of molecular structure design and device performance. To comprehensively reveal the structure‐performance correlation of passivation molecules, it was separately discussed how the functional groups, organic frameworks, and side chains affect the corresponding PV parameters of PSCs. Finally, a guideline was provided for researchers to select more suitable passivation agents, and a perspective was given on future trends in development of passivation strategies.
The effects of early weaning on Pavlovian fear conditioning in young rats
Authors: Kreiker Malaz , Perez Katelyn , Brown Kevin L. 
Published: August 2021

AbstractEarly life stress enhances memory for Pavlovian fear conditioning. Stress enhancements on fear conditioning following early weaning, however, have yet to be studied in periweaning rats. Early weaning is a relevant animal model for human early life trauma, and Pavlovian fear conditioning is useful for identifying links between stress‐induced developmental changes and behavior. We hypothesized that early weaning—on postnatal day (P)15—would lead to higher levels of conditional freezing relative to rats weaned later in life. Periweaning rats were trained with a discrete conditional stimulus (CS) and a shock unconditional stimulus (US), and tested 1 or 15 days later. Enhanced retention was observed in early weaned rats receiving forward paired CS–US training in Experiment 1, though this did not replicate in the second experiment. Despite overall enhancements in early weaned rats in Experiment 1, infantile amnesia effects were not overcome in young rats tested 15 days after training. Enhanced freezing levels in early weaned rats were not observed in subjects receiving unpaired CS, US training, and sensitivity to the US was not different due to age at weaning. Potential mechanisms underlying weaning‐related enhancements and considerations for future studies including the role of social transmission of fear information are discussed.
TheTale‐TellHeart: Evolutionary tetrapod shift from aquatic to terrestrial life‐style reflected in heart changes in axolotl (Ambystoma mexicanum)
Authors: Olejnickova Veronika , Kolesova Hana , Bartos Martin , Sedmera David , Gregorovicova Martina 
Published: August 2021

AbstractBackgroundDuring amphibian metamorphosis, the crucial moment lies in the rearrangement of the heart, reflecting the changes in circulatory demands. However, little is known about the exact shifts linked with this rearrangement. Here, we demonstrate such myocardial changes in axolotl (Ambystoma mexicanum) from the morphological and physiological point of view.ResultsMicro‐CT and histological analysis showed changes in ventricular trabeculae organization, completion of the atrial septum and its connection to the atrioventricular valve. Based on Myosin Heavy Chain and Smooth Muscle Actin expression we distinguished metamorphosis‐induced changes in myocardial differentiation at the ventricular trabeculae and atrioventricular canal. Using optical mapping, faster speed of conduction through the atrioventricular canal was demonstrated in metamorphic animals. No differences between the groups were observed in the heart rates, ventricular activation times, and activation patterns.ConclusionsTransition from aquatic to terrestrial life‐style is reflected in the heart morphology and function. Rebuilding of the axolotl heart during metamorphosis was connected with reorganization of ventricular trabeculae, completion of the atrial septum and its connection to the atrioventricular valve, and acceleration of AV conduction.
Conformity to Bergmann's rule in birds depends on nest design and migration
Authors: Mainwaring Mark C. , Street Sally E. 
Published: August 2021

AbstractEcogeographical rules attempt to explain large‐scale spatial patterns in biological traits. One of the most enduring examples is Bergmann's rule, which states that species should be larger in colder climates due to the thermoregulatory advantages of larger body size. Support for Bergmann's rule, however, is not consistent across taxonomic groups, raising questions about what factors may moderate its effect. Behavior may play a crucial, yet so far underexplored, role in mediating the extent to which species are subject to environmental selection pressures in colder climates. Here, we tested the hypothesis that nest design and migration influence conformity to Bergmann's rule in a phylogenetic comparative analysis of the birds of the Western Palearctic, a group encompassing dramatic variation in both climate and body mass. We predicted that migratory species and those with more protected nest designs would conform less to the rule than sedentary species and those with more exposed nests. We find that sedentary, but not short‐ or long‐distance migrating, species are larger in colder climates. Among sedentary species, conformity to Bergmann's rule depends, further, on nest design: Species with open nests, in which parents and offspring are most exposed to adverse climatic conditions during breeding, conform most strongly to the rule. Our findings suggest that enclosed nests and migration enable small birds to breed in colder environments than their body size would otherwise allow. Therefore, we conclude that behavior can substantially modify species’ responses to environmental selection pressures.
Genome‐wide analysis reveals demographic and life‐history patterns associated with habitat modification in landlocked, deep‐spawning sockeye salmon (Oncorhynchus nerka)
Authors: Samad‐zada Farida , van Poorten Brett T. , Harris Shannon , Godbout Lyse , Russello Michael A. 
Published: August 2021

AbstractHuman‐mediated habitat fragmentation in freshwater ecosystems can negatively impact genetic diversity, demography, and life history of native biota, while disrupting the behavior of species that are dependent on spatial connectivity to complete their life cycles. In the Alouette River system (British Columbia, Canada), dam construction in 1928 impacted passage of anadromous sockeye salmon (Oncorhynchus nerka), with the last records of migrants occurring in the 1930s. Since that time, O. nerka persisted as a resident population in Alouette Reservoir until experimental water releases beginning in 2005 created conditions for migration; two years later, returning migrants were observed for the first time in ~70 years, raising important basic and applied questions regarding life‐history variation and population structure in this system. Here, we investigated the genetic distinctiveness and population history of Alouette Reservoir O. nerka using genome‐wide SNP data (n = 7,709 loci) collected for resident and migrant individuals, as well as for neighboring anadromous sockeye salmon and resident kokanee populations within the Fraser River drainage (n = 312 individuals). Bayesian clustering and principal components analyses based on neutral loci revealed five distinct clusters, largely associated with geography, and clearly demonstrated that Alouette Reservoir resident and migrant individuals are genetically distinct from other O. nerka populations in the Fraser River drainage. At a finer level, there was no clear evidence for differentiation between Alouette Reservoir residents and migrants; although we detected eight high‐confidence outlier loci, they all mapped to sex chromosomes suggesting that differences were likely due to uneven sex ratios rather than life history. Taken together, these data suggest that contemporary Alouette Reservoir O. nerka represents a landlocked sockeye salmon population, constituting the first reported instance of deep‐water spawning behavior associated with this life‐history form. This finding punctuates the need for reassessment of conservation status and supports ongoing fisheries management activities in Alouette Reservoir.
Single‐Molecule Magnetic, Catalytic and Photoluminescence Properties of Heterometallic 3d–4f [Ln{PZn2W10O38(H2O)2}2]11− Tungstophosphate Nanoclusters
Authors: Das Vivek , Khan Imran , Hussain Firasat , Sadakane Masahiro , Tsunoji Nao , Ichihashi Katsuya , Kato Chisato , Inoue Katsuya , Nishihara Sadafumi 
Published: August 2021

AbstractA series of eleven lanthanide containing di‐Zinc (II) substituted heterometallic 3d–4f sandwich‐type tungstophosphate nanoclusters [Ln{PZn2W10O38(H2O)2}2]11− (Ln=NdIII, SmIII, EuIII, GdIII, TbIII, DyIII, HoIII, ErIII, TmIII, YbIII, and LuIII) have been synthesized by a single step reaction procedure. These clusters were characterized by various analytical techniques such as single crystal X‐ray diffraction (SC‐XRD), fourier transform infrared (FT‐IR) spectroscopy, high‐resolution electro‐spray ionization mass spectrometry (HR‐ESI‐MS), inductively coupled plasma atomic emission spectroscopy (ICP‐AES), solid UV/Vis, photoluminescence spectroscopy, powder X‐ray diffraction (P‐XRD) and thermogravimetric analysis (TGA). All the polyanions are isostructural and consists of a lanthanide ion sandwiched between two units of (1,5) isomer of di‐Zn substituted α‐Keggin type tungstophosphate. The complexes Sm‐2 a, Eu‐3 a, Tb‐5 a, and Dy‐6 a show good photoluminescence behavior. The catalytic properties were examined for the oxidation of thioethers. The catalyst is stable with a high turn over frequency (TOF) of 6250 h−1 and can be recovered even after 5 consecutive cycles. Furthermore, magnetic properties revealed that Gd‐4 a, Tb‐5 a, Dy‐6 a, Er‐8 a, and Yb‐10 a show single‐molecule magnetic properties.
Sepsis‐associated purpura fulminans caused by emphysematous cystitis
Authors: Fukuta Kyotaro , Shiozaki Keito , Nakanishi Ryoichi , Inai Tohru , Izaki Hirofumi , Yamamura Rie , Nakataki Emiko , Kudo Eiji , Kanda Kazuya 
Published: August 2021

IntroductionEmphysematous cystitis is a rare pathology characterized by gas bubbles within the bladder wall and lumen from gas‐producing bacteria. Sepsis‐associated purpura fulminans is also rare and shows poor clinical outcomes.Case presentationA 73‐year‐old man was hospitalized at a nearby hospital due to chronic subdural hematoma, symptomatic epilepsy, and diabetes mellitus. He was transferred to our hospital with fever, low blood pressure, and cyanosis of the legs, and was diagnosed with septic shock due to emphysematous cystitis with purpura fulminans. He underwent intensive treatment, including retroperitoneal drainage. Urine culture was positive for Citrobacter freundii. His general condition gradually improved and diffuse air decreased after surgery, but progressive purpuric skin necrosis became evident on the legs, which could not be salvaged. He died on the 25th hospital day.ConclusionSepsis‐associated purpura fulminans caused by emphysematous cystitis shows a very poor prognosis irrespective of intensive treatment, including retroperitoneal drainage.
A new strategy for canine visceral leishmaniasis diagnosis based on FTIR spectroscopy and machine learning
Authors: Larios Gustavo , Ribeiro Matheus , Arruda Carla , Oliveira Samuel L. , Canassa Thalita , Baker Matthew J. , Marangoni Bruno , Ramos Carlos , Cena Cícero 
Published: August 2021

AbstractVisceral leishmaniasis is a neglected disease caused by protozoan parasites of the genus Leishmania. The successful control of the disease depends on its accurate and early diagnosis, which is usually made by combining clinical symptoms with laboratory tests such as serological, parasitological, and molecular tests. However, early diagnosis based on serological tests may exhibit low accuracy due to lack of specificity caused by cross‐reactivities with other pathogens, and sensitivity issues related, among other reasons, to disease stage, leading to misdiagnosis. In this study was investigated the use of mid‐infrared spectroscopy and multivariate analysis to perform a fast, accurate, and easy canine visceral leishmaniasis diagnosis. Canine blood sera of 20 noninfected, 20 Leishmania infantum, and eight Trypanosoma evansi infected dogs were studied. The data demonstrate that principal component analysis with machine learning algorithms achieved an overall accuracy above 85% in the diagnosis.
Using redox potential as a feasible marker for banked blood quality and the state of oxidative stress in stored red blood cells
Authors: Daniels Rodney C. , Jun Hyesun , Davenport Robertson D. , Collinson Maryanne M. , Ward Kevin R. 
Published: August 2021

AbstractBackgroundStored red blood cells (RBCs) may undergo oxidative stress over time, with functional changes affecting oxygen delivery. Central to these changes are oxidation‐reduction (redox) reactions and redox potential (RP) that must be maintained for cell function. RP imbalance can lead to oxidative stress that may contribute to storage lesions. This study's purpose was to identify changes in RP over time in banked RBCs, and among RBCs of similar age.MethodsMultiple random RBC segments from RBC units were tested (n = 32), ranging in age from 5 to 40 days, at 5‐day intervals. RP was recorded by measuring open circuit potential of RBCs using nanoporous gold electrodes with Ag/AgCl reference. RP measures were also performed on peripheral venous blood from 10 healthy volunteers. RP measures were compared between RBC groups, and with volunteer blood.ResultsStored RBCs show time‐dependent RP increases. There were significant differences in Day 5 RP compared to all other groups (p ≤ 0.005), Day 10–15 vs. ages ≥ Day 20 (p ≤ 0.025), Day 20–25 vs. Day 40 (p = 0.039), and all groups compared to healthy volunteers. RP became more positive over time suggesting ongoing oxidation as RBCs age; however, storage time alone was not predictive of RP measured in a particular unit/segment.ConclusionsThere are significant differences in RP between freshly stored RBCs and all others, with RP becoming more positive over time. However, storage time alone does not predict RP, indicating RP screening may be an important measure of RBC oxidative stress and serve as an RBC quality marker.
Estimates of the sensible heat of rainfall in the tropics from reanalysis and observations
Authors: Ramos Camila Gomes Martins , Tan Haochen , Ray Pallav , Dudhia Jimy 
Published: August 2021

AbstractPrecipitation cools the surface because the temperature of raindrops is typically lower than the temperature of the surface. This precipitation‐induced sensible heat flux (QP) due to the temperature difference between the surface and raindrops is thought to be small and is typically ignored in weather and climate models. However, there are many instances in which instantaneous values in QP can be large, especially in extreme rainfall events. In this study, we provide a systematic estimate of QP over the tropics based on in‐situ buoy observations, satellite data, and reanalysis. The results show that the highest climatological QP values (~2 to 3 W m−2) are found over the Intertropical Convergence Zone (ITCZ) and the South Pacific Convergence Zone (SPCZ), both associated with higher amount of precipitation. The QP over land, however, is not well correlated with precipitation due to a more complex relationship between the raindrops temperature and surface temperature. Estimation of QP based on in‐situ buoy observations shows that QP can be large at shorter time scales, and can be higher than surface sensible heat flux due to air‐sea temperature difference (QSH), and even surface latent heat flux (QLH), for heavy precipitating events. Implications of these results and possible future research avenues related to QP are discussed.
Mechanical and Thermal Properties of Epoxy/Poly(Styrene‐co‐Acrylonitrile) (SAN)/Organoclay Nanocomposites
Authors: Surendran Anu , Geethamma V. G. , Kalarikkal Nandakumar , Thomas Sabu 
Published: August 2021

AbstractThis article focuses on the investigations on mechanical and thermal properties of the epoxy/poly(styrene‐co‐acrylonitrile) (SAN)/cloisite 20A nanocomposites. The analysis is performed in two particular compositions of epoxy/SAN blends to study the effect of nanoclay addition. The compositions of blends, epoxy/5 phr SAN and epoxy/15 phr SAN, are selected based on the difference in phase separation mechanism and microstructure. An increment in tensile strength is observed for epoxy/5 phr SAN/1 wt% cloisite 20A nanocomposite. Young's modulus is increased in epoxy/15 phr SAN/cloisite 20A nanocomposites. A surge in the toughness and impact properties is observed for the nanocomposites. Beneficial increment in activation energy for thermal degradation is observed for epoxy/SAN blends and epoxy/SAN/cloisite 20A nanocomposites. The nanocomposites are suitable for high temperature applications without much compromise in the mechanical properties.
Effect of MWCNTs on the Wetting Behavior of PP/NR Blends
Authors: Nair Sharika T. , K Bicy , George Soney C. , Thomas Sabu 
Published: August 2021

AbstractBlends of polypropylene (PP) and natural rubber (NR) with different loadings (1, 3, 5, and 7 wt%) of multiwalled carbon nanotubes (MWCNTs) are prepared by melt blending process. Influence of MWCNT concentration and blend ratio on the surface energy characteristics and wetting behavior of PP/NR/MWCNT nanocomposites are investigated using contact angle measurements with water and dimethyl sulfoxide. The surface energy, work of adhesion, spreading coefficient, interfacial energy, and interaction parameter are measured for all composites. It is understood that contact angle value of nanocomposites increases with the increasing MWCNT content and is attributed to the increase in hydrophobic nature of blends due to the presence of hydrophobic MWCNTs. Similar trend of variation of contact angle is found for nanocomposites with different blend ratio. The study also reveals that contact angle and wetting property of the nanocomposite increases with increase in the surface roughness of the sample. Results of contact angle studies show good agreement with the morphology of nanocomposites obtained by atomic force microscopy techniques.
Non‐ribosomal insights into ribosomal P2 protein in Plasmodium falciparum‐infected erythrocytes
Authors: Das Sudipta , Roy Bhaskar , Chakrabarty Saswata 
Published: August 2021

AbstractThe enormous complexity of the eukaryotic ribosome has been a real challenge in unlocking the mechanistic aspects of its amazing molecular function during mRNA translation and many non‐canonical activities of ribosomal proteins in eukaryotic cells. While exploring the uncanny nature of ribosomal P proteins in malaria parasites Plasmodium falciparum, the 60S stalk ribosomal P2 protein has been shown to get exported to the infected erythrocyte (IE) surface as an SDS‐resistant oligomer during the early to the mid‐trophozoite stage. Inhibiting IE surface P2 either by monoclonal antibody or through genetic knockdown resulted in nuclear division arrest of the parasite. This strange and serendipitous finding has led us to explore more about un‐canonical cell biology and the structural involvement of P2 protein in Plasmodium in the search for a novel biochemical role during parasite propagation in the human host.