bluuebunny/crossref_metadata_2025_split huggingface dataset:
α‐Amylase Immobilization on P(HEMA‐co‐PEGMA) Hydrogels: Preparation, Characterization, and Catalytic Investigation
Authors: Doğan Demet , Ulu Ahmet , Sel Evren , Köytepe Süleyman , Ateş Burhan 
Published: May 2021

AbstractThe aims of this study are to synthesize and characterize poly (2‐hydroxyethyl methacrylate‐co‐poly (ethylene glycol) methacrylate) (P(HEMA‐co‐PEG500MA)) structures containing polyethylene glycol (PEG) side groups and to investigate their possible use in α‐amylase immobilization. For this purpose, P(HEMA‐co‐PEG500MA) copolymer structures are synthesized by using different monomer ratios. P(HEMA‐co‐PEG500MA) copolymer structures are confirmed by Fourier transform infrared spectroscopy (FTIR), and elemental analysis techniques. In addition, thermal, and morphological properties of the copolymers are investigated by thermal gravimetric analysis/differential scanning calorimetry, and scanning electron microscopy (SEM). Afterward, α‐amylase from Aspergillus oryzae is immobilized on synthesized copolymer support by using physical interactions. The success of immobilization is elucidated via FTIR, SEM, and energy dispersive X‐ray spectroscopy (EDX) methods. In addition, the influences of temperature, pH, storage time, and repeated uses on the activity of free and immobilized α‐amylase are investigated. According to the outcomes, the immobilized α‐amylase possesses a better pH and thermal resistance than the free one. Additionally, the immobilized α‐amylase maintains about 53% of its original activity after eight reuses and it exhibits about 50% relative activity after 28 days of storage. In conclusion, the immobilized α‐amylase can be utilized as a potential efficient catalyst to produce maltose from the hydrolysis of starch.
Characterization and Antibacterial Activity of Encapsulated Rosemary Essential Oil within Amylose Nanostructures as a Natural Antimicrobial in Food Applications
Authors: Amani Fateme , Sami Masoud , Rezaei Atefe 
Published: May 2021

AbstractRosemary essential oil (REO) is a natural phenolic compound with high antimicrobial activity. However, its application is limited due to the poor solubility in water, instability, and high volatility. In this study, REO is incorporated into the high amylose corn starch (HACS) nanostructures by inclusion complexation. The characterization of the obtained nanostructures is done by SEM, TGA, FTIR, and XRD. Encapsulation efficiency, loading capacity, stability, release, and antibacterial activity of encapsulated REO are analyzed. The nanostructures show spherical nanoparticles with an average size lower than 200 nm. The results of XRD and FTIR confirm the incorporation of REO into the amylose nanostructures. Thermogravimetric analysis indicates that the inclusion complex of REO and HACS increases the thermal stability of REO significantly. The solubility and antibacterial activity of REO are enhanced after complexation with amylose nanostructures. Minimum inhibitory concentration (MIC) of free REO is 3.52 mg mL−1 or 0.39% v/v and for encapsulated REO is decreased to 2.5 mg mL−1. The results suggest that HACS can be used as a potential carrier for sensitive and hydrophobic compounds to enhance their application in the pharmaceutical and food industries.
Systems Chemistry in Self‐Healing Materials
Authors: Li Panpan , Hao Jingcheng , Wang Xu 
Published: May 2021

AbstractSelf‐healing materials are a kind of intelligent materials that have the ability to repair themselves after damage. By using chemical reaction networks to temporarily control the dynamics of covalent or coordination bonds, systems chemistry has recently shown great promise to reconcile the contradiction between the kinetic stability/inertness and intrinsic healing ability of synthetic materials. When compared to the traditional self‐healing strategies for synthetic materials, the regulation of the healing ability of materials by systems chemistry looks clumsy, but it represents a way similar to the self‐healing in biological systems, which is essentially regulated by complex biochemical reaction networks. Therefore, this field is worthy of further studies. In this Minireview, the significance, achievements and expectations of systems chemistry in regulating the healing ability of synthetic materials are discussed. We hope that it would be an inspiration for creating smart self‐healing materials with life‐like properties.
Recent Development in the Synthesis and Catalytic Application of Iridacycles
Authors: Chen Zhenyu , Kacmaz Aysecik , Xiao Jianliang 
Published: May 2021

AbstractCyclometallated complexes are well‐known and have found many applications. This article provides a short review on the progress made in the synthesis and application to catalysis of cyclometallated half‐sandwich Cp*Ir(III) complexes (Cp*: pentamethylcyclopentadienyl) since 2017. Covered in the review are iridacycles featuring conventional C,N chelates and less common metallocene and carbene‐derived C,N and C,C ligands. This is followed by an overview of the studies of their applications in catalysis ranging from asymmetric hydrogenation, transfer hydrogenation, hydrosilylation to dehydrogenation.
Choosing the right exit: How functional plasticity of the nuclear pore drives selective and efficient mRNA export
Authors: Bensidoun Pierre , Zenklusen Daniel , Oeffinger Marlene 
Published: May 2021

AbstractThe nuclear pore complex (NPC) serves as a central gate for mRNAs to transit from the nucleus to the cytoplasm. The ability for mRNAs to get exported is linked to various upstream nuclear processes including co‐transcriptional RNP assembly and processing, and only export competent mRNPs are thought to get access to the NPC. While the nuclear pore is generally viewed as a monolithic structure that serves as a mediator of transport driven by transport receptors, more recent evidence suggests that the NPC might be more heterogenous than previously believed, both in its composition or in the selective treatment of cargo that seek access to the pore, providing functional plasticity to mRNA export. In this review, we consider the interconnected processes of nuclear mRNA metabolism that contribute and mediate export competence. Furthermore, we examine different aspects of NPC heterogeneity, including the role of the nuclear basket and its associated complexes in regulating selective and/or efficient binding to and transport through the pore.This article is categorized under:
RNA Export and Localization > Nuclear Export/Import
RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms
RNA Interactions with Proteins and Other Molecules > Protein‐RNA Interactions: Functional Implications
Dyson’s classification and real division superalgebras
Authors: Geiko Roman , Moore Gregory W. 
Published: May 2021

AbstractIt is well-known that unitary irreducible representations of groups can be usefully classified in a 3-fold classification scheme: Real, Complex, Quaternionic. In 1962 Freeman Dyson pointed out that there is an analogous 10-fold classification of irreducible representations of groups involving both unitary and antiunitary operators. More recently, it was realized that there is also a 10-fold classification scheme involving superdivision algebras. Here we give a careful proof of the equivalence of these two 10-fold ways.
Analysis of some heterogeneous catalysis models with fast sorption and fast surface chemistry
Authors: Augner Björn , Bothe Dieter 
Published: May 2021

AbstractWe investigate limit models resulting from a dimensional analysis of quite general heterogeneous catalysis models with fast sorption (i.e. exchange of mass between the bulk phase and the catalytic surface of a reactor) and fast surface chemistry for a prototypical chemical reactor. For the resulting reaction–diffusion systems with linear boundary conditions on the normal mass fluxes, but at the same time nonlinear boundary conditions on the concentrations itself, we provide analytic properties such as local-in-time well-posedness, positivity, a priori bounds and comment on steps towards global existence of strong solutions in the class$$\mathrm {W}^{(1,2)}_p(J \times \Omega ; {{\,\mathrm{{\mathbb {R}}}\,}}^N)$$Wp(1,2)(J×Ω;RN), and of classical solutions in the Hölder class$$\mathrm {C}^{(1+\alpha , 2 + 2\alpha )}({\overline{J}} \times {\overline{\Omega }}; {{\,\mathrm{{\mathbb {R}}}\,}}^N)$$C(1+α,2+2α)(J¯×Ω¯;RN). Exploiting that the model is based on thermodynamic principles, we further show a priori bounds related to mass conservation and the entropy principle.
Fetale Alkoholspektrumstörungen – Diagnose, Prognose und Prävention
Authors: Moder Judith E. , Ordenewitz Lisa K. , Schlüter Julia A. , Weinmann Tobias , Altebäumer Philine , Jung Jessica , Heinen Florian , Landgraf Mirjam N. 
Published: May 2021

ZusammenfassungDie Fetale Alkoholspektrumstörung ist eine der häufigsten bei Geburt bestehenden chronischen Erkrankungen, die zum Großteil nicht oder fehldiagnostiziert wird. Dies führt zu inadäquater, ineffektiver Förderung und Therapie der erkrankten Kinder sowie mangelnder Unterstützung der betroffenen Familien. Daraus resultiert nicht nur ein hohes Maß an Sekundärerkrankungen, sondern auch eine Einbuße in der Möglichkeit der Sekundär- und Tertiärprävention bei erkrankten Kindern und betroffenen Familien. Sekundär und Tertiärprävention sind jedoch bei richtiger und rechtzeitiger Diagnose möglich. Die Primärprävention im Bereich Alkoholkonsum in der Schwangerschaft und Fetale Alkoholspektrumstörung muss auch in Zukunft sowohl von medizinischer als auch politischer Seite strukturiert, interdisziplinär und wissenschaftlich basiert geplant und durchgeführt werden. Neben der Aufklärung der Allgemeinbevölkerung ist hierbei die Wissensvermittlung an ÄrztInnen und andere medizinisch-psychologisch-pädagogische Fachkräfte besonders relevant.
Increasing longevity and life satisfaction: is there a catch to living longer?
Authors: Nemitz Janina 
Published: May 2021

AbstractHuman longevity is rising rapidly all over the world, but are longer lives more satisfied lives? This study suggests that the answer might be no. Despite a substantial increase in months of satisfying life, people’s overall life satisfaction declined between 1985 and 2011 in West Germany due to substantial losses of life satisfaction in old age. When compared to 1985, in 2011, elderly West Germans were, on average, much less satisfied throughout their last five years of life. Moreover, they spent a larger proportion of their remaining lifetime in states of dissatisfaction, on average. Two important mechanisms that contributed to this satisfaction decline were health and social isolation. Using a broad variety of sensitivity tests, I show that these results are robust to a large set of alternative explanations.
Mental health among clinicians: what do we know and what can we do?
Authors: Patel Mittal , Swift Steven , Digesu Alex 
Published: May 2021

AbstractMental health and mental health disorders among clinicians remain a taboo, despite increasing evidence showing the direct impact on medical teams and patient care. This editorial is aimed at increasing awareness of mental issues amongst healthcare professionals, identifying perceived barriers to seeking help, and suggesting ways in which to seek help. Mental health disorders, including anxiety and depression, are prevalent from medical school, leading to increased burnout and suicide risks at later stages of a clinician’s career. There is often a reluctance to seek help, particularly amongst the surgical specialties, caused by self-criticism, lack of convenient access and the potential negative impact on medical licensure. This editorial has been written in loving memory of our colleague, friend and board member Dr. Nikolaus Veit-Rubin, who sadly passed away at the beginning of the year. It is written in the hope of highlighting the importance of maintaining mental wellbeing amongst the medical team, supporting help-seeking behaviour and changing attitudes toward mental health disorders amongst clinicians.
Shapes of hyperbolic triangles and once-punctured torus groups
Authors: Kim Sang-hyun , Koberda Thomas , Lee Jaejeong , Ohshika Ken’ichi , Tan Ser Peow , Gao Xinghua 
Published: May 2021

AbstractLet$$\Delta $$Δbe a hyperbolic triangle with a fixed area$$\varphi $$φ. We prove that for all but countably many$$\varphi $$φ, generic choices of$$\Delta $$Δhave the property that the group generated by the$$\pi $$π-rotations about the midpoints of the sides of the triangle admits no nontrivial relations. By contrast, we show for all$$\varphi \in (0,\pi ){\setminus }\mathbb {Q}\pi $$φ∈(0,π)\Qπ, a dense set of triangles does afford nontrivial relations, which in the generic case map to hyperbolic translations. To establish this fact, we study the deformation space$$\mathfrak {C}_\theta $$Cθof singular hyperbolic metrics on a torus with a single cone point of angle$$\theta =2(\pi -\varphi )$$θ=2(π-φ), and answer an analogous question for the holonomy map$$\rho _\xi $$ρξof such a hyperbolic structure$$\xi $$ξ. In an appendix by Gao, concrete examples of$$\theta $$θand$$\xi \in \mathfrak {C}_\theta $$ξ∈Cθare given where the image of each$$\rho _\xi $$ρξis finitely presented, non-free and torsion-free; in fact, those images will be isomorphic to the fundamental groups of closed hyperbolic 3-manifolds.
A comprehensive review of imaging findings in COVID-19 - status in early 2021
Authors: Afshar-Oromieh Ali , Prosch Helmut , Schaefer-Prokop Cornelia , Bohn Karl Peter , Alberts Ian , Mingels Clemens , Thurnher Majda , Cumming Paul , Shi Kuangyu , Peters Alan , Geleff Silvana , Lan Xiaoli , Wang Feng , Huber Adrian , Gräni Christoph , Heverhagen Johannes T. , Rominger Axel , Fontanellaz Matthias , Schöder Heiko , Christe Andreas , Mougiakakou Stavroula , Ebner Lukas 
Published: May 2021

AbstractMedical imaging methods are assuming a greater role in the workup of patients with COVID-19, mainly in relation to the primary manifestation of pulmonary disease and the tissue distribution of the angiotensin-converting-enzyme 2 (ACE 2) receptor. However, the field is so new that no consensus view has emerged guiding clinical decisions to employ imaging procedures such as radiography, computer tomography (CT), positron emission tomography (PET), and magnetic resonance imaging, and in what measure the risk of exposure of staff to possible infection could be justified by the knowledge gained. The insensitivity of current RT-PCR methods for positive diagnosis is part of the rationale for resorting to imaging procedures. While CT is more sensitive than genetic testing in hospitalized patients, positive findings of ground glass opacities depend on the disease stage. There is sparse reporting on PET/CT with [18F]-FDG in COVID-19, but available results are congruent with the earlier literature on viral pneumonias. There is a high incidence of cerebral findings in COVID-19, and likewise evidence of gastrointestinal involvement. Artificial intelligence, notably machine learning is emerging as an effective method for diagnostic image analysis, with performance in the discriminative diagnosis of diagnosis of COVID-19 pneumonia comparable to that of human practitioners.
Airflow Limitation Predicts Postoperative Pneumonia after Esophagectomy
Authors: Maruyama Suguru , Okamura Akihiko , Ishizuka Naoki , Kanie Yasukazu , Sakamoto Kei , Fujiwara Daisuke , Kanamori Jun , Imamura Yu , Watanabe Masayuki 
Published: May 2021

AbstractBackgroundChronic obstructive pulmonary disease (COPD) is known to be a risk factor of pneumonia after esophagectomy. In this study, we investigated the relationship of airflow limitation with the occurrence and the severity of pneumonia in esophageal cancer patients who underwent esophagectomy.MethodsWe enrolled 844 patients who underwent curative esophagectomy between 2009 and 2018. The airflow limitation was evaluated using the percent‐predicted forced expiratory volume at 1 s (%FEV1) with spirometry.ResultsThere were 597 (70.7%), 141 (16.7%), 68 (8.1%), and 38 patients (4.5%) with %FEV1 of ≥ 90%, 80–90%, 70–80%, and < 70% categories, respectively. One hundred and ninety‐one patients (22.6%) occurred pneumonia, and the incidences of pneumonia in each category of patients were 18.8%, 28.4%, 29.4%, and 50.0%, respectively. In multivariate analysis, the categories of 80%–90%, 70–80%, and < 70% were significantly associated with a higher incidence of postoperative pneumonia (OR 1.57; 95% CI 1.02–2.43, OR 1.87; 95% CI 1.04–3.36, OR 3.34; 95% CI 1.66–6.71, respectively), with the %FEV1 category of ≥ 90% as reference. The incidence of severe pneumonia of Clavien–Dindo grade III or higher was also significantly associated with the %FEV1. In patients without COPD, the incidence of pneumonia was significantly higher in those with %FEV1 < 90% than in those with %FEV1 ≥ 90% (32.2% versus 17.5%, p < 0.001).ConclusionsThe airflow limitation can help predict the occurrence of pneumonia after esophagectomy in patients with and without COPD. Exclusive preventive measures should be considered in patients with reduced %FEV1 undergoing esophagectomy.
Profiling of bacterial bloodstream infections in hematological and oncological patients based on a comparative survival analysis
Authors: Weber Sarah , Magh Aaron , Hogardt Michael , Kempf Volkhard A. J. , Vehreschild Maria J. G. T. , Serve Hubert , Scheich Sebastian , Steffen Björn 
Published: May 2021

AbstractBloodstream infections (BSI) are a frequent complication in patients with hematological and oncological diseases. However, the impact of different bacterial species causing BSI and of multiple BSI remains incompletely understood. We performed a retrospective study profiling 637 bacterial BSI episodes in hematological and oncological patients. Based on the 30-day (30d) overall survival (OS), we analyzed different types of multiple BSI and grouped BSI-associated bacteria into clusters followed by further assessment of clinical and infection-related characteristics. We discovered that polymicrobial BSI (different organisms on the first day of a BSI episode) and sequential BSI (another BSI before the respective BSI episode) were associated with a worse 30d OS. Different bacterial groups could be classified into three BSI outcome clusters based on 30d OS: favorable (FAV) including mainly common skin contaminants, Escherichia spp. and Streptococcus spp.; intermediate (INT) including mainly Enterococcus spp., vancomycin-resistant Enterococcus spp., and multidrug-resistant gram-negative bacteria (MDRGN); and adverse (ADV) including MDRGN with an additional carbapenem-resistance (MDRGN+CR). A polymicrobial or sequential BSI especially influenced the outcome in the combination of two INT cluster BSI. The presence of a polymicrobial BSI and the assignment into the BSI outcome clusters were identified as independent risk factors for 30d mortality in a Cox multivariate regression analysis. The assignment to a BSI outcome cluster and the differentiated perspective of multiple BSI open new insights into the prognosis of patients with BSI and should be further validated in other patient cohorts.
Numerical and experimental study on turbulence statistics in a large fan-stirred combustion vessel
Authors: Morsy M. E. , Yang J. 
Published: May 2021

AbstractParticle image velocimetry (PIV) has become a popular non-intrusive tool for measuring various types of flows. However, when measuring three-dimensional flows with two-dimensional (2D) PIV, there are some uncertainties in the measured velocity field due to out-of-plane motion, which might alter turbulence statistics and distort the overall flow characteristics. In the present study, three different turbulence models are employed and compared. Mean and fluctuating fields obtained by three-dimensional computational fluid dynamics modeling are compared to experimental data. Turbulence statistics such as integral length scale, Taylor microscale, Kolmogorov scale, turbulence kinetic energy, dissipation rate, and velocity correlations are calculated at different experimental conditions (i.e., pressure, temperature, fan speed, etc.). A reasonably isotropic and homogeneous turbulence with large turbulence intensities is achieved in the central region extending to almost 45 mm radius. This radius decreases with increasing the initial pressure. The influence of the third dimension velocity component on the measured characteristics is negligible. This is a result of the axisymmetric features of the flow pattern in the current vessel. The results prove that the present vessel can be conveniently adopted for several turbulent combustion studies including mainly the determination of turbulent burning velocity for gaseous premixed flames in nearly homogeneous isotropic turbulence.Graphic abstract
Glucagon-like peptide-1 (GLP-1) receptor activation dilates cerebral arterioles, increases cerebral blood flow, and mediates remote (pre)conditioning neuroprotection against ischaemic stroke
Authors: Nizari Shereen , Basalay Marina , Chapman Philippa , Korte Nils , Korsak Alla , Christie Isabel N. , Theparambil Shefeeq M. , Davidson Sean M. , Reimann Frank , Trapp Stefan , Yellon Derek M. , Gourine Alexander V. 
Published: May 2021

AbstractStroke remains one of the most common causes of death and disability worldwide. Several preclinical studies demonstrated that the brain can be effectively protected against ischaemic stroke by two seemingly distinct treatments: remote ischaemic conditioning (RIC), involving cycles of ischaemia/reperfusion applied to a peripheral organ or tissue, or by systemic administration of glucagon-like-peptide-1 (GLP-1) receptor (GLP-1R) agonists. The mechanisms underlying RIC- and GLP-1-induced neuroprotection are not completely understood. In this study, we tested the hypothesis that GLP-1 mediates neuroprotection induced by RIC and investigated the effect of GLP-1R activation on cerebral blood vessels, as a potential mechanism of GLP-1-induced protection against ischaemic stroke. A rat model of ischaemic stroke (90 min of middle cerebral artery occlusion followed by 24-h reperfusion) was used. RIC was induced by 4 cycles of 5 min left hind limb ischaemia interleaved with 5-min reperfusion periods. RIC markedly (by ~ 80%) reduced the cerebral infarct size and improved the neurological score. The neuroprotection established by RIC was abolished by systemic blockade of GLP-1R with a specific antagonist Exendin(9–39). In the cerebral cortex of GLP-1R reporter mice, ~ 70% of cortical arterioles displayed GLP-1R expression. In acute brain slices of the rat cerebral cortex, activation of GLP-1R with an agonist Exendin-4 had a strong dilatory effect on cortical arterioles and effectively reversed arteriolar constrictions induced by metabolite lactate or oxygen and glucose deprivation, as an ex vivo model of ischaemic stroke. In anaesthetised rats, Exendin-4 induced lasting increases in brain tissue PO2, indicative of increased cerebral blood flow. These results demonstrate that neuroprotection against ischaemic stroke established by remote ischaemic conditioning is mediated by a mechanism involving GLP-1R signalling. Potent dilatory effect of GLP-1R activation on cortical arterioles suggests that the neuroprotection in this model is mediated via modulation of cerebral blood flow and improved brain perfusion.