bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eine amphipathische alpha‐Helix lenkt die Modifizierung ribosomal‐synthetisierter Lipolanthine
Authors: Wiebach Vincent , Mainz Andi , Schnegotzki Romina , Siegert Mary‐Ann J. , Hügelland Manuela , Pliszka Nicole , Süssmuth Roderich D. 
Published: June 2020

AbstractDie stark anti‐Gram‐positiven Lipolanthine repräsentieren eine neue Gruppe von lipidierten, ribosomal synthetisierten und post‐translational modifizierten Peptiden (RiPPS). Sie sind bicyclische Octapeptide mit einem zentralen quaternären Kohlenstoffatom in der Aminosäure Avionin, die durch die Klasse‐III Lanthipeptidsynthetase MicKC und die Cystein‐Decarboxylase MicD synthetisiert werden. Genome‐Mining eröffnete eine weit gefächerte und unerwartete biosynthetische Diversität an Lipolanthin‐Genclustern, die Elemente der RiPP‐, Polyketid‐ und der nicht‐ribosomalen Peptidbiosynthese kombiniert. Durch NMR‐Spektroskopie konnten wir zeigen, dass ein (θxx)θxxθxxθ (θ=L, I, V, M oder T)‐Motiv, das konserviert im Leader‐Peptid der Klasse‐III und ‐IV Lanthipeptide vorliegt, eine amphipatische α‐Helix in MicA bildet. Dies hat einen Einfluss auf die enzymatische Prozessierung des Peptidsubstrats. Unsere Ergebnisse liefern allgemeine Regeln für die Substratauswahl und die enzymatische Regulation während der Lipolanthin‐Reifung. Diese Erkenntnisse werden zukünftige Untersuchungen hinsichtlich der Konstruktion neuer Lanthipeptid‐Grundgerüste mit antibakteriellem Potential erleichtern.
Die Carbonyl⋅⋅⋅Tellurazol‐Chalkogenbindung als molekulare Erkennungseinheit: Von Modellstudien zu supramolekularen organischen Gerüstverbindungen
Authors: Mehrparvar Saber , Wölper Christoph , Gleiter Rolf , Haberhauer Gebhard 
Published: June 2020

AbstractIn den letzten Jahren entwickelten sich die Chalkogenbindungen, bei denen die Bindung über nicht‐kovalente Wechselwirkungen unter Beteiligung von Chalkogenzentren erfolgt, in zahlreichen Forschungsfeldern zu einer interessanten Alternative zu den weitverbreiteten Wasserstoffbrückenbindungen. Mittels quantenchemischer Berechnungen auf hohem Niveau konnte gezeigt werden, dass die Carbonyl⋅⋅⋅Tellurazol‐Chalkogenbindung mindestens so stark wie eine konventionelle Wasserstoffbrückenbindung ist. Durch die Verwendung des Carbonyl⋅⋅⋅Tellurazol‐Bindungsmotivs, das in Form von cyclischen Tellurazolpeptiden zum Einsatz kam, gelang uns das Design komplexer supramolekularer Netzwerke in der festen Phase. Röntgenstrukturanalysen belegen, dass die starre Struktur des Cyclopeptids auf Wasserstoffbrückenbindungen zurückzuführen ist, während das supramolekulare Netzwerk durch Chalkogenbindungen zusammengehalten wird. Die Erscheinungsform des supramolekularen Netzwerks hängt vom verwendeten Peptid ab; sowohl lineare Stränge als auch bienenwabenartige supramolekulare organische Gerüstverbindungen (SOF) konnten beobachtet werden. Die einzigartige SOF‐Struktur verfügt über zwei Kanäle, die mit verschiedenen Lösungsmittelgemischen gefüllt sind, die entweder eingeschlossen oder frei beweglich sind.
Highly Efficient Electroreduction of CO2 to C2+ Alcohols on Heterogeneous Dual Active Sites
Authors: Chen Chunjun , Yan Xupeng , Liu Shoujie , Wu Yahui , Wan Qiang , Sun Xiaofu , Zhu Qinggong , Liu Huizhen , Ma Jun , Zheng Lirong , Wu Haihong , Han Buxing 
Published: June 2020

AbstractElectroreduction of CO2 to liquid fuels such as ethanol and n‐propanol, powered by renewable electricity, offers a promising strategy for controlling the global carbon balance and addressing the need for the storage of intermittent renewable energy. In this work, we discovered that the composite composed of nitrogen‐doped graphene quantum dots (NGQ) on CuO‐derived Cu nanorods (NGQ/Cu‐nr) was an outstanding electrocatalyst for the reduction of CO2 to ethanol and n‐propanol. The Faradaic efficiency (FE) of C2+ alcohols could reach 52.4 % with a total current density of 282.1 mA cm−2. This is the highest FE for C2+ alcohols with a commercial current density to date. Control experiments and DFT studies show that the NGQ/Cu‐nr could provide dual catalytic active sites and could stabilize the CH2CHO intermediate to enhance the FE of alcohols significantly through further carbon protonation. The NGQ and Cu‐nr had excellent synergistic effects for accelerating the reduction of CO2 to alcohols.
An Amphipathic Alpha‐Helix Guides Maturation of the Ribosomally‐Synthesized Lipolanthines
Authors: Wiebach Vincent , Mainz Andi , Schnegotzki Romina , Siegert Mary‐Ann J. , Hügelland Manuela , Pliszka Nicole , Süssmuth Roderich D. 
Published: June 2020

AbstractThe recently discovered strongly anti‐Gram‐positive lipolanthines represent a new group of lipidated, ribosomally synthesized and post‐translationally modified peptides (RiPPs). They are bicyclic octapeptides with a central quaternary carbon atom (avionin), which is installed through the cooperative action of the class‐III lanthipeptide synthetase MicKC and the cysteine decarboxylase MicD. Genome mining efforts indicate a widespread distribution and unprecedented biosynthetic diversity of lipolanthine gene clusters, combining elements of RiPPs, polyketide and non‐ribosomal peptide biosynthesis. Utilizing NMR spectroscopy, we show that a (θxx)θxxθxxθ (θ=L, I, V, M or T) motif, which is conserved in the leader peptides of all class‐III and ‐IV lanthipeptides, forms an amphipathic α‐helix in MicA that destines the peptide substrate for enzymatic processing. Our results provide general rules of substrate recruitment and enzymatic regulation during lipolanthine maturation. These insights will facilitate future efforts to rationally design new lanthipeptide scaffolds with antibacterial potency.
A Self‐Assembled Rhombohedral DNA Crystal Scaffold with Tunable Cavity Sizes and High‐Resolution Structural Detail
Authors: Simmons Chad R. , MacCulloch Tara , Zhang Fei , Liu Yan , Stephanopoulos Nicholas , Yan Hao 
Published: June 2020

AbstractDNA is an ideal molecule for the construction of 3D crystals with tunable properties owing to its high programmability based on canonical Watson–Crick base pairing, with crystal assembly in all three dimensions facilitated by immobile Holliday junctions and sticky end cohesion. Despite the promise of these systems, only a handful of unique crystal scaffolds have been reported. Herein, we describe a new crystal system with a repeating sequence that mediates the assembly of a 3D scaffold via a series of Holliday junctions linked together with complementary sticky ends. By using an optimized junction sequence, we could determine a high‐resolution (2.7 Å) structure containing R3 crystal symmetry, with a slight subsequent improvement (2.6 Å) using a modified sticky‐end sequence. The immobile Holliday junction sequence allowed us to produce crystals that provided unprecedented atomic detail. In addition, we expanded the crystal cavities by 50 % by adding an additional helical turn between junctions, and we solved the structure to 4.5 Å resolution by molecular replacement.
Evaluation of scale‐up methodologies and computational fluid dynamics simulation for fucoxanthin production in airlift photobioareactor
Authors: Aslanbay Guler Bahar , Deniz Irem , Demirel Zeliha , Imamoglu Esra 
Published: June 2020

AbstractResearches about commercial‐scale production of fucoxanthin are increasing day by day due to the much interest of its broad beneficial health effects. The aim of this study was to investigate the scale‐up methodologies in airlift photobioreactor and to simulate fluid flow using computational fluid dynamics (CFD) for fucoxanthin production from Phaeodactylum tricornutum microalgae. During the transition process from 1‐L cultivation bottle to the 2‐L airlift photobioreactor, the constant mixing time, the constant volumetric oxygen transfer coefficient, and the constant volumetric power consumption rate were evaluated as scale‐up methodologies under laboratory conditions. Maximum fucoxanthin yield was found as 1.01 ± 0.07 mg g−1 using scale‐up strategy based on constant volumetric power consumption rate. After that, CFD simulation was performed in order to examine flow characteristics, mixing efficiency, hydrodynamics, and gas holdup for selected operation conditions. It was observed that mixing efficiency was low because the draft tube configuration prevented the circulation of fluid and caused a heterogenic culture medium inside the reactor. It is possible to overcome this bottleneck by developing the effective draft tube.
Occurrence of Guiana dolphin (Sotalia guianensis) in southeast of Brazil: Driven by prey distribution or human fishing activity?
Authors: Ferro de Godoy Daniela , Mendonça Jocemar Tomasino , Andriolo Artur 
Published: June 2020

Abstract

This study used models to assess how the type of prey caught by artisanal fishermen influenced the occurrence of Guiana dolphins (Sotalia guianensis) in the region of the estuarine lagunar comple.x of Cananéia (São Paulo, Brazil).
The data were collected from January 2012 to November 2014, during three fieldwork expeditions per season (spring, summer, autumn, winter).
Mullets (Mugil liza) were the fish with the highest association to dolphins, followed by Oligoplites spp. and Lobotes spp.; Mugil curema and shrimp, on the other hand, negatively influenced their distribution. The presence of fish‐weir fisheries in the estuary also had a positive influence on the occurrence of dolphins, since this fishing gear is used as a barrier, minimizing the potential for their prey to escape.
New technical approaches for 3D morphological imaging and quantification of measurements
Authors: Brenna Cinzia , Khan Arif ul Maula , Picascia Tiziana , Sun Quanchao , Heuveline Vincent , Gretz Norbert 
Published: June 2020

Abstract3D imaging is becoming more and more popular, as it allows us to identify interactions between structures in organs. Furthermore, it gives the possibility to quantify and size these structures. To allow 3D imaging, the tissue sample has to be transparent. This is usually achieved by using optical tissue clearing protocols. Although using optical tissue clearing often results in perfect 3D images, these protocols have some pitfalls, like long duration of sample preparation (up to several weeks), use of toxic substances, damage to antibody staining, fluorescent proteins or dyes, high refractive indices, and high costs of sample processing.Recently we described [Huang et al., Scientific Reports 9(1): 521 (2019)] a fast, safe, and inexpensive ethyl cinnamate (ECi) based optical tissue clearing protocol. Here, we present extensions of our protocol with respect to the deparaffinization of old paraffin‐embedded samples allowing 3D imaging of the blocks. In addition, we learned to remove ECi from the samples allowing the use of routine immunolabeling protocols. Furthermore, we demonstrate new pictures of lungs after expansion microscopy and adaptation of already existing protocols. The aim of our work is, in summary, to describe the advances in these methodologies, focusing on the morphological imaging of kidneys and lungs.
Conjugation of micro/nanocurcumin particles to ZnO nanoparticles changes the surface charge and hydrodynamic size thereby enhancing its antibacterial activity against Escherichia coli and Staphylococcus aureus
Authors: Shome Soumitra , Talukdar Anupam Das , Tewari Sujit , Choudhury Sudip , Bhattacharya Mrinal Kanti , Upadhyaya Hrishikesh 
Published: June 2020

AbstractNanobiotechnology‐mediated synthesis of ZnO nanoparticles, micro/nanocurcumin, and curcumin–ZnO nanocomposites and their characterization followed by comparative study of their antibacterial, antioxidant, and iron‐chelating efficiency at various dosages are discussed. Micro/nanocurcumin and ZnO nanoparticles were synthesized using curcumin and zinc nitrate as precursor and then conjugated by sonication to synthesize curcumin–ZnO nanocomposites. The synthesized nanoparticles were then characterized by using ultraviolet‐visible spectroscopy, X‐ray diffraction, Scanning electron microscopy, Fourier‐transform infrared spectroscopy, and dynamic light scattering analysis. After that, the antibacterial activity of the synthesized nanoparticles was evaluated by the optical density (OD600) method against Escherichia coli and Staphylococcus aureus cells. The DPPH (2,2‐diphenyl‐1‐picrylhydrazyl ), hydroxyl radical scavenging activity, and ferrous ion–chelating efficiency of synthesized nanoparticles were evaluated by spectrophotometry analysis. Nanocurcumin (mean zeta potential = −25 mV; average hydrodynamic diameter = 410 nm) based coating of ZnO nanoparticles (mean zeta potential = −15.9 mV; average hydrodynamic diameter = 274 nm) to synthesize curcumin–ZnO nanocomposites (mean zeta potential = −18.8 mV; average hydrodynamic diameter = 224 nm) exhibited enhanced zeta potential, which resulted in reduced agglomeration, smaller hydrodynamic size in water, improved aqueous solubility, and dispersion. All the aforesaid factors including the synergistic antibacterial effect of ZnO nanoparticle and micro/nanocurcumin contributed to increased antibacterial efficiency of curcumin–ZnO nanocomposites. Micro/nanocurcumin due to its better water solubility and small hydrodynamic diameter exhibited enhanced antioxidant and ferrous ion–chelating efficiency than curcumin.
Microfluidic‐assisted fabrication of reverse micelle/PLGA hybrid microspheres for sustained vascular endothelial growth factor delivery
Authors: Omidi Meisam , Almeida Luis , Tayebi Lobat 
Published: June 2020

AbstractIn this study, poly (d, l‐lactide‐co‐glycolide) (PLGA) composite microspheres containing anhydrous reverse micelle (R.M.) dipalmitoylphosphatidylcholine (DPPC) nanoparticles loaded vascular endothelial growth factor (VEGF) were produced using microfluidic platforms. The VEGF‐loaded R.M. nanoparticles (VRM) were achieved by initial self‐assembly and subsequent lipid inversion of the DPPC vesicles. The fabricated VRMs were encapsulated into the PLGA matrix by flow‐focusing geometry microfluidic platforms. The encapsulation efficiency, in vitro release profile, and the bioactivity of the produced composite microspheres were investigated. The release study showed that VEGF was slowly released from the PLGA composite microspheres over 28 days with a reduced initial burst (18  ±  4.17% in the first 24 H). The VEGF stability during encapsulation and release period was also investigated, and the results indicated that encapsulated VEGF was well preserved. Also, the bioactivity assay of the PLGA composite microspheres on human umbilical vein endothelial cells was confirmed that the encapsulated VEGF was utterly active. The present monodisperse and controllable VEGF‐loaded microspheres with reproducible manner could be widely used in tissue engineering and therapeutic applications.
A novel peroxidase/oxidase mimetic Fe‐porphyrin covalent organic framework enhanced the luminol chemiluminescence reaction and its application in glucose sensing
Authors: Zhao Yaxin , Xu Xiaotong , Ma Yuyu , Tan Haonan , Li Yinhuan 
Published: June 2020

AbstractA Fe‐porphyrin covalent organic framework (Fe‐PorCOF) was prepared through a postmodification strategy and characterized using different techniques. Fe‐PorCOF exhibits an inherent peroxidase/oxidase mimetic catalytic activity and sharply accelerates chemiluminescence (CL) reactions between luminol and hydrogen peroxide (H2O2) or dissolved oxygen (O2) under alkaline conditions. The catalytic role was attributed to a significant increase in production of reactive oxygen species. Using the imminent peroxidase mimetic catalytic activity of Fe‐PorCOF, a new CL method was developed for determination of H2O2 over a linear range from 0.01 to 10.0 μmol·L−1 and with a limit of detection of 5.3 nmol·L−1. The combination of the peroxidase mimetic catalytic activity of Fe‐PorCOF with the catalytic activity of glucose oxidase on glucose oxidation presents a sensitive CL method for glucose assay. The linear range and the detection limit for glucose were 0.05–8.0 μmol·L−1 and 4.0 nmol·L−1, respectively. The practicability of this method was assessed by determination of glucose in human sera. As a peroxidase/oxidase mimetic, Fe‐PorCOF is easy to prepare and exhibits good catalytic efficiency in the luminol reaction. We believe that this strategy will promote the development of a CL field with functional COFs as a catalyst.
Impact of anastomotic leak on long-term survival in patients undergoing gastrectomy for gastric cancer
Authors: Kamarajah S K , Navidi M , Griffin S M , Phillips A W 
Published: June 2020

Abstract

Background
The impact of anastomotic leak (AL) on long-term outcomes after gastrectomy for gastric adenocarcinoma is poorly understood. This study determined whether AL contributes to poor overall survival.

Methods
Consecutive patients undergoing gastrectomy in a single high-volume unit between 1997 and 2016 were evaluated. Clinicopathological characteristics, oncological and postoperative outcomes were stratified according to whether patients had no AL, non-severe AL or severe AL. Severe AL was defined as anastomotic leakage associated with Clavien–Dindo Grade III–IV complications.

Results
The study included 969 patients, of whom 58 (6·0 per cent) developed AL; 15 of the 58 patients developed severe leakage. Severe AL was associated with prolonged hospital stay (median 50, 30 and 13 days for patients with severe AL, non-severe AL and no AL respectively; P &lt; 0·001) and critical care stay (median 11, 0 and 0 days; P &lt; 0·001). There were no significant differences between groups in number of lymph nodes harvested (median 29, 30 and 28; P = 0·528) and R1 resection rates (7, 5 and 6·5 per cent; P = 0·891). Cox multivariable regression analysis showed that severe AL was independently associated with overall survival (hazard ratio 3·96, 95 per cent c.i. 2·11 to 7·44; P &lt; 0·001) but not recurrence-free survival. In sensitivity analysis, the results for patients who had neoadjuvant therapy then gastrectomy were similar to those for the entire cohort.

Conclusion
AL prolongs hospital stay and is associated with compromised long-term overall survival.
Effects of oxiracetam combined with ginkgo biloba extract in the treatment of acute intracerebral hemorrhage: A clinical study
Authors: Li Xiu‐Xiu , Liu Shi‐Hui , Zhuang Su‐Jing , Guo Shi‐Feng , Pang Shou‐Liang 
Published: June 2020

AbstractPurposeThe present clinical study was conducted to investigate the effect of oxiracetam combined with ginkgo biloba extract in treating patients with acute intracerebral hemorrhage.MethodsNinety‐eight patients with acute cerebral hemorrhage admitted to our hospital were divided into three groups. The differences of brain edema and cerebral hemorrhage were compared between the three groups after 1 and 2 weeks of treatment, and the recovery of neurological function, serum inflammatory factors, AQP‐4, MMP‐9, cognitive function, activities of daily living, and adverse reactions were compared between the three groups after 2 weeks of treatment.ResultsThere was no significant difference among the three groups before treatment (p > .05). After treatment, the recovery of neurological function, serum inflammatory factors, AQP‐4, MMP‐9 levels, cognitive function, and activities of daily living were improved. Among them, the neurological function recovery, serum inflammatory factors, AQP‐4, MMP‐9 levels, cognitive function, and activities of daily living in the combined treatment group and the control group elicited greater results than those in the routine group. The results of the combined treatment group showed the most significant difference (p < .05). The concentration of IL‐6 decreased from 135.98 ± 12.54 to 91.83 ± 7.69 pg/ml, AQP‐4 from 227.55 μg/L ± 21.06 to 114.31 ± 9.22 μg/L, and MMP‐9 from 172.39 ± 9.81 to 94.98 ± 5.01 ng/ml. In addition, the neurological function recovery, the levels of serum inflammatory factors, cognitive function, and activities of daily living in the combined treatment group were better than those in the control group (p < .05). The mean score of MRS in the combined treatment group decreased from 3.36 ± 0.98 at admission to 1.91 ± 0.38.ConclusionOxiracetam combined with Ginkgo biloba extract in the treatment of acute cerebral hemorrhage has a significant improvement effect.
Expression of hypoxia‐inducible factor 1α, glucose transporter 1, and hexokinase 2 in primary central nervous system lymphoma and the correlation with the biological behaviors
Authors: Shen Na , Wang Yaming , Sun Xuefei , Bai Xueyan , He Jinglan , Cui Qu , Qian Jun , Zhu Hong , Chen Yuedan , Xing Ruixian , Liu Qing , Wu Yuchen , Li Junhong , Lai Wenyuan , Sun Shengjun , Ji Nan , Liu Yuanbo 
Published: June 2020

AbstractBackgroundIt has been indicated that abnormal glucose metabolism mediated by hypoxia‐inducible factor 1α (HIF‐1α) played an essential role in the development of solid tumor. However, there were rare studies about the role of them in primary central nervous system lymphoma (PCNSL).ObjectiveTo investigate the protein levels of HIF‐1α, glucose transporter 1 (GLUT1), and hexokinase 2 (HK2) in PCNSL and whether their levels are associated with prognostic factors.MethodsExpression of HIF‐1α, GLUT1, and HK2 in 39 tumor tissues was evaluated by immunohistochemical stainning. The correlation of the expression of HIF‐1α with the protein level of GLUT1 and HK2 was investigated. In addition, the association between these protein expression levels and clinical parameters and prognosis was analyzed.ResultsIn the tumor specimens of PCNSL, positive stainings of HIF‐1α, GLUT1, and HK2 were in 23 patients (58.97%), 25 patients (64.1%), and 26 patients (66.67%), respectively, which were associated with the expression level of lactic dehydrogenase (LDH), but not with age, gender, number of lesion, ECOG score, or deep structure. The expression of HIF‐1α was positively correlated with the expression of GLUT1 (p < .01, r = .749) and HK2 (p < .01, r = .787). Univariate analysis showed that upregulated GLUT1 was unfavorable predictors of progression‐free survival (PFS) in PCNSL. The results of Cox proportional hazards model showed GLUT1 was significantly associated with shorter PFS (hazard ration: 5.65; 95% confidence interval: 1.23–25.84; p = .026).ConclusionsThis study indicated that there was a hypoxic microenvironment and HIF‐1α was involved in the regulation of glycolysis pathway in PCNSL. GLUT1 might be a potential marker for shorter PFS in PCNSL.
Addressing the challenges of integrating carbon calculation tools in the construction industry
Authors: Jackson David J. , Kaesehage Katharina 
Published: June 2020

AbstractThe construction industry is facing growing pressure to reduce carbon emissions. An important first step is to quantify emissions from construction projects enabling designs to be changed and emissions reduced. Whilst progress has been made in the development of carbon calculation tools, the uptake of these tools has been slow. This paper seeks to understand the reasons for the slow implementation of carbon calculation tools in the construction industry and provide guidance on how to overcome these challenges. We find there are specific issues that prevent tools being used such as data security and usability, but more general issues such as a lack of education or regulation also pose a challenge. Our findings suggest that despite the benefits that can come from using carbon calculation tools to reduce emissions, the use of tools on their own will be insufficient to achieve the needed carbon reduction and wider emissions‐related change. Instead, carbon calculation tools need to be looked at within and across construction organisations through training, industry‐wide standards and regulations as well as organisation‐wide requirements and collaboration. The construction industry has a reputation for being slow to react to change, but if this industry waits for regulation before taking action, then the timescales involved may be too long given the pressing need to reduce emissions now. We recommend that for carbon calculation tools to be successfully integrated, the industry must work together to achieve more immediate change.