bluuebunny/crossref_metadata_2025 huggingface dataset:
4D Printing of a Bioinspired Microneedle Array with Backward‐Facing Barbs for Enhanced Tissue Adhesion
Authors: Han Daehoon , Morde Riddish S. , Mariani Stefano , La Mattina Antonino A. , Vignali Emanuele , Yang Chen , Barillaro Giuseppe , Lee Howon
Published: February 2020

Microneedle (MN), a miniaturized needle with a length‐scale of hundreds of micrometers, has received a great deal of attention because of its minimally invasive, pain‐free, and easy‐to‐use nature. However, a major challenge for controlled long‐term drug delivery or biosensing using MN is its low tissue adhesion. Although microscopic structures with high tissue adhesion are found from living creatures in nature (e.g., microhooks of parasites, barbed stingers of honeybees, quills of porcupines), creating MNs with such complex microscopic features is still challenging with traditional fabrication methods. Here, a MN with bioinspired backward‐facing curved barbs for enhanced tissue adhesion, manufactured by a digital light processing 3D printing technique, is presented. Backward‐facing barbs on a MN are created by desolvation‐induced deformation utilizing cross‐linking density gradient in a photocurable polymer. Barb thickness and bending curvature are controlled by printing parameters and material composition. It is demonstrated that tissue adhesion of a backward‐facing barbed MN is 18 times stronger than that of barbless MN. Also demonstrated is sustained drug release with barbed MNs in tissue. Improved tissue adhesion of the bioinspired MN allows for more stable and robust performance for drug delivery, biofluid collection, and biosensing.
Biocompatible and Biodegradable Organic Transistors Using a Solid‐State Electrolyte Incorporated with Choline‐Based Ionic Liquid and Polysaccharide
Authors: Jo Young Jin , Kim Heyn , Ok Jehyung , Shin Yiel‐Jae , Shin Joo Hwan , Kim Tae Hee , Jung Youngmee , Kim Tae‐il
Published: February 2020

Biocompatible, biodegradable, and solid‐state electrolyte‐based organic transistors are demonstrated. As the electrolyte is composed of all edible materials, which are levan polysaccharide and choline‐based ionic liquid, the organic transistor fabricated on the electrolyte can be biocompatible and biodegrable. Compared to the other ion gel based electrolytes, it has superior electrical and mechanical properties, large specific capacitance (≈40 µF cm−2), non‐volatility, flexibility, and high transparency. Thus, it shows mechanical reliability by maintaining electrical performances under up to 1.11% of effective bending strain, 5% of stretching, and have low operation voltage range when it is utilized in organic transistors. Moreover, the biodegradable electrolyte‐based organic transistors can be applied to bio‐integrated devices, such as electrocardiogram (ECG) recordings on human skin and the heart of a rat. The measured ECG signals from the transistors, compared to signals from electrode‐based sensors, has a superior signal‐to‐noise ratio. The biocompatible and biodegradable materials and devices can contribute to the development of many bioelectronics.
Self‐Supporting Ni‐M (M = Mo, Ge, Sn) Alloy Nanosheets via Topotactic Transformation of Oxometallate Intercalated Layered Nickel Hydroxide Salts: Synthesis and Application for Electrocatalytic Hydrogen Evolution Reaction
Authors: Xie Zhengzhe , Zou Yu , Deng Liujun , Jiang Jiang
Published: February 2020

Metal alloys are valuable for achieving energy‐ and cost‐efficient electrocatalysis. To maximize active sites exposure and electron transport, a general method to prepare binder‐free Ni‐M (M = Mo, Ge, Sn) bimetallic alloy nanosheets electrocatalyst for the hydrogen evolution reaction (HER) is successfully developed for the first time, via topotactic transformation of layered nickel hydroxide salts (Ni‐LHS). The obtained bimetallic alloys show much improved HER performance to that of Ni. In particular, Ni4Mo alloy nanosheets exhibit HER activity with an overpotential of only 69.6 mV at 100 mA cm−2 and a low Tafel slope of 37 mV decade−1 in alkaline medium, due to large electrochemical active surface area and low charge transfer resistance. Moreover, Ni4Mo alloy nanosheets also show high HER activity in both acidic and neutral electrolytes with long‐term stability, demonstrating superior activity comparable to or better than state‐of‐the‐art commercial Pt/C catalyst. This topotactic transformation method using LHS precursors provides a way to design and fabricate cost‐effective and energy‐efficient ultrathin 2D bimetallic alloy nanosheets for electrocatalysis, greatly broadening the scope of the currently available self‐supporting metal alloy electrocatalysts.
Accessing the Hotspots of Cavity Plasmon Modes in Vertical Metal–Insulator–Metal Structures for Surface Enhanced Raman Scattering
Authors: Dai Fang , Horrer Andreas , Adam Pierre‐Michel , Fleischer Monika
Published: February 2020

In metal–insulator–metal structures such as Au nanodiscs on an Au film separated by a thin oxide spacer layer, the metal/insulator interfaces can form a Fabry–Perot cavity in which gap surface plasmons are confined. As a result, these cavity plasmon modes show the advantageous properties of strong field enhancement and very narrow resonance line shapes due to the confinement in a cavity. In this work, the hotspots of the electromagnetic near‐field of cavity plasmon modes are exposed to make the strongly enhanced field accessible to Raman molecules. This is achieved by creating an undercut in the spacer between the Au discs and the gold film by wet etching of the spacer. The electromagnetic field distributions as well as the resonance wavelengths of two different cavity plasmon modes in such cavities both with and without undercut are studied by simulations based on the finite element method. The size of the undercut is estimated by relating the measured spectral shift before and after reducing the spacer disc to the one obtained in simulations. Surface enhanced Raman scattering measurements are conducted on arrays of cavities. The effect of the undercut on the Raman scattering intensity is investigated and a notable increase is found.
Strategies for Semiconductor/Electrocatalyst Coupling toward Solar‐Driven Water Splitting
Authors: Thalluri Sitaramanjaneya Mouli , Bai Lichen , Lv Cuncai , Huang Zhipeng , Hu Xile , Liu Lifeng
Published: February 2020

Hydrogen (H2) has a significant potential to enable the global energy transition from the current fossil‐dominant system to a clean, sustainable, and low‐carbon energy system. While presently global H2 production is predominated by fossil‐fuel feedstocks, for future widespread utilization it is of paramount importance to produce H2 in a decarbonized manner. To this end, photoelectrochemical (PEC) water splitting has been proposed to be a highly desirable approach with minimal negative impact on the environment. Both semiconductor light‐absorbers and hydrogen/oxygen evolution reaction (HER/OER) catalysts are essential components of an efficient PEC cell. It is well documented that loading electrocatalysts on semiconductor photoelectrodes plays significant roles in accelerating the HER/OER kinetics, suppressing surface recombination, reducing overpotentials needed to accomplish HER/OER, and extending the operational lifetime of semiconductors. Herein, how electrocatalyst coupling influences the PEC performance of semiconductor photoelectrodes is outlined. The focus is then placed on the major strategies developed so far for semiconductor/electrocatalyst coupling, including a variety of dry processes and wet chemical approaches. This Review provides a comprehensive account of advanced methodologies adopted for semiconductor/electrocatalyst coupling and can serve as a guideline for the design of efficient and stable semiconductor photoelectrodes for use in water splitting.
High‐Performance Trifunctional Electrocatalysts Based on FeCo/Co2P Hybrid Nanoparticles for Zinc–Air Battery and Self‐Powered Overall Water Splitting
Authors: Shi Qing , Liu Qiao , Ma Yu , Fang Zhi , Liang Zhao , Shao Gang , Tang Bin , Yang Weiyou , Qin Lin , Fang Xiaosheng
Published: February 2020

Currently, it is still a significant challenge to simultaneously boost various reactions by one electrocatalyst with high activity, excellent durability, as well as low cost. Herein, hybrid trifunctional electrocatalysts are explored via a facile one‐pot strategy toward an efficient oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The catalysts are rationally designed to be composed by FeCo nanoparticles encapsuled in graphitic carbon films, Co2P nanoparticles, and N,P‐codoped carbon nanofiber networks. The FeCo nanoparticles and the synergistic effect from Co2P and FeCo nanoparticles make the dominant contributions to the ORR, OER, and HER activities, respectively. Their bifunctional activity parameter (∆E) for ORR and OER is low to 0.77 V, which is much smaller than those of most nonprecious metal catalysts ever reported, and comparable with state‐of‐the‐art Pt/C and RuO2 (0.78 V). Accordingly, the as‐assembled Zn–air battery exhibits a high power density of 154 mW cm−2 with a low charge–discharge voltage gap of 0.83 V (at 10 mA cm−2) and excellent stability. The as‐constructed overall water‐splitting cell achieves a current density of 10 mA cm−2 (at 1.68 V), which is comparable to the best reported trifunctional catalysts.
Changing body norms in the context of increasing body size: Samoa in 1995 and 2018
Authors: To Sophie B. , Brewis Alexandra A. , Pomer Alysa , Naseri Take , Reupena Muagututia S. , McGarvey Stephen T. , Hawley Nicola L.
Published: February 2020

Objective

To understand how body size preferences changed in Samoa between 1995 and 2017 to 2019.

Methods

Data were from adults aged from 31 to 59 years, who participated in two separate cross‐sectional studies of obesity and cardiometabolic risk conducted in Samoa in 1995 and 2017 to 2019. Participants nominated line drawings representing their current size, ideal size, the most attractive and healthiest size, and the lower/upper limits of “normal” size.

Results

In both sexes, body size preferences and perceived current average body size have increased, yet preference for bodies smaller than one's perceived current size has persisted. Furthermore, the range of body sizes that people considered “normal” has narrowed, suggesting decreased tolerance for extremes of body size.

Conclusions

These findings may have implications for mental and physical health outcomes, inform development of future health initiatives, and contribute to a deeper understanding of how body norms and weight‐related public health efforts interface.
First analysis of mitochondrial lineages from the eastern Pampa–Patagonia transition during the final late Holocene
Authors: Postillone María Bárbara , Martínez Gustavo , Flensborg Gustavo , Dejean Cristina B.
Published: February 2020

Objective

Studies on population genetics have become highly relevant for understanding the evolutionary history of human settlement in southern South America. The eastern Pampa–Patagonia transition is an area that stands out due to its complex population dynamics, especially during the last about 1,000 years BP. The aim of this work is to characterize the maternal lineages of individuals buried in the Paso Alsina 1 archaeological site (ca. 500 years BP) through the analysis of mitochondrial genetic variability, in order to discuss the population models previously proposed for the southern cone of South America.

Methods

Mitochondrial HyperVariable Region I sequences were analyzed on teeth belonging to 20 adult individuals. Statistical analyses were carried out to compare the interpopulation and intrapopulation molecular variability between the results obtained in this work and those previously published data from pre‐Hispanic human groups. D1 haplotype network was constructed drawing from data on ancient and extant population group samples.

Results

Thirteen sequences (65%) were obtained from the 20 analyzed samples. The maternal lineages or subhaplogroups identified were D1g (69.24%), C1 (15.38%), D1 (7.69%), and D1j (7.69%). There was low haplotype variability within the site; some individuals could be matrilineally related.

Discussion

The subhaplogroups registered in Paso Alsina 1 site are in accordance with those reported for ancient and contemporary Patagonian populations. The results suggest that an initial nucleus of individuals carrying mostly subhaplogroup D1g settled in northern Patagonia, from which local diversity of this matrilineage could have arisen. The existence of gene flow in the final late Holocene with groups from Northern Andean Patagonia, as well as from Central Argentina, is proposed. The D1j variant probably developed in the latter region.
Nasal vestibular body treatment for recalcitrant nasal obstruction
Authors: Ibrahim Nour , Tyler Matthew A. , Borchard Nicole A. , Rathor Aakanksha , Nayak Jayakar V.
Published: February 2020

Background

The nasal vestibular body (NVB) is a recently reported dynamic swell body present in the inferolateral internal nasal valve. The contribution of NVB presence to persistent nasal obstruction, and effects of NVB treatment, are undefined.

Methods

Thirty‐five patients with recalcitrant nasal obstruction and NVB presence were retrospectively reviewed between 2013 and 2019, including 25 patients (48 sides) who had NVBs reduced via radiofrequency ablation (RFA) and 10 patients (20 sides) who had untreated NVBs. Posttreatment healing and complications were reviewed at early (<1 month) and late (mean, 7.3 months) time‐points after RFA of the NVB. A subset of the NVB‐treatment patients (18 of 25 patients) were compared with 10 NVB‐control patients for pre‐/posttreatment outcomes using 22‐item Sino‐Nasal Outcome Test (SNOT‐22) and subdomain scoring.

Results

NVBs were successfully reduced in 100% of cases (48 of 48 sides) over both time‐points. Early sequelae of NVB treatment, such as local crusting (22 of 23, 95.6%) and bone exposure (4 of 23, 17.3%), resolved by the late time‐point, with complete remucosalization (23 of 23, 100%) of all NVB treatment sites. No persistent pain, sensory loss, or pyriform aperture stenosis was noted from any patient/side. Significant reductions between mean pre‐ and postoperative SNOT‐22 (−24, p = 0.001) and individual subdomain (−2, p = 002) scores were seen in the NVB‐treatment patients compared to the reductions in NVB‐controls (−8 and −1, respectively, both p > 0.001).

Conclusion

NVB treatment using RFA is safe and highly effective, providing complete swell body reduction with only transient local morbidity. NVB presence contributes to persistent/recalcitrant nasal obstruction, with significant improvement in nasal airway function noted after NVB soft tissue reduction.
Ligand‐Supported Facile Conversion of Uranyl(VI) into Uranium(IV) in Organic and Aqueous Media
Authors: Faizova Radmila , Fadaei‐Tirani Farzaneh , Bernier‐Latmani Rizlan , Mazzanti Marinella
Published: February 2020

Reduction of uranyl(VI) to UV and to UIV is important in uranium environmental migration and remediation processes. The anaerobic reduction of a uranyl UVI complex supported by a picolinate ligand in both organic and aqueous media is presented. The [UVIO2(dpaea)] complex is readily converted into the cis‐boroxide UIV species via diborane‐mediated reductive functionalization in organic media. Remarkably, in aqueous media the uranyl(VI) complex is rapidly converted, by Na2S2O4, a reductant relevant for chemical remediation processes, into the stable uranyl(V) analogue, which is then slowly reduced to yield a water‐insoluble trinuclear UIV oxo‐hydroxo cluster. This report provides the first example of direct conversion of a uranyl(VI) compound into a well‐defined molecular UIV species in aqueous conditions.
A series of (NHC)Pd(N˄O)(OAc) complexes: synthesis, characterization and catalytic activities towards desulfinative Sonogashira coupling of arylsulfonyl hydrazides with arylalkynes
Authors: Yang Jin , Lu Jian‐Zhong , Wang Tian , Zhao Ya‐Yu , Zhu Guang‐Hao
Published: February 2020

A series of well‐defined N‐heterocyclic carbene palladium (II) complexes with general formula (NHC)Pd(N˄O)(OAc) were prepared through reaction of Pd (NHC)(OAc)2(H2O) with 1‐methyl‐1H‐pyrazole‐3‐carboxylic acid or 1‐methyl‐1H‐indazole‐3‐carboxylic acid in the presence of K2CO3. These complexes were then used for desulfinative Sonogashira coupling of arylsulfonyl hydrazides with terminal alkynes. With low catalyst loading, all synthesized palladium compounds exhibited moderate to high catalytic activities for the reactions.
Effect of chlorination and fluorination of benzothiadiazole on the performance of polymer solar cells
Authors: Zhou Yubing , Qin Yuancheng , Ni Cailing , Xie Yu
Published: February 2020

In order to explore the effects of chlorine and fluorine on photophysical properties and the differences, in this work, we synthesized five new polymers, P1–P5, in which benzo[1,2‐b:4,5‐b]dithiophene as the electron donating and benzothiadiazole as electron withdrawing. Analysis of these five polymers showed that the introduction of Cl and F atoms can deeper the highest occupied molecular orbital of these polymers and enhance the absorption of light by the species, thereby improving Voc and Jsc. Chlorination has a stronger ability to reduce energy levels and broaden the absorption spectrum compared to fluorination. Among them, P2 showed an efficiency of 4.08% with Jsc of 11.28 mA/cm2, Voc of 0.79 V, and fill factor (FF) of 0.45. Since chlorination is easier than fluorination in terms of synthesis, it is advantageous for practical applications. Therefore, we think that chlorination should not be ignored when designing high efficiency photovoltaic materials, especially when their fluorinated counterparts have proven to have good properties.
Fabrication and characterization of silane‐functionalized Na‐bentonite polysulfone/polyethylenimine nanocomposite membranes for dye removal
Authors: Saki Seda , Senol‐Arslan Dilek , Uzal Nigmet
Published: February 2020

In this study, tetraethoxysilane (TEOS)‐functionalized Na‐bentonite incorporated into polysulfone/polyethylenimine (PSF/PEI) membranes were fabricated by phase inversion method for the efficient removal of methylene blue dye. For the preparation of PSF/PEI nanocomposite membranes, silane‐functionalized Na‐bentonite and pure Na‐bentonite were used at three different concentrations (0.5, 1, and 2 wt%). The prepared membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, porosity, hydrophilicity, and water permeability measurements. Antifouling behaviors and methylene blue dye rejections of the PSF/PEI nanocomposite membranes were also tested. The obtained results showed that the addition of pure Na‐bentonite and silane‐functionalized Na‐bentonite both increased the water permeability of the membranes. The PSF/PEI membrane containing 2 wt% silane‐functionalized Na‐bentonite showed the highest water flux of 105 L m−2 h−1, while the lowest water flux of 1.2 L m−2 h−1 was recorded for pure PSF membrane. Filtration results demonstrated that the antifouling capacity was significantly increased due to the negatively charged surface of the newly generated silane‐functionalized Na‐bentonite PSF/PEI membranes. In summary, TEOS‐functionalized Na‐bentonite can be used to fabricate PSF/PEI nanocomposite membranes with effective filtration ability, antifouling capacity with lower decay ratio, higher flux recovery ratio, and 99% methylene blue dye removal performance.
Synthesis and properties of castor oil‐based polyurethane containing short fluorinated segment
Authors: Li Jia‐Wun , Cheng Yung‐Hsin , Lee Hsun‐Tsing , Wang Chyung‐Chyung , Chiu Chih‐Wei , Suen Maw‐Cherng
Published: February 2020

This study successfully incorporated a short‐segment fluorine‐containing chain extender (2,2,3,3‐tetrafluoro‐1,4‐butanediol [TF]) into castor oil‐based polyurethane (COPU) to synthesize TF/COPUs. The interactions between TF and COPU components were identified by Fourier transform infrared and X‐ray photoelectron spectroscopies, the results revealed that the increase in the TF content increased the van der Waals forces in CF…CO and the hydrogen bonding force in CF…HN. Atomic force microscopy indicated that the addition of more TF contributed to a higher level of microphase separation in the TF/COPUs. Thermogravimetric analysis showed that the TF component can enhance the thermal resistance of TF/COPUs. Differential scanning calorimetry and dynamic mechanical analysis indicated that the glass transition temperature (Tg) of TF/COPUs increased with the TF content. The stress–strain testing showed that the tensile strength and elongation at break values decreased with the TF content. This tensile behavior may be due to the molecular weight of a TF/COPU decreased with the TF content as evidenced by the gel permeation chromatography results. The hydrolytic degradation tests of dipping TF/COPUs in 3 wt% NaOH solution indicated that TF could lower the surface free energy and enhance the degradation stability of TF/COPUs.
Enhanced CO2 selectivity of polyimide membranes through dispersion of polyethyleneimine decorated UiO‐66 particles
Authors: Liu Bing , Li Dan , Yao Jie , Sun Hao
Published: February 2020

Branched polyethyleneimine (PEI) functionalized UiO‐66 were synthesized and used as fillers to fabricated mixed‐matrix membranes (MMMs) for CO2/CH4 separation. The purpose of introducing amino‐functional groups in the filler is to improve the interfacial compatibility of the filler with the polymer through the formation of hydrogen bonds with the carbonyl group of 6FDA‐ODA. Additionally, the amino group can facilitate CO2 transport through a reversible reaction, enhancing the CO2/CH4 separation properties of MMM. The chemical structure and morphology of fillers and membranes were characterized by employing X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FTIR), X‐ray diffraction (XRD), thermogravimetric (TGA), Derivative thermogravimetry (DTG) and scanning electron microscope (SEM). Furthermore, the effects of filler loading and feed pressure on CO2 permeability and CO2/CH4 selectivity have been investigated. MMMs present higher gas separation performance than pure 6FDA‐ODA due to the presence of amino groups and the improvement of interface morphology. In particular, the MMM with 15 wt% loading of UiO‐66‐PEI shows optimum CO2 permeability of 28.23 Barrer and CO2/CH4 selectivity of 56.49. Therefore, post‐synthetic modification of UiO‐66 particle with PEI is a promising alternative to improved membrane performance.
Organophotoredox‐Catalyzed Cascade Radical Annulation of 2‐(Allyloxy)arylaldehydes with N‐(acyloxy)phthalimides: Towards Alkylated Chroman‐4‐one Derivatives
Authors: Das Sanju , Parida Sushanta Kumar , Mandal Tanumoy , Sing Laxmikanta , De Sarkar Suman , Murarka Sandip
Published: February 2020

An organophotoredox catalyzed efficient and robust approach for the synthesis of highly important 3‐alkyl substituted chroman‐4‐one scaffold is developed using visible light induced radical cascade cyclization strategy. The reaction is initiated through the generation of alkyl radicals from N‐(acyloxy)phthalimides under photoredox conditions, which subsequently undergo intermolecular cascade radical cyclization on 2‐(allyloxy)arylaldehydes to afford chroman‐4‐one scaffolds. The presented strategy is attractive with regard to mild reaction conditions, operational simplicity, high functional group tolerance and broad substrate scope.
Analysis of carotenoid profile changes and carotenogenic genes transcript levels inRhodosporidium toruloidesmutants from an optimizedAgrobacterium tumefaciens‐mediated transformation method
Authors: Sun Zeping , Lv Jing , Ji Chaofan , Liang Huipeng , Li Shengjie , Yang Zhaoxia , Xu Wenhuan , Zhang Sufang , Lin Xinping
Published: February 2020

Rhodosporidium toruloideshas been reported as a potential biotechnological microorganism to produce carotenoids. The most commonly used molecular and genetic manipulation methods based onAgrobacterium‐mediated transformation (ATMT). However, this method was of relatively lower transformation efficiency. In this study, we optimized the ATMT method forR. toruloideson account of the promoter on T‐DNA, the ratio ofA. tumefacienstoR. toruloidesNP11, acetosyringone concentration, cocultivation temperature and time, and a transformation efficiency of 2,369 cells per 105recipient cells was obtained and was 24 times as that of the previous report. With this optimized method, four redder mutants and four yellower mutants were selected out with torularhodin and β‐carotene production preference, respectively. The highest torularhodin production was 1,638.15 µg/g dry cell weight in A1‐13. The yellower mutants were found to divert the metabolic flux from torularhodin and torulene to γ‐carotene and β‐carotene, and the proportion of γ‐carotene and β‐carotene were all over 92%. TAIL‐PCR was carried out to found T‐DNA insertion in these mutants, and insertion hotspot was found. RT‐qPCR results showed thatCTA1 genes in these mutants were closely related to the synthesis of total carotenoids, especially torularhodin, and was a potenial metabolic engineering site in the future.
The effects of procedural integrity errors during auditory–visual conditional discrimination training: A preliminary investigation
Authors: Breeman Samantha L. , Vladescu Jason C. , DeBar Ruth M. , Grow Laura L. , Marano Kathleen E.
Published: February 2020

Procedural integrity errors have widespread implications for the success or failure of behavior analytic interventions. However, previous research has not examined the effects of procedural integrity errors during auditory–visual conditional discrimination with clinical populations. The purpose of this preliminary investigation was to replicate and extend the work of Carroll, Kodak, and Fisher by evaluating the effects of procedural integrity errors compared with perfect integrity during auditory–visual conditional discrimination training with a child with autism spectrum disorder. A descriptive assessment, which identified omission of reinforcement and omission of error correction as the most common clinician errors, informed error selection. The participant required twice as many sessions to master targets taught under low‐integrity conditions compared with those taught under high‐integrity conditions. These results suggest that procedural integrity errors hinder skill acquisition and affect teaching efficiency. Future researchers should evaluate the effects of errors during auditory–visual conditional discrimination training across task arrangements.
Truly continuous low pH viral inactivation for biopharmaceutical process integration
Authors: Martins Duarte L. , Sencar Jure , Hammerschmidt Nikolaus , Flicker Andreas , Kindermann Johanna , Kreil Thomas R. , Jungbauer Alois
Published: February 2020

Continuous virus inactivation (VI) has received little attention in the efforts to realize fully continuous biomanufacturing in the future. Implementation of continuous VI must assure a specific minimum incubation time, typically 60 min. To guarantee the minimum incubation time, we implemented a packed bed continuous viral inactivation reactor (CVIR) with narrow residence time distribution (RTD) for low pH incubation. We show that the RTD does not broaden significantly over a wide range of linear flow velocities—which highlights the flexibility and robustness of the design. Prolonged exposure to acidic pH has no impact on bed stability, assuring constant RTD throughout long term operation. The suitability of the packed bed CVIR for low pH inactivation is shown with two industry‐standard model viruses, that is xenotropic murine leukemia virus and pseudorabies virus. Controls at neutral pH showed no system‐induced VI. At low pH, significant VI is observed, even after only 15 min. Based on the low pH inactivation kinetics, the continuous process is equivalent to traditional batch operation. This study establishes a concept for continuous low pH inactivation and, together with previous reports, highlights the versatility of the packed bed reactor for continuous VI, regardless of the inactivation method.
Glycosynthase reaction meets the flow: Continuous synthesis of lacto‐N‐triose II by engineered β‐hexosaminidase immobilized on solid support
Authors: Ruzic Lucija , Bolivar Juan M. , Nidetzky Bernd
Published: February 2020

The D746E variant of Bifidobacterium bifidum β‐N‐acetyl‐hexosaminidase is a promising glycosynthase (engineered glycosidase deficient in hydrolase activity) for the synthesis of lacto‐N‐triose II (LNT II), a core structural unit of human milk oligosaccharides. Here, we develop a flow process for the glycosynthase reaction, which is the regioselective β‐1,3‐glycosylation of lactose from a d‐glucosamine 1,2‐oxazoline donor. Using the glycosynthase immobilized on agarose beads (∼30 mg/g) packed into a fixed bed (1 ml), we show stable continuous production of LNT II (145–200 mM) at quantitative yield from the donor substrate. The wild‐type β‐N‐acetyl‐hexosaminidase used under exactly comparable conditions gives primarily (∼85%) the hydrolysis product d‐glucosamine. By enabling short residence times (2 min) that are challenging for mixed‐vessel types of reactor to establish, the glycosynthase flow reactor succeeds in an effective uncoupling of the LNT II formation (∼80–100 mM/min) from the slower side reactions (decomposition of donor substrate, enzymatic hydrolysis of LNT II) to obtain optimum synthetic efficiency. Our study thus provides a strong case for the application of flow chemistry principles to glycosynthase reactions and by that, it reveals the important synergy between enzyme and reaction engineering for biocatalytic synthesis of oligosaccharides.
Statistical modeling of cell‐to‐cell variability in viral infection during passaging in suspension cell culture: Application in Monte‐Carlo simulation
Authors: Saxena Abha , Ravutla Suryateja , Upadhyay Vikas , Jana Soumya , Murhammer David , Giri Lopamudra
Published: February 2020

Packaging during the passaging of viruses in cell cultures yields various phenotypes and is regulated by viral protein expression in infected cells. Although such a packaging mechanism has a profound effect in controlling the virus yield, little is known about the underlying statistical models followed by virus packaging and protein expression among cells infected with the virus. A predictive framework combining identification of the probability density function (PDF) based on log‐likelihood and using the PDF for Monte‐Carlo simulations is developed. The Birnbaum–Saunders distribution was found to be consistent with all three‐virus packaging levels, including nucleocapsids/occlusion‐derived virus (ODV), ODVs/polyhedra, and polyhedra/cell for both wild‐type and genetically modified AcMNPV. Next, it was demonstrated that PDF fitting could be used to compare two viruses having distinctly different genetic configurations. Finally, the identified PDF can be incorporated in RNA synthesis parameters for baculovirus infection to predict the cell‐to‐cell variability in protein expression using Monte‐Carlo simulations. The proposed tool can be used for the estimation of uncertainty in the kinetic parameter and prediction of cell‐to‐cell variability for other biological systems.
Der Kaiserpinguin – ein Vogel der Superlative
Authors: Kostrzewa Achim
Published: February 2020

Nach vorsichtigen Schätzungen beherbergt das antarktische Ökosystem knapp 200 Millionen Seevögel, davon sind etwa 26 Millionen Pinguine. Kaiserpinguine machen davon nur ca. 600.000 Individuen aus. Sie gehören zu den am wenigsten untersuchten Pinguinarten, weil sie nur auf dem Antarktischen Kontinent vorgelagerten Meereis brüten. Im Winter – während Eiablage und Brutzeit – sind sie durch einen bis zu 1.000 Kilometer breiten Meereisgürtel isoliert, der nur von Polynjas unterbrochen wird, offene Stellen im Eis, die den Vögeln Zugang zum Meer ermöglichen. Erst ab Oktober kommen auch Eisbrecher wieder in die Nähe einzelner Kolonien, so dass das Studium des ganzen Jahreszyklus, ja nicht einmal des ganzen Brutzyklus, nicht ohne weiteres möglich ist. 1902 wurde überhaupt die erste Kolonie in der Ostantarktis entdeckt. Ab den 1950er Jahren kamen gut 40 weitere dazu. Der Kontinent hat sehr lange (17.968 km) und unübersichtliche Küsten. Erst durch neue Techniken der Fernerkundung konnten neue Kolonien aus dem Weltraum entdeckt werden, heute zählt man mehr als 54 und gewinnt auch einen guten Überblick über die Population. Ihre Zukunft wird stark vom Eisregime abhängen. Die Tendenz in der West‐Antarktis ist stark rückläufig. Neue Auswertungen der letzten 40 Jahre der Eisentwicklung auf Satellitenfotos bestätigen auch deutliche Rückgänge für Teile der Ost‐Antarktis [23].
Interdisziplinarität in der Forensik
Authors: Amendt Jens , Zissler Angela , Lutz Lena , Szelecz Ildikò , Habermann Antje , Pittner Stefan
Published: February 2020

Die Ermittlung der Todeszeit ist eine wichtige Aufgabe der forensischen Wissenschaften. Nach 1–2 Tagen wird sie jedoch durch Autolyse und Fäulnis drastisch erschwert. Eine Kombination aus etablierten und neuen Methoden unterschiedlicher Disziplinen soll hier Abhilfe schaffen. Die morphologische Veränderungen eines Leichnams sind von dessen Liegezeit abhängig und können in einem Punktesystem klassifiziert werden: Die Altersbestimmung und Artenzusammensetzung von sich am Leichnam entwickelnden nekrophagen Insekten erlauben taggenaue Eingrenzungen des Besiedlungszeitpunktes, der Abbau von Proteinen der Skelettmuskulatur folgt einem charakteristischen, zeitabhängigen Degradationsmuster, Bodenorganismen unterhalb eines verwesenden Leichnams können durch Leichenflüssigkeiten negativ beeinträchtigt werden oder durch den damit verbundenen Eintrag von Nährstoffen wie Proteinen, Lipiden und Kohlenhydraten profitieren. Die kombinierte, interdisziplinäre Bewertung all dieser Parameter bietet vollkommen neue Möglichkeiten bei der Bestimmung von Todeszeiten, die Tage, Wochen oder Monate zurückliegen.
Zellkompartimente nach dem Baukastenprinzip
Authors: Hille-Rehfeld Annette
Published: February 2020

Die Encapsulin‐Nanokompartimente prokaryontischer Zellen sind Reaktionsräume bzw. Speicherorte, die funktionell mit eukaryontischen Zellkompartimenten vergleichbar sind. Im Gegensatz zu letzteren tragen sie aber eine Hülle aus Proteinen, die den polyedrischen Capsiden von Bakteriophagen ähnelt. Die Hüllproteine, die sog. Encapsuline, bilden durch Selbstassoziation eine Ikosaederstruktur. Encapsulin‐Nanokompartimente können sich auch de novo in eukaryontischen Zellen bilden, wenn diesen die genetische Information für die Proteinkomponenten eingefügt wird.
Wie Krankheitserreger die Entstehung der Pflanzenzelle beeinflussten
Authors: Björn Lars Olof
Published: February 2020

Dass Mitochondrien und Chloroplasten von einem Alpha‐Proteobakterium und einem Cyanobakterium abstammen, ist unter dem Begriff Endosymbiontentheorie seit längerem gängige Lehrmeinung. Offensichtlich waren an der Entstehung von Pflanzenzellen aber noch weitere Bakterien beteiligt, deren nähere Verwandte noch dazu als Krankheitserreger gefürchtet sind. So hat die Forschung der letzten Jahre Gene von Chlamydien, Rickettsien und Spirochäten im Pflanzengenom zutage befördert.
Multicentre study of short-course radiotherapy, systemic therapy and resection/ablation for stage IV rectal cancer
Authors: Kok E N D , Havenga K , Tanis P J , Wilt J H W , Hagendoorn J , Peters F P , Buijsen J , Rutten H J T , Kuhlmann K F D , Beets G L , Aalbers A G J , Kok N F M , Ruers T J M , Kobus C B H A , Siemons S V , Grootscholten C , Dewit L G H , Berg J G , Zavrakidis I , Jong K P , Hospers G A P , Karrenbeld A , Geijsen E D , Punt C J A , Rutten H , Radema S , Intven M P W , Roodhart J M L , Holman F , Kapiteijn E , Melenhorst J , Cnossen J S , Creemers G-J M
Published: February 2020

Background

The optimal treatment sequence for patients with rectal cancer and synchronous liver metastases remains unclear. The aim of this study was to evaluate the feasibility and effectiveness of short-course pelvic radiotherapy (5 × 5 Gy) followed by systemic therapy and local treatment of all tumour sites in patients with potentially curable stage IV rectal cancer in daily practice.

Methods

This was a retrospective study performed in eight tertiary referral centres in the Netherlands. Patients aged 18 years or above with rectal cancer and potentially resectable liver ± extrahepatic metastases, treated between 2010 and 2015, were eligible. Main outcomes included full completion of treatment schedule, symptom control and survival.

Results

In total, 169 patients were included with a median follow-up of 49·5 (95 pr cent c.i. 43·6 to 55·6) months. The completion rate for the entire treatment schedule was 65·7 per cent. Three-year progression-free survival and overall survival (OS) rates were 24·2 (95 per cent c.i. 16·6 to 31·6) and 48·8 (40·4 to 57·2) per cent respectively. Median OS of patients who responded well and completed the treatment schedule was 51·5 months, compared with 15·1 months for patients who did not complete the treatment (P < 0·001). Adequate symptom control of the primary tumour was achieved in 87·0 per cent of all patients.

Conclusion

Multimodal treatment leads to relief of symptoms in most patients, and is associated with good survival rates in those able to complete the schedule. [Correction added on 12 February 2020, after first online publication: the Conclusion has been reworded for clarity]
Is ultrasound effective in determining variation of the insertion of the extensor hallucis longus tendon?
Authors: Olewnik Łukasz , Podgórski Michał , Polguj Michał , Ruzik Kacper , Grzelak Piotr
Published: February 2020

Background

The extensor hallucis longus (EHL) is located in the anterior compartment of the leg, between the tibialis anterior muscle and extensor digitorum longus. The EHL is characterized by a number of morphological variations, concerning mainly the accessory bands and their insertion. The aim of our research was to evaluate the effectiveness of ultrasound in determining the anatomical variations of the EHL.

Methods

The morphology of the EHL was evaluated by ultrasound (high‐frequency linear probe of Samsung RS80 apparatus) in 50 healthy volunteers. The types of EHL morphology were determined according to a threefold classification.

Results

Only two types of the threefold anatomical classification were observed: Type I in 76 limbs (76%) and Type IIa in 24 limbs (24%). The accessory bands of the EHL were found in 24% of cases, all of which demonstrated a course that was located medially in relation to the main tendon.

Conclusion

Ultrasound allows for visualization of the EHL; however, the potential recognition of morphological variance is limited.

Level of Evidence

I – Clinical Research.
The interaction effect of ad appeal and need for cognition on consumers' intentions to share viral advertisements
Authors: Kulkarni Kalpak K. , Kalro Arti D. , Sharma Dinesh
Published: February 2020

Viral advertising has become a popular form of persuasive communication to promote brands on social media. Extant research on viral advertising has focused mostly on evaluating content characteristics as drivers of virality, but very few studies have examined the potential influence of consumers' personality variables that affect their information processing and subsequent ad‐sharing behavior. By taking a consumer‐centric approach, two experimental studies were conducted to examine how consumer's need for cognition (NFC: high vs. low) interacts with message appeal (emotional vs. informational) used in the branded viral advertisements and extent of brand information (high vs. low brand prominence) present in the branded viral advertisement to influence consumers' intentions to share viral advertisements. As compared with low‐NFC individuals, high‐NFC individuals reported higher sharing intentions for viral ads that use informational appeal and also for an emotional viral ad where brand prominence is high. This finding is consistent with the elaboration likelihood model (ELM). Further, the results of these studies show an interesting finding that contradicts the existing understanding originating from ELM; that is, high‐NFC individuals reported higher sharing intentions for viral ads with an emotional appeal as compared with low‐NFC individuals, even when the brand prominence is low. Possible explanations and implications of the findings are discussed in this paper.
Arousal enhances herding tendencies when decision making
Authors: Coker Brent
Published: February 2020

This research examines how arousal enhances consumer tendencies to be influenced by the majority when decision making, also known as “herding.” Physiological arousal was manipulated in three controlled experiments, using discrete choice decisions as the dependent variable. The results suggest that arousal enhances tendencies to choose more popular options and that deindividuation mediates the effect of arousal on choice. This research enriches our understanding of the theoretical relationship between arousal and consumer decision making, by suggesting that arousal increases herding. The practical relevance of our findings suggests that strategies to increase herding effects, such as “popular choice” stickers and social media metrics, may be enhanced by making the experience more arousing.
A universal drug delivery catheter for the treatment of infrapopliteal arterial disease using liquid therapy
Authors: Bunch Frank , Nair Pradeep , Aggarwala Gaurav , Dippel Eric , Kassab Elias , Khan Muhammad A. , LeCroy Christopher , McClure John M. , Tolleson Thaddeus , Walker Craig
Published: February 2020

Objective

The objective of this study was to investigate the safety and feasibility of treating infrapopliteal lesions using a novel drug delivery catheter locally delivering liquid paclitaxel.

Background

Balloon angioplasty is currently the Gold Standard to treat below‐the‐knee disease; however, restenosis continues to be a great challenge following these percutaneous revascularization procedures.

Methods

The Occlusion Perfusion Catheter for Optimal Delivery of Paclitaxel for the Prevention of Endovascular Restenosis (COPPER‐A) study—Below‐the‐Knee Cohort was a prospective, nonrandomized, multicenter, feasibility, and safety study that enrolled 35 patients at 11 participating sites. The safety endpoints at 1, 3, and 6 months were freedom from thrombosis, major amputation in the target limb and target limb related death. The efficacy endpoints were primary patency and freedom from clinically driven target lesion revascularization at 6 months.

Results

All patients tolerated the procedure well with no reports of adverse procedural events. Thirty‐five patients were treated with a mean lesion length of 112 ± 81.2 mm with the lesion length range of 20–286 mm. At 6‐month follow‐up, primary patency was 89.3% and freedom from clinically driven target lesion revascularization was 96.4%. No patients demonstrated thrombosis, major amputation in the target limb and target limb related death at the 1‐, 3‐ and 6‐months follow‐up intervals.

Conclusions

The results of this multi‐center study demonstrated that infrapopliteal arteries can be safely and effectively treated with liquid paclitaxel using the occlusion perfusion catheter.
Evaluation of the quality of nixtamalized maize flours for tortilla production with a new Mixolab protocol
Authors: Espinosa‐Ramírez Johanan , Rosell Cristina M. , Serna‐Saldivar Sergio O. , Pérez‐Carrillo Esther
Published: February 2020

Background and objectives

Nixtamalized maize flours (NMF) are convenient products to obtain an array of nixtamalized products such as table tortillas and chips. In the present study, a Mixolab protocol was set up for the analysis of NMF and to predict mixing conditions in tortilla making. The validity of the procedure was tested with 10 commercial NMF. Water absorption (WA) and mixing times obtained from Mixolab analysis were used to produce doughs and tortillas. The correlations among the Mixolab parameters and quality features of NMF, doughs, and tortillas were determined.

Findings

Mixolab curves permitted to characterize the NMF dough development time, mixing stability, starch gelatinization, starch gel stability, and retrogradation. This analysis was efficient to discern among the quality of different samples. Tortillas produced with the WA and mixing time predicted with the Mixolab analysis using the optimized protocol had adequate moisture and textural characteristics. Good correlations among the Mixolab parameters and the tortilla moisture and texture confirmed the validity of the method.

Conclusion

The optimized Mixolab test proved to be a useful tool to evaluate the quality of NMF.

Significance and novelty

The new Mixolab protocol could be used to predict relevant process parameters for tortilla production.
Effects of dynamic low temperature during the grain filling stage on starch morphological structure, physicochemical properties, and eating quality of soft japonica rice
Authors: Hu Yajie , Li Luan , Tian Jinyu , Zhang Chengxin , Wang Jie , Yu Enwei , Xing Zhipeng , Guo Baowei , Wei Haiyan , Huo Zhongyang , Zhang Hongcheng
Published: February 2020

Background and objectives

Temperature during the grain filling stage is the critical environmental factor affecting rice quality and starch physicochemical properties. Two soft japonica rice varieties were used to investigate starch morphological structure, gelatinization, and pasting properties, as well as the overall sensory quality of cooked rice under different ripening dynamic temperatures.

Findings

Compared to normal temperature (NT), dynamic low temperature (LT) during the grain filling stage increased amylose content and significantly influenced the crystalline structure of starch. These structural changes included the reduction in the relative crystallinity, IR ratio of 1,045/1,022 cm−1, the lamellar peak intensity, and lamellar distance. With regard to pasting properties, LT increased the setback and decreased the peak, trough, final viscosities, and breakdown. However, LT reduced gelatinization temperature and enthalpy. For eating quality, the palatability of cooked rice under LT decreased, which was related to higher hardness as well as lower stickiness and gel consistency.

Conclusions

Low temperature during grain filling led to the deterioration of eating quality of cooked rice, and this deterioration could be attributed to high amylose content, low pasting viscosity, and reduced gel consistency.

Significance and novelty

The mean temperature at 22°C during the grain filling stage improved eating quality in soft japonica rice by enhancing pasting properties and gel consistency.
Effect of Supports and Promoters on the Performance of Ni‐Based Catalysts in Ethanol Steam Reforming
Authors: Phung Thanh Khoa , Pham Thong Le Minh , Nguyen Anh-Nga T. , Vu Khanh B. , Giang Ha Ngoc , Nguyen Tuan-Anh , Huynh Thanh Cong , Pham Hong Duc
Published: February 2020

Ethanol steam reforming (ESR) is one of the potential processes to convert ethanol into valuable products. Hydrogen produced from ESR is considered as green energy for the future and can be an excellent alternative to fossil fuels with the aim of mitigating the greenhouse gas effect. The ESR process has been well studied, using transition metals as catalysts coupled with both acidic and basic oxides as supports. Among various reported transition metals, Ni is an inexpensive material with activity comparable to that of noble metals, showing promising ethanol conversion and hydrogen yields. Additionally, different promoters and supports were utilized to enhance the hydrogen yield and the catalyst stability. This review summarizes and discusses the influences of the supports and promoters of Ni‐based catalysts on the ESR process.