bluuebunny/crossref_metadata_2025 huggingface dataset:
Increasing the length and hydrophobicity of the C‐terminal sequence of transthyretin strengthens its binding affinity to retinol binding protein
Authors: Poodproh Rattawan , Kaewmeechai Supavadee , Leelawatwattana Ladda , Prapunpoj Porntip
Published: October 2017

Transthyretin (TTR) is a transporter for thyroid hormone (TH) and retinol, the latter via binding with retinol binding protein (RBP). Both the N‐terminal and C‐terminal regions of theTTRsubunit are located in close proximity to the central binding channel for ligands. During the evolution of vertebrates, these regions changed in length and hydropathy. The changes in the N‐terminal sequence were demonstrated to affect the binding affinities forTHs andRBP. Here, the effects of changes in the C‐terminal sequence were determined. Three chimericTTRs, namely pigC/huTTR(humanTTRwith the C‐terminal sequence changed to that ofSus scrofaTTR), xenoN/pigC/huTTR(humanTTRwith the N‐terminal and C‐terminal sequences changed to those ofXenopus laevisandS. scrofa, respectively), and pigC/crocTTR(Crocodylus porosusTTRwith the C‐terminal sequence changed to that ofS. scrofaTTR), were constructed and their binding affinities for humanRBPwere determined at lowTTR/RBPmolar ratio using chemiluminescence immunoblotting. The binding dissociation constant (Kd) values of pigC/huTTR, xenoN/pigC/huTTRand pigC/crocTTRwere 3.20 ± 0.35, 1.53 ± 0.38 and 0.31 ± 0.04 μm, respectively, and theKdvalues of human andC. porosusTTRwere 4.92 ± 0.68 and 1.42 ± 0.45 μm, respectively. These results demonstrate chimericTTRs boundRBPwith a higher strength than wild‐typeTTRs, and the changes in the C‐terminal sequence ofTTRhad a positive effect on its binding affinity forRBP. In addition, changes to the N‐terminal and C‐terminal sequences showed comparable effects on the binding affinity.
Photo‐Induced Charge‐Variable Conjugated Polyelectrolyte Brushes Encapsulating Upconversion Nanoparticles for Promoted siRNA Release and Collaborative Photodynamic Therapy under NIR Light Irradiation
Authors: Zhao Hui , Hu Wenbo , Ma Hengheng , Jiang Rongcui , Tang Yufu , Ji Yu , Lu Xiaomei , Hou Bing , Deng Weixing , Huang Wei , Fan Quli
Published: October 2017

Combination of photodynamic therapy (PDT) with small interfering RNA (siRNA) therapy has become a major strategy in cancer treatment for enhancing anticancer efficacy. However, developing nanoplatform that can promote siRNA release and collaborate with efficient PDT under NIR light irradiation is still a big challenge. Photo‐induced charge‐variable conjugated polyelectrolyte brushes encapsulating upconversion nanoparticles (UCNP@CCPEB) as an efficient nanoplatform are reported. Cationic conjugated polyelectrolyte brush (CCPEB) is synthesized through quaternary ammoniation of N‐functionalized polyfluorene brush by photodegradable 2‐nitrobenzyl‐2‐bromoacetate. CCPEB with abundant positive charges and intrinsic photosensitizer (PS) performance is good for integrating siRNA carrier and PS into one molecule. The obtained CCPEB next encapsulates upconversion nanoparticle for realizing its NIR light excitation. Agarose gel electrophoresis experiments show that UCNP@CCPEB present good stability and excellent siRNA‐loading capacity (1 mol UCNP@CCPEB to at least 32.5 mol siRNA). Under 980 nm light irradiation, UCNP@CCPEB exhibit efficient single oxygen production for PDT. Concurrently, the photoresponsive cationic side‐chain of CCPEB turns into zwitterionic chain and thus accelerates its siRNA release to 80%. In vitro and in vivo experiments show that the successful A549 tumor suppression is achieved by UCNP@CCPEB/siPlk1 complex under 980 irradiation. It is envisioned that UCNP@CCPEB can serve as an efficient platform for combining various phototherapies together.
Organ‐on‐a‐Chip Systems for Women's Health Applications
Authors: Nawroth Janna , Rogal Julia , Weiss Martin , Brucker Sara Y. , Loskill Peter
Published: October 2017

Biomedical research, for a long time, has paid little attention to the influence of sex in many areas of study, ranging from molecular and cellular biology to animal models and clinical studies on human subjects. Many studies solely rely on male cells/tissues/animals/humans, although there are profound differences in male and female physiology, which can significantly impact disease mechanisms, toxicity of compounds, and efficacy of pharmaceuticals. In vitro systems have been traditionally very limited in their capacity to recapitulate female‐specific physiology and anatomy such as dynamic sex‐hormone levels and the complex interdependencies of female reproductive tract organs. However, the advent of microphysiological organ‐on‐a‐chip systems, which attempt to recreate the 3D structure and function of human organs, now gives researchers the opportunity to integrate cells and tissues from a variety of individuals. Moreover, adding a dynamic flow environment allows mimicking endocrine signaling during the menstrual cycle and pregnancy, as well as providing a controlled microfluidic environment for pharmacokinetic modeling. This review gives an introduction into preclinical and clinical research on women's health and discusses where organ‐on‐a‐chip systems are already utilized or have the potential to deliver new insights and enable entirely new types of studies.
Recent Advances in Electrochromic Smart Fenestration
Authors: Cai Guofa , Eh Alice Lee‐Sie , Ji Lin , Lee Pooi See
Published: October 2017

Fenestration, such as windows, plays a key role in modern architecture as it has enormous impact on the energy efficiency and comfort to the occupants of the building. Herein, current state‐of‐art strategies of nanostructured electrochromic materials, the fabrication of large scale smart windows, rational design of multifunctional smart chromogenic devices, and their performance are highlighted. Moreover, the current challenges from material selection to smart window performance are discussed and feasible solutions are provided. Development of a novel, simple, and economical synthesis of electrochromic materials is the first step in realizing high‐performance smart window. In addition, electrolyte, packaging materials, and judicious design of the fabrication process also play critical roles in the development of multifunctional and energy‐efficient smart windows. Finally, the concept of energy‐efficient multifunctional smart windows is addressed in which the smart windows are powered by sustainable energy in daytime, while the windows dynamically control the solar radiation into the building through transmittance modulation, enabling adjustable occupant's privacy. Sustainable energy can be stored in the smart windows during daytime and can be discharged to power other electronic devices at night. It is envisioned that this review shall promote a rapid development on electrochromic materials and novel multifunctional smart windows.
Intrinsic Charge Transport in Stanene: Roles of Bucklings and Electron–Phonon Couplings
Authors: Nakamura Yuma , Zhao Tianqi , Xi Jinyang , Shi Wen , Wang Dong , Shuai Zhigang
Published: October 2017

The intrinsic charge transport of stanene is investigated by using density functional theory and density functional perturbation theory coupled with Boltzmann transport equations at the first‐principles level. The Wannier interpolation scheme is applied to calculate the charge carrier scatterings with all branches of phonons considering dispersion for the whole range of the first Brillouin zone. The intrinsic electron and hole mobilities are calculated to be (2–3) × 103 cm2 V−1 s−1 at 300 K. It is found that the intervalley scatterings from the out‐of‐plane and the transverse acoustic phonon modes dominate the carrier transport process. By contrast, the mobilities obtained by the conventional deformation potential approach are found to be as large as (2–3) × 106 cm2 V−1 s−1 at 300 K, in which the longitudinal acoustic phonon scattering in the long wavelength limit is assumed to be the dominant scattering mechanism. The inadequacy of the deformation potential approximation in stanene is attributed to the buckling in its honeycomb structure, which originates from the sp2–sp3 orbital hybridization and breaks the planar symmetry. This paper further proposes a strategy to enhance carrier mobilities by suppressing the out‐of‐plane vibrations through clamping by a substrate.
Hands‐off Ultrasound Technique: Utilizing Simultaneous Modeling to Enhance Ultrasound Training
Authors: Gottlieb Michael
Published: October 2017

Image acquisition can be a challenging component of obtaining ultrasound proficiency. To assist with obtaining the correct image, instructors may take the transducer away or guide the learner's hand. However, this passive form of learning has been suggested to be much less valuable, as it removes learner autonomy and somatosensory cueing. This paper describes the hands‐off ultrasound technique, a simultaneous modeling teaching strategy using multimodal feedback to improve ultrasound image acquisition.
Alternate use of thrombopoietin receptor agonists in adult primary immune thrombocytopenia patients: A retrospective collaborative survey from Italian hematology centers
Authors: Cantoni Silvia , Carpenedo Monica , Mazzucconi Maria Gabriella , De Stefano Valerio , Carrai Valentina , Ruggeri Marco , Specchia Giorgina , Vianelli Nicola , Pane Fabrizio , Consoli Ugo , Artoni Andrea , Zaja Francesco , D'adda Mariella , Visentin Andrea , Ferrara Felicetto , Barcellini Wilma , Caramazza Domenica , Baldacci Erminia , Rossi Elena , Ricco Alessandra , Ciminello Angela , Rodeghiero Francesco , Nichelatti Michele , Cairoli Roberto
Published: October 2017

Sequential use of the TPO‐RAs romiplostim and eltrombopag in ITP patients failing either agent was retrospectively evaluated to assess efficacy and impact of clinical characteristics on outcome. Patients were grouped into 5 categories: efficacy issues: 1st TPO‐RA failure; loss of response; non‐efficacy issues: platelet fluctuations; patient's preference; adverse event development. Either one TPO‐RA sequence was analyzed at 3 month and at last follow‐up. 106/546 patients on TPO‐RA underwent switch and 65% achieved, regained or maintained a short‐ term response independent of switch sequence, gender or age; lower response rates were associated with lines of previous therapy; disease duration lowers probability to respond. Clinically, patients switched for efficacy issue did not differ from those switched for non‐efficacy issues. Response was achieved/regained in 57.8% of patients switched for efficacy issues, the lowest response rates were observed in non‐responders to 1st TPO‐RA; 80% of patients switched for non‐efficacy issues maintained a response. Platelet fluctuation resolved in 44.4%. Of the 49 patients evaluable for long‐term outcome, 27 were in response on therapy; 16 discontinued the TPO‐RA for reasons other than efficacy, while only 6 were non responders. We confirm the efficacy of TPO‐RA switch; once achieved, response to the 2nd TPO‐RA seems durable.
Validation of multi‐frequency bioelectrical impedance analysis versus dual‐energy X‐ray absorptiometry to measure body fat percentage in overweight/obese Colombian adults
Authors: Ramírez‐Vélez Robinson , Tordecilla‐Sanders Alejandra , Correa‐Bautista Jorge Enrique , González‐Ruíz Katherine , González‐Jiménez Emilio , Triana‐Reina Hector Reynaldo , García‐Hermoso Antonio , Schmidt‐RioValle Jacqueline
Published: October 2017

Objectives

To verify the validity of multi‐frequency bioelectrical impedance analysis (mBCA) for predicting body fat percentage (BF%) in overweight/obese adults using dual‐energy X‐ray absorptiometry (DXA) as the reference method.

Methods

Forty‐eight adults participated (54% women, mean age = 41.0 ± 7.3 years old). The Pearson's correlation coefficient was used to evaluate the correlation between BIA and BF% assessed by DXA. The concordance between BF% measured by both methods was obtained with Lin's concordance correlation coefficient and Bland–Altman difference plots.

Results

Measures of BF% were estimated as 39.0 (SD = 6.1) and 38.3 (SD = 6.5) using DXA and mBCA, respectively. The Pearson's correlation coefficient reflected a strong correlation (r =.921, P = .001). The paired t‐test showed a significant mean difference between these methods for obese men BF% of −0.6 [(SD 1.95; 95% CI = −4.0 to 3.0), P =.037]. Overall, the bias of the mBCA was −0.6 [(SD 2.2; 95% CI = −5.0 to 3.7), P =.041], which indicated that the mBCA method significantly underestimated BF% in comparison to the reference method. Finally, in both genders, Lin's concordance correlation coefficient showed a strong agreement. More specifically the DXA value was ρc = 0.943 (95% CI = 0.775 to 0.950) and the mBCA value was ρc = 0.948 (95% CI = 0.778 to 0.978).

Conclusions

Our analysis showed a strong agreement between the two methods as reflected in the range of BF%. These results show that mBCA and DXA are comparable methods for measuring body composition with higher body fat percentages. However, due to broad limits of agreement, we can only recommend mBCA for groups of populations.
Social interactions and activity patterns of old Barbary macaques: Further insights into the foundations of social selectivity
Authors: Almeling Laura , Sennhenn‐Reulen Holger , Hammerschmidt Kurt , Freund Alexandra M. , Fischer Julia
Published: October 2017

Human aging is accompanied by a decrease in social activity and a narrowing in social networks. Studies in nonhuman primates may provide valuable comparative insights in which way aging impacts social life, in the absence of cultural conventions and an awareness of a limited lifetime. For female Barbary macaques at “La Forêt des Singes” in Rocamadour, France, we previously reported an age‐associated decrease in active grooming time and network size. Here, we aimed to extend these findings by investigating in which way physical decline, spatial proximity, and aggression vary with age in female Barbary macaques. We analyzed >1,200 hr of focal observations for 46 females aged 5–29 years. As expected, older females engaged less frequently in challenging locomotor activity, such as climbing or running, than younger ones. The previously reported decrease in grooming time was not due to shorter grooming bout duration. Instead, active grooming bouts lasted even longer, which discounts the idea that manual fatigue explains the shift in grooming pattern. We found that older females tended to be spatially reclusive and that they were less frequently the targets of aggression. Although older females showed aggressive behaviors at similar rates as younger females, the proportion of low‐level aggression (i.e., threats) increased with age. We suggest that these threats are not simply a signal of dominance, but also function to deter approaches by others. Overall, these findings are in line with the idea that older females aim to avoid potentially negative interactions, specifically if these are costly. In sum, these findings support the idea that shifts in female Barbary macaques' grooming activity, do not simply result from physical deterioration, but are instead due to a higher selectivity in the choice of social partners.
Construction of fetal inferior facial angle and hemi‐mandible length reference ranges at 18–21 weeks’ gestation in an Australian population
Authors: Qiu Robert , MacKinlay Katie , Suen Melissa , McLennan Andrew
Published: October 2017

Objective

The aim of this pilot study was to provide modern reference intervals for both inferior facial angle and hemi‐mandible length in fetuses of 18–21 weeks’ gestation.

Methods

Prospectively, 296 apparently normal fetuses were sonographically assessed at 18–21 weeks’ gestation. Inferior facial angle and hemi‐mandible length were measured and parametrically analysed with respect to gestational age. Regression models were derived for each parameter and compared with models of previous studies.

Results

The mean inferior facial angle remained constant over the studied gestational age range at 63.9°, with 5th and 95th percentiles of 56.6° and 73.4°, respectively. Hemi‐mandible length was found to be positively correlated with gestational age over the studied range, and the mean value is described by the equation 40.89 mm – (6327.495 × GA−2) with a standard deviation of 1.231 mm.

Conclusion

Modern reference intervals for inferior facial angle and hemi‐mandible length were defined within this pilot study. These reference intervals will aid in improving accuracy diagnosing micrognathia and our ability to differentiate true micrognathia from retrognathia.
Postoperative sinonasal morbidity in sellar reconstruction: mucosal autograft versus acellular dermal allograft
Authors: Roxbury Christopher R. , Magruder J. Trent , Ramanathan Murugappan , Lim Michael , Gallia Gary L. , Ishii Masaru , Reh Douglas D.
Published: October 2017

Background

Sellar pathology is increasingly addressed using the expanded endonasal approach (EEA). Although avascular graft reconstruction is an acceptable means to prevent cerebrospinal fluid leak, there are few data regarding sinonasal morbidity in these patients. In this study we compare rates of persistent postoperative crusting (PPC) and rhinosinusitis in patients undergoing sellar reconstruction with mucosal autografting and acellular dermal allografting (ADA).

Methods

Patients undergoing the EEA between 2008 and 2014 were categorized into 2 subgroups: mucosal reconstruction and ADA reconstruction. Univariate analyses were performed to compare differences in PPC and rhinosinusitis in these groups and to identify risk factors for sinonasal morbidity. Multivariate propensity matching analysis was performed to match ADA and mucosa reconstruction groups with respect to age, race, gender, smoking status, diabetes status, tumor type, tumor size, and revision vs primary surgery.

Results

A total of 149 patients were identified. There were 105 patients reconstructed with autologous mucosa (70.5%) and 44 reconstructed with ADA (29.5%). Overall, PPC was seen in 20 patients (13.4%) and rhinosinusitis in 10 patients (6.7%). Propensity matching generated 39 patients reconstructed with ADA and 39 reconstructed with mucosa. There was a significant increase in PPC in patients reconstructed with ADA compared to those reconstructed with mucosa (8 of 39 [20.5%] vs 2 of 39 [5.1%], p = 0.04). There was no association between reconstruction with ADA and increased rhinosinusitis (3 of 39 [7.7%] vs 4 of 39 [10.3%], p = 0.64).

Conclusion

Sinonasal morbidity is not uncommon after sellar reconstruction. Patients undergoing sellar reconstruction with ADA may be at increased risk of postoperative crusting compared with those undergoing reconstruction with mucosa.
Experimental and Computational Exploration of para‐Selective Silylation with a Hydrogen‐Bonded Template
Authors: Maji Arun , Guin Srimanta , Feng Sheng , Dahiya Amit , Singh Vikas Kumar , Liu Peng , Maiti Debabrata
Published: October 2017

The regioselective conversion of C−H bonds into C−Si bonds is extremely important owing to the natural abundance and non‐toxicity of silicon. Classical silylation reactions often suffer from poor functional group compatibility, low atom economy, and insufficient regioselectivity. Herein, we disclose a template‐assisted method for the regioselective para silylation of toluene derivatives. A new template was designed, and the origin of selectivity was analyzed experimentally and computationally. An interesting substrate–solvent hydrogen‐bonding interaction was observed. Kinetic, spectroscopic, and computational studies shed light on the reaction mechanism. The synthetic significance of this strategy was highlighted by the generation of a precursor of a potential lipophilic bioisostere of γ‐aminobutyric acid (GABA), various late‐stage diversifications, and by mimicking enzymatic transformations.
Co‐adsorption of Cations as the Cause of the Apparent pH Dependence of Hydrogen Adsorption on a Stepped Platinum Single‐Crystal Electrode
Authors: Chen Xiaoting , McCrum Ian T. , Schwarz Kathleen A. , Janik Michael J. , Koper Marc T. M.
Published: October 2017

The successful deployment of advanced energy‐conversion systems depends critically on our understanding of the fundamental interactions of the key adsorbed intermediates (hydrogen *H and hydroxyl *OH) at electrified metal–aqueous electrolyte interfaces. The effect of alkali metal cations (Li+, Na+, K+, Cs+) on the non‐Nernstian pH shift of the step‐related voltammetric peak of the Pt(553) electrode is investigated over a wide pH window (1 to 13) by means of experimental and computational methods. The co‐adsorbed alkali cations along the step weaken the OH adsorption at the step sites, causing a positive shift of the potential of the step‐related peak on Pt(553). Density functional calculations explain the observations on the identity and concentration of alkali cations on the non‐Nernstian pH shift, and demonstrate that cation–hydroxyl co‐adsorption causes the apparent pH dependence of “hydrogen” adsorption in the step sites of platinum electrodes.
A Copper‐Catalyzed Aerobic [1,3]‐Nitrogen Shift through Nitrogen‐Radical 4‐exo‐trig Cyclization
Authors: Li Yan , Wang Rui , Wang Tao , Cheng Xiu‐Fen , Zhou Xin , Fei Fan , Wang Xi‐Sheng
Published: October 2017

A novel radical [1,3]‐nitrogen shift catalyzed by copper diacetate under an oxygen atmosphere (1 atm) has been developed for the construction of a diverse range of indole derivatives from α,α‐disubstituted benzylamine. In this reaction, oxygen was used as a clean terminal oxidant, and water was produced as the only by‐product. Five inert bonds were cleaved, and two C−N bonds and one C−C double bond were constructed in one pot during this transformation. This unique method demonstrated broad application protential for the late‐stage modification of biologically active natural products and drugs. Mechanistic investigations indicate that a unique 4‐exo‐trig cyclization of an aminyl radical onto a phenyl ring is involved in the catalytic cycle.
Compatibilization of poly(lactic acid)/high impact polystyrene interface using copolymer poly(stylene‐ran‐methyl acrylate)
Authors: Gong Xinghou , Gao Xiang , Tang Chak Yin , Law Wing‐Cheung , Chen Ling , Hu Tao , Wu Chonggang , Tsui Chi Pong , Rao Nanxi
Published: October 2017

In this work, a surfactant‐free emulsion polymerization method was utilized to synthesize poly(styrene‐ran‐methyl acrylate) (PSMA) at a styrene/(methyl acrylate) mole ratio of 75/25 with the aim to compatibilize high impact polystyrene (HIPS)/poly(lactic acid) (PLA) interface. HIPS/PLA blends with different PSMA contents were prepared. Their phase morphologies, mechanical properties, and rheological and crystallization behaviors were investigated using scanning electron microscopy, tensile tests, rotational rheometry, and differential scanning calorimetry. The rheological results showed that the complex viscosity, storage moduli, and loss moduli of PLA/HIPS blends were enhanced with increasing PSMA content. A decrease in the degree of crystallinity of PLA in PLA/HIPS blends with the addition of PSMA was observed in the differential scanning calorimetry results. It was also revealed that the addition of a small amount of PSMA can effectively improve the compatibility and thus the interfacial adhesion of the PLA/HIPS blends, thereby reducing the size of the HIPS dispersion phase. When 1 wt % of PSMA was used, compared with the PLA/HIPS blends without PSMA, the tensile strength and notched Charpy impact strength of PLA/HIPS blends were improved by 95.3% and 104.8%, respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45799.
Li2MnSnSe4: A New Quaternary Diamond‐Like Semiconductor with Nonlinear Optical Response and Antiferromagnetic Property
Authors: Li Xiaoshuang , Li Chao , Zhou Molin , Wu Yicheng , Yao Jiyong
Published: October 2017

A new selenide with a diamond‐like structure, Li2MnSnSe4, was synthesized for the first time by using a conventional high‐temperature solid‐state reaction method. Li2MnSnSe4 crystallizes in the space group Pmn21 (no. 31) of the orthorhombic system. Its three‐dimensional framework is constructed by corner‐sharing LiSe4, MnSe4, and SnSe4 tetrahedra. The title compound has been discovered to have both type I phase‐matchable behavior and to exhibit moderate powder second‐harmonic generation intensity, about 0.5 times that of commercial AgGaS2 in the particle size of 200–250 μm at a laser radiation of 2.09 μm. In addition, Li2MnSnSe4 exhibits congruent melting behavior, which makes the bulk single‐crystal growth by the Bridgman–Stockbarger method possible. The temperature‐dependent susceptibility measurement indicates an antiferromagnetic interaction with a Néel temperature (TN) of 8.6 K for this compound.
Der Einbau der neuen Hilfsbrücke ZH 31 an der Eisenbahnüberführung Stauffenbergallee in Dresden
Authors: Tusche Jens
Published: October 2017

Im Zuge der Eisenbahnstrecke Görlitz–Dresden befindet sich die Eisenbahnüberführung über die Stauffenbergallee in Dresden. Diese Brücke wurde bedingt durch ihren schlechten Zustand durch Hilfsbrücken ersetzt. Dabei handelt es sich um einen der ersten Einsätze der neu entwickelten Zwillingsträgerhilfsbrücke ZH 31, die Stützweiten von 28,80–31,20 m ermöglicht und damit das Zwillingsträgerhilfsbrückensortiment der Deutschen Bahn von Stützweiten von bisher bis 26,40 auf 31,20 m ergänzt.
The Role of Independence and Stationarity in Probabilistic Models of Binary Choice
Authors: Regenwetter Michel , Davis‐Stober Clintin P.
Published: October 2017

After more then 50 years of probabilistic choice modeling in economics, marketing, political science, psychology, and related disciplines, theoretical and computational advances give scholars access to a sophisticated array of modeling and inference resources. We review some important, but perhaps often overlooked, properties of major classes of probabilistic choice models. For within‐respondent applications, we discuss which models require repeated choices by an individual to be independent and response probabilities to be stationary. We show how some model classes, but not others, are invariant over variable preferences, variable utilities, or variable choice probabilities. These models, but not others, accommodate pooling of responses or averaging of choice proportions within participant when underlying parameters vary across observations. These, but not others, permit pooling/averaging across respondents in the presence of individual differences. We also review the role of independence and stationarity in statistical inference, including for probabilistic choice models that, themselves, do not require those properties. Copyright © 2017 John Wiley & Sons, Ltd.
An Integrated Bioprocess for the Expansion and Chondrogenic Priming of Human Periosteum‐Derived Progenitor Cells in Suspension Bioreactors
Authors: Gupta Priyanka , Geris Liesbet , Luyten Frank P. , Papantoniou Ioannis
Published: October 2017

The increasing use of microcarrier‐based suspension bioreactors for scalable expansion of adult progenitor cells in recent years reveals the necessity of such approaches to address bio manufacturing challenges of advanced therapeutic medicinal products. However, the differentiation of progenitor cells within suspension bioreactors for the production of tissue modules is of equal importance but not well investigated. This study reports on the development of a bioreactor‐based integrated process for expansion and chondrogenic priming of human periosteum‐derived stem cells (hPDCs) using Cultispher S microcarriers. Spinner flask‐based expansion and priming of hPDCs were carried out over 12 days for expansion and 14 days for priming. Characterization of the cells were carried out every 3rd day. Our study showed that hPDCs were able to expand till confluency with fold increase of 3.2±0.64 and to be subsequently primed toward a chondrogenic state within spinner flasks. During expansion, the cells maintained their phenotypic markers, trilineage differentiation capabilities and viability. Upon switching to TGF‐β containing media the cells were able to differentiate toward chondrogenic lineage by clustering into mm‐sized macrotissues containing hundreds of microcarriers. Chondrogenic priming was further evidenced by the expression of relevant markers at the mRNA level while maintaining their viability. Ectopic implantation of macrotissues highlighted that they were able to sustain their chondrogenic properties for 8 weeks in vivo. The method indicated here, suggests that expansion and relevant priming of progenitor cells can be carried out in an integrated bioprocess using spinner flasks and as such could be potentially extrapolated to other stem and progenitor cell populations.
Adsorption Behavior of Charge Isoforms of Monoclonal Antibodies on Strong Cation Exchangers
Authors: Steinebach Fabian , Wälchli Ruben , Pfister David , Morbidelli Massimo
Published: October 2017

In this work, the adsorption behavior of the different charge isoforms of the same monoclonal antibody (mAb) on strong cation‐exchange resins is analyzed. While charge isoforms of the same antibody mainly differ in their effective charge, the similar structure and size allows developing a simplified model, which describes the adsorption behavior of mAb charge isoforms independently of the number of isoforms with only four parameters. In contrast to classical model‐based descriptions of the adsorption isotherm, the proposed work enables retrieving some physical meaning in the definition of the model parameters. These model parameters are determined for several resin‐antibody combinations. Thereby it is found that for mAbs on commercial cation exchangers an effective resin charge density of 0.22 ± 0.08 mmol mL−1 of solid phase is used for protein binding, which was found to be independent of the absolute resin charge density measured by titration. The presented results help to understand the adsorption behavior of mAbs on cation‐exchangers, which is applicable both for the isolation of the main charge isoform or for preserving a certain charge isoform pattern during the polishing processes.
Identifying HIPK1 as Target of miR‐22‐3p Enhancing Recombinant Protein Production From HEK 293 Cell by Using Microarray and HTP siRNA Screen
Authors: Inwood Sarah , Buehler Eugen , Betenbaugh Michael , Lal Madhu , Shiloach Joseph
Published: October 2017

Protein expression from human embryonic kidney cells (HEK 293) is an important tool for structural and clinical studies. It is previously shown that microRNAs (small, noncoding RNAs) are effective means for improved protein expression from these cells, and by conducting a high‐throughput screening of the human microRNA library, several microRNAs are identified as potential candidates for improving expression. From these, miR‐22‐3p is chosen for further study since it increased the expression of luciferase, two membrane proteins and a secreted fusion protein with minimal effect on the cells’ growth and viability. Since each microRNA can interact with several gene targets, it is of interest to identify the repressed genes for understanding and exploring the improved expression mechanism for further implementation. Here, the authors describe a novel approach for identification of the target genes by integrating the differential gene expression analysis with information obtained from our previously conducted high‐throughput siRNA screening. The identified genes were validated as being involved in improving luciferase expression by using siRNA and qRT‐PCR. Repressing the target gene, HIPK1, is found to increase luciferase and GPC3 expression 3.3‐ and 2.2‐fold, respectively.
Comparison of platform host cell protein ELISA to process‐specific host cell protein ELISA
Authors: Gunawan Feny , Nishihara Julie , Liu Peter , Sandoval Wendy , Vanderlaan Marty , Zhang Heidi , Krawitz Denise
Published: October 2017

During expression of biotherapeutic proteins, complex mixtures of additional proteins are also produced by normal expression machinery of the host cell (termed “host cell proteins,” or HCP). HCPs pose a potential impact to patient safety and product efficacy, and therefore must be well‐characterized and the ability of the process to clear these proteins must be demonstrated. Due to the complexity of HCP, the method(s) used for monitoring must be demonstrated to provide sufficient information about relevant proteins. The most commonly used analytical method for monitoring HCP is an enzyme‐linked immunosorbent assay (ELISA). To ensure development of a suitable HCP ELISA, careful selection of critical reagents (anti‐HCP antibodies and analytical standard) is crucial. During a recent major update to the manufacturing process of a biotherapeutic, we re‐evaluated the suitability of the existing HCP ELISA for monitoring the HCP population in the updated process. In the evaluation, we compared a process‐specific ELISA to a platform ELISA. Despite qualitative differences in the HCP profiles in 2D PAGE, LC‐MS/MS showed that the HCP populations in the two analytical standards were similar. The process‐specific HCP antibody had adequate HCP coverage, but was more sensitive to a few dominant proteins that were present in the upstream purification process. The platform HCP antibody had very broad coverage and additionally, could detect the majority of potential HCP impurities from this process. Furthermore, the platform HCP antibody was not biased toward a few dominant proteins and was more sensitive in the downstream purification process. Due to its broad HCP coverage and sensitivity, we conclude that our platform HCP ELISA method is superior to the process‐specific HCP ELISA method.
One‐step affinity capture and precipitation for improved purification of an industrial monoclonal antibody using Z‐ELP functionalized nanocages
Authors: Swartz Andrew R. , Xu Xuankuo , Traylor Steven J. , Li Zheng J. , Chen Wilfred
Published: October 2017

Protein A chromatography has been identified as a potential bottleneck in the monoclonal antibody production platform, leading to increased interest in non‐chromatographic capture technologies. Affinity precipitation using environmentally responsive, Z‐domain‐elastin‐like polypeptide (Z‐ELP) fusion proteins has been shown to be a promising alternative. However, elevated temperature and salt concentrations necessary for precipitation resulted in decreased antibody monomer content and reduced purification capacity. To improve upon the existing technology, we reported an enhanced affinity precipitation of antibodies by conjugating Z‐ELP to a 25 nm diameter, self‐assembled E2 protein nanocage (Z‐ELP‐E2). The enlarged scale of aggregate formation and IgG‐triggered crosslinking through multi‐valent binding significantly outperformed traditional Z‐ELP‐based methods. In the current work, we sought to develop an affinity precipitation process capable of purifying industrial monoclonal antibodies (mAbs) at ambient temperature with minimal added salt. We discovered that the mAb‐nanocage complex aggregated within 10 min at room temperature without the addition of salt due to the enhanced multi‐valent cross‐linking. After precipitating out of solution, the complex remained insoluble under all wash buffers tested, and only resolubilized after a low pH elution. Through optimization of key process steps, the affinity precipitation yield and impurity clearance met or exceeded protein A chromatography performance with 95% yield, 3.7 logs host cell protein reduction, and >5 logs of DNA reduction from mAb cell culture. Because of the operational flexibility afforded by this one‐step affinity capture and precipitation process, the Z‐ELP‐E2 based approach has the potential to be a viable alternative to platform mAb purification.
Biocatalytic conversion of cycloalkanes to lactones using an in‐vivo cascade in Pseudomonas taiwanensis VLB120
Authors: Karande Rohan , Salamanca Diego , Schmid Andreas , Buehler Katja
Published: October 2017

Chemical synthesis of lactones from cycloalkanes is a multi‐step process challenged by limitations in reaction efficiency (conversion and yield), atom economy (by‐products) and environmental performance. A heterologous pathway comprising novel enzymes with compatible kinetics was designed in Pseudomonas taiwanensis VLB120 enabling in‐vivo cascade for synthesizing lactones from cycloalkanes. The respective pathway included cytochrome P450 monooxygenase (CHX), cyclohexanol dehydrogenase (CDH), and cyclohexanone monooxygenase (CHXON) from Acidovorax sp. CHX100. Resting (non‐growing) cells of the recombinant host P. taiwanensis VLB120 converted cyclohexane, cyclohexanol, and cyclohexanone to ϵ‐caprolactone at 22, 80–100, and 170 U gCDW−1, respectively. Cyclohexane (5 mM) was completely converted with a selectivity of 65% for ϵ‐caprolactone formation in 2 hr without accumulation of intermediate products. Promiscuity of the whole‐cell biocatalyst gave access to analogous lactones from cyclooctane and cyclodecane. A total product concentration of 2.3 g L−1 and a total turnover number of 36,720 was achieved over 5 hr with a biocatalyst concentration of 6.8 gCDW L−1.
Enzymatic synthesis of chiral amino‐alcohols by coupling transketolase and transaminase‐catalyzed reactions in a cascading continuous‐flow microreactor system
Authors: Gruber Pia , Carvalho Filipe , Marques Marco P. C. , O'Sullivan Brian , Subrizi Fabiana , Dobrijevic Dragana , Ward John , Hailes Helen C. , Fernandes Pedro , Wohlgemuth Roland , Baganz Frank , Szita Nicolas
Published: October 2017

Rapid biocatalytic process development and intensification continues to be challenging with currently available methods. Chiral amino‐alcohols are of particular interest as they represent key industrial synthons for the production of complex molecules and optically pure pharmaceuticals. (2S,3R)‐2‐amino‐1,3,4‐butanetriol (ABT), a building block for the synthesis of protease inhibitors and detoxifying agents, can be synthesized from simple, non‐chiral starting materials, by coupling a transketolase‐ and a transaminase‐catalyzed reaction. However, until today, full conversion has not been shown and, typically, long reaction times are reported, making process modifications and improvement challenging. In this contribution, we present a novel microreactor‐based approach based on free enzymes, and we report for the first time full conversion of ABT in a coupled enzyme cascade for both batch and continuous‐flow systems. Using the compartmentalization of the reactions afforded by the microreactor cascade, we overcame inhibitory effects, increased the activity per unit volume, and optimized individual reaction conditions. The transketolase‐catalyzed reaction was completed in under 10 min with a volumetric activity of 3.25 U ml−1. Following optimization of the transaminase‐catalyzed reaction, a volumetric activity of 10.8 U ml−1 was attained which led to full conversion of the coupled reaction in 2 hr. The presented approach illustrates how continuous‐flow microreactors can be applied for the design and optimization of biocatalytic processes.
Impact of carbon monoxide partial pressures on methanogenesis and medium chain fatty acids production during ethanol fermentation
Authors: Esquivel‐Elizondo Sofia , Miceli Joseph , Torres Cesar I. , Krajmalnik‐Brown Rosa
Published: October 2017

Medium‐chain fatty acids (MCFA) are important biofuel precursors. Carbon monoxide (CO) is a sustainable electron and carbon donor for fatty acid elongation, since it is metabolized to MCFA precursors, it is toxic to most methanogens, and it is a waste product generated in the gasification of waste biomass. The main objective of this work was to determine if the inhibition of methanogenesis through the continuous addition of CO would lead to increased acetate or MCFA production during fermentation of ethanol. The effects of CO partial pressures (PCO; 0.08–0.3 atm) on methanogenesis, fatty acids production, and the associated microbial communities were studied in batch cultures fed with CO and ethanol. Methanogenesis was partially inhibited at PCO ≥ 0.11 atm. This inhibition led to increased acetate production during the first phase of fermentation (0–19 days). However, a second addition of ethanol (day 19) triggered MCFA production only at PCO ≥ 0.11 atm, which probably occurred through the elongation of acetate with CO‐derived ethanol and H2:CO2. Accordingly, during the second phase of fermentation (days 20–36), the distribution of electrons to acetate decreased at higher PCO, while electrons channeled to MCFA increased. Most probably, Acetobacterium, Clostridium, Pleomorphomonas, Oscillospira, and Blautia metabolized CO to H2:CO2, ethanol and/or fatty acids, while Peptostreptococcaceae, Lachnospiraceae, and other Clostridiales utilized these metabolites, along with the provided ethanol, for MCFA production. These results are important for biotechnological systems where fatty acids production are preferred over methanogenesis, such as in chain elongation systems and microbial fuel cells.
Metabolic engineering of Bacillus subtilis for production of D‐lactic acid
Authors: Awasthi Deepika , Wang Liang , Rhee Mun S. , Wang Qingzhao , Chauliac Diane , Ingram Lonnie O. , Shanmugam Keelnatham T.
Published: October 2017

Poly lactic acid (PLA) based plastics is renewable, bio‐based, and biodegradable. Although present day PLA is composed of mainly L‐LA, an L‐ and D‐ LA copolymer is expected to improve the quality of PLA and expand its use. To increase the number of thermotolerant microbial biocatalysts that produce D‐LA, a derivative of Bacillus subtilis strain 168 that grows at 50°C was metabolically engineered. Since B. subtilis lacks a gene encoding D‐lactate dehydrogenase (ldhA), five heterologous ldhA genes (B. coagulans ldhA and gldA101, and ldhA from three Lactobacillus delbrueckii) were evaluated. Corresponding D‐LDHs were purified and biochemically characterized. Among these, D‐LDH from L. delbrueckii subspecies bulgaricus supported the highest D‐LA titer (about 1M) and productivity (2 g h−1 g cells−1) at 37°C (B. subtilis strain DA12). The D‐LA titer at 48°C was about 0.6 M at a yield of 0.99 (g D‐LA g−1glucose consumed). Strain DA12 also fermented glucose at 48°C in mineral salts medium to lactate at a yield of 0.89 g g−1 glucose and the D‐lactate titer was 180 ± 4.5 mM. These results demonstrate the potential of B. subtilis as a platform organism for metabolic engineering for production of chemicals at 48°C that could minimize process cost.
A synthetic biology approach to transform Yarrowia lipolytica into a competitive biotechnological producer of β‐carotene
Authors: Larroude Macarena , Celinska Ewelina , Back Alexandre , Thomas Stephan , Nicaud Jean‐Marc , Ledesma‐Amaro Rodrigo
Published: October 2017

The increasing market demands of β‐carotene as colorant, antioxidant and vitamin precursor, requires novel biotechnological production platforms. Yarrowia lipolytica, is an industrial organism unable to naturally synthesize carotenoids but with the ability to produce high amounts of the precursor Acetyl‐CoA. We first found that a lipid overproducer strain was capable of producing more β‐carotene than a wild type after expressing the heterologous pathway. Thereafter, we developed a combinatorial synthetic biology approach base on Golden Gate DNA assembly to screen the optimum promoter‐gene pairs for each transcriptional unit expressed. The best strain reached a production titer of 1.5 g/L and a maximum yield of 0.048 g/g of glucose in flask. β‐carotene production was further increased in controlled conditions using a fed‐batch fermentation. A total production of β‐carotene of 6.5 g/L and 90 mg/g DCW with a concomitant production of 42.6 g/L of lipids was achieved. Such high titers suggest that engineered Y. lipolytica is a competitive producer organism of β‐carotene.
Metabolite profiling of ginsenosides in rat plasma, urine and feces by LC–MS/MS and its application to a pharmacokinetic study after oral administration of Panax ginseng extract
Authors: Dong Wei‐Wei , Han Xiong‐Zhe , Zhao Jinhua , Zhong Fei‐Liang , Ma Rui , Wu Songquan , Li Donghao , Quan Lin‐Hu , Jiang Jun
Published: October 2017

Panax ginseng is widely consumed as a functional food in the form of tea, powder, capsules, among others, and possesses a range of pharmacological activities including adaptogenic, immune‐modulatory, anti‐tumor, anti‐aging and anti‐inflammatory effects. The aim of this study was to identify and quantify the major ginsenosides and their metabolites in rat plasma, urine and feces after administration of P. ginseng extract using LC–MS/MS. We collected rat plasma samples at 0.5, 1, 2, 4, 8, 12, 24 and 48 h, and the amounts of urine and fecal samples accumulated in 24 h. Fourteen major ginsenosides and their metabolites were observed in fecal samples at high levels; however, low levels of 11 ginsenosides were detected in urine samples. The pharmacokinetics of the major ginsenosides and their metabolites was investigated in plasma. The results indicated that the maximum plasma concentration, time to maximum concentration and area under the curve of compound K were significantly greater than those of other ginsenosides. This study thus provides valuable information for drug development and clinical application of P. ginseng.
Vision In Stroke cohort: Profile overview of visual impairment
Authors: Rowe Fiona J. ,   the VIS writing Group
Published: October 2017

Aim

To profile the full range of visual disorders from a large prospective observation study of stroke survivors referred by stroke multidisciplinary teams to orthoptic services with suspected visual problems.

Methods

Multicenter prospective study undertaken in 20 acute Trust hospitals. Standardized screening/referral forms and investigation forms documented data on referral signs and symptoms plus type and extent of visual impairment.

Results

Of 1,345 patients referred with suspected visual impairment, 915 were recruited (59% men; mean age at stroke onset 69 years [SD 14]). Initial visual assessment was at median 22 days post stroke onset. Eight percent had normal visual assessment. Of 92% with confirmed visual impairment, 24% had reduced central visual acuity <0.3 logMAR and 13.5% <0.5 logMAR. Acquired strabismus was noted in 16% and acquired ocular motility disorders in 68%. Peripheral visual field loss was present in 52%, most commonly homonymous hemianopia. Fifteen percent had visual inattention and 4.6% had other visual perceptual disorders. Overall 84% were visually symptomatic with visual field loss the most common complaint followed by blurred vision, reading difficulty, and diplopia. Treatment options were provided to all with confirmed visual impairment. Targeted advice was most commonly provided along with refraction, prisms, and occlusion.

Conclusions

There are a wide range of visual disorders that occur following stroke and, frequently, with visual symptoms. There are equally a wide variety of treatment options available for these individuals. All stroke survivors require screening for visual impairment and warrant referral for specialist assessment and targeted treatment specific to the type of visual impairment.
Write right, quite right
Authors: Neumann Paul E.
Published: October 2017

Spelling variants are common in Latin anatomical terms. Some of these variants cause confusion with respect to the meaning of the word by altering the base of the word to resemble a different word base. Thus these variants should be considered errors, comparable to errors in declension of nouns and adjectives, and errors in the formation of neologisms. Use of correct Latin words in Latin anatomical terms should increase the rigor, stability, and universality of the nomenclature. Clin. Anat. 31:77–80, 2018. © 2017 Wiley Periodicals, Inc.