bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of cytoskeletal mechanics and cell membrane fluidity in the intracellular delivery of molecules mediated by laser‐activated carbon nanoparticles
Authors: Holguin Stefany Y. , Anderson Caleb F. , Thadhani Naresh N. , Prausnitz Mark R. 
Published: June 2017

ABSTRACTExposure of cells and nanoparticles to near‐infrared nanosecond pulsed laser light can lead to efficient intracellular delivery of molecules while maintaining high cell viability by a photoacoustic phenomenon known as transient nanoparticle energy transduction (TNET). Here, we examined the influence of cytoskeletal mechanics and plasma membrane fluidity on intracellular uptake of molecules and loss of cell viability due to TNET. We found that destabilization of actin filaments using latrunculin A led to greater uptake of molecules and less viability loss caused by TNET. Stabilization of actin filaments using jasplakinolide had no significant effect on uptake or viability loss caused by TNET. To study the role of plasma membrane fluidity, we increased fluidity by depletion of membrane cholesterol using methyl‐β‐cyclodextrin and decreased fluidity by enrichment of the membrane with cholesterol using water‐soluble cholesterol. Neither of these membrane fluidity changes significantly altered cellular uptake or viability loss caused by TNET. We conclude that weakening mechanical integrity of the cytoskeleton can increase intracellular uptake and decrease loss of cell viability, while plasma membrane fluidity does not appear to play a significant role in uptake or viability loss caused by TNET. The positive effects of cytoskeletal weakening may be due to an enhanced ability of the cell to recover from the effects of TNET and maintain viability. Biotechnol. Bioeng. 2017;114: 2390–2399. © 2017 Wiley Periodicals, Inc.
Use of a protein engineering strategy to overcome limitations in the production of “Difficult to Express” recombinant proteins
Authors: Hussain Hirra , Fisher David I. , Abbott W. Mark , Roth Robert G. , Dickson Alan J. 
Published: June 2017

ABSTRACTCertain recombinant proteins are deemed “difficult to express” in mammalian expression systems requiring significant cell and/or process engineering to abrogate expression bottlenecks. With increasing demand for the production of recombinant proteins in mammalian cells, low protein yields can have significant consequences for industrial processes. To investigate the molecular mechanisms that restrict expression of recombinant proteins, naturally secreted model proteins were analyzed from the tissue inhibitors of metalloproteinase (TIMP) protein family. In particular, TIMP‐2 and TIMP‐3 were subjected to detailed study. TIMP proteins share significant sequence homology (∼50% identity and ∼70% similarity in amino acid sequence). However, they show marked differences in secretion in mammalian expression systems despite this extensive sequence homology. Using these two proteins as models, this study characterized the molecular mechanisms responsible for poor recombinant protein production. Our results reveal that both TIMP‐2 and TIMP‐3 are detectable at mRNA and protein level within the cell but only TIMP‐2 is secreted effectively into the extracellular medium. Analysis of protein localization and the nature of intracellular protein suggest TIMP‐3 is severely limited in its post‐translational processing. To overcome this challenge, modification of the TIMP‐3 sequence to include a furin protease‐cleavable pro‐sequence resulted in secretion of the modified TIMP‐3 protein, however, incomplete processing was observed. Based on the TIMP‐3 data, the protein engineering approach was optimized and successfully applied in combination with cell engineering, the overexpression of furin, to another member of the TIMP protein family (the poorly expressed TIMP‐4). Use of the described protein engineering strategy resulted in successful secretion of poorly (TIMP‐4) and non‐secreted (TIMP‐3) targets, and presents a novel strategy to enhance the production of “difficult” recombinant targets. Biotechnol. Bioeng. 2017;114: 2348–2359. © 2017 Wiley Periodicals, Inc.
Proteomic analysis of host cell protein dynamics in the supernatant of Fc‐fusion protein‐producing CHO DG44 and DUKX‐B11 cell lines in batch and fed‐batch cultures
Authors: Park Jin Hyoung , Jin Jong Hwa , Ji In Jung , An Hyun Joo , Kim Jong Won , Lee Gyun Min 
Published: June 2017

ABSTRACTChinese hamster ovary (CHO) cells are the most widely used host cell lines for the commercial production of therapeutic proteins including Fc‐fusion proteins. During the culture of recombinant CHO (rCHO) cells, host cell proteins (HCPs), secreted from viable cells and released from dead cells, accumulate extracellularly, potentially impairing product quality. In this study, the HCPs that accumulated extracellularly in batch and fed‐batch cultures of Fc‐fusion protein‐producing rCHO cell lines (DG‐Fc and DUKX‐Fc) were identified and quantified using nanoflow liquid chromatography–tandem mass spectrometry (LC–MS/MS), followed by gene ontology and functional analysis. When the proteome database of Cricetulus griseus was used as a reference to identify the HCPs, more HCPs were identified for DG‐Fc (1632 HCPs in batch culture and 1733 HCPs in fed‐batch culture) than for DUKX‐Fc (1114 HCPs in batch culture and 1002 HCPs in fed‐batch culture). Clustering analysis of HCPs, which were classified into four clusters according to their concentration profiles during culture, showed that the concentration profiles of HCPs affecting the quality of Fc‐fusion proteins correlated with changes in Fc‐fusion protein quality. Taken together, the dataset of HCPs obtained in this study using the two different rCHO cell lines provides insights into the determination of appropriate target proteins to be removed during the culture and purification steps so as to ensure good Fc‐fusion protein quality. Biotechnol. Bioeng. 2017;114: 2267–2278. © 2017 Wiley Periodicals, Inc.
Enzyme‐free cell detachment mediated by resonance vibration with temperature modulation
Authors: Kurashina Yuta , Hirano Makoto , Imashiro Chikahiro , Totani Kiichiro , Komotori Jun , Takemura Kenjiro 
Published: June 2017

ABSTRACTCell detachment is an essential process in adherent cell culture. However, trypsinization, which is the most popular detachment technique used in culture, damages cellular membranes. Reducing cellular membrane damage during detachment should improve the quality of cell culture. In this article, we propose an enzyme‐free cell detachment method based on resonance vibration with temperature modulation. We developed a culture device that can excite a resonance vibration and control temperature. We then evaluated the cell detachment ratio and the growth response, observed the morphology, and analyzed the cellular protein of the collected cells—mouse myoblast cell line (C2C12). With the temperature of 10°C and the maximum vibration amplitude of 2 μm, 77.9% of cells in number were successfully detached compared with traditional trypsinization. The 72‐h proliferation ratio of the reseeded cells was similar to that with trypsinization, whereas the proliferation ratio of proposed method was 12.6% greater than that of trypsinization after freezing and thawing. Moreover, the cells can be collected relatively intact and both intracellular and cell surface proteins in the proposed method were less damaged than in trypsinization. These results show that this method has definite advantages over trypsinization, which indicates that it could be applied to subcultures of cells that are more susceptible to trypsin damage for mass culture of sustainable clinical use. Biotechnol. Bioeng. 2017;114: 2279–2288. © 2017 Wiley Periodicals, Inc.
Meta-analysis of determinants of survival following treatment of recurrent hepatocellular carcinoma
Authors: Erridge S , Pucher P H , Markar S R , Malietzis G , Athanasiou T , Darzi A , Sodergren M H , Jiao L R 
Published: June 2017

Abstract

Background
Intrahepatic recurrence of hepatocellular carcinoma (HCC) following resection is common. However, no current consensus guidelines exist to inform management decisions in these patients. Systematic review and meta-analysis of survival following different treatment modalities may allow improved treatment selection. This review aimed to identify the optimum treatment strategies for HCC recurrence.

Methods
A systematic review, up to September 2016, was conducted in accordance with MOOSE guidelines. The primary outcome was the hazard ratio for overall survival of different treatment modalities. Meta-analysis of different treatment modalities was carried out using a random-effects model, with further assessment of additional prognostic factors for survival.

Results
Nineteen cohort studies (2764 patients) were included in final data analysis. The median 5-year survival rates after repeat hepatectomy (525 patients), ablation (658) and transarterial chemoembolization (TACE) (855) were 35·2, 48·3 and 15·5 per cent respectively. Pooled analysis of ten studies demonstrated no significant difference between overall survival after ablation versus repeat hepatectomy (hazard ratio 1·03, 95 per cent c.i. 0·68 to 1·55; P = 0·897). Pooled analysis of seven studies comparing TACE with repeat hepatectomy showed no statistically significant difference in survival (hazard ratio 1·61, 0·99 to 2·63; P = 0·056).

Conclusion
Based on these limited data, there does not appear to be a significant difference in survival between patients undergoing repeat hepatectomy or ablation for recurrent HCC. The results also identify important negative prognostic factors (short disease-free interval, multiple hepatic metastases and large hepatic metastases), which may influence choice of treatment.
Amplicon Competition Enables End‐Point Quantitation of Nucleic Acids Following Isothermal Amplification
Authors: Jiang Yu Sherry , Stacy Apollo , Whiteley Marvin , Ellington Andrew D. , Bhadra Sanchita 
Published: June 2017

AbstractIt is inherently difficult to quantitate nucleic acid analytes with most isothermal amplification assays. We developed loop‐mediated isothermal amplification (LAMP) reactions in which competition between defined numbers of “false” and “true” amplicons leads to order of magnitude quantitation by a single endpoint determination. These thresholded LAMP reactions were successfully used to directly and quantitatively estimate the numbers of nucleic acids in complex biospecimens, including directly from cells and in sewage, with the values obtained closely correlating with qPCR quantitations. Thresholded LAMP reactions are amenable to endpoint readout by cell phone, unlike other methods that require continuous monitoring, and should therefore prove extremely useful in developing one‐pot reactions for point‐of‐care diagnostics without needing sophisticated material or informatics infrastructure.
DFT Studies of Dimerization Reactions of Boroles
Authors: Wang Zheng , Zhou Yu , Lee Ka‐Ho , Lam Wai Han , Dewhurst Rian D. , Braunschweig Holger , Marder Todd B. , Lin Zhenyang 
Published: June 2017

AbstractBoroles undergo dimerization reactions to give Diels–Alder (DA) dimers, bridged‐bicyclic (BB) dimers or spiro dimers (SD) depending on the substituents on the borole. We performed DFT calculations to investigate how different substituents at the carbon atoms of the butadiene backbone as well as at the boron atom influence the dimerization reaction pathways. The DFT results show that, in general, both the DA and BB dimers are easily accessible kinetically, and the DA dimers are thermodynamically more stable than the BB dimers. When the substituent–substituent repulsive steric interactions are alleviated to a certain extent, the BB dimers are more stable than the DA dimer, and become accessible. The SD dimers are generally kinetically difficult to obtain. However, we found that aryl substituents promote the formation of the SD dimers.
Synthesis of gem‐Dinitromethylated and Fluorodinitromethylated Derivatives of 5,5′‐Dinitro‐bis‐1,2,4‐triazole as Promising High‐Energy‐Density Materials
Authors: Huang Shi , Tian Junjun , Qi Xiujuan , Wang Kangcai , Zhang Qinghua 
Published: June 2017

Abstractgem‐Dinitromethylated and fluorodinitromethylated 5,5′‐dinitro‐3,3′‐bis‐1,2,4‐triazole (DNBT) (2 and 3) along with seven ionic derivatives 4–9, were synthesized and characterized by NMR and IR spectroscopies, elemental analysis, single‐crystal X‐ray diffraction (XRD), and differential scanning calorimetry (DSC). XRD revealed that compounds 2 and 3 crystallized in the monoclinic P21/n space group and compound 5 crystallized in the monoclinic P21/c space group. The physicochemical properties of the as‐synthesized compounds 2–9 were investigated and the results indicated that compounds 3, 6, and 7 exhibited a good balance between high energy and low sensitivity, demonstrating their potential as new high‐energy‐density materials (HEDMs). The proposed synthetic strategy for introducing gem‐dinitromethyl and fluorodinitromethyl groups into the DNBT framework to prepare materials with high energy and low sensitivity suitable for HEDMs looks promising.
Synthesis and Characterization of Heterobenzenacyclo‐octaphanes Derived from Cyclotetrabenzoin
Authors: Hahn Sebastian , Alrayyani Maymounah , Sontheim Anna , Wang Xiqu , Rominger Frank , Miljanić Ognjen Š. , Bunz Uwe H. F. 
Published: June 2017

AbstractInvited for the cover of this issue is the groups of Ognjen Š. Miljanić at the University of Houston (United States) and Uwe H. F. Bunz at the Ruprecht‐Karls‐University of Heidelberg (Germany). The image depicts the versatility of our system, demonstrated by single crystal structures of our target molecules with different substitution and functionalities. Read the full text of the article at 10.1002/chem.201701125.
Transition and Alkali Metal Complex Ternary Amides for Ammonia Synthesis and Decomposition
Authors: Cao Hujun , Guo Jianping , Chang Fei , Pistidda Claudio , Zhou Wei , Zhang Xilun , Santoru Antonio , Wu Hui , Schell Norbert , Niewa Rainer , Chen Ping , Klassen Thomas , Dornheim Martin 
Published: June 2017

AbstractA new complex ternary amide, Rb2[Mn(NH2)4], which simultaneously contains both transition and alkali metal catalytic sites, is developed. This is in line with the recently reported TM‐LiH composite catalysts, which have been shown to effectively break the scaling relations and achieve ammonia synthesis under mild conditions. Rb2[Mn(NH2)4] can be facilely synthesized by mechanochemical reaction at room temperature. It exhibits two temperature‐dependent polymorphs, that is, a low‐temperature orthorhombic and a high‐temperature monoclinic structure. Rb2[Mn(NH2)4] decomposes to N2, H2, NH3, Mn3N2, and RbNH2 under inert atmosphere; whereas it releases NH3 at a temperature as low as 80 °C under H2 atmosphere. Those unique behaviors enable Rb2[Mn(NH2)4], and its analogue K2[Mn(NH2)4], to be excellent catalytic materials for ammonia decomposition and synthesis. Experimental results show both ammonia decomposition onset temperatures and conversion rates over Rb2[Mn(NH2)4] and K2[Mn(NH2)4] are similar to those of noble metal Ru‐based catalysts. More importantly, these ternary amides exhibit superior capabilities in catalyzing NH3 synthesis, which are more than 3 orders of magnitude higher than that of Mn nitride and twice of that of Ru/MgO. The in situ SR‐PXD measurement shows that manganese nitride, synergistic with Rb/KH or Rb/K(NH2)xH1−x, are likely the active sites. The chemistry of Rb2/K2[Mn(NH2)x] and Rb/K(NH2)xH1−x with H2/N2 and NH3 correlates closely with the catalytic performance.
A Simple Route to Strong Carbon‐13 NMR Signals Detectable for Several Minutes
Authors: Roy Soumya S. , Norcott Philip , Rayner Peter J. , Green Gary G. R. , Duckett Simon B. 
Published: June 2017

AbstractNuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) suffer from low sensitivity and limited nuclear spin memory lifetimes. Although hyperpolarization techniques increase sensitivity, there is also a desire to increase relaxation times to expand the range of applications addressable by these methods. Here, we demonstrate a route to create hyperpolarized magnetization in 13C nuclear spin pairs that last much longer than normal lifetimes by storage in a singlet state. By combining molecular design and low‐field storage with para‐hydrogen derived hyperpolarization, we achieve more than three orders of signal amplification relative to equilibrium Zeeman polarization and an order of magnitude extension in state lifetime. These studies use a range of specifically synthesized pyridazine derivatives and dimethyl p‐tolyl phenyl pyridazine is the most successful, achieving a lifetime of about 190 s in low‐field, which leads to a 13C‐signal that is visible for 10 minutes.
Application of SWATH Proteomics to Mouse Biology
Authors: Wu Yibo , Williams Evan G. , Aebersold Ruedi 
Published: June 2017

AbstractThe quantitative measurement of the proteome has been shown to yield new insights into physiology and cell biology that cannot be determined from the genome and transcriptome because the quantitative relationship between transcriptome and proteome is complex. MS‐based proteomics techniques, such as SWATH‐MS, have recently advanced to the point at which they may be reliably applied by biologists who are not specialists in mass spectrometry. Here we provide standard protocols for preparation of tissue samples for input into the SWATH‐MS analytical pipeline. These protocols are designed for high‐throughput processing of tissues with ≥5 mg of sample available for analysis. Studies with extremely limited amounts of tissue should consider PCT‐SWATH. An experienced single user should be able to process 48 samples per day for injection into the mass spectrometer, or up to 144 samples a week. The machine time necessary for running these samples with SWATH is approximately 1.5 hr per sample. Data acquisition protocols are also provided. © 2017 by John Wiley & Sons, Inc.
A High‐Throughput Process for the Solid‐Phase Purification of Synthetic DNA Sequences
Authors: Grajkowski Andrzej , Cieślak Jacek , Beaucage Serge L. 
Published: June 2017

AbstractAn efficient process for the purification of synthetic phosphorothioate and native DNA sequences is presented. The process is based on the use of an aminopropylated silica gel support functionalized with aminooxyalkyl functions to enable capture of DNA sequences through an oximation reaction with the keto function of a linker conjugated to the 5′‐terminus of DNA sequences. Deoxyribonucleoside phosphoramidites carrying this linker, as a 5′‐hydroxyl protecting group, have been synthesized for incorporation into DNA sequences during the last coupling step of a standard solid‐phase synthesis protocol executed on a controlled pore glass (CPG) support. Solid‐phase capture of the nucleobase‐ and phosphate‐deprotected DNA sequences released from the CPG support is demonstrated to proceed near quantitatively. Shorter than full‐length DNA sequences are first washed away from the capture support; the solid‐phase purified DNA sequences are then released from this support upon reaction with tetra‐n‐butylammonium fluoride in dry dimethylsulfoxide (DMSO) and precipitated in tetrahydrofuran (THF). The purity of solid‐phase‐purified DNA sequences exceeds 98%. The simulated high‐throughput and scalability features of the solid‐phase purification process are demonstrated without sacrificing purity of the DNA sequences. © 2017 by John Wiley & Sons, Inc.
Label‐Free Dynamic Mass Redistribution and Bio‐Impedance Methods for Drug Discovery
Authors: Grundmann Manuel 
Published: June 2017

AbstractLabel‐free biosensors are increasingly employed in drug discovery. Cell‐based biosensors provide valuable insights into the biological consequences of exposing cells and tissues to chemical agents and the underlying molecular mechanisms associated with these effects. Optical biosensors based on the detection of dynamic mass redistribution (DMR) and impedance biosensors using cellular dielectric spectroscopy (CDS) capture changes of the cytoskeleton of living cells in real time. Because signal transduction correlates with changes in cell morphology, DMR and CDS biosensors are exquisitely suited for recording integrated cell responses in an unbiased, yet pathway‐specific manner without the use of labels that may interfere with cell function. Described in this unit are several experimental approaches utilizing optical label‐free system capturing dynamic mass redistribution (DMR) in living cells (Epic System) and an impedance‐based CDS technology (CellKey). In addition, potential pitfalls associated with these assays and alternative approaches for overcoming such technical challenges are discussed. © 2017 by John Wiley & Sons, Inc.
An integrity verification scheme of completeness and zero‐knowledge for multi‐Cloud storage
Authors: Cao Laicheng , He Wenwen , Liu Yufei , Guo Xian , Feng Tao 
Published: June 2017

SummaryTo resist the attacks from the malicious Cloud service providers and the organizer, an integrality verification of completeness and zero‐knowledge property (IVCZKP) scheme for multi‐Cloud environment is proposed. First, the bilinear pairing maps are adopted as a basis of theoretical support for IVCZKP scheme. Second, the change of file blocks is recorded, and the hash value of each block is generated through the index‐hash table in the verification process. Finally, the hash value of each block is updated through this index‐hash table to support the dynamic updates to user's data, such as data modification, data insertion, and data deletion. Compared with the original scheme, IVCZKP scheme can resist the forgery attacks and has the completeness and zero‐knowledge property. Theory analysis and the experimental results show that this scheme can reduce the computation time and has more performance on integrity verification in multi‐Cloud environment.
Posture Stabilization Control of Personal Robot Based on Model Predictive Control
Authors: HIROSE NORIAKI , TAJIMA RYOSUKE , SUKIGARA KAZUTOSHI , KOYAMA NAGISA , TANAKA MINORU , ITO SEIGO 
Published: June 2017

SummaryThe aging of the elderly is a significant problem in developed countries. We address this problem by using a personal robot that follows elderly people. To accomplish its task, the robot needs to satisfy two main specifications: compact size and excellent traveling performance. In this paper, we introduce a prototype of our compact personal robot and propose a posture control approach based on model predictive control. Our approach can control the zero moment point within the desired range to achieve quick turning. The effectiveness of the proposed approach is evaluated by both simulations and experiments using the prototype robot.
Synthesis of the Highly Reduced [Fe6C(CO)15]4– Carbonyl Carbide Cluster and Its Reactions with H+ and [Au(PPh3)]+
Authors: Bortoluzzi Marco , Ciabatti Iacopo , Cesari Cristiana , Femoni Cristina , Iapalucci Maria Carmela , Zacchini Stefano 
Published: June 2017

AbstractInvited for the cover of this issue is the group of Stefano Zacchini from Bologna University, Italy. The cover image shows the effect of aurophilic interactions on the assembly of a hexanuclear iron carbide tetraanionic cluster with two cationic gold–phosphine fragments.