bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcium‐Modified Silk as a Biocompatible and Strong Adhesive for Epidermal Electronics
Authors: Seo Ji‐Won , Kim Hyojung , Kim KyuHan , Choi Siyoung Q. , Lee Hyunjoo J.
Published: July 2018

With the increasing interest and demand for epidermal electronics, a strong interface between a sensor and a biological surface is essential, yet achieving such interface is still a challenge. Here, a calcium (Ca)‐modified biocompatible silk fibroin as a strong adhesive for epidermal electronics is proposed and the physical principles behind its interfacial and adhesive properties are reported. A strong adhesive characteristic (>800 N m−1) is observed because of the increase in both viscoelastic property and mechanical interlocking through the incorporation of Ca ions. Furthermore, additional key characteristics of the Ca‐modified silk: reusability, stretchability, biocompatibility, and conductivity, are reported. These characteristics enable a wide range of applications as demonstrated in four epidermal electronic systems: capacitive touch sensor, resistive strain sensor, hydrogel‐based drug delivery, and electrocardiogram monitoring sensor. As a reusable, biocompatible, conductive, and strong adhesive with water‐degradability, the Ca‐modified silk adhesive is a promising candidate for the next‐generation adhesive for epidermal biomedical sensors.
Surface Defect Engineering in 2D Nanomaterials for Photocatalysis
Authors: Xiong Jun , Di Jun , Xia Jiexiang , Zhu Wenshuai , Li Huaming
Published: July 2018

2D Nanomaterials, with unique structural and electronic features, have shown enormous potential toward photocatalysis fields. However, the photocatalytic behavior of pristine 2D photocatalysts are still unsatisfactory, and far below the requirements of practical applications. In this regard, surface defect engineering can serve as an effective means to tune photoelectric parameters of 2D photocatalysts through tailoring the local surface microstructure, electronic structure, and carrier concentration. In this review, recent progress in the design of surface defects with the classified anion vacancy, cation vacancy, vacancy associates, pits, distortions, and disorder on 2D photocatalysts to boost the photocatalytic performance is summarized. The strategies for controlling defects formation and technique to distinguish various surface defects are presented. The crucial roles of surface defects for photocatalysis performance optimization are proposed and advancement of defective 2D photocatalysts toward versatile applications such as water oxidation, hydrogen production, CO2 reduction, nitrogen fixation, organic synthesis, and pollutants removal are discussed. Surface defect modulated 2D photocatalysts thus represent a powerful configuration for further development toward photocatalysis.
Investigation of Magnetotaxis of Reconfigurable Micro‐Origami Swimmers with Competitive and Cooperative Anisotropy
Authors: Huang Hen‐Wei , Huang Tian‐Yun , Charilaou Michalis , Lyttle Sean , Zhang Qi , Pané Salvador , Nelson Bradley J.
Published: July 2018

Recent advances in magnetic nanocomposites have enabled untethered micromachines with controllable shape transformations and programmable magnetic anisotropy, paving the way for a variety of biomedical applications using soft microrobots. Magnetic anisotropy is programmed by assembling the embedded magnetic nanoparticles (MNPs) in polymeric materials to overcome the shape anisotropy of a given structure. However, this approach is questionably effective in reconfigurable structures, as shape changes naturally result in rearrangement of the embedded MNPs. A naturally occurring solution to this problem is found in magnetotactic bacteria, which build chains of MNPs in a linear‐chain formation in their cells to create a permanent magnetic dipole moment. This dipole moment enables them to actively sense magnetic fields and coordinate their movement in response, a behavior called magnetotaxis. Inspired by this, self‐folding micro‐origami swimmers comprising magnetic nanocomposite bilayer structures that exhibit controllable shape transformations and programmable, shape‐independent magnetotaxis is fabricated. A study of these structures reveals that their magnetic anisotropy results from competition or cooperation between anisotropy of assembled chains of MNPs and overall shape anisotropy. Moreover, how the magnetotaxis of the reconfigurable micro‐origami swimmers depends only on the embedded permanent dipole moment, independent of the overall magnetic anisotropy, is demonstrated.
Intrinsically 32P‐Labeled Diamond Nanoparticles for In Vivo Imaging and Quantification of Their Biodistribution in Chicken Embryos
Authors: Happel Patrick , Waag Thilo , Schimke Magdalena , Schweeberg Sarah , Muzha Andreas , Fortak Katrin , Heesch Daniel , Klask Laura , Pilscheur Mathias , Hoppe Franziska , Lenders Thomas , Meijer Jan , Lepperdinger Günter , Krueger Anke
Published: July 2018

Nanoparticles, especially from carbon, have great potential in biomedicine. However, prior to clinical use, biocompatibility and biodistribution of these nanoobjects have to be assessed. Currently, particle detection is mostly based on surface‐bound labels, inevitably altering materials' properties by surface modification. Further obstacles include bleaching, dissociation of labels from the surface, weak emission of fluorophores due to insufficient tissue opacity or hampered light penetration or the need for specific excitation wavelengths. These characteristics greatly constrain employment of such nanoparticles to address complex analytical questions. To overcome these drawbacks, the use of intrinsic structural features of nanoobjects is highly desirable: the particle surface remains unchanged and the nanoobject exhibits its innate behavior. Thus, for sensitive detection and quantification, labels should be incorporated in the nanoparticle core, thereby avoiding cleavage and warranting unchanged surface characteristics. The incorporation of clinically approved radionuclide 32P into the lattice of nanodiamond particles using highly defined ion implantation is described here. The properties, uptake, and biodistribution are studied in vivo, in the developing hen's egg model (hen's egg test on chorioallantoic membrane assay). It is found that 32P labeling of diamond nanoparticles allows their reliable localization and sensitive quantification in a cost efficient, highly reliable, and safe way using available autoradiographic devices and analytical methods.
Near‐Infrared IIb Fluorescence Imaging of Vascular Regeneration with Dynamic Tissue Perfusion Measurement and High Spatial Resolution
Authors: Ma Zhuoran , Zhang Mingxi , Yue Jingying , Alcazar Cynthia , Zhong Yeteng , Doyle Timothy C. , Dai Hongjie , Huang Ngan F.
Published: July 2018

Real‐time optical imaging is a promising approach for visualizing in vivo hemodynamics and vascular structure in mice with experimentally induced peripheral arterial disease (PAD). The application of a novel fluorescence‐based all‐optical imaging approach in the near‐infrared IIb (NIR‐IIb, 1500–1700 nm emission) window, for imaging hindlimb microvasculature and blood perfusion in a mouse model of PAD is reported. In phantom studies, lead sulfide/cadmium sulfide (PbS/CdS) quantum dots show better retention of image clarity, in comparison with single‐walled nanotube (SWNT) NIR‐IIa (1000–1400 nm) dye, at varying depths of penetration. When systemically injected to mice, PbS/CdS demonstrates improved clarity of the vasculature, compared to SWNTs, as well as higher spatial resolution than in vivo microscopic computed tomography. In a mouse model of PAD, NIR‐IIb imaging of the ischemic hindlimb vasculature shows significant improvement in blood perfusion over the course of 10 days (P < 0.05), as well as a significant increase in microvascular density over the first 7 days after induction of PAD. In conclusion, NIR‐IIb imaging of PbS/CdS vascular contrast agent is a useful multifunctional imaging approach for high spatial resolution imaging of the microvasculature and quantification of blood perfusion recovery.
Nanoparticle Assembly at Liquid–Liquid Interfaces: From the Nanoscale to Mesoscale
Authors: Shi Shaowei , Russell Thomas P.
Published: July 2018

In the past few decades, novel syntheses of a wide range of nanoparticles (NPs) with well‐defined chemical composition and structure have opened tremendous opportunities in areas ranging from optical and electronic devices to biomedical markers. Controlling the assembly of such well‐defined NPs is important to effectively harness their unique properties. The assembly of NPs at liquid–liquid interfaces is becoming a central topic both in surface and colloid science. Hierarchical structures, including 2D films, 3D capsules, and structured liquids, have been generating significant interest and are showing promise for physical, chemical, and biological applications. Here, a brief overview of the development of the self‐assembly of NPs at liquid–liquid interfaces is provided, from theory to experiment, from synthetic NPs to bio‐nanoparticles, from water–oil to water–water, and from “liquid‐like” to “solid‐like” assemblies.
Gadolinium‐Encapsulated Graphene Carbon Nanotheranostics for Imaging‐Guided Photodynamic Therapy
Authors: Chen Hongmin , Qiu Yuwei , Ding Dandan , Lin Huirong , Sun Wenjing , Wang Geoffrey D. , Huang Weicheng , Zhang Weizhong , Lee Daye , Liu Gang , Xie Jin , Chen Xiaoyuan
Published: July 2018

Photosensitizers (PS) are an essential component of photodynamic therapy (PDT). Conventional PSs are often porphyrin derivatives, which are associated with high hydrophobicity, low quantum yield in aqueous solutions, and suboptimal tumor‐to‐normal‐tissue (T/N) selectivity. There have been extensive efforts to load PSs into nanoparticle carriers to improve pharmacokinetics. The approach, however, is often limited by PS self‐quenching, pre‐mature release, and nanoparticle accumulation in the reticuloendothelial system organs. Herein, a novel, nanoparticle‐based PS made of gadolinium‐encapsulated graphene carbon nanoparticles (Gd@GCNs), which feature a high 1O2 quantum yield, is reported. Meanwhile, Gd@GCNs afford strong fluorescence and high T1 relaxivity (16.0 × 10−3m−1 s−1, 7 T), making them an intrinsically dual‐modal imaging probe. Having a size of approximately 5 nm, Gd@GCNs can accumulate in tumors through the enhanced permeability and retention effect. The unbound Gd@GCNs cause little toxicity because Gd is safely encapsulated within an inert carbon shell and because the particles are efficiently excreted from the host through renal clearance. Studies with rodent tumor models demonstrate the potential of the Gd@GCNs to mediate image‐guided PDT for cancer treatment. Overall, the present study shows that Gd@GCNs possess unique physical, pharmaceutical, and toxicological properties and are an all‐in‐one nanotheranostic tool with substantial clinical translation potential.
tert‐Butyl Nitrite Mediated Different Functionalizations of Internal Alkenes: Paths to Furoxans and Nitroalkenes
Authors: Mir Bilal Ahmad , Singh Sarangthem Joychandra , Kumar Ritush , Patel Bhisma K.
Published: July 2018

tert‐Butyl nitrite (TBN) reacts differently with various internal alkenes leading to interesting and useful products. Synthesis of 1,2,5‐oxadiazole‐N‐oxides (furoxans) has been achieved from internal alkenes using tert‐butyl nitrite (TBN), quinoline and K2S2O8. Under an identical reaction condition α,β‐unsaturated carboxylic acids and cyclic and acyclic internal alkenes both afforded nitroalkenes as the sole product via decarboxylative and direct nitration path respectively.

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MaxMIF: A New Method for Identifying Cancer Driver Genes through Effective Data Integration
Authors: Hou Yingnan , Gao Bo , Li Guojun , Su Zhengchang
Published: July 2018

Identification of a few cancer driver mutation genes from a much larger number of passenger mutation genes in cancer samples remains a highly challenging task. Here, a novel method for distinguishing the driver genes from the passenger genes by effective integration of somatic mutation data and molecular interaction data using a maximal mutational impact function (MaxMIF) is presented. When evaluated on six somatic mutation datasets of Pan‐Cancer and 19 datasets of different cancer types from TCGA, MaxMIF almost always significantly outperforms all the existing state‐of‐the‐art methods in terms of predictive accuracy, sensitivity, and specificity. It recovers about 30% more known cancer genes in 500 top‐ranked candidate genes than the best among the other tools evaluated. MaxMIF is also highly robust to data perturbation. Intriguingly, MaxMIF is able to identify potential cancer driver genes, with strong experimental data support. Therefore, MaxMIF can be very useful for identifying or prioritizing cancer driver genes in the increasing number of available cancer genomic data.
The Introduction of Fluorine and Sulfur Atoms into Benzotriazole‐Based p‐Type Polymers to Match with a Benzotriazole‐Containing n‐Type Small Molecule: “The Same‐Acceptor‐Strategy” to Realize High Open‐Circuit Voltage
Authors: Tang Ailing , Xiao Bo , Chen Fan , Zhang Jianqi , Wei Zhixiang , Zhou Erjun
Published: July 2018

“The Same‐Acceptor‐Strategy” (SAS) adopts benzotriazole (BTA)‐based p‐type polymers paired with a new BTA based non‐fullerene acceptor BTA13 to minimize the trade‐off between the open‐circuit voltage (VOC) and short circuit current (JSC). The fluorination and sulfuration are introduced to lower the highest occupied molecular orbitals (HOMO) of the polymers. The fluorinated polymer of J52‐F shows the higher power conversion efficiency (PCE) of 8.36% than the analog polymer of J52, benefited from a good balance between an improved VOC of 1.18 V and a JSC of 11.55 mA cm−2. Further adding alkylthio groups on J52‐F, the resulted polymer, J52‐FS, exhibits the highest VOC of 1.24 V with a decreased energy loss of 0.48 eV, compared with 0.67 eV for J52 and 0.54 eV for J52‐F. However, J52‐FS shows an inferior PCE (3.84%) with a lower JSC of 6.74 mA cm−2, because the small ΔEHOMO between J52‐FS and BTA13 (0.02 eV) gives rise to the inefficient hole transfer and high charge recombination, as well as low carrier mobilities. The results of this study clearly demonstrate that the introduction of different atoms in p‐type polymers is effective to improve the SAS and realize the high (VOC) and PCE.
Predictors of acute care utilization and acute pain treatment outcomes in adults with sickle cell disease: The role of non‐hematologic characteristics and baseline chronic opioid dose
Authors: Carroll C. Patrick , Cichowitz Cody , Yu Tiffany , Olagbaju Yetunde O. , Nelson Julie Anne , Campbell Timothy , Lanzkron Sophie
Published: July 2018

Despite its rarity in the United States, sickle cell disease accounts for a disproportionate amount of healthcare utilization and costs. The majority of this is due to acute care for painful crises. A small subpopulation of patients accounts for most these costs due to frequent visits to emergency departments and acute care facilities. Previous investigations have found that these high utilizing patients are distinguished by both a more severe disease course and certain non‐hematologic characteristics, which may include higher socioeconomic status and some psychiatric and psychological characteristics. This prospective observational cohort study was undertaken to test the ability of these characteristics to prospectively predict acute pain care outcomes, including visit frequency, total opioid doses, and pain improvement at the Johns Hopkins Sickle Cell Infusion Center (SCIC). Seventy‐three participants were followed for 12 months and SCIC utilization and treatment outcomes were tabulated for 378 visits. Participants who visited the SCIC most frequently had markedly worse pain improvement despite higher within‐visit opioid doses. Higher utilization was associated with indicators of greater illness severity, more aggressive treatment for sickle cell disease, higher baseline opioid doses, higher socioeconomic status, greater pain‐related anxiety, and a history of psychiatric treatment. Overall, poor acute pain treatment response was associated with higher utilization and higher baseline opioid doses. The pattern of association between high utilization, poor acute care outcomes, and higher baseline opioid doses is discussed in terms of prior research and future directions.
Rituximab maintenance therapy for mantle cell lymphoma: A systematic review and meta‐analysis
Authors: Hilal Talal , Wang Zhen , Almader‐Douglas Diana , Rosenthal Allison , Reeder Craig B. , Jain Tania
Published: July 2018

Mantle cell lymphoma is characterized by relapse and progressive disease, despite initial response to chemoimmunotherapy. We conducted a systematic review and meta‐analysis to determine the efficacy of rituximab maintenance (RM) therapy in patients with mantle cell lymphoma. We searched PubMed, Embase and Cochrane Central Register of Controlled Trials from database inception through November 1, 2017. Only full‐text articles were included. Prespecified data elements were extracted from each trial. Outcomes of interest included progression‐free survival (PFS) and overall survival (OS). The overall effect was pooled using the Der Simonian‐Laird random effects model. Three randomized controlled trials and four observational studies met our inclusion criteria and were identified in the analyses. Six studies compared RM therapy to observation, and one compared RM therapy to interferon alfa. Meta‐analysis evaluating outcomes of patients treated after ASCT revealed that RM improved for both PFS (HR = 0.33, 95% CI = 0.23‐0.49) and OS (HR of death = 0.35, 95% CI = 0.17‐0.69). A second meta‐analysis of studies evaluating outcomes of patients who are ASCT‐ineligible treated with anthracycline‐based induction therapy revealed that RM improved PFS (HR = 0.38, 95% CI = 0.25‐0.58). There is a paucity of data on the role of RM in ASCT‐ineligible patients and those with relapsed disease. Overall, RM therapy appears to improve PFS and OS in previously untreated patients with mantle cell lymphoma who undergo induction chemoimmunotherapy followed by ASCT.
ROS‐Responsive N‐Alkylaminoferrocenes for Cancer‐Cell‐Specific Targeting of Mitochondria
Authors: Reshetnikov Viktor , Daum Steffen , Janko Christina , Karawacka Weronika , Tietze Rainer , Alexiou Christoph , Paryzhak Solomiya , Dumych Tetiana , Bilyy Rostyslav , Tripal Philipp , Schmid Benjamin , Palmisano Ralf , Mokhir Andriy
Published: July 2018

Mitochondrial membrane potential is more negative in cancer cells than in normal cells, allowing cancer targeting by delocalized lipophilic cations (DLCs). However, as the difference is rather small, these drugs affect also normal cells. Now a concept of pro‐DLCs is proposed based on an N‐alkylaminoferrocene structure. These prodrugs are activated by the reaction with reactive oxygen species (ROS) forming ferrocenium‐based DLCs. Since ROS are overproduced in cancer, the high‐efficiency cancer‐cell‐specific targeting of mitochondria could be achieved as demonstrated by fluorescence microscopy in combination with two fluorogenic pro‐DLCs in vitro and in vivo. We prepared a conjugate of another pro‐DLC with a clinically approved drug carboplatin and confirmed that its accumulation in mitochondria was higher than that of the free drug. This was reflected in the substantially higher anticancer effect of the conjugate.
Photoredoxkatalyse als Strategie zur synthetischen Nutzung von CO2: Direkter Zugang zu Carbonsäuren aus einem erneuerbaren Rohstoff
Authors: Yeung Charles S.
Published: July 2018

Kohlendioxid stellt aus Sicht globaler Nachhaltigkeitsbemühungen ein attraktives Rohmaterial dar. Sein vielfältiger Einsatz wird allerdings durch seine geringe Reaktivität erschwert. Neue Katalysatoren und Technologien, die den Aufbau von C‐C‐Bindungen ermöglichen, sind daher von hohem Wert. Dieser Kurzaufsatz beschreibt aktuelle Fortschritte auf dem Gebiet der Photoredoxkatalyse als Strategie für Carboxylierungen.
Umpolung Reactivity of Aldehydes toward Carbon Dioxide
Authors: Juhl Martin , Lee Ji‐Woong
Published: July 2018

Carbon dioxide is an intrinsically stable molecule. Therefore, its activation requires extra energy input in the form of reactive reagents and/or activated catalysts and, often, harsh reaction conditions. Reported here is a direct carboxylation reaction of aromatic aldehydes with carbon dioxide to afford α‐keto acids as added‐value products. In situ generation of a reactive cyanohydrin was the key to the successful carboxylation reaction under operationally mild reaction conditions (25–40 °C, 1 atm CO2). The resulting α‐keto acids served as a platform for α‐amino acid synthesis by reductive amination reactions, illustrating the chemical synthesis of essential bioactive molecules from carbon dioxide.
Photocontrolled Multidirectional Differentiation of Mesenchymal Stem Cells on an Upconversion Substrate
Authors: Yan Zhengqing , Qin Hongshuang , Ren Jinsong , Qu Xiaogang
Published: July 2018

The effective guidance of mesenchymal stem cell (MSC) differentiation on a substrate by near‐infrared (NIR) light is particularly attractive for tissue engineering and regenerative medicine. However, most of current substrates cannot control multidirectional differentiation of MSCs like natural tissues. Herein, a photocontrolled upconversion‐based substrate was designed and constructed for guiding multidirectional differentiation of MSCs. The substrate enables MSCs to maintain their stem‐cell characteristics due to the anti‐adhesive effect of 4‐(hydroxymethyl)‐3‐nitrobenzoic acid modified poly(ethylene glycol) (P1) attached on the upconversion substrate. Upon NIR irradiation, the P1 is released from the substrate by photocleavage. The detachment of P1 can change cell–matrix interactions dynamically. Moreover, MSCs cultured on the upconversion substrate can be specifically induced to differentiate to adipocytes or osteoblasts by adjusting the NIR laser. Our work provides a new way of using NIR‐based upconversion substrate to modulate the multidirectional differentiation of MSCs.
Experimental Evidence for a Triboluminescent Antiperovskite Ferroelectric: Tris(trimethylammonium) catena‐Tri‐μ‐chloro‐manganate(II) Tetrachloromanganate(II)
Authors: Li Peng‐Fei , Tang Yuan‐Yuan , Liao Wei‐Qiang , Shi Ping‐Ping , Hua Xiu‐Ni , Zhang Yi , Wei Zhenhong , Cai Hu , Xiong Ren‐Gen
Published: July 2018

The perovskite structure is rich in ferroelectricity. In contrast, ferroelectric antiperovskites have been scarcely confirmed experimentally since the discovery of M3AB‐type antiperovskites in the 1930s. Ferroelectricity is now revealed in an organic–inorganic hybrid X3AB antiperovskite structure, which exhibits a clear ferroelectric phase transition 6/mmmF6mm with a high Curie point of 480 K. The physical properties across the phase transition are obviously changed along with the symmetry requirements, providing solid experimental evidence for the ferroelectric phase transition. More interestingly, the discovered antiperovskite shows intense photoluminescence and triboluminescence properties. The confirmation of the triboluminescent ferroelectric antiperovskite will open new avenues to explore excellent optoelectronic properties in the antiperovskite family.
Photoredox Catalysis as a Strategy for CO2 Incorporation: Direct Access to Carboxylic Acids from a Renewable Feedstock
Authors: Yeung Charles S.
Published: July 2018

Carbon dioxide is an attractive reagent for organic synthesis from the standpoint of global sustainability. Its widespread use, however, is hampered by the fact that it is poorly reactive. New catalysts and technologies that enable C−C bond constructions are thus of high intrinsic value. This Minireview describes recent advances in the area of photoredox catalysis as an enabling strategy for promoting carboxylations.
Manganese‐Catalyzed Redox‐Neutral C−H Olefination of Ketones with Unactivated Alkenes
Authors: Hu Yuanyuan , Zhou Bingwei , Chen Hui , Wang Congyang
Published: July 2018

Since 1987, stoichiometric cyclomanganation of ketones and subsequent reactions with olefins in the presence of either palladium salts or trimethylamine N‐oxide (Me3N+O−) have been reported, but the catalytic versions remain untouched so far. Herein, the first manganese‐catalyzed redox‐neutral C−H olefination of ketones with unactivated alkenes is described, and shows a distinct reactivity with its parent stoichimetric reactions. Remarkably, mechanistic experiments and DFT calculations uncovers a unique concerted bis‐metalation deprotonation (CBMD) mechanism of the Mn‐Zn‐enabled C−H bond activation.
A novel pathway for in situ synthesis of modified gelatin microspheres by silane coupling agents as a bioactive platform
Authors: Ghorbani Farnaz , Zamanian Ali , Behnamghader Aliasghar , Daliri Joupari Morteza
Published: July 2018

This study investigated the fabrication and modification of gelatin microspheres via single emulsion method and silane coupling agents, respectively. Herein, the influence of oil phase and washing procedure on morphology and uniformity of microspheres was evaluated. The results of field emission scanning electron microscopy indicated a positive effect of olive oil on the production of uniform and approximately mono‐size spheres while monodispersity increased after samples were washed under ultrasonication. Investigation of crosslinking degree demonstrated that GPTMS could not show efficiency as high as glutaraldehyde, but the lack of toxicity and inducing bioactive behavior to the microspheres has made them appropriate for bone applications. Moreover, the stability of spheres after 14 days in phosphate buffered saline proved the ability of (3‐glycidyloxypropyl)trimethoxysilane to crosslink gelatin. The presence of silane coupling agents in prepared spheres caused the biomimetic formation of hydroxyapatite after a 14‐day immersion in simulated body fluid as observed by field emission scanning electron microscopy‐energy‐dispersive X‐ray spectroscopy, changes in pH, Fourier transform infrared spectroscopy, X‐ray diffraction, and atomic force microscopy. Adhesion, spreading, and proliferation of L929 cells on the hybrid microspheres corroborated the potential of gelatin spheres for biomedical application. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46739.
Functionalization of poly(3‐hydroxybutyrate) with different thiol compounds inhibits MDM2–p53 interactions in MCF7 cells
Authors: Abdelwahab M. A. , El‐Barbary A. A. , El‐Said K. S. , Betiha M. , Elkholy H. M. , Chiellini E. , El‐Magd M. A.
Published: July 2018

High‐molecular‐weight poly(3‐hydroxybutyrate) (PHB) has a low reactivity toward its terminal functional groups. Thus, the chemical reactivity of PHB was enhanced by the chemical degradation that occurred via β‐elimination through the functionalization of PHB with ethylene glycol to give a low‐molecular‐weight PHB–diol. The reaction of PHB–diol with acryloyl chloride gave PHB–diacrylate, which was grafted by thiol compounds, such as ethane dithiol, 2‐mercaptoethanol, ethane thiol, dithiothreitol, butane thiol, and thioglycolic acid, via a Michael‐type addition reaction. The chemical and thermal properties of the functionalized PHB–thiol products were characterized with Fourier transform infrared spectroscopy, 1H‐NMR, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis techniques. X‐ray diffraction showed that the PHB–thiol polymers had slight differences in crystallinity compared with neat PHB. The biological activities of the neat polymer and new PHB–thiol polymers, including the antibacterial and anticancer activities, were tested, and some of these products showed antibacterial and anticancer activities. These anticancer activities were attributed to the ability of these PHB–thiol polymers to induce apoptosis (as revealed by the higher expression of Bax and caspase 9 and the lower expression of Bcl2) and cell‐cycle arrest in the G0/G1 phase, which is associated with the higher expression of p53 and p21 and the lower expression of the p53 inhibitor, MDM2. Thus, the anticancer effect of these PHB–thiol polymers may have been due to their ability to inhibit MDM2–p53 interactions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46924.
Schiff bases and their amines: Synthesis and discovery of carbonic anhydrase and acetylcholinesterase enzymes inhibitors
Authors: Yiğit Beyhan , Yiğit Murat , Taslimi Parham , Gök Yetkin , Gülçin İlhami
Published: July 2018

Three series of symmetrical Schiff bases were synthesized from 1,2‐diaminoethane, 1,3‐diaminopropane and 1,4‐diaminobutane and substituted benzaldehydes, and reduced by sodium borohydride to the corresponding benzylic diamines 4–6. All of the compounds obtained were characterized using elemental analysis, FT‐IR, 1H NMR, and 13C NMR spectroscopy. The enzyme inhibitory properties of these compounds were tested and the influence of the alkane chain length and the substituents on the phenyl group on the enzyme inhibition activity were examined. The novel Schiff bases and their amine derivatives (1a–d, 2a–d, 3b–d, 4a–c, 5a–c, 6a, 6c, 6d) were effective inhibitors of the cytosolic carbonic anhydrase I and II isoforms (hCA I and II), and acetylcholinesterase (AChE) with Ki values in the range of 159.43 ± 30.03 to 563.73 ± 115.30 nM for hCA I, 104.88 ± 18.44 to 524.32 ± 95.03 nM for hCA II, and 3.95 ± 0.74 to 30.83 ± 6.81 nM for AChE.
Tissue‐Resident Memory CD8+ T Cells Acting as Mediators of Salivary Gland Damage in a Murine Model of Sjögren's Syndrome
Authors: Gao Cai‐Yue , Yao Yuan , Li Liang , Yang Shu‐Han , Chu Hui , Tsuneyama Koichi , Li Xiao‐Mei , Gershwin M. Eric , Lian Zhe‐Xiong
Published: July 2018

Objective

Although a role for CD4+ T cells in the pathogenesis of Sjögren's syndrome (SS) has been documented, the pathogenic significance of CD8+ T cells is unclear. The aim of this study was to investigate the role of CD8+ T cells in the development of SS.

Methods

Flow cytometry and immunofluorescence analyses were utilized to detect T cell infiltration within the labial salivary glands of patients with primary SS. In parallel, p40−/−CD25−/− mice were used as a murine model of SS. In addition, mice with genetic knockout of CD4, CD8a, or interferon‐γ (IFNγ) were crossed with p40−/−CD25−/− mice to study the pathogenic significance of specific lineage subpopulations, including functional salivary gland tests as well as histopathologic and serologic data. A CD8+ T cell–specific depletion antibody was used in this murine SS model to evaluate its potential as a therapeutic strategy.

Results

CD8+ T cells with a tissue‐resident memory phenotype outnumbered CD4+ T cells in the labial salivary glands of patients with SS, and were primarily colocalized with salivary duct epithelial cells and acinar cells. Furthermore, infiltrating CD8+ T cells with a CD69+CD103+/− tissue‐resident phenotype and with a significant elevation of IFNγ production were dominant in the submandibular glands of mice in this murine SS model. CD8a knockout abrogated the development of SS in these mice. Knockout of IFNγ decreased CD8+ T cell infiltration and gland destruction. More importantly, depletion of CD8+ T cells fully protected mice against the pathologic manifestations of SS, even after the onset of disease.

Conclusion

These data reveal the pathogenic significance of CD8+ T cells in the development and progression of SS in the salivary glands. Treatment directed against CD8+ T cells may be a rational therapy for the management of SS in human subjects.
Tracking Control for Stochastic Multi‐Agent Systems Based on Hybrid Event‐Triggered Mechanism
Authors: Xing Mali , Deng Feiqi
Published: July 2018

This paper deals with the leader‐following consensus for nonlinear stochastic multi‐agent systems. To save communication resources, a new centralized/distributed hybrid event‐triggered mechanism (HETM) is proposed for nonlinear multi‐agent systems. HETMs can be regarded as a synthesis of continuous event‐triggered mechanism and time‐driven mechanism, which can effectively avoid Zeno behavior. To model the multi‐agent systems under centralized HETM, the switched system method is applied. By utilizing the property of communication topology, low‐dimensional consensus conditions are obtained. For the distributed hybrid event‐triggered mechanism, due to the asynchronous event‐triggered instants, the time‐varying system method is applied. Meanwhile, the effect of network‐induced time‐delay on the consensus is also considered. To further reduce the computational resources by constantly testing whether the broadcast condition has been violated, self‐triggered implementations of the proposed event‐triggered communication protocols are also derived. A numerical example is given to show the effectiveness of the proposed method.
A tailor‐made, self‐sufficient and recyclable monooxygenase catalyst based on coimmobilized cytochrome P450 BM3 and glucose dehydrogenase
Authors: Valikhani Donya , Bolivar Juan M. , Dennig Alexander , Nidetzky Bernd
Published: July 2018

Cytochrome P450 monooxygenases (P450s) promote hydroxylations in a broad variety of substrates. Their prowess in C–H bond functionalization renders P450s promising catalysts for organic synthesis. However, operating P450 reactions involve complex management of the main substrates, O2 and nicotinamide adenine dinucleotide phosphate (NAD(P)H) reducing equivalents against an overall background of low operational stability. Whole‐cell biocatalysis, although often used, offers no general solution to these problems. Herein, we present the design of a tailor‐made, self‐sufficient, operationally stabilized and recyclable P450 catalyst on porous solid support. Using enzymes as fusion proteins with the polycationic binding module Zbasic2, the P450s BM3 (from Bacillus megaterium) was coimmobilized with glucose dehydrogenase (type IV; from B. megaterium) on anionic sulfopropyl‐activated carrier (ReliSorb SP). Immobilization via Zbasic2 enabled each enzyme to be loaded in controllable amount, thus maximizing the relative portion of the rate limiting P450 BM3 (up to 19.5 U/gcarrier) in total enzyme immobilized. Using lauric acid as a representative P450 substrate that is poorly accessible to whole‐cell catalysts, we demonstrate complete hydroxylation at low catalyst loading (≤0.1 mol%) and efficient electron coupling (74%), inside of the catalyst particle, to the regeneration of NADPH from glucose (27 cycles) was achieved. The immobilized P450 BM3 showed a total turnover number of ∼18,000, thus allowing active catalyst to be recycled up to 20 times. This study therefore supports the idea of practical heterogeneous catalysis by P450s systems immobilized on solid support.
Electrochemical and Spectroelectrochemical Behavior of a Tetracyanotriphenodioxazine in Solution and Thin‐Films
Authors: Meunier‐Prest Rita , Gruntz Guillaume , Castet Frédéric , Nicolas Yohann , Wannebroucq Amélie , Bouvet Marcel , Toupance Thierry
Published: July 2018

We report the electrochemical behavior of a tetracyano triphenodioxazine bearing two triisopropylsilylethynyl moieties (TiPS‐TPDO‐tetraCN) during its reduction studied either in solution or after vacuum evaporation deposition on indium tin oxide (ITO) support. While in dichloromethane, it typically proceeds in two successive monoelectronic reactions, in acetonitrile, the mechanism appears more complex. Fine analysis of the spectroelectrochemical results combined with simulation of the voltammograms with various amount of water suggest the involvement of water and of a restructured dianion in the electrochemical process. In the solid‐state, the formation of the diprotonated compound was demonstrated and the equilibrium diagram of the different species formed as a function of the pH was drawn. The deprotonated form is unstable and decomposes immediately in solution. Its stabilization in solid‐state is attributed to π–π and charge transfer interactions.
Anion‐Binding Macrocycles Operate Beyond the Electrostatic Regime: Interaction Distances Matter
Authors: Sengupta Arkajyoti , Liu Yun , Flood Amar H. , Raghavachari Krishnan
Published: July 2018

Anion recognition impacts many areas of chemistry and often relies on receptors with multiple hydrogen‐bond donors. Previous studies of these donors in small molecules have long promoted the idea that electrostatic interactions alone correlate with association strength, yet this correlation has not been critically evaluated in the framework of larger, macrocyclic receptors. Here, we provide that assessment by evaluating how much electrostatics contributes to the gas‐phase binding energy of macrocyclic receptors with various anions. Whereas small‐molecule complexes behave as expected, we find that electrostatic interactions fail to accurately describe total binding energies of many common macrocyclic receptors: calix[4]pyrroles, dipyrrolyldiketones, indolocarbazoles, amido‐pyrroles, triazolophanes, and cyanostars. This deviation arises from the fact that most macrocycles have multiple points of contact with the anion. Whereas the hydrogen‐bond donors collectively stabilize the anion, the interaction distances are typically larger than equilibrium values seen with small molecules. This leads to increases in the relative contributions of the attractive components such as induction (e.g., induced dipoles) and dispersion, which are found to be as high as 32 % for CH‐donor based tricarbazole triazolophane complex with large polarizable ClO4−. This study augments previous observations of the importance of dispersion and induction towards anion binding of macrocyclic receptors in solution.
Luminescence of Amphiphilic PtII Complexes Controlled by Confinement
Authors: Atoini Youssef , Prasetyanto Eko Adi , Chen Pengkun , Silvestrini Simone , Harrowfield Jack , De Cola Luisa
Published: July 2018

The formation of hybrid silica‐based systems to study the effect of the confinement on the emission properties of self‐assembled platinum(II) complexes is reported. The complexes behave as surfactants since they possess a hydrophobic moiety and, on the ancillary ligand, a relatively long hydrophilic chain terminated with a positively charged group. The compounds, soluble in water, self‐assemble, even at very low concentration, in supramolecular structures which display an orange luminescence. The properties of the assemblies have been studied in detail and in order to stabilize these supramolecular architectures and to enhance their emission properties hybrid silica porous nanoparticles have been prepared. In particular the PtII complexes have been employed as co‐surfactant for the template formation of mesoporous silica nanoparticles (MSNs) using a sol gel synthesis. Interestingly, upon encapsulation in the silica pores, the platinum aggregates exhibit an emission profile similar in energy to the complexes assembled in solution, but the photoluminescence quantum yields of the hybrid systems are significantly higher (up to 45 %), and the excited state lifetimes much longer than those recorded in solution. Such enhancement of the photophysical properties together with the possibility to process the hybrid silica nanomaterials can pave the way to new type of emitters.
Topology Controls the Electronic Absorption and Delocalization of Electron Holes in Guanine Quadruplexes
Authors: Martínez‐Fernández Lara , Banyasz Akos , Markovitsi Dimitra , Improta Roberto
Published: July 2018

Guanine quadruplexes (G4) are four‐stranded DNA structures involved in biological processes and are promising candidates for potential nanotechnological applications. This study examines how the G4 topology affects the electronic absorption and the delocalization of electron holes, which play a key role in charge transport and oxidative damage. Combining transient absorption spectroscopy with PCM/TD‐DFT calculations both parallel (P) and antiparallel (A) G4 are investigated, which are formed, respectively, by association of four TGGGGT strands and folding of the human telomeric sequence GGG(TTAGGG)3. The experimental absorption spectra obtained upon photo‐ionization of A and P are different. This is explained by the different topology of the two G4, as well as by hole delocalization between two stacked guanines, possible only in P+. The spectral signature of delocalized hole in guanine‐rich regions is provided and the chemical physical effects which rule the hole delocalization are discussed.
Rational Design of a 310‐Helical PIP‐Box Mimetic Targeting PCNA, the Human Sliding Clamp
Authors: Wegener Kate L. , McGrath Amy E. , Dixon Nicholas E. , Oakley Aaron J. , Scanlon Denis B. , Abell Andrew D. , Bruning John B.
Published: July 2018

Invited for the cover of this issue is the group of John B. Bruning at The University of Adelaide. The image depicts PCNA (the human sliding clamp) shown as a protein surface representation (colored in grey) in complex with the first p21‐derived peptide mimetic inhibitor (shown as sticks colored by element). Read the full text of the article at 10.1002/chem.201801734.
Aggregation‐Induced Emission of EuIII Complexes Balanced with Bulky and Amphiphilic Imidazolium Cations in Ethanol/Water Binary Mixtures
Authors: Zhang Geping , Zhu Hongxia , Chen Mengjun , Pietraszkiewicz Marek , Pietraszkiewicz Oksana , Li Hongguang , Hao Jingcheng
Published: July 2018

A series of EuIII complexes with thenoyltrifluoroacetone (tta) as the ligands were synthesized, which are balanced with imidazolium cations bearing naphthyl and branched alkyl chains. The complex with the longest alkyl chain (1Eu(tta)4) shows aggregation behavior in ethanol and water mixtures. It exists as individuals at low water percentages (VH2O), and form particles with solid interiors at VH2O≥50 % the sizes of which decrease with the increase of VH2O. At VH2O=90 %, vesicles were observed. The aggregation of 1Eu(tta)4 in ethanol and water binary mixtures induced changes of the photoluminescence (PL) properties where an abrupt increase in PL intensity, quantum yield, and lifetime were noticed above VH2O=50 %. This PL enhancement can be explained by the encapsulation of 1Eu(tta)4 inside the aggregates, preventing it from quenching by the active hydroxyls of water molecules. Contrary to the aggregation‐induced emission (AIE) of the Eu complex, the naphthyl group in the imidazolium cation exhibited an aggregation‐caused quenching (ACQ) effect. When the length of the alkyl chain in the imidazolium cation is reduced, no PL enhancement can be observed owing to the difficulty in forming the aggregates.
Continuous‐time linear equalizer with automatic boosting gain adaptation and input offset cancellation
Authors: Lim Baek‐Jin , Yoo Changsik
Published: July 2018

A continuous‐time linear equalizer (CTLE) for high‐speed serial link is presented whose adaptive boosting gain is obtained with the data and edge values sampled by clock and data recovery circuit. The input offset of the serial link receiver is estimated by the data and edge values as well and cancelled by the CTLE. The adaptation of the CTLE boosting gain is immune to the phase error of the clock and data recovery sampling clock, and the cancellation of the input offset is independent of the boosting gain adaptation. The performance of the proposed adaptive CTLE has been evaluated by applying it to a 5‐Gb/s serial link receiver implemented in a 65‐nm CMOS technology.
Throughput maximization in wireless powered communication networks with minimum node throughput requirement
Authors: Chi Kaikai , Wei Xinchen , Li Yanjun , Tian Xianzhong
Published: July 2018

This paper considers wireless powered communication network consisting of one hybrid access point and a set of one‐hop nodes. Hybrid access point conducts wireless energy transfer (WET) in the downlink and nodes conduct wireless information transmissions (WITs) in the uplink based on the time division multiple access (TDMA) mode. Specifically, for the scenario where each node has its own minimum throughput requirement and different nodes' data have different levels of utility, we aim to achieve the minimum node throughput constrained weighted sum throughput maximization (MT‐WSTM) by jointly optimizing the time allocations of the WET and the WITs. First, we formulate the MT‐WSTM problem as a nonlinear optimization problem and further transform it into a more tractable form. Then, we prove the MT‐WSTM problem is convex and develop an efficient algorithm utilizing the dual decomposition technique to obtain the optimal solution of this problem. Compared with two schemes which use the optimal WET time and allocate the surplus WIT time evenly to all nodes and solely to the best node, respectively, the weighted sum throughput of the MT‐WSTM scheme is obviously larger in both homogeneous and heterogeneous scenarios.
Neural sensitivity to natural texture statistics in infancy
Authors: Balas Benjamin , Saville Alyson , Schmidt Jamie
Published: July 2018

During infancy, vision becomes tuned to environmental statistics. For example, infant face recognition “narrows” in response to the frequency of face categories in the visual world, inducing out‐group effects that disadvantage other‐race, other‐species, and other‐age face recognition. There are many other low‐level statistical regularities in visual experience that infants may also become tuned to during this period. In particular, natural scenes have lawful properties that adults and children are sensitive to. To what extent do infants become tuned to these regularities during the first year of life? In particular, do infants exhibit evidence of perceptual narrowing that excludes atypical images from fluent processing? We examined this question by measuring 6‐ and 9‐month‐old infants’ event‐related potentials (ERPs) to natural and artificial textures created by: (a) Disrupting local statistics via contrast negation, (b) Disrupting global statistics via parametric texture synthesis, or (c) both of these. We predicted that younger infants’ would be sensitive to both manipulations of natural appearance, but that older infants might not distinguish between different kinds of atypical images. Instead, we found that sensitivity to synthetic appearance is only evident late in infancy. We discuss what these results imply for our understanding of visual statistical learning in infancy.
Association of visceral adiposity and its longitudinal increase with the risk of diabetes in Chinese adults: A prospective cohort study
Authors: Xia Ming‐Feng , Lin Huan‐Dong , Chen Ling‐Yan , Wu Li , Ma Hui , Li Qian , Aleteng Qiqige , Chen Ying , Sun Yi‐Xuan , Hu Yu , Pan Bai‐shen , Li Xiao‐Ying , Gao Xin
Published: July 2018

Objective

A Chinese visceral adiposity index (CVAI) was recently established to estimate the visceral fat area in Chinese adults. This study aimed to investigate the risk of incident prediabetes and diabetes in relation to visceral adiposity calculated by CVAI.

Methods

A total of 2558 subjects with normal plasma glucose levels from the Shanghai Changfeng Study were enrolled in a prospective cohort study. The independent associations of basal visceral fat area by CVAI and its longitudinal change with incident prediabetes and diabetes were identified using Cox regression analyses.

Results

During an average of 4.4 years of follow‐up, 546 (21.3%) and 99 (3.9%) of 2558 nondiabetic subjects developed prediabetes and diabetes, respectively. Visceral fat area by CVAI and its longitudinal increase were independently associated with incident prediabetes and diabetes in Chinese adults. In a multivariable‐adjusted regression model, CVAI, as well as its annual change, was the strongest independent predictor of incident prediabetes (HR, 1.383 [1.162‐1.647]) and diabetes (HR, 1.607 [1.092‐2.364]) compared with other estimates of obesity (BMI and waist circumference). Receiver operating characteristic curve analyses showed that CVAI had better performance than BMI and waist circumference for the prediction of prediabetes and diabetes in Chinese adults.

Conclusions

Visceral adiposity plays a pivotal role in the pathogenesis of diabetes, and the visceral adiposity estimated by CVAI is superior to the traditional estimates of obesity for the prediction of incident prediabetes and diabetes in Chinese adults.