bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Atomic Force Microscopy of the Reconfiguration of On‐Surface Self‐Assembled DNA‐Nanoparticle Superlattices
Authors: Shekhirev Mikhail , Sutter Eli , Sutter Peter 
Published: January 2019

AbstractThe ability to dynamically reconfigure superlattices in response to external stimuli is an intriguing prospect for programmable DNA‐guided nanoparticle (NP) assemblies, which promises the realization of “smart” materials with dynamically adjustable interparticle spacing and real‐time tunable properties. Existing in situ probes of reconfiguration processes have been limited mostly to reciprocal space methods, which can follow larger ordered ensembles but do not provide access to real‐space pathways and dynamics. Here, in situ atomic force microscopy is used to investigate DNA‐linked NP assemblies and their response to external stimuli, specifically the contraction and expansion of on‐surface self‐assembled monolayer superlattices upon reversible DNA condensation induced by ethanol. In situ microscopy allows observation and quantification of key processes in solution, e.g., lattice parameter changes, defects, and monomer displacements in small groups of NPs. The analysis of imaging data uncovers important boundary conditions due to DNA bonding of NP superlattices to a substrate. Tension in the NP–substrate DNA bonds, which can elastically extend, break, and re‐form during contraction/expansion cycles, counteracts the changes in lattice parameter and causes hysteresis in the response of the system. The results provide insight into the behavior of supported DNA‐linked NP superlattices and establish a foundation for designing and probing tunable nanocrystal‐based materials in solution.
Cardiac Fibrotic Remodeling on a Chip with Dynamic Mechanical Stimulation
Authors: Kong Ming , Lee Junmin , Yazdi Iman K. , Miri Amir K. , Lin Yi‐Dong , Seo Jungmok , Zhang Yu Shrike , Khademhosseini Ali , Shin Su Ryon 
Published: January 2019

AbstractCardiac tissue is characterized by being dynamic and contractile, imparting the important role of biomechanical cues in the regulation of normal physiological activity or pathological remodeling. However, the dynamic mechanical tension ability also varies due to extracellular matrix remodeling in fibrosis, accompanied with the phenotypic transition from cardiac fibroblasts (CFs) to myofibroblasts. It is hypothesized that the dynamic mechanical tension ability regulates cardiac phenotypic transition within fibrosis in a strain‐mediated manner. In this study, a microdevice that is able to simultaneously and accurately mimic the biomechanical properties of the cardiac physiological and pathological microenvironment is developed. The microdevice can apply cyclic compressions with gradient magnitudes (5–20%) and tunable frequency onto gelatin methacryloyl (GelMA) hydrogels laden with CFs, and also enables the integration of cytokines. The strain–response correlations between mechanical compression and CFs spreading, and proliferation and fibrotic phenotype remolding, are investigated. Results reveal that mechanical compression plays a crucial role in the CFs phenotypic transition, depending on the strain of mechanical load and myofibroblast maturity of CFs encapsulated in GelMA hydrogels. The results provide evidence regarding the strain–response correlation of mechanical stimulation in CFs phenotypic remodeling, which can be used to develop new preventive or therapeutic strategies for cardiac fibrosis.
Recruitment and Collection of Dermal Interstitial Fluid Using a Microneedle Patch
Authors: Kolluru Chandana , Williams Mikayla , Chae Jeremy , Prausnitz Mark R. 
Published: January 2019

AbstractInterstitial fluid (ISF) that surrounds cells in tissues of the body is a novel source of biomarker that complements conventional sources like blood, urine, and saliva. To overcome difficulties in harvesting ISF, a minimally invasive, rapid, simple‐to‐use, cost‐effective method is developed to collect ISF from the skin involving a microneedle (MN) patch. By pressing 650 µm long MNs at an angle just below the skin surface, blood‐free ISF flows through micropores to the skin surface and is absorbed into a thin strip of paper on the MN patch backing for subsequent analysis. An optimized method in rat skin in vivo is well tolerated and able to collect >2 µL of ISF within 1 min. Brief skin pretreatment with MNs followed by a 5 min delay dramatically increases subsequent ISF collection by a mechanism believed to involve increased skin hydration. ISF collection using an MN patch has the potential to simplify access to biomarkers in ISF for research and future medical diagnostic and monitoring applications.
Inhaled Nanoformulated mRNA Polyplexes for Protein Production in Lung Epithelium
Authors: Patel Asha Kumari , Kaczmarek James C. , Bose Suman , Kauffman Kevin J. , Mir Faryal , Heartlein Michael W. , DeRosa Frank , Langer Robert , Anderson Daniel G. 
Published: January 2019

AbstractNoninvasive aerosol inhalation is an established method of drug delivery to the lung, and remains a desirable route for nucleic‐acid‐based therapeutics. In vitro transcribed (IVT) mRNA has broad therapeutic applicability as it permits temporal and dose‐dependent control of encoded protein expression. Inhaled delivery of IVT‐mRNA has not yet been demonstrated and requires development of safe and effective materials. To meet this need, hyperbranched poly(beta amino esters) (hPBAEs) are synthesized to enable nanoformulation of stable and concentrated polyplexes suitable for inhalation. This strategy achieves uniform distribution of luciferase mRNA throughout all five lobes of the lung and produces 101.2 ng g−1 of luciferase protein 24 h after inhalation of hPBAE polyplexes. Importantly, delivery is localized to the lung, and no luminescence is observed in other tissues. Furthermore, using an Ai14 reporter mouse model it is identified that 24.6% of the total lung epithelial cell population is transfected after a single dose. Repeat dosing of inhaled hPBAE‐mRNA generates consistent protein production in the lung, without local or systemic toxicity. The results indicate that nebulized delivery of IVT‐mRNA facilitated by hPBAE vectors may provide a clinically relevant delivery system to lung epithelium.
Hydrogel Microelectromechanical System (MEMS) Resonators: Beyond Cost‐Effective Sensing Platform
Authors: Yoon Yeowon , Chae Inseok , Thundat Thomas , Lee Jungchul 
Published: January 2019

AbstractMechanical resonators have been used for various applications including timing references, filters, accelerometers, and inertial sensors. Mostly, silicon‐based materials have been thought to be ideal considering robustness and stability and thus used to fabricate micro and nanoscale mechanical resonators. When enhanced sensitivity becomes more important than long‐term stability, materials repertoires other than silicon might be better suited. Herein, a novel manufacturing approach is proposed, which rapidly fabricates microelectromechanical system resonators with hydrogel by single UV exposure via dynamic mask and dry‐state “plugging out” sacrificial process where hydrogel structures are defined by spatially modulated UV light. For practical demonstrations, rectangular cantilevers and closed circular membranes are employed for humidity and pressure sensing applications, respectively. The cost‐effective fabrication route suggested herein not only enables rapid prototyping of suspended hydrogel structures outside a cleanroom, but also offers spatially tunable elastic modulus. Most remarkably, sensitivity enhancement resulting from high swelling rate and/or low elastic modulus exceeds stability deterioration, one of the major concerns for polymeric materials. Such exclusive beneficial features, yet demonstrated with any microfabrication materials and methods or their combinations, open a new avenue for photocurable polymeric materials to be used for specific applications as well as fundamental investigations.
Predictions of Thermo‐Mechanical Properties of Cross‐Linked Polyacrylamide Hydrogels Using Molecular Simulations
Authors: An Meng , Demir Baris , Wan Xiao , Meng Han , Yang Nuo , Walsh Tiffany R. 
Published: January 2019

AbstractHydrophilic acrylamide‐based hydrogels are emerging platforms for numerous applications, but the resources to fully exploit these materials are currently limited. A deep understanding of the molecular‐level structure/property relationships in hydrogels is crucial to progressing these efforts. Such relationships can be challenging to elucidate on the basis of experimental data alone. Here, molecular simulations are used as a complementary strategy to reveal the molecular‐level phenomena that govern the thermo‐mechanical properties of hydrogels. The focus is on acrylamide‐based hydrogels cross‐linked with N,N′‐methylenebisacrylamide, generated using previously established computational cross‐linking procedure. The water content is found to be a key determinant in the elastic response of these hydrogels, with enhanced tensile and shear properties at low water content. However, it is also found that increasing water content enhances the hydrogel's thermal conductivity, with the dominant contribution arising from the non‐bonded contributions to the heat flux. In addition, chemical cross‐linking improves the heat transfer properties of the hydrogel, whereas a reduction in convective heat transfer is predicted with an increase in hydrogel cross‐linking. These simulations provide a rational basis for designing and testing customized hydrogel formulations for maximizing both thermal conductivity and mechanical properties.
Hydrothermal reaction of K‐feldspar powder in NaOHCa (OH)2 mixed medium
Authors: Liu Changjiang , Ma Hongwen , Gao Yuan 
Published: January 2019

AbstractThe hydrothermal reactions between K‐feldspar powder and NaOHCa (OH)2 mixed alkaline medium at 240°C were investigated. The effects of Na ratio (xNa, Na2O/(Na2O + CaO) in mole) on the phase and composition change in solid products were explored in detail. Results showed that increase in xNa led to the orderly formation of compounds following the sequence of CaOSiO2H2O → Na2OCaOSiO2H2O → Na2OAl2O3SiO2H2O, and K+ was accessible into solution after reaction. The new products after reaction was tobermorite, pectorite, nepheline hydrate, analcime, and hydroxycancrinite, depending on different xNa. The hydrothermal reaction was deduced to be a coupled dissolution and reprecipitation process, which was governed by the chemical equilibrium with the change in solution chemistry.
Chemical structure modifications and nano‐technology applications for improving ADME‐Tox properties, a review
Authors: Farouk Faten , Shamma Rehab 
Published: January 2019

AbstractThe chemical structure of a drug molecule affects its physicochemical properties and subsequent biological activities. Many pharmacologically active molecules fail to reach the market or have an inconvenient route of administration due to their chemical structure. This is especially important with the recent tendency to develop drug candidates beyond the drug‐likeness space for addressing difficult targets such as protein–protein interfaces. The objective of this review is to discuss chemical and pharmaceutical approaches for circumventing structure‐related problems and achieving acceptable ADME‐Tox properties. The chemical structure‐associated limitations are critically discussed. Chemical modifications and pharmaceutical technology applications for improving drug‐likeness are illustrated. Attention is paid to modern therapeutic candidates and targets. In conclusion, chemical modifications as well as nanotechnology applications can be used effectively to enhance absorption, permeability, and selective distribution to a body compartment, to improve drug specificity, to limit off‐target toxicity as well as to enhance stability and to protect against metabolism. The nano‐technology‐based solutions are relatively easier to develop over a new molecular entity, but adopting the chemical approach is more established in terms of safety, quality control, and regulatory assessment methods.
Knockdown of LncRNA GHET1 suppresses prostate cancer cell proliferation by inhibiting HIF‐1α/Notch‐1 signaling pathway via KLF2
Authors: Zhu Yanfeng , Tong Yue , Wu Jianhua , Liu Yuejuan , Zhao Mingjia 
Published: January 2019

AbstractProstate cancer (PC) is one of the most common cancers in male groups worldwide. Long noncoding RNAs (LncRNAs) are reported to be dysregulated in a variety of cancers, including PC. This study aimed to explore the role of LncRNA GHET1 in the pathogenesis of PC. RT‐qPCR was carried out to examine the relative expression level of GHET1 in PC patients. In vitro, GHET1 siRNA (si‐GHET1) was used to investigate the biological role of GHET1 in PC cell lines. Cell proliferation was detected by CCK‐8 and colony formation assay, while cell cycle and cell apoptosis were analyzed using flow cytometry. Moreover, western blot was carried out to measure the protein expression levels of KLF2 and HIF‐1α/Notch‐1 signal pathway. We found that GHET1 showed higher expression in PC tissues and had a negative correlation with KLF2 expression. Knockdown of GHET1 significantly suppressed the cell proliferation, induced cell cycle arrest at G0/G1 phase and promoted cell apoptosis. Additionally, si‐GHET1 transfection induced KLF2 upregulation and HIF‐1α/Notch‐1 signal pathway suppression, which could be rescued by si‐KLF2 transfection. These results suggest the key role of GHET1 in PC progression. Moreover, GHET1 might be explored to be a potential target for clinical treatment of PC. © 2019 BioFactors, 45(3):364–373, 2019
Occupational class and male cancer incidence: Nationwide, multicenter, hospital‐based case–control study in Japan
Authors: Zaitsu Masayoshi , Kaneko Rena , Takeuchi Takumi , Sato Yuzuru , Kobayashi Yasuki , Kawachi Ichiro 
Published: January 2019

AbstractLittle is known about socioeconomic inequalities in male cancer incidence in nonwestern settings. Using the nationwide clinical and occupational inpatient data (1984‐2016) in Japan, we performed a multicentered, matched case–control study with 214 123 male cancer cases and 1 026 247 inpatient controls. Based on the standardized national classifications, we grouped patients’ longest‐held occupational class (blue‐collar, service, professional, manager), cross‐classified by industrial cluster (blue‐collar, service, white‐collar). Using blue‐collar workers in blue‐collar industries as the referent group, odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by conditional logistic regression with multiple imputation, matched for age, admission date, and admitting hospital. Smoking and alcohol consumption were additionally adjusted. Across all industries, a reduced risk with higher occupational class (professionals and managers) was observed for stomach and lung cancer. Even after controlling for smoking and alcohol consumption, the reduced odds persisted: OR of managers in white‐collar industries was 0.80 (95% CI 0.72‐0.90) for stomach cancer, and OR of managers in white‐collar industries was 0.66 (95% CI 0.55‐0.79) for lung cancer. In white‐collar industries, higher occupational class men tended to have lower a reduced risk for most common types of cancer, with the exception of professionals who showed an excess risk for prostate cancer. We documented socioeconomic inequalities in male cancer incidence in Japan, which could not be explained by smoking and alcohol consumption.
Harnessing the Chemistry of the Indole Heterocycle to Drive Discoveries in Biology and Medicine
Authors: Norwood Verrill M. , Huigens Robert W. 
Published: January 2019

AbstractIndole‐containing compounds demonstrate an array of biological activities relevant to numerous human diseases. The biological activities of diverse indole‐based agents are driven by molecular interactions between indole agent and critical therapeutic target. The chemical inventory of medicinally useful or promising indole compounds spans the entire structural spectrum, from simple synthetic indoles to highly complex indole alkaloids. In an analogous fashion, the chemistry behind the indole heterocycle is unique and provides rich opportunities for extensive synthetic chemistry, enabling the construction and development of novel indole compounds to explore chemical space. This review will present heterocyclic chemistry of the indole nucleus, indole compounds of clinical use, complex indole alkaloids and indole‐inspired discovery efforts by multiple research groups interested in using novel indole‐containing small molecules to drive discoveries in human biology and medicine.
Working with prisoners who self‐harm: A qualitative study on stress, denial of weakness, and encouraging resilience in a sample of correctional staff
Authors: Smith Hayden P. , Power Jenelle , Usher Amelia M. , Sitren Alicia H. , Slade Karen 
Published: January 2019

AbstractBackgroundRates of self‐harm are high among prisoners. Most research focuses on the vulnerable prisoner, and there is little on the impact of these behaviours on staff.AimsTo investigate staff perceptions of self‐harming behaviours by prisoners, including their views on its causes, manifestation, prevention in institutions, and impact on them.MethodsSemistructured interviews were conducted with 20 administrative and 21 therapeutic prison staff who are responsible in various ways for prisoners who self‐harm. Their narratives were explored using interpretative phenomenological analysis.ResultsDespite prison staff being experienced with prisoners' self‐harming behaviours, including severe acts of self‐harm, they were apt to reject any negative impact on their own mental health or well‐being. This denial of negative impact was accompanied by perceptions of the inmate's actions being manipulative and attention seeking. Prison staff also perceived institutional responses to self‐harming behaviours by prisoners as being mixed, ambiguous, or showing preference for relying on existing suicide protocols rather than task‐specific guidance.ConclusionsAlthough staff gave explanations of prisoner self‐harm in terms of “manipulative behaviour,” prisoners' self‐harm is, in fact, complex, challenging, and often severe. This staff perception may reflect denial of impact of often distressing behaviours on them personally and their own coping mechanisms. This could be feeding in to a perceived lack of clear and effective institutional responses to the self‐harm, so further research is needed to determine how staff could broaden their views, and respond more effectively to prisoners. Psychologically informed group work and/or reflective practice are among the candidates for such help for staff.
N‐Doped Hierarchical Porous Carbon with Open‐Ended Structure for High‐Performance Supercapacitors
Authors: Cao Shubo , Qu Ting , Zhang Ang , Zhao Yongbin , Chen Aihua 
Published: January 2019

AbstractN‐doped hierarchical porous carbon with an open‐ended nanostructures were prepared through activating hollow carbon spheres (HCS), which were synthesized by using the self‐assembled amphiphilic block copolymer polystyrene‐b‐poly(4‐vinyl pyridine) (PS‐b‐P4VP) as template and pyrrole as carbon and nitrogen source. Through chemical activation with KOH, the original close‐ended HCS became open‐ended nanostructures (denoted as A‐HCS). This unique structure possesses several important properties as electrode for application in supercapacitors: (a) large surface area (1583 m2/g) and pore volume (3.82 cm3/g), (b) hierarchical porous carbon with small size (<100 nm) and thin curved walls (thickness <20 nm), (c) high N content (6.73 at%). Compared with the close‐ended HCS, the open‐ended A‐HCS exhibits better performance. The A‐HCS electrode presents a high specific capacitance (284 F/g at 0.2 A/g), good rate capability (70 % retention as the current density increased from 0.2 to 30 A/g), and superior cycling stability (96 % retention after 5000 cycles at 10 A/g). These results demonstrate that the N‐doped hierarchical porous carbon material with open‐ended nanostructure represents an alternative promising candidate as an efficient electrode material for supercapacitors.
Experimental investigation of dynamic asphaltene adsorption on calcite packs: The impact of single and mixed‐salt brine films
Authors: Monjezi Reza , Ghotbi Cyrus , Jafari Behbahani Taraneh , Bakhshi Puyan 
Published: January 2019

AbstractIn this study, the dynamic adsorption of asphaltene on a calcite surface is investigated. This study investigates the effect of mixed‐salt brines on asphaltene adsorption. The results of this work can facilitate the understanding of the complex wettability behaviour of carbonate reservoirs. All experiments were performed in porous media, which were sand‐packs filled with calcite powder, to study the influence of the type and concentration of salt on adsorption. The experiments were conducted with asphaltene concentration of 500 mg/L for brines of NaCl, Na2SO4, and a mixture of the two at various ionic strengths. In addition, two tests were performed with an asphaltene concentration of 2000 mg/L to observe the effect of increasing the asphaltene concentration on the adsorption. Moreover, the impact of brine film on asphaltene adsorption was investigated by conducting an additional experiment without brine saturation. The results show that by increasing the ionic strength, asphaltene adsorption increased at first owing to the reduction of electrostatic forces, then it reached its maximum, and it finally decreased as a result of the rise in the hydration force. The results show that in the presence of Na2SO4 brine, the asphaltene adsorption is more than that of the NaCl brine. For the mixed‐salt brine, as the ionic strength was increased, the asphaltene adsorption decreased at first and then it became constant. Furthermore, quadrupling the initial asphaltene concentration increased the adsorption up to 3.4 times. Additionally, the presence of brine film reduced the asphaltene adsorption by ∼80 %.
An Overview, Advantages and Therapeutic Potential of Nonpeptide Positive Allosteric Modulators of Glucagon‐Like Peptide‐1 Receptor
Authors: Smelcerovic Andrija , Lazarevic Jelena , Tomovic Katarina , Anastasijevic Marija , Jukic Marko , Kocic Gordana , Anderluh Marko 
Published: January 2019

AbstractDue to uncomfortable injection regimens of peptidic agonists of glucagon‐like peptide‐1 receptor (GLP‐1R), orally available nonpeptide positive allosteric modulators (PAMs) of GLP‐1Rs are foreseen as the possible future mainstream therapy for type 2 diabetes. Herein, current GLP‐1R PAMs are reviewed. Based on the effectiveness and in silico predicted physicochemical properties, pharmacokinetics, and toxicity, possible candidates for further development as oral drugs were selected. The suggestion is that GLP‐1R PAMs might be used orally alone or in combination with dipeptidyl peptidase‐4 (DPP‐4) inhibitors, which could offer an optimal treatment option next to metformin monotherapy in type 2 diabetes mellitus, or in a wider spectrum of indications. Quercetin acts as a GLP‐1R PAM and DPP‐4 inhibitor, and therefore, might be considered as a pioneering agent with a dual mechanism of action, in terms of GLP‐1R positive allosteric modulation and DPP‐4 inhibition for potentiating GLP‐1 dependent effects.