bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Changes of Hierarchically Nanoporous Organosilica/Silica Hybrid Materials by Pseudomorphic Transformation
Authors: Bilo Malina , Münzner Maximilian , Küster Christian , Enke Dirk , Lee Young Joo , Fröba Michael
Published: March 2020

Herein, it is reported how pseudomorphic transformation of divinylbenzene (DVB)‐bridged organosilica@controlled pore glasses (CPG) offers the possibility to generate hierarchically porous organosilica/silica hybrid materials. CPG is utilized to provide granular shape/size and macroporosity and the macropores of the CPG is impregnated with organosilica phase, forming hybrid system. By subsequent pseudomorphic transformation, an ordered mesopore phase is generated while maintaining the granular shape and macroporosity of the CPG. Surface areas and mesopore sizes in the hierarchical structure are tunable by the choice of the surfactant and transformation time. Two‐dimensional magic angle spinning (MAS) NMR spectroscopy demonstrated that micellar‐templating affects both organosilica and silica phases and pseudomorphic transformation induces phase transition. A double‐layer structure of separate organosilica and silica layers is established for the impregnated material, while a single monophase consisting of randomly distributed T and Q silicon species at the molecular level is identified for the pseudomorphic transformed materials.
Pyrrole‐Protected β‐Aminoalkylzinc Reagents for the Enantioselective Synthesis of Amino‐Derivatives
Authors: Leroux Marcel , Huang Wan‐Yun , Lemke Yannick , Koller Thaddäus J. , Karaghiosoff Konstantin , Knochel Paul
Published: March 2020

Chiral β‐aminoalkylzinc halides were prepared starting from optically pure commercial β‐amino‐alcohols. These amino‐alcohols were converted to the corresponding N‐pyrrolyl‐protected alkyl iodides which undergo a zinc insertion in the presence of LiCl (THF, 25 °C, 10–90 min). Subsequent Negishi cross‐coupling or acylation reactions with acid chlorides produced amino‐derivatives with retention of chirality. Diastereoselective CBS‐reductions of some prepared N‐pyrrolyl‐ketones provided 1,3‐subsituted N‐pyrrolyl‐alcohols with high diastereoselectivity. Additionally, a deprotection procedure involving an ozonolysis allowed the conversion of the pyrrole‐ring into a formamide without loss of optical purity.
Ultrasensitive and Selective Copper(II) Detection: Introducing a Bioinspired and Robust Sensor
Authors: Müller Lena K. , Duznovic Ivana , Tietze Daniel , Weber Wadim , Ali Mubarak , Stein Viktor , Ensinger Wolfgang , Tietze Alesia A.
Published: March 2020

A nanopore‐based CuII‐sensing system is reported that allows for an ultrasensitive and selective detection of CuII with the possibility for a broad range of applications, for example in medical diagnostics. A fluorescent ATCUN‐like peptide 5/6‐FAM‐Dap‐β‐Ala‐His is employed to selectively bind CuII ions in the presence of NiII and ZnII and was crafted into ion track‐etched nanopores. Upon CuII binding the fluorescence of the peptide sensor is quenched, permitting the detection of CuII in solution. The ion transport characteristics of peptide‐modified nanopore are shown to be extremely sensitive and selective towards CuII allowing to sense femtomolar CuII concentrations in human urine mimics. Washing with EDTA fully restores the CuII‐binding properties of the sensor, enabling multiple repetitive measurements. The robustness of the system clearly has the potential to be further developed into an easy‐to‐use, lab‐on‐chip CuII‐sensing device, which will be of great importance for bedside diagnosis and monitor of CuII levels in patients with copper‐dysfunctional homeostasis.
Boranediyl‐ and Diborane(4)‐1,2‐diyl‐Bridged Platinum A‐Frame Complexes
Authors: Brunecker Carina , Müssig Jonas H. , Arrowsmith Merle , Fantuzzi Felipe , Stoy Andreas , Böhnke Julian , Hofmann Alexander , Bertermann Rüdiger , Engels Bernd , Braunschweig Holger
Published: March 2020

Diplatinum A‐frame complexes with a bridging (di)boron unit in the apex position were synthesized in a single step by the double oxidative addition of dihalo(di)borane precursors at a bis(diphosphine)‐bridged Pt02 complex. While structurally analogous to well‐known μ‐borylene complexes, in which delocalized dative three‐center‐two‐electron M‐B‐M bonding prevails, theoretical investigations into the nature of Pt−B bonding in these A‐frame complexes show them to be rare dimetalla(di)boranes displaying two electron‐sharing Pt−B σ‐bonds. This is experimentally reflected in the low kinetic stability of these compounds, which are prone to loss of the (di)boron bridgehead unit.
Rational Design of a N,S Co‐Doped Supermicroporous CoFe–Organic Framework Platform for Water Oxidation
Authors: Huang Zhao‐Qian , Wang Bin , Pan Dong‐Sheng , Zhou Ling‐Li , Guo Zheng‐Han , Song Jun‐Ling
Published: March 2020

It remains a challenge to rational design of a new metal–organic framework (MOF) as highly efficient direct electrocatalysts for the oxygen evolution reaction (OER). Herein, we developed a simple and effective method to explore a new pillared‐layered MOF with syringic acid as a promising OER electrocatalyst. The isostructural mono‐, heterobimetallic MOF and N,S co‐doped MOF by mixing thiourea were quickly synthesized in a high yield under solvothermal condition. Moreover, the optimized N,S co‐doped MOF exhibits the lowest overpotential of 254 mV at 10 mA cm−2 on a glass carbon electrode and a small Tafel slope of 50 mV dec−1, especially, this catalyst also possesses long‐term electrochemical durability for at least 16 h. According to the characterization, the incorporation of N and S atoms into this heterobimetallic CoFe‐based MOF could modify its pore structure, tune the electronic structure, accordingly, improve the mass and electron transportation, and facilitate the formation of active species, as a consequence, the improved activity of this new N,S co‐doped MOF for OER should be mainly be ascribed to higher electrochemical activation toward the active species via in situ surface modification during the OER process.
Enhancing Molecular Electrocatalysis of CO2 Reduction with Pressure‐Tunable CO2‐Expanded Electrolytes
Authors: Sconyers David J. , Shaughnessy Charles I. , Lee Hyun‐Jin , Subramaniam Bala , Leonard Kevin C. , Blakemore James D.
Published: March 2020

Electrochemical studies of CO2 conversion by molecular catalysts are typically carried out in a narrow range of near‐ambient CO2 pressures wherein low CO2 solubilities in the liquid phase can limit the rate of CO2 reduction. In this study, five‐fold rate enhancements are enabled by pairing CO2‐expanded electrolytes (CXEs), a class of media that accommodate multimolar concentrations of CO2 in organic solvents at modest pressures, with a homogeneous molecular electrocatalyst, [Re(CO)3(bpy)Cl] (1, bpy=2,2′‐bipyridyl). Analysis of cyclic voltammetry data reveals pressure‐tunable rate behavior, with first‐order kinetics at moderate CO2 pressures giving way to zero‐order kinetics at higher pressures. The significant enhancement in the space‐time yield of CO demonstrates that CXEs offer a simple yet powerful strategy for unlocking the intrinsic potential of molecular catalysts by mitigating CO2 solubility limitations commonly encountered in conventional liquid electrolytes. Moreover, our findings reveal that 1, a workhorse molecular catalyst, performs with intrinsic kinetic behavior, which is competitive with fast enzymes under optimal conditions in CXEs.
Crystalline Copper Selenide as a Reliable Non‐Noble Electro(pre)catalyst for Overall Water Splitting
Authors: Chakraborty Biswarup , Beltrán‐Suito Rodrigo , Hlukhyy Viktor , Schmidt Johannes , Menezes Prashanth W. , Driess Matthias
Published: March 2020

Electrochemical water splitting remains a frontier research topic in the quest to develop artificial photosynthetic systems by using noble metal‐free and sustainable catalysts. Herein, a highly crystalline CuSe has been employed as active electrodes for overall water splitting (OWS) in alkaline media. The pure‐phase klockmannite CuSe deposited on highly conducting nickel foam (NF) electrodes by electrophoretic deposition (EPD) displayed an overpotential of merely 297 mV for the reaction of oxygen evolution (OER) at a current density of 10 mA cm−2 whereas an overpotential of 162 mV was attained for the hydrogen evolution reaction (HER) at the same current density, superseding the Cu‐based as well as the state‐of‐the‐art RuO2 and IrO2 catalysts. The bifunctional behavior of the catalyst has successfully been utilized to fabricate an overall water‐splitting device, which exhibits a low cell voltage (1.68 V) with long‐term stability. Post‐catalytic analyses of the catalyst by ex‐situ microscopic, spectroscopic, and analytical methods confirm that under both OER and HER conditions, the crystalline and conductive CuSe behaves as an electro(pre)catalyst forming a highly reactive in situ crystalline Cu(OH)2 overlayer (electro(post)catalyst), which facilitates oxygen (O2) evolution, and an amorphous Cu(OH)2/CuOx active surface for hydrogen (H2) evolution. The present study demonstrates a distinct approach to produce highly active copper‐based catalysts starting from copper chalcogenides and could be used as a basis to enhance the performance in durable bifunctional overall water splitting.
Microemulsion and bovine serum albumin nanoparticles as a novel hybrid nanocarrier system for efficient multifunctional drug delivery
Authors: Gharbavi Mahmoud , Danafar Hossein , Sharafi Ali
Published: March 2020

The present study aims to: (a) design the versatile microemulsions (MEs) system for drug delivery; (b) use the bovine serum albumin nanoparticles for MEs system development; (c) characterize the physicochemical properties, cytotoxicity, and biocompatibility of the modified MEs (MMEs) system; (d) load of paclitaxel (PTX) and folate conjugate of MEs system; and (e) assess the potential of anticancer activity of MEs system. The physicochemical possessions, in vitro and in vivo cytotoxicity, and stability of MMEs system were characterized. The results of our study show that the MEs system was stable, having narrow particle size distribution, nontoxic, biocompatible, and not active for leukocyte proliferation. So it can be concluded that the MMEs system as a promising candidate for a targeted multifunctional drug delivery system (PTX and folate) that is called a smart MEs system.
Preparation of galactosylated curcumol liposomes
Authors: Li Wenjie , Lu Yan , Cheng Yi , Luo Hui , Jia Zhenbin , Li Ning
Published: March 2020

Curcumol (Cur), which is the primary active anti‐liver cancer component of Chinese traditional medicine Rhizoma zedoariae, was encapsulated in galactosylated liposomes to enhance its liver‐targeting efficacy. In this study, we optimized the preparation methods, prescription, and process of galactosylated curcumol liposomes (Gal‐Cur‐L). The experimental results showed that the encapsulation efficiency, particle diameter, and stability coefficient of Gal‐Cur‐L obtained by the two‐step emulsification method were improved compared with those of it obtained by other methods. Single‐factor investigation showed that two factors, pH and the amount of triolein, contribute at least partly to the encapsulation efficiency and particle diameter of Gal‐Cur‐L. The best prescription and process were obtained through orthogonal test: the ratio of lecithin to cholesterol was 2:1, the ratio of drug to lipid was 1:2, and the amount of ether and Twain‐80 were 4 ml and 1.6 g/L, respectively, 15 min for ultrasonic time, 100 W for ultrasonic power, and 20 min for homogeneous time. Using the best method, prescription, and process mentioned earlier, the basic test results of Gal‐Cur‐L were obtained, which demonstrated that our methods, prescription, and process of Gal‐Cur‐L were applicable. The encouraging results of this study provided references for the research of liver‐targeting reagents of curcumol.
Experimental and theoretical approaches to the study of the reactivity and mechanism of the substitution of phenyl 1‐(2,4‐dinitronaphthyl) ether with anilines derivatives
Authors: Moghazy Yasmen M. , Fathalla Magda F. , Hamada Nagwa M. M. , Elmarassi Yasser R. , Hamed Ezzat A.
Published: March 2020

Reactions of aniline derivatives in dimethyl sulfoxide with phenyl 1‐(2,4‐dinitronaphthyl) ether yield aryl 1‐(2,4‐dinitronaphthyl) amine, which results in substitution of the phenoxy groups at the naphthyl ipso carbon atom. Rate constants were measured spectrophotometrically, and reaction proton transfer was rate limiting. The values of the rate coefficients indicate a rate‐limiting proton transfer mechanism with significant substituent effects. The calculated activation parameters were of regular variation with substituents in 4‐ and 3‐position in the aniline nucleophile, and the reaction proceeded through a common mechanism. Hammett's reaction constant showed that the reaction rate constants depend on the electron density of the nitrogen atom of aniline derivative, whereas the coefficient value obtained from the Brönsted relation indicated that the reaction was significantly associative and quite zwitterion like. Computational studies of the substitution were carried out based on density functional theory, and theoretical to the experimental agreement was achieved.
The reverse Napoleon effect: The brand appreciation of looking up by tall people
Authors: Orth Ulrich R. , Machiels Casparus J. A. , Rose Gregory M.
Published: March 2020

Integrating the embodied cognition framework with research on the self, this study shows that head canting (the vertical tilt of the head to look up vs. down) interacts with a viewer's physical height to influence perceived brand power and behavioral intentions. Three studies use a variety of brand cues in both laboratory and field contexts to test the effect of head canting on brand power evaluations, the role of a person's physical height as a moderator and boundary condition, and the mediating role of consumer–brand identification. Study 1, an experiment, showed that tall, but not short individuals, evaluate a brand as more powerful when looking up (rather than down) at a brand story from a standing position, with differences in brand power impacting brand attitudes and choice. Study 2 replicates these findings with 30 brands, consumers positioned in a seated position, and brand logos. Both studies rule out the construal level as a process mediator. Study 3 further examines the process and demonstrates that the interaction of head canting with a person's height impacts consumer–brand identification, which mediates brand evaluations. These findings add a brand management and physical‐self perspective to previous embodiment research by specifically examining the effects of sensorimotor experiences.
The creation and validation of a short form of the Neurogenic Bladder Symptom Score
Authors: Welk Blayne , Lenherr Sara , Elliott Sean , Stoffel John , Gomes Cristiano M. , de Bessa Jose , Cintra Lisley K. L. , Myers Jeremy B. ,   for the Neurogenic Bladder Research Group
Published: March 2020

Aim

To develop a short form (SF) of the 24‐item Neurogenic Bladder Symptom Score (NBSS).

Methods

We used three previously published datasets. First, we selected the most responsive questions within each of the domains. Internal validity of the NBSS‐SF was assessed using Cronbach's α. External validity was assessed by evaluating hypothesized relationships with other questionnaires and testing correlations with the full NBSS domains. Test‐retest reliability of the NBSS‐SF domains was determined using an intraclass coefficient (ICC).

Results

Using data from a prior responsiveness study, we selected questions for the NBSS‐SF from the incontinence domain (three), storage/voiding domain (three), consequences domain (two); these would make up the NBSS‐SF. We used the original NBSS validation cohort of 230 patients with multiple sclerosis (MS), spinal cord injury (SCI), or spina bifida, and found the Cronbach's α was .76 for the NBSS‐SF; the external validity was high, with correlations between specific NBSS‐SF domains/total scores and the Qualiveen‐SF, ICIQ, and AUASS generally similar to those seen with the NBSS. Correlations between the NBSS‐SF domains and the full NBSS domains were high. The NBSS‐SF ICC in a subset of 120 patients was 0.84. The NBSS‐SF performed similarly in two additional independent datasets.

Conclusions

The total score of the NBSS‐SF has appropriate validity, reliability, and could be used instead of the full NBSS to minimize the assessment burden. The full NBSS may be better suited if the primary focus of the study is on neurogenic bladder symptoms, or if individual NBSS domains are of interest.
miRNA expression can classify pediatric thyroid lesions and increases the diagnostic yield of mutation testing
Authors: Franco Aime T. , Labourier Emmanuel , Ablordeppey Kenny Kwabena , Surrey Lea F. , Mostoufi‐Moab Sogol , Isaza Amber , Adzick N. Scott , Kazahaya Ken , Kumar Gyanendra , Bauer Andrew J.
Published: March 2020

Background

Genetic alterations in multiple cell signaling pathways are involved in the molecular pathogenesis of thyroid cancer. Oncogene mutation testing and gene‐expression profiling are routinely used for the preoperative risk management of adult thyroid nodules. In this study, we evaluated the potential value of miRNA biomarkers for the classification of pediatric thyroid lesions.

Procedure

Double‐blind case‐control study with 113 resected pediatric lesions: 66 malignant and 47 benign. Quantitative and qualitative molecular data generated with a 10‐miRNA expression panel (ThyraMIR) and a next‐generation sequencing oncogene panel (ThyGeNEXT) were compared with clinicopathological parameters.

Results

miRNAs were differentially expressed in benign versus malignant tumors with distinct expression patterns in different histopathology categories. The 10‐miRNA classifier identified 39 (59%) malignant lesions with 100% specificity. A positive classifier score was associated with lymph node metastasis, extrathyroidal extension and intrathyroidal spread. Genetic alterations associated with increased risk for malignancy were detected in 35 (53%) malignant cases, 20 positive for point mutations in BRAF, HRAS, KRAS, NRAS, PIK3CA, or TERT and 15 positive for gene rearrangements involving ALK, NTRK3, PPARG, or RET. The 10‐miRNA classifier correctly identified 11 mutation‐negative malignant cases. The performance of the combined molecular test was 70% sensitivity and 96% specificity with an area under the curve of 0.924.

Conclusions

These data suggest that the regulatory miRNA pathways underlying thyroid tumorigenesis are similar in adults and children. miRNA expression can identify malignant lesions with high specificity, augment the diagnostic yield of mutation testing, and improve the molecular classification of pediatric thyroid nodules.
Assessing the effects of beta‐blockers on pancreatic cancer risk: A nested case‐control study
Authors: Saad Akram , Goldstein Jeffrey , Margalit Ofer , Shacham‐Shmueli Einat , Lawrence Yaacov R. , Yang Yu‐Xiao , Reiss Kim A. , Golan Talia , Mamtani Ronac , Halpern Naama , Aderka Dan , Mouallem Meir , Goldstein Adam , Giantonio Bruce , Boursi Ben
Published: March 2020

Purpose

Both β1‐ and β2‐adrenoceptor proteins were detected on the cell surface of pancreatic ductal adenocarcinoma. The current study evaluated the association between beta‐blocker use and pancreatic cancer risk.

Methods

We conducted a nested case‐control study in a large population representative database. Each pancreatic cancer case was matched with four controls based on age, sex, practice site, and duration of follow‐up using incidence density sampling. Beta‐blocker use was defined as any prescription prior to index date and was stratified into non‐selective and selective β1‐blockers. The odds ratios (ORs) and 95% confidence intervals (95% CIs) for pancreatic cancer risk associated with beta‐blocker use was estimated using conditional logistic regression.

Results

The study included 4113 patients with pancreatic cancer and 16 072 matched controls. When compared to never users, there was no association between any beta‐blocker use and pancreatic cancer risk (adjusted OR 1.06, 95% CI 0.97‐1.16, P = .16). Analysis by receptor selectivity showed use of non‐selective beta‐blockers for more than 2 years was associated with a reduced pancreatic cancer risk (OR 0.75, 95% CI 0.57‐1.00, P = .05). When compared to former users both users of selective β1‐blockers and non‐selective beta‐blockers had a reduced pancreatic cancer risk (OR 0.78, 95% CI 0.67‐0.90, P = .001) and (OR 0.67, 95% CI 0.49‐0.92, P = .01), respectively.

Conclusion

Beta‐blocker use was not associated with increased pancreatic cancer risk. However, long‐term use of beta‐blockers may be associated with decreased pancreatic cancer risk.
Forming submicron in micron texture on the diamond‐wire‐sawn mc‐Si wafer by introducing artificial defects
Authors: Wu Chengkun , Zou Shuai , Zhu Jingyan , Ye Xiaoya , Ding Jianming , Sun Hua , Wang Xusheng , Xing Guoqiang , Zhang Xiaohong , Su Xiaodong
Published: March 2020

Based on a traditional acid etch system (i.e., HNO3/HF), a complex texture comprising microscale and submicroscale structures was produced on the surface of a diamond‐wire‐sawn (DWS) multicrystalline Si (mc‐Si) wafer, upon whose surface it is typically difficult to form an effective texture for suppressing the reflection of incident light. Immersing the as‐cut wafer into an HF/HNO3/AgNO3 solution introduced a large number of artificial defects onto the wafer surface. A subsequent HNO3/HF etch induced a micron texture expanded from the original DWS‐induced damage as well as a submicron texture converted from the artificial defects. The multiscale textured DWS exhibited a reflectivity of ~19%, which is much lower than the reflectivity after only an HNO3/HF etch (~28%). Therefore, the solar cell performance was improved owing primarily to improved optical antireflection and surface passivation. The method is simple and can be easily scaled up into the in‐line texture process.
Multifunctional Sulfur‐Hyperdoped Silicon Nanoparticles with Engineered Mid‐Infrared Sulfur‐Impurity and Free‐Carrier Absorption
Authors: Nastulyavichus Alena A. , Saraeva Irina N. , Rudenko Andrey A. , Khmelnitskii Roman A. , Shakhmin Alexander L. , Kirilenko Demid A. , Brunkov Pavel N. , Melnik Nikolay N. , Smirnov Nikita A. , Ionin Andrey A. , Kudryashov Sergey I.
Published: March 2020

Si nanoparticles (NPs), which are innovative promising light‐harvesting components of thin‐film solar cells and key‐enabling biocompatible theranostic elements of infrared‐laser and radiofrequency hyperthermia‐based therapies of cancer cells in tumors and metastases, are significantly advanced in their near/mid‐infrared band‐to‐band and free‐carrier absorption via donor sulfur‐hyperdoping during high‐throughput facile femtosecond‐laser ablative production in liquid carbon disulfide. High‐resolution transmission electron microscopy and Raman microscopy reveal their mixed nanocrystalline/amorphous structure, enabling the extraordinary sulfur content of a few atomic percents and very minor surface oxidation/carbonization characterized by energy‐dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy. A 200‐nm thick layer of the nanoparticles exhibits near−mid‐infrared absorbance, comparable to that of the initial 380‐micron thick n‐doped Si wafer (phosphor‐dopant concentration ≈1015 cm−3), with the corresponding extinction coefficient for the hyperdoped NPs being 4–7 orders higher over the broadband spectral range of 1–25 micrometers. Such ultimate, but potentially tunable mid‐IR structured, multi‐band absorption of various sulfur‐impurity clusters and smooth free‐carrier absorption are break through advances in mid‐infrared (mid‐IR) laser and radiofrequency (RF) hyperthermia‐based therapies, as envisioned in the RF‐heating tests, and in fabrication of higher‐efficiency thin‐film and bulk photovoltaic devices with ultra‐broad (UV−mid‐IR) spectral response.
Enhanced Electromechanical Properties of 0.65Bi1.05FeO3–0.35BaTiO3 Ceramics through Optimizing Sintering Conditions
Authors: Ahmed Tauseef , Khan Salman Ali , Akram Fazli , Bae Jihee , Choi Soo Yong , Hussain Ali , Song Tae Kwon , Sung Yeon Soo , Kim Myong-Ho , Lee Soonil
Published: March 2020

Lead‐free piezoelectric 0.65Bi1.05FeO3–0.35BaTiO3 (BF–35BT) ceramics are synthesized via conventional solid‐state reaction by varying sintering dwell time (ts). The crystalline phase, microstructures, and piezoelectric properties of BF–35BT are evaluated at room temperature. BF–35BT ceramics with improved electrical properties in a narrow range of ts are obtained. Enhanced electromechanical properties are obtained in ceramics sintered at 1000 °C for 3 h. X‐ray diffraction reveals a single perovskite structure with pseudocubic symmetry. A prominent enhancement in remanent polarization (Pr) and coercive field (Ec) is obtained. Typical ferroelectric behaviors are obtained, whereas unipolar and bipolar strains are enhanced with increasing ts. The static piezoelectric constants (d33) = 187 pC N−1, whereas dynamic piezoelectric constants (d*33) = 387 pm V−1 at a field of 5 kV mm−1 with Curie temperature (TC) = 422 °C.
Mie Scattering in the Macroscopic Response and the Photonic Bands of Metamaterials
Authors: Juárez-Reyes Lucila , Mendoza Bernardo S. , Mochán W. Luis
Published: March 2020

Herein, a general approach for the numerical calculation of the effective dielectric tensor of metamaterials is presented, and it is shown that the formalism may be used to study metamaterials beyond the long‐wavelength limit. A system composed of high‐refractive‐index cylindrical inclusions is considered, and it is shown that the method reproduces the Mie resonant features and photonic band structure obtained from a multiple scattering approach, hence opening the possibility to study arbitrarily complex geometries for the design of resonance‐based negative refractive metamaterials at optical wavelengths.
The Dynamic Mixed Metal–Insulator Phase in Self‐Heated Needle‐Like VO2 Single Crystals
Authors: Fisher Bertina , Kornblum Lior , Patlagan Larisa , Reisner George M.
Published: March 2020

Reported herein is the mixed metal–insulator phase induced in needle‐like VO2 single crystals by direct current (DC) electric currents applied at ambient temperature; it appears in the current‐controlled negative differential resistivity (CC‐NDR) regime of the nonlinear I–V characteristic governed by self‐heating. In this regime, the I–V characteristic is stable for RL ≥ |dV/dI|max, (RL—the load resistance); for lower RL, portions of I–V are unstable and switching occurs between initial and final steady states (SSs). In high‐quality needle‐like VO2 single crystals (cross‐sectional area < 2 × 10−5 cm2) the SS NDR regime is “unique,” whereas crossing from the insulating to the mixed phase I(V) is almost—or perfectly—smooth, the dissipation power (P = IV) versus current bends and this bend is accompanied by the appearance of insulating domains sliding along the metallic background in the sense of the current. The periodic domain emission, the variation of the dynamic parameters (domains’ frequency and sliding velocity) over the steady‐state NDR regime, and the energetics of the process are discussed. These results show that the process of domain emission and sliding is fairly expensive at low frequencies but there is some evidence that the process becomes more efficient at higher frequencies.
Astragaloside III activates TACE/ADAM17‐dependent anti‐inflammatory and growth factor signaling in endothelial cells in a p38‐dependent fashion
Authors: Wang Haifang , Yuan Ruihua , Cao Qingwen , Wang Mian , Ren Dezhi , Huang Xiaoyan , Wu Min , Zhang Linping , Zhao Xiangrong , Huo Xueping , Pan Yalei , Liu Qinshe
Published: March 2020

Astragaloside III (AS‐III) is a triterpenoid saponin contained in Astragali Radix and has potent anti‐inflammatory effects on vascular endothelial cells; however, underlying mechanisms are unclear. In this study, we provided the first piece of evidence that AS‐III induced phosphorylation of TNF‐α converting enzyme (TACE) at Thr735 and enhanced its sheddase activity. As a result, AS‐III reduced surface TNFR1 level and increased content of sTNFR1 in the culture media, leading to the inhibition of NF‐κB signaling pathway and attenuation of downstream cytokine gene expression. Furthermore, AS‐III induced TACE‐dependent epidermal growth factor receptor (EGFR) transactivation and activation of downstream ERK1/2 and AKT pathways. Finally, AS‐III induced activation of p38. Both TACE activation and EGFR transactivation induced by AS‐III were significantly inhibited by p38 inhibitor SB203580. Taken together, we concluded that AS‐III activates TACE‐dependent anti‐inflammatory and growth factor signaling in vascular endothelial cells in a p38‐dependent fashion, which may contribute to its cardiovascular protective effect.
Different absorption and metabolism of ginsenosides after the administration of total ginsenosides and decoction of Panax ginseng
Authors: Liu Jihua , Li Ting , Wang Jia , Zhao Chunfang , Geng Cong , Meng Qin , Du Guangguang , Yin Jianyuan
Published: March 2020

Rationale

Panax ginseng C.A. Meyer (PG), which contains polysaccharides and ginsenosides as the major bioactive components, has been used to promote health and treat diseases for thousands of years in China. Total ginsenosides were extracted from a decoction of Panax ginseng (GD), which included both ginsenosides and polysaccharides, and dissolved in water to obtain a total ginsenosides aqueous solution (TGAS). To study their absorption and metabolism, the pharmacokinetics (PK) and metabolites of ginsenosides in vivo were investigated after the administration of GD and TGAS.

Methods

Rat and mice plasma samples were collected after the administration of GD and TGAS. Ultra‐performance liquid chromatography coupled with time‐of‐flight mass spectrometry was used with the UNIFI platform to identify metabolites in the plasma sample. The pharmacokinetic parameters were calculated using a noncompartmental method in the Drug and Statistics software package.

Results

Thirty ginsenoside metabolites were identified in mice plasma, of which only seven were found in the rat plasma after the administration of GD. The PK of ginsenosides Rb1, Rc, and Rd were also determined after the oral administration of GD and TGAS and showed significant differences in the pharmacokinetic parameters.

Conclusions

There was no difference in the biotransformation pathways after the oral administration of GD and TGAS, indicating that there was no influence of polysaccharides on the biotransformation of ginsenosides in vivo. However, the pharmacokinetic parameters were different after the administration of GD and TGAS, possibly because of the polysaccharides in GD. This study should be of significance in exploring the basis of PG bioactivities and lays the foundation for the further development of new drugs using PG.
Modularity of Erdős‐Rényi random graphs
Authors: McDiarmid Colin , Skerman Fiona
Published: March 2020

For a given graph G, each partition of the vertices has a modularity score, with higher values indicating that the partition better captures community structure in G. The modularity q∗(G) of the graph G is defined to be the maximum over all vertex partitions of the modularity score, and satisfies 0 ≤ q∗(G)<1. Modularity is at the heart of the most popular algorithms for community detection. We investigate the behaviour of the modularity of the Erdős‐Rényi random graph Gn,p with n vertices and edge‐probability p. Two key findings are that the modularity is 1+o(1) with high probability (whp) for np up to 1+o(1) and no further; and when np ≥ 1 and p is bounded below 1, it has order (np)−1/2 whp, in accord with a conjecture by Reichardt and Bornholdt in 2006. We also show that the modularity of a graph is robust to changes in a few edges, in contrast to the sensitivity of optimal vertex partitions.
Preparation and Application of Lignin‐Based Epoxy Resin from Pulping Black Liquor
Authors: Zhu Yanchao , Li Zheng , Wang Xiaofeng , Ding Na , Tian Yumei
Published: March 2020

In the present work, lignin was isolated from pulping black liquor. Selective precipitation was achieved by adding hydrochloricacid to adjust pulping black liquor pH from 1 to 5. Reaction pH, reaction temperature and the content of lignin were investigated in the total process. A considerable increase in the amount of precipitate was observed while pH was decreasing. Lignin obtained from pulping black liquor had been used as the reactant to partly replace bisphenol A in preparing epoxy resins with different lignin additives at 90 °C. The mechanical and the thermal properties of cured lignin‐based epoxy resins were compared with those at different contents of lignin and reaction temperatures with ethylenediamine as the curing agent. The cured lignin‐based epoxy resins with 20 wt. % lignin at 90 °C showed the highest viscosity up to 396 MPa⋅s. We had successfully got good performance lignin‐based epoxy resin.
Synthesis and Physicochemical Transformations of Size‐Sorted Graphene Oxide during Simulated Digestion and Its Toxicological Assessment against an In Vitro Model of the Human Intestinal Epithelium
Authors: Bitounis Dimitrios , Parviz Dorsa , Cao Xiaoqiong , Amadei Carlo A. , Vecitis Chad D. , Sunderland Elsie M. , Thrall Brian D. , Fang Mingliang , Strano Michael S. , Demokritou Philip
Published: March 2020

In the last decade, along with the increasing use of graphene oxide (GO) in various applications, there is also considerable interest in understanding its effects on human health. Only a few experimental approaches can simulate common routes of exposure, such as ingestion, due to the inherent complexity of the digestive tract. This study presents the synthesis of size‐sorted GO of sub‐micrometer‐ or micrometer‐sized lateral dimensions, its physicochemical transformations across mouth, gastric, and small intestinal simulated digestions, and its toxicological assessment against a physiologically relevant, in vitro cellular model of the human intestinal epithelium. Results from real‐time characterization of the simulated digestas of the gastrointestinal tract using multi‐angle laser diffraction and field‐emission scanning electron microscopy show that GO agglomerates in the gastric and small intestinal phase. Extensive morphological changes, such as folding, are also observed on GO following simulated digestion. Furthermore, X‐ray photoelectron spectroscopy reveals that GO presents covalently bound N‐containing groups on its surface. It is shown that the GO employed in this study undergoes reduction. Toxicological assessment of the GO small intestinal digesta over 24 h does not point to acute cytotoxicity, and examination of the intestinal epithelium under electron microscopy does not reveal histological alterations. Both sub‐micrometer‐ and micrometer‐sized GO variants elicit a 20% statistically significant increase in reactive oxygen species generation compared to the untreated control after a 6 h exposure.
Genotyping on the ark: A synthesis of genetic resources available for species in zoos
Authors: Jensen Evelyn L. , McClenaghan Beverly , Ford Brett , Lentini Andrew , Kerr Kevin C. R. , Russello Michael A.
Published: March 2020

Using molecular genetic information to guide population management can improve the sustainability of species in captivity. However, empirical population genetics has not been commonly applied to species management programs in zoos. One limitation may be the availability of genetic resources (e.g., markers, primers, etc.) for species held in zoos. To assess the extent to which species held in zoos have been studied using population genetics in the wild, we conducted a systematic literature review of close to 8,000 papers. We synthesized information on the availability and scale of population genetics studies across amphibian, bird, mammal, and reptile species held in zoos, and discussed their potential for informing ex situ management. We found that more than half of the species in zoos (52%) already have some genetic markers described in the literature specific for them, or a congeneric species, that could be further developed to aid the management of zoo populations, and the accumulation of these resources has been steady over the past decades. Furthermore, the proportion of species with genetic resources is even higher (62%) for species that are being managed through a formal breeding program in zoos. Our study provides encouraging results for captive program managers interested in integrating population genetics into ex situ management strategies.
Composite operators near the boundary
Authors: Procházka Vladimír , Söderberg Alexander
Published: March 2020

Abstract

We use renormalization group methods to study composite operators existing at a boundary of an interacting conformal field theory. In particular we relate the data on boundary operators to short-distance (near-boundary) divergences of bulk two-point functions. We further argue that in the presence of running couplings at the boundary the anomalous dimensions of certain composite operators can be computed from the relevant beta functions and remark on the implications for the boundary (pseudo) stress-energy tensor. We apply the formalism to a scalar field theory in d = 3−𝜖 dimensions with a quartic coupling at the boundary whose beta function we determine to the first non-trivial order. We study the operators in this theory and compute their conformal data using 𝜖 −expansion at the Wilson-Fisher fixed point of the boundary renormalization group flow. We find that the model possesses a non-zero boundary stress-energy tensor and displacement operator both with vanishing anomalous dimensions. The boundary stress tensor decouples at the fixed point in accordance with Cardy’s condition for conformal invariance. We end the main part of the paper by discussing the possible physical significance of this fixed point for various values of 𝜖.
On Subadditive Functions Bounded Above on a “Large” Set
Authors: Bingham Nicholas H. , Jabłońska Eliza , Jabłoński Wojciech , Ostaszewski Adam J.
Published: March 2020

It is well known that boundedness of a subadditive function need not imply its continuity. Here we prove that each subadditive function $$f:X\rightarrow {\mathbb {R}}$$f:X→R bounded above on a shift–compact (non–Haar–null, non–Haar–meagre) set is locally bounded at each point of the domain. Our results refer to results from Kuczma’s book (An Introduction to the theory of functional equations and inequalities. Cauchy’s equation and Jensen’s inequality, 2nd edn, Birkhäuser Verlag, Basel, 2009, Chapter 16) and papers by Bingham and Ostaszewski [Proc Am Math Soc 136(12):4257–4266, 2008, Aequationes Math 78(3):257–270, 2009, Dissert Math 472:138pp., 2010, Indag Math (N.S.) 29:687–713, 2018, Aequationes Math 93(2):351–369, 2019).
Cutaneous warmth, but not touch, increases muscle sympathetic nerve activity during a muscle fatigue hand-grip task
Authors: Ackerley Rochelle , Sverrisdόttir Yrsa B. , Birklein Frank , Elam Mikael , Olausson Håkan , Krämer Heidrun H.
Published: March 2020

In homeostasis, somatosensory C fibre afferents are hypothesised to mediate input to the brain about interactions with external stimuli and sympathetic efference provides the output that regulates bodily functions. We aimed to test this hypothesis and whether different types of innocuous somatosensory input have differential effects. Healthy volunteers performed a muscle fatigue (hand-grip) task to exhaustion, which produces increased muscle sympathetic nerve activity (MSNA), as measured through microneurography. Participants completed the muscle fatigue task without concurrent cutaneous sensory stimulation (control) or we applied skin warming (heat pack) as a C fibre stimulation, slow brush stroking as C and Aβ fibre stimulation, or vibration as Aβ fibre stimulation, to the participant’s forearm. We also measured heart rate, the duration of the hand-grip task, and ratings of pain at the end of the task. Concurrent skin warming showed increased MSNA compared to the other conditions. Tactile stimuli (brushing, vibration) were not significantly different to the control (no intervention) condition. Warming increased the pain from the muscle contraction, whereas the tactile stimuli did not. We interpret the effect of warming on MSNA as providing relevant afferent information during muscle contraction, which needed to be counteracted via vasoconstriction to maintain homeostasis. Brushing and vibration were less homeostatically relevant stimuli for the muscle contraction and hence had no significant effect. The findings add sensory specificity to our current understanding of homeostatic regulation through somatosensory afferent and sympathetic efferent pathways.
Packing Tree Degree Sequences
Authors: Gollakota Aravind , Hardt Will , Miklós István
Published: March 2020

A degree sequence is a list of non-negative integers, $${D = d_1, d_2, \ldots , d_n}$$D=d1,d2,…,dn. It is called graphical if there exists a simple graph G such that the degree of the ith vertex is $$d_i$$di; G is then said to be a realization of D. A tree degree sequence is one that is realized by a tree. In this paper we consider the problem of packing tree degree sequences: given k tree degree sequences, do they have simultaneous (i.e. on the same vertices) edge-disjoint realizations? We conjecture that this is true for any arbitrary number of tree degree sequences whenever they share no common leaves (degree-1 vertices). This conjecture is inspired by work of Kundu (SIAM J Appl Math 28:290–302, 1975) that showed it to be true for 2 and 3 tree degree sequences. In this paper, we give a proof for 4 tree degree sequences and a computer-aided proof for 5 tree degree sequences. We also make progress towards proving our conjecture for arbitrary k. We prove that k tree degree sequences without common leaves and at least $$2k-4$$2k-4 vertices which are not leaves in any of the trees always have edge-disjoint tree realizations. Additionally, we show that to prove the conjecture, it suffices to prove it for $$n \le 4k - 2$$n≤4k-2 vertices. The main ingredient in all of the presented proofs is to find rainbow matchings in certain configurations.
Dietary intake of choline and phosphatidylcholine and risk of type 2 diabetes in men: The Kuopio Ischaemic Heart Disease Risk Factor Study
Authors: Virtanen Jyrki K. , Tuomainen Tomi-Pekka , Voutilainen Sari
Published: March 2020

Purpose

To investigate associations of total dietary choline intake and its major dietary form, phosphatidylcholine, with type 2 diabetes risk.

Methods

We included 2332 men aged 42–60 years at baseline in 1984–1989 from the Kuopio Ischaemic Heart Disease Risk Factor Study in eastern Finland. Dietary intakes were assessed with 4-d food recording at baseline. Type 2 diabetes diagnosis was based on self-administered questionnaires, fasting and 2-h oral glucose tolerance test blood glucose measurements, or by record linkage to national health registries. Multivariable-adjusted Cox proportional hazards regression models were used for statistical analysis.

Results

During the mean 19.3-year follow-up, 432 men had type 2 diabetes diagnosis. After multivariable adjustments, those in the highest vs. lowest choline intake quartile had 25% (95% CI 2–43%) lower relative risk(Ptrend across quartiles = 0.02) and those in the highest vs. lowest phosphatidylcholine quartile had 41% (95% CI 22–55%) lower relative risk (Ptrend < 0.001) of type 2 diabetes.

Conclusions

Higher choline intake, especially phosphatidylcholine, was associated with lower type 2 diabetes risk among men.
Fertility navigators in female oncofertility care in an academic medical center: a qualitative evaluation
Authors: van den Berg M. , Nadesapillai S. , Braat D. D. M. , Hermens R. P. M. G. , Beerendonk C. C. M.
Published: March 2020

Purpose

To explore patients’ and professionals’ experiences with fertility navigators in female oncofertility care.

Methods

Semi-structured in-depth interviews were conducted with nine female cancer patients and six healthcare professionals to explore their experiences. They were recruited from an academic medical center (referral clinic for female fertility preservation care). Data were analyzed using the concepts of grounded theory.

Results

Patients were satisfied about the supportive role of the fertility navigator in their fertility preservation process: fertility navigators added value as they became “familiar faces” and provided information, emotional support, personal care, and served as patients’ primary contact person. The fertility navigators had a pleasant collaboration with professionals and supported professionals by taking over tasks. To improve the role of fertility navigators, it was suggested that they should always be present in fertility preservation counseling, and attention should be paid to their availability to improve continuity of care.

Conclusion

Fertility navigators provide personal care, improve satisfaction in patients in their oncofertility process, and support professionals. The overview of issues that need to be addressed when assigning fertility navigators in female oncofertility care combined with the improvement suggestions could be used by other centers when considering implementing fertility navigators.
Gaining advantage by winning contests
Authors: Clark Derek J. , Nilssen Tore , Sand Jan Yngve
Published: March 2020

We consider a principal who faces many identical competitors, and who can distribute a prize fund over two consecutive contests. The winner of contest one gains an advantage in contest two where his effort is more productive than all rivals. We identify a tipping point for the productivity parameter, below which it is optimal for an effort-maximizing principal to place the whole prize in the second contest. Above this level, a single symmetric contest is preferred. The institution chosen depends inextricably upon the number of competitors and their valuation of future gains and costs. We identify the optimal setting of the productivity parameter, showing that introducing asymmetry can increase total efforts by as much as one quarter compared to a single symmetric contest.
Consumption of Synthetic Cannabinoids in Adult Attention-Deficit/Hyperactivity Disorder: a Pilot Study
Authors: Lam Alexandra P. , Moeller Sebastian , Speitling Christine , Lam Martin C. , Philipsen Alexandra , Müller Helge H. O.
Published: March 2020

Attention-deficit/hyperactivity disorder (ADHD) is associated with an increased risk for substance abuse and addiction. Synthetic cannabinoids (SC) have gained rising importance as their consumption increased rapidly in the last few years. However, SC consumption in patients with adult ADHD has not been investigated yet. A prospective clinical pilot study was conducted, including 60 adults with ADHD, assessing the prevalence of SC consumption and its associations with psychiatric comorbidities and patient characteristics. A drug consumption survey was utilized to investigate the use of SC and other drugs. Current ADHD symptoms were evaluated via ADHD Self-Rating Scale (ADHD-SR) and retrospective childhood ADHD symptom severity via Wender Utah Rating Scale (WURS-k) questionnaire. A positive lifetime prevalence of SC consumption was found in 15.0% of the analyzed sample. SC consumption was significantly associated with current smoking, lifetime use of natural cannabis (NC), cocaine, amphetamines, and benzodiazepines. Lifetime NC consumption was indicated by 65.0% and found to antecede SC use in adult ADHD patients. Logistic regression analysis identified substance use disorder and male sex as predictive for SC consumption. Patients with history of SC use scored significantly higher in both WURS-k and ADHD-SR questionnaire compared with nonusers and suffered significantly more frequently from psychiatric comorbidities. Main side-effects of SC included gastrointestinal, cardiovascular, and neuropsychiatric symptoms. SC consumption in adults with ADHD is frequent and associated with stronger ADHD symptom severity. Given the underestimated dangerous effects and related comorbidities, SC use should be subject to scrutiny by clinicians treating ADHD patients. More studies are needed to further elucidate the impact of SC use in ADHD.