bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacterial formate dehydrogenase. Increasing the enzyme thermal stability by hydrophobization of alpha‐helices
Authors: Rojkova Alexandra M. , Galkin Andrey G. , Kulakova Ludmila B. , Serov Alexander E. , Savitsky Pavel A. , Fedorchuk Vladimir V. , Tishkov Vladimir I.
Published: July 2002

NAD+‐dependent formate dehydrogenase (EC 1.2.1.2, FDH) from methylotrophic bacterium Pseudomonas sp.101 exhibits the highest stability among the similar type enzymes studied. To obtain further increase in the thermal stability of FDH we used one of general approaches based on hydrophobization of protein α‐helices. Five serine residues in positions 131, 160, 168, 184 and 228 were selected for mutagenesis on the basis of (i) comparative studies of nine FDH amino acid sequences from different sources and (ii) with the analysis of the ternary structure of the enzyme from Pseudomonas sp.101. Residues Ser‐131 and Ser‐160 were replaced by Ala, Val and Leu. Residues Ser‐168, Ser‐184 and Ser‐228 were changed into Ala. Only Ser/Ala mutations in positions 131, 160, 184 and 228 resulted in an increase of the FDH stability. Mutant S168A was 1.7 times less stable than the wild‐type FDH. Double mutants S(131,160)A and S(184,228)A and the four‐point mutant S(131,160,184,228)A were also prepared and studied. All FDH mutants with a positive stabilization effect had the same kinetic parameters as wild‐type enzyme. Depending on the position of the replaced residue, the single point mutation Ser/Ala increased the FDH stability by 5–24%. Combination of mutations shows near additive effect of each mutation to the total FDH stabilization. Four‐point mutant S(131,160,184,228)A FDH had 1.5 times higher thermal stability compared to the wild‐type enzyme.
Binding of amyloid β‐peptide to mitochondrial hydroxyacyl‐CoA dehydrogenase (ERAB): regulation of an SDR enzyme activity with implications for apoptosis in Alzheimer's disease
Authors: Oppermann Udo C.T. , Salim Samina , Tjernberg Lars O. , Terenius Lars , Jörnvall Hans
Published: July 2002

The intracellular amyloid β‐peptide (Aβ) binding protein, ERAB, a member of the short‐chain dehydrogenase/reductase (SDR) family, is known to mediate apoptosis in different cell lines and to be a class II hydroxyacyl‐CoA dehydrogenase. The Aβ peptide inhibits the enzymatic reaction in a mixed type fashion with a K
i of 1.2 μmol/l and a K
iES
of 0.3 μmol/l, using 3‐hydroxybutyryl‐CoA. The peptide region necessary for inhibition comprises residues 12–24 of Aβ1–40, covering the 16–20 fragment, which is the minimum sequence for the blockade of Aβ polymerization, but that minimal fragment is not sufficient for more than marginal inhibition. The localization of ERAB to the endoplasmic reticulum and mitochondria suggests a complex interaction with components of the programmed cell death machinery. The interaction of Aβ with ERAB further links oxidoreductase activity with both apoptosis and amyloid toxicity.
Introducing transglycosylation activity in a liquefying α‐amylase
Authors: Saab-Rincón Gloria , del-Rı́o Gabriel , Santamarı́a Rosa I , López-Munguı́a Agustı́n , Soberón Xavier
Published: July 2002

By mutating Ala‐289 by Phe or Tyr in the Bacillus stearothermophilus α‐amylase, we induced this enzyme to perform alcoholytic reactions, a function not present in the wild‐type enzyme. This residue was selected from homology analysis with neopullulanase, where the residue has been implicated in the control of transglycosylation [Kuriki et al. (1996) J. Biol. Chem. 271, 17321–17329]. We made some inferences about the importance of electrostatic and geometrical modifications in the active site environment of the amylase to explain the behavior of the modified enzyme.
Actinomycin D as a novel SH2 domain ligand inhibits Shc/Grb2 interaction in B104‐1‐1 (neu*‐transformed NIH3T3) and SAA (hEGFR‐overexpressed NIH3T3) cells
Authors: Kim Hyae-Kyeong , Nam Ji-Youn , Han Mi Young , Lee Eun Kyung , Choi Jung-Do , Bok Song Hae , Kwon Byoung-Mog
Published: July 2002

Actinomycins, a family of bicyclic chromopeptide lactones with strong antineoplastic activity, were screened as inhibitors of Shc/Grb2 interaction in in vitro assay systems. To investigate the effects of actinomycin D on Shc/Grb2 interaction in cell‐based experiments, we used SAA (normal hEGFR‐overexpressed NIH3T3) cells and B104‐1‐1 (neu*‐transformed NIH3T3) cells, because a large number of the Shc/Grb2 complexes were detected. Associated protein complexes containing Shc were immunoprecipitated from actinomycin D‐treated cell lysates with polyclonal anti‐Shc antibody. Then the association with Grb2 was assessed by immunoblotting with monoclonal anti‐Grb2 antibody. The result of the immunoblotting experiment revealed that actinomycin D inhibited Shc/Grb2 interaction in a dose‐dependent manner in both B104‐1‐1 and EGF‐stimulated SAA cells. The inhibition of Shc/Grb2 interaction by actinomycin D in B104‐1‐1 cells also reduced tyrosine phosphorylation of MAP kinase (Erk1/Erk2), one of the major components in the Ras‐MAP kinase signaling pathway. These results suggest that actinomycin D could be a non‐phosphorylated natural and cellular membrane‐permeable SH2 domain antagonist.
Subunit C of the vacuolar H+‐ATPase of Hordeum vulgare
Authors: Tavakoli Nastaran , Eckerskorn Christoph , Golldack Dortje , Dietz Karl-Josef
Published: July 2002

The molecular cloning of the first subunit C of the plant vacuolar H+‐ATPase is reported. Tonoplast vesicles were purified from barley leaves by sucrose gradient centrifugation, and the tonoplast polypeptides were separated by two‐dimensional (2‐D) gel electrophoresis. Using an anti‐ATPase holoenzyme antibody, a polypeptide was recognized in the molecular mass range of 40 kDa with an isoelectric point of about 6.0, and tentatively identified as subunit C. The polypeptide spot was excised from about 50 2‐D gels and subjected to endo Lys C proteolysis. Two proteolytic peptides were sequenced and the amino acid sequences were used to design degenerated oligonucleotides, followed by PCR amplification with cDNA template and screening of a cDNA library synthesized from Hordeum vulgare poly A mRNA of epidermis strips. The full length clone of 1.5 kbp contains an open reading frame of 1062 bp encoding a polypeptide of 354 amino acids with a molecular mass of 39 982 Da and an isoelectric point of 6.04. Amino acid identity with sequences of SUC from animals and fungi is in the range of 36.7 to 38.5%. Expression of the cloned gene was demonstrated by Northern blotting and RT‐PCR.
Exciton levels structure of antenna bacteriochlorophyll c aggregates in the green bacterium Chloroflexus aurantiacus as probed by 1.8–293 K fluorescence spectroscopy
Authors: Mauring K. , Novoderezhkin V. , Taisova A. , Fetisova Z.
Published: July 2002

We have demonstrated temperature‐dependence of the steady‐state fluorescence lineshape of the bacteriochlorophyll (BChl) c band measured for intact cells of the green bacterium Chloroflexus aurantiacus over the 1.8–293 K range. The measured temperature‐dependence has been shown to be in good agreement with the theoretical one, calculated for our original model of pigment organization in the chlorosomal oligomeric antenna of green photosynthetic bacteria based on spectral hole‐burning studies (Fetisova, Z.G. et al. (1996) Biophys. J. 71, 995–1010). This model implies that the BChl c antenna unit is a tubular aggregate of six exciton‐coupled linear pigment chains having the exciton level structure with strongly allowed higher levels.
Rotenone and pyruvate prevent the tert‐butylhydroperoxide‐induced necrosis of U937 cells and allow them to proliferate
Authors: Sestili Piero , Brambilla Liliana , Cantoni Orazio
Published: July 2002

Exposure of U937 cells to tert‐butylhydroperoxide (tB‐OOH) led to cyclosporin A‐sensitive mitochondrial membrane permeability transition and necrosis. Pyruvate and rotenone, which increase mitochondrial NADH via different mechanisms, prevented these responses and the cells which received these treatments proliferated with kinetics similar to those observed in untreated cells. In contrast with these results, cells rescued by cyclosporin A were unable to proliferate. Thus, mitochondrial NADH plays a pivotal role in preventing upstream events which result in the onset of mitochondrial membrane permeability transition and death in cells exposed to tB‐OOH. These events appear to be critical for recovery of the ability of the cells to proliferate.
Risk factors for pre‐eclampsia in an Asian population
Authors: Lee C.‐J. , Hsieh T.‐T. , Chiu T.‐H. , Chen K.‐C. , Lo L.‐M. , Hung T.‐H.
Published: July 2002

Objective: To identify the risk factors for pre‐eclampsia in an Asian population. Method: We conducted a retrospective cohort study involving 29 375 Taiwanese women who delivered between July 1990 and September 1998, excluding pregnancies complicated by chronic hypertension or fetal malformations. Result: Four hundred and fifteen women had pre‐eclampsia (1.4%). Women who had a history of pre‐eclampsia (OR 6.3, 95% CI 4.4, 9.2), multiple gestation (OR 3.6, 95% CI 2.4, 5.5), a prepregnancy BMI>24.2 kg/m2 (OR 2.4, 95% CI 1.8, 3.1), were>34 years of age (OR 1.8, 95% CI 1.4, 2.4), nulliparous (OR 1.3, 95% CI 1.2, 1.5), had urinary tract infection (OR 4.8, 95% CI 1.5, 15.8), or worked during pregnancy (OR 1.9, 95% CI 1.4, 2.4) were at increased risk of pre‐eclampsia. Conclusion: Some of the risk factors for pre‐eclampsia among Asian women are the same as those of other ethnic groups, whereas some of the risk factors are different.
Lessons learned from the PMM Network experience
Authors: Kamara A
Published: July 2002

For eight years, the Prevention of Maternal Mortality (PMM) Network in West Africa designed, implemented and evaluated projects to reduce barriers to care for women with obstetric complications. Many valuable lessons were learned concerning program development and implementation. A multidisciplinary approach enabled the Network to address the various aspects of the problem; collaboration between teams encouraged the sharing of resources and experiences; and collaboration with government and communities enhanced project sustainability. Capacity building through long‐term, systematic technical support resulted in a Network of proficient researchers. Existing human and material resources were utilized to enhance the feasibility and sustainability of projects — a strategy that could be adopted in other developing countries. Cost‐tracking was used as a management and evaluation tool. The collective experience of the Network offers guidance for program planners and researchers working on maternal mortality in developing countries. © 1997 International Federation of Gynecology and Obstetrics
The clinician's view of endometriosis
Authors: Thomas E.J
Published: July 2002

Clinicians have a number of unmet needs regarding the diagnosis and management of endometriosis. The fulfilment of these would result in better advice for patients.
Small fetal size: a risk factor for breech birth at term
Authors: Roberts C.L. , Algert C.S. , Peat B. , Henderson‐Smart D.
Published: July 2002

Objective: To examine fetal size as a risk factor for breech birth at term. Methods: Singleton breech or cephalic births of gestational age ≥37 weeks in New South Wales (NSW), Australia from 1990 to 1996 were analyzed. Birthweight percentile was used as a measure of fetal size at the time of birth. Factors associated with breech birth at term were analyzed using logistic regression. Results: There were 18 914 singleton breech and 540 164 cephalic births in the study period. The important independent predictors of breech birth at term were advancing maternal age, primiparity, female sex and small size for gestational age. Infants <10th percentile had an adjusted odds ratio of 1.33 (95% CI 1.28–1.38) for breech birth at term compared with 25th–75th percentile infants. Conclusions: Breech birth at term was associated with smaller fetal size for gestational age. This was shown directly through an association with birthweight‐for‐gestational‐age percentiles and indirectly through association with female sex, primiparous birth and congenital anomalies.
JIT purchasing and performance: an exploratory analysis of buyer and supplier perspectives
Authors: Dong Yan , Carter Craig R , Dresner Martin E
Published: July 2002

In this exploratory analysis, a model is developed and tested to determine whether the use of JIT purchasing reduces logistics costs for both suppliers and buyers. The results indicate that JIT purchasing directly reduces costs only for buyers. An indirect path, however, was found between JIT purchasing and logistics costs for suppliers. To the extent that JIT purchasing may result in suppliers adopting JIT manufacturing techniques, then suppliers too can benefit, at least indirectly, from JIT purchasing.
Genetic loci influencing natural variations in femoral bone morphometry in mice
Authors: Drake Thomas A. , Hannani Kambiz , Kabo J. Michael , Villa Veronica , Krass Kelly , Lusis Aldons J.
Published: July 2002

This study identifies genetic loci affecting femoral bone length and width measures in mature mice. Sixteen month old female F2 progeny of a C57BL/6J and DBA/2J intercross were examined for femur length and width of the femoral head, intertrochanteric region and three locations of the diaphysis using digitized images of femur radiographs obtained in the anterior‐posterior and lateral projections. A genome wide linkage map was constructed using microsatellite markers at an average density of 20 cM, and quantitative trait locus analysis used to identify regions of the genome showing linkage with the traits measured. Femur length showed significant linkage with loci on proximal chromosome 3 (lod 6.1), and suggestive linkage with a locus on chromosome 14. A major locus on mid‐chromosome 7 controlled width of the diaphysis (lod 6.8). Other loci were identified on chromosomes 2 and 4. Width at the intertrochanteric region had suggestive linkage with loci on chromosomes 6 and 19. No loci were found with linkage for width of the femoral head. Candidate genes related to bone development or metabolism are present at most of these loci. These findings show that genetic regulation of femoral bone morphology is complex, and are consistent with the distinct biologic processes that control longitudinal and lateral growth of the femur. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
No evidence for systolic or diastolic left ventricular dysfunction at rest in selected patients with long‐term Type I diabetes mellitus
Authors: Romanens Michel , Fankhauser Simon , Saner Brigitte , Michaud Lil , Saner Hugo
Published: July 2002

We assessed left ventricular systolic and diastolic function using pulsed‐waved Doppler echocardiography in a selected group of 20 patients with insulin‐dependent diabetes mellitus (IDDM) (mean age, 35±8 years; mean diabetes duration, 17±7 years). Our patients were free of autonomic neuropathy and major micro‐ or macrovascular complications and had no evidence of ischemic heart disease or hypertension. The results were compared with those of 20 age‐ and sex‐matched control subjects. We found that left ventricular geometry and mass, systolic function by M‐mode and 2D‐echocardiography, isovolumetric relaxation time, deceleration time and the PEP/LVET ratio were not significantly different between patients and control subjects. Hemodynamic parameters were also not significantly different except for a slightly higher heart rate in the patient group (75±11 vs. 68±6 bpm, P=0.019). After correction of A‐peak velocities for differences in heart rate, there was no significant difference of Doppler indices of diastolic left ventricular function between patients and control subjects. The absence of significant left ventricular systolic and diastolic dysfunction by Doppler echocardiography in our study patients may be explained by our patient selection. Left ventricular dysfunction in diabetic patients without concomitant hypertensive or ischemic heart disease may only occur in conjunction with microvascular disease in other organ systems, with autonomic neuropathy or with poor metabolic control.
Distribution and prognostic significance of gluconeogenesis and glycolysis in lung cancer
Authors: Smolle Elisabeth , Leko Petra , Stacher‐Priehse Elvira , Brcic Luka , El‐Heliebi Amin , Hofmann Lilli , Quehenberger Franz , Hrzenjak Andelko , Popper Helmut H. , Olschewski Horst , Leithner Katharina
Published: August 2020

Inhibition of glycolysis has been considered as a therapeutic approach in aggressive cancers including lung cancer. Abbreviated gluconeogenesis, mediated by phosphoenolpyruvate carboxykinase (PEPCK), was recently discovered to partially circumvent the need for glycolysis in lung cancer cells. However, the interplay of glycolysis and gluconeogenesis in lung cancer is still poorly understood. Here, we analyzed the expression of GLUT1, the prime glucose transporter, and of PCK1 and PCK2, the cytoplasmic and mitochondrial isoforms of PEPCK, in 450 samples of non‐small cell lung cancer (NSCLC) and in 54 NSCLC metastases using tissue microarrays and whole tumor sections. Spatial distribution was assessed by automated image analysis. Additionally, glycolytic and gluconeogenic gene expression was inferred from The Cancer Genome Atlas (TCGA) datasets. We found that PCK2 was preferentially expressed in the lung adenocarcinoma subtype, while GLUT1 expression was higher in squamous cell carcinoma. GLUT1 and PCK2 were inversely correlated, GLUT1 showing elevated expression in larger tumors while PCK2 was highest in smaller tumors. However, a mixed phenotype showing the presence of both, glycolytic and gluconeogenic cancer cells was frequent. In lung adenocarcinoma, PCK2 expression was associated with significantly improved overall survival, while the opposite was found for GLUT1. The metabolic tumor microenvironment and the 3‐dimensional context play an important role in modulating both pathways, since PCK2 expression preferentially occurred at the tumor margin and hypoxia regulated both, glycolysis and gluconeogenesis, in NSCLC cells in vitro, albeit in opposite directions. PCK1/2 expression was enhanced in metastases compared to primary tumors, possibly related to the different environment. The results of this study show that glycolysis and gluconeogenesis are activated in NSCLC in a tumor size and oxygenation modulated manner and differentially correlate with outcome. The frequent co‐activation of gluconeogenesis and glycolysis in NSCLC should be considered in potential future therapeutic strategies targeting cancer cell metabolism.
Adversary effects and the tactics of violent offenders
Authors: Felson Richard B. , Hullenaar Keith L.
Published: August 2020

We examine the implication of adversary effects for target choice, lethal intent, and the use of weapons and allies in violent incidents. Adversary effects refer to the tendency of offenders to make tactical decisions based on the coercive power of victims and potential victims. Using the victim's gender as a proxy for coercive power, we analyzed violent incidents from the National Incident‐Based Reporting System (2005–2014). The sample included over six million assaults, robberies, and homicides. Consistent with adversary effects, offenders who attack males (vs. females) are more likely to (a) kill victims; (b) use guns, knives, blunt objects, poison, and automobiles; (c) use male (but not female) allies; and (d) use multiple allies. The evidence for target choice is mixed: unarmed female offenders, but not unarmed male offenders, are more likely to target females than males. The evidence shows how a simple theoretical principle can parsimoniously account for basic patterns of violence in society related to gender, weapons, and group violence.
Microstructural Refinement and α‐Dispersoid Evolution in Direct‐Chill Cast Al–Mg–Si–Fe Alloy
Authors: Wang Dongtao , Zhang Haitao , Nagaumi Hiromi , Li Xueke , Cui Jianzhong
Published: August 2020

High Fe levels, coarse grains, microstructural inhomogeneities, and coarse dispersoids for recrystallization suppression remain problems for industrial application of Al–Mg–Si (6xxx) alloys. Herein, Al–0.81%Mg–0.81%Si–0.7%Fe alloy billets are fabricated by direct chill (DC) casting at different casting speeds. The results indicate that high‐speed (300 mm min−1) DC casting can provide fine grains, refined Fe‐containing phases, relatively high solid–solute content, and improved distribution of Mn and Cr. After homogenization at 500 °C for 6 h, the α‐AlFeMnCrSi dispersoids in the high‐speed cast billet decrease in size and increase in number density, compared with the conventional cast billet (100 mm min−1). The low homogenization temperature (440 °C) also contributes to the size reduction and increases the number density of dispersoids. Air cooling after homogenization (holding temperature ≥500 °C) results in Q‐AlCuMgSi precipitation, which depends on the precipitated substrate of the α‐AlFeMnCrSi dispersoids. Moreover, the precipitation processes of α‐dispersoids and Q phases are discussed according to transmission electron microscopy (TEM) and high‐angle annular dark‐field scanning transmission election microscope (HAADF‐STEM) results. These results mean that high‐speed DC casting can effectively improve the as‐cast microstructure by increasing the cooling rate, and the as‐cast microstructural evolution promotes the precipitation of fine and dense α‐dispersoids from the α‐Al matrix.
2D Materials Based on Main Group Element Compounds: Phases, Synthesis, Characterization, and Applications
Authors: Lu Ziyang , Neupane Guru Prakash , Jia Guohua , Zhao Haitao , Qi Dongchen , Du Yaping , Lu Yuerui , Yin Zongyou
Published: August 2020

2D materials based on main group element compounds have recently attracted significant attention because of their rich stoichiometric ratios and structure motifs. This review focuses on the phases in various 2D binary materials including III–VI, IV–VI, V–VI, III–V, IV–V, and V–V materials. Reducing 3D materials to 2D introduces confinement and surface effects as well as stabilizes unstable 3D phases in their 2D form. Their crystal structures, stability, preparation, and applications are summarized based on theoretical predictions and experimental explorations. Moreover, various properties of 2D materials, such as ferroelectric effect, anisotropic optical and electrical properties, ultralow thermal conductivity, and topological state are discussed. Finally, a few perspectives and an outlook are given to inspire readers toward exploring 2D materials with new phases and properties.
Hierarchically Divacancy Defect Building Dual‐Activated Porous Carbon Fibers for High‐Performance Energy‐Storage Devices
Authors: Wang Qing , Liu Fangyan , Jin Zeyuan , Qiao Xiaoru , Huang Haichao , Chu Xiang , Xiong Da , Zhang Haitao , Liu Yan , Yang Weiqing
Published: August 2020

Renewable and environmentally friendly biomass‐based carbon electrode materials naturally possess fast ion transport, high adsorption, and excellent chemical stability for high‐performance energy‐storage devices. However, intelligently building the effectively biomass‐transferred carbon materials for the requirement of high energy density is still a big challenge to date. Here, a hierarchically divacancy defect building platform is reported for effectively biomass‐transferred and highly interconnected 3D dual‐activated porous carbon fibers (DACFs) based on the internal−external dual‐activation function of the pre‐embedded KOH and CO2 molecular. This uniquely interconnected frameworks not only fully provide the abundant active sites for ion interaction, but also efficiently guarantee the substantial accommodation for ion storage. Based on this, the as‐prepared DACFs‐based supercapacitors deliver a high energy density of 61.3 Wh kg−1 at a power density of 875 W kg−1 in the EMIMBF4 ionic liquid. This work not only provides a simple and efficient technique to enhance the energy density of carbon materials, but also probably promotes its additional application in environmental remediation.
Advances on Emerging Materials for Flexible Supercapacitors: Current Trends and Beyond
Authors: Benzigar Mercy R. , Dasireddy Venkata D. B. C. , Guan Xinwei , Wu Tom , Liu Guozhen
Published: August 2020

The progressive size reduction of electronic components is experiencing bottlenecks in shrinking charge storage devices like batteries and supercapacitors, limiting their development into wearable and flexible zero‐pollution technologies. The inherent long cycle life, rapid charge–discharge patterns, and power density of supercapacitors rank them superior over other energy storage devices. In the modern market of zero‐pollution energy devices, currently the lightweight formula and shape adaptability are trending to meet the current requirement of wearables. Carbon nanomaterials have the potential to meet this demand, as they are the core of active electrode materials for supercapacitors and texturally tailored to demonstrate flexible and stretchable properties. With this perspective, the latest progress in novel materials from conventional carbons to recently developed and emerging nanomaterials toward lightweight stretchable active compounds for flexi‐wearable supercapacitors is presented. In addition, the limitations and challenges in realizing wearable energy storage systems and integrating the future of nanomaterials for efficient wearable technology are provided. Moreover, future perspectives on economically viable materials for wearables are also discussed, which could motivate researchers to pursue fabrication of cheap and efficient flexible nanomaterials for energy storage and pave the way for enabling a wide‐range of material‐based applications.
Microengineering Pressure Sensor Active Layers for Improved Performance
Authors: Ruth Sara Rachel Arussy , Feig Vivian Rachel , Tran Helen , Bao Zhenan
Published: August 2020

Pressure sensors play an integral role in a wide range of applications, such as soft robotics and health monitoring. In order to meet this demand, many groups microengineer the active layer—the layer that deforms under pressure and dictates changes in the output signal—of capacitive, resistive/piezoresistive, piezoelectric, and triboelectric pressure sensors in order to improve sensor performance. Geometric microengineering of the active layer has been shown to improve performance parameters such as sensitivity, dynamic range, limit of detection, and response and relaxation times. There are a wide range of implemented designs, including microdomes, micropyramids, lines or microridges, papillae, microspheres, micropores, and microcylinders, each offering different advantages for a particular application. It is important to compare the techniques by which the microengineered active layers are designed and fabricated as they may provide additional insights on compatibility and sensing range limits. To evaluate each fabrication method, it is critical to take into account the active layer uniformity, ease of fabrication, shape and size versatility and tunability, and scalability of both the device and the fabrication process. By better understanding how microengineering techniques and design compares, pressure sensors can be targetedly designed and implemented.
Electroless‐Plated Gold Contacts for High‐Performance, Low Contact Resistance Organic Thin Film Transistors
Authors: Makita Tatsuyuki , Nakamura Ryohei , Sasaki Mari , Kumagai Shohei , Okamoto Toshihiro , Watanabe Shun , Takeya Jun
Published: August 2020

Deposition of metallic electrodes on a semiconductor medium is an indispensable factor in governing carrier injection, and a metal/semiconductor contact that can be formed via solution process is highly desired in printed electronics. However, fine‐patterning the solution processes of metallic electrodes without damaging the excellent electronic properties of organic semiconductors (OSCs) is still a challenge. In this work, electroless plating, a metal coating technique that involves auto‐catalytic reaction in an aqueous solution, is used to fabricate top‐contact organic thin‐film transistors (OTFTs). An electroless‐plated gold pattern with a spatial resolution of 10 micrometers is transferred and laminated on a monolayer of OSCs to serve as a hole‐injection electrode. The fabricated OTFTs exhibit reasonably high field‐effect mobility of up to 13 cm2 V−1 s−1 and decent contact resistance as low as 120 Ω · cm, which implies that an ideal metal/semiconductor contact can be realized. This electroless plating technique can provide possibilities for practical mass production of organic integrated circuits because it is in principle cost‐effective, capable of covering large areas, high‐vacuum free, and environmentally friendly.
A Review of the Effects of Electrode Fabrication and Assembly Processes on the Structure and Electrochemical Performance of 2D MXenes
Authors: Orangi Jafar , Beidaghi Majid
Published: August 2020

MXenes are 2D materials with relatively high surface areas, high electrical conductivities, functional transition metal surfaces, tunable surface chemistries, and solution processability. Due to these properties, 2D MXenes have attracted widespread attention as electrode materials for energy storage devices, including electrochemical capacitors, with high power and energy densities. However, many studies have shown that the electrochemical performance of MXene electrodes is considerably affected by their structure and morphology. These properties are, for the most part, controlled by the method used for the assembly of 2D MXene flakes and the electrode fabrication methods. A successful electrode assembly and fabrication method should address several challenges, such as the restacking of 2D flakes, to achieve electrode structures and morphologies that deliver high ionic transport properties, electrical conductivity, and mechanical stability. This review aims to provide insight into the current state‐of‐the‐art assembly and fabrication methods used to design and fabricate high performance electrodes based on MXenes. The major challenges to be addressed and possible future directions in the fabrication of MXene electrodes for practical energy storage applications are highlighted.
Perovskite Films with Reduced Interfacial Strains via a Molecular‐Level Flexible Interlayer for Photovoltaic Application
Authors: Zhang Cong‐Cong , Yuan Shuai , Lou Yan‐Hui , Liu Qing‐Wei , Li Meng , Okada Hiroyuki , Wang Zhao‐Kui
Published: August 2020

Interface strains and lattice distortion are inevitable issues during perovskite crystallization. Silane as a coupling agent is a popular connector to enhance the compatibility between inorganic and organic materials in semiconductor devices. Herein, a protonated amine silane coupling agent (PASCA‐Br) interlayer between TiO2 and perovskite layers is adopted to directionally grasp both of them by forming the structural component of a lattice unit. The pillowy alkyl ammonium bromide terminals at the upper side of the interlayer provide well‐matched growth sites for the perovskite, leading to mitigated interface strain and ensuing lattice distortion; meanwhile, its superior chemical compatibility presents an ideal effect on healing the under‐coordinated Pb atoms and halogen vacancies of bare perovskite crystals. The PASCA‐Br interlayer also serves as a mechanical buffer layer, inducing less cracked perovskite film when bending. The developed molecular‐level flexible interlayer provides a promising interfacial engineering for perovskite solar cells and their flexible application.
Superhigh Uniform Magnetic Cr Substitution in a 2D Mo2C Superconductor for a Macroscopic‐Scale Kondo Effect
Authors: Xu Chuan , Liu Zhen , Zhang Zongyuan , Liu Zhibo , Li Jingyin , Pan Minghu , Kang Ning , Cheng Hui‐Ming , Ren Wencai
Published: August 2020

Substitutional doping provides an effective strategy to tailor the properties of 2D materials, but it remains an open challenge to achieve tunable uniform doping, especially at high doping level. Here, uniform lattice substitution of a 2D Mo2C superconductor by magnetic Cr atoms with controlled concentration up to ≈46.9 at% by chemical vapor deposition and a specifically designed Cu/Cr/Mo trilayer growth substrate is reported. The concentration of Cr atoms can be easily tuned by simply changing the thickness of the Cr layer, and the samples retain the original structure of 2D Mo2C even at a very high Cr concentration. The controlled uniform Cr doping enables the tuning of the competition of the 2D superconductor and the Kondo effect across the whole sample. Transport measurements show that with increasing Cr concentration, the superconductivity of the 2D Cr‐doped Mo2C crystals disappears along with the emergence of the Kondo effect, and the Kondo temperature increases monotonously. Using scanning tunneling microscopy/spectroscopy, the mechanism of the doping level effect on the interplay and evolution between superconductivity and the Kondo effect is revealed. This work paves a new way for the synthesis of 2D materials with widely tunable doping levels, and provides new understandings on the interplay between superconductivity and magnetism in the 2D limit.
SI‐ATRP Polymer‐Functionalized Graphene Oxide for Water Vapor Separation
Authors: Aliyev Elvin , Shishatskiy Sergey , Abetz Clarissa , Lee Young Joo , Neumann Silvio , Emmler Thomas , Filiz Volkan
Published: August 2020

Graphene oxide is functionalized with poly(2‐diethylaminoethyl) methacrylate (PDEAEMA), and the resulting material is used as a selective layer of a thin‐film composite membrane (TFCM). The polymer synthesis is carried out by surface‐initiated atom transfer radical polymerization (SI‐ATRP) from bulk and also from single‐layer graphene oxide (GO). The polymer brushes synthesized by the “grafting from” method are characterized by size exclusion chromatography (SEC), nuclear magnetic resonance spectroscopy (NMR), Fourier‐transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), and TGA‐FTIR. The TFCMs are prepared by the deposition of the selective layer from a stable polymer solution. The molecular weight of the polymer is sufficiently high to obtain a continuous defect‐free layer on a porous support. The thickness of the selective layer is ≈400 nm, as found in morphological investigations by scanning electron microscopy (SEM). The obtained membranes are utilized for gas and water vapor transport experiments in a wide temperature range. The water vapor permeability coefficient of the investigated materials is up to 4500 Barrer; this value increases threefold upon quaterization of the amine. The high permeance and selectivity for water vapor make this type of thin‐film membranes a potential candidate for membrane distillation.
Fabrication of Multilayer Si/TiN/Sb NR Arrays as Anode for 3D Si‐Based Lithium/Sodium Ion Microbatteries
Authors: Yue Chuang , Wu Manyu , Cheng Boshi , Dang Man , Liu Gaozhan , Hu Fang , Li Jing
Published: August 2020

Micro/nano lab‐on‐chip power systems with poor energy storage/conversion ability are one of the major obstacles that circumvent the further practical applications of the micro/nano smart devices. In this work, the multilayer Si/TiN/Sb nanorod (NR) arrays composites anodes are successfully fabricated and impressively display improved electrochemical properties in 3D Si‐based lithium/sodium ion microbatteries (L/SIMBs). Both the 3D Si configuration and the efficient TiN interlayer are together responsible for the obtained enhanced cyclability of the Sb nanoelectrode. Moreover, the Li/Na ion storage behaviors are also experimentally investigated from the postmorphology characterizations and further evidences the structure stability of the whole Si/TiN/Sb NRs anodes during the repeated Li/Na ions inserting/de‐inserting process. These multilayer Si/Ti/Sb NR arrays composites should be a promising anode for the 3D Si‐based L/SIMBs.
Voltage‐Controlled Dielectric Function of Bilayer Graphene
Authors: Okano Shun , Sharma Apoorva , Ortmann Frank , Nishimura Akira , Günther Christoph , Gordan Ovidiu D. , Ikushima Kenji , Dzhagan Volodymyr , Salvan Georgeta , Zahn Dietrich R. T.
Published: August 2020

The refractive index and the extinction coefficient are usually inherent (noncontrollable) material characteristics. Recently, it was reported that the reflectivity of graphene in the mid‐infrared spectral range can be modified by an external bias. This report attracted much attention, but the controllable frequency/energy range is too narrow for possible applications. In this work, it is demonstrated that the potential of graphene is not limited to mid‐infrared wavelengths, but spans a much wider range including the visible spectral range. Here, back‐gated bilayer graphene is characterized in air using spectroscopic ellipsometry with a lateral resolution in the micrometer range. By applying a back‐gate voltage, the dielectric function can be modified in a broad spectral range, including the visible spectrum. To explain the change in the dielectric function, a simplified phenomenological approach which assumes that the back‐gating‐induced change in the carrier density of graphene can be described by a modified 2D Drude model is introduced. The trend of increasing values for the dielectric function with increasing sheet charge carrier density is confirmed by theoretical calculations performed in the independent particle picture.
Micro–Nano Hierarchical Structure Enhanced Strong Wet Friction Surface Inspired by Tree Frogs
Authors: Zhang Liwen , Chen Huawei , Guo Yurun , Wang Yan , Jiang Yonggang , Zhang Deyuan , Ma Liran , Luo Jianbin , Jiang Lei
Published: August 2020

Superior wet attachment and friction performance without the need of special external or preloaded normal force, similar to the tree frog's toe pad, is highly essential for biomedical engineering, wearable flexible electronics, etc. Although various pillar surfaces are proposed to enhance wet adhesion or friction, their mechanisms remain on micropillar arrays to extrude interfacial liquid via an external force. Here, two‐level micropillar arrays with nanocavities on top are discovered on the toe pads of a tree frog, and they exhibit strong boundary friction ≈20 times higher than dry and wet friction without the need of a special external or preloaded normal force. Microscale in situ observations show that the specific micro–nano hierarchical pillars in turn trigger three‐level liquid adjusting phenomena, including two‐level liquid self‐splitting and liquid self‐sucking effects. Under these effects, uniform nanometer‐thick liquid bridges form spontaneously on all pillars to generate strong boundary friction, which can be ≈2 times higher than for single‐level pillar surfaces and ≈3.5 times higher than for smooth surfaces. Finally, theoretical models of boundary friction in terms of self‐splitting and self‐sucking are built to reveal the importance of liquid behavior induced by micro–nano hierarchical structure.
Oxidative stress in elderly population: A prevention screening study
Authors: Gorni Davide , Finco Annarosa
Published: August 2020

Background

Aging is a multifactorial phenomenon, characterized by a progressive decline in the efficiency of biochemical and physiological processes and an increased susceptibility to disease. There is increasing evidence that aging and age‐related disease are correlated with an oxidative stress (OS) condition. The latter is characterized by an imbalance between reactive species (RS), in particular reactive oxygen species (ROS) and antioxidant reserve.

Objectives

The aim of this study is to evaluate the two main markers of oxidative stress, plasmatic peroxide concentration (through d‐ROMs FAST test, derivates‐Reactive Oxygen Metabolites) and plasmatic antioxidant power measured by iron‐reducing power (PAT test, Plasma Antioxidant Test) in 290 apparently healthy volunteers over 60, and their possible correlation with age and gender.

Materials and methods

Human capillary blood samples from healthy volunteers were used in this observational study for the evaluation of the markers of OS.

Results

The data obtained broadly demonstrate that the majority of elderly people display an OS condition characterized by increased levels of peroxides and a slight reduction in antioxidant reserve.

Conclusions

Seniors have a greater propensity to develop a condition of oxidative stress, and therefore it is important to associate the monitoring of oxidative stress markers and, if necessary, antioxidant supplementation, with a healthy lifestyle.
Application of the Minority Stress Theory: Understanding the Mental Health of Undocumented Latinx Immigrants
Authors: Valentín‐Cortés Mislael , Benavides Quetzabel , Bryce Richard , Rabinowitz Ellen , Rion Raymond , Lopez William D. , Fleming Paul J.
Published: August 2020

This paper applies the Minority Stress framework to data collected from an ongoing community‐based participatory research project with health and social service agencies in Southeast Michigan. We examine the stressors and coping strategies employed by undocumented Latinx immigrants and their families to manage immigration‐related stress. We conducted in‐depth interviews with 23 immigrant clients at Federally Qualified Health Care Centers (FQHC) in Southeast Michigan and 28 in‐depth interviews with staff at two FQHC's and a non‐profit agency serving immigrants. Findings suggest that immigrants face heightened anxiety and adverse mental health outcomes because of unique minority identity‐related stressors created by a growing anti‐immigrant social environment. Chronic stress experienced stems from restrictive immigration policies, anti‐immigrant rhetoric in the media and by political leaders, fear of deportation, discriminatory events, concealment, and internalized anti‐immigrant sentiment. Though identity can be an important effect modifier in the stress process, social isolation in the immigrant community has heightened the impact of stress and impeded coping strategies. These stressors have resulted in distrust in community resources, uncertainty about future health benefits, delayed medical care, and adverse mental health outcomes. Findings provide a framework for understanding the unique stressors experienced by immigrants and strategies for interventions by social service agencies.
A phase I study of lenalidomide plus chemotherapy with idarubicin and cytarabine in patients with relapsed or refractory acute myeloid leukemia and high‐risk myelodysplastic syndrome
Authors: Saygin Caner , Larkin Karilyn , Blachly James S. , Orwick Shelley , Ngankeu Apollinaire , Gregory Charles T. , Phelps Mitch A. , Mani Shylaja , Walker Alison , Garzon Ramiro , Vasu Sumithira , Walsh Katherine J. , Bhatnagar Bhavana , Klisovic Rebecca B. , Grever Michael R. , Marcucci Guido , Byrd John C. , Blum William , Mims Alice S.
Published: August 2020

Patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) have poor outcomes and hematopoietic cell transplantation (HCT) is the only curative treatment. New targeted therapies improved survival in select patients with specific mutations, however management of patients without these molecular alterations is an unmet need. We conducted a phase one study of lenalidomide in combination with cytarabine/idarubicin salvage chemotherapy in patients with R/R AML and high‐risk myelodysplastic syndromes. A total of 33 patients were enrolled in the study (30 AML, 3 MDS), and treated at three dose levels with 3 + 3 design. Dose‐limiting toxicity (DLT) was seen in eight patients, including four hematologic DLTs. The most commonly observed non‐hematologic serious adverse events were febrile neutropenia, rash, sepsis and renal injury. Dose level −1, consisting of 25 mg/d lenalidomide D1‐21, 1 g/m2 cytarabine D5‐8, and 8 mg/m2 idarubicin D5‐7 was determined to be the maximum tolerated dose. Note, 15/33 (45%) of patients were able to receive pre‐planned 21 days of lenalidomide. Overall, 18 patients achieved complete remission (CR) (n = 14) or CR with incomplete count recovery (CRi) (n = 4) with total CR/CRi rate of 56%. The 1‐year and 2‐year overall survival (OS) were 24% and 10%, respectively. Among responders, 10/18 underwent allogeneic HCT and had a 1‐year OS of 40%. There was no molecular pattern associated with response. These data demonstrate that the combination had clinical activity in R/R AML. This regimen should be further investigated for patients who relapsed after HCT, and as a bridge therapy to HCT. (ClinicalTrials.gov identifier: NCT01132586).
Whole genome sequence analysis identifies a PAX2 mutation to establish a correct diagnosis for a syndromic form of hyperuricemia
Authors: Stevenson Mark , Pagnamenta Alistair T. , Reichart Silvia , Philpott Charlotte , Lines Kate E. ,   OxClinWGS, Gorvin Caroline M. , Lhotta Karl , Taylor Jenny C. , Thakker Rajesh V.
Published: August 2020

Hereditary hyperuricemia may occur as part of a syndromic disorder or as an isolated nonsyndromic disease, and over 20 causative genes have been identified. Here, we report the use of whole genome sequencing (WGS) to establish a diagnosis in a family in which individuals were affected with gout, hyperuricemia associated with reduced fractional excretion of uric acid, chronic kidney disease (CKD), and secondary hyperparathyroidism, that are consistent with familial juvenile hyperuricemic nephropathy (FJHN). However, single gene testing had not detected mutations in the uromodulin (UMOD) or renin (REN) genes, which cause approximately 30–90% of FJHN. WGS was therefore undertaken, and this identified a heterozygous c.226G>C (p.Gly76Arg) missense variant in the paired box gene 2 (PAX2) gene, which co‐segregated with renal tubulopathy in the family. PAX2 mutations are associated with renal coloboma syndrome (RCS), which is characterized by abnormalities in renal structure and function, and anomalies of the optic nerve. Ophthalmological examination in two adult brothers affected with hyperuricemia, gout, and CKD revealed the presence of optic disc pits, consistent with optic nerve coloboma, thereby revising the diagnosis from FJHN to RCS. Thus, our results demonstrate the utility of WGS analysis in establishing the correct diagnosis in disorders with multiple etiologies.
Lifestyle, multi‐omics features, and preclinical dementia among Chinese: The Taizhou Imaging Study
Authors: Jiang Yanfeng , Cui Mei , Tian Weizhong , Zhu Sibo , Chen Jinhua , Suo Chen , Liu Zhenqiu , Lu Ming , Xu Kelin , Fan Min , Wang Jiucun , Dong Qiang , Ye Weimin , Jin Li , Chen Xingdong ,   the Taizhou Imaging Study Group
Published: August 2020

China has the largest number of patients with dementia in the world. However, dementia in the Chinese population is still poorly understood and under‐researched. Given the differences in genetic, demographic, sociocultural, lifestyle, and health profiles among Chinese and other ethnic/racial groups, it is crucial to build appropriate infrastructure for long‐term longitudinal studies to advance Chinese cognitive aging and dementia research. We initiated a community‐based prospective cohort—the Taizhou Imaging Study (TIS)—to accelerate the understanding of dementia and cerebrovascular diseases in Chinese. This article presents the rationale, aims, study design, and organization of TIS. In addition, we described some examples of the types of studies such a resource might support. The TIS provides a new framework for facilitating Chinese dementia research, encompassing invaluable resources including detailed epidemiological, sociocultural, neuroimaging, and omics data.