bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and fabrication of electro‐conductive polymer nanocomposites with mechanical and thermal resistance
Authors: Batool Maria , Nadeem QuratulAin , Gill Rohama , Nadeem Raziya
Published: May 2018

The commencement of the industrial revolution paved the way for the fabrication of flexible polymers with high‐strength metalloceramics as novel materials of all kinds. Fabricating metal–ceramic/polymer conductive composites is one such dimension followed for the present research work making use of the properties of the three components. Electroless deposition, for permanent metallic coating, was performed to coat Al2O3 with metallic Cu followed by the inclusion of the Cu–Al2O3 filler into a poly(vinyl chloride) (PVC) matrix. X‐ray diffraction and energy‐dispersive X‐ray studies predicted a prominent growth of metallic Cu crystallites onto Al2O3 with an increased average size and variation in elemental composition, respectively, when compared to pristine Al2O3. Morphological behaviour via scanning electron microscopy also envisioned uniform Cu coating onto Al2O3 and a homogeneous dispersion throughout the polymer matrix. When incorporated into PVC, electrical conductivity analysis highlighted a distinct variation in composite phases from insulating (7.14 × 10−16 S cm−1) to semiconducting behaviour (8.33 × 10−5 S cm−1) as a function of Cu–Al2O3 filler. Mechanical behaviour (tensile strength, Young's modulus and elongation at break) and thermal properties of the prepared composites also indicated a substantial improvement in material strength with Cu–Al2O3 incorporation. The enhanced electrical conductivity along with improved thermomechanical status with significant filler–matrix interaction permits the potential usage of such novel composites in a range of state‐of‐the‐art semiconducting electronic devices. © 2018 Society of Chemical Industry
Coumarins: Spectroscopic measurements and first principles calculations of C4‐substituted 7‐aminocoumarins
Authors: Singh Shraddha , Begoyan Vagarshak V. , Tanasova Marina , Waters Kevin , Seel Max , Pandey Ravindra
Published: May 2018

Coumarins are widely applied in sensing devices due to their diverse fluorescence properties. In this paper, we consider the C4‐substituted 7‐aminocoumarins to investigate the structure‐property relationship via examining the effect of the various substitutions on their optical properties. Absorption and fluorescence measurements together with time‐dependent density functional theory calculations are described. We find that the significant red shift in the fluorescence spectra is associated with the cyclic carbonyl group of coumarins due to a substantial increase in the dipole moment in the photoexcited state. The apparent correlation between experimental and calculated results provides an atomistic‐level insight into the role of the functionality at the C4 of coumarins and sets the basis for using computational analysis to predict the fluorescence properties of coumarins.
On the origin and consequences of high DMAEMA reactivity ratio in ATRP copolymerization with MMA: An experimental and theoretical study#
Authors: Mella Massimo , La Rocca Mario Vincenzo , Miele Ylenia , Izzo Lorella
Published: May 2018

Designing and tuning a copolymerization process to obtain specific material properties is still fundamentally empirical and requires the determination of apparent reactivity ratiosrs. To this end, PEG–(MMA–DMAEMA)ncopolymers obtained via ATRP of MMA and DMAEMA using a PEG‐based initiator in toluene were analyzed to extract monomer relative reactivities; the impact of changing solvent on the latter was also tested. Differing from previous free radical and controlled radical copolymerizations (CRcoP), we found that DMAEMA is preferentially included (and) in toluene; increasing the solvent polarity decreased the gap betweenrs. With these data, kMC simulations based on the copolymerizationterminal modelwere used to investigate copolymer microstructure, which is not amenable to NMR investigation. kMC simulations evidenced both a gradient‐like nature of the copolymers and a somewhat unexpected qualitative change in the probability of finding MMA‐rich triads along the chain depending on initial feed composition. An additional DFT analysis suggested the likely formation of a DMAEMA:CuBr:2‐2′‐bipyridine complex, which being involved in the regeneration of reactive radicals from dormant species, is expected to locally increase DMAEMA concentration favoring its addition to the growing chains. The formation of such complex is also supported by1H‐NMR experiments. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2018,56, 1366–1382
Development of a 3D Light Scattering Sensor for Online Characterization of Aerosol Particles
Authors: Pitz Michael , Hellmann Albert , Ripperger Siegfried , Antonyuk Sergiy
Published: May 2018

The measurement of the shape, surface, and aggregate structure of solid particles on the micro and nanoscale become even more important for the design and characterization of products and processes. Currently, these properties are determined offline via imaging techniques such as scanning electron microscope or transmission electron microscope. This requires a suitable sampling, and the subsequent workup and analysis step is very costly and time consuming. Therefore, a suitable measurement technology is required, which is able to capture the properties online. In this work, a novel sensor system based on the principle of elastic light scattering of particles in the gas phase is developed and described. Here, the single particles of an aerosol stream are illuminated by monochromatic laser light and the scattered light intensity is measured with high temporal resolution at several points around the particles. The measured data is evaluated and used to obtain certain particle properties such as size, sphericity, and fractal dimension. The modular setup of the sensor is suitable for the adaption to different measuring tasks. In addition to the detailed description of the design of the developed system, first measurements on polystyrene latex monospheres are presented.
Host and environmental factors influencing ‘Candidatus Liberibacter asiaticus’ acquisition in Diaphorina citri
Authors: Wu Fengnian , Huang Jiaquan , Xu Meirong , Fox Eduardo G P , Beattie G Andrew C , Holford Paul , Cen Yijing , Deng Xiaoling
Published: May 2018

Background

Diaphorina citri is a vector of ‘Candidatus Liberibacter asiaticus’ (CLas) associated with citrus Huanglongbing. In this study, the infection and titers of CLas in the psyllid, were monitored for life cycle stage, sex, host‐plant CLas titer, host‐plant genotype, and ambient temperature.

Results

Acquisition efficiency of CLas by D. citri was highest in nymphs reared at 25 °C on a host plant with high CLas titers but was independent of the host genotypes assessed and of vector sex. We further observed that D. citri nymphs acquired CLas more rapidly than adults based on acquisition access periods (AAPs). CLas did not multiply in the alimentary canal, hemolymph, and salivary glands of adults for 18 days after a 3‐day AAP as adult. However, CLas multiplication was detected in hemolymph and salivary gland of adults after the bacterium was acquired by nymphs. Eighty percent of salivary glands of adults contained CLas 18 days after a 3‐day AAP as nymph compared to 10% 18 days after a 3‐day AAP as adults.

Conclusion

Different factors tested herein influenced CLas acquisition efficiency of D. citri, CLas multiplication and spread inside the psyllid. These observations serve to better understand mechanisms of CLas infection in D. citri. © 2018 Society of Chemical Industry
Design and inference for 3‐stage bioequivalence testing with serial sampling data
Authors: Yan Fangrong , Zhu Huihong , Liu Junlin , Jiang Liyun , Huang Xuelin
Published: May 2018

A bioequivalence test is to compare bioavailability parameters, such as the maximum observed concentration (Cmax) or the area under the concentration‐time curve, for a test drug and a reference drug. During the planning of a bioequivalence test, it requires an assumption about the variance of Cmax or area under the concentration‐time curve for the estimation of sample size. Since the variance is unknown, current 2‐stage designs use variance estimated from stage 1 data to determine the sample size for stage 2. However, the estimation of variance with the stage 1 data is unstable and may result in too large or too small sample size for stage 2. This problem is magnified in bioequivalence tests with a serial sampling schedule, by which only one sample is collected from each individual and thus the correct assumption of variance becomes even more difficult. To solve this problem, we propose 3‐stage designs. Our designs increase sample sizes over stages gradually, so that extremely large sample sizes will not happen. With one more stage of data, the power is increased. Moreover, the variance estimated using data from both stages 1 and 2 is more stable than that using data from stage 1 only in a 2‐stage design. These features of the proposed designs are demonstrated by simulations. Testing significance levels are adjusted to control the overall type I errors at the same level for all the multistage designs.
Flavonoids from Boldoa purpurascens inhibit proinflammatory cytokines (TNF‐α and IL‐6) and the expression of COX‐2
Authors: González Mosquera D.M. , Hernández Ortega Y. , Fernández P.L. , González Y. , Doens D. , Vander Heyden Y. , Foubert K. , Pieters L.
Published: May 2018

The flavonoids comprise a large class of plant metabolites distributed in food plants. These compounds have antioxidant, antitumor, antiallergic, and anti‐inflammatory effects. The molecular mechanisms of their biological activities remain to be clearly understood. We investigated the in vitro anti‐inflammatory potential of a flavonoid mixture and isolated compounds from the leaves of Boldoa purpurascens. Our results provide direct evidence of the anti‐inflammatory effects of the mixture, which are mediated by the inhibition of the proinflammatory cytokines tumor necrosis factor α and interleukin 6 as well as the modulation of the expression of cyclooxygenase 2.
The nature of the chemical bond in borazine (B3N3H6), boroxine (B3O3H3), carborazine (B2N2C2H6), and related species
Authors: Kalemos Apostolos
Published: May 2018

The bonding problem in borazine (B3N3H6), boroxine (B3O3H3), and carborazine (B2N2C2H6) is successfully addressed through the consideration of the excited states of the constituent fragments, namely BH(
), NH(
), and CH(
). We propose the participation of resonant structures for all three species that help to explain the experimental findings. A discussion on the chemical pattern of the parental molecule benzene (C6H6) helps to make coherent the whole bonding analysis on the titled species.
Salt‐Induced Microstructural Transitions in Aqueous Dispersions of Ionic‐Liquids‐Based Surfactants
Authors: Vaid Zuber S. , Rajput Sargam M. , Shah Ankit , Kadam Yogesh , Kumar Arvind , El Seoud Omar A. , Mata Jitendra P. , Malek Naved I.
Published: May 2018

Applicability and performance ability of the surfactants are controlled through their aggregation behavior, which are modulated by employing external additives. In order to achieve favorable shape and sized nano‐aggregates, we have investigated the role of structure making hydrotop; sodium salicylate (NaSal) on the micellar transition of the functionalized and non‐functionalized ionic liquid based surfactants (ILBSs) (1‐hexadecyl‐3‐vinylimidazolium bromide and 1‐hexadecyl‐3‐methylimidazolium bromide) in aqueous medium. The micelle to vesicle transitions in the studied systems is explored using viscosity, dynamic light scattering and transmission electron microscopy measurements. For the first time we report the nano and micro‐structural aggregates of the vinylfunctionalized ILBSs with respect to the composition, and concentration of the additives; alkyl chain length and head group of ILBSs. Transmissions electron microscopy (TEM) revealed the formation of vesicles at high concentration of NaSal (∼1000 mM) for the vinylfunctionalized ILBS.
A Ligand/Additive/Base‐Free C(sp2)‐H Activation and Isocyanide Insertion in PEG‐400: Synthesis of Indolizine/Imidazoline‐Fused Heterocycles
Authors: Kumar K. Shiva , Rajesham Bandari , Kumar N. Praveen , Ramulu Meesa Siddi , Dandela Rambabu
Published: May 2018

A ligand/base/metal oxidant free Pd‐catalyzed C(sp2)–H activation, followed by isocyanide insertion to synthesize indolizine/imidazoline fused heterocyclics in PEG‐400 as a recyclable solvent. The present transformation is greener and an efficient strategy using oxygen as external oxidant. The spectroscopic properties of selected indolizine/imidazoline fused heterocyclics were studied by UV−visible and fluorescence spectroscopy.
Visualizing Oxidative Cellular Stress Induced by Nanoparticles in the Subcytotoxic Range Using Fluorescence Lifetime Imaging
Authors: Balke Jens , Volz Pierre , Neumann Falko , Brodwolf Robert , Wolf Alexander , Pischon Hannah , Radbruch Moritz , Mundhenk Lars , Gruber Achim D. , Ma Nan , Alexiev Ulrike
Published: May 2018

Nanoparticles hold a great promise in biomedical science. However, due to their unique physical and chemical properties they can lead to overproduction of intracellular reactive oxygen species (ROS). As an important mechanism of nanotoxicity, there is a great need for sensitive and high‐throughput adaptable single‐cell ROS detection methods. Here, fluorescence lifetime imaging microscopy (FLIM) is employed for single‐cell ROS detection (FLIM‐ROX) providing increased sensitivity and enabling high‐throughput analysis in fixed and live cells. FLIM‐ROX owes its sensitivity to the discrimination of autofluorescence from the unique fluorescence lifetime of the ROS reporter dye. The effect of subcytotoxic amounts of cationic gold nanoparticles in J774A.1 cells and primary human macrophages on ROS generation is investigated. FLIM‐ROX measures very low ROS levels upon gold nanoparticle exposure, which is undetectable by the conventional method. It is demonstrated that cellular morphology changes, elevated senescence, and DNA damage link the resulting low‐level oxidative stress to cellular adverse effects and thus nanotoxicity. Multiphoton FLIM‐ROX enables the quantification of spatial ROS distribution in vivo, which is shown for skin tissue as a target for nanoparticle exposure. Thus, this innovative method allows identifying of low‐level ROS in vitro and in vivo and, subsequently, promotes understanding of ROS‐associated nanotoxicity.
A Novel 2-Phenylamino-Quinazoline-Based Compound Expands the Neural Stem Cell Pool and Promotes the Hippocampal Neurogenesis and the Cognitive Ability of Adult Mice
Authors: Lu Hui , Cheng Gang , Hong Feng , Zhang Lei , Hu Youhong , Feng Linyin
Published: May 2018

The adult neurogenesis occurs throughout the life of the mammalian hippocampus and is found to be essential for learning and memory. Identifying new ways to manipulate the number of neural stem cells (NSCs) and enhance endogenous neurogenesis in adults is very important. Here we found that a novel compound, N2-(4-isopropylphenyl)-5-(3-methoxyphenoxy)quinazoline-2,4-diamine (code-named Yhhu-3792), enhanced the self-renewal capability of NSCs in vitro and in vivo. In vitro, Yhhu-3792 increased the ratio of 5-Bromo-2-deoxyuridine+/4′-6-diamidino-2-phenylindole+ embryonic NSCs and accelerated the growth of neurospheres significantly. We demonstrated that Yhhu-3792 activated Notch signaling pathway and promoted the expression of Notch target genes, Hes3 and Hes5. And the Notch signaling inhibitor DAPT could inhibit its function. Thus, we concluded Yhhu-3792 increased the number of embryonic NSCs via activating the Notch signaling pathway. We measured the effect of Yhhu-3792 on epidermal growth factor receptor signaling, which demonstrated Yhhu-3792 act via a different mechanism with the quinazoline parent chemical group. In the eight-week-old male C57BL/6 mice, chronic Yhhu-3792 administration expanded the NSCs pool and promoted endogenous neurogenesis in the hippocampal dentate gyrus (DG). It also increased the spatial and episodic memory abilities of mice, when evaluated with the Morris water maze and Fear conditioning tests. In conclusion, Yhhu-3792 could be a novel drug candidate to promote the self-renew of NSCs and adult neurogenesis. And it may have therapeutic potential in the impairment of learning and memory associated DG dysfunction.
Differential Regulation of Human Bone Marrow Mesenchymal Stromal Cell Chondrogenesis by Hypoxia Inducible Factor-1α Hydroxylase Inhibitors
Authors: Taheem Dheraj K. , Foyt Daniel A. , Loaiza Sandra , Ferreira Silvia A. , Ilic Dusko , Auner Holger W. , Grigoriadis Agamemnon E. , Jell Gavin , Gentleman Eileen
Published: May 2018

The transcriptional profile induced by hypoxia plays important roles in the chondrogenic differentiation of marrow stromal/stem cells (MSC) and is mediated by the hypoxia inducible factor (HIF) complex. However, various compounds can also stabilize HIF's oxygen-responsive element, HIF-1α, at normoxia and mimic many hypoxia-induced cellular responses. Such compounds may prove efficacious in cartilage tissue engineering, where microenvironmental cues may mediate functional tissue formation. Here, we investigated three HIF-stabilizing compounds, which each have distinct mechanisms of action, to understand how they differentially influenced the chondrogenesis of human bone marrow-derived MSC (hBM-MSC) in vitro. hBM-MSCs were chondrogenically-induced in transforming growth factor-β3-containing media in the presence of HIF-stabilizing compounds. HIF-1α stabilization was assessed by HIF-1α immunofluorescence staining, expression of HIF target and articular chondrocyte specific genes by quantitative polymerase chain reaction, and cartilage-like extracellular matrix production by immunofluorescence and histochemical staining. We demonstrate that all three compounds induced similar levels of HIF-1α nuclear localization. However, while the 2-oxoglutarate analog dimethyloxalylglycine (DMOG) promoted upregulation of a selection of HIF target genes, desferrioxamine (DFX) and cobalt chloride (CoCl2), compounds that chelate or compete with divalent iron (Fe2+), respectively, did not. Moreover, DMOG induced a more chondrogenic transcriptional profile, which was abolished by Acriflavine, an inhibitor of HIF-1α-HIF-β binding, while the chondrogenic effects of DFX and CoCl2 were more limited. Together, these data suggest that HIF-1α function during hBM-MSC chondrogenesis may be regulated by mechanisms with a greater dependence on 2-oxoglutarate than Fe2+ availability. These results may have important implications for understanding cartilage disease and developing targeted therapies for cartilage repair.
Regulation of Eclipta prostrata L. components on cigarette smoking‐induced autophagy of bronchial epithelial cells via keap1‐Nrf2 pathway
Authors: Ding Shumin , Hou Xuefeng , Wang Fujing , Wang Gang , Tan Xiaobin , Liu Ying , Zhou Yuanli , Qiu Huihui , Sun E. , Jiang Nan , Li Zihao , Song Jie , Feng Liang , Jia Xiaobin
Published: May 2018

Cigarette smoking extract (CSE)‐induced autophagic injury has been regarded as an important contributor to the pathogenesis of lung cancer. We previously found that Eclipta prostrata L. component (CCE) reduced CSE‐induced bronchial epithelial cells damage. However, the mechanism remains unknown. Human normal bronchial epithelial cells (NHBE) were exposed to CSE to establish stress model. Nrf2‐siRNA and Keap1‐siRNA transfection were performed. mRFP‐GFP‐LC3 dual fluorescence and transmission electron microscopy were used to observe the autophagic characteristics. CCE prevented CSE‐induced Nrf2 transfer into cytoplasm and up‐regulated Keap1 level of NHBE cells. Furthermore, CCE significantly increased p‐p16, p‐p21 and p‐p53 phosphorylation levels in Nrf2‐siRNA‐ or Keap1‐siRNA‐transfected cells. As demonstrated by transmission electron microscopy and mRFP‐GFP‐LC3 dual fluorescence assays, CCE mitigated autophagic injury, and also down‐regulated autophagy‐related Beclin‐1, LC3II/LC3I ratio, Atg5 and ATF4 levels. Our findings showed the attenuation of CCE on CSE‐induced NHBE cells injury was associated with Nrf‐2‐mediated oxidative signaling pathway.
Re: Maternal hemodynamics in normal pregnancy: reference ranges and role of maternal characteristics. D. Vinayagam, B. Thilaganathan, O. Stirrup, E. Mantovani and A. Khalil. Ultrasound Obstet Gynecol 2018; 51: 665–671.
Authors: Germanakis I.
Published: May 2018

Linked Comment: Ultrasound Obstet Gynecol 2018; 51: 665–671
On the BV formalism of open superstring field theory in the large Hilbert space
Authors: Matsunaga Hiroaki , Nomura Mitsuru
Published: May 2018

Abstract

We construct several BV master actions for open superstring field theory in the large Hilbert space. First, we show that a naive use of the conventional BV approach breaks down at the third order of the antifield number expansion, although it enables us to define a simple “string antibracket” taking the Darboux form as spacetime antibrackets. This fact implies that in the large Hilbert space, “string fields-antifields” should be reassembled to obtain master actions in a simple manner. We determine the assembly of the string anti-fields on the basis of Berkovits’ constrained BV approach, and give solutions to the master equation defined by Dirac antibrackets on the constrained string field-antifield space. It is expected that partial gauge-fixing enables us to relate superstring field theories based on the large and small Hilbert spaces directly: reassembling string fields-antifields is rather natural from this point of view. Finally, inspired by these results, we revisit the conventional BV approach and construct a BV master action based on the minimal set of string fields-antifields.
Is Intraoperative Blood Loss Underestimated in Patients Undergoing Laparoscopic Hepatectomy?
Authors: Tomimaru Yoshito , Noguchi Kozo , Morita Shunji , Imamura Hiroshi , Iwazawa Takashi , Dono Keizo
Published: May 2018

Background

Less intraoperative blood loss is frequently reported as an advantage of laparoscopic hepatectomy (LH) over open hepatectomy (OH). However, the small work space during laparoscopic surgery could lead to insufficient blood suction from the abdominal cavity, with possible underestimation of intraoperative blood loss. This study compared estimated blood loss (E‐BL) with intraoperatively counted blood loss (IC‐BL) in patients undergoing LH.

Methods

This study included 110 consecutive patients undergoing partial hepatectomy for solitary liver tumors (59 had OH and 51 had LH). IC‐BL and E‐BL were determined, and the difference between them was calculated based on the surgical approach. Factors affecting the difference were investigated. IC‐BL was quantified from the suction fluid volume and weight of surgical gauzes used for blood and fluid collection. E‐BL was calculated with the total blood volume and change in hematocrit.

Results

Although there were no significant differences between IC‐BL and E‐BL in the OH group (292 ± 198 vs. 259 ± 167 mL, p = 0.1239), E‐BL was significantly greater than IC‐BL in the LH group (273 ± 166 vs. 128 ± 177 mL, p < 0.0001). Percentage of patients with E‐BL > IC‐BL in the LH group was significantly greater than in the OH group (86.3 vs. 42.4%, p < 0.0001). The surgical approach (OH/LH) was the only significant independent factor determining E‐BL > IC‐BL status.

Conclusions

E‐BL was significantly greater than IC‐BL only in patients undergoing LH, and the surgical approach (OH/LH) was the only factor affecting E‐BL > IC‐BL status. These results suggest that intraoperative blood loss may be underestimated during LH.
Implementation of new hybrid lightweight cryptosystem
Authors: Thorat C.G. , Inamdar V.S.
Published: May 2018

Embedded systems, Internet of Things (IoT) and mobile computing devices are used in various domains which include public-private infrastructure, industrial installation and critical environment. Generally, information handled by these devices is private and critical. Therefore, it must be appropriately secured from different attacks and hackers. Lightweight cryptography is an aspiring field which investigates the implementation of cryptographic primitives and algorithms for resource constrained devices. In this paper, a new compact hybrid lightweight encryption technique has been proposed. Proposed technique uses the fastest bit permutation instruction PERMS with S-box of PRESENT block cipher for non-linearity. An arbitrary n-bit permutation is performed using PERMS instruction in less than log (n) number of instructions. This new hybrid system has been analyzed for software performance on Advanced RISC Machine (ARM) and Intel processor whereas Cadens tool is used to analyze the hardware performance. The result of the proposed technique is improved by the factor of eight as compared to the PRESENT-GRP hybrid block cipher. Moreover, PERMS instruction bit permutation properties result a very good avalanche effect and compact implementation in the both hardware and software environment.
Obstetric and perinatal health outcomes related to schizophrenia: A national register-based follow-up study among Finnish women born between 1965 and 1980 and their offspring
Authors: Simoila Laura , Isometsä Erkki , Suvisaari Jaana , Halmesmäki Erja , Lindberg Nina
Published: May 2018

Background:

This national register-based study assesses obstetric and perinatal health outcomes in women with schizophrenia and their offspring.

Methods:

Using the Care Register for Health Care, we identified Finnish women who were born in 1965- 1980 and diagnosed with schizophrenia. For each case, five age- and place-of-birth- matched controls were obtained from the Central Population Register of Finland. They were followed from the day when the disorder was diagnosed in specialized health-care (the index day) until 31.12.2013. Information related to births was obtained from the Medical Birth Register and the Register of Congenital Malformations. We focused on singleton pregnancies that led to a delivery after the index day. We restricted the analysis of deliveries in controls to those that occurred after the index day of the case. Maternal age, marital status, smoking status, sex of the newborn, and parity were used as covariates in adjusted models.

Results:

We identified 1162 singleton births among women with schizophrenia and 4683 among controls. Schizophrenic women had a 1.4-fold increased risk of induction of labor, delivery by cesarean section, and delivery by elective cesarean section. Regarding offspring, the risk of premature birth and the risk of low Apgar score at 1 min (<7) were 1.6-fold, of resuscitation 2.5-fold, and of neonatal monitoring 2.1-fold higher.

Conclusions:

Schizophrenia associates with some specific delivery methods, but delivery complications are rare and their prevalence does not differ from that observed among community women. Maternal schizophrenia associates with some negative perinatal health outcomes of the offspring.
Geometrical structure analysis of a zero-pressure-gradient turbulent boundary layer
Authors: Li Weipeng , Wang Lipo
Published: May 2018

The present work focuses on the geometrical features of a zero-pressure-gradient turbulent boundary layer based on vectorline segment analysis. In a turbulent vector field, tracing from any non-singular point, along either the vector or the inverse direction, one will reach a local extremum of the vector magnitude. The vectorline between the two local extrema is defined as the vectorline segment corresponding to the given spatial point. Specifically the vectorline segment can be the streamline segment for the velocity vector case, or the vorticity line segment for the vorticity vector case. Such a quantitatively defined and space-filling vectorline segment structure reflects the natural vectorial topology. Because of inhomogeneity in the wall-normal direction, vectorline segments corresponding to the grid points at specified wall-normal distances are sampled for statistics. For streamline segments, the probability density function (p.d.f.) of the normalized segment length in different flow regions matches a model solution, and for vorticity line segments such a p.d.f. in the log-law region and beyond matches the same model solution, which indicates some universality of different flow regions and different vector field structures. Typically the joint p.d.f. of the characteristic parameters of streamline segments presents clear asymmetry, which is closely related to the skewness of the velocity derivative. Moreover, the orientation statistics of vectorline segments, characterized by the coordinate difference between the segment starting point and ending point, have been provided to quantify the flow anisotropy.
The Charismatic Corporation: Finance, Administration, and Shop Floor Management under Henry Ford
Authors: Link Stefan
Published: May 2018

After assuming sole ownership of the Ford Motor Company in 1919, Henry Ford transformed his business into a mission-driven organization that prioritized improvements in production and engineering over investment returns. At the same time, the company programmatically rejected bureaucratic management in favor of informal procedures and ingrained collective protocols, both in administration and on the shop floor. This article references Max Weber's view of “charismatic” authority to explain the company’s organizational structure, its culture, its ambivalence toward Henry Ford’s worst tendencies and prejudices, and its resilience during the decline of his leadership in the 1930s and 1940s.
TheNegro Digest: Race, Exceptionalism and the Second World War
Authors: GRANT NICHOLAS
Published: May 2018

This article examines the border-crossing journalism of theNegro Digest, a leading African American periodical, published from 1942 to 1951. The first title produced by the Johnson Publishing Company, theDigesthad an international focus that connected Jim Crow to racial oppression around the world. However, while the magazine challenged white supremacy on a local and global level, its patriotic tone and faith in American democracy occasionally restricted its global analysis of racism. Ultimately, the internationalism of theNegro Digestwas quintessentially American – wedded to the exceptional status of American freedom and an overriding belief that the US could change the world for the better.
Automatic Acquisition and Image Analysis of 2D Crystals
Authors: Coudray N , Beck F , Buessler J-L , Korinek A , Karathanou A , Rémigy H , Kihl H , Engel A , Plitzko JM , Urban J-P
Published: May 2018

2D-crystallization in combination with transmission electron microscopy (TEM) is one of the few methods for the structural analysis of membrane proteins in their native state. However, the parameters for the generation of large crystalline sheets are typically difficult to identify for a given protein. Many repetitive and time consuming screening steps by TEM are therefore necessary to find the best crystallization and preparation conditions. Although several software packages offer the possibility to control an electron microscope, none is completely adapted for a fully automated and completely integrated acquisition and analysis of 2D crystals. Here we report on the development of a fully automatic screening and on-line analysis software for the fast and automatic survey of large quantities of negatively stained EM samples for 2D crystallography.
Improving EDS For Low Energy X-Rays Under 1000eV Using an Attachable Detector Optic
Authors: O’Hara David , Brown Greg , Lochner Eric
Published: May 2018

Although considerable advances have been made in Energy Dispersive Detectors for microanalysis, low energy analysis under 1000eV is still relatively poor due to detector response and inefficient production of low energy x-rays. X-ray optics fabrication methods by O’Hara and measurements by McCarthy et. al. indicated that it should be possible to fabricate x-ray optics that could be used to significantly increase the low energy x-ray flux seen by an EDS detector without increasing the beam current. Such an optic would be useful to increase low energy counts without moving the detector closer, which would simply increase the high energy counts and dead time.
Extending Depth of Field in LC-SEM Scenes by Partitioning Sharpness Transforms
Authors: Hariharan H , Koschan A , Abidi B , Page D , Abidi M , Frafjord J , Dekanich S
Published: May 2018

When imaging a sample, it is desirable to have the entire area of interest in focus in the acquired image. Typically, microscopes have a limited depth of field (DOF) and this makes the acquisition of such an all-in-focus image difficult. This is a major problem in many microscopic applications and applies equally in the realm of scanning electron microscopy as well. In multifocus fusion, the central idea is to acquire focal information from multiple images at different focal planes and fuse them into one all-in-focus image where all the focal planes appear to be in focus.Large chamber scanning electron microscopes (LC-SEM) are one of the latest members in the SEM family that has found extensive use for nondestructive evaluations. Large objects (~1 meter) can be scanned in micro- or nano-scale using this microscope. An LC-SEM can provide characterization of conductive and non-conductive surfaces with a magnification from 10× to 200,000×. The LC-SEM, as with other SEMs, suffers from the problem of limited DOF making it difficult to inspect a large object while keeping all areas in focus.
A Simple Method for Imaging DNA using SEM
Authors: Chatterjee N , Andresen K , Thomas M , Pollack L , Kirkland E
Published: May 2018

The intricate relationship between molecular structure and function is a common theme in molecular biology. Visualizing the structure of biological macromolecules through imaging is therefore useful in understanding their varied biological roles. The process is often complex; imaging in a high voltage Transmission Electron Microscope (TEM) involves extensive staining and freezing. The aim of this experiment was to image DNA easily in a close to natural environment in a simple microscope. Samples were imaged using a Leo (Zeiss) 1550 Scanning Electron Microscope (SEM) with a Schottky field emitter in the 15-30kV range to reduce radiation damage. After imaging off-the-shelf DNA, two more DNA samples were dialyzed with RbCl and NaCl and imaged to elucidate what made the DNA visible.
Electron Microscopy Vacuum Pump Basics
Authors: Tring Howard
Published: May 2018

The fact that the machinery is “behind the wall” or out of sight may mean that it is not being looked after as well as it should. Do you have a regular schedule to check the vacuum pumps and accessories in your microscopy lab, or do you wait till it fails? Do you keep a service record of the repairs done to your vacuum pumps and the vacuum levels measured after each service? In a department where there are instruments that last ten years or more and the operators and technicians regularly change it makes good sense to keep a record of the vacuum pumps oil changes, service and performance.
Quick Sample Preparation and EFTEM Elemental Characterization of FAB Based Defects
Authors: Schamp CT , Valdez BT , Gazda J
Published: May 2018

A purpose of microscopy is to magnify and enhance contrast between different regions of a sample, whether those regions may be different structures, different orientations of the same structure, regions of different atomic weight, or different chemistries. In the present case, elemental mapping in the energy filtered transmission electron microscope (EFTEM) is used to enhance contrast between elements in an apparent bundle of fibers previously seen through scanning electron microscopy (SEM) and a particle that appears to be a catalytic source for the fibers.
Comparing Binary Image Analysis Measurements - Euclidean Geometry, Centroids and Corners
Authors: Hetzner Dennis W
Published: May 2018

During the past several years, ASTM Subcommittee E04.14 on Quantitative Metallography has been developing an Image Analysis (I/A) methodology to determine the degree of circularity, roundness or sphericity of graphite nodules in ductile cast iron. In the as-polished condition, ideally the iron nodules should appear as dark circular objects in a light gray matrix, Figure 1. When performing Image Analysis measurements for these types of materials, complex gray image procedures should not be required to properly threshold the images to obtain an acceptable binary image on which to perform the measurements.
Microscopy and Microanalysis of Magmatic and Metamorphic Minerals – Part 1: Cordierite
Authors: Sturm Robert
Published: May 2018

Cordierite represents an orthorhombic (Mg,Fe)Al-silicate (Table 1) that is observed in a wide range of natural occurrences. As outlined in numerous mineralogical overviews published during the past decades, cordierite mainly crystallizes in thermally metamorphosed rocks, particularly in those derived from argillaceous sediments. Additionally, the mineral can be a major constituent of parageneses formed under high-grade regional metamorphism and therefore occurs in respective schists, gneisses and granulites. The metamorphic formation of cordierite is generally restricted to conditions of deficient or low shearing stress producing only moderate lithological pressures. With rising pressure due to transpression cordierite often breaks down to enstatite and sillimanite or, at higher temperature, to sapphirine and quartz (see also Fig. 5). Besides its crystallization in metamorphic rocks, cordierite is also found in specific igneous rocks like peraluminous granites and related high-grade anatectic terrains.
Nanotectonica: Architectural Design Studio and Table Top SEM
Authors: Coersmeier Jonas , Leonard Donovan N
Published: May 2018

Inspired by architect Frei Otto and design scientist Buckminster Fuller, third year Pratt Institute design students from Jonas Coersmeier’s design studio and research seminar (of Spring 2008) utilized a Table Top SEM to observe micro and nano-scale features produced solely by Mother Nature. After analyzing and documenting the intricacy, beauty and functionality of natural structures, students selected structural entities typically not observed on the macro scale, and utilized the micrograph data to generate analytical drawings followed by generative models for design of a large span structure that would become an aquatic center in the Williamsburg neighborhood of Brooklyn, N.Y.
Designing a Rate System for an Imaging Recharge Center
Authors: Sherman Debby
Published: May 2018

As you all know, recharge: the price or rate a microscopy facility charges others to use their instruments, is a big topic on the MSA listserver and everybody struggles with designing rate systems. My talk is geared to U.S. labs and a lot of our restrictions regarding rates are not the same in Canada or other countries around the world. Our goal is designing recharge systems that will encourage facility use that will also recover the cost of the operation. How much you have to recover depends on your particular operation, your administration, and institutional requirements.
Preparing Micrographs and Applying Scale Bars Using Adobe Photoshop Elements™
Authors: Lancelle Susan A
Published: May 2018

As part of our introductory Cell Biology course, our students acquire images through microscopes using consumer cameras with memory cards. They then transfer the images to a computer and prepare them using Adobe Photoshop Elements.™ An important part of this process is learning to apply a scale bar, which calibrates the specimen image. Photoshop Elements is a relatively cheap and widely available software package that easily accomplishes this task for anyone who is using a camera system or software that does not automatically apply a scale bar or calibration data to the image. The instructions and figures herein refer to Photoshop Elements version 4.0, but they apply to other versions of the software.
Reassessing Sea Ice Drift and Its Relationship to Long‐Term Arctic Sea Ice Loss in Coupled Climate Models
Authors: Tandon Neil F. , Kushner Paul J. , Docquier David , Wettstein Justin J. , Li Camille
Published: May 2018

Results of an earlier study suggest that sea ice drift in climate models is unrealistic, and this has undermined confidence in model projections of “long‐term” (i.e., secular) Arctic sea ice loss. We revisit this by analyzing 22 models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5). It is shown that, when consistent temporal sampling is applied, sea ice drift speed in models and observations come into closer agreement than previously suggested. There is still considerable intermodel scatter in climatological drift speed, and we show that much of this likely relates to prescribed parameters in the sea ice models. Since 1979, observations show a long‐term positive trend of annual mean Arctic average sea ice drift speed resulting primarily from sea ice thinning, and most of the CMIP5 models qualitatively reproduce this. The simulated annual mean drift speed trends reflect strong cancellation between winter trends (which are positive in most models and in good agreement with observations) and summer trends (which are negative in most models and in poor agreement with observations). Positive Arctic average drift speed trends do not consistently coincide with positive trends of Fram Strait outflow. The simulated regional relationship between sea ice strength and drift speed changes dramatically as the Arctic transitions from full to partial ice cover, and this “sea ice extent effect” likely influences simulated summer drift speed trends. Altogether, these results highlight aspects in which models show encouraging agreement with observations, while pinpointing aspects in which models require improvement.
Microphysical Properties of Tropical Tropopause Layer Cirrus
Authors: Woods Sarah , Lawson R. Paul , Jensen Eric , Bui T. P. , Thornberry Troy , Rollins Andrew , Pfister Leonhard , Avery Melody
Published: May 2018

Pervasive cirrus clouds in the tropical tropopause layer (TTL) play an important role in determining the composition of stratospheric air through dehydration of tropospheric air entering the stratosphere. This dehydration affects Earth's energy budget and climate, yet uncertainties remain regarding the microphysical processes that govern TTL cirrus. TTL cirrus were sampled with the NASA Global Hawk UAV for over 30 hr in the Western Pacific in 2014 during the Airborne Tropical TRopopause EXperiment. In situ measurements by a Fast Cloud Droplet Probe and Hawkeye probe (combination Fast Cloud Droplet Probe, Two‐Dimensional Stereo optical array probe, and Cloud Particle Imager) provided particle concentrations and sizing between 1‐ and 1,280‐μm diameter and high resolution images for habit identification. We present the variability in ice concentrations, size distributions, and habits as functions of temperature, altitude, and time since convective influence. Observed ice particles were predominantly small and quasi‐spheroidal in shape, with the percentage of quasi‐spheroids increasing with decreasing temperature. In comparison to the large fraction of the population consisting of quasi‐spheroids, faceted habits (columns, plates, rosettes, and budding rosettes) constituted a smaller percentage of the overall population and exhibited the opposite correlation with temperature. The trend of higher percentages of faceted crystals occurring at warmer temperatures may be due to diffusional growth or aggregation as particles descend through cloud, and/or the more rapid diffusional growth rate at warmer temperatures. Sampling was typically well away from deep convection, however, and very few aggregates were observed, so the trend of higher percentages of faceted habits is likely attributable to diffusional growth.
Improving Tropical Cyclone Predictions in the Gulf of Mexico
Authors: Cook Terri
Published: May 2018

The National Oceanic and Atmospheric Administration’s newest High Resolution Atmospheric Model captures the influence of intraseasonal oscillations on tropical cyclone activity.
Regional Distance PL Phase in the Crustal Waveguide—An Analog to the Teleseismic W Phase in the Upper‐Mantle Waveguide
Authors: Furumura Takashi , Kennett B. L. N.
Published: May 2018

Dense strong ground motion observations of the shallow Mw 6.6 2004 Mid‐Niigata earthquake, Japan, show a strong, moderately long‐period disturbance (5–20 s) immediately following P. The associated ground motion is as large or larger as that in the S waves and surface waves. The nature of this PL phase is revealed with the aid of 3‐D finite difference simulations for heterogeneous crust and mantle structures. A strong near‐field contribution at the nearest stations grades into an interference packet of multiple PmP waves beyond 100 km that develops normal dispersion with prograde motion. This partially trapped P wave in the crustal waveguide loses energy by conversion to SV at the surface, and these S waves are then lost to the mantle. However, the amplification of PL is strong in the presence of near‐surface low‐velocity sediments since conversion to S waves is weakened. The behavior of the PL phase in the crustal waveguide at regional distances is a direct analog of the well‐recognized W phase that travels in the upper‐mantle waveguide. The W phase is a very long period disturbance (100–1,000 s) between P and S phases that can travel to teleseismic distances (1,000–10,000 km) as a superposition of multiple reflections from the mantle that has widely been applied for rapid source inversion for large earthquakes. The PL‐W analogy gives the possibility to extend W‐phase type source inversion to much smaller events, exploiting the early arrival of PL to give rapid warning of damaging long‐period ground motion at regional distances carried by S and surface waves.
Characterizing Global Ozonesonde Profile Variability From Surface to the UT/LS With a Clustering Technique and MERRA‐2 Reanalysis
Authors: Stauffer Ryan M. , Thompson Anne M. , Witte Jacquelyn C.
Published: May 2018

Our previous studies employing the self‐organizing map (SOM) clustering technique to ozonesonde data have found significant links among meteorological and chemical regimes, and the shape of the ozone (O3) profile from the troposphere to the lower stratosphere. Those studies, which focused on specific northern hemisphere midlatitude geographical regions, demonstrated the advantages of SOM clustering by quantifying O3 profile variability and the O3/meteorological correspondence. We expand SOM to a global set of ozonesonde profiles spanning 1980 to present from 30 sites to summarize the connections among O3 profiles, meteorology, and chemistry, using the Modern‐Era Retrospective Analysis for Research and Applications, version 2 (MERRA‐2) reanalysis and other ancillary data. Four clusters of O3 mixing ratio profiles from the surface to the upper troposphere/lower stratosphere (UT/LS) are generated for each site, which show dominant profile shapes and typical seasonality (or lack thereof) that generally correspond to latitude (i.e., tropical, subtropical, midlatitude, and polar). Examination of MERRA‐2 output reveals a clear relationship among SOM clusters and covarying meteorological fields (geopotential height, potential vorticity, and tropopause height) for polar and midlatitude sites. However, these relationships break down within ±30° latitude. Carbon monoxide satellite data, along with velocity potential, a proxy for convection, calculated from MERRA‐2 wind fields assist characterization of the tropical and subtropical sites, where biomass burning and convective transport linked to the Madden‐Julian oscillation (MJO) dominate O3 variability. In addition to geophysical characterization of O3 profile variability, these results can be used to evaluate chemical transport model output and satellite measurements of O3 profiles.