bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacterial surface charge in “layers”: revealed by wash buffers of different ionic strength
Authors: Ng Wenfa
Published: January 2018

Bacterial surface charge derives its meaning from the cell’s environment such as the solution in contact with the cell. Determining the surface charge of bacteria in its native environment requires measuring the proxy variable, zeta potential, using cells obtained from field studies. However, lack of adequate cell mass and concerns over measurement of a mixed species consortia rather than a specific species meant that bacterial surface charge measurement require biomass obtained from pure culture. Often grown in rich medium where myriad proteins and ions nonspecifically adsorbed onto the cell envelope or peptidoglycan layer, standard procedures for preparing the cell mass incorporated repeated steps of washing and centrifugation with various wash buffers, the efficacies of which are poorly understood. This report describes the results of a systematic study on how wash buffers of different composition and ionic strength affect the efficiency of removing nonspecifically adsorbed biomolecules and ions from Escherichia coli DH5α (ATCC 53868) cultured aerobically (shake flask, 37 oC and 230 rpm) in LB Lennox medium with 2 g/L glucose and a formulated medium. Using zeta potential-pH profiles over pH 1 to 12 as readout, the results showed that efficiency of removing nonspecifically adsorbed ions and metabolites positively correlated with wash buffer ionic strength. More importantly, 0.15M ionic strength (i.e., 9 g/L NaCl) seemed to be the minimum below which there was incomplete removal of nonspecifically adsorbed biomolecules. On the other hand, high ionic strength of 0.6M (e.g., 0.1M sodium citrate) significantly changed the point of zero charge (pHzpc), a reference marker for removal of ions intrinsic to the cell envelope. Collectively, results obtained inform wash buffer choice with regards to preserving cell envelope integrity, and avoidance of adsorption of buffer ions such as citrate. But, is there a true cell surface charge? Yes, but how do we define it in number of “layers” of adsorbed biomolecules? Philosophically, cells in culture broth are coated with layers of metabolites, proteins and ions. Hence, desire to reveal the true surface charge is essentially a decoating process, where wash buffers of increasing ionic strength remove each layer via charge screening. However, where is the endpoint? This research offers a different perspective and answer. Imagine a single bacterium suspended in LB medium, where there is constant adsorption and desorption of biomolecules as the cell grows: what is its relevant surface charge? It is the one where the loosely associated ions and metabolites are removed while retaining the nonspecifically adsorbed ions and biomolecules. Thus, deionized water wash provides a good estimate of the bacterial surface charge as grown in specific medium.
The first report of the prevalence ofNosema ceranaein Bulgaria
Authors: Shumkova Rositsa , Georgieva Ani , Radoslavov Georgi , Sirakova Daniela , Dzhebir Gyulnas , Neov Boyko , Bouga Maria , Hristov Peter
Published: January 2018

Nosema apisandNosema ceranaeare the two main microsporidian parasites causing nosematosis in the honey beeApis mellifera. The aim of the present study is to investigate the presence ofNosema apisandNosema ceranaein the area of Bulgaria. The 16S (SSU) rDNA gene region was chosen for analysis. A duplex PCR assay was performed on 108 honey bee samples from three different parts of the country (South, North and West Bulgaria). The results showed that the samples from the northern part of the country were with the highest prevalence (77.2%) forNosema ceranaewhile those from the mountainous parts (the Rodopa Mountains, South Bulgaria) were with the lowest rate (13.9%). Infection withNosema apisalone and co-infectionN. apis/N. ceranaewere not detected in any samples. These findings suggest thatNosema ceranaeis the dominant species in the Bulgarian honey bee. It is not known when the introduction ofNosema ceranaein Bulgaria has occurred, but as in the rest of the world, this species has become the dominant one in BulgarianApis mellifera. In conclusion, this is the first report for molecular detection ofNosemainfection of honey bee in Bulgaria. The results showed thatN. ceranaeis the mainNosemaspecies in Bulgaria.
Analytic Theory of Equilibrium Fluvial Landscapes: The Integration of Hillslopes and Channels
Authors: Smith Terence R.
Published: January 2018

A physically based theory for equilibrium fluvial landscapes undergoing transport‐limited or detachment‐limited erosion is derived from equations for water flow, erosion, and hillslope stability. A scaling analysis of the equations identifies submodels for overland and channelized flows. The channel‐slope boundary (CSB) defines the interface between the two flow environments, marking the bifurcation of stable overland flows into unstable sheet flows and stable channel flows. The characteristics of CSBs are derived from an equilibrium condition of the hillslope submodel and stability conditions derived from the time‐dependent model. Equilibrium hillslopes are characterized by proportional flows of water and sediment, uniformly constant and maximum values of water flow (qc) and slope occurring on the CSB, and the minimization of a Lagrangian function of energy. Equilibrium solutions are readily derived for laminar overland flows. Power law sediment transport functions for channel flow lead to stable self‐similar solutions for channel segments characterized by realistic hydraulic geometries. Uniform equilibrium inflows qc result in straight segments of channel that are combinable into networks satisfying admissibility constraints. The aggregate length of CSB upstream of any network point determines total channel discharge and hence channel slope and elevation, providing boundary conditions that determine hillslope elevations. Large equilibrium landmasses with rainfall rate R have relatively uniform drainage densities
. Changes to channel networks induced by environmental fluctuations may occur at any network location because maximum, neutrally stable overland flows qc occur on the CSB. Stable equilibrium surfaces are conjectured to correspond to local minima of the Lagrangian over the space of admissible networks.
Climate Impacts in Europe Under +1.5°C Global Warming
Authors: Jacob Daniela , Kotova Lola , Teichmann Claas , Sobolowski Stefan P. , Vautard Robert , Donnelly Chantal , Koutroulis Aristeidis G. , Grillakis Manolis G. , Tsanis Ioannis K. , Damm Andrea , Sakalli Abdulla , van Vliet Michelle T. H.
Published: January 2018

The Paris Agreement of the United Nations Framework Convention on Climate Change aims not only at avoiding +2°C warming (and even limit the temperature increase further to +1.5°C), but also sets long‐term goals to guide mitigation. Therefore, the best available science is required to inform policymakers on the importance of and the adaptation needs in a +1.5°C warmer world. Seven research institutes from Europe and Turkey integrated their competencies to provide a cross‐sectoral assessment of the potential impacts at a pan‐European scale. The initial findings of this initiative are presented and key messages communicated. The approach is to select periods based on global warming thresholds rather than the more typical approach of selecting time periods (e.g., end of century). The results indicate that the world is likely to pass the +1.5°C threshold in the coming decades. Cross‐sectoral dimensions are taken into account to show the impacts of global warming that occur in parallel in more than one sector. Also, impacts differ across sectors and regions. Alongside the negative impacts for certain sectors and regions, some positive impacts are projected. Summer tourism in parts of Western Europe may be favored by climate change; electricity demand decreases outweigh increases over most of Europe and catchment yields in hydropower regions will increase. However, such positive findings should be interpreted carefully as we do not take into account exogenous factors that can and will influence Europe such as migration patterns, food production, and economic and political instability.
Alternative Palladium‐Catalyzed Vinylic C−H Difluoroalkylation of Ketene Dithioacetals Using Bromodifluoroacetate Derivatives
Authors: Tian Shuangquan , Song Xiaoning , Zhu Dongsheng , Wang Mang
Published: January 2018

A palladium‐catalyzed cross‐coupling of α‐oxo ketene dithioacetals and bromodifluoroacetate derivatives has been developed for the synthesis of a class of CF2‐containing tetra‐substituted olefins, which has potential to extend to drug design and material application. The process is proposed to involve two single electron transfer processes accompanied by an alternative loop from palladium(0) to palladium(I), likely due to unique structural properties of ketene dithioacetals with β,β‐dialkylthiol substituents on the olefin double bond.

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Interpenetrating Triphase Cobalt‐Based Nanocomposites as Efficient Bifunctional Oxygen Electrocatalysts for Long‐Lasting Rechargeable Zn–Air Batteries
Authors: Jiang Yi , Deng Ya‐Ping , Fu Jing , Lee Dong Un , Liang Ruilin , Cano Zachary Paul , Liu Yangshuai , Bai Zhengyu , Hwang Sooyeon , Yang Lin , Su Dong , Chu Weiguo , Chen Zhongwei
Published: January 2018

Rational construction of atomic‐scale interfaces in multiphase nanocomposites is an intriguing and challenging approach to developing advanced catalysts for both oxygen reduction (ORR) and evolution reactions (OER). Herein, a hybrid of interpenetrating metallic Co and spinel Co3O4 “Janus” nanoparticles stitched in porous graphitized shells (Co/Co3O4@PGS) is synthesized via ionic exchange and redox between Co2+ and 2D metal–organic‐framework nanosheets. This strategy is proven to effectively establish highways for the transfer of electrons and reactants within the hybrid through interfacial engineering. Specifically, the phase interpenetration of mixed Co species and encapsulating porous graphitized shells provides an optimal charge/mass transport environment. Furthermore, the defect‐rich interfaces act as atomic‐traps to achieve exceptional adsorption capability for oxygen reactants. Finally, robust coupling between Co and N through intimate covalent bonds prohibits the detachment of nanoparticles. As a result, Co/Co3O4@PGS outperforms state‐of‐the‐art noble‐metal catalysts with a positive half‐wave potential of 0.89 V for ORR and a low potential of 1.58 V at 10 mA cm−2 for OER. In a practical demonstration, ultrastable cyclability with a record lifetime of over 800 h at 10 mA cm−2 is achieved by Zn–air batteries with Co/Co3O4@PGS within the rechargeable air electrode.
Perthes disease: A new finding in Floating‐Harbor syndrome
Authors: Milani Donatella , Scuvera Giulietta , Gatti Marta , Tolva Gianluca , Bonarrigo Francesca , Esposito Susanna , Gervasini Cristina
Published: January 2018

Floating‐Harbor Syndrome (FHS; OMIM #136140) is an ultra‐rare autosomal dominant genetic condition characterized by expressive language delay, short stature with delayed bone mineralization, a triangular face with a prominent nose, and deep‐set eyes, and hand anomalies. First reported in 1973, FHS is associated with mutations in the SRCAP gene, which encodes SNF2‐related CREBBP activator protein. Mutations in the CREBBP gene cause Rubinstein‐Taybi Syndrome (RSTS; OMIM #180849, #613684), another rare disease characterized by broad thumbs and halluces, facial dysmorphisms, short stature, and intellectual disability, which has a phenotypic overlap with FHS. We describe a case of FHS associated with a novel SRCAP mutation and characterized by Perthes disease, a skeletal anomaly described in approximately 3% of patients with RSTS. Thus Perthes disease can be added to the list of clinical features that overlap between FHS and RSTS.
Computational Insights into the Reaction Mechanisms of Nickel‐Catalyzed Hydrofunctionalizations and Nickel‐Dependent Enzymes
Authors: Zhang Tonghuan , Zhang Xiaoyong , Chung Lung Wa
Published: January 2018

For several decades, transition‐metal catalysis has been a popular method for many functional group transformations in organic chemistry. Recent developments in sustainability and applications of earth‐abundant metals have resulted in a synthetic renaissance and have attracted considerable interest in less toxic and inexpensive first‐row transition‐metal catalysts such as nickel. Herein, we highlight some recent computational insights into the reaction mechanisms of Ni‐catalyzed hydrofunctionalizations (i.e., hydrogenation, hydrovinylation, hydroacylation, hydroheteroarylation, hydrosilylation, and hydroalkoxylation) and Ni‐dependent enzymes (i.e., lactate racemase, methyl‐CoM reductase, and [NiFe]‐hydrogenase). These computational studies provide insights into these reaction mechanisms and thus assist in the development and design of sustainable catalysts.
Copper‐Catalyzed Direct C−H Bond Arylation of Benzoxazoles with Anilines
Authors: Feng Pengju , Ma Guojian , Zhang Tianyu , Wang Changwei
Published: January 2018

An efficient and easily managed protocol was developed for the synthesis of 2‐aryl‐substituted benzoxazoles by using a copper‐catalyzed C−H arylation reaction between benzoxazole derivatives and in situ generated aryl diazonium salts. Under the optimized conditions, a wide variety of products were selectively obtained in moderate to good yields. Diphenylamine and 2,3′‐bipyridine were also obtained under the same reaction conditions by employing aniline and pyridin‐3‐amine, respectively, as the sole starting material.
Facile Syntheses, Characterization, and Physical Properties of Sulfur‐Decorated Pyran‐Annulated Perylene Diimides
Authors: Wang Ran , Li Gang , Zhou Yecheng , Hao Pin , Shang Qiaoyan , Wang Shuaihua , Zhang Yu , Li Dandan , Yang Shufan , Zhang Qichun , Shi Zhiqiang , Tang Bo
Published: January 2018

Three sulfur‐containing pyran‐annulated perylene diimides (PDIs) were synthesized from commercially available PDIs through a nucleophilic substitution/cyclization reaction sequence. The as‐synthesized compounds were fully characterized by 1H and 13C NMR, and FT‐IR spectroscopy, as well as HRMS and TGA. The as‐prepared PDI derivatives exhibited significantly narrow HOMO–LUMO band gaps and high photochemical and thermal stability. Moreover, these materials exhibited quite different absorptions and emissions in dichloromethane, which were in agreement with the DFT‐calculated results.
Palladium‐Catalyzed Regioselective Aromatic Extension of Internal Alkynes through a Norbornene‐Controlled Reaction Sequence
Authors: Zhao Qingyang , Fu Wai Chung , Kwong Fuk Yee
Published: January 2018

A regioselective aromatic π‐extension reaction of internal alkynes is reported. The proposed method employs three easily available components, namely aryl halides, 2‐haloarylcarboxylic acids, and disubstituted acetylenes. The transformation is driven by a controlled reaction sequence of C−H activation, decarboxylation, and annulation to give poly(hetero)aromatic compounds in a site‐selective fashion. Unlike in previously reported palladium‐catalyzed three‐component annulations, alkyne carbopalladation is the last step of this tandem reaction.
Interaction of Amino Acid Schiff Base Metal Complexes with DNA/BSA Protein and Antibacterial Activity: Spectral Studies, DFT Calculations and Molecular Docking Simulations
Authors: Neelakantan M.A. , Balamurugan K. , Balakrishnan Chithiraivel , Subha L.
Published: January 2018

Cu(II), Ni(II) and Zn(II) complexes of (E)‐2‐((2,4‐dihydroxybenzylidene)amino)‐3‐(1H‐indol‐3‐yl)propanoic acid Schiff base (L) were synthesized and characterized by various spectral methods. ESI‐MS was used to confirm the structure of synthesized compounds. Molecular geometries of the complexes were predicted by optimizing the structure by DFT/B3LYP method with LANL2DZ basis set in the gas phase. The interaction of the metal complexes with CT‐DNA and BSA protein has been examined by UV‐vis, fluorescence and viscometer titrations reveal that the complexes bind to DNA through intercalation binding mode. The copper complexes exhibit effective cleavage of pUC19 DNA by the oxidative mechanism. The synthesized compounds screened for their antibacterial activities against various bacteria strains exhibit the L and copper complex show potential activity against Pseudomonas aeruginosa and Escherichia coli, respectively. Subsequently, molecular docking studies were performed on to understand the binding of the compounds with DNA, BSA and bacteria.
The Meaning of Intraoperative Errors: Perioperative Nurse Perspectives
Authors: Chard Robin , Tovin Melissa
Published: January 2018

Medical errors involve different health care professionals, are multifaceted, and can occur at the individual practitioner or system level. The conditions for errors vary in the health care environment; some practice areas may be more vulnerable to errors than others. Limited research exists that explores perioperative nursing errors. The purpose of this study was to describe and interpret the experiences of perioperative nurses related to intraoperative errors. We used the hermeneutic phenomenological method. Ten perioperative RNs participated in focus group interviews that we audio‐recorded and transcribed. We analyzed data using thematic analysis, and three themes emerged that represent the essence of the experience of nurses involved in intraoperative errors: environment, being human, and moving forward. The findings support efforts to improve quality care and foster a culture of safety in the OR through strategies such as perioperative staff training, interprofessional team building, and controlling environmental factors that are distracting.
Effectiveness of modified hyper‐CVAD chemotherapy regimen in the treatment of adult acute lymphoblastic leukemia: a retrospective experience
Authors: Jalaeikhoo Hasan , Rajaeinejad Mohsen , Keyhani Manoutchehr , Zokaasadi Mohammad , Dehghani Firoozabadi Mohammad Mehdi
Published: January 2018

Several chemotherapy regimens have been developed for the treatment of acute lymphoblastic leukemia (ALL), but relapse still presents the most common obstacles to attaining long‐term survival. The hyper‐CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and prednisolone)/HD MTX and Ara‐C (high‐dose methotrexate and cytarabine) chemotherapy regimen was first started in the MD Anderson Cancer Center as an intensive regimen for adult patients with ALL. The purpose of this study was to evaluate the effectiveness of a modified hyper‐CVAD protocol. We used hyper‐CVAD as consolidation/maintenance after remission induction with daunorubicin, vincristine, and prednisolone (and cyclophosphamide for T‐cell ALL only) rather than standard hyper‐CVAD in order to reduce treatment complications. This study was conducted as a retrospective review of medical records of ALL patients at 501 army hospital, Tehran, Iran, from 2005 to 2015. Three hundred and one patients underwent modified hyper‐CVAD chemotherapy regimen. Complete remission and overall survival (OS) rates were measured as primary endpoints. Two hundred and forty‐six (81.7%) reached complete remission (CR) during the first 6 months of treatment, and 55 patients (18.3%) did not reach CR. The 5‐year OS rate was 51.8% (95% CI (confidence interval): 45.1–57.8%). Modified hyper‐CVAD regimen is an efficient intensive chemotherapy regimen for consolidation/maintenance of adults with newly diagnosed ALL and has an acceptable 5‐year overall that is comparable to standard hyper‐CVAD regimen.
Pyridone Luciferins and Mutant Luciferases for Bioluminescence Imaging
Authors: Zhang Brendan S. , Jones Krysten A. , McCutcheon David C. , Prescher Jennifer A.
Published: January 2018

New applications for bioluminescence imaging require an expanded set of luciferase enzymes and luciferin substrates. Here, we report two novel luciferins for use in vitro and in cells. These molecules comprise regioisomeric pyridone cores that can be accessed from a common synthetic route. The analogues exhibited unique emission spectra with firefly luciferase, although photon intensities remained weak. Enhanced light outputs were achieved by using mutant luciferase enzymes. One of the luciferin–luciferase pairs produced light on par with native probes in live cells. The pyridone analogues and complementary luciferases add to a growing set of designer probes for bioluminescence imaging.
Enhanced Efficiency of Electron–Hole Separation in Bi2O2CO3 for Photocatalysis via Acid Treatment
Authors: Huang Yongchao , Li Kunshan , Lin Ying , Tong Yexiang , Liu Hong
Published: January 2018

We herein prepared defective Bi2O2CO3 microspheres via a simple nitric acid treatment method. Upon generation from Bi2O2CO3, electrons and holes were superbly separated with the existence of defects. Combined with the advantages of multiple scattering and reflection, a large surface area and increased range of visible‐light absorption, the defective Bi2O2CO3 dispalyed a high efficiency for the photodegradation of HCHO gases and methyl orange. The defective Bi2O2CO3 also possessed a superior stability, which is important for practical applications. This work opens up new opportunities for the design and fabrication of high‐activity Bi‐based photocatalysts for environmental protection.
Advanced Continuous Flow Platform for On‐Demand Pharmaceutical Manufacturing
Authors: Zhang Ping , Weeranoppanant Nopphon , Thomas Dale A. , Tahara Kohei , Stelzer Torsten , Russell Mary Grace , O'Mahony Marcus , Myerson Allan S. , Lin Hongkun , Kelly Liam P. , Jensen Klavs F. , Jamison Timothy F. , Dai Chunhui , Cui Yuqing , Briggs Naomi , Beingessner Rachel L. , Adamo Andrea
Published: January 2018

As a demonstration of an alternative to the challenges faced with batch pharmaceutical manufacturing including the large production footprint and lengthy time‐scale, we previously reported a refrigerator‐sized continuous flow system for the on‐demand production of essential medicines. Building on this technology, herein we report a second‐generation, reconfigurable and 25 % smaller (by volume) continuous flow pharmaceutical manufacturing platform featuring advances in reaction and purification equipment. Consisting of two compact [0.7 (L)×0.5 (D)×1.3 m (H)] stand‐alone units for synthesis and purification/formulation processes, the capabilities of this automated system are demonstrated with the synthesis of nicardipine hydrochloride and the production of concentrated liquid doses of ciprofloxacin hydrochloride, neostigmine methylsulfate and rufinamide that meet US Pharmacopeia standards.
Diffusion, Ion Pairing and Aggregation in 1‐Ethyl‐3‐Methylimidazolium‐Based Ionic Liquids Studied by 1H and 19F PFG NMR: Effect of Temperature, Anion and Glucose Dissolution
Authors: D'Agostino Carmine , Mantle Mick D. , Mullan Claire L. , Hardacre Christopher , Gladden Lynn F.
Published: January 2018

In this work, using 1H and 19F PFG NMR, we probe the effect of temperature, ion size/type and glucose dissolution on the rate of transport in 1‐ethyl‐3‐methylimidazolium ([EMIM]+)‐based ionic liquids by measuring self‐diffusion coefficients. Using such data, we are able to establish the degree of ion pairing and quantify the extent of ionic aggregation during diffusion. For the neat 1‐ethyl‐3‐methylimidazolium acetate ([EMIM][OAc]) a strong degree of ion pairing is observed. The substitution of the [OAc]− anion with the bis{(trifluoromethyl)sulfonyl}imide ([TFSI]−) anion reduces the pairing between the ions, which is attributed to a lower electric charge density on the [TFSI]− anion, hence a weaker electric interaction with the [EMIM]+ cation. The effect of glucose, important for applications of ionic liquids as extracting media, on the strongly paired [EMIM][OAc] sample was also investigated and it is observed that the carbohydrate decreases the degree of ion pairing, which is attributed to the ability of glucose to disrupt inter‐ionic interactions by forming hydrogen bonding, particularly with the [OAc]− anion. Calculations of aggregation number from diffusion data show that the [OAc]− anion diffuses as a part of larger aggregates compared to the [EMIM]+ cation. The results and analysis presented here show the usefulness of PFG NMR in studies of ionic liquids, giving new insights into ion pairing and aggregation and the factors affecting these parameters.
Development of an electrophoretic method based on nanostructured materials for HbA1c determination
Authors: Hamer Mariana , Bassi Narella , Agata Grela Denise
Published: January 2018

Glycosylated hemoglobin (HbA1c) detection is performed routinely in hospitals as it is the most widespread confirmatory diagnosis of diabetes mellitus. Here we present a novel CE method for measuring HbA1c by introducing silica nanoparticles (NPs) modified with a boronic acid derivative (sugar loadings of 51 ± 2 μg/mg) as pseudo‐stationary phase. Before the sample injection, SiO2NP─B(OH)2 were introduced via pressure. Electrophoretic separation was explored through variation of the buffer pH and separation voltage, being the best separation, resolution and shorter separation time achieved with a 25 mM phosphate buffer pH 6.5. The calibration curve obtained was expressed as Area = 182.05%−1 × HbA1c − 377.02; R2 = 0.9826, using a UV/VIS absorbance detector at 415 nm (diode array). No interferences were observed from carbamylated or acetylated hemoglobin and the method shows a noteworthy stability. A paired t‐test was applied to compare the developed CE method with a commercial HbA1c test and no significant variations have been observed at a 90% significance level.
miR147b:Anovel key regulator of interleukin 1 beta‐mediated inflammation in human astrocytes
Authors: van Scheppingen Jackelien , Mills James D. , Zimmer Till S. , Broekaart Diede W.M. , Iori Valentina , Bongaarts Anika , Anink Jasper J. , Iyer Anand M. , Korotkov Anatoly , Jansen Floor E. , van Hecke Wim , Spliet Wim G. , van Rijen Peter C. , Baayen Johannes C. , Vezzani Annamaria , van Vliet Erwin A. , Aronica Eleonora
Published: January 2018

Astrocytes are important mediators of inflammatory processes in the brain and seem to play an important role in several neurological disorders, including epilepsy. Recent studies show that astrocytes produce several microRNAs, which may function as crucial regulators of inflammatory pathways and could be used as therapeutic target. We aim to study which miRNAs are produced by astrocytes during IL‐1β mediated inflammatory conditions in vitro, as well as their functional role and to validate these findings in human epileptogenic brain tissue. Sequencing was used to assess miRNA and mRNA expression in IL‐1β‐stimulated human fetal astrocyte cultures. miRNAs were overexpressed in cell cultures using miRNA mimics. Expression of miRNAs in resected brain tissue from patients with tuberous sclerosis complex or temporal lobe epilepsy with hippocampal sclerosis was examined using in situ hybridization. Two differentially expressed miRNAs were found: miR146a and miR147b, which were associated with increased expression of genes related to the immune/inflammatory response. As previously reported for miR146a, overexpression of miR147b reduced the expression of the pro‐inflammatory mediators IL‐6 and COX‐2 after IL‐1β stimulation in both astrocyte and tuberous sclerosis complex cell cultures. miR146a and miR147b overexpression decreased proliferation of astrocytes and promoted neuronal differentiation of human neural stem cells. Similarly to previous evidence for miR146a, miR147b was increased expressed in astrocytes in epileptogenic brain. Due to their anti‐inflammatory effects, ability to restore aberrant astrocytic proliferation and promote neuronal differentiation, miR146a and miR147b deserve further investigation as potential therapeutic targets in neurological disorders associated with inflammation, such as epilepsy.
Application of Sal classification to parotid gland fine‐needle aspiration cytology: 10‐year retrospective analysis of 312 patients
Authors: Kilavuz Ahmet Erdem , Songu Murat , İmre Abdulkadir , Arslanoğlu Secil , Özkul Yilmaz , Pinar Ercan , Ateş Düzgün
Published: January 2018

Background

The accuracy of fine‐needle aspiration biopsy (FNAB) is controversial in parotid tumors. We aimed to compare FNAB results with the final histopathological diagnosis and to apply the “Sal classification” to our data and discuss its results and its place in parotid gland cytology.

Methods

The FNAB cytological findings and final histological diagnosis were assessed retrospectively in 2 different scenarios based on the distribution of nondefinitive cytology, and we applied the Sal classification and determined malignancy rate, sensitivity, and specificity for each category.

Results

In 2 different scenarios FNAB sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were found to be 81%, 87%, 54.7%, and 96.1%; and 65.3%, 100%, 100%, and 96.1%, respectively. The malignancy rates and sensitivity and specificity were also calculated and discussed for each Sal category.

Conclusion

We believe that the Sal classification has a great potential to be a useful tool in classification of parotid gland cytology.
Dividend policy and bank opacity
Authors: Tran Dung Viet , Ashraf Badar Nadeem
Published: January 2018

Does dividend policy increase or decrease bank opaqueness? Under the Dividend–Transparency Channel, paying dividends involves banks having greater discipline from the markets due to external financing and reduces private benefits of control, leading to lower earnings management concerns. Under the Dividend–Opacity Channel, due to a hesitancy to change dividend policy, banks have high vocations to engage earnings management to circumvent payout policy restrictions in debt covenants or to keep their dividend target unchanged. Employing a large sample of 2,483 U.S. bank holding companies from 2001:Q1–2013:Q4, the study documents the double‐edged sword of dividends on the discretionary behaviours of banks. Paying dividends makes banks less opaque to compare with nonpayers, which is consistent with the Dividend–Transparency Channel, however among dividend paying banks, excessive dividends involve banks to manage more their numbers, which is consistent with the Dividend–Opacity Channel. The findings are robust under different specifications. The results are of important interest to bank regulators.
THE EFFECTS OF VARIOUS SUBSTANCES ON THE COMPARATIVE GROWTH OF EXCISED TOMATO ROOTS OF CLONES CARRYING DWARF AND NORMAL ALLELES
Authors: Lee Addison E.
Published: January 2018

Lee, Addison E. (U. Texas, Austin.) The effects of various substances on the comparative growth of excised tomato roots of clones carrying dwarf and normal alleles. Amer. Jour. Bot. 46(1) : 16‐21. Illus. 1959.—Excised tomato roots carrying the wd gene for dwarfness and its comparable normal allele, wd+, were cultured under various conditions in an effort to provide information as to the physiological differences between the 2 root clones. Two percent is the optimal sucrose concentration for both roots, although wd roots appear to be relatively more tolerant to high sucrose concentration than wd+ roots. The addition of yeast extract, casein hydrolysate, 1, 3‐diphenylurea, and a combination of the last 2 in standard medium fail to improve growth of either wd or wd+ roots. The growth of wd roots is favored by the dark while that of wd+ roots is favored by the light. The addition of IAA to the medium fails to stimulate either type. The effects of eosin added to the medium in various concentrations were studied. High concentrations were inhibitory, but the effect of a concentration of 10‐9 g./ml. provided some evidence of an auxin differential between the two clones of roots. The effects of antiauxins were also investigated, but all of those used reduced the growth of both wd and wd+ roots. It was concluded that although there may be some differences in the auxin metabolism between wd and wd+ roots, it is not likely that this is the cause of dwarfism in the wd roots. Kinetin was found to stimulate both wd and wd+ roots in a concentration of 1.0γ/l. but the stimulation was not differential. Gibberellic acid was found to inhibit both wd and wd+ roots in relatively high concentrations. It had little effect on wd roots in relatively low concentrations, but was inhibitory to wd+ roots even in very low concentrations. Thus these substances appear not to be the cause of the dwarf condition of the wd roots.
A COMPARATIVE STUDY OF SEXUAL REPRODUCTION IN FOUR SPECIES OF CHLAMYDOMONAS
Authors: Trainor Francis R.
Published: January 2018

Trainor, Francis R. (U. Connecticut, Storrs.) A comparative study of sexual reproduction in four species of Chlamydomonas. Amer. Jour. Bot. 46(2) : 65‐70. 1959.—This paper reports results of comparative experiments on some factors affecting sexual reproduction in 4 species of Chlamydomonas. Sexuality can be controlled in 3 of these species (C. chlamydogama, C. eugametos and C. reinhardti) by the level of ammonium nitrate in the harvesting medium. It was demonstrated that periodicity of illumination was of importance for high zygospore yields with C. chlamydogama and C. eugametos. Other variables, e.g., various aspects of nitrogen level, illumination and inter‐fertility, were investigated and the results summarized in tabular form.
INFLUENCE OF ENVIRONMENTAL FACTORS ON ORIGIN OF COLCHICINE‐INDUCED TRUE‐BREEDING DIPLOID MUTANTS IN SORGHUM
Authors: Sanders Mary E. , Franzke Clifford J. , Ross James G.
Published: January 2018

Sanders, Mary E., Clifford J. Franzke, and James G. Ross. (South Dakota State Coll., Brookings.) Influence of environmental factors on origin of colchicine‐induced true‐breeding diploid mutants in sorghum. Amer. Jour. Bot. 46(2) : 119‐125. Illus. 1959.—Factors involved in the induction of true‐breeding diploid mutants following colchicine treatment of sorghum seedlings (line ‘Experimental 3‘) were studied by growing untreated and treated seedlings in aseptic cultures under controlled conditions and examining mature plants and progenies for genetic changes. Factors found to increase rate of early growth and survival of treated seedlings are: use of agar media rather than quartz sand plus liquid media, presence of major minerals in the medium, and presence of up to 2% sucrose in the medium. The beneficial effect of sucrose is contingent upon the presence of major minerals. IAA from 0.01 p.p.m. to 0.1 p.p.m. increased rate of both root and top growth of treated seedlings during early development. Increased osmotic values of the medium increased early growth rate and survival of treated seedlings up to a concentration equivalent to 0.123 molar sucrose while early growth of control seedlings fell off with every increase in osmotic value. This shift in optimum osmotic value of the medium would seem to indicate an increase in the osmotic concentration of the tissues of colchicine‐treated seedlings. Progeny tests of some of the treated plants from the culture experiments demonstrated that, out of 137, none were true‐breeding diploid mutants. There were instances of polyploidy and minor changes, but the 2 treated plants which were the only obvious mutants gave progenies which segregated for many characters. Improved growing conditions for treated seedlings decreased the colchicine effect of induction of true‐breeding diploid mutants as well as the colchicine effects of retarded seedling growth and decreased survival.
THE MECHANISM OF STOMATAL MOVEMENT
Authors: Ketellapper H. J.
Published: January 2018

Ketellapper, H. J. (California Inst. Tech., Pasadena.) The mechanism of stomatal movement. Amer. Jour. Bot. 46(3) : 225‐231. IIlus. 1959.—A review of the pertinent literature reveals that fairly exact knowledge is available about the effects of light, CO2, and water content of the leaf on stomatal movement. Two distinct types of light action can be distinguished: an indirect effect, mediated through photosynthesis and the resulting lower CO2 concentration within the leaf, and a direct effect which occurs even when the intercellular spaces are washed out with CO2‐free air. The CO2 concentration occupies a very central position in the regulation of stomatal movement. The action of CO2 and light will be influenced, or even counteracted, by the value of the water deficit in the leaf. A large number of changes in the guard cells, accompanying stomatal movement, has been described in the literature and some of these have been discussed in the present review: for example, the changes in osmotic value, in starch content, and in permeability. These observations led to the formulation of the classical theories of stomatal movement. It has been concluded that the classical theories are not adequate to explain stomatal movement. At present one can choose between 2 alternatives: an osmotic theory incorporating the pathways of the classical theories and bringing these together in one general scheme hinging on the sugar‐starch conversion, or else a theory incorporating non‐osmotic processes for the removal of water or osmotic active material. These alternatives have been discussed in some detail. It has been concluded that more experimental evidence is required before a valid theory of stomatal movement can be brought forward.
MINERAL OIL OVERLAY FOR CONSERVATION OF PLANT TISSUE CULTURES
Authors: Caplin Samuel M.
Published: January 2018

Caplin, Samuel M. (Calif. Inst. Technol., Pasadena.) Mineral oil overlay for conservation of plant tissue cultures. Amer. Jour. Bot. 46(5): 324–329. Illus. 1959.—Used successfully by other workers for conservation of stock cultures of bacteria and fungi, mineral oil (m.o.) may also be used to conserve plant tissue cultures. Prolonged growth under m.o. does not appear to affect the ability of carrot tissue cultures to grow subsequently on subculture in air. In contrast with growth under liquid nutrient, which permitted little or no growth at depths greater than 15 mm., growth under m.o. was maintained at approximately ¼ of that of the controls up to 45 mm., the greatest depth tested. Better growth under m.o. is attributed to the 4 to 5 X greater solubility of oxygen in m.o. than in water. Insensitivity to depth under m.o. is ascribed to maintenance by diffusion of the oxygen concentration at the surface of the tissue. Under m.o. in the light, cultures became green and grew better, probably due to increased oxygen availability as the result of photosynthesis. Heavy m.o. appears to be equally as good as light oil for use as an overlay. Because of the slower growth of cultures under m.o., subculture periods may be lengthened from the order of 4–6 weeks to as many months, with attendant savings in effort, time, and materials.
ANASTOMOSES IN THE VENATION OF GINKGO BILOBA
Authors: Arnott Howard J.
Published: January 2018

Arnott, Howard J. (Northwestern U., Evanston, Ill.) Anastomoses in the venation of Ginkgo biloba. Amer. Jour. Bot. 46(6): 405–411. Illus. 1959.—Although the vasculature of the lamina of Ginkgo biloba has been described as open dichotomous and devoid of anastomoses, vein unions were found in a survey of 1065 leaves collected from both long and short shoots of 11 trees. When studied by directing a strong light through the lamina and by clearings, 9.9% of the leaves possessed 1 or more anastomoses. Long shoot‐leaves showed 13.4% anastomoses while short shoot‐leaves showed 8.2% anastomoses. Multiple anastomoses were found in almost half of the leaves bearing anastomoses. In the 105 leaves having vein unions, 163 anastomoses were counted. These anastomoses could be grouped into 4 types which are easily distinguished by the number of dichotomies involved and by the presence or absence of dichotomies above the point of vein union. Other deviations were found from the “normal” venation pattern; these consisted of unconnected veins, veins anastomosed marginally but unconnected basally, and veins ending a considerable distance from the margin. It was speculated that the anastomoses found in Ginkgo biloba are of a simple, archaic type and are apparently analogous to the anastomoses in the leaves of certain ferns and in the leaflets of various cycads. The evolutionary significance of these anastomoses must be assessed by a broad study of venation patterns in the seed‐plants.
LIGHT AND ELECTRON MICROSCOPE STUDIES OF THE CELL WALL STRUCTURE OF THE ROOT HAIRS OF RAPHANUS SATIVUS
Authors: Dawes Clinton J. , Bowler Edwin
Published: January 2018

Dawes, ClintonJ., and EdwinBowler. (U. of California, Los Angeles.)Light and electron microscope studies of the cell wall structure of the root hairs of Raphanus sativus.Amer. Jour. Bot. 46(8): 561–565. Illus. 1959.—The structure and development of the cell wall of the root hair ofRaphanus sativuswere studied under the light and electron microscopes. The outer layer of the root hair consists of mucilage which covers the entire hair and forms a thick cap at the tip. Beneath the mucilage a thin cuticle covers the inner layers of the cell wall. These layers consist of cellulose microfibrils, varying in pattern, in a granular matrix, presumably pectic in nature. The microfibrils of the outer layer, apparently laid down at the tip, are reticulate in arrangement. In mature regions of the root hair, the wall is thickened by an inner layer of parallel and longitudinally orientated microfibrils. Pores in the cellulose wall are evident and increase in number and size near the base of the hair.
STUDIES OF PALEOZOIC FERNS: TUBICAULIS STEWARTII SP. NOV. AND EVOLUTIONARY TRENDS IN THE GENUS
Authors: Eggert Donald A.
Published: January 2018

Eggert, Donald A. (Yale U., New Haven, Conn.) Studies of Paleozoic ferns: Tubicaulis stewartii sp. nov. and evolutionary trends in the genus. Amer. Jour. Bot. 46(8): 594–602. Illus. 1959.—Tubicaulis stewartii, a new species of the order Coenopteridales is described. The specimen was derived from the Upper Pennsylvanian of Berryville, Illinois, and is characterized by having a lacunar middle cortex, a well‐developed integumentary system bearing uniseriate hairs, and xylem parenchyma organized into vertically anastomosing strands. In addition, multiseriate (somewhat transitional to reticulate) bordered pitting is present in the petiolar metaxylem elements, while those of the stem stele are multiseriate scalariform. The habit is intermediate between that of a form such as Osmunda and a tree fern, having an upright tapering stem which gives off prominently decurrent petioles in a 2/5 divergence. A reinvestigation of the type specimen of the most closely allied species, T. multiscalariformis, of Upper‐Middle Pennsylvanian age, has shown that it has similar features in the cortex, metaxylem, and integumentary layers. Tubicaulis multiscalariformis and T. stewartii form a distinct group in the 6 species now known, whose evolution has most likely involved the retention of a more primitive form of pitting (multiseriate scalariform) with parenchymatization of the xylem. The remaining species of the genus have not developed xylem parenchyma but have developed circular bordered pitting. The relationships of the genus to other genera in the Coenopteridales remain obscure.
MINERAL NUTRITION AND FLOWER TO FLOWER POLLEN SIZE VARIATION
Authors: Bell C. Ritchie
Published: January 2018

Bell, C. Ritchie. (U. of North Carolina, Chapel Hill.) Mineral nutrition and flower to flower pollen size variation. Amer. Jour. Bot. 46(9): 621–624. 1959.—Mineral nutrition appears to affect the amount of variability of pollen size in both clone and heterozygous seedling material grown on 6 different, deficient, nutrient solutions. In no case did the controls on complete nutrient solution have the largest mean pollen size. No pattern of pollen‐size variation related to blooming date or to type of mineral deficiency could be detected in this experiment: the largest mean pollen size for tomato clone 1 came from plants on the —N solution, the smallest from plants on the –S solution (a 5.4 μ difference); for petunia clone 1, largest on –K, smallest on –S (a 2.3 μ difference); petunia clone 2, largest on –N, smallest on –P (a 1.9μ difference); dill set 1, largest on –K, smallest on –N (a 2.9μ difference); dill set 2, largest on –S, smallest on –N (an 8.2μ difference); portulaca (both sets presumably heterozygous) set 1, largest on –Mg, smallest on Ca (a 9.7μ difference); portulaca set 2, largest on –N, smallest on –Mg (a 13.6μ difference), note that set 1 was largest on –Mg. In the case of petunia pollen, there was greater size variation from flower to flower on the same plant than between flowers from different plants of the same clone on different nutrient solutions. Such variation offers further proof of the danger of using pollen size as an indicator of polyploidy or as a taxonomic characteristic until such correlations have been proven, in each separate instance, to be valid.
DEVELOPMENT OF THE CUTICULAR LAYERS IN ANGIOSPERM LEAVES
Authors: Schieferstein R. H. , Loomis W. E.
Published: January 2018

Schieferstein, R. H., and W. E. Loomis. (Iowa State U., Ames.) Development of the cuticular layer in angiosperm leaves. Amer. Jour. Bot. 46(9): 625–635. Illus. 1959.—The cuticularized layers of leaves and other plant surfaces consist of a primary cuticle, formed by the oxidation of oils on exposed cell walls, plus various surface and subsurface wax deposits. The primary cuticle appears to form rapidly on the walls of any living cell which is exposed to air. Surface wax is present on the mature leaves of about half of the 50 or 60 species studied. In general, wax is extruded at random through the newly formed cuticle of young leaves and accumulated in various reticulate to semicrystalline patterns. No wax pores through the cuticle or primary wall can be observed in electron‐micrographs of dewaxed mature leaves. Wax accumulations on older leaves are generally subcuticular and may involve the entire epidermal wall. These deposits appear to be of considerably greater ecological significance than those on the surface. Isolated cuticular membranes from Hedera helix increased slightly in permeability to water with age of the leaf, but permeability to 2,4‐D decreased 50 times. Evidence based on the patterns of cellulose in primary walls, of surface wax on growing leaves, of the appearance of the cuticle at the margins of growing epidermal cells, of the forms of the cuticle plates digested from growing and older leaves, and of the marginal location of new wax deposits on growing maize leaves is presented to support the thesis that the enlargement of the outer surface of the epidermal cells of leaves occurs at the margins of the surface. Earlier formed cuticle and wax are thus undisturbed during growth. These observations, coupled with evidence for apical growth in fibers, root hairs, etc. suggest that the primary walls of angiosperm cells are formed in specific, localized growth regions, rather than by plastic extension and apposition.