bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting drought tolerance from slope aspect preference in restored plant communities
Authors: Kimball Sarah , E. Lulow Megan , R. Balazs Kathleen , Huxman Travis E.
Published: March 2017

Plants employ strategies of tolerance, endurance, and avoidance to cope with aridity in space and time, yet understanding the differential importance of such strategies in determining patterns of abundance across a heterogeneous landscape is a challenge. Are the species abundant in drier microhabitats also better able to survive drought? Are there relationships among occupied sites and temporal dynamics that derive from physiological capacities to cope with stress or dormancy during unfavorable periods? We used a restoration project conducted on two slope aspects in a subwatershed to test whether species that were more abundant on more water‐limited S‐facing slopes were also better able to survive an extreme drought. The attempt to place many species uniformly on different slope aspects provided an excellent opportunity to test questions of growth strategy, niche preference, and temporal dynamics. Perennial species that established and grew best on S‐facing slopes also had greater increases in cover during years of drought, presumably by employing drought tolerance and endurance techniques. The opposite pattern emerged for annual species that employed drought‐escape strategies, such that annuals that occupied S‐facing slopes were less abundant during the drought than those that were more abundant on N‐facing slopes. Our results clarify how different functional strategies interact with spatial and temporal heterogeneity to influence population and community dynamics and demonstrate how large restoration projects provide opportunities to test fundamental ecological questions.
Watershed characteristics shape the landscape genetics of brook stickleback (Culaea inconstans) in shallow prairie lakes
Authors: Kremer Cory S. , Vamosi Steven M. , Rogers Sean M.
Published: March 2017

Investigating the consequences of landscape features on population genetic patterns is increasingly important to elucidate the ecological factors governing connectivity between populations and predicting the evolutionary consequences of landscapes. Small prairie lakes in Alberta, Canada, and the brook stickleback (Culaea inconstans) that inhabit them, provide a unique aquatic system whereby populations are highly isolated from one another. These heterogeneous and extreme environments are prone to winterkills, an event whereby most of the fish die and frequent bottlenecks occur. In this study, we characterized the genetic population structure of brook stickleback among several lakes, finding that the species is hierarchically influenced by within‐lake characteristics in small‐scale watersheds. Landscape genetic analyses of the role of spatial features found support for basin characteristics associated with genetic diversity and bottlenecks in 20% of the sampled lakes. These results suggest that brook stickleback population genetic patterns may be driven, at least in part, by ecological processes that accelerate genetic drift and landscape patterns associated with reduced dispersal. Collectively, these results reinforce the potential importance of connectivity in the maintenance of genetic diversity, especially in fragmented landscapes.
The Origins of the Differences between Alkyne Hydroalkoxylations Catalyzed by 8‐Quinolinolato‐ and Dipyrrinato‐Ligated RhI Complexes: A DFT Mechanistic Study
Authors: Liu Zheyuan , Guo Jiandong , Song Chunyu , Hu Wenping , Dang Yanfeng , Wang Zhi‐Xiang
Published: March 2017

Hydroalkoxylations of terminal alkynes with methanol, catalyzed by 8‐quinolinolato‐ and dipyrrinato‐ligated RhI complexes, afford anti‐Markovnikov (Z)‐ and (E)‐enol ethers, respectively. Herein we performed a DFT study to gain insight into the mechanisms of the two reactions, aiming at understanding why and how the two ligands differ. Of the two possible mechanisms, namely, Cβ‐HT and Rh‐HT, characterized by a RhI Fisher carbene and vinyl RhIII–H hydride complex, respectively, the hydroalkoxylation with 8‐quinolinolato prefers the Cβ‐HT mechanism, while that with dipyrrinato favors the Rh‐HT mechanism. The root cause for the mechanistic difference is that the O atom in 8‐quinolinolato, due to its large electronegativity and exposure, is more favorable than the N atom in dipyrrinato in stabilizing the protic hydrogen as methanol undergoes a 1,3‐addition, thus the addition in the former is much easier than that in the latter. Consequently, the addition in the hydroalkoxylation with dipyrrinato controls the reaction selectivity, giving the (E)‐enol ether. In contrast, the selectivity of the hydroalkoxylation with 8‐quinolinolato is determined by the RhI Fisher carbene to undergo a 1,2‐hydrogen transfer, leading to the (Z)‐enol ether. Furthermore, a DMA solvent molecule substantially facilitates the methanol addition in the reaction with dipyrrinato but not in the reaction with 8‐quinolinolato.
Electronic Influences on the Stability and Kinetics of Cp* Rhodium(III) Azide Complexes in the iClick Reaction with Electron‐Poor Alkynes
Authors: Waag‐Hiersch Luisa , Mößeler Jan , Schatzschneider Ulrich
Published: March 2017

Rhodium(III) azide half‐sandwich complexes of general formula [Rh(Cp*)(N3)(bpyR,R)]CF3SO3 with R = H, OCH3 were prepared in three steps in an overall yield of 55–65 %. Their stability strongly depends on the 4,4′‐substituent on the 2,2′‐bipyridine (bpy) ligand and increases in the order COOCH3 < H < OCH3. Consequently, no stable product could be isolated for the complex with the methyl ester substituent. The title compounds easily underwent cycloaddition reactions with ethyl 4,4,4‐trifluoro‐2‐butynoate in acetonitrile at room temperature in the absence of catalyst. The resulting triazolate products were simply isolated by precipitation in 65–75 % yield. The trifluoromethyl group enabled facile monitoring of the reaction by 19F NMR spectroscopy. Kinetic studies with solution IR spectroscopy revealed pseudo‐first‐order rate constants of 2.4 to 3.8 × 10–3 s–1, and the reactions were accelerated by the presence of electron‐donating groups at the 4,4′‐position of the bpy coligand. These values are of a similar magnitude as those for the Staudinger ligation utilized for bio(macro)molecule functionalization.
Straightforward Synthesis of a Vicinal Double‐Bridgehead Iodo Trimethylsilyl Octacycle: Unprecedented Lack of Reactivity of the Silyl Group in the Presence of Fluoride Anions
Authors: Camps Pelayo , Lozano David , Guitián Enrique , Peña Diego , Pérez Dolores , Font‐Bardia Mercè , Llamas‐Saíz Antonio L.
Published: March 2017

A convenient synthesis of an octacyclic compound containing an iodo and a trimethylsilyl group in vicinal double‐bridgehead positions, as a possible precursor of a pyramidalized alkene, is described. The key step of the synthesis consists of a double nucleophilic substitution of two neopentyl‐type iodides by cyclopentadienide anions followed by two intramolecular Diels–Alder cycloadditions. All attempts to generate the expected pyramidalized alkene from the above precursor on reaction with different sources of fluoride failed. This octacyclic compound, which contains two disubstituted C=C bonds, underwent a chemo‐ and stereoselective Pd0‐catalyzed co‐cyclotrimerization with dimethyl acetylenedicarboxylate to give a nonacyclic cyclohexadiene derivative that can be aromatized upon reaction with CsF or transformed into a related fluoride upon reaction with AgF.
Preconcentration of β‐blockers using functionalized ordered mesoporous silica as sorbent for SPE and their determination in waters by chiral CE
Authors: Silva Mariana , Morante‐Zarcero Sonia , Pérez‐Quintanilla Damián , Marina María Luisa , Sierra Isabel
Published: March 2017

A method for simultaneous separation and determination of four enantiomeric pairs of β‐blockers in waters by chiral CE has been developed. Off‐line SPE was employed using functionalized ordered mesoporous silica as sorbent. Separation by CE was achieved using a BGE composed by methylated‐β‐CD (1.25% w/v) dissolved in a 50 mM phosphate buffer (pH 2.5) and 30°C, with good chiral resolution for all enantiomers. Mesoporous silica functionalized with octadecyl groups (denoted SBA15‐C18) was prepared by a postsynthesis method and applied for the preconcentration of atenolol, propranolol, metoprolol, and pindolol enantiomers in waters by off‐line SPE. Under optimized conditions, a preconcentration factor of 300 was achieved, employing 100 mg of SBA15‐C18 as sorbent, with recoveries between 96 and 105% in tap water and good repeatability (% RSD = 7–11%, n = 6). Commercial C18 amorphous silica (ExtraBondR C18) was also tested as sorbent for SPE, but results revealed better extraction capacity with higher recoveries for the SBA15‐C18 material. The analytical characteristics of the off‐line SPE‐chiral CE method were evaluated, showing good precision, linearity, and accuracy with method quantification limits between 5.3 and 13.7 μg/L for all enantiomers. The SBA15‐C18 material allowed the extraction of four enantiomeric pairs of β‐blockers spiked in tap water, river water, and ground water with recoveries between 58 and 105%.
Using clinically acquired MRI to construct age‐specific ADC atlases: Quantifying spatiotemporal ADC changes from birth to 6‐year old
Authors: Ou Yangming , Zöllei Lilla , Retzepi Kallirroi , Castro Victor , Bates Sara V. , Pieper Steve , Andriole Katherine P. , Murphy Shawn N. , Gollub Randy L. , Grant Patricia Ellen
Published: March 2017

Diffusion imaging is critical for detecting acute brain injury. However, normal apparent diffusion coefficient (ADC) maps change rapidly in early childhood, making abnormality detection difficult. In this article, we explored clinical PACS and electronic healthcare records (EHR) to create age‐specific ADC atlases for clinical radiology reference. Using the EHR and three rounds of multiexpert reviews, we found ADC maps from 201 children 0–6 years of age scanned between 2006 and 2013 who had brain MRIs with no reported abnormalities and normal clinical evaluations 2+ years later. These images were grouped in 10 age bins, densely sampling the first 1 year of life (5 bins, including neonates and 4 quarters) and representing the 1–6 year age range (an age bin per year). Unbiased group‐wise registration was used to construct ADC atlases for 10 age bins. We used the atlases to quantify (a) cross‐sectional normative ADC variations; (b) spatiotemporal heterogeneous ADC changes; and (c) spatiotemporal heterogeneous volumetric changes. The quantified age‐specific whole‐brain and region‐wise ADC values were compared to those from age‐matched individual subjects in our study and in multiple existing independent studies. The significance of this study is that we have shown that clinically acquired images can be used to construct normative age‐specific atlases. These first of their kind age‐specific normative ADC atlases quantitatively characterize changes of myelination‐related water diffusion in the first 6 years of life. The quantified voxel‐wise spatiotemporal ADC variations provide standard references to assist radiologists toward more objective interpretation of abnormalities in clinical images. Our atlases are available at https://www.nitrc.org/projects/mgh_adcatlases. Hum Brain Mapp 38:3052–3068, 2017. © 2017 Wiley Periodicals, Inc.
Long‐term outcomes of entecavir monotherapy for chronic hepatitis B after liver transplantation: Results up to 8 years
Authors: Fung James , Wong Tiffany , Chok Kenneth , Chan Albert , Cheung Tan‐To , Dai Jeff Wing‐Chiu , Sin Sui‐ling , Ma Ka‐Wing , Ng Kelvin , Ng Kevin Tak‐Pan , Seto Wai‐Kay , Lai Ching‐Lung , Yuen Man‐Fung , Lo Chung‐Mau
Published: March 2017

Long‐term antiviral prophylaxis is required to prevent hepatitis B recurrence for patients with chronic hepatitis B after liver transplantation. We determined the long‐term outcome of 265 consecutive chronic hepatitis B liver transplant recipients treated with entecavir monotherapy without hepatitis B immune globulin. Viral serology, viral load, and liver biochemistry were performed at regular intervals during follow‐up. The median duration of follow‐up was 59 months. The cumulative rates of hepatitis B surface antigen (HBsAg) seroclearance were 90% and 95% at 1 and 5 years, respectively. At 1, 3, 5, and 8 years, 85%, 88%, 87.0%, and 92% were negative for HBsAg, respectively, and 95%, 99%, 100%, and 100% had undetectable hepatitis B virus (HBV) DNA, respectively. Fourteen patients remained persistently positive for HBsAg, all of whom had undetectable HBV DNA. There was no significant difference in liver stiffness for those who remained HBsAg‐positive compared to those who achieved HBsAg seroclearance (5.5 versus 5.2 kPa, respectively; P = 0.52). The overall 9‐year survival was 85%. There were 37 deaths during the follow‐up period, of which none were due to hepatitis B recurrence. Conclusion: Long‐term entecavir monotherapy is highly effective at preventing HBV reactivation after liver transplantation for chronic hepatitis B, with a durable HBsAg seroclearance rate of 92%, an undetectable HBV DNA rate of 100% at 8 years, and excellent long‐term survival of 85% at 9 years. (Hepatology 2017;66:1036‐1044).
Double balloon tamponade for postpartum hemorrhage
Authors: Breen Michael
Published: March 2017

A double tamponade system, with one balloon in the uterus and a second in the vagina, controlled all non‐traumatic cases of postpartum hemorrhage.
Rab3A Inhibition of Ca2+‐Dependent Dopamine Release From PC12 Cells Involves Interaction With Synaptotagmin I
Authors: Dai Zhipan , Tang Xia , Chen Jia , Tang Xiaochao , Wang Xianchun
Published: March 2017

Rab3 and synaptotagmin have been suggested to play important roles in the regulation of neurotransmitter release and, however, the molecular mechanism has not been completely clear. Here, we studied the effects of Rab3A and synaptotagmin I (Syt I) on dopamine release using PC12 cells as a model system. Rab3A was demonstrated to have effects on both Ca2+‐independent and Ca2+‐dependent dopamine releases from the PC12 cells. Application of Rab3A (up to 2500 nM) gradually decreased the amount of Ca2+‐dependently released dopamine, indicating that Rab3A is a negative modulator that was further supported by the increase in dopamine release caused by Rab3A knockdown. Syt I knockdown weakened the Ca2+‐dependent dopamine release, suggesting that Syt I plays a positive regulatory role in the cellular process. Treatment of the Syt I‐knocked down PC12 cells with Rab3A further decreased Ca2+‐dependent dopamine release and, however, the decrease magnitude was significantly reduced compared with that before Syt I knockdown, thus for the first time demonstrating that the inhibitory effect of Rab3A on Ca2+‐dependent dopamine release involves the interaction with Syt I. This work has shed new light on the molecular mechanism for Rab3 and synaptotamin regulation of neurotransmitter release. J. Cell. Biochem. 118: 3696–3705, 2017. © 2017 Wiley Periodicals, Inc.
Randomized controlled trial of perioperative antimicrobial therapy based on the results of preoperative bile cultures in patients undergoing biliary reconstruction
Authors: Okamura Kunishige , Tanaka Kimitaka , Miura Takumi , Nakanishi Yoshitsugu , Noji Takehiro , Nakamura Toru , Tsuchikawa Takahiro , Okamura Keisuke , Shichinohe Toshiaki , Hirano Satoshi
Published: March 2017

Background

The high frequency of surgical site infections (SSIs) after hepato‐pancreato‐biliary (HPB) surgery is a problem that needs to be addressed. This prospective, randomized, controlled study examined whether perioperative prophylactic use of antibiotics based on preoperative bile culture results in HPB surgery could decrease SSI.

Methods

Participants comprised 126 patients who underwent HPB (bile duct, gallbladder, ampullary, or pancreatic) cancer surgery with biliary reconstruction at Hokkaido University Hospital between August 2008 and March 2013 (UMIN Clinical Trial Registry #00001278). Before surgery, subjects were randomly allocated to a targeted group administered antibiotics based on bile culture results or a standard group administered cefmetazole. The primary endpoint was SSI rates within 30 days after surgery. Secondary endpoint was SSI rates for each operative procedure.

Results

Of the 126 patients, 124 were randomly allocated (targeted group, n = 62; standard group, n = 62). Frequency of SSI after surgery was significantly lower in the targeted group (27 patients, 43.5%) than in the standard group (44 patients, 71.0%; P = 0.002). Among patients who underwent pancreaticoduodenectomy and hepatectomy, SSI occurred significantly less frequently in the targeted group (P = 0.001 and P = 0.025, respectively).

Conclusions

This study demonstrated that preoperative bile culture‐targeted administration of prophylactic antibiotics decreased SSIs following HBP surgery with biliary reconstruction.
Design and Synthesis of Diverse Pyrrole‐2‐carboxamide Derivatives as a Potent Antibacterial Agents
Authors: Mane Yogesh D. , Surwase Santosh M. , Biradar Dhanraj O. , Sarnikar Yuvraj P. , Jawle Balaji H. , Shinde Vishnu S. , Khade Bhimrao C.
Published: March 2017

A series of pyrrole–2–carboxamide derivatives (4a–j) were synthesized and evaluated for theirantibacterial activity. Among the tested compounds, the most effective were 4a, 4b, 4c, 4d, 4e, 4g and 4h with MIC value in the range of 1.05–12.01 μg/mL against Gram–positive and Gramnegativebacterial strains. Further, the synthesized compounds have been screened for their invitro antifungal activity. In the present study, design and expeditious synthesis of novel 1–(4–chlorobenzyl)–N–(4–methoxybenzyl)–1H–pyrrole–2–carboxamide hybrid molecules as promising antibacterial agents.
A SERS investigation of antimicrobial adsorption on silver nanoparticles as mediated by surface modifiers
Authors: Filgueiras Aline Luciano , Dutra Tailine Mara Freire , Paschoal Diego , Dos Santos Hélio F. , Sant'Ana Antonio Carlos
Published: March 2017

In this work, the adsorptions of the antimicrobial drugs aztreonam, tinidazole and metronidazole on silver nanoparticle surfaces were investigated using surface‐enhanced Raman scattering (SERS) spectroscopy. The chemical properties of silver surface were modified by using mercaptoethanol, polyvinyl alcohol or chloride ions for changing the adsorption mechanisms, which led to distinct SERS spectral patterns. These were analyzed regarding the proximity of molecular moiety from the analyte to the silver surface. The adsorption processes were monitored by the localized surface plasmon resonance bands, which were recorded through ultraviolet‐visible spectroscopy. Theoretical models were obtained from density functional theory and used for supporting the vibrational assignments. The analyses of the SERS spectral patterns allow inferring aztreonam adsorbed through carboxylate moiety while tinidazole and metronidazole adsorbed via nitro group. The surface modifiers led to changes of the adsorption geometries of the molecules on the silver surfaces, which were rationalized based on differences in the relative intensities of the bands assigned to the out‐of‐plane modes. Copyright © 2017 John Wiley & Sons, Ltd.
3‐(2‐Bromoacetamido)‐N‐(9‐ethyl‐9H)‐carbazol fluorescent probe and its application for the determination of thiophenols in rubber products by HPLC with fluorescence detection and atmospheric chemical ionization mass spectrometry identification
Authors: You Jinmao , Dou Kun , Song Cuihua , Li Guoliang , Sun Zhiwei , Zhang Shijuan , Chen Guang , Zhao Xianen , Hu Na , Zhou Wu
Published: March 2017

A rapid, sensitive, and selective precolumn derivatization method for the simultaneous determination of eight thiophenols using 3‐(2‐bromoacetamido)‐N‐(9‐ethyl‐9H)‐carbazol as a labeling reagent by high‐performance liquid chromatography with fluorescence detection has been developed. The labeling reagent reacted with thiophenols at 50°C for 50 min in aqueous acetonitrile in the presence of borate buffer (0.10 mol/L, pH 11.2) to give high yields of thiophenol derivatives. The derivatives were identified by online postcolumn mass spectrometry. The collision‐induced dissociation spectra for thiophenol derivatives gave the corresponding specific fragment ions at m/z 251.3, 223.3, 210.9, 195.8, and 181.9. At the same time, derivatives exhibited intense fluorescence with an excitation maximum at λex = 276 nm and an emission maximum at λem = 385 nm. Excellent linear responses were observed for all analytes over the range of 0.033–6.66 μmol/L with correlation coefficients of more than 0.9997. Detection limits were in the range of 0.94–5.77 μg/L with relative standard deviations of less than 4.54%. The feasibility of derivatization allowed the development of a rapid and highly sensitive method for the quantitative analysis of trace levels of thiophenols from some rubber products. The average recoveries (n = 3) were in the range of 87.21–101.12%.
Online stacking of carboxylated magnetite core–shell nanoparticles in capillary electrophoresis
Authors: Baron Daniel , Dolanská Petra , Medříková Zdenka , Zbořil Radek , Petr Jan
Published: March 2017

The stacking effect on carboxylated magnetite core–shell nanoparticles using sodium borate buffer pH 9.5 as the background electrolyte is presented. The ionic strength of the background electrolyte ranged from 5 to 100 mM, and the ionic strength of a sample zone ranged from 5 to 100 mM. Moreover, water was used as the sample dispersant. Both stacking and de‐stacking effects were observed when conductivities of the sample zone and the background electrolyte differed. An explanation of carboxylated magnetic core‐shell nanoparticles behavior was suggested based on the Derjaguin–Landau–Verwey–Overbeek theory supposing that the aggregation point is defined by the energetic barrier as the sum of energies given by electrostatic interactions and Van der Waals interactions. Moreover, the stacking conditions were applied for the evaluation of the lowest detectable dilution of magnetic nanoparticles. The carboxylated magnetic nanoparticles were dispersed in 10 mM borate/NaOH pH 9.5 and injected for 60 s to the background electrolyte composed of 100 mM borate/NaOH pH 9.5 that allowed the detection of 100‐fold diluted nanoparticles.
Trophic discrimination of stable isotopes and potential food source partitioning by leaf‐eating crabs in mangrove environments
Authors: Kristensen Erik , Lee Shing Yip , Mangion Perrine , Quintana Cintia O. , Valdemarsen Thomas
Published: March 2017

Diet composition of leaf‐eating mangrove crabs is a puzzle among mangrove ecologists. Nutrient‐poor leaf litter can in most cases not support animal growth. Food partitioning (mangrove leaves, animal tissue, and microphytobenthos [MPB]) of sesarmid and ucidid mangrove crabs from eight locations in four countries was assessed using the concentration‐dependent stable isotope mixing model, IsoConc. While stable C and N isotopes have the potential to track the origin and proportion of food sources for these crabs, only few values of trophic discrimination are available. This problem was addressed here for crabs foraging on leaf litter to identify discrimination values that provide a balanced diet with sufficient nutrients (i.e., N) when combined with other food sources. The data from all mangrove locations suggest that sesarmid and ucidid crabs ingest and assimilate mixtures of available food items. Leaf litter in the form of brown leaves was always the most important C source, while animal tissue in the form live and dead “prey” or MPB in the form of diatoms at the sediment surface were the dominant N sources. Model scenarios were generated to obtain the upper thresholds of trophic 13C discrimination between the examined crab species and leaf litter, while complying with the molar C/N < 20 requirement for sustainable invertebrate nutrition. The model predicts litter 13C discrimination thresholds of +1.5‰ to +6.0‰ for sesarmid crabs and −0.3‰ to +0.6‰ for ucidid crabs. The difference is probably caused by metabolic disparities between these two crab families. Deviations in 15N discrimination have in most cases only minor influence on the model‐based 13C discrimination thresholds. The present findings lead us to suggest a modified Optimal Foraging Theory for leaf‐eating mangrove crabs.
Efficacy of ultra short sub‐30 minute incubation of 5‐aminolevulinic acid photodynamic therapy in vitro
Authors: Koo Eugene , Austin Evan , Mamalis Andrew , Jagdeo Jared
Published: March 2017

Background and Objective

The estimated incidence of cutaneous squamous cell carcinoma (SCC) is 700,000 cases per year. In the US, SCC incidence is highest among fair skinned adults older than 50 years of age. Thus, as the population ages, the reported number of SCCs will likely increase in the future. Photodynamic therapy (PDT) is an FDA approved therapy for treatment of actinic keratoses (AKs), a precursor to cutaneous SCC lesions. The FDA approved incubation time of the photosensitizing agent 5‐aminolevulinic acid (ALA) is 14–18 hours. Recent studies have investigated short ALA incubation times of 1–3 hours with ALA and PDT demonstrating treatment success. Therefore, the question exists whether ALA incubation periods of less than 30 minutes are efficacious. Herein, we evaluate the efficacy of short ALA incubation periods by measuring apoptosis after 10, 15, and 20 minutes of ALA incubation.

Study Design/Materials and Methods

AG13145 normal human dermal fibroblasts HDFs were incubated with 10, 15, or 20 minute of ALA at various concentrations (0, 0.05, 0.075, 0.1, 0.25, 0.375, 0.5, 1, and 2 mM). After ALA incubation, samples were treated with 1,000 seconds (16 minutes 40 seconds) of Blu‐U fluorescent blue light (417 ± 5 nm) for a fluence of 10 J/cm2. Immediately following treatment with blue light, samples were collected and stained for apoptosis and necrosis with annexin‐V and 7‐aminoactinomycin D (7‐AAD), and then analyzed by flow cytometry.

Results

HDFs incubated with ALA for 10 minute at 36 °C followed by 10 J/cm2 of blue light had no statistically significant changes in apoptosis. HDFs incubated with ALA for 15 or 20 minutes at 36 °C followed by 10 J/cm2 of blue light had statistically significant increases in the percentages of cells positive for apoptosis in the 0.5, 1.0, and 2.0 mM ALA doses (P < 0.05).

Conclusions

We found that incubation of ALA for at least 15 minutes followed by 10 J/cm2 of blue light resulted in a statistically significant increase in apoptosis. Lasers Surg. Med. 49:592–598, 2017. © 2017 Wiley Periodicals, Inc.
Quaternized and Thiazole‐Functionalized Free Radical‐Generating Organometallic Dendrimers as Antimicrobial Platform against Multidrug‐Resistant Microorganisms
Authors: Abd‐El‐Aziz Alaa S. , Agatemor Christian , Etkin Nola , Bissessur Rabin , Overy David , Lanteigne Martin , McQuillan Katherine , Kerr Russell G.
Published: March 2017

New macromolecules such as dendrimers are increasingly needed to drive breakthroughs in diverse areas, for example, healthcare. Here, the authors report hybrid antimicrobial dendrimers synthesized by functionalizing organometallic dendrimers with quaternary ammonium groups or 2‐mercaptobenzothiazole. The functionalization tunes the glass transition temperature and antimicrobial activities of the dendrimers. Electron paramagnetic resonance spectroscopy reveals that the dendrimers form free radicals, which have significant implications for catalysis and biology. In vitro antimicrobial assays indicate that the dendrimers are potent antimicrobial agents with activity against multidrug‐resistant pathogens such as methicillin‐resistant Staphylococcus aureus and vancomycin‐resistant Enterococcus faecium as well as other microorganisms. The functionalization increases the activity, especially in the quaternary ammonium group‐functionalized dendrimers. Importantly, the activities are selective because human epidermal keratinocytes cells and BJ fibroblast cells exposed to the dendrimers are viable after 24 h.

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The Deeply Understanding of the Self‐Healing Mechanism for Self‐Healing Behavior of Supramolecular Materials Based on Cyclodextrin–Guest Interactions
Authors: Guo Kun , Lin Mu‐Song , Feng Jun‐Feng , Pan Min , Ding Li‐Sheng , Li Bang‐Jing , Zhang Sheng
Published: March 2017

Cyclodextrin (CD)‐based host–guest interactions are one of the important supramolecular interactions and have been playing significant role in the design of self‐healing materials due to high selectivity and dynamic equilibrium. However, a deeper understanding of the self‐healing mechanism is still rare, although self‐healing materials based on CD–guest interactions have many advantages. This study provides a first step for the fundamental understanding of the influence factors on self‐healing behavior of materials containing CD–guest complexes. It is found that the healing motifs are CD–guest interactions. Sufficient polymer chains mobility, a small amount of water, and high inclusion constant (K) of host–guest interactions are also essential to the self‐healing process. The threshold of K value is around 102 M−1.

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Hollow Microcapsules with Enhanced Stability via Stereocomplex Assemblies
Authors: Brzeziński Marek
Published: March 2017

This paper presents a microfluidic approach for fabricating stereocomplexed hollow microcapsules that uses water‐in‐oil‐in‐water double‐emulsion droplets as templates. The polylactides functionalized with 2‐ureido‐4[1H]‐pyrimidinone (UPy) end groups are intermolecularly stereocomplexed by polylactides with opposite configurations to promote their self‐assembly at a water‐chloroform interface. This intermolecular interaction can significantly enhance the stability of resulting hollow microcapsules so that they preserve their shape and size after drying. Moreover, because these stimuli‐responsive polylactides can assemble and disassemble into superstructures, they can be made to release their cargo by varying the pH values. The interfacially assembled supramolecular microcapsules, which possess stimuli‐responsiveness and long‐term stability, are potentially useful for encapsulation and delivery of drugs.

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Forcing with adequate sets of models as side conditions
Authors: Krueger John
Published: March 2017

We present a general framework for forcing on ω2 with finite conditions using countable models as side conditions. This framework is based on a method of comparing countable models as being membership related up to a large initial segment. We give several examples of this type of forcing, including adding a function on ω2, adding a nonreflecting stationary subset of , and adding an ω1‐Kurepa tree.
MIR‐27a regulates the TGF‐β signaling pathway by targeting SMAD2 and SMAD4 in lung cancer
Authors: Chae Dong‐Kyu , Ban Eunmi , Yoo Young Sook , Kim Eunice EunKyeong , Baik Ja‐Hyun , Song Eun Joo
Published: March 2017

The transforming growth factor‐β (TGF‐β) signaling pathway is associated with carcinogenesis and various biological processes. SMAD2 and SMAD4, which are putative tumor suppressors, have an important role in TGF‐β signaling. The aberrant expression of these genes is implicated in some cancers. However, the mechanisms of SMAD2 and SMAD4 dysregulation are poorly understood. In this study, we observed that miR‐27a was upregulated in lung cancer cell lines and patients. In addition, SMAD2 and SMAD4 genes were identified as targets of miR‐27a by several target prediction databases and experimental validation. Functional studies revealed that miR‐27a overexpression decreased SMAD2 and SMAD4 mRNA and protein levels. Furthermore, miR‐27a contributed to cell proliferation and invasion by inhibiting TGF‐β‐induced cell cycle arrest. These results suggest that miR‐27a may function as an oncogene by regulating SMAD2 and SMAD4 in lung cancer. Thus, miR‐27a may be a potential target for cancer therapy.
Sliding solutions of second‐order differential equations with discontinuous right‐hand side
Authors: da Silva Clayton E. L. , da Silva Paulo R. , Jacquemard Alain
Published: March 2017

We consider second‐order ordinary differential equations with discontinuous right‐hand side. We analyze the concept of solution of this kind of equations and determine analytical conditions that are satisfied by typical solutions. Moreover, the existence and uniqueness of solutions and sliding solutions are studied. Copyright © 2017 John Wiley & Sons, Ltd.
Analysis of DG approximations for Stokes problem based on velocity‐pseudostress formulation
Authors: Barrios Tomás P. , Bustinza Rommel , Sánchez Felipe
Published: March 2017

In this article, we first discuss the well posedness of a modified LDG scheme of Stokes problem, considering a velocity‐pseudostress formulation. The difficulty here relies on the fact that the application of classical Babuška‐Brezzi theory is not easy, so we proceed in a nonstandard way. For uniqueness, we apply a discrete version of Fredholm's alternative theorem, while the a priori error analysis is done introducing suitable projections of exact solution. As a result, we prove that the method is convergent, and under suitable regularity assumptions on the exact solution, the optimal rate of convergence is guaranteed. Next, we explore two stabilizations to the previous scheme, by adding least squares type terms. For these cases, well posedness and the a priori error estimates are proved by the application of standard theory. We end this work with some numerical experiments considering our third scheme, whose results are in agreement with the theoretical properties we deduce.© 2017 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 1540–1564, 2017
New unconditionally stable scheme for telegraph equation based on weighted Laguerre polynomials
Authors: Zhang Di , Miao Xiaoping
Published: March 2017

This article proposes a new unconditionally stable scheme to solve one‐dimensional telegraph equation using weighted Laguerre polynomials. Unlike other numerical schemes, the time derivatives in the equation can be expanded analytically based on the Laguerre polynomials and basis functions. By applying a Galerkin temporal testing procedure and using the orthogonal property of weighted Laguerre polynomials, the time variable can be eliminated from computations, which results in an implicit equation. After solving the equation recursively one can obtain the numerical results of telegraph equation by using the expanded coefficients. Some numerical examples are considered to validate the accuracy and stability of this proposed scheme, and the results are compared with some existing numerical schemes.© 2017 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 1603–1615, 2017
Identifying rare diseases using electronic medical records: the example of allergic bronchopulmonary aspergillosis
Authors: Maguire Andrew , Johnson Michelle E. , Denning David W. , Ferreira Germano L.C. , Cassidy Adrian
Published: March 2017

Purpose

The purpose of the study is to evaluate whether primary care electronic medical records (EMRs) from patients with severe asthma can be used to identify allergic bronchopulmonary aspergillosis (ABPA) cases.

Methods

This cross‐sectional feasibility study was conducted in adults with active and severe asthma registered with the Clinical Practice Research Datalink. A set of keywords flagged terms potentially indicative of ABPA in free‐text comments of patients' EMRs to produce a grid on the basis of keywords' hit or miss. The grid was examined for occurrence and concurrence of keywords to discern patterns of concurrence potentially indicative of an underlying diagnosis of ABPA.

Results

The analyses included 3 653 169 free‐text items from 21 054 patients. In total, 52 patients (0.25%) had at least one mention of ‘ABPA’ in their medical record; 67% of these patients also had a mention of ‘aspergillus/aspergillosis’, 54% of ‘bronchiectasis’, 42% of ‘itraconazole’ and 62% of ‘IgE’. The term ‘aspergillus/aspergillosis’ occurred with a proportion of 1.84% (N = 387); 9% of these patients also had a mention of ‘ABPA’, and the remaining 91% were potential additional cases of ABPA. From the observed concurrence of keywords, we were able to devise a potential algorithm to identify cases with varying degrees of specificity.

Conclusions

This study suggests that analysis of free text within asthmatic patients' EMRs may be used to identify potential cases of ABPA. This could be an efficient approach to identify rare conditions and to quantify their potential burden. © 2017 The Authors. Pharmacoepidemiology & Drug Safety Published by John Wiley & Sons Ltd.
Cationic amphiphilic copolymers: synthesis, characterization, self‐assembly and drug‐loading capacity
Authors: Wang Zhongwei , Li Renjie , Chen Huimin , Ma Fulong , Zhang Xiuxuan , Cheng Yu , Gu Xiaofei , Qi Zhengjian
Published: March 2017

Amphiphilic copolymers with cationic hydrophilic moieties and different ratios of hydrophobic portion to hydrophilic portion were designed and synthesized via the combination of hydrosilylation reactions and quaternization reactions. The structures were characterized through Fourier transform infrared spectroscopy, 1H NMR, 13C NMR and gel permeation chromatography. The measurements of critical micelle concentrations, electrical conductivities and zeta potentials indicated that the copolymers could self‐assemble into nanoparticles with charges around the surface in aqueous solution. The sizes of the micelles were between 67 nm and 104 nm detected by dynamic light scattering. The self‐assembled micelles were used as drug carriers to encapsulate a model drug (tocopherol), and their drug‐loading content (DLC) and efficiency (DLE) were determined by UV−visible spectra, resulting in considerable drug‐loading capacity to a tocopherol maximum up to 17.2% (DLC) and 80.3% (DLE) with a size of 90 nm. The blank micelles and drug‐loaded micelles displayed a spherical shape detected by transmission electron microscopy, which demonstrated not only the self‐assembly behaviors but also the drug‐loading performances of the cationic amphiphilic copolymers. All the results demonstrated that the cationic amphiphilic copolymers could be used as potential electric‐responsive drug carriers. © 2017 Society of Chemical Industry
Discotic Liquid Crystals with Graphene: Supramolecular Self‐assembly to Applications
Authors: Kumar Manish , Gowda Ashwathanarayana , Kumar Sandeep
Published: March 2017

In past decades many breakthroughs have been witnessed in research on liquid crystals (LCs) and the application of LCs has spread. On another side graphene is considered as a rapidly rising star on the horizon of materials science, soft condensed matter physics and promising applications. Supramolecular chemistry of LCs and graphene together is described as “chemistry beyond the molecule”. A new class of 2D colloidal graphene oxide liquid crystalline material consisting discotic liquid crystallinity and their interactions with LCs present a platform for number of versatile properties and applications. This review focuses on discotic liquid crystalline (DLC) behavior of graphene oxide/reduced graphene oxide in various solvents, their characterization and application for energy storage, wet‐spinning fibers, electro‐optical devices, and displays etc. In the first part of this review, a brief introduction of discotic graphene oxide liquid crystals (GOLCs), their fundamental, synthesis process, supramolecular structures of graphene‐DLC composites is highlighted. In the second part, some important physical studies and application of this largest polycyclic aromatic core of DLCs are discussed. Finally, an outlook on this emerging two dimensional material in liquid crystal field with relevant scientific application background is presented.
Detection and imaging of thermochromic ink compounds in erasable pens using desorption electrospray ionization mass spectrometry
Authors: Khatami Amin , Prova Shamina S. , Bagga Aafreen K. , Yan Chi Ting Michelle , Brar Gurnoor , Ifa Demian R.
Published: March 2017

Rationale

Thermochromic ink pens are widely accessible worldwide and have gained popularity among the general public. These pens are very useful to undo mistakes while writing important documents or exams. They are also, however, misused in committing crimes such as counterfeiting checks or wills. Thus, the forensics community is in need of techniques that will allow these forgeries to be detected rapidly, reliably and conveniently.

Methods

Thermochromic ink compounds were investigated using Desorption Electrospray Ionization (DESI) coupled with an LTQ mass spectrometer and Thin‐Layer Chromatography (TLC). Tandem mass spectrometric analysis was conducted using Electrospray Ionization (ESI) coupled with an Orbitrap LTQ mass spectrometer performing Collision‐Induced Dissociation (CID) for identification of ink traces.

Results

Chemical marker ions characteristic of the state of ink (visible or invisible) were identified and mapped in ink traces by the use of DESI‐MS imaging. These ions can be employed by forensic experts as fingerprint markers in forged documents. The marker ions were also characterised by conducting tandem mass spectrometry using paper spray in an Orbitrap LTQ mass spectrometer.

Conclusions

Specific chemical components yielding ions ofm/z400, 405, 615 and 786 were distinguished as only being apparent in the invisible and reappeared state of the ink. The absence of these compounds in the original state of the ink enabled their recognition as useful chemical determinants in detecting forgery. DESI‐MSI was thus shown to be a very useful, convenient and reliable technique for detecting forgery in paper documents due to its fast and reproducible mode of analysis, with no sample preparation and minimal damage to the document under investigation. Copyright © 2017 John Wiley & Sons, Ltd.
Effect of Blend Composition on Bulk Heterojunction Organic Solar Cells: A Review
Authors: Wright Matthew , Lin Rui , Tayebjee Murad J. Y. , Conibeer Gavin
Published: March 2017

Significant research and development in the field of organic photovoltaics (OPVs) has been undertaken in recent years. Impressive results relating to both device performance and fabrication techniques suggest it will be a promising renewable energy technology for future low‐cost electricity generation. The necessity of the heterojunction in OPV cells, due to the large exciton binding energy, places constraints on the design of the photoactive layer. The blend composition, meaning the concentration of the donor and acceptor material in the film, is crucial in determining many aspects of the bulk heterojunction (BHJ) active layer film. In this article, the influence of the blend composition on the film morphology and device performance is reviewed. The mechanisms determining this relationship is explored for three different active layer designs, binary polymer: fullerene blends, ternary blends, and organic–inorganic blend films. Finally, the perovskite solar cell is discussed, with an emphasis on the different perovskite ion compositions which have thus far been explored.
Carbon pricing in climate policy: seven reasons, complementary instruments, and political economy considerations
Authors: Baranzini Andrea , van den Bergh Jeroen C. J. M. , Carattini Stefano , Howarth Richard B. , Padilla Emilio , Roca Jordi
Published: March 2017

Carbon pricing is a recurrent theme in debates on climate policy. Discarded at the 2009COPin Copenhagen, it remained part of deliberations for a climate agreement in subsequent years. As there is still much misunderstanding about the many reasons to implement a global carbon price, ideological resistance against it prospers. Here, we present the main arguments for carbon pricing, to stimulate a fair and well‐informed discussion about it. These include considerations that have received little attention so far. We stress that a main reason to use carbon pricing is environmental effectiveness at a relatively low cost, which in turn contributes to enhance social and political acceptability of climate policy. This includes the property that corrected prices stimulate rapid environmental innovations. These arguments are underappreciated in the public debate, where pricing is frequently downplayed and the erroneous view that innovation policies are sufficient is widespread. Carbon pricing and technology policies are, though, largely complementary and thus are both needed for effective climate policy. We also comment on the complementarity of other instruments to carbon pricing. We further discuss distributional consequences of carbon pricing and present suggestions on how to address these. Other political economy issues that receive attention are lobbying, co‐benefits, international policy coordination, motivational crowding in/out, and long‐term commitment. The overview ends with reflections on implementing a global carbon price, whether through a carbon tax or emissions trading. The discussion goes beyond traditional arguments from environmental economics by including relevant insights from energy research and innovation studies as well.WIREs Clim Change2017, 8:e462. doi: 10.1002/wcc.462

This article is categorized under:

Climate Economics > Economics of Mitigation
Computational protein structure refinement: almost there, yet still so far to go
Authors: Feig Michael
Published: March 2017

Protein structures are essential in modern biology yet experimental methods are far from being able to catch up with the rapid increase in available genomic data. Computational protein structure prediction methods aim to fill the gap while the role of protein structure refinement is to take approximate initial template‐based models and bring them closer to the true native structure. Current methods for computational structure refinement rely on molecular dynamics simulations, related sampling methods, or iterative structure optimization protocols. The best methods are able to achieve moderate degrees of refinement but consistent refinement that can reach near‐experimental accuracy remains elusive. Key issues revolve around the accuracy of the energy function, the inability to reliably rank multiple models, and the use of restraints that keep sampling close to the native state but also limit the degree of possible refinement. A different aspect is the question of what exactly the target of high‐resolution refinement should be as experimental structures are affected by experimental conditions and different biological questions require varying levels of accuracy. While improvement of the global protein structure is a difficult problem, high‐resolution refinement methods that improve local structural quality such as favorable stereochemistry and the avoidance of atomic clashes are much more successful. WIREs Comput Mol Sci 2017, 7:e1307. doi: 10.1002/wcms.1307

This article is categorized under:

Structure and Mechanism > Computational Biochemistry and Biophysics

Molecular and Statistical Mechanics > Molecular Dynamics and Monte-Carlo Methods

Software > Molecular Modeling
Big Data Privacy and Anonymization
Authors: Torra Vicenç , Navarro-Arribas Guillermo
Published: March 2017

Data privacy has been studied in the area of statistics (statistical disclosure control) and computer science (privacy preserving data mining and privacy enhancing technologies) for at least 40 years. In this period models, measures, methods, and technologies have been developed to effectively protect the disclosure of sensitive information.

The coming of big data, with large volumes of data, dynamic and streaming data, poses new challenges to the field. In this paper we will review some of these challenges and propose some lines of research in the field.