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Objectives To evaluate and present the data regarding clinical, laboratory, radiological and the results of molecular genetic analysis of patients with hyperinsulinemic hypoglycemia in our clinics. Methods A total of 9 patients with CHI followed at Istanbul Medipol University. Data related to gender, age at presentation, birth weight, gestational age, consanguinity, glucose and insulin levels at diagnosis, treatment modalities, response to treatment, the results of genetic analysis and radiological evaluation were gathered from the files. Results The oldest age at presentation was 6 months. KATP channel mutation was detected in 55% (n: 5). Diazoxide unresponsiveness was seen in 55% (n: 5). Octreotide was effective in 3 of them. 18F-DOPA PET performed in 4 diazoxide unresponsive patients revealed focal lesion in 3 of them. Spontaneous remission rate was 66% (n:6). All the patients with normal genetic result achieved spontaneous remission. Spontaneous remission was even noted in diazoxide unresponsive patients and in patients with focal lesion on 18F-DOPA PET. Conclusions Clinical presentation of patients with congenital hypereinsulinism is heterogeneous. Spontaneous remission rate is quite high even in patients with severe clinical presentation. It is important to develop methods that can predict which patients will have spontaneous remission. Reporting the clinical and laboratory data of each patient is important and will help to guide the management of patients with hyperinsulinemic hypoglycemia.

The possibility to design composites with superior properties by incorporation of nanoscale reinforcing material still remains to be fulfilled. In the current study, bisphenol A diglycidyl ether-based epoxy resin has been successfully modified with polyhedral oligomeric silsesquioxane (POSS) nanoparticles to give epoxy/POSS nanocomposites. Carbon fiber reinforced composites with different fiber orientations are processed via vacuum bagging technique using this composite as the matrix. Scanning electron microscopy indicated that POSS nanofillers homogeneously distributed in the matrix. As proved by the tensile, flexural, and interlaminar shear strength tests, the inclusion of POSS nanofillers in the polymer matrix has promoted significant improvements in the mechanical properties of the carbon fiber reinforced POSS/epoxy hybrid composites compared to the analogues with neat epoxy matrix. Thus, hybrid composites with exceptional properties are obtained via a straightforward modification in the matrix and a novel paradigm without using any expensive compound has been added to the library of nanocomposite formulations.

Early diagnosis of mastitis is essential to reduce the expenses it imparts on the dairy industry. Existing techniques fail to provide rapid and pathogen-specific information to direct the prescript...

Selective control of chemical reactions is critical for the proper regulation of processes ranging from intricate biological systems to large scale industrial manufacturing. The progression of synthetic chemistry toward the complexity seen in Nature requires increased control over many concurrent chemical reactions in a non-interfering (orthogonal) fashion. Fortunately, the practically endless pool of synthetic chemical reactions developed to date can often be combined in an orthogonal manner to provide elegant solutions to complex chemical problems. In this review, we first highlight some of the many photochemical reactions that have been applied in orthogonal reaction protocols; the highly selective nature of photochemical reactions makes them well-suited for independent activation in the presence of other reaction components. The application of these orthogonal reactions, especially photochemical reactions, for the synthesis and modification of polymers and polymeric materials is also summarized. Importantly, the use of orthogonal chemical reactions can provide additional opportunities for synthesizing advanced and functional polymeric materials compared to traditional synthetic procedures.

The synthesis of polyethylene

Prior research suggests that last-in-first-out (LIFO) inventory policy produces higher accruals quality than first-in-first-out (FIFO), leading to lower information risk for LIFO firms. Equity investors, in turn, price lower information risk by giving a premium to LIFO firms. Prior research also suggests that LIFO inventory policy, by understating aggregate earnings and net assets, creates hidden reserves that can be released to produce higher future earnings. Prior research, however, is silent on how debtholders price inventory policy choice. Focusing on private debtholders, we explore three research questions: (a) Do private debtholders price LIFO differently from FIFO? (b) If so, how does downside risk affect the pricing of LIFO? and (c) What is the underlying reason for the pricing effect, accounting quality, or hidden reserves? First, we find that LIFO is associated with a lower loan spread than FIFO. Not surprisingly, the pricing effect of LIFO is larger in high-inflation years than in other years. Second, we find that the pricing effect of LIFO is much larger for unrated firms than for rated firms. Third, we find that the negative association between LIFO and loan spread is driven primarily by hidden LIFO reserves rather than accounting quality. Overall, our evidence shows that inventory policy choice affects private debtholders’ pricing decisions, and this effect is primarily due to future earnings implications of hidden LIFO reserves.

Dimanganese decacarbonyl (Mn2(CO)10) and alkyl halide combination has unique visible light radical generating property which is useful in the fabrication of many complex macromolecular structures. Herein, we present a generic simple and rapid synthetic approach for the preparation amphiphilic hyperbranched macromolecular structures with controlled branching density and hydrophilicity. The method is based on the visible light induced self-condensing vinyl copolymerization of methyl methacrylate (MMA), 2-(2-bromoisobutryloxy)ethyl methacrylate (BIBEM) and poly(ethylene glycol) methyl ether methacrylate as monomer, inimer and hydrophilic comonomer, respectively, in the presence of Mn2(CO)10. The resulting polymers possess both hydrophobic and hydrophilic sequences offering many potential bio applications such as controlled drug delivery and release. Moreover, the resulting polymers contain also unreacted bromide groups in the final structure which allow postfunctionalization through copper(I)-catalyzed alkyne-azide cycloaddition “click” reactions.

We investigate the impact of the magnitude of current sales changes on asymmetric cost behavior. We expect that managers are likely to consider small (large) current sales decreases as temporary (permanent). Therefore, they will be less (more) likely to cut costs for small (large) current sales decreases. Accordingly, we predict and find that, conditional on a prior sales increase, cost stickiness is greater for small current sales changes than for large current sales changes. In addition, prior research suggests that, conditional on a prior sales decrease, slack resources retained from the prior period might lead to cost anti-stickiness. We expect that slack resources retained from the prior period will have a greater (smaller) impact on cost behavior for small (large) current sales changes. Accordingly, we predict and find that, conditional on a prior sales decrease, cost anti-stickiness is greater for small current sales changes than for large current sales changes. JEL Classifications: M41; M46; G12.

A new polymerization mechanistic transformation strategy, combining two different controlled polymerization techniques of different modes, atom transfer radical polymerization (ATRP) and photoinduced radical oxidation/addition/deactivation (PROAD), is successfully applied for the synthesis of block copolymers. Thus, mono- or bi- bromide functional polystyrenes (PS-Br or Br-PS-Br) synthesized by light induced ATRP were used as macroinitiator for the living cationic polymerization of isobutyl vinyl ether via PROAD process to give the corresponding block copolymers. In this way, depending on the structure of the macroinitiator, AB or ABA type block copolymers (PS-b-PIBVE or PIBVE-b-PS-b-PIBVE) were formed. The final polymers and precursor polymers were characterized by spectral and chromatographic analyses.

In the present study, homogeneous mixtures of halloysite nanotubes (HNTs)-epoxy nanocomposites are prepared through chemical treatments. Naturally present halloysite nanotubes (HNT) are primarily modified by 3-(glycidyloxypropyl)trimethoxysilane and subsequently utilized as nanofillers in a mixture of bisphenol A diglycidyl ether and trimethylolpropane triglycidyl ether by varying weight % of modified HNT from 0 to 8%. Photoinitiated cationic crosslinking polymerization of this mixture facilitates the in-situ preparation of HNT/thermoset nanocomposites at room temperature. The covalent attachment of HNT in the thermoset matrix has been confirmed by monitoring the characteristic signals of the mixture, nanofiller, neat thermoset, and final nanocomposite using fourier transformed infrared (FT-IR) spectroscopy. Furthermore, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses proved the existence and distribution of HNT in the thermoset nanocomposites. Indeed, a combination of agglomerated/non-agglomerated HNTs in the thermoset matrix is also determined. On the other hand, mechanical properties of nanocomposites are significantly improved with increase in HNT loading up to 4% ratio. Adding 4% of modified HNT into epoxy increased its tensile strength and elasticity modulus by 6.9 times and 2.3 times than the corresponding neat epoxy thermoset, respectively, without scarifying thermal stability. Therefore, the HNT/epoxy thermoset nanocomposites are suitable candidates for various applications as an alternative of expensive carbon nanotube containing analogues.

We investigate the relationship between cost stickiness and management earnings forecasts. Prior research suggests that earnings are more volatile for sticky cost firms resulting in greater earnings forecast errors. The greater forecast errors might increase investors' demand for information and induce managers to issue earnings forecasts. Alternatively, managers might refrain from issuing earnings forecasts for sticky cost firms because greater forecast errors might damage managers' credibility and adversely affect their job security. We find that cost stickiness is positively associated with management earnings forecast issuance, suggesting that the benefits outweigh the costs. Prior research also suggests that cost stickiness has negative implications for earnings. We find a positive association between cost stickiness and management earnings forecast errors, suggesting that managers do not fully incorporate the negative implications of cost stickiness into their forecasts. Finally, we find that analysts' forecast errors for sticky cost firms are greater than managers'. JEL Classifications: M41; M46; G12.

Current food date marking tools fail to take into account variables that impact shelf life, leading to food waste and posing human health risks. Herein, we develop a polydiacetylene/zinc oxide (PDA/ZnO) colorimetric sensor that can indicate milk freshness in real time. The PDA/ZnO system is engineered to indicate the freshness of full cream milk by monitoring its pH based on lactic acid concentration, an indicator of bacterial spoilage. The sensitivity is tuned by selection of the diacetylene monomers from which it is composed. Designs constructed from shorter chain diacetylenes are found to undergo chromatic transitions at a lower lactic acid concentration. Two new methods to tune PDA/ZnO sensitivity to lactic acid are explored, including relocation of the diacetylene functional group and lipid doping. A system constructed from 5,7-hexadecadiynoic acid (HDDA) and ZnO can discriminate between fresh (pH 6.8-6.0), spoiling (pH 6.0-4.5), and spoiled milk (pH 4.5-4.0) by a respective blue to purple to red color change. The chromatic stability of the PDA/ZnO sensor in food is studied as previous reports have shown the system to be unstable. We present a new method that stabilizes the nanocomposite by pre-exposure to the food matrix prior to photopolymerization.

Synthesis of amphiphilic polysulfone graft copolymers by ‘‘Click’’ chemistry is described. First, a commercial PSU was chloromethylated to give chloro-funtional PSU (PSU-Cl). Subsequently, chloride groups were converted into azide moieties by nucleophilic substitution. Hydrophilic poly(N,Ndimethylacrylamide) (PDMA) side chains were then attached via a “grafting to” approach by using coppercatalyzed azide–alkyne cycloaddition (CuAAC). Precursor polymer and the final amphiphilic copolymers were characterized by proton nuclear magnetic resonance ( 1H NMR), fourier-transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC) and contact angle measurements.

A straightforward transformation protocol combining two distinct living polymerization methods for the controlled synthesis of block copolymers is described. In the first step, bromo-terminated poly(methyl methacrylate) is prepared by atom transfer radical polymerization (ATRP). Then, a bromide end group is substituted with a triphenylmethyl (trityl) functionality under visible light irradiation using dimanganese decacarbonyl (Mn2 (CO)10 ) photochemistry. The resulting polymers with trityl end groups are used as macroiniferter for the polymerization of styrene and tert-butyl acrylate (tBA) to yield desired block copolymers with narrow molecular weight distribution. Moreover, the amphiphilic copolymers with acrylic acid functionalities are obtained by the hydrolyzation of poly(tert-butyl acrylate) containing block copolymers with trifluoroacetic acid.

Linear poly(hydroxyethyl methacrylate-co-methyl methacrylate) P(HEMA-co-MMA) and poly(dimehylaminoethyl methacrylate-co-methyl methacrylate) P(DMAEMA-co-MMA) and their corresponding hyperbranched copolymers were synthesized by conventional photoinitiated free radical polymerization and self-condensing vinyl polymerization (SCVP) using Type I and Type II photoinitiators, respectively. Then, the polymers were processed by electrospraying in N, N-dimethylformamide. The surface of the resulting electrospray coatings was examined by SEM, XPS, and WCA then compared with those prepared by drop casting. Regardless of the structural nature of the polymers, electrospraying allows the preparation of rough surface that shows more hydrophobic behavior. Electrospray coatings with linear and hyperbranched copolymers exhibited WCA as ∼150° and ∼130°, respectively, indicating that branching reduces the WCA., Istanbul Technical University; Scientific and Technological Research Council of Turkey (TUBITAK)

The synthesis of polyethylene-graft-polystyrene copolymers by a multistep “grafting from” approach is described. In the first step, a bromo-functional polyethylene (PE-Br) was synthesized via ring-opening metathesis polymerization (ROMP) of cis-cyclooctene (COE) and quantitative hydrobromination. Subsequent irradiation of PE-Br under visible light in the presence of dimanganese decacarbonyl (Mn2(CO)10) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) resulted in the formation of TEMPO-substituted polyethylene (PE-TEMPO). Polystyrene (PS) chains were then grown via nitroxide mediated radical polymerization (NMRP) from the PE-TEMPO precursor to give desired PE-g-PS copolymers in a controlled manner. The intermediates at each step and final graft copolymers were characterized by 1H NMR, FT-IR, GPC, and DSC analyses.

We investigate the relationship between R&D investments and loan spread. Prior research documents that R&D is associated with greater future benefits and risks, suggesting that the valuation of R&D depends on a tradeoff between the two. Some research finds that bondholders consider that the benefits of R&D outweigh its risks: R&D is negatively associated with bond yields. This is surprising given that debt holders are more concerned about downside risk due to asymmetric payoffs. Using data on private debt from the US, we find an overall positive association between loan spread and R&D intensity, suggesting that the riskiness of R&D appears to outweigh its benefits for private lenders. Furthermore, an asymmetric payoff structure implies that the risks of R&D for lenders increase with default risk. Consistent with this argument, we find a positive association between R&D and loan spread for firms that are smaller, with high default-risk ratings, unrated (no public debt), or in industries with weaker legal protection. Unrated firms are in the most R&D-intensive group and make up nearly 60% of the firms with private debt. Consequently, studies that exclude unrated firms are likely to present an incomplete picture of the perspective of debt holders on R&D.

A facile strategy for synthesizing block copolymers by the combination of two different living polymerization techniques, namely, photoinduced radical oxidation/addition/deactivation (PROAD) and iniferter processes is described. In the first step, PROAD polymerization of isobutyl vinyl ether using bromotriphenylmethane, dimanganese decacarbonyl (Mn2 (CO)10 ), and diphenyliodonium bromide (Ph2 I+ Br- ) is carried out to yield polymers with triphenylmethyl (trityl) end groups. These prepolymers are used as macroiniferters in thermally induced free radical polymerization of vinyl monomers such as methyl methacrylate, tert-butyl acrylate, and styrene, resulting in the formation of corresponding block copolymers free from homopolymers. The precursor polymer and final block copolymers are characterized by 1 H NMR, FT-IR, GPC, and DSC analyses.

Hyperbranched polymers (HBPs), a unique class of dendritic macromolecules, have received continuous interest from macromolecular scientists due to their inherent properties such as high level of functional terminal units, high solubility, and low viscosity. Despite enormous efforts devoted to the synthesis of HBPs by traditional methods such as single and double monomer strategies involving step-growth polymerization and self-condensing vinyl polymerization (SCVP) processes, there have been limited attempts to employ light-induced processes. Photochemical methods, however, exhibit distinct advantages not characteristically disclosed by traditional ones, such as spatial and temporal control, low energy, and site-specific activation. This review, after a brief summary of the conventional methods, presents the unique features and the key functionalities of the inimers for photoinduced SCVP and strategies for preparing HBPs.

A novel polymerization mechanism transformation strategy, combining ring-opening metathesis polymerization (ROMP) and visible light induced cationic polymerization, is successfully applied for the synthesis of polyethylene-graft-poly(cyclohexene oxide) (PE-g-PCHO). First, cis-cyclooctene (COE) was polymerized via ROMP in the presence of a chain transfer agent and quantitatively hydrobrominated to give bromo functional polyethylene (PE-Br). Subsequent irradiation of PE-Br in the visible range using dimanganese decacarbonyl (Mn-2(CO)(10)) and diphenyl iodonium hexafluorophosphate (Ph2I+PF6) as radical generator and oxidant, respectively, initiated cationic polymerization of cyclohexene oxide (CHO) resulting in the formation of PE-g-PCHO. The effect of irradiation time and Mn-2(CO)(10) concentration on the grafting density and efficiency was evaluated. Both the precursor polymers and the corresponding graft copolymers were characterized by H-1 NMR and Fourier transform infrared (FT-IR) spectroscopy, gel-permeation chromatography (GPC), and differential scanning calorimetric (DSC) analyses.

Recent work in management accounting offers several novel insights into firms' cost behavior. This study explores whether financial analysts appropriately incorporate information on two types of cost behavior in predicting earnings—cost variability and cost stickiness. Since analysts' utilization of information is not directly observable, we model the process of earnings prediction to generate empirically testable hypotheses. The results indicate that analysts “converge to the average” in recognizing both cost variability and cost stickiness, resulting in substantial and systematic earnings forecast errors. Particularly, we find a clear pattern—inappropriate incorporation of available information on cost behavior in earnings forecasts leads to larger errors in unfavorable scenarios than in favorable ones. Overall, enhancing analysts' awareness of the expense side is likely to improve their earnings forecasts, mainly when sales turn to the worse. JEL Classifications: M41; M46; G12.

Prior research suggests that loss firms are valued based on their abandonment/adaptation option values, while profit firms are valued as going concerns. However, conservative accounting treatment of expensing of R&D leads many R&D-intensive firms to report losses even though they are not in financial distress. In this paper we investigate the difference in valuation of profit and loss firms that invest in intangibles, either through internal development (R&D) or purchases. The accounting treatment for internally developed intangibles is conservative in that US GAAP requires immediate expensing. Yet, it allows recognition of purchased intangibles. We find that in valuation of firms with high recognized-intangible assets, book value has more prominence in loss firms than profit firms, while that is not the case for firms with high R&D expenditures. This suggests that their abandonment/adaptation option explains the difference in valuation between profit and loss firms with high recognized-intangibles, while conservative accounting explains the valuation difference between profit and loss firms with high R&D intensity. This result suggests that recognition of intangibles in financial statements might mitigate the conservative bias in accounting numbers.

In the present study, two amphiphilic star-hyperbranched copolymers based on poly(methyl methacrylate)-b-poly(2-hydroxyethyl methacrylate) (PMMA-b-PHEMA), with different hydrophilic PHEMA segment contents (PMMA-b-PHEMA-1, and PMMA-b-PHEMA-2), were synthesized, and their drug loading and release profiles were examined using Paclitaxel (PTX) as a model drug. The drug loading capacities and encapsulation efficiencies were found to be similar in both polymers. The encapsulation efficiencies were found to be prominent at 98% and 98.5% for PMMA-b-PHEMA-1 and PMMA-b-PHEMA-2, respectively. On the other hand, the drug release behaviors varied in favor of the block copolymer comprising shorter PHEMA chains (PMMA-b-PHEMA-1). Additionally, to assess the biological effects of PTX-loaded polymers, human non-small cell lung carcinoma (A549) cells were used. Cell viability and cell cycle analysis showed that both polymers were non-toxic to cells. The cytotoxic effect of PTX-loaded PMMA-b-PHEMA-1 on A 549 cells was greater (66.49% cell viability at 5.0 ng mL(-1) PTX) than that of PMMA-b-PHEMA-2 (72.47% cell viability at 5.0 ng mL(-1) PTX), consistent with the drug release experiments.

A simple approach for the preparation of a clickable poly(ethylene glycol)-based hydrogel as a polymeric support for protein immobilization via photoinitiated free radical polymerization of poly(ethylene glycol) diacrylate and propargyl acrylate is established. Bioconjugation to the obtained gels was achieved by azide–alkyne click reaction with azido-functionalized anti-immunoglobulin G (anti-IgG) and anti-His tag antibodies. Evaluation of the affinities of the PEG hydrogels to the corresponding substrates (IgG and His-tagged YFP, respectively) indicates their specific binding capability.

A facile synthesis method for the preparation of clickable hydrogels and linear polymers is described. The strategy pertains to the photochemical generation of initiating radicals by hydrogen abstraction of excited camphorquinone from acetylenic alcohol followed by free radical polymerization. For hydrogels, poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) diacrylate were used in the system as monomer and crosslinker, respectively. Fluorescent pyrene groups were anchored onto the hydrogels through copper-catalyzed Huisgen 1,3-dipolar azide/alkyne click reaction by using 2-azidomethyl pyrene as evidenced by Fourier transform infrared and fluorescence spectroscopy. The applicability of the method for macromolecular synthesis is also demonstrated. For this purpose, poly(methyl methacrylate) with alkyne terminal groups was prepared by photoinitiated free radical polymerization of methyl methacrylate using camphorquinone and 3-(trimethylsilyl)propargyl alcohol as sensitizer and hydrogen donor, respectively. After deprotection, the click reaction with azido polystyrene obtained by atom transfer radical polymerization followed by azidation resulted in the formation of polystyrene-b-poly(methyl methacrylate). The intermediates at various stages and the final block copolymer were characterized by spectral analysis and gel permeation chromatography. © 2014 Society of Chemical Industry

Recent achievements and future opportunities for the design of 2D, 3D, and 4D materials using photochemical reactions are summarized. Light is an attractive stimulus for material design due to its outstanding spatiotemporal control, and its ability to mediate rapid polymerization under moderate reaction temperatures. These features have been significantly enhanced by major advances in light generation/manipulation with light-emitting diodes and optical fiber technologies which now allows for a broad range of cost-effective fabrication protocols. This combination is driving the preparation of sophisticated 2D, 3D, and 4D materials at the nano-, micro-, and macrosize scales. Looking ahead, future challenges and opportunities that will significantly impact the field and help shape the future of light as a versatile and tunable design tool are highlighted.

Recent research documents the empirical phenomenon of “sticky costs” and attributes it to a theory of deliberate managerial decisions in the presence of adjustment costs. We refine this theoretical explanation and show that it gives rise to a more complex pattern of asymmetric cost behavior that combines two opposing processes: cost stickiness conditional on a prior sales increase, and cost anti-stickiness conditional on a prior sales decrease. These predictions reflect the structure of optimal decisions with adjustment costs and the impact of prior sales changes on managers' expectations about future sales changes. Empirical estimates for Compustat data support our hypotheses. We further verify our predictions using additional proxies for managers' expectations, and show that our model offers important new insights. JEL Classifications: D24; M41.

A new photoredox catalyst system for atom transfer radical polymerization is developed on the basis of visible light photocatalysis using dimanganese decacarbonyl (Mn2(CO)10) that initiates and controls the polymerization at ambient temperature. The polymerization was performed by a Mn2(CO)10–alkyl halide system with visible- or sunlight in the presence of parts per million (ppm) copper catalysts. The photogenerated ˙Mn(CO)5 radicals are not only able to abstract halogen atoms from alkyl halides to generate carbon centered radicals but also reduce the CuIIBr2 to CuIBr directly, which was used as an activator in the Atom Transfer Radical Polymerization (ATRP) of vinyl monomers such as methyl methacrylate, methyl acrylate and styrene. The method was also used to synthesize graft copolymers from commercially available poly(vinyl chloride) without additional modification.

The recently developed photoinitiated atom transfer radical polymerization has been implemented in the inverse microemulsion polymerization of oligo(ethylene glycol) monomethyl ether methacrylate. Two different mechanisms including a simultaneous reverse and normal initiated ATRP and a combination of activators generated by electron transfer and initiators for continuous activator regeneration ATRP are investigated under UV light. The effects of various reaction parameters on the resulting particles have been systematically investigated, and it has been demonstrated that the particle size can be tuned based on UV light, initial stoichiometry, and aqueous phase fraction. The formed particles contained well-defined water-soluble polymers with relatively narrow molecular weight distribution (M-w/M-n < 1.4).

The structural shift in the USA from a tangible- to an intangible-intensive economy raises a concern that reporting based on generally accepted accounting principles (GAAP) might have lost its usefulness to investors. Amir and Lev [(1996) Value relevance of nonfinancial information: the wireless communications industry, Journal of Accounting and Economics, 22(1–3), pp. 3–30] argue that accounting information is not useful for intangible-intensive firms. In contrast, Collins et al. [(1997) Changes in the value relevance of earnings and book values over the past forty years, Journal of Accounting and Economics, 24(1), pp. 39–67] find that the value relevance (measured by R-squared) of accounting information has increased over time and that value relevance for intangible-intensive industries is as high as that for tangible-intensive industries. In this article, we attempt to resolve the above discrepancy by examining the impact of scale on R-squared (Brown, S., Lo, K. and Lys, T. (1999) Use of R2 in ...

Visible light induced self-condensing vinyl polymerization is explored using 2-bromoethyl methacrylate (2-BEMA) and methyl methacrylate (MMA) as inimer and comonomer, respectively, in the presence of dimanganese decacarbonyl (Mn2(CO)10) for the preparation of hyperbranched polymers. Upon photoexcitation in the visible range, Mn2(CO)10 undergoes irreversible decomposition leading to the formation of initiating radicals through bromine abstraction from 2-BEMA. Depending on the concentrations of 2-BEMA and Mn2(CO)10 and irradiation time, hyperbranched polymers with different branching density and cross-linked polymers were formed. The resulting polymers possess unreacted bromide groups in the structure which allow postfunctionalization through visible light photopolymerization and Cu(I)-catalyzed click reactions.

Polyethylene-graft-poly(tert-butylacrylate) (PE-g-PtBA) copolymers were prepared by using a combination of ring-opening metathesis polymerization (ROMP), hydrobromination, and visible light-induced free radical polymerization. First, cis-cyclooctene was polymerized via ROMP in the presence of a chain transfer agent and quantitatively hydrobrominated. Poly(tert-butyl acrylate) (PtBA) chains were then grown via a grafting from approach from the Br-substituted linear poly(ethylene) (PE) backbone using dimanganese decacarbonyl (Mn2(CO)10) under visible light. The effect of Mn2(CO)10 concentration and irradiation time on the grafting density and efficiency was evaluated. The tert-butyl acrylate (tBA) esters of the graft copolymers were hydrolyzed into acrylic acid functionalities by acidolysis to obtain hydrophilic polyolefins. The precursor polymer, graft copolymer, and hydrolyzed polymer were characterized by 1H and 13C NMR, Fourier transform infrared, atomic force microscopy, and contact angle measurements.

Visible light-induced reverse and simultaneous reverse and normal initiation (SR&NI) atom transfer radical polymerizations of vinyl monomers are examined using various dyes and type I photoinitiators. The effect of photoinitiator types on the control of molecular weight and distribution is described. In both dye and type I photoinitiator sensitized SR&NI ATRP systems, the molecular weights increase linearly with conversion. However, the experimental molecular weights are considerably higher than the theoretical values and the polymers show broad-molecular-weight distributions ranging from 1.28 to 1.60 in the dye-sensitized SR&NI ATRP. However, the polymers obtained by SR&NI ATRP using type I photoinitiator system had molecular weight values close to the theoretical ones and very narrow-molecular-weight distributions ranging from 1.11–1.18.

This study shows that future abnormal returns to R&D increases are concentrated around subsequent earnings announcements. It further shows that market expectations, implied from stock prices, underestimate the future earnings benefits of increase in R&D. Finally, it documents that in their forecasts of future earnings, security analysts also underestimate the effect of increase in R&D spending. These results suggest that future abnormal returns following R&D increases are at least in part due to the market's underestimation of the earnings benefits of R&D increases. The finding in this study contributes to the longstanding debate in accounting on whether the US GAAP requirement to expense R&D costs when incurred causes investors to underestimate the benefits of R&D.

Using returns to scale as a conceptual foundation, we explore how R&D-related earnings performance and earnings variability depend upon firm size. We find that the positive association between the level of future earnings and R&D intensity increases with firm size, and that the positive association between the volatility of future earnings and R&D intensity decreases with firm size, consistent with R&D productivity increasing with scale. We also show that R&D scale is associated with lower market returns, consistent with the idea that R&D investment risk declines with scale.

Research has established that research and development (R&D)-intensive firms are characterized by substantial future risk-adjusted stock returns. The reasons for this phenomenon and its policy implications, however, are widely debated. Some attribute the excess returns to investors' systematic undervaluation of R&D firms and argue for improved disclosure to mitigate the mispricing. whereas others claim that the excess returns are just compensating for an R&D-speciftc risk factor We aim to provide insights into this controversy by examining R&D firms with substantial R&D outlays, that is, firms with R&D as an important ingredient in their strategy. Among such firms, we compare firms with high and low industry-adjusted R&D intensity. The high industry-adjusted R&D intensity firms are more likely to engage in basic research activities, whereas the low Indus try-adjusted R&D intensity firms are likely to mimic and extend existing technologies. As such, compared with the low industry-adjusted R&D intensity firms, the high industry-adjusted R&D intensity firms are likely to suffer from higher information asymmetry. We find that high industry-adjusted R&D intensity firms generate larger risk-adjusted returns compared with low industry-adjusted R&D intensity firms in the first five future years, after which the excess returns for the high group converge to those of the low group in the long run. This reversal in returns is consistent with undervaluation of high industry-adjusted R&D intensity firms. The long-term excess returns are positive for both the high and the low industry-adjusted R&D intensity firms, and these excess returns are partly attributable to information risk. We also show that the future excess returns of high industry-adjusted R&D intensity firms are lower for those firms who provide voluntary disclosure (earnings guidance) suggesting that the short-term undervaluation is likely due to mispricing.

Type II photoinitiated self-condensing vinyl polymerization for the preparation of hyperbranched polymers is explored using 2-hydroxyethyl methacrylate (HEMA) or 2-(dimethylamino) ethyl methacrylate (DMAEMA), and methyl methacrylate as hydrogen donating inimers and comonomer, respectively, in the presence of benzophenone and camphorquinone under UV and visible light. Upon irradiation at the corresponding wavelength, the excited photoinitiator abstracts hydrogen from HEMA or DMAEMA leading to the formation of initiating radicals. Depending on the concentration of inimers, type of the photoinitiator, and irradiation time, hyperbranched polymers with different branching densities and cross-linked polymers are formed.