bluuebunny/crossref_metadata_2025 huggingface dataset:
Refractive, Tomographic and Biomechanical Outcomes after Implantation of Ferrara ICRS in Keratoconus Patients
Authors: Salgado-Borges José M , Costa-Ferreira Cláudia , Monteiro Manuel , Guilherme-Monteiro José
Published: April 2012

Background

Nowadays, ICRS are a step in the treatment of keratoconus. The purpose of this study was to evaluate the refractive effect and the tomographic and biomechanical parameters in keratoconus patients implanted with Ferrara ICRS, and their stability after 18 months.

Materials and methods

Twenty eyes of 20 keratoconus patients implanted with ICRS were evaluated. The average follow-up was 18 months. UDVA, CDVA, biomicroscopy, tomography (Pentacam) and biomechanics (ORA) of the cornea were evaluated before and after surgery. For the comparison of groups, the Wilcoxon test was used.

Results

The mean UDVA improved from 1.00 to 0.30 and the mean CDVA improved from 0.51 to 0.12; both were statistically significant (p = 0.0001). The average keratometry decreased from 50.7D to 47.5D (p = 0.0003), and the average astigmatism decreased from 5.5D to 3.5D (p = 0.0058). The mean CCT did not change significantly after surgery, but the mean TPP increased from 441.2 to 455.2 µm (p = 0.004). There was a significant reduction in the anterior cornea elevation, both the central (from 16.2-8.8; p = 0.0066) and the minimum (from–43.2 to −57.1; p = 0.0228). No significant change was found for posterior corneal elevation and for biomechanical parameters (hysteresis or CRF).

Discussion

There was a significant improvement of UDVA and CDVA after ICRS implantation, in keratoconic eyes. There was a significant and stable corneal flattening, and a decrease of the astigmatism. Corneal biomechanic parameters did not change.

How to cite this article

Salgado-Borges JM, Costa-Ferreira C, Monteiro M, Guilherme-Monteiro J, Torquetti L, Ferrara P, Ambrósio R Jr. Refractive, Tomographic and Biomechanical Outcomes after Implantation of Ferrara ICRS in Keratoconus Patients. Int J Keratoco Ectatic Corneal Dis 2012;1(1):16-21.
Long-term Follow-up of Pachymetric and Topographic Alterations after Corneal Collagen Cross-Linking for Keratoconus
Authors: Zotta Paraskevi G , Almaliotis Diamantis D , Kymionis George D , Diakonis Vasilios F , Moschou Kostas A , Karampatakis Vasileios E
Published: April 2012

Purpose

To determine the long-term alterations of corneal thickness, along with topographic outcomes, after corneal collagen cross-linking treatment (CXL) for keratoconus.

Materials and methods

In this retrospective case series, 46 patients (52 eyes), 32 males and 14 females, with progressive keratoconus were included. All eyes underwent CXL in accordance with the standard protocol (Dresden) for the treatment of their ectatic corneal disorder between January 2006 and June 2007. Pachymetric and topographic outcomes were evaluated preoperatively and at 1, 3, 6, 12, 24 and 36 months postoperatively.

Results

Mean follow-up was 28.08 ± 8.39 months (range, from 12 to 36 months). A statistically significant decline in corneal pachymetric values (at the thinnest location) when compared with preoperative values (467.65 ± 41.08 µm) was demonstrated at 1 (437.63 ± 50.57 µm), 3 (439.08 ± 52.27 µm), 6 (449.37 ± 52.73 µm), 12 (449.63 ± 83.53 µm) and 24 (459.97 ± 47.32 µm) months after CXL (p < 0.05, for all mentioned time intervals). Return to preoperative pachymetric values (469.52 ± 40.52 µm) was revealed 36 months post-CXL (p > 0.05). With respect to topographic (flat and steep keratometric values, keratoconus index), no statistically significant differences between preoperative and all postoperative intervals were found (p > 0.05, for all values for all time intervals).

Conclusion

Corneal pachymetric values reduce significantly up to 24 months after CXL treatment, while a return to preoperative values was revealed 36 months after the procedure. No significant changes’ concerning topographic outcomes was demonstrated after CXL, indicating stability of these parameters.

How to cite this article

Zotta PG, Almaliotis DD, Kymionis GD, Diakonis VF, Moschou KA, Karampatakis VE. Long-term Follow-up of Pachymetric and Topographic Alterations after Corneal Collagen Cross-Linking for Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):22-25.
Predictors of Clinical Outcomes after Intrastromal Corneal Ring Segments Implantation
Authors: Torquetti Leonardo
Published: April 2012

Purpose

To evaluate the influence of age and severity of keratoconus in the clinical outcomes of implantation of Ferrara intrastromal corneal ring segments (ICRS).

Methods

A total of 1,073 eyes of 810 patients, consecutively operated from January 2006 to July 2008, were evaluated. Two independent analysis were made according to the age of patients and keratoconus staging. Four groups were created according to the age of patients: < 20 years old, 20 to 30, 30 to 40 and >40 years old. The patients were also evaluated according to the keratoconus stage (I to IV). The outcome analysis included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry (K), asphericity (Q), corneal volume (CV) and pachymetry. All patients were evaluated using the Pentacam.

Results

The postoperative increase in UDVA and CDVA was statistically significant in all groups (p < 0.05). The magnitude of improvement of CDVA was larger for patients between 21 and 30-year-old (CDVA = 20/40) and patients with keratoconus grade I (CDVA = 20/35) (p < 0.05). There was a statistically significant increase in CV and pachymetry postoperatively in all groups. The keratometry (3.95D) and asphericity (–0.77) reduction were larger in patients younger than 20-year-old and in patients with keratoconus grade IV (p < 0.05).

Conclusion

The best clinical outcomes are seen in patients between 20 and 30-year-old and initial cases of keratoconus (grade I). The more advanced the keratoconus, the larger magnitude of K and Q reduction after ICRS implantation.

How to cite this article

Torquetti L, Ferrara G, Ferrara P. Predictors of Clinical Outcomes after Intrastromal Corneal Ring Segments Implantation. Int J Keratoco Ectatic Corneal Dis 2012;1(1):26-30.
Impact of aerosol composition on cloud condensation nuclei activity
Authors: Zhang Q. , Meng J. , Quan J. , Gao Y. , Zhao D. , Chen P. , He H.
Published: April 2012

Abstract. The impact of aerosol composition on cloud condensation nuclei (CCN) activity were analyzed in this study based on field experiments carried out at downtown Tianjin, China in September 2010. In the experiments, the CCN measurements were performed at supersaturation (SS) of 0.1%, 0.2% and 0.4% using a thermal-gradient diffusion chamber (DMT CCNC), whereas the aerosol size distribution and composition were simultaneously measured with a TSI SMPS and an Aerodyne Aerosol Mass Spectrometer (AMS), respectively. The results show that the influence of aerosol composition on CCN activity is notable under low SS (0.1%), and their influence decreased with increasing SS. For example, under SS of 0.1%, the CCN activity increases from 4.5±2.6% to 12.8±6.1% when organics fraction decrease from 30–40% to 10–20%. The rate of increase reached up to 184%. While under SS of 0.4%, the CCN activity increases only from 35.7±19.0% to 46.5±12.3% correspondingly. The calculated NCCN based on the size-resolved activation ratio and aerosol number size distribution correlated well with observed NCCN at high SS (0.4%), but this consistence decreased with the falling of SS. The slopes of linear fitted lines between calculated and observed NCCN are 0.708, 0.947, and 0.995 at SS of 0.1%, 0.2% and 0.4% respectively. Moreover, the stand deviation (SD) of calculated NCCN increased with the decreasing of SS. A case study of CCN closure analyses indicated that the calculated error of NCCN could reach up to 34% at SS of 0.1% if aerosol composition were not included, and the calculated error decreased with the raising of SS. It is decreased to 9% at SS of 0.2%, and further decreased to 4% at SS of 0.4%.
Aerosol forcing based on CAM5 and AM3 meteorological fields
Authors: Zhou C. , Penner J. E. , Ming Y. , Huang X. L.
Published: April 2012

Abstract. We use a single aerosol model to explore the effects of the differing meteorological fields from the NCAR CAM5 and GFDL AM3 models. We simulate the global distributions of sulfate, black carbon, organic matter, dust and sea salt using the University of Michigan IMPACT model and use these fields to calculate aerosol direct and indirect forcing, thereby isolating the impacts of the differing meteorological fields. Over all, the IMPACT-AM3 model predicts larger burdens and longer aerosol lifetimes than the IMPACT-CAM5 model. However, the IMPACT-CAM5 simulations transport more black carbon to the polar regions and more dust from Asia towards North America. These differences can mainly be attributed to differences in: (1) the vertical cloud mass flux and large-scale precipitation fields which determine the wet deposition of aerosols; (2) the in-cloud liquid water content and the cloud coverage which determine the wet aqueous phase production of sulfate. The burden, lifetime and global distribution, especially black carbon in polar regions, are strongly affected by choice of the parameters used for wet deposition. The total annual mean aerosol optical depth (AOD) at 550 nm ranges from 0.087 to 0.122 for the IMPACT-AM3 model and from 0.138 to 0.186 for the IMPACT-CAM5 model (range is due to different parameters used for wet deposition). Even though IMPACT-CAM5 has smaller aerosol burdens, its AOD is larger due to the much higher relative humidity in CAM5 which leads to more hygroscopic growth. The corresponding global annual average anthropogenic and all-sky aerosol direct forcing at the top of the atmosphere ranges from −0.25 to −0.30 W m−2 for IMPACT-AM3 and from −0.48 to −0.64 W m−2 for IMPACT-CAM5. The global annual average anthropogenic 1st aerosol indirect effect at the top of the atmosphere ranges from −1.26 to −1.44 W m−2 for IMPACT-AM3 and from −1.74 to −1.77 W m−2 for IMPACT-CAM5.
Antarctic ozone loss in 1989–2010: evidence for ozone recovery?
Authors: Kuttippurath J. , Lefèvre F. , Pommereau J.-P. , Roscoe H. K. , Goutail F. , Pazmiño A. , Shanklin J. D.
Published: April 2012

Abstract. We present a detailed estimation of chemical ozone loss in the Antarctic polar vortex from 1989 to 2010. The analyses include ozone loss estimates for 12 Antarctic ground-based (GB) stations. All GB observations show minimum ozone in the late September–early October period. Among the stations, the lowest minimum ozone values are observed at South Pole and the highest at Dumont d'Urville. The ozone loss starts by mid-June at the vortex edge and then progresses towards the vortex core with time. The loss intensifies in August–September, peaks by the end of September–early October, and recovers thereafter. The average ozone loss in the Antarctic is revealed to be about 33–50% in 1989–1992 in agreement with the increase in halogens during this period, and then stayed at around 48% due to saturation of the loss. The ozone loss in the warmer winters (e.g. 2002, and 2004) is lower (37–46%) and in the colder winters (e.g. 2003, and 2006) is higher (52–55%). Because of small inter-annual variability, the correlation between ozone loss and the volume of polar stratospheric clouds yields ~0.51. The GB ozone and ozone loss values are in good agreement with those found from the space-based observations of the Total Ozone Mapping Spectrometer/Ozone Monitoring Instrument (TOMS/OMI), the Global Ozone Monitoring Experiment (GOME), the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and the Aura Microwave Limb Sounder (MLS), where the differences are within ±5% and are mostly within the error bars of the measurements. The piece-wise linear trends computed from the September–November vortex average GB and TOMS/OMI ozone show about −4 to −5.6 DU (Dobson Unit) yr−1 in 1989–1996 and about +1 DU yr−1 in 1997–2010. The trend during the former period is significant at 95% confidence intervals, but the trend in 1997–2010 is significant only at 85% confidence intervals. Our analyses suggest a period of about 9–10 yr to get the first detectable ozone recovery signal at the 95% confidence intervals with the current ozone trends in the Antarctic. Thus, this study reveals that the recovery of the Antarctic ozone is well on course.
A New Species of the Genus Dactylochelifer Beier from Shanxi, China (Pseudoscorpiones: Cheliferidae)
Authors: Gao Zhi-zhong , Zhang Feng
Published: April 2012

A new pseudoscorpion species, Dactylochelifer luyaensis sp. nov., belonging to the family Cheliferidae Risso, 1826, is described and illustrated in this paper. The specimens were collected from leaf litter in Shanxi province, China.
Assessing Ammonia Treatment Options
Authors: Blute Nicole , Ghosh Amlan , Lytle Darren
Published: April 2012

This is the second of three articles to help water system operators understand ammonia and how to monitor and control its effects at the plant and in the distribution system. The first article (Opflow, April 2012) provided an overview of ammonia's chemistry, origins, and water system effects. This article focuses on treatment options for removing ammonia from source water prior to distribution and how to monitor and control ammonia. Next month's article will provide case studies explaining how utilities have dealt with ammonia.
Synthesis in Green Solvents
Authors: Orha László , Akien Geoffrey , Horváth István T.
Published: April 2012

The sections in this article are

The Role of Solvents in Synthesis

Types of Solvent

Atomic Liquids

Molecular Liquids

Ionic Liquids

Solvent Polarity

Protic Solvents

Problems with Solvents

Application of Green Solvents

Water

Fluorous Solvents

Supercritical Carbon Dioxide

Ionic Liquids

Conclusion
SynthesesviaC–HBond Functionalizations
Authors: Ackermann Lutz , Kapdi Anant R. , Potukuchi Harish K. , Kozhushkov Sergei I.
Published: April 2012

The sections in this article are

Introduction

Direct Arylations of Arenes

“Green” Aspects of Direct Arylation of ArylC–HBonds

Chelation‐Assisted Direct Arylations of Arenes

Non‐Directed Direct Arylations of Arenes

Direct Arylations of Heteroarenes

Direct Arylations of Electron‐Deficient Heteroarenes

Direct Arylations of Electron‐Rich Heteroarenes

Catalytic Oxidative Arylations of (Hetero)arenes

Introduction

Oxidative Homocouplings

Cross‐Dehydrogenative Arylations

Conclusion

Acknowledgments
Synthesis Without Metals
Authors: Akiyama Takahiko
Published: April 2012

The enantioselective synthesis of organic compounds is one of the key issues to be resolved in the field of synthetic organic chemistry because chiral organic compounds are important as pharmaceutical products, agrochemicals, and fine chemicals. Until fairly recently, transition metal complexes and enzymes had been utilized primarily as catalysts for enantioselective synthesis. List, Lerner, and Barbas reported an aldol reaction catalyzed by (
S
)‐proline, and MacMillan reported MacMillan's catalyst for the Diels–Alder reaction. Following these two seminal reports, organocatalysis has emerged as a novel asymmetric methodology viable for a number of transformations. Metal‐based catalysts, which are sensitive to oxygen and water, are therefore prepared
in situ
from a metal salt and a chiral ligand and employed directly. In contrast, asymmetric organocatalysts are generally stable and thus easy to handle. Recently, chiral organocatalysts were found to complement metal‐based catalysts. In this chapter, an overview of chiral organocatalysts, including the seminal work, is presented, focusing on the recently developed chiral Brønsted acid catalysts. The catalysts discussed include proline and derivatives, MacMillan's catalyst, peptide catalysts, ketone catalysts, phase‐transfer catalysts, amine catalysts, guanidinium salt catalysts, hydrogen‐bond catalysts, and Brønsted acid catalysts.
Photocatalysis by NanostructuredTiO2‐based Semiconductors
Authors: Cargnello Matteo , Fornasiero Paolo
Published: April 2012

Photocatalysis is one of the most promising fields for sustainable chemistry of the twenty‐first century. It can contribute to solving environmental, energetic, and chemical problems and to the sustainable production of commodities in the near future. It has a close relationship with green chemistry since sunlight, which is an intrinsic infinite source of energy, can be used to promote chemical transformations which are generally performed with expensive chemical treatments at medium/high temperatures. The advent of nanotechnology offered the possibility of careful tuning of the properties of the semiconducting materials used in photocatalysis. This resulted in a tremendous improvement in the efficiency of photocatalytic processes in many sectors. Nanomaterials can possess significantly different characteristics to those of the corresponding bulk systems. The manipulation of materials down to the nanometric scale led to a new generation of photocatalysts, which, often under visible light, are significantly more stable and active. TiO2‐based materials today represent the major photocatalysts, and their reactivity is strictly related to their nanostructure. This chapter focuses on some key photocatalytic applications of TiO2and TiO2‐related materials, without the intention of being an exhaustive review.
Toxicity of Carbon Nanotubes
Authors: Movia Dania , Giordani Silvia
Published: April 2012

The sections in this article are

Introduction – Nanotoxicology: Should We Worry?

Toxicity of Carbon Nanotubes

Challenges in the Assessment ofCNTToxicity

Interaction with Dispersing Medium

Interaction with Cytotoxicity Assays

Effect of Impurities

Effect of Dispersion

Dermal Exposure toCNTs

Dermal Cytotoxicity

In VivoDermal Toxicity

Pulmonary Response toCNTs

Pulmonary Cytotoxicity

In VivoPulmonary Toxicity

Toxic Response toCNTsin the Intra‐Abdominal Cavity

CNTCytotoxicity in the Intra‐Abdominal Cavity

In VivoCNTToxicity in the Intra‐Abdominal Cavity

CNTsand Immunity

Recognition ofCNTsby Macrophages

In VitroResponses of Macrophages Exposed toCNTs

CNTsand ImmunityIn Vivo

Local Immune Responses

Allergic Immune Responses

Systemic Immune Alterations

CNTInteractions with the Cardiovascular Homeostasis

In VitroInteractions

In VivoCNTToxicity to Cardiovascular Homeostasis

Genotoxicity and Mutagenicity ofCNTs

In VitroStudies

In VivoStudies

Biodistribution and Pharmacokinetics ofCNTs

Internalization ofCNTsinto Mammalian Cells

Biodegradation ofCNTs

Biocompatibility ofCNT‐Based Biomaterials

Conclusions – AreCNTssafe?

Abbreviations
The Design of Safer Chemicals: Past, Present, and Future Perspectives
Authors: DeVito Stephen C.
Published: April 2012

The sections in this article are

Evolution of the Concept

In the Development of Drug Substances: Emergence of the Medicinal Chemist

In the Development of Pesticide Substances

In the Development of Industrial Chemical Substances

Stagnation of the Concept Because of Section 5 of the
TSCA

Characteristics of a “Safer Chemical”

Types of Safer Chemicals

The Ideal Chemical

The Future of the Concept

Disclaimer
Informing Substitution to Safer Alternatives
Authors: Lavoie Emma , DiFiore David , Marshall Meghan , Lin Chuantung , Grant Kelly , Hart Katherine , Arnold Fred , Morlacci Laura , Vokes Kathleen , Hetfield Carol , Sommer Elizabeth , Vrabel Melanie , Cushmac Mary , Auer Charles , Davies Clive
Published: April 2012

The sections in this article are

Design for Environment Approaches to Risk Reduction: Identifying and Encouraging the Use of Safer Chemistry

Assessment of Safer Chemical Alternatives: Enabling Scientific, Technological, and Commercial Development

Informed Substitution

Functional Use as an Analytical Construct

Defining Safer Chemistry – theDfECriteria for Safer Chemical Ingredients

Continuous Improvement to Advance Green Chemistry

Best Practices to Manage Risks in the Absence of Safer Substitutes

Life‐Cycle Thinking: A Holistic Approach

Examples that Illustrate Informed Substitution

Informing Real‐Time Substitution Decisions: Chemical Alternative Assessment for Pentabromodiphenyl Ether

The Partnership

The Alternatives Assessment

Encouraging Informed Substitution: Safer Product Labeling Program

Substituting to Safer Surfactants

The Safer Detergents Stewardship Initiative

CleanGredients®

Developing and Applying Best Practices in the Absence of Safer Substitutes: Isocyanates

Best Practices as an Important Risk Management Approach

New Developments in Manufacturing Polyurethanes Without Using Isocyanates

Safer Manufacture of Diisocyanates Without Using Phosgene

Life‐Cycle Assessment to Inform Alternatives to Leaded Solder for Electronics

Conclusion

Disclaimer
Design of Safer Chemicals – Ionic Liquids
Authors: Beadham Ian , Gurbisz Monika , Gathergood Nicholas
Published: April 2012

The sections in this article are

Introduction

Environmental Considerations

Ionic Liquids – a Historical Perspective

First‐Generation
ILs

From Ionic Liquid Stability to Biodegradability

Overcoming the Inertness of 1‐Substituted–3‐Methylimidazolium Cation

Conclusion

Acknowledgements
Designing Safer Organocatalysts – What Lessons Can Be Learned When the Rebirth of an Old Research Area Coincides with the Advent of Green Chemistry?
Authors: Beadham Ian , Gurbisz Monika , Gathergood Nicholas
Published: April 2012

The sections in this article are

Introduction

A Brief History of Organocatalysis

Pre‐1950s: From Humble Beginnings

1950s–1960s

1970s: Organocatalysis Begins in Earnest

1980s

1990s

2000–Present

Advantages of Organocatalysts

Catalysts from the Chiral Pool

“Rules of Thumb” for Small Molecule Biodegradability Applied to Organocatalysts

Selecting Simple Guidelines for Biodegradability

Process of Catalyst Development

Analogy Between Organocatalyst Development and Drug Design

Analogs of Nornicotine – an Aldol Catalyst Exemplifying “Natural” Toxicity

Pharmaceutically Derived Organocatalysts and the Role of Cocatalysts

Criteria to Assess the Environmental Impact of an Organocatalyst

Conclusion

Acknowledgements
Improvements to the Environmental Performance of Synthetic‐Based Drilling Muds
Authors: Bakhtyar Sajida , Gagnon Marthe Monique
Published: April 2012

Drilling muds used by the petroleum exploration and production industry have the role of lubricating and cooling the drilling bits and facilitating the transport of crushed rocks to the surface of the well. The chemical formulations of the drilling muds influence their fate when discharged into the marine environment and, along with ambient parameters, determine the biodegradability and toxicity of the muds. A case study describes the comparison of aquatic toxicity and biodegradability of two different synthetic‐based drilling mud systems (SBMs), Syndrill 80:20 and Syndrill 90:10, and also individual mud ingredients. Chronic fish toxicity was measured using a suite of biomarkers of fish health. Preliminary tests led to the selection of the drilling mud Syndrill 80:20, and toxicity testing of individual ingredients of this mud showed that the primary emulsifier was the most aggressive component among all the mud ingredients tested. The present study aimed at developing an ecologically safe, green SBM by further improvements to Syndrill 80:20 through replacement of the most aggressive emulsifier with an alternative low/non‐toxic alternative. The existing Syndrill 80:20 formulation was re‐engineered by the incorporation of two alternative emulsifiers as replacements for the existing aggressive emulsifier. The new modified Syndrill 80:20 was then evaluated for its chronic toxicity against the existing Syndrill 80:20 using a suite of biomarkers of fish health. Following exposure to the modified mud system, pink snapper (Pagrus auratus) demonstrated weaker biological reactions as measured by ethoxyresorufin‐O‐deethylase (EROD) activity, biliary metabolites, and serum sorbitol dehydrogenase (SDH) activity. Closed‐bottle biodegradation tests also indicated that the new formulation is actively biodegrading under marine anaerobic conditions. Therefore, the information on the toxicity of the re‐engineered SBM provides an initial basis for evaluating its environmental performance in marine ecosystems, and may assist regulatory authorities in gaining a better understanding of the fate of SBMs in the marine environment.
Reducing Carcinogenicity and Mutagenicity Through Mechanism‐Based Molecular Design of Chemicals
Authors: Lai David Y. , Woo Yin‐tak
Published: April 2012

The sections in this article are

Introduction

Mechanisms of Chemical Carcinogenesis and Structure–Activity Relationship (SAR)

General Molecular Parameters Affecting the Carcinogenic and Mutagenic Potential of Chemicals

Physicochemical Properties

Molecular Weight

Molecular Size and Shape

Solubility

Volatility

Nature and Position of Substituents

Molecular Flexibility, Polyfunctionality, and Spacing/Distance Between Reactive Groups

Resonance Stabilization of the Electrophilic Metabolites

Specific Structural Criteria of Different Classes of Chemical Carcinogens and Mutagens

Aromatic Amines and Azo Dyes/Pigments

Polycyclic Aromatic Hydrocarbons (PAHs)

N‐Nitrosamines

Hydrazo, Aliphatic Azo and Azoxy Compounds, and Arydialkyltriazenes

Organophosphorus Compounds

Carbamates

Epoxides and Aziridines

Lactones and Sultones

Alkyl Esters of Moderately Strong and Strong Acids

Haloalkanes and Substituted Haloalkanes

N‐Mustards andS‐Mustards

N‐Nitrosamides

Aldehydes and Substituted Aldehydes

Michael Addition Acceptors

Arylating Agents

Acylating Agents and Isocyanates

Organic Peroxides

Quinones and Quinoid Compounds

Molecular Design of Chemicals of Low Carcinogenic and Mutagenic Potential

General Approaches

Specific Approaches

Aromatic Amines and Azo Dyes/Pigments

Polycyclic Aromatic Hydrocarbons (PAHs)

N‐Nitrosamines

Hydrazo, Aliphatic Azo and Azoxy Compounds, and Arydialkyltriazenes

Organophosphorus Compounds

Carbamates

Epoxides and Aziridines (Ethylenimines)

Lactones and Sultones

Alkyl Esters of Moderately Strong and Strong Acids

Haloalkanes and Substituted Haloalkanes

N‐Mustards andS‐Mustards

N‐Nitrosamides

Aldehydes and Substituted Aldehydes

Michael Addition Acceptors

Arylating Agents

Acylating Agents and Isocyanates

Organic Peroxides

Quinones and Quinoid Compounds

Conclusion

Disclaimer
Reducing Ecotoxicity
Authors: Solomon Keith R , Hanson Mark
Published: April 2012

The sections in this article are

Introduction to Key Aspects of Ecotoxicology

Protection Goals and Assessment Endpoints

Structure and Function in Ecosystems

Diversity of Sensitivity in Ecosystems

Hazard Assessment and Uncertainty

Environmental Fate and Pathways of Exposure to Chemicals in the Environment

Properties Affecting Bioavailability

Properties Affecting Bioconcentration and Biomagnification

Absorption, Distribution, Metabolism, and Excretion of Chemicals

Modeling Exposure

Mechanisms of Toxic Action

Properties Affecting Toxicity

Modeling Toxicity

Examples of Methods That Can Be Used in Designing Chemicals with Reduced Ecological Risks

Fluorinated Surfactants

Pesticides

Designing Pesticides for Lack of Persistence

Designing Specific Isomers to Reduce Risk in the Environment

Developing Pesticides That Are More Specific to the Target Organism

Ranking and Prioritizing Pesticides in Terms of Risk to the Environment

Pharmaceuticals

Macro‐ and Micro‐Contaminants Produced During Manufacture

Overview, Conclusions, and the Path Forward
New Configuration of Solid‐State Neutron Detector Made Possible with Solution‐Based Semiconductor Processing
Authors: Zhou Huiqiong , Coates Nelson E. , Hernandez‐Sosa Gerardo , Moses Daniel
Published: April 2012

The unique benefit of solution‐based fabrication of solid‐state p‐n junctions is demonstrated for radiation detection. In particular, an in situ inorganic semiconductor synthesis and film deposition facilitates a novel neutron detector configuration consisting of a host inorganic semiconductor matrix impregnated with a guest neutron sensitizing material. Spectroscopic investigations of the structural order of the top detector active layer indicate that it consists of interpenetrating networks of the host semiconductor nanocrystals and sensitizing guest material that self‐assemble during film formation. The host semiconductor network exhibits a good charge transport as evidenced by steady‐state photoconductivity measurements. The detectors developed indicate high sensitivity to ionizing radiation and a demonstrated ability to detecting thermal neutrons.
Electrostatic Self‐Assembly Conjugated Polyelectrolyte‐Surfactant Complex as an Interlayer for High Performance Polymer Solar Cells
Authors: Chang Yi‐Ming , Zhu Rui , Richard Eric , Chen Chun‐Chao , Li Gang , Yang Yang
Published: April 2012

A simple method is demonstrated to improve the film‐forming properties and air stability of a conjugated polyelectrolyte (CPE) without complicated synthesis of new chemical structures. An anionic surfactant, sodium dodecybenzenesulfonate (SDS), is mixed with cationic CPEs. The electrostatic attraction between these two oppositely‐charged materials provides the driving force to form a stable CPE‐surfactant complex. Compared with a pure CPE, this electrostatic complex is not only compatible with highly hydrophobic bulk‐heterojunction (BHJ) films, e.g. poly(3‐hexylthiophene):[6,6]‐phenyl C61 butyric acid methyl ester (P3HT:PCBM), but also works well with other low bandgap polymer‐based BHJ films. Using this complex as a cathode interface layer, a high power conversion efficiency of 4% can be obtained in P3HT:PCBM solar cells together with improved stability in air. Moreover, ∼20% performance enhancement can also be achieved when the complex is used as an interlayer to replace calcium metal for low bandgap polymer‐based BHJ systems.
Using Stated Preference and Prior Purchase Intention in the Estimation of Willingness to Pay a Premium for Genetically Modified Foods
Authors: Chiang Jeng‐Tung , Lin Chen‐Yen , Fu Tsu‐Tan , Chen Chen‐Hsin
Published: April 2012

This study provides an appropriate analytical approach using stated preference analysis and the contingent valuation method to investigate consumers’ willingness to pay a premium for genetically modified (GM) foods together with their prior purchase intentions. Although most analyses treat consumers’ attitudes and willingness to pay as separate issues, we introduce the idea of prior purchase intention to analyze these two issues as a whole. To achieve this purpose, a modeling technique invoking the multinomial logistic model and the accelerated failure time model is presented. Based on the data collected from an essential double‐bounded design, our empirical results suggest that Taiwanese consumers are willing to pay a premium of about 11NTdollars (7% of the given average market price of 150NTdollars for the non‐GMsalmon) to avoidGM‐soybean‐fed salmon. In addition, the results of this study provide evidence that our stated‐preference double‐bounded design has a better‐off statistical efficiency than the single‐bounded one.
Water‐resistant plywood adhesives prepared from phenolated larch bark in the presence of various combination catalysts
Authors: Bai Yumei , Gao Zhenhua
Published: April 2012

The properties of larch barks phenolated with various combinations of acidic catalysts and the properties of adhesives synthesized with these phenolated barks have been investigated. The results have indicated that the catalyst species used has great effects on bark phenolation and many properties of the resultant bark adhesives (BA). High‐performance liquid chromatography (HPLC) and Gel permeation chromatography (GPC) analyses have indicated that the amount of phenol bound to the bark and recondensation of phenolated components decreased with decreasing acidity of the combination catalysts used, resulting in decreases in the extent of phenolation, bound phenol content, and molecular weight but an increase in the number of active sites on the phenolated bark. Larch bark phenolated with combined catalysts can be used to prepare water‐resistant wood adhesives with low formaldehyde emission. By judiciously decreasing the acidity of the catalyst used for bark phenolation, the properties of BA, such as storage life, bond strength, and formaldehyde emission, could be effectively improved. BA‐C showed the acceptable wet bond strength and a sufficiently low formaldehyde emission, making it a good potential candidate for commercial applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Enhancement of adhesion between copper foil and polyimide film containing thermally decomposable polystyrene particles
Authors: Tsai Mei‐Hui , Huang Yi‐Chia , Tseng I‐Hsiang , Yu Hsin‐Pei , Lin Yin‐Kai
Published: April 2012

A facile method was developed to synthesize porous polyimide (PI) films with enhanced adhesion to Cu foil. Various amounts (0.1–4 wt %) of polystyrene (PS) spheres with the diameter of 250 nm were mixed with the PI precursor synthesized from pyromellitic dianhydride (PMDA) and 4,4′‐oxydianiline in N,N′‐dimethylacetamide. PS was decomposed during thermal imidization process to create the porous PI structure. The increase in surface area and surface roughness was observed from the obtained porous PI films and was a function of the PS content up to 4 wt %. A significant improvement in the adhesion strength between porous PI film and Cu foil, which was determined by 90° peel test, was achieved. The adhesion strength of PI containing 4 wt % PS to Cu was 1.53 kgf/cm compared with pure PI of 1.08 kgf/cm. Meanwhile, the synthesized porous PI films exhibit sufficient mechanical strength and thermal stability for practical applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Ageing of polymeric surfaces exhibiting flow marks—Effects on surface characteristics
Authors: Iannuzzi G. , Nafari A. , Boldizar A. , Rigdahl M.
Published: April 2012

Surface defects associated with manufacturing processes can severely impair the appearance of polymeric products. These defects can be enhanced with ageing (time, UV‐light, heat and weather conditions). In the present contribution, the interest is focused on the defects generated during injection molding of elastomer‐modified polymers that are often used in the automotive sector to produce interior and exterior components. In particular, defects denoted as “flow marks” or “tiger stripes” were investigated. Two different grades of elastomer‐modified polypropylene (PP)‐containing mineral fillers were studied here before and after heat ageing for 9 weeks at a constant temperature of 95°C. Although injection moldings are one of the grades that did not exhibit any flow marks, moldings of other PP‐grade showed such defects and they were enhanced after the ageing process. The properties and structure of the glossy and the dull bands (as well as the effect of the thermal ageing) have been assessed by several characteristics such as microhardness, nanohardness, crystallinity, and surface composition. An increase in surface hardness was noted after the ageing treatment as a consequence of increased crystallinity. Dull and glossy bands also exhibited different values of the nanohardness, glossy bands were harder, and the dull bands appeared to be less crystalline. The surface composition of glossy and dull regions was slightly different; the surface regions of the glossy areas contained higher amounts of filler particles. The effect of the ageing on the striped appearance is furthermore discussed in relation to possible depletion of the stabilizer system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Wash–dry cycle induced changes in low‐ordered parts of regenerated cellulosic fibers
Authors: Široká Barbora , Manian Avinash P. , Noisternig Michael F. , Henniges Ute , Kostic Mirjana , Potthast Antje , Griesser Ulrich J. , Bechtold Thomas
Published: April 2012

Three regenerated cellulosic fiber types: lyocell, viscose, and modal were subjected to repetitive wet–dry treatments. Simulated treatments showed reorganization of the internal fiber structure which could be determined by accessibility studies. The reduction in liquid water retention capacity was found to be greater for lyocell than that for modal and viscose, sorption of iodine, and water vapor reduced for all studied fibers. The wet–dry treatment did not have influence on chemical reactivity of cellulosic fibers characterized by complexation of iron under highly alkaline conditions. The effect of wet–dry treatment on the tenacity, elongation at break, abrasion resistance, and molecular weight distribution of fibers was also explored in this study. The reduced strength in treated specimens was not accompanied by changes in molecular weight distributions. Based on these results, the changes observed in wet–dry‐treated specimens were observed mainly owing to polymer reorganization in amorphous parts of the fibers. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Polyolefin composites with natural fibers and wood‐modification of the fiber/filler–matrix interaction
Authors: Sobczak L. , Brüggemann O. , Putz R. F.
Published: April 2012

Numerous strategies to improve the fiber–matrix interaction in natural fiber composites (NFCs) and wood polymer composites (WPCs) have been proposed and investigated. We have reviewed literature on polyolefin‐based NFCs and WPCs to get an overview of the current state of the art of compatibilization methods. Those are classified in two categories here, namely fiber‐based strategies and matrix‐based strategies. Although this issue has been covered by several reviews before, as yet no work exists that is focused on polyolefin‐based NFCs and WPCs. Furthermore, a ranking of the compatibilization methods based on their effects on material properties such as tensile/flexural strength and modulus, impact strength and water absorption, allows for an assessment of the efficiency of the various methods. As to the fiber‐based strategies, silanes, maleated polyolefins (MA‐POs), mercerization and acetylation are most thoroughly investigated. Silanes are most effective judged by achievable material property improvements, allowing for increases in tensile and flexural strength of more than 100%. Among the matrix‐based strategies, MA‐POs and isocyanates are most prominent in the literature. The first class enables the more significant material improvements, with reported increases of tensile and flexural strength of 132% and 85%, respectively. While strengths can be enhanced by many compatibilization methods, moduli, and impact strength (notched in particular) are in most cases improved to a lesser degree or even reduced. Especially, the last point calls for further attention, because impact strength is still a weak point of NFCs and WPCs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Emulsion copolymerization of styrene and butyl acrylate by reverse atom transfer radical polymerization
Authors: Wu Yumin , Dong Guoliang , Xu Jun , Ni Guangdi
Published: April 2012

Reverse atom transfer radical copolymerization of styrene (St) and butyl acrylate was carried out in emulsion under normal emulsion conditions, using CuBr2/bpy complex as catalyst. The effects of surfactant type, initiator type and concentration, and CuBr2 addition on the system livingness, polymer molecular weight control, and latex stability were examined in detail. It was found that the Polysorbate 80 (Tween 80) and azodiisobutyronitrile gave the best exhibition in this system, polymer samples were got with narrow molecular‐weight dispersity (Mw/Mn = 1.1–1.2) and linear relationships of molecular weight versus monomer conversion, as well as a relatively low polydispersity index (<0.1). Through the GPC and SEM analysis, the polymerization processes under these conditions showed good living/control characteristics relative to the processes under normal emulsion polymerization, although the latex stability was susceptible to the CuBr2 catalyst. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Properties of natural cotton stalk bark fiber under alkali treating
Authors: Li Long , Sun Jianlei , Jia Guiqin
Published: April 2012

The natural cotton stalk (CS) bark fiber was obtained through degumming of CS bark, and then treated by sodium hydroxide solution. To investigate the influence of sodium hydroxide treatment on the properties of the natural CS bark fiber, the fineness, length, breaking strength, X‐ray diffraction, and morphology were tested. The results showed that the fineness, length, and crystallinity of the fiber decreased when the fiber was treated by sodium hydroxide solution. When the sodium hydroxide content increased from 10 to 50 g/L, the strengths of the fiber increased. The surface of the fiber after treating was bright compared with before treating, and the single cell had convolutions after alkali treating. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Removal of methyl orange from aqueous solutions by magnetic maghemite/chitosan nanocomposite films: Adsorption kinetics and equilibrium
Authors: Jiang Ru , Fu Yong‐Qian , Zhu Hua‐Yue , Yao Jun , Xiao Ling
Published: April 2012

Magnetic maghemite (γ‐Fe2O3)/chitosan nanocomposite films were prepared by solution casting method and characterized by Fourier transform infrared spectra, thermogravimetric analysis, differential scanning calorimetry and X‐ray diffraction. Batch adsorption experiments were carried out utilizing the composite films to adsorb a typical azo dye, i.e., methyl orange (MO) from aqueous solutions. The effects of adsorbent dosage, solution pH, coexisting anions, and temperature were studied. Adsorption kinetic was verified by pseudo‐first‐order and pseudo‐second‐order kinetic models. Results indicated that the rate of dye adsorption followed pseudo‐second‐order kinetic model for the initial dye concentration range studied. MO adsorption onto magnetic γ‐Fe2O3/chitosan composite films was better described by Langmuir isotherm. Thermodynamic studies showed that MO adsorption was exothermic and spontaneous in nature. Because magnetic maghemite/chitosan nanocomposite films could be recovered conveniently and possessed of excellent adsorptive property, it can be developed as an economical and alternative adsorbent to decolorize or treat dye wastewater. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Design, Synthesis, and Antibacterial Activity of Novel Pleuromutilin Derivatives Bearing an Amino Thiazolyl Ring
Authors: Ling Yong , Wang Xinyang , Wang Hui , Yu Jianghe , Tang Junming , Wang Donggeng , Chen Guangtong , Huang Jinhua , Li Yuqin , Zheng Heng
Published: April 2012

A series of novel pleuromutilin derivatives containing the amino thiazolyl ring were designed, synthesized, and evaluated for their antibacterial activities in vitro against Gram‐positive clinical bacteria. All the target compounds showed better aqueous solubility compared with the lead compound (10). Most compounds displayed strong antibacterial activities against both susceptible and resistant bacteria, particularly for the compound (12f) which showed extraordinary antibacterial properties superior to amoxicillin and tiamulin. Molecular docking studies revealed that the amino thiazolyl ring, the side chains of the pleuromutilin derivatives, can be adopted in the binding pocket of the 50S ribosomal subunit near the mutilin core. Therefore, our novel findings may provide new insights into the design of novel pleuromutilin derivatives and lay the basis for further studies on these promising antibiotics for human clinical use.
Synthesis and Evaluation of 2(3H)‐Thiazole Thiones as Tyrosinase Inhibitors
Authors: Emami Saeed , Hosseinimehr Seyed Jalal , Shahrbandi Kami , Enayati Ahmad Ali , Esmaeeli Zahra
Published: April 2012

A series of 2(3H)‐thiazole thiones 3–5 was synthesized and evaluated for tyrosinase inhibition and DPPH radical scavenging activities. Among them, 3‐methyl‐4‐phenyl‐2(3H)‐thiazole thione (4a) showed good tyrosinase inhibitory activity, even better than that of the well‐known tyrosinase inhibitor, namely, kojic acid. From the structure–activity point of view, although it was found that the phenolic hydroxyl group in prototype 3–5 might contribute to the scavenging activity against DPPH radicals, there was no correlation between the potency of tyrosinase inhibition and the presence of the phenolic moiety. The in silico ADME‐Tox screening revealed that the drug‐likeness and drug‐score values of the most potent compound 4a were significantly higher than those of kojic acid.
Short‐term exposure to 50 Hz ELF‐EMF alters the cisplatin‐induced oxidative response in AT478 murine squamous cell carcinoma cells
Authors: Bułdak Rafał Jakub , Polaniak Renata , Bułdak Łukasz , Żwirska‐Korczala Krystyna , Skonieczna Magdalena , Monsiol Aleksandra , Kukla Michał , Duława‐Bułdak Anna , Birkner Ewa
Published: April 2012

The aim of this study was to assess the influence of cisplatin and an extremely low frequency electromagnetic field (ELF‐EMF) on antioxidant enzyme activity and the lipid peroxidation ratio, as well as the level of DNA damage and reactive oxygen species (ROS) production in AT478 carcinoma cells. Cells were cultured for 24 and 72 h in culture medium with cisplatin. Additionally, the cells were irradiated with 50 Hz/1 mT ELF‐EMF for 16 min using a solenoid as a source of the ELF‐EMF. The amount of ROS, superoxide dismutase (SOD) isoenzyme activity, glutathione peroxidase (GSH‐Px) activity, DNA damage, and malondialdehyde (MDA) levels were assessed. Cells that were exposed to cisplatin exhibited a significant increase in ROS and antioxidant enzyme activity. The addition of ELF‐EMF exposure to cisplatin treatment resulted in decreased ROS levels and antioxidant enzyme activity. A significant reduction in MDA concentrations was observed in all of the study groups, with the greatest decrease associated with treatment by both cisplatin and ELF‐EMF. Cisplatin induced the most severe DNA damage; however, when cells were also irradiated with ELF‐EMF, less DNA damage occurred. Exposure to ELF‐EMF alone resulted in an increase in DNA damage compared to control cells. ELF‐EMF lessened the effects of oxidative stress and DNA damage that were induced by cisplatin; however, ELF‐EMF alone was a mild oxidative stressor and DNA damage inducer. We speculate that ELF‐EMF exerts differential effects depending on the exogenous conditions. This information may be of value for appraising the pathophysiologic consequences of exposure to ELF‐EMF. Bioelectromagnetics 33:641–651, 2012. © 2012 Wiley Periodicals, Inc.
Synthesis and effect of Ce and Mn co‐doping on photoluminescence characteristics of Ca6AlP5O20:Eu novel phosphors
Authors: Shinde K. N. , Dhoble S. J.
Published: April 2012

A series of Ca6AlP5O20 doped with rare earths (Eu and Ce) and co‐doped (Eu, Ce and Eu,Mn) were prepared by combustion synthesis. Under Hg‐free excitation, Ca6AlP5O20:Eu exhibited Eu2+ (486 nm) emission in the blue region of the spectrum and under near Hg excitation (245 nm), Ca6AlP5O20:Ce phosphor exhibited Ce3+ emission (357 nm) in the UV range. Photoluminescence (PL) peak intensity increased in Ca6AlP5O20:Eu,Ce and Ca6AlP5O20:Eu, Mn phosphors due to co‐activators of Ce3+ and Mn2+ ions. As a result, these ions played an important role in PL emission in the present matrix. Ca6AlP5O20:Eu, Ce and Ca6AlP5O20:Eu, Mn phosphors provided energy transfer mechanisms via Ce3+ → Eu2+ and Eu2+ → Mn2+, respectively. Eu ions acted as activators and Ce ions acted as sensitizers. Ce emission energy was well matched with Eu excitation energy in the case of Ca6AlP5O20:Eu, Ce and Eu ions acted as activators and Mn ions acted as sensitizers in Ca6AlP5O20:Eu, Mn. This study included synthesis of new and efficient phosphate phosphors. The impact of doping and co‐doping on photoluminescence properties and energy transfer mechanisms were investigated and we propose a feasible interpretation. Copyright © 2012 John Wiley & Sons, Ltd.
PEGylated protein separations: Challenges and opportunities
Authors: Yoshimoto Noriko , Yamamoto Shuichi
Published: April 2012

See accompanying article by Seyfried et al. DOI: 10.1002/biot.201100407