Chemical Regulation Research Articles

Chemical regulation of lignin spatial conformation for a multifunctional soft material with a novel energy dissipation mechanism

Chemical regulation of lignin spatial conformation for a multifunctional soft material with a novel energy dissipation mechanism

Large scale OECD health valuation study to estimate the economic benefits of chemical regulation

Abstract Chemical regulation aims at protecting human health and the environment from the risks of chemicals, while recognizing the economic importance of the use of chemicals. Assessment of the societal impacts of chemical regulation and different policy options requires information on both costs and benefits. So far, regulators assessing chemicals regulations has not had access to high quality and internationally comparable data on the full monetary benefit of reducing health and environmental risk. The OECD has implemented a multi-country stated preference valuation project that covers ten chemicals-related health conditions (e.g. asthma, kidney disease, infertility, etc.) with more than 80 surveys with large samples in 22 countries. The OECD Surveys on Willingness-to-Pay to Avoid Negative Chemicals-Related Health Impacts (SWACHE) project aims to establish internationally comparable values for the willingness-to-pay (WTP) to avoid negative health effects due to exposure to chemicals. The values can be used to demonstrate and measure the economic benefits of minimising the morbidity impacts of chemical regulations, environmental policies and public policies in general. The latest valuation results of the project will be presented, along with key aspects of the joint methodology used and the plans to further expand this work. In addition, the OECD is collaborating with other intergovernmental organisations via the Inter-Organization Programme for the Sound Management of Chemicals (IOMC) to update the cost of inaction estimates for chemicals as part of the Global Framework on Chemicals. An update on this initiative, that can benefit from the results of the SWACHE project, will be provided.

Effect of Different Seed Treatment on Germination of Fishtail Palm (Caryota urens) under Naturally Ventilated Poly-house Conditions

An investigation was conducted to study the effect of different seed treatments comprising of mechanical scarification, chemical and plant growth regulator on germination of Fishtail palm (Caryota urens) seeds under naturally ventilated poly-house at sheth D. M. Polytechnic in Horticulture College, Anand Agricultural University, Vadodara during 2021 to 2023. There were total 12 treatments under study which was replicated trice and statistically analysed by completely randomized design at 90 days after sowing. The results revealed that treatment T12 i.e. seeds treated with GA3 1000 ppm for one day recorded significantly lesser days to initiation of germination (46.33 days) along with higher germination percentage (86.67 % and 85.00 %), germination rate index (5.90 %/day and 5.70 %/day) and germination index (255 and 243.67), coefficient of velocity of germination (6.18 and 6.02), timpson’s germination index (1275 and 1218), modified timpson germination index (42.50 and 40.61) and survival percentage (88.33 and 86.67) at 90 days after sowing during first and second year respectively. While, seed without any treatment kept in open condition treatment T1 showed poor performance in germination percentage as well as survival percentage. Thus, Fishtail palm (Caryota urens) seeds soaked in solution of 1000 ppm GA3 along with sowing them in polybags and kept under NVPH condition provides better germination and survival.

Exploring Aqueous Solution-Processed Pseudohalide Rare-Earth Double Perovskite Ferroelectrics toward X-Ray Detection with High Sensitivity.

Three-dimensional (3D) pseudohalide rare-earth double perovskites (PREDPs) have garnered significant attention for their versatile physical properties, including ferroelectricity, ferroelasticity, large piezoelectric responses, and circularly polarized luminescence. However, their potential for X-ray detection remains unexplored, and the low Curie temperature (TC) limits the performance window for PREDP ferroelectrics. Here, by applying the chemical regulation strategies involving halogen substitution on the organic cation and Rb/Cs substitution to the PREDP [(R)-M3HQ]2RbEu(NO3)6 [(R)-M3HQ=(R)-N-methyl-3-hydroxylquinuclidinium] with a low TC of 285 K, a novel 3D PREDP ferroelectric [(R)-CM3HQ]2CsEu(NO3)6 [(R)-CM3HQ=(R)-N-chloromethyl-3-hydroxylquinuclidinium] are successfully synthesized, for which the TC reaches 344 K. More importantly, such a strategy endowed [(R)-CM3HQ]2CsEu(NO3)6 with notable X-ray detection capabilities. Centimeter-sized [(R)-CM3HQ]2CsEu(NO3)6 single crystals fabricated from aqueous solutions demonstrated a sensitivity of 1307 μC Gyair -1 cm-2 and a low detectable dose rate of 152 nGyair s-1, the highest sensitivity reported for hybrid double perovskite ferroelectric detectors. This work positions PREDPs as promising candidates for the next generation of eco-friendly optoelectronic materials and also offers substantial insights into the interaction between structure, composition, and functionality in ferroelectric materials.

Exploring Aqueous Solution‐Processed Pseudohalide Rare‐Earth Double Perovskite Ferroelectrics toward X‐Ray Detection with High Sensitivity

AbstractThree‐dimensional (3D) pseudohalide rare‐earth double perovskites (PREDPs) have garnered significant attention for their versatile physical properties, including ferroelectricity, ferroelasticity, large piezoelectric responses, and circularly polarized luminescence. However, their potential for X‐ray detection remains unexplored, and the low Curie temperature (TC) limits the performance window for PREDP ferroelectrics. Here, by applying the chemical regulation strategies involving halogen substitution on the organic cation and Rb/Cs substitution to the PREDP [(R)‐M3HQ]2RbEu(NO3)6 [(R)‐M3HQ=(R)‐N‐methyl‐3‐hydroxylquinuclidinium] with a low TC of 285 K, a novel 3D PREDP ferroelectric [(R)‐CM3HQ]2CsEu(NO3)6 [(R)‐CM3HQ=(R)‐N‐chloromethyl‐3‐hydroxylquinuclidinium] are successfully synthesized, for which the TC reaches 344 K. More importantly, such a strategy endowed [(R)‐CM3HQ]2CsEu(NO3)6 with notable X‐ray detection capabilities. Centimeter‐sized [(R)‐CM3HQ]2CsEu(NO3)6 single crystals fabricated from aqueous solutions demonstrated a sensitivity of 1307 μC Gyair−1 cm−2 and a low detectable dose rate of 152 nGyair s−1, the highest sensitivity reported for hybrid double perovskite ferroelectric detectors. This work positions PREDPs as promising candidates for the next generation of eco‐friendly optoelectronic materials and also offers substantial insights into the interaction between structure, composition, and functionality in ferroelectric materials.

Multiple-Criteria Decision Analysis for Assessments of Chemical Alternatives (MCDA-ACA).

A comprehensive assessment of chemical alternatives (ACA) is necessary to avoid regrettable substitution. In a preceding study, an analysis of six hazard assessment methods found that none of them are fully aligned with the hazard assessment criteria of Article 57 of the European REACH regulation, indicating a need for a method better reflecting hazard assessment schemes in European chemical regulations. This paper presents a multiple-criteria decision analysis (MCDA) method for the ACA that takes the criteria of Article 57 of REACH into account. Investigated and presented are objective hierarchies, the aggregation of objectives, the curvature of the value functions, weights, and the introduction of a classification threshold. The MCDA-ACA method allows for the aggregation of hazards in such a way that poor performance in one hazard cannot be compensated for by good performance in another hazard. The method parameters were developed and tested using two data sets with the aim to classify chemical alternatives into acceptable (nonregrettable) and unacceptable (regrettable) alternatives according to the regulations set in Europe. The flexibility of the general method was explored by adapting the method to align with two hazard assessment schemes, Article 57 of REACH and GreenScreen. The results show that MCDA-ACA is so flexible and transparent that it can easily be adapted to various hazard assessment schemes.

Passivation of Deep‐Level Defects through Chemical Environment Regulation for Efficient CZTSSe Solar Cells Based on Active Selenium Adsorption–Desorption Process

AbstractInsufficient selenization and uneven distribution of elements caused by the poor diffusion and reaction activity of selenium clusters is one of the main issues limiting the efficiency of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells. Here, this work designs a simple and feasible strategy to improve the activity of selenium (Se) by implementing high‐temperature treatment on graphite boxes loaded with Se pellets. The rapid adsorption/desorption characteristics of graphite on active gaseous small‐molecule selenium have successfully introduced hyperactive Se4, Se3, and Se2 into the selenization process. The results indicate that the adsorbed non‐toxic gaseous active Se3 and Se4 can quickly and uniformly diffuse into the precursor film at low temperatures, thereby inducing nucleation and grain growth at both surface and back interface simultaneously, which inhibits the upward migration and aggregation of cations, especially Cu, and promotes the homogenization of elements. The overall relatively Cu‐poor chemical environment suppresses the formation of CuZn defects and [2CuZn+SnZn] defect clusters, and also promotes the generation of favorable VCu. The band tail states and non‐radiative recombination are then optimized. Finally, the CZTSSe solar cells achieve a power conversion efficiency (PCE) of 14.5%, with VOC/VOCSQ of 67% being one of the highest in the literature.

EthoCRED: a framework to guide reporting and evaluation of the relevance and reliability of behavioural ecotoxicity studies.

Behavioural analysis has been attracting significant attention as a broad indicator of sub-lethal toxicity and has secured a place as an important subdiscipline in ecotoxicology. Among the most notable characteristics of behavioural research, compared to other established approaches in sub-lethal ecotoxicology (e.g. reproductive and developmental bioassays), are the wide range of study designs being used and the diversity of endpoints considered. At the same time, environmental hazard and risk assessment, which underpins regulatory decisions to protect the environment from potentially harmful chemicals, often recommends that ecotoxicological data be produced following accepted and validated test guidelines. These guidelines typically do not address behavioural changes, meaning that these, often sensitive, effects are not represented in hazard and risk assessments. Here, we propose a new tool, the EthoCRED evaluation method, for assessing the relevance and reliability of behavioural ecotoxicity data, which considers the unique requirements and challenges encountered in this field. This method and accompanying reporting recommendations are designed to serve as an extension of the "Criteria for Reporting and Evaluating Ecotoxicity Data (CRED)" project. As such, EthoCRED can both accommodate the wide array of experimental design approaches seen in behavioural ecotoxicology, and could be readily implemented into regulatory frameworks as deemed appropriate by policy makers of different jurisdictions to allow better integration of knowledge gained from behavioural testing into environmental protection. Furthermore, through our reporting recommendations, we aim to improve the reporting of behavioural studies in the peer-reviewed literature, and thereby increase their usefulness to inform chemical regulation.

Are Hazard Assessment Methods in the Assessment of Chemical Alternatives Suitable for REACH?

The assessment of chemical alternatives for hazardous substances is an important prerequisite for avoiding regrettable substitution, and several methods have been developed in the past to perform such a hazard assessment for chemical alternatives. We investigate here whether GreenScreen, Cradle to Cradle, multiple-criteria decision analysis (MCDA), the Pollution Prevention Options Analysis System, the U.S. EPA Safer Choice Standard and Criteria, and the GHS column model 2020 from IFA use similar criteria for the evaluation of substances as Article 57 of the European chemicals regulation, REACH, and how suitable these methods are for assessing per- and polyfluoroalkyl substances. MCDA and GreenScreen were analyzed in detail using two different data sets. The results of the assessments show that none of the investigated hazard assessment methods use the same criteria as described in Article 57 of REACH. It was also not possible to parametrize multi-attribute value theory (MAVT), a commonly used MCDA method, to align with Article 57 of REACH by using the relatively simple objective hierarchy that has been proposed in previous publications. There is therefore an urgent need for a modified/new method that can be used in the future to assess organic substances that are used within the European Economic Area.

Regulating zeolite acid-base sites for selective hydrogenation of 5-hydroxymethylfurfural

The hydrogenation of biomass-derived 5-hydroxymethylfurfural (HMF) to the value-added chemicals plays a vital role in the development of renewable resources, while the precisely chemical regulation of products selectivity remains a great challenge. Herein, Zr-Beta based catalysts were fabricated with the controllable acid-base sites for the selective hydrogenation of HMF. Importantly, the products selectivity could be facilely switched over Zr-Beta based catalysts: 100 % of 2,5-bis(isopropoxymethyl)furan (BPMF) selectivity was acquired over Zr-Beta, whereas 99.4 % of 2,5-bis(hydroxymethyl)furan (BHMF) selectivity was achieved over K-Zr-Beta. The characterization analysis revealed that more Lewis acid sites in Zr-Beta facilitated Meerwein-Ponndorf-Verley (MPV) reduction of HMF and the further etherification of BHMF to acquire BPMF. However, the incorporation of K+ into Zr-Beta could exchange with silanol protons and Zr(IV) sites, which resulted in the decrease of Lewis acid amount accompanied with the generation of base sites. Notably, the regulated acid and base sites in K-Zr-Beta catalyst synergistically acted in the selective hydrogenation of HMF to BHMF. This work provides a feasible strategy for adjusting selectivity of HMF hydrogenation products by tuning the catalysts acid-base sites.

Analyzing the Impact of Residential Chemicals upon the Heartbeat of Daphnia magna

The controversial consensus among toxicology researchers is that the country's regulation of chemicals has always been insufficient. One critical aspect that has been debated is the government's ability to determine the criteria of what makes a commercially available chemical dangerous, especially considering that these chemicals haven’t undergone rigorous testing. In this experiment, the Daphnia magna’s heart rate change was evaluated through the serial dilution of residential chemicals, particularly for insecticides and herbicides. We utilized the change in the bpm of the Daphnia magna as an indicator of stress, which was used to analyze the environmental stress associated with the tested chemicals. An important parameter, the Cardiac Disturbance Indicator (CDI), was defined as the sum of the average heartbeat changes at the set time points we measured. Results showed a broad spectrum of CDI from 0.0 to 90%, while the magnitude of CDI could be predicted by considering other published toxicological data. The CDI was found to be a somewhat useful surrogate for scrutinizing any harmful effects in future studies.

Chemical Investigation and Regulation of Adipogenic Differentiation of Cultivated Moringa oleifera.

Background/Objectives: Moringa oleifera is a matrix plant with the high potential to cure several diseases with its medicinal and ethnopharmacological value and nutraceutical properties. In this study, we investigated the chemical and biological properties of this plant cultivated in our local region. Methods: Leaves, roots, seeds, stem bark, and twigs of oleifera were extracted and evaluated bioactivities targeting intracellular lipid accumulation and adipocyte differentiation in 3T3-L1 preadipocytes, and UHPLC-ESI-Orbitrap-MS/MS-Based molecular networking guided isolation and dereplication of metabolites from these extracts. Results: Five extracts of different organs of M. oleifera significantly stimulated intracellular lipid accumulation and adipocyte differentiation in 3T3-L1 preadipocytes in a concentration-dependent manner. These extracts markedly increased the expression of genes related to adipogenesis and lipogenesis. Notably, these extracts promoted peroxisome proliferator-activated receptor γ (PPARγ) activity and the expression of its target genes, including phosphoenolpyruvate carboxykinase, fatty acid-binding protein 4, and perilipin-2. These adipogenic and lipogenic effects of Moringa extracts through the regulation of PPARγ activity suggests their potential efficacy in preventing or treating type 2 diabetes. Furthermore, chemical investigation revealed high contents of phytonutrients as rich sources of secondary metabolites including glycosides, flavones, fatty acids, phenolics, and other compounds. In addition, in silico studies on major components of these extracts revealed the bioavailability of major components through their binding affinity to respective proteins targeting adipocyte differentiation.

UNVEILING THE LEGAL COMPLEXITIES SURROUNDING DUAL USE OF CHEMICAL IN GLOBAL AND INDONESIAN CONTEXTS

The use of white phosphorus as a weapon is highly dangerous, causing direct physical damage to victims and environmental harm. White phosphorus is just one of many dual-use chemicals that have industrial benefits but also pose significant health and environmental risks. This situation leads to violations of fundamental human rights. This study discusses the legal complexities related to the use of dual-use chemicals in both global and Indonesian contexts, with a focus on Indonesia’s Health Law No. 17 of 2023. The research aims to identify legal gaps in the regulation of hazardous chemical use, from both international and national perspectives, and to provide recommendations for improving national regulations to better protect the public from the threats posed by dual-use chemicals. This study uses a normative legal approach with descriptive-analytical methods. It evaluates the gaps between national and international regulations on dual-use chemicals and the practical impact of these differences on public health protection in Indonesia. The study finds significant gaps between national and international regulations, particularly in terms of oversight and regulation of dual-use chemicals. The implementation of current health laws in Indonesia remains weak. International regulations are stricter, but they have not been fully integrated into national policies, resulting in gaps in public health protection from the threats posed by these chemicals.

Burden of chemical poisoning and contributing factors in the case of the Amhara Region, Ethiopia

BackgroundThis study aimed to evaluate the burden of chemical poisoning and its associated factors at the Chemical, Biological, Radiological, and Nuclear (CBRN) pilot surveillance sites in the Amhara region, Northwest Ethiopia. The analysis of burdens and contributing factors is intended to inform targeted interventions and enhance public health strategies.MethodsA cross-sectional study was conducted at TibebeGhionComprehensive Specialized Hospital(TGCSH) and FelegeHiwot Comprehensive Specialized Hospital(FHCSH) in the Amhara region of Ethiopia from June to November 2021. Data were collected using structured tools and analyzed with SPSS version 26. Descriptive statistics assessed the burden of chemical poisoning, while Chi-square analysis identified significant factors associated with the burden of chemical poisoning.ResultsThe study reported a total of 184 chemical poisoning cases at TGCSH and FHCSH in the Amhara region, with a case fatality rate of 17%. The most affected age group was 16 to 25 years, and females accounted for 60% of the cases. Geographic distribution showed that Bahir Dar had the highest incidence, contributing to 64.7% of the cases, while the South Gondar zone, particularly the Fogera district, accounted for 30.88%. Organophosphates emerged as the most prevalent toxic agents, responsible for 53% of the cases. Chi-square analysis highlighted several significant associations with a higher burden of chemical poisoning, including being female (X² = 4.463, p = 0.035), being 35 years or younger (X² = 4.629, p = 0.031), ingestion of rodent poison (X² = 4.154, p = 0.042), intentional poisoning (X² = 7.488, p = 0.006), and inhalation exposure (X² = 4.154, p = 0.042) and educational level (X² = 5.764, p = 0.016).Conclusions and recommendationsThe study reveals a significant burden of chemical poisoning in the Amhara Region, Ethiopia, with a 17% fatality rate, predominantly impacting young adults and females, particularly in areas with high pesticide use, such as Bahir Dar and South Gondar. Key issues include cases with no antidotes, inhalation exposure, and intentional poisoning. Recommendations: Implement stricter chemical regulations, limit pesticide sales, enhance community education on safe handling, and improve mental health support for high-risk groups. Develop sustained CBRN surveillance systems and conduct further research on regional disparities and chemical agent assessments.

Optimization of Exon-Skipping Riboswitches and Their Applications to Control Mammalian Cell Fate.

Mammalian riboswitches that can regulate transgene expression via RNA-small molecule interaction have promising applications in medicine and biotechnology, as they involve no protein factors that can induce immunogenic reactions and are not dependent on specially engineered promoters. However, the lack of cell-permeable and low-toxicity small molecules and cognate aptamers that can be exploited as riboswitches and the modest switching performance of mammalian riboswitches have limited their applications. In this study, we systematically optimized the design of a riboswitch that regulates exon skipping via an RNA aptamer that binds ASP2905. We examined two design strategies to modulate the stability of the aptamer base stem that blocks the 5' splice site to fine-tune the riboswitch characteristics. Furthermore, an optimized riboswitch was used to generate a mouse embryonic stem cell line that can be chemically induced to differentiate into myogenic cells by activating Myod1 expression and a human embryonic kidney cell line that can be induced to trigger apoptosis by activating BAX expression. The results demonstrate the tight chemical regulation of transgenes in mammalian cells to control their phenotype without exogenous protein factors.

Molecular and cytogenetic characterization of Osteospermum fruticosum lines harboring wild type pRi rol genes.

Transgenic lines engineered through wild type Rhizobium rhizogenes display an altered phenotype known as the Ri phenotype. This phenotype includes a more compact plant habit, which has proved useful to obtain more compact varieties that require less chemical growth regulation. Here, we develop a method for the molecular and cytogenetic characterization of Cape daisy (Osteospermum fruticosum Norl.) Ri lines in order to predict segregation of pRi T-DNA genes. Analysis of copy number variation (CNV) by means of digital PCR indicated large variation in the copy number of the inserted root oncogenic loci (rol) genes, ranging from 1 to more than 15 copies. In addition, up to 9 copies of the auxin biosynthesis genes (aux) were present in a single Ri line. Visualization of pRiA4 and pRi1724 rol and aux insertion in 4 Ri lines was performed through Fluorescence In Situ Hybridization. The number of rol integrated loci varied from 1 to 3 loci. In contrast, the different TR-gene copies were confined to a single locus which consistently co-localized with a TL locus, this was demonstrated for the first time. Based on CNV and FISH a single Ri line, harboring 7 pRi1724 rol gene copies dispersed over 3 integration loci, was selected for breeding. Copy number segregation in R1 progeny of 2, 3, 4 and 5 pRi1724 copies was confirmed, indicating that the evaluation of the breeding value of first generation Ri lines is possible through CNV and FISH.

Cocktail effects of clothianidin and imidacloprid in zebrafish embryonic development, with high and low concentrations of mixtures.

There is growing concern that sprayed neonicotinoid pesticides (neonics) persist in mixed forms in the environmental soil and water systems, and these concerns stem from reports of increase in both the detection frequency and concentration of these pollutants. To confirm the toxic effects of neonics, we conducted toxicity tests on two neonics, clothianidin (CLO) and imidacloprid (IMD), in embryos of zebrafish. Toxicity tests were performed with two different types of mixtures: potential mixture compounds and realistic mixture compounds. Potential mixtures of CLO and IMD exhibited synergistic effects, in a dose-dependent manner, in zebrafish embryonic toxicity. Realistic mixture toxicity tests that are reflecting the toxic effects of mixture in the aquatic environment were conducted with zebrafish embryos. The toxicity of the CLO and IMD mixture at environmentally-relevant concentrations was confirmed by the alteration of the transcriptional levels of target genes, such as cell damage linked to oxidative stress response and thyroid hormone synthesis related to zebrafish embryonic development. Consequently, the findings of this study can be considered a strategy for examining mixture toxicity in the range of detected environmental concentrations. In particular, our results will be useful in explaining the mode of toxic action of chemical mixtures following short-term exposure. Finally, the toxicity information of CLO and IMD mixtures will be applied for the agricultural environment, as a part of chemical regulation guideline for the use and production of pesticides.

Testing the sensitivity of the medaka Transgenic Eleuthero-embryonic THYroid-Specific assay (TETHYS) to different mechanisms of action

There are many concerns about the impacts of Endocrine-Disrupting Chemicals on both wildlife and human populations. A plethora of chemicals have been shown to interfere with the Hypothalamic–Pituitary–Thyroid (HPT) axis in vertebrates. Disruption of the HPT axis is one of main endocrine criteria considered for the regulation of chemicals, along with the estrogen axis, androgen axis and steroidogenesis (EATS). In response to these concerns, the Organization for Economic Cooperation and Development (OECD) initiated the validation of test guidelines (TGs) covering the EATS modalities. Regarding thyroid activity and/or disruption assessment, three OECD TGs are validated, all of them using amphibians. To date, no OECD TGs based on fish are available for the detection of Thyroid Active Chemicals (TACs). To fill this gap, we developed a new test for the detection of TACs, the TETHYS assay (Transgenic Eleuthero-embryonic THYroid-Specific assay). This assay uses a medaka (Oryzias latipes) transgenic line Tg(tg:eGFP) expressing Green Fluorescent Protein in the thyroid follicles, under the control of the thyroglobulin promoter. This assay is performed at eleuthero-embryonic life-stages with an exposure length of 72 h. In the present study, the following reference chemicals with known thyroid hormone system mechanism of action have been tested: methimazole, sodium perchlorate, sodium tetrafluoroborate, diclofenac, iopanoic acid, sobetirome, NH-3 and 1–850. Except for the thyroid receptor antagonists, all chemicals tested were identified as thyroid active, modifying the total fluorescence and the size of the thyroid follicles. To investigate the test specificity, we tested three chemicals presumed to be inert on the HPT axis: cefuroxime, abamectin and 17α-ethinylestradiol. All were found to be inactive in the TETHYS assay. This promising New Approach Methodology can serve as a foundation for the development of a new OECD TG in the frame of regulatory assessment of chemicals for thyroid activity.

Effects of chemical regulation on the growth, yield and fiber quality of cotton varieties with different plant architectures

Chemical regulation has beneficial effects on the growth, yield, and fiber quality of cotton with different plant architectures. This study aimed to investigate the combined effects of chemical regulators such as mepiquat chloride (1,1-dimethyl-piperidiniuchloride, DPC), chlormequat chloride (CCC), thidiazuron (TDZ), and ethephon (ETH) during the growth period of cotton. Different combinations of chemical regulators were applied to examine the growth, development, yield, and quality of cotton. The results showed that the application of different chemical regulators had varying effects on the yields of the two cotton varieties with distinct plant architecture. Specifically, K1C1 (before and after topping with 1:1 25% DPC, 50% TDZ, and 40% ETH) and K2C2 (before topping with 25% DPC and after topping with 50% CCC, 50% TDZ, and 40% ETH) were sprayed on ‘Wankemian-1’ and ‘Wanmian-191’, thereby increasing the cotton yield. The K2C2 treatment increased the upper half mean length and fiber strength of the two varieties but decreased the fiber length uniformity index. The fiber strength, fiber length uniformity index, and spinning consistency index of ‘Wankemian-1’ were higher than those of ‘Wanmian-191’. Based on comprehensive yield, quality, and economic benefits, K1C1 and K2C2 were determined to be the most effective chemical regulators of ‘Wankemian-1’ and ‘Wanmian-191’, respectively.

Welcome to 310 Environmental Working Group! A Group Project That Places Students in the Role of Consultants Helping Businesses Choose the Most Climate Friendly Fluorinated Gas.

The Montreal Protocol is an international treaty that controls substances that deplete the ozone layer. Through the control of halogenated gases, it has been one of the most successful climate legislations to date. This success is driven by the interplay between chemical regulation and smart chemical design, demonstrating the positive impact chemistry can have on the world. This Article describes a group project that includes four assignments, a group presentation, and a writing task where students take on the role of consultants to assess the environmental friendliness of two fluorinated gases. Through the assignments students determine the global warming potential of two chemicals and pair this assessment with an evaluation of their potential to produce persistent products, such as trifluoroacetic acid, via atmospheric oxidation. Students worked together to take these, sometimes conflicting, pieces of evidence to make a final recommendation to their client as to the most "environmentally friendly" option in a mock Board of Directors meeting and then individually through a written recommendation. The project effectively addressed the learning goals of a third-year environmental chemistry class and was well received by students as a means of contextualizing the course material and providing students with a clear peer network in the class. This project is an effective application of fundamental chemistry topics (e.g., spectroscopy and the relationship between structure and reactivity) within a real-world context that emphasizes the ability of chemistry to have a positive impact on important environmental issues such as climate.