Equilibrium Association Research Articles

Economic performance of India amidst high CO2 emissions

Abstract In recent times, the Indian economy has enjoyed a positive economic trajectory. However, the economy remains vulnerable to domestic and geographical risk as it relates to environmental degradation. The Indian economy is reputed as one of the leading emitters of carbon dioxide ( C O 2 ) emissions globally.. In the literature, there is no consensus on the contradiction between decoupling economic growth from CO2 emission in India and other regions of the globe. By drawing on the Sustainable Development Goals (SDGs) agenda and its 2030 targets, this study examines the relationship between responsible energy consumption (SDGs 7, 12), climate issues (SDGs 13), and economic growth (SDGs 8) for the case of India. Thus, the present study seeks to investigate the implications of CO2 emissions on Indian economic growth (GDP) with a focus on the energy intensity in the country's economy. To explore the nexus between economic growth and environmental degradation in a carbon income function, openness to trade and energy use were added as additional variables to circumvent the problem of omitted variable bias. Autoregressive Distributed Lag (ARDL) with the modified Wald test of Toda Yamamoto (T-Y) were applied to annual time series data from 1975-2017. The study reveals a long-term equilibrium association among the described variables over the considered period. Furthermore, a statistically significant negative relationship is observed between C O 2 emissions and trade openness and economic growth. This study validates the energy-induced economic growth as reported by the ARDL regression. This is also corroborated by the causality analysis results, as a uni-directional relationship was observed running from energy utilization to income (GDP). Thus, the Indian government officials should not adopt conservative energy policies, as this will be detrimental for economic growth given that the economy is dependent on energy. However, based on the growing environmental consciousness around the world, there is a need to shift the energy mix in India to renewables to make uses of cleaner energy sources and create environmentally friendly ecosystems.

Removal of dye waste by weak cation-exchange nanofiber membrane immobilized with waste egg white proteins

In this research, a protein nanofiber membrane (P-COOH-CEW) was developed to treat the dye waste. Initially, polyacrylonitrile nanofiber membrane (PAN) was prepared by electrospinning, followed by heat treatment, alkaline treatment, and neutralization to obtain weak cation exchange nanofiber membrane (P-COOH). The P-COOH membrane was chemically coated with chicken egg white (CEW) proteins to obtain a 3D structure of complex protein nanofiber membrane (P-COOH-CEW). The composite prepared was characterized with Fourier Transform Infrared analysis (FTIR), Scanning Electron Microscopy (SEM), and thermogravimetric analysis (TGA). Further, the composite was evaluated by investigating the removal of Toluidine Blue O (TBO) from aqueous solutions in batch conditions. Different operating parameters - coupling of CEW, shaking rate, initial pH, contact time, temperature, and dye concentration were studied. From the results, maximum removal capacity and equilibrium association constant was determined to be 546.24 mg/g and 10.18 mg/mg, respectively at pH 10 and 298 K. The experimental data were well fitted to pseudo-second order model. Furthermore, desorption studies revealed that the adsorbed TBO can be completely eluted by using 50% ethanol or 50% glycerol in 1 M NaCl solution. Additionally, the reuse of P-COOH-CEW membrane reported to have 97.32% of removal efficiency after five consecutive adsorption/desorption cycles.

Interaction of Miltefosine with Microcavity Supported Lipid Membrane: Biophysical Insights from Electrochemical Impedance Spectroscopy

AbstractMiltefosine an alkylphosphocholine analogue, is the only drug taken orally for the treatment of leishmaniasis‐a parasitic disease caused by sandflies. Although it is believed that Miltefosine exerts its activity by acting at the lipid membrane, detailed understanding of the interaction of this drug with eukaryotic membranes is still lacking. Herein, we exploit microcavity pore suspended lipid bilayers (MSLBs) as a biomimetic platform in combination with a highly sensitive label‐free electrochemical impedance spectroscopy (EIS) technique to gain biophysical insight into the interaction of Miltefosine with host cell membrane as a function of lipid membranes composition. Four membrane compositions with increasing complexity were evaluated; DOPC, DOPC : Chol (75 : 25), domain forming DOPC : SM : Chol (40 : 40 : 20) and mammalian plasma membrane (MPM) mimetic DOPC:DOPE:Chol:SM:DOPS (32 : 25 : 20 : 15 : 8) and used to study the interaction of Miltefosine in a concentration‐dependent manner using EIS. The membrane resistance changes in response to Miltefosine were modelled by an empirical Langmuir isotherm binding model to provide estimates of binding saturation and equilibrium association constant. Miltefosine was found to have greatest impact on electrochemical properties of the simpler membrane systems; DOPC and DOPC : Chol, where these membranes were found to be more susceptible to membrane thinning, attributed to strong permeation/penetration of the drug whilst, compositions that included both Chol and SM, expected to contain large liquid‐ordered domains exhibited weaker changes to membrane resistance but strongest drug association. In contrast, at the MPM membrane, Miltefosine exerts weakest association, which is tentatively attributed to electrostatic effects from the anionic DOPS but some membrane thinning is observed reflected in change in resistance and capacitance values attributed to some weak permeation.

Methanol: association behaviour, third-law entropy analysis and determination of the enthalpy of formation

Chemical equilibrium constants for the methanol from CO/H2 reaction calculated from literature thermodynamic parameters are too high as compared to experimental results. Therefore, both the entropy value and the enthalpy of formation value of methanol were reviewed. A rigorous analysis of the association behaviour of methanol vapour confirms that dimers and cyclic tetramers play an important role, but physical non-ideal gas behaviour must also be taken into account. Accurate relationships for the association equilibrium constants and the physical contribution to the second virial coefficient were derived with the use of a combined fit of multiple experimental data sources including heat capacity, speed of sound, thermal conductivity, excess molar enthalpy of methanol and nitrogen and heat of vaporization. Additionally, high temperature second virial coefficients and measures for the consistent temperature dependencies of the entropy and enthalpy of formation were included in the parameter optimization to support the accuracy of the model. All experimental results and supporting data were taken or derived from the literature. The resulting virial equation of state was used to calculate new ideal-gas entropy and enthalpy of formation values of methanol, which now turn out to be consistent with values derived from experimental chemical equilibrium data. Furthermore, the new third-law entropy value turns out to be consistent with the current literature value. A new enthalpy of formation value is recommended and an improved chemical equilibrium relationship for the methanol from CO/H2 reaction is presented.

Stylized heterogeneous dynamic links among healthcare expenditures, land urbanization, and CO2 emissions across economic development levels

This research examines the heterogeneous dynamic links among healthcare expenditures, land urbanization, and CO2 emissions across the development levels of China. To this end, data of 27 Chinese provinces are considered from 1999 to 2018. Theoretically, this research developed a healthcare expenditures-augmented Stochastic Impacts of Regression by Population, Affluence, and Technology (STIRPAT) model to incorporate healthcare expenditures as a determinant of affluence. Empirically, this research established a system of simultaneous equations based on the healthcare expenditures-augmented STIRPAT model to estimate the links among the variables. As a pre-analysis, second-generation Westerlund cointegration is applied and found the long-term equilibrium association among the variables. The long-run estimations and short-run causality are done by employing dynamic common correlated effects mean group method (DCCEMGM) and Dumitrescu-Hurlin causality. A heterogeneous long-run equilibrium linkage is confirmed to exist among the variables of interest. Concerning the long-run estimates, firstly, the healthcare expenditures growth and land urbanization exhibited a bilateral positive link. Secondly, CO2 emissions and healthcare expenditures growth manifested the existence of a bilateral positive link. And thirdly, a unilateral positive (negative) link is revealed to exist from a linear term (squared term) of land urbanization to CO2 emissions. Concerning the short-run results, firstly, a bilateral causal bond exists between the land urbanization and healthcare expenditures growth. Secondly, a bilateral causal bond prevails between CO2 emissions growth and healthcare expenditures growth. Finally, a unilateral causal bond is operational from land urbanization to CO2 emissions growth. In terms of the nature of the link, the long-run findings are consistent across the data samples. However, considering the degree of influence, heterogeneity is confirmed across the development levels for both long- and short-run. It infers that relatively more (less) developed regions showed relatively strong (weak) influence. Based on empirical findings, relevant policies are recommended.

On the use of Europium (Eu) for designing new metal-based anticancer drugs

Europium oxide (Eu2O3) was used to evaluate the affinity of this rare earth element for interacting with double-stranded (ds) DNA molecules. To perform the study, we used single molecule force spectroscopy with optical tweezers and gel electrophoresis assays. Force spectroscopy experiments show that Eu2O3 presents a strong interaction with dsDNA, and the binding is independent on the ionic strength used in the surrounding environment. Among the main characteristics of the interaction, Eu2O3 tends to bind in a cooperative way, forming bound clusters of ∼ 3 molecules, and presents a high equilibrium association binding constant on the order of 105 M−1. In addition, gel electrophoresis confirm the weak electrostatic character of the interaction and explicit show that Eu2O3 does not interfere on drug intercalation into the double-helix. Such results demonstrate the potential of europium for interacting with nucleic acids and strongly suggest that this rare earth element may be considered for the design of new metal-based anticancer drugs in the future.

Conceptualizing Pathways of Sustainable Development in the Union for the Mediterranean Countries with an Empirical Intersection of Energy Consumption and Economic Growth.

The availability of sufficient and trustworthy energy services at the reasonable cost in a securely and environmentally friendly manner, and conventionality with economic and social development requirements, is an important factor of sustainable development (SD). Energy plays a significant role in eliminating poverty and increasing living standards. However, most of the present energy forms of energy supply and consumption are unsustainable. This paper analyzes the association between economic growth (EG), energy consumption (EC), and sustainable development (SD) among other economic factors. The sample of 14 developed and developing member states of the Union for the Mediterranean (UFM) was selected. To deal with the endogeneity issue, the system- generalized method of moment (GMM) model was employed. Moreover, panel co-integration, Granger causality tests, and robustness tests were employed to examine the long-run and short-run causality among variables of interest. The results confirmed the short-run dynamic association from sustainable development (SD) to energy consumption (EC), and economic growth (EG) to sustainable development (SD). Moreover, the results validated the presence of long-run equilibrium association in the equations of EC and sustainable development (SD). The findings of this study will be supportive for the policymakers to formulate sustainable energy policies to stimulate the economic growth (EG) in the way of sustainable development (SD) in the UFM countries.

LINEAR AND NON-LINEAR GRANGER CASUALITY BETWEEN FOREIGN DIRECT INVESTMENT AND ECONOMIC GROWTH: EVIDENCE FROM INDIA

The present study tries to understand the association among Foreign Direct Investment (FDI) and Economic growth in India. This paper applies the causality test of Granger (1969) based on the VECM and non-linear causality test of Dike and Panchenko over the period 1993-2016. This study gives a proof about the continuation of a long-run equilibrium association between FDI and Gross Domestic Product (GDP) or Economic Growth for the period being investigated. Unidirectional causality runs from FDI to GDP in the long run. The apparent non-linear causality running from FDI to GDP means that FDI is a policy instrument in stimulating Indian economic growth and provides support for the bi-directional non-linear causal connection between FDI and economic growth with 1, 2 and 4 lags. There has been no definitive investigation as of recently to find “linear and non-linear” Granger causality between Foreign Direct Investment and Economic Growth in India” and this study goes a stage advancing and present exact models that can be used to find the association among Foreign Direct Investment and economic growth.

Transplatin ineffectiveness against cancer from a molecular perspective: A single-molecule force-spectroscopy study

By performing single-molecule force spectroscopy with optical tweezers, we have characterized the interaction between the platinum-based compound transplatin and the DNA molecule, establishing a critical comparison with its isomer cisplatin. While transplatin is ineffective against tumor cells, its isomer is one of the most used drugs in current chemotherapies, and a molecular study on this difference performed at the single-molecule level was lacking until the present work. Our experiments show that transplatin binds DNA under low chloride concentrations (a situation usually found inside many cells) with an equilibrium association binding constant about four orders of magnitude lower than cisplatin. In addition, we have found that, at saturation, transplatin binds preferentially forming interstrand cross links and monoadducts, a situation very different from cisplatin, which forms preferentially intrastrand cross links. Such differences explain the ineffectiveness of transplatin in killing tumor cells. From a physical point of view, the present study advances in using the mechanical properties of the DNA molecule as sensors to evaluate the therapeutic efficiency of drugs.

The use of isothermal titration calorimetry to unravel chemotactic signalling mechanisms.

Chemotaxis is based on the action of chemosensory pathways and is typically initiated by the recognition of chemoeffectors at chemoreceptor ligand-binding domains (LBD). Chemosensory signalling is highly complex; aspect that is not only reflected in the intricate interaction between many signalling proteins but also in the fact that bacteria frequently possess multiple chemosensory pathways and often a large number of chemoreceptors, which are mostly of unknown function. We review here the usefulness of isothermal titration calorimetry (ITC) to study this complexity. ITC is the gold standard for studying binding processes due to its precision and sensitivity, as well as its capability to determine simultaneously the association equilibrium constant, enthalpy change and stoichiometry of binding. There is now evidence that members of all major LBD families can be produced as individual recombinant proteins that maintain their ligand-binding properties. High-throughput screening of these proteins using thermal shift assays offer interesting initial information on chemoreceptor ligands, providing the basis for microcalorimetric analyses and microbiological experimentation. ITC has permitted the identification and characterization of many chemoreceptors with novel specificities. This ITC-based approach can also be used to identify signal molecules that stimulate members of other families of sensor proteins.

Quantitative Kinetic Modeling in Photoresponsive Supramolecular Chemistry: The Case of Water-Soluble Azobenzene/Cyclodextrin Complexes.

Hydrophilic host-guest complexes, consisting of water-soluble azobenzene and α-, β-, or γ-cyclodextrins, have been proposed as a model to study supramolecular photoresponsive systems in aqueous environments through a full spectrometric approach combined with a simulation and data fitting methodology. Various essential and complementary spectroscopic techniques have been used: circular dichroism to determine whether the complex is formed or not, NMR for the stoichiometry elucidation, and UV-visible spectrophotometry to obtain the association equilibrium constant of each complex and the quantum yield for each photochemical process. A step-by-step fitting procedure is presented, which enables the determination of all thermodynamic and photokinetic parameters. A sequential methodology is applied to dissipate all uncertainties on the variability of the results and to develop a relevant and reliable protocol applicable to other types of complexes. The proposed procedure has thus been shown to be very robust and largely applicable to other photoresponsive host-guest systems.

Revisiting the Environmental Kuznets Curve in Malaysia: The role of globalization in sustainable environment

The present study examines the presence of Environmental Kuznets Curve (EKC) in Malaysia by investigating impact of globalization (including overall, social, economic and political) on ecological footprint in the Malaysian economy using quarterly data from 1970 to 2018. This research utilizes the Quantile Autoregressive Distributed Lag (QARDL) method. This approach is useful as it depicts the causality patterns through various quantiles of the globalization and environmental degradation by providing more comprehensive explanations of the over-all dependence among the aforementioned variables almost ignored by the traditional approach (for instance ARDL and OLS). The outcomes of QARDL showed that the error correction coefficient is significant with the anticipated negative sign for all quantiles. This outcome provides evidence on the presence of considerable return to the long-run equilibrium association between the factors of interest and environmental degradation. Overall, the results recommended that overall globalization and economic globalization enhance the level of environmental degradation in the long run, however, political and social globalization help to reduce the level of environmental degradation in the long term. Moreover, the results of QARDL also confirmed the existence of inverted U-Shape curve in the Malaysian economy. In the shorter-run period, this study found a significant negative impact of overall globalization and political globalization on environmental degradation. The results recommended that the Malaysian government and policymakers need to give more attention to social and political globalization to achieve the goals of sustainable environment in the long-run equilibrium.

Quantitative and Selective Surface Plasmon Resonance Response Based on a Reduced Graphene Oxide-Polyamidoamine Nanocomposite for Detection of Dengue Virus E-Proteins.

Dengue viral infection is one of the most common deadliest diseases and has become a recurrent issue for public health in tropical countries. Although the spectrum of clinical diagnosis and treatment have recently been established, the efficient and rapid detection of dengue virus (DENV) during viremia and the early febrile phase is still a great challenge. In this study, a dithiobis (succinimidyl undecanoate, DSU)/amine-functionalized reduced graphene oxide-–polyamidoamine dendrimer (DSU/amine-functionalized rGO–PAMAM) thin film-based surface plasmon resonance (SPR) sensor was developed for the detection of DENV 2 E-proteins. Different concentrations of DENV 2 E-proteins were successfully tested by the developed SPR sensor-based system. The performance of the developed sensor showed increased shift in the SPR angle, narrow full-width–half-maximum of the SPR curve, high detection accuracy, excellent figure of merit and signal-to-noise ratio, good sensitivity values in the range of 0.08–0.5 pM (S = 0.2576°/pM, R2 = 0.92), and a high equilibrium association constant (KA) of 7.6452 TM−1. The developed sensor also showed a sensitive and selective response towards DENV 2 E-proteins compared to DENV 1 E-proteins and ZIKV (Zika virus) E-proteins. Overall, it was concluded that the Au/DSU/amine-functionalized rGO–PAMAM thin film-based SPR sensor has potential to serve as a rapid clinical diagnostic tool for DENV infection.

Sensitive Detection of Dengue Virus Type 2 E-Proteins Signals Using Self-Assembled Monolayers/Reduced Graphene Oxide-PAMAM Dendrimer Thin Film-SPR Optical Sensor

In this work, sensitive detection of dengue virus type 2 E-proteins (DENV-2 E-proteins) was performed in the range of 0.08 pM to 0.5 pM. The successful DENV detection at very low concentration is a matter of concern for targeting the early detection after the onset of dengue symptoms. Here, we developed a SPR sensor based on self-assembled monolayer/reduced graphene oxide-polyamidoamine dendrimer (SAM/NH2rGO/PAMAM) thin film to detect DENV-2 E-proteins. Surface characterizations involving X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirms the incorporation of NH2rGO-PAMAM nanoparticles in the prepared sensor films. The specificity, sensitivity, binding affinity, and selectivity of the SPR sensor were then evaluated. Results indicated that the variation of the sensing layer due to different spin speed, time incubation, and concentration provided a better interaction between the analyte and sensing layer. The linear dependence of the SPR sensor showed good linearity (R2 = 0.92) with the lowest detection of 0.08 pM DENV-2 E-proteins. By using the Langmuir model, the equilibrium association constant was obtained at very high value of 6.6844 TM−1 (R2 = 0.99). High selectivity of the SPR sensor towards DENV-2 E-proteins was achieved in the presence of other competitors.

Crigler-Najjar Syndrome Type 1: Pathophysiology, Natural History, and Therapeutic Frontier.

We describe the pathophysiology, treatment, and outcome of Crigler-Najjar type 1 syndrome (CN1) in 28 UGT1A1 c.222C>A homozygotes followed for 520 aggregate patient-years. Unbound ("free") bilirubin (Bf ) was measured in patient sera to characterize the binding of unconjugated bilirubin (BT ) to albumin (A) and validate their molar concentration ratio (BT /A) as an index of neurological risk. Two custom phototherapy systems were constructed from affordable materials to provide high irradiance in the outpatient setting; light dose was titrated to keep BT /A at least 30% below intravascular BT binding capacity (i.e., BT /A=1.0). Categorical clinical outcomes were ascertained by chart review, and a measure (Lf ) was used to quantify liver fibrosis. Unbound bilirubin had a nonlinear relationship to BT (R2 =0.71) and BT /A (R2 =0.76), and Bf as a percentage of BT correlated inversely to the bilirubin-albumin equilibrium association binding constant (R2 =0.69), which varied 10-fold among individuals. In newborns with CN1, unconjugated bilirubin increased 4.3±1.1mg/dL per day. Four (14%) neonates developed kernicterus between days 14 and 45 postnatal days of life; peak BT ≥30mg/dL and BT /A≥1.0 mol:mol were equally predictive of perinatal brain injury (sensitivity 100%, specificity 93.3%, positive predictive value 88.0%), and starting phototherapy after age 13days increased this risk 3.5-fold. Consistent phototherapy with 33-103µW/cm2 •nm for 9.2±1.1hours/day kept BT and BT /A within safe limits throughout childhood, but BT increased 0.46mg/dL per year to reach dangerous concentrations by 18years of age. Liver transplantation (n=17) normalized BT and eliminated phototherapy dependence. Liver explants showed fibrosis ranging from mild to severe. Seven decades after its discovery, CN1 remains a morbid and potentially fatal disorder.

Determinants of capital structure; a sector-level analysis for Indian manufacturing firms

PurposeThe purpose of this paper is to empirically analyze the determinants of capital structure and their long-run equilibrium relationships with firm-specific and macroeconomic indicators for Indian manufacturing firms.Design/methodology/approachThe study is conducted using the panel semi-parametric and non-parametric regression models to identify the key determinants of capital structure. Panel cointegration models are also employed for analyzing the long-run equilibrium association of capital structure with its determinants.FindingsThe study finds that each manufacturing sector has unique determinants of capital structure. The debt level is significantly affected by asset tangibility, growth opportunity, effective tax rate, non-debt tax shield, cash flow, profitability, firm size, foreign investment, government borrowing, economic growth, and interest rate. All these firm-specific and macroeconomic variables have strong long-run equilibrium relationship with capital structure as a whole.Practical Implication of the StudyThe study analyzes the determinants of capital structure for eight manufacturing sectors of India, which helps firm managers and policy-makers to identify appropriate factors that maximize firm value. The sector-specific features of firms may lead to a new path with regard to corporate governance and ownership structure to enhance stakeholder's satisfaction.Originality/valueThe use of semi-parametric and non-parametric panel regression models to analyze the determinants of capital structure, and the use of panel cointegration approach to explore the long-run equilibrium relationship between the determinants and its factors are the unique contributions of the present research.

Model for DNA Interactions with Proteins and Other Large Ligands: Extracting Physical Chemistry from Pure Mechanical Measurements.

We present a new model to describe DNA interactions with large ligands such as proteins, based on a quenched-disorder equation for ligand binding along the double helix and on Manning's description for the local changes of the persistence length at the binding sites. Such a model allows one to extract the physical chemistry of the interactions from pure mechanical measurements, such as those typically performed with DNA-protein complexes in force spectroscopy assays. We have tested the proposed methodology here to investigate the DNA interaction with the protein lysozyme, determining binding parameters such as the equilibrium association constant, the cooperativity degree of the binding reaction, and the fraction of neutralized charges on the phosphate backbone. The model also allows one to get information on the size and positional conformation of the bound proteins.

Stoichiometric molecular imprinting using polymerisable urea and squaramide receptors for the solid phase extraction of organo-arsenic compound roxarsone.

The design, preparation and evaluation of molecularly imprinted polymers for roxarsone (4-hydroxy-3-nitrophenylarsonic acid), an organo-arsenic swine and poultry feed additive, using bi-substituted ureas and squaramide receptors as the functional monomers, are demonstrated. Pre-polymerisation studies of the template-monomer complexation performed by 1H NMR experiments show that squaramide-based monomers provide association equilibrium constant values higher than urea-based monomers. Equilibrium rebinding experiments in methanol show that two squaramide-based materials have good molecular recognition properties towards roxarsone, with high affinity (Keq = 16.85 × 103 L mol-1 and 14.65 × 103 L mol-1, respectively), high imprinting factors (4.73 and 3.64 respectively) and good selectivity towards two roxarsone-related compounds, acetarsone (3-acetamido-4-hydroxyphenylarsonic acid) and nitarsone (4-nitrophenylarsonic acid). Polymer MIP-SQ2 was successfully used to setup an experimental protocol for the direct solid phase extraction of roxarsone from surface water samples. The method gives clean HPLC traces, with recoveries between 91% and 95% at concentration levels of 5.0, 10, and 25 mg L-1. Sample preconcentration with good recoveries between 87% and 97%, are shown, confirming that it is possible to employ the developed materials to measure roxarsone down to 1 μg L-1 in water samples.

Impact of sanitation, safe drinking water and health expenditure on infant mortality rate in developing economies

AbstractDespite of significant growth in all walks of life, the issue of infant mortality still a major concern in most of the developing economies. The World Development Indicators have reported that 4.45 million infants died across the globe in 2015, meaning that 32 deaths per every 1,000 live births. A number of times, the World Health Organization (WHO) have stressed the significance of sanitation, safe drinking water and healthcare facilities in reducing infant mortality rate, though most developing countries still lacks in these services. Given this background, the present study aims to examine the role of sanitation, water facilities and health expenditure on infant mortality rate across a panel of 84 developing economies using annual data from 1995 to 2013. The study also account for per capita income and depth of food deficiency as the control factors in the model. The findings of this study establish a significant long‐run equilibrium association among the variables. The long‐run elasticities on infant mortality suggest that improved water and sanitation facilities, health expenditure and per capita income substantially reduce infant mortality rate, while food deficiency increases. Given these findings, we suggest that increasing access to improved water, sanitation and healthcare facilities will significantly reduce child mortality in developing economies around the world.

Association kinetics and equilibrium in solutions of cross-associating chains that contain inactive spacers

Thermodynamic and kinetic characteristics of chemical reactions in soft matter are affected by volume exclusion caused by an inert component (crowder). In previous molecular dynamics simulations we examined the crowding effect on the association equilibrium in solutions of cross-associating macromolecules that contain, as part of the chains, inactive monomers acting as crowders. Here, we extend our studies to association kinetics. For a number of mixtures where one or both chain species contain inert spacers, a simple mean field approximation describes quite well the composition dependence of the association equilibrium in a wide concentration range. Two main factors determine this dependence: the local distribution of the stickers (the relative excess of one kind of stickers in vicinity of the other) and the local steric effects. The kinetic characteristics of dissociation/association show somewhat similar pattern: the bonded pairs dissociate and recombine slower in solutions with higher content of inactive monomer units. However, the dissociation and recombination dynamics also depends on the reactants’ diffusion and its interplay with effects of chain connectivity and chemical structure. Particularly, when one of the associating components does not carry inert spacers, the recombination accelerates because it makes easier for the sticker from the other chain species to find a new partner for bond formation near its previous partner. These local effects and variations in the subdiffusive behavior of chain molecules are important to take into account for advancing the theory of reversible association in macromolecular systems.