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Introduction: Reduction of maternal mortality ratio to achieve the target set for MMR for SDG is a global challenge. Maternal death has devastating impact on the newborn, family as well as in the society in long run. Most of the developing countries could not achieve the target MMR for MDG and are now far away from the target set for Sustainable Development Goal for maternal mortality ratio because of its gradual reduction. There are great differences in MMR in developed and developing countries as well as within the countries, states, districts depending upon the education ,socioeconomic status and provision of quality health care and its accessibility . This study was conducted to estimate the MMR , evaluate the causes of maternal deaths at Obstetrics and Gynaecology department of Assam Medical college and Hospital ,Dibrugarh Assam, India. Aim: To nd out the MMR and to evaluate the risk factors and causes of maternal deaths. Materials And Methods: A retrospective study of risk factors and causes of maternal deaths from 1st January 2019 to 31st December 2020 at Obstetrics and Gynaecology Department of Assam Medical College and Hospital Dibrugarh ,Assam ,India .The data were collected from Maternal Death Surveillance and Response Records ,Facility Based Maternal Death Review Form and Bed head tickets and analysis were made to nd out causes of death and MMR. MDSR meetings were conducted for all the maternal deaths at community , facility and CMO levels . The risk factors and causes responsible for maternal deaths were expressed in percentage Results: Results and Observations: There were 174 maternal deaths out of 22,209 live births resulting MMR of 783. Hypertensive disorders of pregnancy (37.93%) followed by Puerperal sepsis (12.64%) and Post partum haemorrhage (8.04%) were the leading direct causes and severe Anemia (10.92%) and Jaundice (5.17%) were the leading indirect causes of maternal death in our study. Conclusion:Reduction of maternal death is a global challenge to achieve the MMR target of SDG .Causes of maternal death are multifactorial .Though pregnancy and labour is a physiological condition, rapid deterioration occurs when complication arises. Targeted approach to the socioeconomically poorer section of the society is the need of the hour.

A new bilayer-nanostructured photoanode with mesoporous titanium phosphate (MTP1) as overlayer and titanium dioxide (TiO2) as underlayer has been fabricated. Mesoporous titanium phosphate material with high surface area (442 m2 g−1) has been synthesized hydrothermally by using a new tailor made gemini surfactant under acidic pH conditions. HR TEM and N2 sorption analysis revealed the presence of disordered mesopores of dimension ca. 4.50 nm in MTP1 material. Open-circuit voltage decay (OCVD) spectroscopy is used to investigate the kinetic process of electron transport and recombination within TiO2/TiO2, MTP1/TiO2, or MTP1/MTP1 based DSSCs, revealing a faster electron transport rate and a lower recombination rate in the MTP1/TiO2 photoanode. The energy conversion efficiency of dye-sensitized solar cells (DSSCs) based on such a MTP1/TiO2 photoelectrode shows a significant enhancement (6.0%) compared to TiO2/TiO2 photoelectrode (5.5%) with similar thickness (∼7 μm), suggesting the favorable electron transport rate in former.

A comparative study of the interactions of the cationic gemini surfactant tetramethylene-1,4-bis(dimethyltetradecylammonium bromide) (14-4-14) with anionic polymer sodium carboxymethylcellulose (NaCMC), with two different molar masses, was performed in water and isopropanol (IP)–water media. The interaction process was studied in detail using conductometry, tensiometry, turbidimetry and viscometry. At very low concentration, 14-4-14 monomers interact with the polymer. Above the critical aggregation concentration (cac), small micelle-like aggregates form complexes with the polymer. During the interaction process, coacervates are formed beyond Cs (polymer saturation concentration), which initially grow by aggregation and stay in the solution throughout the process. The interaction process is affected by addition of isopropanol into the medium. The intrinsic viscosities of the two NaCMCs were determined by using Huggins and Kraemer equations. Dynamic light scattering (DLS) study helps to determine the hydrodynamic size of the dispersed polymer and its surfactant-interacting complexes. The hydrodynamic size of the dispersed polymer and its interacting complex in IP–water media is lower than that obtained in aqueous solution. The surface morphology of the solvent removed polymer and its surfactant-interacting complex were examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The pattern of the morphologies depends on the polymer–surfactant composition and the solvent environment.

The cholesterol (Chol) aided micelle to vesicle transition of the cationic (14-4-14) gemini surfactant (GS) (tetramethylene-1,4-bis(dimethyltetradecylammonium bromide)) has been investigated employing spectrophotometry (visible and fluorescence), dynamic light scattering (DLS) and high resolution transmission electron microscopy (HRTEM) at different R (R = [Chol]/[GS]) values. Turbidity of the mixed solutions gradually increased with increasing R, and was highest at R = 1. There were hypsochromic spectral shifts with varied R, supporting transformation of micelles to vesicles, corroborated by DLS measurements. The vesicle sizes ranged between ∼160–240 nm. The steady state fluorescence anisotropy measurements suggested Chol induced anisotropy to the formed vesicles; they were structurally incongruent. The vesicle phase was found to be stable in the studied temperature range of 15–60 °C. The increased rotational relaxation time of the probe molecule C-153 (coumarin 153) supported enhanced rigidity of the local environment of the vesicles with an increasing proportion of Chol in the mixture.

The interactions between myoglobin, a monomeric water soluble heme protein, and cationic gemini surfactants 14-3-14, 14-4-14, 14-5-14 have been studied in phosphate buffer at pH 7.4 using different techniques such as surface tension, UV–visible spectroscopy, fluorescence spectroscopy and circular dichroism. Myoglobin is a surface active protein and it is bound with surfactant molecules. The spin states of the heme group of myoglobin change depending on the concentration of surfactant. The unfolding process of protein in the presence of surfactant is observed from fluorescence spectra. With increasing surfactant concentration, α-helicity of myoglobin decreases with the appearance of β-sheet and random coil. The extent of interaction of myoglobin with gemini surfactant increases with increasing spacer length.

The proposed fuzzy control method in this paper depicts for MPPT i.e. maximum power point tracking of for photovoltaic system considering the variations in irradiation and temperature active conditions. Here fuzzy control (FC) method has been compared with perturb and observe (P&O) method which is taken as one of the most user applicable conventional method applied to this area. Both techniques in the study has been analyzed, compared and simulated. Mainly fuzzy control technique provides effective and reliable operational control for PV application.

The objective of this study was to assess the association between previous antibiotic use, particularly long-term prophylaxis, and the occurrence of subsequent resistant infections in children with index infections due to extended-spectrum-cephalosporin-resistant Enterobacteriaceae . We also investigated the concordance of the index and subsequent isolates. Extended-spectrum-cephalosporin-resistant Escherichia coli and Klebsiella spp. isolated from normally sterile sites of patients aged fumC-fimH ( E. coli ) or tonB ( Klebsiella pneumoniae ) type were identical to those of the index isolate. In total, 323 patients had 396 resistant isolates; 45 (14%) patients had ≥1 subsequent resistant infection, totaling 73 subsequent resistant isolates. The median time between the index and first subsequent infections was 123 (interquartile range, 43 to 225) days. In multivariable Cox proportional hazards analyses, patients were 2.07 times as likely to have a subsequent resistant infection (95% confidence interval, 1.11 to 3.87) if they received prophylaxis in the 30 days prior to the index infection. In 26 (58%) patients, all subsequent isolates were concordant with their index isolate, and 7 (16%) additional patients had at least 1 concordant subsequent isolate. In 12 of 17 (71%) patients with E. coli sequence type 131 (ST131)-associated type 40-30, all subsequent isolates were concordant. Subsequent extended-spectrum-cephalosporin-resistant infections are relatively frequent and are most commonly due to bacterial strains concordant with the index isolate. Further study is needed to assess the role prophylaxis plays in these resistant infections.

A comprehensive study of micellization and microemulsion formation of a cationic gemini surfactant (tetramethylene-1,4-bis(dimethyltetradecylammonium bromide; 14-4-14) in the absence or presence of hydrophobically modified polyelectrolyte, sodium carboxymethylcellulose (NaCMC), has been conducted by conductometry, tensiometry, microcalorimetry, and fluorimetry methods at different temperatures. Both critical micelle concentration and degree of ionization of the surfactant have been observed to increase with increasing temperature. The interfacial and thermodynamic parameters were evaluated. The standard Gibbs free energy of micellization (ΔGm°) is negative, which decreases with increase in temperature. Larger entropic contribution is observed compared to the enthalpy. The interaction of 14-4-14 with NaCMC produces coacervates which was determined from turbidimetry method. The pseudoternary phase behavior of the microemulsion systems comprising water (or NaCMC as additive), 14-4-14, isopropanol (IP) or n-butanol (Bu) as cosurfactant, and isopropyl myristate (IPM) were studied at 298 K. Phase diagrams reveal that IP derived microemulsions (in the absence of NaCMC) offer a large isotropic region compared to Bu-derived systems at comparable physicochemical conditions. Increasing the concentration of IP or Bu decreases the isotropic region in the phase diagram. NaCMC influences the microemulsion zone, depending upon its concentration, and type of cosurfactant and surfantant/cosurfactant ratio. Dynamic light scattering and conductometric measurements show the size of the droplet, threshold temperature of percolation, scaling parameters, and activation energy of the percolation process of 14-4-14/IP or Bu derived microemulsion systems without/with NaCMC at various physicochemical conditions. Bu exerts a greater effect to reduce θt than IP as a cosurfactant (in the absence of NaCMC) at comparable ω. On the other hand, IP showed better percolating effect than Bu in the presence of NaCMC. Bu and IP (as cosurfactant) and NaCMC (as additive) influenced the microemulsion droplet size (Dh) to different extents under comparable conditions. Temperature insensitive microemulsions have been reported at the studied temperature range (298–353 K). 14-4-14/IP (1:2)-derived microemulsion showed a fractured surface at fixed ω = 15, where ω is the water and surfactant molar ratio, and temperature (298 K); whereas, large scale mesospheres comprising multiple closely winded nanoslices and spheroid morphology were formed in 14-4-14/IP and 14-4-14/Bu microemulsions, respectively, in the presence of 0.01 g % NaCMC, at comparable conditions. These systems revealed good antimicrobial activity toward the strains of Gram-positive Bacillus subtilis and Gram-negative Escherichia coli bacteria at 298 K, and inhibitory effect was governed by ω, type of cosurfactant, and bacterial strains.

The micellar and surface properties of single as well as equimolar binary mixed systems of some cationic gemini and monomeric ionic surfactants have been studied by conductivity, surface tension and fluorescence measurements at 300 K. The critical micelle concentration (CMC), Γmax (maximum surface excess), Amin (minimum surface area per molecule), πcmc (surface pressure at the CMC) and thermodynamic parameters viz. standard Gibbs free energies of adsorption ( Δ G ads ° ), standard Gibbs free energies of micellization ( Δ G m ° ) and minimum free energy of the surface ( Δ G min ( s ) ) of gemini with cationic monomeric surfactants were also evaluated. The negative values of Δ G ads ° and Δ G m ° indicate the spontaneity and stability of the mixed micelle. The experimental CMC values are less than the ideal CMC values, indicating negative deviation from ideal behavior for all the equimolar binary surfactant systems. Aggregation number (Nagg) and Stern–Volmer quenching constant (Ksv) have been evaluated by Fluorescence measurement. The solubilization capacities of selected single and equimolar binary surfactant systems toward polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, anthracene and pyrene have been evaluated and discussed in terms of the molar solubilization ratio (MSR), the micelle-water partition coefficient (K(m)), the deviation ratio (R), and the free energy of solubilization ( Δ G s ° ) of PAHs. The negative value of Δ G s ° shows spontaneity of solubilization process.

The effect of cosolvent (ethane-1,2-diol and dimethyl sulfoxide) on the self-assembly of three surfactants, N,N,N-trimethyl-1-dodecanaminium bromide (DTAB), sodium [dodecanoyl(methyl)amino]acetate (SDDS), and polyoxyethylene (20) sorbitan monolaurate (Tween-20) in aqueous solution have been investigated by conductometric, tensiometric, and viscometric techniques at 298 K. The main focus was on the effect of solvent on critical micelle concentration (cmc), free energy contribution to micellization (ΔGm0), tail transfer Gibbs free energy (ΔGtrans0), Gibbs adsorption energy (ΔGads0), and some micellar interfacial parameters, for example, Gibbs surface excess (Γmax), minimum area per surfactant molecule (Amin), surface pressure (Πcmc), and pC20(= −log(C20), where C20 is the surfactant molar concentration required to reduce the surface tension of mixed solvent by 20 mN m–1). With increasing concentration of cosolvent in the binary mixture, the cohesive force decreases, and surfactant molecules are more soluble...

The interaction of a cationic dye crystal violet, in aqueous solution with different types of surfactants, such as anionic, cationic, non-ionic, gemini and their mixtures has been investigated spectrophotometrically and fluorimetrically in premicellar and post micellar concentration regions. In the premicellar concentration region of anionic surfactants, the dimer of the dye is formed; in the micellar concentration region, the monomer of the dye predominates. With cationic and nonionic surfactants, crystal violet is solubilised primarily as the monomer. In case of anionic and nonionic mixture, stability of dye–surfactant complex increases with increase in mole fraction of anionic surfactant. Cationic surfactant, cetyltrimethylammonium bromide (CTAB) has no interaction with crystal violet.

Two biofriendly anionic amino acid surfactants (AAS), N-n-decanoyl-L-valine (C10-val) and N-n-decanoyl-L-leucine (C10-leu) were synthesized and mixed micellization of them with nonionic surfactant N-decanoyl-N-methyl-glucamine (Mega-10) was investigated by tensiometry and fluorimetry in 50 mM Tris-buffer (pH = 9) medium at 298 K. The critical micelle concentration (cmc), surface properties, e.g., Gibbs surface excess (Γmax), area of exclusion per surfactant monomer (Amin) and surface pressure at cmc (Πcmc) were determined. Gibbs free energy of micellization (ΔG0m) and Gibbs free energy of adsorption (ΔG0ads) were also determined. Both the free energy values are negative indicating the spontaneity and stability of the mixed micelles. The size of the micelles was determined by dynamic light scattering (DLS) measurements. The deviation of mixed micelles from the ideal behavior was discussed on the basis of Clint, Motomura, Rubingh (regular solution theory), Rosen and Maeda's theory. Rubingh–Holland theory was applied on the ternary systems made by these three surfactants. The compositions of mixed micelle, the activity coefficients and the corresponding interaction parameters were evaluated from these theories. The interaction parameters (β) are negative, indicating attractive interaction between the ionic and nonionic surfactants. The micellar aggregation number (Nagg) and micropolarity were evaluated using steady state fluorescence measurements and the packing parameter (P) was determined on the basis of Israelachvili's theory. The standard free energy changes associated with the transfer of surfactant tail due to micellization of pure, binary and ternary combinations of surfactants were determined from Nagarajan's model. We report for the first time in detail the binary and ternary combinations using amino acid based surfactants.

The micellar properties of gemini surfactant, tetramethylene-1,4-bis(dimethyltetradecylammonium bromide) (14-4-14) in binary aqueous mixtures of isopropanol (IP) and 1,4-dioxane (DO) were investigated by tensiometric, conductometric and microcalorimetric methods in the temperature range of 298 to 323 K. The values of both critical micelle concentration (cmc) and degree of dissociation increase with increasing temperature and concentration of cosolvent. The energetics of micellization was determined from the temperature dependence of critical micelle concentration values. The standard Gibbs free energy of micellization (ΔG) was found to be negative and the negative value decreases with both temperature and concentration of cosolvent. The Gibbs free energy of micellization (ΔG) is mainly controlled by tail transfer free energy. The enthalpy of micellization obtained from direct calorimetry, Gibbs-Helmholtz equation and van't Hoff methods are presented and compared. Entropic contribution is found to be larger than the enthalpy and for all the systems, an enthalpy-entropy compensation phenomenon was obtained. Some interfacial parameters, e.g., Gibbs surface excess (Γmax), minimum area per surfactant molecule (Amin), surface pressure (Πcmc) were been calculated. The fluorimetric technique was used to understand the microenvironment of the solution under the influence of cosolvent. The micellar aggregation number of 14-4-14 in a binary mixed solvent was also determined from fluorimetry using pyrene as a probe. Two fluorophores, fluorescein and curcumin delivered the information of the peripheral region of the micellar interface and palisade region. The self-diffusion coefficients of the micellar media were evaluated using the cyclic voltammetry (CV) method. Such multi-technique investigation provides a new look into the role of solvation in micellization.