Intercalation vs Adsorption Strategies of Myo-Inositol Hexakisphosphate into Zn-Fe Layered Double Hydroxide: A Tiff between Anion Exchange and Coprecipitation.

Myo-inositol hexakisphosphates (IHPs) or phytates are the most abundant organic phosphates having the potential to serve as a phosphorus reserve in soil. Understanding the fate of IHP interaction with soil minerals tends to be crucial for its efficient storage and utilization as a slow-release organic phosphate fertilizer. We have systematically compared the effective intercalation strategy of a phytate onto Zn-Fe layered double hydroxide (LDH) acting as storage/carrier material through coprecipitation and anion exchange. Powder X-ray diffraction, X-ray photoelectron spectroscopy, elemental analysis, thermogravimetric analysis, FTIR spectra, and molecular modeling demonstrated the formation of phytate-intercalated Zn-Fe LDH through coprecipitation with a maximum loading of 41.34% (w/w) in the pH range of ∼9-10 in a vertical alignment through monolayer formation. No intercalation product was obtained from the anion exchange method, which was concluded based on the absence of shifting in the XRD (003) peak. A change in the zeta potential values from positive to negative and subsequent increase in solution pH, with decreasing phytate concentration, are suggestive of adsorption of IHP onto the LDH surface. The batch adsorption data were best fitted with Langmuir isotherm equation and followed the pseudo-second-order kinetic model. The maximum adsorption capacity was found to be 45.87 mg g-1 at a temperature of 25 ± 0.5 °C and pH 5.63.

Understanding Photophysical Properties of Molecules Relevant in Organic Semiconductor Laser Diodes from Electron Localization Function-Tuned and Solvent-Tuned Range-Separated Functionals.

Organic semiconductor laser diodes (OSLDs) are prevalent in optoelectronics because of their sustainable energy applications. Organic molecules used in such diodes are usually large; hence, their studies are computationally challenging with high-end benchmark methods. Computational methods with reliable accuracy and efficiency are always indispensable. In the present work, we have applied our computationally inexpensive, nonempirically tuned [electron localization function (ELF*) and solvent (Sol*)] range-separated (RS) functionals to study five molecules used in OSLDs. The emission energies in three different environments [toluene, CBP (4,4'-bis(n-carbazolyl)-1,1'-biphenyl) film, and gas] have been computed with the tuned functionals and compared with the experimental emission energies. ELF* and Sol* functionals can accurately reproduce emission energies in toluene and CBP film environments. On the other hand, both ELF* and IP-tuned functionals with excited-state geometry (IP*) perform better in the gas phase. In addition, a comparative study is performed between time-dependent density functional theory and the Tamm-Dancoff approximation. Along with the emission energy, oscillator strength values have also been reported. Different IP-tuned RS parameters were obtained with the ground- and excited-state geometries. Interestingly, it has been observed that the optimally tuned RS parameter with excited-state geometry (IP*) performs better compared to that with ground-state geometries (IP). Fractional occupation calculations show that the tuned functionals exhibit less localization and delocalization error. The study envisages that ELF* and Sol* functionals can be used to design future candidates for OSLDs.

COVID-19 associated rhabdomyolysis leading to major amputation in the absence of macrovascular thrombosis.

A 50 year old patient presented with bilateral lower extremity weakness, lethargy, and dyspnea. Nasopharyngeal swab was positive for SARS-CoV-2. She progressed to acute hypoxemic respiratory failure and hemodynamic instability requiring intubation, pressor support, and hemodialysis. Maculopapular rashes developed on bilateral lower extremities with progressively worsening rhabdomyolysis. Bilateral lower extremity fasciotomies were performed with subsequent serial operative debridements to remove necrotic muscle. One month later, she required a right above knee amputation. There was no evidence of macrovascular thrombosis. A high clinical suspicion of rhabdomyolysis in COVID-19 patients is necessary to avoid major limb loss.

Excited-State Properties of Some Thermally Activated Delayed Fluorescence Emitters: Quest for an Accurate and Reliable Computational Method.

Thermally activated delayed fluorescence (TADF) finds application in organic light-emitting diodes. The molecules exhibiting TADF are characterized by small singlet-triplet energy gaps that help reverse intersystem crossing. Recently, ionization potential (IP)-tuned range-separated (RS) density functionals have been well accepted for studying excited-state properties. In the present work, two efficient descriptor-based tuning schemes [electron localization function (ELF) and Sol] of RS density functionals have been used to accurately reproduce the excited-state properties of TADF emitters by performing a single self-consistent field calculation. The lowest singlet vertical excitation energies (EVA(S1)) and the vertical singlet-triplet energy gaps (ΔEVST) are computed with ELF-, Sol-, and IP-tuned RS functionals (LC-BLYP, ωB97, ωB97X, and ωB97XD). Encouraging mean absolute deviations from the experimental values with ELF*-, Sol*-, and IP-tuned functionals are observed. Consistent performance of the non-empirical tuned functionals is noted in different solvent dielectrics. In addition to these, fractional occupation calculations have shown that our tuned functionals almost satisfy the energy linearity curve. Thus, ELF*- and Sol*-tuned functionals are promising and reliable alternatives in computing the excited-state properties. Considering the small experimental singlet-triplet gap, we recommend ELF* to calculate EVA(S1) and Sol* to calculate ΔEVST.

Repair of a high-flow superficial femoral arteriovenous fistula using a bell-bottom iliac limb endoprosthesis.

A 50-year-old patient had presented with recalcitrant right lower extremity venous stasis ulceration, atrial fibrillation, and congestive heart failure. He had a history of a gunshot wound to the right thigh >30 years previously, which had been managed without surgery. Computed tomography angiography indicated a fistulous communication between the right superficial femoral artery and vein with massively dilated right iliofemoral venous and arterial systems. He was treated with stent-graft coverage of the superficial femoral arteriovenous fistula using a bell-bottom iliac limb endoprosthesis. This stent-graft accommodated the diameter asymmetry in the superficial femoral artery caused by the long-standing fistula and ameliorated the symptoms that had afflicted him for decades.

Vascular coil extrusion into the duodenum 6 years after hepatic artery aneurysm embolization.

A 50-year-old man with a history of coil embolization of a symptomatic 5.3-cm hepatic artery aneurysm 6 years previously presented with a massive gastrointestinal bleed. He was found to have embolization coils extruding into the duodenum from a hepaticoduodenal arterioenteric fistula. The present case demonstrates that endovascular intervention for a large hepatic artery aneurysm can have long-term consequences. We have described a novel complication of embolization of a giant hepatic artery aneurysm that necessitated complex open repair.

Performance of Range Separated Density Functional in Solvent Continuum: Tuning Long-range Hartree-Fock Exchange for Improved Orbital Energies.

Performance of the density functionals mainly depends on the proper approximation of exchange-correlation functionals. Modification of various parameters of such functionals, according to the demand of the system, has brought their accuracy level to a new height. Recent reports highlight that Long-range Corrected (LC) functionals are not encouraging in reproducing orbital energies in solvent. Therefore, in this article, we have proposed a tuning scheme for the LC functional for improved orbital energies. In this scheme, the optimized long-range HF exchange and the dielectric constant of the medium are included to modify the form of functionals. The proposed tuning is tested over a set of 103 molecules from IP131 database and fifteen solvent dielectrics. The tuned range separated functionals reproduce orbital eigenvalues in solvent continuum with good accuracy. More importantly, there is a consistency in the error for the tuned functional across the solvent media. © 2019 Wiley Periodicals, Inc.

How does the presence of an oxyradical influence the behavior of polyphenolic antioxidant? A case study on gallic acid.

Polyphenolic antioxidants are an integral component of the present-day lifestyle due to growing environmental and pollution-related issues. Gallic acid (GA), a popular polyphenolic antioxidant, is widely distributed in different fruits and vegetables. It scavenges free radicals mostly through the hydrogen atom transfer (HAT) mechanism. The present work reports a fundamental understanding of the atom transfer involved in the antioxidant activity of GA in the presence of prototype oxyradicals. In this article, the behavior of GA in the presence of three prototype oxyradicals, based on the availability in biological systems, viz. hydroxyl (•OH), hydroperoxyl (•OOH), and methyl peroxyl (•OOMe) is studied. On radical scavenging, a sharp change in the structural, electronic, and thermodynamic properties of GA is observed. Finally, a new descriptor based on chemical hardness, which describes the stability of the antioxidant molecule during a HAT reaction, is also proposed. Graphical abstract The present work reports a fundamental understanding of the atom transfer involved in antioxidant activity of gallic acid in presence of prototype oxyradicals.

Microhydration of 2-Naphthol at Ground, First Excited Triplet, and First Excited Singlet States: A Case Study on Photo Acids.

Molecular interactions of 2-naphthol (nap) with water molecules are studied at the ground, first excited triplet and first excited singlet states, applying DFT and TD-DFT methods. The minimum energy structure of hydrated clusters of 2-naphthol up to four water molecules are selected from several possible input geometries. It is observed that the minimum energy conformer of the tetra-hydrate of 2-naphthol has proton transfer occurring from nap to solvent water molecules, in its first excited singlet state. This is however not observed in case of its ground or first excited triplet state. It is consistent with the fact that the pKa of nap in the first excited singlet state is very much lower compared to the ground and first excited triplet state. This is also reflected in the O-H potential energy profile of tetrahydrate of nap, obtained by performing a rigid potential energy scan of the dissociating O-H bond of nap at ground, first excited triplet and first excited singlet states. Frequency of O-H stretching vibration of 2-napthol and its hydrated clusters in the ground (S0) as well as in the first excited singlet (S1) state are calculated and compared with the available experimental data. The performance of macroscopic solvation model is also examined in the ground and these excited states.

Implementation of a Radio-frequency Identification System to Improve the Documentation and Compliance of Attending Physicians' Arrival to Trauma Activations.

Background The documentation of physician arrival is an important component of trauma resuscitation. The American College of Surgeons (ACS) requires attending physicians at Level I and Level II trauma centers to arrive to the most critical traumas, full trauma team activations (full activations), within 15 minutes at 80% compliance, and to limited trauma team activations (limited activations) within a timely manner, which we designated as 60 minutes. However, our institution's rates of documentation and compliance using a paper-based trauma flowsheet (TFS) were found to be well below the 80% compliance rate. Methods Physicians began using a radio-frequency identification (RFID) badge to swipe into the emergency department (ED) upon arrival to the trauma room. Arrival times were taken from the swipes data and used to supplement missing or non-compliant times on the TFS. If a TFS was missing a time, it was considered both undocumented and noncompliant. A two-proportion z-test was used to compare the rates of documentation and compliance before and after the addition of swipes data. Results Documentation rates for full activations rose from 76% to 90%. Compliance rates for full activations rose from 70% (below the requirement) to 84% (compliant). Limited activation documentation and compliance rose significantly from 47.2% and 45.3% to 67.4% and 63.4%, respectively. Total documentation rose significantly from 49.9% to 69.7%. We went from below compliance to above compliance with the addition of the RFID system. Conclusion The use of the RFID technology improved the rates of documentation and compliance of attending physician arrival to trauma activations. Rates rose between 14 and 20 percentage points in each category, significantly in total documentation and in limited activation documentation and compliance. The addition of RFID swipes data made our rates improve to become compliant.

A new nonempirical tuning scheme with single self-consistent field calculation: Comparison with global and IP-tuned range-separated functional.

System-dependent nonempirical tuning of range-separated functional provides a way to minimize the delocalization error of the system. However, existing nonempirical tuning method requires the computation of several ΔSCF calculations to determine the optimal µ value. In this article, we have defined a scheme to evaluate the optimal µ value with single self-consistent field calculation. Our method is based on the evaluation of the spherically symmetric average Electron localization function (ELF) region. According to this scheme, the radius of the spherically symmetric average ELF region gives is a measure of the distance at which the long-range part of the range-separated functional becomes dominant. Numerical results indicate that our method improves the reproduction of HOMO energies and HOMO-LUMO gap in comparison to global and IP-tuned range-separated functional. Moreover, in case of HOMO energies, maximum error of the ELF-tuned functional is considerably smaller than the global and IP-tuned functional. Furthermore, our method gives considerably smaller deviation of HOMO energies from ΔSCF IP than global range-separated functional. © 2017 Wiley Periodicals, Inc.

Assessment of range-separated functionals in the presence of implicit solvent: Computation of oxidation energy, reduction energy, and orbital energy.

Recently, we have investigated the ionization potential (IP) theorem for some small molecules in the presence of external electric field [M. P. Borpuzari et al., J. Chem. Phys. 144, 164113 (2016)]. In this article, we assess the performance of some density functionals, local density approximation, generalized-gradient approximation (GGA), hybrid, meta-GGA hybrid, and range-separated functionals in the presence of two different solvent dielectrics, water and cyclohexane, in reproducing the vertical oxidation energy, reduction energy, and the frontier orbital energies. We also study the accessibility of different computational solvent models like the polarizable continuum model (PCM) and non-equilibrium PCM (NEPCM) in reproducing the desired properties. In general, the range-separated functionals do not perform well in reproducing orbital energies in the PCM. Range separation with the NEPCM is better. It is found that CAM-B3LYP, M06-2X, and ωB97XD functionals reproduce highest occupied molecular orbital energy in solvents, which may be due to the cancellation of PCM and density functional theory errors. Finally, we have tested the validity of the IP theorem in the solvent environment.

An immobilized symmetrical bis-(NHC) palladium complex as a highly efficient and recyclable Suzuki-Miyaura catalyst in aerobic aqueous media.

A bis-N-heterocyclic carbene (NHC) functionalized with chloropropyltriethoxysilane over silica was used to synthesize a well-defined immobilized palladium complex. This complex is a suitable and easily retrievable catalyst for Suzuki-Miyaura cross-coupling reactions under mild aqueous conditions. Excellent yields and conversions were obtained with low palladium loadings (down to 0.03 mol% Pd). The catalyst can be reused up to six cycles without the loss of its activity. The catalytic role of the NHC complex of palladium during coupling between bromobenzene and phenylboronic acid was investigated theoretically. The oxidative addition step is predicted to be endothermic in agreement with the experimental conditions.

Ionisation potential theorem in the presence of the electric field: Assessment of range-separated functional in the reproduction of orbital and excitation energies.

Recently, the range-separated density functionals have been reported to reproduce gas phase orbital and excitation energies with good accuracy. In this article, we have revisited the ionisation potential theorem in the presence of external electric field. Numerical results on six linear molecules are presented and the performance of the range-separated density functionals in reproducing highest occupied molecular orbital (HOMO) energies, LUMO energies, HOMO-LUMO gaps in the presence of the external electric field is assessed. In addition, valence and Rydberg excitation energies in the presence of the external electric field are presented. It is found that the range-separated density functionals reproduce orbital and excitation energies accurately in the presence of the electric field. Moreover, we have performed fractional occupation calculation using cubic spline equation and tried to explain the performance of the functional.

Experimental and theoretical study of urea and thiourea based new colorimetric chemosensor for fluoride and acetate ions.

Two new anion receptors 1,1-(4-nitro-1,2-phenylene) bis(3-phenylurea) (1) and 1,1-(4-nitro-1,2-phenylene) bis(3-phenylthiourea) (2) have been reported here. The binding and colorimetric sensing properties of receptors 1 and 2 with different anions were investigated by naked-eye, (1)H-NMR and UV-Vis spectroscopy. They showed effective and selective binding with two biologically important anions F(-) and CH3COO(-), in presence of other anions, such as Cl(-), Br(-), I(-), NO2(-), ClO4(-), HSO4(-), H2PO4(-), N3(-), CN(-) in acetonitrile. The relative binding mode of fluoride and acetate anions towards receptors 1 and 2 were studied using density functional theory (DFT), in gas phase and in acetonitrile solvent. Computational studies revealed that receptor 1 formed complexes by two intermolecular hydrogen bonds while receptor 2 by three intermolecular hydrogen bonds. In addition, time dependent DFT (TD-DFT) calculations qualitatively match the experimental UV-Vis spectra.

Biosynthesis of Ag nanoparticles using pedicellamide and its photocatalytic activity: an eco-friendly approach.

The synthesis of silver (Ag) nanoparticles using by pedicellamide (A), isolated from Piper pedicellatum C.DC leaf is demonstrated here. TEM analysis revealed that the Ag nanoparticles predominantly form spherical in shape. The compound 'A' act as a reducing, stabilizing and capping agent. The reaction mechanism was established by using density functional theory (DFT). Photocatalytic property of the Ag nanoparticles is investigated by degradation of Methyl Red (MR) dye under UV light. The kinetic, reaction mechanism and rate constant of photocatalytic degradation of MR was evaluated. The results show that Ag nanoparticles have suitable photocatalytic activity for the degradation of MR dye.

Long-range corrected density functionals combined with local response dispersion: A promising method for weak interactions.

Density functional theory, in general, is considered to underestimate the weak van der Waals type of intermolecular interactions. We optimized parameters of the local response dispersion (LRD) method applied to the long-range corrected exchange-correlation functionals (LC-BOP12+LRD and LCgau-BOP+LRD) on the interaction energy for the complexes in the recently compiled S66 database and found to be comparable with the high-level wave function-based methods reported in Rezác et al. (J. Chem. Theory Comput. 2011, 7, 2427). Our calculations with the S66 intermolecular complexes at equilibrium geometries suggests that the LC-BOP12+LRD and LCgau-BOP+LRD are well-balanced and lower cost alternatives to the methods reported in the database. Further, test on the S66X8 database (with eight nonequilibrium points) and the HBC6 and NBC10 database shows LC+LRD method with newly optimized parameters is a promising candidate for dealing such weak interactions. Finally, the new parameterized LC+LRD method was tested on X40 benchmark halogenated complexes.

Prothrombin complex concentrate for warfarin-induced bleeding in a patient with a mechanical aortic valve.

Reversal of anticoagulation-induced bleeding in the perioperative period can be challenging, particularly with an unstable patient with a mechanical valve. We present a case of life-threatening bleeding successfully managed with a prothrombin complex concentrate as an alternative to fresh frozen plasma.

Long-range corrected functionals satisfy Koopmans' theorem: calculation of correlation and relaxation energies.

In this article, we show that the long-range-corrected (LC) density functionals LC-BOP and LCgau-BOP reproduce frontier orbital energies and highest-occupied molecular orbital (HOMO)-lowest-unoccupied molecular orbital (LUMO) gaps better than other density functionals. The negative of HOMO and LUMO energies are compared with the vertical ionization potentials (IPs) and electron affinities, respectively, using CCSD(T)/6-311++G(3df,3pd) for 113 molecules, and we found LC functionals to satisfy Koopmans' theorem. We also report that the frontier orbital energies and the HOMO-LUMO gaps of LC-BOP and LCgau-BOP are better than those of recently proposed ωM05-D (Lin et al., J. Chem. Phys. 2012, 136, 154109). We express the exact IP in terms of orbital relaxation, and correlation energies and hence calculate the relaxation and correlation energies for the same set of molecules. It is found that the LC functionals, in general, includes more relaxation effect than Hartree-Fock and more correlation effect than the other density functionals without LC scheme. Finally, we scan µ parameter in LC scheme from 0.1 to 0.6 bohr(-1) for the above test set molecules with LC-BOP functional and found our parameter value, 0.47 bohr(-1), is usefully applicable to our tested systems.

The influence of electric field on the global and local reactivity descriptors: reactivity and stability of weakly bonded complexes.

The response of the global and local reactivity density-based descriptors (chemical potential, hardness, softness, Fukui function, and local softness) in the presence of external electric field has been studied for some of the simple prototype molecular systems. In addition to the analysis on the reactivity of these systems, the influence of the electric field on the interaction energy of the complexes formed by these systems has also been studied using the recently proposed semiquantitative model based on the local hard-soft acid-base principle. By using the inverse relationship between the global hardness and softness parameters, a simple relationship is obtained for the variation of hardness in terms of the Fukui function under the external electric field. It is shown that the increase in the hardness values for a particular system in the presence of external field does not necessarily imply that the reactivity of the system would be deactivated or vice versa.