Low-Symmetry Phthalocyanines Bearing Carboxy-Groups: Synthesis, Spectroscopic and Quantum-Chemical Characterization

The synthesis and characterization of A3B-type phthalocyanines, ZnPc1–4, bearing bulky 2,6-diisopropylphenoxy-groups or chlorine atoms on isoindoline units “A” and either one or two carboxylic anchors on isoindoline unit “B” are reported. A comparison of molecular modelling with the conventional time dependent—density functional theory (TD-DFT) approach and its simplified sTD-DFT approximation provides further evidence that the latter method accurately reproduces the key trends in the spectral properties, providing colossal savings in computer time for quite large molecules. This demonstrates that it is a valuable tool for guiding the rational design of new phthalocyanines for practical applications.

Lipid-Head-Polymer-Tail Chimeric Nanovesicles

Lipid nanovesicles (LNVs) and polymer nanovesicles (PNVs), also known as liposomes and polymersomes, are becoming increasingly vital in global health. One recent example is the widely distributed mRNA Covid-19 vaccines. However, the two major classes of nanovesicles both exhibit their own issues that significantly limit potential applications. Here, by covalently attaching a naturally occurring phosphate “lipid head” and a synthetic polylactide “polymer tail” via facile ring-opening polymerization on a 500-gram scale, a type of “chimeric” nanovesicles (CNVs) can be easily produced. Compared to LNVs, the reported CNVs exhibit reduced permeability for small and large molecules; on the other hand, the CNVs are less hydrophobic and exhibit enhanced tolerance toward proteins in buffer solutions without the need for hydrophilic polymeric corona such as poly(ethylene glycol), in contrast to conventional PNVs. The proof-of-concept in vitro delivery experiments using hydrophilic solutions of fluorescein-PEG, rhodamine-PEG, and anti-cancer drug doxorubicin demonstrate that these CNVs, as a structurally diverse class of nano-materials, are highly promising as alternative carriers for therapeutic molecules in translational nanomedicine.

Quantum harmonic free energies for biomolecules and nanomaterials

Obtaining the free energy of large molecules from quantum mechanical energy functions is a longstanding challenge. We describe a method that allows us to estimate, at the quantum mechanical level, the harmonic contributions to the thermodynamics of molecular systems of unprecedented size, with modest cost. Using this approach, we compute the vibrational thermodynamics of a series of diamond nanocrystals, and show that the error per atom decreases with system size in the limit of large systems. We further show that we can obtain the vibrational contributions to the binding free energies of prototypical protein-ligand complexes where the exact computation is too expensive to be practical. Our work raises the possibility of routine quantum mechanical estimates of thermodynamic quantities in complex systems.

Efficiency of Zinc in Plants, its Deficiency and Sensitivity for Different Crops

Optimal crop nutrition is a significant factor in increasing agricultural vintage and quality of products. Zinc (Zn) is an immobile important micronutrient, which is taken up by plants in Zn2+ form to complete their life cycle efficiently. It plays a critical metabolic role in plants and is an important constituent of proteins and other large-molecules, and serves as structural and functional unit, or controlling cofactor for a wide range of enzymes. The Zn is needed in small and in appropriate amounts for plants main physiological processes to work normally. These processes play critical roles in photosynthetic activity of plants and forming carbohydrates, synthesis of protein, reproduction and seed development, growth, and disease protection. After Zn deficiency in plants, these physical functions are decreased, and plant health and productivity suffer greatly, subsequent in reduced production or even failure of crops and often bad quality of crop products. Plant Zn deficiencies occur on variety of soils and are severe due to a combination of symptoms like chlorosis, resetting, dieback and suppressed or irregular vegetative development. In addition, various crops require varying amount of Zn. So the knowledge regarding this is not up to date. The present review discusses the Zn importance in plants, its deficiency in soil and required level of Zn for crops.

An Overview of Microneedles: Types, Materials, Processes, Emerging Approach and Applications in Dermatology

Drug delivery through the skin by transdermal patches has a long history. Subsequent growth of transdermal science proved prominent utility of transdermal systems meant for passive diffusion of the drug. It was followed by the development of Iontophoresis and Sonophoresis based transdermal delivery systems. Microneedle array has now caught attention of the investigators owing to its immense utility in transdermal delivery of very large molecules with ionic and hydrophilic nature. In this technical note, we present the current scenario, applications, and recent advances in microneedle array-based delivery of the most critical molecules through the skin. The application of microneedle has widely been investigated, and these technologies are being developed for the delivery of bio-therapeutics, biomacromolecules, insulin, growth hormones, immunobiologicals, proteins, siRNA and peptides. Potential of microneedles to transform the global transdermal market is highlighted in terms of the success rate of the microneedle technologies in clinical trials reaching to the global market. The arrival of the commercial microneedle-based products in the market is highly anticipated as they have potential to portray remarkable impact on clinical medicine in near future.

Severe Hypertriglyceridaemia Leading to Factitious Hypobicarbonataemia

Anion gap metabolic acidosis is a laboratory finding commonly encountered in patients with sepsis, diabetic ketoacidosis, acute kidney injury and toxic alcohol ingestion. Serum blood chemistry assessment detects this abnormality. However, this can be falsely low in situations of high triglyceride levels due to lipid interference with measurement of the bicarbonate levels and through volume displacement by these large molecules. Arterial blood gas analysis and a lipid panel are required to confirm accurate bicarbonate levels. Clinicians handling acid-base disorders in hospitalized patients need to be aware of this spurious laboratory value to avoid unnecessary tests and to determine accurate total bicarbonate levels.

NH Stretching Frequencies of Intramolecularly Hydrogen-Bonded Systems: An Experimental and Theoretical Study

The vibrational NH stretching transitions in secondary amines with intramolecular NH···O hydrogen bonds were investigated by experimental and theoretical methods, considering a large number of compounds and covering a wide range of stretching wavenumbers. The assignment of the NH stretching transitions in the experimental IR spectra was, in several instances, supported by measurement of the corresponding ND wavenumbers and by correlation with the observed NH proton chemical shifts. The observed wavenumbers were correlated with theoretical wavenumbers predicted with B3LYP density functional theory, using the basis sets 6-311++G(d,p) and 6-31G(d) and considering the harmonic as well as the anharmonic VPT2 approximation. Excellent correlations were established between observed wavenumbers and calculated harmonic values. However, the correlations were non-linear, in contrast to the results of previous investigations of the corresponding OH···O systems. The anharmonic VPT2 wavenumbers were found to be linearly related to the corresponding harmonic values. The results provide correlation equations for the prediction of NH stretching bands on the basis of standard B3LYP/6-311++G(d,p) and B3LYP/6-31G(d) harmonic analyses, with standard deviations close to 38 cm−1. This is significant because the full anharmonic VPT2 analysis tends to be impractical for large molecules, requiring orders of magnitude more computing time than the harmonic analysis.