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The main aim of this paper is to define the asymptotically Wijsman lacunary equivalent sequences of order (α,β)and study certain properties of this concept. We also make an effort to define Musielak–Orlicz asymptotically Wijsman lacunary statistical sequences of order (α,β)and examine some topological properties.

In the present paper we introduce the sequence spaces c0{ℳ, Λ , p, q}, c{ℳ, Λ, p, q} and l∞{ℳ, Λ, p, q} defined by a Musielak-Orlicz function ℳ = (ℳk). We study some topological properties and prove some inclusion relations between these spaces.

In this article, we use the notion of lacunary statistical convergence of order (α,β)\left(\alpha ,\beta )to introduce new sequence spaces by lacunary sequence, invariant means defined by Musielak-Orlicz function ℳ=(ℵk){\mathcal{ {\mathcal M} }}=\left({\aleph }_{k}). We also examine some topological properties and prove inclusion relations between newly constructed sequence spaces.

Rice husks are an agricultural residue of great annual production and have a high cellulose content. In this study, we have prepared highly charged carboxyl cellulose nanofibers (CNFs) from rice husks using the TEMPO-oxidation method and the extracted CNFs were evaluated as an adsorbent for the removal of lead(ii) and lanthanum(iii) (Pb(ii) and La(iii)) ions from contaminated water. Three different forms of nanocellulose adsorbents were prepared: suspension, freeze-dried, and nanocomposite containing magnetic nanoparticles, where their adsorption performance was tested against the removal of the two chosen heavy metal ions. The maximum adsorption capacity of rice husk based CNFs was found to be the highest in the nanocellulose suspension, i.e., 193.2 mg g−1for Pb(ii) and 100.7 mg g−1for La(iii). The separation of the used adsorbent in the suspension was further facilitated by the gelation of the CNFs and metal cations, where the resulting floc could be removed by gravity-driven filtration. The absorption mechanism of the investigated CNF system is mainly due to electrostatic interactions between negatively charged carboxylate groups and multivalent metal ions. It was found that 90% lanthanum content in the form of lanthanum oxychloride (determined by X-ray powder diffraction) could be obtained by incinerating the CNF/LaCl3gel. This study demonstrates a viable and sustainable solution to upcycle agricultural residues into remediation nanomaterials for the removal and recovery of toxic heavy metal ions from contaminated water.

We developed an intracavity frequency-doubled acousto-optic Q-switched Nd:YAG laser generating ~ 260 W of average green power using two identical diode-pumped gain modules with fivefold pumping symmetry in a simple two mirror linear cavity configuration. The corresponding optical to optical conversion efficiency was estimated to be ~ 16.8%. At maximum output power, individual green pulse duration (FWHM) was measured to be ~ 73 ns with a pulse repetition rate of 18 kHz. The output average green power was highly stable with measured fluctuation in average green power ± 0.83 W over 5 h of continuous operation. The jitter in pulse delay time and pulse to pulse amplitude fluctuation was measured to be within ± 4.25 ns and ± 5%, respectively. The maximum beam drift recorded at 5 m distance away from the laser system was ~ 14 micron corresponding to beam pointing stability of ± 2.8 micro-rad.

Understanding the morphology and flow behavior of cellulose nanofibers (CNFs) dispersed in organic solvents can improve the process of fabricating new cellulose-based nanocomposites. In this study, jute-based 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized CNFs with two different charge densities (0.64 and 1.03 mmol/g) were dispersed in ethylene glycol (EG) and propylene glycol (PG) using the solvent exchange method. The morphology and dimensions of CNFs in dry and suspension states were characterized using transmission electron microscopy, atomic force microscopy, and small-angle X-ray scattering techniques. The results showed that the cross-sectional dimensions remained the same in different solvents. Rheological measurements revealed that CNF suspensions in water or glycol (EG and PG) behaved similar to typical polymer solutions with a solvent-independent overlap concentration corresponding to the crowding factor of about 14. Furthermore, a thixotropic behavior was found in the concentrated CNF/glycol systems as observed in typical CNF aqueous suspensions. The fact that TEMPO-oxidized CNFs can be well dispersed in organic solvents opens up new possibilities to improve the CNF–polymer matrix blending, where the use of a viscous solvent can delay the transition to turbulence in processing and improve the control of fiber orientation because of a slower Brownian diffusive motion.

Introduction: Steroid compounds are widely distributed in nature throughout scientific history. Living organisms such as animals and vegetables have steroids that show a significant effect on their vital activities. Sterols are key components of all eukaryotic cell membranes. Methods: Steroidal compounds; 3β-oxo-[1’,3’,2’-oxathiaphos-phalidine-2’-one] stigmast-5-ene and 3β- oxo[1`,3`,2`-dioxaphosphalidine-2`-one]-stigmast-5-ene were successfully prepared using easily accessible 3β-hydroxy stigmast-5-ene with phosphorous oxychloride (POCl3), 2- mercaptoethanol/ethylene glycol and triethylamine (Et3N) in dry diethyl ether. Products were obtained in semi-solid state and characterized using physicochemical techniques. Results: The results of the bioassay showed that the synthesized compound containing the sulfur atom had antibacterial activity. Molecular docking was also done in order to show in silico antibacterial activity and to make out the probable binding mode of compound with the amino acid residues of protein. Conclusion: The results of the docking study showed that synthesized compound 2 had minimal binding energy with substantial affinity for the active site.

The global COVID-19 pandemic arising from SARS-CoV-2 has impacted many lives, gaining interest worldwide ever since it was first identified in December 2019. Till 2023, 752 million cumulative cases and 6.8 million deaths were documented globally. COVID-19 has been rapidly evolving, affecting virus transmissibility and properties and contributing to increased disease severity. The Omicron is the most circulating variant of concern. Although success in its treatment has indicated progress in tackling the virus, limitations in delivering the current antiviral agents in battling emerging variants remain remarkable. With the latest advancements in nanotechnology for controlling infectious diseases, liposomes have the potential to counteract SARS-CoV-2 because of their ability to employ different targeting strategies, incorporating monoclonal antibodies for the active and passive targeting of infected patients. This review will present a concise summary of the possible strategies for utilizing immunoliposomes to improve current treatment against the occurrence of SARS-CoV-2 and its variants.

We report, for what we believe is the first time, generation of stable chair-like pulses (a pulse shape with an initial long flat portion followed by a short high peak power portion resembling the shape of a chair) by mode locking of a Ytterbium (Yb)-doped fiber laser. Chair-like pulse shapes are achieved by implementing dual saturable absorbers, one based on a nonlinear optical loop mirror (NOLM) and the other based on nonlinear polarization rotation (NPR) inside the cavity. The transmission characteristics of the NOLM-NPR pair leading to the formation of chair-like pulses are numerically investigated. We also report the amplification characteristics of chair-like pulses in an external multistage Yb-doped fiber amplifier setup at different repetition rates of the pulse train. It was found that the chair-like pulses are suitable for amplification, and more than 10 W of average power at 460 kHz repetition rate have been obtained at total pump power of ∼20  W coupled to the power amplifier. At a lower repetition rate (115 kHz), ∼8  W of average power were obtained corresponding to ∼70  μJ of pulse energy with negligible contribution from amplified spontaneous emission or stimulated Raman scattering. We believe that such an oscillator-amplifier system could serve as an attractive tool for micromachining applications.

In the present paper we introduce the sequence spaces defined by a sequence of modulus function F=(fk). We study some topological properties and inclusion relations between these spaces.

Chromones (1-benzopyran-4-ones) are natural occurring compounds present in representative amounts in a normal human diet and are associated with interesting physiological activities such as antiinflammatory, antidiabetic, antitumor, anticancer etc. These biological activities are thought to be related to the antioxidant properties of chromones i.e. to neutralize active oxygen and to cut off free radicals processes that can delay or inhibit cell impairment which leads to various diseases. In this review, we have summarized the literature reports published in about 70 research articles during the period January 2004 to March 2014 on more than 400 naturally as well as the synthetically derived chromone derivatives having antioxidant potential. The literature reports suggest that the double bond, a carbonyl group of chromone and 3´,4´-dihydroxy group (catechol) in ring B along with the C-3 and C-5 hydroxyl groups are important for radical scavenging activity. In turn, a decrease in the radical scavenging potential has been observed upon methylation / glycosylation of the hydroxyl groups on chromone nucleus.

A method was developed to estimate greenhouse gas (GHG) emission reductions, using a set of calculations to quantify the changes in biomass carbon when conventional logging (CL) is replaced by improved forest management (IFM) with reduced impact logging (RIL). A case study of 30,000 ha net harvestable area of tropical rainforest in Paragominas, Pará, Brazil, was employed, where 25 m3 ha−1was harvested over 30 years. To simulate changes from CL to RIL, the residual stand damage factor was reduced from 1.94 to 1.5 Mg C damaged per Mg C extracted, losses in harvested wood volumes were reduced from 16 to 5% while the lumber recovery fraction was increased from 0.47 to 0.55, the area for landing, roads and skid trails was decreased from 20% to 10%, and regrowth rate increased from 0.5 to 2.5 Mg of dry matter ha−1yr−1. The simulations attained emissions reductions in the order of 3,175,212 Mg CO2-e, which equates to 28.8 Mg C ha−1or 0.96 Mg C ha−1yr−1, an approximate 82% reduction from CL baseline emissions. The increase in regrowth rate in RIL areas provided the largest affect on emission reductions (51%). The simulated results were comparable with both field and model studies, and demonstrate that RIL can achieve carbon credit revenue of USD 105,840 per year, or approximately USD 3,175,212 after 30 years, based on a 2014 carbon price of USD 1.00 per Voluntary Carbon Unit (VCU).

Long-term harvested wood products (Lt-HWPs) are not released to the atmosphere immediately after tree harvesting, but retire over a period of time depending on the types of their uses. Two different approaches, one accounting for carbon emissions from possible end of life pathways after retirement of HWPs and another assuming immediate carbon release, were applied to the Verified Carbon Standard (VCS) approved Improved Forest Management-Logged Protected Forest project in Australia. Exponential and logistic functions using Tier 2 parameters were used to track the annual retirement from Lt-HWPs and compared the results to exponential (Winjum et al. parameters) function and linear 20 years (VCS method). Exponential (Winjum et al. parameters) function with the immediate release of carbon that retire/decay annually generated the lowest greenhouse gas (GHG) emissions (69,382 tCO2-e), followed by exponential (Tier 2) function with 234,628 tCO2-e. Linear 20-year (VCS method) generated the highest GHG emissions among all methods (367,299 tCO2-e) over 25 project crediting period. For a project producing sawnwood (30%), exponential function (Winjum et al. parameters) also produced the lowest estimation of GHG emissions from Lt-HWPs. Although the exponential annual decay (Winjum et al. parameters) function which assumes immediate carbon release, generated the lowest GHG emission from Lt-HWPs in the temperate climatic region, the end of life pathway approach employing exponential or logistic functions with Tier 2 parameters, can simulate carbon emissions from Lt-HWPs more accurately and yield an unbiased estimation of GHG emission from HWPs, Interestingly, linear 20-year (VCS method) using a fixed timeframe of a 20-year linear function was neither found conservative in terms of net GHG emissions, nor flexible enough to take into account different wood product types and climatic region specific decay rates that may vary with project location and forest types.

Classic cancer research for several decades has focused on understanding the biology of tumor cells in vitro. However, extending these findings to in vivosettings has been impeded owing to limited insights on the impact of microenvironment on tumor cells. We hypothesized that tumor cell biology and treatment response would be more informative when done in the presence of stromal components, like endothelial cells, which exist in the tumor microenvironment. To that end, we have developed a system to grow three-dimensional cultures of GFP-4T1 mouse mammary tumor and 2H11 murine endothelial cells in hanging drops of medium in vitro. The presence of 2H11 endothelial cells in these three-dimensional cocultures was found to sensitize 4T1-GFP tumor cells to chemotherapy (Taxol) and, at the same time, protect cells from ionizing radiation. These spheroidal cultures can also be implanted into the dorsal skinfold window chamber of mice for fluorescence imaging of vascularization and disease progression/treatment response. We observed rapid neovascularization of the tumor-endothelial spheroids in comparison to tumor spheroids grown in nude mice. Molecular analysis revealed pronounced up-regulation of several proangiogenic factors in the tumor tissue derived from the tumor-endothelial spheroids compared with tumor-only spheroids. Furthermore, the rate of tumor growth from tumor-endothelial spheroids in mice was faster than the tumor cell-only spheroids, resulting in greater metastasis to the lung. This three-dimensional coculture model presents an improved way to investigate more pertinent aspects of the therapeutic potential for radiation and/or chemotherapy alone and in combination with antiangiogenic agents.

Polymeric nanocarriers possess advanced physicochemical properties that improve bioavailability, enhance cellular dynamics, and control target ability in drug delivery. In particular, dendritic polyglycerol is a promising new biocompatible scaffold for drug delivery. The present study explores the chemo-enzymatic modifications on dendritic hyperbranched polyglycerol (dPG) leading to amphiphilic polymeric architectures with easily hydrolysable ester linkages. Furthermore, these architectures were studied for nile red solubilization with capacity up to 5.6 mg/L at 0.1 wt % polymer conc. This corresponds to an ~10 fold increase in solubility of nile red. The release of nile red from these polymers was observed with a half life of 8 hours at pH 5.0, while no release was found at pH 7.4. The cell viability studies of our polymeric architectures showed them to be relatively nontoxic and to have the potential for future drug delivery applications.

Glycerol is one of the most versatile and valuable chemical substances and is utilized in a variety of commercial products with no known adverse pharmacological or environmental effects. Moreover, it exhibits good chemical stability and inertness under biological conditions. We have designed and developed Candida antarcticalipase CAL B catalyzed biocatalytic method to synthesize novel polymeric systems using glycerol and polyethylene glycol biscarboxymethyl ether dimethylester. Both synthons are biocompatible, nontoxic, and are readily available. The polymerization occurs regioselectively through the primary hydroxyl groups of glycerol leaving the secondary hydroxyls for postpolymerization chemical modifications and also for attaching drugsbioactive molecules. We have utilized these sites for the synthesis of amphiphilic polymers by attaching alkyl chains at the secondary hydroxyl groups simply by acylation. The drug encapsulation abilities of the resulting polymers have been evaluated for potential biomedical applications.

Polyvinyl chloride (PVC) is one of the most widely used polymers today. One of its major applications is in electrical and control cables. Although PVC is intrinsically self-extinguishing, it supports flame spread along its length because of the additives used during processing. The spread of fire along electrical cables may be alleviated either by using flame-retardant smoke-suppressant (FRSS) additives or by applying fire-retardant intumescent coatings to the surface of the cable sheath. The intumescent coating also acts as a fire-protective barrier for electrical cables. Plasticized PVC compositions incorporating a molybdenum-based organic (MBO) complex were prepared and evaluated for their fire performance. Excellent smoke suppression was observed in the specimens modified using the complex, which acts as an FRSS additive. The limiting oxygen index (LOI) was also found to be fairly high, particularly when the PVC samples were plasticized with a phosphate plasticizer. FRSS intumescent coatings were applied on PVC-sheathed electrical cables. Their fire performance was evaluated using national and international standard procedures. Significantly low levels of smoke generation was observed along with zero flame spread when the coated cables were exposed to standard test conditions. The formulations used in both the treatments — coating as well as additive — offer improved resistance to ignition, flame spread and smoke generation.

The synthetic potential of enzymes related to organic synthesis has been applied profusely, especially since the introduction of their use in organic solvents. Enzymes offer the opportunity to carry out highly chemo-, regio-, and enantioselective transformations. The use of enzymes in the synthetic sequence provides unique advantages of efficiency and environmental friendliness. Owing to their low cost and applicability to a broad range of substrates, lipases have become the most versatile class of biocatalysts in organic synthesis. We have screened a battery of lipases to carry out highly selective reactions for the synthesis of a wide range of organic compounds and polymeric materials.

Biocatalytic polymerization reactions on a variety of substrates leading to value-added polymers have been summarized. The main focus of this review is on the control of molecular architecture during enzymatic polymerization reactions. Combined with chemical reactions, several extremely flexible chemo-enzymatic synthetic procedures are described to produce families of new polymeric materials with novel properties. The properties of the synthesized polymers and their applications in various fields, such as drug delivery and flame retardant materials, have also been studied and discussed.

A wide variety of polyphenolic compounds (i.e., 4-methylcoumarins, xanthones, pyrazoles, and pyrazolylacrylonitriles) have been examined for their antioxidant effect on NADPH-catalyzed liver-microsomal lipid peroxidation with a view to establishing their structure–activity relationship. Dihydroxy-/diacetoxy-4-methylcoumarin derivatives have been shown to be radical scavengers. The effect of nine different xanthones has been examined on the modulation of cytokine-induced expression of intercellular adhesion molecule-1 (ICAM-1) in human endothelial cells. 1,4-Dihydroxyxanthone showed enhanced antioxidant activity as well as ICAM-1 inhibitory activity.

The development of anti-invasive and anti-metastatic drugs is a major challenge in current cancer research. A model to study invasion in vitro consisted of organotypic confronting cultures of human MCF-7/6 mammary cancer cells with embryonic chicken heart fragments. Untreated cultures show occupation and destruction of the normal heart fragments within eight days. Inhibition of invasion was observed after addition of the following alkaloids and (poly)phenolics to the culture medium: (+)-catechin, tangeretin, xanthohumol, 3,7-dimethoxyflavone, prenylated chalcones, a pyrazole derivative, an isoxazolylcoumarin, and a prenylated desoxybenzoin. The action targets have been found both in the cancer cells and the surrounding host tissue. We hope that the further characterization of these targets will eventually lead to the development of clinically applicable anti-invasive drugs.

The enzymatic transfer of acetyl groups from acetylated xenobiotics to specific proteins is a relatively grey area in the evergreen field of biotransformation of foreign compounds. In this paper, we have documented evidence for the existence of a transacetylase in liver microsomes that catalyses the transfer of acetyl groups from 7,8-diacetoxy-4-methylcoumarin (DAMC) to glutathione S-transferase (GST), either purified or present in cytosol leading to the irreversible inhibition of GST. A simple procedure is described for the assay of transacetylase by preincubation of DAMC with liver microsomes and pure GST/liver cytosol, followed by the addition of 1-chloro-2, 4-dinitrobenzene (CDNB) and reduced glutathione (GSH) in order to quantify GST activity by the conventional procedure. The extent of inhibition of GST by DAMC under the conditions of the assay is indicative of DAMC:protein transacetylase activity. Following the assay procedure described here, the transacetylase was shown to exhibit hyperbolic kinetics. The bimolecular nature of the transacetylase reaction was apparent by the demonstration of Kmand νmaxvalues. 7,8-Dihydroxy-4-methylcoumarin (DHMC), one of the products of transacetylase reaction was identified and quantified using the partially purified enzyme. The fact that p-hydroxymercuribenzoate (PHMB) and iodoacetamide abolished irreversible inhibition of GST upon the action of transacetylase on DAMC strongly characterized transacetylase as a protein containing thiol group at the active site. In addition, the relative specificities of acetoxy 4-methylcoumarins to transacetylase have been demonstrated.

The existence of a novel microsomal deacetylase in rat liver catalysing deacetylation of diacetoxy 4-methylcoumarins has been reported. A simple method is outlined for the enzyme assay based upon the quantification of the dihydroxy derivative by measuring the UV absorption of its complex with ADP and Fe3+at 600 nm. The enzyme can be routinely assayed using 7,8-diacetoxy-4-methylcoumarin (DAMC) as the substrate and demonstrated hyperbolic kinetics and yielded Kmand νmaxvalues of 1250 μM and 500 units, respectively. The pH optima was found to be 7.5 for the enzyme. No DAMC deacetylase activity was found in hepatic cytosol and the enzyme activity was not discernible in extrahepatic tissues.

Char formation that preserves the structural integrity of the polymer is one of the most efficient methods of reducing its flammability. Enhanced char formation from polymers such as PVC may also be associated with a decrease in smoke production, as is observed when the polymer is modified by a flame retardant smoke suppressant (FRSS) complex. A correlation had been made between the FRSS characteristics and char morphology. The effect of different flame retardant smoke suppressants on char formation has been highlighted.

7,8-Dihydroxy-4-methylcoumarin (1, DHMC) and 7,8-diacetoxy-4-methylcoumarin (2, DAMC) were shown to possess radical scavenging property and strongly inhibit membrane lipid peroxidation. Although free polyphenolic compounds are known to be antioxidants, the antioxidant action of the acetoxy compound DAMC was intriguing. Hence, pulse radiolysis studies were undertaken to explain the antioxidant action of DAMC. Accordingly, DAMC and DHMC were separately reacted with the system generating azide radicals and the resulting transient spectra were recorded. The spectra so obtained in both the cases demonstrated peak at 410 nm, characteristic of phenoxyl radical. The rate constants for the formation of phenoxyl radical from DHMC and DAMC were 34×108M−1s−1and 6.2×108M−1s−1, respectively. We propose that the free radical mediated oxidation of DAMC initially produces a radical cation that loses an acetyl carbocation to yield the phenoxyl radical. It is possible to conclude that the mechanism of the antioxidant action of DAMC follows the pathway similar to that of DHMC involving the formation of a stable phenoxyl radical.

Invasion of MCF-7/6 human mammary carcinoma cells into embryonic chick heart fragments was studied in organ culture during 8 days. The effect of 31 polyphenolic compounds, belonging to the flavonoids, chalcones, or coumarins, was tested in this assay for invasion. The anti-invasive activity of 3,7-dimethoxyflavone was found at concentrations ranging from 1 to 100 μM. At these anti-invasive concentrations, no cytotoxic effects could be detected: the anti-invasive effect was reversible upon omission of the molecule from the medium, and treatment of MCF-7/6 cells or heart fragments did not affect subsequent outgrowth from explants on tissue culture plastic. The molecule did not inhibit growth of MCF-7/6 cell aggregates nor of heart fragments kept in suspension culture. The action mechanism of 3,7-dimethoxyflavone is the subject of our ongoing research.

We have evaluated the influence of aromatic and hydrophobic interactions on the strength and selectivity of encapsulation using polymeric nanospheres.

Amano PS and CAL çatalysed prochiral asymmetrization of the title compound 1has been studied.

A reprint of the article "200,000 Skeletons in Richard Holbrooke's Closet," by Sunil K. Shama, which appeared in the March 22, 1999 issue, is presented. Richard Holbrooke of the U.S. State Department was reportedly complicit in the Indonesian campaign of genocide against East Timor. He headed the department's Bureau of East Asian and Pacific Affairs, which created the U.S. policy toward East Timor. It describes his service to state power as a crime against humanity.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

For Abstract see ChemInform Abstract in Full Text.

For Abstract see ChemInform Abstract in Full Text.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.