Porosity, Powder X-Ray Diffraction Patterns, Skeletal Density, and Thermal Stability of NIST Zeolitic Reference Materials RM 8850, RM 8851, and RM 8852.

This paper reports the powder X-ray diffraction patterns, argon isotherms at 87 K, Brunauer-Emmett-Teller surface areas, pore size distributions, pore volumes, skeletal densities, and thermal gravimetric analyses for three National Institute of Standards and Technology zeolitic reference materials, RM 8850 (zeolite Y), RM 8851 (zeolite A), and RM 8852 (ZSM-5).

Understanding Material Characteristics through Signature Traits from Helium Pycnometry.

Although helium pycnometry is generally the method of choice for skeletal density measurements of porous materials, few studies have provided a wide range of case studies that demonstrate how to best interpret raw data and perform measurements using it. The examination of several different classes of materials yielded signature traits from helium pycnometry data that are highlighted. Experimental parameters important in obtaining the most precise and accurate value of skeletal density from the helium pycnometer are as high as possible percent fill volume and good thermostability. The degree of sample activation is demonstrated to affect the measured skeletal density of porous zeolitic, carbon, and hybrid inorganic-organic materials. In the presence of a significant amount of physisorbed contaminants (water vapor, atmospheric gases, residual solvents, etc.), which was the case for ZSM-5, MIL-53, and F400, but not ZIF-8, the skeletal density tended to be overestimated in the low percent volume region. In addition, the kinetic data (i.e., skeletal density vs measurement cycle) reveals distinctive traits for a properly activated vs a nonactivated sample for all examined samples: activated samples with a significant amount of mass loss show a curved down plot that eventually reaches the equilibrium value, whereas nonactivated, nonporous, or extremely hydrophobic samples exhibit a flat line. This work illustrates how helium pycnometry can provide information about the structure of a material, and that, conversely, when  the structure of the material and its percent mass loss after activation (amount of physisorbed contaminants) are known, the behavior of activated and nonactivated samples in terms of skeletal density, percent fill volume, and measurement cycle can be predicted.

An experimental and modelling study of water vapour adsorption on SBA-15.

Many publications have been dedicated to the study of water vapour adsorption on the ordered silica-based material Santa Barbara Amorphous-15 (SBA-15). However, two aspects still need to be clarified: whether the solid is stable under repeated adsorption-desorption cycles and whether the experimental data can be predicted with a simple yet accurate analytical equilibrium model. In this study, SBA-15 showed good long-term structural stability when exposed to repeated adsorption-desorption cycles using water vapour as adsorptive up to 90 % relative humidity at 288 K, 298 K and 308 K. The reproducibility of the equilibrium isotherm was investigated using different commercial gravimetric instruments designed for water vapour adsorption measurements. The experimental measurements show a modification of the microporous structure of the solid after the first full isotherm measurement. Some water is strongly adsorbed and trapped during the first experiment on a fresh sample. After the first adsorption-desorption cycle, the water isotherm is characterized by a low value of the Henry law constant and by a nearly vertical capillary condensation and evaporation branches. Quite interestingly, the experimental scanning curves do not simply cross from one branch to the other as would be expected for cylindrical independent pores. The experimental data are correlated using new analytical models able to predict the amount adsorbed in the entire concentration range for the main adsorption-desorption branches and for the adsorption-desorption scanning curves.

Structure of a new usnic acid derivative from a deacylating Mannich reaction: NMR studies supported by theoretical calculations of chemical shifts.

In a conventional Mannich reaction using piperidine, hydroxypiperidines, morpholine, and N-methylpiperazine with usnic acid, a deacetylation was observed resulting in a substitution at C-2, a loss of an acetyl group, and a Mannich base with a stabilized enol. The enol has a hydrogen bond to the nitrogen of the secondary amine. The structure was investigated by nuclear magnetic resonance and deuterium isotope effects on 13 C chemical shifts as well as with density functional theory calculations to study the changed hydrogen bond pattern. It was found that the hydrogen bond involving the OH-9 group in chloroform forms a strong hydrogen bond than in usnic acid itself and that this hydrogen bond becomes even stronger in the more polar solvent, dimethylsulfoxide. Tautomerism was observed in the Mannich base as demonstrated by deuterium isotope effects on chemical shifts. The position of the tautomeric equilibrium depends on the solvent, and the position of the equilibrium governs the strength of the OH-9…O═C hydrogen bond.

Antitumor effect of the integrin α4 signaling inhibitor JK273 in non-small cell lung cancer NCI-H460 cells.

Lung cancer accounts for the highest death rate among cancers worldwide, with most patients being diagnosed with non-small cell lung cancer (NSCLC), urging more effective therapies. We report that JK273, a pyrrolo[2,3-d]pyrimidine analog, which inhibits α4 integrin signaling, showed a selective cytotoxic effect against HCI-H460 NSCLC cells, with an IC50 of 0.98 ± 0.15 µM, but showed less sensitivity to fibroblasts with a selectivity index (SI) greater than 30. This effect was attributed to cell cycle arrest at S phase by JK273 treatment, resulting in the apoptosis of NCI-H460 cells, further confirmed by exposing phosphatidylserine and morphological changes. Taken together with the previous study of JK273 inhibiting cell migration, we propose that JK273 could serve as an antitumor compound to specifically target cancer cells but not non-cancerous cells by triggering programmed cell death, in addition to anti-metastatic effects in cancer therapy.

A Dataset of Electrical Components for Mesh Segmentation and Computational Geometry Research.

Data quality is of crucial importance in the field of automated or digitally assisted assembly. This paper presents a comprehensive data set of triangle meshes representing electrical and electronic components obtained by scraping Computer Aided Design (CAD) models from the Internet. Consisting of a total of 234 triangle meshes with labelled vertices, this data set was specifically created for segmentation tasks. Its versatility for multimodal tasks is underscored by the presence of various labels, including vertex labels, categories, and subcategories. This paper presents the data set and provides a thorough statistical analysis, including measures of shape, size, distribution, and inter-rater reliability. In addition, the paper suggests several approaches for using the data set, considering its multimodal characteristics. The data set and related findings presented in this paper are intended to encourage further research and advancement in the field of manufacturing automation, specifically spatial assembly.

High biocompatible FITC-conjugated silica nanoparticles for cell labeling in both in vitro and in vivo models.

Fluorescence nanosilica-based cell tracker has been explored and applied in cell biological research. However, the aggregation of these nanoparticles at physiological pH is still the main limitation. In this research, we introduced a novel fluorescence nano-based cell tracker suitable for application in live cells. The silica-coated fluorescein isothiocyanate isomer (FITC-SiO2) nanoparticles (NPs) were modified with carboxymethylsilanetriol disodium salt (FITC-SiO2-COOH), integrating the dianion form of FITC molecules. This nanosystem exhibited superior dispersion in aqueous solutions and effectively mitigated dye leakage. These labeled NPs displayed notable biocompatibility and minimal cytotoxicity in both in vitro and in vivo conditions. Significantly, the NPs did not have negative implications on cell migration or angiogenesis. They successfully penetrated primary fibroblasts, human umbilical vein endothelial cells and HeLa cells in both 2D and 3D cultures, with the fluorescence signal enduring for over 72 h. Furthermore, the NP signals were consistently observed in the developing gastrointestinal tract of live medaka fish larvae for extended periods during phases of subdued digestive activity, without manifesting any apparent acute toxicity. These results underscore the promising utility of FITC-SiO2-COOH NPs as advanced live cell trackers in biological research.

Improved Apparatus for Dynamic Column Breakthrough Measurements Relevant to Direct Air Capture of CO2.

Dynamic column breakthrough (DCB) measurements are valuable for characterizing the adsorption of gaseous species by solid sorbents and are typically used for high concentrations of adsorptives, often at elevated temperatures and pressures. However, adsorbents for the direct capture of carbon dioxide from natural air demand measurement capability at low partial pressures of CO2 at atmospherically relevant temperatures and pressures. We have developed a new apparatus focused on the measurement of DCB curves under typical tropospheric conditions. The new apparatus is described in detail and validated with breakthrough curve measurements. Adsorption capacities are reported at (233.1 to 323.1) K and (351 to 1078) hPa for low carbon dioxide concentrations on 13X zeolite samples on the order of a few hundred milligrams. Measurement uncertainties related to timing, flow, temperature, and concentrations are analyzed and the present results at 273 K, 298 K, and 323 K are compared with static measurements obtained with a manometric adsorption analyzer. In addition, experiments at a typical atmospheric CO2 concentration of 400 µL · L-1 have been performed.

Tobacco mosaic virus as a new carrier for tumor associated carbohydrate antigens.

Tumor-associated carbohydrate antigens (TACAs) are being actively studied as targets for antitumor vaccine development. One serious challenge was the low immunogenecity of these antigens. Herein, we report the results of using the tobacco mosaic virus (TMV) capsid as a promising carrier of a weakly immunogenic TACA, the monomeric Tn antigen. The copper(I) catalyzed azide-alkyne cycloaddition reaction was highly efficient in covalently linking Tn onto the TMV capsid without resorting to a large excess of the Tn antigen. The location of Tn attachment turned out to be important. Tn introduced at the N terminus of TMV was immunosilent, while that attached to tyrosine 139 elicited strong immune responses. Both Tn specific IgG and IgM antibodies were generated as determined by enzyme-linked immunosorbent assay and a glycan microarray screening study. The production of high titers of IgG antibodies suggested that the TMV platform contained the requisite epitopes for helper T cells and was able to induce antibody isotype switching. The antibodies exhibited strong reactivities toward Tn antigen displayed in its native environment, i.e., cancer cell surface, thus highlighting the potential of TMV as a promising TACA carrier.

Ethanol and Water Adsorption in Conventional and Hierarchical All-Silica MFI Zeolites.

Hierarchical zeolites containing both micro- (<2 nm) and mesopores (2-50 nm) have gained increasing attention in recent years because they combine the intrinsic properties of conventional zeolites with enhanced mass transport rates due to the presence of mesopores. The structure of the hierarchical self-pillared pentasil (SPP) zeolite is of interest because all-silica SPP consists of orthogonally intergrown single-unit-cell MFI nanosheets and contains hydrophilic surface silanol groups on the mesopore surface while its micropores are nominally hydrophobic. Therefore, the distribution of adsorbed polar molecules, like water and ethanol, in the meso- and micropores is of fundamental interest. Here, molecular simulation and experiment are used to investigate the adsorption of water and ethanol on SPP. Vapor-phase single-component adsorption shows that water occupies preferentially the mesopore corner and surface regions of the SPP material at lower pressures (P/P 0 < 0.5) while loading in the mesopore interior dominates adsorption at higher pressures. In contrast, ethanol does not exhibit a marked preference for micro- or mesopores at low pressures. Liquid-phase adsorption from binary water-ethanol mixtures demonstrates a 2 orders of magnitude lower ethanol/water selectivity for the SPP material compared to bulk MFI. For very dilute aqueous solutions of ethanol, the ethanol molecules are mostly adsorbed inside the SPP micropore region due to stronger dispersion interactions and the competition from water for the surface silanols. At high ethanol concentrations (C EtOH > 700 g L-1), the SPP material becomes selective for water over ethanol.

Altering the landscape of viruses and bionanoparticles.

In recent years, protein-based nanoparticles or bionanoparticles (BNPs), have been used as primary building blocks to generate ornate nanomaterials for a wide-range of applications. Over the past fifty years, numerous BNPs have been chemically modified or genetically engineered to function as smart drug/gene delivery vehicles, advanced vaccine vehicles, and isolated reaction vessels for inorganic, metallic, and semi-conductive depositions. These studies have contributed invaluable insights to the expansive capabilities of these simple, yet highly robust, nanosized building materials. Here we highlight some of the recent progress in the chemical modifications of BNPs and hopefully inspire the development of many new materials in the near future.

Temperature-insensitive silicone composites as ballistic witness materials: the impact of water content on the thermophysical properties.

In this work, different formulations of a room-temperature silicone composite backing material (SCBM) composed of polydimethylsiloxane (PDMS), fumed silica and corn starch were investigated using different characterization techniques, i.e., differential scanning calorimetry, thermogravimetry analysis, X-ray diffraction (XRD) and small-angle X-ray scattering, as a function of controlled relative humidity. At ambient relative humidities in the range of about 20-80%, the equilibrium water content in the SCBM ranges from approximately 4-10%, which is predominantly absorbed by the corn starch. This amount of water content has been shown to have minimal effect on thermal transition temperatures (melting and glass transition) of the SCBMs. The enthalpy of melting increases with increasing relative humidity, which reflects the heterogeneous semicrystalline structure of starch granules and the role of moisture in facilitating the formation of amylopectin double helices mainly in the imperfect crystalline regions. The thermal degradation of SCBM exhibits three major mass loss steps that correspond to dehydration, decomposition of corn starch and decomposition of PDMS. The XRD patterns reveal a characteristic diffuse peak for amorphous PDMS and an A-type crystallinity for the corn starch. The XRD results show no observable changes in the crystal type and crystallinity as a function of moisture content. Results from this work help clarify the fundamental structure-property relationships in SCBMs, which are important for future development of documentary standards, especially the handling and storage specifications of next-generation ballistic witness materials for body armor testing.

Catalyst-Enabled In Situ Linkage Reduction in Imine Covalent Organic Frameworks.

New linkages for covalent organic frameworks (COFs) have been continuously pursued by chemists as they serve as the structure and property foundation for the materials. Developing new reaction types or modifying known linkages have been the only two methods to create new COF linkages. Herein, we report a novel strategy that uses H3PO3 as a bifunctional catalyst to achieve amine-linked COFs from readily available amine and aldehyde linkers. The acidic proton of H3PO3 catalyzes the imine framework formation, which is then in situ reduced to the amine COF by the reductive P-H moiety. The amine-linked COF outperforms its imine analogue in promoting Knoevenagel condensation because of the more basic sites and higher stability.

Chemical modification of M13 bacteriophage and its application in cancer cell imaging.

The M13 bacteriophage has been demonstrated to be a robust scaffold for bionanomaterial development. In this paper, we report on the chemical modifications of three kinds of reactive groups, i.e., the amino groups of lysine residues or N-terminal, the carboxylic acid groups of aspartic acid or glutamic acid residues, and the phenol group of tyrosine residues, on M13 surface. The reactivity of each group was identified through conjugation with small fluorescent molecules. Furthermore, the regioselectivity of each reaction was investigated by HPLC-MS-MS. By optimizing the reaction condition, hundreds of fluorescent moieties could be attached to create a highly fluorescent M13 bacteriophage. In addition, cancer cell targeting motifs such as folic acid could also be conjugated onto the M13 surface. Therefore, dual-modified M13 particles with folic acid and fluorescent molecules were synthesized via the selective modification of two kinds of reactive groups. Such dual-modified M13 particles showed very good binding affinity to human KB cancer cells, which demonstrated the potential applications of M13 bacteriophage in bioimaging and drug delivery.

Viruses and their potential in bioimaging and biosensing applications.

Successful development of ultrasensitive constructs for bioimaging and biosensing is a challenging task. Recently, viruses have drawn increasing attention due to their exquisite three-dimensional structures and unique properties, including multivalency, orthogonal reactivities, and responsiveness to genetic modifications. With such well-characterized structures, functional units, such as imaging and binding motifs, can be engineered on the surface of viruses in a programmable, polyvalent manner, which leads to novel nanosized sensing/imaging systems with enhanced signaling and targeting performance. This review highlights some recent progress in the applications of viruses in bioimaging and biosensing.

Vapor- and Liquid-Phase Adsorption of Alcohol and Water in Silicalite-1 Synthesized in Fluoride Media.

In this work, batch-adsorption experiments and molecular simulations are employed to probe the adsorption of binary mixtures containing ethanol or a linear alkane-1,n-diol solvated in water or ethanol onto silicate-1. Since the batch-adsorption experiments require an additional relationship to determine the amount of solute (and solvent adsorbed, as only the bulk liquid reservoir can be probed directly, molecular simulations are used to provide a relationship between solute and solvent adsorption for input to the experimental bulk measurements. The combination of bulk experimental measurements and simulated solute-solvent relationship yields solvent and solute loadings that are self-consistent with simulation alone, and allow for an assessment of the various assumptions made in literature. At low solution concentrations, the solute loading calculated is independent of the assumption made. At high concentrations, a negligent choice of assumption can lead to systematic overestimation or underestimation of calculated solute loading.

Upregulation of osteogenesis of mesenchymal stem cells with virus-based thin films.

A major aim of tissue engineering is to develop biomimetic scaffolding materials that can guide the proliferation, self-renewal and differentiation of multipotent stem cells into specific lineages. Cellular functions can be controlled by the interactions between cells and biomaterials. Therefore, the surface chemistry and topography of support materials play a pivotal role in modulating cell behaviors at many stages of cell growth and development. Due to their highly ordered structure and programmable surface chemistries, which provide unique topography as biomaterials, viral nanoparticles have been utilized as building blocks for targeted cell growth and differentiation. This review article discusses the fabrication of two-dimensional virus-based thin film on substrates and highlights the study of the effect of chemical and physical cues introduced by plant virus nanoparticle thin films on the promotion of osteogenic differentiation of BMSCs.

Fabrication of Plant Virus-Based Thin Films to Modulate the Osteogenic Differentiation of Mesenchymal Stem Cells.

Stem cells can interact and respond to the extracellular nanoscale environment. Viral nanoparticles have been utilized as building blocks to control cell growth and differentiation. By integrating stem cell research and virus nanoparticle chemistry together, a systematic analysis of the effects of nanotopography on stem cell differentiation can be accomplished. The fabrication of thin films of the viral nanoparticles is particularly valuable for such studies. Here, we describe two methods to fabricate plant virus-based thin films and procedures to study the osteogenic differentiation of mesenchymal stem cells on plant virus-based substrates. The method makes use of wild-type tobacco mosaic virus (wt-TMV), RGD-modified TMV (TMV-RGD), turnip yellow mosaic virus (TYMV), cowpea mosaic virus (CPMV), turnip vein clearing virus (TVCV), and potato virus X (PVX) for development of bone tissue engineering biomaterials.

Experimental aspects of buoyancy correction in measuring reliable highpressure excess adsorption isotherms using the gravimetric method.

Addressing reproducibility issues in adsorption measurements is critical to accelerating the path to discovery of new industrial adsorbents and to understanding adsorption processes. A National Institute of Standards and Technology Reference Material, RM 8852 (ammonium ZSM-5 zeolite), and two gravimetric instruments with asymmetric two-beam balances were used to measure high-pressure adsorption isotherms. This work demonstrates how common approaches to buoyancy correction, a key factor in obtaining the mass change due to surface excess gas uptake from the apparent mass change, can impact the adsorption isotherm data. Three different approaches to buoyancy correction were investigated and applied to the subcritical CO2 and supercritical N2 adsorption isotherms at 293 K. It was observed that measuring a collective volume for all balance components for the buoyancy correction (helium method) introduces an inherent bias in temperature partition when there is a temperature gradient (i.e. analysis temperature is not equal to instrument air bath temperature). We demonstrate that a blank subtraction is effective in mitigating the biases associated with temperature partitioning, instrument calibration, and the determined volumes of the balance components. In general, the manual and subtraction methods allow for better treatment of the temperature gradient during buoyancy correction. From the study, best practices specific to asymmetric two-beam balances and more general recommendations for measuring isotherms far from critical temperatures using gravimetric instruments are offered.

Phytochemical investigation on Vitex negundo leaves and their anti-inflammatory and analgesic activities

Abstract The phytochemical investigation on Vitex negundo leaves has led to the isolation of one new iridoid glucoside (8α-hydroxy-4-carboxyl-5ßH-9ßH-iridoid-1α-O-(6'-O-(6,7-dihydrofoliamenthonyl)-ß-ᴅ-glucopyranoside, 3), together with three known compounds, namely agnuside (1), 6'-O-E-caffeoylmussaenosidic acid (2), and 3,5-dicaffeoylquinic acid (4). The HPLC analytical study was also performed to quantify the content of agnuside (1) in dried leaves. The results indicated the very high content of 1 (3.04 ± 0.02%). The method was also validated by various parameters, including linearity (R2= 0.9999), precision (intra-day RSD ≤ 2.50%, inter-day RSD= 0.76%), and accuracy (recovery rates 96.58-101.86%). The animal testing data showed that the extract did not reduce pain at the doses of 9.6 and 28.8 g /kg (leaf weight/body weight) in the hot plates and pain measuring models but showed the pain reduction in the acetic acid-induced pain model. The extract at the dose of 5.6 g/kg (leaf weight/body weight) also had effects on the acute inflammation in the carrageenin-induced edema model. The extract at the dose 9.6 and 28.8 g/kg (leaf weight/body weight) also showed significant chronic anti-inflammation, comparable to methylprednisolone at the dose 10 mg/kg on the mouse peritoneal