Investigating vertical distributions and photochemical indications of formaldehyde, glyoxal, and NO from MAX-DOAS observations in four typical cities of China.

Formaldehyde (HCHO), glyoxal (CHOCHO), and nitrogen dioxide (NO) are crucial in atmospheric photochemical processes at both surface and elevated altitudes. This study presents synchronous multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements of the vertical distributions of summertime HCHO, CHOCHO and NO in four representative megacities within the Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), Sichuan Basin (SB), and Pearl River Delta (PRD) regions of China. The vertical distributions of HCHO and CHOCHO tended to occur at higher altitudes compared to NO, influenced by both primary emissions near the ground and photochemical oxidation processes at elevated altitudes.

De Novo Purine Metabolism is a Metabolic Vulnerability of Cancers with Low p16 Expression.

Unlabelled: p16 is a tumor suppressor encoded by the CDKN2A gene whose expression is lost in approximately 50% of all human cancers. In its canonical role, p16 inhibits the G1-S-phase cell cycle progression through suppression of cyclin-dependent kinases. Interestingly, p16 also has roles in metabolic reprogramming, and we previously published that loss of p16 promotes nucleotide synthesis via the pentose phosphate pathway.

ATR promotes mTORC1 activity via cholesterol synthesis.

DNA damage and cellular metabolism exhibit a complex interplay characterized by bidirectional feedback mechanisms. Key mediators of the DNA damage response and cellular metabolic regulation include Ataxia Telangiectasia and Rad3-related protein (ATR) and the mechanistic Target of Rapamycin Complex 1 (mTORC1), respectively. Previous studies have established ATR as a regulatory upstream factor of mTORC1 during replication stress; however, the precise mechanisms by which mTORC1 is activated in this context remain poorly defined.

Improving Acetic Acid and Furfural Resistance of Xylose-Fermenting Saccharomyces cerevisiae Strains by Regulating Novel Transcription Factors Revealed via Comparative Transcriptomic Analysis.

Acetic acid and furfural are the two prevalent inhibitors coexisting with glucose and xylose in lignocellulosic hydrolysate. The transcriptional regulations of in response to acetic acid (Aa), furfural (Fur), and the mixture of acetic acid and furfural (Aa_Fur) were revealed during mixed glucose and xylose fermentation. Carbohydrate metabolism pathways were significantly enriched in response to Aa, while pathways of xenobiotic biodegradation and metabolism were significantly enriched in response to Fur.

Improving xylitol yield by deletion of endogenous xylitol-assimilating genes: a study of industrial Saccharomyces cerevisiae in fermentation of glucose and xylose.

Engineered Saccharomyces cerevisiae can reduce xylose to xylitol. However, in S.cerevisiae, there are several endogenous enzymes including xylitol dehydrogenase encoded by XYL2, sorbitol dehydrogenases encoded by SOR1/SOR2 and xylulokinase encoded by XKS1 may lead to the assimilation of xylitol.

Different transcriptional responses of haploid and diploid S. cerevisiae strains to changes in cofactor preference of XR.

Background: Xylitol accumulation is a major barrier for efficient ethanol production through heterologous xylose reductase-xylitol dehydrogenase (XR-XDH) pathway in recombinant Saccharomyces cerevisiae. Mutated NADH-preferring XR is usually employed to alleviate xylitol accumulation. However, it remains unclear how mutated XR affects the metabolic network for xylose metabolism.

Enlarged Pore Size Chiral Mesoporous Silica Nanoparticles Loaded Poorly Water-Soluble Drug Perform Superior Delivery Effect.

Large mesopores of chiral silica nanoparticles applied as drug carrier are worth studying. In this study, chiral mesoporous silica nanoparticles (CMSN) and enlarged chiral mesoporous silica nanoparticles (E-CMSN) with a particle size from 200 to 300 nm were synthesized. Fourier transform infrared spectrometer (FTIR), circular dichroism spectrum, scanning electron microscopy (SEM), transmission electron microscope (TEM), and nitrogen adsorption/desorption measurement were adopted to explore their characteristics.

Surface Wettability Modulated by Surfactant and Its Effects on the Drug Release and Absorption of Fenofibrate Solid Dispersions.

The objective of this study is to explore the surface wettability modulated by a surfactant and its effects on the drug release and absorption of fenofibrate solid dispersions (FF SDs). Both the polyvinylpyrrolidone/sodium lauryl sulfate (PVP/SLS) coprecipitate and FF SDs were prepared by solvent evaporation method. The contact angle of PVP/SLS coprecipitate with various PVP/SLS weight ratios was determined to screen out the suitable content of SLS incorporated in FF SDs.

Comparative Transcriptome Analysis of Recombinant Industrial Saccharomyces cerevisiae Strains with Different Xylose Utilization Pathways.

A heterologous xylose utilization pathway, either xylose reductase-xylitol dehydrogenase (XR-XDH) or xylose isomerase (XI), is usually introduced into Saccharomyces cerevisiae to construct a xylose-fermenting strain for lignocellulosic ethanol production. To investigate the molecular basis underlying the effect of different xylose utilization pathways on the xylose metabolism and ethanol fermentation, transcriptomes of flocculating industrial strains with the same genetic background harboring different xylose utilization pathways were studied. A different source of xylA did not obviously affect the change of the strains transcriptome, but compared with the XR-XDH strain, several key genes in the central carbon pathway were downregulated in the XI strains, suggesting a lower carbon flow to ethanol.

Effects of Polymer/Surfactant as Carriers on the Solubility and Dissolution of Fenofibrate Solid Dispersion.

The purpose of this work is to investigate the effects of polymer/surfactant as carriers on the solubility and dissolution of fenofibrate solid dispersions (FF SDs) with the aid of systematic research on the physicochemical properties of the polymer/surfactant system and further highlight the importance of studying polymer/surfactant interaction in the preformulation. The critical micelle concentration (CMC) of sodium lauryl sulfate (SLS) and critical aggregation concentration (CAC) of polymer/SLS solutions were obtained through conductivity measurement. Meanwhile, surface tension, viscosity, morphology, and wettability of polymer/SLS with different weight ratios of SLS were analyzed to screen out the suitable content of SLS (weight%, 5% in carriers) incorporated in SDs.

Evaluation of biomimetically synthesized mesoporous silica nanoparticles as drug carriers: Structure, wettability, degradation, biocompatibility and brain distribution.

Herein, three kinds of mesoporous silica nanoparticles (BMSs) were biomimetically synthesized by using heterocyclic amino acid derivatives as template and their the basic capacity in being drug carriers that covered structure, wettability, degradation, brain uptake, hemocompatibility and toxicity were systematically evaluated. The results indicated that BMSs were kinds of spherical nanoparticles with good biocompatibility. Their in vitro and in vivo behaviors, including degradation, biodistribution and biocompatibility were mainly governed by the wettability which was closely related to the structure and pore diameter of mesoporous silica nanoparticles.

Application of Solvent Parameters for Predicting Organogel Formation.

Solvents, accounting the majority of the organogel system, have a tremendous impact on the characteristics of gels. To date, there is a large variety of organogel systems; relatively few have been investigated in the field of structure-solvent correlation. Here, a series of solvent parameters were applied to explore the role of solvent effect on network forming and gel property, intending to build the connection between the precise solvent parameter and gel property.

Evaluation about wettability, water absorption or swelling of excipients through various methods and the correlation between these parameters and tablet disintegration.

Objective: To evaluate parameters about wettability, water absorption or swelling of excipients in forms of powders or dosage through various methods systematically and explore its correlation with tablet disintegration.

Material And Methods: The water penetration and swelling of powders with different proportions of excipients including microcrystalline cellulose (MCC), mannitol, low-substituted hydroxypropyl cellulose (L-HPC), crospolyvinylpyrrolidone (PVPP), carboxymethyl starch sodium (CMS-Na), croscarmellose sodium (CCMC-Na) and magnesium stearate (MgSt) were determined by Washburn capillary rise. Both contact angle of water on the excipient compacts and surface swelling volume were measured by sessile drop technique.

Contact Angle Measurements: an Alternative Approach Towards Understanding the Mechanism of Increased Drug Dissolution from Ethylcellulose Tablets Containing Surfactant and Exploring the Relationship Between Their Contact Angles and Dissolution Behaviors.

The addition of surfactant in tablet was a well-defined approach to improve drug dissolution rate. While the selected surfactant played a vital role in improving the wettability of tablet by medium, it was equally important to improve the dissolution rate by permeation effect due to production of pores or the reduced inter-particle adhesion. Furthermore, understanding the mechanism of dissolution rate increased was significant.

Association between the physical stability of flurbiprofen suspension and the interaction of HPMC/SDS.

The anionic surfactant sodium dodecylsulfate (SDS) has improved the physical stability of flurbiprofen (FBP) suspension, which was suspended by 0.2% (w/v) hydroxypropylmethyl cellulose (HPMC, K4M). Therefore, the physical stability of FBP suspensions and the interaction of HPMC/SDS were studied, and a certain association between them was revealed.

Influence of hydroxypropyl methylcellulose, methylcellulose, gelatin, poloxamer 407 and poloxamer 188 on the formation and stability of soybean oil-in-water emulsions.

Macromolecules of polysaccharides, proteins and poloxamers have a hydrophobic portion and a hydrophilic one that can be used as emulsifiers. Parts of these emulsifiers are safe pharmaceutical excipients, which can replace the irritant low molecular weight surfactants to formulate emulsions for the pharmaceutical field. This project focused on preparing O/W emulsions stabilized with polymers for pharmaceuticals such as polysaccharides, proteins and poloxamers, including hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), gelatin, poloxamer 407 (F127) and poloxamer 188 (F68).

Polymer brush hexadecyltrimethylammonium bromide (CTAB) modified poly (propylene-g-styrene sulphonic acid) fiber (ZB-1): CTAB/ZB-1 as a promising strategy for improving the dissolution and physical stability of poorly water-soluble drugs.

The feasibility of polymer brush as drug delivery vehicle was demonstrated with the goal of improving the dissolution and physical stability of poorly water-soluble drugs. Polymer brush CTAB/ZB-1 was synthesized by electrostatic interaction using a physical modification method with anionic poly (propylene-g-styrene sulphonic acid) fiber (ZB-1) as the substrate and cationic hexadecyltrimethylammonium bromide (CTAB) as the modifier. The polymer brush structure of CTAB/ZB-1 was validated by atomic force microscopy (AFM) and the channels of brush provided the drug loading sites.

Quorum sensing influences phage infection efficiency via affecting cell population and physiological state.

Bacterial growth phase has been reported affecting phage infection. To underpin the related mechanism, infection efficiency of Pseudomonas aeruginosa phage K5 is characterized. When infecting the logarithmic cells, phage K5 produced significantly more infection centers than the stationary cells, well concordant with the viable cell ratio in the different growth phases.

Modulation of the wettability of excipients by surfactant and its impacts on the disintegration and release of tablets.

Objective: To investigate the modulation of the wettability of excipients by different types of surfactants and its impacts on the disintegration of tablets and drug release.

Materials And Methods: The critical micelle concentration (CMC) of surfactants, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), dodecyl trimethyl ammonium bromide (DTAB), cetyltrimethyl ammonium bromide (CTAB) and polysorbate (Tween-20 and Tween-80), was obtained using the platinum ring method. Contact angles of surfactant solutions on the excipient compacts and double-distilled water on the mixture of surfactant and the other excipient (magnesium stearate (MgSt) or sodium alginate (SA)) were measured by the sessile drop technique.

[Determination of contact angle of pharmaceutical excipients and regulating effect of surfactants on their wettability].

To study the effects of surfactants on wettability of excipients, the contact angles of six types of surfactants on the surface of two common excipients and mixture of three surfactants with excipients were measured using hypsometry method. The results demonstrated that contact angle of water on the surface of excipients was associated with hydrophilcity of excipients. Contact angle was lowered with increase in hydrophilic groups of excipient molecules.

Comparison of bare and amino modified mesoporous silica@poly(ethyleneimine)s xerogel as indomethacin carrier: Superiority of amino modification.

The purpose of this study was to facilely develop amino modified mesoporous silica xerogel synthesized using biomimetic method (B-AMSX) and to investigate its potential ability to be a drug carrier for loading poorly water-soluble drug indomethacin (IMC). For comparison, mesoporous silica xerogel without amino modification (B-MSX) was also synthesized using the same method. The changes of characteristics before and after IMC loading were systemically studied using fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS) and nitrogen adsorption/desorption analysis.

Control-release microcapsule of famotidine loaded biomimetic synthesized mesoporous silica nanoparticles: Controlled release effect and enhanced stomach adhesion in vitro.

In the present work, control-release microcapsule of famotidine (FMT) loaded biomimetic synthesized mesoporous silica nanoparticles (B-MSNs) was developed, and controlled release effect and stomach adhesion of this formulation in vitro were mainly investigated. B-MSN was previously synthesized and it was amorphous mesoporous nanoparticles with helical channels. Cytotoxicity of B-MSN was studied using human breast cancer cells (MCF-7) and the result indicated that cytotoxicity of B-MSN can be neglected.

Facile synthesis of functionalized ionic surfactant templated mesoporous silica for incorporation of poorly water-soluble drug.

The present paper reported amino group functionalized anionic surfactant templated mesoporous silica (Amino-AMS) for loading and release of poorly water-soluble drug indomethacin (IMC) and carboxyl group functionalized cationic surfactant templated mesoporous silica (Carboxyl-CMS) for loading and release of poorly water-soluble drug famotidine (FMT). Herein, Amino-AMS and Carboxyl-CMS were facilely synthesized using co-condensation method through two types of silane coupling agent. Amino-AMS was spherical nanoparticles, and Carboxyl-CMS was well-formed spherical nanosphere with a thin layer presented at the edge.

Biomimetic synthesized chiral mesoporous silica: Structures and controlled release functions as drug carrier.

This work initially illustrated the formation mechanism of chiral mesoporous silica (CMS) in a brand new insight named biomimetic synthesis. Three kinds of biomimetic synthesized CMS (B-CMS, including B-CMS1, B-CMS2 and B-CMS3) were prepared using different pH or stirring rate condition, and their characteristics were tested with transmission electron microscope and small angle X-ray diffraction. The model drug indomethacin was loaded into B-CMS and drug loading content was measured using ultraviolet spectroscopy.