Exploring Brominated Aromatic Butenolides from Aspergillus terreus EGF7-0-1 with Their Antifungal Activities.

Fungal diseases could severely harm agricultural productions. To develop new antifungal agents, based on the Global Natural Products Social Molecular Networking, typical bromine isotope peak ratios, and ultraviolet absorptions, cultivation of the soft coral-derived endophytic fungi Aspergillus terreus EGF7-0-1 with NaBr led to the targeted isolation of 14 new brominated aromatic butenolides (1-14) and six known analogues (15-20). Their structures were elucidated by extensive spectroscopic analysis and quantum chemical calculations. Compounds 1-14 exhibited wildly antifungal activities (against Colletotrichum gloeosporioides, Pestalotiopsis microspora, Fusarium oxysporum f. sp. cubense, Botrytis cinerea, and Diaporthe phoenicicola). The bioassay results showed that compounds 1-14 exhibited excellent antifungal activities against C. gloeosporioides, with concentration for 50% of maximal effect (EC50) values from 2.72 to 130.41 nM. The mechanistic study suggests that compound 1 may disrupt nutrient signaling pathways by reducing the levels of metabolites, such as carbohydrates, lipids, and amino acids, leading to an increase in low-density granules and a decrease in high-density granules in the cytoplasm, accompanied by numerous vacuoles, thereby inhibiting the growth of C. gloeosporioides. Monobrominated γ-butenolide 1 may be expected to exploit a novel agriculturally antifungal leading drug. Meanwhile, compound M1 has conformed antifugual activities against C. gloeosporioides by papayas in vivo.

NaBr-Assisted Sintering of Na3Zr2Si2PO12 Ceramic Electrolyte Stabilizes a Rechargeable Solid-state Sodium Metal Battery.

Solid-state metal batteries with nonflammable solid-state electrolytes are regarded as the next generation of energy storage technology on account of their high safety and energy density. However, as for most solid electrolytes, low room temperature ionic conductivity and interfacial issues hinder their practical application. In this work, Na super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) electrolytes with improved ionic conductivity are synthesized by the NaBr-assisted sintering method. The effects of the NaBr sintering aid on the crystalline phase, microstructure, densification degree, and electrical performance as well as the electrochemical performances of the NZSP ceramic electrolyte are investigated in detail. Specifically, the NZSP-7%NaBr-1150 ceramic electrolyte has an ionic conductivity of 1.2 × 10-3 S cm-1 (at 25 °C) together with an activation energy of 0.28 eV. A low interfacial resistance of 35 Ω cm2 is achieved with the Na/NZSP-7%NaBr-1150 interface. Furthermore, the Na/NZSP-7%NaBr-1150/Na3V2(PO4)3 battery manifests excellent cycling stability with a capacity retention of 98% after 400 cycles at 1 C and 25 °C.

Carboxylated cellulose nanocrystal films with tunable chiroptical properties.

Carboxylated cellulose nanocrystals prepared by TEMPO-mediated oxidation exhibit a distinct ability to form nematic order, however, their ability to form chiral nematic films remains relatively unexplored. In this study, bleached cotton pulp hydrolyzed with hydrochloric acid and oxidized by TEMPO-mediated oxidation produce carboxylated cellulose nanocrystals with different aspect ratios 33.1, 32.8, 30.9, 29.0 and 28.9, and surface charge densities 0.16, 0.56, 1.00, 1.25, and 1.42 e·nm-2. By tuning the aspect ratio and surface charge density, the optimal carboxylated cellulose nanocrystals producing left-handed chiral nematic films by evaporation-induced self-assembly are obtained. The left-handed chiral nematic films enable selective reflection of left-handed circularly polarized light with the peak wavelength tunable from the visible to the near-infrared regime by modifying the characteristics of nanorods and suspensions. Such carboxylated cellulose nanocrystal films transform spontaneous luminescence to right-handed circularly polarized luminescence with the peak luminescence dissymmetry factor of -0.51.

Development of Flexible Plasticized Ion Conducting Polymer Blend Electrolytes Based on Polyvinyl Alcohol (PVA): Chitosan (CS) with High Ion Transport Parameters Close to Gel Based Electrolytes.

In the current study, flexible films of polyvinyl alcohol (PVA): chitosan (CS) solid polymer blend electrolytes (PBEs) with high ion transport property close enough to gel based electrolytes were prepared with the aid of casting methodology. Glycerol (GL) as a plasticizer and sodium bromide (NaBr) as an ionic source provider are added to PBEs. The flexible films have been examined for their structural and electrical properties. The GL content changed the brittle and solid behavior of the films to a soft manner. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) methods were used to examine the structural behavior of the electrolyte films. X-ray diffraction investigation revealed that the crystalline character of PVA:CS:NaBr declined with increasing GL concentration. The FTIR investigation hypothesized the interaction between polymer mix salt systems and added plasticizer. Infrared (FTIR) band shifts and fluctuations in intensity have been found. The ion transport characteristics such as mobility, carrier density, and diffusion were successfully calculated using the experimental impedance data that had been fitted with EEC components and dielectric parameters. CS:PVA at ambient temperature has the highest ionic conductivity of 3.8 × 10 S/cm for 35 wt.% of NaBr loaded with 55 wt.% of GL. The high ionic conductivity and improved transport properties revealed the suitableness of the films for energy storage device applications. The dielectric constant and dielectric loss were higher at lower frequencies. The relaxation nature of the samples was investigated using loss tangent and electric modulus plots. The peak detected in the spectra of tanδ and M" plots and the distribution of data points are asymmetric besides the peak positions. The movements of ions are not free from the polymer chain dynamics due to viscoelastic relaxation being dominant. The distorted arcs in the Argand plot have confirmed the viscoelastic relaxation in all the prepared films.

High-Efficiency, Low-Hysteresis Planar Perovskite Solar Cells by Inserting the NaBr Interlayer.

With great research potential, the perovskite solar cells (PSCs) have been well developed in recent years, but there are still some urgent issues like efficiency and hysteresis defects that severely limit their commercialization. Interface modification is a significant measure to reduce defects and promote performance. In the article, an easy and effective strategy of modifying the electron transport layer (ETL) with NaBr is proposed to improve efficiency and reduce hysteresis. The charge carrier dynamics can be greatly optimized by diffusing NaBr on the ETL. The efficiency of the NaBr coated device can achieve 21.16%, which is extremely higher than the control one and shows low hysteresis behavior with a hysteresis index reduced from 0.135 to 0.025. The results indicate that the NaBr modification provides a novel strategy for preparing PSCs with high efficiency and low hysteresis.

Oxidation of dextran using H2O2 and NaClO/NaBr and their applicability in iron chelation.

The structural modification of polysaccharides directly affects their physicochemical properties and applications. Dextran, a chained polysaccharide, consists of multiple d-glucose molecules with repetitive structures. In this study, the physicochemical properties of oxidized dextran (DO) at different concentrations of NaClO/NaBr and H2O2 were compared. The results showed that NaClO/NaBr oxidation is more conducive to the formation of carboxyl groups. Oxidized dextran with NaClO/NaBr (DOB) showed good iron (III) chelating ability, and the DOB­iron (III) complex (DOBIC) had an iron content of 28.31%. According to structural analysis, NaClO/NaBr (2 g/100 g of active chlorine) and H2O2 (4 g/100 g), respectively, oxidize the C1 and C2 hydroxyl groups of dextran to carboxyl groups and open the ring when DO and iron have the strongest chelation ability. The complex is indeed a chelate iron complex, and iron core is composed of iron oxyhydroxide or the ß-FeOOH mineral polymorph. These results indicate that DOBIC is expected to be a good iron supplement or food additive to strengthen iron.

Crystal structure of 2,3,5,6-tetra-bromo-tereph-thalo--nitrile.

The title crystal (systematic name: 2,3,5,6-tetra-bromo-benzene-1,4-dicarbonitrile), C8Br4N2, is the first bromo analog in a study of cyano-halo (C≡N⋯X) non-bonded contacts in crystals of halogenated di-cyano-benzenes. The complete mol-ecule is generated by a crystallographic center of symmetry. In the extended structure, each Br atom accepts one C≡N⋯Br inter-action, and each N atom is bis-ected by two. This contact network forms a nearly planar sheet structure propagating in the (01) plane, similar to that reported in hexa-methyl-benzene co-crystals of the tetra-chloro analog.

Crystal structures of methyl 3,5-di-bromo-4-cyano-benzoate and methyl 3,5-di-bromo-4-iso-cyano-benzoate.

The title crystals, C9H5Br2NO2, are the first reported 2,6-dihalophenyl cyanide-isocyanide pair that have neither three- nor two-dimensional isomorphism. Both crystals contain contacts between the carbonyl O atom and a Br atom. In the crystal of the cyanide, R22(10) inversion dimers form based on C≡N⋯Br contacts, a common packing feature in this series of crystals. In the isocyanide, the corresponding N≡C⋯Br contacts are not observed. Instead, the iso-cyano C atom forms contacts with the meth-oxy C atom. RNC was refined as a two-component pseudo-merohedral twin.

Understanding the Effects of NaCl, NaBr and Their Mixtures on Silver Nanowire Nucleation and Growth in Terms of the Distribution of Electron Traps in Silver Halide Crystals.

In recent years, many research groups have synthesized ultra-thin silver nanowires (AgNWs) with diameters below 30 nm by employing Cl- and Br- simultaneously in the polyol process. However, the yield of AgNWs in this method was low, due to the production of Ag nanoparticles (AgNPs) as an unwanted byproduct, especially in the case of high Br- concentration. Here, we investigated the roles of Cl- and Br- in the preparation of AgNWs and then synthesized high aspect ratio (up to 2100) AgNWs in high yield (>85% AgNWs) using a Cl- and Br- co-mediated method. We found that multiply-twinned particles (MTPs) with different critical sizes were formed and grew into AgNWs, accompanied by a small and large amount of AgNPs for the NaCl and NaBr additives, respectively. For the first time, we propose that the growth of AgNWs of different diameters and yields can be understood based on the electron trap distribution (ETD) of the silver halide crystals. For the case of Cl- and Br- co-additives, a mixed silver halide crystal of AgBr1-xClx was formed, rather than the AgBr/AgCl mixture reported previously. In this type of crystal, the ETD is uniform, which is beneficial for the synthesis of AgNWs with small diameter (30~40 nm) and high aspect ratio. AgNW transparent electrodes were prepared in air by rod coating. A sheet resistance of 48 Ω/sq and transmittance of 95% at 550 nm were obtained without any post-treatment.

A 2:1 co-crystal of 3,5-di-bromo-4-cyano-benzoic acid and anthracene.

The title co-crystal, C8H3Br2NO2·0.5C14H10, was self-assembled from a 2:1 mixture of the components in slowly evaporating di-chloro-methane. The mol-ecules adopt a sheet structure parallel to (1-12) in which carb-oxy hydrogen-bonded dimers and anthracene mol-ecules stagger in both dimensions. Within the sheets, six individual cyano acid mol-ecules surround each anthracene mol-ecule. Cyano acid mol-ecules form one of the two possible R22(10) rings between neighboring cyano and bromo groups. Compared to the di-chloro analog [Britton (2012 ▸). J. Chem. Crystallogr.42, 851-855], the dihedral angle between the best-fit planes of acid and anthracene mol-ecules has decreased from 7.1 to 0.9 (2)°.

Specific oxidation pattern of soluble starch with TEMPO-NaBr-NaClO system.

Oxidized starch, one of the most important starch derivatives, has many different properties and applications. Currently, there are two ways to produce oxidized starch, through specific and nonspecific oxidation. Specific oxidation using the stable nitroxyl radical, 2,2,6,6-tetramethyl preparidinloxy (TEMPO), with NaBr and NaClO can produce oxidized starches with different properties under good quality control. In the current study, we examine the products of specifically oxidized starch. As the amount of oxidant and the temperature, two critical factors impacting the oxidation of starch were thoroughly investigated. Analysis of the molecular weight (MW), degree of oxidization (DO) and the detailed structures of corresponding products was accomplished using gel permeation chromatography with multi-angle laser light scattering (GPC-MALLS), infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and quadrapole time-of-flight mass spectrometry (Q/TOF-MS). According to the analytical results, the oxidation patterns of starch treated with specific oxidant TEMPO-NaBr-NaClO were established. When high amounts of oxidant was applied, more glucose residues within starch were oxidized to glucuronic acids (higher DO) and substantial degradation to starch oligosaccharides was observed. By selecting a reaction temperature of 25°C a high DO could be obtained for a given amount of oxidant. The reducing end sugar residue within oxidized starch was itself oxidized and ring opened in all TEMPO-NaBr-NaClO reactions. Furthermore, extra oxidant generated additional novel structures in the reducing end residues of some products, particularly in low temperature reactions.

Two new polytypes of 2,4,6-tri-bromo-benzo-nitrile.

Three polymorphs of 2,4,6-tri-bromo-benzo-nitrile (RCN), C7H2Br3N, two of which are novel and one of which is a redetermination of the original structure first determined by Carter & Britton [(1972). Acta Cryst. B28, 945-950] are found to be polytypic. Each has a layer structure which differs only in the stacking of the layers. Each layer is composed of mol-ecules associated through C N⋯Br contacts which form R (2) 2(10) rings. Two such rings are associated with each N atom; one with each ortho-Br atom. No new polytypes of 1,3,5-tri-bromo-2-iso-cyano-benzene (RNC) were found but a re-determination of the original structure by Carter et al. [(1977). Cryst. Struct. Commun. 6, 543-548] is presented. RNC was found to be isostructural with one of the novel polytypes of RCN. Unit cells were determined for 23 RCN samples and 11 RNC samples. Polytypes could not be distinguished based on crystal habits. In all four structures, each mol-ecule of the asymmetric unit lies across a mirror plane.

Carboplatin binding to histidine.

Carboplatin is a second-generation platinum anticancer agent used for the treatment of a variety of cancers. Previous X-ray crystallographic studies of carboplatin binding to histidine (in hen egg-white lysozyme; HEWL) showed the partial conversion of carboplatin to cisplatin owing to the high NaCl concentration used in the crystallization conditions. HEWL co-crystallizations with carboplatin in NaBr conditions have now been carried out to confirm whether carboplatin converts to the bromine form and whether this takes place in a similar way to the partial conversion of carboplatin to cisplatin observed previously in NaCl conditions. Here, it is reported that a partial chemical transformation takes place but to a transplatin form. Thus, to attempt to resolve purely carboplatin binding at histidine, this study utilized co-crystallization of HEWL with carboplatin without NaCl to eliminate the partial chemical conversion of carboplatin. Tetragonal HEWL crystals co-crystallized with carboplatin were successfully obtained in four different conditions, each at a different pH value. The structural results obtained show carboplatin bound to either one or both of the N atoms of His15 of HEWL, and this particular variation was dependent on the concentration of anions in the crystallization mixture and the elapsed time, as well as the pH used. The structural details of the bound carboplatin molecule also differed between them. Overall, the most detailed crystal structure showed the majority of the carboplatin atoms bound to the platinum centre; however, the four-carbon ring structure of the cyclobutanedicarboxylate moiety (CBDC) remained elusive. The potential impact of the results for the administration of carboplatin as an anticancer agent are described.

Correlated sodium and potassium imbalances within the ischemic core in experimental stroke: a 23Na MRI and histochemical imaging study.

This study addresses the spatial relation between local Na(+) and K(+) imbalances in the ischemic core in a rat model of focal ischemic stroke. Quantitative [Na(+)] and [K(+)] brain maps were obtained by (23)Na MRI and histochemical K(+) staining, respectively, and calibrated by emission flame photometry of the micropunch brain samples. Stroke location was verified by diffusion MRI, by changes in tissue surface reflectivity and by immunohistochemistry with microtubule-associated protein 2 antibody. Na(+) and K(+) distribution within the ischemic core was inhomogeneous, with the maximum [Na(+)] increase and [K(+)] decrease typically observed in peripheral regions of the ischemic core. The pattern of the [K(+)] decrease matched the maximum rate of [Na(+)] increase ('slope'). Some residual mismatch between the sites of maximum Na(+) and K(+) imbalances was attributed to the different channels and pathways involved in transport of the two ions. A linear regression of the [Na(+)]br vs. [K(+)]br in the samples of ischemic brain indicates that for each K(+) equivalent leaving ischemic tissue, 0.8±0.1 Eq, on average, of Na(+) enter the tissue. Better understanding of the mechanistic link between the Na(+) influx and K(+) egress would validate the (23)Na MRI slope as a candidate biomarker and a complementary tool for assessing ischemic damage and treatment planning.

A comparison between different existing methods used to separate epidermal cells from skin biopsies for autologous transplantation.

BACKGROUND: Burn surgeons use autologous skin graft technique for patients, but a challenge remains for large surface wounds. Recently, a method was described which used a small piece of skin to cover a 70 times greater surface by spraying epidermal cells on injured skin. We designed a comparative study to find the best method to make an epidermal cell suspension. MATERIALS AND METHODS: Eleven discarded skin samples were sent to our laboratory from Ghotboddin Burn Hospital, Shiraz. Each sample was sliced into four small pieces (1 cm(2)) and each piece was treated with a different chemical including sodium bromide (2N) and (4N), ammonium hydroxide (2N), and trypsin (0.05%) for 20 minutes. The epidermis and dermis were separated using forceps. Trypsin was added to all samples (except the trypsinized sample) to begin the intercellular detachment. Afterward, epidermis was sliced into small pieces followed by filtration and centrifugation. Cells were counted using hemocytometer. Identification of keratinocytes and melanocytes was made through immunocytochemical staining for cytokeratin and melanosome antigens, respectively. RESULTS: There was a significant difference in alive cell counts comparing cells obtained from NaBr (4N) method to other methods. Considering total cell count and alive cell count, NaBr (4N) yielded the most cells. Immunocytochemical staining showed that in all methods, some cells are stained positively for cytokeratin antibody and some for melanosome antibody. CONCLUSION: Although recent papers had advised trypsin method to make a cell suspension to use for burn patients, we found that NaBr (4N) method yields more alive cells and less toxicity.

Definição de níveis aceitáveis baseados no risco para hidrocarbonetos no Município de Porto Alegre segundo a metodologia RBCA / Definition of risk-based screening levels to hydrocarbons in Porto Alegre municipality according to the RBCA methodology

O presente estudo definiu valores de NABR (Níveis Aceitáveis Baseados no Risco) para hidrocarbonetos no Município de Porto Alegre, de acordo a metodologia RBCA, adotando-se dados hidrogeológicos dos compartimentos Embasamento Cristalino alterado e Depósitos Sedimentares Quaternários. Os parâmetros de exposição adequados à população do município, bem como dados de toxicidade dos compostos selecionados, foram definidos a partir de fontes bibliográficas e bancos toxicológicos disponíveis. As tabelas de referência geradas são, em geral, mais restritivas para o Embasamento Cristalino em relação aos Depósitos Sedimentares. Comparados às tabelas de referência da Cetesb, os valores correspondentes a Porto Alegre são inferiores, resultando na necessidade de investigações ambientais mais detalhadas em áreas impactadas por hidrocarbonetos.

This study defined RBSL (Risk Based Screening Levels) values to hydrocarbons in Porto Alegre, Southern Brazil. The values were obtained through the RBCA methodology, using hydrogeological data from the Crystalline Altered Basement and the Quaternary Sedimentary Deposits. The exposure parameters appropriate to the urban population, as well as toxicity data of selected compounds, were obtained from bibliographical sources and toxicological databases. The reference tables demonstrated that the Crystalline Altered Basement values, in general, are more restrictive than those from the Quaternary Sedimentary Deposits. In comparison to Cetesb's reference tables, the values in Porto Alegre are lower, resulting in the need of more detailed environmental investigations in hydrocarbons polluted areas.