Oxygen- and Nitrogen-Embedded Zigzag Hydrocarbon Belts.

Despite the aesthetically appealing structures and tantalizing physical and chemical properties, zigzag hydrocarbon belts and their heteroatom-embedded analogues remain challenging synthetic targets. We report herein the synthesis of diverse O/N-doped zigzag hydrocarbon belts based on selective bridging of the fjords of resorcin[4]arene derivatives through intramolecular SN Ar and palladium-catalyzed intermolecular C-N bond formation reactions. Preorganized conformations of mono-macrocyclic, half-belt and quasi-belt compounds were revealed to facilitate cyclization reactions to construct heteroatom-linked octahydrobelt[8]arenes. The acquired products had strained square-prism-shaped belt structures in which all six-membered heterocyclic rings adopted an unusual boat conformation with equatorially configured alkyl groups. The unprecedented heteroatom-bearing belts also exhibited different photophysical and redox properties to those of octahydrobelt[8]arene analogues.

[Quality evaluation methods for standard decoction of Nelumbinis Folium].

The quality evaluation method for standard decoction of Chinese herbal slices is the basis for the quality evaluation of granules and preparations of classical formula(decoction)of traditional Chinese medicine. This study aimed to establish a method for the determination of quercetin-3-O-glucuronic acid in Nelumbinis Folium(NF)and its standard decoction, so as to provide reference for the quality control of NF and its standard decoction. Fifteen batches of representative NF were collected to prepare standard decoction, and the parameters of dry extract rate, transfer rate of index component, and pH value were calculated. HPLC was used to establish the content determination method for quercetin-3-O-glucuronic acid in NF and its standard decoction. The concentration range of quercetin-3-O-glucuronic acid in the standard decoction of NF was 1.09-3.06 g·L~(-1), while the concentration range of nuciferine was 0.01-0.17 g·L~(-1). The average extraction rate of NF standard decoction was(14.4±2.6)%, the average transfer rate of quercetin-3-O-glucuronic acid was(70.7±18.6)%, and the average transfer rate of nuciferine was(9.6±5.4)%. Compared with Nuciferine, quercetin-3-O-glucuronic acid had a high content and stable transfer rate in standard decoction, and was recommended to be the quality control marker for NF and its standard decoction. This paper establishes a quality evaluation method for NF standard decoction, and can provide reference for the quality control of all preparations derived from NF and its decoction.

Promoting water dissociation performance by borinic acid for the strong-acid/base-free hydrogen evolution reaction.

A new type of organic proton donor for the strong-acid/base-free hydrogen evolution reaction is reported, by taking advantage of the electron deficiency of the boron center of borinic acid and the strong affinity and hydrolysis reaction between borinic acid and water with hydrogen ion formation. The borinic acid proton donor exhibits even higher current density than H2SO4 to promote hydrogen evolution performance in DMF.

Anion-π-Directed Self-Assembly between Di- and Trisulfonates and a Rigid Molecular Cage with Three Electron-Deficient V-Clefts.

Anion-π-directed self-assembly between a series of di- and trisulfonate anions and a rigid molecular cage 1 was presented. The self-assembly study was established on a combination of X-ray crystallography, NMR, mass spectrometry (MS), and scanning electron microscopy (SEM) techniques. As revealed in the crystal structures, the cage provided two V-shaped electron-deficient clefts to accommodate sulfonate groups through anion-π interactions. Depending on their structure, the series of anions showed different intermolecular interaction details with the cage and led to the formation of diverse self-assembly motifs. For 1,2-ethanedisulfonate (EDS2-), 1,3-propanedisulfonate (PDS2-), and 1,4-butanedisulfonate (BDS2-), very similar and uniform 2D ladder-like self-assemblies were formed. For 1,6-hexanedisulfonate (HDS2-) with a longer alkyl chain, a helical chain assembly was formed, while 1,3,5-tris(4-sulfophenyl)benzene (TSPB3-) led to a 3D frame structure. In solution, NMR titrations suggested that the cage can complex these anions, with association constants falling in range of 5-114 M-1. NMR spectra recorded at variable concentrations and temperatures and electrospray ionization MS further confirmed self-assembly formation. The morphologies of the diverse self-assemblies formed between the cage and sulfonates were revealed by SEM. This study, hence, provides evidence that anion-π interactions can play decisive roles in self-assembly.

Toward Anion-π Interactions Directed Self-Assembly with Predesigned Dual Macrocyclic Receptors and Dianions.

Realizing anion-π interaction induced self-assembly with charge-neutral π receptors as building components is extremely challenging. We designed and synthesized a series of bisoxacalix[2]arene[2]triazines 7-11 in which two macrocyclic motifs are linked in diverse branching angle and rigidity. Crystal structures showed the use of rigid linkers is able to control the orientation of the two macrocyclic cavities. The interplay between the two cavities was revealed by binding studies of 8-11 with chloride in solution. Whereas 180°- and 120°-branched hosts 8 and 9 possess dual complexation ability, 60°-branched and flexibly linked hosts 10 and 11 only form 1:1 complex with chloride. Association and self-assembly of these bismacrocyclic building units with dianionic naphthalene-1,5-disulfonate were systematically investigated. The formation of oligomeric self-assemblies and large aggregates in solution was suggested by 1H NMR titrations, concentration- and temperature-variable 1H NMR, diffusion-ordered spectroscopy (DOSY), ESI-MS, and dynamic light scattering (DLS). The anion-π induced long-distance self-assembly with coherent particle formation was revealed by SEM, TEM, cryo-TEM, and AFM techniques. The systematic studies allowed us to draw the conclusion that the dianion served to bridge the initial host aggregates through anion-π interactions and was responsible for the coherent particle formation. The cavity orientation of the bismacrocycle components was found to have a significant influence on the coherent particle morphology.

Synthesis, Structure, Property, and Dinuclear Cu(II) Complexation of Tetraoxacalix[2]arene[2]phenanthrolines.

A number of novel tetraoxacalix[2]arene[2]phenanthrolines 7-11 containing phenanthroline and diverse aromatic linkages were conveniently synthesized by a one-pot protocol between a series of dihydroxy arenes and 1,10-phenanthroline derivatives. Single-crystal diffraction analysis revealed that the resulting macrocycles possess diverse conformational and cavity structures which are regulated by the different aromatic linkages. In line with the length of the aromatic linkages, the distance between the two phenanthroline moieties ( dN-N) gradually increases from 6.92 to 13.30 Å, respectively. The physicochemical properties of these macrocyclic compounds were investigated by spectroscopic, CV, and DPV measurements. Owing to the coordination ability of the phenanthroline moieties and the tunable conformational structure, the macrocyclic hosts can form distinct dinuclear complexation with Cu2+. Typically, with a short aromatic linkage the 7b-2Cu(II) complex gives an O-bridged dicopper structure, while with long linkage the 11b-2Cu(II) complex possesses two discrete copper centers. The spectroscopic structure and the redox property of the dicopper complexes were investigated by XPS, CV, and DPV techniques. This work hence provides a platform to access biomimetic copper-containing small-molecule models with well-defined structures.

Properties of afterdischarges from electrical stimulation in patients with epilepsy.

OBJECTIVE: To investigate the properties of afterdischarges (ADs) from intracerebral electrical stimulation (ES) in patients with epilepsy who underwent stereotactic electroencephalography (SEEG) and determine the relationship between epileptogenic zone (EZ) or irritative zone (IZ) and ADs. METHODS: We retrospectively analyzed 10 patients with intractable epilepsy who underwent SEEG. ESs were delivered following the given parameters: bipolar, biphasic, 50Hz, 0.2ms pulse duration, 0.5-10mA. The properties of ADs were documented, including their incidence, location, threshold, morphology and evolution. RESULTS: A total of 213 ADs (5%) were elicited by 4701 trains of ES. Stimulation through contacts implanted in the hippocampus (59%) generally evoked more ADs than contacts elsewhere (19%). AD thresholds for hippocampal stimulation were significantly lower than those for stimulation in grey matter. Polyspikes (58%) were the most common AD morphology. Evolution occurred more commonly with sequential spikes (47%) than with other AD morphologies (14%). There was no significant correlation between the location of ADs and EZ. However, ADs were significantly more frequently localized to IZ than areas outside IZ (P<0.05). CONCLUSIONS: There seemed to be a lack of correlation between the location of ADs and EZ. However, ADs were more likely to be elicited in IZ.

Assessment of Age-Related Morphometric Changes of Subcortical Structures in Healthy People Using Ultra-High Field 7 Tesla Magnetic Resonance Imaging.

Objective: To assess the age-related morphometric changes of subcortical structures in healthy people. Materials and Methods: Ultra-high field 7 tesla magnetic resonance (MR) imaging in humans was used to visualize the subcortical structures of healthy young, middle-aged and elderly participants. Using the magnetization-prepared two rapid acquisition gradient echo (MP2RAGE) sequence, we assessed the visibility of the margins of the thalamus and white matter in the thalamus, as well as the anterior commissure (AC) and posterior commissure (PC) length, the maximal height of the thalamus, the half width of the third ventricle and the distance between the AC and the center of the mammillothalamic tract (MTT) at the level of the AC-PC plane. All quantitative data were statistically evaluated. Results: The AC-PC length did not differ significantly among the three groups. The maximal height of the thalamus decreased with age (rs(53) = -0.719, p < 0.001). The half width of the third ventricle (rs(53) = 0.705, p < 0.001) and the distance between the AC and the center of the MTT (rs(53) = 0.485, p < 0.001) increased with age. The distance between the AC and the center of the MTT of the young and the elderly participants differed significantly (p = 0.007). Conclusion: The AC-PC length is not a good candidate for proportional correction during atlas-to-patient registration. The maximal height of the thalamus and the half width of the third ventricle correlated strongly with age, and the MTT position in relation to the AC shifted posteriorly as age increased. These age-related morphometric changes of subcortical structures should be considered in targeting for functional neurosurgery.

Primary chondrosarcoma presenting as an intrathoracic mass: A report of three cases.

Primary intrathoracic chondrosarcomas are rare tumors. The present study reports three cases of primary intrathoracic chondrosarcomas in two males and one female aged between 45 and 64 years. Clinically, one case presented with cough and blood sputum, while the other two cases of primary intrathoracic chondrosarcoma were found incidently during a routine health examination. Radiologically, the chondrosarcomas presented as large masses with intratumoral calcification. Chondrosarcoma should be distinguished from other calcified pulmonary lesions. In this study, all three cases underwent surgical treatment, and in one case, the surgery was accompanied by radiotherapy. To date, all patients have been followed up for between two and three years and are alive.