Reverse Separation of Carbon Dioxide and Acetylene in Two Isostructural Copper Pyridine-Carboxylate Frameworks.

Separating acetylene from carbon dioxide is important but highly challenging due to their similar molecular shapes and physical properties. Adsorptive separation of carbon dioxide from acetylene can directly produce pure acetylene but is hardly realized because of relatively polarizable acetylene binds more strongly. Here, we reverse the CO2 and C2H2 separation by adjusting the pore structures in two isoreticular ultramicroporous metal-organic frameworks (MOFs). Under ambient conditions, copper isonicotinate (Cu(ina)2), with relatively large pore channels shows C2H2-selective adsorption with a C2H2/CO2 selectivity of 3.4, whereas its smaller-pore analogue, copper quinoline-5-carboxylate (Cu(Qc)2) shows an inverse CO2/C2H2 selectivity of 5.6. Cu(Qc)2 shows compact pore space that well matches the optimal orientation of CO2 but is not compatible for C2H2. Neutron powder diffraction experiments confirmed that CO2 molecules adopt preferential orientation along the pore channels during adsorption binding, whereas C2H2 molecules bind in an opposite fashion with distorted configurations due to their opposite quadrupole moments. Dynamic breakthrough experiments have validated the separation performance of Cu(Qc)2 for CO2/C2H2 separation.

Linkage conversions in single-crystalline covalent organic frameworks.

Single-crystal X-ray diffraction is a powerful characterization technique that enables the determination of atomic arrangements in crystalline materials. Growing or retaining large single crystals amenable to it has, however, remained challenging with covalent organic frameworks (COFs), especially suffering from post-synthetic modifications. Here we show the synthesis of a flexible COF with interpenetrated qtz topology by polymerization of tetra(phenyl)bimesityl-based tetraaldehyde and tetraamine building blocks. The material is shown to be flexible through its large, anisotropic positive thermal expansion along the c axis (αc = +491 × 10-6 K-1), as well as through a structural transformation on the removal of solvent molecules from its pores. The as-synthesized and desolvated materials undergo single-crystal-to-single-crystal transformation by reduction and oxidation of its imine linkages to amine and amide ones, respectively. These redox-induced linkage conversions endow the resulting COFs with improved stability towards strong acid; loading of phosphoric acid leads to anhydrous proton conductivity up to ca. 6.0 × 10-2 S cm-1.

Polarization-Sensitive Asymmetric Scattering at the Single-Particle Scale via Surface Plasmon Resonance Microscopy.

Surface plasmon resonance microscopy (SPRM), based on the scattering of single molecules at the interface, is a highly efficient analytical platform widely used in the fields of biology and chemistry. Due to the interference scattering, the imaging pattern exhibits typical parabolic tail and phase transition features, providing a quantitative means of observing the changes in the physical and chemical properties of single molecules. In this work, we reported another unique asymmetric parabolic distribution pattern resulting from polarization conversion in the experiment based on SPRM. This microscopic-level feature is derived from the switching between SPR resonant and nonresonant states. Starting from energy flux theory, we constructed an analysis model and conducted full-wave numerical simulations to verify the experimental results. Furthermore, we demonstrate that the optical rotation induced by chiral thin films can be directly measured through imaging with asymmetric features, providing valuable insights into the field of chiral materials. The quantitative interpretation of asymmetric scattering not only advances the fundamental understanding of the imaging mechanism of SPRM, but also opens up possibilities for utilizing this polarization-sensitive characteristic for single-particle detection and sensing in the future.

Observation of Interpenetrated Topology Isomerism for Covalent Organic Frameworks with Atom-Resolution Single Crystal Structures.

Rational control and understanding of isomerism are of significance but still remain a great challenge in reticular frameworks, in particular, for covalent organic frameworks (COFs) due to the complicated synthesis and energy factors. Herein, reaction of 3,3',5,5'-tetra(4-formylphenyl)-2,2',6,6'-tetramethoxy-1,1'-biphenyl (TFTB) with 3,3',5,5'-tetrakis(4-aminophenyl)bimesityl (TAPB) under different reaction conditions affords single crystals of two 3D COF isomers, namely, USTB-20-dia and USTB-20-qtz. Their structures with resolutions up to 0.9-1.1 Å have been directly solved by three-dimensional electron diffraction (3D ED) and synchrotron single crystal X-ray diffraction, respectively. USTB-20-dia and USTB-20-qtz show rare 2 × 2-fold interpenetrated dia-b nets and 3-fold interpenetrated qtz-b frameworks. Comparative studies of the crystal structures of these COFs and theoretical simulation results indicate the crucial role of the flexible molecular configurations of building blocks in the present interpenetrated topology isomerism. This work not only presents the rare COF isomers but also gains an understanding of the formation of framework isomerism from both single crystal structures and theoretical simulation perspectives.

Pore Modulation of Hydrogen-Bonded Organic Frameworks for Efficient Separation of Propylene.

Developing hydrogen-bonded organic frameworks (HOFs) that combine functional sites, size control, and storage capability for targeting gas molecule capture is a novel and challenging venture. However, there is a lack of effective strategies to tune the hydrogen-bonded network to achieve high-performance HOFs. Here, a series of HOFs termed as HOF-ZSTU-M (M=1, 2, and 3) with different pore structures are obtained by introducing structure-directing agents (SDAs) into the hydrogen-bonding network of tetrakis (4-carboxyphenyl) porphyrin (TCPP). These HOFs have distinct space configurations with pore channels ranging from discrete to continuous multi-dimensional. Single-crystal X-ray diffraction (SCXRD) analysis reveals a rare diversity of hydrogen-bonding models dominated by SDAs. HOF-ZSTU-2, which forms a strong layered hydrogen-bonding network with ammonium (NH4 + ) through multiple carboxyl groups, has a suitable 1D "pearl-chain" channel for the selective capture of propylene (C3 H6 ). At 298 K and 1 bar, the C3 H6 storage density of HOF-ZSTU-2 reaches 0.6 kg L-1 , representing one of the best C3 H6 storage materials, while offering a propylene/propane (C3 H6 /C3 H8 ) selectivity of 12.2. Theoretical calculations and in situ SCXRD provide a detailed analysis of the binding strength of C3 H6 at different locations in the pearl-chain channel. Dynamic breakthrough tests confirm that HOF-ZSTU-2 can effectively separate C3 H6 from multi-mixtures.

Joint Detection of Serum Vitamin D, Body Mass Index, and Tumor Necrosis Factor Alpha for the Diagnosis of Crohn's Disease.

OBJECTIVE: Vitamin D (VD) deficiency was reported to contribute to the progression of Crohn's disease (CD) and affect the prognosis of CD patients. This study investigated the role of serum VD, body mass index (BMI), and tumor necrosis factor alpha (TNF-α) in the diagnosis of Crohn's disease. METHODS: CD patients (n=76) and healthy subjects (n=76) were enrolled between May 2019 and December 2020. The serum 25-hydroxyvitamin D [25(OH)D] levels, BMI, and TNF-α levels, together with other biochemical parameters, were assessed before treatment. The diagnostic efficacy of the single and joint detection of serum 25(OH)D, BMI, and TNF-α was determined using receiver operating characteristic (ROC) curves. RESULTS: The levels of 25(OH) D, BMI, and nutritional indicators, including hemoglobin, total protein, albumin, and high-density lipoprotein cholesterol, were much lower, and the TNF-α levels were much higher in the CD patients than in the healthy subjects (P<0.05 for all). The areas under the ROC curve for the single detection of 25(OH)D, BMI, and TNF-α were 0.887, 0.896, and 0.838, respectively, with the optimal cutoff values being 20.64 ng/mL, 19.77 kg/m2, and 6.85 fmol/mL, respectively. The diagnostic efficacy of the joint detection of 25(OH)D, BMI, and TNF-α was the highest, with an area under the ROC curve of 0.988 (95%CI: 0.968-1.000). CONCLUSION: The joint detection of 25(OH)D, TNF-α, and BMI showed high sensitivity, specificity, and accuracy in CD diagnosis; thus, it would be effective for the diagnosis of CD in clinical practice.

Directing-Group-Assisted Markovnikov-Selective Hydrothiolation of Styrenes with Thiols by Photoredox/Cobalt Catalysis.

In contrast with the well-developed radical thiol-ene reaction to access anti-Markovnikov-type products, the research on the catalytic Markovnikov-selective hydrothiolation of alkenes is very restricted. Because of the catalyst poisoning of metal catalysts by organosulfur compounds, limited examples of transition-metal-catalyzed thiol-ene reactions have been reported. However, in this work, a directing-group-assisted hydrothiolation of styrenes with thiols by photoredox/cobalt catalysis is found to proceed smoothly to afford Markovnikov-type sulfides with excellent regioselectivity.

Exohedral Cuprofullerene: Sequentially Expanding Metal Olefin Up to a C60@Cu24 Rhombicuboctahedron.

Exohedral cuprofullerenes with 6-, 12-, or 24-nuclearity were obtained by utilizing fluorocarboxylic/dicarboxylic acid under solvothermal conditions. The 24-nuclear molecule presents a C60@Cu24 core-shell structure with a rhombicuboctahedron Cu24 coated on the C60 core, representing the highest nuclearity in metallofullerene. The resultant complexes show an efficient absorption of visible light as opposed to the pristine C60. TD-DFT calculations revealed the charge transfer from Cu(I) and O atoms to the fullerene moiety dominates the photophysical process.

Coordination disk-type nano-Saturn complexes.

The first coordination disk-type nano-Saturn complexes, [Cu10(Mim)10]⊃C60 and [Cu10(Mim)10]⊃C70 (Mim = 2-methylimidazolate), were assembled under one-pot solvothermal conditions. The highest number of 30 C-Hπ interactions between the [Cu10(Mim)10] disk and the C60/C70 surfaces drives the formation of the nano-Saturns. The calculated interaction energy is much larger than that of most of the reported disk-type nano-Saturns. Different photoinduced charge/energy transfer mechanisms are present for both nano-Saturn systems to quench the intrinsic luminescence of the [Cu10(Mim)10] disk.

A luminescent edge-interlocked prismatic heteroleptic metallocage assembled through a ligand replacement reaction.

A luminescent edge-interlocked heteroleptic metallocage based on Cu3(pyrazolate)3 was prepared through a ligand replacement reaction from a homoleptic metallocage and a new ligand. Its structure was confirmed by XRD and MALDI-TOF mass spectrometry. Theoretical calculations revealed the new ligand was evidently responsible for the bathochromic shift of the optimal excitation. This work provides a heteroleptic strategy to regulate the interlocking fashion and photophysical mechanism of metallocages based on Cu3(pyrazolate)3.

Photoinduced synthesis of fluorinated dibenz[b,e]azepines via radical triggered cyclization.

A simple, mild and efficient approach to access fluorinated dibenz[b,e]azepines via visible-light photoredox catalysis is presented. Inexpensive and commercially available fluoroalkyl anhydrides in concert with pyridine N-oxide are employed as the source of the fluoroalkyl radicals. A one-pot process involving the trifluoroacetylation of unprotected secondary benzyl amines followed by radical cyclization could also afford the desired fluorinated dibenz[b,e]azepines.

Spectroscopic Study on the Interaction of Human Cytoglobin with Copper(â ¡) Ion.

Cytoglobin (Cygb), a recently discovered member of the vertebrate globin family, exhibits a traditional globin fold with a three-over-three α-helical sandwich. The interaction between copper(Ⅱ) ion (Cu2+) and Cygb has been investigated by UV-Vis, fluorescence, synchronous fluorescence and circular dichroism (CD) spectra. Results showed that the absorption intensity of Cygb at 280 nm increased and the intrinsic fluorescence of Cygb was quenched when Cu2+ was added. This fluorescence quenching of Cygb has been proven that it belongs to static quenching. The synchronous fluorescence spectra indicated that there were small changes about the microenvironment of tryptophan residues and tyrosine residues; furthermore, the binding site of Cu2+ is closer to tryptophan residues than tyrosine residues. No obvious change was observed about the secondary structure of Cygb with the addition of Cu2+ from the CD spectra.

The status of amur beak gudgeon Microphysogobio amurensis (Taranetz 1937) inferred from complete mitochondrial genome analysis.

The complete mitogenome sequence of Microphysogobio amurensis has been amplified and sequenced in this study. The overall base composition of M. amurensis mitogenome is: A (30%), C (26.8%), G (17.2%), T (26%), with an obvious A + T bias (56%). The assembled mitogenome, consisting of 16605 bp, has 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a control region. To estimate the status of M. amurensis, all available mitogenomes of Microphysogobio were downloaded from GenBank for phylogenetic analysis. The result strongly supported the traditional taxonomic hypothesis that M. amurensis was sister to M. brevirostris and M. koreensis. However, taxonomic confusion on its generic assignment remains to be further studied, as this study and other relevant molecular studies not only suggested that Microphysogobio could be divided in two major clusters (viz. the Palearctic species group and the Oriental species group), but also that two allied genera (Biwia, Rostrogobio) were embedded within the Palearctic species group of Microphysogobio.

The complete mitochondrial genome sequence of Vanmanenia stenosoma (Teleostei: Gastromyzontidae).

Vanmanenia stenosoma belongs to the order Cypriniformes, and it is a typical torrent loach in China. In this study, we successfully determined the complete mitochondrial genome sequence of V. stenosoma (type species of Vanmanenia), which is 16,560 base pairs (bp) and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a putative control region. The genome has the same gene order as that found in other species of the family Gastromyzontidae. This suggests those genera share a common ancestral mitogenome. Nevertheless, phylogenetic reconstructions did not support the monophyly of the genus Vanmanenia.

Effect of electrochemotherapy in treating patients with venous malformations.

OBJECTIVE: To evaluate the efficacy and safety of electrochemotherapy in treating venous malformations. METHODS: Electrochemotherapy was applied to 665 patients with venous malformations of limbs and trunk, and 505 cases were followed up for half to 6 years. In this study, 228 male and 277 female patients were involved. Diagnosis was made by clinical manifestations and magnetic resonance imaging. The platinum electrodes were inserted into tumor through a trocar with plastic insulating cannula percutaneously and connected with the electrochemical therapeutic apparatus in anodes and cathodes separately. Then electricity was given. The treating voltage is 6-12 V and volume 100-180 mA, the total electricity used is in general 80-100 coulombs per 1.0 square centimeter of tumors' area. The treating time was usually from several dozen minutes to over 2 h depending on the size of the tumor. The severe cases which needed to be treated once again usually were operated after 6 months. RESULTS: The primary efficacy end point was defined as an improvement of patients' symptoms and a reduction in size of tumor 6 months after treatment. Effects were divided into 4 grades, and the efficacy rate decreased from grade 1 to grade 4. The efficacy turned out that 30.1% (152/505) of patients was classified as grade 1; 46.3% (234/505) as grade 2; 19.0% (96/505) as grade 3 and 4.6% (23/505) as grade 4. CONCLUSIONS: Electrochemotherapy shows special superiorities in treating venous malformations. It might bring a confirmed clinical efficacy with the advantages of less injury, quick recovery, simple operation and less complications.

[Significance of soluble DLL1 in diagnosis of intracranial infectious diseases in children].

OBJECTIVE: To investigate the significance of soluble DLL1 (Delta-like-1) levels of cerebrospinal fluid (CSF) and serum in the diagnosis of intracranial infection in children. METHODS: Fifty children with intracranial infection, including 20 cases of tuberculous meningitis (TM), 20 cases of viral meningitis (VM) and 10 cases of purulent meningitis (PM), and 20 children without intracranial infection (control group) were enrolled. The levels of soluble DLL1 in CSF and serum were measured using ELISA. RESULTS: The level of CSF soluble DLL1 in the TM group was significantly higher than that in the VM, PM and control groups (2.89 ± 1.72 ng/mL vs 0.14 ± 0.14 ng/mL, 0.27 ± 0.21 ng/mL, 0.13 ± 0.12 ng/mL; P<0.01). The level of serum soluble DLL1 in the TM group was also significantly higher than that in the VM, PM and control groups (12.61 ± 6.45 ng/mL vs 2.28 ± 2.27 ng/mL, 2.38 ± 1.79 ng/mL, 2.26 ± 2.10 ng/mL; P<0.01). The levels of soluble DLL1 in the CSF and serum in the VM and PM groups were not significantly different from those in the control group. CONCLUSIONS: Soluble DLL1 as a novel indicator might have potentially important value in the diagnosis of TM.

Graphene-polymer composite: extraction of polycyclic aromatic hydrocarbons from samples by stir rod sorptive extraction.

Due to the excellent mechanical, thermal and electrical properties, graphene/polymer composite is expected to have a variety of applications in analytical chemistry. In this study, a new poly(ethylene glycol dimethacrylate)/graphene composite was prepared by in situ polymerization. The new composite was used for the first time as the extraction coating of stir rod sorptive extraction for the preconcentration of polycyclic aromatic hydrocarbons (PAHs) from water samples. Because of the high specific surface area and π-π electrostatic stacking properties of graphene, the graphene-polymer composite showed higher extraction efficiencies towards most target PAHs from water samples than the neat polymer. Under the optimal conditions, a method for the determination of PAHs in water samples was proposed based on the combination of stir rod sorptive extraction (SRSE) and gas chromatography-mass spectrometry (GC-MS). The limit of detection (LODs) of the developed method for 16 PAHs ranged from 0.005 to 0.429 ng mL-1, depending on the compound. Good reproducibility of method was obtained as intra- and inter-day precisions, the relative standard deviations (RSDs) were less than 12.5% and 12.6%, respectively.

Effect of electro-acupuncture in treating patients with lingual hemangioma.

OBJECTIVE: To explore the clinical effect of electro-acupuncture (EA) in treating patients with lingual hemangioma (LHG). METHODS: EA therapy was applied on 36 patients by directly inserting the platinum needles into LHG through a trocar with plastic insulating cannula to protect the normal tissues and connecting the needles with the electro-chemical therapeutic apparatus of model ZAY-B. Then electricity was given until the tumor body got contracted and rigid. The result was assessed 6 months after EA was started. RESULTS: All patients were treated effectively, namely, the effective rate was 100%, with the therapeutic effect reaching grade I in 29 patients (80.6%), grade II in 7 (19.4%), and all having the function of tongue recovered to normal. CONCLUSION: EA shows special superiorities in treating LHG, proved to bring about less injury and quick recovery and being simple in operation. Especially when applied on huge LHG, it could not only remove the tumor, but also preserve the function of the tongue, so it is a brand-new approach that is likely to be accepted by patients.

Differentiating atrioventricular nodal reentrant tachycardia from tachycardia via concealed accessory pathway.

Studies analyzing the diagnostic value of 12-lead electrocardiographic criteria differentiating slow-fast atrioventricular nodal reentrant tachycardia (AVNRT) from atrioventricular reentrant tachycardia (AVRT) due to concealed accessory pathway have shown inconsistent results. In 97 patients (50 with AVNRT, 47 with AVRT) 12-lead electrocardiograms (ECGs) were recorded during sinus rhythm and tachycardia (QRS <120 ms). The ECGs were blinded for diagnosis and patient and analyzed independently by 2 electrophysiologists. The studied criteria differentiating AVNRT from AVRT included pseudo-r'/S, the presence of a retrograde P wave, RP interval, ST-segment depression >/=2 mm with the number and location of the affected leads, QRS amplitude, and cycle length alternans.

[Repair of the rabbit ear cartilage defects with transforming growth factor-beta1 and allogenic chondrocyte/poly-DL-lactide higher porosity polymer].

OBJECTIVE: To study the repair of the rabbit ear cartilage defects with transforming growth factor-beta1 (TGF-beta1) and allogenic chondrocyte/poly-DL-lactide (PDLLA) higher porosity polymer. METHODS: A total of 18 rabbits were divided into the TGF-beta1 and chondrocytes/PDLLA graft group, the chondrocytes/PDLLA graft group, and the blank control group. Samples were taken out at 4, 12 and 18 weeks after implantation. The histological characteristics were investigated. RESULTS: After 18 weeks of the transplantation, the repaired effects of TGF-beta1 and allogenic chondrocytes/PDLLA graft group was better than the allogenic chondrocytes/PDLLA graft group not only on general sample but also histology, and the blank control group were repaired with fibrous tissue. CONCLUSIONS: The allogenic chondrocytes/PDLLA graft could repair the rabbit ear cartilage defects while TGF-beta1 could improve the quality of the rabbit ear cartilage defects.