Clinical predictors of surgical intervention for gastrointestinal magnetic foreign bodies in children.

BACKGROUND/AIMS: To investigate the clinical situation, treatment methods, and clinical predictors of surgical intervention in children with magnetic foreign bodies in the digestive tract. MATERIALS AND METHODS: From January 2019 to June 2022, we retrospectively analyzed the clinical data of 72 children who ingested magnetic foreign bodies inadvertently in our hospital, including their general information, admissions, clinical manifestations, and treatment methods, as well as pertinent literature and statistical data. Following software processing, univariate and multivariate logistic regression analyses were conducted to determine the independent risk factors of this study. RESULTS: In this study, 16 patients (22.2%) were discharged smoothly following conservative treatment and 19 patients (26.4%) were cured by gastroscopy. The remaining 37 patients (51.4%) were underwent surgery, in which 26 cases developed gastrointestinal perforation. There were statistical differences between surgery group and non- surgery group in the days of eating by mistake, clinical manifestations (nausea and vomiting, intermittent abdominal pain, abdominal muscle tension) and movement trajectory by every 24-h radiograph (P < 0.01). Logistic regression analysis showed that intermittent abdominal pain and abdominal muscle tension were independent risk factors for surgical treatment. CONCLUSION: Magnetic foreign bodies seriously endanger children's health. This study offers a single-center basis for the choice of surgical opportunity for intestinal obstruction or perforation caused by magnetic foreign bodies. Clinicians need immediate surgical intervention if the child shows symptoms of abdominal pain or abdominal tension.

Constructing Built-in Electric Field in Heterogeneous Nanowire Arrays for Efficient Overall Water Electrolysis.

Efficient bifunctional electrocatalysts for hydrogen and oxygen evolution reactions are key to water electrolysis. Herein, we report a built-in electric field (BEF) strategy to fabricate heterogeneous nickel phosphide-cobalt nanowire arrays grown on carbon fiber paper (Ni2 P-CoCH/CFP) with large work function difference (ΔΦ) as bifunctional electrocatalysts for overall water splitting. Impressively, Ni2 P-CoCH/CFP exhibits a remarkable catalytic activity for hydrogen and oxygen evolution reactions to obtain 10 mA cm-2 , respectively. Moreover, the assembled lab-scale electrolyzer driven by an AAA battery delivers excellent stability after 50 h electrocatalysis with a 100 % faradic efficiency. Computational calculations combining with experiments reveal the interface-induced electric field effect facilitates asymmetrical charge distributions, thereby regulating the adsorption/desorption of the intermediates during reactions. This work offers an avenue to rationally design high-performance heterogeneous electrocatalysts.

Facile Strategy for Preparing a Rosin-Based Low-k Material: Molecular Design of Free Volume.

Low-k dielectrics are urgently needed in modern integrated circuits. The introduction of free volume instead of porous structures has become a powerful strategy to reduce the k value. According to this strategy, the biomass resource rosin-containing hydrogenated phenanthrene ring was introduced into benzocyclobutene (BCB) resin to reduce the k value; then a rosin-based BCB monomer was successfully synthesized. Meanwhile, the BCB monomer without a rosin skeleton was prepared. After converting the monomers into thermo-crosslinked materials, notably that the rosin skeleton has a great influence on the free volume and k value of the material. The fractional free volume and k value of the former are 26% and 2.44, respectively, and those of the latter are 14% and 2.84, respectively. In addition, the distances between molecular chains and the density of the former are 0.60 nm and 1.06 g cm-3, respectively; those of the latter are 0.56 nm and 1.28 g cm-3, respectively. These data show that introducing hydrogenated phenanthrene rings occupies part of the space and hinders the packing of molecular chains, which increases the distance between molecular chains and reduces the density of the polymer, resulting in an increasing free volume and a reducing k value. Notably that introducing hydrogenated phenanthrene rings cannot affect other properties of the material. Therefore, this research indicates that introducing rosin skeletons can prepare high-performance materials, which provide some promising low-k materials for the development of electronics and microelectronics.

Coordination Polymer-Mediated Molecular Surgery for Precise Interconversion of Dicyclobutane Compounds.

A Cd(II)-based coordination polymer {[Cd2(5-F-1,3-bpeb)2(FBA)4]·H2O}n (CP1) was obtained from Cd(II) salt, 5-fluoro-1,3-bis[2-(4-pyridyl)ethenyl]benzene (5-F-1,3-bpeb), and p-fluorobenzoic acid (HFBA). Within the one-dimensional chain structure of CP1, a pair of 5-F-1,3-bpeb was arranged in a face-to-face style. Upon UV irradiation and heat treatment, multiple cyclobutane isomers, including specific monocyclobutanes (1 with an endo-cyclobutane ring in CP1-1 and 1' with an exo-cyclobutane ring in CP1-1') and dicyclobutanes (endo,endo-dicyclobutane 2α in CP1-2α, exo,endo-dicyclobutane 2ß in CP1-2ß, and exo,exo-dicyclobutane 2γ in CP1-2γ) were stereoselectively produced. These isomers could be interconverted inside the CP via cutting/coupling specific bonds, which may be regarded as a type of molecular surgery. The precision of cutting/coupling relied on the thermal stability of the cyclobutanes and the alignment of the reactive alkene centers. The conversion processes were tracked through nuclear magnetic resonance, in situ powder X-ray diffraction, and IR spectroscopy. This approach can be considered as skeletal editing to construct complex organic compounds directly from one precursor.

Coordination-Driven Stereospecific Control Strategy for Pure Cycloisomers in Solid-State Diene Photocycloaddition.

To obtain a pure product without the isomer byproducts is a goal that many chemists are pursuing. As one kind of very important synthesis method, the photochemical reaction is simple and straightforward yet low-selective. In this work, a coordination interaction-based oriented synthesis strategy has been proposed to realize the precise stereochemical control of the isomeric cyclic compounds in the photocycloaddition reaction. Through fixing the reactants via coordination interactions, the arrangements and configurations of the reactants can be adjusted, thereby successfully producing all of the related photocycloaddition products without isomer byproducts for the first time. This work not only provides a new route to synthesize the pure cyclic compounds but also expands the application of the photocycloaddition reaction.

Stereoselective Solid-State Synthesis of Substituted Cyclobutanes Assisted by Pseudorotaxane-like MOFs.

Regioselective photodimerization of trans-4-styrylpyridine (4-spy) derivatives is performed using pseudorotaxane-like Zn-based metal organic frameworks MOFs as templates. The formation of rctt-HT (head-to-tail) dimers is achieved by confining pairs of coordinated 4-spy derivative ligands within hexagonal windows and then irradiating them with UV light. It is also possible to achieve a photodimerization reaction where two different substituted 4-spy ligands are included in such a MOF material. The ether bond formation is employed to protect the sensitive -OH group of HO-spy and the methyl group of CH3 O-spy is subsequently removed after the formation of cyclobutane derivative in the CH3 O-spy-based MOF. Introducing substituents at the 2- or 3-position of the phenyl group of 4-spy does not significantly affect the rate of the dimerization process except in the case of the strongly electron-withdrawing nitro group where the rate is significantly decreased. These results are in striking contrast to the mixtures of photoproducts and low yields obtained by untemplated photodimerization in organic solvents.

Coordination Site Selective Occupation Strategy for Tuning the Photosalient Effects of Photoactive Cd Complexes.

The application of photo responsive crystals to useful actuation demands a rational design to elicit controllable movement. The [2+2] photocycloaddition reaction triggers mechanical motion using associated photosalient (PS) effects. We herein report a coordination site selective occupation strategy to modulate the arrangement of C=C bonds and thereby tune the PS effect. Replacing or repositioning the donor atom at one end of the linear ligand allowed for a greater level of molecular structural flexibility, facilitating [2+2] photocycloaddition. The distance between photoreactive centres and coordination sites was adjusted by ligand design to regulate PS behaviour. This work suggests new avenues for modulating PS movement to achieve useful motion.

Photomechanical responses of coordination polymers regulated by precise organization of the photoactive centers.

Three photoactive Cd(II) coordination polymers (CPs), [Cd (Fsbpe)(DBBA)2]·2DMF (CP1), [Cd(Fepbpe)(DBBA)2]·2DMF (CP2) and [Cd(Fsbpeb)(DBBA)2] (CP3) (DBBA = 3,5-dibromobenzoic acid, DMF = dimethyl formamide) with similar 1D chain motifs exhibited completely different photosalient behaviors (PS) in response to UV light. Mechanical motion was triggered by [2+2] photocycloaddition and regulated by positioning of the photoactive alkene centers relative to the crystal axis. This solid-state reaction was reversed by heating and photomechanical behaviour was repeated over several cycles. A simple photoactuating device was prepared using a CP3-PVA composite.

Tunable photosalient behaviours within coordination polymers via functional molecular prearrangements.

Four Cd(II)/diene coordination polymers (CPs) with similar 1D chain motifs exhibit different photosalient (PS) behaviours in response to UV light. The [2+2] photoreaction between the CC groups within these CPs results in diverse PS behaviours of their crystals with different CC pair arrangements. The interesting PS behaviours of these CPs can be applied in design and fabrication of advanced photoactuating materials.

Controllable multiple-step configuration transformations in a thermal/photoinduced reaction.

Solid-state photochemical reactions of olefinic compounds have been demonstrated to represent powerful access to organic cyclic molecules with specific configurations. However, the precise control of the stereochemistry in these reactions remains challenging owing to complex and fleeting configuration transformations. Herein, we report a unique approach to control the regiospecific configurations of C = C groups and the intermediates by varying temperatures in multiple-step thermal/photoinduced reactions, thus successfully realizing reversible ring closing/opening changes using a single-crystal coordination polymer platform. All stereochemical transitions are observed by in situ single-crystal X-ray diffraction, powder X-ray diffraction and infrared spectroscopy. Density functional theory calculations allow us to rationalize the mechanism of the synergistic thermal/photoinduced transformations. This approach can be generalized to the analysis of the possible configuration transformations of functional groups and intermediates and unravel the detailed mechanism for any inorganic, organic and macromolecular reactions susceptible to incorporation into single-crystal coordination polymer platforms.

CircRNA-ACAP2 contributes to the invasion, migration, and anti-apoptosis of neuroblastoma cells through targeting the miRNA-143-3p-hexokinase 2 axis.

BACKGROUND: Circulating RNAs (Circ-RNAs) are tightly related to the processes of neuroblastoma. The circ-ACAP2 has been reported as dysregulated in various cancers; however, its biological roles and mechanisms in neuroblastoma remain largely unclear. METHODS: We collected 40 neuroblastoma tissues and adjacent noncancerous tissues. Quantitative reverse transcription polymerase chain reaction (qRT-RCR) or western blot were used to examine ACAP2, miR-143-3p, and HK2 abundances. Cell migration, invasion, glycolysis, and apoptosis were assessed via wound healing, transwell, glucose uptake and lactate, 3-(4,5-diamethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and flow cytometry. The association between circRNA, microRNA (miRNA), and messenger RNA (mRNA) was examined by dual-luciferase reporter analysis and RNA immunoprecipitation. RESULTS: The abundances of ACAP2 and HK2 were remarkedly increased in neuroblastoma tissues and cell lines. Silencing ACAP2 significantly constrained neuroblastoma cell migration, invasion, and glycolysis, and promoted apoptosis. Bioinformatics prediction, luciferase assay, and RNA pull-down assay consistently demonstrated that ACAP2 sponged miR-143-3p to downregulate its expression in neuroblastoma cells. Furthermore, we identified that hexokinase 2, a glycolysis key enzyme, was a direct target of miR-143-3p in neuroblastoma cells. Rescue of miR-143-3p in ACAP2-overexpressing cells effectively mitigated the influence of ACAP2 on neuroblastoma cell processes. CONCLUSIONS: Our study revealed biological roles and molecular mechanisms for circ-ACAP2 in the oncogenic characteristics of neuroblastoma, facilitating the development of circRNA-based treatment approaches for anti-brain tumor therapy.

New structurally diverse photoactive cadmium coordination polymers.

Four structurally diverse coordination polymers 1-4 (CP1-CP4) were designed and constructed from Cd(II) ions and various carboxyl ligands (H2oba, 4,4'-oxydibenzoic acid; H2bpa, (E)-4,4'-(ethene-1,2-diyl)dibenzoic acid; H2pbda, 4,4'-((1,3-phenylenebis(methylene))bis(oxy))dibenzoic acid) and the alkene containing ligand (CH3-bpeb, 4,4'-((1E,1'E)-(2,5-dimethyl-1,4-phenylene)bis(ethene-2,1-diyl))dipyridine). CP1-CP4 possess Cd2 binuclear secondary building units (SBUs). The geometry of the dicarboxylate ligands and the reaction conditions determined the final structure with a variety of motifs. CP1 possesses an interdigitated 2D structure, while CP2 consists of a 1D channel-like motif with isolated CH3-bpeb molecules embedded in the channels. The solid-state structure of CP3 consists of two unique layers interpenetrated to form a 2D + 2D → 2D polycatenated backbone, while a 1D channel-like motif filled by isolated CH3-bpeb molecules was observed for CP4. In all four coordination polymers pairs of CH3-bpeb molecules were bound or encapsulated by the Cd2 secondary building units at an appropriate distance and orientation for solid-state [2 + 2] photodimerization of one pair of CC bonds. Desolvation of CP3 with heat resulted in a decrease in solid-state fluorescence and a slowing of the rate of solid-state photodimerization.

Tuning the configuration of the flexible metal-alkene-framework affords pure cycloisomers in solid state photodimerization.

The photochemical [2+2] cycloaddition of 3,5-bis-(2-(pyridin-4-yl)vinyl)pyridine (bpvp) in the flexible Cd-based metal-alkene frameworks produced different isomeric photoproducts depending on the auxiliary and guest molecules. The bulkiness of the guest molecules influenced the conformation of the ligand, and thus the outcome of the cycloaddition reaction.

catena-Poly[[[diaqua-sodium]-di-µ-aqua] 2-(2-pyrid-yl)quinoline-4-carboxyl-ate].

In the title compound, [Na(H(2)O)(4)](C(15)H(9)N(2)O(2)), the Na(+) ion is coordinated by six water mol-ecules in an octa-hedral geometry. The NaO(6) octa-hedra are connected by sharing edges, forming a cationic chain along the b-axis direction. O-H⋯O and O-H⋯N hydrogen bonds link the chains and the 2-(2-pyrid-yl)quinoline-4-carboxyl-ate anions into a two-dimensional network parallel to (100).

Bis[µ-2-(2,4-difluoro-phen-yl)-1,3-bis-(1H-1,2,4-triazol-1-yl)propan-2-olato]dicopper(II) bis-(perchlorate).

The title complex, [Cu(2)(C(13)H(11)F(2)N(6)O)(2)](ClO(4))(2), which was hydro-thermally synthesized, contains a binuclear copper cluster (2 symmetry) with a Cu(2)O(2) rhombus [Cu-O = 1.927 (2) Å] formed by donation of two O atoms from two chelate rings. The tridentate function of each ligand is completed by two N atoms coordinated to the two Cu(II) atoms [Cu-N = 1.933 (2) Å]. The separation distance of two Cu(II) atoms in a cluster is 2.988 (1) Å. The dihedral angle between the six-membered chelate rings is 2.13 (9)°. The perchlorate counter-anion is disordered over two sites in a 0.58 (10):0.42 (10) ratio.

[Study on synthesis and fluorescence characterization of europium and terbium complexes of 1-(5-(2-hydroxyphenyl)-3-methyl-4,5-dihydropyrazol-1-yl) ethanone].

Six solid complexes(TbL3 x 2H2O, TbL2 (phen) x H2O, TbL2 (TPPO), EuL3 x 2H2O, EuL2 (phen) x 2H2O and EuL2 (TPPO) x 2H2O) have been synthesized based on the pyrazole ligand(HL)(phen = 1,10-phenanthroline, TPPO = Tri-phenylphosphine oxide, HL=1-(5-(2-hydroxyphenyl)-3-methyl-4,5-dihydropyrazol-1-yl) ethanone). These complexes were characterized by elemental analysis, IR spectra, and fluorescence spectra. The IR spectra indicated that all complexes exhibited the characteristic peaks of asymmetric stretching vibration v (C=O) and symmetric stretching vibration v (C=N) peaks. The C=O stretching band at 1,644 cm(-1) of HL molecule shifted to lower band in the complexes. The O-H band at 3,072 of the HL ligand is also shifted to lower band. All these shifts indicated that carbonyl group, O-H and C=N take part in coordinating with the rare-earth ion in the form of bridging tridentate. The excitation and emission spectra of the six complexes were determined at room temperature and the results show that EuL2 (Phen) x 2H2O and TbL2 (Phen) X 2H2O display the strongest relative fluorescence intensity with the excited bands at 310 and 320 nm, respectively. Meanwhile, the emission intensities of Eu3+ and Tb3+ complexes were greatly sensitized by phen.

Amino group decorated coordination polymers for enhanced detection of folic acid.

A series of fluorescent coordination polymers (CPs) {[Cd2(CH3-bpeb)2(BDC)2] CP1, (BDC)0.5/(NH2-BDC)0.5-CP1, (BDC)0.34/(NH2-BDC)0.66-CP1, (BDC)0.25/(NH2-BDC)0.75-CP1, (BDC)0.2/(NH2-BDC)0.8-CP1, (NH2-BDC)-CP1} were prepared from conjugated ligand 4,4'-((2-methyl-1,4-phenylene)bis(ethene-2,1-diyl))bipyridine (CH3-bpeb), terephthalic acid (BDC), aminoterephthalic acid (NH2-BDC) and CdSO4 under solvothermal conditions. The fluorescence of aqueous suspensions of these CPs was quenched by folic acid (FA) in a concentration dependent manner. The efficiency of quenching increasing with an increased proportion of NH2-BDC ligand in the CP with (NH2-BDC)-CP1 exhibiting a low detection limit of 1.7 × 10-7 M.

Modulating the regioselectivity of solid-state photodimerization in coordination polymer crystals.

Coordination polymers [Cd(1,4-bpeb)(L1)] (1), [Zn2(1,4-bpeb)2(L2)2(SO42-)2] (2) and [Cd(1,4-bpeb)(L3)] (H2O) (3) (H2L1, 3-[2-(3-hydroxy-phenoxymethyl)-benzyloxy]-benzoic acid; HL2, 1H-Indazole-3-carboxylic acid; H3L3, benzene-1,2,3-tricarboxylic acid; 1,4-bpeb, 1,4-bis[2-(4-pyridyl)vinyl]benzene have been synthesized under solvothermal conditions. Complexes 1-3 underwent photodimerization in the solid-state to give quantitative yields of single isomeric products. The choice of carboxyl ligands L and metal center determined the arrangement of 1,4-bpeb ligands, which in turn directed the regiochemistry of the final photoproducts. The solid-state network structures of cadmium based 1 and 3 had 1,4-bpeb pairs aligned face-to-face with both C[double bond, length as m-dash]C centres in each ligand at an appropriate distance and alignment for photodimerization to give the corresponding para-[2.2]cyclophane (pCP) exclusively. By contrast, compound 2 possessed dinuclear (ZnSO4)2 metallocycles that positioned the 1,4-bpeb "arms" face-to-face, but with C[double bond, length as m-dash]C centres offset at an appropriate distance for only one pair to undergo [2 + 2] cycloaddition to yield a single stereoisomer of the monocyclobutane photo-product bpbpvpcb. This work highlights crystal engineering design principles that can be used to facilitate regio- and stereospecificity in solid-state transformations.

Bis[µ-2-(2,4-difluoro-phen-yl)-1,3-bis-(1,2,4-triazol-1-yl)propan-2-olato-κN,O:O,N]bis-[(acetato-κO,O')nickel(II)] methanol hemisolvate.

In the title complex, [Ni(2)(C(13)H(11)F(2)N(6)O)(2)(C(2)H(3)O(2))(2)]·0.5CH(3)OH, there are two half-molecules in the asymmetric unit. The two centrosymmetrically related Ni(II) atoms, each attached to an acetate ligand, are linked by two fluconazole ligands. Each Ni(II) atom is six-coordinated in a distorted octa-hedral geometry by two N atoms of the triazole groups and two bridging O atoms from two different fluconazole ligands and two O atoms from a chelating acetate ligand. In the crystal structure, the half-occupied methanol solvent mol-ecule is linked to a triazole group via an O-H⋯N hydrogen bond.

Aqua-[2-(5-ethyl-2-pyridyl-κN)-4-iso-propyl-4-methyl-5-oxo-4,5-dihydroxy-imidazol-1-ido-κN](5-methyl-1H-pyrazole-3-carboxyl-ato-κN,O)copper(II) 1.33-hydrate.

In the title complex, [Cu(C(5)H(5)N(2)O(2))(C(14)H(18)N(3)O)(H(2)O)]·1.33H(2)O, the Cu(II) ion is coordinated in a slightly distorted square-pyramidal environment. The basal plane is formed by two N atoms from a 2-(5-ethyl-2-pyridyl-κN)-4-isopropyl-4-methyl-5-oxo-4,5-dihydroxy-imidazol-1-ide ligand and by one O atom and one N atom from a 5-methyl-1H-pyrazole-3-carboxyl-ate ligand. The apical position is occupied by a water mol-ecule. In the crystal structure, O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds lead to a three-dimensional supra-molecular network.