[en] Purpose: To evaluate the diagnostic efficacy of magnification mammography with 0.1 mm ultra-microfocus tube in nonpalpable breast cancer. Methods: 35 cases of nonpalpable breast cancer proved by operation and pathology. Were studied with conventional mammography and magnification mammography with 0.1 mm ultra-microfocus tube. The detecting ability and image resolution of the two techniques were compared. Results: The image quality of magnification mammography was better than that of conventional mammography. Conclusion: The magnification mammography should be the technique of choice for investigation of nonpalpable breast cancer

[en] The reaction mechanism of SiF₂ radical with HNCO has been investigated by the B3LYP method of density functional theory(DFT), while the geometries and harmonic vibration frequencies of reactants, intermediates, transition states and products have been calculated at the B3LYP/6-311++G^** level. To obtain more precise energy result, stationary point energies were calculated at the CCSD(T)/6-311++G^**//B3LYP/6-311++G^** level. SiF₂+HNCO→IM3→TS5→IM4→TS6→OSiF₂CNH(P3) was the main channel with low potential energy, OSiF₂CNH was the main product. The analyses for the combining interaction between SiF₂ radical and HNCO with the atom-in-molecules theory (AIM) have been performed

[en] The reaction mechanism between Fe⁺ in the ground state and the excited state with CO and N₂ O has been studied using the density functional theory (DFT) at UB3LYP/6-311 + G (2d) level. The geometries for reactants, the transition states and the products were completely optimized. All the transition states were verified by the vibrational analysis and the intrinsic reaction coordinate calculations. For each stationary point, the single-point energy calculations were carried out by UB3LYP/6-311 + + G (3df, 3pd) method. The potential energy curve-crossing diagrams were investigated for the state correlation between quartet and sextet states in the reaction of Fe⁺ with CO and N₂O. The results showed that this reaction is a two-step reaction and the reaction mechanism is an insertion-elimination mechanism. There are two crossing points between the quartet and the sextet potential energy surfaces (PESs), which would effectively reduce the activation energy and play a significant and beneficial role in the kinetic and thermodynamic aspects of this catalytic reaction. (authors)

[en] 5, 7, 12, 14-pentacenetetrone (PT), polycyclic quinone derivatives, are rich in carbonyl, which were investigated as a novel organic electrode material for supercapacitors. PT with a π conjugated system, is a flat molecule, generating strong π–π interactions between molecules. PT molecules were uniformly fixed on conductive reduced graphene oxide (rGO) through π–π interaction by one-step solvothermal method, forming a three-dimensional cross-linked PT@rGO hydrogel. This composite structure was conducive to reducing the charge transfer resistance and promoting the Faraday reaction of electrode, which achieved the superposition of electric double-layer capacitance and pseudocapacitance. Appropriate organic molecular loading can effectively improve electrochemical performance. The optimal PT@rGO electrode material displayed the specific capacitance of 433.2 F g⁻¹ at 5 mV s⁻¹ with an excellent rate capability in 1 mol l⁻¹ H₂SO₄ electrolyte. Finally, the fully pseudocapacitive asymmetric supercapacitor has been assembled by using PT@rGO as positive electrode and benz[a]anthracene-7,12-quinone (BAQ) modified rGO(BAQ/rGO)as negative electrode, which exhibited the good energy storage performance in a cell voltage of 1.8 V. (paper)

[en] Highlights: • Reduced graphene oxide was non-covalently functionalized by organic molecules. • The BDTD-rGO exhibits an ultra-long cycle life (96.4% for 10,000 cycle). • The BDTD-rGO possesses an excellent specific capacitance of 360 F g⁻¹ at 1 A g⁻¹. • Negative and positive electrodes can generate potential self-matching behavior. • As-fabricated the asymmetric supercapacitor delivers a superior cyclic stability. -- Abstract: A redox-active organic molecular electrode is prepared for supercapacitors. Benzo[1,2-b:4,5-b']dithiophene-4,8-dione (BDTD), planar molecule with fused heteroaromatic structure, has been adsorbed on conductive reduced graphene oxide (rGO) by π–π interactions to form a 3D interconnected and functionalized xerogel (BDTD-rGO). Because the five-membered aromatic heterocycle is more electron-rich than the six-membered aromatic ring, which enlarges the electronic interaction between the BDTD molecule and the conjugated graphene network and accordingly reduce the solubility of BDTD molecule in electrolyte. As a result, the optimized BDTD-rGO electrodes achieve specific capacitance of 360 F g⁻¹ at 1 A g⁻¹, with ultra-long cycle life of 96.4% after 10,000 cycles, and even 80% after 50,000 cycles at 5 A g⁻¹ in 1 M H₂SO₄. Furthermore, the asymmetric supercapacitor (ASC), which is assembled by using the BDTD-rGO as the negative electrode and lamellar holey graphene hydrogel (LGH) as the positive electrode respectively, exhibits better energy storage performance.

[en] The present work reports an organic molecule electrode (OME) based on the graphene and graphene nanomesh (GNM) hydrogel non-covalently functionalized by caffeic acid (CFA) molecules (denoted as G&GMH-CFA). In such electrode system, the three-dimensional conductive network has a cross-linking channel constructed by means of the in-plane pores on the graphene nanomesh, which is benefit for exposing more active sites accessible to electrolyte and accordingly enhancing supercapacitive behaviors of the OME. The G&GMH-CFA delivers a specific capacitance of 482.6 F g⁻¹ at current density of 1 A g⁻¹. And it is noted that the Faraday current response peaks are located in the positive potential range of 0.6 V, which is superior to the organic molecules electrode reported in the correlative works. In addition, the density functional theory (DFT) calculations are used to illuminate the core issue of charge storage mechanism and binding interactions between CFA and graphene. To match with the resultant positive electrode, AQ functionalize graphene-like nanoflower (CNF-AQ) was prepared as counterpart (negative) electrode. The assembled asymmetric supercapacitors (ASC) CNF-AQ//G&GMH-CFA2 could exhaustively release the supercapacitive performance due to match and self-coordination based on the reasonable matching of two electrodes in structure, charge quantity and kinetics during the electrochemical energy storage process. The CNF-AQ//G&GMH-CFA2 delivered energy density of 26.4 Wh kg⁻¹ at the power density of 0.7 kW kg⁻¹. Two tandem CNF-AQ//G&GMH-CFA2 devices could easily light 88 LEDs.