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Objective To discuss the strategy for cervical dumbbell⁃shaped tumors and develop a proposal for individualized therapy. Methods and Results Total 32 patients with cervical dumbbell⁃shaped tumors were recruited from The First Affiliated Hospital of Anhui Medical University from March 2017 to March 2022. All patients received surgical treatments, while the tumors located in C1-2 levels among 7 patients and C2-7 levels among 25 patients. Preoperative McCormick spinal cord function gradeⅠin 9 cases, gradeⅡin 12 cases, grade Ⅲ in 11 cases. Individualized surgical strategies were set according to the results of Toyama typing, preoperative imaging examination and intraoperative spinal stability. Surgery through posterior approach was performed in 26 cases, 2 patients underwent a lateral posterior sternocleidomastoid approach, 2 patients underwent surgery through combined posterior⁃anterolateral approach, and 2 patients received anterior cervical approach. Ninteen out of 32 patients with preoperatively unstable spinal factors or changes in spinal stability resulting from surgery received one⁃stage internal fixation. One patient underwent anterior cervical corpectomy and fusion followed by titanium cage implantation, and 18 patients underwent posterior trans⁃pedicle and lateral mass screw fixation. The results showed a gross total resection for all patients and the success rate was 100% (32/32). The average intraoperative blood loss was about 210 ml. Imaging examinations were performed for all patients within a week after the surgery, the internal fixator were all in good position. One month after the surgery McCormick spinal cord function gradeⅠin 20 cases, gradeⅡin 10 cases, grade Ⅲ in 2 cases. All patients had varying degrees of improvement in symptoms, no cerebrospinal fluid leakage, no serious nervous system infection and other complications, no postoperative cervical kyphosis, and no loosening or breakage of the screws and rods were found in 28 months after surgery, the bone graft fusion and vertebral body shape were good. Conclusions The size of the intervertebral foramen is one of the important factors to be considered in the surgical strategy of cervical dumbbell⁃typed tumors. The surgical management of C1-2 dumbbell⁃typed tumors is different from that of other levels, it is necessary to understand the patient's medical history, symptoms and signs in detail and to improve imaging evaluation before surgery. The development of multiple techniques and typing methods facilitate the development of individualized surgical plans.

Training teachers to manage their instruction and the class is known to be important and challenging. In traditional teacher training programmes, micro-teaching is frequently adopted; however, its effectiveness could be limited if the learners do not have good opportunities to immerse themselves in and interact in the learning contexts. Virtual Reality (VR) technology could be a good approach to coping with this problem. Nevertheless, the development cost of a VR scene is high from the perspectives of time and money. Hence, a spherical view VR-based training system of classroom misbehaviour management (TrainCM2) is proposed in this study. TrainCM2 can situate learners in a real situation at a low cost. To verify the effectiveness of TrainCM2, an experiment was conducted. The experimental results showed that the TrainCM2 learners outperformed the micro-teaching learners in terms of misbehaviour detection rate and processing performance, showing the benefits of the proposed approach.

Three dinuclear dysprosium complexes 1–3 with structural formulas [Dy2(bptz)(tta)6]·2CH2Cl2 (1), [Dy2(H2bmtz)(tta)6] (2) and [Dy2(H2bmtz)(hfac)6(H2O)2] (3) (bptz = 3,6-di(2-pyridyl)-1,2,4,5-tetrazine, H2bmtz = 3,6-di(2-pyrimidyl)-1,4-dihydro-1,2,4,5-tetrazine, tta = 2-thenoyltrifluoroacetonate, hfac = hexafluoroacetylacetonate) were synthesized by the use of two tetrazine derivative ligands containing six and eight nitrogen atoms in combination with β-diketonate co-ligands, which are a good research platform to study the synergistic influence of the local coordination environment and magnetic interaction on magnetic relaxation. Complexes 1 and 2 possess the same peripheral co-ligands and nearly the same coordination environment (approaching an ideal triangular dodecahedron), but different multi-nitrogen bridges involving N6 (bptz) and N8 (H2bmtz) tetrazine derivatives. The structural difference leads to distinct magnetic relaxation properties with a hysteresis temperature of 2.5 K and 5.5 K at a rate of 200 Oe s−1 in 1 and 2, respectively, which is most likely due to the different magnetic coupling transmitted by H2bmtz and bptz in the direction close to the vertical magneto axis. Combined with a suitable local coordination environment, the energy barrier of complex 2 bridged by H2bmtz can reach three times that of complex 3. Considering the local ligand field, the important influence of this multi-nitrogen bridge transmitting magnetic coupling on the SMM properties is demonstrated with the aid of ab initio calculations. Also of note is that complexes 2 and 3 are the first reported lanthanide SMMs constructed from dihydro-tetrazine. [ABSTRACT FROM AUTHOR]

Two lanthanide complexes with formulae [DyIII(LN5)(pentafluoro-PhO)3] (1) and [DyIII(LN5)(2,6-difluoro-PhO)2](BPh4) (2) (LN5 = 2,14-dimethyl-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadecal (19),2,13,15,17-pentaene) were structurally and magnetically characterized. DyIII ions lie in the cavity of a five coordinate nitrogen macrocycle, and in combination with the introduction of multi-fluorinated monodentate phenoxyl coligands a high axiality coordination symmetry is built. Using the pentafluorophenol co-ligand, complex 1 with a D2d coordination environment, is obtained and displays moderate single-molecule magnets (SMMs) behavior. When difluorophenol co-ligands were used, a higher local axisymmetric pentagonal bipyramidal coordination geometry was observed in complex 2, which displays apparent slow magnetic relaxation behavior with a hysteresis temperature of up to 5 K. Further magnetic studies of diluted samples combined with ab initio calculations indicate that the high axiality plays a crucial role in suppressing quantum tunneling of magnetization (QTM) and consequently results in good slow magnetic relaxation behavior. Different fluoro-substituted phenoxyl co-ligands have phenoloxy oxygen atoms with different electrostatic potentials as well as a different number of phenoloxy coligands along the magnetic axis, resulting in different ligand field strengths and coordination symmetries. [ABSTRACT FROM AUTHOR]

A new hydrazone Schiff base ligand was condensed from 2-hydroxy-3-methoxybenzaldehyde and pyrimidine-4-carbohydrazide {H2L = (E)-N′-(2-hydroxy-3-methoxybenzylidene)pyrimidine-4-carbohydrazide}, which was used to assemble two new Dy2 complexes Dy2L2(DMF)2(NO3)2 (1) and Dy2L2(DMF)2(AcO)2 (2). Notably, the coordinated anions have a subtle effect on the coordination configurations of the Dy3+ ions and the magnetic properties of the two Dy2 complexes. The Dy3+ ions in 1 and 2 have the same N2O5 coordination environment but show the triangular dodecahedron and the biaugmented trigonal prism coordination configurations, respectively. Magnetic measurements revealed that both 1 and 2 have intramolecular ferromagnetic interactions between the Dy3+ ions and show single-molecule magnet behaviors at 0 Oe, with Ueff/k values of 58.2 K for 1 and 59.9 K for 2. These magnetic properties may be explained by theoretical calculations. [ABSTRACT FROM AUTHOR]

Synthesis of 3d–4f single molecule magnets (SMMs) with novel topologies and exploration of the magnetic relaxation mechanism of SMMs have continuously received considerable attention because high performance SMMs could be obtained. In this work, we selected N-3-methoxysalicylidene-2-amino-3-hydroxypyridine (H2L) and di-2-pyridyl ketone (dpk) for reaction with Ni(NO3)2·6H2O, Dy(NO3)3·5H2O and trimethylamine in a CH3OH solution, and a novel Ni4Dy4 complex, [Ni4Dy4(L)6(L′)2{(py)2C(OCH3)O}2(μ3-CO3)2(CH3OH)2]·10CH3OH·13H2O (1, (py)2C(OCH3)(OH) = the hemiacetal form of dpk), was obtained. The magnetic diluted complex, [Ni4Y3.91Dy0.09(L)6(L′)2{(py)2C(OCH3)O}2(μ3-CO3)2(CH3OH)2]·10CH3OH·12H2O (2), and the Y analogue of 1, [Ni4Y4(L)6(L′)2{(py)2C(OCH3)O}2(μ3-CO3)2(CH3OH)2]·10CH3OH·11H2O (3), were also obtained. The carbonate ions in 1–3 were formed by spontaneous fixation of atmospheric CO2. Structural analysis revealed that the metallic core in 1 can be viewed as a Ni2Dy2 butterfly connecting two NiDy subunits on each side. To our knowledge, the structural topologies of 1–3 were not reported previously. The magnetic susceptibilities of 3 were fitted by PHI, indicating that the magnetic coupling between Ni1 and Ni1a in the "Ni2Y2 butterfly" subunit of 3 is ferromagnetic. Alternating-current (ac) susceptibility studies revealed that 1–2 exhibit single molecule magnet behavior under a zero dc field. [ABSTRACT FROM AUTHOR]

Photocontrolled magnetic properties are fundamental for the applications of molecular magnets, which have the features of high time and space resolution; however, such magnetic properties are highly challenging to be achieved owing to the weak light–matter interactions. Herein, the influence of in situ light irradiation on the field-induced magnetization dynamics of two Er(III) coordination polymers 1 and 2 with the same coordination skeletons but different halogen substituents was studied. 1 and 2, and their in situ photoexcited products 1a and 2a, display field-induced magnetization dynamics based on Orbach and/or Raman processes. The magnetization dynamics are fine-modulated by the synergetic effect of light irradiation and a ligand substituent, due to the charge re-distribution of the excited states of the ligand. [ABSTRACT FROM AUTHOR]