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In low-dimensional Ising spin systems, an interesting observation is the presence of step magnetization at low temperatures. Here we combine both DC and pulsed magnetic fields to study the 1/3 magnetization plateau and multiple steps in the Ising spin-chain material α-CoV 2 O 6 . Magnetization in pulsed fields is quite different from that in DC fields, showing multiple steps in an intermediate range of 4.2-6 K, inverted hysteresis below 4.2 K and asymmetric magnetization in negative fields below 11 K. We demonstrate that these unusual behaviors in magnetization are caused by the spin dynamics and the anomalous magnetocaloric effect (MCE) in α-CoV 2 O 6 , i.e., abrupt changes of sample temperature in adiabatic conditions. We successfully separate the influence between the intrinsic slow spin dynamics and the quasi-extrinsic temperature change. From the MCE, we find that some irreversible behavior is originated from the slow spin dynamics. Two different slow dynamics associated with the metastable steps are observed: one is sensitive to the slow field sweep rate at the order of ∼mT s -1 and weakly depends on temperature, while the other responds to the rapid field sweep rate of ∼kT s -1 and dominates at lowest temperature. We also distinguish that the metastable transition at H 4 is the first order and crucial for the ferrimagnetic to ferromagnetic transition. This study is useful to the understanding of multistep magnetization in α-CoV 2 O 6 and sheds light on recent experimental findings of related compounds., (© 2021 IOP Publishing Ltd.)

Objective: To observe the efficacy and safety of recombinant tissue-type plasminogen activator (rtPA) intravenous thrombolysis (IVT) in the treatment of acute cerebral infarction with hyperdense middle cerebral artery sign (HMCAS). Methods: Acute cerebral infarction patients with HMCAS from July 2010 to November 2015 at the First Affiliated Hospital of Dalian Medical University were collected.These patients were divided into two groups depending on whether they received IVT or not.The Nation Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were used to evaluate early and long-time therapeutic effects.Efficacy and safety were compared between the two groups. Results: A total of 93 patients were eligible for the analysis, with 45 cases in IVT group and 48 cases in non-IVT group.As time went by, NIHSS score in IVT group showed significant downward trend than the non-IVT group.The rate of patients with good outcome in IVT group was higher than that in non-IVT group ( P <0.05). The rate of hemorrhage transformation (HT) in IVT group and non-IVT group was 35.6% (16/45) and 10.4% (11/48), respectively, and the difference was statistically significant ( P <0.05). While no statistically significant difference was found about the rate of symptomatic intracranial hemorrhage (sICH) (8.9% vs 2.1%, P >0.05) and mortality (33.3% vs 27.1%, P >0.05) between these two groups.Logistic regression analysis identified relativity between IVT treatment and good outcome ( P <0.05), hemorrhage transformation ( P <0.05), rather than mortality ( P >0.05). Conclusions: Intravenous thrombolysis with rt-PA is an effective and safe treatment for most acute ischemic stroke patients with HMCAS and can promote early neurologic improvement and significantly improve long-term functional prognosis.Although Ⅳ thrombolysis can increase the risk of overall HT, it does not add risk in sICH and mortality.

Reaction of [Mo3Y(mu-S)3(dtp)4(H2O)] (Y = O, S; dtp = S2P(OC2H5)2(-)) with HgI2 gave the novel compound [[Mo3S7(dtp)3]4 x I][(HgI3)3] x 4H2O (1), which contains a [[Mo3S7(dtp)3]4 x I] tetramer and (HgI3)-. Compound 1 has been characterized by IR, Raman, UV/Vis, and NMR spectroscopy and single-crystal X-ray diffraction analysis. It is shown that this formation process can be referred to as a new cluster reaction. The structure and spectroscopic data of the tetramer is also compared with that of the related discrete cluster [Mo3S7(dtp)3 x I]. Crystal data: space group F23, a = 26.786(3) A, V = 19218.7(4) A3, Z = 4, R = 0.059.

Three heterometallic cubane-like clusters, [Mo3(mu 3-O)(mu 3-S)3(SnCl3)(dtp)3(py)3] (dtp = S2P(OC2H5)2-, py = C5H5N) (1), (PPN)[Mo3(mu 3-O)(mu 3-S)3(SnCl3)(dtp)3(mu-OAc)(py)] (OAc = CH3COO-, PPN = (C6H5)3PNP(C6H5)3+) (2), and (Et4N)[Mo3(mu 3-O)(mu 3-S)3(SnCl3)(dtp)2(mu-OAc)2(py)] (3) have been prepared by the reaction of [Mo3(mu 3-O)-(mu-S)3(dtp)4(H2O)] (4), [Mo3(mu 3-O)(mu-S)3(dtp)3(OAc) (py)] (5), and [Mo3(mu 3-O)(mu-S)3(dtp)2(OAc)2 (py)] (6) with SnCl2, respectively. They have been characterized by IR, UV-vis, 31P NMR, 95Mo NMR, and X-ray structure analysis. All of these heterometallic clusters have a [Mo3OS3Sn]6+ core but contain a different arrangement of peripheral ligands. As far as the neutral cluster 1 is concerned, there is no bridging OAc ligand, while only one bridging OAc ligand is observed for cluster 2 and two are for cluster 3. The Mo-Mo distances are about 0.03-0.04 A shorter than those of the starting trimolybdenum clusters. This indicates that the incorporation of SnCl3- fragment into (Mo3) clusters makes the Mo-Mo bonding enhanced. Crystal data for 1: triclinic, space group P-1, a = 10.7423(2) A, b = 14.0357(1) A, c = 16.9346(2) A, alpha = 84.054(1) degrees, beta = 87.095(1) degrees, gamma = 84.517(1) degrees, V = 2525.82(6) A3, Z = 2, R = 0.038 for 5584 reflections (I > 2.0 sigma(I)). Crystal data for 2: triclinic, space group P-1, a = 12.9529(1) A, b = 15.6324(2) A, c = 19.6355(1) A, alpha = 92.083(1) degrees, beta = 97.908(1) degrees, gamma = 110.337(1) degrees, V = 3677.41(6) A3, Z = 2, R = 0.034 for 8665 reflections (I > 2.0 sigma(I)). Crystal data for 3: monoclinic, space group P2(1)/n, a = 14.0852(5) A, b = 15.1324(5) A, c = 23.2691(7) A, beta = 97.371(1) degrees, V = 4918.7(3) A3, Z = 4, R = 0.049 for 4970 reflections (I > 2.0 sigma(I)).

The structures and identification of five flavonoids from Oxytropis glabra are described. The five flavonoids are kaempferol, quercetin, kaempferol-3-beta-D-glucoside, kaempferol-7-alpha-L-rhamnoside and kaempferol-3-diglucoside. All of them were isolated from this plant for the first time.