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Find video protocols related to scientific articles indexed in Pubmed.
[Nerve baby-sitter in reverse end-to-side neurorrhaphy preserves the structure of denervated muscle in rats].
Beijing Da Xue Xue Bao
PUBLISHED: 10-22-2014
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To explore the protected effect of sensory baby-sitter in reverse end-to-side fashion on denervated muscle.
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[Influence factors on the cryosurvival rate of post-thaw spermatozoa from sperm donors].
Zhonghua Nan Ke Xue
PUBLISHED: 07-18-2014
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To investigate the influence of seasons, blood types and semen parameters on the cryosurvival rate of frozen-thawed spermatozoa from sperm donors.
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Heterodinuclear M(II)-Ln(III) single molecule magnets constructed from exchange-coupled single ion magnets.
Dalton Trans
PUBLISHED: 06-12-2014
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The synthesis and characterization of four dinuclear 3d-4f complexes [M(II)Ln(III)(L)(DBM)3] (ZnDy = 1, CoY = 2, CoDy = 3·3.5CH3CN, CoGd = 4·3.5CH3CN) are reported (H2L = N,N'-dimethyl-N,N'-(2-hydroxy-3-methoxy-5-methyl-benzyl)ethylenediamine, DBM(-) = anion of 1,3-diphenyl-propane-1,3-dione). In each of the four complexes, the M(II) ion occupies the internal N2O2 site whereas the Ln(III) ion occupies the external O4 site. There are diphenoxo bridges between the M(II) and Ln(III) ions in these complexes. The remaining coordination sites are occupied by three DBM(-) anions. Direct current (dc) magnetic susceptibility measurements indicate the presence of intramolecular ferromagnetic interactions in complexes 3 and 4. The magnetic coupling constant, JCoGd, of complex 4 is estimated to be 0.26 cm(-1) (H = -2JCoGdSCoSGd). Alternating current (ac) magnetic susceptibility studies reveal that complexes 1 and 2 show field-induced single molecule magnet behavior, with ?E values of 36.5 K and 8.56 K, respectively. Complex 3 shows frequency dependent out-of-phase signals, indicating the presence of a slow relaxation of the magnetization, whereas complex 4 does not display slow magnetization relaxation.
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Effect of active Notch signaling system on the early repair of rat sciatic nerve injury.
Artif Cells Nanomed Biotechnol
PUBLISHED: 05-29-2014
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It is all known that dedifferentiated Schwann cells (SCs) play an important role in neural regeneration, and Notch signaling has complex and extensive regulatory functions in dedifferentiated SCs. So studies have focused on how to improve peripheral nerve repair by regulating proliferation and dedifferentiation in SCs with Notch signaling meloculars.We have found SCs can be activated when adding Recombinant rat jagged1/FC chimera (an activator of the Notch signaling system) in vivo. Compared with that of the control groups, at 4 weeks post-surgery nerve regeneration and functional rehabilitation in the Recombinant rat jagged1/FC chimera group were advanced significantly, and the expression of neurotrophic factors in the regenerated nerves was elevated largely. These results indicated that SCs activated by Notch signaling could promote nerve repair effectively in the early regenerative stage, suggesting the possible clinical application for the treatment of peripheral nerve defects.
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Toward higher nuclearity: tetranuclear cobalt(II) metallogrid exhibiting spin crossover.
Inorg Chem
PUBLISHED: 02-20-2014
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Supramolecular strategy was employed to achieve the highest nuclearity Co(II) cluster exhibiting spin-crossover (SCO) behavior. Magnetic susceptibility characterization of the Co4(II) complex shows that two different spin-transition processes occur. The SCO behavior is directed by the partially deprotonated polydentate ligand, which favors the structural distortion required by the spin transition.
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A cyano-bridged single-chain magnet featuring alternate high- and low-spin manganese(III) porphyrins.
Chem. Commun. (Camb.)
PUBLISHED: 01-13-2014
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The chains in complex [Mn(TPP)][Mn(TPP)(CN)2] (H2TPP = meso-tetra(4-phenyl)-porphyrin) demonstrate perfect linearity, and are well isolated with the nearest interchain Mn-Mn separation of 12.95 Å. Ferromagnetic coupling is present among adjacent Mn(III) ions, and single-chain magnet (SCM) behaviour is verified.
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[Radix hedysari extract promotes peripheral nerve regeneration].
Beijing Da Xue Xue Bao
PUBLISHED: 10-19-2013
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Treatment of peripheral nerve injury is a major challenge in clinical practice. With advances in molecular biology and development of microsurgical techniques and tissue engineering, peripheral nerve repair procedures have been greatly improved. In the last 10 decades, most treatments for peripheral nerve injury in animal models have achieved histological and functional recovery, the treatments in humans, however, produce insufficient recovery, especially for proximal nerve injury. Increasing attention has been paid to the Traditional Chinese Medicine (TCM) for promoting peripheral nerve regeneration, since these remedies often display effective clinical outcome, minor side effects and effectiveness for multiple targets. Although TCM has complex ingredients and the specific pharmacological mechanisms for their effectiveness are still unclear, an effective clinical outcome is welcomed by many clinicians. In the past 20 years, we have made a series of detailed studies including the toxicity tests, pharmacodynamic tests, pharmacological experiments etc, about a new traditional formula which mainly contains the Radix hedysari, Epimedium etc. RESULTS have shown that this formula is safe to be used in both animals and humans with no toxicity and adverse effect, and systemic administration of this formula could enhance the peripheral nerve regeneration.
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[Generation and characterization of peripheral nerve animal model of pure motor/sensory nerve fibers].
Beijing Da Xue Xue Bao
PUBLISHED: 10-19-2013
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To generate peripheral nerve animal model of pure motor nerve fibers/pure sensory nerve fibers, and identify them.
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[Pain assessment of biological conduit small gap tubulization in rat sciatic nerve multilation model].
Beijing Da Xue Xue Bao
PUBLISHED: 10-19-2013
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To explore the pain sensation recovery discipline of 2 mm small gap biological conduit tubulization and epineurial neurorrhaphy in rat sciatic nerve multilation model.
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Prehospital road traffic injuries among the elderly in Beijing, China: data from the Beijing Emergency Medical Center, 2004-2010.
Chin. Med. J.
PUBLISHED: 08-09-2013
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Road traffic injuries (RTIs) are a worldwide issue associated with increasing development and motorization. However, statistical studies do not include any analyses of Beijings geriatric population. Using data from the Beijing Emergency Medical Center, we present the main characteristics of traffic injuries involving the elderly in Beijing. We also provide objective information for those concerned with the safety of traffic systems and the prevention of traffic injuries.
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Synthesis, crystal structure and magnetic properties of dinuclear NiIILnIII complexes based on a flexible polydentate ligand.
Dalton Trans
PUBLISHED: 06-29-2013
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The synthesis and characterization of three isomorphous complexes [NiII(L)LnIII(DBM)?] (Ln = Gd (1·2.5CH?CN·0.5H?O), Tb (2·2CH?CN·0.5MeOH), and Dy (3·2CH?CN·0.5MeOH·0.5H?O)) are reported (H?L = N,N-dimethyl-N,N-(2-hydroxy-3-methoxy-5-methylbenzyl)ethylenediamine, DBM? = anion of 1,3-diphenylpropane-1,3-dione). The flexible ligand L²? contains an N?O?-inner and an O?-outer coordination site. There are diphenoxo bridges between NiII and LnIII ions in these complexes. The remaining coordination sites are occupied by DBM? anions. Direct current (dc) magnetic susceptibility measurements indicate the presence of intramolecular ferromagnetic interactions in desolvated complexes 1-3. The magnetic coupling constant JNiGd in complex 1 is estimated to be 1.11 cm?¹ (H = -2JNiGdSNiSGd). Alternating current (ac) magnetic susceptibility studies reveal that complexes 2 and 3 show frequency-dependent out-of-phase signals, which indicate that they exhibit SMM behavior. The energy barriers for complexes 2 and 3 under a 2 kOe applied direct current (dc) magnetic field are estimated from Arrhenius plots to be 14.4 and 11.3 K, respectively.
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Morphological study on the collaterals developed by one axon during peripheral nerve regeneration.
Artif Cells Nanomed Biotechnol
PUBLISHED: 06-13-2013
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Outgrowth of collateral sprouts from axons is a natural process that arises during development of and regeneration in the peripheral nervous system. Our previous study showed that if there are enough distal endoneurial tubes into which the proximal regenerative axons can grow, one axon can support three to four collaterals, at most. Here, the proximal half tibial nerve was fixed to the distal stump and served as the donor nerve. The number of myelinated axons was calculated after 4 months. The ratio of distal regenerative myelinated axon number to proximal donor nerve axon number was 1.83 with the tibial function index and the nerve conduction velocities of - 48.6 ± 6.8 and 27.8 ± 5.3 m/s. The regenerated collaterals were isolated and observed to sprout from the node of Ranvier with almost the same features of normal fibers, but with different electrophysiological characteristics. This finding shows the evidence of one-axon trunk several-collateral model in peripheral nerve regeneration and suggests that such multi-collateral regeneration model may be useful in peripheral nerve reconstruction.
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Syntheses, structure, and magnetic properties of heteronuclear Cu(II)4Fe(III)4 cluster and Cu(II)8 bimetallacycles.
Dalton Trans
PUBLISHED: 06-06-2013
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The compartmental Schiff base ligands N,N-ethylenebis(3-hydroxysalicylidene) (H(4)L) and N,N-propylenebis(3-hydroxysalicylidene) (H(4)L) have been employed in the synthesis of a cyclic tetranuclear Cu(II) complex [Cu(4)(L)(2)(MeOH)(3)(H(2)O)]·[Cu(4)(L)(2)(MeOH)(3)] (1), a novel octanuclear Cu(II) complex [Cu(8)(L-L)(2)(H(2)O)(4)(?(2)-H(2)O)]·3DMF·3H(2)O (2) and a hetero-octanuclear Cu(II)-Fe(III) complex [Cu(4)Fe(4)(L)(4)(H(2)O)(3)(?(3)-O)(2)]·3DMF·3H(2)O (3). During the formation of the Cu(8) complex (2), a new bis-Schiff base ligand (L-L)(8-) forms via the ortho-para C-C coupling of two H(4)L ligands. The bicyclic complex (2) is comprised of two cyclic Cu(4) units that are similar to that of complex 1. In the Cu(4) unit, the alternate Cu(II) ions are singly bridged by phenoxo groups. The three complexes display overall antiferromagnetic coupling, and the Cu(II)-Cu(II) magnetic coupling constant falls in the range -117.2 to -473.6 cm(-1) for complexes 1 and 2 corresponding to the bridging Cu-O(phenoxide)-Cu bond angles of 124.3-131.0°.
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Hypothesis of peripheral nerve regeneration induced by terminal effectors.
Artif Cells Nanomed Biotechnol
PUBLISHED: 05-02-2013
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Peripheral nerve injury (PNI) is a common trauma in clinical practice. A number of techniques to deal with PNI repair have been designed in clinics. From these methods for nerve repairing shown to be effective in clinics, as well as related experiments, we formulated a hypothesis that PNI regeneration and functional repair are induced by terminal effectors. Regeneration of peripheral nerves is the process whereby the nerve fibers regenerated by the induction of terminal effectors establish connections with effector organs and induce the spinal cord and upper centers to recognize effector organs and to re-model them for effective innervations. The hypothesis has two major components: (1) after surgical repairing of the injured nerves, the functional localization of regenerated nerves is determined by the connected effector organs and (2) the upper nervous system enables structural remodeling and functional changes according to the functions of the effector organs.
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Spin transitions in Fe(II) metallogrids modulated by substituents, counteranions, and solvents.
J. Am. Chem. Soc.
PUBLISHED: 04-11-2013
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Two bis(tridentate) Schiff base ligands H2L(x) were used to construct three 2×2 grid-type tetranuclear Fe(II) complexes 1-3 to obtain polynuclear spin-crossover materials. Magnetic susceptibility measurements show that the spin states of the complexes are related to the substituents of H2L(x), and that spin transition occurs only in complexes 1 and 2, which are derived from a bulky ligand, whereas complex 3 is diamagnetic. The transition temperatures of complexes 1 and 2 are close to room temperature and are dependent on counteranions. The spin transition of complex 1 can be reversibly tuned by the dehydration and hydration process.
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Supramolecular lanthanide metallogrids exhibiting field-induced single-ion magnetic behavior.
Dalton Trans
PUBLISHED: 02-21-2013
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A supramolecular strategy has been applied to construct two tetranuclear lanthanide complexes for investigating the magnetic properties of individual lanthanide ions. The Ln(III) complexes (Ln = Dy, Tb) display field-induced slow magnetization relaxation, typical of single-molecule magnet behavior. The four lanthanide ions in the molecules are well separated by distances of ca. 9 Å, and thus the slow magnetization relaxation should be assigned to single-ion magnet (SIM) behavior. Therefore, the present complexes are novel supramolecular aggregates of four isolated SIMs.
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Effect of Modified Formula Radix Hedysari on the Amplification Effect during Peripheral Nerve Regeneration.
Evid Based Complement Alternat Med
PUBLISHED: 01-23-2013
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Many studies have demonstrated a compensatory amplification phenomenon during nerve regeneration. When a relatively fine nerve is used as a donor to connect to a distal nerve after transection, the donor nerve regenerates more collaterals than its own fibers, which extend to the distal stump, grow into distal endoneurial tubes, and finally reach and dominate the target organs. This is known as the amplification phenomenon. In this study, we investigated the amplification phenomenon in rats treated with Modified Formula Radix Hedysari (MFRH) as adjuvant therapy for 12 weeks. The rats were divided into three groups at random (six animals in each group). In the model group and the treatment group, the proximal common peroneal nerve was used as a donor nerve to connect to the distal tibial nerve. Rats in the normal group did not undergo surgery. After surgery, the treatment group was administered MFRH as systemic therapy, while the model group and the normal group were not given treatment. The results demonstrated that the nerve conduction velocity, the fiber diameter, the axon diameter, the number of regenerating nerve fibers, and the amplification ratio were better in the treatment group than in the model group, suggesting that MFRH promoted the nerve amplification effect.
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Functional recovery of denervated skeletal muscle with sensory or mixed nerve protection: a pilot study.
PLoS ONE
PUBLISHED: 01-01-2013
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Functional recovery is usually poor following peripheral nerve injury when reinnervation is delayed. Early innervation by sensory nerve has been indicated to prevent atrophy of the denervated muscle. It is hypothesized that early protection with sensory axons is adequate to improve functional recovery of skeletal muscle following prolonged denervation of mixed nerve injury. In this study, four groups of rats received surgical denervation of the tibial nerve. The proximal and distal stumps of the tibial nerve were ligated in all animals except for those in the immediate repair group. The experimental groups underwent denervation with nerve protection of peroneal nerve (mixed protection) or sural nerve (sensory protection). The experimental and unprotected groups had a stage II surgery in which the trimmed proximal and distal tibial nerve stumps were sutured together. After 3 months of recovery, electrophysiological, histological and morphometric parameters were assessed. It was detected that the significant muscle atrophy and a good preserved structure of the muscle were observed in the unprotected and protective experimental groups, respectively. Significantly fewer numbers of regenerated myelinated axons were observed in the sensory-protected group. Enhanced recovery in the mixed protection group was indicated by the results of the muscle contraction force tests, regenerated myelinated fiber, and the results of the histological analysis. Our results suggest that early axons protection by mixed nerve may complement sensory axons which are required for promoting functional recovery of the denervated muscle natively innervated by mixed nerve.
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N-terminal domain of soluble epoxide hydrolase negatively regulates the VEGF-mediated activation of endothelial nitric oxide synthase.
Cardiovasc. Res.
PUBLISHED: 11-08-2011
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The mammalian soluble epoxide hydrolase (sEH) has both an epoxide hydrolase and a phosphatase domain. The role of sEH hydrolase activity in the metabolism of epoxyeicosatrienoic acids (EETs) and the activation of endothelial nitric oxide synthase (eNOS) in endothelial cells (ECs) has been well defined. However, far less is known about the role of sEH phosphatase activity in eNOS activation. In the present study, we investigated whether the phosphatase domain of sEH was involved in the eNOS activation in ECs.
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[Neurofilament immune fluorescence staining: a new method for observing the morphology of the motor endplate].
Beijing Da Xue Xue Bao
PUBLISHED: 10-20-2011
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To investigate the effect of neurofilament (NF) immune fluorescence staining on observing morphology of the motor endplate.
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[Effect of calcitonin gene-related peptide on RUNX2 expression in primary rat osteoblasts].
Beijing Da Xue Xue Bao
PUBLISHED: 10-20-2011
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To investigate the effects of exogenous calcitonin gene-related peptide (CGRP) on RUNX2 expression in primary cultured rat osteoblasts.
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[Small-gap bridging technology for peripheral nerve injury repair and the new sleeve material].
Beijing Da Xue Xue Bao
PUBLISHED: 10-20-2011
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The peripheral nerve injury is a common injury in clinical practice. For centuries, traditional epineurial and perineurial suture techniques have been used to repair nerve transection after peripheral nerve injuries. As there are several types of nerve fibers in neural stump, accurate and effective regeneration of the fibers is limited. The outcome of repairing nerve injury has little improvement till now. Meanwhile , the selective regeneration of peripheral nerve fibers has been gradually confirmed by researchers. The limitation of traditional epineurial and perineurial suture techniques and the phenomenon of selective regeneration of nerve fibers had inspired us with the creative idea: the small-gap bridging suture techniques, which might take the place of the conventional epineurial and perineurial suture methods. We had made a series of detailed studies about this new method, devised a simple and reliable suture method and established an animal model of small-gap bridging suture technique. By observing peripheral nerve regeneration effect of nerve suture with small gap bridging by different gap lengths, we found that the optimal gap was between 1 to 3 mm, developed an artificial conduit with good biocompatibility and gradually applied this new conduit to mammals and primate animal experiments and clinical trials. All the studies obtained reliable results, which confirmed that the small-gap bridging suture was suitable to replace the traditional epineurium suture repairing the peripheral nerve injury. In 2010, this series of research gained the First Prize of Outstanding Scientific Achievement Award by the Ministry of Education.
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Portion of a nerve trunk can be used as a donor nerve to reconstruct the injured nerve and donor site simultaneously.
Artif Cells Blood Substit Immobil Biotechnol
PUBLISHED: 05-17-2011
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This study aims to estimate the effects of using a portion of a nerve trunk to repair itself and the injured nerve simultaneously. Proximal 1/2 median nerve served as donor nerve to repair the distal 1/2 median and whole ulnar nerve. Four months postoperation, the number of myelinated axons and nerve conduction velocities of the distal half median and ulnar nerve were (2033 ± 135 and 24.6 ± 5.3 m/s) and (1138 ± 228 and 30.3 ± 7.2 m/s). It suggests that using a portion of a nearby nerve truck to reconstruct itself and the injured nerve simultaneously is a practical method for severe peripheral nerve injury.
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Mesoporous ?-Fe2O3 nanospheres: structural evolution and investigation of magnetic properties.
Chemistry
PUBLISHED: 03-08-2011
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A solvothermal route is adopted to produce mesoporous ?-Fe(2)O(3) nanospheres by using polyethylene glycol as soft template and n-butanol/H(2)O as mixed solvent. The mesoporous ?-Fe(2)O(3) nanospheres are subjected to calcination at different temperatures, and the specific surface area, pore size, and magnetic properties of the as-prepared nanospheres are investigated. The studies reveal that the pore sizes of the mesoporous ?-Fe(2)O(3) nanospheres increase with higher calcination temperature, and high-temperature calcination brings about tightness of the pore wall. Magnetic studies show that aggregation of the small particles raises the Morin transition temperature.
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Can "dor to dor+rec neurorrhaphy" by biodegradable chitin conduit be a new method for peripheral nerve injury?
Artif Cells Blood Substit Immobil Biotechnol
PUBLISHED: 01-04-2011
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This study aims to estimate the effects of using one donor nerve to repair the injured nerve and itself simultaneously by biodegradable chitin conduit. Proximal median nerve served as donor nerve to repair the distal median and whole ulnar nerve. Four months postoperation, the number of myelinated axons and nerve conduction velocities of the distal median and ulnar nerve were (2085 ± 215 and 24.4 ± 5.9 m/s), and (1193 ± 102 and 30.7 ± 11.2 m/s). Recovery of the tetanic muscle forces of the reinvervated muscles were also observed. It suggests that Dor to Dor+Rec neurorrhaphy is a practical method for severe peripheral nerve injury.
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Pyrazine-2-amidoxime Ni(II) complexes: from ferromagnetic cluster to antiferromagnetic layer.
Inorg Chem
PUBLISHED: 12-22-2010
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Tetranuclear [Ni(4)(Hpzaox)(2)(pzaox)(2)(py)(4)](ClO(4))(2)·2py (1), [Ni(4)(Hpzaox)(2)(pzaox)(2)(py)(4)](NO(3))(2)·4py (2), and two-dimensional (2D) [Ni(4)(Hpzaox)(2)(pzaox)(2)(H(2)O)(2)](NO(3))(2)·2H(2)O (3) are prepared via the reaction of NiX(2)·6H(2)O and pyrazine-2-amidoxime (H(2)pzaox). All compounds contain [Ni(4)(Hpzaox)(2)(pzaox)(2)](2+) fragments, which assemble to form a tetranuclear or polymeric network. Magnetic studies show that the tetranuclear compounds display usual ferromagnetic coupling via the oxime N-O bridges, and the 2D compound displays unusual antiferromagnetic behavior.
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Ferromagnetic coupling in oximato-bridged multi-decker Ni(II) clusters.
Dalton Trans
PUBLISHED: 08-27-2010
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Single-, double- and triple-decker oximato-bridged Ni(ii) clusters based on pyridine-2-amidoxime (H(2)pyaox) have been synthesized and characterized. The decks have the same tetranuclear cationic units [Ni(4)(Hpyaox)(2)(pyaox)(2)](2+) that are stably present in the reaction solution. Magnetic studies show that uncommon ferromagnetic exchange between the adjacent Ni(ii) ions through the oxime bridges is operative in the compounds with the magnetic coupling constant (J) in the range 0.6-6.3 cm(-1) (H = -2JS(Ni1)S(Ni2)). Density function theoretical (DFT) calculations and the experimental data confirm that the N-O bond distances of the bridging oxime group have a decisive effect in magnetic coupling. For the present Ni(ii) species, the elongation of N-O bond distances are responsible for the switching from antiferromagnetic to ferromagnetic exchange with the critical bond distance of 1.394 Å.
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Multi-component synthesis of trimetallic tetranuclear clusters [Cu(L)(H(2)O)](2)Ln(H(2)O)(2)Cr(C(2)O(4))(3).12H(2)O (H(2)L = 1,4,8,11-tetraazacyclotradecane-2,3-dione, Ln(3+) = Gd, Tb and Dy).
Chem. Commun. (Camb.)
PUBLISHED: 08-12-2010
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Novel tetranuclear Cu(ii)-Ln(iii)-Cr(iii) complexes with oxamidate and oxalate bridges have been prepared using [Cu(L)], LnCl(3).6H(2)O and K(3)[Cr(ox)(3)] components (ox(2-) = oxalate) during the development of new multimetallic complexes as molecular magnets. Overall ferromagnetic properties have been observed in the Cu(2)GdCr compound, and no single-magnet behavior has been found in the Cu(2)TbCr and Cu(2)DyCr compounds.
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Supramolecular metallomacrocycles based on trans-dicyanoferrite(III) building blocks: synthesis, crystal structure and magnetic properties.
Dalton Trans
PUBLISHED: 02-23-2009
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The reaction of trans-[Fe(R-bpb)(CN)2]- (R-bpb2-=R-substituted-1,2-bis(pyridine-2-carboxamido)benzenate) with trans-Mn(III) Schiff base complexes [Mn(5-X-saltn)]ClO4 (5-X-saltn2-=N,N-propanolbis(5-X-substituted-salcylideneiminato) dianion) gave rise to cyanide-bridged neutral binuclear [MnFe] compounds [Mn(saltn)(MeOH)][Fe(bpb)(CN)2].3H2O (), [Mn(saltn)(H2O)Fe(bpmb)(CN)2].H2O (), [Mn(saltn)(MeOH)Fe(bpClb)(CN)2].2H2O (), and ionic [Mn2Fe]+-[Fe]- complexes [Mn2(5-Br-saltn)2(H2O)(EtOH)Fe(bpb)(CN)2][Fe(bpb)(CN)2].6H2O () and [Mn2(5-Cl-saltn)2(CH3OH)(EtOH)Fe(bpb)(CN)2][Fe(bpb)(CN)2].5H2O.MeCN (). Four binuclear units of complexes assemble in a head-to-tail way via hydrogen bonding giving rise to a metallo-supramolecular [MnFe]4 square, while two [Mn2Fe]+-[Fe]- units of complexes form a metallo-supramolecular macrocyclic structure. Magnetic studies reveal that complexes and exhibit intermetallic ferromagnetic coupling, while complex displays antiferromagnetic interaction between low-spin Fe(III) and high-spin Mn(III) through the cyanide bridges. Complexes , and display frequency dependent of current-alternating (ac) magnetic susceptibility, typical of the presence of slow magnetization relaxation. Because of the existence of intermolecular magnetic interaction, complex shows an exchange-biased single-molecule magnet (SMM) behavior below 0.5 K.
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[Establishment and evaluation of animal model for studying the effect of traumatic brain injury on bone fracture healing].
Beijing Da Xue Xue Bao
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To establish a stable animal model for studying the effect of traumatic brain injury on bone fracture healing.
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Experimental study on the repair of tibial plateau defect.
Chin. J. Traumatol.
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Objective: To evaluate the effect of autograft bone, allograft bone, calcium sulfate bone cement, and calcium phosphate bone cement on the repair of tibial plateau defect in rabbits. Methods: We used autograft bone, allograft bone, calcium sulfate bone cement, and calcium phosphate bone cement to repair tibial plateau defect in rabbits. Gross and histologic observations, X-ray examination, and biomechanical test were conducted at 1, 2, 4, 8 weeks after operation. Results: X-ray examination found that the bone density was evidently reduced in calcium sulfate group at 8 weeks after operation; there were no marked changes in other groups. The maximal load measurements showed that autograft and allograft groups were greater than calcium sulfate and calcium phosphate groups at 1 and 2 weeks after operation. However at 4 and 8 weeks after operation, no significant difference was found among the four groups. In autograft and allograft groups, there was no significant difference in biomechanical intensity at 2, 4, and 8 weeks, but it was significantly higher than that at 1 week. In calcium sulfate and calcium phosphate groups, the outcome was ranked in descending order as 1 week less than 2 week less than 4 week equal to 8 week. Histologic examination found a great amount of new bones at 8 week in both autograft and allograft groups. In calcium sulfate group, calcium sulfate was almost absorbed and there were numerous bone trabeculations. There was a large amount of unabsorbed calcium phosphate in calcium phosphate group. Conclusion: At 1-2 weeks postoperatively, the biomechanical intensity is higher in autograft and allograft groups than calcium sulfate and calcium phosphate groups, but after 4-8 weeks, there is no significant difference among groups. At 1-2 weeks, the biomechanical intensity in all groups is increased, but at 4-8 weeks, there is no significant increase. The rates of absorption and bone formation are quicker in calcium sulfate group than calcium phosphate group.
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Positioning study of cervical vertebra pedicle axial line projective point by computed tomography image reconstruction.
Chin. Med. J.
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Safe placement of the screws is a critical aspect of trans-pedicle internal fixation, and little information on in vivo morphology of the cervical vertebrae pedicle measured with imaging methods is available. The aim of this study was to measure the dimensions of cervical vertebrae C3 to C7 and provide screw length, screw diameter and tilt angle for clinical cervical vertebra trans-pedicle internal fixation.
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Syntheses, structure, and magnetic properties of hexanuclear Mn(III)(2)M(III)(4) (M = Y, Gd, Tb, Dy) complexes.
Dalton Trans
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The synthesis and characterizations of a family of isomorphous [Mn(III)(2)M(III)(4)L(2)(?(4)-O)(2)(N(3))(2)(CH(3)O)(2)(CH(3)OH)(4)(NO(3))(2)]·2H(2)O (M = Y(1), Gd(2), Tb(3), Dy(4)) are reported, where H(4)L = N,N-dihydroxyethyl-N,N-(2-hydroxy-4,5-dimethylbenzyl)ethylenediamine. They were obtained from the reactions of H(4)L with M(NO(3))(3)·6H(2)O, Mn(ClO(4))(2)·6H(2)O, NaN(3) and NEt(3) in a 1:1:1:2:2 molar ratio. The core structure consists of a Mn(2)M(4) unit. The four M(III) ions that are held together by two ?(4)-bridging oxygen atoms form a butterfly M(4) moiety. The M(4) core is further connected to the two five-coordinate trigonal-bipyramidal Mn(III) ions via one ?(4)-O(2-), two alkyloxo and one methoxo triple bridges. Magnetic susceptibility measurements indicate the presence of intramolecular antiferromagnetic interactions in complex 2, and overall intramolecular ferromagnetic interactions in complexes 3 and 4. The alternating current (AC) magnetic susceptibility studies revealed that complexes 3 and 4 showed frequency-dependent out-of-phase signals, which indicates that they exhibit slow relaxation of the magnetization.
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