Stem cell transplantation and/or adenoviral glial cell line-derived neurotrophic factor promote functional recovery in hemiparkinsonian rats

BACKGROUND Parkinson’s disease(PD)is a neurological disorder characterized by the progressive loss of midbrain dopamine(DA)neurons.Bone marrow mesenchymal stem cells(BMSCs)can differentiate into multiple cell types including neurons and glia.Transplantation of BMSCs is regarded as a potential approach for promoting neural regeneration.Glial cell line-derived neurotrophic factor(GDNF)can induce BMSC differentiation into neuron-like cells.This work evaluated the efficacy of nigral grafts of human BMSCs(hMSCs)and/or adenoviral(Ad)GDNF gene transfer in 6-hydroxydopamine(6-OHDA)-lesioned hemiparkinsonian rats.AIM To evaluate the efficacy of nigral grafts of hMSCs and/or Ad-GDNF gene transfer in 6-OHDA-lesioned hemiparkinsonian rats.METHODS We used immortalized hMSCs,which retain their potential for neuronal differentiation.hMSCs,preinduced hMSCs,or Ad-GDNF effectively enhanced neuronal connections in cultured neurons.In vivo,preinduced hMSCs and/or Ad-GDNF were injected into the substantia nigra(SN)after induction of a unilateral 6-OHDA lesion in the nigrostriatal pathway.RESULTS Hemiparkinsonian rats that received preinduced hMSC graft and/or Ad-GDNF showed significant recovery of apomorphine-induced rotational behavior and the number of nigral DA neurons.However,DA levels in the striatum were not restored by these therapeutic treatments.Grafted hMSCs might reconstitute a niche to support tissue repair rather than contribute to the generation of new neurons in the injured SN.CONCLUSION The results suggest that preinduced hMSC grafts exert a regenerative effect and may have the potential to improve clinical outcome.

Petrogenesis of the microcrystalline-dioritic enclaves from Jiuling granitoids in the eastern segment of Jiangnan Orogen and constraints on magma source materials

Numerous dark enclaves with different shapes are found in Jiuling Neoproterozoic granitoids.Precise LAICP-MS U-Pb dating was conducted on zircons extracted from two microcrystalline enclave samples,yielding crystallization ages of 822.6±5.8 Ma and 822.2±6.2 Ma,respectively.The consistent ages within analytical errors with the host granitoids suggested that they were the products of the same magmatism.The microcrystalline-dioritic enclaves commonly show plastic forms and contain similar plagioclase megacrysts to the host rocks,and both of the enclaves and host granitoids showed a complex composition and structural imbalance in plagioclases.Furthermore,the apatites with a euhedral acicular shape occurred widely in the microcrystalline-dioritic enclaves.All of these petrographic features above imply magma mixing is involved in their diagenesis.The enclaves and host granitoids show a marked zircon trace element difference and Hf isotopic signatures without correlation in zircon trace element pairs but form their own system between enclaves and host granitoids.Additionally,most of the zircons show extremely high εHf (t) with εHf (t) =3.54?11.94 from the southern samples,and εHf (t) =1.0?9.09 from the central region.Some zircons with the higher εHf (t) are similar to the zircons from the juvenile island arc in the eastern segment of Jiangnan Orogen.Integrated geological and Hf isotopic characteristics suggest microcrystalline-dioritic enclaves were derived from the partial melting process of the Mesoproterozoic crust which enriched juvenile island arc materials and mixed with the granitic magma that remelted from the Mesoproterozoic continental crust which relatively enriched ancient sediments and mixed with the host granitoid in diagenesis.

Microglia-conditioned medium promotes locomotor recovery and neuroprotection after rat spinal cord injury

This work examines whether microglia-conditioned medium (MCM) is beneficial in stressed spinal cord cells or tissues. MCM was separated into two fractions by 50 kDa molecular cut-off centrifugation. MCM not only promoted survival of neuronal and oligodendroglial cells but effectively reduced LPS stimulation in spinal cord cultures. We further utilized the NYU weight-drop device to induce contusive spinal cord injury (SCI) in rats. Immediately after dropping the impactor from a height of 25 mm onto thoracic spinal segment, MCM was intrathecally administered. At 6 weeks post-injury, SCI rats receiving MCM > 50 kDa treatment showed significant hind-limb improvement over MCM 50 kDa, of microglia was neuroprotective against spinal cord injury.

Improving dehydrogenation properties of Mg/Nb composite films via tuning Nb distributions

t To investigate the effect of Nb on the dehydro- genation properties of Mg-Nb composite films, Mg/Nb eight- layer film and Mg- 10 at% Nb alloy film with the similar Mg- to-Nb atomic ratio were prepared by magnetron sputtering. Results show that both Mg/Nb eight-layer film and Mg- 10 at% Nb alloy film exhibit excellent de/hydrogenation properties. Mg- 10 at% Nb alloy film starts to release hydrogen at 108 ℃, and its desorption peak temperature is lower to 146 ℃, which is much better than that of pure MgH2 under the same condi- tion. Scanning electron microscopy （SEM） results demon- strate that the dispersive Nb nanoparticles in Mg/Nb eight- layer film may serve as nucleation sites for Mg ←→ MgH2 reactions, which can provide channels for H diffusion. For Mg- 10 at% Nb alloy film, the uniform distributions of Nb can accelerate the hydrogen diffusion and effectively improve the dehydrogenation kinetics for MgH2. This study provides an enlightening way for designing and preparing Mg-based composite films with excellent dehydrogenation properties.

Exotic ferromagnetism in the two-dimensional quantum material C3N

The search for and study of exotic quantum states in novel low-dimensional quantum materials have triggered extensive research in recent years. Here, we systematically study the electronic and magnetic structures in the newly discovered two-dimensional quantum material C3N within the framework of density functional theory. The calculations demonstrate that C3N is an indirect-band semiconductor with an energy gap of 0.38 eV, which is in good agreement with experimental observations. Inter- estingly, we find van Hove singularities located at energies near the Fermi level, which is half that of graphene. Thus, the Fermi energy easily approaches that of the singularities, driving the system to ferromagnetism, under charge carrier injection, such as electric field gating or hydrogen doping. These findings not only demonstrate that the emergence of magnetism stems from the itinerant electron mechanism rather than the effects of local magnetic impurities, but also open a new avenue to de- signing field-effect transistor devices for possible realization of an insulator-ferromagnet transition by tuning an external electric field.