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BACKGROUND: Under physiological conditions, CXCL12 modulates cell proliferation, survival, angiogenesis, and migration mainly through CXCR4. Interestingly, the newly discovered receptor CXCR7 for CXCL12 is highly expressed in many tumor cells as well as tumor-associated blood vessels, although the level of CXCR7 in normal cells is low. Recently, many studies have suggested that CXCR7 promotes cell growth and metastasis in more than 20 human malignancies, among which lung cancer is the leading cause of cancer-associated deaths worldwide. Thus, the mechanism of CXCR7 in the progression of lung cancer is urgently needed. METHODS: First, we explored CXCR4 and CXCR7 expression in human lung cancer specimens and cell lines by immunohistochemistry, western blot and flow cytometry. Then, we chose the human lung adenocarcinoma cell line A549 that stably overexpressed CXCR7 through the way of lentivirus-mediated transduction. Next, "wound healing" assay and transwell assay were applied to compare the cell migration and invasion ability, and stripe assay was used to evaluate the cell polarization. Last, our team established a mouse xenograft model of human lung cancer and monitored tumor proliferation and metastasis by firefly luciferase bioluminescence imaging in SCID/Beige mice. RESULTS: In clinical lung cancer samples, CXCR7 expression was almost not detected in normal tissue but upregulated in lung tumor tissue, whereas, CXCR4 was highly expressed in both normal and tumor tissues. Furthermore, overexpression of CXCR7 enhanced A549 cell migration and polarization in vitro. Besides, mouse xenograft model of human lung cancer showed that CXCR7 promoted primary lung tumor's growth and metastasis to the second organ, such as liver or bone marrow in SCID/Beige mice in vivo. CONCLUSIONS: This study describes the multiple functions of CXCR7 in lung cancer. Thus, these results suggest that CXCR7 may be a malignancy marker and may provide a novel target for anticancer therapy.
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Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Receptores CXCR/biossíntese , Células A549 , Animais , Movimento Celular/fisiologia , Feminino , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Neoplasias Pulmonares/genética , Camundongos , Camundongos SCID , Invasividade Neoplásica/patologia , Receptores CXCR/genética , Carga Tumoral/fisiologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
Motor function injuries mostly block or interfere with motor nerve conduction pathways. Theinnovative multi-target magnetic stimulation (MS) technology stimulates the cortex and nerve roots to activate the human central and peripheral nervous system, and has achieved preliminary results in scientificand clinical exploration. The mechanismsof these researches involve the activation of neurons, nerve conduction, the regulation of the microenvironment of the injured area, and gene regulation. However, how to make the multi-target MS technology achieve more accurate and effective nerve repair in rehabilitation is a bottleneck problem, which may need to break through neural circuit reconstruction and task-oriented training. This topic focuses on Nerve Regeneration Modulation and Rehabilitation, aiming to apply the concepts of nerve regeneration and neuromodulation totreatment of rehabilitation, and to supportfor exploring the neurobiological mechanism of rehabilitation. This review will explore the important role of multi-target synergistic enhanced neural circuit modulation technology in neural circuit reconstruction, and establish more accurate and effective multi-target innovative technologies and clinical pathways, so as to promote the basic and clinical research of neuromodulation.
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Regeneração Nervosa , Plasticidade Neuronal , Humanos , Neurônios , Nervos PeriféricosRESUMO
OBJECTIVE: To investigate the effects of exosomes of mouse astrocytes on the viability of neural stem cells. METHODS: Cultured and isolated the mouse astrocytes, and collected the cell supernatant for obtain the exosomes by ultracentrifugation. Neural stem cells that primary cultured for 2 nd to 6 th generation were obtained and treated with medium contained 0, 20, 40, 60 µg/mL of exosomes respectively. Screening the optimal exosome concentration for culturing neural stem cells by CCK-8 method. The optimal exosome concentration for neural stem cells was 40 µg/mL according to CCK-8 results. Then cells were intervened with 40 µg/mL of exosome in experimental group for 72 h, and the control group was added with the same volume of PBS. After intervention, the positive stem cells were labeled with EdU kit. Using the Transwell model, the number of nucleus stained by DAPI in the lower chamber in 40 µg/mL exosome treatment group and the control group were counted under a fluorescence microscope. RESULTS: â Identification of astrocyte exosomes: The successful obtain of exosomes of cell supernatant were confirmed by techniques such as electron microscopy, Western blot, exosome concentration and particle size measurement. â¡ CCK8 experiment: As the increasement of the concentration of exosomes, cell proliferation of primary neural stem cells gradually increased. Compared with the control group, proliferation of the cells in 40 µg/mL and 60 µg/mL exosome treatment groups was significantly enhanced, but there was no significant difference between the two groups. So, 40 µg/mL was selected as the best intervention concentration. ⢠EdU detection: Number of EdU positive labeled cells in the 40 µg/mL exosome group was higher than that in the control group (P<0.05). ⣠Transwell experiment: In the Transwell model, more neural stem cells in the 40 µg/mL exosome group migrated from the upper layer to the lower layer of the Transwell membrane, and the number was higher than that of the control group (P<0.05). CONCLUSION: Mouse astrocyte exosomes can improve the viability of neural stem cells.
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Astrócitos , Exossomos , Células-Tronco Neurais , Animais , Astrócitos/fisiologia , Proliferação de Células , CamundongosRESUMO
This article reports a patient with spinal cord injury who was treated with conventional rehabilitation therapy plus repeated transcranial magnetic stimulation (rTMS) during the postoperative rehabilitation, and to observe the effects of rTMS on dystonia. A 66-year-old male patient fell from the bed 8 months ago. At that time, he felt pain in his neck, dysfunction in limbs movement, and loss of sensation in trunk and limbs. Magnetic resonance imaging (MRI) revealed spinal cord injury. Under general anesthesia, anterior cervical decompression and bone graft fusion (ACDF) and cervical spine internal fixation of C 3-C 6 were performed. Postoperative hyperbaric oxygen chamber and conventional rehabilitation treatment were performed. Eight months after surgery, he was admitted to the hospital due to motor function, balance dysfunction, neurogenic bladder/rectal dysfunction. After admission, the patient was treated with rTMS plus rehabilitation treatment, once per day, 5 times/week, for 4 weeks. rTMS worked by wearing a positioning cap for transcranial magnetic stimulation (80% resting motor threshold, 1 Hz, 30 min), and then conduct walking, balance proprioception, muscle strength training, and coordination training. After 4 weeks, MEP, sEMG and H reflex were improved. Therefore, rTMS on the premotor cortex to improve the dystonia after spinal cord injury is effective in this case, which can be further studied.
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Distonia , Córtex Motor , Traumatismos da Medula Espinal , Estimulação Magnética Transcraniana , Idoso , Distonia/etiologia , Distonia/terapia , Humanos , Masculino , Medição da Dor , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/terapiaRESUMO
OBJECTIVE: To study the effect of bone marrow mesenchyml stem cell (BMSC) exosomes (Exo) on the proliferation and migration of brain microvascular endothelial cells in rats. METHODS: BMSCs were extracted from rats and identified. The BMSCs were co-cultured with bEnd.3 cells in Transwell chamber for 24 h (BMSCs group). Extracted and identified the BMSCs exosomes (BMSC-Exo). Observed and qualitatively evaluated the cells' abilities on swallowing the BMSC-Exo under a fluorescence microscope. The optimal work concentration of BMSC-Exo was selected by detecting the cell vitality under different BMSC-Exo concentrations by CCK8 method. bEnd.3 cells were co-cultured with BMSC-Exo for 24 h (BMSC-Exo group). bEnd.3 cells cultured alone was set as control group. The proliferation and migration of bEnd.3 cells in the three groups were respectively detected by EDU and cell scratching experiment after 24 h of culture. RESULTS: Flow cytometry showed that P3 BMSCs were CD90 and CD29 positive and CD45 negative, with osteogenic differentiation and adipogenesis differentiation, indicating the extracted BMSCs high purity. The BMSC-Exo under transmission electron microscopy was round-shaped with a diameter of about 100 nm; NTA analysis found the diameter distribution of BMSC-Exo ranged from 50 to 600 nm, with a peak size of 150 nm. Immunofluorescence showed that the endothelial cells could swallow BMSC-Exo. CCK8 showed that supplement of 20 µg/mL BMSC-Exo had the best effect on cell proliferation. EDU results showed that BMSCs group and BMSC-Exo group could promote the proliferation of bEnd.3 cells compared with the control group (P<0.05), and there was no difference between BMSCs group and BMSC-Exo group (P>0.05). Cell scratch test showed that the cell mobility of the BMSC-Exo group was higher than that of the control group (P<0.05), but there was no significant difference between the BMSC-Exo group and the BMSCs group (P>0.05). CONCLUSION: BMSC-Exo can replace BMSCs in effectively promoting the proliferation and migration of cerebral microvascular endothelial cells, which provide a new potential treatment for angiogenesis after stroke.
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Exossomos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Células da Medula Óssea , Encéfalo , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Células Endoteliais , Osteogênese , RatosRESUMO
OBJECTIVE: To study the effect and mechanism of modified constraint-induced movement therapy (mCIMT) on motor function recovery in cerebral ischemia-reperfusion rats. METHODS: The rats were randomly divided into the control group and the mCIMT group, with 12 rats in each group. The left middle cerebral artery occlusion (MCAO) model was established by the Longa suture method. In the mCIMT group, the rats started continuous training for 14 d on the 7 th day after modeling. The unaffected limb was tied to the chest with elastic bandages, and the affected limb was trained in the compulsory runner equipment. In the control group, rats moved freely in the cage. The body mass of rats was recorded within 20 d after modeling, and behavior was assessed by the foot-fault test. Some of the rats were euthanized 18 d after modeling, and high performance liquid chromatography (HPLC) was used to detect monoamine neurotransmitters (5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIVV), homovanillic acid (HVA) ), and amino acid neurotransmitters (glutamic acid (Glu), asparaginic acid (ASP), glutamine (Gln), glycine (Gly), taurine (Tau), gamma aminobutyric acid (GABA) ) in the motor cortex and striatum, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of total P70 ribosomal protein S6 kinase (p70s6k) and p70s6k phosphorylated protein (p-p70s6k) in motor cortex and striatum, respectively. RESULTS: Compared with the control group, the body mass of rats in the mCIMT group was comparable (P >0.05) within 21 d after modeling, foot-fault rate of the mCIMT group was significantly lower at 17 d after modeling (P<0.05). At 18 d after modeling, compared with the control group, the level of 5-HIVV in the motor cortex increased significantly (P<0.05), and the relative content of amino acid neurotransmitters (the ratio of Glu) in the motor cortex including Gln, Gly, Tau and GABA to Glu increased significantly (P<0.05 or P<0.01) except for decreased ASP/Glu (P<0.05). Moreover, compared with the control group, the expression of p-p70s6k in the motor cortex of the mCIMT was significantly decreased (P<0.05). There were no significant differences in monoamine neurotransmitters and amino acid neurotransmitters in the striatum between two groups (P>0.05). CONCLUSION: mCIMT improved the motor function of MCAO rats, and the mechanism might be related to the increase of amino acid neurotransmitters and 5-HIVV and decrease of p-p70s6k expression in the motor cortex.
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Isquemia Encefálica , Córtex Cerebral , Terapia por Exercício , Córtex Motor , Traumatismo por Reperfusão , Animais , Isquemia Encefálica/terapia , Córtex Cerebral/metabolismo , Movimento , Neurotransmissores , Ratos , Ratos Sprague-Dawley , ReperfusãoRESUMO
A novel fiber-optic based earth pressure sensor (FPS) with an adjustable measurement range and high sensitivity is developed to measure earth pressures for civil infrastructures. The new FPS combines a cantilever beam with fiber Bragg grating (FBG) sensors and a flexible membrane. Compared with a traditional pressure transducer with a dual diaphragm design, the proposed FPS has a larger measurement range and shows high accuracy. The working principles, parameter design, fabrication methods, and laboratory calibration tests are explained in this paper. A theoretical solution is derived to obtain the relationship between the applied pressure and strain of the FBG sensors. In addition, a finite element model is established to analyze the mechanical behavior of the membrane and the cantilever beam and thereby obtain optimal parameters. The cantilever beam is 40 mm long, 15 mm wide, and 1 mm thick. The whole FPS has a diameter of 100 mm and a thickness of 30 mm. The sensitivity of the FPS is 0.104 kPa/µÎµ. In addition, automatic temperature compensation can be achieved. The FPS's sensitivity, physical properties, and response to applied pressure are extensively examined through modeling and experiments. The results show that the proposed FPS has numerous potential applications in soil pressure measurement.
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A measurement approach for small deformations of soil specimens has been proposed in this study. The proposed approach consists of a small deformation transducer (SDT) based on fiber Bragg grating sensors which could provide an alternative tool to measure local small deformations of a soil specimen with high accuracy. The working principle, design procedures, calibrations and applications of the SDT are presented. An analytical solution is derived to obtain the relationship between the small deformation of the transducer and the wavelength shift of the FBG sensor, which was further evident in the laboratory calibration tests. The measurement range and resolution of the SDT can be adjusted by choosing different length and thickness of the material. The SDT can achieve a strain resolution of 4.45 micro-strains for a soil specimen with 80 mm in height. Measurement errors and stability were also examined and the results show that the maximum measurement error was around 0.01 mm. The designed SDT was further installed in a modified triaxial apparatus. Three shearing tests under different confining pressures were conducted. Results measured by the newly developed SDT are analyzed with comparisons to the results using external linear variable differential transformer (LVDT) transducers. The results provide evidence that this measurement approach is suitable for measuring the local deformations of soil specimens with high accuracy and stability.
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With the rapid construction of metro tunnels in many metropolises, a fast and convenient solution to capture tunnel deformation is desired by civil engineers. This contribution reports an automatic and wireless tunnel deformation monitoring system using ultrasonic transducers. A processing algorithm of the redundant ultrasonic information (RUI) approach is proposed to improve measurement accuracy. The feasibility of this tunnel deformation monitoring method is carefully examined with various probe angles, distances, and surrounding temperature variations. The results indicate that high accuracy can be achieved with different coefficients for various probe angles and sensor distances, as well as temperatures. In addition, a physical tunnel model was fabricated to verify the new processing algorithm of the RUI approach for a wireless tunnel deformation sensing system. The test results reveal that average measurement errors decreased from 7% to 3.75% using the RUI approach. Therefore, it can be concluded that the proposed approach is well suited to the automatic detection of critical conditions such as large deformation events in metro tunnels.
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Two new pyrrolo[1,2-α]azepine-type stemona alkaloids, named as tuberostemonoxirine (1) and 9α-epi-tuberospironine (2), were isolated from the roots of Stemona tuberosa. The structures and relative configurations of new compounds were established on the basis of extensive spectroscopic evidences, especially 1D and 2D NMR and HR-MS experiments.
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Alcaloides/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Stemonaceae/química , Alcaloides/química , Medicamentos de Ervas Chinesas/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Raízes de Plantas/química , Compostos de EspiroRESUMO
BACKGROUND: Tui Na (Chinese massage) is a relatively simple, inexpensive, and non-invasive intervention, and has been used to treat stroke patients for many years in China. Tui Na acts on specific parts of the body which are called meridians and acupoints to achieve the role of treating diseases. Yet the underlying neural mechanism associated with Tui Na is not clear due to the lack of detection methods. OBJECTIVE: Functional near-infrared spectroscopy (fNIRS) was used to explore the changes of sensorimotor cortical neural activity in patients with upper limb motor dysfunction of stroke and healthy control groups during Tui Na Hegu Point. METHODS: Ten patients with unilateral upper limb motor dysfunction after stroke and eight healthy subjects received Tui Na. fNIRS was used to record the hemodynamic data in the sensorimotor cortex and the changes in blood flow were calculated based on oxygenated hemoglobin (Oxy-Hb), the task session involved repetitive Tui Na on Hegu acupoint, using a block design [six cycles: rest (20 seconds); Tui Na (20 seconds); rest (30 seconds)]. The changes in neural activity in sensorimotor cortex could be inferred according to the principle of neurovascular coupling, and the number of activated channels in the bilateral hemisphere was used to calculate the lateralization index. RESULT: 1. For hemodynamic response induced by Hegu acupoint Tui Na, a dominant increase in the contralesional primary sensorimotor cortex during Hegu point Tui Na of the less affected arm in stroke patients was observed, as well as that in healthy controls, while this contralateral pattern was absent during Hegu point Tui Na of the affected arm in stroke patients. 2. Concerning the lateralization index in stroke patients, a significant difference was observed between lateralization index values for the affected arm and the less affected arm (P < 0.05). Wilcoxon tests showed a significant difference between lateralization index values for the affected arm in stroke patients and lateralization index values for the dominant upper limb in healthy controls (P < 0.05), and no significant difference between lateralization index values for the less affected arm in stroke patients and that in healthy controls (P = 0.36). CONCLUSION: The combination of Tui Na and fNIRS has the potential to reflect the functional status of sensorimotor neural circuits. The changes of neuroactivity in the sensorimotor cortex when Tui Na Hegu acupoint indicate that there is a certain correlation between acupoints in traditional Chinese medicine and neural circuits.
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Terapia por Acupuntura , Massagem , Medicina Tradicional Chinesa , Transtornos Motores , Córtex Sensório-Motor , Acidente Vascular Cerebral , Humanos , Pontos de Acupuntura , População do Leste Asiático , Córtex Sensório-Motor/diagnóstico por imagem , Córtex Sensório-Motor/fisiopatologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/terapia , Terapia por Acupuntura/métodos , Medicina Tradicional Chinesa/métodos , Extremidade Superior/inervação , Extremidade Superior/fisiopatologia , Transtornos Motores/etiologia , Transtornos Motores/fisiopatologia , Transtornos Motores/reabilitação , Reabilitação do Acidente Vascular Cerebral/métodos , Meridianos , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
BACKGROUND: The study aimed to find predictive biomarkers to evaluate donor kidney function to predict graft dysfunction as well as to assess an early signs of acute graft rejection. METHOD: Twenty-seven deceased donors and 54 recipients who underwent a successful kidney transplantation were enrolled in the study. An assessment was made in serum and urine from donors and recipients to measure the following biomarkers: neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), tissue inhibitor of metalloproteinase 2 (TIMP-2) and urinary N-acetyl-b-D-glucosaminidase (uNAG). These biomarkers were used to establish a model for predicting a reduced graft function (RGF) classified as either a delayed or slow graft function. RESULT: Our analysis suggest that out of four tested biomarkers, the serum TIMP-2 and uNAG levels of the donors had a predictive value for RGF; the area under the receiver operating characteristic curves (AUROC) of serum TIMP-2 and uNAG were 0.714 and 0.779, respectively. The combined best fitting prediction model of serum TIMP-2, uNAG, and creatinine levels was better in predicting RGF than the serum creatinine level alone. In addition, the recipient serum TIMP-2 level on the third day post-transplantation (D3) was associated with the estimated glomerular filtration rate (eGFR) on the seventh day post-transplantation (D7; OR 1.119, 95% CI 1.016-1.233, p = 0.022). Furthermore, the ROC curve value revealed that the AUROC of TIMP-2 on D3 was 0.99 (95% CI 0.97-1, p < 0.001), and this was the best predictive value of the renal function on D7. CONCLUSIONS: Donor serum TIMP-2 and uNAG levels are useful predictive biomarkers because they can provide the donor-based prediction for RGF.
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Injúria Renal Aguda , Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , Inibidor Tecidual de Metaloproteinase-2 , Lipocalinas , Proteínas Proto-Oncogênicas , Proteínas de Fase Aguda , Função Retardada do Enxerto/diagnóstico , Estudos Prospectivos , Rim , Biomarcadores , Rejeição de Enxerto/diagnósticoRESUMO
Characterized by high morbidity, mortality, and disability, stroke usually causes symptoms of cerebral hypoxia due to a sudden blockage or rupture of brain vessels, and it seriously threatens human life and health. Rehabilitation is the essential treatment for post-stroke patients suffering from functional impairments, through which hemiparesis, aphasia, dysphagia, unilateral neglect, depression, and cognitive dysfunction can be restored to various degrees. Noninvasive brain stimulation (NIBS) is a popular neuromodulatory technology of rehabilitation focusing on the local cerebral cortex, which can improve clinical functions by regulating the excitability of corresponding neurons. Increasing evidence has been obtained from the clinical application of NIBS, especially repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). However, without a standardized protocol, existing studies on NIBS show a wide variation in terms of stimulation site, frequency, intensity, dosage, and other parameters. Its application for neurorehabilitation in post-stroke patients is still limited. With advances in neuronavigation technologies, functional near-infrared spectroscopy, and functional MRI, specific brain regions can be precisely located for stimulation. On the basis of our further understanding on neural circuits, neuromodulation in post-stroke rehabilitation has also evolved from single-target stimulation to co-stimulation of two or more targets, even circuits and the network. The present study aims to review the findings of current research, discuss future directions of NIBS application, and finally promote the use of NIBS in post-stroke rehabilitation.
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Multi-target neural circuit-magnetic stimulation has been clinically shown to improve rehabilitation of lower limb motor function after spinal cord injury. However, the precise underlying mechanism remains unclear. In this study, we performed double-target neural circuit-magnetic stimulation on the left motor cortex and bilateral L5 nerve root for 3 successive weeks in a rat model of incomplete spinal cord injury caused by compression at T10. Results showed that in the injured spinal cord, the expression of the astrocyte marker glial fibrillary acidic protein and inflammatory factors interleukin 1ß, interleukin-6, and tumor necrosis factor-α had decreased, whereas that of neuronal survival marker microtubule-associated protein 2 and synaptic plasticity markers postsynaptic densification protein 95 and synaptophysin protein had increased. Additionally, neural signaling of the descending corticospinal tract was markedly improved and rat locomotor function recovered significantly. These findings suggest that double-target neural circuit-magnetic stimulation improves rat motor function by attenuating astrocyte activation, thus providing a theoretical basis for application of double-target neural circuit-magnetic stimulation in the clinical treatment of spinal cord injury.
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Conditional gene editing animals and viral vectors have been widely applied in the research fields of biology and medicine. Recently, they are also used as the effective approaches to reveal the underlying mechanism of acupuncture from the nervous system to the specific molecules. In order to further understand the application of conditional gene editing animals and viral vectors, in this article, we analyze their characteristics, advantages and recent development in the field of acupuncture research and discuss their potential roles and prospect in the future.
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Terapia por Acupuntura , Acupuntura , Animais , Edição de Genes/métodos , Vetores Genéticos/genéticaRESUMO
Modified constraint-induced movement therapy (mCIMT) has shown beneficial effects on motor function improvement after brain injury, but the exact mechanism remains unclear. In this study, amplitude of low frequency fluctuation (ALFF) metrics measured by resting-state functional magnetic resonance imaging was obtained to investigate the efficacy and mechanism of mCIMT in a control cortical impact (CCI) rat model simulating traumatic brain injury. At 3 days after control cortical impact model establishment, we found that the mean ALFF (mALFF) signals were decreased in the left motor cortex, somatosensory cortex, insula cortex and the right motor cortex, and were increased in the right corpus callosum. After 3 weeks of an 8-hour daily mCIMT treatment, the mALFF values were significantly increased in the bilateral hemispheres compared with those at 3 days postoperatively. The mALFF signal values of left corpus callosum, left somatosensory cortex, right medial prefrontal cortex, right motor cortex, left postero dorsal hippocampus, left motor cortex, right corpus callosum, and right somatosensory cortex were increased in the mCIMT group compared with the control cortical impact group. Finally, we identified brain regions with significantly decreased mALFF values at 3 days postoperatively. Pearson correlation coefficients with the right forelimb sliding score indicated that the improvement in motor function of the affected upper limb was associated with an increase in mALFF values in these brain regions. Our findings suggest that functional cortical plasticity changes after brain injury, and that mCIMT is an effective method to improve affected upper limb motor function by promoting bilateral hemispheric cortical remodeling. mALFF values correlate with behavioral changes and can potentially be used as biomarkers to assess dynamic cortical plasticity after traumatic brain injury.
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We report on the first controlled alternation between memory and threshold resistance switching (RS) in single Ni/NiO core-shell nanowires by setting the compliance current (I(CC)) at room temperature. The memory RS is triggered by a high I(CC), while the threshold RS appears by setting a low I(CC), and the Reset process is achieved without setting a I(CC). In combination with first-principles calculations, the physical mechanisms for the memory and threshold RS are fully discussed and attributed to the formation of an oxygen vacancy (Vo) chain conductive filament and the electrical field induced breakdown without forming a conductive filament, respectively. Migration of oxygen vacancies can be activated by appropriate Joule heating, and it is energetically favorable to form conductive chains rather than random distributions due to the Vo-Vo interaction, which results in the nonvolatile switching from the off- to the on-state. For the Reset process, large Joule heating reorders the oxygen vacancies by breaking the Vo-Vo interactions and thus rupturing the conductive filaments, which are responsible for the switching from on- to off-states. This deeper understanding of the driving mechanisms responsible for the threshold and memory RS provides guidelines for the scaling, reliability, and reproducibility of NiO-based nonvolatile memory devices.
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Dispositivos de Armazenamento em Computador , Armazenamento e Recuperação da Informação/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Nanotecnologia/instrumentação , Níquel/química , Impedância Elétrica , Desenho de Equipamento , Análise de Falha de EquipamentoRESUMO
The geological conditions of the Bortala River basin are complex, and the transformation of surface water and groundwater is frequent. It is great significance to study the hydrochemical characteristics and transformation relationship of surface water and groundwater for the reasonable development and allocation of water resources in the basin. Based on 15 surface water samples and 39 groundwater samples collected in April and May 2021, the APCS/MLR model and the combination of stable hydrogen and oxygen isotopes with hydrochemistry were used in this study to analyze the hydrochemical types and the distribution characteristics of hydrogen and oxygen isotopes, the source contribution of chemical components, and the transformation relationship between surface water and groundwater. The results showed that the surface water was mainly HCO3·SO4-Ca type and HCO3-Ca type, and the groundwater was mainly HCO3·SO4-Ca·Na type, HCO3-Ca type, and HCO3·SO4-Ca type. The contribution rates of the dissolution-migration-enrichment factor, human activities factor, environment factor, and native geological factor to the chemical components were 28.8%, 17.7%, 12.0%, and 6.5%, respectively. Bortala River water D and 18O was enriched along the distance, and groundwater D and 18O in the north bank was generally more enriched than groundwater in the south bank as a whole. Under the control of geological conditions such as geological structure and hydrogeological conditions, the transformation of river water and groundwater was concentrated in the middle reaches of the Bortala River, which was generally manifested in both unconfined groundwater and spring overflow in the sides of the recharge river water, and the recharge proportion ranged from 1.0% to 70.9%.
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Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Água Subterrânea/química , Humanos , Hidrogênio , Isótopos de Oxigênio , Rios/química , Água , Poluentes Químicos da Água/análiseRESUMO
Following a spinal cord injury, there are usually a number of neural pathways that remain intact in the spinal cord. These residual nerve fibers are important, as they could be used to reconstruct the neural circuits that enable motor function. Our group previously designed a novel magnetic stimulation protocol, targeting the motor cortex and the spinal nerve roots, that led to significant improvements in locomotor function in patients with a chronic incomplete spinal cord injury. Here, we investigated how nerve root magnetic stimulation contributes to improved locomotor function using a rat model of spinal cord injury. Rats underwent surgery to clamp the spinal cord at T10; three days later, the rats were treated with repetitive magnetic stimulation (5 Hz, 25 pulses/train, 20 pulse trains) targeting the nerve roots at the L5-L6 vertebrae. The treatment was repeated five times a week over a period of three weeks. We found that the nerve root magnetic stimulation improved the locomotor function and enhanced nerve conduction in the injured spinal cord. In addition, the nerve root magnetic stimulation promoted the recovery of synaptic ultrastructure in the sensorimotor cortex. Overall, the results suggest that nerve root magnetic stimulation may be an effective, noninvasive method for mobilizing the residual spinal cord pathways to promote the recovery of locomotor function.
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Classic paired associative stimulation can improve synaptic plasticity, as demonstrated by animal experiments and human clinical trials in spinal cord injury patients. Paired associative magnetic stimulation (dual-target peripheral and central magnetic stimulation) has been shown to promote neurologic recovery after stroke. However, it remains unclear whether paired associative magnetic stimulation can promote recovery of lower limb motor dysfunction after spinal cord injury. We hypothesize that the current caused by central and peripheral magnetic stimulation will converge at the synapse, which will promote synapse function and improve the motor function of the relevant muscles. Therefore, this study aimed to examine the effects of paired associative magnetic stimulation on neural circuit activation by measuring changes in motor evoked and somatosensory evoked potentials, motor and sensory function of the lower limbs, functional health and activities of daily living, and depression in patients with spinal cord injury. We will recruit 110 thoracic spinal trauma patients treated in the Department of Spinal Cord Injury, China Rehabilitation Hospital and randomly assign them to experimental and control groups in a 1:1 ratio. The trial group (n = 55) will be treated with paired associative magnetic stimulation and conventional rehabilitation treatment. The control group (n = 55) will be treated with sham stimulation and conventional rehabilitation treatment. Outcomes will be measured at four time points: baseline and 4, 12, and 24 weeks after the start of intervention (active or sham paired associative magnetic stimulation). The primary outcome measure of this trial is change in lower limb American Spinal Injury Association Impairment Scale motor function score from baseline to last follow-up. Secondary outcome measures include changes in lower limb American Spinal Injury Association sensory function score, motor evoked potentials, sensory evoked potentials, modified Ashworth scale score, Maslach Burnout Inventory score, and Hamilton Depression Scale score over time. Motor evoked potential latency reflects corticospinal tract transmission time, while amplitude reflects recruitment ability; both measures can help elucidate the mechanism underlying the effect of paired associative magnetic stimulation on synaptic efficiency. Adverse events will be recorded. Findings from this trial will help to indicate whether paired associative magnetic stimulation (1) promotes recovery of lower limb sensory and motor function, reduces spasticity, and improves quality of life; (2) promotes neurologic recovery by increasing excitability of spinal cord motor neurons and stimulating synaptic plasticity; and (3) improves rehabilitation outcome in patients with spinal cord injury. Recruitment for this trial began in April 2021 and is currently ongoing. It was approved by the Ethics Committee of Yangzhi Affiliated Rehabilitation Hospital of Tongji University, China (approval No. YZ2020-018) on May 18, 2020. The study protocol was registered in the Chinese Clinical Trial Registry (registration number: ChiCTR2100044794) on March 27, 2021 (protocol version 1.0). This trial will be completed in April 2022.