Bo Song

Southwest University in Chongqing, Pehpei, Chongqing Shi, China

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Publications (56)101.41 Total impact

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    ABSTRACT: Profuse extension twinning was activated in compression of a rolled Mg alloy along the transverse direction. The variant selection in twin pairs, twin chains and multiple twins inside one grain was studied by geometric compatibility factor (m′) and Schmid factor (SF). The results show that most connected twins have both high SF and high m′. In some cases (∼23%), m′ rank is more important than SF rank for variant selection in the connected twins. Due to the importance of local strain compatibility, synergetic nucleation of twins, twin transfer across neighboring grains and coexistence of ortho-position variants inside one grain are prevalent in the compressed sample. Such characteristics of variant selection affect microstructural evolution and plasticity of materials and should be considered into the development of physics-based simulation models for Mg alloys.
    Materials and Design 07/2015; 76. DOI:10.1016/j.matdes.2015.03.041 · 3.17 Impact Factor
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    ABSTRACT: The influence of torsion deformation on textures of cold drawing pearlitic steel wires was investigated by twisting the wires to different number of revolutions. Macro-texture (over the entire wire cross section) associated with torsion deformation was investigated by X-ray diffraction, while micro-texture (near the wire surface) was characterized by EBSD. The results show that the \( \left\langle { 1 10} \right\rangle \) macro-texture increases at the beginning of torsion and then decreases with increasing of torsion strain, while the \( \left\langle { 1 10} \right\rangle \) micro-texture decreases linearly with increasing of torsion strain. The relationships between the \( \left\langle { 1 10} \right\rangle \) fiber texture and the microhardness of the wires are also discussed.
    Acta Metallurgica Sinica (English Letters) 06/2015; 28(6). DOI:10.1007/s40195-015-0251-7 · 0.43 Impact Factor
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    ABSTRACT: We used a combined approach of whole-exome sequencing and candidate mutation validation to identify the disease-causing gene in a hereditary spastic paraplegia (HSP) patient with lower motor neuron involvement, mild cerebellar signs and dysgenesis of the corpus callosum. HSP is a clinically and genetically heterogeneous neurodegenerative disorder characterized by degeneration of the corticospinal tract motor neurons and resulting in progressive lower limb spasticity, often with a complicated phenotype. We identified novel compound heterozygous mutations in the SPG11 gene in this patient as follows: a mutation in exon 32, c.6194C>G transition (p.S2056X) and a novel c.5121+1C>T splicing mutation. Our finding suggests that these novel compound heterozygous mutations in SPG11 are associated with HSP and lower motor neuron involvement, mild cerebellar signs and dysgenesis of the corpus callosum. This study also demonstrates that exome sequencing is an efficient and rapid diagnostic tool for identifying the causes of some complex and genetically heterogeneous neurodegenerative diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Journal of Clinical Neuroscience 05/2015; DOI:10.1016/j.jocn.2015.01.014 · 1.32 Impact Factor
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    ABSTRACT: Stem cell to be a new intervention for treating intracerebral hemorrhage (ICH) might benefit humans. Therefore, we collected animal studies to find the effect of this innovative treatment. In July 2014, we searched Medline (from 1950), Embase (from 1980), China Biology Medicine disk (from 1978) for studies on stem cells used for treating experimental ICH in animal models that reported neurobehavioral and structural outcome. We evaluated the quality of these studies and used a weighted mean difference random affects model for the meta-analysis. We have collected 30 studies from 650 publications identified through systematic review describing the effects of 5 different type of stem cells on 12 different neurobehavioral scales with 1101 rodents or monkeys. Although there is lack of uniformity of the evaluation methods, these researches showed consistent improvements both in neurobehavioral function and structural outcomes. Besides, the quality of these studies needs to be raised. In conclusion, stem cells hold extensive potential in treating ICH, which should be further evaluated with more evidence-based, high-quality animal studies.
    Neurological Sciences 05/2015; DOI:10.1007/s10072-015-2238-6 · 1.50 Impact Factor
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    ABSTRACT: Background The association between atherogenic dyslipidemia and stroke recurrence remains unclear, and may be influenced by different subtypes of ischemic stroke.AimsWe aimed to investigate whether atherogenic dyslipidemia contributed to stroke recurrence in ischemic stroke patients and in those with certain subtypes of ischemic stroke.Methods We conducted a prospective hospital-based study enrolling patients with acute ischemic stroke. Atherogenic dyslipidemia was defined as high-density lipoprotein cholesterol <40 mg/dl and triglycerides ≥200 mg/dl. Ischemic stroke subtypes were classified according to the Trial of Org 10172 in Acute Stroke Treatment criteria. The patients were followed up at 3, 6, 12 and 24 months after stroke onset. The association between atherogenic dyslipidemia and stroke recurrence was analyzed by using multivariable Cox regression model.ResultsIn the 510 ischemic stroke patients, 64 patients (12·5%) had atherogenic dyslipidemia, and 66 patients (12·9%) experienced stroke recurrence events within 24 months. Kaplan–Meier analysis revealed that stroke recurrence rate was significantly higher in patients with atherogenic dyslipidemia than those without in all the stroke patients (20·3% vs. 11·9%; P = 0·048), and more evident in those of large-artery atherosclerosis subtype (31·0% vs. 14·1%; P = 0·014), but not in the other subtypes. Multivariable Cox regression analysis revealed that atherogenic dyslipidemia was associated with higher stroke recurrence risk among stroke patients of large-artery atherosclerosis subtype (hazard ratio, 2·79; 95% confidence interval, 1·24–6·28), but not significant in all the stroke patients (hazard ratio, 1·69; 95% confidence interval, 0·85–3·37).Conclusions Atherogenic dyslipidemia is associated with higher risk of stroke recurrence in ischemic stroke patients. Such association might be more pronounced in large-artery atherosclerosis subtype and needs further investigation to establish such relationship.
    International Journal of Stroke 05/2015; DOI:10.1111/ijs.12471 · 4.03 Impact Factor
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    ABSTRACT: Reducing serious tension-compression yield asymmetry is one important concern for wrought Mg alloys. This study aims to exploit the influence of aging time on tensile and compressive deformation behaviors in rolled ZK60 alloy sheets. The experimental results show that the type and amount of precipitates are greatly dependent on aging time at 175 °C. A number of disc-like β′2 precipitates are present after aged for 10 h. However, rod-like β′1precipitates are observed after 30 h and the amount of disc-like precipitates reduces. The tension-compression yield asymmetry of the as-solution ZK60 specimens is very serious. It is significantly improved with the formation of disc-like precipitates, while becomes worse with the presence of rod-like precipitates and the reduction of disc-like precipitates. This should be attributed to the disc-like and rod-like precipitates have different hardening effects on the main deformation modes of tension and compression deformations in the present ZK60 alloys.
    Materials Science and Engineering A 05/2015; 639. DOI:10.1016/j.msea.2015.05.088 · 2.41 Impact Factor
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    ABSTRACT: Progressive pseudorheumatoid dysplasia (PPD) is an extremely rare autosomal recessive genetic disease caused by mutation of the Wnt1-inducible signaling pathway protein 3 (WISP3) gene. Here, we characterize the clinical manifestations and features of PPD and screen for WISP3 mutations. We performed genetic testing for PPD in a Chinese family, after investigating the clinical particulars and family history, in addition to 200 healthy individuals, who served as the controls for this study. All 5 exons and the exon-intron boundaries of the WISP3 gene were amplified by polymerase chain reaction (PCR) and sequenced directly. We identified a missense mutation (c.667T>G, p.C223G) in the maternal allele and a nonsense mutation (c.756C>A, p.C252X) in the paternal allele in the two affected individuals. To our knowledge, the mutation c.756C>A has not been reported previously. In these patients, there was a specific period when their condition markedly improved after having been very serious. Moreover, severe compression of lumbar spinal cord led to conspicuous spinal disorders in the proband. Our study suggests that novel C223G and C252X mutations in exon 4 of the WISP3 gene are responsible for PPD in Chinese patients. Furthermore, we report certain unique phenotypic characteristics in our patients. Copyright © 2015. Published by Elsevier B.V.
    Gene 03/2015; 564(1). DOI:10.1016/j.gene.2015.03.029 · 2.08 Impact Factor
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    ABSTRACT: It is commonly accepted that weakening or tilting basal texture is an effective way to improve stretch formability of Mg alloy sheets. In this study, contraction twins (including double twins) were introduced in rolled AZ31 sheet by pre-cold rolling to a thickness reduction of 10%. It was noted that the stretch formability of rolled AZ31 sheet can be greatly enhanced by pre-cold rolling and subsequent recrystallization annealing. The Erichsen value of rolled AZ31 sheet was increased up to 66% by pre-cold rolling and annealing at 400 °C. The improvement in stretch formability was mainly attributed to the formation and growth of recrystallization grains with weak texture nucleated at contraction twins during annealing.
    Materials Science and Engineering A 03/2015; 627:369-373. DOI:10.1016/j.msea.2015.01.027 · 2.41 Impact Factor
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    ABSTRACT: Cerebral hemorrhage (ICH) is a serious stroke subtype, currently lacking effective treatment. Recent research has shown that CD4(+)CD25(+)FOXP3(+) regulatory T cells (Tregs) play a key role in the immune response of ischemic stroke. However, Tregs in human hemorrhagic stroke are poorly investigated. In this study, a total of 90 ICH patients and 60 healthy controls were recruited. The frequency of circulating Tregs, plasma levels of TGF-β and IL-10, and the severity of neural dysfunction in ICH patients were investigated at different time points post ICH. We found that the peripheral frequency of Tregs in ICH patients was significantly increased, accompanied by boosted activated T cells. Importantly, the elevation of circulating Tregs in patients with severe dysfunction was much higher than that in less-severe patients, suggesting that disease severity affects circulating Tregs to exert regulatory function. Furthermore, both TGF-β and IL-10 that are related to the function of Tregs, were also increased in the peripheral blood of ICH patients. Our results demonstrate that Tregs-mediated immune imbalance might affect the development and severity of ICH, and suggest that Tregs may be used as tools and targets of cellular immunotherapy to effectively treat acute hemorrhagic stroke. Copyright © 2015. Published by Elsevier Ireland Ltd.
    Neuroscience Letters 02/2015; 591. DOI:10.1016/j.neulet.2015.02.042 · 2.06 Impact Factor
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    ABSTRACT: Background: Spinocerebellar ataxia type 3 (SCA3) is the most common subtype of SCA worldwide, and runs a slowly progressive and unremitting disease course. There is currently no curable treatment available. Growing evidence has suggested that nerve growth factor (NGF) may have therapeutic effects in neurodegenerative diseases, and possibly also in SCA3. The objective of this study was to test the efficacy of NGF in SCA3 patients. Methods: We performed an open-label prospective study in genetically confirmed adult (>18 years old) SCA3 patients. NGF was administered by intramuscular injection (18 μg once daily) for 28 days consecutively. All the patients were evaluated at baseline and 2 and 4 weeks after treatment using the Chinese version of the scale for assessment and rating of ataxia (SARA). Results: Twenty-one SCA3 patients (10 men and 11 women, mean age 39.14 ± 7.81 years, mean disease duration 4.14 ± 1.90 years, mean CAG repeats number 77.57 ± 2.27) were enrolled. After 28 days of NGF treatment, the mean total SARA score decreased significantly from a baseline of 8.48 ± 2.40 to 6.30 ± 1.87 (P < 0.001). Subsections SARA scores also showed significant improvements in stance (P = 0.003), speech (P = 0.023), finger chase (P = 0.015), fast alternating hand movements (P = 0.009), and heel-shin slide (P = 0.001). Conclusions: Our preliminary data suggest that NGF may be effective in treating patients with SCA3.
    Chinese medical journal 02/2015; 128(3):291-294. DOI:10.4103/0366-6999.150087 · 1.02 Impact Factor
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    ABSTRACT: Calcium intake has been associated with stroke risk in a prior meta-analysis, however, newly published results are inconsistent. Dairy food benefits on stroke incidence may involve a calciumrelated mechanism. We have therefore updated this meta-analysis with particular references to any possibility of a calcium-mediated dairy food risk reduction of stroke risk. We searched multiple databases and bibliographies for prospective cohort studies. Reports with multivariate-adjusted relative risk (RR) and corresponding 95% confidence intervals (CI) for the association of calcium intake with stroke incidence were considered. Ten studies with 371,495 participants and 10,408 stroke events were analyzed. The pooled analysis showed no statistically significant association of the risk of total stroke (RR=0.96; 95% CI: 0.89-1.04) and stroke subtypes with the highest and lowest calcium intake quantiles. Nevertheless, high dairy calcium intake was significantly associated with an approximately 24% reduction of stroke risk. (RR=0.76; 95% CI: 0.66-0.86). Furthermore, a long-term follow-up (>=14 years) was helpful to reduce the risk of stroke (RR=0.67; 95% CI: 0.51-0.88). Additionally, a non-linear dose-response relationship was predicted between calcium intake and stroke risk. Dairy calcium intake is inversely associated with stroke incidence. There is a non-linear dose-response relationship between calcium intake and stroke risk. However, when the follow-up time is long enough, the inverse relationship is independent of dose. Additional large cohort studies are required to illustrate this relationship in detail.
    Asia Pacific Journal of Clinical Nutrition 01/2015; 24(2):245-52. · 1.36 Impact Factor
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    ABSTRACT: Little is known about the effects of induced pluripotent stem cell (iPSC) treatment on acute cerebral inflammation and injuries after intracerebral hemorrhage (ICH), though they have shown promising therapeutic potentials in ischemic stoke. An ICH model was established by stereotactic injection of collagenase VII into the left striatum of male Sprague-Dawley (SD) rats. Six hours later, ICH rats were randomly divided into two groups and received intracerebrally 10 μl of PBS with or without 1×106 of iPSCs. Subsequently, neural function of all ICH rats was assessed at days 1, 3, 7, 14, 28 and 42 after ICH. Inflammatory cells, cytokines and neural apoptosis in the rats' perihematomal regions, and brain water content were determined on day 2 or 3 post ICH. iPSC differentiation was determined on day 28 post ICH. Nissl+ cells and glial fibrillary acidic protein (GFAP)+ cells in the perihematoma and the survival rates of rats in two groups were determined on post-ICH day 42. Compared with control animals, iPSCs treatment not only improved neurological function and survival rate, but also resulted in fewer intracephalic infiltrations of neutrophils and microglia, along with decreased interleukin (IL)-1β, IL-6 and tumour necrosis factor-alpha (TNF-α), and increased IL-10 in the perihematomal tissues of ICH rats. Furthermore, brain oedema formation, apoptosis, injured neurons and glial scar formation were decreased in iPSCs-transplanted rats. Our findings indicate that iPSCs transplantation attenuate cerebral inflammatory reactions and neural injuries after ICH, and suggests that multiple mechanisms including inflammation modulation, neuroprotection and functional recovery might be involved simultaneously in the therapeutic benefit of iPSC treatment against hemorrhagic stroke.
    PLoS ONE 01/2015; 10(6):e0129881. DOI:10.1371/journal.pone.0129881 · 3.53 Impact Factor
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    ABSTRACT: Background Whether patients presenting with mild stroke should or should not be treated with intravenous rtPA is still controversial. This systematic review aims to assess the safety and outcome of thrombolysis in these patients. Material/Methods We systematically searched PubMed and Cochrane Central Register of Controlled Trials for studies evaluating intravenous rtPA in patients with mild or rapidly improving symptoms except case reports. Excellent outcome (author reported, mainly mRS 0-1), symptomatic intracranial hemorrhage (sICH) and mortality were analyzed. Results Fourteen studies were included (n=1906 patients). Of these, 4 studies were comparative (2 randomized and 2 non-randomized). The remaining were single-arm studies. On the basis of 4 comparative studies with a total of 1006 patients, the meta-analysis did not identify a significant difference in the odds of excellent outcome (OR=0.86; 95% CI: 0.64–1.15; I2=0) between IV rtPA-treated minor stroke and those without rtPA treatment. Eleven studies involving 1083 patients showed the pooled rate of excellent outcome was 76.1% (95% CI: 69.8–81.5%, I2=42.5). Seven studies involving 378 patients showed the mortality rate was 4.5% (95% CI: 2.6–7.5%, I2=1.4). Twelve studies involving 831 patients showed the pooled rate of sICH was 2.4% (95% CI: 1.5–3.8, I2=0). Conclusions Although efficacy is not clearly established, this study reveals the adverse event rates related to thrombolysis are low in mild stroke. Intravenous rtPA should be considered in these patients until more RCT evidence is available.
    Medical science monitor: international medical journal of experimental and clinical research 11/2014; 20:2117-2124. DOI:10.12659/MSM.892259 · 1.22 Impact Factor
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    ABSTRACT: For basal textured Mg alloy plates, {10-12} twins can be easily generated by pre-compression perpendicular to the c-axis of grains. Thus, it should be practical to strengthen Mg alloy plates by introducing twin boundaries. In this study, we show that control of the a-axis distribution is also important for enhancing the strengthening effect by pre-inducing {10-12} twins. Pre-tension along rolling direction (RD) is applied on a rolled AZ31 Mg alloy plate, and then the sample is compressed along transverse direction (TD) to generate {10-12} twins. The experimental results show that pre-tension causes 〈10-10〉 orientations concentrating toward RD, which promotes the activation of multiple twin variants in each grain for subsequent compression along TD. As a consequence, twin nucleation rather than twin growth is favored, and the number of twin lamellae per grain is increased, which enhances the refinement hardening effect during compression of the twinned sample along RD. The underline mechanism is analyzed, which can also provide some insights into understanding deformation mechanism of Mg alloys.
    Materials Science and Engineering A 10/2014; 621. DOI:10.1016/j.msea.2014.10.061 · 2.41 Impact Factor
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    ABSTRACT: Background and Purpose The A2DS2 score was recently developed from the Berlin Stroke Registry for predicting in-hospital pneumonia after acute ischemic stroke and performed well in an external validation in the North-west Germany Stroke Registry. It could be a useful tool for risk stratification in clinical practice or stroke trials. We aimed to prospectively validate the predictive value of A2DS2 score in a Chinese stroke population. Methods The prognostic model was used to predict stroke-associated pneumonia (SAP) from Henan Province Stroke Registry (HNSR) in which data were prospectively collected. The receiver-operating characteristic curves were plotted, and the C statistics were calculated to assess the discrimination ability. The Hosmer–Lemeshow goodness-of-fit test and the plot of observed versus predicted SAP risk were used to assess model calibration. Results Among 1142 eligible patients, the overall in-hospital SAP was 18.8%, which ranged from 9.0% in patients with lower A2DS2 scores (0–4) to 65.0% in those with higher scores of 5 to 10 (P for trend <0.001). The C statistic was 0.836 (95% confidence interval, 0.803–0.868) through the A2DS2 score, suggesting excellent discrimination in the HNSR. The A2DS2 score also showed excellent calibration (Cox and Snell R2 = 0.243) in the external validation sample from the HNSR. Conclusions The A2DS2 score could reliably predict in-hospital SAP in Chinese stroke patients. It might be helpful for the assessment of increased risk monitoring and prophylactic treatment in identified high-risk patients for SAP in clinical routine.
    PLoS ONE 10/2014; 9(10):e109665. DOI:10.1371/journal.pone.0109665 · 3.53 Impact Factor
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    ABSTRACT: Twinning can generate the change of texture and a large of twin boundaries, which can greatly influence the mechanical properties of magnesium alloys. Thus, pre-twinning can be considered to be a simple and feasible method to improve the mechanical properties of magnesium alloys. Recently, some studies have confirmed that pre-twinning can be an effective way to enhance the strength, formability and mechanical anisotropy of magnesium alloys. Based on these results, some aspects of the present research on the improvement of mechanical properties via pre-twinning are reviewed. The relevant mechanisms have been summarized. Finally, for this research field, a few critical scientific problems are also proposed.
    Materials and Design 10/2014; 62:352–360. DOI:10.1016/j.matdes.2014.05.034 · 3.17 Impact Factor
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    ABSTRACT: AZ31 Mg alloy sheets were processed by the conventional symmetrical extrusion (CSE) and the asymmetric extrusion (ASE). Progressive-asymmetric extrusion (PASE) and severe strain-asymmetric extrusion (SASE) were employed for ASE processes. The texture at near-surface and mid-layer zones of ASE sheets was diverse penetrating the normal direction (ND). This was attributed to an additional asymmetric shear strain deformation during the ASE process. (0002) basal planes of PASE sheets tilt to the shear deformation direction. Meanwhile, the basal texture intensity of PASE sheets has been weakened compared with one in CSE sheets. Grain refinement and tilted weak basal texture obtained by SASE process dramatically enhances the room temperature strength and plasticity of the extruded AZ31 magnesium alloy sheets. The microstructure and mechanical responses were examined and discussed.
    09/2014; 2(3):220-224. DOI:10.1016/j.jma.2014.10.001
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    ABSTRACT: {10−12} Twinning is one of the most important strain accommodation mechanisms for Mg alloy especially at room temperature deformation. Accompanying with twining, the lattice of matrix is rotated by large angles, and hence pre-twinning can be utilized to tailor texture of wrought Mg alloy. To better utilize this method, the present study aims to understand the twinning characteristic and variant selection in compression of a pre-side-rolled Mg alloy sheet. It confirms that the pre-generated twin lamellae can significantly enhance the yield strength for subsequent in-plane compression. But the amount of pre-side-rolling has different effect on the strain hardening rate between the two subsequent compression directions (transverse direction and rolling direction, designated as TD and RD, respectively). Moreover, the {10−12} twins in the two samples exhibit different morphology although the area fraction is nearly the same. Crystallographic analysis indicates that the variant selection in most twinned grains is consistent with Schmid law i.e., the twins are activated from the variant pair with the highest Schmid factor. In the cases of twin–twin transfer at grain boundaries, local strain accommodation is also important for variant selection. It reveals that a modified Schmid factor for rolling is effective in prediction of twin variants in pre-side-rolling. Further analysis on ideal texture indicates that the preference order of the six possible variants in side-rolling is the same with that in the subsequent TD compression, but varies from that in RD compression. This is consistent with the experimental observation that twin growth and coalescence is dominant in the former, whereas new twin variant is formed in the latter.
    Materials Science and Engineering A 09/2014; 614:106–115. DOI:10.1016/j.msea.2014.07.026 · 2.41 Impact Factor
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    ABSTRACT: Objective. To study risk factors related to ischemic stroke (IS) in youth and the influence of sleep quality on youth ischemic stroke incidence. Methods. 223 patients aged 18 to 45 years who were admitted to Puyang People's Hospital from June 2011 to February 2013 with a first-ever ischemic stroke were selected as the research cases. 158 young people with a normal physical examination were selected as the control group. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to analyse the correlation between sleep quality and youth IS incidence. The US National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (MRS) scores were used to assess cases' state of illness and prognosis three months after IS. Results. Univariate and multivariate logistic regression analysis showed that the association of these risk factors with youth IS incidence, from highest to lowest, was hypertension, hyperlipidaemia, smoking history, high homocysteine, the quality of sleep, family history of stroke, and alcoholism. Poor sleep quality ranked fifth among all risk factors and was positively correlated with poor prognosis for youth IS patients. Conclusion. The results of this study showed that sleep quality is an important factor in the pathogenesis and prognosis of youth IS.
    Behavioural neurology 08/2014; 2014:246841. DOI:10.1155/2014/246841 · 1.64 Impact Factor

Publication Stats

218 Citations
101.41 Total Impact Points

Institutions

  • 2014–2015
    • Southwest University in Chongqing
      Pehpei, Chongqing Shi, China
  • 2012–2015
    • Zhengzhou University
      Cheng, Henan Sheng, China
  • 2011–2014
    • Chongqing University
      • • School of Material Science and Engineering
      • • National Engineering Research Center for Magnesium Alloys
      Ch’ung-ch’ing-shih, Chongqing Shi, China