Effects of Alternating Magnetic Fields on the OER of Heterogeneous Core-Shell Structured NiFe2O4@(Ni, Fe)S/P.

Composition optimization, structural design, and introduction of external magnetic fields into the catalytic process can remarkably improve the oxygen evolution reaction (OER) performance of a catalyst. NiFe2O4@(Ni, Fe)S/P materials with a heterogeneous core-shell structure were prepared by the sulfide/phosphorus method based on spinel-structured NiFe2O4 nanomicrospheres. After the sulfide/phosphorus treatment, not only the intrinsic activity of the material and the active surface area were increased but also the charge transfer resistance was reduced due to the internal electric field. The overpotential of NiFe2O4@(Ni, Fe)P at 10 mA cm-2 (iR correction), Tafel slope, and charge transfer resistance were 261 mV, 42 mV dec-1, and 3.163 Ω, respectively. With an alternating magnetic field, the overpotential of NiFe2O4@(Ni, Fe)P at 10 mA cm-2 (without iR correction) declined by 45.5% from 323 mV (0 mT) to 176 mV (4.320 mT). Such enhancement of performance is primarily accounted for the enrichment of the reactive ion OH- on the electrode surface induced by the inductive electric potential derived from the Faraday induction effect of the AMF. This condition increased the electrode potential and thus the charge transfer rate on the one hand and weakened the diffusion of the active substance from the electrolyte to the electrode surface on the other hand. The OER process was dominantly controlled by the charge transfer process under low current conditions. A fast charge transfer rate boosted the OER performance of the catalyst. At high currents, diffusion exerted a significant effect on the OER process and low OH- diffusion rates would lead to a decrease in the OER performance of the catalyst.

Hemorrhagic pure sensory strokes in the thalamus and striatocapsular area: causes, clinical features and long-term outcome.

BACKGROUND: Although there have been sporadic reports of patients with hemorrhagic pure sensory strokes (HPSS) in the thalamus and striatocapsular areas, the causes, clinical featuring and long-term outcome have not been adequately investigated. METHODS: We recruited 7 consecutive patients without hemiparetic stroke who had HPSS in the thalamic and striatocapsular areas. A CT scan was performed to verify brain imaging patterns, and their causes, clinical featuring and long-term outcome were observed. RESULTS: We studied 7 patients who had HPSS in the thalamic and striatocapsular areas as seen in CT scans. The 7 patients had hypertension, and small hemorrhages were found in the thalamus of 2 patients and in the posterior quarter of the posterior limb of the internal capsule in 4 patients; only 1 patient had a microhemorrhage in the thalamus. The volume of the hemorrhages ranged from 0.3 to 6.3 ml, with a mean of 2.3 ± 1.9 ml. Three patients showed a decreased sense of spinothalamic modality, and position and vibration senses were spared. Four patients showed a sensory deficit of both spinothalamic and medial lemniscal type. The outcomes were excellent and without post-stroke pain in all patients. CONCLUSION: HPSS in the thalamus and striatocapsular area are usually small hemorrhages or microhemorrhages from rupturing of the microvessels or the branches of small vessels. HPSS only have an impact on the adjacent sensory nucleus or pathway, and have a good outcome without post-stroke pain.

Metabolic Syndrome Is a Strong Risk Factor for Minor Ischemic Stroke and Subsequent Vascular Events.

BACKGROUND: Minor ischemic stroke (MIS) represents a major global public health problem worldwide due to high incidence. The aim of this study was to investigate whether metabolic syndrome (MetS) is a strong risk for MIS and subsequent vascular events (SVE). METHODS: A retrospective cohort study was performed examining symptomatic MIS in a Chinese neurologic outpatient population aged over 25 years without history of stroke. MetS was defined using the International Diabetes Federation criteria. MIS was diagnosed by magnetic resonance imaging-diffusion weighted images or fluid-attenuated inversion recovery. RESULTS: Of 1361 outpatients, a total of 753 (55.3%) patients were diagnosed with MIS; of them, 80% had a score of 0 using the MIS had a 0 score on the National Institutes of Health Stroke Scale. Among these, 303 (40.2%) individuals with MIS were diagnosed with MetS. Diagnosed of MIS with MetS significantly correlated with abdominal obesity (30.7% v.s 18.0%), hypertension (91.1% v.s 81.6%), increased blood glucose (6.9±2.4 v.s 5.0±0.4), dyslipidemia (78.2% v.s 48.2%), and SVE (50.5% v.s 11.3%) when compared with the controls group. On adjusted analysis, the risk of SVE was also significantly associated with three additional MetS criterion (RR,9.0; 95% CI, 5.677-14.46). Using Cox proportional analysis, risk of SVE in patient with MIS was significantly associated with MetS (RR, 3.3; 95% CI, 1.799-6.210), older age (RR, 1.0; 95% CI, 1.001-1.048), and high blood glucose (RR,1.1; 95%CI, 1.007-1.187). CONCLUSIONS: The MetS is a strong risk factor for MIS, and patients presenting with MIS and MetS are at a high risk of SVE. Further studies are required to determine the improvement of Mets prevention in the reduction of MIS and SVE.

Transient and persistent symptoms in patients with lacunar infarction: results from a prospective cohort study.

BACKGROUND: The transient symptoms with lacunar infarction (TSI) and persistent symptoms with lacunar infarction (PSI) are the most common forms of symptomatic lacunar infarction (LI). The aim of this study was to compare the differences in TSI and PSI of symptomatic LI. METHODS: A prospective cohort study was conducted in the neurologic outpatients of the tertiary teaching hospital in Northern China between February 2011 and February 2012. The TSI and PSI in participants aged 35 years or over were assessed. Patients were followed up and their outcomes were compared. RESULTS: Of the 453 symptomatic outpatients, 251 patients with LI were diagnosed by magnetic resonance imaging. Approximately 77.3% (194/251) of the patients with LI at this time had TSI. and the remaining 23.7% had PSI. After the adjusted odds ratios, only middle age (risk ratio [RR], 1.1; 95% confidence interval [CI], 1.157-1.189), lower National Institutes of Health Stroke Scale score (RR, 20.6; 95% CI, 6.705-13.31), smaller lacunae on brain images (RR, 2.9; 95% CI, 1.960-4.245), and LI frequently in the anterior circulation territory (RR, 0.2; 95% CI, 0.079-0.721) were independently associated with TSI. During a mean follow-up of 6 months, survival rate was significantly higher among patients with TSI than among those with PSI (log rank, 6.9; P=0.010); estimated unadjusted incidence of vascular subsequent events (30.9% vs 54.4%, P=0.001) was significantly lower in TSI than in PSI. CONCLUSION: The TSI has a higher prevalence and is associated with a lower risk of vascular subsequent events and death than PSI. The implications of these findings for TSI and PSI may require different interventions.

Early prediction and outcome of septic encephalopathy in acute stroke patients with nosocomial coma.

BACKGROUND: Septic encephalopathy (SE) is the most common acute encephalopathy in ICU; however, little attention has been focused on risk of SE in the course of acute stroke. Our aim is to investigate the early prediction and outcome of SE in stroke patients with nosocomial coma (NC). METHODS: A retrospective cohort study was conducted in an ICU of the tertiary teaching hospital in China from January 2006 to December 2009. Ninety-four acute stroke patients with NC were grouped according to with or without SE. Risk factors for patients with SE were compared with those without SE by univariate and multivariate analysis. RESULTS: Of 94 stroke patients with NC, 46 (49%) had NC with SE and 48 (51%) had NC without SE. The onset-to-NC time was significant later in stroke patients with SE than those without SE (P < 0.01). There was a significant difference in body temperature, heart rate, respiratory rate, white blood cell (WBC), systolic blood pressure (SBP), diastolic blood pressure (DBP), systemic inflammatory response syndrome (SIRS), acute respiratory failure, septic shock, hypernatremia, and sequential organ failure assessment (SOFA) score between the SE and non-SE group (P < 0.05). On a repeat head imaging, vasogenic edema (P = 0.023) and subcortical white matter lesions (P = 0.011) were significantly higher in patients with SE than those without SE, while hematoma growth (P = 0.000), infarction progress (P = 0.003), and recurrent subarachnoid hemorrhage (SAH) (P = 0.011) were significantly lower in patients with SE than those without SE. Patients with SE had higher adjusted rates of fever ≥ 39 °C (odds ratio (OR): 2.753; 95% confidence interval (CI): 1.116 - 6.794; P = 0.028) and SIRS ≥ 3 items (OR: 6.459; 95% CI: 2.050 - 20.351; P = 0.001). The 30-day mortality in stroke patients with SE was higher than those without SE (76.1% vs. 45.8%, P = 0.003). CONCLUSION: High fever and severe SIRS are two early predictors of stroke patients with SE, and survival rates were worse in stroke patients with SE than those without SE.

[Protective effect of Na2SeO3 against cerebral ischemia-reperfusion injury to the hippocampal neurons in rats].

OBJECTIVE: To investigate the protective effects of selenium on rat hippocampal neurons against ischemia-reperfusion (IR) injury. METHODS: Thirty-two rats were randomly divided into sham-operated group, IR group and selenium-treated group, and in the latter two groups, cerebral IR injury was induced by middle cerebral artery occlusion; Na2SeO3 treatment was administer in selenium-treated group. At 14 days after reperfusion, the brain tissues were harvested from the rats and hippocampal neuron injuries were observed by TUNEL and Methylene Blue staining. The levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and nerve growth factor (NGF) in the hippocampal tissues were measured by ELISA. RESULTS: Compared with IR group, the rats in selenium-treated group showed no significant increase in the expression of m-NGF (P>0.05), but pro-NGF expression was significantly increased (P<0.05) in the hippocampal tissue. Na2SeO3 treatment significantly inhibited the expressions of TNF-α and IL-1ß and decreased the apoptosis of hippocampal neurons following cerebral IR injury (P<0.05). CONCLUSION: Selenium produces antiapoptotic effect to protect the hippocampal neurons following cerebral IR injury possibly not by increasing the level of m-NGF but by decreasing the expressions of the inflammatory factors.

[Age structure and growth characteristic of Castanopsis fargesii population].

In this paper, the age structure and growth characteristics of Castanopsis fargesii population in a shade-tolerant broadleaved evergreen forest were studied, aimed to understand more about the regeneration patterns and dynamics of this population. The results showed that the age structure of C. fargesii population was of sporadic type, with two death peaks of a 30-year gap. This population had a good plasticity in growth to light condition. Because there were no significant differences in light condition under the canopy in vertical, the saplings came into their first suppression period when they were 5-8 years old, with a height growth rate less than 0. 1 m x a(-1) lasting for 10 years. The beginning time of the first growth suppression period was by the end of the first death peak of the population, and the ending time of the first growth suppression period was at the beginning of the second death peak of the population, demonstrating that growth characteristic was the key factor affecting the age structure of C. fargesii.