Finite sample properties of virtual reference feedback tuning with two degrees of freedom controllers.

Here the problem of designing two degrees of freedom controllers for an unknown plant based on input-output measurements is discussed. Virtual reference feedback tuning aims at minimizing a cost function of the L2-norm type by using a set of data, as no identification process is needed. When constructing this cost function, two model-matching problems are considered between closed loop transfer function and sensitivity function simultaneously. In model-matching procedures, we design virtual input and virtual disturb respectively. Further two filters used to reprocess the input-output measurements are derived to prove the equivalence between virtual reference feedback tuning and model reference control. After constructing one identification cost without any knowledge of the plant, we derive one bound on the difference between the expected identification cost and its sample identification cost under the condition that the number of data points is finite. Further the correlation property between the input and external noise is considered in deriving this bound. Then we continue to derive one probabilistic bound to quantify this difference through using some probability inequalities and knowledge of control theory. The number of data points is obtained by using generalization of independent block sequence. Finally two simulation examples have been performed to demonstrate the effectiveness of the theories proposed in this paper.

Clinical features and long-term outcomes of seizures associated with autoimmune encephalitis: A follow-up study in East China.

PURPOSE: To evaluate the clinical characteristics, treatment outcomes, prognosis and potential risk factors of patients in East China with seizure secondary to autoimmune encephalitis. METHODS: From February 2014 to June 2016, 113 patients diagnosed with autoimmune encephalitis in Huashan Hospital, Fudan University, were enrolled in our study. After at least two years of follow-up, we retrospectively analyzed the patients' clinical details, electroencephalograph performance, brain MRI findings, and the therapeutic outcome. Patients underwent clinical evaluation every 3 months. We compared the clinical characteristics and epileptic prognosis of autoimmune encephalitis per antibody type. The association of the epileptic prognosis and EEG abnormalities was evaluated. GTE (Grand Total EEG) Score was used to evaluate EEG abnormalities. Statistic methods included ANOVA, Bonferroni correction test. RESULTS: Treatment outcomes were assessabled in 103 patients (10 patients died or withdrew), including anti-GABABR encephalitis (11), anti-LGI1 encephalitis (16), anti-NMDAR encephalitis (73), Caspr2 antibody encephalitis (3). 83 patients had seizures, who underwent both immunotherapy and anti-epileptic drugs therapy. In terms of seizure type, 57 (68.7%) patients exhibited focal to bilateral tonic-clonic seizure (FBTCS), 51 (61.4%) patients exhibited focal-impaired awareness seizure (FIAS) or focal aware seizure (FAS). 18 (21.7%) patients developed to status epilepticus. 30 (36%) patients had multiple types of seizures. 39 (47%) patients had daily seizures. 80.7% (67/83) of patients with epilepsy had seizure remission. During the 24 months of follow-up, 11 (11%) patients had clinical relapses. GTE scores were significantly different between the group with seizure reduction < 75% and the group with seizure remission (p = 0.009). Imaging abnormalities existed in 53% of the patients in our cohort, but lacked specificity during the acute phase. CONCLUSION: Autoimmune encephalitis (AE) presents with large seizure burden with differing seizure semiology among different antibody types. Except for anti-GABAb receptor encephalitis, it may not be necessary for other AE types to apply long-term use of anti-epileptic drugs (AEDs). The GTE Score can be used to evaluate the EEG abnormalities and may be a predictor of seizure outcomes. MRI findings during the acute phase are non-specific. Long-term follow-up MRIs may be much more meaningful in evaluating prognosis.

Dose-Dependent Changes in Auditory Sensory Gating in the Prefrontal Cortex of the Cynomolgus Monkey.

BACKGROUND Sensory gating, often described as the ability to filter out irrelevant information that is repeated in close temporal proximity, is essential for the selection, processing, and storage of more salient information. This study aimed to test the effect of sensory gating under anesthesia in the prefrontal cortex (PFC) of monkeys following injection of bromocriptine, haloperidol, and phencyclidine (PCP). MATERIAL AND METHODS We used an auditory evoked potential that can be elicited by sound to examine sensory gating during treatment with haloperidol, bromocriptine, and PCP in the PFC in the cynomolgus monkey. Scalp electrodes were located in the bilateral PFC and bilateral temporal, bilateral parietal, and occipital lobes. Administration of bromocriptine (0.313 mg/kg, 0.625 mg/kg, and 1.25 mg/kg), haloperidol (0.001 mg/kg, 0.01 mg/kg, and 0.05 mg/kg), and the N-methyl-D-aspartic acid receptor antagonist PCP (0.3 mg/kg) influenced sensory gating. RESULTS We demonstrated the following: (1) Administration of mid-dose bromocriptine disrupted sensory gating (N100) in the right temporal lobe, while neither low-dose nor high-dose bromocriptine impaired gating. (2) Low-dose haloperidol impaired gating in the right prefrontal cortex. Mid-dose haloperidol disrupted sensory gating in left occipital lobe. High-dose haloperidol had no obvious effect on sensory gating. (3) Gating was impaired by PCP in the left parietal lobe. CONCLUSIONS Our studies showed that information processing was regulated by the dopaminergic system, which might play an important role in the PFC. The dopaminergic system influenced sensory gating in a dose- and region-dependent pattern, which might modulate the different stages that receive further processing due to novel information.

A new MRI approach for accurately implanting microelectrodes into deep brain structures of the rhesus monkey (Macaca mulatta).

The accurate implantation of microelectrodes is a significant difficulty facing many neurophysiologists. This paper reports on a new method used to promote the precise positioning of electrode implantation through magnetic resonance imaging (MRI), allowing both the relevant brain structure and the MRI-visible external markers anchored on the skull (in this case rigid glass tubes with a 0.5mm internal diameter) to be displayed. By referencing these markers, the coordinates of the brain target were calculated. Using this novel approach, recording electrodes were successfully implanted into the superior colliculus (SC) of rhesus monkeys, with an error <1mm, and its neuronal discharge signals were obtained. This new method allows neurophysiologists to precisely target the small deep brain structures of monkeys and study their electrophysiological characteristics in detail.

KCNE2, a down-regulated gene identified by in silico analysis, suppressed proliferation of gastric cancer cells.

It is important to identify the differentially expressed gene in gastric cancer for elucidating the molecular mechanisms of tumorigenesis of stomach. Here, 38 genes differentially expressed genes between gastric cancer and normal gastric mucosa by in silico approaches. A potassium channel protein KCNE2, identified as a down-regulated gene in gastric cancer, was chosen for further study. We investigated the expression of KCNE2 in gastric cancer tissues and cell lines and examined the effect of KCNE2 on proliferation of gastric cancer. The expression of KCNE2 was markedly down-regulated in gastric cancer tissues and cell lines. Forced overexpression of KCNE2 suppressed the growth of SGC7901 cells and cell cycle progression significantly, which might be related to the down-regulation of Cyclin D1. KCNE2 also inhibited SGC7901 cell growth in soft agar and its tumorigenicity in nude mice. Taken together, our work showed that in silico analysis approaches could be used to identify cancer-related genes effectively. KCNE2, as a novel down-regulated gene in gastric cancer, suppressed cell proliferation and tumorigenesis of stomach.