Deep brain stimulation (DBS), which usually utilizes high frequency stimulation (HFS) of electrical pulses, is effective for treating many brain disorders in clinic. Studying the dynamic response of downstream neurons to HFS and its time relationship with stimulus pulses can reveal important mechanisms of DBS and advance the development of new stimulation modes (e.g., closed-loop DBS). To exhibit the dynamic neuronal firing and its relationship with stimuli, we designed a two-dimensional raster plot to visualize neuronal activity during HFS (especially in the initial stage of HFS). Additionally, the influence of plot resolution on the visualization effect was investigated. The method was then validated by investigating the neuronal responses to the axonal HFS in the hippocampal CA1 region of rats. Results show that the new design of raster plot is able to illustrate the dynamics of indexes (such as phase-locked relationship and latency) of single unit activity (i.e., spikes) during periodic pulse stimulations. Furthermore, the plots can intuitively show changes of neuronal firing from the baseline before stimulation to the onset dynamics during stimulation, as well as other information including the silent period of spikes immediately following the end of HFS. In addition, by adjusting resolution, the raster plot can be adapted to a large range of firing rates for clear illustration of neuronal activity. The new raster plot can illustrate more information with a clearer image than a regular raster plot, and thereby provides a useful tool for studying neuronal behaviors during high-frequency stimulations in brain.
ObjectiveTo study the effects of visceral adipose tissue area (VTA) and subcutaneous adipose tissue area (STA) on pulmonary ventilation function (PVF), and then to evaluate the impact of abdominal fat distribution on PVF.Methods Patients who underwent both PVF examination and abdominal CT between January 1st and December 31st, 2017 were selected from the electronic medical record system of West China Hospital of Sichuan University. The demographic data and PVF indexes [vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and 1 s rate (FEV1/FVC)] were collected. VTA and STA were obtained by abdominal CT measurement. The correlations between PVF indexes and VTA or STA were compared. Results A total of 224 patients were included. According to the VTA/STA ratio, there were 92 cases (41.07%) in group VTA/STA<1 and 132 cases (58.93%) in group VTA/STA≥1. VTA was not correlated with FVC (rs=−0.078, P=0.244), but negatively correlated with VC (rs=−0.138, P=0.040), FEV1 (rs=−0.141, P=0.034) and FEV1/FVC (rs=−0.137, P=0.041); STA had no correlation with VC, FVC, FEV1 or FEV1/FVC (P>0.05). VTA/STA was negatively correlated with VC (rs=−0.220, P=0.001), FEV1 (rs=−0.273, P<0.001) and FEV1/FVC (rs=−0.380, P<0.001), but it had no correlation with FVC (rs=−0.083, P=0.214). In group VTA/STA<1, VTA/STA was negatively correlated with FEV1 (rs =−0.205, P=0.050) and FEV1/FVC (rs=−0.317, P=0.002), but it had no correlation with VC or FVC (P>0.05). In group VTA/STA≥1, VTA/STA was negatively correlated with VC, FVC, FEV1 and FEV1/FVC (P<0.05). Conclusions VTA and STA are negatively correlated with PVF. The ratio of VTA/STA can be used as an index to evaluate the effect of abdominal fat distribution on lung function.
ObjectiveTo analyse the hundred top-cited articles in obstructive sleep apnea hypopnea syndrome (OSAHS), and summarize the development trend of OSAHS research.MethodsWe searched the Web of Science core collection for all published articles on OSAHS or sleep disorders from January 1st, 1992 to May 23th, 2018. The hundred top-cited articles with the most frequent citation were selected. The publication time, country of origin, journal, institution, professional field of corresponding author, funding type, publication type, etc. were analyzed.ResultsThe hundred top-cited articles were published between 1992 and 2013, with 300～5 980 citations and a total of 65 719 citations. The main types of articles were clinical studies (73 articles), reviews (20 articles), guidelines (4 articles) and basic research (3 articles). Fourteen authors published more than one first-author paper, and fifteen authors published more than one articles as corresponding authors. These authors were distributed across 22 subject areas. The most cited country was the United States (60 articles), and the most cited institution was the University of Wisconsin (10 articles). The hundred top-cited articles were published in 31 journals, most of which were cited less than 1 000 times, and a few articles were cited more than 2 000 times.ConclusionsOSAHS has attracted much attention in respiratory medicine, neurology, epidemiology and other fields, and many articles about clinical research types of OSAHS have been cited. In addition, most of the highly cited articles in the OSAHS field come from the developed countries; our country needs to devote more resources to OSAHS research.