Impaired Resting-State Functional Integrations within Default Mode Network of Generalized Tonic-Clonic Seizures Epilepsy

Generalized tonic-clonic seizures (GTCS) are characterized by unresponsiveness and convulsions, which cause complete loss of consciousness. Many recent studies have found that the ictal alterations in brain activity of the GTCS epilepsy patients are focally involved in some brain regions, including thalamus, upper brainstem, medial prefrontal cortex, posterior midbrain regions, and lateral parietal cortex. Notably, many of these affected brain regions are the same and overlap considerably with the components of the so-called default mode network (DMN). Here, we hypothesize that the brain activity of the DMN of the GTCS epilepsy patients are different from normal controls, even in the resting state. To test this hypothesis, we compared the DMN of the GTCS epilepsy patients and the controls using the resting state functional magnetic resonance imaging. Thirteen brain areas in the DMN were extracted, and a complete undirected weighted graph was used to model the DMN for each participant. When directly comparing the edges of the graph, we found significant decreased functional connectivities within the DMN of the GTCS epilepsy patients comparing to the controls. As for the nodes of the graph, we found that the degree of some brain areas within the DMN was significantly reduced in the GTCS epilepsy patients, including the anterior medial prefrontal cortex, the bilateral superior frontal cortex, and the posterior cingulate cortex. Then we investigated into possible mechanisms of how GTCS epilepsy could cause the reduction of the functional integrations of DMN. We suggested the damaged functional integrations of the DMN in the GTCS epilepsy patients even during the resting state, which could help to understand the neural correlations of the impaired consciousness of GTCS epilepsy patients

An Analytical Method for Coaxial Helicopter Ground Resonance

A time-frequency analytical method is presented to analyze physical mechanism of coaxial helicopter ground resonance. Eigenvalue calculation and numerical integration of disturbance equations of motions are used to obtain modal characters and time-domain response characters of coaxial helicopter ground resonance, and the interaction between rotors and body is revealed according to response of various DOFs. The analysis results show that regressive lag mode with upper rotor character is the most instability mode. In dynamic instability region, coaxial helicopter ground resonance is mainly due to energy transferred between periodic lag motion of upper rotor and body roll rotation. For this instability mode, energy transferred between periodic lag motion of lower rotor and body roll rotation is also existed, and it can enhance ground resonance instability of coaxial helicopter

An Analytical Method for Coaxial Helicopter Ground Resonance

A time-frequency analytical method is presented to analyze physical mechanism of coaxial helicopter ground resonance. Eigenvalue calculation and numerical integration of disturbance equations of motions are used to obtain modal characters and time-domain response characters of coaxial helicopter ground resonance, and the interaction between rotors and body is revealed according to response of various DOFs. The analysis results show that regressive lag mode with upper rotor character is the most instability mode. In dynamic instability region, coaxial helicopter ground resonance is mainly due to energy transferred between periodic lag motion of upper rotor and body roll rotation. For this instability mode, energy transferred between periodic lag motion of lower rotor and body roll rotation is also existed, and it can enhance ground resonance instability of coaxial helicopter

An Analytical Method for Coaxial Helicopter Ground Resonance

A time-frequency analytical method is presented to analyze physical mechanism of coaxial helicopter ground resonance. Eigenvalue calculation and numerical integration of disturbance equations of motions are used to obtain modal characters and time-domain response characters of coaxial helicopter ground resonance, and the interaction between rotors and body is revealed according to response of various DOFs. The analysis results show that regressive lag mode with upper rotor character is the most instability mode. In dynamic instability region, coaxial helicopter ground resonance is mainly due to energy transferred between periodic lag motion of upper rotor and body roll rotation. For this instability mode, energy transferred between periodic lag motion of lower rotor and body roll rotation is also existed, and it can enhance ground resonance instability of coaxial helicopter.</jats:p

Epstein-Barr Virus EBNA-2 Polymorphic Patterns in Nasopharyngeal Carcinoma in Southern China

&lt;b&gt;&lt;i&gt;Objectives:&lt;/i&gt;&lt;/b&gt; The aim of this study was to characterize the specific Epstein-Barr virus (EBV) polymorphisms from nasopharyngeal carcinoma (NPC) patients and healthy donors in Southern China, and to explore the relationship between EBV genotypes and NPC. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; The EBNA-2 gene of 32 EBV-positive NPCs and 39 EBV-positive throat washing (TW) samples from healthy individuals from Southern China was analyzed using PCR and sequencing. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; We found E2-A to be the predominant subtype in Southern China. The distribution of EBNA-2 subtypes between NPCs and TWs was significantly different (p &lt; 0.01) and the E2-A subtype was overly represented in NPCs. &lt;b&gt;&lt;i&gt;Conclusions:&lt;/i&gt;&lt;/b&gt; E2-A is the predominant subtype in Southern China, and the distribution of EBNA-2 subtypes between NPCs and TWs is significantly different. In Southern China, the E2-A subtype is significantly more frequent in NPCs than TWs, and is also more common than in Northern China. This suggests that the E2-A subtype may play an important role in the pathogenesis of NPC and that EBNA-2 gene variations are tumor-specific polymorphisms.</jats:p

Study on the Migration Pattern of Concentrated Brine in Underground Concentrated Brine Storage Reservoir: A Case Study in Ling Xin Mining Area

The discharge of mine water from underground coal mines in arid areas is leading to extensive water loss and secondary pollution. To eliminate the water loss and environmental pollution, sealing the concentrated brine after the mine water treatment in the underground storage and pumping the clean water to the surface for recycling are effective methods. In this study, focusing on the Ling Xin mining area, China, a coupled model of concentrated brine flow and solute transport in underground reservoir was established. The migration patterns of concentrated brine under two simulation scenarios of long-term penetration and sudden leakage were analyzed. At the same time, it also initially revealed the essence of the environmental pollution caused by the penetration and leakage of the concentrated brine in the underground concentrated brine storage reservoir. Results show that the concentrated brine would penetrate the bottom aquifer in about 60 years in long-term penetration while approximately 40 days in sudden leakage. In addition, the storage time, reservoir permeability, and groundwater head difference were important factors affecting the migration of concentrated brine, where the influence of permeability varieties was the most significant. The results of this study provide technical options for the subsequent study of the environmental risk of underground concentrated brine reservoirs and have important technical significance for the study and engineering application of underground reservoirs in arid areas.</jats:p