Normal and Abnormal Sharp Wave Ripples in the Hippocampal-Entorhinal Cortex System: Implications for Memory Consolidation, Alzheimer's Disease, and Temporal Lobe Epilepsy.

The appearance of hippocampal sharp wave ripples (SWRs) is an electrophysiological biomarker for episodic memory encoding and behavioral planning. Disturbed SWRs are considered a sign of neural network dysfunction that may provide insights into the structural connectivity changes associated with cognitive impairment in early-stage Alzheimer's disease (AD) and temporal lobe epilepsy (TLE). SWRs originating from hippocampus have been extensively studied during spatial navigation in rodents, and more recent studies have investigated SWRs in the hippocampal-entorhinal cortex (HPC-EC) system during a variety of other memory-guided behaviors. Understanding how SWR disruption impairs memory function, especially episodic memory, could aid in the development of more efficacious therapeutics for AD and TLE. In this review, we first provide an overview of the reciprocal association between AD and TLE, and then focus on the functions of HPC-EC system SWRs in episodic memory consolidation. It is posited that these waveforms reflect rapid network interactions among excitatory projection neurons and local interneurons and that these waves may contribute to synaptic plasticity underlying memory consolidation. Further, SWRs appear altered or ectopic in AD and TLE. These waveforms may thus provide clues to understanding disease pathogenesis and may even serve as biomarkers for early-stage disease progression and treatment response.

[Raman spectra calculation and analysis of plasticizer dioctyl phthalate].

In recent years, with frequent domestic food safety incidents related to the plasticizing agent, the detection of plasticizers in food research becomes increasingly urgent. DEHP is one of the plasticizer. In the present paper, theoretical Raman spectrum and experimental Raman spectrum of DEHP were given. DEHP molecular structure was optimized by DFT(B3LYP) method. DEHP molecular Raman spectra and infrared spectra were calculated with. HF theory and DFT theory based on 3-2G level. The analytical reagent level DEHP Raman spectra was measured, and was compared with theoretical spectra, and good agreements were obtained between the theoretical and experimental results. Because of different calculation methods, we can see that both the wave number and relative intensity of peaks have small differences. DEHP structure parameters were also given in the paper including bond lengths and bond angles etc. Vibrational modes were assigned to all bands between 400 and 3 500 cm-1. Raman spectroscopy study of the commonly used plasticizer dioctyl phthalate was reported in this paper for the first time. This effort will contribute to the research and application of Raman spectroscopy in the field of food testing.

[Optimization of melamine structure using density functional theory and vibrational spectra studies].

Melamine was used in foodstuff and feed industry as a feed additive occasionally. In the present work, melamine geometry structure was optimized by density functional theory (DFT) method. Raman and infrared spectra were calculated based on MP2/6-31G sets and DFT/DGTIVP sets, and then two theoretical Raman spectra were carefully compared with other experimental spectra. Good agreements were obtained between the theoretical and experimental results. Melamine structure parameters were given also in the paper including bond lengths and bond angles. Vibrational modes were assigned to all bands in the 550-4 000 cm(-1) range. This work will benefit the measurement research of the content of melamine in foods.

[Raman scattering calculations studies of malachite green isothiocyanate].

Malachite green isothiocyanate (MGITC) is a Raman probe molecule that was applied to cells detection, tissue composition detection and cells stain imaging. In the present work, MGITC molecular structure was optimized by density functional theory(DFT) calculation. MGITC molecular Raman spectra and infrared spectra were calculated with Hartree-Fork theory and MP2 theory based on STO-3G level, then two theoretical Raman spectra were carefully compared with experimental spectra, and good agreements were obtained between the theoretical and experimental results. MGITC structure parameters were given also in the paper including bond lengths and bond angles etc. Vibrational modes were assigned to all bands in the range between 550 and 4 200 cm(-1). This work will facilitate the application of MGITC Raman probe for biology.