AI Empowered Virtual Reality Integrated Systems for Sleep Stage Classification and Quality Enhancement.

Insomnia is a common public health problem and an open biomedical research topic. Insomnia results in various health problems, including memory decline, decreases concentration and weakens problem-solving ability. The insufficient sleep also leads to skin ageing, heart disease, high blood pressure, arrhythmia and stroke. While it remains as a global health concern, sleep quality improvement using modern technologies, such as machine learning, classification technologies, virtual reality (VR), becomes an open and hot research problem. These modern technologies offer new curing solutions under certain conditions. In this paper, we present a sleeping-aid system with a single-channel electroencephalogram (EEG) sleep stage classification algorithm to improve the sleep quality. The sleeping-aid system promotes machine learning integrated VR and multimedia technology for sleep improvement. Ninety participants were invited to test on three different systems with 3D VR, 2D video, and music only. An adequate stimulus of audio-vision can be a complement of the drug treatment. The experimental results showed that the proposed method demonstrated superior performance over existing methods.

An Improved Neural Network Based on SENet for Sleep Stage Classification.

Sleep staging is an important step in analyzing sleep quality. Traditional manual analysis by psychologists is time-consuming. In this paper, we propose an automatic sleep staging model with an improved attention module and hidden Markov model (HMM). The model is driven by single-channel electroencephalogram (EEG) data. It automatically extracts features through two convolution kernels with different scales. Subsequently, an improved attention module based on Squeeze-and-Excitation Networks (SENet) will perform feature fusion. The neural network will give a preliminary sleep stage based on the learned features. Finally, an HMM will apply sleep transition rules to refine the classification. The proposed method is tested on the sleep-EDFx dataset and achieves excellent performance. The accuracy on the Fpz-Cz channel is 84.6%, and the kappa coefficient is 0.79. For the Pz-Oz channel, the accuracy is 82.3% and kappa is 0.76. The experimental results show that the attention mechanism plays a positive role in feature fusion. And our improved attention module improves the classification performance. In addition, applying sleep transition rules through HMM helps to improve performance, especially N1, which is difficult to identify.

Effect of Oxygen Concentration on the Oxidative Thermodynamics and Spontaneous Combustion of Pulverized Coal.

Spontaneous combustion of pulverized coal has become a safety topic and has been extensively researched. This study using differential scanning calorimetry investigated the exothermic characteristics and spontaneous combustion risk of three metamorphic pulverized coal samples during oxidative combustion, for oxygen concentrations of 21, 19, 17, 15, 13, 11, 9, 7, and 5 vol %. Results indicated that decreased oxygen concentrations reduced exothermic intensity and substantially increased ignition temperatures. The oxidative thermal release observed during the combustion stage was conspicuously higher than during the low-temperature oxidation stage. Thermal release during low-temperature oxidation was low during low oxygen concentrations; however, when the oxygen concentration was less than 13.0 vol.%, it had a considerable influence on exothermic combustion. When the oxygen level was lowered from 21.0 to 5.0 vol %, spontaneous combustion risk indexes lessened from 2.07 (sample A), 1.85 (sample B), and 0.81 [J/(mg min °C2)] (sample C) to 1.08 (sample A), 1.13 (sample B), and 0.40 [J/(mg min °C2)] (sample C), respectively. Both apparent activation energy and spontaneous combustion risk indexes of the samples decreased saliently as oxygen concentration decreased. Thus, reducing oxygen concentration would be an effective method of inhibiting or possibly even preventing the spontaneous combustion of pulverized coal.

Theoretical Derivation of a Prediction Model for CO2 Adsorption by Coal.

Adsorption characteristics of CO2 by coal are an important reservoir parameter to determine the CO2 storage capacity of the coal seam. The Langmuir isotherm adsorption model is commonly used to describe the isothermal adsorption line of coal. However, we cannot predict the CO2 adsorption capacity at other temperatures by using the Langmuir model based on the experimental data at a fixed temperature. This paper analyzes the ε-V ad adsorption characteristic curves of three coal samples over a range of temperatures and pressures. The study demonstrates that the adsorption characteristic curves of CO2 gas are independent of temperature and depend mainly on the dispersion force between coal and the CO2 molecules. In addition, the adsorption potential of CO2 gas has a negative correlation with the volume of the adsorbed phase. Hence, the CO2 adsorption characteristic curve of coal conforms to the logarithmic function. Based on the adsorption potential theory, the prediction model of CO2 adsorption by coal is derived. The deviation analysis from measured data shows that the average relative deviation of the three coal samples is ∼5%, and the prediction results are accurate and reliable. Under different temperature and pressure conditions of the three coal samples, the results from the prediction model of CO2 adsorption by coal and the Langmuir model have a strong correlation with the experimental results. In comparison with the Langmuir model, the prediction model of CO2 adsorption by coal can predict the adsorption capacity under different temperature and pressure conditions. Hence, it has a wide range of applications when compared to that of the Langmuir model. In practical applications, better results are achieved with a significant reduction in experimental time and labor.

Inhibiting effect of CO2 on the oxidative combustion thermodynamics of coal.

A thermal analysis experiment was conducted in O2/N2/CO2 and O2/N2 atmospheres (O2 concentrations were 21, 14, 8, and CO2 concentrations were 0, 39, 46, 52) to investigate the thermal behavior of coal oxidation and combustion. Results demonstrated that an elevated CO2 concentration or decreased O2 concentration had a delaying effect on the thermogravimetric analysis and differential scanning calorimetry (DSC) curves; moreover, the characteristic temperatures were substantially augmented. When the O2 concentration was 21 vol%, the total heat released by coals A (highly volatile bituminous coal) and B (anthracite coal) decreased by 5.8% and 4.1%, respectively, after CO2 addition. The comprehensive combustion performance index was also lowered. The DSC curve can be divided into two exothermic peaks, and the ratio of the peak 1 to peak 2 areas decreased with the addition of CO2, which indicated that CO2 inhibited the oxidation of the active functional groups of coal structures. Apparent activation energy in O2/CO2/N2 was less than that in O2/N2.

[A novel improved TOPSIS method and its application in medical science].

The TOPSIS method is a static comprehensive evaluation method for wide range applications. However, it encounters the reverse order problem in practical applications. Moreover, its evaluation value Ci only reflects the relative proximity of each evaluation object inside but not to the degree of closeness to the ideal optimal solution. The evaluation value is also limited to distinguish between the ranges of merit ranking. Since TOPSIS method has the wide range of applications, it is necessary to overcome the drawbacks of TOPSIS method. This article proposes a new improved TOPSIS method, which shows strict isotonicity and is more sensitive than the traditional TOPSIS method. The medical application based on this improved TOPSIS method is introduced.

[Novel dynamic TOPSIS method in evaluation for quality of medical care].

The quality of medical care shows characteristics of dynamic state with changes in time. However, many of appraisal and evaluation projects usually keep on the status of "past" or "present". Most of these models are static evaluation approach. In this study, besides the "past" and "present" status, we took one step further to unveil the future development trends of the medical therapeutical effects. Based on the index value and index increment, a dynamic TOPSIS method is presented. This method pays attention to both transverse and lengthwise information and can not only perform the evaluation on each time section but also can make the final dynamic evaluation. We applied this new method to the evaluation of quality of medical care, which was proved to be effective.

Meso-tetra (carboxyphenyl) porphyrin (TCPP) nanoparticles were internalized by SW480 cells by a clathrin-mediated endocytosis pathway to induce high photocytotoxicity.

We studied the uptake of meso-tetra (carboxyphenyl) porphyrin (TCPP) nanoparticles by SW480 cells and carried out a systematic investigation of the cellular internalization mechanism of TCPP nanoparticles, also studied the photocytotoxicity of TCPP nanoparticles. At first, meso-tetra (carboxyphenyl) porphyrin (TCPP) nanoparticles were prepared by the method of mixing solvent techniques. SW480 cellular uptakes of photosensitizers (TCPP nanoparticles, TCPP-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles and free TCPP) were analyzed by the method of fluorospectrophotometry. Endocytosis mechanism investigation was carried out by preincubating SW480 cells at 4 degrees C, and preincubating SW480 cells with sucrose, K+-free buffer solution and filipin. Clathrin HC expression after incubating SW480 cells with these three photosensitizers was analyzed by methods of Western blot and RT-PCR. At last, we analyzed the photo-cytotoxicity after incubating SW480 cells with photosensitizers and receiving irradiation. SW480 cells showed rapid uptake (0.0083fmoles TCPP/cell) of TCPP nanoparticles after 1h incubation. We also demonstrated that the uptake of TCPP nanoparticles by SW480 cells was a clathrin-mediated endocytosis pathway. As a result of rapid internalization of TCPP nanoparticles by SW480 cells, this special photosensitizer showed very high photocytotoxic effect on SW480 cells in vitro. The nano-sized photosensitizer with no matrix cover: TCPP nanoparticles, can produce higher photocytotoxicity than other photosensitizers (TCPP-loaded PLGA nanoparticles and free TCPP). The in vivo tumor growth inhibition experiment indicated that TCPP nanoparticles plus PDT treatment induced the most dramatic tumor-inhibiting efficacy in all TCPP treated groups. The results of this study suggest that TCPP nanoparticles represent a potential and powerful photodynamic therapy agent.

Inhibiting colorectal carcinoma growth and metastasis by blocking the expression of VEGF using RNA interference.

Angiogenesis plays an essential role in tumor growth and metastasis and is a promising target for cancer therapy. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. The present study was designed to determine the role of VEGF in tumor growth and metastasis using RNA interference (RNAi) technology. Four small interfering RNA (siRNA) sequences for the VEGF gene were cloned into expression plasmids and transfected into human colorectal carcinoma (CRC) SW620 cells. Stable transfection of these plasmids decreased VEGF protein expression, leading to the potent suppression of tumor cell proliferation, migration, invasion, and angiogenesis in vitro. Furthermore, in subcutaneous and intrasplenic/portal injection models involving athymic nude mice, the tumor growth and metastasis of SW620 cells expressing VEGF siRNA were significantly inhibited compared with untransfected cells or cells transfected with control vector alone. Immunohistochemical analyses of tumor sections revealed a decreased vessel density and decreased VEGF expression in the animals where siRNA against VEGF were expressed. These results indicate that RNAi of VEGF can be an effective antiangiogenic strategy for CRC.

Arg-Gly-Asp (RGD) peptide conjugated poly(lactic acid)-poly(ethylene oxide) micelle for targeted drug delivery.

In this study, a new poly(lactic acid)-poly (ethylene oxide)-Arg-Gly-Asp (PLA-PEO-RGD) derivative was synthesized, and paclitaxel-loaded PLA-PEO-RGD micelles were prepared by this derivative. The solubility assay showed that micelles mixed with Pluronic F-68 as surfactant could increase the solubility of this hydrophobic paclitaxel in aqueous solution. The cell-binding assay showed that PLA-PEO-RGD micelle (IC(50) = 11.13 +/- 1.38 nmol/L) had about 3.6-fold higher integrin avidity than PLA-PEO-RGD conjugates (IC(50) = 40.33 +/- 3.12 nmol/L). The avidity of micelle was also higher than RGD4C peptide (IC(50) = 24.44 +/- 1.21 nmol/L). The in vitro drug release profile of drug-loaded PLA-PEO-RGD micelles exhibited initial burst release to 37% +/- 2% (w/w) during the first 12 h, and then the release rate became steady in a controlled release manner. Furthermore, treatment of the MDA-MB-435 breast cancer cell line with paclitaxel-loaded PLA-PEO-RGD micelles yielded cytotoxicities, with EC(50) values of approximately 30 mumol/L. The paclitaxel-loaded PLA-PEO-RGD micelles treated group showed the most dramatic tumor reduction in MDA-MB-435 tumor-bearing nude mice, and the final mean tumor load was 31 +/- 16 mm(3) (mean +/- SD; n = 8). (125)I-labeled micelles administration resulted in significant (p < 0.001) higher tumor uptake (2.68% +/- 0.14%, ID/g) of PLA-PEO-RGD micelles compared to PLA-PEO micelles (0.84% +/- 0.09%, ID/g) after 2.5 h postinjection. Biodistribution study showed the best blood clearance of PLA-PEO-RGD micelles after 4.5 h postinjection. The results of this study suggest that paclitaxel-loaded PLA-PEO-RGD micelles based on the specific recognition of alpha(V)beta(3) integrin represent a potential and powerful target delivery technology.

Screening and identification of a targeting peptide to hepatocarcinoma from a phage display peptide library.

Ligands specific to cell surface receptors have been heavily investigated in cancer research. Phage display technology is a powerful tool in this field and may impact clinical issues including functional diagnosis and targeted drug delivery. In this study, a hepatocellular carcinoma cell line (HepG2) and a normal hepatocyte line (L-02) were used to carry out subtractive screening in vitro with a phage display-7 peptide library. After four rounds of panning, there was an obvious enrichment for the phages specifically binding to the HepG2 cells, and the output/input ratio of phages increased about 976-fold (from 0.3x10(-7) to 292.8x10(-7)). A group of peptides capable of binding specifically to the hepatoma cells were obtained, and the affinity of these peptides to the targeting cells and tissues was studied. Through a cell-based ELISA, immunocytochemical staining, immunohistochemical staining, and immunofluorescence, the S1 phage and synthetic peptide HCBP1 (sequence FQHPSFI) were shown to bind to the tumor cell surfaces of two hepatoma cell lines and biopsy specimens, but not to normal hepatocytes, other different cancer cells, or nontumor liver tissues. In conclusion, the peptide HCBP1 may be a potential candidate for targeted drug delivery in therapy of hepatoma cancer.

Polybutylcyanoacrylate nanoparticles as novel vectors in cancer gene therapy.

To make progress toward an efficient gene vector for cancer gene therapy, a novel nonviral vector of polybutylcyanoacrylate nanoparticles (PBCA NPs) was developed. Cetyltrimethyl ammonium bromide (CTAB) was used to modify the surface of PBCA NPs, and then the plasmid DNA (pDNA) of pAFP-TK was wrapped into PBCA-CTAB NPs. Atomic force microscopy and zeta potential demonstrated that PBCA-CTAB NPs were 80-200 nm in diameter and had +15.6 mV positive surface charges. Assay using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide showed that PBCA-CTAB NPs had less cytotoxicity to 3T3 cells than HepG2 cells. The analysis of PBCA-CTAB-DNA complexes could not only protect DNA from degradation by DNase I, it could also transfer pDNA into targeted cells with high transfection efficiency. Furthermore, when PBCA-CTAB NPs combined with suicide gene pAFP-TK, alpha-fetoprotein-positive cells transfected by it were highly sensitive to ganciclovir treatment, and cell survival declined precipitously. Therefore, this target strategy using a pAFP-TK/GCV suicide gene therapy system in which PBCA-CTAB NPs serve as gene delivery vectors explores a promising area for alpha-fetoprotein-positive hepatocellular carcinoma and associated carcinoma therapy.

Panning and identification of a colon tumor binding peptide from a phage display peptide library.

Tumor-targeting therapy can be an efficacious way to cure a malignant tumor in clinical trials. Phage display is a molecular diversity technology that allows the presentation of a large number of peptides or proteins on the surface of filamentous phage for various applications. In this study, we report on using phage display to generate peptide libraries that bind to colon cancer tissues. To accomplish this, we developed a screening protocol that contained 3 rounds of in vitro positive panning on colon cancer cells (SW480) and 2 rounds of subtractive screening in vitro on normal human intestinal epithelial cells with a phage display-7 peptide library. After several rounds of panning, both phage titer and recovery efficiency were significantly improved. Through a cell-based enzyme-linked immunosorbent assay, immunofluorescence, in vivo binding assay, immunocytochemical staining, and immunohistochemical staining, peptide CP15 (VHLGYAT) was demonstrated to be the most effective peptide in targeting tumor cells (SW480 and HT29 cells) and tumor tissues but not the normal human intestinal epithelial cells and control colon tissue. These studies suggest that peptide CP15 may be a promising lead candidate in the development of a useful colon tumor diagnostic and targeted drug delivery agent.

[Effects of monofluorphosphate and alphaD3 on the bone mineral density of mandibular of ovariectomy rats].

OBJECTIVE: To investigate the effects of monofluorphosphate and alphaD3 on the bone mineral density of mandibular of ovariectomy rats. METHODS: 39 female Sprague-Dawley rats about 90 days of age were randomly divided into the following treatment groups and treated for 12 weeks: SHAM group, OVX group, MFP group, MFP+alphaD3 group. Rats of MFP group received monofluorphosphate by gastric feeding. Rats of MFP+alphaD3 group received monofluorphosphate and alphatD3 by gastric feeding. The femur and the mandibles were collected for histomorphometry and bone mineral density measurement. RESULTS: The bone area, bone thick, and bone mineral density of femur in the OVX group were significantly lower than those of other groups, while the trabecular separation of the OVX group was significantly higher than that of other groups. The bone mineral density of mandible was increased in OVX group and MFP+alphaD3 group compared with SHAM group. CONCLUSION: Monofluorphosphate and alphaD3 can obviously increase the mass of mandible. The bone mineral density of femur decreased after ovariectomy while it increased in mandibular.

A novel PEGylation of chitosan nanoparticles for gene delivery.

CS (chitosan) has emerged as a promising non-viral vector for gene delivery because of its ability to form complexes with pDNA (plasmid DNA) and enhance its transport across cellular membranes through endocytosis. Complexes of CS and pDNA may improve transfection efficiency; however, they are not capable of sustained DNA release and prolonging gene transfer. In order to achieve prolonged delivery of CS-DNA complexes, we prepared CS NP (nanoparticle) and CS-DNA complexes. alpha-Methoxy-omega-succinimidylpoly(ethylene glycol) was then conjugated to the surface of CS-DNA complexes using an active ester scheme; finally, the potential of PEGylation [poly(ethylene glycol)ylation] of CS NP as a non-viral gene-delivery vector to transfer exogenous genes in vitro and in vivo were examined. Electrophoretic analysis suggested that CS NPs could protect the DNA from nuclease degradation. The pDNA carried by CS NPs could enter and be expressed in HepG2 cells. However, the transfection efficiency was very low and the highest dose of DNA transferred was 1.6 microg. The transfection activities of CS-DNA-PEG were preserved and a higher dose (2.4 microg) of pDNA was transferred. This indicated that the transfection efficiency of the PEGylated complexes had been improved. In vivo experiments also showed that CS-DNA-PEG complexes mediated higher gene expression in tissues than did CS-DNA complexes, and that gene expression in tumours induced by CS-DNA-PEG complexes was the highest of all. These results suggested that PEGylation of CS-DNA complexes improves non-viral gene delivery in vitro or in vivo and has the potential to deliver therapeutic genes directly into hepatoma tissues.

Expression of epidermal growth factor and epidermal growth factor receptor in rat periodontal tissues during orthodontic tooth movement.

OBJECTIVE: To detect the expression and distribution of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) in periodontal tissues, and analyze the role of EGF in orthodontic tooth movement. METHODS: According to Kings methods, 40 g mesial force was applied to pull the left maxillary first molar in the rat. Using immunohistochemical method (HI-SABC method) to localize and examine the expression of EGF and EGFR in decalcified alveodental connective tissues at 24 hours and 168 hours of tooth movement. RESULTS: EGF and EGFR were stained at some of periodontal ligament of furcation and radical regions in control group. These expressions of EGF and EGFR increased in periodontal tissues (P < 0.01), with the expressions at 168 hours higher than those at 24 hours (P < 0.01). And levels of EGF and EGFR at tension side were higher than those at pressure side at the same time (P < 0.01). CONCLUSIONS: Epidermal growth factor participated in the tissues remodeling during orthodontic tooth movement and especially played a more important role in orthodontic bone formation.