Study on the Swelling Characteristics of the Offshore Natural Gas Hydrate Reservoir.

The swelling characteristics of porous media in the offshore natural gas hydrate reservoir have an important effect on the stability of the reservoir. In this work, the physical property and the swelling of porous media in the offshore natural gas hydrate reservoir were measured. The results show that the swelling characteristics of the offshore natural gas hydrate reservoir are influenced by the coupling of the montmorillonite content and the salt ion concentration. The swelling rate of porous media is directly proportionate to water content and the initial porosity, and inversely proportionate to salinity. Compared with water content and salinity, the initial porosity has much obvious influence on the swelling, which the swelling strain of porous media with the initial porosity of 30% is three times more than that of montmorillonite with the initial porosity of 60%. Salt ions mainly affect the swelling of water bound by porous media. Then, the influence mechanism of the swelling characteristics of porous media on the structural characteristics of reservoir was tentatively explored. It can provide a basic date and scientific basis for furthering the mechanical characteristics of the reservoir in the hydrate exploitation in the offshore gas hydrate reservoir.

Bayesian hierarchical model for analyzing multiresponse longitudinal pharmacokinetic data.

Traditional Chinese medicine (TCM) is a very complex mixture containing many different ingredients. Thus, statistical analysis of traditional Chinese medicine data becomes challenging, as one needs to handle the association among the observed data across different time points and across different ingredients of the multivariate response. This paper builds a 3-stage Bayesian hierarchical model for analyzing multivariate response pharmacokinetic data. Usually, the dimensionality of the parameter space is very huge, which leads to the parameter-estimation difficulty. So we take the hybrid Markov chain Monte Carlo algorithms to obtain the posterior Bayesian estimation of corresponding parameters in our model. Both simulation study and real-data analysis show that our theoretical model and Markov chain Monte Carlo algorithms perform well, and especially the correlation among different ingredients can be calculated very accurately.

Molecular Dynamics Simulation of the Crystal Nucleation and Growth Behavior of Methane Hydrate in the Presence of the Surface and Nanopores of Porous Sediment.

The behavior of hydrate formation in porous sediment has been widely studied because of its importance in the investigation of reservoirs and in the drilling of natural gas hydrate. However, it is difficult to understand the hydrate nucleation and growth mechanism on the surface and in the nanopores of porous media by experimental and numerical simulation methods. In this work, molecular dynamics simulations of the nucleation and growth of CH4 hydrate in the presence of the surface and nanopores of clay are carried out. The molecular configurations and microstructure properties are analyzed for systems containing one H2O hydrate layer (System A), three H2O hydrate layers (System B), and six H2O hydrate layers (System C) in both clay and the bulk solution. It is found that hydrate formation is more complex in porous media than in the pure bulk solution and that there is cooperativity between hydrate growth and molecular diffusion in clay nanopores. The hydroxylated edge sites of the clay surface could serve as a source of CH4 molecules to facilitate hydrate nucleation. The diffusion velocity of molecules is influenced by the growth of the hydrate that forms a block in the throats of the clay nanopore. Comparing hydrate growth in different clay pore sizes reveals that the pore size plays an important role in hydrate growth and molecular diffusion in clay. This simulation study provides the microscopic mechanism of hydrate nucleation and growth in porous media, which can be favorable for the investigation of the formation of natural gas hydrate in sediments.

Harpagoside attenuates MPTP/MPP⁺ induced dopaminergic neurodegeneration and movement disorder via elevating glial cell line-derived neurotrophic factor.

Parkinson's disease is a chronic neurodegenerative movement disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. New therapeutic approaches aiming at delaying or reversing the neurodegenerative process are under active investigations. In this work, we found that harpagoside, an iridoid purified from the Chinese medicinal herb Scrophularia ningpoensis, could not only prevent but also rescue the dopaminergic neurodegeneration in MPTP/MPP(+) intoxication with promising efficacy. Firstly, in cultured mesencephalic neurons, harpagoside significantly attenuated the loss of TH-positive neuron numbers and the shortening of axonal length. Secondly, in a chronic MPTP mouse model, harpagoside dose-dependently improved the loco-motor ability (rotarod test), increased the TH-positive neuron numbers in the substantia nigra pars compacta (unbiased stereological counting) and increased the striatal DAT density ((125) I-FP-CIT autoradiography). Thirdly, harpagoside markedly elevated the GDNF mRNA and GDNF protein levels in MPTP/MPP(+) lesioned models. However, the protecting effect of harpagoside on the dopaminergic degeneration disappeared when the intrinsic GDNF action was blocked by either the Ret inhibitor PP1 or the neutralizing anti-GDNF antibody. Taken together, we conclude that harpagoside attenuates the dopaminergic neurodegeneration and movement disorder mainly through elevating glial cell line-derived neurotrophic factor.

[Synaptic vesicle recycling and Alzheimer's disease].

Loss of synapses correlates well with cognitive decline in Alzheimer's disease (AD). However, the molecular mechanisms underlying the synaptic dysfunction and loss are not well understood. Synaptic vesicle (SV) recycling is a key process for synaptic transmission. A body of evidences suggested that malfunction or loss of the machinery for SV recycling occurred in AD, which could result in disruption of neuronal circuitry. In this article, we summarized the recent progress in the research of synaptic proteins for SV recycling and the pathological changes of some proteins in AD.

Multiview PCA: A Methodology of Feature Extraction and Dimension Reduction for High-Order Data.

Facing with rapidly increasing demands for analyzing high-order data or multiway data, feature-extracting methods become imperative for analysis and processing. The traditional feature-extracting methods, however, either need to overly vectorize the data and smash the original structure hidden in data, such as PCA and PCA-like methods, which is unfavorable to the data recovery, or cannot eliminate the redundant information very well, such as tucker decomposition (TD) and TD-like methods. To overcome these limitations, we propose a more flexible and more powerful tool, called the multiview principal components analysis (Multiview-PCA) in this article. By segmenting a random tensor into equal-sized subarrays called sections and maximizing variations caused by orthogonal projections of these sections, the Multiview-PCA finds principal components in a parsimonious and flexible way. In so doing, two new operations on tensors, the S -direction inner/outer product, are introduced to formulate tensor projection and recovery. With different segmentation ways characterized by section depth and direction, the Multiview-PCA can be implemented many times in different ways, which defines the sequential and global Multiview-PCA, respectively. These multiple Multiview-PCA take the PCA and PCA-like, and TD and TD-like as the special cases, which correspond to the deepest section depth and the shallowest section depth, respectively. We propose an adaptive depth and direction selection algorithm for the implementation of Multiview-PCA. The Multiview-PCA is then tested in terms of subspace recovery ability, compression ability, and feature extraction performance when applied to a set of artificial data, surveillance videos, and hyperspectral imaging data. All numerical results support the flexibility, effectiveness, and usefulness of Multiview-PCA.

Enhanced metabolism confers a high level of cyhalofop-butyl resistance in a Chinese sprangletop (Leptochloa chinensis (L.) Nees) population.

BACKGROUND: Chinese sprangletop (Leptochloa chinensis (L.) Nees) is one of main grass weeds invading Chinese rice fields. The target-site resistance (TSR) of cyhalofop-butyl have been widely reported in L. chinensis populations, but the non-target-site resistance (NTSR) mechanisms have not yet been well-characterized. This study aims to investigate the likely NTSR in a cyhalofop-butyl-resistant L. chinensis population (YZ-R), which was collected from Yangzhou city, Jiangsu Province, China. RESULTS: Dose-response assays showed the YZ-R population exhibited 191.6-fold resistance to cyhalofop-butyl, compared to the susceptible population (YZ-S). This resistance is not target-site based, because no mutations in the two ACCase genes were detected in the YZ-R plants compared to the YZ-S plants, and the ACCase genes expression levels were similar in YZ-S and YZ-R plants. In addition, the cytochrome P450 inhibitor malathion and piperonyl butoxide (PBO), and glutathione S-transferase (GST) inhibitor 4-chloro-7-nitrobenzoxadiazole (NBD-Cl) did not significantly reverse cyhalofop-butyl resistance in the YZ-R population. However, liquid chromatography-mass spectrometry (LC-MS) analysis indicated that the metabolic rates of cyhalofop acid in YZ-R plants was significantly faster (5 to 10- fold) than in YZ-S plants. Furthermore, the YZ-R population showed no cross-resistance to other ACCase-inhibiting herbicides. CONCLUSION: These results indicated that cyhalofop-butyl resistance in the YZ-R population is due to non-target-site based enhanced herbicide metabolism. Resistance in this population is likely involved in a specific detoxification enzyme, with possible high catalytic efficiency and strong substrate specificity, therefore leading to high-level and single resistance to cyhalofop-butyl. © 2021 Society of Chemical Industry.

Aggregation-induced emission luminogens for image-guided surgery in non-human primates.

During the past two decades, aggregation-induced emission luminogens (AIEgens) have been intensively exploited for biological and biomedical applications. Although a series of investigations have been performed in non-primate animal models, there is few pilot studies in non-human primate animal models, strongly hindering the clinical translation of AIE luminogens (AIEgens). Herein, we present a systemic and multifaceted demonstration of an optical imaging-guided surgical operation via AIEgens from small animals (e.g., mice and rabbits) to rhesus macaque, the typical non-human primate animal model. Specifically, the folic conjugated-AIE luminogen (folic-AIEgen) generates strong and stable fluorescence for the detection and surgical excision of sentinel lymph nodes (SLNs). Moreover, with the superior tumor/normal tissue ratio and rapid tumor accumulation, folic-AIEgen successfully images and guides the precise resection of invisible cancerous metastases. Taken together, the presented strategies of folic-AIEgen based fluorescence intraoperative imaging and visualization-guided surgery show potential for clinical applications.

Gram-scale synthesis of highly biocompatible and intravenous injectable hafnium oxide nanocrystal with enhanced radiotherapy efficacy for cancer theranostic.

Based on the ionizing radiation applied to the malignant tumor tissue, radiation therapy (RT) is the frequently-used non-surgical approach for cancer treatment. Hafnium Oxide (HfO2) based nanoagent has been used in clinical trials for radiosensitized tumor therapy. However, the current reported clinically used HfO2 nanoparticles are relay on intratumoral injectable, and the unmodified HfO2 nanoparticles tend to be aggregated in serum and cannot be injected by intravenous route, which significantly limited the types of treatable cancer. To overcome the limitation, in this work, we developed a large-scalable, intravenously injectable, and clearable HfO2 nanoassemblies (NAs) to enhance the radiotherapeutic effects. The HfO2 NAs exhibited meaningfully promoted free-radical generation upon X-ray radiation for cancer cell killing due to the improved the sensitiveness of the breast cancer cells. The PEGylated HfO2 NAs demonstrated efficient tumor-homing ability via intravenous injection and manifested by HfO2 NAs enhanced CT imaging in a 4T1 breast tumor model. Utilizing the radiation sensitization function of HfO2 NAs, excellent tumor killing efficacy was achieved via both intratumoral and intravenously injection administration. Importantly, our HfO2 NAs could be degraded and excreted efficiently in a reasonable period in living body and avoid long-term toxicity. Taken together, our work provides a new technique by an injectable CT imaging-guided radio-sensitivitiable nanosystem for the further potential clinic translation.

Cyhalofop-butyl and Glyphosate Multiple-Herbicide Resistance Evolved in an Eleusine indica Population Collected in Chinese Direct-Seeding Rice.

Eleusine indica is a typical xerophytic weed species with a cosmopolitan distribution. It is invasive and highly adaptable to diverse habitats and crops. Due to rice cropping-pattern changes, E indica has become one of the main dominant grass weeds infecting direct-seeding paddy fields. A Chinese E. indica population has evolved multiple-herbicide resistance to cyhalofop-butyl and glyphosate. In this study, the multiple-resistance profile of E. indica to these two different types of herbicides and their resistance mechanisms were investigated. Whole-plant dose-response assays indicated that the multiple-herbicide-resistant (MHR) population exhibited 10.8-fold resistance to cyhalofop-butyl and 3.1-fold resistance to glyphosate compared with the susceptible (S) population. ACCase sequencing revealed that the Asp-2078-Gly mutation was strongly associated with E. indica resistance to cyhalofop-butyl. The MHR plants accumulated less shikimic acid than S plants at 4, 6, and 8 days after glyphosate treatment. In addition, no amino acid substitution in the EPSPS gene was found in MHR plants. Further analysis revealed that the relative expression level of EPSPS in MHR plants was 6-10-fold higher than that in S plants following glyphosate treatment, indicating that EPSPS overexpression may contribute to the glyphosate resistance. Furthermore, the effectiveness of nine post-emergence herbicides against E. indica were evaluated, and one PPO inhibitor pyraclonil was identified as highly effective in controlling the S and MHR E. indica populations.

Catalpol protects synaptic proteins from beta-amyloid induced neuron injury and improves cognitive functions in aged rats.

Synapse loss is one of the common factors contributing to cognitive disorders, such as Alzheimer's disease (AD), which is manifested by the impairment of basic cognitive functions including memory processing, perception, problem solving, and language. The current therapies for patients with cognitive disorders are mainly palliative; thus, regimens preventing and/or delaying dementia progression are urgently needed. In this study, we evaluated the effects of catalpol, isolated from traditional Chinese medicine Rehmannia glutinosa, on synaptic plasticity in aged rat models. We found that catalpol markedly improved the cognitive function of aged male Sprague-Dawley rats and simultaneously increased the expression of synaptic proteins (dynamin 1, PSD-95, and synaptophysin) in the cerebral cortex and hippocampus, respectively. In beta-amyloid (Aß) injured primary rat's cortical neuron, catalpol did not increase the viability of neuron but extended the length of microtubule-associated protein 2 (MAP-2) positive neurites and reversed the suppressive effects on expression of synaptic proteins induced by Aß. Additionally, the effects of catalpol on stimulating the growth of MAP-2 positive neurites and the expression of synaptic proteins were diminished by a PKC inhibitor, bisindolylmaleimide I, suggesting that PKC may be implicated in catalpol's function of preventing the neurodegeneration induced by Aß. Altogether, our study indicates that catalpol could be a potential disease-modifying drug for cognitive disorders such as AD.

[Therapeutic evaluation of He-wei Jie-gu (Chinese characters)Decoction on femoral intertrochanteric fracture after internal fixation in elderly: a randomized controlled trial].

OBJECTIVE: To observe the efficacy of He-wei Jie-gu (Chinese characters) decoction on femoral intertrochanteric fractures after internal fixation in elderly. METHODS: From January 2010 to January 2012, 90 elderly patients with osteoporotic intertrochanteric fracture were randomly divided into two groups. The patients in experimental group were treated with open reduction and internal fixation, He-wei Jie-gu decoction and Caltrate D in oral, including 18 males and 27 females with an average age of (77.8±11.3) years old ranging from 65 to 89 years old;the time from injured to operation was 2 to 9 days with an average of (6.6±2.1) days; according to Evans-Jensen classification, 17 cases were in type I, 8 in type II, 15 in type III, 3 in type IV, 2 in type V. Meanwhile, the patients in control group were treated with open reduction and internal fixation, Caltrate D in oral, including 16 males and 29 females with an average age of (81.2±9.6) years old ranging from 67 to 91 years old; the time from injury to operation was 2 to 10 days with an average of (6.8±2.6) days; according to Evans-Jensen classification, 15 cases were in type I, 10 in type II, 14 in type III, 4 in type W, 2 in type V. The VAS score, hip BMD value before and after treatment, fracture healing and the Harris function score after operation were recorded and compared. RESULTS: All patients were followed up from 3 to 9 months with an average of (5.6±2.8) months. Compared with the control group, the VAS score of the experimental group had an obviously reduction (F=98.138, P<0.01) after treatment; the hip BMD value at 3 months after treatment in the experimental group was higher than that of the control group (P<0.05); the fracture healing rate of the experimental group was higher than that of the control group (P<0.05); Harris score in 3 months of follow-up in the experimental group was higher than that of the control group (t=2.542, P<0.05); all the differences between two groups were statistically significant (P<0.05). CONCLUSION: He-wei Jie-gu decoction can reduce postoperative pain and increase bone mineral density after internal fixation of femoral intertrochanteric fracture in elderly, promote the fracture healing and functional recovery in the hip joint.

Metabolic status and personality affect the prognosis of patients with continuous ambulatory peritoneal dialysis.

Continuous ambulatory peritoneal dialysis (CAPD) is recognized as an effective and economical therapy for end-stage renal disease (ESRD). However, the drop-out and mortality rates of this treatment remain high. The aim of the present study was to investigate the potential effects of metabolic status and personality on the prognosis of ESRD patients receiving CAPD. A total of 835 patients (455 men and 380 women) were enrolled in the cross-sectional survey. Analysis of variance and Spearman correlations were used to analyze variables in two groups of ESRD patients: group L (dialysis duration < 3 years) and group H (dialysis duration ≥ 3 years). The variables included gender, age, duration of dialysis, primary diseases, blood pressure, body mass index (BMI), hemoglobin (Hb), serum albumin, Subjective Global Assessment (SGA), blood lipids, fasting blood glucose, renal function, immunoreactive parathyroid hormone (iPTH), serum phosphorus and calcium, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Kt/V, and Life Orientation Test-Revised (LOT-R) scores. Levels of DBP, BUN, glucose, CRP, SBP, SGA, TG, LDL, creatinine, iPTH, ESR, and LOT-R scores were significantly higher in group H than in Group L, whereas Hb and Kt/V were significantly lower in group H. The dialysis duration was positively correlated with the blood pressure, SGA scores, TG, LDL, PTH, CRP, and LOT-R scores, but negatively correlated with Kt/V. Our results suggest that hypertension, anemia, hypoproteinemia, SGA, TG, LDL, iPTH, CRP, Kt/V, and personalities are potentially important factors affecting the prognosis of ERSD patients with CAPD.

Memory defect induced by ß-amyloid plus glutamate receptor agonist is alleviated by catalpol and donepezil through different mechanisms.

Our previous studies demonstrate that a non-cholinesterase inhibitor (AChEI) compound catalpol, purified from a traditional Chinese medicinal herb Rehmannia glutinosa, could improve the symptoms and pathological changes in animal and cellular models of memory related neurodegenerative diseases. In this study, we compared catalpol with the most commonly used AChEI donepezil in respect to their mechanism of action on the neurodegenerative changes in an animal model induced by beta-amyloid (Aß) plus glutamate receptor agonist. It was found that the model mice showed significant deficit in the learning ability and memory in Y maze avoidance test, and meanwhile both donepezil and catalpol greatly improve the learning ability and memory after 2 to 3 months' administration. At the selected doses, donepezil only partially raised the declined brain muscarinic acetylcholine receptor (M receptor) density and choline acetyltransferase (ChAT) activity resulting in these levels still lower than normal control, while catalpol completely retrieved these two parameters. ELISA revealed that catalpol, instead of donepezil, possessed the capability of elevating the declined brain BDNF level of the animal model. The ELISA results on the BDNF protein level was confirmed by quantitative RT-PCR measurement of BDNF mRNA in Aß25₋35-treated primary culture of forebrain neurons. In combination with our previous work, we think the neuroprotective effects of donepezil and catalpol are mediated through different mechanisms. Since BDNF has been proved to be an important intrinsic factor in protecting neurodegenerative diseases, catalpol may be a hopefully effective compound against neurodegenerative changes induced by Aß and glutamate receptor agonist.