Effects of extracellular vesicles for ischemic stroke: A meta­analysis of preclinical studies.

Ischemic stroke is a common occurrence worldwide, posing a severe threat to human health and leading to negative financial impacts. Currently available treatments still have numerous limitations. As research progresses, extracellular vesicles are being found to have therapeutic potential in ischemic stroke. In the present study, the literature on extracellular vesicle therapy in animal studies of ischemic stroke was screened by searching databases, including PubMed, Embase, Medline, Web of Science and the Cochrane Library. The main outcomes of the present study were the neurological function score, apoptotic rate and infarct volumes. The secondary outcomes were pro-inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß and IL-6. The study quality was assessed using the CAMARADES Checklist. Subgroup analyses were performed to evaluate factors influencing extracellular vesicle therapy. Review Man3ager5.3 was used for data analysis. A total of 20 relevant articles were included in the present meta-analysis. The comprehensive analysis revealed that extracellular vesicles exerted a significant beneficial effect on neurobehavioral function, reducing the infarct volume and decreasing the apoptotic rate. Moreover, extracellular vesicles were found to promote nerve recovery by inhibiting pro-inflammatory factors (TNF-α, IL-1ß and IL-6). On the whole, the present meta-analysis examined the combined effects of extracellular vesicles on nerve function, infarct volume, apoptosis and inflammation, which provides a foundation for the clinical study of extracellular vesicles.

Revealing a causal relationship between gut microbiota and lung cancer: a Mendelian randomization study.

Background: The gut microbiota has been found to be associated with the risk of lung cancer. However, its causal relationship with various types of lung cancer remains unclear. Methods: We conducted a Mendelian randomization (MR) study using the largest genome-wide association analysis of gut microbiota data to date from the MiBioGen consortium, with pooled statistics for various types of lung cancer from the Transdisciplinary Research in Cancer of the Lung, the International Lung Cancer Consortium, and FinnGen Consortium R7 release data. Inverse variance weighted, weighted model, MR-Egger regression, and weighted median were adapted to assess the causal relationship between gut microbiota and various types of lung cancer. Sensitivity analysis was used to test for the presence of pleiotropy and heterogeneity in instrumental variables. A reverse MR analysis was performed on these bacteria to determine their potential role in causing lung cancer. A reverse MR analysis was performed on these bacteria to determine their potential role in causing lung cancer. Multivariable Mendelian randomization (MVMR) was conducted to assess the direct causal impact of gut microbiota on the risk of various types of lung cancer. Results: Using IVW as the primary analytical method, we identified a total of 40 groups of gut microbiota with potential causal associations with various subtypes of lung cancer, of which 10 were associated with lung cancer, 10 with lung adenocarcinoma, 9 with squamous cell lung cancer, and 11 groups of bacteria associated with small cell lung cancer. After performing FDR correction, we further found that there was still a significant causal relationship between Peptococcaceae and lung adenocarcinoma. Sensitivity analyses demonstrated the robustness of these results, with no heterogeneity or pleiotropy found. Conclusions: Our results confirm a causal relationship between specific gut microbiota and lung cancer, providing new insights into the role of gut microbiota in mediating the development of lung cancer.

Inhibition of chitin deacetylases to attenuate plant fungal diseases.

Phytopathogenic fungi secrete chitin deacetylase (CDA) to escape the host's immunological defense during infection. Here, we showed that the deacetylation activity of CDA toward chitin is essential for fungal virulence. Five crystal structures of two representative and phylogenetically distant phytopathogenic fungal CDAs, VdPDA1 from Verticillium dahliae and Pst_13661 from Puccinia striiformis f. sp. tritici, were obtained in ligand-free and inhibitor-bound forms. These structures suggested that both CDAs have an identical substrate-binding pocket and an Asp-His-His triad for coordinating a transition metal ion. Based on the structural identities, four compounds with a benzohydroxamic acid (BHA) moiety were obtained as phytopathogenic fungal CDA inhibitors. BHA exhibited high effectiveness in attenuating fungal diseases in wheat, soybean, and cotton. Our findings revealed that phytopathogenic fungal CDAs share common structural features, and provided BHA as a lead compound for the design of CDA inhibitors aimed at attenuating crop fungal diseases.

Mechanical effects of needle texture on acupoint tissue.

OBJECTIVE: This study aims to clarify how the stimulation of acupuncture points is achieved by needles with different surface texture during acupuncture; it also seeks to lessen injury at the insertion site and increase the therapeutic efficacy of acupuncture, by simulating the mechanical effects of various needle surface patterns on Zusanli (ST36) without changing the radius of acupuncture needles. METHODS: Five acupuncture needle models with different surface patterns, including the smooth needle, the lined needle, the ringed needle, the left-hand threaded needle and the right-hand threaded needle, and a layered model of the Zusanli acupoint were used to investigate how to reduce tissue damage and increase stimulation during acupuncture treatment. Puncturing of the skin as well as lifting-inserting and twisting needle manipulations were simulated using these models, and the degree of damage and force of stimulation caused by the acupuncture needles with different surface patterns during acupuncture were compared. RESULTS: The smooth needle and the lined needle caused the least tissue damage during insertion, while the left-hand threaded and the right-hand threaded needles caused the most damage. The ringed needle, the left-hand threaded needle and the right-hand threaded needle stimulated the acupoint tissue more during lifting-inserting manipulations, while the lined needle and the smooth needle produced less stimulation. The stimulation of the lined needle on the acupoint tissue was the largest during twisting manipulation, whereas the left-hand threaded needle and the right-hand threaded needle had smaller effects. In lifting-inserting and twisting manipulations, both the left-hand threaded needle and right-hand threaded needle provided more stimulation, but the torsion direction in which they produced better stimulation was the opposite. CONCLUSION: According to the simulation results, the ringed pattern enhances stimulation best in the lifting-inserting manipulation, whereas the lined pattern enhances stimulation best in the twisting manipulation. Both the right-hand and left-hand thread patterns have certain enhancing effects in these two operations. Taking the geometric properties of the pattern into account, the left-hand thread pattern and the right-hand thread pattern have the geometric characteristics of both the lined pattern and the ringed pattern. To conclude, a pattern perpendicular to the movement direction during the acupuncture manipulation creates more stimulation. These results have significance for future needle design. Please cite this article as: Sun MZ, Wang X, Li YC, Yao W, Gu W. Mechanical effects of needle texture on acupoint tissue. J Integr Med. 2023; 21(3): 254-267.

A randomized double-blind controlled study protocol on the efficacy and safety of Sangdantongluo granule in the treatment of post-stroke spasticity.

Introduction: Stroke is the first leading cause of mortality and disability worldwide, and post-stroke spasticity (PSS) is the common complication of stroke. Sangdantongluo Granule (Z20210481000), a modern patent Chinese medicine, is widely used in clinical practice to treat PSS. Whereas, there is limited evidence of effectiveness for Sangdantongluo Granule to treat PSS. This study will evaluate the clinical efficacy and safety of Sangdantongluo granule in the treatment of PSS. Methods: and Analysis This multicenter, randomized, double-blind and placebo-controlled study will recruit 132 participants in China who develops PSS 15 days-90 days after stroke. Participants will be randomly assigned in an equal ratio to receive either Sangdantongluo granule or placebo for 2 months twice a day orally. The primary measure is the Modified Ashworth Scale (MAS), Secondary outcome measures include Composite Spasticity Scale (CSS), Simplified Fugl-Meyer Motor Scale (S-FM), National Institute of Health stroke scale (NIHSS), Modified Rankin Scale (mRS), Modified Barther Index (MBI), and Surface electromyography. Adverse events will be supervised throughout the trial. SPSS V. 26.0 statistical software will be used for statistical analysis. Enrolment will be started in April 2022. Ethics and dissemination: The trial and protocol were approved by the Ethics Committee of Hunan Academy of Chinese Medicine Affiliated Hospital (No. [202102]20). We will report the results of this trial in a peer-reviewed journal. Trial registration: ClinicalTrials.gov ChiCTR2100044544. Registered on 23 March 2021.

Mast Cells and Acupuncture Analgesia.

Mast cells are widely distributed in various parts of the human body and play a vital role in the progression of many diseases. Recently, the close relationship between mast cells and acupoints was elucidated, and the role of mast cells in acupuncture analgesia has attracted the attention of researchers worldwide. Using mast cells, acupuncture analgesia and acupoint as key words to search CNKI, PubMed, Web of Science and other databases, combining the representative articles in these databases with the published research papers of our group, we summarized: The enrichment of mast cells and the dense arrangement of collagen fibers, microvessels, and nerves form the basis for acupoints as the reaction sites of acupuncture; acupuncture can cause the deformation of collagen fibers and activate TRPV channels on mast cells membrane, so as to stimulate mast cells to release bioactive substances and activate nerve receptors to generate analgesic effect; system biology models are set up to explain the quantitative process of information initiation and transmission at acupuncture points, and indicate that the acupuncture effect depends on the local mast cells density. In a conclusion, this review will give a scientific explanation of acupuncture analgesia from the material basis of acupoints, the local initiation, and afferent biological mechanism.

Predicting plant diversity in beach wetland downstream of Xiaolangdi reservoir with UAV and satellite multispectral images.

Accurate and timely acquisition of plant diversity information downstream of the reservoir is helpful to understand the impact mechanism of reservoir operation on wetland plant diversity and formulate reasonable water and sediment regulation strategies. In this study, we conducted field surveys in two communities (Phragmites australis and Tamarix chinensis) at a typical wetland in the lower reaches of Xiaolangdi Reservoir on the Yellow River, and employed UAV and Gaofen 1B multispectral images to estimate the wetland plant diversity. Results showed that most diversity indexes had a higher correlation with the mean of spectral vegetation indexes (DVI, RVI, NDVI, SAVI, and MSAVI). The diversity indexes (C_SP and C_SW) constructed by relative coverage had a better overall correlation with spectral indexes. Interestingly, opposite correlations were found between Tamarix chinensis and Phragmites australis plots. We further gave a deep insight into the interspecific associations in Phragmites australis and Tamarix chinensis plots with the variance ratio (VR) method. It was found that plant species in Tamarix chinensis plot showed positive association (VR > 1), with a VR value of 1.095. Plant species in Phragmites australis plot had a negative association (VR < 1), with a VR value of 0.983. In Phragmites australis plot, C_SP and C_SW showed a significant decreasing trend (r2 of 0.36 and 0.33 respectively, and P values less than 0.001) with the increase of Phragmites australis coverage. Moreover, the effect of spatial resolution was not significant on plant diversity estimation. Correlations between remote sensing indexes and diversity indexes were improved with the quadrat size changing from 2 m × 2 m to 4 m × 4 m. These findings demonstrate promising approaches for remote sensing of wetland plant diversity and indicate that the type of wetland plant community determines the relationship between diversity index and spectral index.

Effects and mechanisms of land-types conversion on greenhouse gas emissions in the Yellow River floodplain wetland.

The mechanism and extent of changes in greenhouse gas (GHG) emissions from seasonal river-floodplain wetlands subjected to land-type conversion are unknown. We monitored GHG fluxes and characterized soil microbial communities in four types of wetland (Riverside lower-beach wetland (RLW), Riverside higher-beach wetland (RHW), Cultivated wetland (CW), Mesophytic wetland (MW)) in the Yellow River flood land. Results revealed that land reclamation activities altered the distribution patterns of carbon (C) and nitrogen (N) in soil, as well as the structure and activities of microbial communities, leading to changes in the GHG emissions. Cumulative CO2 and N2O emissions were highest in CW, which were 2.10-10.71 times and 3.19-8.61 times greater than the other three wetlands, respectively, whereas cumulative CH4 emissions were highest in RLW (1850.192 mg·m-2). CW exhibited the highest 100-years-scale Global Warming Potential (GWP100-CO2-eq) (81.175 t CO2-eq·ha-1), which was 9.93, 3.12, and 2.11 times greater than RLW, RHW, and MW. Moreover, reclaiming riverside wetland as farmland will increase CO2 and N2O emission fluxes by 54.546-72.684 t·ha-1 and 2.615-2.988 kg·ha-1, respectively. 16S rRNA high throughput sequencing revealed that bacterial community composition changed significantly overtime and seasons. GHG fluxes showed a significant positive linear correlation with bacterial OTUs (y = 0.71x-319.4, R2 = 0.304) and Shannon index (y = 228.62x-796.6, R2 = 0.336). Structure equation models indicated that soil C, N and moisture content were the primary factors influencing bacterial community evolution, which had an impact on GHG fluxes. Actinomycetes were significantly affected by total carbon (TC) content, dissolved organic carbon (DOC), and C/N, while ammonia oxidizing and nitrifying bacteria were greatly influenced by NO3--N rather than TN and NH4+-N content. Opportunities exist to reduce GHG emissions and mitigate climate change by maintaining the original state of riverside wetland or restoring cultivated land to wetland in the Yellow River floodplain wetland.

Association between diffusion tensor imaging findings and domain-specific cognitive impairment in cerebral small vessel disease: a protocol for systematic review and meta-analysis.

INTRODUCTION: Cognitive impairment is the main clinical manifestation of cerebral small vessel disease (CSVD). However, the mechanism and structural damage in different domains of cognitive disorders are poorly understood. There is an urgent need to quantify the relation between diffusion tensor imaging (DTI) data and impaired cognitive testing in CSVD, which may help to find biomarkers for early diagnosis or treatment evaluation. We aim to summarise the understanding of association between DTI findings and domain-specific cognitive impairment. METHODS AND ANALYSIS: PubMed, EMBASE, Web of science, Cochrane library, Chinese National Knowledge Infrastructure Databases, Wanfang, SinoMed and VIP will be searched, from 1 January 1994 to 1 August 2021. The ClinicalTrials.gov and Chictr.org.cn records will also be searched to identify further potential studies. The included studies should report fractional anisotropy and/or and mean diffusivity/apparent diffusion coefficient data for one or more individual regions of interest in DTI analysis. Meanwhile, cognitive testing scores are also needed. This systematic review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The quality of cohort or case-control studies will be evaluated by the Newcastle-Ottawa Scale, and the cross-section studies will be evaluated by Agency for Healthcare Research and Quality scale. Meta-analysis, subgroup and sensitivity analyses, and publication bias will be all performed with Stata. ETHICS AND DISSEMINATION: Patients and the public will not be involved in this study. The existing data from published studies will be used. The findings from this research will be relevant information regarding the association of DTI metrics with cognitive disorder, which will be published in a peer-reviewed journal. If we need to amend this protocol, we will give the date of each amendment, describe the change and give the rationale. Changes will not be incorporated into the protocol. PROSPERO REGISTRATION NUMBER: CRD42021226133.

Flexible Ta/TiOx/TaOx/Ru memristive synaptic devices on polyimide substrates.

It is very urgent to build memristive synapses and even wearable devices to simulate the basic functions of biological synapses. The linear conductance modulation is the basis of analog memristor for neuromorphic computing. By optimizing the interface engineering wherein Ta/TiOx/TaOx/Ru was fabricated, all the memristor devices with different TiOxthickness showed electroforming-free property. The short-term and long-term plasticity in both potentiation and depression behaviors can be mimicked when TiOxwas fixed at 25 nm. The presented memristive synapses simulated the stable paired-pulse facilitation and spike-timing dependent plasticity performance. The potentiation and depression in linearity and symmetry improved with the TiOxthickness increasing, which provides the feasibility for the application of artificial neural network. In addition, the device deposited on polyimide (PI) still exhibits the synaptic performance until the bending radii reaches 6 mm. By carefully tuning the interface engineering, this study can provide general revelation for continuous improvement of the memristive performance in neuromorphic applications.

An overall look at insect chitin deacetylases: Promising molecular targets for developing green pesticides.

Chitin deacetylase (CDA) is a key enzyme involved in the modification of chitin and plays critical roles in molting and pupation, which catalyzes the removal of acetyl groups from N-acetyl-D-glucosamine residues in chitin to form chitosan and release acetic acid. Defects in the CDA genes or their expression may lead to stunted insect development and even death. Therefore, CDA can be used as a potential pest control target. However, there are no effective pesticides known to target CDA. Although there has been some exciting research progress on bacterial or fungal CDAs, insect CDA characteristics are less understood. This review summarizes the current understanding of insect CDAs, especially very recent advances in our understanding of crystal structures and the catalytic mechanism. Progress in developing small-molecule CDA inhibitors is also summarized. We hope the information included in this review will help facilitate new pesticide development through a novel action mode, such as targeting CDA.

Involvement of mTOR/Survivin signaling pathway in TUA(2ß, 3ß, 23-trihydroxy-urs-12-ene-28-olic acid)-induced apoptosis in human gastric cancer cell line BGC823 cells.

ETHNO-PHARMACOLOGICAL RELEVANCE: A natural ursolic compound, 2ß,3ß,23-trihydroxy-urs-12-ene-28-olic acid (TUA) was isolated from the root of Actinidiafulvicoma Hance. (A.fulvicoma Radix), which is used as a traditional hebal medicine to cure innominate inflammation of unknown origin of the digestive tract in the She nationality. AIM OF THE STUDY: The aim of present study was to investigate the effects of TUA on gastric cancer and to clarify the potential mechanisms in human gastric cancer cell line BGC823 cells in vitro and in vivo. MATERIALS AND METHODS: Cell proliferation, apoptosis, cell cycle, autophagy were all measured by MTS assay, flow cytometry following exposure to TUA. The mRNA expressions of PI3K, AKT, mTOR, P70S6K, Survivin and the protein expressions of p-PI3K, p-AKT, p-mTOR, p-P70S6K, Survivin were determined by qRT-PCR and Western blotting analysis, respectively. In vivo antitumor activity of TUA was assessed in a xenograft model. RESULTS: In vitro studies showed that TUA significantly suppressed the viability of BGC823 cells in a concentration- and time-dependent manner but not GES-1 non-tumorigenic human gastric epithelial cells. TUA also significantly increased the apoptosis rate and the sub G2 population by cell cycle analysis in a concentration dependent manner. Exposure to TUA decreased PI3K, AKT, mTOR, P70S6K, Survivin mRNA, inhibited the phosphorylation of major receptors involved in autophagy and apoptosis, such as PI3K, AKT, mTOR and P70S6K, while reduced the expression of Survivin in BGC cells. In vivo studies showed that TUA decreased tumor volume and tumor weight and also down regulated the autophagy-related proteins expression. CONCLUSIONS: TUA occupies underlying antitumor effects, the potential mechanisms may involve the suppression of mTOR/Survivin pathways connected to autophagy and the activation of apoptotic pathways in gastric cancer cells.

Electrocardiogram criteria of limb leads predicting right coronary artery as culprit artery in inferior wall myocardial infarction: A meta-analysis.

BACKGROUND: Prior studies have proposed several electrocardiogram (ECG) criteria in limb leads for identifying the culprit coronary artery (CCA) in patients with acute inferior wall myocardial infarction (IWMI). The aim of our study was to conduct an evidence-based evaluation and test accuracy comparison of these criteria. METHODS: We searched the PubMed, Embase, and Ovid. Eligible studies to assess the diagnostic performance of ECG criteria predicting CCA in IWMI were reviewed for inclusion. A diagnostic meta-analysis of bivariate approach was performed for pooled estimates of sensitivity and specificity, and meta-regression was implemented to investigate sources of heterogeneity. RESULTS: Twenty-four studies with 4431 unique participants met the inclusion criteria. The pooled sensitivity and specificity for ST-segment elevation (STE) in III > II, ST-segment depression (STD) in I, STD in aVL, STD in aVL > I, STE in III > II, and STD in aVL > I were 0.91 (0.88-0.94) and 0.69 (0.53-0.81), 0.80 (0.73-0.87) and 0.69 (0.62-0.76), 0.90 (0.81-0.95) and 0.41 (0.22-0.62), 0.84 (0.75-0.91) and 0.72 (0.48-0.88), and 0.79 (0.62-0.90) and 1.00 (0.37-1.00), respectively. Heterogeneity investigation showed that whether multi-vessel diseased patients were excluded, sample size, publication year, etc., could influence the diagnostic performance. CONCLUSION: STE in III > II performed better than other criteria for predicting RCA as CCA in IWMI, and STE in III > II and STD in aVL > I were potential and simple algorithms. ECG could be an effective tool to identify the CCA, but future studies are clearly needed to address the potential of diagnostic and prognostic value.

Extracellular vesicles in mesenchymal stromal cells: A novel therapeutic strategy for stroke.

A stroke is a focal cerebral insult that frequently causes severe neurological deficit and mortality. Recent studies have demonstrated that multipotent mesenchymal stromal cells (MSCs) hold great promise for neurovascular remodeling and neurological function recovery following a stroke. Rather than a direct replacement of parenchymal brain cells, the therapeutic mechanism of MSCs is suggested to be the secretion of soluble factors. Specifically, emerging data described MSCs as being able to release extracellular vesicles (EVs), which contain a variety of cargo including proteins, lipids, DNA and various RNA species. The released EVs can target neurocytes and vascular cells and modify the cell's functions by delivering the cargo, which are considered to mediate the neural restoration effects of MSCs. Therefore, EVs may be developed as a novel cell-free therapy for neurological disorders. In the present review, the current advances regarding the components, functions and therapeutic potential of EVs are summarized and the use of MSC-derived EVs as a promising approach in the treatment of stroke are highlighted.

CRA(Crosolic Acid) isolated from Actinidia valvata Dunn.Radix induces apoptosis of human gastric cancer cell line BGC823 in vitro via down-regulation of the NF-κB pathway.

A natural ursolic compound, 2α,3ß-dihydroxy-urs-12-en-28-oic acid (corosolic acid, CRA) was isolated from the root of Actinidia valvata Dunn. (A. valvata Radix). Since a large number of triterpenoid compound has marked anticancer effects toward various types of cancer cell lines in vitro, this study was carried out to investigate the anticancer effect of CRA in human gastric cancer cell line BGC823 cells and the underlying apoptotic mechanism of CRA was examined in BGC823 cell lines. The results showed that CRA significantly suppressed the viability of BGC823 cells in a concentration- and time-dependent manner. CRA also significantly increased the sub G1 population by cell cycle analysis in a concentration dependent manner. Exposure to CRA decreased p65, bcl-2, Fas, smac mRNA and protein expression, and increased IκBα, bax, survivin mRNA and protein expression. Results of immunofluorescence staining and EMSA further indicated CRA induced apoptosis by inhibiting nuclear translocation of nuclear factor NF-κB subunit p65. Consistently overall, our findings suggest that CRA induces apoptosis via inhibition of NF-κB (p65) expression level and activation of IκBα in BGC cells as a potent anticancer candidate for gastric cancer treatment.

[Characteristics of Dissolved CH4 and N2O Concentrations of Weihe River in Xinxiang Section in Spring].

Distributions of CH4 and N2O concentrations in Weihe River in Xinxiang City were monitored in spring of 2015, and their influencing factors were discussed. The result showed that CH4 and N2O were super-saturated in surface water of Weihe River. The variation ranges of two gases' saturations in the surface water of Weihe River were 147.59-2667.85 (CH4) and 4.06-188.25 (N2O). In the urban area, significant correlation existed between N2O and NH4⁺-N concentrations (P < 0.01), but in the new district, dissolved N2O concentration showed sharp increase because of the water input from the urban sewage plants, illustrating that the controlling mechanism on N2O production varied as pollutant characteristics changed. Stepwise regression analysis showed that CH4 concentrations could be explained by NH4⁺-N concentrations and water temperature, and CH4 concentrations in the surface water of Weihe River was significantly correlated with NH4⁺-N concentrations (R² = 0.70, P < 0.01), suggesting that NH4⁺-N was the key factor in regulating the production and assumption of CH4oxidation in Weihe River in spring. Besides, this study showed that when there was less NO3⁻-N but more NH4⁺-N in river water, CH4and N2O concentrations would be positively correlated, indicating that different nitrogen sources would impact the coupling mechanism of CH4and N2O productions.

[Gas Transfer Velocity of CH4 at Extremely Low Wind Speeds].

Thin boundary theory equation (TBL) is widely used to determine gas fluxes across water-air interfaces, and the gas transfer velocity (k600) is the key environmental factor in the equation. A monthly field campaign was carried out during one year to measure CH4 flux and to probe its exchange rate across the air-water interface in a drinking reservoir and 5 adjacent ponds. The ranges of wind speed and surface water temperature were 0-0.75 m·s-1 and 6.3-30.9℃respectively, and their average values were 0.19 m·s-1 and 19.3℃ respectively. The gas transfer velocity of CH4 varied from 0.20 to 1.99 cm·h-1 with an average of 0.50 cm·h-1. Correlation functions between the gas transfer velocity and the wind speed at 10 m height (U10) and surface water temperature (Tw) were given here to quantify k600. There were significant correlations between the fitted values and actual values both for original and bin-averaged data.

[Partial Pressure of Carbon Dioxide and Methane from Autumn to Winter in Xiangxi Bay of the Three Gorges Reservoir].

The Concentrations of dissolved CH4 and CO2 in Xiangxi Bay of the Three Gorges Reservoir from autumn to winter in 2014 were determined with headspace gas chromatography technology. Then their partial pressures of CH4 and CO2 were calculated according to the Henry's law. Their temporal variation and the effects of environmental parameters were also discussed. The results indicated that the CH4 partial pressure in the surface water ranged 0.64-4.43Pa, with an average of (1.69±0.94)Pa. The CO2 partial pressure varied from 49.90 to 868.91Pa, with the average of (328.48±251.63)Pa. The pCO2 and pCH4 had a strong negative correlation (r=-0.618,P<0.01). During the period of monitoring, the pCO2 and pCH4 in surface water were significantly correlated with pH, DO, chlorophyll a, TP, surface water temperature and water level. Compared with pCH4, pCO2 was more closely correlated with various environmental factors.

[Characteristics of Methane Flux Across the Water-air Interface in Subtropical Shallow Ponds].

Five shallow ponds of Yichang were selected to illustrate the characteristics of methane(CH4) in subtropical eutrophic shallow ponds. CH4 flux across the water-air interface was quantified with static floating chamber method for one year. Annual CH4 fluxes of the five ponds were 4.495, 12.702, 6.827, 8.920, 17.560 mg·(m2·h)-1 respectively. Diffusive CH4 fluxes were 0.075, 0.087, 0.118, 0.086, 0.151 mg·(m2·h)-1 respectively and bubble emissions were 4.420, 12.616, 6.709, 8.834, 17.409 mg·(m2·h)-1 respectively. Over 98% of total CH4 flux was bubble emission and CH4 flux was apparently higher than other aquatic ecosystems. So the CH4 flux of shallow waters was high and bubble emission was the dominant way. CH4 emission would be largely underestimated if the research only focus on the diffusion discharge and ignore the bubble emission.

Implantation of human umbilical cord mesenchymal stem cells for ischemic stroke: perspectives and challenges.

Ischemic stroke is a focal cerebral insult that often leads to many adverse neurological complications severely affecting the quality of life. The prevalence of stroke is increasing throughout the world, while the efficacy of current pharmacological therapies remains unclear. As a neuroregenerative therapy, the implantation of human umbilical cord mesenchymal stem cells (hUC-MSCs) has shown great possibility to restore function after stroke. This review article provides an update role of hUC-MSCs implantation in the treatment of ischemic stroke. With the unique "immunosuppressive and immunoprivilege" property, hUC-MSCs are advised to be an important candidate for allogeneic cell treatment. Nevertheless, most of the treatments are still at primary stage and not clinically feasible at the current time. Several uncertain problems, such as culture conditions, allograft rejection, and potential tumorigenicity, are the choke points in this cellular therapy. More preclinical researches and clinical studies are needed before hUC-MSCs implantation can be used as a routinely applied clinical therapy.