Publications by authors named "Sha Zhang"

86 Publications

Monitoring soil salinization and its spatiotemporal variation at different depths across the Yellow River Delta based on remote sensing data with multi-parameter optimization.

Environ Sci Pollut Res Int 2021 Nov 25. Epub 2021 Nov 25.

Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, China.

Soil salinization is recognized as a key issue negatively affecting agricultural productivity and wetland ecology. It is necessary to develop effective methods for monitoring the spatiotemporal distribution of soil salinity at a regional scale. In this study, we proposed an optimized remote sensing-based model for detecting soil salinity in different depths across the Yellow River Delta (YRD), China. A multi-dimensional model was built for mapping soil salinity, in which five types of predictive factors derived from Landsat satellite images were exacted and tested, 94 in-situ measured soil salinity samples with depths of 30-40 cm and 90-100 cm were collected to establish and validate the predicting model result. By comparing multiple linear regression (MLR) and partial least squares regression (PLSR) models with considering the correlation between predictive factors and soil salinity, we established the optimized prediction model which integrated the multi-parameter (including SWIR1, SI9, MSAVI, Albedo, and SDI) optimization approach to detect soil salinization in the YRD from 2003 to 2018. The results indicated that the estimates of soil salinity by the optimized prediction model were in good agreement with the measured soil salinity. The accuracy of the PLSR model performed better than that of the MLR model, with the R of 0.642, RMSE of 0.283, and MAE of 0.213 at 30-40 cm depth, and with the R of 0.450, RMSE of 0.276, and MAE of 0.220 at 90-100 cm depth. From 2003 to 2018, the soil salinity showed a distinct spatial heterogeneity. The soil salinization level of the coastal shoreline was higher; in contrast, lower soil salinization level occurred in the central YRD. In the last 15 years, the soil salinity at depth of 30-40 cm experienced a decreased trend of fluctuating, while the soil salinity at depth of 90-100 cm showed fluctuating increasing trend.
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http://dx.doi.org/10.1007/s11356-021-17677-yDOI Listing
November 2021

Effects of home medication review on drug-related problems and health-related quality of life among community-dwelling older adults in China.

J Am Pharm Assoc (2003) 2021 Oct 26. Epub 2021 Oct 26.

Background: There is a lack of research on the nature of drug-related problems (DRPs) in older adult communities in China and the impact of home medication review on DRP reduction and health-related quality-of-life (HRQoL) improvement.

Objectives: To identify and categorize DRPs in older adults in China and to assess the impact of home medication review.

Methods: The prospective study was conducted in 2 community health service centers in Shanghai, China from December 2018 to December 2019. Eligible patients received a home medication review by a clinical pharmacist to assess for DRPs and adherence, propose pharmaceutical interventions, and measure outcomes of HRQoL. All enrolled patients were followed up for 3 months.

Results: Medication use in 412 patients was analyzed. A total of 362 DRPs were identified, an average of 0.88 per patient. Treatment effectiveness was the primary DRP type (249; 68.8%). The most common causes of DRPs were patient-related (35.1%) and drug selection (31.0%). Pharmacists made 733 interventions, an average of 2 per DRP. A total of 82.1% of these interventions were accepted. At a 3-month follow-up, home medication review led to a statistically significant reduction in the mean number of DRPs (0.4 vs. 0.88, P < 0.001) and an increase in medication adherence (1.42 vs. 0.85, P < 0.001). Both HRQoL indicators also improved, EuroQol 5 Dimension scale (0.75 vs. 0.78, P < 0.001) and EuroQol-visual analog scale (70 vs. 77.65, P < 0.001).

Conclusion: Home medication review is a practical means to optimize drug therapy and improve patients' HRQoL in community settings.
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http://dx.doi.org/10.1016/j.japh.2021.10.023DOI Listing
October 2021

Effects of dietary tributyrin and physterol ester supplementation on growth performance, intestinal morphology, microbiota and metabolites in weaned piglets.

J Appl Microbiol 2021 Oct 27. Epub 2021 Oct 27.

College of Animal Science and Technology, Hunan Agricultural University, Hunan Co-Innovation of Animal Production Safety, Changsha, Hunan, China.

Aim: This study was conducted to investigate the effects of dietary tributyrin (TB) and physterol ester (PSE) supplementation on the growth performance and intestinal health of weaned piglets.

Methods And Results: Ninety-six piglets were randomly allocated to one of four groups, including a control group (basal diet), TB group (basal diet + 1500 g t  TB), PSE group (basal diet + 300 g t PSE) and TB + PSE group (basal diet + 1500 g t  TB + 300 g t PSE). All groups had eight replicates with three piglets per replicate. The experiment lasted for 28 days. The results showed that dietary TB supplementation increased (p < 0.05) average daily feed intake and average daily gain, as well as the acetate and butyrate concentration in ileum, and dietary PSE supplementation decreased (p < 0.05) the ratio of feed to gain (F/G) on days 1-14 of the trial. Dietary TB or PSE alone supplementation improved the ratio of villus height to crypt depth (VH/CD) and the expression level of Occludin in ileum. The linear discriminant analysis effect size analysis identified eight biomarkers in the control group, 18 in the TB + PSE group, two in the PSE group in ileum respectively. Correlation analysis showed that the relative abundances of Enterococcus, and Streptococcus were positively correlated (p < 0.05) with propionate concentration, while the relative abundance of Clostridium_sensu_stricto_1 was negatively correlated (p < 0.05) with acetate concentration in ileum.

Conclusion: These findings suggest that dietary TB or PSE alone supplementation could alter the growth performance, intestinal morphology, microbiota community and metabolites of weaned piglets.

Significance And Impact Of The Study: Weaning stress is a major cause of slow growth and increased diarrhoea in piglets. This study demonstrated that dietary TB and PSE presented a beneficial role in growth performance and gut health via regulating intestinal morphology, microbiota composition and metabolites.
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http://dx.doi.org/10.1111/jam.15321DOI Listing
October 2021

Rhytidhylides A and B, Two New Phthalide Derivatives from the Endophytic Fungus sp. BZM-9.

Molecules 2021 Oct 9;26(20). Epub 2021 Oct 9.

Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, China.

Two new phthalide derivatives, rhytidhylides A () and B (), together with ten known compounds (-) were isolated from cultures of sp. BZM-9, an endophyte isolated from the leaves of . Their structures were identified by an extensive analysis of NMR, HRESIMS, ECD, and through comparison with data reported in the literature. In addition, the cytotoxic activities against two human hepatoma cell lines (HepG2 and SMMC7721) and antibacterial activities against MRSA and were evaluated.
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http://dx.doi.org/10.3390/molecules26206092DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8540479PMC
October 2021

Naringin Promotes Skeletal Muscle Fiber Remodeling by the AdipoR1-APPL1-AMPK Signaling Pathway.

J Agric Food Chem 2021 Oct 29;69(40):11890-11899. Epub 2021 Sep 29.

Centre of Sport Nutrition and Health, School of Physical Education, Zhengzhou University, Zhengzhou 450001, China.

Naringin, a natural flavonoid mainly found in citrus fruit, has been reported to exert a positive effect on improving skeletal muscle health. However, the effects and potential mechanisms of naringin on skeletal muscle fiber switching is still unclear. Here, we discovered that oral administration of naringin increased the low-speed running time, four-limb hanging time, body oxygen consumption in mice, enhanced aerobic enzyme activity, MyHC I expression, and slow-twitch fiber percentage in mice skeletal muscle. By contrast, naringin decreased α-GPDH enzyme activity, MyHC IIb expression, and fast-twitch fiber percentage. Moreover, naringin increased the concentration of serum adiponectin and activated the expression of AdipoR1, APPL1, AMPK, and PGC-1α. Furthermore, by the experiment and AdipoR1 knockdown, we found that inhibition of the AdipoR1 signaling pathway significantly reduced the effect of naringin on slow-twitch fiber-/fast-twitch fiber-related gene and protein expression. In conclusion, our results indicated that naringin could induce skeletal muscle fiber transition from fast twitch to slow twitch the AdipoR1 signaling pathway. This study may provide new strategy for improving exercise endurance and slow muscle fiber deficiency-related diseases.
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http://dx.doi.org/10.1021/acs.jafc.1c04481DOI Listing
October 2021

Biflavonoids from as Potential Antitumor Agents for Intervention of Non-Small Cell Lung Cancer.

Molecules 2021 Sep 5;26(17). Epub 2021 Sep 5.

Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, China.

Four new biflavonoids (-) were isolated from together with a known biflavonoid derivative (). Their structures contained a rare linker of individual flavones to each other by direct C-3-O-C-4''' bonds, and were elucidated by extensive spectroscopic data, including HRESIMS, NMR and ECD data. All isolates significantly inhibited the proliferation of NSCLC cells (IC = 2.3-8.4 μM) with low toxicity to non-cancer MRC-5 cells, superior to the clinically used drug DDP. Furthermore, the most active compound suppressed XIAP and survivin expression, promoted upregulation of caspase-3/cleaved-caspase-3, as well as induced cell apoptosis and cycle arrest in A549 cells. Together, our findings suggest that may be worth studying further for intervention of NSCLC.
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http://dx.doi.org/10.3390/molecules26175401DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8434134PMC
September 2021

Evaluating the performance of eight drought indices for capturing soil moisture dynamics in various vegetation regions over China.

Sci Total Environ 2021 Oct 17;789:147803. Epub 2021 May 17.

College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China. Electronic address:

Drought is pervasive global hazard and seriously impacts ecology. Particularly, vegetation drought, which is chiefly driven by soil moisture (SM) deficiency, has a direct bearing on grain production and human livelihoods. Various drought indices associated with vegetation and SM conditions have been proposed to monitor and detect vegetation drought. In this study, we evaluated the performance of eight drought indices, including Drought Severity Index (DSI), Evaporation Stress Index (ESI), Normalized Vegetation Supply Water Index (NVSWI), Temperature-Vegetation Dryness Index (TVDI), Temperature Vegetation Precipitation Dryness Index (TVPDI), Vegetation Health Index (VHI), Self-calibrating Palmer Drought Severity Index (SC-PDSI) and Standardized Precipitation Evapotranspiration Index (SPEI), for capturing SM dynamic (derived from Copernicus Climate Change Service) across the six main vegetation coverage types of China. Our results showed DSI and ESI had the best overall performance. When exploring the reasons for the uncertainty of these indices (except SC-PDSI and SPEI) in the evaluation, we found that, in the non-arable regions, the time lag effect of drought indices on SM, the average state and rangeability of corresponding variables and the climatic conditions (precipitation and temperature) all impacted the performance of DSI, ESI, NVSWI, TVPDI and VHI. In the arable region, cropland types (paddy field and non-paddy field) and the uncertainty of SM data mainly caused the uncertainties of the above five indices. With regard to the TVDI, abnormalities of dry and wet edges fitting may be the primary factor affecting its performance. These results demonstrated that these drought indices with reliable and robust performance of capturing SM dynamics can be suggested to characterize the trend of SM. Certainly, this study can provide a reference for the improvement of existing drought indices and the establishment of new drought indices.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147803DOI Listing
October 2021

Sesquiterpenes and Steroids from an Endophytic .

J Nat Prod 2021 06 25;84(6):1715-1724. Epub 2021 May 25.

Key Laboratory of Plant Resources Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China.

A chemical investigation on the EtOAc extract of the endophytic fungus SCBG-8 led to the isolation of eight new sesquiterpenes eutyscoparins A-H (), one C-28 steroid eutyscoparene A (), one triterpenoid eutyscoparene B (), six known terpenoids, and two known steroids. Their structures including absolute configurations were established on the basis of spectroscopic data analysis, single-crystal X-ray diffraction experiments, and electronic circular dichroism (ECD) calculations. Compound displayed antibacterial activity against and MRSA (methicillin-resistant ) with MIC values of 6.3 μg/mL.
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http://dx.doi.org/10.1021/acs.jnatprod.0c01167DOI Listing
June 2021

Evaluating global ecosystem water use efficiency response to drought based on multi-model analysis.

Sci Total Environ 2021 Jul 11;778:146356. Epub 2021 Mar 11.

State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China; College of Resources and Environment, University of Chinese Academy of Sciences, China.

Drought has serious consequences on terrestrial ecosystems, particularly for their carbon and water processes. As an important indicator to examine the balance of ecosystem water and carbon cycles, ecosystem water use efficiency (WUE) has been widely used to investigate ecosystem responses to drought. However, the response of WUE to drought and the role of different ecosystem processes in controlling the response of WUE to drought are not well studied. In this paper, we used four WUE datasets from different remote sensing-driven (RS-driven) models and three drought indices (Standardized Precipitation Evapotranspiration Index, soil moisture anomaly index and water storage anomaly-based drought index) to comprehensively investigate the response of WUE to drought and its dominant ecosystem processes during the period of 2001-2018. The results showed the WUE datasets from four different RS-driven models had discrepancies in WUE temporal trends, particularly in tropical and subtropical forest and semi-arid regions. The Spearman correlation analysis revealed that the positive correlations between WUE and drought accounted for more than half of global vegetated lands, while negative relationship mainly occurred in the high latitude regions. We further explored the dominant ecosystem processes (represented by GPP and ET) in controlling WUE response to drought, and found ET controlled WUE-drought relationship in the high latitude areas and semi-arid/sub-humid regions, while GPP dominated it in tropical forest regions. Additionally, the effects of GPP and ET on controlling WUE response to drought were examined to change with different drought indices, especially in the semi-arid regions. Our study suggests multi-model analysis tend to reduce uncertainties in analyzing WUE response to drought caused by a single WUE data. Moreover, our results highlight the different role of ecosystem processes in controlling WUE response to drought and provide new information for the underlying mechanism of drought impacts on ecosystem water and carbon cycles.
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http://dx.doi.org/10.1016/j.scitotenv.2021.146356DOI Listing
July 2021

Hypertriglyceridemic waist phenotype and risk of chronic kidney disease in community-dwelling adults aged 60 years and older in Tianjin, China: a 7-year cohort study.

BMC Nephrol 2021 05 19;22(1):182. Epub 2021 May 19.

Graduate School of Tianjin Medical University, Tianjin, 300070, China.

Background: The hypertriglyceridemic waist (HTGW) phenotype has been proposed to be related to the occurrence and progression of chronic kidney disease (CKD). The ageing trend of the Chinese population continues to intensify, and elderly individuals are at high risk of CKD. The purpose of this study was to investigate the cross-sectional and longitudinal associations between the HTGW phenotype and the risk of CKD by following community-dwelling adults aged 60 years and older in Tianjin, China, for 7 years.

Methods: This study was an observational cohort study conducted between 2013 and 2019. Of 2050 participants aged 60 years and older who underwent an annual health examination in 2013, 1605 individuals with complete data were enrolled in the cross-sectional analysis. Among them, 1271 individuals were observed until 2019. Detailed follow-up records were available for 816 participants, of whom 600 participants without CKD at baseline were eligible for inclusion in the retrospective analysis. The HTGW phenotype was defined as a waist circumference of 90 cm or more and triglyceride concentrations of 2.0 mmol/L or more in males or a waist circumference of 85 cm or more and triglyceride concentrations of 1.5 mmol/L or more in females. CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m and/or proteinuria (urinary albumin-to-creatinine ratio (ACR) ≥ 30 mg/g). Multivariable logistic regression analyses were performed to evaluate the relationship between the HTGW phenotype and CKD.

Results: In 2013, the prevalence of CKD among older adults was 31.03%, and the prevalence of CKD in the HTGW phenotype group was 37.81%. Over a 7-year observation period, 195 individuals developed CKD, with an incidence rate of 32.50%. Statistically significant associations were observed between the HTGW phenotype and CKD in older adults in both cross-sectional surveys and retrospective analyses, with odds ratios and 95% confidence intervals of 1.38 (95% CI: 1.03-1.86, P = 0.033) and 2.27 (95% CI: 1.30-3.97, P = 0.004), respectively, after adjustment for confounders.

Conclusions: In this community-based cohort study, the HTGW phenotype was confirmed to be independently associated with an increased risk of prevalent and incident CKD in older adults aged 60 years and above in Tianjin, China.
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http://dx.doi.org/10.1186/s12882-021-02339-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8132422PMC
May 2021

Mechanisms of Broad-Band UVB Irradiation‒Induced Itch in Mice.

J Invest Dermatol 2021 10 1;141(10):2499-2508.e3. Epub 2021 Apr 1.

Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA; Department of Anesthesiology, Center for the Study of Itch & Sensory Disorders, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.

Although sunburn can produce severe uncontrollable itching, the underlying mechanisms of UV irradiation‒induced itch are poorly understood because of a lack of experimental animal models of sunburn itch. In this study, we established a sunburn-related mouse model and found that broad-band UVB irradiation elicited scratching but not wiping behavior in mice. Using a combination of live-cell calcium ion imaging and quantitative RT-PCR on dorsal root ganglion neurons, H&E staining, immunofluorescence staining of skin preparations, and behavioral testing, in combination with genetic and pharmacological approaches, we showed that TRPV1-positive dorsal root ganglion neurons but not mast cells are involved in broad-band UVB irradiation‒induced itch. Moreover, both genetic and pharmacological inhibition of TRPV1 function significantly alleviated the broad-band UVB irradiation‒induced itch response. Collectively, our results suggest that broad-band UVB irradiation evokes itch sensation in mice by promoting TRPV1 channel function in dorsal root ganglion neurons and provide potential therapeutic targets for sunburn-related itch.
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http://dx.doi.org/10.1016/j.jid.2021.03.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8464484PMC
October 2021

Rhytidhyesters A - D, 4 New Chlorinated Cyclopentene Derivatives from the Endophytic Fungus Rhytidhysteron sp. BZM-9.

Planta Med 2021 May 23;87(6):489-497. Epub 2021 Mar 23.

Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, China.

Four new chlorinated cyclopentene derivatives, rhytidhyesters A - D (1:  - 4: ), were isolated from sp. BZM-9, an endophytic fungus from . The planar structures of compounds 1:  - 4: were mainly elucidated by 1D, 2D NMR, and HRESIMS data. Their absolute configurations were established by X-ray crystallographic analysis, quantum chemical C NMR, and electronic circular dichroism calculations. Compounds 1: and 2: are a pair of epimers. Moreover, all the isolated compounds were evaluated for cytotoxic activities against 3 human colon cancer cell lines (SW620, HT29, SW480) and antimicrobial activity against . All compounds exhibited weak to moderate antiproliferative activities with IC values ranging from 15.4 to 37.7 µM but were inactive against .
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http://dx.doi.org/10.1055/a-1429-3396DOI Listing
May 2021

Establishment and Verification of Multiaxis Fatigue Life Prediction Model.

Scanning 2021 2;2021:8875958. Epub 2021 Feb 2.

Department of Mechanical and Electronic Engineering, Changsha University, Changsha 410022, China.

A fatigue life prediction model with multiaxis load is proposed. The model introduces a new effective cyclic parameter, equivalent stress on the critical surface, to modify the Suntech model. The new damage parameters are not related to empirical constants, hence more applicable for practical application in engineering. The multiaxis fatigue test was carried out with high-strength aluminum alloy 7075-T651, and the multiaxis fatigue life prediction of the test piece was conducted with the finite element software. The experiment result shows that the model proposed is effective for predicting the fatigue life under multiaxis load.
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http://dx.doi.org/10.1155/2021/8875958DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7872777PMC
February 2021

The CB index predicts prognosis of critically ill COVID-19 patients.

Ann Transl Med 2020 Dec;8(24):1654

Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.

Background: The global outbreak of COVID-19 is a significant threat to public health. Among COVID-19 cases, critically ill patients account for most in-hospital deaths. Given the pressing clinical needs, identification of potential prognostic factors that would assist clinicians to determine appropriate therapeutic interventions is urgently needed.

Methods: A retrospective analysis of 171 critically ill COVID-19 patients from two medical centers in Wuhan was conducted. The training and validation cohorts were comprised of 77 and 94 patients, respectively. Univariate and multivariate Logistic regression analyses were used to identify independent prognostic factors, and the linear prediction index was established and externally validated.

Results: Blood urine nitrogen (BUN) and high-sensitive C-reactive protein (hs-CRP) were independent factors negatively correlated with patient survival in the training cohort. A linear prediction model, named as the CB index (hs-CRP combined with BUN), was established and logistic regression analysis showed that this was associated with a 13% increase in death rate, with high sensitivity (86.7%) and specificity (89.7%). Patients were then divided into a high-risk group (CB index >32) and low-risk group (CB index <32) and the high-risk group showed a 56.3-fold risk of death compared with the low-risk group. Importantly, these findings were readily recaptured in the validation cohort. The efficacy of the CB index in predicting prognosis in real-world patients was then determined, which showed that patients with a higher CB index had an increased risk of death in comparison to those with a lower CB index.

Conclusions: The CB index may be an important prognostic factor in critically ill COVID-19 patients.
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http://dx.doi.org/10.21037/atm-20-7447DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7812180PMC
December 2020

AtFH14 crosslinks actin filaments and microtubules in different manners.

Biol Cell 2021 May 1;113(5):235-249. Epub 2021 Feb 1.

Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, Center for Biological Science and Technology, Advanced Institute of Natural Science, Beijing Normal University, Zhuhai, 519087, China.

Background Information: In many cellular processes including cell division, the synergistic dynamics of actin filaments and microtubules play vital roles. However, the regulatory mechanisms of these synergistic dynamics are not fully understood. Proteins such as formins are involved in actin filament-microtubule interactions and Arabidopsis thaliana formin 14 (AtFH14) may function as a crosslinker between actin filaments and microtubules in cell division, but the molecular mechanism underlying such crosslinking remains unclear.

Results: Without microtubules, formin homology (FH) 1/FH2 of AtFH14 nucleated actin polymerisation from actin monomers and capped the barbed end of actin filaments. However, in the presence of microtubules, quantitative analysis showed that the binding affinity of AtFH14 FH1FH2 to microtubules was higher than that to actin filaments. Moreover, microtubule-bound AtFH14 FH1FH2 neither nucleated actin polymerisation nor inhibited barbed end elongation. In contrast, tubulin did not affect AtFH14 FH1FH2 to nucleate actin polymerisation and inhibit barbed end elongation. Nevertheless, microtubule-bound AtFH14 FH1FH2 bound actin filaments and the bound actin filaments slid and elongated along the microtubules or elongated away from the microtubules, which induced bundling or crosslinking of actin filaments and microtubules. Pharmacological analyses indicated that AtFH14 FH1FH2 promoted crosslinking of actin filaments and microtubules in vivo. Additionally, co-sedimentation and fluorescent dye-labelling experiments of AtFH14 FH2-truncated proteins in vitro revealed the essential motifs of bundling actin filaments or microtubules, which were 63-92 aa and 42-62 aa in the AtFH14 FH2 N-terminal, respectively, and 42-62 aa was the essential motif to crosslink actin filaments and microtubules.

Conclusions And Significance: Our results aid in explaining how AtFH14 functions as a crosslinker between actin filaments and microtubules to regulate their dynamics via different manners during cell division. They also facilitate further understanding of the molecular mechanisms of the interactions between actin filaments and microtubules.
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http://dx.doi.org/10.1111/boc.202000147DOI Listing
May 2021

Worldwide cadmium accumulation in soybean grains and feasibility of food production on contaminated calcareous soils.

Environ Pollut 2021 Jan 27;269:116153. Epub 2020 Nov 27.

Department of Health and Environmental Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou, Jiangsu, 215123, China. Electronic address:

Elevated toxins in soybeans extensively threaten Asian residents and over one billion vegetarians worldwide. An integrated dataset of toxic trace metal(loid)s especially cadmium (Cd) analysis in soybean grain samples (n = 5217) from 12 countries/regions of origin was compiled for risk analysis. Worldwide grain Cd averaged 0.093 mg kg, but mean values varied 16-fold between regions, with South China (0.32 mg kg) > Argentina (0.15 mg kg) = German (0.13 mg kg) > Japan (0.11 mg kg) > the United States (0.064 mg kg) > Central-North China (0.020-0.60 mg kg) ≥ Iran (0.042 mg kg) = Brazil (0.023 mg kg) = South Korea (0.020 mg kg). Regression analysis suggested widespread contamination and acidic soil features significantly contributed the elevated food Cd contamination worldwide. Arsenic (As) and lead (Pb) are also of concern because excessive levels were often observed in grains. Given that soil Cd bioavailability is generally low in alkaline pH ranges, the feasibility of producing safe food from contaminated land was investigated by greenhouse experiments with one low-Cd soybean cultivar grown on 20 contaminated calcareous soils. Equilibrium-based approaches i.e., 0.01 M CaCl and in-situ porewater extractions, and diffusion-based diffusive gradients in thin-films technique were used to determine the plant-available fractions of soil metal(loid)s to explain the bioaccumulation variation. The results suggested that soybean grains bioaccumulated mean 0.76 mg Cd kg, ranging from 0.16 to 2.1 mg kg, whereas As and Pb bioaccumulation was low. Cadmium accumulation was closely correlated with plant-available Cd fractions especially the 0.01 M CaCl-extractable Cd, but negatively correlated with soil pH. Even in the alkaline pH range, a slight decrease of soil pH would increase grain Cd significantly. Study region and those arable lands that have similar soil conditions are not recommended for growing soybean unless novel remediation strategies are developed.
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http://dx.doi.org/10.1016/j.envpol.2020.116153DOI Listing
January 2021

Myocardium injury biomarkers predict prognosis of critically ill coronavirus disease 2019 (COVID-19) patients.

Ann Palliat Med 2020 Nov;9(6):4156-4165

Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, China; Department of Infectious Diseases, Hubei Women & Children Healthcare Hospital (Guanggu District), Wuhan, China.

Background: The coronavirus disease 2019 (COVID-19) pandemic is a once-in-century crisis to public health. Although the pathogen for COVID-19, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has been identified, the pandemic is still ongoing. The critically ill COVID-19 patients account for most disease-associated death; thus, there is an urgent need to identify prognostic factors that would help determine therapeutic approaches.

Methods: In this study, we retrospectively analyzed the clinical and laboratory findings in 100 critically ill COVID-19 patients in Hubei Women & Children Healthcare Hospital (Guanggu District), of whom 22 patients died in hospital, and 78 patients survived.

Results: We found that age, lymphocyte count, and total bilirubin concentration were an independent prognostic factor for critically ill COVID-19 patients. Of particular importance, we observed a significant elevation of myocardium injury biomarkers, including CK-MB, high-sensitivity cardiac troponini I (hs-cTnI), and Mb, in the non-survivor group. These myocardium injury biomarkers appeared to correlate with the time of survival, and two multivariate models have suggested hs-cTnI was a novel prognostic factor with a sensitivity of 75.0% and a specificity of 84.9%.

Conclusions: Altogether, our study highlighted the prognostic significance of myocardium injury biomarkers in critically ill COVID-19 patients. Monitoring myocardium injury biomarkers would predict patient survival and guide therapeutic strategy.
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http://dx.doi.org/10.21037/apm-20-2112DOI Listing
November 2020

A Network Pharmacology Technique to Investigate the Synergistic Mechanisms of and in Treatment of Cardio-Cerebral Vascular Diseases.

Evid Based Complement Alternat Med 2020 5;2020:6937186. Epub 2020 Oct 5.

College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China.

Objective: This study is aimed to analyze the active ingredients, drug targets, and related pathways in the combination of (SM) and (RP) in the treatment of cardio-cerebral vascular diseases (CCVDs).

Method: The ingredients and targets of SM and RP were obtained from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), and the disease targets were obtained from Therapeutic Target Database (TTD), National Center for Biotechnology Information (NCBI), and Online Mendelian Inheritance in Man (OMIM) Database. The synergistic mechanisms of the SM and RP were evaluated by gene ontology (GO) enrichment analyses and Kyoto encyclopedia of genes and genomes (KEGG) path enrichment analyses.

Result: A total of 61 active ingredients and 58 common targets were identified in this study. KEGG pathway enrichment analysis results showed that SM- and RP-regulated pathways were mainly inflammatory processes, immunosuppression, and cardiovascular systems. The component-target-pathway network indicated that SM and RP exert a synergistic mechanism for CCVDs through PTGS2 target in PI3k-Akt, TNF, and Jak-STAT signaling pathways.

Conclusion: In summary, this study clarified the synergistic mechanisms of SM and RP, which can provide a better understanding of effect in the treatment of CCVDs.
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http://dx.doi.org/10.1155/2020/6937186DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7566220PMC
October 2020

Recent advances in ultrathin two-dimensional materials and biomedical applications for reactive oxygen species generation and scavenging.

Nanoscale 2020 Oct 23;12(38):19516-19535. Epub 2020 Sep 23.

School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, P.R. China.

Graphene and graphene-like two-dimensional (2D) nanomaterials, such as black phosphorus (BP), transition metal carbides/carbonitrides (MXene) and transition metal dichalcogenides (TMD), have been extensively studied in recent years due to their unique physical and chemical properties. With atomic-scale thickness, these 2D materials and their derivatives can react with ROS and even scavenge ROS in the dark. With excellent biocompatibility and biosafety, they show great application potential in the antioxidant field and ROS detection for diagnosis. They can also generate ROS under light and be applied in antibacterial, photodynamic therapy (PDT), and other biomedical fields. Understanding the degradation mechanism of 2D nanomaterials by ROS generated under ambient conditions is crucial to developing air stable devices and expanding their application ranges. In this review, we summarize recent advances in 2D materials with a focus on the relationship between their intrinsic structure and the ROS scavenging or generating ability. We have also highlighted important guidelines for the design and synthesis of highly efficient ROS scavenging or generating 2D materials along with their biomedical applications.
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http://dx.doi.org/10.1039/d0nr05746kDOI Listing
October 2020

Zbtb20 deficiency causes cardiac contractile dysfunction in mice.

FASEB J 2020 10 26;34(10):13862-13876. Epub 2020 Aug 26.

Department of Pathophysiology, Naval Medical University, Shanghai, China.

The zinc-finger protein ZBTB20 regulates development and metabolism in multiple systems, and is essential for postnatal survival in mice. However, its potential role in the cardiovascular system remains undefined. Here, we demonstrate that ZBTB20 is critically involved in the regulation of cardiac contractility and blood pressure in mice. At the age of 16 days, the relatively healthy Zbtb20-null mice exhibited hypotension without obvious change of heart rate or other evidence for heart failure. Moreover, Zbtb20 deletion led to a marked reduction in heart size, left ventricular wall thickness, and cell size of cardiomyocytes, which was largely proportional to the decreased body growth. Notably, echocardiographic and hemodynamic analyses showed that cardiac contractility was greatly impaired in the absence of ZBTB20. Mechanistically, ZBTB20 deficiency decreased cardiac ATP contents, and compromised the enzyme activity of mitochondrial complex I in heart as well as L-type calcium current density in cardiomyocytes. Furthermore, the developmental activation of some mitochondrial function-related genes was significantly attenuated in Zbtb20-null myocardium, which included Hspb8, Ckmt2, Cox7a1, Tfrc, and Ogdhl. Put together, these results suggest that ZBTB20 plays a crucial role in the regulation of heart development, energy metabolism, and contractility.
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http://dx.doi.org/10.1096/fj.202000160RRDOI Listing
October 2020

Downregulation of RRM2 Attenuates Retroperitoneal Liposarcoma Progression via the Akt/mTOR/4EBP1 Pathway: Clinical, Biological, and Therapeutic Significance.

Onco Targets Ther 2020 3;13:6523-6537. Epub 2020 Jul 3.

Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Hepato-Pancreato-Biliary Surgery, Peking University Cancer Hospital & Institute, Beijing 100142, People's Republic of China.

Background: Retroperitoneal liposarcoma (RLPS) is a rare tumor with high recurrence rate. Ribonucleotide reductase small subunit M2 (RRM2) protein is essential for DNA synthesis and replication. Our previous study has demonstrated that RRM2 downregulation inhibited the proliferation of RLPS cells, but further association between RRM2 and RLPS and relevant mechanisms remains to be explored.

Methods: RRM2 expression was evaluated in RLPS tumor tissues and cell lines by using real-time PCR and immunohistochemical analysis. The effect of RRM2 downregulation on cell proliferation, apoptosis, cell cycle, cell migration and invasion was tested by lentivirus. The effect of RRM2 inhibition on tumor growth in vivo was assessed by using patient-derived tumor xenograft (PDX) of RLPS and RRM2 inhibitor. The underlying mechanisms of RRM2 in RLPS were explored by protein microarray and Western blotting.

Results: The results showed that RRM2 mRNA expression was higher in RLPS tissues than in normal fatty tissues (P<0.001). RRM2 expression was higher in the dedifferentiated, myxoid/round cell, and pleomorphic subtypes (P=0.027), and it was also higher in the high-grade RLPS tissues compared to that in the low-grade RLPS tissues (P=0.004). There was no correlation between RRM2 expression and overall survival (OS) or disease-free survival (DFS) in this group of RLPS patients (P>0.05). RRM2 downregulation inhibited cell proliferation, promoted cell apoptosis, facilitated cell cycle from G1 phase to S phase and inhibited cell migration and invasion. Inhibition of RRM2 suppressed tumor growth in NOD/SCID mice. Protein microarray and Western blot verification showed that activity of Akt/mammalian target of rapamycin/eukaryotic translation initiation factor 4E binding protein 1 (Akt/mTOR/4EBP1) pathway was downregulated along with RRM2 downregulation.

Conclusion: RRM2 was overexpressed in RLPS tissues, and downregulation of RRM2 could inhibit RLPS progression. In addition, suppression of RRM2 is expected to be a promising treatment for RLPS patients.
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http://dx.doi.org/10.2147/OTT.S246613DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7342604PMC
July 2020

Eutyscoparols A-G, polyketide derivatives from endophytic fungus Eutypella scoparia SCBG-8.

Fitoterapia 2020 Oct 3;146:104681. Epub 2020 Jul 3.

Key Laboratory of Plant Resources Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China; Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, People's Republic of China. Electronic address:

The chemical investigation on Eutypella scoparia SCBG-8, an endophytic fungus isolated from the leaves of Leptospermum brachyandrum, has resulted in the isolation of six new phenolic compounds eutyscoparols A-F (1-6) and one new natural product eutyscoparol G (7). The structures and absolute configurations of compounds 1-7 were determined by extensive chemical and spectroscopic analyses such as single crystal X-ray diffractions. Moreover, all compounds were evaluated for their antibacterial and cytotoxic activities in vitro.
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http://dx.doi.org/10.1016/j.fitote.2020.104681DOI Listing
October 2020

Identification of TYMS as a promoting factor of retroperitoneal liposarcoma progression: Bioinformatics analysis and biological evidence.

Oncol Rep 2020 08 5;44(2):565-576. Epub 2020 Jun 5.

Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Hepato‑Pancreato‑Biliary Surgery, Peking University Cancer Hospital and Institute, Beijing 100142, P.R. China.

Retroperitoneal liposarcoma (RLPS) is one of the most common types of retroperitoneal sarcomas, and has a high recurrence rate. There is an urgent need to further explore its pathogenesis and develop more effective treatment strategies. The aim of the present study was to identify potential driver genes of RLPS through bioinformatics analysis and molecular biology to elucidate potential targets that are suitable for further analysis for the treatment of RLPS. Differentially expressed genes (DEGs) between liposarcoma and normal fatty (NF) tissues were identified based on microarray data through bioinformatics analysis, and thymidylate synthase (TYMS) was selected from the DEGs, based on high content screening (HCS). TYMS expression was evaluated in RLPS tumor tissues and cell lines. A total of 21 RLPS tissues and 10 NF frozen tissues were used for reverse transcription‑quantitative PCR, and 47 RLPS formalin‑fixed specimens were used for immunohistochemical analysis. The effect of TYMS downregulation on cell proliferation, apoptosis, cell cycle progression, and cell migration and invasion were evaluated using lentivirus‑mediated short hairpin RNA. The underlying mechanisms of TYMS in RLPS were examined by protein microarray and verified by western blotting. A total of 855 DEGs were identified. TYMS knockdown had the most notable effect on the proliferative capacity of RLPS cells according to the HCS results. TYMS mRNA expression levels were higher in RLPS tissues compared with NF tissues (P<0.001). TYMS expression was higher in high‑grade RLPS tissues compared with low‑grade RLPS tissues (P=0.003). The patients with positive TYMS expression had a worse overall survival (OS) and disease‑free survival (DFS) compared with the patients with negative TYMS expression (OS, P=0.024; DFS, P=0.030). The knockdown of TYMS reduced proliferation, promoted apoptosis, facilitated cell cycle progression from G1 to S phase, and reduced cell migration and invasion of RLPS cells. Protein microarray analysis and western blotting showed that the Janus Kinase/Signal transducers and activators of transcription pathway was downregulated following TYMS knockdown. In conclusion, TYMS expression is upregulated in RLPS tissues, and downregulation of TYMS reduces RLPS progression.
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http://dx.doi.org/10.3892/or.2020.7635DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7336505PMC
August 2020

Triterpenoids with antiproliferative activities from the twigs and leaves of .

J Asian Nat Prod Res 2021 Aug 1;23(8):796-802. Epub 2020 Jul 1.

Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, China.

One new pentacyclic triterpenoid, urs-12,16-dien-3-one (), together with twelve known pentacyclic triterpenoids (), were isolated from the twigs and leaves of . Their structures were characterized by their 1D- and 2 D-NMR spectra analysis and mass spectra studies. Furthermore, all isolated compounds were tested the inhibitory effect on proliferation of six human cancer cell lines , including NCI-H441, NCI-H460, A549, SKOV3, hela, and caki-1 cells. Among them, compounds , , , , , and exhibited moderate antiproliferative activities with IC values ranging from 3.85 to 33.31 M.
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http://dx.doi.org/10.1080/10286020.2020.1779708DOI Listing
August 2021

Roles of Mso1 and the SM protein Sec1 in efficient vesicle fusion during fission yeast cytokinesis.

Mol Biol Cell 2020 07 20;31(15):1570-1583. Epub 2020 May 20.

Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.

Membrane trafficking during cytokinesis is essential for the delivery of membrane lipids and cargoes to the division site. However, the molecular mechanisms are still incompletely understood. In this study, we demonstrate the importance of uncharacterized fission yeast proteins Mso1 and Sec1 in membrane trafficking during cytokinesis. Fission yeast Mso1 shares homology with budding yeast Mso1 and human Mint1, proteins that interact with Sec1/Munc18 family proteins during vesicle fusion. Sec1/Munc18 proteins and their interactors are important regulators of SNARE complex formation during vesicle fusion. The roles of these proteins in vesicle trafficking during cytokinesis have been barely studied. Here, we show that fission yeast Mso1 is also a Sec1-binding protein and Mso1 and Sec1 localize to the division site interdependently during cytokinesis. The loss of Sec1 localization in cells results in a decrease in vesicle fusion and cytokinesis defects such as slow ring constriction, defective ring disassembly, and delayed plasma membrane closure. We also find that Mso1 and Sec1 may have functions independent of the exocyst tethering complex on the plasma membrane at the division site. Together, Mso1 and Sec1 play essential roles in regulating vesicle fusion and cargo delivery at the division site during cytokinesis.
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http://dx.doi.org/10.1091/mbc.E20-01-0067DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7521796PMC
July 2020

Two New Abietane Diterpenoids from Selaginella moellendorffii Hieron.

Chem Biodivers 2020 Jun 7;17(6):e2000111. Epub 2020 May 7.

Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410013, P. R. China.

Two new abietane diterpenoids, (3S,5R,10S)-3-hydroxy-12-O-demethyl-11-deoxy-19(4→3)-abeo-cryptojaponol, 12,19-dihydroxyabieta-8,11,13-trien-7-one, were isolated from Selaginella moellendorffii Hieron., together with one known abietane diterpenoid and four known tetracyclic triterpenoids. Their structures were characterized by their 1D- and 2D-NMR, ECD and mass spectral studies. All compounds were tested for their inhibitory effects on proliferation of three human cancer cells (human non-small-cell lung carcinoma cell lines A549 and human breast adenocarcinoma cell lines MDA-MB-231 and MCF-7) in vitro. Among them, three compounds displayed modest cytotoxic activities against the above three human cancer cell lines with IC values ranging from 16.28 to 40.67 μM.
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http://dx.doi.org/10.1002/cbdv.202000111DOI Listing
June 2020

A time series of land cover maps of South Asia from 2001 to 2015 generated using AVHRR GIMMS NDVI3g data.

Environ Sci Pollut Res Int 2020 Jun 2;27(16):20309-20320. Epub 2020 Apr 2.

University of Chinese Academy of Sciences, Beijing, 100049, China.

In South Asia, key differences in annual land use and land cover (LULC) take place due to climate change, global warming, human activity, biodiversity, and hydrology. So, it is very important to get accurate land cover information for this region. An annual LULC map that covers a comprehensive period is a major dataset for climatologically study. While yearly worldwide maps of LULC are produced from Moderate Resolution Imaging Spectroradiometer (MODIS) dataset, in 2001, the first LULC map of MODIS is generated which restrictions the perspective climatologically analysis. This research work generated a time series of yearly LULC maps of South Asia from 2001 to 2015 by using random forest classification from AVHRR GIMMS NDVI3g data. The MODIS land cover product such as (MCD12Q1) was used as a reference data for the trained classifier. The result was validated by using time series of annual LULC maps, and the spatiotemporal dynamic of LULC maps was illustrated in the last 15 years from 2001 to 2015. The simplified sixteen class versions of our 15-year overall accuracy of a land cover map are 86.70%, and 1.23% higher than that of MODIS maps. The change detection indicated that, for the last 15 years, the class of closed shrublands, savannas, croplands, urban and built-up land, barren, and cropland per natural vegetation mosaics increase notably during the 2001 to 2015, and in contrast, the class of woody savannas, evergreen needleleaf forests, open shrublands, grasslands, mixed forests, permanent wetlands, permanent snow and ice, evergreen broadleaf forests, and water bodies decrease notably during 2001 to 2015. These yearly land cover maps will be an essential dataset for the upcoming climate study, where time series of LULC maps accessibility is restricted.
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http://dx.doi.org/10.1007/s11356-020-08433-9DOI Listing
June 2020

Monitoring drought using composite drought indices based on remote sensing.

Sci Total Environ 2020 Apr 22;711:134585. Epub 2019 Nov 22.

College of Computer Science and Technology, Excellent Research Center of Space Information and Earth Big Data, Qingdao University, Shandong, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address:

Drought is one of the most frequent disasters occurring in North China and has a great influence on agriculture, ecology and economy. To monitor drought of typical dry areas in North China, Shandong Province, this paper proposed composite drought indices using multivariable linear regression (MCDIs) to integrate Tropical Rainfall Measuring Mission (TRMM) derived precipitation, Global Land Data Assimilation System Version 2.1 (GLDAS-2.1) derived soil moisture, Moderate Resolution Imaging Spectroradiometer (MODIS) derived land surface temperature (LST) and normalized difference vegetation index (NDVI) from 2013 to 2017 (March to September). Pearson correlation analyses were performed between single remote sensing drought indices and in-situ drought indices, standardized precipitation evapotranspiration index (SPEI), in different time scales to assess the capability of single indices over Shandong Province. The multivariable linear regression method was used to established MCDIs, and mediator and moderator variables were introduced to optimize the model. The correlation coefficients (r) between MCDIs and SPEIs was higher than that between each single index and SPEIs. Additionally, when we investigate the correlations of different MCDIs with both standardized precipitation index (SPI) and moisture index (MI), the highest r values with both 1-month SPI and MI were acquired by the MCDI based on 1-month SPEI (MCDI-1). This suggested MCDI-1 was suitable to monitor meteorological drought. Also, the comparison between MCDI based on 9-month SPEI (MCDI-9) and soil moisture showed MCDI-9 was a good indicator for agricultural drought. Therefore, multivariable linear regression and MCDIs were recommended to be an effective method and indices for monitoring drought across Shandong Province and similar areas.
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http://dx.doi.org/10.1016/j.scitotenv.2019.134585DOI Listing
April 2020

Monitoring land cover change detection with NOAA-AVHRR and MODIS remotely sensed data in the North and West of Africa from 1982 to 2015.

Environ Sci Pollut Res Int 2020 Feb 20;27(6):5873-5889. Epub 2019 Dec 20.

School of Automation, Qingdao University, Qingdao, 266071, China.

Mapping land cover changes (LCC) cover three decades over North and West Africa regions provides critical insights for the climate research that inspects the land-atmosphere interaction. LCC is a serious problem in the Earth science domain for this impacts the regional climate by modifying the distribution of terrestrial carbon stocking and roughness of the Earth's surface. In this study, the normalized difference vegetation index (NDVI) generated from advanced very high resolution radiometer (AVHRR) was used to produce a continuous set of annual land cover (LC) maps of land cover over North and West Africa between 1982 and 2015, based on the random forest classification. We used the MODIS land cover product (MCD12Q1) as a reference data for training the classifier. The result has validated using annual LC maps listed by time series and the spatio-temporal dynamics of land cover has illustrated over the last three decades. The comparison with Google Earth image 2015 shows that the overall accuracy of the simpler nine-class type of our land cover 2015 map is 76% and 2% higher than that of the MODIS map of the same year. The detection of changes indicated that over the last three decades, the urban and built-up, barren or sparsely vegetated, savannas and deciduous broadleaf forest have increased; in contrast, the open shrublands, woody savannas and water bodies have decreased.
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http://dx.doi.org/10.1007/s11356-019-07216-1DOI Listing
February 2020

Assessment of climate impact on vegetation dynamics over East Africa from 1982 to 2015.

Sci Rep 2019 11 14;9(1):16865. Epub 2019 Nov 14.

Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, 100094, China.

Located across the equator, the East Africa region is among regions of Africa which have previously known the severe vegetation degradation. Some known reasons are associated with the climate change events and unprofessional agricultural practices. For this purpose, the Advanced Very High Resolution Radiometer (AVHRR) version 3 NDVI (NDVI3g) and Climate Research Unit (CRU) datasets for precipitation and temperature were used to assess the impact of climate factors on vegetation dynamics over East Africa from 1982 to 2015. Pearson correlation of NDVI and climate factors were also explored to investigate the short (October - December) rainy seasons. The phenological metrics of the region was also extracted to understand the seasonal cycle of vegetation. The results show that a positive linear trend of 14.50 × 10 for mean annual NDVI before 1998, where as a negative linear trend of -9.64 × 10 was found after 1998. The Break Point (BP) was obtained in 1998, which suggests to nonlinear responses of NDVI to climate and non-climate drivers. ENSO-vegetation in El-nino years showed a weak teleconnection between ENSO and vegetation growth changes of croplands. Also, the analyzed correlations on NDVI data resulted to the higher correlation between NDVI and precipitation than that with temperature. The Hurst exponent result showed that about, 18.63% pixels exhibited a behavior, typical of random walk (H = 0.5) suggesting that NDVI growth changes may eventually persist, overturn or fluctuate randomly in the future depending on the drivers. Vegetation trends with sustainable (unsustainable) trends were 36.8% (44.6%). Strikingly, about 20% of the total vegetated area showed unsustainable trend from degradation to amelioration. More so, results reveal that the vegetation of the croplands (non-croplands) over East Africa changed insignificantly by 6.9 × 10/yr (5.16 × 10/yr), suggesting that non-croplands are fast getting reduced Nonetheless, the NDVI growth responses to monthly and seasonal changes in climate were adjudged to be complex and dynamic. Seasonally, the short rainy season showed the higher variability in NDVI than the long rainy season. Also, the DJF, MAM and SON seasons are strongly driven by precipitation variation effect of ENSO versus NDVI series.
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http://dx.doi.org/10.1038/s41598-019-53150-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6856068PMC
November 2019
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