The frequency of extreme weather events, such as drought, is increasing under climate change in some areas. Grassland ecosystems are extremely sensitive to drought. Here we sought to determine which ...vegetation types are the most vulnerable drought within the Xilinguole grasslands of Inner Mongolia and to establish methods to quantitatively evaluate the effects of different drought levels on grassland productivity and economic losses. Over the past 20 years, the total annual precipitation in the Xilinguole League decreased by 24–52%, resulting in a reduction in annual pasture yield of 31–237 kg/ha and a loss of livestock grazing capacity of 3–20 head/10 ha, causing 4–26 billion yuan in direct economic losses. Across the league, 78% of drought-induced direct economic losses were concentrated in ecologically vulnerable areas, including sandy and desert grasslands and typical grasslands at the northern end and in southwestern areas. Grassland net primary productivity (NPP) was sensitive to and significantly affected by drought. As the standardised precipitation evapotranspiration index (SPEI) drought level increased, NPP loss rate increased significantly by more than 20% for each drought level. The effects of increasing drought on NPP varied within grassland types, and the effects of a given drought level were different across grassland types. Typical grasslands suffered high losses at all drought stages. Meadow grasslands adjusted relatively well to drought as the rate of grassland NPP loss changed relatively slowly with increasing drought. Desert grasslands were less affected by light-to-moderate drought than by moderate-to-severe drought. This study provides a scientific basis for improving ecosystem resilience and drought prevention and management.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•The effects of flash drought on productivity and the relationship among influencing factors are revealed.•The sensitivity and anomaly of grassland productivity response to flash drought are ...discussed.•The time stage and type of flash drought had the greatest impact on grassland productivity.•The drought tolerance of grassland and the grassland type with the greatest risk of flash drought are determined.
Flash droughts have attracted worldwide attention because of their rapid outbreak and extensive influence. However, studies regarding the characteristics and effects of flash droughts in grassland ecosystems are insufficient. In this study, the frequency and intensity characteristics of flash droughts in the Xilinguole Grassland in China were studied. The response characteristics of the productivity of different types of grassland to flash droughts and the relationship between these characteristics and the drought tolerance of grassland were revealed. The results show that (1) flash droughts had the greatest impact on grassland net primary productivity (NPP) and rain use efficiency (RUE) in summer and spring, respectively, with a level of intensity above that of moderate drought. Strong evapotranspiration flash droughts (SEFD) require more attention from decision-makers than heat wave flash droughts (HWFD). A higher frequency and intensity of flash droughts had a greater impact on vegetation. (2) Flash droughts caused moderate negative anomalies in the NPP and RUE indices in more than 90 % of the grasslands. The longest lag time of the NPP response to flash droughts was 2 months, and NPP anomalies were affected by flash droughts for nearly 2 months. RUE was more sensitive to flash droughts than NPP. RUE responded to flash droughts within 10 days, with a decrease of more than 80 % in magnitude, which was 30 % higher than that of the NPP, and the duration of the anomaly was half that of the NPP. (3) Grasslands with a high sensitivity to flash droughts had shorter response durations, fewer abnormalities, better recovery abilities and better drought tolerance. The drought tolerance of grasslands did not increase in association with large NPP and RUE values. Desert grasslands were the most drought tolerant, while meadow grasslands were the least drought tolerant, with the highest risk of flash droughts. This study provides theoretical support for improving the ability of an ecosystem to cope with flash drought risk and scientific grassland management.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
HER3 (ErbB3), a member of the human epidermal growth factor receptor family, is frequently overexpressed in various cancers. Multiple HER3-targeting antibodies and antibody-drug conjugates (ADCs) ...were developed for the solid tumor treatment, however none of HER3-targeting agent has been approved for tumor therapy yet. We developed DB-1310, a HER3 ADC composed of a novel humanized anti-HER3 monoclonal antibody covalently linked to a proprietary DNA topoisomerase I inhibitor payload (P1021), and evaluate the efficacy and safety of DB-1310 in preclinical models.
The binding of DB-1310 to Her3 and other HER families were measured by ELISA and SPR. The competition of binding epitope for DB-1310 and patritumab was tested by FACS. The sensitivity of breast, lung, prostate and colon cancer cell lines to DB-1310 was evaluated by in vitro cell killing assay. In vivo growth inhibition study evaluated the sensitivity of DB-1310 to Her3 + breast, lung, colon and prostate cancer xenograft models. The safety profile was also measured in cynomolgus monkey.
DB-1310 binds HER3 via a novel epitope with high affinity and internalization capacity. In vitro, DB-1310 exhibited cytotoxicity in numerous HER3 + breast, lung, prostate and colon cancer cell lines. In vivo studies in HER3 + HCC1569 breast cancer, NCI-H441 lung cancer and Colo205 colon cancer xenograft models showed DB-1310 to have dose-dependent tumoricidal activity. Tumor suppression was also observed in HER3 + non-small cell lung cancer (NSCLC) and prostate cancer patient-derived xenograft (PDX) models. Moreover, DB-1310 showed stronger tumor growth-inhibitory activity than patritumab deruxtecan (HER3-DXd), which is another HER3 ADC in clinical development at the same dose. The tumor-suppressive activity of DB-1310 synergized with that of EGFR tyrosine kinase inhibitor, osimertinib, and exerted efficacy also in osimertinib-resistant PDX model. The preclinical assessment of safety in cynomolgus monkeys further revealed DB-1310 to have a good safety profile with a highest non severely toxic dose (HNSTD) of 45 mg/kg.
These finding demonstrated that DB-1310 exerted potent antitumor activities against HER3 + tumors in in vitro and in vivo models, and showed acceptable safety profiles in nonclinical species. Therefore, DB-1310 may be effective for the clinical treatment of HER3 + solid tumors.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The research of the runoff structure and its influencing factors in the Xilinhe River Basin not only provides indispensable basic data for the economic development, but also has long-term ...significance for the protection of grasslands. Based on the runoff data of Xilinhot Hydrological Station from 1960 to 2010 and the daily meteorological data of three surrounding weather stations from 1960 to 2010, the paper calculated the potential evapotranspiration with Penman’s formula and used the combination of Mann-Kendall and Pettitt to diagnose the variation points of characteristic value of runoff distribution during the year. The cumulant slope change rate method is used to quantitatively analyze the contribution rate of climate change and human activities to the uneven distribution coefficient and the complete adjustment coefficient of runoff during the year. The results show that (1) the monthly distribution of runoff in the Xilinhe River Basin is obviously “bimodal” during the year, and the uneven coefficient, complete adjustment coefficient, and concentration in the 2000s are significantly higher than those of 60s-90s. (2) In 1998, the coefficient of uneven distribution of runoff in the Xilinhe River Basin and the coefficient of complete adjustment both showed abrupt changes. (3) Climate change and human activities contributed 11.48% and 88.52% and 9.35% and 90.65% to the uneven distribution coefficient and the complete adjustment coefficient, respectively, of the runoff in the Xilinhe River Basin. Human activities are the main driving factors for changes in the distribution of runoff in the Xilinhe River Basin during the year.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
At present, flash droughts are poorly understood. Mature prevention and control measures are not available. This study aims to thoroughly explore the evolution characteristics of flash droughts in ...grassland ecosystems and to determine the meteorological driving conditions for inducing and relieving flash droughts.
We propose the concept of the strong evapotranspiration flash drought (SEFD), a new type of flash drought in mid-temperate grasslands. The frequency of SEFDs is lower than that of heat wave flash droughts (HWFDs), but the intensity and impact of SEFDs are greater than those of HWFDs. Flash droughts in grasslands exhibit a high outbreak period from May to August, with the intensity basically above that of moderate drought. HWFDs occur most frequently in June and SEFDs in May. Meadow grasslands are the type of grassland with the highest risk of flash drought. Typical grasslands are more prone to HWFDs, while desert grasslands are more prone to SEFD outbreaks.
In this study, a multifactor method was established to quantitatively evaluate the key influencing factors inducing flash droughts of different intensities in different time periods and to quantitatively predict the evolution of flash droughts into seasonal droughts. The temperature, water vapor pressure, precipitation, and wind speed were the key influencing factors of flash droughts and that the most important period in terms of inducing flash droughts is one pentad before the onset of flash drought. The outbreak rate and threshold of key influencing factors are the driving conditions for inducing flash droughts, and the recovery rate can be used as the basis for predicting whether an flash drought will evolve into a seasonal drought.
The results showed that the characteristics and driving conditions of flash droughts are different in different types of grasslands and different time periods and are different for different types of flash droughts. In the future, the impact of flash droughts will become more severe.
Display omitted
•Important research is performed in terms of improving the ability to respond to flash drought events.•A definition for a new type of flash drought in mid-temperate grassland is proposed.•The time periods and grassland types most susceptible to flash drought are obtained.•The driving conditions of flash drought induced by grassland in different months are obtained.•Quantitative prediction of the transformation of flash drought into seasonal drought is achieved.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
Glypican 3 (GPC3) expression has proved to be a critical risk factor related to prognosis in hepatocellular carcinoma (HCC) patients.
Purpose
To investigate the performance of MRI‐based ...radiomics signature in identifying GPC3‐positive HCC.
Study Type
Retrospective.
Population
An initial cohort of 293 patients with pathologically confirmed HCC was involved in this study, and patients were randomly divided into training (195) and validation (98) cohorts.
Field Strength/Sequences
Contrast‐enhanced T1‐weight MRI was performed with a 1.5T scanner.
Assessment
A total of 853 radiomic features were extracted from the volume imaging. Univariate analysis and Fisher scoring were utilized for feature reduction. Subsequently, forward stepwise feature selection and radiomics signature building were performed based on a support vector machine (SVM). Incorporating independent risk factors, a combined nomogram was developed by multivariable logistic regression modeling.
Statistical Tests
The predictive performance of the nomogram was calculated using the area under the receive operating characteristic curve (AUC). Decision curve analysis (DCA) was applied to estimate the clinical usefulness.
Results
The radiomics signature consisting of 10 selected features achieved good prediction efficacy (training cohort: AUC = 0.879, validation cohort: AUC = 0.871). Additionally, the combined nomogram integrating independent clinical risk factor α‐fetoprotein (AFP) and radiomics signature showed improved calibration and prominent predictive performance with AUCs of 0.926 and 0.914 in the training and validation cohorts, respectively.
Data Conclusion
The proposed MR‐based radiomics signature is strongly related to GPC3‐positive. The combined nomogram incorporating AFP and radiomics signature may provide an effective tool for noninvasive and individualized prediction of GPC3‐positive in patients with HCC. J. MAGN. RESON. IMAGING 2020;52:1679–1687.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
This study measured physiological factors of Ulmus pumila,namely the net photosynthetic rate( Pn),upper epidermis stomatal conductance( Gs-u),and lower epidermis stomatal conductance( Gs-l),in ...Otinday Sandland(42degrees23'N,115degrees37'E) of Inner Mongolia using Li-6400 portable photosynthesis system. Ecological factors,namely the atmospheric temperature( Ta),photosynthetically active radiation(PAR),concentration of carbon dioxide in the atmosphere(Ca),and relative humidity of the air( RH) were also examined. Based on the measured data,the relationship between Pndiurnal variation in U. pumila at various growth periods and ecological factors and physiological factors was assessed using correlation analysis,path analysis,decision coefficient analysis,and grey correlation analysis. This knowledge is essential to reveal the physiological characteristics and formulate generalizations regarding the cultivation of U. pumila in Otinday Sandland. Regardless of growth period,Pnexhibited bimodal diurnal variation w
Blood dendritic cell antigen 2 (BDCA2) is exclusively expressed on plasmacytoid dendritic cells (pDCs) whose uncontrolled production of type I IFN (IFN-I) is crucial in pathogenesis of SLE and other ...autoimmune diseases. Although anti-BDCA2 antibody therapy reduced disease activity in SLE patients, its clinical efficacy needs further improvement. We developed a novel glucocorticoid receptor agonist and used it as a payload to conjugate with an anti-BDCA2 antibody to form an BDCA2 antibody-drug conjugate (BDCA2-ADC). The activation of BDCA2-ADC was evaluated in vitro.
Inhibitory activity of BDCA2-ADC was evaluated in peripheral blood mononuclear cells or in purified pDCs under ex vivo toll-like receptor agonistic stimulation. The global gene regulation in purified pDCs was analysed by RNA-seq. The antigen-dependent payload delivery was measured by reporter assay.
The BDCA2-ADC molecule causes total suppression of IFNα production and broader inhibition of inflammatory cytokine production compared with the parental antibody in human pDCs. Global gene expression analysis confirmed that the payload and antibody acted synergistically to regulate both type I IFN signature genes and glucocorticoid responsive genes in pDCs.
Taken together, these data suggest dual mechanisms of BDCA2-ADC on pDCs and the potential for BDCA2-ADC to be the first ADC treatment for SLE in the world and a better treatment option than anti-BDCA2 antibody for SLE patients.
Continuous, smooth, and highly linear displacement output with centimeter-scale stroke and nanometer-scale resolution is greatly attractive for an ultraprecision positioning system. On the foundation ...of piezoelectric actuation and compliant mechanism, a novel linear piezomotor with minimized backward and nonlinear motion property is designed. Specifically, a driving unit capable of <inline-formula><tex-math notation="LaTeX">xy</tex-math></inline-formula>-direction decoupling displacement output is proposed to make the generated motion linear, and a flexure mechanism is introduced into the contact part to make the motion output continuous and nonbackward. Combined with double driving units and the flexure contact mechanism, a motion generation strategy is presented. For performing the motion generation strategy well, the kinematics model of the piezomotor is established. Then, the dimension parameters are optimized. After theoretical derivations, the piezomotor is analyzed and evaluated by finite-element analysis simulation. Finally, a proper control waveform is designed, and the motion generation performance tests are successfully carried out. The results uniformly confirm that the proposed piezomotor can output ultraprecision motion with 8-nm resolution and 10-mm stroke in a continuous and smooth manner, and the backward and nonlinear effects are successfully minimized within 100 Hz.
PDF
