Overexpression of AtMYB2 Promotes Tolerance to Salt Stress and Accumulations of Tanshinones and Phenolic Acid in Salvia miltiorrhiza.

Salvia miltiorrhiza is a prized traditional Chinese medicinal plant species. Its red storage roots are primarily used for the treatment of cardiovascular and cerebrovascular diseases. In this study, a transcription factor gene AtMYB2 was cloned and introduced into Salvia miltiorrhiza for ectopic expression. Overexpression of AtMYB2 enhanced salt stress resistance in S. miltiorrhiza, leading to a more resilient phenotype in transgenic plants exposed to high-salinity conditions. Physiological experiments have revealed that overexpression of AtMYB2 can decrease the accumulation of reactive oxygen species (ROS) during salt stress, boost the activity of antioxidant enzymes, and mitigate oxidative damage to cell membranes. In addition, overexpression of AtMYB2 promotes the synthesis of tanshinones and phenolic acids by upregulating the expression of biosynthetic pathway genes, resulting in increased levels of these secondary metabolites. In summary, our findings demonstrate that AtMYB2 not only enhances plant tolerance to salt stress, but also increases the accumulation of secondary metabolites in S. miltiorrhiza. Our study lays a solid foundation for uncovering the molecular mechanisms governed by AtMYB2 and holds significant implications for the molecular breeding of high-quality S. miltiorrhiza varieties.

Multilayer network-based channel selection for motor imagery brain-computer interface.

Objective. The number of electrode channels in a motor imagery-based brain-computer interface (MI-BCI) system influences not only its decoding performance, but also its convenience for use in applications. Although many channel selection methods have been proposed in the literature, they are usually based on the univariate features of a single channel. This leads to a loss of the interaction between channels and the exchange of information between networks operating at different frequency bands.Approach. We integrate brain networks containing four frequency bands into a multilayer network framework and propose a multilayer network-based channel selection (MNCS) method for MI-BCI systems. A graph learning-based method is used to estimate the multilayer network from electroencephalogram (EEG) data that are filtered by multiple frequency bands. The multilayer participation coefficient of the multilayer network is then computed to select EEG channels that do not contain redundant information. Furthermore, the common spatial pattern (CSP) method is used to extract effective features. Finally, a support vector machine classifier with a linear kernel is trained to accurately identify MI tasks.Main results. We used three publicly available datasets from the BCI Competition containing data on 12 healthy subjects and one dataset containing data on 15 stroke patients to validate the effectiveness of our proposed method. The results showed that the proposed MNCS method outperforms all channels (85.8% vs. 93.1%, 84.4% vs. 89.0%, 71.7% vs. 79.4%, and 72.7% vs. 84.0%). Moreover, it achieved significantly higher decoding accuracies on MI-BCI systems than state-of-the-art methods (pairedt-tests,p< 0.05).Significance. The experimental results showed that the proposed MNCS method can select appropriate channels to improve the decoding performance as well as the convenience of the application of MI-BCI systems.

Perioperative Electroacupuncture Can Accelerate the Recovery of Gastrointestinal Function in Cancer Patients Undergoing Pancreatectomy or Gastrectomy: A Randomized Controlled Trial.

The effect of perioperative acupuncture on accelerating gastrointestinal function recovery has been reported in colorectal surgery and distal gastrectomy (Billroth-II). However, the evidence in pancreatectomy and other gastrectomy is still limited. A prospective, randomized controlled trial was conducted between May 2018 and August 2019. Consecutive patients undergoing pancreatectomy or gastrectomy in our hospital were randomly assigned to the electroacupuncture (EA) group and the control group. The patients in the EA group received transcutaneous EA on Bai-hui (GV20), Nei-guan (PC6), Tian-shu (ST25), and Zu-san-li (ST36) once a day in the afternoon, and the control group received sham EA. Primary outcomes were the time to first flatus and time to first defecation. In total, 461 patients were randomly assigned to the groups, and 385 were analyzed finally (EA group, n = 201; control group, n = 184). Time to first flatus (3.0 ± 0.7 vs 4.2 ± 1.0, P < 0.001) and first defecation (4.2 ± 0.9 vs 5.4 ± 1.2, P < 0.001) in the EA group were significantly shorter than those in the control group. Of patients undergoing pancreatectomy, those undergoing pancreaticoduodenectomy and intraoperative radiation therapy (IORT) surgery benefitted from EA in time to first flatus (P < 0.001) and first defecation (P < 0.001), while those undergoing distal pancreatectomy did not (P flatus=0.157, P defecation=0.007) completely. Of patients undergoing gastrectomy, those undergoing total gastrectomy and distal gastrectomy (Billroth-II) benefitted from EA (P < 0.001), as did those undergoing proximal gastrectomy (P=0.015). Patients undergoing distal gastrectomy (Billroth-I) benefitted from EA in time to first defecation (P=0.012) but not flatus (P=0.051). The time of parenteral nutrition, hospital stay, and time to first independent walk in the EA group were shorter than those in the control group. No severe EA complications were reported. EA was safe and effective in accelerating postoperative gastrointestinal function recovery. Patients undergoing pancreaticoduodenectomy, IORT surgery, total gastrectomy, proximal gastrectomy, or distal gastrectomy (Billroth-II) could benefit from EA. This trial is registered with NCT03291574.

How to rescue high-dose methotrexate induced nephrotoxicity and literature review about hemodiafiltration?

Methotrexate (MTX) is a highly renal and liver toxicity drug used in hematological malignancy treatment in children and adults. High-dose methotrexate (HD-MTX) therapy may cause impairment of kidney and decrease the elimination of MTX, at the same time, the serum concentration of MTX increased. Today the treatment for preventing MTX toxicity after renal shutdown is Carboxypeptidase. We report a patient who experienced nephrotoxicity after the HD-MTX infusions during the treatment for non-Hodgkin lymphoma (NHL) and received hemodiafiltration (HDF) with large dose of leucovorin (LV) to treat MTX intoxication. LV is very potent in the prevention of neurotoxicity and administration of LV could protect the normal cells, but the dosage and duration of LV should be according to the MTX concentration. Although a large dose of LV was applied, the patient's condition did not improve. It was found that the HDF with large dose of LV to save the patient and steadily improved the patient's clinical condition.

Deep Learning of Motor Imagery EEG Classification for Brain-Computer Interface Illiterate Subject.

BCI illiterate subject is defined as the subject who cannot achieve accuracy higher than 70%. BCI illiterate subject cannot produce stronger contralateral ERD/ERS activity, thus most of the frequency band-based algorithms cannot obtain higher accuracy. Deep learning with convolutional neural networks (CNN) has revolutionized in many recent studies to learn features and classify different types of data through end-to-end learning. We designed a CNN to extract motor imagery EEG features and then do classification for BCI illiterate subjects in this work. Results showed that the average classification accuracy increased by 18.4% compared with the CSP+LDA algorithm, and the accuracies obtained by CNN exceed 70% for 9 of 11 subjects particularly. CNN requires only a little prior knowledge, thus the features it extracted are not limited in frequency band, but because the poor interpretability of deep learning, we do not know which kind of feature CNN extracted until now. Our future study will focus on visualizing the extracted features to support our conclusions.

Identification of Glutathione Peroxidase (GPX) Gene Family in Rhodiola crenulata and Gene Expression Analysis under Stress Conditions.

Glutathione peroxidases (GPXs) are important enzymes in the glutathione-ascorbate cycle for catalyzing the reduction of H2O2 or organic hydroperoxides to water. GPXs play an essential role in plant growth and development by participating in photosynthesis, respiration, and stress tolerance. Rhodiola crenulata is a popular traditional Chinese medicinal plant which displays an extreme energy of tolerance to harsh alpine climate. The GPXs gene family might provide R. crenulata for extensively tolerance to environment stimulus. In this study, five GPX genes were isolated from R. crenulata. The protein amino acid sequences were analyzed by bioinformation softwares with the results that RcGPXs gene sequences contained three conserve cysteine residues, and the subcellular location predication were in the chloroplast, endoplasmic reticulum, or cytoplasm. Five RcGPXs members presented spatial and temporal specific expression with higher levels in young and green organs. And the expression patterns of RcGPXs in response to stresses or plant hormones were investigated by quantitative real-time PCR. In addition, the putative interaction proteins of RcGPXs were obtained by yeast two-hybrid with the results that RcGPXs could physically interact with specific proteins of multiple pathways like transcription factor, calmodulin, thioredoxin, and abscisic acid signal pathway. These results showed the regulation mechanism of RcGPXs were complicated and they were necessary for R. crenulata to adapt to the treacherous weather in highland.

Photoluminescence mechanism and applications of Zn-doped carbon dots.

Heteroatom-doped carbon dots (CDs) with excellent optical characteristics and negligible toxicity have emerged in many applications including bioimaging, biosensing, photocatalysis, and photothermal therapy. The metal-doping of CDs using various heteroatoms results in an enhancement of the photophysics but also imparts them with multifunctionality. However, unlike nonmetal doping, typical metal doping results in low fluorescence quantum yields (QYs), and an unclear photoluminescence mechanism. In this contribution, we detail results concerning zinc doped CDs (Zn-CDs) with QYs of up to 35%. The zinc ion charges serve as a surface passivating agent and prevent the aggregation of graphene π-π stacking, leading to an increase in the QY of the Zn-CDs. Structural and chemical investigations using spectroscopic and first principle simulations further revealed the effects of zinc doping on the CDs. The robust Zn-CDs were used for the ultra-trace detection of Hg2+ with a detection limit of 0.1 µM, and a quench mechanism was proposed. The unique optical properties of the Zn-CDs have promise for use in applications such as in vivo sensing and future phototherapy applications.

Overexpression of the Glutathione Peroxidase 5 (RcGPX5) Gene From Rhodiola crenulata Increases Drought Tolerance in Salvia miltiorrhiza.

Excessive cellular accumulation of reactive oxygen species (ROS) due to environmental stresses can critically disrupt plant development and negatively affect productivity. Plant glutathione peroxidases (GPXs) play an important role in ROS scavenging by catalyzing the reduction of H2O2 and other organic hydroperoxides to protect plant cells from oxidative stress damage. RcGPX5, a member of the GPX gene family, was isolated from a traditional medicinal plant Rhodiola crenulata and constitutively expressed in Salvia miltiorrhiza under control of the CaMV 35S promoter. Transgenic plants showed increased tolerance to oxidative stress caused by application of H2O2 and drought, and had reduced production of malondialdehyde (MDA) compared with the wild type. Under drought stress, seedlings of the transgenic lines wilted later than the wild type and recovered growth 1 day after re-watering. In addition, the reduced glutathione (GSH) and total glutathione (T-GSH) contents were higher in the transgenic lines, with increased enzyme activities including glutathione reductase (GR), ascorbate peroxidase (APX), and GPX. These changes prevent H2O2 and O2 - accumulation in cells of the transgenic lines compared with wild type. Overexpression of RcGPX5 alters the relative expression levels of multiple endogenous genes in S. miltiorrhiza, including transcription factor genes and genes in the ROS and ABA pathways. In particular, RcGPX5 expression increases the mass of S. miltiorrhiza roots while reducing the concentration of the active ingredients. These results show that heterologous expression of RcGPX5 in S. miltiorrhiza can affect the regulation of multiple biochemical pathways to confer tolerance to drought stress, and RcGPX5 might act as a competitor with secondary metabolites in the S. miltiorrhiza response to environmental stimuli.

Modulating AtDREB1C Expression Improves Drought Tolerance in Salvia miltiorrhiza.

Dehydration responsive element binding proteins are transcription factors of the plant-specific AP2 family, many of which contribute to abiotic stress responses in several plant species. We investigated the possibility of increasing drought tolerance in the traditional Chinese medicinal herb, Salvia miltiorrhiza, through modulating the transcriptional regulation of AtDREB1C in transgenic plants under the control of a constitutive (35S) or drought-inducible (RD29A) promoter. AtDREB1C transgenic S. miltiorrhiza plants showed increased survival under severe drought conditions compared to the non-transgenic wild-type (WT) control. However, transgenic plants with constitutive overexpression of AtDREB1C showed considerable dwarfing relative to WT. Physiological tests suggested that the higher chlorophyll content, photosynthetic capacity, and superoxide dismutase, peroxidase, and catalase activity in the transgenic plants enhanced plant drought stress resistance compared to WT. Transcriptome analysis of S. miltiorrhiza following drought stress identified a number of differentially expressed genes (DEGs) between the AtDREB1C transgenic lines and WT. These DEGs are involved in photosynthesis, plant hormone signal transduction, phenylpropanoid biosynthesis, ribosome, starch and sucrose metabolism, and other metabolic pathways. The modified pathways involved in plant hormone signaling are thought to be one of the main causes of the increased drought tolerance of AtDREB1C transgenic S. miltiorrhiza plants.

Dynamic adhesion forces between microparticles and substrates in water.

The interactions between micrometer-sized particles and substrates in aqueous environment are fundamental to numerous natural phenomena and industrial processes. Here we report a dynamically induced enhancement in adhesion interactions between microparticles and substrates immerged in water, air, and hexane. The dynamic adhesion force was measured by pulling microsized spheres off various substrate (hydrophilic/hydrophobic) surfaces at different retracting velocities. It was observed that when the pull-off velocity varies from 0.02 to 1500 µm/s, there is 100-200% increase in adhesion force in water while it has a 100% increase in nitrogen and hexane. The dynamic adhesion enhancement reduces with increasing effective contact angle defined by the average cosine of wetting angles of the substrates and the particles, and approaches the values measured in dry nitrogen and hexane as the effective contact angle is larger than 90(o). A dynamic model was developed to predict the adhesion forces resulting from this dynamic effect, and the predictions correlate well with the experimental results. The stronger dynamic adhesion enhancement in water is mainly attributed to electrical double layers and the restructuring of water in the contact area between particles and substrates.

Synthesis of near-infrared-emitting CdTeSe and CdZnTeSe quantum dots.

We exploited the synthesis of near-infrared (NIR) emitting ternary-alloyed CdTeSe and quaternary-alloyed CdZnTeSe quantum dots (QDs) with rod and tetrapod morphologies, which have tunable emission in the NIR electromagnetic spectrum. The morphologies of the QDs depended strongly on their growth kinetics, probably due to the coordinating ligands used in the preparation. Using oleic acid, stearic acid and hexadecylamine as ligands and keeping the same reaction parameters, QDs with tetrapod and rod morphologies were created. Not only had the capping ligands influenced the morphologies of QDs, but also they influenced the optical properties of QDs. The molar ratios of Cd/Zn and Te/Se upon preparation were adjusted for investigating the effect of composition on the properties of resulting QDs. By varying the composition of QDs, the photoluminescence (PL) wavelength of QDs was tuned from 650 nm to 800 nm. To enhance PL efficiency and stability, QDs were coated with a CdZnS shell. As NIR PL has numerous advantages in biological imaging detection, these QDs hold great potential for application.

Caffeic acid 3,4-dihydroxy-phenethyl ester induces cancer cell senescence by suppressing twist expression.

Compared with traditional cytotoxic cancer therapy, therapy-induced cancer cell senescence attracts much interest because it is similarly effective, has fewer side effects, and is more efficiently cleared by immune cells. In this study, we demonstrate that unlike caffeic acid phenethyl ester, caffeic acid 3,4-dihydroxy-phenethyl ester (CADPE), which is isolated from the medicinal plants Sarcandra glabra and Teucrium pilosum, inhibits human cancer cell growth and colony formation by inducing cancer cell senescence, not apoptosis. CADPE induces cell senescence and morphology changes by increasing cellular size and cytoplasmic granularity, enhancing senescence-associated ß-galactosidase activity and differentiated embryo-chondrocyte expressed gene 1 expression, and blocking cell-cycle arrest in the G(1) phase. To help understand the underlying mechanisms, we show that CADPE significantly suppressed the expression of Twist1 and led to the up-regulation of rat sarcoma, p53, p21(WAF1/CIP1), and p16(INK4a) proteins in a dose-dependent manner, resulting in the hypophosphorylation of retinoblastoma protein. Furthermore, overexpression of Twist1 prevented CADPE-induced cell senescence in tumor cells. Therefore, our studies provide evidence for a novel role of CADPE in cancer cell senescence by targeting the Twist1-dependent senescence signaling pathway.