Epidemic spreading with migration in networked metapopulation.

Migration plays a crucial role in epidemic spreading, and its dynamic can be studied by metapopulation model. Instead of the uniform mixing hypothesis, we adopt networked metapopulation to build the model of the epidemic spreading and the individuals' migration. In these populations, individuals are connected by contact network and populations are coupled by individuals migration. With the network mean-field and the gravity law of migration, we establish the N-seat intertwined SIR model and obtain its basic reproduction number ℛ 0 . Meanwhile, we devise a non-markov Node-Search algorithm for model statistical simulations. Through the static network migration ansatz and ℛ 0 formula, we discover that migration will not directly increase the epidemic replication capacity. But when ℛ 0 > 1 , the migration will make the susceptive population evolve from metastable state (disease-free equilibrium) to stable state (endemic equilibrium), and then increase the influence area of epidemic. Re-evoluting the epidemic outbreak in Wuhan, top 94 cities empirical data validate the above mechanism. In addition, we estimate that the positive anti-epidemic measures taken by the Chinese government may have reduced 4 million cases at least during the first wave of COVID-19, which means those measures, such as the epidemiological investigation, nucleic acid detection in medium-high risk areas and isolation of confirmed cases, also play a significant role in preventing epidemic spreading after travel restriction between cities.

Ginsenoside Rgl regulates autophagy through AMPK/mTOR signaling pathway and delays brain aging in mice / 中国药理学通报

Aim To investigate the mechanism by which ginsenoside Rgl regulates autophagy anrl delays brain aging in mice through AMPK/mTOR signaling pathway.Methods C57BL/6J male mice were ran¬domly divided into four groups, namely brain aging model group ,control group, Rgl anti-aging group,auto¬phagy activator Rapamycin anti-aging group.After the modeling was completed, the test of each experimental index would be carried out on the next day.Morris wa¬ter maze experiment was used to detect the learning and memory ability of mice.Paraffin sections of the hippocampus were prepared, HE , Nissl and immunohis- tochemical staining were used to observe the morpholo¬gy of hippocampal neurons, the number of neurons and Nissl bodies was counted, and autophagy-related proteins p62 , ATG5 , ULK1 were detected.Brain tissue homogenates were prepared to detect the aetivity of brain tissue acetylcholinesterase ( AChE ).Western blot was userl to detect brain tissue autophagy-related proteins LC3II, P62, beclinl, P-AMPK/AMPK, P- mTOR/mTOR and apoptosis protein P53.Results Water maze test showed that Rgl and Hap significantly improved the learning and memory abilities of brain-ag¬ing mice.HE and Nissl staining showed that Rgl and Rap decreased necrotic cells and increased the number of Nissl bodies in the hippocampus of brain-aging mice.Immunohistochemistry staining showed that Rgl and Rap decreased the expression of neuronal autoph- agv protein P62 in hippocampus and increased the ex-pression of ATG5 and ULK1.Rgl and Rap decreased the activity of AhcE in brain-aging mice.Western blot showed that Rgl and Rap increased autophagy-related proteins LC3II, Beclinl , P-AMPK/AMPK, but de¬creased the expression of P-mTOR/mTOR, P62, P53.Conclusions Ginsenoside Rgl can effectively antago¬nize the aging effect of D-gal on mouse brain.The pos¬sible mechanism is related to the regulation of autoph- agv by Rgl through AMPK/mTOR signaling pathway.

Effects of Angelica Sinensis polysaccharide on proliferation in vitro and transplantation of human leukemia stem cells in vivo / 解剖学报

Objective To investigate the effect of Angelica Sinensis polysaccharide (ASP) on proliferation, differentiation and transplantation of human leukemia stem cells (LSCs) . Methods 1. Effect of angelica sinensis polysaccharides on proliferation of CD34

Molecular and Biochemical Characterization of Carbendazim-Resistant Botryodiplodia theobromae Field Isolates.

Stem-end rot caused by Botryodiplodia theobromae is a destructive disease of mango. B. theobromae field isolates resistant to carbendazim (MBC) were collected in Hainan Province, China. In this study, the characteristics of these field isolates with resistance to MBC were investigated. The resistance of B. theobromae isolates to MBC was stably inherited. Both the MBC-resistant and MBC-sensitive isolates had similar mycelial growth rates, pathogenicity, sensitivity to high glucose, glycerol content, and peroxidase activity. Compared with MBC-sensitive isolates, MBC-resistant isolates were more sensitive to low temperature and had a significant decrease in sensitivity to high NaCl and a significant increase in catalase (CAT) and glutathione S-transferase (GST) activities. After MBC treatment, the cell membrane permeability of the sensitive isolates was markedly increased compared with that of the resistant isolates. Analysis of the ß-tubulin gene sequence revealed point mutations resulting in substitutions at codon 198 from glutamic acid (GAG) to alanine (GCG) in moderately resistant isolates, and at codon 200 from phenylalanine (TTC) to tyrosine (TAC) in highly resistant isolates. These ß-tubulin gene mutations were consistently associated with MBC resistance. Overall, we infer that the altered cell membrane permeability and the increase in CAT and GST activities of the resistant isolates are linked to MBC resistance.

Tension-Induced Raman Enhancement of Graphene Membranes in the Stretched State.

The intensity ratio of the 2D band to the G band, I2D /IG , is a good criterion in selecting high quality monolayer graphene samples; however, the evaluation of the ultimate value of I2D /IG for intrinsic monolayer graphene is a challenging yet interesting issue. Here, an interesting tension-induced Raman enhancement phenomenon is reported in supported graphene membranes, which show a transition from the corrugated state to the stretched state in the vicinity of wells. The I2D /IG of substrate-supported graphene membranes near wells are significantly enhanced up to 16.74, which is the highest experimental value to the best of knowledge, increasing by more than 600% when the testing points approach the well edges.The macroscopic origin of this phenomenon is that corrugated graphene membranes are stretched by built-in tensions. A lattice dynamic model is proposed to successfully reveal the microscopic mechanism of this phenomenon. The theoretical results agree well with the experimental data, demonstrating that tensile stresses can depress the amplitude of in-plane vibration of sp2 -bonded carbon atoms and result in the decrease in the G band intensity. This work can be helpful in furthering the development of the method of suppressing small ripples in graphene and acquiring ultraflat 2D materials.

A transparent wound dressing based on bacterial cellulose whisker and poly(2-hydroxyethyl methacrylate).

The current study was aimed to develop a transparent wound dressing comprised of bacterial cellulose (BC) and poly (2-hydroxyethyl methacrylate) (PHEMA) hydrogel coated with silver (Ag) nanoparticles. Briefly, different concentrations of BC whiskers (BCWs) were added into the HEMA solution to form PHEMA/BCWs hydrogel with volume ratio of monomer HEMA and BCWs as 7:3 and 1:1. The addition of BCWs into PHEMA matrix improved its equilibrium water content and light transmittance about 20%-40% and 10%, respectively. The Young's modulus for PHEMA was found to be 0.72MPa, which was improved to 0.57MPa and 0.50MPa for PHEMA/BCWs 7:3 and PHEMA/BCWs 1:1, respectively. Further, immersion of PHEMA/BCWs hydrogel in the AgNO3 and NaBH4 solutions bestowed it with antibacterial property and produced inhibition zones of 0.5±0.15cm and 0.25±0.15cm against Escherichia coli and Staphylococcus aureus, respectively. Similarly, PHEMA/BCWs prepared with 0.001M AgNO3 and 0.001M NaBH4 solutions showed 99% and 90% reduction in colony forming unit (CFU) for E. coli and S. aureus, respectively, after 24h. The PHEMA/BCWs/Ag hydrogel facilitated the growth of NIH3T3 fibroblast, showing their low toxicity. These results demonstrate the suitability of PHEMA/BCWs/Ag hydrogel for its application as potential transparent wound dressing material for skin repair.

LKB1 regulates epithelial-mesenchymal transition in Peutz-Jeghers hamartoma and intestinal epithelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the molecular mechanism by which LKB1 regulates epithelial-mesenchymal transition (EMT) in Peutz-Jeghers hamartoma and intestinal epithelial cells.</p><p><b>METHODS</b>Immunohistochemistry was used to detect gene expression of LKB1, E-cadherin, and vimentin in 20 hamartoma tissues and 10 normal intestinal tissues, and collagen fiber deposition was analyzed using Masson trichrome staining. Normal intestinal epithelial NCM460 cells were transfected with LKB1 shRNA plasmid or negative control via lentiviral vectors, and the role of LKB1 in cell polarization and migration were determined using CCK8 and Transwell assays. Western blotting, quantitative real-time PCR (qPCR) and immunofluorescence were used to assess the alterations of EMT markers in the cells with LKB1 knockdown.</p><p><b>RESULTS</b>Compared with normal intestinal tissues, hamartoma polyps showed significantly decreased LKB1 and E-cadherin expressions and increased vimentin expression with increased collagen fiber deposition. The cells with LKB1 knockdown exhibited enhanced cell proliferation and migration activities (P<0.01). Western blot analysis, qPCR and immunofluorescence all detected decreased E-cadherin and increased N-cadherin, vimentin, Snail, and Slug expressions in the cells with LKB1 knockdown.</p><p><b>CONCLUSION</b>s LKB1 deficiency triggers EMT in intestinal epithelial cells and Peutz-Jeghers hamartoma, suggesting that EMT can serve as the therapeutic target for treatment of Peutz-Jeghers syndrome.</p>

Discussion on Clinical and Diagnosis Program of Integrative Medicine / 中国中西医结合杂志

Facing current situation of integrative medicine (IM), authors put forward that clinical and diagnosis program of IM could be carried out from clinical path, pathogenesis, treatment theory and philosophy, and so on, but with different integration degrees. Meanwhile, formulation of concrete program should be disease-targetedly set up, and adjusted from person to person, from place to place, from time to time. As for settled IM program , authors could evaluate it from whether Chinese medicine and Western medicine have formed complementary, synergistic, excitatory actions, and toxicity attenuation; whether more problems could be solved in efficacy, safety, practicability, and economy than previous single mode.

Influence of SNCG transfection on the effectiveness of anti-tumor drugs in PC-3 cell lines / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the sensitivity of the PC-3 cell lines transfected with the PCI-NEO-SNCG plasmid to Cisplatin (DDP), 5-Fluorouracil (5-FU), Adriamycin (ADM), Vincristine (VCR) and Paclitaxel (TAX), and to explore the influence of the SNCG expression on the effectiveness of anti-tumor drugs.</p><p><b>METHODS</b>The plasmids PCI-NEO and PCI-NEO-SNCG were transfected into the hormone-independent prostate cancer cell lines PC-3. RT-PCR was adopted to examine the expression of SNCG in the PC-3 cell lines. The MTT method was employed to detect the suppressive effects of different anti-tumor drugs (DDP, ADM, 5-FU, VCR and TAX) on the cell lines transfected with PCI-NEO and PCI-NEO-SNCG. Flow cytometry was used to analyze the cell cycles and apoptosis of the transfected cells treated with TAX.</p><p><b>RESULTS</b>The 5 anti-tumor drugs suppressed the growth of the cell lines transfected with the plasmids PCI-NEO and PCI-NEO-SNCG in a time-dependant manner. The comparison between the growth-suppressing effects of different anti-tumor drugs on the PC-3 cell lines showed no significant differences between the group transfected with PCI-NEO and that with PCI-NEO-SNCG in DDP, 5-FU, ADM and VCR (P > 0.05), while the rate of suppression of TAX on the latter cell lines was significantly lower than that on the former (P < 0.01). Compared with the PCI-NEO-SNCG plasmid transfected cell lines, after treated with TAX for 48 hours, those transfected with the PCI-NEO plasmid exhibited a significantly larger proportion of cells remaining in the G2-M stage (P < 0.01), a smaller proportion in the G0-G1 and S stages (P < 0.01) and a significantly higher expression of Caspase-3 (P < 0.01).</p><p><b>CONCLUSION</b>The significant reduction of the growth-suppressing effect of TAX in the SNCG-transfected PC-3 cell lines suggests that the expression of SNCG may restrain the effect of TAX. These findings have provided evidence and guide to the individual chemotherapy of prostate cancer.</p>