Multiagent-Based Reactive Power Sharing and Control Model for Islanded Microgrids

In islanded microgrids (MGs), the reactive power cannot be shared proportionally among distributed generators (DGs) with conventional droop control, due to the mismatch in feeder impedances. For the purpose of proportional reactive power sharing, a multiagent system (MAS)-based distributed control model for droop-controlled MGs is proposed. The proposed control model consists of two layers, where the bottom layer is the electrical distribution MG, while the top layer is a communication network composed of agents. Moreover, agents on the communication network exchange the information acquired from DGs with neighbors, and calculate set points for DGs they connect to, according to the control laws. Furthermore, a theorem is demonstrated, which yields a systematic method to derive the control laws from a given communication network. Finally, three cases are carried out to test the performance of the control model, in which the uncertainty of intermittent DGs, variations in load demands, as well as impacts of time delays are considered. The simulation results demonstrate the effectiveness of the control model in proportional reactive power sharing, and the plug and play capability of the control model is also verified.Feixiong Chen, Minyou Chen, Qiang Li, Kaikai Meng, Josep M. Guerrero, Fellow and Derek Abbot

Cost-Based Droop Schemes for Economic Dispatch in Islanded Microgrids

In this paper, cost-based droop schemes are proposed, to minimize the total active power generation cost in an islanded microgrid (MG), while the simplicity and decentralized nature of the droop control are retained. In cost-based droop schemes, the incremental costs of distributed generators (DGs) are embedded into the droop schemes, where the incremental cost is a derivative of the DG cost function with respect to output power. In the steady state, DGs share a single common frequency, and cost-based droop schemes equate incremental costs of DGs, thus minimizing the total active power generation cost, in terms of the equal incremental cost principle. Finally, simulation results in an islanded MG with high a penetration of intermittent renewable energy sources are presented, to demonstrate the effectiveness, as well as plug and play capability of the cost-based droop schemes.Feixiong Chen, Minyou Chen, Qiang Li, Kaikai Meng, Yongwei Zheng, Josep M. Guerrero, Derek Abbot

A novel nanoparticle drug delivery system based on PEGylated hemoglobin for cancer therapy

Proteins such as albumin, gelatin, casein, transferrin, and collagen are widely used as drug delivery systems. However, only albumin-based paclitaxel (PTX) formulation AbraxaneVR (PTX-albumin NPs prepared by nab-technology) has been successfully developed for treating metastatic breast cancer clinically due to abundant materials, simple industrial scale-up process, and well tumor-targeting ability. Hemoglobin (Hb) is another protein used for drug delivery with similar advantages. In this study, we successfully synthesized PEG-Hb nanoparticles loading with PTX based on previously well-established acid-denatured method. PEG-Hb-PTX NPs showed enhanced cellular uptake and great cellular inhibition ability in vitro. Moreover, our animal study showed that PEGylated NPs greatly accumulated in tumor tissues and exhibited excellent anticancer activity in vivo. We found that PEG-Hb-PTX NPs possess a better in vivo antitumor effect than the commercially available TaxolVR formulation. We believe that PEG-Hb has great potential as an efficient drug delivery system for further clinic study

Anti-PD-L1/TGF-βR fusion protein (SHR-1701) overcomes disrupted lymphocyte recovery-induced resistance to PD-1/PD-L1 inhibitors in lung cancer

Background Second-generation programmed cell death-protein 1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors, such as bintrafusp alfa (M7824), SHR-1701, and YM101, have been developed to simultaneously block PD-1/PD-L1 and transforming growth factor-beta/transforming growth factor-beta receptor (TGF-β/TGF-βR). Consequently, it is necessary to identify predictive factors of lung cancer patients who are not only resistant to PD-1/PD-L1 inhibitors but also sensitive to bifunctional drugs. The purpose of this study was to search for such predictors. Methods Multivariable Cox regression was used to study the association between the clinical outcome of treatment with PD-1/PD-L1 inhibitors and lymphocyte recovery after lymphopenia in lung cancer patients. Murine CMT167 lung cancer cells were engineered to express the firefly luciferase gene and implanted orthotopically in the lung of syngeneic mice. Bioluminescence imaging, flow cytometry, and immunohistochemistry were employed to determine response to immunotherapy and function of tumor-infiltrating immune cells. Results For lung cancer patients treated with anti-PD-1/PD-L1 antibodies, poor lymphocyte recovery was associated with a shorter progression-free survival (PFS; P < 0.001), an accumulation of regulatory T cells (Tregs), and an elimination of CD8+ T cells in the peripheral blood. Levels of CD8+ T cells and Treg cells were also imbalanced in the tumors and peripheral immune organs of mice with poor lymphocyte recovery after chemotherapy. Moreover, these mice failed to respond to anti-PD-1 antibodies but remained sensitive to the anti-PD-L1/TGF-βR fusion protein (SHR-1701). Consistently, SHR-1701 but not anti-PD-1 antibodies, markedly enhanced IFN-γ production and Ki-67 expression in peripheral CD8+ T cells from patients with impaired lymphocyte recovery. Conclusions Lung cancer patients with poor lymphocyte recovery and suffering from persistent lymphopenia after previous chemotherapy are resistant to anti-PD-1/PD-L1 antibodies but might be sensitive to second-generation agents such as SHR-1701.publishedVersio

Spatial patterns and evolution trend of coupling coordination of pollution reduction and carbon reduction along the Yellow River Basin, China

Collaborative efforts to reduce pollution and carbon emissions are a notable feature of the current era. Achieving the “pollution reduction” and “carbon reduction” dual-driven new development model is the inevitable requirement and significant practical measure for building a new development pattern and realizing a comprehensive green transformation of economic and social development. The synergistic effects between pollution reduction and carbon reduction (PRCR) have been demonstrated. However, the measurement and quantitative analysis of the coupling coordination degree (CCD) of PRCR have not received enough attention. Therefore, the evaluation index system was constructed based on the scientific connotation of PRCR, and the CCD of PRCR in cities along the Yellow River Basin (YRB) from 2009 to 2018 was measured quantitatively by constructing the coupling coordination model in this paper. In addition, we comprehensively investigated its spatial pattern, distribution characteristics, and evolution trend using ESDA, Kernel density estimation, and Markov chain. The primary findings can be summarized as: (1) PRCR levels and their CCD fluctuated and increased in the YRB, with “east-high and west-low” spatial differentiation characteristics, and the coupling phenomenon of “pollution reduction is hindered and carbon reduction is lagging”. (2) There is a phenomenon of “spatial club” clustering in the coordination degree of PRCR in the YRB, with most cities in the downstream areas belonging to the type of high-high clustering, while the middle and upstream areas had the opposite type. (3) The CCD of PRCR in the whole and upper reaches of the YRB have transformed from low-level divergence to high-level convergence. (4) Spatial geographic factors have a significant spillover effect on the evolution of the CCD of PRCR, and there is a phenomenon of the “Matthew effect”. This paper provides a comprehensive framework for analyzing the synergistic effects between PRCR, and the research findings can also provide insights for other regions

Saxifraga damingshanensis (S. sect. Irregulares, Saxifragaceae), a new species from Guangxi, China

Saxifraga damingshanensis (Saxifragaceae), a new species from Damingshan Nature Reserve in Guangxi Province, is described and illustrated. A morphological comparison between the new species and its putative relatives, S. mengtzeana and S. luoxiaoensis, is presented. The new species is morphologically similar to S. mengtzeana, but it can be easily distinguished by its non-peltate leaf, both surfaces of mature leaf blade covered with white glandular trichome, petals 3-veined and margin entire. Phylogenetic analysis, based on two chloroplast DNA regions (matK and psbA-trnH), confirmed that the new species belongs to S. sect. Irregulares. The new species is currently only known from Damingshan, Guangxi and we assign it an IUCN Red List preliminary status as Data Deficient

Isolation and identification of EST‐SSR markers in Ixonanthes chinensis (Ixonanthaceae)

Premise Ixonanthes (Ixonanthaceae) consists of between three and 19 species, among which I. chinensis and I. khasiana are considered vulnerable. Here, 58 microsatellite markers were developed for further conservation of these two Ixonanthes species. Methods and Results RNA transcripts of I. chinensis were sequenced and assembled into 19,545 unigenes, and 994 simple sequence repeat (SSR) loci were identified from 920 contigs. Based on these, 106 primer pairs were designed, 58 were successfully amplified, and 12 demonstrated polymorphism among five populations. The number of alleles per locus varied from three to 10, and the levels of observed and expected heterozygosity ranged from 0.000 to 1.000 and 0.000 to 0.844, respectively. Further assessment of the transferability of the 58 amplifiable primers reported 30 being successfully cross‐amplified in I. icosandra and three in Erythroxylum sinense. Conclusions These novel SSR markers will be useful for future genetic conservation studies on these Ixonanthes species

A new species of Eriobotrya (Rosaceae) from Yunnan Province, China

Eriobotrya laoshanica, a new species of Rosaceae from Yunnan, China, is described and illustrated. The new species is easily distinguished from the most similar species E. malipoensis K. C. Kuan by its longer petioles (2–5 vs. 0.5–1 cm); indumentum on the lower leaf surfaces (densely tomentose vs. glabrous); much fewer flowers (15- to 30-flowered vs. 50- to 100-flowered) on the panicle; larger flowers (2.5–3 vs. 1.5–2 cm in diameter); and non-angulated (vs. angulated) young fruits