The photovoltaic (PV) string under partially shaded conditions exhibits complex output characteristics, i.e., the current-voltage (I-V) curve presents multiple current stairs while the power-voltage (P-V) curve shows multiple power peaks. Thus, the conventional maximum power point tracking (MPPT) method is not acceptable either on tracking accuracy or on tracking speed. In this paper, two global MPPT methods, namely, the search-skip-judge global MPPT (SSJ-GMPPT) and rapid global MPPT (R-GMPPT) methods are proposed in term of reducing the searching voltage range based on comprehensive study of I-V and P-V characteristics of PV string. The SSJ-GMPPT method can track the real maximum power point (MPP) under any shading conditions and achieve high accuracy and fast tracking speed without additional circuits and sensors. The R-GMPPT method aims to enhance the tracking speed of long string with vast PV modules, and reduces more than 90% of the tracking time that is consumed by the conventional global searching method. The improved performance of two proposed methods have been validated by experimental results on a PV string. The comparison with other methods highlights the two proposed methods more powerful. Index Terms-Photovoltaic generation system, maximum power point tracking (MPPT), partially shaded conditions (PSC), global maximum power point (GMPP) Manuscript

Background: AMPA-type glutamate receptor-mediated synaptic transmission is enhanced in descending pain modulatory circuits under pain conditions. Results: Epigenetic regulation of BDNF by persistent inflammation triggers AMPA receptor GluA1 phosphorylation. Conclusion: Synaptic delivery of GluA1 in the brain stem is initiated by BDNF/TrKB activation under pain conditions. Significance: We investigate how GluA1 is delivered to synapses to understand the molecular mechanisms underlying pain in descending pain modulatory circuits.

Marking the end of the five-year programme initiated by the Chinese Government to lift more than 70 million people out of poverty, the year 2020 is a milestone. Poverty alleviation has moved strongly forward in China and the major health indicators are now better than the average of all middle-and high-income countries. However, the dual burden of infectious and chronic diseases remains a challenge with respect to achieving the health target in the United Nations 2030 Agenda for sustainable development goals (SDGs). In 2015, about 44% of the poor population in China were impoverished by illness but already in 2018, multi-sectoral actions delivered by the Health-related Poverty Alleviation programme had reduced the number almost by half. In the past three years 15 million poor people (98% of the poor population) with infectious and chronic diseases had been treated and taken care of thanks to financial support through multiple health insurance schemes and other governmental subsidies. This article discusses the lessons learnt with regard to health-related poverty alleviation in China with special reference to those still remaining impoverished by illness. Consolidation of the achievements reached and provision of basic needs to those still disadvantaged and in poor health will require a major improvement of accessibility to, and affordability of, health services. The next step towards enhanced productivity and better living conditions will involve upgrading of the capacity of health professionals in the poor regions, promotion of coherent efforts in health-related poverty alleviation and rural revitalization measures. As an additional measure, data monitoring and research on health poverty alleviation should be strengthened as they are essential to generate the evidence and knowledge needed to support the move in the direction envisioned by the SDGs, and the new Healthy China 2030 programme.

Three-dimensional (3D) printing technology has great potential for constructing structurally and functionally complex scaffold materials for tissue engineering. Bio-inks are a critical part of 3D printing for this purpose. In this study, based on dynamic hydrazone-crosslinked hyaluronic acid (HA-HYD) and photocrosslinked gelatin methacrylate (GelMA), a double-network (DN) hydrogel with significantly enhanced mechanical strength, self-healing, and shear-thinning properties was developed as a printable hydrogel bio-ink for extrusion-based 3D printing. Owing to shear thinning, the DN hydrogel bio-inks could be extruded to form uniform filaments, which were printed layer by layer to fabricate the scaffolds. The self-healing performance of the filaments and photocrosslinking of GelMA worked together to obtain an integrated and stable printed structure with high mechanical strength. The in vitro cytocompatibility assay showed that the DN hydrogel printed scaffolds supported the survival and proliferation of bone marrow mesenchymal stem cells. GelMA/HA-HYD DN hydrogel bio-inks with printability, good structural integrity, and biocompatibility are promising materials for 3D printing of tissue engineering scaffolds.

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