Search

Temperature change affects human health and asthma.[[1]] Serum IgE concentrations were shown to be significantly lower in experimental asthmatic mice treated at thermoneutral (30°C) than those treated at standard housing temperature (20°C).[3] A recent study found that the exosomes of mast cells (MC) can compete with MC to bind serum IgE and reduce asthma symptoms.[4] This study aimed to investigate whether temperature directly affects MC-derived exosomes in mediating the high-affinity receptor for IgE (Fc RI)-dependent MC activation and ovalbumin-induced asthma. In summary, this study provides evidence of the temperature-dependent regulation of MC-derived exosomes through regulation of Rab3a expression, which protected against Fc RI-dependent MC activation in vitro and experimental asthma in vivo. Temperature regulates Rab3a and mast cell-derived exosomal Fc RI to inhibit mast cell activation. [Extracted from the article]

Photodynamic therapy (PDT) has been extensively investigated for decades for tumor treatment because of its non-invasiveness, spatiotemporal selectivity, lower side-effects, and immune activation ability. It can be a promising treatment modality in several medical fields, including oncology, immunology, urology, dermatology, ophthalmology, cardiology, pneumology, and dentistry. Nevertheless, the clinical application of PDT is largely restricted by the drawbacks of traditional photosensitizers, limited tissue penetrability of light, inefficient induction of tumor cell death, tumor resistance to the therapy, and the severe pain induced by the therapy. Recently, various photosensitizer formulations and therapy strategies have been developed to overcome these barriers. Significantly, the introduction of nanomaterials in PDT, as carriers or photosensitizers, may overcome the drawbacks of traditional photosensitizers. Based on this, nanocomposites excited by various light sources are applied in the PDT of deep-seated tumors. Modulation of cell death pathways with co-delivered reagents promotes PDT induced tumor cell death. Relief of tumor resistance to PDT with combined therapy strategies further promotes tumor inhibition. Also, the optimization of photosensitizer formulations and therapy procedures reduces pain in PDT. Here, a systematic summary of recent advances in the fabrication of photosensitizers and the design of therapy strategies to overcome barriers in PDT is presented. Several aspects important for the clinical application of PDT in cancer treatment are also discussed. [ABSTRACT FROM AUTHOR]

Due to high carrier mobility, excellent stability, and tunable optical properties, 2D monoelemental germanene has attracted considerable attention in recent years. Herein, few-layered 2D germanium nanosheets (GeNS) were obtained via a facile liquid-phase exfoliated method and fabricated as electrode materials to assemble self-powered photo-electrochemical (PEC) type photodetectors. Such 2D GeNS-based PEC-type photodetectors exhibit a responsivity of 7.81 μA W−1, a detectivity of 5.2 × 109 Jones, and the rise and decay times of 0.15 s and 0.76 s, respectively, under simulated light. At the specific wavelength of 380 nm, it demonstrates a responsivity of 340.91 μA W−1 and a detectivity of 1.82 × 1011 Jones. In addition, the GeNS-based PEC-type device also exhibits good air-stability (over one-month). The present work demonstrates low-cost and facile fabrication techniques for preparing 2D monoelemental germanene and suggests that the as-prepared GeNS is a promising candidate for PEC-type photodetector applications. [ABSTRACT FROM AUTHOR]

During photothermal therapy (PTT), hyperthermia up to 50 °C is required for efficient induction of tumor cell death. Additional increases in temperature can lead to severe damage to adjacent tissues. Conversely, insufficient heating of deep‐seated tumor tissues results in tumor recurrence. Sensitization of tumor cells to PTT may solve this problem. Stress granules (SGs) function in integration of various internal and external stresses to regulate cell viability. However, the role of SGs in PTT is currently unknown. Here, with black phosphorus (BP) nanosheets as photothermal agents, it is found that SGs are induced in tumor by PTT through eukaryotic initiation factor 2α‐dependent pathway and participate in tumor resistance to PTT. To modulate SG formation in tumor, a BP hydrogel is prepared for tumor‐specific delivery and near‐infrared (NIR) light‐controlled release of the SG inhibitor Emetine. Upon NIR‐light irradiation, photothermal conversion of BP nanosheets enables PTT of tumor. Meanwhile, light‐controlled release of Emetine in tumor tissues effectively inhibits PTT‐induced SG formation and sensitizes tumor to PTT, resulting in enhanced tumor inhibition. These results reveal the role of SGs in PTT and present a novel strategy for tumor sensitization to enhance the therapeutic efficacy and reduce the side effects of PTT. [ABSTRACT FROM AUTHOR]

Nanomaterials‐based photothermal therapy (PTT) could efficiently eliminate cancer cells in a noninvasive manner. However, nanoscale photosensitizers still suffer from several drawbacks, limiting them from being an ideal PTT approach against cancer. These include unfavorable biodistribution and poor retention in tumor tissue. In this study, acid‐activatable smart self‐assembly of black phosphorous (BP) and polyoxometalates (POM) is carried out to yield POM@BP with prolonged tumor retention and enhanced efficacy of PTT. The as‐rationally designed POM@BP photosensitizers in acidic tumor microenvironments self‐assemble into nanoparticles with larger sizes, remarkably increasing the light absorption ability of BP nanosheets in PTT of cancer. The as‐obtained POM@BP endows prolonged retention and enhances the photothermal response in tumor tissue by smart self‐assembly of BP into larger nanoparticles. In summary, the proposed potent approach for the rational design and tailor photosensitizer for cancer treatment looks very promising for future scientific breakthroughs in nanomedicine. [ABSTRACT FROM AUTHOR]

The Quaternary sediments in the Yangtze delta are loose and lack precise stratification marks in the lithology. Moreover, due to the limitations of dating methods, it is difficult for Quaternary cores to deliver accurate age constraints. Thus, it is a challenge to establish the Quaternary stratigraphic framework. Gravity core LZK1 was drilled on Hengsha Island, Shanghai, in the Yangtze delta, in 2012. The core was terminated at 403.83 m below the local land surface, the uppermost 291.2 m comprising a thick sequence of Quaternary sediments. This study investigated the stratigraphic subdivision and paleoenvironmental change of the Quaternary sediments. From bottom to top, the Quaternary stratigraphic sequence can be subdivided into the lower Pleistocene Anting Formation, Middle Pleistocene Jiading Formation, Upper Pleistocene Chuansha Formation and Nanhui Formation, Holocene Loutang Formation, Shanghai Formation, and Rudong Formation. According to this study, the Hengsha Island area was dominated by a freshwater lacustrine environment during the early Pleistocene, an alternation of shallow lake and shore lake environment during the Middle Pleistocene, a delta plain to lagoonal environment during the early Upper Pleistocene, a fluvial channel to floodplain environment from the LGM (Last Glacial Maximum) to the end of the Upper Pleistocene, and a delta environment during the Holocene. [ABSTRACT FROM AUTHOR]

β-Catenin, the core element of the Wnt/β-catenin pathway, is a multifunctional and evolutionarily conserved protein which performs essential roles in a variety of developmental and homeostatic processes. Despite its crucial roles, the mechanisms that control its context-specific functions in time and space remain largely unknown. The Wnt/β-catenin pathway has been extensively studied in planarians, flatworms with the ability to regenerate and remodel the whole body, providing a ‘whole animal’ developmental framework to approach this question. Here we identify a C-terminally truncated β-catenin (β-catenin4), generated by gene duplication, that is required for planarian photoreceptor cell specification. Our results indicate that the role of β-catenin4 is to modulate the activity of β-catenin1, the planarian β-catenin involved in Wnt signal transduction in the nucleus, mediated by the transcription factor TCF-2. This inhibitory form of β-catenin, expressed in specific cell types, would provide a novel mechanism to modulate nuclear β-catenin signaling levels. Genomic searches and in vitro analysis suggest that the existence of a C-terminally truncated form of β-catenin could be an evolutionarily conserved mechanism to achieve a fine-tuned regulation of Wnt/β-catenin signaling in specific cellular contexts. [ABSTRACT FROM AUTHOR]

To examine the applicability of C/N and organic carbon stable isotope (δ13C) in studies of the Holocene sea level and freshwater discharge in the large river mouth of Yangtze, we observed the distribution of carbon, nitrogen and δ13C in a late-Quaternary core (ZK9) collected from the present subaqueous delta. We also collected published data of the two proxies for the suspended particulate matter (SPM) and surficial sediments from the lower Yangtze River to the adjacent East China Sea. The results show that the estuarine front is an important boundary for terrestrial and marine contribution of the organic component in the modern sedimentary environment. In the core ZK9, sediments deposited during c. 13–9 cal. ka BP are characterized by high values of TOC (0.54–1.16%), CaCO3 (0.35% on average), and C/N (>12), which reflect an inner tidal estuarine environment dominated by C3 terrestrial organic carbon input. During c. 9–0.7 cal. ka BP, both TOC content (0.57% on average) and C/N ratio (<10) decrease remarkably while TN increases, indicating a lower estuarine or shallow marine environment. An abrupt sea level rise from c. 9 cal. ka BP resulted in a deeper water environment and reduced terrestrial input at the core location. The low δ13C values (−24.23‰ on average) before c. 6 cal. ka BP reflect a dominantly terrestrial source of organic matter associated with increased freshwater discharge into the estuary during that time. The sediments since c. 6 cal. ka BP are characterized by increasing δ13C up to −24.1 to −23.39‰, reflecting more contribution from marine algae as freshwater discharge fell. We suggest that in the Yangtze River mouth the C/N ratio indicates an abrupt sea level rise at c. 9 cal. ka BP, while δ13C is more useful in reflecting freshwater discharge. [ABSTRACT FROM AUTHOR]

Eupatorium adenophorum is a noxious invasive weed that is distributed throughout subtropical areas worldwide. Enemy release may be at least one of the reasons underlying its success as an invader. In this study, we observed damage to the epidermis, cortex, phloem, cambium, and xylem tissues of roots and stems around the root collar of E. adenophorum growing in an experimental field in Yunnan Province, southwest China. The damage was caused by Dorylus orientalis, a polyphagous ant feeding on the weed and resulted in the death of the plants by interrupting nutrient exchange between shoots and roots. This ant showed selectivity for the invader to some extent. The finding of D. orientalis and other native enemies indicate that E. adenophorum may gradually naturalize in introduced landscapes. In addition, this ant may have potential for use as a biocontrol agent against the invader. [ABSTRACT FROM AUTHOR]

Abstract: Planarians can regenerate their head within days. This process depends on the direction of adult stem cells to wound sites and the orchestration of their progenitors to commit to appropriate lineages and to arrange into patterned tissues. We identified a zinc finger transcription factor, Smed-ZicA, as a downstream target of Smed-FoxD, a Forkhead transcription factor required for head regeneration. Smed-zicA and Smed-FoxD are co-expressed with the Wnt inhibitor notum and the Activin inhibitor follistatin in a cluster of cells at the anterior-most tip of the regenerating head – the anterior regeneration pole – and in surrounding stem cell progeny. Depletion of Smed-zicA and Smed-FoxD by RNAi abolishes notum and follistatin expression at the pole and inhibits head formation downstream of initial polarity decisions. We suggest a model in which ZicA and FoxD transcription factors synergize to control the formation of Notum- and Follistatin-producing anterior pole cells. Pole formation might constitute an early step in regeneration, resulting in a signaling center that orchestrates cellular events in the growing tissue. [Copyright &y& Elsevier]