Thermokarst lakes are potentially important sources of methane (CH4) and carbon dioxide (CO2). However, considerable uncertainty exists regarding carbon emissions from thermokarst lakes owing to a ...limited understanding of their patterns and motivators. In this study, we measured CH4 and CO2 diffusive fluxes in 163 thermokarst lakes in the Qinghai–Tibet Plateau (QTP) over 3 years from May to October. The median carbon emissions from the QTP thermokarst lakes were 1440 mg CO2 m−2 day−1 and 60 mg CH4 m−2 day−1, respectively. The diffusive rates of CO2 and CH4 are related to the catchment land cover type. Sediment microbial abundance and hydrochemistry explain 51.9% and 38.3% of the total variance in CH4 diffusive emissions, respectively, while CO2 emissions show no significant relationship with environmental factors. When upscaling carbon emissions from the QTP thermokarst lakes, the annual average CH4 release per lake area is equal to that of the pan‐Arctic region. Our findings highlight the importance of incorporating in situ observation data with different emission pathways for different land cover types in predicting carbon emissions from thermokarst lakes in the future.
The median carbon emissions from the QTP thermokarst lakes were 1440 mg CO2 m−2 day−1 and 60 mg CH4 m−2 day−1. Diffusive rates of CO2 and CH4 are related to the catchment land cover type in the thermokarst lakes. Sediment microbial abundance and hydrochemistry are the controlling factors for CH4 diffusive emissions.
Measuring multiple omics profiles from the same single cell opens up the opportunity to decode molecular regulation that underlies intercellular heterogeneity in development and disease. Here, we ...present co-sequencing of microRNAs and mRNAs in the same single cell using a half-cell genomics approach. This method demonstrates good robustness (~95% success rate) and reproducibility (R
= 0.93 for both microRNAs and mRNAs), yielding paired half-cell microRNA and mRNA profiles, which we can independently validate. By linking the level of microRNAs to the expression of predicted target mRNAs across 19 single cells that are phenotypically identical, we observe that the predicted targets are significantly anti-correlated with the variation of abundantly expressed microRNAs. This suggests that microRNA expression variability alone may lead to non-genetic cell-to-cell heterogeneity. Genome-scale analysis of paired microRNA-mRNA co-profiles further allows us to derive and validate regulatory relationships of cellular pathways controlling microRNA expression and intercellular variability.
Mineral bone disorders in chronic kidney disease Hou, Yi‐Chou; Lu, Chien‐Lin; Lu, Kuo‐Cheng
Nephrology (Carlton, Vic.),
October 2018, 2018-Oct, 2018-10-00, 20181001, Letnik:
23, Številka:
S4
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
As the GFR loss aggravates, the disturbed mineral metabolism worsens the bone microstructure and remodelling ‐ scenario, which is known as CKD‐mineral bone disease (MBD). CKD‐MBD is ...characterized by : (i) abnormal metabolism of calcium, phosphorus, parathyroid hormone (PTH), or vitamin D; (ii) abnormalities in bone turnover, mineralization, volume linear growth or strength; (iii) soft‐tissue calcifications, either vascular or extra‐osseous. Uremic vascular calcification and osteoporosis are the most common complications related to CKD‐MBD. Disregulated bone turnover by uremic toxin or secondary hyperparathyroidism disturbed bone mineralization and makes it difficult for calcium and inorganic phosphate to enter into bone, resulting in increased serum calcium and inorganic phosphate. Vascular calcification worsens by hyperphosphatemia and systemic inflammation. Since vitamin D deficiency plays an important role in renal osteodystrophy, supplement of nutritional vitamin D is important in treating uremic osteoporosis and vascular calcification at the same time. Its pleotropic effect improves the bone remodeling initiated by osteoblast and alleviates the risk factors for vascular calcification with less hypercalcemia than vitamin D receptor analogs. Therefore, nutritional vitamin D should be considered in managing CKDMBD.
Summary at a Glance
This article is a systematic review of the mechanism of CKDMBD and the complication about CKDMBD, including uremic vascular calcification and osteoporosis. Nutritional vitamin D, should play a role in managing CKDMBD.
We use novel data for Taiwan to examine the relationship between wage differential and corporate cash holdings. The two main forces behind wage expenses, manager and employee wages, play different ...roles in this relationship. We find that employee wages positively affect cash holdings, and their effect mainly results from the precautionary motive. Manager wages have a relatively weak effect on cash holdings, but their effect is only visible when the agency motive is high. We identify these motives through the heterogeneity of employee turnover rate, female-worker coverage ratio, and financial constraints. Important revisions in the Labor Standards Act and Business Entity Accounting Act help address endogeneity. We also find that firms are likely to save cash from internal cash flows when employee wages increase, while firms with higher manager wages prefer debt financing. By decomposing wage expenses, we show that firms are likely to save cash for employees from firm's pockets.
•We use novel data for Taiwan to examine the relationship between wage differential and corporate cash holdings.•We find that employee wages positively affect cash holdings, and their effect mainly results from the precautionary motive.•The effect of manager wages on cash holdings is only visible when the agency motive is high.•Firms are likely to save cash from internal cash flows when employee wages increase, while firms with higher manager wages prefer debt financing.
d-limonene, with bactericide, antioxidant, chemo-preventative and therapeutic activities, has received cosmetic and pharmaceutical interest in the last decade. d-limonene is poorly soluble; ...therefore, incorporation into nanoemulsions may help solubilize and encapsulate the component. We investigated the physical stabilities of d-limonene nanoemulsions during 98-day storage and at 4 °C, 25 °C and 50 °C, respectively. d-limonene nanoemulsions were disk-shaped, and the zeta potential was approximately −35 mV at original the pH 6.4. The zeta potential, droplet size, viscosity and turbidity were affected by the storage conditions, for decreased stability during storage. The encapsulated ratio of d-limonene in nanoemulsions was significantly decreased during storage with increasing temperature, which resulted in increased release rate constant of d-limonene. This study provides a strategy to manufacture promising o/w nanoemulsions for a system to deliver lipophilic flavor to agrochemical, cosmetic and food products.
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•d-limonene is a monocyclic monoterpene that exhibits beneficial health effects.•Hydrophobic, reactive and volatile limit d-limonene use.•Nanoemulsion technology is probably a good method to encapsulate this component.•Nanoemulsion stability was strongly influenced by the storage conditions.•This information useful for designing d-limonene delivery systems.
Calreticulin is a highly conserved endoplasmic reticulum chaperone protein which participates in various cellular processes. It was first identified as a Ca2+-binding protein in 1974. Accumulated ...evidences indicate that calreticulin has great impacts for the development of different cancers and the effect of calreticulin on tumor formation and progression may depend on cell types and clinical stages. Cell surface calreticulin is considered as an “eat-me” signal and promotes phagocytic uptake of cancer cells by immune system. Moreover, several reports reveal that manipulation of calreticulin levels profoundly affects cancer cell proliferation and angiogenesis as well as differentiation. In addition to immunogenicity and tumorigenesis, interactions between calreticulin and integrins have been described during cell adhesion, which is an essential process for cancer metastasis. Integrins are heterodimeric transmembrane receptors which connect extracellular matrix and intracellular cytoskeleton and trigger inside-out or outside-in signaling transduction. More and more evidences reveal that proteins binding to integrins might affect integrin-cytoskeleton interaction and therefore influence ability of cell adhesion. Here, we reviewed the biological roles of calreticulin and summarized the potential mechanisms of calreticulin in regulating mRNA stability and therefore contributed to cancer metastasis.
Arctic warming may cause the release of vast amounts of soil organic carbon (SOC) from permafrost, which will manifest itself in the fluxes and composition of organic carbon in northern rivers and ...Arctic coastal regions. To elucidate the transport pathways of SOC, radiocarbon composition was measured for dissolved organic carbon (DOC), particulate organic carbon (POC), sediments and SOC from the Mackenzie, Sagavanirktok, and Yukon river basins, and soil leaching experiments were conducted. The radiocarbon ages of riverine suspended POC and sediments ranged from 4430 to ∼7970 yr BP, while DOC was much younger (390–1440 yr BP) except samples from the Sag River. Soil leaching experiments released <1% of SOC as DOC. The decoupling in age and partitioning between POC and DOC indicates that POC in these rivers is dominated by old SOC derived from permafrost thawing and river‐bank erosion in contrast to DOC, which is more readily influenced by modern terrestrial biomass, especially in large river basins which also drain subarctic regions. These observations imply that melting of permafrost will be manifest in the age and amounts of POC in arctic rivers whereas change in DOC will reflect altered plant ecology.
Deep soil profiles containing permafrost (Gelisols) were characterized for organic carbon (C) and total nitrogen (N) stocks to 3 m depths. Using the Community Climate System Model (CCSM4) we ...calculate cumulative distributions of active layer thickness (ALT) under current and future climates. The difference in cumulative ALT distributions over time was multiplied by C and N contents of soil horizons in Gelisol suborders to calculate newly thawed C and N. Thawing ranged from 147 PgC with 10 PgN by 2050 (representative concentration pathway RCP scenario 4.5) to 436 PgC with 29 PgN by 2100 (RCP 8.5). Organic horizons that thaw are vulnerable to combustion, and all horizon types are vulnerable to shifts in hydrology and decomposition. The rates and extent of such losses are unknown and can be further constrained by linking field and modelling approaches. These changes have the potential for strong additional loading to our atmosphere, water resources, and ecosystems.
Key Points
Field‐based knowledge of soil C and N data improves models of Arctic C and N
Specific C and N vulerabilities of Arctic soils to thaw are identified
International dataset is made available
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is still an ongoing global health crisis. Immediately after the inhalation of SARS-CoV-2 ...viral particles, alveolar type II epithelial cells harbor and initiate local innate immunity. These particles can infect circulating macrophages, which then present the coronavirus antigens to T cells. Subsequently, the activation and differentiation of various types of T cells, as well as uncontrollable cytokine release (also known as cytokine storms), result in tissue destruction and amplification of the immune response. Vitamin D enhances the innate immunity required for combating COVID-19 by activating toll-like receptor 2. It also enhances antimicrobial peptide synthesis, such as through the promotion of the expression and secretion of cathelicidin and β-defensin; promotes autophagy through autophagosome formation; and increases the synthesis of lysosomal degradation enzymes within macrophages. Regarding adaptive immunity, vitamin D enhances CD4+ T cells, suppresses T helper 17 cells, and promotes the production of virus-specific antibodies by activating T cell-dependent B cells. Moreover, vitamin D attenuates the release of pro-inflammatory cytokines by CD4+ T cells through nuclear factor κB signaling, thereby inhibiting the development of a cytokine storm. SARS-CoV-2 enters cells after its spike proteins are bound to angiotensin-converting enzyme 2 (ACE2) receptors. Vitamin D increases the bioavailability and expression of ACE2, which may be responsible for trapping and inactivating the virus. Activation of the renin–angiotensin–aldosterone system (RAS) is responsible for tissue destruction, inflammation, and organ failure related to SARS-CoV-2. Vitamin D inhibits renin expression and serves as a negative RAS regulator. In conclusion, vitamin D defends the body against SARS-CoV-2 through a novel complex mechanism that operates through interactions between the activation of both innate and adaptive immunity, ACE2 expression, and inhibition of the RAS system. Multiple observation studies have shown that serum concentrations of 25 hydroxyvitamin D are inversely correlated with the incidence or severity of COVID-19. The evidence gathered thus far, generally meets Hill’s causality criteria in a biological system, although experimental verification is not sufficient. We speculated that adequate vitamin D supplementation may be essential for mitigating the progression and severity of COVID-19. Future studies are warranted to determine the dosage and effectiveness of vitamin D supplementation among different populations of individuals with COVID-19.
Helicobacter pylori(H.pylori)infection is highly associated with the occurrence of gastrointestinal diseases,including gastric inflammation,peptic ulcer,gastric cancer,and gastric mucosa-associated ...lymphoid-tissue lymphoma.Although alternative therapies,including phytomedicines and probiotics,have been used to improve eradication,current treatment still relies on a combination of antimicrobial agents,such as amoxicillin,clarithromycin,metronidazole,and levofloxacin,and antisecretory agents,such as proton pump inhibitors(PPIs).A standard triple therapy consisting of a PPI and two antibiotics(clarithromycin and amoxicillin/metronidazole)is widely used as the first-line regimen for treatment of infection,but the increased resistance of H.pylori to clarithromycin and metronidazole has significantly reduced the eradication rate using this therapy and bismuth-containing therapy or 10-d sequential therapy has therefore been proposed to replace standard triple therapy.Alternatively,levofloxacin-based triple therapy can be used as rescue therapy for H.pylori infection after failure of first-line therapy.The increase in resistance to antibiotics,including levofloxacin,may limit the applicability of such regimens.However,since resistance of H.pylori to amoxicillin is generally low,an optimized high dose dual therapy consisting of a PPI and amoxicillin can be an effective first-line or rescue therapy.In addition,the concomitant use of alternative medicine has the potential to provide additive or synergistic effects against H.pylori infection,though its efficacy needs to be verified in clinical studies.
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