Dendrite growth of alkali metal anodes limited their lifetime for charge/discharge cycling. Here, we report near-perfect anodes of lithium, sodium, and potassium metals achieved by electrochemical ...polishing, which removes microscopic defects and creates ultra-smooth ultra-thin solid-electrolyte interphase layers at metal surfaces for providing a homogeneous environment. Precise characterizations by AFM force probing with corroborative in-depth XPS profile analysis reveal that the ultra-smooth ultra-thin solid-electrolyte interphase can be designed to have alternating inorganic-rich and organic-rich/mixed multi-layered structure, which offers mechanical property of coupled rigidity and elasticity. The polished metal anodes exhibit significantly enhanced cycling stability, specifically the lithium anodes can cycle for over 200 times at a real current density of 2 mA cm
with 100% depth of discharge. Our work illustrates that an ultra-smooth ultra-thin solid-electrolyte interphase may be robust enough to suppress dendrite growth and thus serve as an initial layer for further improved protection of alkali metal anodes.
Although the respiratory and immune systems are the major targets of Coronavirus Disease 2019 (COVID-19), acute kidney injury and proteinuria have also been observed. Currently, detailed pathologic ...examination of kidney damage in critically ill patients with COVID-19 has been lacking. To help define this we analyzed kidney abnormalities in 26 autopsies of patients with COVID-19 by light microscopy, ultrastructural observation and immunostaining. Patients were on average 69 years (19 male and 7 female) with respiratory failure associated with multiple organ dysfunction syndrome as the cause of death. Nine of the 26 showed clinical signs of kidney injury that included increased serum creatinine and/or new-onset proteinuria. By light microscopy, diffuse proximal tubule injury with the loss of brush border, non-isometric vacuolar degeneration, and even frank necrosis was observed. Occasional hemosiderin granules and pigmented casts were identified. There were prominent erythrocyte aggregates obstructing the lumen of capillaries without platelet or fibrinoid material. Evidence of vasculitis, interstitial inflammation or hemorrhage was absent. Electron microscopic examination showed clusters of coronavirus-like particles with distinctive spikes in the tubular epithelium and podocytes. Furthermore, the receptor of SARS-CoV-2, ACE2 was found to be upregulated in patients with COVID-19, and immunostaining with SARS-CoV nucleoprotein antibody was positive in tubules. In addition to the direct virulence of SARS-CoV-2, factors contributing to acute kidney injury included systemic hypoxia, abnormal coagulation, and possible drug or hyperventilation-relevant rhabdomyolysis. Thus, our studies provide direct evidence of the invasion of SARSCoV-2 into kidney tissue. These findings will greatly add to the current understanding of SARS-CoV-2 infection.
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Nitrogen (N) is a critical element for plant growth and productivity that influences photosynthesis and chlorophyll fluorescence. We investigated the effect of low-N stress on leaf photosynthesis and ...chlorophyll fluorescence characteristics of maize cultivars with difference in tolerance to low N levels. The low-N tolerant cultivar ZH311 and low-N sensitive cultivar XY508 were used as the test materials. A field experiment (with three N levels: N0, 0 kg ha-1; N1, 150 kg ha-1; N2, 300 kg ha-1) in Jiyanyang, Sichuan Province, China, and a hydroponic experiment (with two N levels: CK, 4 mmol L-1; LN, 0.04 mmol L-1) in Chengdu, Sichuan Province, China were conducted. Low-N stress significantly decreased chlorophyll content and rapid light response curves of the maximum fluorescence under light (Fm'), fluorescence instable state (Fs), non-photochemical quenching (qN), the maximum efficiency of PSII photochemistry under dark-adaption (Fv/Fm), potential activity of PSII (Fv/Fo), and actual photochemical efficiency of PSII (ΦPSII) of leaves. Further, it increased the chlorophyll (Chl) a/Chl b values and so on. The light compensation point of ZH311 decreased, while that of XY508 increased. The degree of variation of these indices in low-N tolerant cultivars was lower than that in low-N sensitive cultivars, especially at the seedling stage. Maize could increase Chl a/Chl b, apparent quantum yield and light saturation point to adapt to N stress. Compared to low-N sensitive cultivars, low-N tolerant cultivars maintained a higher net photosynthetic rate and electron transport rate to maintain stronger PSII activity, which further promoted the ability to harvest and transfer light. This might be a photosynthetic mechanism by which low-N tolerant cultivar adapt to low-N stress.
In silico to in vivo: The design strategy for silicon‐based fluorescent nanospheres with controllable sizes was based on the results of theoretical calculations. These nanospheres are fully water ...dispersible, highly photoluminescent, extremely photostable, and suitably biocompatible. Cell imaging results further demonstrate the nanospheres are remarkably efficacious for real‐time and long‐term cell monitoring (see picture).
Acute kidney injury (AKI) is a critical condition with a mortality rate as high as 50% and significantly contributes to the burden of end-stage renal disease (ESRD) requiring renal replacement ...therapy. The incidence and prognosis of AKI have been shown to vary with patient age, with younger individuals being more resistant to AKI. In mice, clamping the renal artery for 45min causes substantial kidney damage in 4-month-old animals but only mild renal injury in 2-month-old animals. Here, younger mice were found to express higher levels of the NAD+-dependent histone deacetylase SIRT1 in the kidney. A small molecule SIRT1 activator, SRT-1720, markedly improved renal tubular pathology and overall renal function in adult mice following ischemia/reperfusion. Genetic ablation of one allele (SIRT1+/-) significantly enhanced the level of kidney damage relative to that in wild-type (SIRT1+/+) mice. The mechanisms underlying the protective effect of SIRT1 included the suppression of cell apoptosis. Hence, our results suggest that SIRT1 might be a novel therapeutic target for ischemia/reperfusion-induced kidney damage.
Sirtuin 1 (Sirt1) is a NAD+-dependent deacetylase that exerts many of the pleiotropic effects of oxidative metabolism. Due to local hypoxia and hypertonicity, the renal medulla is subject to extreme ...oxidative stress. Here, we set out to investigate the role of Sirt1 in the kidney. Our initial analysis indicated that it was abundantly expressed in mouse renal medullary interstitial cells in vivo. Knocking down Sirt1 expression in primary mouse renal medullary interstitial cells substantially reduced cellular resistance to oxidative stress, while pharmacologic Sirt1 activation using either resveratrol or SRT2183 improved cell survival in response to oxidative stress. The unilateral ureteral obstruction (UUO) model of kidney injury induced markedly more renal apoptosis and fibrosis in Sirt1+/- mice than in wild-type controls, while pharmacologic Sirt1 activation substantially attenuated apoptosis and fibrosis in wild-type mice. Moreover, Sirt1 deficiency attenuated oxidative stress-induced COX2 expression in cultured mouse renal medullary interstitial cells, and Sirt1+/- mice displayed reduced UUO-induced COX2 expression in vivo. Conversely, Sirt1 activation increased renal medullary interstitial cell COX2 expression both in vitro and in vivo. Furthermore, exogenous PGE2 markedly reduced apoptosis in Sirt1-deficient renal medullary interstitial cells following oxidative stress. Taken together, these results identify Sirt1 as an important protective factor for mouse renal medullary interstitial cells following oxidative stress and suggest that the protective function of Sirt1 is partly attributable to its regulation of COX2 induction. We therefore suggest that Sirt1 provides a potential therapeutic target to minimize renal medullary cell damage following oxidative stress.
CdTe/CdS/ZnS corre‐shell‐shell (CSS) quantum dots (QDs) are synthesized in the aqueous phase assisted by microwave irradiation. As‐prepared CSS QDs are suitable novel fluorescent probes in biological ...applications because of their outstanding aqueous dispersibility, good spectral properties, excellent photostability, and favorable biocompatibility.
Surgical residual tumor lesions (R1 resection of surgical procedures (e.g., liver cancer infiltrating the diaphragm, surgical residual breast cancer, postoperative residual ovarian cancer) or ...boundary residual after ablation) and lymph node metastasis that cannot be surgically resected (retroperitoneal lymph nodes) significantly affect postoperative survival of tumor patients. This clinical conundrum poses three challenges for local drug delivery systems: stable and continuous delivery, good biocompatibility, and the ability to package new targeted drugs that can synergize with other treatments. Here, a drug‐laden hydrogel generated from pure DNA strands and highly programmable in adjusting its mesh size is reported. Meanwhile, the DNA hydrogel can assist the microcrystallization of novel radiosensitizing drugs, ataxia telangiectasia and rad3‐related protein (ATR) inhibitor (Elimusertib), further facilitating its long‐term release. When applied to the tumor site, the hydrogel system demonstrates significant antitumor activity, minimized systemic toxicity, and has a modulatory effect on the tumor‐immune cell interface. This drug‐loaded DNA‐hydrogel platform represents a novel modality for adjuvant therapy in patients with surgical residual tumor lesions and lymph node metastasis.
Surgical residual tumor lesions and lymph node metastasis significantly affect postoperative survival of tumor patients. Here, a drug‐laden hydrogel platform which assists the microcrystallization of novel radiosensitizing drugs, ATR inhibitor (Elimusertib), further facilitating its long‐term release is developed. The hydrogel system demonstrates significant antitumor activity, minimized systemic toxicity, and has a modulatory effect on the tumor‐immune cell interface.
This paper studies the boundary feedback stabilization for spacial multi‐dimensional coupled fractional reaction–diffusion systems with non‐collocated or collocated outputs in the case that the ...system state is unmeasurable. By employing the backstepping method, we introduce a target system and analyze its Mittag–Leffler stability. For each pair of sides of the region boundary, assuming that system state is hinged on one side, while the controller is designed on the opposite side. These boundary controllers work together to achieve the state feedback Mittag–Leffler stabilization of the considered system. In addition, for both kinds of outputs, feedback controllers are also established to achieve the asymptotical stability of the corresponding closed‐loop system. Two numerical experiments are carried out to illustrate our results.
Five-target magnetron sputtering was used to prepare an AlTiCrNiTa high-entropy alloy (HEA) coating on an X80 steel substrate. The phase, morphology, and composition of the as-deposited coating were ...investigated by using XRD, SEM, AFM, and EDX. Moreover, its corrosion resistance in 3.5 wt% NaCl solution was studied by electrochemical methods. The obtained results indicate that the AlTiCrNiTa HEA coating exhibited a single BCC fine nanocrystalline structure, which can effectively improve the corrosion resistance of X80 steel in 3.5 wt% NaCl solution. After electrochemical corrosion, the AlTiCrNiTa HEA coating still effectively maintained an integrated and dense surface. The mechanisms behind the development of corrosion resistance in the AlTiCrNiTa high-entropy alloy coating are evaluated in detail.
•A novel AlTiCrNiTa HEA coating was prepared on X80 steel by the five-target magnetron sputtering technique.•The single BCC fine nanocrystalline provided a high corrosion resistance.•The corrosion mechanism of “layer by layer” was proposed.
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