Micro- and Nanoengineered Metal Additively Manufactured Surfaces for Enhanced Anti-Frosting Applications.

The greater geometrical design freedom offered by additive manufacturing (AM) as compared to the conventional manufacturing method has attracted increasing interest in AM to develop innovative and complex designs for enhanced performance. However, the difference in material composition and surface properties from conventional alloys has made surface micro-/nanostructuring of AM metals challenging. Frost accretion is a safety hazard in numerous engineering applications. To expand the application of AM, this study experimentally investigates the antifrosting performance of superhydrophobic and slippery lubricant-infused porous surfaces (SLIPSs) generated on AM alloy, AlSi10Mg. By strategically utilizing the subgrain structure in the metallography of the AM alloy, the functionalized superhydrophobic AM surface featuring hierarchical structures was shown to greatly reduce frost formation as compared to functionalized single-tier structured surfaces, hierarchical structures formed on conventional aluminum alloy surfaces, and SLIPSs. Optical observation of frost propagation demonstrated that the mechanism of frost delay is governed by the inhibition of spontaneous droplet freezing through exceptional Cassie state stability during condensation frosting. The Cassie stability results from the unique AM structure morphology, which creates a higher structural energy barrier to prevent condensate from infiltrating the cavities. This phenomenon also enables the formation of a high surface-to-droplet thermal resistance, which eliminates spontaneous droplet freezing down to a -15 °C surface temperature. Our work demonstrates a scalable structuring method for AM metals, which can result in delayed frost formation, and it also provides guidelines for the development of engineered surfaces requiring the antifrosting function for several industries.

LncRNA CRNDE Exacerbates IgA Nephropathy Progression by Promoting NLRP3 Inflammasome Activation in Macrophages.

BACKGROUND: Activation of NLRP3 inflammasome in macrophages contributes greatly to IgA nephropathy (IgAN) progression. This study intended to investigate the underlying mechanism of NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation in the development of IgAN. METHODS: We examined the expression levels of colorectal neoplasia differentially expressed (CRNDE), NLRP3 inflammasome-related proteins in peripheral blood mononuclear cells (PBMCs) and J774A.1 cells and detected inflammatory cytokine levels in the serum of IgAN patients and cell supernatants of in vitro IgAN model. RNA pull-down and RNA immunoprecipitation (RIP) experiments were conducted to evaluate the interaction between CRNDE and NLRP3. Then, the ubiquitin level of NLRP3 and its binding ability to TRIM family member 31 (TRIM31) were determined. RESULTS: Compared with the control group, the expressions of CRNDE and NLRP3 inflammasome-related proteins in PBMCs and J774A.1 cells and levels of IL-1ß, TNF-α and IL-12 in serum of IgAN patients and cell supernatants of IgA-IC-induced J774A.1 cells were all increased. CRNDE silencing down-regulated NLRP3 inflammasome-related proteins and the levels of IL-1ß, TNF-α and IL-12 in cell supernatants, while NLRP3 overexpression reversed these effects. Additionally, CRNDE could interact with NLRP3 and promote NLRP3 expression. Furthermore, inhibition of CRNDE reduced NLRP3 protein level and promoted TRIM31-mediated NLRP3 ubiquitination and degradation. CONCLUSION: CRNDE exacerbates IgA nephropathy progression through restraining ubiquitination and degradation of NLRP3 and facilitating NLRP3 inflammasome activation in macrophages.

Intermolecular vibrations mediate ultrafast singlet fission.

Singlet fission is a spin-allowed exciton multiplication process in organic semiconductors that converts one spin-singlet exciton to two triplet excitons. It offers the potential to enhance solar energy conversion by circumventing the Shockley-Queisser limit on efficiency. We study the primary steps of singlet fission in a pentacene film by using a combination of TG and 2D electronic spectroscopy complemented by quantum chemical and nonadiabatic dynamics calculations. We show that the coherent vibrational dynamics induces the ultrafast transition from the singlet excited electronic state to the triplet-pair state via a degeneracy of potential energy surfaces, i.e., a multidimensional conical intersection. Significant vibronic coupling of the electronic wave packet to a few key intermolecular rocking modes in the low-frequency region connect the excited singlet and triplet-pair states. Along with high-frequency local vibrations acting as tuning modes, they open a new channel for the ultrafast exciton transfer through the resulting conical intersection.

Protective Effect and Possible Mechanisms of Astragaloside IV in Animal Models of Diabetic Nephropathy: A Preclinical Systematic Review and Meta-Analysis.

Astragaloside IV (AS-IV) has a variety of biological activities and is widely used to treat kidney diseases. We conducted a systematic review of 24 animal studies including 424 animals to evaluate the efficacy of AS-IV for diabetic nephropathy (DN); all current possible mechanisms were summarized. A search strategy was applied to eight databases from inception to June 2020. The CAMARADES 10-item quality checklist and Rev-Man 5.3 software were used to analyze the risks of bias of each study and data regarding outcome measures, respectively. The mean study quality score was 5.4 points (range 3-8 points). Meta-analyses data and comparisons between groups showed that AS-IV significantly slowed the progression of pathological signs in the kidney including glomeruli and tubules, increasing creatinine clearance rate, decreasing blood urea nitrogen, serum creatinine, 24-h urinary neutrophil gelatinase-associated lipocalin and N-acetyl-ß-D-glucosaminidase, 24-h urinary albumin, 24-h urinary microalbumin and HbA1c. There were no significant differences between experimental and control groups with respect to mortality or levels of alanine aminotransferase and aspartate aminotransferase. In terms of the possible mechanisms of treatment of DN, AS-IV acts through antifibrotic, antioxidant, and antiapoptotic mechanisms, thereby alleviating endoplasmic reticulum stress, inhibiting mitochondrial fission, and increasing autophagic activity. Taken together, our findings suggest that AS-IV is a multifaceted renoprotective candidate drug for DN.

Kruppel-like factor 4 improves obesity-related nephropathy through increasing mitochondrial biogenesis and activities.

Obesity is positively linked to multiple metabolic complications including renal diseases. Several studies have demonstrated Kruppel-like factor 4 (KLF4) participated in renal dysfunction and structural disorders in acute kidney injuries, but whether it affected the process of chronic kidney diseases was unknown. Therefore, present study was to disclose the role of renal KLF4 in dietary-induced renal injuries and underlying mechanisms in obesity. Through utilizing high-fat diet-fed mice and human renal biopsies, we provided the physiological roles of KLF4 in protecting against obesity-related nephropathy. Decreased levels of renal KLF4 were positively correlated with dietary-induced renal dysfunction, including increased levels of creatinine and blood urea nitrogen. Overexpression of renal KLF4 suppressed inflammatory response in palmitic acid-treated mouse endothelial cells. Furthermore, overexpressed KLF4 also attenuated dietary-induced renal functional disorders, abnormal structural remodelling and inflammation. Mechanistically, KLF4 maintained renal mitochondrial biogenesis and activities to combat obesity-induced mitochondrial dysfunction. In clinical renal biopsies and plasma, the renal Klf4 level was negatively associated with circulating levels of creatinine but positively associated with renal creatinine clearance. In conclusions, the present findings firstly supported that renal KLF4 played an important role in combating obesity-related nephropathy, and KLF4/mitochondrial function partially determined the energy homeostasis in chronic kidney diseases.

Down-regulation of the long non-coding RNA XIST ameliorates podocyte apoptosis in membranous nephropathy via the miR-217-TLR4 pathway.

NEW FINDINGS: What is the central question of this study? What is the role of the long non-coding RNA X-inactive specific transcript (XIST), which is up-regulated in injured podocytes and membranous nephropathy, in the pathogenesis of membranous nephropathy? What is the main finding and its importance? XIST was up-regulated in kidney tissue with membranous nephropathy and in injured podocytes. Down-regulation of XIST inhibited podocyte apoptosis. XIST negatively regulated miR-217, and miR-217 modulated Toll-like receptor 4. Inhibition of XIST suppressed podocyte apoptosis induced by angiotensin II via miR-217. ABSTRACT: Membranous nephropathy is often characterized by glomerular podocyte injury. Up-regulation of the long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) has been verified in membranous nephropathy and in injured podocytes. Here the role of XIST in podocyte injury and membranous nephropathy was explored. Quantitative real-time PCR and western blot were performed to detect the expression of XIST and miR-217, and Toll-like receptor 4 (TLR4) protein, respectively. Podocyte apoptosis was evaluated with flow cytometry. Interaction between XIST and miR-217 was analysed by RNA immunoprecipitation and RNA pull-down assay. A dual luciferase reporter assay was used to examine the interplay between miR-217 and TLR4. Up-regulation of the lncRNA XIST and angiotensin II (Ang II) and kidney and podocyte injury were indicated in kidney tissue of patients with membranous nephropathy. Increase of XIST and apoptosis were induced by Ang II in podocytes. Down-regulation of XIST reversed podocyte apoptosis induced by Ang II. MiR-217 was negatively regulated by XIST. MiR-217 controlled TLR4 by targeting its 3'-untranslated region. XIST modulated TLR4 through miR-217 and inhibition of XIST reduced podocyte apoptosis induced by Ang II via regulating miR-217. Down-regulation of XIST ameliorates podocyte apoptosis via the miR-217-TLR4 pathway, which may improve membranous nephropathy.

MiR-133a/133b inhibits Treg differentiation in IgA nephropathy through targeting FOXP3.

OBJECTIVE: The aim of this study was to investigate the effect of miR-133a and miR-133b on regulatory T cell (Treg) differentiation in IgA nephropathy (IgAN) through targeting forkhead box P3 (FOXP3). METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from IgAN patients (n = 20) and healthy controls (n = 20). Percentage of Tregs defined as CD4 + CD25 + FOXP3 + T cells were determined by flow cytometry. The mRNA expression levels of miR-133a, miR-133b and FOXP3 were measured by real-time PCR. FOXP3 protein level was analyzed by western blotting. RESULTS: Tregs percentage in PBMCs of IgAN patients was significantly lower than that of healthy controls, whereas the expression levels of miR-133a and miR-133b in IgAN patients were dramatically higher than that in the control group. Treg percentage was negatively correlated with miR-133a and miR-133b expressions. Meanwhile, miR-133a and miR-133b modulated FOXP3 expression by detecting of its gene 3'-untranslated region. MiR-133a or miR-133b overexpression significantly decreased the % Tregs (CD4 + CD25 + FOXP3+) of the total CD4 + T cells while miR-133a or miR-133b knockdown led to an opposite effect. Moreover, FOXP3 levels in IgAN patients was significantly lower than that in the control group and was negatively correlated with miR-133a and miR-133b expression. CONCLUSION: MiR-133a and miR-133b inhibited Treg differentiation in IgA nephropathy through targeting FOXP3.

Brazilin Ameliorates Diabetic Nephropathy and Inflammation in db/db Mice.

Hyperglycemia and inflammation play important roles in the pathogenesis of diabetic nephropathy (DN). Brazilin might be an effective pharmacological agent against hyperglycemia and inflammation. In our present study, we explored whether brazilin mitigated pathological progression, inflammation, and extracellular matrix (ECM) accumulation in a mouse model of diabetic nephropathy. Brazilin reduced aggravated biochemical indices of DN (proteinuria and the serum glucose level) and renal hypertrophy. Brazilin also improved renal morphology and inhibited macrophage infiltration, as manifested by different pathological staining methods. Brazilin reduced the levels of pro-inflammatory cytokines and CD68, a macrophage marker, in the kidney cortex, as revealed by both RT-PCR and western blotting experiments. Furthermore, brazilin significantly downregulated the serum levels of pro-inflammatory cytokines and chemokines. Interestingly, brazilin significantly upregulated the levels of the anti-inflammatory factor IL-10, and prevented ECM accumulation. Brazilin reduced nuclear translocation of the NF-κB p65 subunit both in vitro and in vivo. Thus, brazilin might be a useful treatment for DN, through mitigating hypoglycemia, inflammation, and ECM accumulation.

Chlorogenic Acid Attenuates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting TLR4/NF-κB Signal Pathway.

Chlorogenic acid (CGA), a polyphenolic compound, exists widely in medicinal herbs, which has been shown a strong antioxidant and anti-inflammatory effect. This study investigated the protective effects and mechanism of CGA on lipopolysaccharide (LPS)-induced acute kidney injury (AKI). Treatment of CGA successfully ameliorates LPS-induced renal function and pathological damage. Moreover, CGA dose-dependently suppressed LPS-induced blood urea nitrogen (BUN), creatinine levels, and inflammatory cytokines TNF-α, IL-6, and IL-1ß in serum and tissue. The relative proteins' expression of TLR4/NF-κB signal pathway was assessed by western blot analysis. Our results showed that CGA dose-dependently attenuated LPS-induced kidney histopathologic changes, serum BUN, and creatinine levels. CGA also suppressed LPS-induced TNF-α, IL-6, and IL-1ß production both in serum and kidney tissues. Furthermore, our results showed that CGA significantly inhibited the LPS-induced expression of phosphorylated NF-κB p65 and IκB as well as the expression of TLR4 signal. In conclusion, our results provide a mechanistic explanation for the anti-inflammatory effects of CGA in LPS-induced AKI mice through inhibiting TLR4/NF-κB signaling pathway.

The attenuation of chlorogenic acid on oxidative stress for renal injury in streptozotocin-induced diabetic nephropathy rats.

The present study was undertaken to investigate whether chlorogenic acid (CGA) could protect kidney function against oxidative stress in the diabetic nephropathy (DN) rats. The treatment with CGA could decrease significantly the levels of blood glucose, blood urea nitrogen and serum creatinine in DN rats. Moreover, CGA significantly increased the activity of superoxide dismutase, glutathione peroxidase, and catalase. Moreover, the level of lipid peroxidation malondialdehyde was reduced markedly after CGA administration. Immunohistochemical analysis also showed that CGA downregulated significantly cyclooxygenase-2 protein expression in renal tissue, which is considered as one of the major pathogeneses of oxidative stress. Furthermore, we demonstrated that CGA could block the expression of activating transcription factor-6, C/EBP homology protein and the phosphorylation of eukaryotic initiation factor 2α and double stranded RNA-activated protein kinase-like endoplasmic reticulum kinase. In addition, we attempted to detect the presence of diabetic renal tissues apoptosis-related proteins. Our data provided evidence to support this fact that CGA attenuated oxidative stress in streptozocin-induced DN rats. Its molecular mechanism may inhibit the endoplasmic reticulum-stress response in DN.

Cytotoxicity and Genotoxicity in Human Embryonic Kidney Cells Exposed to Surface Modify Chitosan Nanoparticles Loaded with Curcumin.

The rapid progress in the development and scientific investments of modified nanoparticles are due to their owed activity to various diseased conditions for which they are prepared. But the toxicity which they cause cannot be overlooked. The present study demonstrates the development of phosphatidylserine (PS)-coated chitosan (CS) nanoparticles (NPs) loaded with curcumin (CU), which was then investigated against human embryonic kidney cells (HEK 293) for its cytotoxic and genotoxic effect in rats. The CU-loaded CNPs (CNPs-CU) have been prepared by ionic gelation method, later which were grafted with PS. CNPs-CU and PS-CNPs-CU have been evaluated for their size, poly dispersity index, amount of drug entrapped, and in vitro CU release. CNPs-CU has an average size 167.6 ± 3.53 nm and polydispersity index (PDI) 0.115 ± 0.014, whereas PS-CNPs-CU shows average size 220 ± 3.67 nm and PDI 0.148 ± 0.019. Surface morphology of prepared NPs was confirmed by high-resolution transmission electron microscopy (HR-TEM). There was no major difference in cell viability between PS-CNPs-CU and CNPs-CU when they were exposed to HEK 293 cells at all equivalent concentrations. A series of genotoxic studies were conducted, which revealed the non-genotoxicity potential of the developed complexes. These results demonstrated that PS-CNPs-CU may be useful as potential delivery system.

Three-dimensional scanning near field optical microscopy (3D-SNOM) imaging of random arrays of copper nanoparticles: implications for plasmonic solar cell enhancement.

In order to investigate the suitability of random arrays of nanoparticles for plasmonic enhancement in the visible-near infrared range, we introduced three-dimensional scanning near-field optical microscopy (3D-SNOM) imaging as a useful technique to probe the intensity of near-field radiation scattered by random systems of nanoparticles at heights up to several hundred nm from their surface. We demonstrated our technique using random arrays of copper nanoparticles (Cu-NPs) at different particle diameter and concentration. Bright regions in the 3D-SNOM images, corresponding to constructive interference of forward-scattered plasmonic waves, were obtained at heights Δz ≥ 220 nm from the surface for random arrays of Cu-NPs of ∼ 60-100 nm in diameter. These heights are too large to use Cu-NPs in contact of the active layer for light harvesting in thin organic solar cells, which are typically no thicker than 200 nm. Using a 200 nm transparent spacer between the system of Cu-NPs and the solar cell active layer, we demonstrate that forward-scattered light can be conveyed in 200 nm thin film solar cells. This architecture increases the solar cell photoconversion efficiency by a factor of 3. Our 3D-SNOM technique is general enough to be suitable for a large number of other applications in nanoplasmonics.

[Clinical and pathological characteristics in patients with clinically presumed hypertensive nephrosclerosis].

OBJECTIVE: To investigate the clinical and pathological characteristics of patients with clinically presumed hypertensive nephrosclerosis (HN). METHODS: Clinical data and renal biopsy results were obtained in 63 patients diagnosed clinically as HN (primary hypertension plus renal injury). RESULTS: HN was confirmed by biopsy in 47 out of 63 patients (74.6%, 12 malignant nephrosclerosis and 35 benign nephrosclerosis). Primary nephritis (PN) was diagnosed by biopsy in 10 patients (7 IgA nephropathy, 2 mesangial proliferative nephritis, 1 chronic interstitial nephritis) and focal and segmental glomerulosclerosis (FSGS) in 6 patients. Blood pressure, body mass index, GFR and blood lipids were similar among groups. HN patients were related to higher age, more frequent family history of hypertension, longer hypertension duration, higher left ventricular mass index, lower serum creatinine and lower incidence of microscopic hematuria. Most patients with malignant nephrosclerosis and FSGS patients showed grades III and IV retinopathy. CONCLUSION: Our results show that HN was misdiagnosed in nearly 25% patients in this cohort. Since the clinical features are similar between HN, PN and FSGS, renal biopsy is needed to establish the diagnosis of HN.