Scavenger receptor BI: A multi-purpose player in cholesterol and steroid metabolism

Scavenger receptor class B type Ⅰ (SR-BI) is an important member of the scavenger receptor family of integral membrane glycoproteins. This review highlights studies in SR-BI knockout mice, which concern the role of SR-BI in cholesterol and steroid metabolism. SR-BI in hepatocytes is the sole molecule involved in selective uptake of cholesteryl esters from high-density lipoprotein (HDL). SR-BI plays a physiological role in binding and uptake of native apolipoprotein B (apoB)-containing lipoproteins by hepatocytes, which identif ies SR-BI as a multipurpose player in lipid uptake from the blood circulation into hepatocytes in mice. In adrenocortical cells, SR-BI mediates the selective uptake of HDL-cholesteryl esters, which is eff iciently coupled to the synthesis of glucocorticoids (i.e. corticosterone). SR-BI knockout mice suffer from adrenal glucocorticoid insuff iciency, which suggests that functional SR-BI protein is necessary for optimal adrenal steroidogenesis in mice. SR-BI in macrophages plays a dual role in cholesterol metabolism as it is able to take up cholesterol associated with HDL and apoBcontaining lipoproteins and can possibly facilitate cholesterol efflux to HDL. Absence of SR-BI is associated with thrombocytopenia and altered thrombosis susceptibility, which suggests a novel role for SR-BI in regulating platelet number and function in mice. Transgenic expression of cholesteryl ester transfer protein in humanized SR-BI knockout mice normalizes hepatic delivery of HDL-cholesteryl esters. However, other pathologies associated with SR-BI def iciency, i.e. increased atherosclerosis susceptibility, adrenal glucocorticoid insuffi ciency, and impaired platelet function are not normalized, which suggests an important role for SR-BI in cholesterol and steroid metabolism in man. In conclusion, generation of SR-BI knockout mice has signif icantly contributed to our knowledge of the physiological role of SR-BI. Studies using these mice have identif ied SR-BI as a multi-purpose player in cholesterol and steroid metabolism because it has distinct roles in reverse cholesterol transport, adrenal steroidogenesis, and platelet function.

Synergistic impact of cocatalysts and hole scavenger for promoted photocatalytic H2 evolution in mesoporous TiO2–NiSx hybrid

Photocatalytic solar energy conversion to hydrogen is sustainable and attractive for addressing the global energy and environmental issue. Herein, a novel photocatalytic system (NiS/Ni3S4 cocatalysts modified mesoporous TiO2) with superior photocatalytic hydrogen evolution capability through the synergistic impact of NiS/Ni3S4 (NiSx) cocatalyst and efficient hole scavenger has been demonstrated. The photocatalytic hydrogen evolution of TiO2-NiSx hybrids with the different content of NiSx and upon different organic hole scavengers was both investigated. The hybrid of TiO2 decorated with 3%(mole ratio of Ni^2+) NiSx cocatalyst in methanol solution showed the optimal photocatalytic hydrogen evolution rate of 981.59 μmol h^-1 g^-1 which was about 20 times higher than that of bare mesoporous TiO2. Our results suggested that the boosted hydrogen production performance is attributed to both the improved photoinduced electrons migration between NiS and Ni3S4 in cocatalyst and the high hole captured efficiency by hole scavengers of methanol.

Effects of a nitric oxide donor and nitric oxide scavengers on Sorbus pohuashanensis embryo germination

The effects of an exogenous nitric oxide donor(sodium nitroprusside, SNP), a NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxode(PTIO) and carboxy-PTIO potassium salt(c PTIO) on the embryo germination of Sorbus pohuashanensis were studied in a petri dish test. SNP at 0.5–5 mmol L-1 increased germination percentage, mean time to germination, germination index and germination energy compared with the control to different degrees. Treatment with 2 mmol L-1 SNP improved germination most significantly; embryo germination percentage for mother tree 1(91.11%) and mother tree 2(64.44%) were much higher than the control. In addition,excessive SNP levels did not enhance embryo germination.Combined treatment with SNP and an NO scavenger delayed embryo germination. Treatment with c PTIO inhibited embryo germination; germination percentage was 42.22% and was lower than that of the control. These results show that low concentrations of exogenous NO can enhance the embryo germination of S. pohuashanensis,providing a simple, effective way for promoting germination of S. pohuashanensis.

The gut microbiome and metabolome of Himalayan Griffons(Gyps himalayensis):insights into the adaptation to carrion-feeding habits in avian scavengers

Background:Himalayan Griffons(Gyps himalayensis),large scavenging raptors widely distributed in Qinghai-Tibetan Plateau,have evolved a remarkable ability to feed on carcasses without suffering any adverse effects.The gut microbiome plays an important role in animal physiological and pathological processes,and has also been found to play a health protective role in the vulture adaptation to scavenging.However,the microbial taxonomic diversity(including nonculturable and culturable microbes),functions,and metabolites related to Himalayan Griffons have not been fully explored.Methods:In the present study,the 28 fecal samples of the Himalayan Griffons and 8 carrion samples were collected and sequenced using high-throughput 16 S rRNA gene sequencing methods to analyze the composition and functional structures of the microbiomes.Twelve fecal samples of the Himalayan Griffons were analyzed using untargeted Liquid Chromatography Mass Spectroscopy(LC-MS)to identify metabolites.We used different culture conditions to grow Himalayan Griffons gut microbes.Inhibitory effects of gut beneficial bacteria on 5 common pathogenic bacteria were also tested using the Oxford cup method.Results:According to the results of the culture-independent method,a high abundance of four major phyla in Himalayan Griffons were identified,including Fusobacteria,Firmicutes,Bacteroidetes,and Proteobacteria.The most abundant genera were Fusobacterium,followed by Clostridium_sensu_stricto_1,Cetobacterium,Epulopiscium,and Bacteroides.The predicted primary functional categories of the Himalayan Griffons'gut microbiome were associated with carbohydrate and amino acid metabolism,replication and repair,and membrane transport.LC-MS metabolomic analysis showed a total of 154 metabolites in all the fecal samples.Cultivation yielded 184 bacterial isolates with Escherichia coli,Enterococcus faecium,Enterococcus hirae,and Paeniclostridium sordellii as most common isolates.Moreover,7 potential beneficial gut bacteria isolated showed certain inhibition to 5 common pathogenic bacteria.Conclusions:Our findings broaden and deepen the understanding of Himalayan Griffons'gut microbiome,and highlighted the importance of gut microbiome-mediated adaptation to scavenging habits.In particular,our results highlighted the protective role of gut beneficial bacteria in the Himalayan Griffons against pathogenic bacteria that appear in rotten food resources.

Non-peptidyl low molecular weight radical scavenger IAC attenuates DSS-induced colitis in rats

AIM:To investigate the effects of the free radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl) decandioate(IAC) in the dextran sodium sulphate(DSS) experimental model of ulcerative colitis.METHODS:Colitis was induced in Sprague Dawley male rats by administration of 5% DSS in drinking water.IAC(30 mg/kg,lipophilic or hydrophilic form) was administered daily(orally or ip) for 6 d until sacrifice.Colonic damage was assessed by means of indirect(Disease Activity Index score) and direct measures(macroscopic and microscopic scores) and myeloperoxidase(MPO)activity.Neutrophil infiltration within the tissue and glutathione S-transferase activity were also investigated.RESULTS:DSS-induced colitis impaired body weight gain and markedly increased all inflammatory parameters.Six-day treatment with lipophilic IAC significantly reduced intestinal damage caused by inflammation,induced a down-regulation in MPO activity(0.72 ± 0.12 and 0.45 ± 0.12 with lipophilic IAC po and ip,respectively,vs 1.10 ± 0.27 in untreated DSS colitis animals) and minimized DSS-induced neutrophil infiltration,while hydrophilic IAC administered orally did not ameliorate DSS-induced damage.CONCLUSION:These results support the hypothesis that reactive oxygen metabolites contribute to inflammation and that the radical scavenger IAC has therapeutic potential in inflammatory bowel disease.

Increase the Degradation Efficiency of Organic Pollutants with a Radical Scavenger (Cl) in a Novel Photoelectrocatalytic Reactor

Photoelectrocatalytic degradation performance of quinoline in saline water was investigated using a new-designed continuous flow three-dimensional electrode-packed bed photocatalytic reactor. It is interesting to find that chloride ion has an obvious enhancement effect rather than a scavenging effect on the photoelectrocatalytic degradation of quinoline, and create a kinetic synergetic effect in the photoelectrocatalytic reactor.

The effective transfection of a low dose of negatively charged drug-loaded DNA-nanocarriers into cancer cells via scavenger receptors

DNA-nanotechnology-based nano-architecture scaffolds based on circular strands were designed in the form of DNA-nanowires(DNA-NWs) as a polymer of DNA-triangles. Circularizing a scaffold strand(84-NT) was the critical step followed by annealing with various staple strands to make stiff DNAtriangles. Atomic force microcopy(AFM), native polyacrylamide gel electrophoresis(PAGE), UVanalysis, MTT-assay, flow cytometry, and confocal imaging were performed to assess the formulated DNA-NWs and cisplatin(CPT) loading. The AFM and confocal microscopy images revealed a uniform shape and size distribution of the DNA-NWs, with lengths ranging from 2 to 4 mm and diameters ranging from 150 to 300 nm. One sharp band at the top of the lane(500 bp level) with the loss of electrophoretic mobility during the PAGE(native) gel analysis revealed the successful fabrication of DNA-NWs. The loading efficiency of CPT ranged from 66.85% to 97.35%. MTT and flow cytometry results showed biocompatibility of the blank DNA-NWs even at 95% concentration compared with the CPT-loaded DNANWs. The CPT-loaded DNA-NWs exhibited enhanced apoptosis(22%) compared to the apoptosis(7%)induced by the blank DNA-NWs. The release of CPT from the DNA-NWs was sustained at < 75% for 6 h in the presence of serum, demonstrating suitability for systemic applications. The IC_(50) of CPT@DNA-NWs was reduced to 12.8 nM CPT, as compared with the free CPT solution exhibiting an IC_(50) of 51.2 n M.Confocal imaging revealed the targetability, surface binding, and slow internalization of the DNA-NWs in the scavenger-receptor-rich cancer cell line(HepG2) compared with the control cell line.

Genetic variants of the class A scavenger receptor gene are associated with coronary artery disease in Chinese

The class A scavenger receptor, encoded by the macrophage scavenger receptor 1 （MSR1） gene, is a pattern recognition receptor （PPR） primarily expressed in macrophages. It has been reported that genetic polymorphisms of MSR1 are significantly associated with the number of diseased vessels and coronary artery narrowing greater than 20% in Caucasians. However, whether it links genetically to coronary artery disease （CAD） in Chinese is not defined. Here, we performed an independent case-control study in a Chinese population consisting of 402 CAD cases and 400 controls by genotyping ten single nucleotide polymorphisms （SNPs） of MSR1. We found that rs416748 and rs13306541 were significantly associated with an increased risk of CAD with per allele odds ratio （OR） of 1.56 [95% confidence interval （CI） = 1.28-1.90; P 〈 0.001] and 1.70 （95% CI = 1.27-2.27; P 〈 0.001）, re- spectively. Our results indicate that genetic variants of MSR1 may serve as predictive markers for the risk of CAD / in combination with traditional risk factors of CAD in Chinese population.

Hyperglycemia promotes overexpression of SR-BII isoform of the scavenger receptor class B type I in type 2 diabetes mellitus: A study in Juana Koslay City, San Luis, Argentina

The scavenger receptor class B type I (SR-BI) is a high-density lipoprotein (HDL) receptor involved in reverse cholesterol transport. Some studies reported the association to be stronger in the presence of diabetes. The full length gene encoding SR-BI is comprised in 13 exons that are alternatively spliced to produce two major transcripts: the full length SR-BI and the splice variant SR-BII, in which exon 12 is skipped. Considering that type 2 diabetes status is characterized by changes in the concentration of plasma lipids, modifications in lipoprotein size and composition, which may be important modulators of the SR-BI expression;the aims of the study were to examine the influence of SR-BI polymorphism (rs838895) on lipid profile and SR-BI mRNA expression in a population of diabetic patients living in Juana Koslay City. Blood samples were drawn from controls (n = 40) and Type 2 diabetic patients (n = 66) and DNA and total RNA were obtained. SR-BI mRNA expression was measured by RT-PCR and SR-BI polymorphism was detected by Tetra Primer ARMSPCR. Compared to controls, diabetic patients had higher fasting serum glucose, glycated hemoglobin, triglycerides, total cholesterol, lowdensity lipoprotein cholesterol, and lower highdensity lipoprotein cholesterol. SR-BI mRNA expression was lower in T2DM when compared to controls, suggesting that the hyperglycemia presents in T2DM patients down-regulates SR-BI mRNA expression. Interestingly, we found that decreased SR-BI expression resulted in markedly increased plasma LDL concentrations in T2DM subjects, and the overexpression of SRBII isoform is responsible for the markedly increased plasma LDL-c concentrations. The polymorphism (rs838895) did not modify the mRNA level of SR-BI in leucocytes from control and diabetic patients. This study provides novel evidence suggesting that hyperglycemia may affect reverse cholesterol transport by controlling SRBI expression in diabetic patients. LDL cholesterol levels are associated with low SR-BI mRNA expression in T2DM.

Comparative Efficacy of Polyamine-Based Scavenger Resins

Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes) from solutions has been studied. As expected, the scavenging efficiency is directly proportional to the number of nucleophic nitrogens present on the resin. The results have been compared with the performance of the popular scavenger resin, namely, tris(2-aminoethyl)amine resin, to conclude that the low-cost polyamine resins now prepared can be conveniently used as effectively as the expensive commercial product.

Assessment of the Activities of Scavengers in Obio/Akpor Local Government, Rivers State, Nigeria

This study was carried out based on consistent observations on the activities of scavengers of scrap metal in Obio/Akpor local government Rivers State. The study was carried out to ascertain the profitability of scrap metal scavenging and how scrap metal waste can generate wealth to the public and the government. The study made use of primary and secondary data with the former being the main focus. The data were analyzed using the simple percentage, while the hypothesis was tested by means of the chi-square. The study findings revealed that there was a relationship between waste and wealth in relation to scrap metal scavenging. The researches therefore make the following recommendations;that scavengers should form co-operatives so that they can pull their efforts and resources together and bargain collectively. Government and nongovernmental organization should enlighten them through seminars, workshops, etc., on how to carry out their activities in an environmentally safe manner. The state government should encourage scavenging by enacting a law to back the profession and make it attractive for the teaming youths to venture into.

Possible Synergistic Toxicity of Oxygen Scavenger and Defoamer on the Niger Delta Freshwater <i>Tilapia guineensis</i>

Globally, the generation of produced water keeps increasing due to depleting wells and about 40% of this wastewater is disposed of into the environment. Produced water is made up of several components that are toxic in nature, like production chemicals that are used for oil and gas production activities. Oxygen scavenger and defoamer are commonly used for corrosion prevention as both are applied at different stages of corrosion prevention. Evaluation of the possible synergistic toxicity contribution of oxygen scavenger and defoamer formed the basis of this research and was conducted using the Tilapia guineensis as bio-indicator. The toxicity test was carried out using the ELIMINOX (oxygen scavenger) and EC9017A (defoamer) individually and both chemicals were combined together. The choice of these chemicals was premised on previous researches that have confirmed that they are toxic individually, without further research on how they interact when they are combined. These chemicals and freshwater were used to generate produced water samples in the laboratory. The experiment was set up by adding ten fishes into each of the glass containers, containing the produced water samples at different concentrations and a control sample without the chemicals. The rate of mortality of the fish for the individual chemicals ranged from 100% to 10% for the different percentage concentrations. While on the other hand, a combination of the two chemicals had more survival than mortality, the percentage survival rate ranged from 100% to 90% across all the percentage concentrations. The lethal concentration also showed that the oxygen scavenger was more toxic than the defoamer, however, when they were combined;they showed an antagonistic relationship as the toxicity of the oxygen scavenger drastically reduced. The research findings intend to create awareness of the possible interaction of production chemicals when they are used for oil and gas activities and their combined toxicity contribution to produced water. This will in turn aid government regulators in their decision-making for disposal of produced water.

Enterococcus faecalis provides protection during scavenging in carrion crow (Corvus corone)

The gut microbiota significantly influences host physiology and provides essential ecosystem services.While diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to specific dietary habits.The carrion crow(Corvus corone),an urban facultative scavenger bird,hosts an abundance of pathogens due to its scavenging behavior.Despite this,carrion crows infrequently exhibit illness,a phenomenon related to their unique physiological adaptability.At present,however,the role of the gut microbiota remains incompletely understood.In this study,we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing,China.Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria(75.51%)and Firmicutes(22.37%).Significant differences were observed in the relative abundance of Enterococcus faecalis among groups,highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows.Subsequently,E.faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection.Results showed that E.faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha(TNF-α),interferon gamma(IFN-γ),and interleukin 6(IL-6),prevented S.enterica colonization,and regulated the composition of gut microbiota in mice,thereby modulating the host’s immune regulatory capacity.Therefore,E.faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior,offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.

Expression pattern and tissue localization of the class B scavenger receptor BmSCRBQ4 in Bombyx moil

Class B scavenger receptors （SR-Bs） are cell surface glycoproteins involved in various physiological processes in vivo, including the transport and metabolism of lipids, binding and phagoeytosis of xenobiotics, and signaling. But little information is available about silkworm SR-Bs; it is necessary to study these SR-Bs for revealing their function. In this study, we cloned the full-length coding sequence of BrnSCRBQ4, a SR-B gene from the silkworm Bombyx mori L. We found that the BmSCRBQ4 gene consists of nine exons and eight introns, with an open reading frame of 1371 bp encoding 456 amino acids. Gene expression studies determined that BmSCRBQ4 messenger RNA （mRNA） was expressed in unfertilized eggs, during embryonic development and throughout the majority of the larval period. Expression of mRNA was detected in the mid gut, middle silk gland, posterior silk gland, head, integumentum, fat body, testes and the ovaries of the larval B. mori Dazao strain, as well as in the silkworm cell lines BmN and BmE. Protein expression studies found BmSCRBQ4 protein was expressed only in the testes, fat body and middle silk gland of larvae, as well as in the silkworm cell lines BmN and BmE. The BmSCRBQ4 protein showed variability in banding patterns in different tissues and cells when analyzed by Western blotting. Immunohistochemical staining showed that the BmSCRBQ4 protein localizes to the constitutive membranes or cellular membranes of these tissues. These results indicated that BmSCRBQ4 gene may play some physiologically relevant roles at the cell surface in each tissue.

Mechanism linking atherosclerosis and type 2 diabetes: increased expression of scavenger receptor CD_(36) in monocytes

Background We investigated the pathogenesis of atherosclerosis in diabetes, and detected the expression of scavenger receptor CD36 in monocytes in patients with type 2 diabetes.Methods According to the criteria by WHO, diabetic patients were classified into two groups： well controlled diabetic patients （WCP） and poorly controlled diabetic patients （PCP）. The expression of CD36 protein and mRNA were evaluated by flow cytometry and reversal transcription polymerase chain reaction （RT-PCR）. Plasma levels of accumulution of oxidized LDL （oxLDL） were immunosorbent assay （ELISA） method. directly measured by sandwich enzyme-linkedResults Flow cytometry and RT-PCR showed that the mean fluorescence intensity （MFI） of CD36 in monocyte and CD36 mRNA were significantly higher in the PCP and WCP in comparison with healthy controls （P 〈 O. O1 ）. CD36 MFI and mRNA in the PCP were increased by 78% and 36% compared to the WCP. In both groups, CD36 MFI and mRNA were significantly higher in patients with diabetic atherosclerosis in comoparison with those without diabetic atherosclerosis （P 〈0. 05）. No significant difference was found in CDt4 expression between the groups （P〉0. 05 ）. The concentrations of plasma oxLDL were higher in the PCP group compared to WCP and control group （P 〈0. 05 ）, whereas oxLDL average values did not differ significantly between WCP and control groups （P〉0.05 ） . In the WCP and PCP groups, oxLDL levels were higher in patients with diabetic atherosclerosis than those without diabetic atherosclerosis （ P 〈0.05 ）.Conclusions The increased expression of scavenger receptor CD36 may be one of the mechanism of accelerated atherosclerosis in diabetic. The poorly controlled diabetes patients are at higher risk for the vascular complications than the well controlled diabetic patients.

Can scavengers save zebras from anthrax? A modeling study

Namibia’s Etosha National Park(ENP)is home to many different animals such as lions,jackals,hyenas,zebras,elephants,etc.Each year,grazing animals are infected and die from anthrax caused by the bacteria Bacillus anthracis.This increases the number of carcasses in the park,which serve as food for scavengers such as jackals.This study investigates the interplay between anthrax transmission in zebras and the scavenging of zebra carcasses in ENP,using a deterministic mathematical model to describe the population dynamics.We strive to answer the following research questions:Under what conditions can the presence of scavengers control anthrax outbreaks in zebra populations=Does carcass production by anthrax help or hurt scavengers in the long term?Standard qualitative analysis techniques distinguished outcomes(stable equilibria)using reproduction numbers as threshold quantities.We found that,when scavengers feed on anthrax-laden carcasses,the scavengers help the zebras,by eliminating potential infection zones for the zebras.In this way they reduce anthrax’s spread by orders of magnitude.We also identify conditions under which the presence of anthrax benefits the scavengers,in terms of death-to-birth ratios for zebras,scavengers and anthrax.

Nanozyme‑Engineered Hydrogels for Anti‑Inflammation and Skin Regeneration

Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare system.Conventional therapies,such as corticosteroids and nonsteroidal anti-inflammatory drugs,are limited in efficacy and associated with adverse effects.Recently,nanozyme(NZ)-based hydrogels have shown great promise in addressing these challenges.NZ-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of hydrogels.The multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and differentiation.This review highlights the current state of the art in NZ-engineered hydrogels(NZ@hydrogels)for anti-inflammatory and skin regeneration applications.It also discusses the underlying chemo-mechano-biological mechanisms behind their effectiveness.Additionally,the challenges and future directions in this ground,particularly their clinical translation,are addressed.The insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels,offering new possibilities for targeted and personalized skin-care therapies.

Integrated high-performance and accurate shaping technology of low-cost powder metallurgy titanium alloys: A comprehensive review

The practical engineering applications of powder metallurgy (PM) Ti alloys produced through cold compaction and pressure-less sintering are impeded by poor sintering densification, embrittlement caused by excessive O impurities, and severe sintering deforma-tion resulting from the use of heterogeneous powder mixtures. This review presents a summary of our previous work on addressing the above challenges. Initially, we proposed a novel strategy using reaction-induced liquid phases to enhance sintering densification. Near- complete density (relative density exceeding 99%) was achieved by applying the above strategy and newly developed sintering aids. By focusing on the O-induced embrittlement issue, we determined the onset dissolution temperature of oxide films in the Ti matrix. On the basis of this finding, we established a design criterion for effective O scavengers that require reaction with oxide films before their dissol-ution. Consequently, a ductile PM Ti alloy was successfully obtained by introducing 0.3wt% NdB6 as the O scavenger. Lastly, a powder- coating strategy was adopted to address the sintering deformation issue. The ultrafine size and shell-like distribution characteristics of coating particles ensured rapid dissolution and homogeneity in the Ti matrix, thereby facilitating linear shrinkage during sintering. As a result, geometrically complex Ti alloy parts with high dimensional accuracy were fabricated by using the coated powder. Our fundament-al findings and related technical achievements enabled the development of an integrated production technology for the high-performance and accurate shaping of low-cost PM Ti alloys. Additionally, the primary engineering applications and progress in the industrialization practice of our developed technology are introduced in this review.

MIR1868 negatively regulates rice cold tolerance at both the seedling and booting stages

Low temperature causes rice yield losses of up to 30%–40%,therefore increasing its cold tolerance is a breeding target.Few genes in rice are reported to confer cold tolerance at both the vegetative and reproductive stages.This study revealed a rice-specific 24-nt miRNA,miR1868,whose accumulation was suppressed by cold stress.Knockdown of MIR1868 increased seedling survival,pollen fertility,seed setting,and grain yield under cold stress,whereas its overexpression conferred the opposite phenotype.Knockdown of MIR1868 increased reactive oxygen species(ROS)scavenging and soluble sugar content under cold stress by increasing the expression of peroxidase genes and sugar metabolism genes,and its overexpression produced the opposite effect.Thus,MIR1868 negatively regulated rice cold tolerance via ROS scavenging and sugar accumulation.

Diamond-Like Carbon Depositing on the Surface of Polylactide Membrane for Prevention of Adhesion Formation During Tendon Repair

Post-traumatic peritendinous adhesion presents a significant challenge in clinical medicine.This study proposes the use of diamond-like carbon(DLC)deposited on polylactic acid(PLA)membranes as a biophysical mechanism for anti-adhesion barrier to encase ruptured tendons in tendon-injured rats.The results indicate that PLA/DLC composite membrane exhibits more efficient anti-adhesion effect than PLA membrane,with histological score decreasing from 3.12±0.27 to 2.20±0.22 and anti-adhesion effectiveness increasing from 21.61%to 44.72%.Mechanistically,the abundant C=O bond functional groups on the surface of DLC can reduce reactive oxygen species level effectively;thus,the phosphorylation of NF-κB and M1 polarization of macrophages are inhibited.Consequently,excessive inflammatory response augmented by M1 macrophage-originated cytokines including interleukin-6(IL-6),interleukin-1β(IL-1β),and tumor necrosis factor-α(TNF-α)is largely reduced.For biocompatibility evaluation,PLA/DLC membrane is slowly absorbed within tissue and displays prolonged barrier effects compared to traditional PLA membranes.Further studies show the DLC depositing decelerates the release of degradation product lactic acid and its induction of macrophage M2 polarization by interfering esterase and PLA ester bonds,which further delays the fibrosis process.It was found that the PLA/DLC membrane possess an efficient biophysical mechanism for treatment of peritendinous adhesion.