Enhanced wear resistance,antibacterial performance,and biocompatibility using nanotubes containing nano-Ag and bioceramics in vitro

A good Ti-based joint implant should prevent stress shielding and achieve good bioactivity and anti-infection performance.To meet these requirements,the low-elastic-modulus alloy—Ti–35Nb–2Ta–3Zr—was used as the substrate,and functional coatings that contained bioceramics and Ag ions were prepared for coating on TiO_(2)nanotubes(diameter:(80±20)nm and(150±40)nm)using anodization,deposition,and spin-coating methods.The effects of the bioceramics(nano-β-tricalcium phosphate,microhydroxyapatite(micro-HA),and meso-CaSiO_(3))and Ag nanoparticles(size:(50±20)nm)on the antibacterial activity and the tribocorrosion,corrosion,and early in vitro osteogenic behaviors of the nanotubes were investigated.The tribocorrosion and corrosion results showed that the wear rate and corrosive rate were highly dependent on the features of the nanotube surface.Micro-HA showed great wear resistance with a wear rate of(1.26±0.06)×10^(−3)mm^(3)/(N·m)due to adhesive and abrasivewear.Meso-CaSiO_(3)showed enhanced cell adhesion,proliferation,and alkaline phosphatase activity.The coatings that contained nano-Ag exhibited good antibacterial activity with an antibacterial rate of≥89.5%against Escherichia coli.These findings indicate that hybrid coatings may have the potential to accelerate osteogenesis.

Virtual screening,molecular docking and identification of umami peptides derived from Oncorhynchus mykiss

Oncorhynchus mykiss is delicious and contains abundant flavor substances.However,few studies focused on umami peptides of O.mykiss.In the current work,umami peptides derived from O.mykiss were identified using virtual screening,molecular docking,and electronic tongue analysis.First,the O.mykiss protein was hydrolyzed using the PeptideCutter online enzymolysis program.Subsequently,water-soluble and toxicity screening were performed by Innovagen and ToxinPred software,respectively.The potential peptides were docked with umami receptor T1R1/T1R3.Furthermore,taste properties of potential peptides were validated by electronic tongue.Docking results suggested that the three tetrapeptide EANK,EEAK,and EMQK could enter the binding pocket in the T1R1 cavity,wherein Arg151,Asp147,Gln52,and Arg277 may play key roles in the production of umami taste.Electronic tongue results showed that the umami value of EANK,EEAK,and EMQK were stronger than monosodium glutamate.This work provides a new insight for the screening of umami peptides in O.mykiss.

Effects of dietary coenzyme Q10 supplementation during gestation on the embryonic survival and reproductive performance of high‑parity sows

Background Fertility declines in high-parity sows.This study investigated whether parity-dependent declines in embryonic survival and reproductive performance could be restored by dietary coenzyme Q10(CoQ10)supplementation.Methods Two experiments were performed.In Exp.1,30 young sows that had completed their 2nd parity and 30 high-parity sows that had completed their 10^(th)parity,were fed either a control diet(CON)or a CON diet supple-mented with 1 g/kg CoQ10(+CoQ10)from mating until slaughter at day 28 of gestation.In Exp.2,a total of 314 post-weaning sows with two to nine parities were fed the CON or+CoQ10 diets from mating throughout gestation.Results In Exp.1,both young and high-parity sows had a similar number of corpora lutea,but high-parity sows had lower plasma CoQ10 concentrations,down-regulated genes involved with de novo CoQ10 synthesis in the endome-trium tissues,and greater levels of oxidative stress markers in plasma and endometrium tissues.High-parity sows had fewer total embryos and alive embryos,lower embryonic survival,and greater embryo mortality than young sows.Dietary CoQ10 supplementation increased the number of live embryos and the embryonic survival rate to levels simi-lar to those of young sows,as well as lowering the levels of oxidative stress markers.In Exp.2,sows showed a parity-dependent decline in plasma CoQ10 levels,and sows with more than four parities showed a progressive decline in the number of total births,live births,and piglets born effective.Dietary supplementation with CoQ10 increased the number of total births,live births,and born effective,and decreased the intra-litter covariation coefficients and the percentage of sows requiring farrowing assistance during parturition.Conclusions Dietary CoQ10 supplementation can improve the embryonic survival and reproductive performance of gestating sows with high parity,probably by improving the development of uterine function.

Toric Intraocular Lens vs. Peripheral Corneal Relaxing Incisions to Correct Astigmatism in Eyes Undergoing Cataract Surgery

Purpose:.To compare toric intraocular lens implantation(ToricIOL).with peripheral corneal relaxing incisions(PCRIs) for astigmatism correction in patients undergoing cataract surgery.Methods: 54 patients(54 eyes) with more than 0.75 diopter(D).of preexisting corneal astigmatism were classified as group A(0.75-1.50D) or group B(1.75-2.50D). The patients were randomized to undergo Toric-IOL or PCRIs in the steep axis with spherical IOL implantation..Log MAR uncorrected visual acuity(Log MAR UCVA), Log MAR best corrected vi sual acuity.(Log MAR BCVA),.error of vector(|EV|), surgery induced refraction correction.(|SIRC |),.and correction rates(CR) were measured 1 month and 6 months postoperatively.Results: At 6 months postoperatively, all 54 eyes had LogMAR BCVA≤0.2. Patients who underwent PCRIs and ToricIOL with Log MAR BCVA≤0.1 showed no significant differences in group A(P=1.00) or in group B(P=0.59). Group A showed no significant differences in Log MAR UCVA(P =0.70), |EV|(P=0.13), |SIRC|(P=0.71), and CR(P=0.56)in patients underwent PCRIs and Toric-IOL. However, group B showed significant differences in Log MAR UCVA(P <0.01), |EV|(P<0.01)), |SIRC|(P<0.01), and CR(P<0.01).The Log MAR UCVA and |EV | between 1 and 6 months showed no significant differences in patients in group A. However, in group B, they are significant differences.Conclusion:.The efficacy and stability of Toric-IOL and PCRIs were equal in low astigmatic patients..Toric-IOL achieved an enhanced effect over PCRIs in higher astigmatic patients.PCRIs had the more refractive regression than Toric-IOL in 6months.

Porphyromonas gingivalis exacerbates ulcerative colitis via Porphyromonas gingivalis peptidylarginine deiminase

Abstract:Ulcerative Colitis(UC)has been reported to be related to Porphyromonas gingivalis(P.gingivalis).Porphyromonas gingivalis peptidylarginine deiminase(PPAD),a virulence factor released by P.gingivalis,is known to induce inflammatory responses.To explore the pathological relationships between PPAD and UC,we used homologous recombination technology to construct a P.gingivalis strain in which the PPAD gene was deleted(Δppad)and aΔppad strain in which the PPAD gene was restored(comΔppad).C57 BL/6 mice were orally gavaged with saline,P.gingivalis,Δppad,or comΔppad twice a week for the entire 40 days(days 0-40),and then,UC was induced by dextran sodium sulfate(DSS)solution for 10 days(days 31-40).P.gingivalis and comΔppad exacerbated DDS-induced colitis,which was determined by assessing the parameters of colon length,disease activity index,and histological activity index,butΔppad failed to exacerbate DDS-induced colitis.Flow cytometry and ELISA revealed that compared withΔppad,P.gingivalis,and comΔppad increased T helper 17(Th17)cell numbers and interleukin(IL)-17 production but decreased regulatory T cells(Tregs)numbers and IL-10 production in the spleens of mice with UC.We also cocultured P.gingivalis,Δppad,or comΔppad with T lymphocytes in vitro and found that P.gingivalis and comΔppad significantly increased Th17 cell numbers and decreased Treg cell numbers.Immunofluorescence staining of colon tissue paraffin sections also confirmed these results.The results suggested that P.gingivalis exacerbated the severity of UC in part via PPAD.

Identification and molecular mechanism of angiotensin-converting enzyme inhibitory peptides from Larimichthys crocea titin

This study aimed to identify novel ACEI peptides from Larimichthys crocea titin using in silico approaches and to clarify the molecular interaction mechanism.The hydrolyzed peptides of titin were compared with known ACEI peptides in the AHTPDB and BIOPEP-UWM database.Furthermore,peptides were evaluated for their solubility,ADMET properties,ΔG(kcal/mol)values,and in vitro ACEI activity.Molecular mechanism of ACE-peptide was performed by molecular interactions and binding orientation study.The results revealed that IC50 values of Trp-Ala-Arg(WAR)and Trp-Gln-Arg(WQR)were(31.2±0.8)and(231.33±0.02)mol/L,respectively.The docking interactions result suggested that ACE-WAR and ACEWQR complexes have same binding site,including the residues LYS511,TYR520,TYR523,HIS353,and HIS513.Molecular docking of two tripeptides WAR and WQR with ACE studies predicted their binding site and clarified the interaction between ACE and its inhibitors.The molecular docking data are consistent with the ACE inhibitory activity of the studied peptides.The results showed that Larimichthys crocea titin may be a valuable source for developing nutraceutical food.

Identifi cation of egg protein-derived peptides as xanthine oxidase inhibitors:virtual hydrolysis,molecular docking,and in vitro activity evaluation

The purpose of this study was to screen the xanthine oxidase(XO)inhibitory peptides from egg white proteins through virtual hydrolysis,in vitro activity validation,and molecular docking.The results demonstrated that tripeptide EEK from ovalbumin exhibited potent XO inhibitory activity with an IC50 value of 141μmol/L.The molecular docking results showed that tripeptide EEK bound with the active center of XO via 3 carbon hydrogen bond interactions,2 salt bridges,5 conventional hydrogen bond interactions,and 4 attractive charge interactions.The residues Glu802,Phe1009,and Arg880 may play key roles in the XO catalytic reaction.Especially,the key intermolecular forces of inhibiting XO activity may be special type of hydrogen bonds including carbon hydrogen bond interactions and attraction charge interactions.The novel tripeptide EEK is potential candidates for controlling hyperuricemia.

Structural requirements and interaction mechanisms of ACE inhibitory peptides:molecular simulation and thermodynamics studies on LAPYK and its modifi ed peptides

The understanding of the structural requirements and the intermolecular-interaction mechanism are important for discovering potent angiotensin-converting enzyme(ACE)inhibitory peptides.In this study,we modifi ed an egg-white derived peptide,LAPYK,using the amino acids with different properties to produce the LAPYK-modified peptides.The ACE inhibitory activities of the modified peptides were determined to explore the structural requirements of ACE inhibitory peptides(ACEIPs).Molecular simulation and isothermal titration calorimetry analysis were used to investigate interactions between the peptides and ACE.We found that hydrophobicity and the amino acids with ring structures were benefi cial for the ACE inhibitory activities of the peptides.The results of the molecular mechanics poisson boltzmann surface area(MMPBSA)binding free energy calculations indicated that the polar solvation free energy(ΔG_(polar))of the charged peptides(LAPYK,LAPYE)were unfavorable for binding to ACE.On the other hand,the results of isothermal titration calorimetry analyses suggested that the enthalpy-driven ACE-peptide interactions were more favorable than the entropy-driven ACE-peptide interaction counterparts.

Biological evaluation and interaction mechanism of beta-site APP cleaving enzyme 1 inhibitory pentapeptide from egg albumin

Inhibition of beta-site APP cleaving enzyme1(BACE1)is one of the most promising therapeutic approaches for Alzheimer’s disease.To find natural products for the treatment of Alzheimer’s disease,absorption,distribution,metabolism,excretion and toxicity(ADMET)properties and in vitro BACE1 inhibitory activity of the peptides isolated from egg albumin were evaluated.Then,molecular docking and molecular dynamics simulation were used to explain the molecular mechanism of the interactions between BACE1 and peptides.The IC50 value of peptide KLPGF,with satisfactory ADMET properties,against BACE1 was(8.30±0.56)mmol/L.Molecular docking revealed that KLPGF contacted with the residues of BACE1’s active sites through twelve hydrogen bonds interactions,two hydrophobic interactions,one electrostatic interaction,and two Pi-cation interactions.The 5 ns molecular dynamics simulations confirmed that the structure of KLPGF with BACE1 was stable.Peptide KLPGF contacted the residues Lys321,Asp228,and Asn233 with stable hydrogen bonds.KLPGF may be a potential anti-BACE1 candidate.

Interaction mechanism of egg white-derived ACE inhibitory peptide TNGIIR with ACE and its effect on the expression of ACE and AT1 receptor

The egg white-derived hexapeptide TNGIIR inhibits angiotensin-converting enzyme(ACE)activity in vitro.In this work,molecular docking revealed that TNGIIR established hydrogen bonds with the S1(Ala 354),S2(Gln 281,His 513,Tyr 520 and Lys 511)and S1(Glu 162)pockets of ACE.In addition,the potential antihypertensive effect of the oral administration of TNGIIR in spontaneously hypertensive rats(SHR)was investigated,as was the effect of this peptide on the mRNA expression of ACE and angiotensin type 1(AT1)and type 2(AT2)receptors in renal tissue.The oral administration of TNGIIR(2,10 and 50 mg/kg)for up to four weeks did not reduce the blood pressure of SHR,in contrast to captopril(10 mg/kg,orally),but attenuated the mRNA expression of ACE and AT1 receptor(as did captopril).In contrast,both TNGIIR and captopril enhanced the expression of AT2 receptor mRNA.There was no change in the circulating concentration of angiotensin I,but a slight decrease(about 10%)was seen in the concentration of circulating angiotensin II with TNGIIR and captopril.

Seismic fragility analysis of composite frame structure based on performance

Steel-concrete composite structures that share the advantages of both steel structure and concrete structure have been developed rapidly and used widely. It has been a popular structure in high-rise buildings in recent years. Although more and more composite structures have been used in earthquake area, only a few literatures about fragility analysis of this type of structure are available. In this paper, a fragility analysis method based on performance is proposed, in which both the uncertainty due to variability in structures and ground motion are considered. Seismic fragility analysis is performed for a 15-story composite beam-concrete-filled square steel tube column frame by the proposed method. The top-drift-angle and the story-drift-angle are used as quantitative indexes to define the four different performance levels. Then seismic demand probability analysis is carried out and fragility curves are derived to assess the seismic performance of this type of structure.

A comparative analysis of seismic response of shallow buried underground structure under incident P,SV and Rayleigh waves

In this study,A time-domain seismic response analysis method and a calculation model of the underground structure that can realize the input of seismic P,SV and Rayleigh waves are established,based on the viscoelastic artificial boundary elements and the boundary substructure method for seismic wave input.After verifying the calculation accuracy,a comparative study on seismic response of a shallow-buried,double-deck,double-span subway station structure under incident P,SV and Rayleigh waves is conducted.The research results show that there are certain differences in the cross-sectional internal force distribution characteristics of underground structures under different types of seismic waves.The research results show that there are certain differences in the internal force distribution characteristics of underground structures under different types of seismic waves.At the bottom of the side wall,the top and bottom of the center pillar of the underground structure,the section bending moments of the underground structure under the incidences of SV wave and Rayleigh wave are relatively close,and are significantly larger than the calculation result under the incidence of P wave.At the center of the side wall and the top floor of the structure,the peak value of the cross-sectional internal force under the incident Rayleigh wave is larger than the calculation result under SV wave.In addition,the floor of the underground structure under Rayleigh waves vibrates in both the horizontal and vertical directions,and the magnification effect in the vertical direction is more significant.Considering that the current seismic research of underground structures mainly considers the effect of body waves such as the shear waves,sufficient attention should be paid to the incidence of Rayleigh waves in the future seismic design of shallow underground structures.

Multifunctional nano-herb based on tumor microenvironment for enhanced tumor therapy of gambogic acid

Multifunctional drug delivery systems(DDSs)have shown great prospects in overcoming the heterogeneous barrier of delivery drugs to the complex tumor microenvironment(TME).In this study,multifunctional AS/Ge-pNAB microgels with dual-active targeting,triple environment responsiveness,and fluorescence imaging capability were prepared through a straightforward procedure.This was aimed to improve the antitumor therapeutic application of gambogic acid(GA)based on the biological characteristics of TME.The microgels have a uniform double-layer structure with aptamer in the outer layer which helps in recognizing receptors on the tumor cells.The GA loaded nano-herb exhibited environment-responsive drug release profiles under acidic pH,reductant and high temperature.The nano-herb significantly improved the accumulation of GA in tumor sites through the synergistic combination of the enhanced permeability and retention effect and dual-ligand mediated internalization.Then,it accelerated intracellular drug release and killed tumor cells.Therefore,the nano-herb had specific therapeutic effects on the tumor in vitro and in vivo as they remarkably inhibited tumor growth while depicting optimal biosafety and lower levels of off-target toxicity.Overall,these findings demonstrate the great potential of the multifunctional AS/Ge-pNAB microgels for precisely targeted GA delivery and open a new avenue for the facile preparation of multifunctional DDSs.

Synthesis,biological activities and 3D-QSAR studies of(R)-2-phenyl-4,5-dihydrothiazole-4-carboxamide derivatives containing a sulfur ether moiety

A series of(R)-2-phenyl-4,5-dihydrothiazole-4-carboxamide derivatives containing a sulfur ether moiety were synthesized and characterized on the basis of NMR and elemental analysis(EA). The crystal structure of(R)-N-(2-methyl-1-(methylthio)propan-2-yl)-2-(4-nitrophenyl)-4,5-dihydrothiazole-4-carboxamide(13 d) was determined to show R configuration. The bioasssy results indicated that most title compounds displayed good and broad spectrum antifungal activities against several phytopathogenic fungi. The structure activity relationships were discussed. Based on the antifungal activity of title compounds against Phytophthora capsici, a CoMSIA calculation was performed to establish a 3 D-QSAR model, which revealed that electrostatic and hydrophobic fields were the two most significant factors for antifungal activity. According to the established 3D-QSAR model, structure optimization was carried out to find(R)-N-((R)-1-(methylthio)propan-2-yl)-2-(p-tolyl)-4,5-dihydrothiazole-4-carboxamide(15 h)with excellent activity against Phytophthora capsici, thus emerging as a new lead compound for novel antiphytopathogenic fungus agent development.

Fluid inclusions in whiteschist in the ultrahigh-pressure metamorphic belt of Dabie Shan,China

Hualiangting whiteschist in the Dabie Shan ultrahigh-pressure eclogite complex is a specific Mg-Al-rich metamorphic rock. Its protolith was a felsic dyke, which suffered replacement by high-pressure fluids during ec-logite-facies metamorphism. Based on fluid inclusion results in whiteschist, primary high-pressure fluids are CO2-bearing aqueous solutions. Those prove that there exists CO2-H2O fluid during the ultrahigh-pressure metamorphism. Pseu-dosecondary H2O inclusions were trapped during ultra-high-pressure exhumation, whereas secondary H2O inclusions were related to the latest evolutionary stage of the ultrahigh-pressure exhumation.

Phosphorus nutrition of growing pigs

Phosphorus(P)is an essential nutrient for diverse biological processes,which aggregate to the animal's requirement for P,and nutritionists strive to meet this requirement accurately.The P demand for a growing pig comprises requirements for maintenance and tissue deposition.The P in feed ingredients,however,must be digested and absorbed before its ultimate partition between the 2 aforementioned requirement components.Phosphorus from various sources could behave differently during digestion and absorption,which results in their disparate bioavailability for pigs.The system of standardized total tract digestibility reflects true total tract digestibility of P and feed ingredient effects on specific endogenous P loss with relative ease of implementation,and this system guarantees satisfactory additivity in digestible P among the ingredients in a dietdthe foundation for diet formulation.The basal endogenous P loss,which is much easier to measure than the specific endogenous P loss,is considered as part of the pig's maintenance requirement.With this arrangement,a digestibility framework is established both for measuring the P-providing capacity of various feed ingredients and for describing the pig's P requirement.This framework entails basic understanding of the function,digestion,absorption,excretion,and homeostasis of P as support pillars.Understanding the workings of this framework enables potential integration of factors such as environment conditions and disease status in future P requirement models.The current review discusses dietary sources,digestion,absorption,bioavailability and requirement of P for growing pigs to understand the status quo,revealing the points of consensus as well as those of debate,and to encourage further investigation to provide more clarity.

Could tectonic overpressure cause ultrahigh-pressure metamorphism?

Could ultrahigh-pressure metamorphic rocks be caused, at depth of 32 km, by tectonic overpressure resulting from differential stress? The differential stress is limited by rock strength, which depends on strain rate and temperature. Therefore, tectonic overpressure could not go beyond 1 GPa, and could not cause the uitrahigh-pressure metamorphism.

Tectonic Boundary and Ceasing Time of Amalgamation between the North China Craton and the North Qinling Belt

The Qinling orogenic belt is a composite orogen, consisting of the north and south Qinling belts with different collision ages. The North Qinling belt is composed of several petro-tectonic units, including the Kuanping, Erlangping, Qinling and Danfeng groups with numerous granitoid plutons from Neoproterzoic to Middle Devonian. To the north of the Kuanping Group, a mylonitized granite body in the Luanchuan Group was determined to have the magmatic age of 850 Ma, which is the northernmost Neoprotozoic granite body. The volcanic rocks of the Dahongkou Formation from the Luanchuan Group had the eruptive age of -1 600 Ma, obtained from zircon U-Pb LA-ICP-MS analysis. The detrital zircons in meta-sandstones from the Taowan Group have three populations of-920-1 400, -1 600-2 100, and 〉2 200 Ma ages, whereas those from the Kuanping Group shows six populations with the peaks of -590, -767, -952, -1 590, -2 485, and -3 200 Ma. These data suggest that the boundary between the North China Craton and the North Qinling belt cannot simply be constrained by using the events determined from zircon U-Pb ages. The granitoid plutons with the magmatic age of 430 Ma were strongly deformed, while those with the magmatic age of -390 Ma show no or less deformation, indicating that the deformation of amalgamation between the North China Craton and the North Qinling belt ceased between 390 and 430 Ma.

Effects of dietary cellulose levels on the estimation of endogenous amino acid losses and amino acid digestibility for growing pigs

Two experiments were conducted to investigate the effects of dietary cellulose levels on the determination of the ileal endogenous losses(IEL) of amino acids(AA), apparent ileal digestibility(AID) and standardized ileal digestibility(SID) of AA in corn-soybean meal diets for growing pigs. In the first experiment, 28 pigs(BW, 45.1 ± 2.0 kg) that were fitted with simple T-cannulas at the distal ileum were fed 4 nitrogen-free diets consisting of 4 dietary cellulose levels(0, 3%, 6% and 9%) in a randomized complete block design. In the second experiment, 28 pigs(BW, 45.6 ± 2.0 kg) fitted with simple Tcannulas at the distal ileum were fed 4 corn-soybean meal diets consisting of 4 dietary cellulose levels(0,3%, 6% and 9%) in a randomized complete block design. There were 7 replicates per diet with 1 pig as a replicate in each treatment. Both experiments consisted of a 7-d adjustment period and a 2-d ileal digesta collection period on d 8 and 9. Chromic oxide was used as an indigestible marker to calculate IEL and digestibility of AA. The results showed that the IEL of AA for growing pigs was not influenced by dietary cellulose supplementation(P > 0.05). The AID of Thr, Ser, Glu, Cys, Ile, Tyr, Phe, Lys and His decreased with increasing cellulose supplementation levels for pigs fed corn-soybean meal diets(P < 0.05). The SID of Thr, Ser, Cys, Val, Ile, Tyr, Phe, Lys and His decreased with increasing cellulose supplementation levels in corn-soybean meal diets(P < 0.05). In summary, dietary cellulose levels had no effect on the estimation of IEL of AA for growing pigs. The AID and SID of most AA in corn-soybean meal diets decreased with increasing levels of dietary cellulose supplementation.