Rational engineering S1' substrate binding pocket to enhance substrate specificity and catalytic activity of thermal-stable keratinase for efficient keratin degradation.

This study reports the rational engineering of the S1' substrate-binding pocket of a thermally-stable keratinase from Pseudomonas aeruginosa 4-3 (4-3Ker) to improve substrate specificity to typical keratinase (K/C > 0.5) and catalytic activity without compromising thermal stability for efficient keratin degradation. Of 10 chosen mutation hotspots in the S1' substrate-binding pocket, the top three mutations M128R, A138V, and V142I showing the best catalytic activity and substrate specificity were identified. Their double and triple combinatorial mutants synergistically overcame limitations of single mutants, fabricating an excellent M128R/A138V/V142I triple mutant which displayed a 1.21-fold increase in keratin catalytic activity, 1.10-fold enhancement in keratin/casein activity ratio, and a 3.13 °C increase in half-inactivation temperature compared to 4-3Ker. Molecular dynamics simulations revealed enhanced flexibility of critical amino acid residues at the substrate access tunnel, improved global protein rigidity, and heightened hydrophobicity within the active site likely underpinned the increased catalytic activity and substrate specificity. Additionally, the triple mutant improved the feather degradation rate by 32.86 % over the wild-type, far exceeding commercial keratinase in substrate specificity and thermal stability. This study exemplified engineering a typical keratinase with enhanced substrate specificity, catalytic activity, and thermal stability from thermally-stable 4-3Ker, providing a more robust tool for feather degradation.

Analysis of the Genomic Sequences and Metabolites of Bacillus velezensis YA215.

Discovering more novel antimicrobial compounds has become a keen research problem. In this study, YA215 genome was sequenced by the Illumina HiSeq + PacBio sequencing platform. Genome assembly was performed by Unicycler software and the gene clusters responsible for secondary metabolite biosynthesis were predicted by antiSMASH. The genome comprised 3976514 bp and had a 46.56% G + C content. 3809 coding DNA sequences, 27 rRNAs, 86 tRNAs genes, and 79 sRNA were predicted. Strain YA215 was re-identified as Bacillus velezensis based on ANI and OrthoANI analysis. In the COG database, 23 functional groups from 3090 annotations were predicted. In the GO database, 2654 annotations were predicted. 2486 KEGG annotations linked 41 metabolic pathways. Glycosyl transferases, polysaccharide lyases, auxiliary activities, glycoside hydrolases, carbohydrate esterases, and carbohydrate-binding modules were predicted among the 127 annotations in the CAZy database. AntiSMASH analysis predicted that B. velezensis YA215 boasted 13 gene clusters involved in synthesis of antimicrobial secondary metabolites including surfactin, fengycin, macrolactin H, bacillaene, difficidin, bacillibactin, bacilysin, and plantazolicin. Three of the gene clusters (gene cluster 5, gene cluster 9, and gene cluster 10) have the potential to synthesize unknown compounds. The research underscore the considerable potential of secondary metabolites, identified in the genomic composition of B. velezensis YA215, as versatile antibacterial agents with a broad spectrum of activity against pathogenic bacteria.

One-step synthesis of phytic acid-assisted hydrochar boost selective sorption and in situ passivation of lanthanum.

The rare earth metal element lanthanum (La) possesses carcinogenic, genotoxic, and accumulative properties, necessitating urgent development of an efficient and cost-effective method to remove La. However, current sorbents still encounter challenges such as poor selectivity, low sorption capacity, and high production costs. This study therefore proposes a promising solution: the creation of phytic acid-assisted sludge hydrochars (P-SHCs) to eliminate La from water and soil environments. This method harnesses phytic acid's exceptional binding ability and the economical hydrothermal carbonization process. P-SHCs exhibit robust sorption affinity, fast sorption kinetics, and excellent sorption selectivity for La when compared with pristine hydrochars (SHCs). This advantage arises from the remarkable binding ability of phosphate functional groups (polyphosphates) on P-SHCs, forming P-O-La complexes. Moreover, P-SHCs demonstrate sustained sorption efficiency across at least five cycles, with a slight decrease attributed to the loss of phosphorus species and mass during recycling. Furthermore, P-SHCs demonstrated superior economic feasibility, with a higher estimated cost-benefit ratio than that of other sorbents. Our study further validates the exceptional passivation capability of P-SHCs, showcasing relative stabilization efficiency ranging from 37.6 % to 79.6 % for La contamination. Additionally, acting as soil passivation agents, P-SHCs foster the enrichment of specific soil microorganisms such as Actinobacteria and Proteobacteria, capable of solubilizing phosphorus and resisting heavy metals. These findings present novel ideas and technical support for employing P-SHCs in combatting environmental pollution stemming from rare earth metals.

Novel Antioxidant Peptides Derived from Feather Keratin Alleviate H2O2-Induced Oxidative Damage in HepG2 Cells via Keap1/Nrf2 Pathway.

Reactive oxygen species (ROS) are crucial for signal transduction and the maintenance of cellular homeostasis. However, superfluous ROS may engender chronic pathologies. Feather keratin is a promising new source of antioxidant peptides that can eliminate excess ROS and potentially treat oxidative stress-related diseases, but the underlying mechanisms have remained elusive. This study investigated the antioxidant effects and mechanisms against H2O2-induced oxidative damage in HepG2 cells of the two latest discovered antioxidant peptides, CRPCGPTP (CP-8) and ANSCNEPCVR (AR-10), first decrypted from feather keratin. The results revealed that CP-8 and AR-10 did not exhibit cytotoxicity to HepG2 cells while reducing intracellular ROS accumulation. Simultaneously, they enhanced the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px), thus alleviating H2O2-induced cell apoptosis. Molecular docking analysis demonstrated that CP-8, AR-10 interacted well with the key amino acids in the Kelch domain of Keap1, thereby directly disrupting the Keap1-Nrf2 interaction. The peptides' biosafety and antioxidant activity via Keap1/Nrf2 signaling lay the groundwork for further animal studies and applications as functional food additives.

Preparation, Purification, and Identification of Novel Feather Keratin-Derived Peptides with Antioxidative and Xanthine Oxidase Inhibitory Activities.

Feather keratin is an underappreciated protein resource of high quality, with limited bioavailability, and it urgently requires eco-friendly methods to enhance its value. Here, we report on the preparation, purification, and identification of novel peptides with antioxidant and xanthine oxidase (XOD) inhibitory activities from fermented feather broth, using Bacillus licheniformis 8-4. Two peptides, namely, DLCRPCGPTPLA (DA-12) and ANSCNEPCVR (AR-10), displayed remarkable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging abilities with half-maximal inhibitory concentrations (IC50) values of 0.048, 0.034, and 0.95, 0.84 mg/mL, respectively. These values exceed those of the previously reported feather keratin-derived antioxidant peptides. Another peptide, GNQQVHLQSQDM (GM-12), demonstrated XOD activity inhibition, with an IC50 value of 12.15 mg/mL, and it quenched the fluorescence of XOD. Furthermore, after simulating gastrointestinal digestion, DA-12, AR-10, and GM-12 retained their biological activities. Meanwhile, DA-12 and GM-12 showed an unexpected synergistic inhibition on XOD activity accompanied by fluorescence quenching. This study provides new insights into the potential applications of feather keratin, including functionalized feed with antioxidative and antigout (anti-hyperuricemia) activities.

Utilization of feather keratin waste to antioxidant and migration-enhancer peptides by Bacillus licheniformis 8-4.

AIMS: Feathers are keratin-rich byproducts of poultry processing, but those are often frequently abandoned as garbage and thus polluting the environment. Therefore, the study focused on the efficient biodegradation, bioactivity, and high-value application of feather keratin. METHODS AND RESULTS: Feather-degrading bacteria were identified, and the degradation properties were characterized. DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) and ABTS (2,2'-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid))radical scavenging assays, cytotoxicity assays, intracellular reactive oxygen scavenging assays, and cell migration assays were used to examine the biological activities of the feather keratin hydrolysis peptides (FKHPs). The results showed that we screened a feather-degrading strain of Bacillus licheniformis 8-4, which achieved complete degradation of 2% (w/v) feathers within 48 h. Notably, the feather fermentation broth was particularly high in FKHPs, which exhibited good DPPH and ABTS radical scavenging ability. Further studies revealed that FKHPs had both the ability to scavenge H2O2-induced ROS from HaCat cells and the ability to promote HaCat cell migration, while remaining non-toxic. CONCLUSIONS: The effective feather-degrading ability of B. licheniformis 8-4 allowed for the fermentation of feather medium to yield active peptides that were both antioxidants and cell-migration enhancers.

Production and characterization of novel thermo- and organic solvent-stable keratinase and aminopeptidase from Pseudomonas aeruginosa 4-3 for effective poultry feather degradation.

Feather biodegradation is an important premise for efficient resource development and utilization, in which keratinase plays an important role. However, there are few keratinases that combine the high activity, thermal stability, and organic solvent tolerance required for industrialization. This paper reported an efficient feather-degrading Pseudomonas aeruginosa 4-3 isolated from slaughterhouses. After 48 h of fermentation by P. aeruginosa 4-3 in a feather medium at 40 °C, pH 8.0, keratinase was efficiently produced (295.28 ± 5.42 U/mL) with complete feather degradation (95.3 ± 1.5%). Moreover, the keratinase from P. aeruginosa 4-3 showed high optimal temperature (55 °C), good thermal stability, wide pH tolerance, and excellent organic solvent resistance. In addition, P. aeruginosa 4-3-derived aminopeptidases also exhibit excellent thermal stability and organic solvent tolerance. Encouragingly, the reaction of crude keratinase and aminopeptidase with feathers for 8 h resulted in a 78% degradation rate of feathers. These properties make P. aeruginosa 4-3 keratinase and aminopeptidase ideal proteases for potential applications in keratin degradation, as well as provide ideas for the synergistic degradation of keratin by multiple enzymes.

Isolation and purification of antibacterial lipopeptides from Bacillus velezensis YA215 isolated from sea mangroves.

The increasing burden and health risks of antimicrobial resistance (AMR) pose a great threat to society overall. Lipopeptides exhibit great potential as novel and safe alternatives to traditional antibiotics. In this study, the strain YA215, which was isolated from the mangrove area in Beibu Gulf, Guangxi, China, was identified as Bacillus velezensis. Then, YA215 lipopeptide extracts (YA215LE) from B. velezensis was found to exhibit a wide spectrum of antibacterial and antifungal activities. Additionally, YA215LE was identified and found to contain three groups of lipopeptides (surfactin, iturin, and fengycin). Furthermore, one separation fraction (BVYA1) with significant antibacterial activity was obtained. Additionally, liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis of BVYA1 showed three molecular ion peaks ([M + H]+: m/z 980.62; 994.66; 1008.66) corresponding to conventional surfactin homologs. By MS/MS analysis, BVYA1 was identified as sufactin with the precise amino acid sequence Glu-Leu/Ile-Leu-Val-Asp-Leu-Leu/Ile and hydroxyl fatty acids with 11-13 carbons. [M + H]+ at m/z 980.62 was detected for the first time in B. velezensis, which demonstrates that the strain corresponds to a new surfactin variant. In particular, BVYA1 showed antibacterial activity with the minimum inhibitory concentration (MIC) values of 7.5-15 µg/ml. Finally, the preliminary mechanism of inhibiting E. coli treated with BVYA1 showed that BVYA1 effectively permeabilized the cytoplasmic membrane and disrupted the morphology of targeted bacterial cells. In conclusion, this study suggests that the YA215LE from B. velezensis YA215 might be a potential candidate for a bactericide.

Computer-assisted in vitro reconstitution of purine degradation pathway to lower the purine content in food.

BACKGROUND: With the increasing prevalence of gout and its etiological hyperuricemia, dietary control of gout based on low-purine food according to patients' eating habits is becoming a better choice compared to the existing drug treatment such as allopurinol with notorious side effects. Reconstructing the purine metabolic pathway in vitro to degrade purine substances in food into natural functional allantoin appears to be an innovative method for preparing nutritious and healthy food of low purine content. The present study reports a computer-assisted in vitro reconstruction of four purinolytic enzymes metabolizing adenosine into allantoin to reduce purine content in food for personalized dietary control of hyperuricemia and gout. RESULTS: Under the optimum reaction conditions of 40 °C and pH 7, 0.1 U of enzymes and 0.5 mmol L-1 adenosine determined by an orthogonal test design, 16 different enzyme complexes were experimentally tested. The tested enzyme composition and allantoin production values were used as input and output to build a three-layer back propagation artificial neural network (BP-ANN) model, which was further optimized by a genetic algorithm (GA). The optimum enzyme complex predicted by the GA-BP-ANN model produced 248.08±7.832 µmol L-1 allantoin, which was 19.9% higher than equimolar mixture of enzymes, and also more efficiently lowered purine contents in beer, as well as beef and yeast extracts. CONCLUSION: This is the first in vitro reconstitution of complete purine metabolic pathway by combining ANN and GA technologies, with successful application with respect to lowering the purine content in food, indicating a promising application of computer-assisted in vitro reconstitution of purinolytic pathway in low-purine food to prevent hyperuricemia and gout. © 2022 Society of Chemical Industry.

Characterization of a Novel Shewanella algae Arginine Decarboxylase Expressed in Escherichia coli.

Arginine decarboxylase (ADC) catalyzes the decarboxylation of arginine to form agmatine, an important physiological and pharmacological amine, and attracts attention to the enzymatic production of agmatine. In this study, we for the first time overexpressed and characterized the marine Shewanella algae ADC (SaADC) in Escherichia coli. The recombinant SaADC showed the maximum activity at pH 7.5 and 40 °C. The SaADC displayed previously unreported substrate inhibition when the substrate concentration was higher than 50 mM, which was the upper limit of testing condition in other reports. In the range of 1-80 mM L-arginine, the SaADC showed the Km, kcat, Ki, and kcat/Km values of 72.99 ± 6.45 mM, 42.88 ± 2.63 s-1, 20.56 ± 2.18 mM, and 0.59 s/mM, respectively, which were much higher than the Km (14.55 ± 1.45 mM) and kcat (12.62 ± 0.68 s-1) value obtained by assaying at 1-50 mM L-arginine without considering substrate inhibition. Both the kcat values of SaADC with and without substrate inhibition are the highest ones to the best of our knowledge. This provides a reference for the study of substrate inhibition of ADCs.

6-Shogaol from ginger shows anti-tumor effect in cervical carcinoma via PI3K/Akt/mTOR pathway.

PURPOSE: 6-Shogaol, an active phenolic compound from ginger (Zingiber officinale), can inhibit the growth of a variety of human cancer cells. Nevertheless, its underlying molecular mechanisms in cervical cancer remain unclear. In this study, we systematically examine the inhibitory effect of 6-shogaol on cervical cancer in vitro and in vivo. METHODS: Cell proliferation was assessed by CCK8 assay and colony formation assay in HeLa and SiHa cells. We analyzed cell cycle and apoptosis through flow cytometry. GFP-LC3 puncta and transmission electron microscopy were used to observe autophagic bodies. Wound-healing assay and transwell assay were used for evaluating the migration of cells. Western blot was applied to detect protein expression levels. RESULTS: 6-Shogaol could suppress cell proliferation and migration, cause cell cycle arrest in the G2/M phase in HeLa and SiHa cells. Moreover, 6-shogaol triggered the apoptosis process through the mitochondrial pathway by downregulating the expression levels of p-PI3K, p-Akt and p-mTOR. Further research indicated that the induction of apoptosis by 6-shogaol was remarkably decreased after the treatment of ROS scavenger and PI3K agonist. Additionally, 6-shogaol increased the number of LC3-positive puncta and autophagic bodies per cell in both HeLa and SiHa cells. Pretreatment of cells with Bafilomycin A1, an autophagy inhibitor, accelerated 6-shogaol mediated cell apoptosis, suggesting that induction of autophagy by 6-shogaol is suppressive to apoptosis. Furthermore, in vivo data revealed that 6-shogaol significantly inhibited tumor growth and cell proliferation in tumor tissues. CONCLUSION: These findings suggested that 6-shogaol could be developed as a functional food ingredient, which is potentially used as therapeutic agents for patients with cervical cancer.

α-Cyperone inhibits the proliferation of human cervical cancer HeLa cells via ROS-mediated PI3K/Akt/mTOR signaling pathway.

Cervical cancer is the fourth leading killer of female cancer patients worldwide. Each year more than half a million women are diagnosed with cervical cancer and the disease results in over 300, 000 deaths. α-Cyperone is known as the principal active ingredient in the Cyperus rotundus (Family: Cyperaceae). However, the effects of α-Cyperone on cancers, especially on cervical cancer, are yet to be explored. In the present study, the underlying mechanism of the anti-tumor activity of α-Cyperone against HeLa cells was investigated. The results showed that α-Cyperone inhibited proliferation and induced apoptosis in HeLa cells. Mechanistically, α-Cyperone promoted HeLa cells apoptosis via a mitochondrial apoptotic pathway, which was proved by increased level of intracellular reactive oxygen species (ROS) and upregulated expression of cytochrome c, cleaved caspase-3, PARP, and Bax. Further RNA-sequencing revealed α-Cyperone inhibited the activation of PI3K/Akt/mTOR signaling pathway in HeLa cells, which confirmed by PI3K inhibitor and agonist. The PI3K inhibitor (LY294002) synergized with α-Cyperone in arresting the growth of HeLa cells, whereas the PI3K agonist (IGF-1) abrogated such an effect. Interestingly, the expression of PD-L1 was attenuated by both α-Cyperone and LY294002, while the supplement of IGF-1 rescued the low expression of PD-L1. In conclusion, our results reveal that the inhibitory effect of α-Cyperone on HeLa cell growth is triggered via the ROS-mediated PI3K/Akt/mTOR signaling pathway and closely related to a decline in the PD-L1 expression.

14,15ß-dihydroxyklaineanone inhibits HepG2 cell proliferation and migration through p38MAPK pathway.

OBJECTIVES: Eurycoma longifolia Jack (Simaroubaceae) is commonly distributed in the Southeast Asia and Indo China, which has been shown to possess antianxiety, antibacterial, anticancer, antifungal, anti-inflammatory, antimalarial and antioxidant biological activities. 14,15ß-dihydroxyklaineanone is a diterpene isolated from E. longifolia Jack, which is cytotoxic against human lung cancer and human breast cancer cell lines. However, the effects and underlying mechanisms of 14,15ß-dihydroxyklaineanone on hepatocellular carcinoma remain unknown. METHODS: Cell viability assay and colony formation assay were used to measure HepG2 cell proliferation. Flow cytometry was used to analyse cell cycle and apoptosis. Wound-healing assay and transwell assay were used to observe cells migration. RNA sequencing and the enrichment of differentially expressed genes (DEGs) in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were used to find and determine underlying pathways. KEY FINDINGS: We found that 14,15ß-dihydroxyklaineanone inhibited the growth and migration of HepG2 cells but did not induce cell apoptosis. 14,15ß-dihydroxyklaineanone induced S cell cycle arrest by downregulating the expression levels of cyclin A, p-CDK2, cyclin B1, p21, E2F-1 and PCNA. In addition, RNA sequencing showed that 14,15ß-dihydroxyklaineanone regulated MAPK pathway by increasing the expression levels of phosphor-p38. Downregulating of p38 via both p38 inhibitor (SB203580) and p38-siRNA could antagonize the inhibition of cell proliferation and migration and reverse the changes in p-p38, E-cadherin, N-cadherin and PCNA expression induced by 14,15ß-dihydroxyklaineanone treatment. CONCLUSIONS: 14,15ß-dihydroxyklaineanone inhibited cell proliferation and migration through regulating p38 MAPK pathway in HCC cells.

An oriented laterally-growing NiCo2O4 nanowire array on a Fe2O3 microdisc as a high-capacity and excellent rate-performance secondary battery anode.

A novel hierarchical composite consisting of an ordered NiCo2O4 nanowire array growing on the lateral side of a Fe2O3 microdisc is presented, which was confirmed by X-ray holography technology on a synchrotron radiation station. The composite-based Li-ion battery anode exhibits a high capacity of 1528 mA h g-1 after 200 cycles at 0.2C, a recoverable rate-performance after repeated tests, and robust mechanical properties.

Oenothein B inhibits human non-small cell lung cancer A549 cell proliferation by ROS-mediated PI3K/Akt/NF-κB signaling pathway.

Oenothein B has a wide range of biological activities. The present study probed into the underlying mechanism on how Oenothein B inhibits the proliferation of a lung cancer line A549. Our results showed that Oenothein B effectively inhibited the proliferation of A549 cells by inducing apoptosis and arresting cells at G1 stage. Furthermore, Oenothein B not only increased the level of intracellular reactive oxygen species (ROS), but also induced the upregulation of intracellular apoptotic triggers (cleavage caspase-3, PARP, cytochrome c level in the cytosol, Bax). Moreover, ROS inhibitor (N-acetyl-L-cystein, NAC) and PI3K agonist (Insulin-like growth factor 1, IGF-1) could resist cell proliferation inhibition induced by Oenothein B, respectively. ROS inhibitor significantly abrogated the activation of caspase 3/7 and 9 in the presence of Oenothein B. Additionally, suppression of p-PI3K and p-Akt, p-NF-κB by Oenothein B could be compensated by treatment with ROS inhibitor. To summarize, these results demonstrated that Oenothein B was able to prevent cell proliferation probably via ROS-mediated PI3K/Akt/NF-κB signaling pathway.

Into the polymer brush regime through the "grafting-to" method: densely polymer-grafted rodlike viruses with an unusual nematic liquid crystal behavior.

The current work reports an intriguing discovery of how the force exerted on protein complexes like filamentous viruses by the strong interchain repulsion of polymer brushes can induce subtle changes of the constituent subunits at the molecular scale. Such changes transform into the macroscopic rearrangement of the chiral ordering of the rodlike virus in three dimensions. For this, a straightforward "grafting-to" PEGylation method has been developed to densely graft a filamentous virus with poly(ethylene glycol) (PEG). The grafting density is so high that PEG is in the polymer brush regime, resulting in straight and thick rodlike particles with a thin viral backbone. Scission of the densely PEGylated viruses into fragments was observed due to the steric repulsion of the PEG brush, as facilitated by adsorption onto a mica surface. The high grafting density of PEG endows the virus with an isotropic-nematic (I-N) liquid crystal (LC) phase transition that is independent of the ionic strength and the densely PEGylated viruses enter into the nematic LC phase at much lower virus concentrations. Most importantly, while the intact virus and the one grafted with PEG of low grafting density can form a chiral nematic LC phase, the densely PEGylated viruses only form a pure nematic LC phase. This can be traced back to the secondary to tertiary structural change of the major coat protein of the virus, driven by the steric repulsion of the PEG brush. Quantitative parameters characterising the conformation of the grafted PEG derived from the grafting density or the I-N LC transition are elegantly consistent with the theoretical prediction.

Thermoresponsive Chiral to Nonchiral Ordering Transformation in the Nematic Liquid-Crystal Phase of Rodlike Viruses: Turning the Survival Strategy of a Virus into Valuable Material Properties.

The current work investigates the thermoresponsive in situ chiral to nonchiral ordering transformation of a rodlike virus in the naturally assembled state-the chiral nematic liquid crystal (CLC) phase. We take this as an elegant example of reconfigurable self-assembly, through which it is possible to realize in situ transformation from one assembled state to another without disrupting the preformed assembly in general or going through a secondary assembling procedure of the disassembled building blocks. The detailed investigation presented here reveals many unique characteristics of the thermoresponsive 3D chiral ordering of rodlike viruses induced by heat stress. The chiral to nonchiral ordering transformation is highly reversible in the temperature range of up to 60 °C and can be repeated many times. There exists a critical temperature around 40 °C which is independent of the ionic strength and virus concentration. Such reconfigurable ordering in the CLC phase stems from the intrinsic structure change of constituent coat proteins without disrupting the structural integrity of the virus, as revealed by three analytical techniques targeting levels ranging from the molecular, secondary conformation of the constituent proteins to the whole single virus, respectively. Such structural flexibility, also termed polymorphism, is relative to the survival strategies of a biological organism such as the virus and can be transformed into very precious material properties. The potential of the virus-based CLC phase as the chiral matrix to regulate chiro-optical properties of gold nanorods is also presented.

Pure Anisotropic Hydrogel with an Inherent Chiral Internal Structure Based on the Chiral Nematic Liquid Crystal Phase of Rodlike Viruses.

Imparting ordered structures into otherwise amorphous hydrogels is expected to endow these popular materials with novel multiple-stimuli responsiveness that promises many applications. The current contribution reports a method to fabricate pure polymeric hydrogels with an inherent chiral internal structure by templating on the chiral nematic liquid crystal phase of a rodlike virus. A method was developed to form macroscopically homogeneous chiral templates by confinement induced self-assembly in the presence of monomers, cross-linkers and initiators. Polymerization induced gelation was performed without perturbing the elegant 3D chiral organization of the rodlike virus bearing double bonds. Furthermore, a suitable method was found to remove the organic virus template while keeping the desired polymeric replica intact, resulting in a pure polymeric hydrogel with a unique internal chiral feature that originates from the 3D chiral ordering of the cylindrical pores left by the virus. Multiple-stimuli responsiveness has been demonstrated and can be quantified by the change of the pitch of the chiral feature. The chiral structure endows the otherwise featureless hydrogel with a unique material property that might be used as a readout signal for sensing and acts as the basis for responsive, biomimetic nanostructured materials.

[Effectiveness comparison of different tibial intramedullary nail guide rod in total knee arthroplasty].

OBJECTIVE: To compare the effectiveness of the traditional center of tibial plateau as the entry point and digital technology in the design of intramedullary tibial nail point positioning method in total knee arthroplasty (TKA). METHODS: Between October 2011 and October 2012, 60 cases undergoing unilateral TKA and meeting the selection criteria were randomly divided into 2 groups: in group A (30 cases), the tibial plateau center as the entry point of tibial intramedullary positioning was used; in group B (30 cases), Mimics 10.01 software to simulate the guide rod point of tibial intramedullary positioning was used. There was no significant difference in gender, age, etiology, disease duration, sides, and preoperative knee range of motion, Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) between 2 groups (P > 0.05). Postoperative X-ray films were taken to measure the tibiofemoral angle and tibial angle; knee range of motion, and HSS and WOMAC scores were used to assess the activity of knee. RESULTS: The entry point of group B was located in front of the center of tibial plateau, which was inconsistent with the traditional entry point. The incision healed by first intention in all patients of 2 groups. The patients were followed up 6 to 12 months (mean, 8.6 months). The X-ray measurement at 1 week after operation showed no significant difference in tibiofemoral angle between 2 groups (t = -6.65, P = 0.72), but the anteroposterior and lateral tibial angles of group A were significantly lower than those of group B (P < 0.05). The knee range of motion, HSS score, and WOMAC score of 2 groups were significantly higher at 3 and 6 months after operation when compared with preoperative values (P < 0.05), and the values at 6 months were significantly increased than those at 3 months after operation (P < 0.05). HSS score and WOMAC score had no significant difference between 2 groups at 3 months after operation (P > 0.05), but the scores of group B were significantly higher than those of group A at 6 months (P < 0.05). The knee range of motion of group B was significantly better than that of group A at 3 months after operation (t = 2.13, P = 0.04), but no significant difference was found between 2 groups at 6 months (t = 0.58, P = 0.56). CONCLUSION: Compared with the traditional intramedullary guide rod insertion point positioning, digital individualized design of entry point positioning has the advantages of more accurate lower limb force line, better recovery of knee function, and earlier 90 degrees activities, but the long-term effectiveness needs further observation.

[Study on the risk factors of induced abortion among floating women of childbearing age in 5 cities of China].

OBJECTIVE: To understand the status of abortion and risk factors among floating women of childbearing age and to provide reference for further improvement of induced abortion services in this population. METHODS: Data on demography, working, and living conditions as well as the use of contraceptive among 4687 persons from a reproductive health survey regarding floating population in five cities in 2005, were involved, while multivariate logistic regression model was used to find out the relationship. RESULTS: The risks of abortion among the younger than 30 age group and the 30 - 39 age groups were 2.21 times (95%CI: 1.47 - 3.34) and 2.38 times (95%CI: 1.53 - 3.70) of the 40 - 49 age group, respectively. The higher education degree these women had, the higher the risk of abortion was. The risks of abortion among groups having elementary, junior high, senior high school and above, were 2.15 times (95%CI: 1.15 - 4.03), 2.47 times (95%CI: 1.33 - 4.57) and 2.61 times (95%CI: 1.34 - 5.11) of those illiterate women. Those having working experience of 2 - 4 years, 5 years or above at the places where the survey was completed, the risks were 2.62 times (95%CI: 1.83 - 3.76) and 7.78 times (95%CI: 5.63 - 10.75) of the less than 2-year-experienced group. The abortion risk of floating women at childbearing age who were living together with their spouses was 1.49 (95%CI: 1.05 - 2.11) times of those women who were not. CONCLUSION: The demographic and lifestyle as well as working features of floating women at childbearing age might increase their risk of abortion. Providing health education regarding these risk factors on the floating women at childbearing age could effectively reduce and prevent the risk of abortion risk among them.