Design and preparation of Ti-xFe antibacterial titanium alloys based on micro-area potential difference.

Fe was selected as an alloying element for the first time to prepare a new antibacterial titanium alloy based on micro-area potential difference (MAPD) antibacterial mechanism. The microstructure, the corrosion resistance, the mechanical properties, the antibacterial properties and the cell biocompatibility have been investigated in detail by optical microscopy, scanning electron microscopy, electrochemical testing, mechanical property test, plate count method and cell toxicity measurement. It was demonstrated that heat treatment had a significant on the compressive mechanical properties and the antibacterial properties. Ti-xFe (x = 3,5 and 9) alloys after 850 °C/3 h + 550 °C/62 h heat treatment exhibited strong antimicrobial properties with an antibacterial rate of more than 90% due to the MAPD caused by the redistribution of Fe element during the aging process. In addition, the Fe content and the heat treatment process had a significant influence on the mechanical properties of Ti-xFe alloy but had nearly no effect on the corrosion resistance. All Ti-xFe alloys showed non-toxicity to the MC3T3 cell line in comparison with cp-Ti, indicating that the microzone potential difference had no adverse effect on the corrosion resistance, cell proliferation, adhesion, and spreading. Strong antibacterial properties, good cell compatibility and good corrosion resistance demonstrated that Ti-xFe alloy might be a candidate titanium alloy for medical applications.

Feasibility study on Ti-15Mo-7Cu with low elastic modulus and high antibacterial property.

Titanium and titanium alloy with low density, high specific strength, good biological, excellent mechanical compatibility and easy to process have been widely used in the medical materials, but their application in orthopedics and dentistry often face bacterial infection, corrosion failure and stress shielding. In this paper, Ti-15Mo-7Cu (TM-7Cu) alloy was prepared by high vacuum non-consumable electric arc melting furnace and then treated by solution and aging treatment. The microstructure, mechanical properties, antibacterial properties and cytocompatibility were studied by X-ray diffraction, microhardness tester, electrochemical working station, antibacterial test and Live/Dead staining technology. The results have shown that the heat treatment significantly influenced the phase transformation, the precipitation of Ti2Cu phase, the elastic modulus and the antibacterial ability. With the extension of the aging time, the elastic modulus slightly increased and the antibacterial rate obviously increased. TM-7Cu alloy with a low elastic modulus of 83GPa and a high antibacterial rate of > 93% was obtained. TM-7Cu alloy showed no cytotoxicity to MC3T3. It was suggested that TM-7Cu might be a highly competitive medical material.

Fabrication of a highly sensitive electrochemical sensor based on electropolymerized molecularly imprinted polymer hybrid nanocomposites for the determination of 4-nonylphenol in packaged milk samples.

Herein, an imprinted electrochemical sensor based on graphene-Au nanoparticles incorporated with molecularly imprinted polymer (MIP) was fabricated for determination of 4-nonylphenol (4-NP). Grafted MIP electropolymerized on nanoscale multilayer films electrode was achieved using 4-NP as a template and P-aminothiophenol as a functional monomer. The electrochemical properties of the MIP nanoscale multilayer membrances were characterized and measured by cyclic voltammetry and differential pulse voltammetry techniques; using ferrocyanide/ferricyanide-redox marker. Several important parameters were optimized and investigated to improve the performance of the sensor. Under the optimized conditions, the developed sensor showed an excellent linear response over the concentration ranges of 50-500 ng mL-1 (4-NP) with a detection limit of 0.01 ng mL-1(S/N = 3). The developed sensor showed a good selective recognition of 4-NP compared with structural analogue, exhibited a good reproducibility and accuracy with long-term stability. At last, the feasibility of the proposed methodology was successfully applied fordetection of 4-NP in milk and its packaging materials.

Enhancement of fermentable sugar yield by competitive adsorption of non-enzymatic substances from yeast and cellulase on lignin.

BACKGROUND: Enhancement of enzymatic digestibility by some supplementations could reduce enzyme loading and cost, which is still too high to realize economical production of lignocellulosic biofuels. A recent study indicates that yeast hydrolysates (YH) have improved the efficiency of cellulases on digestibility of furfural residues (FR). In the current work, the components of YH were separated by centrifugation and size exclusion chromatography and finally characterized in order to better understand this positive effect. RESULTS: A 60.8% of nitrogen of yeast cells was remained in the slurry (YHS) after hydrothermal treatment. In the supernatant of YH (YHL), substances of high molecular weight were identified as proteins and other UV-absorbing compounds, which showed close molecular weight to components of cellulases. Those substances attributed to a synergetic positive effect on enzymatic hydrolysis of FR. The fraction of YHL ranged from 1.19 to 2.19 mL (elution volume) contained over 50% of proteins in YHL and had the best performance in stimulating the release of glucose. Experiment results proved the adsorption of proteins in YHL on lignin. CONCLUSIONS: Supplementation of cellulases with YH enhances enzymatic digestibility of FR mainly by a competitive adsorption of non-enzymatic substances on lignin. The molecular weight of these substances has a significant impact on their performance. Different strategies can be used for a good utilization of yeast cells in terms of biorefinery concept.

An integrated electrode material based on corn straw cellulose biochar with three-dimensional network porous structure for boosting electrochemical performance of lithium batteries.

In this work an integrated electrode material based on the VS4 nanoparticles grow on three-dimensional network porous biochar is put forward, forming a heterostructure that significantly boost the rate and cycle performance in lithium batteries. Biochar derives from two-steps treatment removing partial cellulose and hemicellulose, possessing three-dimensional network porous structure and naturally nitrogenous. The integrated electrode material constructs the continuous electrons transfer network, accommodates the volume expansion and traps the polar polysulfides efficiently. After 100 cycles at 1C, the integrated electrode with biochar shows the highest specific discharge capacity. Even at 2C, the three-dimensional electrode can display a high specific discharge capacity of 798.6 mAh·g-1. Thus, our study has pointed the innovations approach of constructing integrated electrode materials with porous structure biochar to enhance the electrochemical performance of lithium batteries.

Study of efficient catalytic electrode for hydrogen evolution reaction from seawater based on low tortuosity corn straw cellulose biochar/Mo2C with porous channels.

Porosity and channel structure has important effects on the performance of hydrogen evolution reaction (HER) of nanostructured electrocatalysts in acid solution and seawater. Mesopore usually helps to enhance the reaction kinetics and mass transfer, while the macroporous channel structure also affects the electrocatalyst. Traditional graphene materials do not have such structure. Therefore, this paper designs a method to synthesize Mo2C composite nanomaterial in situ on corn straw biochar, inspires by the natural channel structure of conducting water, salt and organic matter in plants. Characteristic characterization shows that the material also has a large number of mesoporous and vertical distribution of large porous channel structure, through the decrease of tortuosity and porosity, ensure the catalyst surface electrolyte transport and hydrogen timely escape, alleviate the process of metal ion precipitation blocking pore channel, so as to improve the rate of hydrogen evolution reaction. The results shows that the overpotential of the catalyst was 48 mV and 251 mV under 10 mA cm-2 acidic electrolyte and simulated seawater electrolyte, respectively. This method provides new ideas for the design of efficient electrocatalysts for seawater decomposition, then the HER performance in alkaline and neutral environments needs to be further explored.

Implementation of a Specific Set of Intraoperative C-Arm Fluoroscopy Terminologies in Percutaneous Vertebroplasty.

OBJECTIVE: Percutaneous vertebroplasty (PVP) is currently the primary minimally invasive surgical approach for treating vertebral compression fractures caused by senile osteoporosis. The current existing problem is the lack of research on the application of a specific set of intraoperative C-arm fluoroscopy terminologies in PVP. Therefore, the purpose of this study is to explore the use of a specific set of intraoperative C-arm fluoroscopic terminologies in PVP in order to increase fluoroscopy accuracy, decrease fluoroscopy frequencies and ray protection, and minimize operation times through rapid preoperative training of surgeons and radiographers. METHODS: Spine surgeons and radiographers with at least 5 years of experience from nine different hospitals were randomly selected for a series of specialized intraoperative C-arm fluoroscopy terminology training between October 2018 and December 2021. Before and after the training, they were surveyed using a five-point Likert scale to statistically compare their knowledge of the terminology. Simultaneously, 190 PVP cases completed by these surgeons and radiographers before and after the training were chosen for comparison and analysis of fluoroscopy times, effective fluoroscopy rate, fluoroscopy time, repeated puncture rate, and other indicators before and after receiving specialized terminology training. Two-sample tests were mainly used to investigate differences in answers between surgeons and radiographers. RESULTS: After the training, there was a notable improvement in the fluency of intraoperative communication between professional spine surgeons and radiographers. By comparing the indicators of pre-training with post-training, the effective anteroposterior fluoroscopy rate increased from 46.5% to 75.7%; the effective lateral fluoroscopy rate increased from 59.8% to 76.9%. Moreover, a notable decrease in communication barriers, fluoroscopy frequencies, fluoroscopy time, and the rate of repeated punctures, and a notable increase in the effective fluoroscopy rate was observed. CONCLUSION: Smooth intraoperative communication between professional spine surgeons and radiographers can significantly lower the communication barrier, reduce the fluoroscopy frequencies and time, the rate of repeated puncture, and increase the effective fluoroscopy rate, all of which are important in improving the fluoroscopy in PVP.

Comparison of percutaneous vertebroplasty and conservative treatment for one level thoracolumbar osteoporotic compression fracture in a 3-year study.

The efficacy of Mesh optimized versus standard percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures. Grid optimization (102 cases; 38 men, 64 women aged 67.3 ± 8.5) and traditional PVP groups (94 cases) were identified from 196 PVP patients treated from May 2016 to 2019. The optimal puncture site and angle forced bone cement into both groups before surgery. The main indexes were operation time, X-ray fluoroscopy times, bone cement injection volume, leakage, VAS, and injured vertebrae height. Preoperative general data were equivalent between groups (P > 0.05). All patients survived surgery without spinal cord injury, incision infection, pulmonary embolism, or death. The mesh optimization group had improved operation time (34.8 ± 6.5 min), fluoroscopy times (29.5 ± 5.5), bone cement injection volume (5.3 ± 2.1 ml), and bone cement permeability greater (3.9 percent; 4/98) than the standard PVP group (P < 0.05). Similarly, the grid optimization group had superior VAS scores (1.1 ± 0.6; 1.0 ± 0.3; and 0.9 ± 0.2) than the standard PVP group at 3 days, 3 months, and the last follow-up visit (P < 0.05). On day three after surgery, both had similar heights of injured vertebra's anterior and middle edges (P > 0.05). However, in the mesh optimization group, measurements improved to 1.8 ± 0.4 mm and (1.8 ± 0.3) mm by month three and to 1.7 ± 0.3 mm at last follow-up (P < 0.05). Mesh-optimized PVP with a mesh locator treats osteoporotic vertebral compression fractures more safely and effectively than regular PVP.

Unilateral Percutaneous Kyphoplasty Using a Novel Guide Device for Thoracolumbar Osteoporotic Vertebral Fracture.

OBJECTIVES: Unilateral percutaneous kyphoplasty (UPKP) has been effective in reducing the operative time, cement volume, and cement leakage (CL) rate compared with bilateral kyphoplasty. However, no device can help to determine the trajectory during operation, especially the inner inclination angle. To assess the safety and efficacy of a novel guide device (GD) for UPKP in the treatment of thoracolumbar osteoporotic vertebral fractures (TLOVFs). METHODS: From January 2019 to May 2021, 31 patients diagnosed with single TLOVF who underwent UPKP were retrospectively reviewed. The patients were divided into two groups: traditional UPKP (UPKP group, 15 patients) and UPKP assisted with GD (UPKP-GD group, 16 patients). Pre-procedure demographic, clinical and radiologic characteristics, operative procedure details, and clinical and radiologic outcomes at 1 day and 12 months post-procedure were collected. Statistical analyses were carried out using SPSS 24.0. The baseline characteristics of the two groups were compared by the independent sample t test or the χ2 test. The anterior height or local kyphotic angle (LKA) of the fractured vertebrae, visual analog scale (VAS) score, and Oswestry Disability Index (ODI) within groups were compared using the paired t test. RESULTS: A total of 31 patients (five men and 26 women; age range: 58-90 years) completed the full 12-month postoperative follow-up schedule. No significant differences were observed between treatment groups with respect to sex, age, body mass index, preoperative bone mineral density, or surgical level. Compared with the UPKP group, the operation time in the UPKP-GD group was significantly shorter (40.8 ± 5.5 min vs. 48.5 ± 8.5 min, p = 0.005), and the number of intraoperative fluoroscopy times in the UPKP-GD group was significantly decreased (20.6 ± 4.5 vs. 25.2 ± 2.4, p = 0.001). Five (31.3%) patients in the UPKP-GD group and four (26.7%) patients in the UPKP group had bone CL. The VAS and ODI scores, anterior height and LKA of the fractured vertebrae were significantly improved after surgery in each group. No significant differences in postoperative VAS and ODI scores, anterior height or LKA of the fractured vertebrae, volume of injected cement or CL were observed between the two groups. CONCLUSION: Unilateral puncture using a novel GD is a safe and effective technique for patients with TLFs and UPKP assisted with a novel GD is associated with fewer intraoperative fluoroscopy times and shorter operation time.

Efficacy and Safety of a 3D-printed Guide Device During Percutaneous Kyphoplasty for the Treatment of Osteoporotic Vertebral Compression Fractures.

BACKGROUND: During percutaneous kyphoplasty (PKP) for the treatment of osteoporotic vertebral compression fractures (OVCFs), repeated fluoroscopic images to adjust the puncture needle and inject the polymethylmethacrylate (PMMA) are critical steps. A method to further reduce the radiation dose would be of great value. OBJECTIVES: To assess the efficacy and safety of a 3D-printed guide device (3D-GD) for PKP in the treatment of OVCFs and compare the clinical efficacy and imaging outcomes of traditional bilateral PKP, bilateral PKP with 3D-GD and unilateral PKP with 3D-GD. STUDY DESIGN: Retrospective study. SETTING: General Hospital of Northern Theater Command of Chinese PLA. METHODS: From September 2018 through March 2021, 113 patients diagnosed with monosegmental OVCFs underwent PKP. The patients were divided into 3 groups: traditional bilateral PKP (B-PKP group, 54 patients), bilateral PKP with 3D-GD (B-PKP-3D group, 28 patients) and unilateral PKP with 3D-GD (U-PKP-3D group, 31 patients). Their epidemiologic data, surgical indices, and recovery outcomes were collected during the follow-up period. RESULTS: The operation time was significantly shorter in the B-PKP-3D group (52.5 ± 13.7 minutes) than in the B-PKP group (58.5 ± 9.5 minutes) (P = 0.044, t = 2.082). The operation time was significantly shorter in the U-PKP-3D group (43.6 ± 6.7 minutes) than in the B-PKP-3D group (52.5 ± 13.7 minutes) (P = 0.004, t = 3.109). The number of intraoperative fluoroscopy applications was significantly lower in the B-PKP-3D group (36.8 ± 6.1) than in the B-PKP group (44.8 ± 7.9) (P = 0.000, t = 4.621). The number of intraoperative fluoroscopy times was significantly lower in the U-PKP-3D group (23.2 ± 4.5) than in the B-PKP-3D group (36.8 ± 6.1) (P = 0.000, t = 9.778). The volume of injected PMMA was significantly lower in the U-PKP-3D group (3.7 ± 0.8 mL) than in the B-PKP-3D group (6.7 ± 1.7 mL) (P = 0.000, t = 8.766). The Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores were significantly decreased one day after surgery in each group. However, there were no differences in postoperative VAS and ODI scores, anterior height or local kyphotic angle of the fractured vertebrae, PMMA leakage, or refracture of the vertebral body. LIMITATIONS: Relatively small sample size and short-term follow-up period. CONCLUSION: This new innovative 3D technique makes PKP safe and effective. The bilateral PKP with 3D-GD technique, even unilateral PKP with 3D-GD, has the advantages of accurate positioning, a short operation time, and reduced intraoperative fluoroscopy times to the patient and surgeon.

Combined Application of Grid Body Surface Locator and Preemptive Analgesia in Daytime Vertebroplasty.

Objective: To explore the clinical advantages of grid body surface locator combined with preemptive analgesia in the treatment of osteoporotic lumbar fractures in daytime vertebroplasty. Methods: A retrospective study was conducted on 120 patients who underwent lumbar vertebroplasty in the Department of Orthopedics of General Hospital of Northern Theater Command from January 2017 to January 2020. According to the preoperative planning and analgesic mode of treatment, they were divided into the daily operation experimental group and the traditional mode control group. Prone positioning of a patient under anesthetic is safe of ensuring optimum surgical access for many procedures, providing that the risks are fully understood. The general baseline data, intraoperative fluoroscopy times and operation time, bone cement injection volume, bone cement permeability, VAS score before operation, 1 day, and 3 months after operation, and the recovery of anterior vertebral height before and after operation were analyzed. Results: There was no statistically significant difference in the preoperative general data between the two groups. One day after operation, the VAS score of the experimental group was lower than that of the control group, but there was no difference after 3 months. The permeability of bone cement in the experimental group was lower than that in the control group, the height of anterior edge of injured vertebra was better than that in the control group, and the operation time was less than that in the control group. Conclusion: The daytime operation experimental group can significantly alleviate postoperative pain, increase the amount of bone cement injection, and reduce the permeability of bone cement through preoperative planning of puncture path and key puncture points, combined with advanced labor pain, but there is no significant difference in long-term pain relief.

A Comparison between Accurate Unilateral Puncture Paths Planned by Preoperative and Conventional Unilateral Puncture Techniques in Percutaneous Vertebroplasty.

Objective: Comparison of the clinical and radiological effects of precise unilateral puncture pathway prepared by preoperative CT data and traditional unilateral puncture pathway in PVP administration for the treatment of osteoporotic vertebral compression fractures. Summary of background data. PVP is a commonly used vertebral augmentation operation for the treatment of painful spinal compression fractures. A percutaneous unilateral approach is routinely used to get access to the vertebral body. PVP has had positive clinical results in a number of prior investigations. Numerous difficulties and issues, including puncture difficulty, radiation exposure, cement leakage, spinal cord or nerve damage, and intraspinal hematoma, have been described in contrast. Methods: This prospective study included 300 patients with single-level lumbar osteoporotic vertebral compression fractures, 180 females and 120 males, with an average age of 71.5 years. PVP was performed on randomized subjects using two distinct puncture procedures. The patients were separated into two groups: Preoperative planning, in which a precise unilateral puncture path was established using preoperative CT data, and Conventional planning, in which multiple puncture procedures were used. The participants were followed up on after surgery and mostly assessed on clinical and radiological results. The visual analogue scale for pain and the 36-item Short Form Health Survey (SF-36) questionnaire for health status were used to assess clinical outcomes. Radiation dosage, bone cement distribution, vertebral body height, and kyphotic angle were used to evaluate radiological results. Results: Participants remained monitored for 12 to 28 months on average. 151 individuals were treated with accurate unilateral puncture paths planned by preoperative CT data percutaneous vertebroplasty and 149 patients were treated with conventional unilateral paths percutaneous vertebroplasty. The Preoperative planning group's operation time and radiation dose were significantly lower than the Conventional group's; nevertheless, the volume of injected cement was significantly higher in the Preoperative steering committee than in the Conventional group. All patients in both groups had much less pain after the operations when compared to their preoperative suffering. There were no statistically significant variations between groups when the visual analogue scale and the 36-Item Short Form Health Survey were compared. Neither group showed a substantial decrease in the kyphotic angle during the follow-ups. In the Preoperative planning group, the kyphotic angle improved much more than in the Conventional group. At 1 month postoperatively, 16 patients in the Conventional group experienced apparent discomfort in the puncture sites because to facet joint violation. At the latest follow-up, all of the patients' discomfort had vanished after receiving local block therapy. Conclusion: Both preoperatively designed precise unilateral puncture pathways and traditional unilateral puncture procedures PVP are reasonably safe and effective for individuals with painful osteoporotic spinal compression fractures. Unilateral puncture courses planned via preoperative PVP, on the other hand, absorbed less radiation and operation time, as well as a good level of deformity correction and amount of injected cement, and caused less complications than traditional unilateral PVP.

Silver(I) metal-organic framework-embedded polylactic acid electrospun fibrous membranes for efficient inhibition of bacteria.

With recent outbreaks of fatal strains of diseases and the emergency of antibiotic resistance, there is a pressing demand to discover bactericidal materials that can effectively reduce or prevent infections by pathogenic bacteria. Herein, silver(I) metal organic frameworks Ag2(HBTC) were embedded into biocompatible polylactic acid (PLA) fibrous membranes through an electrospinning process as an antibiotic-free material for effective bacterial killing. The as-synthesized Ag2(HBTC)/PLA composite membrane showed an inactivation efficiency of more than 99.9% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) at a concentration of 200-250 mg L-1. Mechanistic investigation indicated that the steady release of Ag+ ions and ˙OH generation from the composites contributed to the efficient antibacterial activities through irreversible damage to the bacterial cell membranes. In-depth proteomic analysis demonstrated that Ag2(HBTC)/PLA exerted a biological effect towards bacterial cells through down-regulating functional proteins, thereby destroying the central biochemical pathways of the cellular energy metabolism process, reducing resistance to oxidative damage and inhibiting cell division. In general, this study shows a promising perspective on designing MOF/PLA membranes with broad-spectrum disinfection capability for potential environmental sterilization and public healthcare protection.

Synthesis and bioactivity of readily hydrolysable novel cationic lipids for potential lung delivery application of mRNAs.

Lipid nanoparticles (LNPs) mediated mRNA delivery has gained prominence due to the success of mRNA vaccines against Covid-19, without which it would not have been possible. However, there is little clinical validation of this technology for other mRNA-based therapeutic approaches. Systemic administration of LNPs predominantly targets the liver, but delivery to other organs remains a challenge. Local approaches remain a viable option for some disease indications, such as Cystic Fibrosis, where aerosolized delivery to airway epithelium is the preferred route of administration. With this in mind, novel cationic lipids (L1-L4) have been designed, synthesized and co-formulated with a proprietary ionizable lipid. These LNPs were further nebulized, along with baseline control DOTAP-based LNP (DOTAP+), and tested in vitro for mRNA integrity and encapsulation efficiency, as well as transfection efficiency and cytotoxicity in cell cultures. Improved biodegradability and potentially superior elimination profiles of L1-L4, in part due to physicochemical characteristics of putative metabolites, are thought to be advantageous for prospective therapeutic lung delivery applications using these lipids.

Improvement of peripheral nerve regeneration in acellular nerve grafts with local release of nerve growth factor.

Previous studies have demonstrated the potential of growth factors in peripheral nerve regeneration. A method was developed for sustained delivery of nerve growth factor (NGF) for nerve repair with acellular nerve grafts to augment peripheral nerve regeneration. NGF-containing polymeric microspheres were fixed with fibrin glue around chemically extracted acellular nerve grafts for prolonged, site-specific delivery of NGF. A total of 52 Wistar rats were randomly divided into four groups for treatment: autografting, NGF-treated acellular grafting, acellular grafting alone, and acellular grafting with fibrin glue. The model of a 10-mm sciatic nerve with a 10-mm gap was used to assess nerve regeneration. At the 2nd week after nerve repair, the length of axonal regeneration was longer with NGF-treated acellular grafting than acellular grafting alone and acellular grafting with fibrin glue, but shorter than autografting (P < 0.05). Sixteen weeks after nerve repair, nerve regeneration was assessed functionally and histomorphometrically. The percentage tension of the triceps surae muscles in the autograft group was 85.33 +/- 5.59%, significantly higher than that of NGF-treated group, acellular graft group and fibrin-glue group, at 69.79 +/- 5.31%, 64.46 +/- 8.48%, and 63.35 +/- 6.40%, respectively (P < 0.05). The ratio of conserved muscle-mass was greater in the NGF-treated group (53.73 +/- 4.56%) than in the acellular graft (46.37 +/- 5.68%) and fibrin glue groups (45.78 +/- 7.14%) but lower than in the autograft group (62.54 +/- 8.25%) (P < 0.05). Image analysis on histological observation revealed axonal diameter, axon number, and myelin thickness better with NGF-treated acellular grafting than with acellular grafting alone and acellular grafting with fibrin glue (P < 0.05). There were no significant differences between NGF-treated acellular grafting and autografting. This method of sustained site-specific delivery of NGF can enhance peripheral nerve regeneration across short nerve gaps repaired with acellular nerve grafts.

Effective lactic acid production from waste paper using Streptococcus thermophilus at low enzyme loading assisted by Gleditsia saponin.

Waste paper has considerable potential as a raw material for lactic acid (LA) production due to high cellulose content, abundance and low cost. In this study, four kinds of waste papers were used for LA production through simultaneous saccharification and fermentation (SSF) by Streptococcus thermophilus. The SSF of office paper achieved the highest LA concentration (39.71 g/L), while the highest LA yield was observed for magazine (99.56%), followed by office paper (82.85%). High LA concentration is unfavorable to total LA conversion because of product inhibition. However, the addition of Gleditsia saponin (GS) could obtain both high yield and high concentration of LA at a low enzyme loading, indicating that product inhibition could be moderated. A lactic acid yield of 86.30% was obtained from office paper at an enzyme loading of 9 FPU/g-cellulose with GS, which was higher than that of without GS at a higher loading of 18 FPU/g-cellulose.

Ophiopogonin D improves osteointegration of titanium alloy implants under diabetic conditions by inhibition of ROS overproduction via Wnt/ß-catenin signaling pathway.

A high failure rate of titanium implants in diabetic patients has been indicated in clinical evidences. Excessive oxidative stress at the bone-implant interface plays an important role in the impaired osteointegration under diabetic conditions. While the underlying mechanisms remain unknown and the targeted treatments are urgently needed. Ophiopogonin D (OP-D), isolated from Chinese herbal Radix Ophiopogon japonicus, is generally reported to be a potent antioxidant agent. In the present study, we hypothesized that OP-D exerted promotive effects on osteointegration against oxidative stress, and investigated the underlying mechanisms associated with alteration of Wnt/ß-catenin signaling pathway. Rabbit osteoblasts incubated on titanium alloy implant were co-cultured with normal serum (NS), diabetic serum (DS), DS + OP-D, DS + NAC (a potent ROS inhibitor) and DS + OP-D + Dkk1 (a Wnt inhibitor) for examinations of osteoblast behaviors. For in vivo study, titanium alloy implants were implanted into the femoral condyle defects on diabetic rabbits. Results demonstrated that diabetes-induced oxidative stress resulted in osteoblast dysfunctions and apoptotic injury at the bone-implant interface, concomitant with the inactivation of Wnt/ß-catenin signaling. Importantly, OP-D administration attenuated oxidative stress, directly reactivating Wnt/ß-catenin signaling. Osteoblast dysfunctions were thus reversed as evidenced by improved osteoblast adhesion, proliferation and differentiation, and ameliorated apoptotic injury, exerting similar effects to NAC treatment. In addition, the positive effects afforded by OP-D were confirmed by improved osteointegration and oetogenesis within the titanium alloy implants in vivo by Micro-CT and histological analyses. Furthermore, the pro-osteogenic effects of OP-D were almost completely abolished by the Wnt inhibitor Dkk1. These results demonstrated, for the first time, OP-D administration alleviated the damaged osteointegration of titanium alloy implants under diabetic conditions by means of inhibiting oxidative stress via a Wnt/ß-catenin-dependent mechanism. The OP-D administration would become a reliable treatment strategy for implant failure therapy in diabetics due to the optimal anti-oxidative and pro-osteogenic properties.

Competitive fluorescence assay for specific recognition of atrazine by magnetic molecularly imprinted polymer based on Fe3O4-chitosan.

A novel fluorescence sensing strategy for determination of atrazine in tap water involving direct competition between atrazine and 5-(4,6-dichlorotriazinyl) aminofluorescein (5-DTAF), and which exploits magnetic molecularly imprinted polymer (MMIP), has been developed. The MMIP, based on Fe3O4-chitosan nanoparticles, was synthesized to recognize specific binding sites of atrazine. The recognition capability and selectivity of the MMIP for atrazine and other triazine herbicides was investigated. Under optimal conditions, the competitive reaction between 5-DTAF and atrazine was performed to permit quantitation. Fluorescence intensity changes at 515 nm was linearly related to the logarithm of the atrazine concentration for the range 2.32-185.4 µM. The detection limit for atrazine was 0.86µM (S/N=3) and recoveries were 77.6-115% in spiked tap water samples.

Comparative study of alkaline hydrogen peroxide and organosolv pretreatments of sugarcane bagasse to improve the overall sugar yield.

Green liquor (GL) combined with H2O2 (GL-H2O2) and green liquor (GL) combined with ethanol (GL-ethanol) were chosen for treating sugarcane bagasse. Results showed that the glucose yield (calculated from the glucose content as a percentage of the theoretical glucose available in the substrates)of sugarcane bagasse from GL-ethanol pretreatment (97.7%) was higher than that from GL-H2O2 pretreatment (41.7%) after 72h hydrolysis with 18 filter paper unit (FPU)/g-cellulose for cellulase, 27,175 cellobiase units (CBU)/g-cellulose for ß-glucosidase. Furthermore, about 94.1% of xylan was converted to xylose after GL-ethanol pretreatment without additional xylanase, while the xylose yield was only 29.2% after GL-H2O2 pretreatment. Scanning electron microscopy showed that GL-ethanol pretreatment could break up the fiber severely. Moreover, GL-ethanol pretreated substrate was more accessible to cellulase and more hydrophilic than that of GL-H2O2 pretreated. Therefore, GL-ethanol pretreatment is a promising method for improving the overall sugar (glucose and xylan) yield of sugarcane bagasse.

Improvement of the enzymatic hydrolysis of furfural residues by pretreatment with combined green liquor and ethanol organosolv.

Furfural residues (FRs) were pretreated with ethanol and a green liquor (GL) catalyst to produce fermentable sugar. Anthraquinone (AQ) was used as an auxiliary reagent to improve delignification and reduce cellulose decomposition. The results showed that 42.7% of lignin was removed and 96.5% of cellulose was recovered from substrates pretreated with 1.0 mL GL/g of dry substrate and 0.4% (w/w) AQ at 140°C for 1h. Compared with raw material, ethanol-GL pretreatment of FRs increased the glucose yield from 69.0% to 85.9% after 96 h hydrolysis with 18 FPU/g-cellulose for cellulase, 27 CBU/g-cellulose for ß-glucosidase. The Brauner-Emmett-Teller surface area was reduced during pretreatment, which did not inhibit the enzymatic hydrolysis. Owing to the reduced surface area, the unproductive binding of cellulase to lignin was decreased, thus improving the enzymatic hydrolysis. The degree of polymerization of cellulose from FRs was too low to be a key factor for improving enzymatic hydrolysis.