Effect of Ultrafine Cement (UFC) on the Corrosion Resistance of Cement Soil in Peat Soil Environment.

Many peat soils are distributed around plateau lakes, and the reinforcement of peat soils with high organic matter content by ordinary cement cannot meet the actual engineering requirements. In order to obtain better mechanical properties and durability of the reinforcement, this experiment prepared peat soil by mixing humic acid reagent into the alluvial clay soil with low organic matter content. The cement soil samples were prepared by adding cement and ultrafine cement (UFC) by stirring method; the samples were then soaked in fulvic acid solution to simulate the cement soil in the peat soil environment. Using the unconfined compressive strength (UCS) test, scanning electron microscope (SEM) test, and pores and cracks analysis system (PCAS) test, the effect of UFC content change on cement soil's humic acid erosion resistance was explored, and the optimal UFC content range was sought. The results of the UCS test show that with an increase in immersion time, the strength curves of cement soil samples gradually increase to the peak strength and then decrease. Significant differences in the time correspond to the peak strength, and the overall presentation is two processes: the strength enhancement stage and the corrosion stage of the sample. The incorporation of UFC makes the cement soil in the peat soil environment exhibit excellent corrosion resistance, and the optimal UFC content is 10%. The results of the SEM and PCAS tests show that the microstructure of cement soil after immersion time exceeds 90 days, increases with an increase in immersion time, and its structural connectivity gradually weakens. The excellent characteristics of UFC particles, such as small particle size, narrow particle size distribution, fast hydration reaction rate, high hydration degree, and many hydration products, weakened the adverse effects of humic acid on the cement soil structure to a certain extent. Therefore, although the number of macropores increases, they are not connected. It still presents a relatively compact honeycomb overall structure, which correlates well with the UCS results.

Role of tranexamic acid in nasal surgery: A systemic review and meta-analysis of randomized control trial.

OBJECTIVE: Nasal surgeries (such as Functional Endoscopic Sinus Surgery, Rhinoplasty, and Septorhinoplasty) are popular procedures. But perioperative bleeding, eyelid edema, and periorbital ecchymosis remain problems. Tranexamic acid (TXA) is an antifibrinolytic, and it was used to reduce the perioperative bleeding. However, there is no enough evidence judging its safety and efficiency. Therefore, a meta-analysis is conducted by us to evaluate the role of TXA in patients undergoing nasal surgeries. METHOD: A search of the literature was performed until June 2018; the PubMed, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar databases were searched for related articles using search strategy. Two authors independently assessed the methodological quality of the included studies and extracted data. Surgical information and postoperative outcomes were analyzed. Only randomized controlled trial (RCT) articles were included, and subgroup analysis was established to deal with heterogeneity. RevMan 5.3 software was selected to conduct the meta-analysis. RESULT: Eleven RCTs were included in our meta-analysis. There were significant differences in blood loss (P < .001), surgical field quality (P < .001), edema rating of upper (P < .001) and lower (P < .001) eyelid, ecchymosis rating of upper (P < .001) and lower eyelid (P < .001) when comparing the TXA group to the placebo group. However, the difference in operation time (P = .57) was not significant between the two groups. CONCLUSION: Perioperative TXA could reduce the blood loss and improve the quality of surgery field during nasal surgery, and it was helpful for reducing the edema and ecchymosis after nasal surgeries, but it has little influence in reducing the operation time.

Erythromycin versus metoclopramide for post-pyloric spiral nasoenteric tube placement: a randomized non-inferiority trial.

PURPOSE: To determine whether erythromycin is non-inferior to metoclopramide in facilitating post-pyloric placement of self-propelled spiral nasoenteric tubes (NETs) in critically ill patients. METHODS: A prospective, multicenter, open-label, parallel, and non-inferiority randomized controlled trial was conducted comparing erythromycin with metoclopramide in facilitating post-pyloric placement of spiral NETs in critically ill patients admitted to intensive care units (ICUs) of eight tertiary hospitals in China. The primary outcome was procedure success defined as post-pyloric placement (spiral NETs reached the first portion of the duodenum or beyond confirmed by abdominal radiography 24 h after tube insertion). RESULTS: A total of 5688 patients were admitted to the ICUs. Of these, in 355 patients there was a plan to insert a nasoenteric feeding tube, of whom 332 were randomized, with 167 patients assigned to the erythromycin group and 165 patients assigned to the metoclopramide group. The success rate of post-pyloric placement was 57.5% (96/167) in the erythromycin group, as compared with 50.3% (83/165) in the metoclopramide group (a difference of 7.2%, 95% CI - 3.5% to 17.9%), in the intention-to-treat analysis, not including the prespecified margin of - 10% for non-inferiority. The success rates of post-D1 (reaching the second portion of the duodenum or beyond), post-D2 (reaching the third portion of the duodenum or beyond), post-D3 (reaching the fourth portion of the duodenum or beyond), and proximal jejunum placement and the incidence of any adverse events were not significantly different between the groups. CONCLUSIONS: Erythromycin is non-inferior to metoclopramide in facilitating post-pyloric placement of spiral NETs in critically ill patients. The success rates of post-D1, post-D2, post-D3, and proximal jejunum placement were not significantly different.

Chemical Peeling with a Modified Phenol Formula for the Treatment of Facial Freckles on Asian Skin.

BACKGROUND: Chemical peeling is an efficient method for the treatment of pigment disorders. For freckles, medium-depth to deep peeling using a phenol solution is one of the most effective chemical peels, and modifications of facial skin can be observed up to 20 years after peeling. However, applying phenol to the skin may cause serious side effects. Phenol peeling has been rarely used in Asia due to its tendency to cause permanent pigmentary changes and hypertrophic scars. METHODS: In total, 896 Chinese inpatients with facial freckles were enrolled in this study. The phenol formula was modified with crystalline phenol, dyclonine, camphor, anhydrous alcohol and glycerin and adjusted to a concentration of 73.6-90.0%. The entire peeling treatment was divided into two procedures performed separately on 2 days. RESULTS: All patients exhibited 26% or greater improvement, and 99.66% of patients exhibited 51% or greater improvement (good and excellent). Scarring and systemic complications were not observed in any patient. CONCLUSIONS: The modified phenol formula is very effective and safe for the treatment of facial freckles in Asian patients. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Platelet-Rich Fibrin Accelerates Skin Wound Healing in Diabetic Mice.

Diabetic foot ulcers (DFUs) are associated with an increased risk of secondary infection and amputation. Platelet-rich fibrin (PRF), a platelet and leukocyte concentrate containing several cytokines and growth factors, is known to promote wound healing. However, the effect of PRF on diabetic wound healing has not been adequately investigated. The aim of the study was to investigate the effect of PRF on skin wound healing in a diabetic mouse model. Platelet-rich fibrin was prepared from whole blood of 8 healthy volunteers. Two symmetrical skin wounds per mouse were created on the back of 16 diabetic nude mice. One of the 2 wounds in each mouse was treated with routine dressings (control), whereas the other wound was treated with PRF in addition to routine dressings (test), each for a period of 14 days. Skin wound healing rate was calculated.Use of PRF was associated with significantly improved skin wound healing in diabetic mice. On hematoxylin and eosin and CD31 staining, a significant increase in the number of capillaries and CD31-positive cells was observed, suggesting that PRF may have promoted blood vessel formation in the skin wound. In this study, PRF seemed to accelerate skin wound healing in diabetic mouse models, probably via increased blood vessel formation.

The roles of knitted mesh-reinforced collagen-chitosan hybrid scaffold in the one-step repair of full-thickness skin defects in rats.

Full-thickness skin defects represent a significant and urgent clinical problem. Dermal substitutes serving as a regenerative template to induce dermal reconstruction provide a promising method to treat serious skin defects. Although collagen-chitosan dermal scaffolds display good biocompatibility and a suitable porous structure for angiogenesis and tissue regeneration, their poor mechanical properties compromise their application. To develop a well-supported dermal substitute, a poly(l-lactide-co-glycolide) (PLGA) knitted mesh was fabricated and integrated with collagen-chitosan scaffold (CCS) to obtain a PLGA knitted mesh-reinforced CCS (PLGAm/CCS). The morphology of this PLGAm/CCS was investigated in vitro. To characterize the tissue response, specifically angiogenesis and tissue regeneration, the PLGAm/CCS was transplanted in combination with thin split-thickness autografts to repair full-thickness skin wounds using a one-step surgical procedure in Sprague-Dawley rats. These results were then compared with CCSs. At weeks 2, 4 and 8 after the operation, the healing wounds were imaged to analyse wound changes, and tissue specimens were harvested for histology, immunohistochemistry, real-time quantitative polymerase chain reaction and Western blot analysis. The results demonstrated that collagen-chitosan sponge in the PLGAm/CCS remained porous, interconnected and occupied the openings of PLGA mesh, and the incorporation of the PLGA knitted mesh into CCS improved the mechanical strength with little influence on its mean pore size and porosity. Following transplantation, PLGAm/CCS inhibited wound contraction, and effectively promoted neotissue formation and blood vessel ingrowth. In conclusion, the mechanical strength of the scaffolds plays an important role in the process of tissue regeneration and vascularization. The ability of PLGAm/CCS to promote angiogenesis and induce in situ tissue regeneration demonstrates its potential in skin tissue engineering.

Morphological quantitative criteria and aesthetic evaluation of eight female Han face types.

BACKGROUND: Human facial aesthetics relies on the classification of facial features and standards of attractiveness. However, there are no widely accepted quantitative criteria for facial attractiveness, particularly for Chinese Han faces. Establishing quantitative standards of attractiveness for facial landmarks within facial types is important for planning outcomes in cosmetic plastic surgery. The aim of this study was to determine quantitatively the criteria for attractiveness of eight female Chinese Han facial types. METHODS: A photographic database of young Chinese Han women's faces was created. Photographed faces (450) were classified based on eight established types and scored for attractiveness. Measurements taken at seven standard facial landmarks and their relative proportions were analyzed for correlations to attractiveness scores. Attractive faces of each type were averaged via an image-morphing algorithm to generate synthetic facial types. Results were compared with the neoclassical ideal and data for Caucasians. RESULTS: Morphological proportions corresponding to the highest attractiveness scores for Chinese Han women differed from the neoclassical ideal. In our population of young, normal, healthy Han women, high attractiveness ratings were given to those with greater temporal width and pogonion-gonion distance, and smaller bizygomatic and bigonial widths. As attractiveness scores increased, the ratio of the temporal to bizygomatic widths increased, and the ratio of the distance between the pogonion and gonion to the bizygomatic width also increased slightly. Among the facial types, the oval and inverted triangular were the most attractive. CONCLUSION: The neoclassical ideal of attractiveness does not apply to Han faces. However, the proportion of faces considered attractive in this population was similar to that of Caucasian populations. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The progress of silver nanoparticles in the antibacterial mechanism, clinical application and cytotoxicity.

Nanotechnology is a highly promising field, with nanoparticles produced and utilized in a wide range of commercial products. Silver nanoparticles (AgNPs) has been widely used in clothing, electronics, bio-sensing, the food industry, paints, sunscreens, cosmetics and medical devices, all of which increase human exposure and thus the potential risk related to their short- and long-term toxicity. Many studies indicate that AgNPs are toxic to human health. Interestingly, the majority of these studies focus on the interaction of the nano-silver particle with single cells, indicating that AgNPs have the potential to induce the genes associated with cell cycle progression, DNA damage and mitochondrial associated apoptosis. AgNPs administered through any method were subsequently detected in blood and were found to cause deposition in several organs. There are very few studies in rats and mice involving the in vivo bio-distribution and toxicity, organ accumulation and degradation, and the possible adverse effects and toxicity in vivo are only slowly being recognized. In the present review, we summarize the current data associated with the increased medical usage of nano-silver and its related nano-materials, compare the mechanism of antibiosis and discuss the proper application of nano-silver particles.

Fabrication and characterization of poly(L-lactide-co-glycolide) knitted mesh-reinforced collagen-chitosan hybrid scaffolds for dermal tissue engineering.

Mechanical properties are essential considerations for the design of porous scaffolds in the field of tissue engineering. To develop a well-supported hybrid dermal substitute, poly(L-lactide-co-glycolide) (PLGA) yarns were knitted into a mesh with relative fixed loops, followed by incorporation into collagen-chitosan scaffolds (CCS) to obtain PLGA knitted mesh-reinforced CCS (PLGAm/CCS). The morphology and tensile strength in both the dry and wet state of PLGAm/CCS were investigated in vitro. To characterize the tissue response, specifically angiogenesis and tissue regeneration, PLGAm/CCS was embedded subcutaneously in Sprague-Dawley rats and compared with two control implants, i.e., PLGA mesh (PLGAm) and CCS. At weeks 1, 2, and 4 post surgery, tissue specimens were harvested for histology, immunohistochemistry, real-time quantitative PCR and Western blot analysis. These results demonstrated that the incorporation of PLGA knitted mesh into CCS can improve the mechanical strength with little influence on its mean pore size and porosity. After implantation, PLGAm/CCS can resist contraction and promote cell infiltration, neotissue formation, and blood vessel ingrowth, effectively. In conclusion, the mechanical strength of scaffolds can play a synergetic role in tissue regeneration and vascularization by maintaining its 3D microstructure. The ability of PLGAm/CCS to promote angiogenesis and induce in situ tissue formation demonstrates its strong potential in the field of skin tissue engineering.

Osmium bipyridine-containing redox polymers based on cellulose and their reversible redox activity.

Thermo-, pH-, and electrochemical-sensitive cellulose graft copolymers, hydroxypropyl cellulose-g-poly(4-vinylpyridine)-Os(bipyridine) (HPC-g-P4VP-Os(bpy)), were synthesized and characterized. The electrochemical properties of the resulting material were investigated via cyclic voltammetry by coating the graft copolymers on the platinized carbon electrode. The results indicated that the electrochemical properties of the graft copolymer modified electrode were responsive to the pH values of the electrolyte solution. The reversible transformation between the active and inactive state originated from the changes in the architecture of the HPC-g-P4VP-Os(bpy) graft copolymer at different pH values. At high pH (e.g., above the pK(a) of P4VP), the chains of P4VP collapsed, and the electrochemical activity of the electrode was reduced. With immobilization of glucose oxidase (GOx) on the graft copolymer decorated electrode, a biosensor for glucose detection was prepared. The current of the biosensor depended on the glucose concentration in the detected solution and increased with the successive addition of glucose.

Promotion of angiogenesis by sustained release of rhGM-CSF from heparinized collagen/chitosan scaffolds.

A novel dermal substitute of combining recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) with a porous heparinized collagen/chitosan scaffolds was developed, considering the inadequate angiogenesis during repair of full-thickness skin defects. The physicochemical properties of heparinized collagen/chitosan scaffolds were examined and in vitro release pattern of rhGM-CSF from scaffolds was measured by ELISA. Four groups of composite scaffolds (heparinized or unheparinized scaffolds loaded with or without rhGM-CSF) were fabricated for subcutaneous implantation in young adult male Sprague-Dawley (SD) rats. Tissue specimens were harvested at different time points after implantation for histopathological, immunohistochemical observation, and Western blotting analysis. The heparinized scaffolds (H(1)E) showed slower biodegradation and sustained release of rhGM-CSF in vitro, although no significantly different release pattern was observed between the H(1)E and unheparinized scaffolds (H(0)E). In vivo investigation revealed that the heparinized scaffolds loaded with rhGM-CSF (H(1)E/rhGM-CSF) had the best cellular adhesion and migration, new vessel formation, and highest expression of VEGF and TGF-ß1, indicating promoted angiogenesis. This study demonstrated that composite dermal substitute of combining rhGM-CSF with a porous heparinized collagen/chitosan scaffolds could be a potential therapeutic agent for full-thickness skin defects because of its sustained delivery of rhGM-CSF.

Epidermal cells delivered for cutaneous wound healing.

Re-epithelialization is the first and most important step in cutaneous wound healing. The vital role of epidermal cells, or keratinocytes, in accelerating wound healing has long been established. The technique of delivering the cultured and uncultured epidermal cells to the wound bed takes a variety of forms including cultured epithelial autografts (CEAs), tissue-engineered skin equivalent, epidermal suspension and microbead-loaded composite. These techniques, together with the keratinocyte culturing method and scaling up equipment, are still the ongoing research. Application of these techniques also bears direct impact on the outcome of the wounded patients. Best understanding of the delivery technique and its relationship with the culturing method and delivery vehicle could benefit not only the wounded patient but also the development of tissue-engineered skin equivalent.

Applications of knitted mesh fabrication techniques to scaffolds for tissue engineering and regenerative medicine.

Knitting is an ancient and yet, a fresh technique. It has a history of no less than 1,000 years. The development of tissue engineering and regenerative medicine provides a new role for knitting. Several meshes knitted from synthetic or biological materials have been designed and applied, either alone, to strengthen materials for the patching of soft tissues, or in combination with other kinds of biomaterials, such as collagen and fibroin, to repair or replace damaged tissues/organs. In the latter case, studies have demonstrated that knitted mesh scaffolds (KMSs) possess excellent mechanical properties and can promote more effective tissue repair, ligament/tendon/cartilage regeneration, pipe-like-organ reconstruction, etc. In the process of tissue regeneration induced by scaffolds, an important synergic relationship emerges between the three-dimensional microstructure and the mechanical properties of scaffolds. This paper presents a comprehensive overview of the status and future prospects of knitted meshes and its KMSs for tissue engineering and regenerative medicine.

[Design and biological evaluation of poly-lactic-co-glycolic acid (PLGA) mesh/collagen-chitosan hybrid scaffold (CCS) as a dermal substitute].

OBJECTIVE: To design and construct a kind of dermal regeneration template with mesh, and to preliminarily evaluate its biological characteristics. METHODS: PLGA mesh was integrated into CCS with freeze-drying method for constructing PLGA mesh/CCS composite (PCCS). The micromorphologies and mechanical properties among PLGA mesh, CCS, and PCCS were compared. PCCS and CCS was respectively implanted into subcutaneous tissue of SD rats (PCCS and CCS groups, 9 rats in each group). The tissue samples were collected at post operation week (POW) 1, 2, and 4 for histopathological and immunohistochemical observation. Protein levels of CD68, MPO, IL-1beta, IL-10 were examined by Western blot, with expression of gray value. Data were processed with one-way analysis of variance and t test. RESULTS: Three-dimensional porous structure of PCCS was similar to that of CCS. Mechanical property of PLGA mesh and PCCS was respectively (3.07 +/- 0.10), (3.26 +/- 0.15) MPa, and they were higher than that of CCS [(0.42 +/- 0.21) MPa, F = 592.3, P < 0.0001)]. The scaffolds were filled with newly formed tissue in PCCS group at POW 2, while those in CCS group were observed at POW 4. A large accumulation of macrophages was observed in both groups, especially at POW 2, and more macrophage infiltration was observed in CCS group. The protein level of IL-10 in PCCS group at POW 2 was obviously higher than that in CCS group, while the protein levels of CD68, MPO, IL-1beta were significantly decreased as compared with those in CCS group (with t value from -4.06 to 2.89, P < 0.05 or P < 0.01). CONCLUSIONS: PCCS has excellent mechanical property with appropriate three-dimensional porous structure. Meanwhile, it can rapidly induce formation of new tissue and vascularization, and it has a prospect of serving as a dermal substitute.

[Preliminary evaluation of the biological properties of poly-lactide-co-glycolic acid (PLGA) knitted mesh].

This is a work aimed to investigate the biodegradability, biocompatibility and mechanical property of the poly-lactide-co-glycolic acid (PLGA) knitted mesh preliminarily and to further explore its applications in tissue engineering and regenerative medicine. The biological property of PLGA mesh was investigated comprehensively with the degradation experiment in vitro, the acute cytotoxicity assay, the intradermal irritation test and the subcutaneous implantation test in vivo utilized. The degradation experiment in vitro demonstrated that the pH value of the removed solution fluctuated between 6.68 and 7.33. The elastic modulus of the PLGA mesh increased at first and then decreased afterwards. The acute toxicity test and the intradermal irritation test indicated that the PLGA mesh was with innocuity safety. The PLGA mesh accelerated degradation and was replaced gradually by the neotissue. The results of immunohistochemical staining demonstrated that the number of ED-1+ cells increased at first and then decreased afterwards. The PLGA mesh with excellent mechanical properties, good biocompatibility and favorable degradation ratio has the potential to be employed as a "skeleton" to reinforce the mechanical property of collagen-based dermal substitutes in tissue engineering.

Topically applied rhGM-CSF for the wound healing: a systematic review.

The process of wound healing involves a complex interplay of cells, mediators, growth factors and cytokines. GM-CSF has been shown to be involved in a number of processes essential in this event. Topically applied rhGM-CSF has been reported to successfully treat wounds with diverse etiology, including burns, chronic venous leg ulcers, pressure ulcers, and leprosy ulcers, both in animal experiments and clinical studies. To evaluate the effect of the rhGM-CSF on wound healing, 8 RCT studies and 23 clinical studies and case reports are collected for analysis of the evidence. The overall effects of rhGM-CSF on the healing of wound are diverse. Topically applied rhGM-CSF is beneficial for deep partial-thickness burn wounds, chronic leg ulcers, and leprosy ulcers. rhGM-CSF may have a positive effect on other type of chronic ulcers such as pressure ulcers and cancer related ulcers, but the evidence is not sufficient for generalised use at present. rhGM-CSF is suggested have no accelerating effect on the healing of healthy wounds or surgical incisions.