Chitosomes-In-Chitosan Hydrogel for Acute Skin Injuries: Prevention and Infection Control

Burns and other skin injuries are growing concerns as well as challenges in an era of antimicrobial resistance. Novel treatment options to improve the prevention and eradication of infectious skin biofilm-producing pathogens, while enhancing wound healing, are urgently needed for the timely treatment of infection-prone injuries. Treatment of acute skin injuries requires tailoring of formulation to assure both proper skin retention and the appropriate release of incorporated antimicrobials. The challenge remains to formulate antimicrobials with low water solubility, which often requires carriers as the primary vehicle, followed by a secondary skin-friendly vehicle. We focused on widely used chlorhexidine formulated in the chitosan-infused nanocarriers, chitosomes, incorporated into chitosan hydrogel for improved treatment of skin injuries. To prove our hypothesis, lipid nanocarriers and chitosan-comprising nanocarriers (≈250 nm) with membrane-active antimicrobial chlorhexidine were optimized and incorporated into chitosan hydrogel. The biological and antibacterial effects of both vesicles and a vesicles-in-hydrogel system were evaluated. The chitosomes-in-chitosan hydrogel formulation demonstrated promising physical properties and were proven safe. Additionally, the chitosan-based systems, both chitosomes and chitosan hydrogel, showed an improved antimicrobial effect against S. aureus and S. epidermidis compared to the formulations without chitosan. The novel formulation could serve as a foundation for infection prevention and bacterial eradication in acute wounds.     

植物素9501的提取及杀钉螺试验

报道了植物素９５０１的提取及纯化新工艺，用优化的生产工艺条件制得的产品纯度高，不吸潮，且成本较低，杀钉螺效果好。     

低温疗法脱除植物病毒研究进展

低温疗法是近几年刚刚兴起的一种新的脱除植物病毒的方法。本文从低温疗法脱除植物病毒的原理、方法、步骤及应用情况等方面进行了综述,旨在为该方法的推广应用提供参考。     

Effect of burning and high temperature on survival of Xanthomonas translucens pv. pistaciae in infected pistachio branches and twigs

This paper reports the efficacy of burning and heat‐treating pistachio branches and twigs as a means of disposing of prunings from trees infected with Xanthomonas translucens pv. pistaciae (Xtp). Burning of pistachio wood, naturally infected with Xtp, was conducted twice under field conditions. Viable Xtp was detected in some non‐burned wood, but not in charcoal, ash or partially burned wood. Controlled laboratory experiments were conducted with pure cultures of Xtp and naturally and artificially infected pistachio wood. In liquid culture, 65°C was lethal to Xtp, whereas survival at 60°C or less varied with culture medium and duration of exposure. Xtp survived in infected wood exposed to 40–55°C for at least 60 min but was killed by exposure to 60°C for 15 min or more. Overall, the results of burning and heat treatment were consistent, and confirmed that burning was a reliable eradication technique to dispose of infected wood, such as prunings, providing the pathogen was exposed to a temperature of 60°C or greater for at least 15 min.     

草莓试管内诱导匍匐茎和高温处理结合茎尖培养脱毒技术研究

【目的】获得可用于生产的无病毒草莓种苗。【方法】在试管内对深山草莓花瓣愈伤组织分化产生的优良变异新品种的试管苗进行匍匐茎诱导,并采取试管内高温处理结合茎尖培养对该品种进行脱毒研究,应用均匀设计法对各步骤主要影响因子进行优化筛选。【结果】该草莓新品种试管苗匍匐茎诱导的适宜培养基为:LS+6-BA1.00mg/L+GA31.90mg/L+KT1.00mg/L,其诱导率为99.5%以上;将含有匍匐茎的试管苗在试管内于56℃条件下培养85d后,切取1mm的茎尖在培养基MS+6-BA0.50mg/L+NAA0.20mg/L中进行茎尖愈伤组织诱导,然后将茎尖愈伤组织转接到培养基MS+6-BA1.00mg/L+NAA0.05mg/L中进行愈伤组织芽苗再分化培养,对再生芽苗进行病毒检测,脱毒率为100%。【结论】利用试管内高温处理结合茎尖脱毒的方法可以完全脱除草莓病毒,从而建立了草莓脱毒体系。     

Efficacy of Vapam fumigant against clubroot (Plasmodiophora brassicae) of canola

Clubroot, caused by Plasmodiophora brassicae, has become a serious threat to canola (Brassica napus) production in western Canada. Experiments were conducted under greenhouse and field conditions to assess the effect of Vapam fumigant (dithiocarbamate; sodium N‐methyldithiocarbamate) on primary and secondary infection by P. brassicae, clubroot severity, and growth parameters in canola. Preliminary trials showed a 12–16‐fold reduction in primary and secondary infection and clubroot severity at all of the Vapam application rates (0·4–1·6 mL L^?1 soil) assessed. Vapam was also found to be effective in reducing clubroot severity and improving seed yield of canola under field conditions. Application of Vapam at soil moisture levels in the range of 10–30% (v:v) had a large effect on both disease severity and infection rates and plant growth parameters. The results suggest that Vapam can effectively reduce clubroot severity and may be useful for the treatment of transplant propagation beds in brassica vegetable production, and for the containment of small, localized clubroot infestations in commercial canola crops.     

Pre-seed Treatment Effects on Avocado （Persea americana L.） Seedlings Health and Growth before Side-Grafting in Ghana

Studies were conducted to detennine the effects of hot water （50 ℃） and fungicide （contizeb ‘5＇） treatments on avocado seeds in terms of seed health, germination and seedling growth before side-grafting. The leathery coverings or seed coat were removed and either 1 cm or 1.5 cm of the narrow top of the seeds was removed before sowing. There were six treatments arranged in a randomized complete block and rephcated three times. In a six week period after germination when side grafting could be done, it was found out that the earliest germination came from the ＇no hot water or fungicide-treated＂ seeds cut at 1 cm but most seeds germinated from the fungicide-treated seeds at 1 cm cut. Most fungi including Fusarium andAspergillus spp found to either delay germination or reduce seedling vigour were minimized in number through the fungicide treatment compared to the hot water-treated seeds. Seedlings performance in terms of shoot extension and canopy development was significantly better in the fungicide-treated seeds than from either the hot water or the non-treated seeds. The study concluded that avocado seed treatment prior to sowing enhanced germination.     

Herbicide efficacy for aquatic Alternanthera philoxeroides management in an early stage of invasion: integrating above‐ground biomass,below‐ground biomass and viable stem fragmentation

Alternanthera philoxeroides is a problematic invasive plant in many regions of the world that is difficult to control once naturalised. It poses a threat to agricultural productivity, biodiversity and social amenity values of aquatic environments. Significant research has been conducted internationally, regarding the efficacy of different herbicides for control of A. philoxeroides. However, no studies have looked at key aspects of control for effective management in an early stage of invasion of aquatic environments, hindering eradication and control programmes. This study evaluates the efficacy of herbicides and surfactants on key A. philoxeroides response metrics, including control of above‐ground biomass, below‐ground biomass and production of viable stem fragments. This study concluded that glyphosate (isopropylamine salt) minimises viable stem fragment production post‐herbicide application, compared with imazapyr and metsulfuron, thus reducing the potential for dispersal throughout catchments and waterways. In contrast, imazapyr and metsulfuron provided more effective control than glyphosate for A. philoxeroides growing on exposed embankments. We propose that an effective management strategy for early invasion of aquatic A. philoxeroides, using herbicides, would be to conduct initial applications of glyphosate to control overwater biomass and limit dispersal of viable stem fragments. Once infestations have been forced back to the embankment, imazapyr or metsulfuron treatments will provide longer term control.