Optimization of corn-stalk skin flake-wood shaving composite technology

We focused on the optimization of corn-stalk skin flake-wood shaving composite technology. We studied the effects of material-mixture ratio, glue content, hot- pressing temperature, and hot-pressing time on the appear- ance, physical, and mechanical properties of the composite by the orthogonal experiment method. Our findings yielded highly significant results in all three cases： the effects of the material-mixture ratio on 2 h of thickness swelling （2hTS） and the modulus of rupture （MOR）; the effects of glue con- tent on 2hTS, internal bond strength, and modulus of elas- ticity （MOE）; and the effects of hot-pressing temperature on MOR and MOE. Product optimization is achieved when the ratio of corn stalk skin flake to wood shaving is 3：7, the glue content is 12 %, the hot-pressing temperature is 150 ℃, and the hot-pressing time is 4.5 min.

Simple HPLC Analysis of Hinokitiol in Skin Lotion with Visible Light Detection after Pre-Column Dabsylation

Hinokitiolis frequently added to personal care products as an antibacterial agent. We previously established an HPLC-UV method for determination of hinokitiol in skin lotion after pre-column derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole. However, the labeling reagent is expensive, and derivatives of degradation products of parabens, which may be added to skin lotion as general preservatives, interfered with the peak of the hinokitiol derivative. In this study, the concentration of hinokitiol in skin lotions was determined by HPLC with a visible light detector (450 nm) after pre-column derivatization with 4-(dimethylamino)azobenzene-4’-sulfonyl chloride (Dabsyl-Cl), a more economical reagent. A standard curve was obtained after derivatization with Dabsyl-Cl in borate buffer (pH 9.5) at 55°C for 10 min. The retention time of Dabsyl-hinokitiol was 6.8 min. The calibration plot was linear in the range of 1.25 to 40 μg/mL with a r2 value of 0.9991, and the lower limit of quantification and detection were 0.60 μg/mL (absolute amount of 0.86 ng/20μL injection, signal-to-noise ratio of 10:1) and 0.18 μg/mL (absolute amount of 0.26 ng/20μL injection, signal-to-noise ratio of 3:1), respectively. The coefficient of variation was less than 8.8%. Seven Dabsyl-paraben derivatives showed little interference with the peak of Dabsyl-hinokitiol. The developed system was used to determine the content of hinokitiol in two skin lotions. Addition-recovery tests gave satisfactory results.

Fingertip skin models for analysis of the haptic perception of textiles

This paper presents finite element models of the fingertip skin which have been created to simulate the contact of textile objects with the skin to gain a better understanding of the perception of textiles through the skin, the so-called hand of textiles. Many objective and subjective techniques have already been developed for analysing the hand of textiles;however, none of them provide exact overall information concerning the sensation of textiles through the skin. As the human skin is a complex heterogeneous hyperelastic body composed of many particles, some simplifications had to be made at the early stage of building the models;however, their utilitarian value was maintained. The models relate only to mechanical loading of the skin. They predict a low deformation of the fingertip skin under the pressure of virtual heterogeneous material: acrylic, coarse wool, and steel.

剖宫产术皮内缝合切口愈合不良分析

目的:探讨剖宫产术皮内缝合切口愈合不良的原因、治疗和预防措施。方法:对960例采用皮内缝合剖宫产患者的临床资料进行回顾性分析,分析切口愈合不良的原因,并进一步探索预防措施和治疗方法。结果:剖宫产术皮内缝合切口愈合不良与肥胖、糖尿病、水肿、贫血、滞产、缝合方式及技术、术后咳嗽、妊娠期高血压疾病、切口张力增加、术前是否使用抗生素密切相关。结论:选择剖宫产术皮肤切口缝合方式、加强剖宫产术后腹部切口护理、合理预防性应用抗生素,可有效预防切口愈合不良并使切口早期愈合。

Near-infrared responsive 5-fluorouracil and indocyanine green loaded MPEG-PCL nanoparticle integrated with dissolvable microneedle for skin cancer therapy

The prevalence of skin cancer is rising along with the rapid population aging in recent years.Traditional therapies,such as surgical treatment,radiotherapy,chemotherapy,photodynamic therapy,and immunotherapy,may accompany serious side effects,limiting their clinical benefits.According to the biological characteristics of skin cancer,we have already established two kinds of synergetic systems of photothermal therapy(microneedle)and chemotherapy,containing gold nanorods(GNR).Although the microneedle system exhibited great potential for skin cancer treatment,the system could be still improved further.So,we designed a near-infrared lightresponsive 5-fluorouracil(5-Fu)and indocyanine green(ICG)loaded monomethoxy-poly(ethylene glycol)-polycaprolactone(MPEG-PCL)nanoparticle(5-Fu-ICG-MPEG-PCL),and then 5-Fu-ICG-MPEG-PCL was integrated with a hyaluronic acid dissolvable microneedle system(HA MN)to get 5-Fu-ICG-MPEG-PCL loaded HA MN for treating skin cancers,including human epidermoid cancer and melanoma.In this system,hyaluronic acid,the microneedle carrier,possesses good skin penetration ability and is approved by FDA as a pharmaceutical adjuvant;5-Fu is recommended by FDA for skin cancer treatment;ICG,a photothermal agent,possesses a strong photothermal ability and is approved by FDA for its use in the human body.We hypothesized that 5-Fu-ICG-MPEG-PCL could be delivered by the dissolvable microneedle through the skin,and the release behavior of the drug in the nanoparticle could be controlled by near-infrared light for achieving a single-dose cure of skin cancer,improving the cure rate of skin cancer and providing a new idea and possibility for the clinical treatment of skin cancer.

MiR-711 and miR-183-3p as potential markers for vital reaction of burned skin

In forensic practice,the identification of antemortem burns and postmortem burns is of the utmost importance.Reports from previous studies have shown that miRNAs,with lengths stretching over 18–25 nucleotides,are highly stable and resistant to degradation.However,there has been little research into the application of miRNAs in identifying antemortem and postmortem burns.This study compared the expression of miR-711 and miR-183-3p levels in mouse and postmortem human burned skins using RT-qPCR assay.RT-qPCR examination of burned mouse skins showed that increased miR-711 and miR-183-3p expression in comparison to intact skin tissues.The increased expressions of these two miRNAs were observed until 120 h after death in burned mouse skins,whereas no significant changes were found in postmortem burned skins.In human burned skins,the increased levels of these two miRNAs at 48 h following autopsy occurred in 19 of 26 subjects,which appeared to be related to the severity of the burn.These findings suggest that miR-711 and miR-183-3p may act as biomarkers for vital reaction of skin burn.

Chemokine Receptor CXCR3 in the Spinal Cord Contributes to Chronic Itch in Mice

Recent studies have shown that the chemokine receptor CXCR3 and its ligand CXCL10 in the dorsal root ganglion mediate itch in experimental allergic contact dermatitis （ACD）. CXCR3 in the spinal cord also con- tributes to the maintenance of neuropathic pain. However, whether spinal CXCR3 is involved in acute or chronic itch remains unclear. Here, we report that Cxcr3-/- mice showed normal scratching in acute itch models but reduced scratching in chronic itch models of dry skin and ACD. In contrast, both formalin-induced acute pain and complete Freund＇s adjuvant-induced chronic inflammatory pain were reduced in Cxcr3-/- mice. In addition, the expression of CXCR3 and CXCL10 was increased in the spinal cord in the dry skin model induced by acetone and diethyl ether followed by water （AEW）. Intrathecal injection of a CXCR3 antagonist alleviated AEW-induced itch. Further- more, touch-elicited itch （alloknesis） after compound 48/80 or AEW treatment was suppressed in Cxcr3-/- mice. Finally, AEW-induced astrocyte activation was inhibited in Cxcr3-/- mice. Taken together, these data suggest that spinal CXCR3 mediates chronic itch and alloknesis, and targeting CXCR3 may provide effective treatment for chronic pruritus.

Collagen/hyaluronan based hydrogels releasing sulfated hyaluronan improve dermal wound healing in diabetic mice via reducing inflammatory macrophage activity

Sustained inflammation associated with dysregulated macrophage activation prevents tissue formation and healing of chronic wounds.Control of inflammation and immune cell functions thus represents a promising approach in the development of advanced therapeutic strategies.Here we describe immunomodulatory hyaluronan/collagen(HA-AC/coll)-based hydrogels containing high-sulfated hyaluronan(sHA)as immunoregulatory component for the modulation of inflammatory macrophage activities in disturbed wound healing.Solute sHA downregulates inflammatory activities of bone marrow-derived and tissue-resident macrophages in vitro.This further affects macrophage-mediated pro-inflammatory activation of skin cells as shown in skin ex-vivo cultures.In a mouse model of acute skin inflammation,intradermal injection of sHA downregulates the inflammatory processes in the skin.This is associated with the promotion of an anti-inflammatory gene signature in skin macrophages indicating a shift of their activation profile.For in vivo translation,we designed HA-AC/coll hydrogels allowing delivery of sHA into wounds over a period of at least one week.Their immunoregulatory capacity was analyzed in a translational experimental approach in skin wounds of diabetic db/db mice,an established model for disturbed wound healing.The sHA-releasing hydrogels improved defective tissue repair with reduced inflammation,augmented pro-regenerative macrophage activation,increased vascularization,and accelerated new tissue formation and wound closure.