Enhanced chondrogenic differentiation of human mesenchymal stems cells on citric acid-modified chitosan hydrogel for tracheal cartilage regeneration applications

Congenital tracheal stenosis in infants and children is a worldwide clinical problem. Tissue engineering is a promising method for correcting long segmental tracheal defects. Nonetheless, the lack of desirable scaffolds always limits the development and applications of tissue engineering in clinical practice. In this study, a citric-acid-functionalized chitosan (CC) hydrogel was fabricated by a freeze–thaw method. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed that citric acid was successfully attached to the chitosan hydrogel. Scanning electron microscopy (SEM) images and compression tests showed that the CC hydrogel had an interconnected porous structure and better wet mechanical properties. Using morphological and proliferation analyses, cell biocompatibility of the CC hydrogel was shown by culturing human mesenchymal stem cells (hMSCs) on it. Specific expression of cartilage-related markers was analyzed by real-time polymerase chain reaction and western blotting. The expression of chondrocytic markers was strongly upregulated in the culture on the CC hydrogel. Hematoxylin and eosin staining revealed that the cells had the characteristic shape of chondrocytes and clustered into the CC hydrogel. Both Alcian blue staining and a sulfated glycosaminoglycan (sGAG) assay indicated that the CC hydrogel promoted the expression of glycosaminoglycans (GAGs). In a nutshell, these results suggested that the CC hydrogel enhanced chondrogenic differentiation of hMSCs. Thus, the newly developed CC hydrogel may be a promising tissue-engineered scaffold for tracheal cartilage regeneration.

A novel citric acid functionalized chitosan hydrogel for tracheal cartilage regeneration applications.     

CXCL10/CXCR3 Signaling in the DRG Exacerbates Neuropathic Pain in Mice

Chemokines and receptors have been implicated in the pathogenesis of chronic pain.Here,we report that spinal nerve ligation(SNL)increased CXCR3 expression in dorsal root ganglion(DRG)neurons,and intra-DRG injection of Cxcr3 shRNA attenuated the SNL-induced mechanical allodynia and heat hyperalgesia.SNL also increased the m RNA levels of CXCL9,CXCL10,and CXCL11,whereas only CXCL10 increased the number of action potentials(APs)in DRG neurons.Furthermore,in Cxcr3^-/-mice,CXCL10 did not increase the number of APs,and the SNL-induced increase of the numbers of APs in DRG neurons was reduced.Finally,CXCL10 induced the activation of p38 and ERK in ND7-23 neuronal cells and DRG neurons.Pretreatment of DRG neurons with the P38 inhibitor SB203580 decreased the number of APs induced by CXCL10.Our data indicate that CXCR3,activated by CXCL10,mediates p38 and ERK activation in DRG neurons and enhances neuronal excitability,which contributes to the maintenance of neuropathic pain.     

南通市糖尿病患者生命质量现状及影响因素研究

目的：了解南通市糖尿病患者的生命质量,并探讨影响因素,为改善该群体生命质量提供参考依据。方法：整群随机抽样抽取南通市狼山社区、平潮镇平西村、吉坝村278例糖尿病患者,调查患者的社会人口学特征、患病情况、自我管理情况,利用欧洲五维生命质量量表（European quality of life 5-dimensions,EQ-5D）评价DM患者健康相关生命质量,采用Tobit回归分析生命质量的影响因素。结果：共发放问卷278份,有效问卷260份,问卷有效率93.5%。糖尿病患者在行动能力、自我照顾、日常活动、疼痛/不适、焦虑/沮丧5个维度有中度以上问题的比例分别为10.8%、3.1%、4.6%、49.2%和25.8%。EQ-5D效用值为1的占42.1%。多因素Tobit回归结果显示,患者月平均医疗开支、健康自评、所患慢性疾病数量和幸福感是健康相关生命质量的影响因素（P＜0.05）。结论：南通市糖尿病患者在疼痛/不适、焦虑/沮丧维度存在较多问题,医疗开支大、健康自评差、患多种慢性病、幸福感低的患者生命质量较差,需要重点关注。     

南通市老年人生活质量及其影响因素

目的了解南通市老年人健康状况和生活质量现状,并对生活质量的影响因素进行分析,为制定提高老年人生活质量的相关干预措施提供依据。方法采用整群抽样的方法,世界卫生组织QOL-BREF及自制量表为调查工具,对南通市60岁以上老年人群进行调查,共收集有效问卷714份。结果南通市老年人的生活质量得分(x±s)分别是:生理领域64.99±11.19,心理领域61.05±9.84,社会关系领域65.74±10.18,环境领域59.06±10.41,QOL自评65.14±17.16,健康自评71.06±14.22。多因素线性回归分析结果显示,年龄、睡眠状况、个性是否乐观、体育锻炼是影响老年人生理领域得分的主要因素;文化程度、医疗费用负担方式、食欲、人际关系、个性是否乐观、体育锻炼及对医疗保险制度的满意度是影响老年人心理领域得分的主要因素;婚姻状况、医疗保险费用的负担方式、人际关系、个性是否乐观、体育锻炼及对医疗保险制度的满意度是影响老年人社会领域得分的主要因素;文化程度、医疗费用负担方式、居住条件、人际关系、个体是否乐观、体育锻炼及对医疗保险制度的满意度是影响老年人环境领域得分的主要因素。结论完善医疗保障制度,鼓励老年人适当地参加体育锻炼,建立良好的社会关系,提高老年人的生活质量。     

Hydrothermal synthesis of cotton-based BiVO4/Ag composite for photocatalytic degradation of C.I. Reactive Black 5

Photocatalytic materials with high efficiency and convenient recyclability have attracted great interest for the treatment of printing and dyeing wastewater. In this paper, a narrow band gap BiVO₄ photocatalyst was loaded onto Ag modified cotton fabric by a hydrothermal method. The prepared composite materials were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet visible light absorption spectroscopy (UV-vis). The composite materials as prepared show superb photocatalytic activity and reusable performance for the degradation of C.I. Reactive Black 5 (RB5). The degradation rate can reach 99% within 90 min under 1 kW xenon lamp irradiation, and over 90% of the photocatalytic performance is preserved even after five recycles. Furthermore, the photocatalytic mechanism was proposed by spectral analysis and free radical trapping experiments.

BiVO₄/Ag/cotton-K composite material exhibited excellent photocatalytic activity and recyclability, and the photodegradation mechanism of RB5 by BiVO₄/Ag/cotton-K was also proposed.     

Sleepiness,driving, and motor vehicle accidents: A questionnaire-based survey

In Switzerland, the prevalence of an excessive daytime sleepiness (EDS) in drivers undergoing a driving capacity assessment is currently not known. In this study, private and professional drivers were evaluated by means of a paper-based questionnaire, including Epworth Sleepiness Scale, Berlin Questionnaire, and additional questions to sleepiness-related accidents, near-miss accidents, health issues, and demographic data.Of the 435 distributed questionnaires, 128 completed were returned. The response rate was 29%. The mean age of the investigated drivers was 42.5 years (20–85 years). According to the Epworth Sleepiness Scale, 9% of the participants are likely to suffer from excessive daytime sleepiness. An equal percentage has a high risk for obstructive sleep apnea syndrome based on the Berlin Questionnaire. 16% admitted an involuntary nodding off while driving a motor vehicle. This subset of the participants scored statistically significant higher on the Epworth Sleepiness Scale (p = 0.036). 8% of the participants already suffered an accident because of being sleepy while driving. An equal number experienced a sleepiness-related near-miss accident on the road. The study shows that a medical workup of excessive daytime sleepiness is highly recommended in each driver undergoing a driving capacity assessment. Routine application of easily available and time-saving assessment tools such as the Epworth Sleepiness Scale questionnaire could prevent accidents in a simple way. The applicability of the Berlin Questionnaire to screen suspected fatal sleepiness-related motor vehicle accidents is discussed.     

Estrogen receptors are involved in polychlorinated biphenyl-induced apoptosis on mouse spermatocyte GC-2 cell line

Polychlorinated biphenyls (PCBs) are widespread persistent environmental contaminants which have been shown to have reproductive toxicity and to disturb spermatogenesis. But the precise mechanism is not clear. A mouse pachytene spermatocyte-derived cell line, GC-2 cells were used in the present study to investigate the toxic effect of PCBs (Aroclor 1254) and explore the underlying molecular mechanism. Results showed that Aroclor 1254 inhibited cell proliferation, caused the arrest of cells in G0/G1 phase and induced apoptosis which might be partly explained by the decreased expression of Bcl-2 and cell cycle regulator cyclin D1 together with the activation of caspase-3. Besides, the treatment of Aroclor 1254 decreased the protein expression of estrogen receptor (ER)-α while increasing that of ERβ. Then the administration of selective ERα agonist PPT partly reversed Aroclor 1254-induced alteration in Bcl-2, caspase-3 and cyclin D1 protein expression while selective ERβ agonist DPN accelerated it. These results suggest that Aroclor 1254, working through ERα and ERβ, interferes with the expression of proteins involved in the balance between cellular apoptosis and proliferation.     

A Research on Durability Degradation of Mineral Admixture Concrete

In order to study the degradation laws and mechanisms of admixture concretes with single-added SO₄²⁻ and composite of Mg²⁺ and SO₄²⁻, respectively, the durability tests were conducted on three types of mineral admixture concretes (concretes with single-added metakaolin (MK), single-added ultra-fine fly ash (UFA), and composite of metakaolin and ultra-fine fly ash (MF), and one reference concrete. In these tests, the 10% Na₂SO₄ solution and the 10% MgSO₄ solution were used as the erosion medium, and the drying-wetting circle method was applied. It can be seen from the compressive tests and grey relational analysis that the MK admixture can improve the anti-Na₂SO₄-erosion capability of the concrete significantly, but weaken its anti-MgSO₄-erosion capability; the UFA admixture can improve both the anti-Na₂SO₄-erosion and the anti-MgSO₄-erosion capability of the concrete; and the composite admixture has superimposed effects and can enhance erosion resistance against these two erosion mediums. The phase composition and the changes of the macro morphology and the micro structure during the erosion process caused by mono sulfate ions and complex ions has been observed through X-ray diffraction (XRD), FTIR spectrum (FTIR), and scanning electron microscope (SEM), based on which it was determined that the erosion of single-added SO₄²⁻ ions can produce erosive outputs of ettringite, gypsum, and mirabilite in the concrete, and cause corner scaling or deformation. Mg²⁺ and SO₄²⁻ reacted in the concrete and produced brucite, M-S-H, ettringite, and gypsum, etc. The erosion of complex ions can cause scaling of the cement mortar and aggregate from the surface or the desquamation of corners.     

Low Recombination Firing-Through Al Paste for N-Type Solar Cell with Boron Emitter

A kind of low recombination firing-through screen-printing aluminum (Al) paste is proposed in this work to be used for a boron-diffused N-type solar cell front side metallization. A front side fire-through contact (FTC) approach has been carried out for the formation of local contacts for a front surface passivated solar cell. With a low contact resistivity (ρ_c) of 1.0 mΩ·cm², good ohmic contact between the boron-doped front surface of the silicon sample and the Al paste was realized. To obtain a good energy conversion efficiency, a balance can be achieved between the open circuit voltage (V_oc) and contact resistivity (ρ_c) of the cell by combining suitable Al powders and appropriate additives. The detailed micro-contact difference in Si/metallization between the firing-through Al paste and silver-aluminum (Ag-Al) paste was analyzed. The dark saturation current density beneath the metal contact (J_{0, metal}) of the Si/metallization region using our firing-through Al paste was discussed, which was proven to be 61% lower than using Ag-Al paste. The pseudo energy conversion efficiency of the cell using Al paste measured by Suns-V_OC was also higher than using Ag-Al paste. The role of Al paste in low surface metal recombination is discussed. The utilization of this new kind of Al paste was much cheaper and more convenient, compared to the traditional process using Ag or Ag-Al paste.