Fine spatial resolution coastline extraction from Landsat-8 OLI imagery by integrating downscaling and pansharpening approaches

Landsat series images are the main data resources used for coastline monitoring. However, the 30 m spatial resolution of multispectral (MS) image is always dominated by mixed pixels around the coast areas. Given that the latest Landsat-8 Operational Lands Imager (OLI) imagery has a 15 m panchromatic (PAN) band, it is instinctive to improve the coastline extracting accuracy by directly using the pansharpening approach. The spatial resolution of the sharpened MS image, however, may still not be sufficient in real applications, due to the meter-level spatial-temporal change of coastline. In this letter, a novel downscaling-then-pansharpening coastline extracting (DTPCE) approach is proposed to extract higher accuracy coastline from Landsat-8 OLI imagery. DTPCE first uses the radial basis function (RBF) method to downscale the 15 m PAN band to a finer spatial resolution, and then produces a fine spatial resolution fused MS image by pansharpening of the downscaled PAN band and original MS bands. Finally, the fused MS image is used for coastline extracting. Comparing the extracted coastline with the reference coastline extracted from 5.8 m ZiYuan-3 (ZY-3) MS image, DTPCE produced coastlines with the state-of-the-art representation in terms of both the visually and quantitatively analysis.     

Nanodiamond-based layer-by-layer nanohybrids mediate targeted delivery of miR-34a for triple negative breast cancer therapy

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer and significantly associated with poor prognosis and high risk of recurrence. miR-34a has been identified as a potent tumor suppressor whose expression is dramatically downregulated in TNBC. Currently, rectification of miRNA abnormality serves as a novel tumor therapeutic strategy. miR-34a is thus used as powerful antitumor agent for miRNA-based therapy against TNBC. However, miRNA-based antitumor therapy is challenged by effective targeted delivery of miRNA. In the present study, nanodiamond (ND), protamine (PS) and folic acid (FA) were used to construct ND-based layer-by-layer nanohybrids through a self-assembly approach for targeted miR-34a delivery in TNBC cells and xenograft TNBC tumors. We found that the targeted delivery of miR-34a remarkably suppressed cell proliferation, migration and induced the apoptosis of TNBC cells in vitro and inhibited tumor growth in vivo via down-regulating Fra-1 expression. The data suggest a great potential of ND-based nanohybrids for targeted intratumoral delivery of miR-34a for TNBC therapy.

The construction of nanodiamond-based layer-by-layer nanohybrids.     

Radioprotector WR-2721 and mitigating peptidoglycan synergistically promote mouse survival through the amelioration of intestinal and bone marrow damage

The identification of an agent effective for the treatment of intestinal and bone marrow injury following radiation exposure remains a major issue in radiological medicine. In this study, we evaluated the therapeutic impact of single agent or combination treatments with 2-(3-aminopropylamino) ethylsulphanyl phosphonic acid (WR-2721) and peptidoglycan (PGN, a toll-like receptor 2 (TLR-2) agonist) on radiation-induced injury of the intestine and bone marrow in lethally irradiated male C57BL/6 mice. A dose of 3 mg of WR-2721 per mouse (167 mg/kg, intraperitoneally) was given 30 min before irradiation, and 30 μg of PGN per mouse (1.7 mg/kg) was injected intraperitoneally 24 h after 10 Gy irradiation. Bone marrow cluster of differentiation (CD)45⁺ and CD34⁺ markers of multiple haematopoietic lineages, number of granulocyte–erythroid–macrophage–megakaryocyte (GEMM) progenitor colonies, bone marrow histopathology, leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) expression in the intestines, xylose absorption and intestinal histopathology were all assessed at various time-points after irradiation. Furthermore, nuclear factor kappa B (NF-κB) p65 protein in the ileum was stained by immunofluorescent labelling. PGN-treated irradiated mice showed an increase in CD45⁺CD34⁺ cells compared with untreated mice 1.25 days after 10 Gy ionizing radiation (IR) (P < 0.05). Furthermore, combined PGN and WR-2721 treatment had an obviously synergistic radio-protective effect in nucleated cells in the bone marrow, including GEMM progenitors and CD45⁺CD34⁺ cells 4 days after 10 Gy IR. Single agent PGN or WR-2721 treatment after 10 Gy IR clearly increased Lgr5-positive pit cells (P < 0.05) and xylose absorption (P < 0.05). However only PGN and WR-2721 combination treatment markedly increased villus height (P < 0.05), number of crypts (P < 0.05) and whole-body weights after 10 Gy whole-body irradiation (WBI). The NF-κB p65 subunit was translocated to the nucleus, and phosphate-IκBα (Ser32/Ser36) was detected after stimulation with either PGN or WR-2721, which indicates that these two agents act synergistically through the activation of the NF-κB pathway. Administration of PGN in combination with WR-2721 was demonstrated to have a synergistic effect on the increase in haematopoietic cells and intestinal reconstitution, as well as improved survival in lethally irradiated mice, but resulted in some degree of an immune disorder.     

LEAP: Biomarker Inference Through Learning and Evaluating Association Patterns

Single nucleotide polymorphism (SNP) high‐dimensional datasets are available from Genome Wide Association Studies (GWAS). Such data provide researchers opportunities to investigate the complex genetic basis of diseases. Much of genetic risk might be due to undiscovered epistatic interactions, which are interactions in which combination of several genes affect disease. Research aimed at discovering interacting SNPs from GWAS datasets proceeded in two directions. First, tools were developed to evaluate candidate interactions. Second, algorithms were developed to search over the space of candidate interactions. Another problem when learning interacting SNPs, which has not received much attention, is evaluating how likely it is that the learned SNPs are associated with the disease. A complete system should provide this information as well. We develop such a system. Our system, called LEAP, includes a new heuristic search algorithm for learning interacting SNPs, and a Bayesian network based algorithm for computing the probability of their association. We evaluated the performance of LEAP using 100 1,000‐SNP simulated datasets, each of which contains 15 SNPs involved in interactions. When learning interacting SNPs from these datasets, LEAP outperformed seven others methods. Furthermore, only SNPs involved in interactions were found to be probable. We also used LEAP to analyze real Alzheimer's disease and breast cancer GWAS datasets. We obtained interesting and new results from the Alzheimer's dataset, but limited results from the breast cancer dataset. We conclude that our results support that LEAP is a useful tool for extracting candidate interacting SNPs from high‐dimensional datasets and determining their probability.     

农村育龄妇女避孕知识及避孕意愿调查研究

目的了解农村育龄妇女对避孕知识知晓率和避孕意愿情况。方法 2013年4月—2014年4月期间在本市郊区5个自然村的6 700多育龄妇女中,采用随机整群抽样方法,选取1 200人进行问卷调查。结果不同学历人群避孕知识知晓率相比,差异有统计学意义(P<0.05)。希望进一步提供避孕知识的有785人(65.42%),优生优育知识220人(18.33%),节育相关知识151人(12.58%),两性相关知识43人(3.58%)。结论农村育龄妇女紧急避孕药知识知晓率和避孕需求人数的比率相对较低。加强对农村育龄妇女避孕知识的宣传教育、普及避孕常识和紧急避孕措施等知识对有效减少非意愿妊娠和保护妇女身心健康至关重要。     

黄芪多糖联合二甲双胍对糖尿病大鼠心肌损伤的实验研究

目的观察黄芪多糖(APS)联合二甲双胍对糖尿病大鼠心肌损伤的影响,并探讨其可能机制。方法选取健康SD大鼠50只,随机分为正常对照组(10只)和高脂组(40只),高脂组给予高糖高脂饮食喂养4周后腹腔注射链脲佐菌素(STZ)30mg/kg,建立2型糖尿病模型。选取造模成功大鼠32只随机分为糖尿病心肌病组(DM组)、黄芪多糖治疗组(黄芪多糖400mg/kg)、二甲双胍治疗组(二甲双胍600mg/kg)及联合用药组(黄芪多糖200mg/kg+二甲双胍300mg/kg),每组8只;继续用药治疗8周后观察大鼠一般情况,检测空腹血糖、动物体重,放射免疫分析法检测血清胰岛素水平;酶联免疫吸附试验检测血清IL-6、Ang-Ⅱ水平。结果与对照组比较,DM组大鼠血糖明显升高,体重下降,血清胰岛素水平明显下降,IL-6、Ang-Ⅱ水平显著升高;联合用药组大鼠空腹血糖、IL-6、Ang-Ⅱ低于黄芪多糖干预组和二甲双胍干预组;联合用药组的体重、胰岛素高于黄芪多糖干预组和二甲双胍干预组(P≤0.05)。结论黄芪多糖与二甲双胍联合应用可降低血糖、抑制IL-6、Ang-Ⅱ表达,促进胰岛素分泌,对糖尿病心肌有协同增强抗损伤的作用。     

乙型肝炎病毒 B、C 基因型与临床表现

目的：研究广东地区乙型肝炎病毒基因型分布情况,B、C 基因型与乙型肝炎患者临床表现之间的关系。方法：回顾性分析172例慢性乙型肝炎病毒患者[慢性乙型病毒性肝炎（CHB）、乙型肝炎后肝硬化（LC）、原发性肝癌（HCC）]的乙型肝炎病毒基因分型结果,并根据基因分型结果进行分组,比较 B、C基因型患者的临床表现、HBeAg 定性、HBV-DNA 定量、ALT 及 AST 结果。结果：172例患者的乙肝病毒型分别为 B 型94例（54.7％）、C 型69例（40.1％）、D 型3例（1.7％）、未分型6例（3.5％）;C 型在 LC 组、HCC组中的比例与 CHB 组比较,差异有统计学意义（P﹤0.05）;C 型的 HBeAg 阳性率高于 B 型（P﹤0.05）;B、C型两组的 ALT、AST 差异有显著统计学意义（P﹤0.01）;两组基因型间 HBV-DNA 水平的差异无统计学意义（P﹥0.05）。结论：广东地区 HBV 感染以 B、C 基因型为主,以 B 型居高;C 基因型肝功能损害更严重,发展为肝硬化、肝癌的可能性更大,感染不同 HBV 基因型与 HBV-DNA 水平无明显相关。     

经典瞬时受体电位通道1在大鼠牙胚发育过程中的表达

目的研究经典瞬时受体电位通道1(TRPC1)在大鼠牙胚发育过程中的表达并探讨其意义。方法 制备大鼠牙胚发育各阶段(蕾状期E14.5、帽状期E16.5、钟状期E18.5、钟状晚期P1及牙根形成期P7)标本,进行TRPC1的免疫组化研究。结果 TRPC1在牙胚发育过程中呈动态时空表达。在蕾状期增厚的牙板上皮,帽状期和钟状早期的内釉上皮和外釉上皮,钟状晚期的成釉细胞和前成牙本质细胞及牙根形成期的成牙本质细胞和成釉细胞均可见阳性信号表达,且呈增强趋势。结论 TRPC1可能是一种新的参与调控牙胚细胞的增殖分化和牙齿发育矿化的跨膜信号转导分子。     

益气活血养阴法治疗慢性萎缩性胃炎的系统评价

目的:系统评价中医益气活血养阴法治疗慢性萎缩性胃炎的疗效。方法:通过数据库检索中英文随机对照试验(RCT)文献,将Jadad积分≥1分的文章纳入研究,并提取纳入研究的特征信息。采用Revman 5.2软件进行Meta-分析,检验异质性,并根据异质性结果选择相应的效应模型,最后绘制漏斗图及Egger回归方程评定有无发表偏倚。结果:最终有9项RCT,共846例患者入选,文献质量普遍较低。益气活血养阴法治疗慢性萎缩性胃炎的总体疗效优于单纯的西医治疗,其汇总OR=4.57,95%CI(3.09~6.77),差异均具有统计学意义(P0.00001)。结论:益气活血养阴法治疗慢性萎缩性胃炎,在总有效率方面可能优于单纯西医治疗组,但尚需更多高质量研究以增加证据的强度。     

多西环素多克隆抗体的制备及鉴定

目的:采用人工偶联方法构建多西环素完全抗原,制备多克隆抗体。方法:分别采用直接偶联法、甲醛一步法、重氮法+混合酸酐法和重氮法+碳二亚胺法等4种方法将多西环素与牛血清白蛋白(bull serum albumin,BSA)或鸡卵清蛋白(ovalbumin,OVA)分别偶联,构建人工完全抗原。选择最好偶联效果制备的抗原免疫BALB/c小鼠,通过直接ELISA法检测多克隆抗体效价,竞争抑制ELISA法分析其灵敏性及特异性。结果:重氮法+碳二亚胺法偶联的多西环素人工完全抗原效果最好,其与BSA的偶联比为8.37∶1,与OVA的偶联比为4.92∶1。采用该方法偶联的抗原免疫小鼠获得的多克隆抗体效价在1∶8 000以上;该抗体对多西环素的半数抑制浓度(IC50)为98.89~120.32μg/L,与其他四环素类药物的交叉反应性较低。结论:重氮法+碳二亚胺法的偶联效率最高,获得的多西环素多克隆抗体效价较高,特异性和灵敏度均较理想。