Prevalence and Factors Associated with Positivity of Antinuclear Antibodies (ANA) Patterns, Native Anti-DNA and Extractable Nuclear Antigens (ENA) Antibodies: Experience from a Laboratory in Dakar

Background: Diagnosis of autoimmune diseases (AID) is challenging, due to overlapping features with other non-immune disorders. Anti-nuclear antibodies (ANA) are sensitive screening tests but anti-deoxyribonucleic acid-antibody (anti-DNA), and anti-extractable nuclear antigens (anti-ENA) are specific for AIDs. We aimed to look at ANA patterns in our patients and correlated them with anti-ENA for proper interpretation and better patient management cost-effectively. Methods: A retrospective study was conducted over 1 year from January to December 2022 who were tested for ANA at biology medical laboratory of Pasteur Institute of Dakar. Anti-ENA and anti-DNA results were also analyzed for ANA-positive patients. Statistical analysis was performed using STATA 14.0, p Results: 216 patients were analyzed. Women predominated at 79.2% and mean age was 48 years [CI 95%, 46 - 50], with extremes of 10 and 89. Most represented age group was [41 - 60] with 38%. ANA was positive in 27 (12.5%) of patients, 59.2% of whom were strongly positive (titer of 1/1000, 1/3200 or 1/6400). The most common pattern was nuclear speckled, which was found in 77.8% of samples. Anti-ENA and anti-DNA positivity in ANA-positive patients was found respectively in 63% (17/27) and 1.4% (3/27) of the samples analyzed. Most commonly identified anti-ENA was anti-Sm 29.6%, anti-SSA 29.6%, anti-Ro-52 25.9%, anti-RNP 18.5% and anti-SSB 14.8% which was associated with speckled pattern. Association results indicated a significant relationship between both tests and between ANA titer in the anti-ENA- and ANA-positive patients (p 0.001). Conclusions: ANA, Anti-ENA and anti-DNA antibodies are essential for AIDS diagnosis. However, the testing repertoire should follow an algorithm comprising of clinical features, followed by ANA results with nuclear, mitotic, and cytoplasmic patterns, anti-ENA, and anti-DNA for a more meaningful, and cost-effective diagnostic approach.

Roles of Aqueous Extract of Marigold on Arsenic-Induced Oxidative Damage in Pancreatic Islet β-Cells

Roles of Marigold extracts (ME) on arsenic trioxide (ATO)-induced oxidative damage to pancreatic β-cells need to be further elucidated. In this study, NIT-1 cells were treated with different concentrations of and/or ATO, following by the cell viability was detected by CCK8 assay. Then, intracellular reactive oxygen species (ROS) levels, lipid peroxide (MDA) contents and superoxide dismutase (SOD) activity were measured with a fluorescence probe method and colorimetric assay, respectively. The apoptosis rate and morphology was detected and observed with hoechst 33,258 staining assay. The mRNA levels and protein expressions of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were measured by real-time fluorescence quantitative polymerase chain reaction and protein immunoblotting assay, respectively. Our results indicated that Co-treatment with ME and ATO exacerbated the cell viability decreasing reduced by ATO, while the addition of ME after ATO treatment effectively promote the recovery of ATO reduced survival rates. The ATO group increased apoptosis (P P β-cells by modulating the activation of the Nrf2 signaling pathway.

植物细胞核基质(Nuclear Matrix)的形态结构及其NuMA蛋白成分的研究

应用细胞选择性抽提并结合DGD包埋去包埋剂电镜技术对植物细胞核基质的形态结构进行了观察。结果显示胡萝卜悬浮培养细胞、银杏花粉细胞和精子细胞的细胞核内存在一个非染色质性的纤维蛋白网络体系。免疫荧光染色结果说明植物细胞核基质中含有与动物NuMA多抗交叉反应的多肽。免疫印迹反应显示胡萝卜悬浮培养细胞核基质蛋白与NuMA蛋白多抗的阳性反应条带为74KD和76 KD;银杏花粉细胞只有78 KD一条阳性带。以动物核基质NuMA蛋白保守杆状区的cDNA片段作为探针,与白菜子叶总DNA进行Southern杂交的结果表明植物细胞基因组中含有动物NuMA蛋白cDNA的同源序列。

Separation of ^(152+154)Eu,^(90)Sr from radioactive waste effluent using liquid–liquid extraction by polyglycerol phthalate

A new polyglycerol phthalate extractant was prepared and characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance(~1H NMR) spectroscopy, and thermogravimetric analysis. A preliminary study of the extraction of long-lived(^(90) Sr and ^(152+154)Eu) and short-lived(^(90) Y) radionuclides by polyglycerol phthalate was performed. The influence of different diluents, concentration of the acid, type of acid, and various interfering ions was explored. The stripping of ^(152+154)Eu radionuclide was studied by using different acid solutions, and it was found that sulfuric acid was the ideal acid for this purpose. Furthermore,^(152+154)Eu was extracted from the fission products(^(90) Sr) and the extraction% of^(90) Sr was found to improve in the presence of interfering ions.

Anti-Aging Effect of <i>Cynara cardunculus</i>L. var. <i>Cynara scolymus</i>L. Extract in D-Galactose-Induced Skin Aging Model in Rats

The aim of the study was to evaluate the efficacy of 2% Cynara scolymus L. extracts in reverse disturbances of collagen metabolism and inflammation in D-galactose induced skin aging model in rats. D-galactose induced aging reproduced in 48 animals of main group, and 12 rats in control group. All animals in main group were randomized for 4 groups: I. aging + saline, II - IV. different manufacturers 2% artichoke extracts (with content of chlorogenic acid 2.5%) in a dose of intradermal injection 0.13 mg twice at weeks during 4 weeks. Influence of artichoke extracts restored skin relative weight and led to an increase of solubility in neutral salt and acid, and decreased pepsin solubility collagen fraction, restored the hexosamine/collagen (hydroxyproline) ratio and decreased the activity of nuclear transcription factor (NF-kB). Local prolonged treatment with artichoke extracts improved collagen metabolism and attenuated the progression of inflammation in D-galactose induced skin aging model.

Potent water extracts of Indonesian medicinal plants against PTP1B

Objective:To examine the potent of water as a solvent agent in the preparation of traditional herbal medicine.Methods:Water extracts of 18 plants were prepared through reflux and examined(25μg/mL) to evaluate their possibility for inhibiting protein tyrosine phosphatase 1B(PTP1B).The determination of IC50 values was performed for the samples possessing more than 80%inhibition.Meanwhile,those exhibiting IC50 values more than 7.0 μg/mL were further profiled for their chemical constituents through nuclear magnetic resonance(NMR) measurement.Results:About 44%(8) of the examined samples showed more than 80%inhibition against PTP1 B.The water extracts of Elephantopus scaber,Helicteres isora aerial parts,Elaeocarpus grandiflorus(E.grandiflorus) fruits,Melaleuca leucadendron leaves,and Quercus infectoria gum had IC50 values ranging from 2.05 to 6.90 μg/mL.Meanwhile,Andropogon nardus and Centella asiatica were at the area of δ 3.0-4.0 ppm.Further,the13 C NMR observation of samples possessing the most intensive signals in their proton NMR Cinnamomum burmannii and E.grandiflorus showed the peaks at the area of δ 60-90 ppm as the supportive evidence for sugar group signals.Intriguingly,a disaccharide from E.grandiflorus could be an active inhibitor towards PTB1 B.Conclusions:In contrast to the mainstream solvents currently used in modern herbal manufactures especially Jamu medicine in Indonesia,pure-water-extracted materials should be reconsidered and could be reemerged for future studies and for the manufacture of herbal medicines.In addition,the activity of Jamu components should be confirmed that their antidiabetes and antiobesity activities could be through the inhibition of PTP1 B.

灵芝提取物通过Nrf2/ARE通路对肝硬化小鼠肝功能的保护作用研究

[目的]探讨灵芝提取物(ganoderma lucidum extract,GLE)对肝硬化小鼠的肝保护作用及机制。[方法]将10只雄性C57BL/6小鼠作为对照组,剩余40只小鼠采用四氯化碳橄榄油混悬液诱导肝硬化模型,并随机分为模型组和GLE低(50 mg/kg·d)、中(100 mg/kg·d)、高(200 mg/kg·d)剂量组,对照组及模型组均灌胃等量0.9%氯化钠溶液。计算肝脏指数;以全自动生化分析仪检测小鼠血清中谷氨酸转氨酶(alanine aminotransferase,ALT)、天冬氨酸转氨酶(aspartate transaminase,AST)活性和总胆固醇(total cholesterol,TC)、总胆红素(total bilirubin,TB)和肌酐(creatinine,Cr)水平;以苏木精-伊红(hematoxylin eosin,HE)染色观察肝组织病理学变化,Masson染色观察肝组织纤维化程度;以脱氧核苷酸末端转移酶介导的dUTP缺口末端标记(terminal-deoxynucleotidyl transferase mediated dUTP nick end labeling,TUNEL)染色观察肝细胞凋亡情况;酶联免疫吸附试验(enzyme linked immunosorbent assay,ELISA)检测血清肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素-1β(interleukin-1β,IL-1β)、IL-6、丙二醛(malondialdehyde,MDA)水平和超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活性;免疫印迹法检测肝组织中总核因子E2相关因子2(nuclear factor E2 related factor 2,Nrf2)和核Nrf2、血红素加氧酶-1(heme oxygenase-1,HO-1)及醌氧化还原酶1[NAD(P)H:quinone oxidoreductase 1,NQO1]、α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、Ⅰ型胶原蛋白(CollagenⅠ)及E-钙黏蛋白(E-cadherin)的表达情况。[结果]与对照组比较,模型组小鼠肝损伤明显,肝脏指数,血清ALT、AST活性,TC、TB及Cr水平,肝纤维化程度,肝细胞凋亡指数,血清TNF-α、IL-1β、IL-6及MDA水平,α-SMA及CollagenⅠ蛋白相对表达量升高(P<0.05),血清SOD和GSH-Px活性、肝组织总Nrf2和核Nrf2、HO-1、NQO1及E-cadherin蛋白表达降低(P<0.05)。与模型组比较,GLE低、中、高剂量组小鼠肝损伤逐步减轻,肝脏指数,血清ALT、AST活性,TC、TB及Cr水平,肝纤维化程度,肝细胞凋亡指数,血清TNF-α、IL-1β、IL-6及MDA水平,α-SMA及CollagenⅠ蛋白表达降低(P<0.05),血清SOD和GSH-Px活性、肝组织总Nrf2和核Nrf2、HO-1、NQO1及E-cadherin蛋白表达升高(P<0.05)。[结论]GLE可减轻肝硬化小鼠组织病理损伤,改善肝功能,这可能与激活Nrf2/ARE通路,抑制氧化应激和炎症反应,进而干预肝纤维化有关。

基于低场核磁共振的烤烟烟叶石油醚提取物含量检测方法

针对当前传统索氏提取法在烤烟烟叶石油醚提取物含量检测上存在的检测速度慢、操作繁琐、溶剂污染等问题,采用低场核磁共振法检测烟叶中石油醚提取物含量,优化烘干时间、样品质量、回波时间、重复扫描次数等参数,验证最优参数下检测方法的重复性和精密度,并与传统索氏提取法的检测结果进行对比。结果表明:将过40目筛的3.0 g烟叶粉末置于80℃烘干4 h,在回波时间0.25 ms和重复扫描次数8次的条件下进行石油醚提取物含量检测,检测结果良好,标准曲线R2达到0.99981,重复性的相对标准差为1.45%~2.99%,日内、日间精密度分别为2.61%、1.10%。低场核磁共振法与索氏提取法的石油醚提取物含量检测结果间的相关系数达0.99855,绝对误差为0.02%~0.35%,相对误差为0.26%~3.69%。相较于传统索氏提取法,低场核磁共振方法简单、快速、准确,且无溶剂污染,适用于大批量烟叶石油醚提取物的准确定量。

壳聚糖复合材料用于铀吸附的应用和研究进展

对近几年国内外关于壳聚糖基复合材料用于从海水或者低浓度含铀中提取铀的研究工作进行了总结,包括复合膜、气凝胶以及其他形态的壳聚糖改性复合材料等;展望了壳聚糖应用于铀吸附的研究前景,以期为从溶液中吸附铀的研究发展提供理论和数据支撑。

Nuclear magnetic resonance spectroscopy is highly sensitive for lipid-soluble metabolites

Although the water-soluble metabolite profile of human mesenchymal stem cells is known, the lipid profile still needs further investigation. In this study, methanol-chloroform was used to extract lipid-soluble metabolites and perchloric acid was used to extract water-soluble metabolites. Fur- thermore, a dual phase extraction method using methanol-chloroform and water was used to obtain both water and lipid fractions simultaneously. All metabolite extractions were analyzed on a 9.4T high-resolution nuclear magnetic resonance spectrometer. Metabolite resonance peaks were as- signed in the acquired spectra according to the chemical shift, and the extraction efficiency of dif- ferent methods was compared. Results showed that in the spectra of water-soluble extracts, major metabolites comprised low molecular weight metabolites, including lactate, acetic acid, fatty acids, threonine, glutamic acid, creatine, choline and its derivatives, while in the spectra of lipid-soluble extracts, most metabolites were assigned to fatty acids. Among the different extraction procedures, perchloric acid was more efficient in extracting water-soluble metabolites and methanol-chloroform was efficient in extracting organic components compared with the dual phase extraction method. Nuclear magnetic resonance spectroscopy showed that as low as 0.7 mg organic yield was enough to obtain clear resonance peaks, while about 6.0 mg water-soluble yield was needed to obtain rela- tively favorable spectral lines. These results show that the efficiency of extracting water and lipid fractions is higher using perchloric acid and methanol-chloroform compared with dual phase ex- traction and that nuclear magnetic resonance spectroscopy is highly sensitive for analyzing lipid-soluble extracts.

Profile of Autoantibodies and Clinical Symptoms in Guinean Patients with Connective Tissue Diseases

Connective tissue diseases (CTDs) are Autoimmune diseases (AIDs) characterized by the appearance of autoantibodies, which are diagnostic markers. Investigations of these autoantibodies play a major role in the management of several autoimmune diseases. The objective of this study was to describe the profile of anti-ENA antibodies according to the clinical symptoms of mixed CTDs in Conakry teaching Hospital. We performed a cross-sectional study during six months. A total of 20 patients was recruited and we measured antibodies using the ELISA technique. The mean age of our patients was 36.5 years, with a predominance of females. Cutaneous and rheumatological signs were the main clinical manifestations. SLP was the most frequent CTDs;the threshold of ENA antibodies positivity was higher in scleroderma with and SLP. Anti-ENA identification reveals the frequency of anti-SSA (83.33%), anti-U1RNP (66.66%) and anti-histone (50%) antibodies. Antinuclear antibodies (ANA) react with various components of the cell nucleus. Their detection is of major interest in the diagnosis of CTDs. Our results highlight the importance of determining the specificity of these antibodies to guide differential diagnosis.

基于遗传算法的核电站汽轮机抽汽流量优化计算

为提高核电站汽轮机系统的效率和运行性能,确保经济、稳定和可靠的电力供应,开展基于遗传算法的核电站汽轮机抽汽流量优化计算研究。利用神经网络预测核电站汽轮机抽汽流量,以核电站汽轮机抽汽流量为优化目标,各抽汽口抽汽流量和一、二级再热蒸汽流量为优化变量,采用遗传算法进行核电站汽轮机抽汽流量优化计算目标函数求解,所得最优解即为抽汽流量优化计算结果。实验结果表明,该方法的核电站汽轮机抽汽流量优化计算结果与实际值更接近,说明该方法的计算精准度高,应用效果好。

某核电厂大规模抽汽供热工况下汽轮机再热调节阀节流运行振动响应特性分析

为评估汽轮机再热调节阀在节流工况下能否长期运行,进行了试验验证,试验时,在热网循环水流量、汽轮机高排压力维持在合理范围内的基础上,通过关小再热调节阀开度,逐步增大抽汽流量至不同平台,在每个平台上至少稳定10min,收集振动数据进行分析。研究结果表明,管道、阀门振动加速度值整体随着阀门开度的减小而增大,节流工况下阀门振动相比全开非节流工况明显增加。因此,无法得出汽轮机再热调节阀在试验工况下可长期节流运行的结论。

基于代谢组学分析野菠萝对急性肝损伤大鼠肝保护作用研究

目的:应用代谢组学方法探寻经对乙酰氨基酚诱导大鼠急性肝损伤的代谢标志物,并评价野菠萝提取物对肝损伤的保护机制。方法:30只大鼠被随机分为空白对照组(蒸馏水)、模型组(蒸馏水)、野菠萝提取物高剂量组(500 mg/kg)、野菠萝提取物低剂量组(200 mg/kg)以及阳性药物组(水飞蓟宾,30 mg/kg)5个组别,每组6只。连续给药7d,每次给药1h后,除空白对照组外,其余组通过灌胃给予对乙酰氨基酚2000mg/kg。给药24 h后,通过腹主动脉采血,测定肝功能指标(ALT、AST)水平并进行病理组织学观察。使用1H-NMR技术对血清样本进行分析,以鉴定潜在的生物标志物并分析相关的代谢通路。结果:野菠萝提取物能显著降低急性肝损伤大鼠的血清ALT和AST水平,并显著减轻肝脏的病理损伤,显示出对肝脏的保护作用,尤其是在低剂量下,其肝保护的效果比高剂量更为突出。野菠萝提取物能调节肝损伤引起的代谢紊乱,提高丙酮和谷氨酰胺水平。代谢组学分析揭示了10个潜在生物标志物和6种代谢通路。结论:野菠萝提取物通过对大鼠肝脏的酮体、糖类和氨基酸代谢,以及丁酸代谢的调节作用,提供对乙酰氨基酚引起的急性肝损伤的保护,从而有效地改善肝功能并缓解肝损伤。

Phaco drill与小切口非超声乳化白内障摘除术治疗硬核白内障患者的效果

目的:探讨Phaco drill与小切口非超声乳化白内障摘除术治疗硬核白内障患者的效果。方法:回顾性选取2020年10月—2022年4月麻城市中医医院收治的60例硬核白内障患者。根据不同手术治疗方法将其分为Phaco组(n=25)和小切口组(n=35)。小切口组给予小切口非超声乳化白内障摘除术,Phaco组给予Phaco drill。比较两组术前、术后1个月眼睛恢复情况,术前,术后3 d、术后1个月及术后3个月角膜散光度,并发症。结果:术后1个月,Phaco组最佳矫正视力(best corrected visual acuity,BCVA)、眼压(intraocular pressure,IOP)、角膜内皮细胞(corneal endothelial cell,CEC)密度均高于小切口组,差异有统计学意义(P<0.05),两组中央角膜厚度(central corneal thickness,CCT)比较,差异无统计学意义(P>0.05)。重复测量方差分析显示,角膜散光度组间、时间、交互比较,差异有统计学意义(P<0.001)。术后3 d、术后1个月,Phaco组角膜散光度均低于小切口组,差异有统计学意义(P<0.05)。Phaco组术后并发症发生率低于小切口组,差异有统计学意义(P<0.05)。结论:Phaco drill治疗硬核白内障可促进患者恢复,近期对角膜散光度的影响较小,对角膜内皮损伤较小,且术后并发症发生率低。

基于HDAC6/NF-κB信号通路探讨莪术提取物治疗慢性萎缩性胃炎的作用机制

目的:探讨莪术提取物治疗慢性萎缩性胃炎(CAG)的作用机制。方法:选取成年雄性C57BL6/J小鼠,通过1-甲基-3-硝基-1-亚硝基胍构建CAG小鼠模型,采用莪术提取物对模型小鼠灌胃处理。采用定量反转录聚合酶链反应(qRT-PCR)、蛋白质印迹法检测组蛋白去乙酰化酶6(HDAC6)表达;采用苏木精-伊红染色观察胃组织病理学变化;采用酶联免疫吸附试验检测胃泌素17(G-17)、白细胞介素8(IL-8)和肿瘤坏死因子α(TNF-α)的含量;采用蛋白质印迹法检测核因子κB(NF-κB)信号通路关键蛋白p65的磷酸化及乙酰化,NF-κB抑制因子α(IκBα)的磷酸化;采用免疫共沉淀检测HDAC6与p65的结合。结果:CAG小鼠胃组织中HDAC6呈低表达,HDAC6可与p65特异性结合。CAG小鼠胃组织细胞形态及排列紊乱,G-17、IL-8和TNF-α含量升高,p65蛋白磷酸化、乙酰化增加,IκBα磷酸化减少;而莪术提取物处理后,HDAC6的表达显著上调,小鼠胃组织细胞形态恢复、结构排列完整,G-17、IL-8和TNF-α含量降低,p65蛋白磷酸化、乙酰化减少,IκBα磷酸化增加。结论:莪术提取物可能通过上调HDAC6促进p65的去乙酰化,从而抑制NF-κB信号通路激活,最终改善CAG。

绣球藤提取物的抗炎活性及机制

目的探讨绣球藤提取物的抗炎活性及潜在机制。方法使用二甲苯致耳廓肿胀建立急性炎症小鼠模型,以阿司匹林(0.25 g/kg)为阳性对照,1.25、2.5、5 g/kg绣球藤提取物对小鼠耳肿胀度的影响。以植入棉球的方法建立慢性炎症大鼠模型,以阿司匹林(0.17 g/kg)为阳性对照,0.88、1.75、3.5 g/kg绣球藤提取物对大鼠肉芽净重的影响。以脂多糖诱导RAW264.7细胞建立炎症损伤细胞模型,考察12.5、25、50μg/mL绣球藤提取物对细胞上清液中一氧化氮(NO)、前列腺素E2(PGE2)、肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、单核细胞趋化蛋白1(MCP-1)含量,细胞中诱导型一氧化氮合酶(iNOS)、环氧合酶2(COX-2)、p65、磷酸化p65(p-p65)蛋白表达水平,以及p65蛋白核转移的影响。结果5 g/kg的绣球藤提取物可显著降低小鼠的耳肿胀度,1.75、3.5 g/kg的绣球藤提取物可显著降低大鼠的肉芽净重(P<0.05)。12.5、25、50μg/mL绣球藤提取物可显著降低细胞上清液中NO(12.5μg/mL绣球藤提取物除外)、PGE2、TNF-α、IL-6、MCP-1含量,以及细胞中iNOS、COX-2蛋白的相对表达量和p-p65、p65蛋白的相对表达量比值(P<0.05或P<0.01);25、50μg/mL绣球藤提取物可阻断p65蛋白的核转移。结论绣球藤提取物具有良好的抗炎活性,其作用机制可能与抑制核因子κB信号通路激活、下调COX-2和i NOS蛋白的表达、减少炎症因子的释放有关。

荷叶提取物在抑制口腔细菌和改善牙龈炎症的有效性分析

分析了荷叶提取物(LLE)在抑制口腔细菌和改善牙龈炎症的有效性。使用不同质量浓度的LLE处理10种常见口腔细菌24 h,分别检测最小抑菌浓度(MIC)和抑菌圈直径。使用CCK-8法检测LLE对人牙龈上皮细胞活力的影响。将人牙龈上皮细胞分为对照组(Control)、脂多糖(LPS)组和LPS+1~500μg/mL LLE组,分别用1μg/mL LPS和不同质量浓度的LLE处理人牙龈上皮细胞24 h。RT-qPCR检测白介素(IL)-1β、IL-6、IL-8、肿瘤坏死因子-α(TNF-α)、细胞间黏附分子-1(ICAM-1)mRNA水平。Western blotting检测核因子-κB(NF-κB)p65和p38丝裂原活化蛋白激酶(MAPK)的磷酸化水平。结果显示,LLE对10种常见口腔细菌的MIC在300~500μg/mL之间。与Control组相比,LPS组人牙龈上皮细胞中IL-1β、IL-6、IL-8、TNF-α和ICAM-1 mRNA相对水平均升高,NF-κB p65和p38 MAPK磷酸化水平均升高(P<0.05)。与LPS组相比,LPS+50~500μg/mL LLE组人牙龈上皮细胞中IL-1β、IL-6、IL-8、TNF-α和ICAM-1 mRNA相对水平均呈LLE剂量依赖性降低,NF-κB p65和p38 MAPK磷酸化水平均呈LLE剂量依赖性降低(P<0.05)。本研究表明,LLE对10种常见口腔细菌和LPS诱导的人牙龈上皮细胞过度炎症具有抑制活性,其可能是口腔护理产品的有效添加成分。

基于MSSA-XGBoost小样本核爆地震事件分类

核爆地震与天然地震事件的分类鉴别是全面禁止核试验条约中的一项重要任务。受限于核爆数据数量缺乏,论文研究了XGBoost模型在小样本场景下两类事件的分类问题,并利用SSA算法对模型关键超参数进行自主寻优。同时针对SSA算法的不足,采用高斯混沌映射方法、提出种群比例动态调整策略和引入步长调整因子进行改进,构建了MSSA-XGBoost分类模型。模型解决了初始种群分布不均匀,导致种群多样性减少,影响算法收敛速度的问题;解决了麻雀种群比例固定,容易陷入局部最优解的问题;以及解决了发现者位置更新步长固定,从而限制算法全局搜索能力与寻优效率的问题,实现了避免人工特征提取和XGBoost迭代次数、最大树深以及学习率三个重要超参数的自主寻优,在小样本地震事件分类中取得了优异的效果。实验结果表明,MSSA-XGBoost模型分类准确率达到了96.37%,优于原模型93.47%,也优于支持向量机与卷积神经网络,同时较原始模型计算效率提升了近30%。

浅析核磁共振在油菜籽含油量测定中的应用

本文比较了索氏抽提法与核磁共振法测定油菜籽含油量的准确度和精密度。结果表明,核磁共振法在油菜籽含油量测定中具有较好的准确度和精密度,与索氏抽提法差别较小,可以作为油菜籽含油量的快速测定法。