450 nm半导体蓝激光对子宫内膜组织汽化切割效应的离体动物实验研究

目的使用450 nm半导体蓝激光手术系统在不同条件下对离体新鲜猪子宫内膜组织进行汽化切割及内镜下模拟手术实验,初步评估蓝激光在妇科手术应用中的安全性、有效性和可行性。方法取产后和未孕新鲜猪离体子宫各8个,使用450 nm纤芯光纤,步进机移动速度为1.0 mm/s、2.0 mm/s,光纤头距离组织0.5~1.0 mm,调试蓝激光功率为5~30 W等条件下对猪子宫内膜组织进行汽化切割,对汽化切割后的标本行拍照记录后,置入4%多聚甲醛内固定48小时,使用游标卡尺测量凝固范围、汽化宽度、汽化深度,将标本行HE染色。使用产后子宫8个,对比等离子电切设备,在体外内镜辅助下进行模拟手术操作,将术后的标本行HE染色。结果激光在不同的功率(5~25 W)下作用于子宫内膜组织,随着激光功率的增大,组织的汽化深度、汽化宽度也逐渐增大;使用双极等离子电切设备与蓝激光在内镜下行汽化切割实验的比较,结果发现蓝激光汽化切割创面更平整,无明显碳化层,热损伤范围局限可控,凝固层、汽化深度及宽度稳定。相较于等离子电切设备,蓝激光产生的热损伤范围相对较小。结论初步研究表明,蓝激光进行猪子宫内膜相关手术是安全、有效且可行的,并且有望成为可选择的一种新型的妇科激光手术设备。

上消化道出血风险预测模型的研究进展

上消化道出血作为临床常见的消化道疾病之一,发病率高,危害性强.本研究对上消化道出血的再出血、内镜干预和死亡风险预测模型进行综述,包括研究人群、研究方法、相关风险因素及模型性能等,以期为临床医护人员尽早开展风险评估,制订有效预防管理方案,改善患者生存结局提供参考.

Novel model combining contrast-enhanced ultrasound with serology predicts hepatocellular carcinoma recurrence after hepatectomy

BACKGROUND Surgery is the primary curative option in patients with hepatocellular carcinoma(HCC).However,recurrence within 2 years is observed in 30%–50%of patients,being a major cause of mortality.AIM To construct and verify a non-invasive prediction model combining contrastenhanced ultrasound(CEUS)with serology biomarkers to predict the early recurrence of HCC.METHODS Records of 744 consecutive patients undergoing first-line curative surgery for HCC in one institution from 2016–2018 were reviewed,and 292 local patients were selected for analysis.General characteristics including gender and age,CEUS liver imaging reporting and data system(LIRADS)parameters including wash-in time,wash-in type,wash-out time,and wash-out type,and serology biomarkers including alanine aminotransferase,aspartate aminotransferase,platelets,and alpha-fetoprotein(AFP)were collected.Univariate analysis and multivariate Cox proportional hazards regression model were used to evaluate the independent prognostic factors for tumor recurrence.Then a nomogram called CEUS model was constructed.The CEUS model was then used to predict recurrence at 6 mo,12 mo,and 24 mo,the cut-off value was calculate by X-tile,and each C-index was calculated.Then Kaplan-Meier curve was compared by logrank test.The calibration curves of each time were depicted.RESULTS A nomogram predicting early recurrence(ER),named CEUS model,was formulated based on the results of the multivariate Cox regression analysis.This nomogram incorporated tumor diameter,preoperative AFP level,and LIRADS,and the hazard ratio was 1.123(95%confidence interval[CI]:1.041-1.211),1.547(95%CI:1.245-1.922),and 1.428(95%CI:1.059-1.925),respectively.The cut-off value at 6 mo,12 mo,and 24 mo was 100,80,and 50,and the C-index was 0.748(95%CI:0.683-0.813),0.762(95%CI:0.704-0.820),and 0.762(95%CI:0.706-0.819),respectively.The model showed satisfactory results,and the calibration at 6 mo was desirable;however,the calibration at 12 and 24 mo should be improved.CONCLUSION The CEUS model enables the well-calibrated individualized prediction of ER before surgery and may represent a novel tool for biomarker research and individual counseling.

Mesenchymal stem cell-derived exosomes: The dawn of diabetic wound healing

Chronic wound healing has long been an unmet medical need in the field of wound repair,with diabetes being one of the major etiologies.Diabetic chronic wounds(DCWs),especially diabetic foot ulcers,are one of the most threatening chronic complications of diabetes.Although the treatment strategies,drugs,and dressings for DCWs have made great progress,they remain ineffective in some patients with refractory wounds.Stem cell-based therapies have achieved specific efficacy in various fields,with mesenchymal stem cells(MSCs)being the most widely used.Although MSCs have achieved good feedback in preclinical studies and clinical trials in the treatment of cutaneous wounds or other situations,the potential safety concerns associated with allogeneic/autologous stem cells and unknown long-term health effects need further attention and supervision.Recent studies have reported that stem cells mainly exert their trauma repair effects through paracrine secretion,and exosomes play an important role in intercellular communication as their main bioactive component.MSC-derived exosomes(MSC-Exos)inherit the powerful inflammation and immune modulation,angiogenesis,cell proliferation and migration promotion,oxidative stress alleviation,collagen remodeling imbalances regulation of their parental cells,and can avoid the potential risks of direct stem cell transplantation to a large extent,thus demonstrating promising performance as novel"cell-free"therapies in chronic wounds.This review aimed to elucidate the potential mechanism and update the progress of MSC-Exos in DCW healing,thereby providing new therapeutic directions for DCWs that are difficult to be cured using conventional therapy.

Engine performance analysis and optimization of a dual-mode scramjet with varied inlet conditions

A dual-mode scramjet can operate in a wide range of flight conditions. Higher thrust can be generated by adopting suitable combustion modes. Based on the net thrust, an analysis and preliminary optimal design of a kerosene-fueled parameterized dual-mode scramjet at a cru- cial flight Mach number of 6 were investigated by using a modified quasi-one-dimensional method and simulated annealing strategy. Engine structure and heat release distrib- utions, affecting the engine thrust, were chosen as analytical parameters for varied inlet conditions （isolator entrance Mach number： 1.5-3.5）. Results show that different opti- mal heat release distributions and structural conditions can be obtained at five different inlet conditions. The highest net thrust of the parameterized dual-mode engine can be achieved by a subsonic combustion mode at an isolator entrance Mach number of 2.5. Additionally, the effects of heat release and scramjet structure on net thrust have been discussed. The present results and the developed analytical method can provide guidance for the design and optimization of high-performance dual-mode scramjets.

Accessibility in key areas of the Arctic in the 21st mid-century

The navigation potential of the Arctic has improved with the rapid retreat of sea ice under continuous warming.The comprehensive evaluation of Arctic accessibility for low ice-breaking ships(civil use)in the mid-century is important to support coordinated international decision-making.In this study,the hydrological conditions and navigation potential in key areas and crucial straits along the Northern Sea Route(NSR)and Northwest Passage(NWP)were assessed under Shared Socioeconomic Pathways(SSPs)using the Polar Operational Limit Assessment Risk Indexing System.The results showed that the most critical areas for navigation in the mid-century(2046-2055)are the waters around the New Siberian Islands and within the Parry Channel.Arctic navigability improves from SSP1-2.6 to SSP2-4.5 to SSP5-8.5,and the accessibility for PC7 ships under SSP2-4.5 is even better for OW ships under SSP5-8.5.The route on the north side of the New Siberian Islands is a relatively good choice within the NSR,and the southern route has a better navigation potential than the Parry Channel within the NWP.In addition,the accessibility of the Dmitri Laptev Strait is better than that of the Sannikov Strait at a monthly scale,although the latter has more navigable days.However,there is little difference in accessibility between the eastern and western parts of the Parry Channel.The best nav-igation potential through the above straits is in September for ordinary ships,and the optimal time window is delayed and extended for PC7 ships.The results can serve as references for policy-making and navigation planning in the Arctic.

免疫球蛋白Y的微胶囊化:响应面法优化及其模拟胃肠道控释

目的:制备、优化、表征和体外评价包埋免疫球蛋白Y(Ig Y)的壳寡糖-海藻酸盐微胶囊,以实现Ig Y的胃肠道控释,提高Ig Y胃肠道消化过程中的活性保持率。创新点:以壳寡糖为涂层,采用两步法制备包埋Ig Y的微胶囊;采用响应面法全面优化了微胶囊的配方工艺;对Ig Y的体外控释进行了系统的评价。方法:通过两步离子凝胶法制备包埋Ig Y的微胶囊,采用响应面法优化微胶囊配方工艺,通过包埋率、负载率、平均粒径、微观形貌、色度和球形度等指标表征微胶囊,采用模拟胃肠道消化体系体外评价Ig Y的释放动力学和免疫活性保持率。结论:采用响应面法优化的微胶囊配方工艺为海藻酸钠浓度1.56%(15.6 g/L)、壳寡糖浓度0.61%(6.1 g/L)和Ig Y/海藻酸钠比率62.44%(质量比),由此制备的微胶囊包埋率达65.19%,负载率达33.75%,平均粒径为588.75μm。壳寡糖涂层通过填充效应和静电相互作用使微胶囊表面更加光滑和连续,从而显著降低了模拟胃肠道消化过程中Ig Y的释放速率。微胶囊中Ig Y的模拟胃部控释和模拟肠道控释分别符合零级动力学方程和一级动力学方程(R2>0.99)。微胶囊在模拟胃肠道消化4h后的Ig Y免疫活性保持率达84.37%,远高于未进行微胶囊化保护的Ig Y(5.33%)。

Fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age

We investigated the fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age. One- and two-year-old fish were cultured in floating net cages and sampled randomly for analysis. Moisture, protein, lipid and ash contents were determined by methods of Association of Analytical Chemist (AOAC) International. Fatty acid profile was deter- mined by gas chromatography. Crude protein, fat, moisture and ash contents showed no significant differences between the two age groups. The contents of total polyunsaturated fatty acids and docosahexaenoic acid (DHA) were significantly higher and eicosapentaenoic acid (EPA) content was significantly lower in the two-year-old large yellow croaker than in the one-year-old (P<0.05). No significant differences were observed in the contents of total saturated fatty acids and monounsaturated fatty acids, or the ratio of n-3/n-6 fatty acids among the large yellow croakers of the two age groups. We conclude that large yellow croakers are good food sources of EPA and DHA.

Insight into the covalent grafting of organic films onto carbon steel surfaces for protection

The novel use of p-nitrophenyldiazonium tetrafluoroborate salt(GG salt)as a protectant that is electrochemically grafted onto carbon steel has been investigated in0.05 mol L-1H2SO4and 5 wt%NaCl solutions using various corrosion monitoring techniques,such as electrochemical impedance spectroscopy,potentiodynamic polarisation,infrared spectra and scanning electron microscopy measurements.The electrochemical study reveals that this compound is a mixed inhibitor that predominantly controls the cathodic reaction.The surface-grafted film decreases the double-layer capacitance and obviously increases the charge transfer resistance relative to a bare carbon electrode.The values of inhibition effect remain nearly unchanged with an increase in temperature range of 298–318 K.The aryl diazonium is covalently bonded on the steel surface,causing a slight decrease in the apparent activation energy.Overall,the surface-grafted films exhibit excellent inhibition performance in acid and saline solutions within the studied temperature range.

Simultaneous Determination of Eleven Bioactive Constituents in Honey-Processed Licorice by High-Performance Liquid Chromatography-Diode Array Detector and Its Application from the Perspective of Processing Influence under Orthogonal Design

Objective:The aim of this study was to develop a reliable approach to simultaneously quantify 11 markers and explore the quality variation in honey-processed licorice.Materials and Methods:A high-performance liquid chromatography-diode array detector method was developed for the simultaneous determination of 11 markers(nine flavonoids and two triterpenoid saponins)in honey-processed licorice.The changes to the 11 markers in honey-processed licorice were investigated using an orthogonal design with three input factors.Results:The established method was precise,accurate,and sensitive enough for the simultaneous quantitative evaluation of 11 markers in honey-processed licorice.Intuitive analysis and variance analysis revealed that(1)the soaking time of crude licorice,stir-frying temperature,and stir-frying time remarkably influenced the content of liquiritin apioside,signifying the decomposition of liquiritin apioside to liquiritin or transformation of liquiritin apioside to isoliquiritin apioside,(2)stir-frying temperature significantly influenced licorice-saponin G2,(3)stir-frying temperature was the most important factor of the three input factors,(4)in terms of composition,honey fried licorice had significant effects on two components,namely liquiritin apioside and licorice-saponin G2.Conclusions:Honey processing influenced the content of the 11 licorice analytes differently.This paper highlights the first report on how the quality of honey-processed licorice varies under different processing conditions and suggests the optimal levels of the investigated three factors as A2B2C3 according to the degrees of influence of these factors on the 11 components.Specifically,the soaking time of crude licorice with honey solution,stir-frying temperature,and stir-frying time were 40 min,100°C,and 20 min,respectively.