高效液相色谱法测定化妆品中3种α-羟基酸及其酯

建立了高效液相色谱法(HPLC)同时测定化妆品中葡糖酸、葡糖酸内酯和乳糖酸的含量,并结合高效液相色谱-串联质谱联用法(HPLC-MS/MS)对结果进行确证。样品经水超声提取,并在氢氧化钠的作用下将葡糖酸、葡糖酸内酯、乳糖酸转化为葡糖酸盐和乳糖酸盐,采用高效液相色谱法,以0.04 mol/L的磷酸氢二铵水溶液和乙腈为流动相进行洗脱,Comixsil HCS(4.6 mm×150 mm,3μm)色谱柱分离,二极管阵列检测器(214 nm)检测,外标法定量。采用高效液相色谱-串联质谱联用法,以0.1%甲酸水溶液和含0.1%甲酸乙腈为流动相进行梯度洗脱,Waters T3-C18(2.1 mm×100 mm,1.8μm)色谱柱分离,电喷雾电离,负离子多反应监测模式定性。结果显示,葡糖酸与乳糖酸在相应线性范围内线性关系良好,相关系数均大于0.999。葡糖酸与葡糖酸内酯的方法检出限为100μg/g,乳糖酸的方法检出限为500μg/g。3种化合物4种基质样品加标平均回收率为90.8%~110.1%,相对标准偏差为0.3%~4.4%。该方法操作简便、准确度好、灵敏度高,适用于化妆品中葡糖酸、葡糖酸内酯和乳糖酸的测定。

市售儿童化妆品中苯氧乙醇的测定及初步风险特征评估

研究市售儿童化妆品中苯氧乙醇防腐剂的暴露参数,对其进行初步风险特征描述,旨在为完善我国化妆品安全风险评估体系提供参考。本实验依据《化妆品安全技术规范》(2015年版)(国家药品监督管理局2021年第17号通告)检验,测得市售50批儿童化妆品中苯氧乙醇含量,并通过ConsExpo Web暴露评估软件建立数学模型,获得适用中国儿童化妆品中苯氧乙醇的暴露参数。结果表明:实验所测的50批市售儿童化妆品中,苯氧乙醇的使用频率为50%。0~3岁儿童有吸吮行为,会增加苯氧乙醇的安全边际风险。市售儿童化妆品中苯氧乙醇的安全边际(MoS)均大于50。结论:儿童化妆品中苯氧乙醇的使用频率较高,市售儿童化妆品中苯氧乙醇的初步风险特征评估为安全。儿童化妆品暴露参数要充分参考到儿童不同年龄段的皮肤特点,儿童特有的行为模式和儿童特定的应用场景,以便更加科学合理地评估儿童化妆品安全。

石墨消解-原子荧光光谱法测定海洋生物体中的砷

为解决电热板消解海洋生物体时存在的消解温度低、前处理时间长、消解不完全、重复性差、正确度差等问题。通过考察不同消解仪器、消解温度、时间、消解管材质和消解液体系等消解条件,建立了以石墨高温消解海洋生物体,用原子荧光光谱法测定海洋生物体中砷的方法,确定了海洋生物体砷前处理与测试的最佳条件,实验结果表明,有证标准物质加标回收率为98.9%~101%,各类型海洋生物体样品的加标回收率为93.4%~95.8%。方法操作简单、快速,适用于各类海洋生物体中砷的分析。

Can a multistage approach improve individual tree mortality predictions across the complex mixed-species and managed forests of eastern North America?

Tree mortality plays a fundamental role in the dynamics of forest ecosystems,yet it is one of the most difficult phenomena to accurately predict.Various modeling strategies have been developed to improve individual tree mortality predictions.One less explored strategy is the use of a multistage modeling approach.Potential improvements from this approach have remained largely unknown.In this study,we developed a novel multistage approach and compared its performance in individual tree mortality predictions with a more conventional approach using an identical individual tree mortality model formulation.Extensive permanent plot data(n=9442)covering the Acadian Region of North America and over multiple decades(1965–2014)were used in this study.Our results indicated that the model behavior with the multistage approach better depicted the observed mortality and showed a notable improvement over the conventional approach.The difference between the observed and predicted numbers of dead trees using the multistage approach was much smaller when compared with the conventional approach.In addition,tree survival probabilities predicted by the multistage approach generally were not significantly different from the observations,whereas the conventional approach consistently underestimated mortality across species and overestimated tree survival probabilities over the large range of DBH in the data.The new multistage approach also predictions of zero mortality in individual plots,a result not possible in conventional models.Finally,the new approach was more tolerant of modeling errors because it based estimates on ranked tree mortality rather than error-prone predicted values.Overall,this new multistage approach deserves to be considered and tested in future studies.

一种多路视频的360度实时拼接技术

针对视频拼接实现过程中图像配准阶段耗时较大的问题,设计出一种基于二进制鲁棒尺度不变性特征算法与运动统计算法的组合式图像配准算法。在二进制鲁棒尺度不变性特征算法快速特征提取特性的基础上,利用网格化方法对重叠区域图像进行划分,使特征点分布更加均匀,从而减少需要操作的特征点数量以提高速率;在匹配环节,利用运动统计算法剔除误匹配对,利用双向匹配策略提高匹配准确率。为使图像融合的更加自然流畅,设计出一种区域化的渐入渐出加权融合算法:为减少求解重叠区域存在的误差,构建融合区域并进行区域化划分,利用最佳缝合线法求得拼接缝,在不同区域使用渐入渐出加权算法实现图像融合,从而获取融合质量更高的全景图像。最后,设计出完整的全景视频拼接系统,通过实验验证了系统方案的可行性和实用性。实验证明,相对于传统的视频拼接技术,新算法在消除拼接时出现的重影和接缝问题的同时,保证了视频拼接的实时性。

Effects of fertilization on the growth dominance of Inland Northwest forests of the United States

Large trees have disproportionally large competitive advantage in access to light, which has been proposed to increase growth dominance of large trees (e.g., a larger proportion of volume growth than standing volume is in large trees in a stand). Tree growth may also be limited by the availability of other resources besides light.Nutrient deficiency, especially of nitrogen, is considered common among temperate forests including mixedconifer forests of the Inland Northwest of the United States. Data from a long-term forest nutrition study across four Inland Northwest states were analyzed to evaluate nitrogen×potassium fertilization?s effects on growth dominance over an eight-year period following treatment. Our results show that growth dominance varied substantially across plots in each vegetation series and fertilization treatment, and its mean values generally were at minuscule magnitudes, negative, and not significantly different from 0. We propose that this lack of a clear pattern in growth dominance was the result of the mixed-species composition where shade-tolerant species remained in lower crown positions, yet their relative growth kept pace with large trees. Limited moisture availability at dry sites may have hampered the development of growth dominance. Growth dominance also was lowered by mortality observed among relatively large trees. The largely negative growth dominance across fertilization treatments indicated that small trees seem to have maintained higher relative growth rates than large trees, even if absolute growth was higher among large trees. In the case fertilization does improve stand growth, a significant part of this improved growth will be lost in density-dependent mortality over time if not captured through thinning/harvesting.

A new thermo-elasto-plasticity constitutive theory for polycrystalline metals

In this study, the behavior of polycrystalline metals at different temperatures is investigated by a new thermo-elasto-plasticity constitutive theory. Based on solid mechanical and interatomic potential, the constitutive equa- tion is established using a new decomposition of the deformation gradient. For polycrystalline copper and magnesium, the stress-strain curves from 77 to 764 K （copper）, and 77 to 870 K （magnesium） under quasi-static uniaxial loading are calculated, and then the calculated results are compared with the experiment results. Also, it is determined that the present model has the capacity to describe the decrease of the elastic modulus and yield stress with the increasing temperature, as well as the change of hardening behaviors of the polycrystalline metals. The calculation process is simple and explicit, which makes it easy to implement into the applications.

Association rules analysis of Fufang Kushen injection in combination with traditional Chinese medicine or modern medications in treating Cervical cancer: real-world retrospective study

Objective: The present study aimed to analyze the association rules of Fufang Kushen injection in combination with other traditional Chinese medicine ( TCM) or modern medications in treating cervical cancer (CC) based on the electrical medical records extracted from real-world hospital information system. Methods: The clinicians’ prescriptions regarding to the combination of with TCM or modern medications were from hospital information system electronic medical data integration warehouse established by the Institute of Basic Medical Research of Chinese Medicine, China Academy of Chinese Medical Sciences, which integrated the hospital information system data of 22 hospitals. The association rules of the drug characteristics were analyzed through Apriori algorithm. Results: A total of 839 patients with CC were included. We found that is often combined with prescriptions which could clear heat, remove toxicity, supplement Qi. also combined with chemotherapeutic drugs, immunomodulatory drugs, 5-HT receptor blockers, and glucocorticoids. The combination presents a specific law. Conclusion: Fufang Kushen injection combined with hepatoprotective drugs, immunomodulators and glucocorticoids is often used to treat cervical cancer.

3D printed porous titanium filled with mineralized UV-responsive chitosan hydrogel promotes cell proliferation and osteogenesis in vitro

The modification of 3D printed porous titanium(Ti),especially for the internal pore structure,is critical and has received more attention to promoting its osteogenesis for clinical use.Ultra-violet(UV)responsive chitosan(CSMA),as an injectable filling material,was firstly incorporated into porous Ti,and then CSMA was in-situ mineralized by carbon oxide(CO_(2))diffusion(CSMA/CaCO_(3)).Their physical-chemical and biological properties were investigated in vitro.CaCO_(3) crystals within CSMA hydrogels were successfully deposited into pores of porous Ti,which exhibited favorable biocompatibility.Ti implants filled with CSMA/CaCO_(3) promoted adhesion and proliferation of bone mesenchymal stem cells(BMSCs).Moreover,Ti implant filled CSMA/CaCO_(3) hydrogels could increase alkaline phosphatase(ALP)activities,up-regulate osteopontin(OPN)and osteocalcin(OCN)expression levels,and enhance extracellular mineralization.3D printed porous Ti filled with mineralized UV-responsive chitosan hydrogel could promote proliferation and osteogenesis of BMSCs,and have great potential for the modification of porous Ti implants in bone tissue engineering.

39例肺肉瘤样癌临床病理特征及预后分析

背景与目的肺肉瘤样癌(pulmonary sarcomatoid carcinoma,PSC)是非小细胞肺癌(non-small cell lung cancer,NSCLC)的罕见类型,具有低发病率、高度恶性、强侵袭性、预后差的特点,当前无标准治疗方案。本研究拟通过收集PSC患者临床病理特征、当前诊治情况并分析预后因素,总结诊治经验,旨在提高临床对PSC的认识。方法回顾性收集2013年12月至2023年12月于北京胸科医院确诊、接受治疗且临床资料完整的39例PSC患者的人口学信息、临床病理特征、肿瘤原发灶-淋巴结-转移(tumor-node-metastasis,TNM)分期和诊疗方案资料,并完成临床预后随访。应用Kaplan-Meier法进行单因素生存分析。结果39例PSC患者年龄范围45-76岁,其中男性35例,女性4例,首诊临床表现缺乏特异性;20例患者接受手术治疗,19例患者行姑息性放化疗或对症支持治疗。患者1、5年生存率分别为61.90%、35.20%。单因素分析结果提示恶性肿瘤家族史、肿瘤部位、TNM分期、淋巴结转移、远处转移、是否手术、手术类型、治疗方案、细胞程序性死亡配体1(programmed cell death ligand 1,PD-L1)蛋白表达≥1%、间质上皮细胞转化因子(mesenchymal-epithelial transition factor,MET)通路异常与患者总生存期(overall survival,OS)有关(P<0.05);多因素分析结果显示,淋巴结转移是患者OS的独立影响因素(P=0.037)。结论PSC临床发病率低,多见于有吸烟史的老年男性。PD-L1蛋白表达≥1%及MET通路异常可提示患者不良预后,淋巴结转移是患者OS的独立危险因素。以手术为主的综合治疗是早期及局部晚期患者的主要治疗模式,靶向治疗和免疫治疗的临床应用价值有待进一步探索。

Advances in the surface modification techniques of bone-related implants for last 10 years

At the time of implanting bone-related implants into human body,a variety of biological responses to the material surface occur with respect to surface chemistry and physical state.The commonly used biomaterials(e.g.titanium and its alloy,Co–Cr alloy,stainless steel,polyetheretherketone,ultra-high molecular weight polyethylene and various calcium phosphates)have many drawbacks such as lack of biocompatibility and improper mechanical properties.As surface modification is very promising technology to overcome such problems,a variety of surface modification techniques have been being investigated.This review paper covers recent advances in surface modification techniques of bone-related materials including physicochemical coating,radiation grafting,plasma surface engineering,ion beam processing and surface patterning techniques.The contents are organized with different types of techniques to applicable materials,and typical examples are also described.

Polyethyleneimine-modified calcium carbonate nanoparticles for p53 gene delivery

In this study,calcium carbonate(CaCO3)nanoparticles with spherical structure were regulated by arginine and successfully synthesized via a facile co-precipitation method.The average particle size of as-prepared CaCO3 was about 900 nm.The properties of nanostructured CaCO3 particles were characterized by scanning electron microscope,Fourier transform infrared spectroscopy,Xray diffraction and size distribution.After modified with polyethyleneimine(PEI),the ability of PEICaCO3 nanoparticles to carry GFP-marked p53 gene(pEGFP-C1-p53)into cancer cells to express P53 protein were studied.Meanwhile,the cytotoxicity,transfection efficiency,cells growth inhibition and the ability to induce apoptosis by expressed P53 protein were conducted to evaluate the performances of PEI-CaCO3 nanoparticles.The results show that prepared PEI-CaCO3 nanoparticles had good biocompatibility and low cytotoxicity in a certain concentration range.PEI-CaCO3 effectively transfected pEGFP-C1 gene into epithelial-like cancer cells.And with the expression of GFP-P53 fusion protein,pEGFP-C1-p53-gene-loaded PEI-CaCO3 particles significantly reduced the proliferation of cancer cells.These findings indicate that our PEI-modified CaCO3 nanoparticles are potential to be successfully used as carriers for gene therapy.

Accelerating BERT inference with GPU-efficient exit prediction

BERT is a representative pre-trained language model that has drawn extensive attention for significant improvements in downstream Natural Language Processing(NLP)tasks.The complex architecture and massive parameters bring BERT competitive performance but also result in slow speed at model inference time.To speed up BERT inference,FastBERT realizes adaptive inference with an acceptable drop in accuracy based on knowledge distillation and the early-exit technique.However,many factors may limit the performance of FastBERT,such as the teacher classifier that is not knowledgeable enough,the batch size shrinkage and the redundant computation of student classifiers.To overcome these limitations,we propose a new BERT inference method with GPU-Efficient Exit Prediction(GEEP).GEEP leverages the shared exit loss to simplify the training process of FastBERT from two steps into only one step and makes the teacher classifier more knowledgeable by feeding diverse Transformer outputs to the teacher classifier.In addition,the exit layer prediction technique is proposed to utilize a GPU hash table to handle the token-level exit layer distribution and to sort test samples by predicted exit layers.In this way,GEEP can avoid batch size shrinkage and redundant computation of student classifiers.Experimental results on twelve public English and Chinese NLP datasets prove the effectiveness of the proposed approach.The source codes of GEEP will be released to the public upon paper acceptance.

Functional engineering strategies of 3D printed implants for hard tissue replacement

Three-dimensional printing technology with the rapid development of printing materials are widely recognized as a promising way to fabricate bioartificial bone tissues.In consideration of the disadvantages of bone substitutes,including poor mechanical properties,lack of vascularization and insufficient osteointegration,functional modification strategies can provide multiple functions and desired characteristics of printing materials,enhance their physicochemical and biological properties in bone tissue engineering.Thus,this review focuses on the advances of functional engineering strategies for 3D printed biomaterials in hard tissue replacement.It is structured as introducing 3D printing technologies,properties of printing materials(metals,ceramics and polymers)and typical functional engineering strategies utilized in the application of bone,cartilage and joint regeneration.