Profiles and Source Apportionment of Nonmethane Volatile Organic Compounds in Winter and Summer in Xi’an, China, based on the Hybrid Environmental Receptor Model

Summer and winter campaigns for the chemical compositions and sources of nonmethane hydrocarbons(NMHCs)and oxygenated volatile organic compounds(OVOCs)were conducted in Xi’an.Data from 57 photochemical assessment monitoring stations for NMHCs and 20 OVOC species were analyzed.Significant seasonal differences were noted for total VOC(TVOC,NMHCs and OVOCs)concentrations and compositions.The campaign-average TVOC concentrations in winter(85.3±60.6 ppbv)were almost twice those in summer(47.2±31.6 ppbv).Alkanes and OVOCs were the most abundant category in winter and summer,respectively.NMHCs,but not OVOCs,had significantly higher levels on weekends than on weekdays.Total ozone formation potential was higher in summer than in winter(by 50%)because of the high concentrations of alkenes(particularly isoprene),high temperature,and high solar radiation levels in summer.The Hybrid Environmental Receptor Model(HERM)was used to conduct source apportionment for atmospheric TVOCs in winter and summer,with excellent accuracy.HERM demonstrated its suitability in a situation where only partial source profile data were available.The HERM results indicated significantly different seasonal source contributions to TVOCs in Xi’an.In particular,coal and biomass burning had contributions greater than half in winter(53.4%),whereas traffic sources were prevalent in summer(53.1%).This study’s results highlight the need for targeted and adjustable VOC control measures that account for seasonal differences in Xi’an;such measures should target not only the severe problem with VOC pollution but also the problem of consequent secondary pollution(e.g.,from ozone and secondary organic aerosols).

Source Apportionment of PM2.5 in the Metropolitan Area of Costa Rica Using Receptor Models

In this work, receptor models were used to identify the PM2.5 sources and its contribution to the air quality in residential, comercial and industrial sampling sites in the Metropolitan Area of Costa Rica. Principal component analysis with absolute principal component scores (PCA-APCS), UNIMX and positive matrix factorization (PMF) was applied to analyze the data collected during 1 year of sampling campaign (2010-2011). The PM2.5 samples were characterized through its composition looking for trace elements, inorganic ions and organic and elemental carbon. These three models identified some common sources of PM2.5: marine aerosol, crustal material, traffic, secondary aerosols (secondary sulfate and secondary nitrate resolved by PMF), a mixed source of heavy fuels combustion and biomass burning, and industrial emissions. The three models predicted that the major sources of PM2.5 in the Metropolitan Area of Costa Rica were related to anthropogenic sources (73%, 65% and 69%, respectively, for PCA-APCS, Unmix and PMF) although natural sources also contributed to PM2.5 (21%, 24% and 26%). On average, PCA and PMF methods resolved 94% and 95% of the PM2.5 mass concentrations, respectively. The results were comparable to the estimate using UNMIX.

Design of N-11-Azaartemisinins Potentially Active against Plasmodium falciparum by Combined Molecular Electrostatic Potential, Ligand-Receptor Interaction and Models Built with Supervised Machine Learning Methods

N-11-azaartemisinins potentially active against Plasmodium falciparum are designed by combining molecular electrostatic potential (MEP), ligand-receptor interaction, and models built with supervised machine learning methods (PCA, HCA, KNN, SIMCA, and SDA). The optimization of molecular structures was performed using the B3LYP/6-31G* approach. MEP maps and ligand-receptor interactions were used to investigate key structural features required for biological activities and likely interactions between N-11-azaartemisinins and heme, respectively. The supervised machine learning methods allowed the separation of the investigated compounds into two classes: cha and cla, with the properties εLUMO+1 (one level above lowest unoccupied molecular orbital energy), d(C6-C5) (distance between C6 and C5 atoms in ligands), and TSA (total surface area) responsible for the classification. The insights extracted from the investigation developed and the chemical intuition enabled the design of sixteen new N-11-azaartemisinins (prediction set), moreover, models built with supervised machine learning methods were applied to this prediction set. The result of this application showed twelve new promising N-11-azaartemisinins for synthesis and biological evaluation.

Source apportionment of polycyclic aromatic hydrocarbons(PAHs) in a sediment core from Lake Dagze Co, Tibetan Plateau, China: Comparison of three receptor models

Receptor models are a useful tool for identifying sources of polycyclic aromatic hydrocarbons(PAHs) in multiple environmental media. In this study, three different receptor models(including the principal component analysis-multiple linear regression(PCA-MLR), positive matrix factorization(PMF), and Unmix models) were used to apportion the sources of 16 priority PAHs in a sediment core of Lake Dagze Co. The ΣPAHs(sum of all 16 measured PAHs) concentrations ranged from 51.89 to 132.82 ng/g with an average of 80.39 ng/g. TheΣ PAHs were dominated by 2-3 ring PAHs, accounting for 80.12% on average, thereby indicating that they mainly originated from biomass and coal combustion and/or from long-range atmospheric transportation. The three models produced consistent source apportionment results. The greatest contributor to ΣPAHs was biomass combustion, followed by coal combustion, vehicle emissions, and petrogenic sources. Moreover, the temporal variation of the common sources was well-correlated among models. The multi-method comparison and evaluation results showed that all three models were useful tools for source apportionment of PAHs, with the PMF model providing better results than the PCA-MLR and Unmix models. The temporal trends of factor contributions were verified by PAHs with different ring numbers. Significant correlations were found between the simulated concentrations of each source factor and the PAHs with different ring numbers(P<0.01), except for the petrogenic source identified by the Unmix model(P>0.05). This study can provide useful information for further investigation of source apportionment of PAHs in the sediment cores.

PM_(2.5) source apportionment in a French urban coastal site under steelworks emission influences using constrained non-negative matrix factorization receptor model

The constrained weighted-non-negative matrix factorization（CW-NMF） hybrid receptor model was applied to study the influence of steelmaking activities on PM_（2.5）（particulate matter with equivalent aerodynamic diameter less than 2.5 μm） composition in Dunkerque,Northern France. Semi-diurnal PM_（2.5）samples were collected using a high volume sampler in winter 2010 and spring 2011 and were analyzed for trace metals, water-soluble ions, and total carbon using inductively coupled plasma – atomic emission spectrometry（ICP-AES）,ICP- mass spectrometry（ICP-MS）, ionic chromatography and micro elemental carbon analyzer. The elemental composition shows that NO_3^-, SO_4^（2-）, NH_4~＋and total carbon are the main PM_（2.5）constituents. Trace metals data were interpreted using concentration roses and both influences of integrated steelworks and electric steel plant were evidenced. The distinction between the two sources is made possible by the use Zn/Fe and Zn/Mn diagnostic ratios. Moreover Rb/Cr, Pb/Cr and Cu/Cd combination ratio are proposed to distinguish the ISW-sintering stack from the ISW-fugitive emissions. The a priori knowledge on the influencing source was introduced in the CW-NMF to guide the calculation. Eleven source profiles with various contributions were identified： 8 are characteristics of coastal urban background site profiles and 3 are related to the steelmaking activities. Between them,secondary nitrates, secondary sulfates and combustion profiles give the highest contributions and account for 93% of the PM_（2.5）concentration. The steelwork facilities contribute in about 2%of the total PM_（2.5）concentration and appear to be the main source of Cr, Cu, Fe, Mn, Zn.

Impact of Probiotics on Toll-like Receptor 4 Expression in an Experimental Model of Ulcerative Colitis

Toll-like receptors （TLRs） are key components of the innate immune system which trigger antimicrobial host defense responses. This study aimed to investigate the impact of probiotics （Lactoba- cillus, Bifiidobacterium） on the expression of TLR4 and tumor necrosis factor-alpha （TNF-α in the co- lon mucosa of rat experimental ulcerative colitis model induced by trinitrobenzene sulfonic acid （TNBS）/ethanol and immune complexes. The gross and histological changes of the colonic mucosa were observed and assessed by the means-standard deviation and independent samples t-test. The pro- tein expression levels of TLR4 and TNF-α were detected by using immunohistochemistry and Westem blotting, respectively. It was revealed that there was visible infiltration of inflammatory cells, formation of crypt abscess, and the reduction of goblet cells in the colon tissue of experimental models. As com- pared with the control group, the levels of TLR4 and TNF-α protein were significantly increased in the model group （P〈0.01 for both）. No significant difference was found in the expression of TLR4 and TNF-α between the two-week probiotics treatment group and the model group （P〉0.05）, whereas sig- nificant reductions were shown in rats which were treated with probiotics for four weeks as compared with the model group （P〈0.01）. There was no significant difference between two probiotics-treated groups. Our results implied that probiotics were likely to play a key role in protecting ulcerative colitis by reducing the inflammatory factor TNF-α expression through inhibiting the TLR4 expression in the colon tissue of experimental models.

Homology Model and Ligand Binding Interactions of the Extracellular Domain of the Human α4β2 Nicotinic Acetylcholine Receptor

Addiction to nicotine, and possibly other tobacco constituents, is a major factor that contributes to the difficulties smokers face when attempting to quit smoking. Amongst the various subtypes of nicotinic acetylcholine receptors (nAChRs), the α4β2 subtype plays an important role in mediating the addiction process. The characterization of human α4β2-ligand binding interactions provides a molecular framework for understanding ligand-receptor interactions, rendering insights into mechanisms of nicotine addiction and may furnish a tool for efficiently identifying ligands that can bind the nicotine receptor. Therefore, we constructed a homology model of human α4β2 nAChR and performed molecular docking and molecular dynamics (MD) simulations to elucidate the potential human α4β2-ligand binding modes for eleven compounds known to bind to this receptor. Residues V96, L97 and F151 of the α4 subunit and L111, F119 and F121 of the β2 subunit were found to be involved in hydrophobic interactions while residues S153 and W154 of the α4 subunit were involved in the formation of hydrogen bonds between the receptor and respective ligands. The homology model and its eleven ligand-bound structures will be used to develop a virtual screening program for identifying tobacco constituents that are potentially addictive.

Multiple templates-based homology modeling and docking analysis of angiotensin Ⅱ type 1 receptor

Using the latest reported homologous Chemokine receptors (PDB ID:3ODU,3OE0 and 3OE6) as templates,twenty models of angiotensin II (Ang II) type 1 (AT1) receptor (known as p30556) were generated by multiple templates homology modeling.According to the results of the initial validation of these twenty models,the model 0020 was finally chosen as the best one for further studies.Then,a 2 ns molecular dynamic (MD) simulation for model 0020 was conducted in normal saline (0.9%,w/V) under periodical boundary conditions,which was followed by docking studies of model 0020 with several existing AT1 receptor blockers (ARBs).The docking results reveal that model 0020 possesses good affinities with these docked ARBs which are in accordance with both the IC50 inhibitor values and their curative effects.The results also show more potent interactions between the model 0020 and its ARBs than those of ever reported results,such as hydrogen bonds,hydrophobic interactions,and especially cation-π interactions and π-π interactions which have never been reported before.This may reveal that the structure of the model 0020 is quite close to its real crystal structure and the model 0020 may have the potential to be used for structure based drug design.

The remedial effect of soluble interleukin-1 receptor type Ⅱ on endometriosis in the nude mouse model

Objective： Recent studies have shown that the local expression of soluble interleukin （IL） -1 receptor type Ⅱ （slL-1 R Ⅱ ） in endometrial tissue of women with endometriosis is decreased, and the depression of IL-1 R Ⅱ was more significant in infertile women than that in fertile women with endometriosis. In this research, we investigated the remedial effect of slL-1-R Ⅱ administration on endometriosis in the nude mouse model. Methods： Nineteen nude model mice with endometriosis were randomly divided into three groups： group A was treated by intraperitoneal administration with only slL-1 R Ⅱ for two weeks, group B was similarly treated with only IL- 1, and group C （control） was administered saline. After 2 weeks, the size of the ectopic endometrial lesions was calculated, and the expression of vascular endothelial growth factor （VEGF） and B-cell lymphoma leukemia-2 （Bcl- 2） were detected by immunohistochemistry. The IL-8 and VEGF levels in the peritoneal fluid （PF） and serum were also measured by enzyme-linked immunosorbent assay （ELISA）. Results： The mean size of ectopic endometrial lesion did not differ between the three groups （P 〉 0.05）. Compared with the control, the expression of VEGF and Bcl-2 was significantly lower in group A, and higher in group B. In the three groups, the levels of IL-8 in the PF and serum were highest in group A, and lowest in group B. Conclusion： slL-1 R Ⅱ may suppresse hyperplasia of ectopic endometriosis, perhaps by reducing the expression of certain cytokines, such as VEGF, IL-8, and Bcl-2, which could provide a new clinical strategy for the treatment of endometriosis.

Administration of soluble activin receptor 2B increases bone and muscle mass in a mouse model of osteogenesis imperfecta

Osteogenesis imperfecta（OI） comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications of OI,many patients also report intolerance to physical activity, fatigue and muscle weakness. Indeed, recent studies have demonstrated that skeletal muscle is also negatively affected by OI, both directly and indirectly. Given the well-established interdependence of bone and skeletal muscle in both physiology and pathophysiology and the observations of skeletal muscle pathology in patients with OI, we investigated the therapeutic potential of simultaneous anabolic targeting of both bone and skeletal muscle using a soluble activin receptor 2B（ACVR2B） in a mouse model of type Ⅲ OI（oim）. Treatment of 12-week-old oim mice with ACVR2 B for 4 weeks resulted in significant increases in both bone and muscle that were similar to those observed in healthy,wild-type littermates. This proof of concept study provides encouraging evidence for a holistic approach to treating the deleterious consequences of OI in the musculoskeletal system.

Molecular Characterization, 3D Modeling of Grass Carp Interleukin-10 Receptor 1 (IL10R1)

Interleukin-10 (IL-10) is an important cytokine that plays a pivotal role in natural and adaptive immune systems. However, in lower vertebrates, especially in teleost the receptor of this cytokine is still largely unknown. This paper described the cloning and characterization of grass carp interleukin-10 receptor 1 (gcIL10R1) and the 3D structure of its extracellular domain was predicted. The gcIL10R1 cDNA included 180 bp5’ untranslated region (UTR), 870 bp3’ UTR and an open reading frame (ORF) of 1632 bp. The ORF was found to encode a 543 amino acid protein with a putative JAK1 binding site, one STAT3 binding site. The phylogenetic analysis clusters gcIL10R1 with other teleost IL10R1s but independently of the amphibian, avian and mammalian IL10R1s. The 3D structure of its extracellular domain was the first homology model of a fish IL10R1 that revealed a high similarity with its mammalian and avian counterparts.

Neuroactive alkaloids that modulate the neuronal nicotinic receptor and provide neuroprotection in an Alzheimer's disease model:the case of Teline monspessulana

Despite the advances in combinatorial or synthetic chemis- try and bioinformatics, recent literature has demonstrated the relevance of nature and biomass as a source of new molecules to treat different pathologies, i.e., bioactive com- pounds obtained from Ecteinascidia turbinate to treat some types of cancer or rapamycin from Streptomyces hygroscop- icus to prevent organ rejection after transplant. This trend will continue simply due to the fact that Mother Nature has been synthesizing molecules for millions of years. In our lab- oratory, we have characterized several compounds obtained from natural sources and that possess important neuronal effects,

铁死亡在不同细菌所致小鼠血流感染模型中的变化规律及生物学意义

背景:发现血流感染新的疾病诊断标志物、治疗疾病及减轻脏器损伤的分子靶点具有重要意义。铁死亡是新发现的一种细胞死亡形式,脓毒症动物模型中铁死亡的过度激活与炎症反应激活以及肝脏、心脏、肾脏等重要脏器的损伤有关,但铁死亡与血流感染的关系尚不十分清楚。目的:探讨铁死亡在不同细菌所致小鼠血流感染模型中的变化规律及生物学意义。方法:建立革兰阴性菌大肠埃希菌、肺炎克雷伯菌及革兰阳性菌金黄色葡萄球菌、粪肠球菌血流感染的SPF级ICR雄性小鼠模型,每组各42只。建模后0.5,1,3,6,12,24,48 h时检测肝脏、心肌、肾脏中铁死亡标志基因转铁蛋白受体1、谷胱甘肽过氧化物酶4 mRNA表达水平。另选用18只SPF级ICR雄性小鼠,随机分为二甲基亚砜(DMSO)对照组、DMSO+肺炎克雷伯菌组、铁死亡抑制剂Ferrostatin-1+肺炎克雷伯菌组,每组6只;后两组采用尾静脉注射肺炎克雷伯菌悬液的方式建立肺炎克雷伯菌血流感染模型,分别在血流感染建模前1 h给予5 mg/kg的Ferrostatin-1及等剂量DMSO腹腔注射;建模后6 h小鼠检测血清中丙氨酸氨基转移酶、天冬氨酸氨基转移酶、血肌酐、血尿素氮、磷酸肌酸激酶同工酶、乳酸脱氢酶以及各组织中铁死亡标志基因的mRNA表达水平。结果与结论:①血流感染建模后,不同细菌血流感染小鼠肝脏、心肌、肾脏中转铁蛋白受体1 mRNA表达水平先升高后降低,谷胱甘肽过氧化物酶4 mRNA表达水平先降低后升高且均在建模后6 h达到峰值;②革兰阴性菌血流感染小鼠中转铁蛋白受体1和谷胱甘肽过氧化物酶4 mRNA表达的变化较革兰阳性菌血流感染小鼠更为显著,其中以肺炎克雷伯菌血流感染小鼠中转铁蛋白受体1和谷胱甘肽过氧化物酶4 mRNA表达的变化最显著;③肺炎克雷伯菌血流感染建模后6 h时,小鼠的丙氨酸氨基转移酶、天冬氨酸氨基转移酶、血肌酐、血尿素氮、磷酸肌酸激酶同工酶、乳酸脱氢酶水平均明显升高;④建模前给予铁死亡抑制剂Ferrostatin-1干预可显著降低丙氨酸氨基转移酶、天冬氨酸氨基转移酶、血肌酐、血尿素氮、磷酸肌酸激酶同工酶、乳酸脱氢酶表达水平;⑤以上结果提示不同细菌致血流感染小鼠中铁死亡明显激活且革兰阴性菌血流感染小鼠的铁死亡激活更为显著;抑制铁死亡可明显减轻肺炎克雷伯菌血流感染小鼠的肝脏、心肌、肾脏损伤。

Expression of metabotropic glutamate receptor 1a in a rat cortical neuronal model of in vitro mechanical injury and the effects of its competitive antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid

The present study established a rat cortical neuronal model of in vitro mechanical injury. At 30 minutes after injury, the survival rate of the injured cortical neurons was decreased compared with normal neurons, and was gradually decreased with aggravated degree of injury. Reverse transcription-polymerase chain reaction results showed that at 1 hour after injury, there was increased expression of metabotropic glutamate receptor la in cortical neurons. Immunohistochemical staining results showed that at 30 minutes after injury, the number of metabotropic glutamate receptor 1a-positive cells increased compared with normal neurons. At 12 hours after injury, lactate dehydrogenase activity in the （RS）-l-aminoindan-1, 5-dicarboxylic acid （AIDA）-treated injury neurons was si[jnificantly decreased than that in the pure injury group. At 1 hour after injury, intracellular free Ca＂＋ concentration was markedly decreased in the AIDA-treated injury neurons than that in the pure injury neurons. These findings suggest that after mechanical injury to cortical neurons, metabotropic glutamate receptor la expression increased. The resulting increase in intracellular free Ca2＋ concentration was blocked by AIDA, indicating that AIDA exhibits neuroprotective effects after mechanical injury.

广州周边地区地表水稀土元素污染特征及来源解析

以广州市周边地区地表水为研究对象,测定地表水中溶解态稀土元素La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb和Lu的浓度,采用单因子评价指数、内梅罗综合污染指数以及潜在生态风险指数对地表水中溶解态稀土元素进行污染和风险评价,通过APCS-MLR受体模型对广州市周边城区地表水中溶解态稀土元素的来源进行定量化解析,探究高度城市化的非矿区地表水中稀土元素的浓度分布特征。结果表明,研究区地表水溶解态稀土元素La、Ce、Nd、Pr、Gd、Dy、Sm、Er、Yb、Ho、Tb、Eu、Tm和Lu的平均浓度分别是背景值的6.97、5.15、4.06、4.58、1.58、1.71、1.14、1.26、1.22、1.67、1.33、0.47、0.83和0.80倍,表明广州市周边地区地表水中稀土元素可能存在富集现象,尤其是La、Ce、Nd和Pr等轻稀土元素。空间分布特征表明,稀土元素浓度较高的区域集中在位于广州市市内的石门山、黄山鲁和白云山,推断轻稀土元素浓度可能会受到城市中剧烈的人为活动影响。单因子污染指数结果表明,研究区地表水主要受轻稀土元素(La、Ce、Pr和Nd)污染;内梅罗综合污染指数分析表明,石门山、罗浮山、白云山和黄山鲁采样区地表水中稀土元素属于重度污染水平。潜在生态风险评价结果表明,轻稀土元素La、Ce、Pr和Nd为主要污染因子,石门山、白云山和黄山鲁采样区地表水中稀土元素污染属于中度风险水平;罗浮山和帽峰山属于低风险水平。皮尔逊相关性分析显示研究区地表水中稀土元素之间存在较强的相关性;由APCS-MLR受体模型分析得出2个主要污染源(源1和源2)和未解析源(源3),源1为自然源,贡献率为80.96%~99.12%,为研究区地表水稀土元素的主要来源;源2为人为源,主要由交通运输、工业活动等引起,其贡献率为0.32%~8.67%,是研究区地表水稀土元素的第二大来源。

大气多环芳烃的浓度水平、来源与健康风险评价综述

多环芳烃(PAHs)主要源于有机材料的不完全燃烧,具有生物蓄积性和毒性(致癌、致畸形和致突变),是一类持久性有毒物质。本文综述了大气PAHs的分类、排放特征、时空分布特征、来源解析和健康风险评价,根据不同相对分子质量、存在形式、化学结构进行PAHs分类。指出了PAHs浓度呈现季节性变化,变化趋势由高到低为:冬季、春季、秋季和夏季。比较了分子诊断比率(DRs)和受体模型,包括主成分分析(PCA)、化学质量平衡模型(CMB)、正矩阵分解(PMF)和多变量受体模型(Unmix)等多种PAHs源解析方法的优缺点。来源解析表明:DRs和PCA是应用最广泛的方法,但是其来源解析结果的准确性受到诸多因素的影响;PMF和Unmix相结合来解析PAHs来源,能仅根据受体部位的测量浓度来分配源,提供了PAHs源贡献的时间序列并且弥补了需要人为解读的局限性。文中展示了如何利用终身癌症风险增量(ILCR)模型将PAHs的来源分配用于评估健康风险,并在此过程中,确定了影响ILCR准确性的关键因素。以期为进一步开展大气PAHs污染相关研究提供参考。

大气挥发性有机物受体模型来源解析研究进展

挥发性有机物(VOCs)是细颗粒物和臭氧的重要前体物,对其开展来源解析研究非常必要。正定矩阵因子分解(PMF)模型是应用较为广泛的受体模型来源解析技术,该文归纳了PMF模型中关键参数的选取,综述了其在大气VOCs来源解析上的应用情况,总结了中国不同区域VOCs来源特点,阐述了特征比值法、潜在污染源区及传输路径分析方法等方法与PMF模型结合开展VOCs来源的研究进展。结果表明:(1)VOCs物种、不确定度、物种权重、因子数等关键参数的选取均会影响解析结果的误差;(2)大气VOCs来源因地区、季节及人为管控等因素影响而存在差异,但机动车相关排放源是北京市、济南市、武汉市、长三角地区及南部城市大气VOCs的主要来源,贡献在16.9%~75.4%;(3)在PMF模型获取源贡献的基础上,利用条件概率函数、潜在源贡献函数、浓度加权轨迹等模型可掌握污染来源空间分布及传输贡献,光化学损耗估算方法可减小高活性VOCs的解析误差,为管理部门提供更加精准的VOCs污染来源信息。研究显示,在PMF模型广泛应用于大气VOCs来源解析的背景下,开展量化VOCs污染本地生成及区域传输贡献、准确估算VOCs损耗方法研究具有重要意义。

河南荥阳市耕地土壤重金属分布特征及来源解析

耕地质量关系着人民生活,而重金属是影响耕地质量的重要因素之一。根据全国土壤污染状况调查显示,中国耕地环境状况不容乐观,对耕地的重金属调查分析迫在眉睫。但仅简单地对重金属含量水平及来源类型进行判断已不足以为区域土壤重金属污染治理提供支持,而通过对各类污染源贡献率的定量计算,不仅可以明确农田土壤重金属分布特征,同时可判别污染源类别及来源,从而识别优先控制的污染元素,为重金属污染精准管控提供关键信息。本文采集河南荥阳市耕地表层土壤样品(0~20cm),应用电感耦合等离子体质谱和发射光谱法(ICP-MS/OES)、原子荧光光谱法(AFS)及离子选择电极法(IES)对As、Cd、Cr、Cu、Hg、Ni、Pb、Zn等8种重金属进行测试和p H分析;利用多元统计、绝对因子分析-多元线性回归(APCS-MLR)受体模型探讨研究区8种重金属污染含量空间分布特征及来源,利用富集因子和地累积指数开展土壤污染评价。结果表明:(1)耕地土壤中重金属含量整体偏高。除Cr外,其他元素为郑州市土壤背景值的1.04~1.40倍,其中Cd的累积效应较明显。(2)研究区重金属高值区主要分布于荥阳市城区周边。(3)基于富集因子法、相关性分析、主成分分析及APCS-MLR源解析结果显示,研究区重金属主要有三个来源:自然源对Ni、As、Cu、Cr的贡献率分别为98%、94%、80%及63%;工业源对Cd的贡献率为78%;其他源则主要是农业化肥源、燃煤源的混合源,对Cr、Pb、Hg的贡献率分别为37%、35%及33%。(4)地累积指数表明,研究区各重金属以无污染为主,而Cd超标率最高,其中度、中-重度污染、重度污染样点数分别为19个、5个及3个,并存在1个极重度污染样点。综上,Cd在研究区耕地中富集较明显,为潜在的主要污染元素;工业源、自然源、农业化肥源及燃煤源是重金属的主要来源,表明人类活动已对研究区耕地产生影响,需采取措施避免该影响进一步加剧。

激素受体阳性乳腺癌常用复发风险预测工具研究现状

乳腺癌是危害全球女性健康的恶性肿瘤之一,激素受体(hormone receptor,HR)阳性是其最常见的分子亚型。乳腺癌的异质性导致患者术后复发风险各异,因此需要高灵敏度的风险预测工具帮助临床医生评估不同患者的预后,制定个性化治疗方案。目前使用较为广泛的HR阳性乳腺癌患者术后复发风险预测工具是基于多基因检测和临床病理因素开发的预后模型,例如Oncotype DX检测、4项免疫组化评分等。此外,基于影像特征建立的预后评估模型也逐渐应用于临床。在临床实践中,依据风险评估模型可较为准确地评估乳腺癌患者术后复发风险和预后,指导患者的个体化临床诊疗方案,以改善患者生存质量,延长总生存期。

固本安神方对围绝经期综合征模型大鼠性激素水平及卵巢雌激素受体蛋白表达水平的影响

目的 探讨固本安神方对围绝经期综合征(PMS)模型大鼠性激素水平及卵巢雌激素受体蛋白表达水平的影响。方法 选取动情周期规则的雌性SD大鼠60只,腹腔注射160 mg/kg去氧乙烯基环己烯(VCD),以复制PMS大鼠模型。造模成功后,将雌性SD大鼠随机分为模型组(B组,等体积生理盐水),中药组[C组,0.56 g/(kg·d)更年安片],西药组[D组,0.1 mg/(kg·d)戊酸雌二醇片],固本安神方高、中、低剂量组[E_(1)组、E_(2)组、E_(3)组,18.0,9.0,4.5 g/(kg·d)],各10只。另取雌性SD大鼠10只为正常组(A组,等体积生理盐水)。各组大鼠分别灌胃给药4周后,摘取其子宫、双侧卵巢,称定湿重,计算子宫指数、卵巢指数;采用酶联免疫吸附试验(ELISA)法测定血清中卵泡刺激素(FSH)、促黄体生成素(LH)、雌二醇(E_(2))的水平;采用免疫印记(Western blot)法测定卵巢组织中雌激素受体α(ERα)、雌激素受体β(ERβ)、G蛋白偶联雌激素受体1(GPER1)蛋白表达水平。结果 与B组比较,C组、D组、E_(1)组大鼠的子宫指数、卵巢指数均显著升高(P<0.01);C组、D组、E_(1)组大鼠血清中FSH和LH水平均显著降低(P<0.01),E_(2)水平均显著升高(P<0.01);C组、D组、E_(1)组大鼠卵巢组织中ERα,ERβ,GPER1蛋白表达水平均显著升高(P<0.01),E_(2)组、E_(3)组大鼠卵巢组织中ERα蛋白表达水平均显著升高(P<0.05),E_(2)组大鼠卵巢组织中GPER1蛋白表达水平显著升高(P<0.05)。结论 固本安神方治疗PMS模型大鼠的作用机制可能与影响性激素分泌及提高卵巢雌激素受体的蛋白表达水平有关。