宁波市某火力发电厂员工免疫功能检测结果分析简

[目的]探讨长期职业暴露对发电厂员工免疫功能的影响。[方法]采用美国BD公司的FAC—SCalibur流式细胞仪检测技术和免疫比浊法,对200例发电厂员工（暴露组）和80例正常健康体检人员（对照组）的细胞免疫和体液免疫功能进行检测分析。[结果]暴露组免疫球蛋白异常率为16．5％,高于对照组的7．5％（P〈0．05）。CD3、CD4、CD8和CD4／CD8值均明显低于对照组（P〈0．05）。暴露组外周血清中免疫球蛋白IgG、IgA的含量降低,与对照组相比,差异有统计学意义（P〈0．05）。[结论]长期发电厂环境下的职业暴露,T淋巴细胞亚群CD3、CD4、CD8和CD4／CD8值可能会降低,体液免疫功能也可能会降低。     

BP神经网络在餐厨垃圾处理厂适宜性评价中的应用

在调研武汉市餐厨垃圾处理厂基础上,以CJJ 184-2012餐厨垃圾处理技术规范作为餐厨垃圾处理厂选址适宜性评价模型指标选取依据,选取规划适宜、交通运输、环境保护、建场条件和社会经济效益5个方面13个指标,采用BP神经网络构建模型,并以此模型对武汉市2个已建成的餐厨垃圾处理厂选址进行适宜性评价.结果表明,2个已建成的餐厨垃圾处理厂的选址为合格选址.评价模型较客观反映了武汉餐厨垃圾处理厂的实际情况,具有较强的适用性和可靠性.     

餐厨垃圾堆肥项目除臭技术选择与设计

通过对比现有除臭技术,分析餐厨垃圾高温好氧堆肥过程的臭气成分和除臭机理,认为化学、生物组合除臭工艺和植物液喷淋除臭工艺相结合是合适的选择.并介绍了除臭系统设计要点.     

某公司顺丁橡胶装置节能降耗改造项目职业病危害控制效果评价

目的明确建设项目产生的职业病危害因素,分析其危害程度及对劳动者健康的影响,评价职业病危害防护措施及其效果,为卫生行政部门对建设项目职业病防护设施竣工验收提供科学依据。方法根据国家相关标准,通过职业卫生现场调查、职业卫生检测、职业健康检查及检查表分析法等方法对建设项目进行评价。结果该项目在职业病防护设施、建筑卫生学、辅助用室、应急救援、职业健康检查和职业卫生管理制度方面基本符合职业卫生的要求,在个体防护用品的配置及警示标识的设置方面有待进一步完善。结论该建设项目在设备布局、毒物危害控制、应急救援、建筑卫生学和辅助用室等方面符合法律、法规和《工业企业设计卫生标准》（GBZ1—2010）的要求。     

Leucoxenols A and B,two new phenolics from Bornean medicinal plant Syzygium leucoxylon

The medicinal plant, Syzygium leucoxylon or commonly known as Obah found in North Borneo was considered as traditional medicine by local committee. Two new phenolics, leucoxenols A (1) and B (2) were isolated and identified as major secondary metabolites from the leaves of S. leucoxylon. Their chemical structures were elucidated based on spectroscopic data such as NMR and HRESIMS. Furthermore, these compounds were active against selected strains of fungi.     

Modulatory effects of Saussurea lappa root aqueous extract against ethephon‐induced kidney toxicity in male rats

Ethephon (2‐chloroethyl phosphonic acid) is a plant growth promoter used to control the plant growth process by liberating ethylene and stimulating the production of endogenous ethylene. Medicinal plants are sources of novel drug discovery targets. Costus (Saussurea lappa) has been used as traditional Chinese medicine. The current study was conducted to examine the possible modifying effects of costus (S. lappa) root aqueous extract against kidney toxicity induced by ethephon in male rats. A total of 50 adult male rats were divided into five groups (first, control; second, costus; third, ethephon; fourth, posttreated ethephon with costus; fifth, ethephon self‐healing). There is a significant increase in the serum levels of urea, creatinine, potassium ions, chloride ions, kidney injury, DNA damage, and proliferating cell nuclear antigen expressions in treated rats with ethephon when compared to the control group. In contrast, the treated rats with ethephon revealed a significant decrease in the levels of sodium ions and an insignificant decrease in the calcium ions. Saussurea lappa extract modified these alterations when compared to the control group. As a result, costus root extract significantly reduced rat kidney toxicity after ethephon administration. We recommend costus to be included in diet for its valuable effects, and also producers and consumers should become more aware about the toxic effects of ethephon.     

Efficacy of different plant extracts in the prevention of radiation dermatitis in radiotherapy patients with nasopharyngeal carcinoma: A protocol for a Bayesian network meta-analysis

Background:Radiation dermatitis is a common complication in patients with nasopharyngeal carcinoma (NPC) when treated with radiotherapy. Plant extracts have good effects on the prevention of radiation dermatitis in patients with NPC when treated with radiotherapy. However, there is insufficient comparison among the currently used plant extracts. Therefore, the purpose of this study was to explore the efficacy of different plant extracts in the prevention of radiation dermatitis in patients with NPC by Bayesian network meta-analysis.Methods:We searched Chinese and English databases to collect all randomized controlled trials (RCT) of plant extracts for the prevention of radiation dermatitis in NPC patients who underwent radiotherapy up to October 2020. Two researchers then independently screened articles, extracted data and evaluated the quality selected literatures. All data were processed by Stata 14.0 and WinBUGS V.1.4.3.Results:We applied Bayesian statistical model for network meta-analysis, ranked the effects of various plant extracts, and adopted GRADE method to explain the results.Conclusion:Our study is expected to provide high-quality evidence-based medicine advice for the prevention of radiation dermatitis in patients suffering from NPC undergoing radiotherapy.Ethics and dissemination:Ethical approval was not required for this study. The systematic review will be published in a peer-reviewed journal, presented at conferences, and will be shared on social media platforms. This review would be disseminated in a peer-reviewed journal or conference presentations.OSF REGISTRATION NUMBER:DOI 10.17605/OSF.IO/6SV45.     

Phenalenone-type phytoalexins mediate resistance of banana plants (Musa spp.) to the burrowing nematode Radopholus similis

The global yield of bananas—one of the most important food crops—is severely hampered by parasites, such as nematodes, which cause yield losses up to 75%. Plant–nematode interactions of two banana cultivars differing in susceptibility to Radopholus similis were investigated by combining the conventional and spatially resolved analytical techniques ¹H NMR spectroscopy, matrix-free UV-laser desorption/ionization mass spectrometric imaging, and Raman microspectroscopy. This innovative combination of analytical techniques was applied to isolate, identify, and locate the banana-specific type of phytoalexins, phenylphenalenones, in the R. similis-caused lesions of the plants. The striking antinematode activity of the phenylphenalenone anigorufone, its ingestion by the nematode, and its subsequent localization in lipid droplets within the nematode is reported. The importance of varying local concentrations of these specialized metabolites in infected plant tissues, their involvement in the plant’s defense system, and derived strategies for improving banana resistance are highlighted.Bananas and plantains (Musa spp.) are among the world’s most important food and cash crops, with a global production of about 138 million tons in 2010. These crops are part of a well-balanced human diet and are a major food staple for more than 400 million people in the tropics (1, 2). About 82% of the world’s banana production is consumed locally, particularly in India, China, and many African countries (Table S1) (1, 2). Export of bananas to the northern hemisphere represents an important source of employment in countries such as Costa Rica, Ecuador, Colombia, and the Philippines (Table S2) (1, 2). Banana yields are severely hampered by fungi, insects, and plant-parasitic nematodes. The burrowing nematode, Radopholus similis (Cobb, 1893) Thorne, 1949, is the key nematode pathogen, causing yield losses up to 75% (3). R. similis is found in all major banana-producing regions of the world; its best-known hosts are bananas, black pepper, Citrus spp. (4), and coffee (5). R. similis causes extensive root lesions that can lead to toppling of banana plants (6).Plant-parasitic nematodes have been effectively managed through the use of nematicides. However, their high toxicity has adverse effects on humans and their toxic residues are known to accumulate through nontarget organisms in the food chain (7). After the withdrawal of many effective nematicides, such as methyl bromide, from the market (8), organophosphate and carbamate nematicides are still intensively applied to banana and therefore continue to threaten the health of agricultural workers and the environment (9). Although several biological control approaches, including the application of both single and multiple control organisms—such as Fusarium oxysporum, Paecilomyces lilacinus, Trichoderma atroviride isolates, and Bacillus firmus—have proved promising under greenhouse conditions, the control they confer to banana plants most probably does not protect plants for more than one cycle in the field, and most of these organisms have yet to be tested under field conditions (10).The in-depth investigation of the plant–nematode interactions at the cellular and molecular level could lead to the development of more rational and efficient control strategies (11). The production of toxic, herbivore-deterrent or -repellent secondary metabolites, which is typical for many plant defense systems, is particularly interesting in this context. Musa cultivars resistant to R. similis have been identified, especially the cultivar Yangambi km5 (Ykm5) (12). Histochemical and ultrastructural investigations of lesions caused by R. similis in Ykm5 revealed the accumulation of phenolic compounds in response to infection (13). Unfortunately, many of these studies were based solely on histochemical staining methods and did not identify the chemical structures of nematicidal secondary metabolites (7, 14, 15). Initial phytochemical analyses of R. similis-infected roots of the Musa cultivar Pisang sipulu identified the phenylphenalenone anigorufone (1) as a phytoalexin produced in response to nematode damage and confirmed earlier suggestions of the significant role of phytoalexins in the plant defense system (16). Phenylphenalenones are a group of special phenylpropanoid-derived natural products (17), which are known as Musaceae phytoalexins (18). The activity of phenylalanine ammonia lyase (EC 4.3.15), the entry-point enzyme of the phenylpropanoid pathway, is correlated to the biosynthesis of specific phenylpropanoids involved in defense and was substantially induced in nematode infected roots of Ykm5 (19). Phenylphenalenone-related compounds show biological activity against bacteria, fungi, algae, and diatoms (18, 20–22). The formation of these compounds has been elicited in banana leaves by Mycosphaerella fijiensis (Black Sigatoka leaf streak disease), in the fruit peels by Colletotrichum musae (anthracnose disease), and in roots and rhizomes by F. oxysporum f. sp. cubense (Panama disease) and R. similis (16, 18, 21, 23).     

Chitin-induced activation of immune signaling by the rice receptor CEBiP relies on a unique sandwich-type dimerization

Perception of microbe-associated molecular patterns (MAMPs) through pattern recognition receptors (PRRs) triggers various defense responses in plants. This MAMP-triggered immunity plays a major role in the plant resistance against various pathogens. To clarify the molecular basis of the specific recognition of chitin oligosaccharides by the rice PRR, CEBiP (chitin-elicitor binding protein), as well as the formation and activation of the receptor complex, biochemical, NMR spectroscopic, and computational studies were performed. Deletion and domain-swapping experiments showed that the central lysine motif in the ectodomain of CEBiP is essential for the binding of chitin oligosaccharides. Epitope mapping by NMR spectroscopy indicated the preferential binding of longer-chain chitin oligosaccharides, such as heptamer-octamer, to CEBiP, and also the importance of N-acetyl groups for the binding. Molecular modeling/docking studies clarified the molecular interaction between CEBiP and chitin oligosaccharides and indicated the importance of Ile₁₂₂ in the central lysine motif region for ligand binding, a notion supported by site-directed mutagenesis. Based on these results, it was indicated that two CEBiP molecules simultaneously bind to one chitin oligosaccharide from the opposite side, resulting in the dimerization of CEBiP. The model was further supported by the observations that the addition of (GlcNAc)₈ induced dimerization of the ectodomain of CEBiP in vitro, and the dimerization and (GlcNAc)₈-induced reactive oxygen generation were also inhibited by a unique oligosaccharide, (GlcNβ1,4GlcNAc)₄, which is supposed to have N-acetyl groups only on one side of the molecule. Based on these observations, we proposed a hypothetical model for the ligand-induced activation of a receptor complex, involving both CEBiP and Oryza sativa chitin-elicitor receptor kinase-1.Plants have the ability to detect potential pathogens through the recognition of microbe-associated molecular patterns (MAMPs; also known as pathogen-associated molecular patterns), such as flagellin, elongation factor Tu (EF-Tu), peptidoglycan, LPS, chitin, and β-glucan, which are typical molecular signatures for whole classes of microbes (1, 2). MAMP-triggered defense is the first barrier to prevent the invasion of pathogens and plays a major role in the basal resistance of plants against various pathogens. It is also well known that this defense system is strikingly similar to the innate immunity of animals (1, 3, 4).Leucine-rich repeat receptor-like kinases, flagellin-sensetive 2 (FLS2), and EF-Tu receptor, have been shown to recognize bacterial flagellin and EF-Tu, respectively, and serve as receptors for these MAMPs (5). On the other hand, two types of lysin motif (LysM) proteins, CEBiP (chitin-elicitor binding protein) and CERK1 (chitin-elicitor receptor kinase-1), were identified as the cell-surface receptor for chitin, a representative fungal molecular pattern (6–8). Knockout/-down experiments of these genes showed that both of these LysM proteins are required for chitin perception and signaling in rice, whereas CEBiP-type molecules are not involved in chitin signaling in Arabidopsis, indicating the difference between the chitin receptor systems in these model plants (8). Additionally, another LysM receptor-like kinase, LYK4, was also indicated to contribute to chitin signaling in Arabidopsis (9). In the case of rice, it was also shown that CEBiP and Oryza sativa (Os)CERK1 form a heterooligomeric receptor complex ligand dependently (10).Both CEBiP and OsCERK1 have LysMs, which have been known to bind peptidoglycan and chitin (11), in their ectodomains. In Arabidopsis, CERK1 was shown to bind chitin and trigger immune responses as a kind of “all-in-one” receptor. On the other hand, CEBiP seems to play a major role in the perception of chitin in rice, as the knockdown of CEBiP almost abolished the binding of a radio-labeled chitin oligosaccharide to the plasma membrane, whereas OsCERK1 was shown not to bind chitin (6, 12). Liu et al. recently reported that two other CEBiP homologs, OsLYP4 and -6, also bind chitin and contribute to chitin responses and disease resistance in rice (13), although it is not clear to what extent these proteins contribute as the cell surface receptor for chitin oligosaccharides.It was also shown that the perception of peptidoglycan in Arabidopsis requires CEBiP-like molecules (14). Arabidopsis homologs of CEBiP, LYM1 and LYM3, play a major role for the binding of peptidoglycan and activation of downstream defense responses through the receptor kinase, CERK1. These results showed that the receptor kinase CERK1 is required for both chitin and peptidoglycan signaling, at least in Arabidopsis. The peptidoglycan receptor system in Arabidopsis seems similar to the rice chitin receptor for the requirement of a binding protein and a receptor kinase, although the receptor complex formation by these two proteins was not confirmed.Thus, the detailed analysis of ligand recognition by these CEBiP-like molecules and succeeding formation and activation of receptor complex is critically important to understand the molecular mechanisms leading to the activation of downstream defense responses triggered by these MAMPs. Such information would also contribute to the design of novel receptor molecules suitable for future biotechnological application. We show herein the results obtained by biochemical studies on the binding site of CEBiP, epitope mapping of chitin oligosaccharides by saturation transfer difference (STD) NMR spectroscopy, and molecular modeling/docking studies combined with site-directed mutagenesis of the ectodomain of CEBiP. These results clearly indicated that two CEBiP molecules simultaneously bind to one N-acetylchitoheptaose/octaose, (GlcNAc)_7/8, through a binding site located in the central LysM region of the ectodomain, resulting in the dimerization of CEBiP. Based on these observations, we proposed a hypothetical model for the ligand-induced activation of a receptor complex, involving both CEBiP and OsCERK1.