Ecotoxicity of Cadmium to Maize and Soybean Seedling in Black Soil

Ecotoxicity and bioavailability of cadmium （Cd） to the maize （Zea mays L.） and the soybean （Glycine max （L.） Merr.） were investigated by acute toxicity experiment in the laboratory with black soil. Ecotoxicity and bioavailability of Cd were quantified by calculating the median effective concentration （ECs0） and bioaccumulation factor （BAF）. The measurement endpoints used were seed germination and seedling growth （shoot and root）. The results showed that concentrations of Cd in the soil had adverse effect on the growth of roots and shoots. Seed germination was not the sensitive indicator for the ecotoxicity of Cd in the soil, while the growth of roots was the most sensitive measurement endpoint. Absorbability and transport of Cd in plants depended on the test crop species and Cd concentrations in the soil. The maize retains more Cd in its roots, while the soybean transports more Cd to the shoots from roots.

Drought and flood characteristics in the farmingpastoral ecotone of northern China based on the Standardized Precipitation Index

The farming-pastoral ecotone of northern China(FPENC)provides an important ecological barrier which restrains the invasion of desert into Northwest China.Studying drought and flood characteristics in the FPENC can provide scientific support and practical basis for the protection of the FPENC.Based on monthly precipitation data from 115 meteorological stations,we determined the changes in climate and the temporal and spatial variations of drought and flood occurrence in the FPENC during 1960-2020 using the Standardized Precipitation Index(SPI),Morlet wavelet transform,and inverse distance weighted interpolation method.Annual precipitation in the FPENC showed a slightly increasing trend from 1960 to 2020,with an increasing rate of about 1.15 mm/a.The interannual SPI exhibited obvious fluctuations,showing an overall non-significant upward trend(increasing rate of 0.02/a).Therefore,the study area showed a wetting trend in recent years.Drought and flood disasters mainly occurred on an interannual change cycle of 2-6 and 9-17 a,respectively.In the future,a tendency towards drought can be expected in the FPENC.The temporal and spatial distribution of drought and flood differed in the northwestern,northern,and northeastern segments of the FPENC,and most of the drought and flood disasters occurred in local areas.Severe and extreme drought disasters were concentrated in the northwestern and northeastern segments,and severe and extreme flood disasters were mainly in the northeastern segment.Drought was most frequent in the northwestern segment,the central part of the northeastern segment,and the northern part of the northern segment.Flood was most frequent in the western part of the northwestern segment,the eastern part of the northeastern segment,and the eastern and western parts of the northern segment.The accurate evaluation of the degrees of drought and flood disasters in the FPENC will provide scientific basis for the regional climate study and critical information on which to base decisions regarding environmental protection and socio-economic development in this region.

10例鹦鹉热衣原体肺炎临床分析

目的探讨鹦鹉热衣原体肺炎患者的临床特点以及具有家禽类接触史的患者尽早进行宏基因二代测序(metagenomics next-generati sequencing,mNGS)在早期诊断中的重要性。方法收集2020年11月—2021年1月新泰市第三人民医院收治的10例鹦鹉热衣原体肺炎患者的临床资料。回顾性分析患者的临床表现、各项实验室检查结果、肺部影像学结果、mNGS病原学结果及治疗转归。结果10例患者中有9例为当地肉食鸭加工厂工人,1例发病前曾接触过鹦鹉。临床表现主要为发热、咳嗽、乏力、肌肉酸痛。8例患者白细胞计数轻度升高,中性粒细胞比例、C反应蛋白(C reactive protein,CRP)10例患者均升高;9例患者血沉(erythrocyte sedimentation rate,ESR)升高;5例患者降钙素原(procaicltonin,PCT)升高;D-二聚体除2例患者正常外其余8例不同程度升高;3例患者出现谷草转氨酶(aspartate aminotransferase,AST)、谷丙转氨酶(Alanine aminotransferase,ALT)轻度升高;4例患者心肌酶异常,主要为肌酸激酶(creatine kinase,CK)和乳酸脱氢酶(lactate dehydrogenase,LDH)轻度升高。胸部CT检查9例患者为单侧肺段或肺叶实变,1例患者为双侧肺叶斑片状实变影,其中2例患者有少量胸腔积液。10例患者均未出现肾功能受损。10例患者均行mNGS检测,检出鹦鹉热衣原体核酸序列,确诊后给予多西环素联合莫西沙星治疗,均治愈。结论鹦鹉热衣原体肺炎发病率低,临床医生重视不足,但在接触禽类养殖和加工人群中若发生短期聚集性发热、咳嗽等症状,需提高警惕,在发病初期对疑似病例应尽早行mNGS检测,避免误诊漏诊。