Zunyi Area Research Articles

A distinct manganese deposit on a Middle Permian carbonate platform in South China

During the Middle Permian, Earth experienced a period of profound environmental changes, including the final stages of the Late Paleozoic Ice Age (LPIA), global seawater regression, the Guadalupian mass extinction event, and the eruption of the Emeishan Large Igneous Province (ELIP) in South China. These events collectively induced significant shifts in both the environment and biosphere, yielding several geochemical anomalies, including deposition of manganese (Mn) deposits. The link between Middle Permian Mn deposits and the prevailing environmental conditions, however, remains unclear. Here, four sections spanning the Middle Permian Maokou Formation to the Late Permian Longtan Formation in the Zunyi area of northern Guizhou, South China are investigated. Through sedimentological and geochemical analyses, this work aims to elucidate the evolution of sedimentary environments over the Middle to Late Permian. During this period, a transition from a shallow-water carbonate platform in the 1st Member of the Maokou Formation to a deeper, siliceous deposit in its 2nd Member was recorded. This shift results in a pronounced paleogeographic differentiation in the 3rd Member, juxtaposing the shallow-water carbonate platform against a deeper Mn-enriched basin. A number of geochemical proxies indicate a strong hydrothermal signal in the Mn deposits. Combined with positive Eu anomalies and low Sr isotopes, the data underscore the profound influence of hydrothermal input linked with early subaqueous eruptions from the ELIP on the nearby marine environment. A detailed examination of carbon isotope profiles from the Maokou Formation indicates that volcanic influences, shifts in marine ecosystems, and changes in primary production caused the fluctuations of δ13Ccarb and δ13Corg. Moreover, the formation of Mn carbonate in deeper waters effectively sequestered organic C. Collectively, our new data demonstrate that the essential conditions for the development of the carbonate-hosted Mn deposits include drowning of the carbonate platform through an increase in sea level, the availability of a sufficient Mn source, and the presence of a redox-stratified water column.

Incidence and influencing factors of iron deficiency anemia among rural children less than 1 year old in Zunyi area

目的 分析遵义地区1岁以下农村儿童缺铁性贫血(IDA)的发病情况，探讨其相关影响因素。 方法 采用队列研究方法，分层抽样选取2017年8月至2018年8月遵义地区1岁以下农村儿童进行IDA筛查，通过问卷调查、血液学检测获得相关资料。采用χ2检验进行单因素分析，采用非条件Logistic回归分析进行多因素分析，探讨婴幼儿IDA的主要影响因素。 结果 共纳入672例儿童，贫血发生率为37.50%(252/672例)，男童发病率为36.19%，女童发病率为39.03%，差异无统计学意义(χ2＝0.576，P＝0.448)。单因素分析显示，IDA与年龄(χ2＝53.546，P<0.001)、出生孕周(χ2＝63.423，P<0.001)、饮食结构(χ2＝27.920，P<0.001)、孕期是否补铁(χ2＝25.036，P<0.001)、喂养方式(χ2＝66.274，P<0.001)、家庭年收入(χ2＝65.153，P<0.001)相关。多因素非条件Logistic回归分析显示：母乳喂养(OR＝0.512，95%CI：0.365～0.718)、6个月～<1岁(OR＝5.333，95%CI：3.069～9.266)、早产儿(OR＝0.039，95%CI：0.015～0.098)、孕前未服用铁(OR＝1.807，95%CI：1.074～3.040)、单一谷物饮食(OR＝0.458，95%CI：0.299～0.701)、家庭人均年收入<5 000元(OR＝0.047，95%CI：0.029～0.077)为IDA的危险因素。 结论 遵义地区1岁以下农村儿童IDA发病率较高，母乳喂养、6个月～<1岁龄、早产儿、孕前未服用铁、单一谷物饮食、家庭人均年收入<5 000元为该地区1岁以下农村儿童IDA发病的主要危险因素。

Analysis on metallogenic environment of the Fuxing bauxite in Zunyi area, northern Guizhou, China

The ore-forming environment of Fuxing bauxite in the Zunyi area of northern Guizhou Province was analyzed by field geological survey, hand specimen observation and geochemical analysis. The results show that the sedimentary environment of Fuxing bauxite is a continental lake or marsh environment, and the sedimentary environment is reduced Environment, but the leaching process is an acidic oxidizing environment; Al has a good positive correlation with Ti, and Al has a negative correlation with Si and Fe; ore-bearing rock is formed in a strong acidic environment. Fe rapidly migrates to the bottom, but leaching when it is insufficient, Si does not have time to migrate, so that the Fe content in the ore is low but the ore grade is still low.

Giant bauxite deposits of South China: Multistage formation linked to Late Paleozoic Ice Age (LPIA) eustatic fluctuations

The Lower Carboniferous Jiujialu Formation bauxite deposits at Zunyi, northern Guizhou are distinguished by their great thickness (to 110 m) and cyclic alternation of bauxite ore and bauxitic claystone layers. These features are typical of the Kazakhstan subtype of karst bauxite deposits, although the genesis of this type of deposit is poorly understood. Here, we undertook a petrological, mineralogical, and geochemical study of the Zunyi deposit in drillcore ZK5600 to gain insights into its formation history. The Zunyi profile contains seven bauxite cycles, as recorded by petrological, mineralogical and geochemical features, indicating a multistage formation history. Each cycle is composed of a lower bauxitic claystone layer and an upper bauxite ore layer. The bauxite ore is characterized by high Al2O3, high Al-mineral (diaspore), and low SiO2 content. Positive Ce anomalies, high CIA values (>90), and strong depletion of major elements indicate that the bauxite ore formed through intense chemical weathering and leaching in a well-drained soil environment. The bauxitic claystone is characterized by relatively lower Al2O3 and higher SiO2 and clay mineral (mostly illite) content. This lithology exhibits both negative and positive Ce anomalies, moderate CIA values (70–80), and enrichment of some elements (e.g., Fe, K), indicating formation through moderate chemical weathering in a poorly drained soil environment. Secular variations in chemical weathering intensity and soil drainage conditions were linked to regional hydrologic changes. During the early Carboniferous, the Zunyi area was located in a karstified coastal upland setting, and its hydrologic system was affected by glacio-eustatic fluctuations. High groundwater table elevations during eustatic highstands led to formation of bauxitic claystone layers, whereas low groundwater table elevations during eustatic lowstands led to formation of bauxite ore layers.

Analysis of drug resistance of Staphylococcus aureus in bone and joint infection in children

Objective To investigate the drug resistance and its changes of Staphylococcus aureus (SA) in children with bone and joint infection caused by hematogenous dissemination in Zunyi area. Methods A retrospective study was performed on the clinical data of 95 cases with bone and joint infections caused by SA from January 2008 to December 2016 in the Affiliated Hospital of Zunyi Medical College, in which there were 53 boys and 42 girls with a mean age of 5.6 years(ranging from 10 days to 14 years), including 39 cases of acute osteomyelitis, 31 cases of acute suppurative arthritis, 19 cases of chronic osteomyelitis, and 6 cases of acute osteomyelitis and arthritis.According to the results of drug sensitivity, the drug resistance of SA was analyzed, and the detection rates of Methicillin resistant Staphylococcus aureus (MRSA) were compared in different genders and timeframes, and the drug resistance of SA to other antibiotics were also analyzed. Results The detection rate of MRSA was 50.53%(48 cases) in 95 cases, the resistance rate to Penicillin was 92.63%(88 cases), and to Lincomycin, Erythromycin, Tetracycline and Cefoxitin were 64.21%(61 cases), 57.90%(55 cases), 55.79%(53 cases) and 53.68%(51 cases) respectively, but to Sulfamethoxazole Co., Gentamicin and Rifampicin it was relatively low[25.26%(24 cases), 11.58%(11 cases), 6.32%(6 cases) respectively], while the resistance to Moxifloxacin, Linezolid, Tigecycline, Vancomycin and Nitrofurantoin was not found.The detection rate of MRSA in boys(52.83%, 28/53 cases) was slightly higher than that of girls(47.62%, 20/42 cases), but the difference was not statistically significant (χ2=0.255, P>0.05). The detection rates of MRSA in 2008-2010, 2011-2013 and 2014-2016 were 27.78%(5/18 cases), 51.61%(16/31 cases) and 58.70%(27/46 cases) respectively, and it was obviously higher in 2014-2016 than in 2008-2010, and the difference was statistically significant (χ2=4.95, P<0.05). The drug resistance rate of SA to Lincomycin, Erythromycin and Cefoxitinis was obviously higher in 2014-2016 than in 2008-2010, and the differences were all statistically significant (all P<0.05). Conclusions The drug resistance of SA is high with the bone and joint infection caused by hematogenous dissemination in children, and the detection rate of MRSA and the drug resistance of SA to a variety of antimicrobial agents are gradually increasing. Key words: Child; Bone and joint infection; Staphylococcus aureus; Drug resistance

Migration laws of major elements of Laowashan bauxite in Zunyi area, northern Guizhou province of China

After exploring migration laws of major elements in Laowashan bauxite of northern Guizhou Province by geochemical methods, it was found that: 1) Si was negatively correlated to Al and Ti; Al showed significant negative correlations with Si and Fe; Al was positively correlated to Ti. 2) The content of Si and Fe was low in the middle part, high at the top and the highest at the bottom. The content of Al and Ti is the highest in the middle, followed by the content at the top and the bottom successively. 3) Karst depressions are favorable for groundwater discharge through leaching, leading to heavy loss of Fe in ZK-CS1.

Features and geological significance of trace elements of Laowashan bauxite in Zunyi area, northern Guizhou, China

By analysing features of trace elements in ZK-CS1 Laowashan Bauxite of Zunyi by geochemical methods, it was found that these elements could be divided into four types according to features of their vertical distribution. For instance, the content of elements such as Ga, Li and Sc was relatively low in the middle part of the ore-bearing rock series, but increasingly higher towards the top and bottom, and the highest at the bottom or near the bottom. Nb and Ta, Zr and Hf migrated in pairs during metallogenesis. The dolomite in the underlying Loushanguan Formation of the ore-bearing rock series was one of provenances of the Laowashan bauxite.

Ore-forming fluid system of bauxite in Zunyi area of northern Guizhou province, China

The ore-forming fluid system of Laowashan bauxite in Zunyi area of northern Guizhou Province was studied through field geological survey and observation of hand specimens. It was concluded that surface runoff, atmospheric precipitation and sea level changes played important roles in the formation of the aforementioned bauxite. Under the impacts of vertical leaching of ore-forming fluids, industrial bauxite deposit and pyrite deposit formed in the upper and lower parts of the ore-bearing rock series respectively.

Rare Earth Lanthanum Oxide of Manganese Slag Ceramic Related Physical Properties of Function

Abstract: By adding rare earth lanthanum oxide on Zunyi area failed comprehensive utilization of manganese slag test, according to a certain proportion to make rare earth ceramics, understanding the effects of rare earth elements on firing, and the influence of the temperature of the compressive, flexural performance and bibulous rate test, the rare earth elements manganese residue to explore the influence of the ceramic certain performance. Sintering temperature from 1220 °C to 1135 °C with the increased amount of rare earth, when the rare earth content is 6% the compressive strength is highest, when the rare earth content is 10% the bending strength is the highest and the bibulous rate is the lowest. It has a guiding significance on the rare earth ceramic materials development in the future, at the same time, providing valuable research material for reducing the manganese slag pile.

Rare Earth Lanthanum Oxide of Manganese Slag Ceramic Related Physical Properties of Function

By adding rare earth lanthanum oxide on Zunyi area failed comprehensive utilization of manganese slag test, according to a certain proportion to make rare earth ceramics, understanding the effects of rare earth elements on firing, and the influence of the temperature of the compressive, flexural performance and bibulous rate test, the rare earth elements manganese residue to explore the influence of the ceramic certain performance. Sintering temperature from 1220 °C to 1135 °C with the increased amount of rare earth, when the rare earth content is 6% the compressive strength is highest, when the rare earth content is 10% the bending strength is the highest and the bibulous rate is the lowest. It has a guiding significance on the rare earth ceramic materials development in the future, at the same time, providing valuable research material for reducing the manganese slag pile.

Genetic Diversity and Drug Susceptibility of Mycobacterium tuberculosis Isolates from Zunyi, One of the Highest-Incidence-Rate Areas in China

Mycobacterium tuberculosis isolates from Zunyi were found more diversified but clustered less frequently to the Beijing family compared to isolates from other areas of China. These observations, on top of the fact that the Zunyi area has a high prevalence of multidrug-resistant tuberculosis (MDR-TB), support the notion that Beijing family isolates may not be linked to MDR-TB.

High prevalence of multidrug-resistant tuberculosis in Zunyi, Guizhou Province of China

Sir, According to the WHO Report 2010, China had the most multidrug-resistant tuberculosis (MDR-TB) cases in 2008, followed by India and Russia, and was ranked 16th in terms of the estimated proportion of primary (5.7%) and acquired (previously treated) MDR-TB cases among the 27 MDR-TB highburden countries. However, our recent drug-susceptibility surveillance results indicated that the prevalence of acquired MDR-TB cases in the Zunyi area, Guizhou province, China, was much higher (45.1%) than the average prevalence of acquired MDR-TB in China (25.6%), but lower than those in the top six MDR-TB high-burden countries (Tajikistan, Kazakhstan, Azerbaijan, Republic of Moldova, Uzbekistan and Lithuania). To determine the prevalence and trends of drug-resistant TB in the Zunyi area, in order to improve the treatment outcomes of TB patients, 263 Mycobacterium tuberculosis clinical isolates were collected at the Affiliated Hospital of Zunyi Medical College from 2008 to 2010 and used in drug susceptibility testing against rifampicin, isoniazid, streptomycin and ethambutol. We used the proportion method on Lowenstein–Jensen media with different concentrations of drugs (rifampicin 40 mg/L, isoniazid 0.2 mg/L, streptomycin 4 mg/L and ethambutol 2 mg/L). The standard M. tuberculosis H37Rv strain was used as a control for all testing. To compare our results with those from other provinces of China, we selected recent survey results from Shanghai and 4 out of the 10 provinces (covering 38% of the total Chinese population) with the highest rates of MDR among new TB cases (5.4%–10.4%), and combined them with ours in Table 1. Results indicated that the Zunyi area had the highest prevalence of MDR-TB among previously treated (45.1%) and the second highest among new (8.1%) TB cases in China. In addition, it was observed that the proportions of rifampicin and isoniazid resistance in previously treated (56.0% versus 59.3%) and new (12.2% versus 14.5%) TB cases from the Zunyi area were similar (Table 1), which indicated that isoniazid resistance might be related to rifampicin resistance and that screening for rifampicin resistance could be used as a marker for the detection of MDR-TB. Since isoniazid has not been widely used as monotherapy for latent TB in China, this could explain the relative lack of single resistance to isoniazid in new TB cases observed in this study. It is obvious that percentages of TB cases with resistance to any of the four drugs in the Zunyi area were much higher than those from other provinces among previously treated TB cases (Table 1), suggesting that the Zunyi area of Guizhou province is one of the worst-affected areas in China and should be included in future surveillance of drug resistance in tuberculosis to better represent the prevalence of MDR-TB in China. To compare our results with those from other high-burden countries, such as India and Russia, we selectively included in Table 1 four studies with the highest proportions of MDR among previously treated patients (from 49% in Haryana to 38.2% in Rajasthan) out of the eight studies from India, five countries with the highest proportions of MDR among new TB cases (from 14.4% in Latvia to 4.0% in Ivanovo Oblast) from 35 countries that participated in the global surveillance (1994–97), and five countries with the highest proportions of MDR among new TB cases (from 22.3% in Azerbaijan to 14.8% in Uzbekistan) out of 83 countries/territories surveyed between 2002 and 2007. Comparison of the results shows that the Zunyi area of Guizhou Province, China, has the highest rate of TB cases resistant to ethambutol among previously treated patients (41.8%), and is one of the top 10 areas in the world in terms of the estimated proportion of MDR-TB cases among previously treated TB cases. Consequently, more surveillance should be conducted in the Zunyi area to monitor the trend of MDR-TB transmission, improve the treatment outcomes of TB patients and control the spread of drug-resistant TB, especially MDR-TB.

Association of HLA-A * 3101, B * 4001, B * 5801 and DRB1 * 1602 alleles with hemorrhagic fever with renal syndrome disease in Han population of Zunyi province

Objective To explore the association between HLA-A*31, B*40, B*58 and DRB1*16 allele polymorphisms and onset of hemorrhagic fever with renal syndrome (HFRS) in Zunyi Han population. Methods Using group study, HLA-A*31, B*40, B*58 and DRB1*16 genotyping was conducted in 100 HFRS cases and 100 controls among Han population in Zunyi area with polymerase chain reactionsequence specific primer(PCR-SSP), gene frequency (GF) and relative risk (RR) were calculated and compared. Results The results showed that the frequencies of A*3101, B*5801 and DRB1*1602 were increased in patients as compared to the healthy controls ( RR = 13. 825, x2 = 4. 296, P = 0. 038; RR =2.614,x2 =6. 133,P=0.013;RR =8.523,x2 =8. 865,P=0. 003). The frequency of B*4001 in patients with HFRS were significantly lower than that in the healthy controls( RR =0.414,x2 =6.640,P =0. 010).Conclusion These results suggest that HLA-A*3101, B*5801 and DRB1*1602 haplotypes were strongly associated with susceptibility to HFRS disease in Zunyi Han population and allele HLA-B*4001 might be associated with protection against hantaviruses infection. Key words: Human leukocyte antigen; Gene haplotype; Hemorrhagic fever with renal syndrome; Association

Tracing the sources of nitrate in karstic groundwater in Zunyi, Southwest China: a combined nitrogen isotope and water chemistry approach

Nitrate (NO3−) is major pollutant in groundwater worldwide. Karst aquifers are particularly vulnerable to nitrate contamination from anthropogenic sources due to the rapid movement of water in their conduit networks. In this study, the isotopic compositions (δ15N–NO3−, δ15N–NH4+) and chemical compositions(e.g., NO3−, NH4+, NO2−, K+) were measured in groundwater in the Zunyi area of Southwest China during summer and winter to identify the primary sources of contamination and characterize the processes affecting nitrate in the groundwater. It was found that nitrate was the dominant species of nitrogen in most of the water samples. In addition, the δ15N–NO3− values of water samples collected in summer were lower than those collected in winter, suggesting that the groundwater received a significant contribution of NO3− from agricultural fertilizer during the summer. Furthermore, the spatial variation in the concentration of nitrate and the δ15N–NO3− value indicated that some of the urban groundwater was contaminated with pollution from point sources. In addition, the distribution of δ15N–NO3− values and the relationship between ions in the groundwater indicated that synthetic and organic fertilizers (cattle manure) were the two primary sources of nitrate in the study area, except in a few cases where the water had been contaminated by urban anthropogenic inputs. Finally, the temporal and spatial variation of the water chemistry and isotopic data indicated that denitrification has no significant effect on the nitrogen isotopic values in Zunyi groundwater.

Diversity analysis of the Early Ordovician Sinorthis Fauna (Brachiopoda) from the Meitan Formation of Zunyi, northern Guizhou, South China

ABSTRACTThe lower Meitan Formation (Floian, upper Lower Ordovician) at the Dajiaosi section, Zunyi District, northern Guizhou Province of South China, contains a moderately rich and diverse Sinorthis Fauna, with 22 species attributable separately to 15 families and seven orders of brachiopods. The fauna can be differentiated into three associations: the Paralenorthis serica, the Sinorthis typica, and the Tarfaya intercalare associations. These occupied a relatively wide palaeoecological range from lower BA3 to upper BA2 settings and from silty to clay substrate conditions. In South China, the Early Ordovician brachiopod radiation was marked by the diversification of the orthide-dominated Sinorthis Fauna, which first appeared and diversified in the middle part (relatively deep water) of the Upper Yangtze Platform in the Didymograptellus eobifidus Biozone, but rapidly declined in the succeeding Corymbograptus deflexus and basal Azygograptus suecicus biozones. During the latest Floian and early Dapingian, it expanded into comparatively shallow-water settings in the onshore direction (Changning area, southern Sichuan), offshore carbonate platform (Yichang, Hubei), and areas adjacent to the submergent Qianzhong Arch (such as the Zunyi area). The first appearance datum of the Sinorthis Fauna in shallower-water settings generally postdates that in the deeper-water environment in the central Upper Yangtze Platform, probably as a result of the fauna tracking a favoured BA3 setting during a gradual marine transgression.