Northern Sichuan Province Research Articles

Status quo and factors influencing dyadic disease appraisal in chronic heart failure based on latent profile analysis in Northern Sichuan Province, China

PurposeThis study explored potential categories of dyadic disease appraisal differences among patients hospitalized with chronic heart failure (CHF) in China and analyzed the main factors influencing these categories.MethodsA survey was conducted using various tools and scales, including the Chinese version of the Memorial Heart Failure Symptom Appraisal Scale, Heart failure self-care index scale, Social Support Rating Scale, Zarit burden interview, and Self-rating anxiety scale. The data was collected from patients who were hospitalized with CHF in the cardiology department of one of two tertiary hospitals in Nanchong City, China. The dyadic disease appraisal categories were identified using latent profile analysis (LPA). Multiple logistic regression analysis was also employed to analyze the factors influencing the formation of potential categories of differences in dyadic disease appraisal in CHF patients.ResultsA total of 262 pairs of hospitalized CHF patients and their caregivers participated in this study. The dyadic disease appraisal of CHF patients was potentially categorized as the "negative difference group" (28 individuals, 10.7%) and the "positive or convergence group" (234 persons, 89.3%). The results showed that the factors influencing the categorization of dyadic disease appraisal differences included the patient's social support, disease progression, and Caregivers anxiety level, burden, gender, educational attainment, and age (p < 0.05).ConclusionThe study findings demonstrated heterogeneity between the two groups of CHF patients in the dyadic disease appraisal. Therefore, it is necessary to focus on patients who have a brief duration of illness and limited social support. Specifically, it is important to prioritize support for female caregivers who are 65 years or older, have lower levels of educational attainment, and experience a significant burden and anxiety. Regular implementation of support person-bilateral co-management strategies can effectively reduce differences in how the disease is perceived and enhance the overall well-being of both caregivers and patients.

Development and application of an integrated methodology for post‐disaster field investigation of debris floods

AbstractDebris floods commonly occur in steep channels with an abundant sediment supply, and they can cause significant damage, primarily due to their higher sediment concentrations and negative impacts upon bank erosion, deep scouring and aggradation. These key hazards pose challenges for traditional assessment methods, making quantification difficult. This became obvious during a recent catastrophic debris flood that occurred on July 12, 2022, in the Heishuigou catchment (102 km2), northern Sichuan Province, China. In this case study, we developed an integrated methodology for assessing this debris flood event by incorporating field surveys, hydrological and hydraulic modelling and sediment transport calculations. Detailed information such as topographic maps, photographs, deposits, grain size distributions and inundation depths was collected to analyse the material sources, validate the parameters and conduct model calculations. The peak debris flood discharge and the supra‐critical bed shear stress ratios, estimated from hydrological and dynamic models, were incorporated to analyse the debris flood's typology and characterize its destructive mechanisms. The regional frequency–volume relationship established through bedload transport calculations was calibrated using the volume of the deposits determined via field investigation. These methods not only contribute to a comprehensive understanding of debris floods but also provide valuable support for future risk assessments and mitigation designs.

Late Permian radiolarian Neoalbaillella caridroiti assemblage from the Loufanggou, Guangyuan-Shangsi area, Sichuan Province, China

A well-preserved Lopingian (Late Permian) radiolarian assemblage including Neoalbaillella has been recovered from the Loufanggou 2 section of the Dalong Formation in northern Sichuan, China. The assemblage consists mainly of spherical radiolarians with spongy tests, such as Entactinaria and Spumellaria. Albaillellaria and Latentifistularia are relatively rare in the assemblage. The occurrence of Neoalbaillella caridroiti nov. sp., Neoalbaillella antaixiangi Yao and Kuwahara and Albaillella triangularis Ishiga, Kito and Imoto indicates that the Loufanggou 2 section may be correlated with the Neoalbaillella optima assemblage zone. Until now, only Neoalbaillella caridroiti nov. sp. and Neoalbaillella antaixiangi were known to occur in the northern Sichuan area. This limited occurrence indicates the possibility that the Dalong Formation depositional basin in northern Sichuan Province was a geographically limited area, and the radiolarian assemblage shows its provincialism.

Genetic history of esophageal cancer group in southwestern China revealed by Y‐chromosome STRs and genomic evolutionary connection analysis

Genetic and environmental factors play crucial roles in the development of esophageal cancer (EC) and contribute uniquely or cooperatively to human cancer susceptibility. Sichuan is located in the interior of southwestern China, and the northern part of Sichuan is one of the regions with a high occurrence of EC. However, the factors influencing the high incidence rate of EC in the Sichuan Han Chinese population and its corresponding genetic background and origins are still poorly understood. Here, we utilized genome-wide single nucleotide polymorphisms (SNPs) and Y-chromosome short tandem repeats (Y-STRs) to characterize the genetic structure, connection, and origin of cancer groups and general populations. We generated Y-STR-based haplotype data from 214 Sichuan individuals, including the Han Chinese EC population and a control group of Han Chinese individuals. Our results, obtained from Y-STR-based population statistical methods (analysis of molecular variance (AMOVA), principal component analysis (PCA), and phylogenetic analysis), demonstrated that there was a genetic substructure difference between the EC population in the high-incidence area of northern Sichuan Province and the control population. Additionally, there was a strong genetic relationship between the EC population in the northern Sichuan high-incidence area and those at high risk in both the Fujian and Chaoshan areas. In addition, we obtained high-density SNP data from saliva samples of 60 healthy Han Chinese individuals from three high-prevalence areas of EC in China: Sichuan Nanchong, Fujian Quanzhou, and Henan Xinxiang. As inferred from the allele frequency of SNPs and sharing patterns of haplotype segments, the evolutionary history and admixture events suggested that the Han population from Nanchong in northern Sichuan Province shared a close genetic relationship with the Han populations from Xinxiang in Henan Province and Quanzhou in Fujian Province, both of which are regions with a high prevalence of EC. Our study illuminated the genetic profile and connection of the Northern Sichuan Han population and enriched the genomic resources and features of the Han Chinese populations in China, especially for the Y-STR genetic data of the Han Chinese EC population. Populations living in different regions with high incidences of EC may share similar genetic backgrounds, which offers new insights for further exploring the genetic mechanisms underlying EC.

A cross-sectional study on the moderating effect of self-efficacy on the relationship between sociodemographic variables and nutrition literacy among older adults in rural areas of North Sichuan.

The purpose of this study is to examine the moderating role of self-efficacy among rural elderly individuals in northern Sichuan Province in the relationship between certain sociodemographic variables and nutritional literacy. Convenience sampling was used to select 264 elderly individuals aged 60 and above from rural communities in Cangxi County, Guangyuan City, Yilong County, Nanchong City, and Bazhou District, Bazhong City, Sichuan Province. A self-designed questionnaire, including sociodemographic variables, the General Self-Efficacy Scale (GSES), and the Nutrition Literacy Questionnaire for the Elderly (NLQ-E), was administered through face-to-face interviews using a paper-based version. The relationships between sociodemographic variables, self-efficacy, and nutritional literacy in the elderly were analyzed using SPSS 26.0 and the Process plugin to examine the relationships between variables and to test for moderation effects. (1) There were significant differences in nutrition literacy scores among elderly people of different ages, genders, marital statuses, educational levels, personal monthly living expenses, dental conditions, and number of chronic diseases (p < 0.05). (2) When elderly individuals have lower self-efficacy, their nutritional literacy is lower as they become older, and they have poorer nutritional literacy with a higher number of chronic diseases. General population demographic data has a significant impact on the nutritional literacy level of elderly people in rural areas of northern Sichuan. Self-efficacy plays a moderating role in the relationship between age and nutritional literacy, as well as the relationship between the number of chronic diseases and nutritional literacy.

Two new species of the genus Laena (Coleoptera, Tenebrionidae, Lagriinae) from northern Sichuan in China based on morphological and molecular data.

In this study, the Laena species from northern Sichuan Province were reviewed using a combination of molecular and morphological datasets. Three molecular methods for species delimitation were firstly used in the genus Laena to explore species boundaries. The results show that the number of morphospecies and putative species using Automatic Barcode Gap Discovery (ABGD) is consistent. Based on the results, two new species are described and illustrated: Laenamounigouicasp. nov. and Laenadentithoraxasp. nov. New materials and distribution of 10 Laena species are also provided in this study. This work also provides valuable molecular data for species identification and phylogenetic analyses of the genus Laena and subfamily Lagriinae.

Mapping the Spatial Relationship Between Sub-basins and Language Variation in Thewo Tibetan

Thewo Tibetan is a Tibetic language of China spoken along the Bailong River in Northern Sichuan Province and Southern Gansu Province. Although typically listed as a dialect of Choni Tibetan (ISO 639-3 cda), Thewo is reported to have a high degree of internal variation (Renzengwangmu 2013). The goal of this paper is to examine whether or not this internal variation can be explained in part by Chamberlain’s (2015) hypothesis of linguistic watersheds. Chamberlain (2015) argues that the distribution of watersheds on the Qinghai-Tibet Plateau provides a spatial model through which we can predict the geographical spread of language variation. This paper’s research reveals some spatial correlation between the distribution of the watersheds and dialectal variation in the Thewo speaking region of Diebu County. These results can neither disprove Chamberlain’s hypothesis nor fully explain the spatial distribution of language variation in Thewo Tibetan. However, the results do demonstrate how watersheds could be a useful model for predicting the location of language documentation needs on the Qinghai-Tibet Plateau.

Numerical analysis of a slope stabilized with piles and anchor cable frame beams

A landslide located in northern Sichuan Province, China was investigated. A series of numerical models of the landslide stabilized with piles and anchor cable frame beams were developed using a three-dimensional finite-element method. The Strength Reduction Method was employed to investigate the stability of slopes, the internal forces of piles, and the axial forces of anchor cables. A parametric study consisting of pile position, pile length, and pile spacing was carried out. The results show that compared to anchor cable frame beams, the combination of piles and anchor cable frame beams is a more effective retaining structure to improve slope stability. During slope destabilization, the proportion of thrust shared by piles gradually increases, while the proportion of thrust shared by anchor cables gradually decreases. Piles installed on the leading edge of a trail-mode landslide can make the slope mostly stable. As the piles move from the leading, middle, and trailing edges of the slope, the proportion of thrust shared by the anchor cables gradually increases, while local instability may occur in front of the pile. Increasing the pile length can improve the stability of the slope. However, excessive embedded length of piles has little effect on further improving the slope stability. The critical embedment length of piles found in this study is 1/3 of the total length of the pile. The critical pile spacing found in this study is 2.5 times the width of the pile section. Beyond this spacing, the effective soil arch between the piles is difficult to develop and the anchor cables may share more proportion of the landslide thrust. This study provides a reference for reinforcement system design of engineering projects considering piles and anchor cable frame beams.

Biostromal unit from the Middle Devonian Jinbaoshi Formation, Sichuan, Southwest China: Implications for ecological structure of coeval reef communities

This study provides a comprehensive palaeontological and palaeoecological analysis of a middle Givetian (Middle Devonian) coral-stromatoporoid biostromal unit from the upper member of the Jinbaoshi Formation, northern Sichuan Province, Southwest China. The biostromal unit is 17.7 m of medium- to thick-bedded limestones, and lacks observable morphological relief in the field. Diverse shallow marine benthic fossils are common elements of the biostromal unit encompassing stromatoporoids (7 genera), tabulate corals (4 genera), brachiopods (2 genera), plus unidentified rugose corals, chaetetids, bryozoans, tubeworms, ostracods, gastropods, crinoids and calcimicrobes. In terms of the biotic composition and biostrome-building contributors, three ecological units are recognized: Alveolites–Clathrocoilona community (EU 1), Salairella–Pseudotrupetostroma community (EU 2) and Scoliopora–Idiostroma community (EU 3). High fragmentation of bioclasts partially with micritic envelopes in wackestone, packstone to grainstone matrix and the dominance of low-profile stromatoporoids indicate deposition in shallow water conditions with episodic high sedimentation rate and frequent turbulent periods. Muddy silt- to sandstone facies overlie the biostromal unit, and are interpreted to represent a shallowing-up sequence, together with terrigenous input, thus triggering termination of the biostromal unit. This biostromal unit is similar to the other early to middle Givetian reefs of South China, East Australia, West Europe, East Europe and North Africa in relation to their fossil composition and reef-building characteristics. The stability of the reef communities (i.e. no conspicuous extinction) and common occurrence of unusual reef structures (e.g. coverstone) are thus interpreted as significant biotic factors for the expansion of large-scale ecosystems during the Phanerozoic reef-building acme.

Geochemical anomaly identification and uncertainty quantification using a Bayesian convolutional neural network model

Geochemical prospecting plays an important role in mineral exploration. In recent years, deep learning algorithms (DLAs) have been applied in mapping geochemical anomalies associated with mineralization. However, few of them evaluated the effects of data and model uncertainty on geochemical anomaly identification, which can introduce bias and risk in geochemical prospecting. In this study, a Bayesian convolutional neural network model (BCNN), which applies Bayes by Backprop to a convolutional neural network, was employed to extract geochemical anomalies associated with mineralization and quantify the two types of uncertainties, i.e., aleatoric (data-related) and epistemic (model-related) uncertainty. A case study on recognizing geochemical anomalies related to gold polymetallic mineralization in northern Sichuan Province of China was conducted. The results show that the geochemical anomalies extracted by BCNN are highly spatially correlated with known gold deposits. Meanwhile, both aleatoric and epistemic uncertainty linked to the identified geochemical anomalies were quantified. Areas with high uncertainty are mainly distributed at the boundaries of the geochemical high anomalous zones. Therefore, future mineral exploration should focus on regions with high anomalies but low uncertainty. The obtained results provide an important decision basis for the prospecting of gold polymetallic deposits in the study area.

Groundwater risk assessment of abandoned mines based on pressure-state-response—The example of an abandoned mine in southwest China

Due to the exhaustion of coal resources, resource integration, backward production capacity elimination, and other reasons, a large number of coal mines in China have been closed or are close to closing. When a mine is closed and the drainage stops, the water level of the mining area will rise rapidly, resulting in acid mine water (AMD), which carries pollutants through mining-induced fracture faults or poorly closed boreholes into groundwater or surface water, resulting in pollution and safety risks to the water environment. Therefore, it is essential to conduct environmental risk assessments of abandoned mine groundwater for mine environment governance and protection. On this basis and employing the pressure-state-response (PSR) risk evaluation system, and considering the abandoned Chuanbei mine in northern Sichuan province, China, mine water inflow, groundwater water chemistry, and the water environment pollution situation are analyzed, considering the AMD release and its environmental impact, while identifying the drivers and sources of pollution. Considering the mine drainage conditions, three first-level indices of environmental sensitivity response and 12 second-level indices of the redox state of aquifer permeability mine were determined, such as the aquifer thickness and relative location. The results show that the groundwater environmental risk in the study area is high, and the groundwater environmental risk index in the southeast is higher than that in the northwest. Heavy metals and other toxic and harmful substances carried by AMD are found to enter the surrounding waters, posing a direct threat to the health of downstream residents. These results can provide theoretical guidance for the comprehensive remediation of mine environments in this area, and also provide a reference for environmental risk assessment of other similar current mining areas.

Epidemiological features and spatial-temporal clustering of visceral leishmaniasis in mainland China from 2019 to 2021.

BackgroundVisceral leishmaniasis (VL) is a serious vector-borne disease in central and western China. In recent years, the number of VL cases increased gradually, particularly the mountain-type zoonotic visceral leishmaniasis (MT-ZVL). This study clarified the epidemiological features and spatial-temporal clustering of VL in China between 2019 and 2021, identified the risk areas for VL transmission, and provided scientific evidence for the prevention and control of VL.Materials and methodsThe information on VL cases in 2019–2021 was collected from the Infectious Disease Reporting Information Management System of the Chinese Center for Disease Control and Prevention. The epidemiological characteristics of VL cases were analyzed. The global Moran’s I and Getis-ORD Gi* statistical data were processed for spatial autocorrelation and hotspot analysis in ESRI ArcGIS software. Also, spatial-temporal clustering analysis was conducted with the retrospective space–time permutation scan statistics.ResultsA total of 608 VL cases were reported from 2019 to 2021, with 158, 213, and 237 cases reported each year, respectively. Of the 608 cases, there were 10 cases of anthroponotic visceral leishmaniasis (AVL), 20 cases of desert-type zoonotic visceral leishmaniasis (DT-ZVL), and 578 cases of MT-ZVL. The age of VL cases was mainly distributed in the group of subjects aged ≥ 15 years. Peasants and infants were the dominant high-risk population. The incidence peak season of VL occurred between March and May. The cases were mainly distributed in Shanxi (299 cases), Shaanxi (118 cases), and Gansu (106 cases) Provinces, accounting for 86.02% (523/608) of the total reported cases in China. Spatial analysis revealed that clustering of infection is mainly located in eastern Shanxi Province and Shaanxi–Shanxi border areas, as well as southern Gansu and northern Sichuan Province. In addition, new reemergence hotspots in Shanxi, Henan, and Hebei Provinces have been detected since 2020. Spatio-temporal clustering analysis revealed an increase in the degree of infection aggregation in eastern Shanxi Province and Shaanxi–Shanxi border areas.ConclusionThe AVL and DT-ZVL were endemic at a lower level in western China, whereas MT-ZVL rebounded rapidly and showed a resurgence in historically endemic counties. The spatial-temporal clustering analysis displayed that the high-incidence areas of VL have shifted to central China, particularly in Shanxi and Shaanxi Provinces. Integrated mitigation strategies targeting high-risk populations are needed to control VL transmission in high-risk areas.

A new Neodima species (Coleoptera: Elateridae: Dimini), with notes on the distribution and morphology of the genus.

The flightless click-beetle Neodima yutangi sp. nov. is described and illustrated from Beichuan County, Northern Sichuan Province, China. Habitus and important diagnostic characters of the new species are illustrated. An updated distribution map of the genus and key to Neodima species are provided. The distribution, habitat and some notable morphological characters of the genus are discussed.

Sedimentology of reefal buildups of the Xiann\xfcdong Formation (Cambrian Series 2), SW China

The reefs in the Xiannüdong Formation (Cambrian Series 2) are the oldest archaeocyathan–microbial bioconstructions in China, but the details of their microbial structures have not been previously described. However, a new section at Tangjiahe site, northern Sichuan Province, contains very well-preserved microbial fabrics that provide these details, and is described in this study. The Tangjiahe section contains three levels of reefal buildups that were constructed by a consortium of archaeocyaths and calcimicrobes in varying proportions. The lowest (oldest) reefal buildup is a calcimicrobial biostrome, possibly in the form of a wide mound with a low relief (unconfirmed due to outcrop limitation), which was formed by Epiphyton with rare small archaeocyaths, and is sandwiched by flat-pebble conglomerates. The middle reefal buildup is a high-relief calcimicrobial mound, enclosed by oolites, that was built by intergrown Renalcis and Tarthinia. Archaeocyath fossils are uncommon, and were bound into the framework by microbial carbonates. The uppermost (youngest) reefal buildup is a low-relief archaeocyathan mound lacking calcimicrobes but partly having microbially-clotted textures attached on archaeocyaths. Calcimicrobes built or aided archaeocyaths to form the framework of Tangjiahe reefs. The three buildups formed in low-energy lagoons behind ooid shoals, and the environment was nutrient-rich due to terrigenous influx from adjacent lands. Tangjiahe reefs thus resemble most Early Cambrian reefs, in settings consistent with eutrophic, calm environments, and are characterized by the domination or aid of calcimicrobial components in framework construction.

Earthquake-triggered landslides affecting a UNESCO Natural Site: the 2017 Jiuzhaigou Earthquake in the World National Park, China

On August 8th, 2017, an Ms 7.0 magnitude earthquake occurred in Jiuzhaigou County, northern Sichuan Province, China. The Jiuzhaigou Valley World National Park was the most affected area due to the epicentre being located in the scenic area of the park. Understanding the distribution characteristics of landslides triggered by earthquakes to help protect the natural heritage sites in Jiuzhaigou Valley remains a scientific challenge. In this study, a relatively complete inventory of the coseismic landslides triggered by the earthquake was compiled through the interpretation of high-resolution images combined with a field investigation. The results indicate that coseismic landslides not only are concentrated in Rize Gulley, Danzu Gully and Zezhawa Gully in the study area but also occur in the front part of Shuzheng Gully along the road network (from the entrance of Jiuzhaigou Valley to Heye Village). The landslides predominantly occur on the east- and southeast-facing slopes in the study area, which is a result of the integrated action of the valley direction and fault movement direction. The back-slope effect and the slope structure caused the difference in coseismic landslide distribution within the three gullies (Danzu Gully, Rize Gully, and Zezhawa Gully) near the inferred fault. In addition, the topographic position index was used to analyse the impact of microlandforms on earthquake-triggered landslides by considering the effect of the slope angle. The study results reveal a higher concentration of landslides in the slope position class of the middle slope (30A degrees-50A degrees) in Jiuzhaigou Valley. These findings can provide scientific guidance for the protection of natural heritage sites and post-disaster reconstruction in Jiuzhaigou Valley.

Terpenoids and Phenylpropanoids in Ligularia duciformis, L. kongkalingensis, L. nelumbifolia, and L. limprichtii.

The diversity in root chemicals and evolutionally neutral DNA regions in the complex of Ligularia duciformis, L. kongkalingensis, and L. nelumbifolia (the d/k/n complex) was studied using eight samples collected in central and northern Sichuan Province of China. Cacalol (14) and epicacalone (15), rearranged eremophilanes, were isolated from the complex for the first time. Two new phenylpropanoids were also obtained. Seven of the eight samples produced phenylpropanoids and the other produced lupeol alone. Two of the seven samples also produced furanoeremophilanes or their derivatives and one produced oplopanes. The geographical distribution of the sesquiterpene-producing populations suggests that the production of sesquiterpenes evolved independently in separate regions. L. limprichtii collected in northern Sichuan was also analyzed and its chemical composition and the sequence of internal transcribed spacers (ITSs) in the ribosomal RNA gene cluster were found to be similar to that in the d/k/n complex and L. yunnanensis, which are morphologically similar.

A new Chinese species of Indonemoura (Plecoptera: Nemouridae) and a new subspecies of I. nigrihamita Li &amp;amp; Yang

A new species of Nemouridae of the genus Indonemoura Baumann 1975, I. furcoloba Li &amp; Yang, sp. nov., is described from both sexes from Guangxi Zhuang Autonomous Region of southern China. The relationships with related species are discussed. Additionally, a new subspecies is proposed for a population of I. nigrihamita Li &amp; Yang, 2008 from northern Sichuan Province of southwestern China.

New material of scalidophoran worms in Orsten-type preservation from the Cambrian Fortunian Stage of South China

AbstractScalidophoran worms diversified in the Cambrian Fortunian, as indicated by recent reports from this stage, with two described species and two more unnamed forms exclusively from Orsten-type Lagerstätten yielding three-dimensionally phosphatized fossils. Here, we report new material of scalidophoran worms in Orsten-type preservation from the Cambrian Fortunian Xinli section in northern Sichuan Province, South China. At least five forms of scalidophoran worms were recovered from this location, includingEokinorhynchus rarusZhang et al., 2015 and four unnamed taxa—Forms A, B, C, and D. Co-occurring disassociated spinose small shelly fossils might also be isolated cuticular elements of these early scalidophoran worms. The ontogeny ofEokinorhynchus rarusis revised. Forms A, C, and D are assigned to total-group Scalidophora to indicate their uncertain positions within Scalidophora, while Form B might be a close relative ofEokinorhynchus rarus. The current work highlights the significance of Orsten-type Lagerstätten in uncovering the morphology, ontogeny, and taxonomy of early Scalidophora and Cycloneuralia, made particularly available by the new finds in China.

Yunotrechus diannanensis n. gen., n. sp., the first troglobitic trechine (Coleoptera: Carabidae) from a tropical area of China

SummaryIn the present paper Yunotrechus diannanensis n. gen., n. sp. is described and illustrated from two limestone caves which are close to each other in Wenshan and Maguan counties of southern Yunnan Province, southwestern China. Yunotrechus is an anophthalmoid, not directly related to any hypogean trechine genera hitherto known in Yunnan or in southeastern Asian countries because all of them are aphaenopsoids, with elongated prothorax and tumid propleura. The phylogenetic position of Yunotrechus within Trechinae in China or southeastern Asia remains unclear, although it may be related to Superbotrechus Deuve & Tian 2009, which was recorded from western Hubei Province, central China, and Sichuanotrechus Deuve 2006, which was recorded from northern Sichuan Province, southwestern China. Y. diannanensis n. sp. is the first troglobitic trechine beetle discovered in a tropical area of China.

ChemInform Abstract: Four New Compounds from Ligularia virgaurea: Isolation of Eremophilane and Noreremophilane Sesquiterpenoids and the Absolute Configuration of 2α‐Hydroxyeremophil‐11‐en‐9‐one by CD Spectrum and DFT Calculation.

Four new compounds, rearranged noreremophilan-8,6-olide, rearranged dinoreremophilanone, epoxy gamma-lactone, and 2 alpha-hydroxyermophil-11-en-9-one, along with eremophilenolides related to ligularol and other known terpenoids, were isolated from Ligularia virgaurea (ligularol type) collected from the northern Sichuan Province of China. Three of the new compounds had degraded and unique structures. The absolute configuration of 2 alpha-hydroxyermophil-11-en-9-one was determined on the basis of density functional theory calculation. The back octant rule cannot be applied to this compound because of the contribution of the hydroxy group to the front octant. (C) 2013 Elsevier Ltd. All rights reserved.