Sichuan Region Research Articles

Thermal Lithospheric Thickness of the Sichuan Basin and its Geological Implications

AbstractThermal lithospheric thickness is an important parameter in studying the tectonic‐thermal evolution of basins and plate dynamics. Based on the measured geothermal data and thermophysical properties of the rocks, the thermal lithospheric thickness of the Sichuan Basin was calculated according to the principles of heat conduction in the crust and lithospheric mantle. The calculation results revealed that the thickness of the thermal lithosphere in the Sichuan Basin is 140–190 km and is unevenly distributed. The thickness of the thermal lithosphere in central Sichuan and southwestern Sichuan is less than 160 km, while that in the western Sichuan depression and eastern Sichuan is larger (∼180 km). The distribution of the thermal lithospheric thickness in the basin has a good correlation with the geological units and the thickness of the sedimentary layers. The thickness of the thermal lithosphere in the depression area, which has thick sedimentary layers and the fault‐fold zone with shallow crustal deformation and thickening, are larger than that in the basement uplifted area, which has thin sedimentary layers. The calculated thermal lithospheric thickness is in good agreement with the geophysical data and reflects the stable conduction temperature field in the Sichuan Basin. The present thermal regime and thermal lithospheric thickness of the Sichuan Basin indicate that flexural thickening of the lithosphere occurred in the eastern Sichuan fault‐fold belt and the Longmen Mountain–Western Sichuan depression foreland basin system, while asthenospheric uplift occurred in the central Sichuan region, which were the result of the expansion of the Xuefeng orogeny from the east and the compression of the Tibetan Plateau from the west.

Spatiotemporal Characteristics and Influencing Factors of Tourism-Urbanization-Technology-Ecological Environment on the Yunnan-Guizhou-Sichuan Region: An Uncoordinated Coupling Perspective.

The tourism, urbanization, technology, and the ecological environment both promote and restrict each other. Coordinating the relationship between the four is of great significance to the realization of high-quality sustainable regional development. Taking the Yunnan–Guizhou–Sichuan region as an example, this paper constructs an uncoordinated coupling model for the tourism–urbanization–technology–ecological environment system. Using exploratory spatial analysis and geographic information systems, this paper reveals the temporal and spatial evolution law affecting the uncoordinated coupling relationship between tourism, urbanization, technology and the ecological environment in the Yunnan–Guizhou–Sichuan region from 2010 to 2020, before establishing a panel Tobit model that is used to explore the factors affecting the four systems. The research shows the following: (1) The level of comprehensive development for tourism, urbanization, technology, and the ecological environment in Yunnan, Guizhou, and Sichuan has increased rapidly. Of all these, the tourism industry was the most affected by COVID-19 in 2020, while the level of urbanization, technology, and ecological environment developments in the three provinces has become similar over time. (2) Uncoordinated development between cities is a prominent problem; while the uncoordinated coupling spatial agglomeration in various regions is relatively stable, the proportion of cities with no significant agglomeration form amounts to more than 70%, with mostly low–low (L–L) and high–high (H–H) agglomeration types. (3) The degree to which uncoordinated coupling exists among the four systems in the Yunnan–Guizhou–Sichuan region is affected by many factors. Only eco-environmental pressure has a significant positive correlation with the degree of uncoordinated coupling, while the tourism scale, economic urbanization, eco-environmental response, and investment in technology have a significant negative correlation. These results provide a theoretical basis and practical references for strengthening the government’s macro-control and promoting collaborative regional development.

Field/Laboratory/Field Cycle Optimizes Fracture Placement, Well Performance

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 204189, “8,070 Miles From the Field to the Laboratory and Back: A Pragmatic Sequencing of Laboratory- and Field-Based Fluid Testing and Quality Assurance/Quality Control—A Case History From Sichuan Region, China,” by A. Casero, SPE, A. Gomaa, and J. Ronderos, SPE, Titan Global Oil Services, et al. The paper has not been peer reviewed. This paper illustrates comprehensive laboratory efforts undertaken to evaluate different high-viscosity friction reducers (HVFRs) and crosslinked gel products, their successful field application supported by a robust and effective field quality-assurance/quality-control (QA/QC) process, and the critical importance of maintaining an effective field/laboratory/field cycle to optimize fluid design and maximize results. A successful execution of several treatments in a challenging shale play in the Sichuan region of China achieved record proppant placements and, just as importantly, demonstrated repeatability and consistency over time, which had not previously been attained. Geological Setting The Sichuan Basin in southern China is a very active unconventional play targeting the Longmaxi Shale, a high-pressure/high-temperature shallow-to-deep marine shale deposited on top of the Baota limestone during the Late Ordovician and Early Silurian ages. The highly complex subsurface geomechanical environment is considered the main root cause of widespread casing deformation and associated challenges facing hydraulic fracturing.

Efficacy and MicroRNA-Gut Microbiota Regulatory Mechanisms of Acupuncture for Severe Chronic Constipation: Study Protocol for a Randomized Controlled Trial.

BackgroundSevere chronic constipation (SCC) is a common functional gastrointestinal (GI) disorder associated with disruptions in GI motility. Abnormalities between gut microbiota and microRNAs (miRNAs) are implicated in the pathogenesis of GI motility in SCC. Acupuncture has been shown to improve constipation-related symptoms and rebalance the gut microbiota. This protocol proposed a plan to explore the hypothesis that the efficacy of acupuncture is associated with the crosstalk between gut microbes and miRNAs in patients with SCC.MethodsThis trial is designed as a randomized, sham-controlled trial involving 80 patients and 40 healthy volunteers. A total of 80 patients with SCC (≤2 mean spontaneous, complete bowel movements per week [CSBMs]) will be randomly allocated to receive either 16-session acupuncture at true acupoints or non-penetrating sham acupuncture at non-acupoints for 4 weeks. The primary outcome will be the proportion of patients with ≥3 mean weekly CSBMs over weeks 1–4 and 5–8. Secondary efficacy endpoints include bowel movements, stool consistency, degree of straining, and the quality of life. Healthy volunteers will not receive any clinical intervention. Fasting plasma and fecal samples will be analyzed by 16S rRNA third-generation sequencing and miRNA high-throughput sequencing technologies. Finally, a tripartite network analysis will be used to investigate the interactions among clinical efficacy, miRNAs, and intestinal microbiota.DiscussionFrom the perspective of microRNA-gut microbiota regulatory mechanisms, our results will partially illuminate the crucial role of fecal miRNAs and intestinal microbiota to understand how acupuncture exerts its anti-constipation role.Trial registrationThis trial is registered with ChiCTR2100048831, registered 18 July 2021; ethical approval has been obtained from the Sichuan Regional Ethics Review of Committee on Traditional Chinese Medicine, approval ID: 2021KL-023.

Effect of Acupuncture on Blood Pressure and Metabolic Profile Among Patients With Essential Hypertension: Protocol of a Randomized Clinical Trial.

Essential hypertension is a polygenic cardiovascular disease that is associated with maladaptive metabolic changes. Acupuncture as a non-pharmacologic intervention is used to lower blood pressure and improve metabolic dysfunction. However, such effects have not been clinically characterized. We will conduct a randomized clinical trial to evaluate the antihypertensive effect of acupuncture among patients with essential hypertension and determine the associated metabolic improvements. This study is a phase II, two-arm, randomized, sham-controlled trial (Trial registration: ChiCTR2100043737), in which biospecimens will be collected for metabolic profiling. A total of 64 patients with a clinical diagnosis of essential hypertension will be randomly assigned to either the acupuncture or the sham acupuncture group in a 1:1 ratio. All participants will receive 10 treatments over 4 weeks, with three sessions per week for the first 2 weeks and two sessions per week for the remaining weeks. The primary outcome is the change of the systolic and diastolic blood pressure measured by the 24-h ambulatory blood pressure monitoring from baseline to 4 weeks. Secondary outcomes include the circadian rhythm of blood pressure, sleep quality measured by the Insomnia Severity Index, cognitive function measured by the Montreal Cognitive Assessment, and others. Fasting blood serum and urine samples will be collected at baseline and 4 weeks for targeted and untargeted metabolomics analysis. We will use the mixed-effects model and other related bioinformatics approaches to analyze the clinical and metabolome data. This metabolomic-based trial will provide important clinical data regarding the efficacy of acupuncture for essential hypertension to better inform evidence-based care delivery for hypertension patients. Moreover, the findings will offer important insights into the mechanism of action of acupuncture for hypertension by revealing its effect on metabolism. The results of this study will be used to inform the design of a statistically powered, multicenter, randomized trial. We will publish the study findings in peer-reviewed journals. The ethical approval of this study has been reviewed and approved by the Sichuan Regional Ethics Review Committee on Traditional Chinese Medicine (ID: 2021KL-006). The outcomes of the trial will be disseminated through peer-reviewed publications.

Impact of Fiscal Expenditure on Farmers’ Livelihood Capital in the Ethnic Minority Mountainous Region of Sichuan, China

Poverty alleviation is the first battle to realize the rural revitalization strategy in China, and research on the sustainable livelihood of rural households is of great significance to solving the problem of rural poverty. Based on the sustainable livelihood framework, the reasonable scale and structure of fiscal expenditure is an inevitable requirement in producing sustainable livelihood capital toward this aim. In this study, the system Gaussian mixed model was used to analyze the impact of fiscal expenditure on farmers’ livelihoods. Representative survey data uses panel data from 48 counties across Liangshan Prefecture, Ganzi Prefecture, and Aba Prefecture in Sichuan, China. The results are as follows: (1) The average stock of human capital in 2010 to 2015 was the highest in the composition of farmers’ livelihood capital; (2) natural capital and physical capital were positively affected by the total scale of fiscal expenditure, agriculture, forestry, and water expenditure, and the former was negatively affected by general public service expenditure, education expenditure, social security and employment expenditure, and medical expenditure; (3) financial capital and the total amount of livelihood capital were positively affected by the total scale of fiscal expenditure, agriculture, forestry and water expenditure, education expenditure, social security and employment expenditure, and medical expenditure, and negatively affected by general public service expenditure; (4) human capital was positively affected by the total scale of fiscal expenditure, education expenditure, social security and employment expenditure, and medical expenditure; and (5) social capital was positively affected by agriculture, forestry and water expenditure, and education expenditure.

Relationships of Illness Perceptions with Depression and Anxiety in People Who Live with HIV/AIDS in a High-prevalence Ethnic Autonomous Region of Sichuan, China.

Poor mental health challenges outcomes and treatment of people living with HIV/AIDS (PLWHA) and may be related to illness perceptions. To investigate if depression and anxiety were associated with illness perceptions, we drew a random sample of 729 PLWHA from 13 administrative units in Liangshan Prefecture, Sichuan, China. Among the PLWHA surveyed, 222 and 175 had probable anxiety or depression. In mixed-effects logistic regression, negative illness perceptions were associated with increased odds of anxiety/depression. In linear mixed-effects quantile regression, the relationship of more negative illness perceptions with more severe and frequent symptoms of anxiety/depression grew stronger in the upper quantiles of the GAD-7 and PHQ-9 distributions, well beyond scale cut-offs for probable clinical relevance. We hypothesize that negative illness perceptions of HIV/AIDS and severity of depression and anxiety symptoms may mutually reinforce each other. Illness perceptions are a promising intervention target for improving the mental health of PLWHA.

A comprehensive comparison of data fusion approaches to multi-source precipitation observations: a case study in Sichuan province, China.

With the complex landform and climate in the Sichuan region, the need for practical and scientific research production by only utilising the rainfall data derived from ground stations or satellites has not been satisfied. To overcome this difficulty, rainfall data from 161 meteorological stations in 2016 are used in this study. According to the distribution of stations, 146 rainfall data from 161 meteorological stations in 2016 are used for inverse distance weighted interpolation, and then, linear regression, weighted regression, and Kalman filter fusion and optimal interpolation method data fusion are performed with TRMM 3B42 satellite rainfall data, respectively. Then, 15 meteorological stations evenly distributed in the study area are selected for the accuracy test. The results show that compared with the measurement at ground stations, linear regression shows the best merging effect on rainfall data derived from ground stations and satellite rainfall estimates across the daily scale: the correlation coefficient is the most significantly improved (0.2-0.7) and the reduction in root-mean-square error (RMSE) is the largest. The method is applicable for use in Sichuan Province when merging rainfall data. At the monthly scale, the rainfall data processed by using the Kalman filter present the highest accuracy (0.72-0.84). At this scale, the Kalman filter is more suitable.

Population Diversity of 'Candidatus Liberibacter asiaticus' and Diaphorina citri in Sichuan: A Case Study for Huanglongbing Monitoring and Interception.

Citrus huanglongbing (HLB) is present in 10 provinces in China and is associated with 'Candidatus Liberibacter asiaticus' (CLas), which is transmitted by the Asian citrus psyllid (Diaphorina citri, ACP). To date, HLB and ACP have expanded to Yibin city of Sichuan Province, posing an imminent threat to the citrus belt of the upper and middle reaches of the Yangtze River, an important late-maturing citrus-producing area in China. To understand the epidemiological route of CLas and ACP in newly invaded regions of Sichuan and thereby better establish an HLB interception zone ranging from Leibo to Yibin, we evaluated the molecular variability of 19 CLas draft genomes from citrus or dodder (Cuscuta campestris). They include three type-specific prophage loci, three variable number tandem repeat loci, a miniature inverted-repeat transposable element, and population diversity of 44 ACP mitochondrial genomes. The results indicated that CLas isolates in the newly invaded area (Pingshan) were more diverse than those in the HLB endemic areas (Leibo and Ningnan). Phylogenetic analysis based on mitochondrial genomes demonstrated that ACPs in Leibo, Pingshan, and Xuzhou (rural areas) represent a new mitochondrial group (MG4), distinguished by the three unique single-nucleotide polymorphisms in cox1, nad4, and cytb. However, the ACPs sampled from the urban areas of Cuiping and Xuzhou belonged to the southeastern China group (MG2-1). Altogether, our study revealed multiple sources of ACP and CLas in the HLB interception zone and proposed their transmission route. This study contributes to the formulation of precise HLB prevention and control strategies in the HLB interception zone in Sichuan and could be useful for HLB management efforts in other regions.

The Impact of Active Screening and Management on COVID-19 in Plateau Region of Sichuan, China.

BackgroundIn December 2019, the cases of pneumonia of unknown etiology emerged in Wuhan, China, and rapidly spread throughout the country. The disease was later designated by the World Health Organization (WHO) as Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). Few studies have assessed the clinical characteristics of COVID-19 and control strategies used to mitigate disease spread in high-altitude plateau regions of China.Study ObjectiveTo assess the impact of real-world strategies to control COVID-19 spread in remote plateau regions.MethodsA retrospective study was performed to assess the epidemiology of COVID-19 and strategies used to control disease spread in the high-altitude plateau of Sichuan, China from 24 January 2020 to 19 March 2020.ResultsCOVID-19 spread and outbreaks in Sichuan were attributed to mass gatherings. A total of 70 patients and 20 asymptomatic individuals were found in the hypoxic plateau region of Sichuan. Twelve patients were admitted after the onset of symptoms, while 58 patients and 20 asymptomatic individuals were found by active screening. The symptomatic patients included those with uncomplicated illness (16/70, 22.9%), mild pneumonia (44/70, 62.9%), and severe pneumonia (10/70, 14.3%). Most patients in the study area showed relatively mild and atypical symptoms such as low or no fever and dyspnea. The incidence of severe pneumonia, fever, dyspnea, and interstitial abnormalities identified by chest CT were all significantly lower in screened patients than those admitted after symptom onset (P < 0.05). Severe pneumonia was noted in patients with chronic conditions like hypertension, diabetes etc. as compared to less severe pneumonia in healthy subjects (P <0.05). No patients died and all were eventually discharged.ConclusionMass gatherings increased risk of spread of SARS-CoV-2 responsible for COVID-19. Active screening and early management have collectively contributed to reduced incidence of severe pneumonia and satisfactory prognoses of infections with COVID-19 in this hypoxic plateau region.

Molecular typing and prevalence of antibiotic resistance and virulence genes in Streptococcus agalactiae isolated from Chinese dairy cows with clinical mastitis.

Bovine mastitis is a common disease occurring in dairy farms and can be caused by more than 150 species of pathogenic bacteria. One of the most common causative organisms is Streptococcus agalactiae, which is also potentially harmful to humans and aquatic animals. At present, research on S. agalactiae in China is mostly concentrated in the northern region, with limited research in the southeastern and southwestern regions. In this study, a total of 313 clinical mastitis samples from large-scale dairy farms in five regions of Sichuan were collected for isolation of S. agalactiae. The epidemiological distribution of S. agalactiae was inferred by serotyping isolates with multiplex polymerase chain reaction. Susceptibility testing and drug resistance genes were detected to guide the clinical use of antibiotics. Virulence genes were also detected to deduce the pathogenicity of S. agalactiae in Sichuan Province. One hundred and five strains of S. agalactiae (33.6%) were isolated according to phenotypic features, biochemical characteristics, and 16S rRNA sequencing. Serotype multiplex polymerase chain reaction analysis showed that all isolates were of type Ia. The isolates were up to 100% sensitive to aminoglycosides (kanamycin, gentamicin, neomycin, and tobramycin), and the resistance rate to β-lactams (penicillin, amoxicillin, ceftazidime, and piperacillin) was up to 98.1%. The TEM gene (β-lactam-resistant) was detected in all isolates, which was in accordance with a drug-resistant phenotype. Analysis of virulence genes showed that all isolates harbored the cfb, cylE, fbsA, fbsB, hylB, and α-enolase genes and none harbored bac or lmb. These data could aid in the prevention and control of mastitis and improve our understanding of epidemiological trends in dairy cows infected with S. agalactiae in Sichuan Province.

Influence of the depositional environment on the formation of organic-rich marine shale: A case study of the first discovery of Anisian shale in the Sichuan Basin

The Leikoupo Formation, which was deposited during the Anisian stage in the central Sichuan Basin, has produced significant amounts of conventional gas but there have been few studies on its unconventional resources. Organic-rich shale in the Leikoupo Formation was discovered for the first time in the wells of CT1 and JY1 in the central Sichuan region, but information on its sedimentary environment and climate evolution is scarce. A series of lithofacies, organic geochemistry and inorganic geochemistry analyses were used to analyse core samples of CT1 and JY1 to estimate their vertical changes. The organic matter characteristics, the sedimentary environment and the factors controlling the Leikoupo Formation shale in the Sichuan basin were revealed. The organic-rich shale of the Lei3-2 sub-member was formed in a semi-restricted lagoon environment. The sedimentary environment was dysoxic-anoxic, with high palaeoproductivity, a warm and humid to semi-arid and semi-humid climate. The vertical sea level decreased for a short period, led to an increase in oxygen content in the mixed shale, clayey shale and calcareous shale that were sequentially deposited from bottom to top. In the vertical direction, the palaeo-productivity and aridity decreased, and there was an increase in the salinity and terrigenous debris input. All of these corresponded well with TOC. According to Mo-TOC and Mo–U patterns, the mixed shale was characterised by the highest values of MoEF, UEF and MoEF/UEF, followed by clayey shale and calcareous shale, which indicated mixed shale was deposited in a moderately restricted water condition, which progressively became more restricted during the deposition of clayey shale and calcareous shale with the fall of relative sea level. Biomarker compounds (steranes, terpanes), Tmax and other pyrolysis parameters indicated that the organic matter had reached the stage of high-to over-maturity. The gammacerane to C30 hopane in the ratio indicated that it was the bottom water in which it was deposited was sratified.

Investigating the severity of non-urban road traffic accidents in typical regions of Sichuan and Guizhou, China

Objective The traffic characteristics of Sichuan and Guizhou differ from those of other regions due to its unique geographical features. In addition, accident studies in China mainly focus on urban roads in the eastern and central regions. However, studies on western regions, especially non-urban roads, are scarce. Thus, this study aims to explore the factors that influence the severity of accidents on non-urban roads in typical regions of Sichuan and Guizhou. Methods A total of 541 cases from 2014 to 2020 were selected from the database of the China In-Depth Accident Study, where 18 variables, which may exert an impact on accident severity, were extracted after screening. First, heterogeneity of data was eliminated through latent class analysis (LCA). The ordered probit (OP) model was then conducted for each class to obtain significant variables that exert an impact on accident severity. The study quantified the degree of influence of the significant variables using marginal effect analysis. Results The LCA results demonstrate that data were categorized into the following classes, namely, (a) two-vehicle accidents involving trucks, (b) pedestrian and multiple-vehicle accidents, (c) two-wheeler accidents, and (d) single-vehicle accidents. The OP results show that most variables could exert impact on accident severity, and some of them exerted varying levels of influence on the severity of different classes, whereas others only influence a specific class. Conclusion According to this study, we obtained the accident characteristics of these regions and put forward some targeted suggestions to further improve the level of road traffic safety. The findings can provide support for the construction of transportation in line with the regional characteristics in China.

Efficacy of acupuncture treatment for chronic spontaneous urticaria: study protocol for a randomised controlled trial

IntroductionChronic spontaneous urticaria (CSU) is a troublesome dermatological problem that can have a significant impact on quality of life. Previous studies have indicated that acupuncture may be beneficial for patients...

GIS-Based Geological Hazard Mapping Using Statistical Analysis and Cell Assignment Method for Western Sichuan Region, China

Geological hazards pose severe threats to the natural ecological environment, which endanger human life, cause damage to the environment, and undermine social stability. Studying geological hazards is intended to minimize or reduce any potential losses or threats. Although geotechnical hazards present a complex problem, hazard mapping and zoning studies can improve predictions and reduce losses. Based on the principle of geological hazard zoning, this paper describes a GIS-based approach to regional mapping for geological hazards, including collapse, landslide, debris flow, and overall geological hazards. First, four main factors affecting the occurrence of geological hazards, namely, digital elevation model (DEM), soil property, vegetation type, and average annual rainfall, are determined for analysis. Afterward, the investigated region of western Sichuan province, China, is divided into cells using GIS. The factors are then valued and assigned to the cells for statistical analysis. According to the relationship between the development/occurrence of geological hazards and various influencing factors, the region is first zoned with different degrees of susceptibility. Moreover, the response degree values for different levels of susceptibility to different influencing factors are determined for each cell, and then the superposition values of response degree for each cell are calculated for different geological hazards. Finally, the mapping of each geological hazard is done based on the calculated superposition value ranges. The mapping result demonstrates that the proposed approach is efficient and practical for determining the hazard susceptibility of regional geological hazards in western Sichuan province. The conclusions of this study can provide valuable information regarding the prevention and management of similar disasters in a region.

Path Attenuation and Source Characteristics during the 2019 Sichuan Changning Earthquake Sequence in China

To give an insight into the path attenuation and source characteristics of the 2019 Sichuan Changning earthquake sequence, 99 strong‐motion recordings at 33 stations were studied. The S‐wave Fourier amplitude spectra were used to determine the path‐attenuation function and key parameters of the seismic source characteristics of this sequence. The results show the following: (1) The geometric spreading effect presents hinged‐trilinear characteristics, and the corresponding geometric spreading rates were −0.97, 0.29, and −0.73 with the crossover distances 90 km and 183 km. (2) The quality factor Q is correlated with frequency and expressed as 217 × f0.82 for the range from 0.1 to 10.0 Hz. (3) The seismic moment was inversely proportional to the cube of the corner frequency, and their product was 2.37 × 1016 N. m/s3. (4) The stress drop varied from 1.18 to 12.44 MPa. Both the attenuation effect and source parameters of this sequence are significantly different from those of the Lushan and the Wenchuan aftershock sequences in the Sichuan region of China.

Evaluation of the Comprehensive Economic Strength of Prefecture-level Cities in Sichuan Province Based on the Factor Clustering Method

Economic strength has always been an important indicator for assessing a country or a city. In this paper, we select 15 economic indicators to evaluate the comprehensive economic strength of 21 prefecture-level cities in Sichuan Province. Through factor analysis, these indicators were grouped into three aspects: urban production capacity, residents' living standard and urban land area constructing an evaluation system for the comprehensive economic strength of prefecture-level cities in Sichuan Province, and based on the factor scores, we arrived at a ranking of the comprehensive economic strength of prefecture-level cities in Sichuan Province, which showed that Chengdu scored much higher than other cities. What’s more, through cluster analysis, we divided the 21 prefecture-level cities in Sichuan Province into four categories, and made suggestions to promote the economic development of the Sichuan region based on the evaluation results.

HIV-1 genetic transmission networks among people living with HIV/AIDS in Sichuan, China: a genomic and spatial epidemiological analysis

SummaryBackgroundSpatialized HIV genetic transmission networks can help understand dynamic changes of HIV-1 at the regional level. This study aimed to combine genomic, epidemiological, and spatial data to investigate the patterns of the HIV-1 epidemic at both individual and regional levels among people living with HIV (PLWH) with virological failure of antiretroviral therapy (ART).MethodsWe evaluated the transmission patterns of 5,790 PLWH with identified pol sequences of the five main HIV-1 subtypes (B, CRF08_BC, CRF85_BC, CRF07_BC, and CRF01_AE) in Sichuan Province, China. A phylogenetic cluster was defined as a group of sequences with genetically similar HIV strains, with all phylogenetic clusters forming an HIV-1 genetic transmission network for each subtype. Logistic regression was used to identify the potential risk factors for phylogenetic clustering. Spatial analysis was applied to demonstrate the geographic patterns of phylogenetic clustering rates; intensity matrices and flow maps were made to demonstrate the intensity of transmission within and between cities.FindingsThere were 2,159 (37.3%) of 5,790 PLWH, distributed in 452 phylogenetic clusters. Some individual clinical and behavioral factors were associated with phylogenetic clustering, including a viral load of >50,000 copies/ml (OR=1.16, 95%CI=1.02-1.33), infection of other sexually transmitted diseases (OR=1.38, 95%CI=1.12-1.69), and ≥5 non-marital sexual partners (OR=1.25, 95%CI=1.03-1.51), while >3 years of treatment since the initial ART was associated with less likelihood of phylogenetic clustering (OR=0.82, 95%CI=0.70-0.97). The phylogenetic clustering rates varied regionally and were highest in the central region of Sichuan, especially for subtype CRF08_BC. The significant spatial clusters of high and low phylogenetic clustering rates were detected in the east (Dazhou for B; Zigong and Luzhou for CFR08_BC) and west (Yaan and Ganzi for CRF07_BC), respectively. The proportion of intercity transmission varied across cities from 0.14 (Yibin) and 1.00 (Ganzi). Stronger intercity transmission than average existed between some cities, e.g., between Deyang and Neijiang. CRF07_BC was the most widespread subtype between cities, and CRF85_BC (a novel HIV-1 subtype) showed strong intercity transmission (e.g., between Yibin and Guangan).InterpretationThe phylogenetic clustering rates and intercity connections of HIV-1 have varied geographically, possibly due to varying human mobility, traffic convenience, and economic activities. Our findings enhanced the understanding of the dynamics of HIV-1 transmission from individual to city level, and demonstrated a novel cross-disciplinary (epidemiological, genetic, and spatial) approach by which we identified high-risk populations and areas. Our approach could be adapted to other regions for precision public health interventions.FundingThe National Natural Science Foundation of China, Sichuan Science and Technology Program, Project of Sichuan Provincial Health Committee, Science and Technology Project of Sichuan Provincial Health Committee, Wuhan University 351 Talent Program, 2020, and the International Institute of Spatial Lifecourse Epidemiology (ISLE).

Research on the method of suppressing power fluctuation of hydro generator unit based on vortex elimination technology

Hydro power is a clean and renewable energy source, and it is one of the important ways to realize “carbon peak” and “carbon neutrality”. With the reform of the power system structure, the Central China Power Grid covering the four provinces of Hubei, Hunan, Jiangxi and Henan and the Southwest Power Grid covering the three regions of Sichuan, Chongqing and Tibet have realized asynchronous operation. In terms of stable operation of the power grid, the Power Grid, which accounts for a large proportion of hydro power, is facing severe challenges. Aiming at the power fluctuation problem of a hydro power station in Southwest China, the mechanism that caused the active power fluctuation problem was explored from the aspects of water, machinery, and electricity. Combined with an example of active power fluctuation of a hydro power station, it was found out that the active power fluctuation was caused by the water inlet vortex caused by large fluctuations in shell inlet pressure. A method of installing a vortex eliminator at the water inlet is proposed to reduce the pressure fluctuation at the inlet of the volute. Numerical simulation and field data measurement prove that this method is effective in reducing the fluctuation of active power, and the problem of power fluctuation has been well solved. It provides an important reference for similar problems of hydroelectric generating units.

A Novel and Efficient In Vitro Organogenesis Approach for Ajuga lupulina Maxim.

This work was aimed at establishing an effective approach for in vitro propagation of Ajuga lupulina Maxim, a medicinal and ornamental plant mainly found in eastern Xizang, in the western Sichuan region of China. We report an optimum response in the proliferation of axillary shoots from nodal segment explants (10.2 shoots/explant) on MS medium containing 3.0 mg L−1 of 6-benzyladenine (BA). When BA and TDZ individually or in combination with NAA were employed for adventitious shoot regeneration, shoots and embryo-like structures (ELSs) were noted in the callus from leaf explants. The maximum response of 26.4 shoots /explant (81.6%) and 12.0 ELSs/explant were ascertained on MS medium with 4.0 mg L−1 TDZ and 0.1 mg L−1 NAA. The leaf despite browning still demonstrated a high regeneration capacity. TDZ (2.0 mg L−1) and BA (2.0 mg L−1) along with NAA (0.01 mg L−1) were found to perform well for shoot regeneration via callus from shoot tip explants. The best for rooting was MS medium (half-strength) containing indole-3-butyric acid (IBA: 1.5 mg L−1) and (NAA: 0.5 mg L−1) with the maximum number of roots (25.8 per shoot) and the highest rooting frequency (81.71%). The survival of the plantlets in the greenhouse was 78.2% indicative of successful acclimatization. This work is the first report of a consistent, definitive, and unique protocol for A. lupulina regeneration, paving the way for the in vitro preservation of such significant genetic resources and also further allied systems based on such callus-based or embryo-based approaches.