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The coexistence of urban expansion and shrinkage in China has become increasingly apparent; therefore, the current strategic model of growth-oriented urban planning as the top-level design needs to be adjusted. This paper focuses on the city of Baishan, which is a typical shrinking city in China, and explores the feasibility of implementing the concept of smart shrinkage planning in shrinking cities in China by constructing a coupled PLUS-SD model. The results demonstrate the following conclusions: (1) The overall simulation of the coupled PLUS-SD model is superior to that of the PLUS model. In Baishan, the areas with the most changes in construction land will be located at the edges of the landforms by 2030. (2) Using the traditional planning scenario would only exacerbate the rate of construction land expansion in Baishan, deepening the incongruity between the city's population and construction land. (3) The smart shrinkage scenario will require strict control of the scale of construction land and optimization of the structure of the urban construction land, which would push the city in the direction of healthy and sustainable development. (4) The concept of smart shrinkage planning is a scientific and feasible plan for realizing the efficient and sustainable use of construction land in shrinking cities. [ABSTRACT FROM AUTHOR]

Objective: Existing studies indicate that advanced colorectal neoplasms exhibit distinct clinical and biological traits based on anatomical sites. However, in China, especially for advanced colorectal neoplasms, there's limited information available on these traits. Our primary objective is to comprehensively study the characteristics of advanced colorectal neoplasm patients in different anatomical sites in China. Methods: We selected information from the colorectal cancer screening database in Tianjin, China, since 2010 as the study subject. We chose valid information from 3113 patients with comprehensive data and diagnosed advanced colorectal neoplasms (ANs) from a pool of 19,308 individuals to be included in the study. We then conducted further analysis to examine the correlation between these epidemiological data and tumor location. Results: Among the 3113 patients, neoplasms in the left side of the colon accounted for the largest proportion, while neoplasms in the right side of the colon had the smallest proportion, followed by rectal neoplasms. The highest proportion of advanced colorectal neoplasms was found among men. In the age group of 39–49 years old, the proportion of left late‐stage advanced colon neoplasms was equal to that of right late‐stage advanced colon neoplasms, while late‐stage advanced rectal neoplasms increased with age. Smoking, drinking, and a history of colon cancer in first‐degree relatives showed statistically significant associations with the location distribution of advanced colorectal neoplasms. A history of appendicitis, appendectomy, cholecystitis, or cholecystectomy did not significantly affect the location distribution of advanced colorectal neoplasms. However, among patients with such histories, there was a statistically significant relationship between advanced colon neoplasms on the right and those on the left and in the rectum. Similar results were observed for BMI. Conclusion: Our research findings demonstrate that advanced colorectal neoplasms display unique epidemiological characteristics depending on their anatomical locations, and these distinctions deviate from those observed in Western populations. These insights contribute to a more comprehensive understanding of the topic and offer valuable guidance for future research in China. We advocate for further investigations centered on the anatomical location of colorectal neoplasms to enhance the precision of colorectal cancer (CRC) screening and treatment. [ABSTRACT FROM AUTHOR]

Northeast China occupies the majority of the eastern Central Asian Orogenic Belt, which mainly consists of continental blocks and accretionary terranes. The Devonian was a tectonic quiet period in the NE China region due to a lack of tectono-magmatism, but the tectonic background of this period has been unclear, especially for the Hegenshan-Heihe Suture between Xing'an and Songliao accretionary terranes, which represents the Paleozoic Nenjiang Ocean (a branch ocean of the eastern Paleo-Asian Ocean). Here we report granitic rocks from the Woluohe area, Northern Great Xing'an Range, NE China, to constrain the tectonic process of the transition from the Devonian quiet period to the Early Carboniferous active tectonic period. Three granitic rock samples produce zircon U-Pb ages of 389 Ma, 368 Ma, and 351 Ma, belonging to the Middle and Late Devonian and Early Carboniferous, respectively. They have high Si, Al, K, and Na contents, but with low Mg, Fe, and Ti contents, together with positive Hf isotopic features and low molar Al2O3/(MgO+FeOT) ratios, we suggest that they were derived from partial melting of lower crustal igneous rocks. Meanwhile, the narrow major element variation at odd with the fractionation process and their negative Nb and Ta anomalies imply the obvious contribution of crustal. Comprehensive tectonic setting analysis shows all samples are in calc-alkali magmatic series with rightward fractionated REE and trace element patterns that are enriched in LREE and LILE and depleted in HREE and HFS, indicating a subduction-related magmatic arc setting. Considering the regional tectonic setting and the small scale of the Devonian plutons, we suggest a limited subduction tectonic setting during the quiet period of the northern Great Xing'an Range, which might indicate the beginning of an initial northwestward subduction of the Nenjiang Oceanic lithosphere beneath the Xing'an Accretionary Terrane in the Middle Devonian, accelerated subduction in the Late Devonian, and bidirectional subduction in the Early Carboniferous. [ABSTRACT FROM AUTHOR]

Shrinking cities are a class of cities that show different trajectories in the urbanization process. Although many studies have examined shrinking cities from multi-dimensional perspectives, the spatiotemporal evolution of land use structure is still poorly understood. This study constructed an analysis framework for spatiotemporal evolution characteristics of land use structure over two 10-year periods based on 334 county-level administrative units in the context of northeast China, a region undergoing substantial population loss and urban shrinkage. This study analyses quantitatively measured population loss and land use conversion and investigated the rationality of the expansion mode of newly added construction land in research units. The results demonstrated that, first, the total population in northeast China continued to decline, but the total construction area continued to grow, and the various types of construction land in most shrinking units did not decline with the loss of population. Second, 67.09% of new construction land came from cropland, and compared with 2000–2010, the growth of new construction land in 2010–2020 slowed down. Third, during the study period, more than half of the expansion area for newly added construction land came from sprawling expansion, and areas in a state of shrinking were no exception. [ABSTRACT FROM AUTHOR]

Background: Village clinic doctors (VCDs) are part of the health service force in rural China. VCDs' job satisfaction (JS) is important to the stability of the three-tiered health service system. Since 2009, the Chinese government launched a new health care system reform (NHCSR) which affected VCDs significantly. This study aimed to analysing the effect of NHCSR on JS among VCDs.Methods: All the data came from three surveys in Shandong Province conducted in 2012, 2015 and 2018. In 2012, an originally designed questionnaire was used to conduct a baseline survey of 405 VCDs from 27 townships in nine counties. In 2015 and 2018, 519 and 223 VCDs in the same counties were surveyed with the same questionnaire. Descriptive analysis and ANOVA were used to analyse the level and changes in VCDs' JS.Results: The mean scores of VCDs' total JS were 2.664 ± 1.069, 3.121 ± 0.931 and 2.676 ± 1.044 in 2012, 2015 and 2018, respectively, with a significant difference (F = 28.732, P < 0.001). The mean scores of the medical practice environment and the job itself showed a continuous downward trend. The trends of the mean scores for job reward, internal work environment and organizational management were consistent with the trend for total JS.Conclusion: The NHCSR had a partly negative impact on VCDs' JS. Policy-makers should pay more attention to VCDs' job reward and medical practice environment. With the implementation of new reform policies, VCDs' JS should be the subject of more systematic and detailed research. [ABSTRACT FROM AUTHOR]

A series of tectonic activities induced by the subduction of the Palaeo‐Asian Ocean (PAO) in the Palaeozoic have been recorded in the North China Craton (NCC). Sedimentary strata provide some precious records to reconstruct the basin evolution in the NCC. In this study, we carried out detrital zircon LA‐ICP‐MS U–Pb dating, sandstone modal analysis, bulk‐rock major, and trace elemental measurements for the Sunjiagou and Liujiagou formations in the eastern Ordos Basin to trace the material source. The results show that the sedimentary rocks were mostly sourced from active continental margins. The detrital zircon ages of the Sunjiagou and Liujiagou formations spread from >3,000 to 250 Ma with peaks of main age populations at 2,508, 1,890, 430, and 270 Ma. Based on the age comparison and the southward palaeocurrents, we consider that the source material of these sedimentary rocks comes from the northern margin of the NCC. This in turn indicates that the amalgamation of the PAO and the NCC should have finished at least by the end of the Late Permian. [ABSTRACT FROM AUTHOR]

Recently, the Cancer Genome Atlas and Asian Cancer Research Group propose two new classifications system of gastric cancer by using multi-platforms of molecular analyses. However, these highly complicated and cost technologies have not yet been translated into full clinical utility. In addition, the clinicians are expected to gain more guidance of treatment for different molecular subtypes. In this study, we developed a panel of gastric cancer patients in population from Southern China using commercially accessible TMA and immunohistochemical technology. A cohort of 259 GC patients was classified into 4 subtypes on the basis of expression of mismatch repair proteins (PMS2, MLH1, MSH2, and MSH6), E-cadherin and p21 protein. We observed that the subtypes presented distinct prognosis. dMMR-like subtype was associated with the best prognosis, and E-cadherin-a subtype was associated with the worst prognosis. Patients with p21-High and p21-Ligh subtypes had intermediate overall survival. In multivariate analysis, the dMMR-like subtype remained an independent prediction power for overall survival in the model. We described a molecular classification of gastric cancers using clinically applicable assay. The biological relevance of the four subtypes was illustrated by significant differences in prognosis. Our molecular classification provided an effective and inexpensive screening tool for improving prognostic models. Nevertheless, our study should be considered preliminary and carries a limited predictive value as a single-center retrospective study. [ABSTRACT FROM AUTHOR]

The Late Palaeozoic Solonker‐Xar Moron‐Changchun‐Yanji Suture (SXCYS) is considered to mark the location of the final closure of the Paleo‐Asian Ocean, which separated the North China Craton to the south and the amalgamated blocks to the north in Northeast China. There has always been controversy about its eastern extension in Northeast China and the final closure time of the Paleo‐Asian Ocean. To explore this issue, we collected gabbro and quartz‐diorite samples in the Hunchun area for the genesis of mafic magma and age dating, and five groups of Permian to Triassic sandstones belonging to both sides of the potential suture locations in the middle and east Jilin Province for the provenance analysis to discuss the final closure time of the Paleo‐Asian Ocean and the possible positions of the eastward termination of the SXCYS. The gabbro reveals a Middle Permian concordia average age of 266.9 ± 5.2 Ma, and the quartz diorite reveals a Late Permian Concordia average age of 258.8 ± 4.8 Ma. Lithological and geochemical analysis reveal the two rock samples belong to low‐K arc tholeiites from the oceanic island and calk‐alkaline volcanics from the active continental margin, respectively, which implies that during the middle to late Permian, the SW margin of the Jiamusi–Khanka Block (JB) continuously experienced the subduction process from the Paleo‐Asian Ocean Plate. The final closure time of the Paleo‐Asian Ocean should be later than the Late Permian. Meanwhile, four groups of sandstone from the east Jilin reveal typically Jiamusi–Mongolia Block (JMB) provenance features, with age components of ~500 Ma, ~0.9–1.5 Ga implying that the Wangqing, Hunchun, Kaishantun area belongs to the northern part of the SXCYS from late Early Permian to Middle Triassic, with youngest age components of 288.2 ± 2.8, 275.5 ± 1.8, 250 ± 1.7, and 244.9 ± 1.7 Ma, respectively. The late Early Permian sandstone from the middle Jilin reveals the youngest age component of 273.8 ± 3.4 Ma and the age component of 487 ± 3 Ma also revealing JMB feature. Comparing to previous studies, we propose that the Paleo‐Asian Ocean finally closed during Middle to Late Triassic. A possible ENE fault separates the eastern extension of SXCYS into two parts, which means the possible position of the eastward extension of the SXCYS should go along the Wangqing‐Kaishantun with NNW direction in the west, Hunchun‐Laoheishan with NW direction in the east. [ABSTRACT FROM AUTHOR]

Beginning in 2016, all couples in China were allowed to have two children without any restrictions. This paper provides population and economic projections under five shared socioeconomic pathways (SSPs) and three fertility policies. By replacing the one‐child policy with the two‐child policy, the population is predicted to continue growing until 2025–2035, with a peak of approximately 1.39–1.42 billion, and then to decline under four SSPs, with the exception of the fragmented world SSP3. As a result, the two‐child policy will lead to mitigation of the pressure from labor shortages and aging problems to a certain extent. In addition, an increase in working‐age people with higher education level relative to projections based on the one‐child policy will lead to an increase in gross domestic product by approximately 38.1–43.9% in the late 21st century. However, labor shortages and aging problems are inevitable, and the proportion of elderly in China will be greater than 14% and 21% by approximately 2025 and 2035, respectively. Full liberalization of fertility is expected to reduce the share of elderly people by 0.7–1.0% and to lead to an increase in gross domestic product by 5.3–6.7% relative to the two‐child policy in the late 21st century. The full liberalization of fertility policies is recommended, supplemented by increases in pension and child‐rearing funds, improvement in the quality of health services for females and children, and extension of compulsory education to meet the needs of an aged society. Plain Language Summary: The one‐child policy in China has been replaced by the two‐child policy since 2016. What might the population and economy change if the one‐child policy is continued in the 21st century? What can China benefit from the fertility policy changes? Is it necessary to allow people to choose their family size in China? We conducted multipopulation policies and multisocioeconomic development pathways combined analysis to explore the effects of fertility policy changes on population and economy in China. We found that population size by the late 21st century might be 28% less than that in 2010 at the one‐child policy, and share of elderly (aged 65+) might be 49%. The implementation of the two‐child policy can mitigate the labor shortages and aging problems to a certain extent, and the increased working‐age population with higher education level can lead to a 38.1–43.9% increase in gross domestic product in the late 21st century. A further 0.7–1.0% reduction in elderly share of the total population and 5.3–6.7% increase in gross domestic product is projected in the late 21st century at the "full relaxation" policy. We believe that introduction of effects from fertility policy changes on socioeconomy can deliver useful information to decision makers. Key Points: The integrated effects of population policies and socioeconomic pathways on the population structure and economy are exploredThe population bust in China caused by the one‐child policy will be relieved after the two‐child policy, as indicated by all the SSPsFull relaxation of fertility control is recommended with the simultaneous implementation of other social policies (e.g., pension funds) [ABSTRACT FROM AUTHOR]

The Songliao Basin is the largest oil-bearing basin in China. In the absence of sufficient evidence, the possibility of seawater incursion(s) into the Songliao Basin remains controversial. Recently, we discovered relatively abundant foraminifera fossils from units 1 and 2 of the Nenjiang Formation of borehole SK-1. Benthic foraminifera (Gavlinella sp., Anomalinoides sp., Pullenia sp., Haplophragmoides sp., Karrorulina hokkaidoana, Clavulinoides sp.), as well as planktonic foraminifera (Archaeoglobigerina blowi, Archaeoglobigerina cretacea and Hedbergella flandrini), were identified. These fossils were widely distributed in the marine Cretaceous. According to the global distribution of the above-mentioned planktonic foraminifera, the age of these fossil bearing strata appears to be Late Coniacian to Santonian. More importantly, these foraminifera provide direct evidence for marine water incursions into the Songliao Basin during deposition of the Lower Nenjiang Formation. [ABSTRACT FROM AUTHOR]

Background: Exposure to natural outdoor environments (NOE) has been shown to be beneficial to older adults' health and functioning, yet this assertion has rarely been tested in China. We investigated the relationships between exposure to NOE and older adults' self-rated health in Shanghai, China and examined whether these relationships varied by sex, age, education and hukou status. Method: This cross-sectional study used micro-data sample of the 2010 Shanghai population census, including 7962 older adults nested within 3345 neighbourhoods. Self-rated health was the outcome variable. Four NOE exposure indicators were calculated for each neighbourhood: the amount of surrounding greenness/blueness and proximity to large green/blue spaces. Multilevel logistic regression was employed to explore the association between natural outdoor environment exposure and self-rated health, adjusting for individual-level and neighbourhood-level covariates. Stratified analyses were used to examine variations by sex, age, education and hukou status. Results: Older adults living in neighbourhoods with higher surrounding greenness and higher proximity to both green spaces and blue spaces were more likely to report good health. Residential surrounding blueness was not significantly related to self-rated health. Females, those aged 60–69 years, those who had elementary school or junior high school education and those with non-local hukou benefit more from residential surrounding greenness, and those aged 70–79 years and who had elementary school or junior high school education benefit more from residential proximity to blue spaces. Conclusions: Higher residential greenness and proximity to both green spaces and blue spaces were associated with better self-rated health, particularly for females, younger older adults, the low educated and non-local hukou holders. Our findings suggest that urban green spaces and urban blue spaces have different effects on health among Chinese older adults and that the assessment of exposure matters to the investigation of NOE-health relationships. [ABSTRACT FROM AUTHOR]

The provision of climate services for assessing and governing environmental problems such as poor air quality requires interactions between scientists and decision-makers. Air quality information services in China mainly focus on the coming days to weeks. However, users may benefit from air quality information on climate time-scales—from months to decades; hereafter air quality climate services. We focused on key decision-makers and stakeholders that are users of air quality climate services and conducted five workshops with these identified users to ascertain their priorities for air quality climate services, and the reasoning behind these priorities. We also conducted a choice-based conjoint experiment via an online survey distributed amongst regional and local Climate Centres and Environmental Monitoring Centres to assess quantitatively the decision-makers' needs. The results from the workshops and the survey showed that the needs for air quality climate services by users in China mainly relate to seasonal forecasting of winter haze events (PM 2.5 levels and/or the meteorological conditions conducive to the dispersion of the air pollution); there is also some interest in long-term projections of haze under climate change and a growing interest in ozone pollution in summer. Spatial relevance is perceived to be important to regional and city-level stakeholders who prefer information on the city-level, whilst national-wide information is important for national government agencies. A high level of reliability of forecasts was needed for uptake. The findings on the needs for air quality climate services by potential users can support researchers and policy-makers in developing the scientific capacity and providing tailored and effective air quality climate services in China. • To understand decision-maker needs on air quality climate services, qualitative and quantitative methods were conducted, and the results were compared and combined. • Decision-makers and stakeholders expressed a strong interest for seasonal forecasting for winter haze. • They also expressed a moderate interest for seasonal forecasting for summer ozone pollution, and a modest interest for long-term projections of haze under climate change. • A high level of reliability of forecasts was needed for uptake while multiple sources of uncertainties were recognised. [ABSTRACT FROM AUTHOR]

Background: Falls place a heavy burden on older adults and families, and there was little research on the relationship between falls and depressive symptoms among older adults in China. This study is designed to examine the association between falls and depressive symptoms in Chinese older adults., Methods: This study was based on 9,539 data sets from the China Health and Retirement Longitudinal Study (CHARLS) in 2018. The 10-item Center for Epidemiologic Studies-Depression Scale (CESD-10) was used to access depressive symptoms in older adults. A logistic regression model was used to calculate multivariate odds ratios (ORs) and 95% confidence intervals (CIs) for falls and depressive symptoms, adjusted for possible confounders. The Classification and regression tree (CART) demonstrates the prediction of the target variable values based on other variables., Results: In this study, 9,539 older people were selected: 60-69 years old accounted for 63.0%, 70-79 years old accounted for 29.7%, and 80 years old and above accounted for 7.3%. Male accounted for 49.7% and female for 50.3%. The rate of falls among older adults was 21.4%, and the rate of depressive symptoms was 33.9%. Adjusted ORs (OR = 1.37, 95% CI: 1.23, 1.53) showed a significant association between falls and depressive symptoms among older adults. Subgroup analysis revealed that this association was statistically significant across male (OR = 1.29, 95% CI: 1.23, 1.53) and female (OR = 1.42, 95% CI: 1.23, 1.64), 60-69 aged (OR = 1.38, 95% CI: 1.19, 1.60) and 70-79 aged (OR =1.42, 95% CI: 1.16, 1.74), rural (OR = 1.42, 95% CI: 1.25, 1.61), <15,000 CNY (OR = 1.35, 95% CI: 1.19, 1.54) and more than 25,000 CNY (OR = 1.42, 95% CI: 1.09, 1.85). Additionally, The CART model showed that the probability (73.0%) of falls was highest among older adults with depressive symptoms who self-rated poor health and female gender., Conclusions: This cross-sectional study demonstrated a significant association between falls and depressive symptoms in Chinese older adults. The findings provide some evidence and support for risk monitoring, screening for depressive symptoms, and early prevention in the high-risk older population., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Feng, Chen, Li, Xue and Hao.)

Residential greenspace quality may be more important for people's mental health than the quantity of greenspace. Existing literature mainly focuses on greenspace quantity and is limited to exposure metrics based on an over-head perspective (i.e., remote sensing data). Thus, whether greenspace quantity and quality influence mental health through different mechanisms remains unclear. To compare the mechanisms through which greenspace quantity and quality influence mental health, we used both remote sensing and street view data. Questionnaire data from 1003 participants in Guangzhou, China were analysed cross-sectionally. Mental health was assessed through the World Health Organization Well-Being Index (WHO-5). Greenspace quantity was measured by both remote sensing-based Normalized Difference Vegetation Index (NDVI) and Street View Greenness-quantity (SVG-quantity). Greenspace quality was measured by both Street View Greenness-quality (SVG-quality) and questionnaire-based self-reported greenspace quality. Structural equation models were used to assess mechanisms through which neighbourhood greenspace exposure has an influence on mental health. Stress, social cohesion, physical activity and life satisfaction were found to mediate both SVG-quality - WHO-5 scores and self-reported greenspace quality - WHO-5 scores associations. However, only NO 2 (nitrogen dioxide) mediated the association between NDVI and WHO-5 scores, while NO 2 , perceived pollution and social cohesion mediated the association between SVG-quantity and WHO-5 scores. The mechanisms through which neighbourhood greenspace exposure influences mental health may vary across different exposure assessment strategies. Greenspace quantity influences mental health through reducing harm from pollution, while greenspace quality influences mental health through restoring and building capacities., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The increase in surface air temperature in China has been faster than the global rate, and more high temperature spells are expected to occur in future. Here we assess the annual heat-related mortality in densely populated cities of China at 1.5 °C and 2.0 °C global warming. For this, the urban population is projected under five SSPs, and 31 GCM runs as well as temperature-mortality relation curves are applied. The annual heat-related mortality is projected to increase from 32.1 per million inhabitants annually in 1986-2005 to 48.8-67.1 per million for the 1.5 °C warming and to 59.2-81.3 per million for the 2.0 °C warming, taking improved adaptation capacity into account. Without improved adaptation capacity, heat-related mortality will increase even stronger. If all 831 million urban inhabitants in China are considered, the additional warming from 1.5 °C to 2 °C will lead to more than 27.9 thousand additional heat-related deaths, annually.

Screening is an effective measure to prevent and control colorectal cancer (CRC). A mass CRC screening programme was conducted in Guangzhou from 2015 to 2017. Public media and reminders from a mobile short message service were used to invite residents aged between 50 and 74 years. A high-risk factor questionnaire (HRFQ) and biennial faecal immunochemical testing (FIT) were chosen as the primary screening methods, and individuals with a positive test result were referred to a defined hospital for an assessment colonoscopy. During the 3 years, 350,581 residents of the total eligible population of 2,283,214 attended the free first stage of screening. In all, 91.0% of the participants finished the HRFQs and FITs. The total uptake rate was 15.4%, which increased with age, female sex, and rural location. There was 15.9% positivity in the first stage of screening, including 8.5% positive HRFQs, 6.2% positive FITs and 1.2% positive HRFQs and FITs. In total, 10,600 individuals with positive HRFQs/FITs completed an assessment colonoscopy. The total uptake rate of colonoscopies was 18.9%, which decreased with age and female sex. Three hundred fifty-one CRCs and 980 advanced adenomas (AAs) were diagnosed with positive predictive values (PPV) of 3.3% and 9.2%, respectively. The PPVs of CRCs in the exclusively FIT-positive population were 4.9%, which was 10 times greater than in the exclusively HRFQ-positive population (0.5%). The PPVs of CRCs and AAs increased with age and male sex. The detection ratio of localized CRCs (including stage I and stage II) increased 68.1% due to screening. Although the compliance rate was low, the PPVs for CRCs and AAs were high. More effective mobilization of the programme's needs and subsidies for colonoscopies should be taken into account to increase compliance.

Objective: To investigate clinical features of infantile hypertrophic pyloric stenosis (IHPS) in Chinese Han population., Methods: Three hundred and sixteen hospitalized patients with IHPS from January 1998 to February 2010 were retrospectively reviewed, and data including patient's sex, onset age, other coexisting congenital defects, pyloric circular muscle thickness evaluated by ultrasonograph, serum electrolytes concentration, and results of arterial blood gas analysis on admission were collected. The patients were divided into two groups: the duration between first onset and admission less than or equal to 10 days (early onset group), and more than 10 days (late onset group). The results of arterial blood gas and serum electrolyte concentration were compared between the two groups., Results: There were 271 males and 45 females in 316 patients; the onset age ranged between 1 and 351 (26.5±26.6) days. The birth weight ranged between 1.6 and 4.5 (3.23±0.44) kilograms; coexisting congenital defects were found in 65 cases (20.6%). Pyloric circular muscle thickness was 4-8 (5.4±1.0) millimetres (mm). For the early onset group, the rates of hypokalemia, hypochloraemia and hypercapnia were significantly lower than those in the late onset group (18.67% VS 50%, P<0.0001; 46.03% VS 71.01%, P = 0.003; 56.58% VS 83.44%, P = 2.17×10(-5); respectively)., Conclusions: The symptom duration in Chinese Han population was longer than that in other populations. And as the prolongation of symptom duration, the incidence of acid-base imbalance increased significantly. Infants with persistent vomiting at the age of 3∼5 weeks after birth should be considered IHPS, and go to hospital as soon as possible in order to reduce the incidence of hypokalemia, hypochloraemia and hypercapnia, and avoid deterioration.