Weihai's urban development model is representative of coastal cities in China. Landsat MSS/ TM/OLI images were used to extract the land use types of Weihai from 1985-2015 using the object-oriented support vector machine (SVM) classification method. The landscape pattern indexes were calculated based on the classification results of land use. The temporal and spatial characteristics of land use and landscape pattern were analyzed by considering Weihai's economic development. The overall kappa (OK) coefficients were greater than 83% and the overall accuracy (OA) values were greater than 85%. Over 80% of both producer's accuracy (PA) and user's accuracy (UA) values of different land use types were greater than 85%. Changes in land use and landscape patterns were closely related to the local economic development. The areas of cultivated land and woodland continued to decrease. The expansion of construction land came mainly from the cultivated land and woodland as with as very little from waters. Under the combined effect of economic development and human activities, the landscape pattern of Weihai as a whole has been decentralized. The internal structure is relatively complex and the fragmentation of land use is increasing. The development model of Weihai is the expansion-aggregation-expansion.

ObjectiveTo develop and internally validate a prediction model for 6-year risk of stroke and its primary subtypes in middle-aged and elderly Chinese population.DesignThis is a retrospective cohort study from a prospectively collected database.ParticipantsWe included a total 3124 adults aged 45–80 years, free of stroke or myocardial infarction at baseline in the 2009–2015 cohort of China Health and Nutrition Survey.Primary and secondary outcome measuresThe outcome of the prediction model was stroke. Investigated predictors were: age, gender, body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), hypertension (HBP), drinking status, smoking status, diabetes and site. Stepwise multiple Cox regression was applied to identify independent predictors. A nomogram was constructed to predict 6-year risk of stroke based on the multiple analysis results. Bootstraps with 1000 resamples were applied to both C-index and calibration curve.ResultThe overall incidence of overall stroke was 2.98%. Age, gender, HBP and TC were found as significant risk predictors for overall stroke; age, gender, HBP and LDL-C were found as significant risk predictors for ischaemic stroke; age, gender, HBP, BMI and HDL-C were found as significant risk predictors for haemorrhagic stroke. The nomogram was constructed using significant variables included in the model, with a C-index of 0.74 (95% CI: 0.72 to 0.76), 0.74 (95% CI: 0.71 to 0.77), and 0.81 (95% CI: 0.78 to 0.84) for overall stroke, ischaemic stroke, and haemorrhagic stroke model, respectively. The calibration curves demonstrated the good agreements between predicted and observed 6-year risk probability.ConclusionOur nomogram could be convenient, easy to use and effective prognoses for predicting 6-year risk of stroke in middle-aged and elderly Chinese population.

Background Phenylalanine hydroxylase deficiency (PAHD) is the most prevalent inherited disorder of amino acid metabolism in China. Its complex phenotype includes many variants and genotypes among different populations. Methods and results In this study, we analyzed the phenylalanine hydroxylase gene (PAH) variants in a cohort of 93 PAHD patients from Fujian Province. We also assessed genotype and phenotype correlation in patients with PAHD. A total of 44 different pathogenic variants were identified, including five novel variants. The three most prevalent variants among all patents were c.158G > A, p.(Arg53His) (18.03%), c.721C > T, p.(Arg241Cys) (14.75%), and c.728G > A, p.(Arg243Gln) (7.65%). The frequency of the c.158G > A, p.(Arg53His) variant was highest in patients with mild hyperphenylalaninemia, whereas the frequency of the c.1197A > T, p.(Val399 =) and c.331C > T, p.(Arg111Ter) variants was highest in patients with classic phenylketonuria. The most abundant genotypes observed in PAHD patients were c.[158G > A];[728G > A], c.[158G > A];[442-1G > A], and c.[158G > A];[721C > T]. Comparing allelic phenotype to genotypic phenotype values yielded fairly accurate predictions of phenotype, with an overall consistency rate was 85.71% for PAHD patients. Conclusions Our study identified a PAH variant spectrum in PAHD patients from Fujian Province, Southeastern China. Quantitative correlation analysis between genotype and phenotype severity is helpful for genetic counseling and management.

It is required that the clinical screening of metabolic disorders in newborns meet International Organization for Standardization 15189-2012 approval. The new tandem mass spectrometry (MS/MS) based screening system and its companion reagent should be independently authenticated before their implementation in clinical diagnosis laboratories. Linearity, stability, accuracy, and precision evaluations were carried out to verify the performance of the Waters ACQUITY TQD MS/MS system with the NeoBase non-derivatized MS/MS PerkinElmer kit for detecting amino acids and acylcarnitine in newborns with metabolic disorders. Statistically, the correlation coefficient ( R 2 ) of 0.9982 to 0.9999 indicates good linearity. The measurements at the beginning and end of the reagent storage procedure were taken for stability verification. No significant difference was detected between the 2 periods. The amino acid exhibited a degree of bias in the range of 0% to 14.17%, with acylcarnitine's being was in the range of 0% to 14.84%; they consequently passed the quality assessment requirements for clinical laboratories of the China National Centre. The amino acids’ within-run, between-run, and day-to-day run precision were 1.19% to 7.68%, 1.63% to 5.01%, and 4.77% to 12.48%, respectively, while the total imprecision was 5.55% to 13.33%. Acylcarnitine's within-run, between-run, and day-to-day run precision was 1.2% to 8.43%, 0.19% to 9.60%, and 2.33% to 10.74%, respectively, while it's total imprecision was 6.57% to 13.99%. The manufacturer declared that the total imprecision of the tests, using Multiple Reaction Monitoring, should be less than or equal to 25% of the coefficient of variation for the kit's high and low-quality control levels. The performance of the non-derivatized MS/MS screening system in detecting the amino acids and acylcarnitines passed the test's requirements. It was maintained in accordance with the routine clinical chemical detection system.