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57 result(s) for "Zhan, Jinfeng"
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Reference values of glomerular filtration rate for healthy adults in southern China: a cross-sectional survey
Background: Currently the global data on the glomerular filtration rate of healthy adults are insufficient, with relatively little data for other races and countries. Especially in China, there are no such figures. Methods: In this cross-sectional study, we included healthy Han adults in southern China. Participants completed a lifestyle and medical history questionnaire and had their blood pressure measured, and blood and urine samples collected. Serum creatinine was measured and used to estimated glomerular filtration rate (eGFR) by the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulae. The normal range of eGFR is described, and the influence of gender and age on eGFR is analyzed by the statistical method. Results: We provided the largest sample size of eGFR research in China at present. The mean age of the 20,930 healthy individuals was 40.9 ± 12.3 years, 58.8% were women. The eGFRMDRD for women and men were 111.3 ± 17.4 mL/min per 1.73 m2 and 103.3 ± 15.9 mL/min per 1.73 m2, respectively. The eGFRCKD-EPI for women and men were 110.3 ± 12.1 mL/min per 1.73 m2 and 103.8 ± 13.3 mL/min per 1.73 m2, respectively. The eGFRMDRD of women and men in all age groups decreased continuously by 7.3 ml/min/1.73 m2/decade and 4.4 ml/min/1.73 m2/decade, respectively. The eGFRCKD-EPI of women and men in all age groups decreased continuously by 8.4 ml/min/1.73 m2/decade and 6.9 ml/min/1.73 m2/decade. Conclusions: The eGFR of women is higher than men and with the increasing age, the eGFR of women declines faster than men.
The value of serum cystatin C in early evaluation of renal insufficiency in patients undergoing chemotherapy: a systematic review and meta-analysis
PurposeSeveral studies have shown that cystatin C levels can be used to detect decline in renal function in cancer patients receiving chemotherapy, and can serve as a supplement to creatinine level measurement for early detection of renal insufficiency. Nevertheless, use of the parameter remains controversial. This study aimed to assess the value of serum cystatin C levels in evaluation of early renal insufficiency due to chemotherapy.MethodsStudies were retrieved from PubMed, Ovid Embase, the Web of Science, the Cochrane Library, Ovid, and the CNKI databases up to May 15, 2018. Serum levels of cystatin C before and after chemotherapy were evaluated for its ability to assess renal function.ResultsA total of 12 studies, including 1775 participants, met our inclusion and exclusion criteria. Pooled analysis revealed that the levels of serum cystatin C in cancer patients after chemotherapy were significantly higher than those of patients prior to treatment [standard mean difference (SMD) = 0.54, 95% CI 0.34–0.74, P = 0.0000]. Compared to creatinine, serum cystatin C increased significantly in the early phases of glomerular filtration rate (GFR) change before and after chemotherapy (GFR ≥ 90 ml/min/1.73 m2, P < 0.05 vs. P > 0.05, 5.83%; 60 < GFR < 90 ml/min/1.73 m2, P < 0.01 vs. P > 0.01, 38.83%) and increased more substantially in the later phases (GFR < 60 ml/min/1.73 m2, P < 0.01 vs. P < 0.01, 70.87% vs. 23.09%). However, creatinine decreased even in the early phases and did not increase in an obvious manner until the later phases (GFR < 60 ml/min/1.73 m2, P < 0.01, 23.09%). The GFR values were derived from measured methods.ConclusionsCystatin C may be superior to creatinine for the detection of minor changes in GFR in early stages of renal insufficiency secondary to chemotherapy. More studies are needed to further verify this result.
Skeletal muscle index and muscle attenuation with liver cirrhosis as survival prognosticators by sex
Background and Objectives: It has been proven that skeletal muscle index (SMI) and muscle attenuation (MA) are correlated with outcomes in liver cirrhosis. However, whether there are sex differences in these factors re-mains unknown. We aimed to analyze the predictive ability of SMI and MA for the prognosis of cirrhotic patients of different sexes and promote computed tomography (CT) use in body composition assessment. Methods and Study Design: CT images taken at the 3rd lumbar vertebra from 223 patients were quantified for body composi-tion. A Cox regression model was used to assess associations between mortality and body composition. Time-dependent receiver operating characteristic curves were calculated to evaluate the predictive ability of SMI and MA for the 1-, 3- and 5- year mortality of cirrhotic patients. Results: The majority of patients with liver cirrhosis were male (64.6%), and there was a weak linear correlation between SMI and MA in males (r=0.33, p<0.001). In the sex stratified multivariate Cox regression analysis, SMI in males (HR=0.95; 95% CI, 0.91-0.98; p=0.002) and MA in females (HR=0.91; 95% CI, 0.87-0.96; p<0.001) were independently associated with mortality. The areas under the curve (AUCs) of SMI (AUC=0.718) and MA (AUC=0.705) were similar in the 5-year mortality predic-tion of males, while in females, MA (AUC=0.797) had a stronger predictive ability than SMI (AUC=0.541). Conclusions: SMI in males and MA in females are independent prognostic factors for liver cirrhosis. For females, MA may be a more sensitive indicator of mortality prediction than SMI, while in males, they are equivalent.
Spatial–temporal atlas of human fetal brain development during the early second trimester
During the second trimester, the human fetal brain undergoes numerous changes that lead to substantial variation in the neonatal in terms of its morphology and tissue types. As fetal MRI is more and more widely used for studying the human brain development during this period, a spatiotemporal atlas becomes necessary for characterizing the dynamic structural changes. In this study, 34 postmortem human fetal brains with gestational ages ranging from 15 to 22weeks were scanned using 7.0T MR. We used automated morphometrics, tensor-based morphometry and surface modeling techniques to analyze the data. Spatiotemporal atlases of each week and the overall atlas covering the whole period with high resolution and contrast were created. These atlases were used for the analysis of age-specific shape changes during this period, including development of the cerebral wall, lateral ventricles, Sylvian fissure, and growth direction based on local surface measurements. Our findings indicate that growth of the subplate zone is especially striking and is the main cause for the lamination pattern changes. Changes in the cortex around Sylvian fissure demonstrate that cortical growth may be one of the mechanisms for gyration. Surface deformation mapping, revealed by local shape analysis, indicates that there is global anterior–posterior growth pattern, with frontal and temporal lobes developing relatively quickly during this period. Our results are valuable for understanding the normal brain development trajectories and anatomical characteristics. These week-by-week fetal brain atlases can be used as reference in in vivo studies, and may facilitate the quantification of fetal brain development across space and time. •We present week-by-week spatial-temporal brain atlases (15-22 gestational weeks).•The subplate zone is the main cause for the lamination pattern changes.•The cortex around Sylvian fissure has a higher growth rate than other area.•The brain undergoes a global anterior-posterior growth pattern during this period.
Shoulder MRI-based radiomics for diagnosis and severity staging assessment of surgically treated supraspinatus tendon tears
Objective To develop and validate MRI-based radiomics models capable of evaluating supraspinatus tendon tears within the shoulder joints by using arthroscopy as the reference standard. Methods A total of 432 patients (332 in the training set and 100 in the external validation set) with intact supraspinatus tendon ( n  = 202) and supraspinatus tendon tear ( n  = 230, 130 full-thickness tears and 100 partial-thickness tears) were enrolled. Radiomics features were extracted from fat-saturated T2-weighted coronal images. Two radiomics signature models for detecting supraspinatus tendon abnormalities (tear or not), and stage lesion severity (full- or partial-thickness tear) and radiomics scores (Rad-score), were constructed and calculated using multivariate logistic regression analysis. The diagnostic performance of the two models was validated using ROC curves on the training and validation datasets. Results For the radiomics model of no tears or tears, thirteen features from MR images were used to build the radiomics signature with an AUC value of 0.98 in the training set, 0.97 in the internal validation set, and 0.98 in the external validation set. For the radiomics model of full- or partial-thickness tears, thirteen features from MR images were used to build the radiomics signature with an AUC value of 0.79 in the training set, 0.69 in the internal validation set, and 0.77 in the external validation set. Conclusion The proposed radiomics models in this study can accurately rule out supraspinatus tendon tears and are capable of assessing the severity staging of tears with moderate accuracy based on shoulder MR images. Key Points • The radiomics model of no tears or tears achieved a high overall accuracy of 93.6%, sensitivity of 91.6%, and specificity of 95.2% for supraspinatus tendon tears. • The radiomics model of full- or partial-thickness tears displayed moderate performance with an accuracy of 76.4%, a sensitivity of 79.2%, and a specificity of 74.3% for supraspinatus tendon tears severity staging.
Development of the human fetal hippocampal formation during early second trimester
Development of the fetal hippocampal formation has been difficult to fully describe because of rapid changes in its shape during the fetal period. The aims of this study were to: (1) segment the fetal hippocampal formation using 7.0T MR images from 41 specimens with gestational ages ranging from 14 to 22weeks and (2) reveal the developmental course of the fetal hippocampal formation using volume and shape analyses. Differences in hemispheric volume were observed, with the right hippocampi being larger than the left. Absolute volume changes showed a linear increase, while relative volume changes demonstrated an inverted-U shape trend during this period. Together these exhibited a variable developmental rate among different regions of the fetal brain. Different sub-regional growth of the fetal hippocampal formation was specifically observed using shape analysis. The fetal hippocampal formation possessed a prominent medial–lateral bidirectional shape growth pattern during its rotation process. Our results provide additional insight into 3D hippocampal morphology in the assessment of fetal brain development and can be used as a reference for future hippocampal studies. •We manually segment the fetal hippocampal formation using 7.0T MRI and specimens.•Linear tendency of the absolute hippocampal volume development•Inverted-U shape tendency of the relative hippocampal volume development•Hemispheric asymmetries, with the right hippocampus being larger than the left•The fetal HF possesses a medial–lateral bidirectional shape growth pattern.
Spatialatemporal atlas of human fetal brain development during the early second trimester
During the second trimester, the human fetal brain undergoes numerous changes that lead to substantial variation in the neonatal in terms of its morphology and tissue types. As fetal MRI is more and more widely used for studying the human brain development during this period, a spatiotemporal atlas becomes necessary for characterizing the dynamic structural changes. In this study, 34 postmortem human fetal brains with gestational ages ranging from 15 to 22 weeks were scanned using 7.0 T MR. We used automated morphometrics, tensor-based morphometry and surface modeling techniques to analyze the data. Spatiotemporal atlases of each week and the overall atlas covering the whole period with high resolution and contrast were created. These atlases were used for the analysis of age-specific shape changes during this period, including development of the cerebral wall, lateral ventricles, Sylvian fissure, and growth direction based on local surface measurements. Our findings indicate that growth of the subplate zone is especially striking and is the main cause for the lamination pattern changes. Changes in the cortex around Sylvian fissure demonstrate that cortical growth may be one of the mechanisms for gyration. Surface deformation mapping, revealed by local shape analysis, indicates that there is global anterioraposterior growth pattern, with frontal and temporal lobes developing relatively quickly during this period. Our results are valuable for understanding the normal brain development trajectories and anatomical characteristics. These week-by-week fetal brain atlases can be used as reference in in vivo studies, and may facilitate the quantification of fetal brain development across space and time.
A new method for determining the pore water pressure around twin shallow circular tunnels
To obtain the distribution rules of pore water pressure for twin shallow circular tunnels, the shallow circular tunnels were regarded as fully saturated, homogeneous, isotropic structures in a semi-infinite space. Coordinate transformations were utilized to obtain the water pressure control equations in a bipolar coordinate system. Through the Schwarz alternating method, the calculation method for the pore water pressure around a single tunnel was generalized to twin tunnels, and a new method for determining the pore water pressure around twin shallow circular tunnels in a semi-infinite space was proposed for the first time by using the bipolar coordinate system method and the Schwarz alternating method. Solutions for the pore water pressure were obtained via multiple iterations. The calculation results obtained via the proposed method were compared with the other theoretical calculation results and numerical simulation results, and we further utilized the proposed method to analyse the influencing factors of the pore water pressure. The results show that the maximum error between the theoretical calculation results and the numerical simulation results was only 2.15%; thus, the rationality of this new method was effectively verified. The relative error between the results obtained by the proposed method and the results obtained by the existing method was only 1.0%, and both very well matched the numerical simulation results; thus, the high accuracy of the proposed method was confirmed. The number of tunnels and the centre distance between the twin tunnels are the main influencing factors of the pore water pressure. According to their influences, the distribution pattern of the pore water pressure around the twin shallow circular tunnels can be preliminarily determined. Therefore, the method proposed in this study provides a theoretical guidance for the development of design and construction programs for water-rich tunnel engineering.
Lipid flippases promote antiviral silencing and the biogenesis of viral and host siRNAs in Arabidopsis
Dicer-mediated processing of virus-specific dsRNA into short interfering RNAs (siRNAs) in plants and animals initiates a specific antiviral defense by RNA interference (RNAi). In this study, we developed a forward genetic screen for the identification of host factors required for antiviral RNAi in Arabidopsis thaliana. Using whole-genome sequencing and a computational pipeline, we identified aminophospholipid transporting ATPase 2 (ALA2) and the related ALA1 in the type IV subfamily of P-type ATPases as key components of antiviral RNAi. ALA1 and ALA2 are flippases, which are transmembrane lipid transporter proteins that transport phospholipids across cellular membranes. We found that the ala1/ala2 single- and double-mutant plants exhibited enhanced disease susceptibility to cucumber mosaic virus when the virus-encoded function to suppress RNAi was disrupted. Notably, the antiviral activity of both ALA1 and ALA2 was abolished by a single amino acid substitution known to inactivate the flippase activity. Genetic analysis revealed that ALA1 and ALA2 acted to enhance the amplification of the viral siRNAs by RNA-dependent RNA polymerase (RdRP) 1 (RDR1) and RDR6 and of the endogenous virus-activated siRNAs by RDR1. RNA virus replication by plant viral RdRPs occurs inside vesicle-like membrane invaginations induced by the recruitment of the viral RdRP and host factors to subcellular membrane microdomains enriched with specific phospholipids. Our results suggest that the phospholipid transporter activity of ALA1/ALA2 may be necessary for the formation of similar invaginations for the synthesis of dsRNA precursors of highly abundant viral and host siRNAs by the cellular RdRPs.
Machine learning models for daily net radiation prediction across different climatic zones of China
Net radiation (R n ), a critical component in land surface energy cycling, is calculated as the difference between net shortwave radiation and longwave radiation at the Earth’s surface and holds significant importance in crop models for precision agriculture management. In this study, we examined the performance of four machine learning models, including extreme learning machine (ELM), hybrid artificial neural networks with genetic algorithm models (GANN), generalized regression neural networks (GRNN), and random forests (RF), in estimating daily R n at four representative sites across different climatic zones of China. The input variables included common meteorological factors such as minimum and maximum temperature, relative humidity, sunshine duration, and shortwave solar radiation. Model performance was assessed and compared using statistical parameters such as the correlation coefficient (R 2 ), root mean square errors (RMSE), mean absolute errors (MAE), and Nash–Sutcliffe coefficient (NS). The results indicated that all models slightly underestimated actual R n , with linear regression slopes ranging from 0.810 to 0.870 across different zones. The estimated R n was found to be comparable to observed values in terms of data distribution characteristics. Among the models, the ELM and GANN demonstrated higher consistency with observed values, exhibiting R 2 values ranging from 0.838 to 0.963 and 0.836 to 0.963, respectively, across varying climatic zones. These values surpassed those of the RF (0.809–0.959) and GRNN (0.812–0.949) models. Additionally, the ELM and GANN models showed smaller simulation errors in terms of RMSE, MAE, and NS across the four climatic zones compared to the RF and GRNN models. Overall, the ELM and GANN models outperformed the RF and GRNN models. Notably, the ELM model's faster computational speed makes it a strong recommendation for R n estimates across different climatic zones of China.