Prefusion spike protein stabilization through computational mutagenesis.

A novel severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2) has emerged as a human pathogen, causing global pandemic and resulting in over 400 000 deaths worldwide. The surface spike protein of SARS-CoV-2 mediates the process of coronavirus entry into human cells by binding angiotensin-converting enzyme 2 (ACE2). Due to the critical role in viral-host interaction and the exposure of spike protein, it has been a focus of most vaccines' developments. However, the structural and biochemical studies of the spike protein are challenging because it is thermodynamically metastable. Here, we develop a new pipeline that automatically identifies mutants that thermodynamically stabilize the spike protein. Our pipeline integrates bioinformatics analysis of conserved residues, motion dynamics from molecular dynamics simulations, and other structural analysis to identify residues that significantly contribute to the thermodynamic stability of the spike protein. We then utilize our previously developed protein design tool, Eris, to predict thermodynamically stabilizing mutations in proteins. We validate the ability of our pipeline to identify protein stabilization mutants through known prefusion spike protein mutants. We finally utilize the pipeline to identify new prefusion spike protein stabilization mutants.

Treatment of Masked Hypertension with a Chinese Herbal Formula: A Randomized, Placebo-Controlled Trial.

BACKGROUND: Masked hypertension is associated with adverse cardiovascular outcomes. Nonetheless, no randomized controlled trials exist in the treatment of masked hypertension. The aim of this randomized, placebo-controlled trial was to investigate the efficacy and safety of blood pressure (BP)-lowering treatment with a Chinese herbal formula, gastrodia-uncaria granules, in patients with masked hypertension. METHODS: Patients with an office BP of <140/90 mm Hg and daytime ambulatory BP of 135 to 150 mm Hg systolic or 85 to 95 mm Hg diastolic were randomly assigned 1:1 to the treatment of gastrodia-uncaria granules or placebo 5 to 10 g twice daily for 4 weeks. The primary efficacy variable was the change in daytime ambulatory BP. RESULTS: At baseline, office and daytime BP of the 251 participants (mean age, 50.4 years; 53.4% men; mean body mass index 24.5 kg/m2; and 2.8%, 1.6%, and 30.7% with cardiovascular disease, diabetes, and smoking, respectively) averaged 129/82 and 135/89 mm Hg, respectively. In the intention-to-treat analysis, daytime systolic/diastolic BP was reduced by 5.44/3.39 and 2.91/1.60 mm Hg in the gastrodia-uncaria granules and placebo groups, respectively. The between-group difference in BP reductions was significant for the daytime (2.52/1.79 mm Hg; P≤0.025) and 24-hour BP (2.33/1.49 mm Hg; P≤0.012), but not for the clinic and nighttime BPs (P≥0.162). The per-protocol analysis in 229 patients produced similar results. Only 1 adverse event (sleepiness during the day) was reported, and no serious adverse event occurred. CONCLUSIONS: BP-lowering treatment with Chinese traditional medicine gastrodia-uncaria granules is efficacious for patients with masked hypertension. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02156024.

Identification of long noncoding natural antisense transcripts (lncNATs) correlated with drought stress response in wild rice (Oryza nivara).

BACKGROUND: Wild rice, including Oryza nivara and Oryza rufipogon, which are considered as the ancestors of Asian cultivated rice (Oryza sativa), possess high genetic diversity and serve as a crucial resource for breeding novel cultivars of cultivated rice. Although rice domestication related traits, such as seed shattering and plant architecture, have been intensively studied at the phenotypic and genomic levels, further investigation is needed to understand the molecular basis of phenotypic differences between cultivated and wild rice. Drought stress is one of the most severe abiotic stresses affecting rice growth and production. Adaptation to drought stress involves a cascade of genes and regulatory factors that form complex networks. O. nivara inhabits swampy areas with a seasonally dry climate, which is an ideal material to discover drought tolerance alleles. Long noncoding natural antisense transcripts (lncNATs), a class of long noncoding RNAs (lncRNAs), regulate the corresponding sense transcripts and play an important role in plant growth and development. However, the contribution of lncNATs to drought stress response in wild rice remains largely unknown. RESULTS: Here, we conducted strand-specific RNA sequencing (ssRNA-seq) analysis of Nipponbare (O. sativa) and two O. nivara accessions (BJ89 and BJ278) to determine the role of lncNATs in drought stress response in wild rice. A total of 1246 lncRNAs were identified, including 1091 coding-noncoding NAT pairs, of which 50 were expressed only in Nipponbare, and 77 were expressed only in BJ89 and/or BJ278. Of the 1091 coding-noncoding NAT pairs, 240 were differentially expressed between control and drought stress conditions. Among these 240 NAT pairs, 12 were detected only in Nipponbare, and 187 were detected uniquely in O. nivara. Furthermore, 10 of the 240 coding-noncoding NAT pairs were correlated with genes enriched in stress responsive GO terms; among these, nine pairs were uniquely found in O. nivara, and one pair was shared between O. nivara and Nipponbare. CONCLUSION: We identified lncNATs associated with drought stress response in cultivated rice and O. nivara. These results will improve our understanding of the function of lncNATs in drought tolerance and accelerate rice breeding.

Detection rate and treatment gap for atrial fibrillation identified through screening in community health centers in China (AF-CATCH): A prospective multicenter study.

BACKGROUND: Atrial fibrillation (AF) is underdiagnosed and especially undertreated in China. We aimed to investigate the prevalence of unknown and untreated AF in community residents (≥65 years old) and to determine whether an education intervention could improve oral anticoagulant (OAC) prescription. METHODS AND FINDINGS: We performed a single-time point screening for AF with a handheld single-lead electrocardiography (ECG) in Chinese residents (≥65 years old) in 5 community health centers in Shanghai from April to September 2017. Disease education and advice on referral to specialist clinics for OAC treatment were provided to all patients with actionable AF (newly detected or undertreated known AF) at the time of screening, and education was reinforced at 1 month. Follow-up occurred at 12 months. In total, 4,531 participants were screened (response rate 94.7%, mean age 71.6 ± 6.3 years, 44% male). Overall AF prevalence was 4.0% (known AF 3.5% [n = 161], new AF 0.5% [n = 22]). The 183 patients with AF were older (p < 0.001), taller (p = 0.02), and more likely to be male (p = 0.01), and they had a higher prevalence of cardiovascular disease than those without AF (p < 0.001). In total, 85% (155/183) of patients were recommended for OAC treatment by the established guidelines (CHA2DS2-VASc ≥ 2 for men; ≥ 3 for women). OAC prescription rate for known AF was 20% (28/138), and actionable AF constituted 2.8% of all those screened. At the 12-month follow-up in 103 patients (81% complete), despite disease education and advice on specialist referral, only 17 attended specialist clinics, and 4 were prescribed OAC. Of those not attending specialist clinics, 71 chose instead to attend community health centers or secondary hospital clinics, with none prescribed OAC, and 15 had no review. Of the 17 patients with new AF and a class 1 recommendation for OAC, only 3 attended a specialist clinic, and none were prescribed OAC. Of the 28 AF patients taking OAC at baseline, OAC was no longer taken in 4. Ischemic stroke (n = 2) or death (n = 3) occurred in 5/126 (4%), with none receiving OAC. As screening was performed at a single time point, some paroxysmal AF cases may have been missed; thus, the rate of new AF may be underestimated. CONCLUSIONS: We demonstrated a noticeable gap in AF detection and treatment in community-based elderly Chinese: actionable AF constituted a high proportion of those screened. Disease education and advice on specialist referral are insufficient to close the gap. Before more frequent or intensive screening for unknown AF could be recommended in China, greater efforts must be made to increase appropriate OAC therapy in known AF to prevent AF-related stroke.

MiR-424 Functions as Potential Diagnostic and Prognostic Biomarker in Melanoma.

BACKGROUND: Melanoma is one of the most aggressive and lethal skin cancers worldwide. To our knowledge, no specific or sensitive biomarkers have been clinically used to diagnose or predict melanoma prognosis. MicroRNAs (miRNAs) have been shown to regulate oncogenesis and tumor development in various cancers including melanoma. The aim of present study was to determine the clinical value of miR-424 in melanoma. METHODS: First, we examined the expression levels of miR-424 in tissue and serum samples of melanoma patients using real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Then, receiver operating characteristic curves were used to determine the diagnostic value of miR-424. Furthermore, the chi-square test was used to analyze the relationship between the expression of miR-424 and the clinical characteristics of the patients. Finally, the Kaplan-Meier survival analysis was applied to validate the prognostic value of miR-424 in melanoma. RESULTS: The results demonstrated that miR-424 expression was remarkably increased in tissues and serum of pa-tients with melanoma. Moreover, results of ROC analysis showed both tissue and serum expression of miR-424 can serve as diagnostic biomarker for melanoma. Meanwhile, miR-424 expression was significantly associated with tumor thickness (p = 0.031), metastasis (p = 0.010) and tumor stage (p = 0.005) and ulceration (p < 0.001). Finally, patients with higher miR-424 expression have shown decreased overall survival and disease-free survival than those with low miR-424 expression, implying that high miR-424 expression will contribute to poor prognosis of melanoma. CONCLUSIONS: MiR-424 may function as a diagnostic and prognostic biomarker for melanoma.

Subtypes of masked hypertension and target organ damage in untreated outpatients.

Purpose: Masked hypertension (MHT) is characterised as an office normotension in the presence of out-of-office hypertension, and can be further categorised as isolated daytime (dMHT), night-time (nMHT) or day-night MHT (dnMHT) according to the time when hypertension is present. MHT is associated with adverse cardiovascular outcome. However, no previous studies contrasted these MHT subtypes in their associations with target organ damage (TOD).Materials and methods: Consecutive untreated patients referred for ambulatory blood pressure (BP) monitoring to our Hypertension Clinic were recruited. Office and ambulatory BPs were measured using the Omron 7051 and SpaceLabs 90217 monitors, respectively. The BP thresholds of daytime and night-time hypertension were of ≥135/85 mmHg and ≥120/70 mmHg, respectively. We performed various TOD measurements, including carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT), left ventricular mass index (LVMI) and E/E', estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR).Results: The 1808 participants (mean age, 51 years; women, 52%) included 672 (37.2%) MHT subjects, among whom 123 (18.3%) had dMHT, 78 (11.6%) nMHT, and 471 (70.1%) dnMHT. In all participants as well as patients with office normotension (n = 1222), ambulatory daytime and night-time BPs were similarly associated with all TOD measurements (p ≥ 0.20) after multivariate adjustment. Compared to normotensive subjects (p < 0.05), patients with dMHT had faster cfPWV (7.81 vs. 7.58 m/s) and thicker cIMT (637.6 vs. 610.4 µm), patients with nMHT had thicker cIMT (641.8 vs. 610.4 µm) and increased UACR (0.79 vs. 0.59 mg/mmol), and patients with dnMHT had all worse TOD measures mentioned-above plus elevated eGFR (120.7 vs. 116.8 ml/min/1.73m2).Conclusion: MHT was associated with TOD irrespective of subtype, although TOD varied slightly across these subtypes. The study highlights the importance of controlling both daytime and night-time BP in hypertensive patients.

Short-term reproducibility of the 24-h ambulatory monitoring of brachial and central hemodynamics in untreated Chinese.

Objective: Advanced technology allows non-invasive monitoring of the 24-h brachial and central hemodynamics simultaneously. However, related reproducibility data was limited in White patients. We therefore explored if the novel measurements would be reproducible in Chinese. Methods: From February 2017 to January 2018, 152 untreated patients who were suspected of hypertension and referred for ambulatory blood pressure (BP) monitoring were recruited. Ambulatory BP monitoring was repeated within one month (median, 12.5 days) using the Mobil-O-Graph monitors (IEM, Germany). Reproducibility was assessed as the intra-class correlation coefficient (ICC), coefficient of variation (CV), and repeatability coefficient (RC). Results: The 152 participants (average age, 58.6 years) included 54 men and 98 women. The first and second means of the ambulatory brachial and central BPs, pulse wave velocity (PWV), augmentation pressure, augmentation index (AIx) and AIx at a heart rate of 75 beats per minute (AIx@75) were all similar (p ≥ 0.065), except that the repeated daytime and 24-h brachial and central systolic BPs and pulse pressure slightly differed by approximately 1-2 mmHg (p ≤ 0.011). ICC ranged from 0.70 to 0.94 for all ambulatory BPs and ≥0.91 for the arterial measurements. CV was in the range from 5.0% to 10.3% for all BPs and PWV measurements, and from 15.5% to 22.3% for AIx and AIx@75. RC expressed as percentages of maximal variation was <15% for the PWVs and ranged from 25.5% to 54.7% for BPs, AIx and AIx@75. Conclusions: The 24-h ambulatory brachial and central BPs and arterial measurements were reproducible within a short time period in Chinese, and could therefore be used in clinical practice and research settings.

The Role of Out-of-Clinic Blood Pressure Measurements in Preventing Hypertension.

PURPOSE OF REVIEW: One of the possible strategies for preventing hypertension is identifying high-risk people and then implementing lifestyle modifications or therapeutic interventions. Out-of-clinic blood pressure measurements, either home or ambulatory blood pressure monitoring, may identify people with early blood pressure elevation or white-coat or masked hypertension and potentially help prevent hypertension. In this review, we will summarize the evidence on the role of out-of-clinic blood pressure measurements in preventing hypertension either from prehypertension or high normal or elevated blood pressure, or from white-coat or masked hypertension. RECENT FINDINGS: Early blood pressure elevation, either termed as prehypertension or as high normal or elevated blood pressure, identified by home blood pressure monitoring was associated with a 3- to 5-fold risk of sustained hypertension. White-coat and masked hypertension, identified by either home or ambulatory blood pressure monitoring, was associated with a 2- to 4-fold risk of sustained hypertension. Out-of-office blood pressure measurements may potentially help prevent hypertension. However, to prove reversibility, controlled clinical trials are required.

Association of pulse wave velocity with single nucleotide polymorphisms related to parathyroid hormone.

OBJECTIVE: Carotid-femoral pulse wave velocity (cfPWV) was associated with serum parathyroid hormone (PTH) in untreated Chinese. We investigated in the same cohort whether cfPWV, brachial-ankle (baPWV) and heart-brachial (hbPWV) pulse wave velocity (PWV) were associated with rs6127099 (CYP24A1) and rs4074995 (RGS14). A previously published genome-wide association study demonstrated that each additional copy of the T (rs6127099) or G (rs4074995) allele was associated with a 7% or 3% higher serum PTH, respectively. METHODS: In 1601 untreated Chinese patients (mean age, 51.0 years; 51.9% women), we measured cfPWV by tonometry (SphygmoCor) and baPWV and hbPWV by combined oscillometry and plethysmography (VP-2000 PWV/ABI analyser), serum PTH by an immunoassay, and genotypes by the SNapShot method. RESULTS: cfPWV, baPWV and hbPWV averaged 7.9, 14.6 and 5.5 m/s and serum PTH 65.7 pg/mL. Genotype frequencies were in Hardy-Weinberg equilibrium, amounting to 41.7% (AA), 44.9% (AT) and 13.4% (TT) for rs6127099 and to 70.7% (GG), 26.9% (GA) and 2.3% (AA) for rs4074995. With adjustments applied for sex, age, body mass index, heart rate and season, hbPWV was 0.05 m/s (p = .042) lower with each additional copy of the minor allele (T) of rs6127099. In similarly adjusted analyses of 157 normotensive participants younger than 50 years, cfPWV was 0.32 m/s (p = .004) higher per additional copy of the T allele. Sensitivity analyses additionally accounting for the total-to-HDL serum cholesterol ratio, plasma glucose, glomerular filtration rate and 24 h systolic blood pressure were consistent. No other association of PWV with the genetic variants reached significance. CONCLUSIONS: With an increasing number of rs6127099 T alleles, arterial stiffness, as exemplified by PWV, was lower in all participants in a muscular artery (hbPWV), but higher in young normotensive participants in an elastic artery (cfPWV).

[Antifungal effects of three medicinal crops on Phytophthora nicotianae].

Tobacco black shank is one of the most harmful soil-borne diseases infected by Phytophthora parasitica. In order to probe the control method to this disease, in this study, the mycelial growth rate method was employed to investigate the antifungal effects of extracts from stem-leaf and root, root exudates, and their combination of Scrophularia ningpoensis, Chuanmingshen violaceum and Pinellia ternata The results showed that: ①Stem-leaf and root extracts of S. ningpoensis, C. violaceum and P. ternata exhibited different antifungal activities, and the inhibition increased with the increase of extract concentration. The antifungal effect of S. ningpoensis extracts at 0.5 g•mL⁻¹ was the strongest than other medicinal plants, the inhibition rate of steam-leaf and root extracts reached 74.88%, 69.27%, respectively. The inhibitory effect of C. violaceum and P. ternata was relatively lower, however, there is a significant gain effect after combination of steam-leaf and root extracts of C. violaceum. ②The root exudates of S. ningpoensis, C. violaceum and P. ternata showed fungistasis to Phytophthora nicotianae, and fungistasis was enhanced with the increase of root exudate concentration. The antifungal effect in the order of C. violaceum > S. ningpoensis > P. ternata. ③The antifungal activity of combination of extract and root exudate from S. ningpoensis was similar with the effect of C. violaceum, they were both stronger than P. ternata, and the antifungal activity for three combination were located between the antifungal activity of their extracts and root exudates. S. ningpoensis and C. violaceum can be potentially applied to prevent and control the tobacco black shank.

Assessment of Aerial Agrichemical Spraying Effect Using Moderate-Resolution Satellite Imagery.

Remote sensing technique can be used to examine the effects of agrichemical application on the performance of field crops at a large scale in an effort to develop precision agricultural aerial spraying technology. In this study, an airplane M-18B at the 4-m flight height was used to spray a mix of agrichemicals (a fungicide and a plant growth regulator) to control rice leaf blast disease and improve the growth vigor of rice plants in the field. After the aerial spraying, satellite imagery of tested area was acquired and processed to calculate vegetation indices (VIs). Ground agrichemical concentration data were also collected. The relationships between droplets deposition and VIs were analyzed. The results indicated that the highest correlation coefficient between single phase spectral feature (NDVI) and droplets deposition points density (DDPD, points·cm-2) was 0.315 with P-value of 0.035 while the highest correlation coefficient between temporal change characteristic (MSAVI) and droplets deposition volume density (DDVD, µL·cm-2) was 0.312 with P-value of 0.038). Rice plants with the greatest growth vigor were all detected within the spraying swath, with a gradual decrease in the vigor of rice plants with the increase of droplets drift distance. There were similar trend patterns in the changes of the spraying effects based on the spatial interpolation maps of droplets deposition data and spectral characteristics. Therefore, vegetation indexes, NDVI and MSAVI calculated from satellite imagery can be used to determine the aerial spraying effects in the field on a large scale.

[Influence of tobacco-Chuanminshen violaceum rotation on microbe community in soil].

Soil microbes are the important indicator of soil quality. For exploring Chuanminshen violaceum planting to microbial effects in tobacco soil, this paper adopted Illumina MiSeq high-throughput sequencing to research the change of bacteria and fungi at the phylum and genus in the soil. The results showed that the Ch. violaceum planting increased the biodiversity of bacteria and fungi. The influence on fungi was greater than that on bacteria. It greatly increased the sequence of fungi, it obtained 32 978 16S rDNA and 32 229 18S rDNA sequence number. There was no change of the top three phylums in bacteria, but the content changed, Proteobacteria and Acidobacteria reduced by 1.73% and 1.4% respectively, and Actinobacteria increased by 0.65%. The advantage phylum Ascomycete in tobacco reduced by 27.99% to be second advantage phylum after Ch. violaceum planting, and the second advantage phylum Basidiomycete increased by 23.69% to become the first dominant fungi. At the genus, Ch. violaceum planting changed the order of dominant genus and the abundance was also changed. Some changed largely such as uncultured Acidobacteriaceae Subgroup-1, Gemmatimonas, Subgroup-2,uncultured Nitrosomonadaceae for bacteria, norank Sordariales, norank Agaricomycetes, Phialophora for fungi. Especially the rotation increased antagonistic microbes and physiological microbes and decreased pathogenic microbes. So the Ch. violaceum planting can improve the microbe community in tobacco soil.

[A Study of FTIR Spectrometry Based on a Long Optical Path on the Emission Rules of Nitrous Oxide from Soil].

The excessive emission of N2O (Nitrous oxide) will destroy the ozone layer, reasonable fertilization and adopting measures of emission reduction of N2O are of great significance to slowing down the greenhouse effect. The article studied the impact of fertilization and water on the emission of N2 0 from the cabbage farmland using FTIR spectrometry. To enhance the sensitivity of the measuring system, we used multi-reflecting mirrors to increase the optical pathlength. By comparing the infrared spectra between the before and after fertilizer application and the NIST spectral library, finally, the band at 2160-2225 cm⁻¹ was chosen as the spectral characteristics band of quantitative calculation of N2O through analyzing. The research found that fertilization and water could promote the emission of N2 0 from the cabbage farmland soil, which could supply theory bases for emission reduction of N2O and slowing down the greenhouse effect. Finally, we also studied the diurnal emission rules of N2O from the fertilized soil; the results showed that the emission of N2O was lower at night and the results were compared with that of previous' studies, which verifies the feasibility of this method. The results proved that FTIR with long optical path was a rapid and effective method to measure the emission rules of N2O from the cabbage farmland soil, which can measure the gas emissions of N2O from the fertilized cabbage farmland soil and compared with other traditional measuring methods, it had the advantages such as rapidness and convenience.

[Chemical constituents from flowers of Scabiosa tschilliensis].

Twenty-two compounds were isolated from the flowers of Scabiosa tschilliensis. Their structures were identified by spectroscopic methods as octacosanol (1), stearic acid (2), ß-sitosterol (3), oleanolic acid (4), apigenin (5), luteolin (6), daucosterol (7), kaempferol-3-O-ß-D-6-O-(p-hydroxycinnamoyl) -glucopyranoside (8), kaempferol-3-O-ß-D- (3, 6-di-p-(hydroxycinnamoyl) -glucopyranoside (9), apigenin-7-O-ß-D-glucopyranoside (10), luteolin-4'-O-ß-D-glucopyranoside (11), apigenin-7-O-rutinoside (12), luteolin-7-O-ß-D-glucopyranoside (13), apigenin-4'-O-ß-D-glucopyranoside (14), caffeic acid methyl ester (15), loganin (16), adenosine (17), luteolin-6-C-ß-D-glycopyranosyl (18), sweroside (19), sylvestrosides I (20), sylvestrosides II (21), urceolide (22). Among them, compounds 1, 2, 7-9, 12, 15, 17-18, 20-22 were isolated from the genus Scabiosa for the first time, and compounds 1-4, 6-9, 11-12, 14-22 were isolated from this plant for the first time. 13C-NMR data of 22 were reported for the first time.

[Assessment of chlorophyll content using a new vegetation index based on multi-angular hyperspectral image data].

The fast estimation of chlorophyll content is significant for understanding the crops growth, monitoring the disease and insect, and assessing the yield of crops. This study gets the hyperspectral imagery data by using a self-developed multi-angular acquisition system during the different maize growth period, the reflectance of maize canopy was extracted accurately from the hyperspectral images under different view angles in the principal plane. The hot-dark-spot index (HDS) of red waveband was calculated through the analysis of simulated values by ACRM model and measured values, then this index was used to modify the vegetation index (TCARI), thus a new vegetation index (HD-TCARI) based on the multi-angular observation was proposed. Finally, the multi-angular hyperspectral imagery data was used to validate the vegetation indexes. The result showed that HD-TCARI could effectively reduce the LAI effects on the assessment of chlorophyll content. When the chlorophyll content was greater than 30 µg x cm(-2), the correlation (R2) between HD-TCARI and LAI was only 26.88%-28.72%. In addition, the HD-TCARI could resist the saturation of vegetation index during the assessment of high chlorophyll content. When the LAI varled from 1 to 6, the linear relation between HD-TCARI and chlorophyll content could be improved by 9% compared with TCARI. The ground validation of HD-TCARI by multi-angular hyperspectral image showed that the linear relation between HD-TCARI and chlorophyll content (R2 = 66.74%) was better than the TCARI (R2 = 39.92%), which indicated that HD-TCARI has good potentials for estimating the chlorophyll content.

[Comparative study on remote sensing invertion methods for estimating winter wheat leaf area index].

The present study aims to explore capability of different methods for winter wheat leaf area index inversion by integrating remote sensing image and synchronization field experiment. There were four kinds of LAI inversion methods discussed, specifically, support vector machines (SVM), discrete wavelet transform (DWT), continuous wavelet transform (CWT) and principal component analysis (PCA). Winter wheat LAI inversion models were established with the above four methods respectively, then estimation precision for each model was analyzed. Both discrete wavelet transform method and principal component analysis method are based on feature extraction and data dimension reduction, and multivariate regression models of the two methods showed comparable accuracy (R2 of DWT and PCA model was 0. 697 1 and 0. 692 4 respectively; RMSE was 0. 605 8 and 0. 554 1 respectively). While the model based on continuous wavelet transform suffered the lowest accuracy and didn't seem to be qualified to inverse LAL It was indicated that the nonlinear regression model with support vector machines method is the most eligible model for estimating winter wheat LAI in the study area.

[Research on universality of least squares support vector machine method for estimating leaf area index of winter wheat].

Leaf area index (LAI) is one of the most important parameters for evaluating winter wheat growth status and forecasting its yield. Hyperspectral remote sensing is a new technical approach that can be used to acquire the instant information of vegetation LAI at large scale. This study aims to explore the capability of least squares support vector machines (LS-SVM) method to winter wheat LAI estimation with hyperspectral data. After the compression of PHI airborne data with principal component analysis (PCA), the sample set based on the measured LAI data and hyperspectral reflectance data was established. Then the method of LS-SVM was developed respectively to estimate winter wheat LAI under four different conditions, to be specific, different plant type cultivars, different periods, different nitrogenous fertilizer and water conditions. Compared with traditional NDVI model estimation results, each experiment of LS-SVM model yielded higher determination coefficient as well as lower RMSE value, which meant that the LS-SVM method performed better than the NDVI method. In addition, NDVI model was unstable for winter wheat under the condition of different plant type cultivars, different nitrogenous fertilizer and different water, while the LS-SVM model showed good stability. Therefore, LS-SVM has high accuracy for learning and considerable universality for estimation of LAI of winter wheat under different conditions using hyperspectral data.

APOE regulates the transport of GM1.

Apolipoprotein E (APOE) is responsible for lipid transport, including cholesterol transport and clearance. While the ε4 allele of APOE (APOE4) is associated with a significant genetic risk factor for late-onset Alzheimer's disease (AD), no mechanistic understanding of its contribution to AD etiology has been established yet. In addition to cholesterol, monosialotetrahexosylganglioside (GM1) is a crucial lipid component in cell membranes and has been implicated in promoting the aggregation of amyloid beta protein (Aß), a key protein associated with AD. Here, we ask whether there are direct interactions between APOE and GM1 that further impact AD pathology. We find that both APOE3 and APOE4 exhibit superior binding affinity to GM1 compared to cholesterol and have an enhanced cellular uptake to GM1 lipid structures than cholesterol lipid structures. APOE regulates the transport process of GM1 depending on the cell type, which is influenced by the expression of APOE receptors in different cell lines and alters GM1 contents in cell membranes. We also find that the presence of GM1 alters the secondary structure of APOE3 and APOE4 and enhances the binding affinity between APOE and its receptor low-density lipoprotein receptor (LDLR), consequently promoting the cellular uptake of lipid structures in the presence of APOE. To understand the enhanced cellular uptake observed in lipid structures containing 20% GM1, we determined the distribution of GM1 on the membrane and found that GM1 clustering in lipid rafts, thereby supporting the physiological interaction between APOE and GM1. Overall, we find that APOE plays a regulatory role in GM1 transport, and the presence of GM1 on the lipid structures influences this transport process. Our studies introduce a plausible direct link between APOE and AD etiology, wherein APOE regulates GM1, which, in turn, promotes Aß oligomerization and aggregation.

Control status of ambulatory blood pressure and its relationship with arterial stiffness in the China nationwide registry of treated hypertensive patients: the REACTION-ABP study.

The control rate of ambulatory blood pressure (BP) is unclear in Chinese hypertensive patients, and whether it would be associated with the ambulatory arterial stiffness indices is also unknown. From June 2018 until December 2022, 4408 treated hypertensive patients (52.8% men, average age 58.2 years) from 77 hospitals in China were registered. Ambulatory BPs were measured with validated monitors and analyzed with a web-based standardized Shuoyun system ( www.shuoyun.com.cn ). The BP control rate was the highest in the office (65.7%), moderate in the daytime (45.0%), low in the morning (34.1%), and the lowest in the nighttime (27.6%, P < 0.001). Only 21.0% had their 24 h BP perfectly controlled. The stepwise regression analyses identified that the factors associated with an imperfect 24 h BP control included male sex, smoking and drinking habits, a higher body mass index, serum total cholesterol and triglycerides, and the use of several specific types of antihypertensive drugs. After adjustment for the above-mentioned factors, the 24 h pulse pressure (PP) and its components, the elastic and stiffening PPs, were all significantly associated with an uncontrolled office and ambulatory BP status with the standardized odds ratios ranging from 1.09 to 4.68 (P < 0.05). The ambulatory arterial stiffness index (AASI) was only associated with an uncontrolled nighttime and 24 h BP status. In conclusion, the control rates of 24 h ambulatory BP, especially that in the nighttime and morning time windows, were low in Chinese hypertensive patients, which might be associated with arterial stiffness in addition to other common risk factors.

Seasonality in nighttime blood pressure and its associations with target organ damage.

There is some evidence that nighttime blood pressure varies between seasons. In the present analysis, we investigated the seasonal variation in ambulatory nighttime blood pressure and its associations with target organ damage. In 1054 untreated patients referred for ambulatory blood pressure monitoring, we performed measurements of urinary albumin-to-creatinine ratio (ACR, n = 1044), carotid-femoral pulse wave velocity (cfPWV, n = 1020) and left ventricular mass index (LVMI, n = 622). Patients referred in spring (n = 337, 32.0%), summer (n = 210, 19.9%), autumn (n = 196, 18.6%) and winter (n = 311, 29.5%) had similar 24-h ambulatory systolic/diastolic blood pressure (P ≥ 0.25). However, both before and after adjustment for confounding factors, nighttime systolic/diastolic blood pressure differed significantly between seasons (P < 0.001), being highest in summer and lowest in winter (adjusted mean values 117.0/75.3 mm Hg vs. 111.4/71.1 mm Hg). After adjustment for confounding factors, nighttime systolic/diastolic blood pressure were significantly and positively associated with ACR, cfPWV and LVMI (P < 0.006). In season-specific analyses, statistical significance was reached for all the associations of nighttime blood pressure with target organ damage in summer (P ≤ 0.02), and for some of the associations in spring, autumn and winter. The association between nighttime systolic blood pressure and ACR was significantly stronger in patients examined in summer than those in winter (standardized ß, 0.31 vs 0.11 mg/mmol, P for interaction = 0.03). In conclusion, there is indeed seasonality in nighttime blood pressure level, as well as in its association with renal injury in terms of urinary albumin excretion. Our study shows that there is indeed seasonal variability in nighttime blood pressure, highest in summer and lowest in winter, and its association with renal injury in terms of urinary albumin excretion varies between summer and winter as well.