Collagen degradation assessment with an in vitro rotator cuff tendinopathy model using multiparametric ultrashort-TE magnetization transfer (UTE-MT) imaging.

PURPOSE: This study aims to assess ultrashort-TE magnetization transfer (UTE-MT) imaging of collagen degradation using an in vitro model of rotator cuff tendinopathy. METHODS: Thirty-six supraspinatus tendon specimens were divided into three groups and treated with 600 U collagenase (Group 1), 150 U collagenase (Group 2), and phosphate buffer saline (Group 3). UTE-MT imaging was performed to assess changes in macromolecular fraction (MMF), macromolecule transverse relaxation time (T2m), water longitudinal relaxation rate constant (R1m), the magnetization exchange rate from the macromolecular to water pool (Rm0 w) and from water to the macromolecular pool (Rm0 m), and magnetization transfer ratio (MTR) at baseline and following digestion and their differences between groups. Biochemical and histological studies were conducted to determine the extent of collagen degradation. Correlation analyses were performed with MMF, T2m, R1m, Rm0 w, Rm0 m, and MTR, respectively. Univariate and multivariate linear regression analyses were performed to evaluate combinations of UTE-MT parameters to predict collagen degradation. RESULTS: MMF, T2m, R1m, Rm0 m, and MTR decreased after digestion. MMF (r = -0.842, p < 0.001), MTR (r = -0.78, p < 0.001), and Rm0 m (r = -0.662, p < 0.001) were strongly negatively correlated with collagen degradation. The linear regression model of differences in MMF and Rm0 m before and after digestion explained 68.9% of collagen degradation variation in the tendon. The model of postdigestion in MMF and T2m and the model of MTR explained 54.2% and 52.3% of collagen degradation variation, respectively. CONCLUSION: This study highlighted the potential of UTE-MT parameters for evaluation of supraspinatus tendinopathy.

Effects of urban green space landscape pattern on flood retention efficiency from "urban-block" scale perspective.

Under the background of frequent flood disasters and stock planning challenges, clarifying the relationship and mechanism of urban green space landscape patterns and flood retention efficiency at multiple spatial scales has become a critical scientific issue in realizing the maximum flood retention efficiency of limited urban green spaces and improving the capabilities of urban flood control. We reviewed and summarized the factors, mechanisms, and scale differences in the influence of green space landscape patterns on flood retention efficacy at the urban and block scales. Based on the causes for differences in conclusions and research deficiencies, we suggested that future studies should focus on watershed-scale research and expand the investigation into three-dimensional green space landscape patterns. Additionally, attention should be paid to urban and suburban areas separately, and a set of research indices with indicative significance for the flooding process should be established for different flood-sensitive areas and block structures. These measures will help quantitatively reveal how green space landscape patterns of urban and block scales affect flooding process, providing theoretical guidance for urban planning and establishing urban flood safety patterns.

A novel method of carotid artery wall imaging: black-blood CT.

OBJECTIVES: To evaluate the application of black-blood CT (BBCT) in carotid artery wall imaging and its accuracy in disclosing stenosis rate and plaque burden of carotid artery. METHODS: A total of 110 patients underwent contrast-enhanced CT scan with two phases, and BBCT images were obtained using contrast-enhancement (CE)-boost technology. Two radiologists independently scored subjective image quality on black-blood computerized tomography (BBCT) images using a 4-point scale and then further analyzed plaque types. The artery stenosis rate on BBCT was measured and compared with CTA. The plaque burden on BBCT was compared with that on high-resolution intracranial vessel wall MR imaging (VW-MR imaging). The kappa value and intraclass correlation coefficient (ICC) were used for consistency analysis. The diagnostic accuracy of BBCT for stenosis rate and plaque burden greater than 50% was evaluated by AUC. RESULTS: The subjective image quality scores of BBCT had good consistency between the two readers (ICC = 0.836, p < 0.001). BBCT and CTA had a good consistency in the identification of stenosis rate (p < 0.001). There was good consistency between BBCT and VW-MR in diagnosis of plaque burden (p < 0.001). As for plaque burden over 50%, BBCT had good sensitivity (93.10%) and specificity (73.33%), with an AUC of 0.950 (95%CI 0.838-0.993). Compared with CTA, BBCT had higher consistency with VW-MR in disclosing low-density plaques and mixed plaques (ICC = 0.931 vs 0.858, p < 0.001). CONCLUSIONS: BBCT can not only display the carotid artery wall clearly but also accurately diagnose the stenosis rate and plaque burden of carotid artery. CLINICAL RELEVANCE STATEMENT: Black-blood CT, as a novel imaging technology, can assist clinicians and radiologists in better visualizing the structure of the vessel wall and plaques, especially for patients with contraindication to MRI. KEY POINTS: • Black-blood CT can clearly visualize the carotid artery wall and plaque burden. • Black-blood CT is superior to conventional CTA with more accurate diagnosis of the carotid stenosis rate and plaque burden features.

Flood economic vulnerability and risk assessment at the urban mesoscale based on land use: A case study in Changsha, China.

With climate change and urbanization, flood disasters have significantly affected urban development worldwide. In this study, we developed a paradigm to assess flood economic vulnerability and risk at the urban mesoscale, focusing on urban land use. A hydrological simulation was used to evaluate flood hazards through inundation analyses, and a hazard-vulnerability matrix was applied to assess flood risk, enhancing the economic vulnerability assessment by quantifying the differing economic value and flood losses associated with different land types. The case study of Wangchengpo, Changsha, China, found average total economic losses of 126.94 USD/m2, with the highest risk in the settlement core. Residential areas had the highest flood hazard, vulnerability, and losses (61.10% of the total loss); transportation areas accounted for 27.87% of the total economic losses due to their high flooding depth. Despite low inundation, industrial land showed greater economic vulnerability due to higher overall economic value (10.52% of the total). Our findings highlight the influence of land types and industry differences on flood vulnerability and the effectiveness of land-use inclusion in urban-mesoscale analyses of spatial flood characteristics. We identify critical areas with hazard and economic vulnerability for urban land and disaster prevention management and planning, helping to offer targeted flood control strategies to enhance urban resilience.

Confused subcutaneous nodules in children: Differential diagnosis of pilomatricoma in children.

BACKGROUND: Pilomatricoma is a common but easily misdiagnosed tumor in children. AIMS: To differentiate pilomatricoma from other common subcutaneous nodules in children. PATIENTS/METHODS: Misdiagnosed subcutaneous nodules in four children were recorded. RESULTS: A red mass on a 7-year-old boy's head which had been misdiagnosed pyogenic granuloma was proved to be pilomatricoma. A red mass on an 8-month-old boy's face which had been misdiagnosed infantile hemangioma also turned to be pilomotricoma. A red mass on a 21-month-old girl's breast, which had been misdiagnosed pilomatricoma, was proved to be infantile myofibroma. A subcutaneous nodule under a 13-month-old girl's armpit, which had been misdiagnosed pilomatricoma, turned to be BCG-associated lymphadenitis. CONCLUSIONS: When a child with a subcutaneous nodule attends, pilomatricoma, vascular tumors, fibrous tumors, and BCG-associated lymphadenitis should be considered.

Efficacy of medical treatment and balloon angioplasty for severe intracranial atherosclerosis: a high-resolution MR vessel wall imaging.

OBJECTIVES: To investigate the efficacy of medical treatment and balloon angioplasty for intracranial atherosclerosis using high-resolution MR vessel wall imaging (HR-MRI). METHODS: In this prospective study, patients with symptomatic severe stenosis from January 2018 to August 2021 were treated with medical treatment or balloon angioplasty. The patients underwent HR-MRI at baseline and at 3, 6, and 12 months. Plaque characteristics at follow-up were compared with those at baseline using paired sample T-test or Wilcoxon rank sum test. The difference in the recurrence of ischemic events between two groups was compared. RESULTS: A total of 37 patients (26 males; mean age = 60.5 ± 11.6 years) were evaluated. Of 68 plaques, 42 (61.8%) were treated with medication only. At 12 months of medical treatment, maximum plaque length (p = 0.004), maximum wall thickness (p = 0.036), and plaque enhancement (p = 0.001) were significantly reduced than baseline. At 3 months after balloon angioplasty, luminal stenosis (p = 0.048) was significantly reduced compared to baseline. At 6 months after balloon angioplasty, maximum plaque length (p = 0.011), maximum wall thickness (p = 0.003), and luminal stenosis (p = 0.001) were significantly reduced than baseline. No difference was found in the recurrence of ischemic events between two groups (p = 0.458). CONCLUSION: Intracranial atherosclerotic plaque shrank and tended to be stable at 12 months of medical treatment. Plaque burden was significantly reduced 6 months after balloon angioplasty. This may provide evidence for the application and selection of treatment strategies for intracranial atherosclerotic disease. KEY POINTS: • Plaque burden and plaque enhancement were significantly reduced at 12 months of medical treatment compared to baseline. • Plaque burden was significantly reduced at 6 months after balloon angioplasty compared with baseline. • No significant difference in the recurrence rate of ischemic stroke between patients treated with medication and balloon angioplasty.

Knowledge-based planning using both the predicted DVH of organ-at risk and planning target volume.

PURPOSE: The purpose of this study was to evaluate the performance of a knowledge-based planning (KBP) method in nasopharyngeal cancer radiotherapy using the predicted dose-volume histogram (DVH) of organ-at risk (OAR) and planning target volume (PTV). METHODS AND MATERIALS: A total of 85 patients previously treated for nasopharyngeal cancer using 9-field 6-MV intensity-modulated radiation therapy (IMRT) were identified for training and 30 similar patients were identified for testing. The dosimetric deposition information, individual dose-volume histograms (IDVHs) induced by a series of fields with uniform-intensity irradiation, was used to predict both OAR and PTV DVH. Two KBP methods (KBPOAR and KBPOAR+PTV) were established for plan generation based on the DVH prediction. The KBPOAR method utilized the dose constraints based on the predicted OAR DVH and the PTV dose constraints obtained according to the planning experience, while the KBPOAR+PTV method applied the dose constraints based on the predicted OAR and PTV DVH. For the plan evaluation, the PTV dose coverage was used D98 and D2, and the maximum dose, mean dose or dose-volume parameters were used for the OARs. Statistical differences of the two KBP methods were tested with the Wilcoxon signed rank test. RESULTS: For patients with T3 tumors, there was no significant difference between the KBPOAR and KBPOAR+PTV methods in dosimetric results at most OARs and PTVs. Both KBP methods achieved a similar number of plans meeting the dose requirements. For patients with T4 tumors, KBPOAR+PTV reduced the maximum dose by more than 1 Gy in the body, spinal cord, optic nerve, eye and temporal lobes and reduced the V50 value by more than 3.9% in the larynx and tongue without reducing the PTV dose compared with KBPOAR. The KBPOAR+PTV method increased the plans by more than 14.2% in meeting the maximum dose requirements at the body, optic nerve, mandible and eye and increased the plans by more than 21.4% in meeting the V50 of the larynx and V50 of the tongue when compared with the KBPOAR method. CONCLUSIONS: For patients with T3 tumors, no significant difference was found between the KBPOAR and KBPOAR+PTV methods in dosimetric results at most OARs and PTVs. For patients with T4 tumors, the KBPOAR+PTV method performs better than the KBPOAR method in improving the quality of the plans. Compared with the KBPOAR method, dose sparing of some OARs was achieved without reducing PTV dose coverage and helped to increase the number of plans meeting the dose requirements when the KBPOAR+PTV method was utilized.

A pilot study of the association between leukoaraiosis and cerebral atherosclerosis using synthetic magnetic resonance imaging.

BACKGROUND: Leukoaraiosis is a type of lesion characterized by tissue rarefaction or myelin pallor resulting from axons loss and gliosis. Synthetic magnetic resonance imaging (MRI) could yield quantitative T1, T2, proton density (PD) values of leukoaraiosis in addition to information on the volume of the lesion. PURPOSE: To investigate the feasibility of quantifying leukoaraiosis using synthetic MRI and to explore the association between leukoaraiosis and cerebral small vascular diseases and cerebral atherosclerosis. MATERIAL AND METHODS: Patients with acute ischemic stroke were enrolled in this study. All participants underwent a conventional T2-weighted image, brain volume, CUBE fluid attenuated inversion recovery, and synthetic MRI acquisition using a 3.0-T MR system. A time-of-flight magnetic resonance angiography was also obtained. We evaluated the T1, T2, PD values and leukoaraiosis volume. RESULTS: Analysis of the leukoaraiosis volume ratios demonstrated a positive association with T2 values, a negative association with T1 values, and no association with PD values. Leukoaraiosis volume ratios were independently correlated with age (P < 0.001), lacunes (P = 0.022), and cerebral microbleeds (P = 0.010). A statistical association was found between both age (P < 0.001) and lacunes (P = 0.047) and leukoaraiosis T2 values. CONCLUSION: Synthetic MRI may enhance the evaluation of leukoaraiosis, in addition to providing information on its volume. Leukoaraiosis may represent a type of cerebral small vascular disease rather than cerebral atherosclerosis and may share the same pathological mechanism as lacunes and cerebral microbleeds.

Seeking sustainable development policies at the municipal level based on the triad of city, economy and environment: evidence from Hunan province, China.

Keeping urbanization, economy and eco-environment in harmony is a core issue for attaining Sustainable Development Goals (SDGs) in any complex geographical regions. Previous studies mainly focused on seeking the balance between urban expansion levels, eco-environment quality and socioeconomic degree. But the challenges still exist in solving the negative influence of urban expansion that affects eco-environmental and economic development. Based on the Environmental Kuznets Curve theory, we involved inclusive indexes to analyze the interlinkages of eco-environment quality, economic level, and urban expansion degree, which closely relate to urban sustainable development goals and spatial complexity, as well as using available data corresponding to waterfront cities. Cities in Hunan were taken as a study-case, and the study period of 2006-2016 covers the last 10 years of the millennium development goals agenda and the first 2 years of SDGs agenda. The key indicators of city-economy-environment relationships were different at the provincial level, urban level and urbanization grade. According to the regression models and inverted N shape curve, urban expansion resulted in high positive effects on economic development level and negative effects on ecological environment quality, partically higher at high urbanization level than that of the low ones. But the overall trends were that the environmental quality of the cities was undergoing slowly improving processes both at low and high urban expansion levels. Promoting adaptations with the eco-environmental capacity when formulating policies and taking actions is necessary for realizing sustainable cities and communities (SDG11), life on land (SDG15), decent work and economic growth (SDG8) and responsible consumption and production (SDG12) at the same time. Regulating citizens' density, urban expansion speed in area, the quantity of enterprises with heavy pollution, and the structure of industry to the suitable urbanization stages is an important way for achieving SDGs at provincial and municipal levels.

Evaluation of dose-volume histogram prediction for organ-at risk and planning target volume based on machine learning.

The purpose of this work is to evaluate the performance of applying patient dosimetric information induced by individual uniform-intensity radiation fields in organ-at risk (OAR) dose-volume histogram (DVH) prediction, and extend to DVH prediction of planning target volume (PTV). Ninety nasopharyngeal cancer intensity-modulated radiation therapy (IMRT) plans and 60 rectal cancer volumetric modulated arc therapy (VMAT) plans were employed in this study. Of these, 20 nasopharyngeal cancer cases and 15 rectal cancer cases were randomly selected as the testing data. The DVH prediction was performed using two methods. One method applied the individual dose-volume histograms (IDVHs) induced by a series of fields with uniform-intensity irradiation and the other method applied the distance-to-target histogram and the conformal-plan-dose-volume histogram (DTH + CPDVH). The determination coefficient R2 and mean absolute error (MAE) were used to evaluate DVH prediction accuracy. The PTV DVH prediction was performed using the IDVHs. The PTV dose coverage was evaluated using D98, D95, D1 and uniformity index (UI). The OAR dose was compared using the maximum dose, V30 and V40. The significance of the results was examined with the Wilcoxon signed rank test. For PTV DVH prediction using IDVHs, the clinical plan and IDVHs prediction method achieved mean UI values of 1.07 and 1.06 for nasopharyngeal cancer, and 1.04 and 1.05 for rectal cancer, respectively. No significant difference was found between the clinical plan results and predicted results using the IDVHs method in achieving PTV dose coverage (D98, D95, D1 and UI) for both nasopharyngeal cancer and rectal cancer (p-values ≥ 0.052). For OAR DVH prediction, no significant difference was found between the IDVHs and DTH + CPDVH methods for the R2, MAE, the maximum dose, V30 and V40 (p-values ≥ 0.087 for all OARs). This work evaluates the performance of dosimetric information of several individual fields with uniform-intensity radiation for DVH prediction, and extends its application to PTV DVH prediction. The results indicated that the IDVHs method is comparable to the DTH + CPDVH method in accurately predicting the OAR DVH. The IDVHs method quantified the input features of the PTV and showed reliable PTV DVH prediction, which is helpful for plan quality evaluation and plan generation.

PCR-RFLP for Detection of Fusarium graminearum Genotypes with Resistance to Phenamacril.

Phenamacril is a cyanoacrylate fungicide that provides excellent control of Fusarium head blight (FHB) or wheat scab, which is caused predominantly by Fusarium graminearum and F. asiaticum. Previous studies revealed that codon mutations of the myosin-5 gene of Fusarium spp. conferred resistance to phenamacril in in vitro lab experiments. In this study, PCR restriction fragment length polymorphism (RFLP) was developed to detect three common mutations (A135T, GCC to ACC at codon 135; S217L, TCA to TTA at codon 217; and E420K, GAA to AAA at codon 420) in F. graminearum induced by fungicide domestication in vitro. PCR products of 841 bp (for mutation of A135T), 802 bp (for mutation of S217L), or 1,649 bp (for mutation of E420K) in the myosin-5 gene were amplified by appropriate primer pairs. Restriction enzyme KpnI, TasI, or DraI was used to distinguish phenamacril-sensitive and -resistant strains with mutation genotypes of A135T, S217L, and E420K, respectively. KpnI digested the 841-bp PCR products of phenamacril-resistant strains with codon mutation A135T into two fragments of 256 and 585 bp. In contrast, KpnI did not digest the PCR products of sensitive strains. TasI digested the 802-bp PCR products of phenamacril-resistant strains with codon mutation S217L into three fragments of 461, 287, and 54 bp. In contrast, TasI digestion of the 802-bp PCR products of phenamacril-sensitive strains resulted in only two fragments of 515 and 287 bp. DraI digested the 1,649-bp PCR products of phenamacril-resistant strains with codon mutation E420K into two fragments of 932 and 717 bp, while the PCR products of phenamacril-sensitive strains was not digested. The three genotypes of resistance mutations were determined by analyzing electrophoresis patterns of the digestion fragments of PCR products. The PCR-RFLP method was evaluated on 48 phenamacril-resistant strains induced by fungicide domestication in vitro and compared with the conventional method (mycelial growth on fungicide-amended agar). The accuracy of the PCR-RFLP method for detecting the three mutation genotypes of F. graminearum resistant to phenamacril was 95.12% compared with conventional method. Bioinformatics analysis revealed that the PCR-RFLP method could also be used to detect the codon mutations of A135T and E420K in F. asiaticum.

Association between type 2 diabetes mellitus, especially recently uncontrolled glycemia, and intracranial plaque characteristics: A high-resolution magnetic resonance imaging study.

AIMS/INTRODUCTION: Type 2 diabetes mellitus is a specific risk factor for intracranial atherosclerosis. The purpose of this study was to investigate the relationship between type 2 diabetes mellitus, especially uncontrolled glycemia, and intracranial plaque characteristics using high-resolution magnetic resonance imaging. MATERIALS AND METHODS: A total of 263 patients (182 men; mean age 62.6 ± 11.5 years) with intracranial atherosclerotic plaques detected on high-resolution magnetic resonance imaging from December 2017 to March 2019 were included in this study. Patients were divided into different groups: (i) patients with and without type 2 diabetes mellitus; (ii) diabetes patients with uncontrolled glycemia (glycated hemoglobin level ≥7.0%) and controlled glycemia; and (iii), diabetes patients with diabetes duration of <5, 5-10 and >10 years. Comparisons of plaque features between groups were made, respectively. RESULTS: Type 2 diabetes mellitus was diagnosed in 118 patients (44.9%). Diabetes patients had a significantly greater prevalence of enhanced plaque, greater maximum plaque length, maximum wall thickness and more severe luminal stenosis than non-diabetes patients. Compared with diabetes patients with controlled glycemia, those with uncontrolled glycemia had a significantly greater prevalence of enhanced plaque and greater maximum plaque length (all P < 0.05). There were no significant differences in plaque features among patients with different durations of type 2 diabetes mellitus. Uncontrolled glycemia was an independent factor for plaque enhancement after adjustment for potential confounding factors (odds ratio 5.690; 95% confidence interval 1.748-18.526; P = 0.004). CONCLUSIONS: Type 2 diabetes mellitus is closely related to intracranial plaque enhancement and burden. Recently uncontrolled glycemia might play an important role in the development of enhanced plaque.

Clinical characteristics, molecular epidemiology and antimicrobial susceptibility of pertussis among children in southern China.

BACKGROUND: Increasing numbers of pertussis cases have been reported in recent years. The reported cases from Shenzhen Children's Hospital were close to one tenth of all cases in China. The epidemiology of antigenic genotype and antibiotic resistance of circulating strains in children have been unknown in Shenzhen, southern China. The aim of this study was to describe the clinical features and explore the genotypes and antimicrobial susceptibility of circulating Bordetella pertussis among children in Shenzhen. METHODS: Data of hospitalized children with pertussis in Shenzhen Children's Hospital from August 2015 to April 2017 were collected. The genetic variability of isolates was investigated and Etest was performed for phenotypic susceptibility to erythromycin, azithromycin, clarithromycin, clindamycin, and trimethoprim/sulfamethoxazole. RESULTS: 469 children with pertussis confirmed by real-time quantitative polymerase chain reaction were hospitalized and strains were isolated from 105 patients. White blood cell count ≥ 20 × 109/L and lymphocyte proportion ≥ 60% were observed in 39.29% of infants younger than 3 months. The two predominant profiles of virulence-associated allelic genes were ptxA1/ptxC1/ptxP1/prn1 (48.6%) and ptxA1/ptxC2/ptxP3/prn2 (44.8%). Among the isolates, 48.6% (51/105) were found resistant to macrolides. CONCLUSIONS: These findings indicate that leukocytosis is not a sensitive indicator of pertussis. Isolates with the gene profile ptxP3/prn2 were highly circulating in Shenzhen and less resistant to macrolides, different from patterns observed in other parts of China.

Prediction of dose-volume histograms in nasopharyngeal cancer IMRT using geometric and dosimetric information.

A method using both patient geometric and dosimetric information was proposed to predict dose-volume histograms (DVHs) of organs at risk (OARs) for a nasopharyngeal cancer (NPC) intensity-modulated radiation therapy (IMRT) plan. A total of 106 nine-field IMRT NPC plans were used in this study. Twenty-six plans were randomly selected as testing cases, and the remaining plans were used as the training data. A method employing geometric and dosimetric information was developed for OAR DVH prediction. The dosimetric information was derived from an initial dose calculation using a simple unoptimized conformal plan. The DVHs were also predicted using only the geometric information. The DVH prediction model was a generalized regression neural network (GRNN). Mean absolute error (MAE) and R 2 values were introduced to evaluate DVH prediction accuracy. Significant differences in the DVH prediction accuracy were found between the method employing the geometric and dosimetric information and the method utilizing the geometric information for the brainstem (R 2, 0.98 versus 0.95, p  = 0.007; MAE, 3.52% versus 7.19%, p  = 0.002), spinal cord (R 2, 0.98 versus 0.96, p  < 0.001; MAE, 2.80% versus 4.36%, p  < 0.001), left optic nerve (R 2, 0.90 versus 0.77, p  = 0.014; MAE, 3.07% versus 11.29%, p  = 0.025) and other organs. On average, the R 2 value increased by ~6.7% and the MAE value decreased by ~46.7% after adding the dosimetric information to the DVH prediction. We developed a method for predicting DVHs of OARs in NPC IMRT plans by using geometric and dosimetric information. Adding dosimetric information can help predict the DVHs of OARs in NPC IMRT plans.

Effects of the dinitroaniline fungicide fluazinam on Fusarium fujikuroi and rice.

Fusarium fujikuroi is the primary causal agent of rice bakanae disease. Fluazinam is a protective dinitroaniline fungicide which could interrupt the fungal cell's energy production. Little is known about the effects of fluazinam on F. fujikuroi. In this study, baseline sensitivity of F. fujikuroi to fluazinam was determined using 103 isolates collected from diseased young rice of different fields in Shaoxing of Zhejiang Province and Huaian of Jiangsu Province of China in 2016. The EC50 values of fluazinam on inhibiting mycelial growth against 103 isolates of F. fujikuroi ranged from 0.0621 to 0.5446 µg/mL with the average value of 0.2038 ±â€¯0.0099 µg/mL (mean ±â€¯standard error). The EC50 values of fluazinam on suppressing conidium germination against 103 isolates of F. fujikuroi ranged from 0.1006 to 0.9763 µg/mL with the mean value of 0.3552 ±â€¯0.0181 µg/mL. Treated with fluazinam, hyphae of F. fujikuroi were contorted, offshoot of top mycelia increased, conidial production descreased significantly and exopolysaccharide (EPS) content did not change significantly while peroxidase (POD) activity significantly decreased. Meanwhile, cell membrane permeability increased after treated with fluazinam. The analysis of cell ultrastructure indicated that fluazinam could damage the membrane structure of F. fujikuroi and cause a large number of vacuoles formed. In addition, fluazinam did not affect germination rate, plant height and fresh weight of rice, which indicated that fluazinam was safe to rice. All the results indicated that fluazinam had strong antifungal activity against F. fujikuroi and a potential application in controlling rice bakanae disease. These results will provide useful information for management of rice bakanae disease caused by F. fujikuroi and further increase our understanding about the mode of action of fluazinam against F. fujikuroi and other phytopathogens.

Antibiotic usage in Chinese children: a point prevalence survey.

BACKGROUND: Children as a population have high antimicrobial prescribing rates which may lead to high resistance of bacteria according to data from some single-center surveys of antibiotic prescribing rates in China. The acquirement of baseline data of antibiotic prescribing is the basis of developing intervention strategies on inappropriate antimicrobial prescriptions. Few studies show clearly the pattern and detailed information on classes of antibiotics and distribution of indications of antibiotic prescriptions in children in China. This study aims to assess the antibiotic prescribing patterns among children and neonates hospitalized in 18 hospitals in China. METHODS: A 24-hour point prevalence survey on antimicrobial prescribing was conducted in hospitalized neonates and children in China from December 1st, 2016 to February 28th, 2017. Information on the antibiotic use of patients under 18 years of age who were administered one or more on-going antibiotics in the selected wards over a 24-hour period was collected. These data were submitted to the GARPEC (Global Antimicrobial Resistance, Prescribing and Efficacy in Children and Neonates) web-based application ( https://pidrg-database.sgul.ac.uk/redcap/ ). For statistical analysis, Microsoft Excel 2007 and SPSS 22.0 were used. RESULTS: The antibiotic data were collected in 35 wards in 18 hospitals from 9 provinces. In total, 67.76% (975/1439) of the patients (n = 1439) were given at least one antibiotic, including 58.1% (173/298) of neonates (n = 298) and 70.3% (802/1141) of children (n = 1141). In neonates, the three most frequently prescribed antibiotics were third-generation cephalosporins (41.7%), penicillins plus enzyme inhibitor (23.8%), and carbapenems (11.2%). In children, the three most frequently prescribed antibiotics were third-generation cephalosporins (35.5%), macrolides (23.2%), and penicillins plus enzyme inhibitors (15.9%). The most common indication for antibiotics was proven or probable bacterial lower respiratory tract infection (30.9% in neonates and 66.6% in children). CONCLUSIONS: Antibiotics are commonly prescribed in the Chinese children population. It is likely that the third-generation cephalosporins and macrolides are currently overused in Chinese children. Efforts must be made to ensure safe and appropriate antibiotic prescribing to reduce and prevent the future development of antibiotic resistance.

Resistance risk assessment for fluazinam in Sclerotinia sclerotiorum.

In the current study, sensitivity distribution of Sclerotinia sclerotiorum populations to fluazinam was determined using 103 strains collected from the fields of Jiangsu Province of China in 2016-2017 and the resistance risk of fluazinam was assessed. The average EC50 (50% effective concentration) values and MIC (minimum inhibitory concentration) values of 103 S. sclerotiorum strains against fluazinam were 0.0073±0.0045µg/ml and <0.3µg/ml for mycelial growth, respectively. Nine mutants with low resistance level were obtained from wild type sensitive strains exposed on PDA medium amended with fluazinam and the resistance was stable after their ten transfers on PDA without the fungicide. Compared with the parental strains, the nine fluazinam-resistant mutants decreased in mycelial growth, sclerotial production, pathogenicity and were more sensitive to 0.7M NaCl. In addition, cell membrane permeability of resistant mutants was higher than that of their parental strains. Cross resistance assay showed that there was no cross-resistance between fluazinam and fludioxonil, dimetachlone, prochloraz, tebuconazole, azoxystrobin, or procymidone in S. sclerotiorum. The above results indicated that there was a low resistance risk for fluazinam in S. sclerotiorum. However, the sensitivity of all fluazinam-resistant mutants to fludioxonil decreased. Sequencing alignment results showed that there were no mutations in the two-component histidine kinase gene (Shk1) of the resistant mutants and the expression levels of Shk1 of three resistant mutants were significantly up-regulated while others were almost the same as their parental strains. These results will contribute to evaluating the resistance risk of fluazinam for management of diseases caused by S. sclerotiorum and further increase our understanding about the mode of action of fluazinam.

Use of intravoxel incoherent motion diffusion-weighted imaging in identifying the vascular and avascular zones of human meniscus.

PURPOSE: To investigate the hypothesis that the intravoxel incoherent motion (IVIM) diffusion-weighted imaging may depict microcirculation of meniscus and the perfusion changes in meniscal disorder. MATERIALS AND METHODS: Fifty patients received diffusion-weighted MRI with multiple b-values ranging from 0 to 400 s/mm2 . The four horns of the menisci were divided into normal, degenerated, and torn groups. IVIM parameters including perfusion fraction (f), pseudo-diffusion coefficient (D*), true diffusion coefficient (D), and the product of f and D* (f D*) of normal meniscal red zone and white zone were derived and compared for microcirculation changes of normal, degenerated, and torn posterior horn of the medial meniscus (PMM). The parameters between red and white zones among the groups were compared. Significant differences were considered when P < 0.05. RESULTS: Mean f and fD* were significantly higher in the red zone than those in the white zone for the normal four meniscal horns (P < 0.05), whereas D* (P = 0.882, 0.011, 0.593, and 0.33) and D (P = 0.186, 0.099, 0.767, and 0.041) did not significantly differ between the two zones. Among the normal, degenerated, and torn PMM, f was observed to be lower in the red zone of torn horns as compared to the normal horns (P = 0.013). D*, fD*, and D did not exhibit statistically significant difference among different groups (P = 0.353, 0.661, and 0.327, respectively). CONCLUSION: This hypothesis driven work shows that IVIM imaging is able to depict microcirculation of meniscus and the perfusion changes in meniscal disorder. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:1090-1096.