The aggregation characteristics of Aspergillus spores under various conditions and the impact on LPUV inactivation: Comparisons with chlorine-based disinfection

Aggregation is the primary step prior to fungal biofilm development. Understanding the attributes of aggregation is of great significance to better control the emergence of waterborne fungi. In this study, the aggregation of Aspergills spores (A. flavus and A. fumigatus) under various salt, culture medium, and humic acid (HA) conditions was investigated for the first time, and the inactivation via low-pressure ultraviolet (LPUV) upon aggregated Aspergillus spores was also presented. The aggregation efficiency and size of aggregates increased over time and at low salt (NaCl and CaCl2) concentration (10 mM) while decreasing with the continuous increase of salt concentration (100 and 200 mM). Increasing the concentration of culture medium and HA promoted the aggregation of fungal spores. Spores became hydrated, swelled, and secreted more viscous substances during the growth period, which accelerated the aggregation process. Results also suggested that fungal spores aggregated more easily in actual water, posing a high risk of biohazard in real-life scenarios. Inactivation efficiency by LPUV decreased with higher aggregation degrees due to the protection from the damaged spores on the outer layer and the shielding of pigments in the cell wall. Compared to chlorine-based disinfection, the aggregation resulted in the extension of shoulder length yet neglectable change of inactivation rate constant under LPUV treatment. Further investigation of cell membrane integrity and intracellular reactive oxygen species was conducted to elucidate the difference in mechanisms between various techniques. This study provides insight into the understanding and controlling of the aggregation of fungal spores.

Changes of characteristics and disinfection by-products formation potential of intracellular organic matter with different molecular weight in metalimnetic oxygen minimum

Metalimnetic oxygen minimum (MOM) occurs in reservoirs or lakes due to stratification and algal blooms, which has low dissolved oxygen (DO) levels and leads to the deterioration of water quality. The transformation mechanism and the impact on the water quality of intracellular organic matter (IOM) derived from algae are poorly understood under MOM conditions. In this study, IOM extracted by Microcystis aeruginosa was divided into five components according to molecular weight (MW), and the changes of characteristics and correlated disinfection by-products formation potential (DBPFP) were analyzed and compared under MOM conditions. The removal efficiency of dissolved organic carbon (DOC) in the <5 kDa fraction (66.6%) was higher than that in the >100 kDa fraction (41.8%) after a 14-day incubation under MOM conditions. The same tendency also occurred in Fmax and DBPFP. The decrease in Fmax was mainly due to the decline in tryptophan-like and tyrosine-like for all IOM fractions. The diversity of microorganisms degrading the MW > 100 kDa fraction was lower than others. Besides low MW fractions, these findings indicated that more attention should be paid to high MW fractions which were resistant to biodegradation under MOM conditions during water treatment.

The improved resistance of germinated spores to ultraviolet irradiation: Comparison with chlorine

Fungi outbreaks in water will include a series of processes, including spore aggregation, germination, biofilm, and finally present in a mixed state in the aquatic environment. More attention is paid to the control of dispersed fungal spores, however, there was little knowledge of the control of germinated spores. This study investigated the inactivation kinetics and mechanism of ultraviolet (UV) treatment for fungal spores with different germination percentages compared with dormant spores. The results indicated that the inactivation rate constants (k) of spores with 5%-45% germination were 0.0278-0.0299 cm2/mJ for Aspergillus niger and 0.0588-0.0647 cm2/mJ for Penicillium polonicum, which were lower than those of dormant spores. It suggested that germinated spores were more tolerant to UV irradiation than dormant spores, and it may be due to the defensive barrier (upregulated pigments) and some reductive substance (upregulated enoyl reductase) by absorbing UV or reacting with reactive oxygen species according to transcriptome analysis. Compared to dormant spores, the k-UV of germinated spores decreased by 18.17%-26.56% for Aspergillus niger, which was less than k-chlorine (62.33%-69.74%). A slighter decrease in k-UV showed UV irradiation can efficiently control fungi contamination, especially when dormant spores and germinated spores coexisted in actual water systems. This study indicates that more attention should be paid to germinated spores.

The apoptosis of Chlorella vulgaris and the release of intracellular organic matter under metalimnetic oxygen minimum conditions

Metalimnetic oxygen minimum (MOM) is a frequent occurrence in lakes and reservoirs, and its formation is related to the blooming and apoptosis of algae. In this study, the apoptosis mechanism of Chlorella vulgaris (C. vulgaris) and the release of intracellular organic matter (IOM) under different MOM conditions were analyzed by changing the dissolved oxygen (DO) (7.0 mg/L, 3.0 mg/L, and 0.3 mg/L) and water pressure (0.3 MPa and normal pressure). The integrity and auto-fluorescence of algae cells decreased rapidly in the first 8 days, and then stabilized gradually during the development of MOM. Compared with that of water pressures, DO had a significant effect on the activity of algal cells, and higher initial DO levels (3.0 mg/L and 7.0 mg/L) accelerated the lysis of algal cells. The integrity of algae cells decreased to 28.8 %, 31.8 % and 56.6 % at the initial DO of 7 mg/L, 3 mg/L and 0.3 mg/L under 0.3 MPa, respectively. Meanwhile, the concentration of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) continued to increase and reached their maximum at 8 or 12 days, respectively, due to the IOM release caused by algal cell rupture, and then gradually decreased due to microbial degradation. Consistent with the results of membrane integrity, the highest DOC and DON concentrations were found at higher initial DO conditions. By parallel factor analysis, the change in total organic matter fluorescence intensity was consistent with DOC, once again increasing in the first 8 days and then gradually decreasing. The increased humic-like component, which is related to higher aromaticity, led to the monotonic increase of HAAFPs and THMFPs. However, the released IOM of C. vulgaris had lower N-DBPFPs, with TCNMFP predominating primarily. In summary, these results shed new lights on exploring the apoptosis of algae and the release of IOM during the development of MOM.

Mechanism of liver X receptor α and ATP binding cassette transporter A1 involved in preeclampsia using an optimized deep learning model

OBJECTIVE

Preeclampsia (PE) is a complex disease-causing multisystem damage. Many genes, environmental factors, and their interactions are involved in the development and progression of PE. The pathogenesis of PE is not fully understood, limiting the prevention and treatment of PE. The aim of this study was to investigate the effect of 4,4'-diisothiocyanato-stilbene-2,2'-disulfonic acid (DIDS), an ATP-binding cassette transporter A1 (ABCA1) blocker, on apoM mRNA and protein levels.

PATIENTS AND METHODS

The role of liver X receptor α (LXRα) and ABCA1 in the pathogenesis of PE was investigated by optimizing the design of DIDS inhibition based on a deep learning model.

RESULTS

The proportion of primipara in the research group, EOPE group, LOPE group, and controls was 59.82%, 65.85%, 56.34%, and 21.43%, respectively. The difference between the research group and the controls was statistically significant (p<0.01). In the clinical data, serum-free triiodothyronine (FT3), gestational age at delivery, high-density lipoprotein cholesterol (HDL-C), hemoglobin (HGB), albumin, and platelet (PLT) in the research group were lower than those in the controls (p<0.05).

CONCLUSIONS

ABCA1 is considered to affect apoM mRNA expression, G/HDL-C may increase the risk of LOPE, and overweight or obesity, abnormal glycemic regulation, and hypothyroidism are independent risk factors closely related to the pathogenesis of PE and its subgroups.

The change of amino acids samples under metalimnetic oxygen minimum condition: Characterization and mechanism

The metalimnetic oxygen minimum (MOM) is a common anaerobic phenomenon that occur between 5.00 and 40.00 m of reservoirs. Amino acids (AAs) are widely found in water, but their change in MOM remain unclear. In this study, four AAs with different side chain groups were selected to explore the change of their samples and related disinfection by-products formation potential (DBPFPs) under MOM condition. The results showed that the final degradation rate of dissolved organic carbon and dissolved organic nitrogen of four AAs samples were 11.71%-59.87% and 26.50%-100.00% under MOM condition. Aspartic acid samples were the easiest to be degraded, whereas glycine samples were the opposite. While the total fluorescence intensity increased by 6.30%-113.40% for the appearance of tryptophan-like substance. The total DBPFPs of glutamic acid, arginine and aspartic acid samples were finally decreased by 4.73%, 8.00% and 98.88% (glycine sample increased by 2.30 times). Compared with the surface condition, the degradation of AAs samples and the change of DBPFPs were significantly inhibited under MOM condition. In addition, the diversities of bacterial communities were significantly reduced under MOM condition, which was very unfavorable to the degradation of AAs samples, and in turn affected the control of DBPs and deteriorated the water quality.

The formation of double metalimnetic oxygen minima in a drinking water reservoir and its influence on bacterial community

Metalimnetic oxygen minima has been reported in many lakes and reservoirs, but the double metalimnetic oxygen minima (DMOM) is so far poorly understood. In this work, we first reported DMOM in the Sanhekou Reservoir, and investigated its formation reason and influence on the bacterial community composition (BCC). The results showed that the two anaerobic layers were formed in DMOM, located at 10 m and 45 m approximately. The rapid water storage process and thermal stratification resulted in the double metalimnions. Algal accumulation, decomposition and oxygen consumption in these regions during the sedimentation process eventually leaded to the formation of DMOM. Water temperature and DO gradients made outstanding contributions to the spatiotemporal environmental heterogeneity and significantly affected the BCC. Depending on the distribution of dissolved oxygen (DO), the storage process could be divided into three periods: DMOM, single MOM period and mixed period. Exiguobacterium and Ralstonia were dominated in DMOM due to the soil discharge and plant decomposition. Besides, BCC presented the largest vertical difference in DMOM and existed the interlayer-similar phenomenon (BCC in the two anaerobic layers were more similar). This study explained the formation of DMOM and its influence on BCC, which was helpful to understand the response of BCC to the storage process and unique DO structure in a moderate eutrophication reservoir.

Occurrence and control of fungi in water: New challenges in biological risk and safety assurance

Recently, the contamination of fungi in water has aroused widespread concern, which will pose a threat to water quality and safety, and raise diseases risk in the immunocompromised individuals. In this review, the characteristics and different physiological state of fungi in water are summarized. A comprehensive evaluation of the control efficiency and mechanism of waterborne fungi by the commonly used disinfection methods is provided as well. During the disinfection processes of chlorine, chlorine dioxide, chloramine and advanced disinfection processes (ADPs) such as O₃-based ADPs and UV-based ADPs, the fungal spores firstly lost their culturability, followed by membrane integrity, and the intracellular reactive oxygen species level increased at the same time, eventually the fungal spores were completely inactivated. The security strategies of drinking water against the contamination of fungi are also discussed in terms of water sources, water treatment plants and pipe network. Finally, future researches need to be explored are proposed: the rapid detection methods, the production laws and control of mycotoxin, and the outbreak conditions of fungi in water. Specifically, exploring efficient, safe and economical technologies, especially ADPs, is still the main direction in the disinfection of fungi in future studies. This review can offer a comprehensive understanding on the occurrence and control of fungi in water to fill the knowledge gap and provide guidance for the future research.

Change of algal organic matter under different dissolved oxygen and pressure conditions and its related disinfection by-products formation potential in metalimnetic oxygen minimum

Most of the reservoirs or lakes will form a metalimnetic oxygen minimum (MOM) with the characterization of a substantial fraction of dissolved oxygen (DO) depleted below the epilimnion. The effect of intracellular organic matter (IOM) of algal cells transformed under MOM conditions is completely different from that of the original IOM on water quality. In this study, the IOM changes of Microcystic aeruginosa under different MOM conditions and its related disinfection by-products formation potentials (DBPFPs) were investigated by changing the pressure and DO concentration of MOM. Total Fmax increased slightly and then decreased under different pressure conditions, finally decreasing by no more than 22.0%. Under aerobic condition, dissolved organic carbon (DOC) and total Fmax decreased significantly, and decreased by 60.4% and 38.8% within the first 2 days. The results of specific UV absorbance (SUVA) and UV₂₅₀/UV₃₆₅ indicated that aromatic compounds and average molecular weight of IOM were gradually increased under different MOM conditions. The total DBPFPs increased firstly and then decreased under different pressure conditions, and finally decreased by 26.2%-33.1%. The decrease of total DBPFPs was significantly higher under aerobic condition than that under anoxic condition, which finally decreased by 64.5%. Redundancy analysis showed that the fluorescence parameter (protein-like and humic-like fluorescence) could be expected as an index to predict the DBPFPs. Moreover, the results revealed that with the decrease of DO, the activity and diversity of natural microbial consortium decreased, which prevented the further degradation and utilization of organic matter by natural microbial consortium. Therefore, lower DO was a key player for the deterioration of water quality under MOM conditions.

Inactivation of fungal spores in water by CuO-activated peracetic acid: Kinetics, mechanism and regrowth

The disinfection of pathogenic microorganisms in water treatment by peracetic acid (PAA)-based advanced oxidation processes (AOPs) has been gaining increasing concern. In this work, the inactivation mechanism, influencing factors and regrowth of two pathogenic Aspergillus species in the system of CuO-activated PAA were studied for the first time. The k values of A. niger and A. flavus inactivated by PAA/CuO system were 3.9 and 2.1-fold higher than those inactivated by PAA alone. PAA concentration and CuO dose were positively correlated with the inactivation efficiency, while humic acid and pH were negatively correlated. The main active species that contributed to the inactivation of fungal spores in PAA/CuO system were •OH, CH₃C(O)OO• and ¹O₂. PAA/CuO system had more intense oxidative stimulation and more serious damage to fungal spores according to the analysis of cell membrane integrity and intracellular ROS levels. In addition, the PAA/CuO system was less impacted by the water matrix and kept a good inactivation efficiency in real water samples. The regrowth potential of fungal spores after disinfection was also reduced in PAA/CuO system so as to avoid the risk of biological regrowth. This study provides a feasible PAA-based advanced oxidation method for activating PAA and inactivating fungal spores.

Remote telemedicine strategy based on multi-risks intervention by intelligent wearable health devices in elderly comorbidities patients with coronary heart disease

Background

Telemedicine based on wearable intelligent health devices becomes increasingly promissing for the elderly due to the accelerated aging population. Especially during COVID-19 pandemic, more elderly coronary heart disease patients with chronic comorbidities are in less secondary prevention management at home.

Objective

To explore the prevention effect on main cardiovascular risk factors and repeated hospitalization in elderly comorbidities patients by telemedicine intervention based on multi-parameter wearable monitoring devices.

Methods

Total of 337 patients with comorbidities of coronary heart disease, hypertension and diabetes, with age more than 65 years old were recruited in the study from October 2019 to January 2021. They were randomly divided into control group and telemedcine intervention group. The latter used remote multi-parameter wearable devices to measure blood pressure, glycemic and electrocardiograph at home every day. A real-time monitoring platform would alarm any abnormal data to the doctors. Both doctors and patients can read the measurement results on a real-time mobile phone APP and interact with each other remotely twice a week routinely. A medical team remotely indicated the medications, while offering guidance on lifestyle. In contrast, the control group adopted traditional outpatient medical strategy to manage diseases.

Results

A total of 306 patients were enrolled in the follow-up experiment finally: 153 in the intervention group and 153 in the control group. Patient characteristics at baseline were balanced between two groups. After 12 months, compared with the control group, the intervention group saw the following metrics significantly reduced: systolic blood pressure (SBP) (131.66±9.43 vs 137.20±12.02 mmHg, P=0.000), total cholesterol (TC) (3.65±0.79 vs 4.08±0.82 mmol/L, P=0.001), low density lipoprotein cholesterol (LDL-C) (2.06±0.53 vs 2.38±0.61 mmol/L, P=0.002), and fasting blood glucose (FBG) (6.26±0.75 vs 6.81±0.97 mmol/L, P=0.000), while the following metrics went up significantly: blood pressure control rate (77.3% vs 59.1%, P=0.039), blood lipid control rate(39.4% vs 21.2%, P=0.037), glycemic control rate (71.2% vs 51.5%, P=0.031), and medication adherence score (7.10±0.77 vs 6.80±0.73, P=0.020). Linear regression model analysis indicates that when interaction frequency ≥1.53, 2.47 and 1.15 times/week, the SBP, LDL-C and FBG levels would be controlled, respectively. Cox survival analysis finds that the hospitalization rate of intervention group is significantly lower than that of the control group (24.18% vs 35.29%, P=0.031).

Conclusion

The telemedicine interactive intervention based on multi-parameter wearable devices provides effectively improvement of cardiovascular risk controlling, medication adherence, while reducing the hospitalization rate of patients. A frequency of doctor-patient interactions more than 2 times/week is beneficial for disease management the elderly at home.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Key scientific research project of Health Commission

The protective role and mechanism of melanin for Aspergillus niger and Aspergillus flavus against chlorine-based disinfectants

Melanin is a critical component of fungal cell wall which protect fungi from adverse environmental tress. However, the role of melanin for fungi during the disinfection with chlorine-based disinfectants has not been elucidated. The results showed that the inactivation rate constants of Aspergillus niger with chlorine and chlorine dioxide decreased from 0.08 to 2.10 min^-1 to 0 after addition of 0.32 mg/L melanin. The results indicated addition of extracted fungal melanin inhibited the inactivation efficiency of chlorine and chlorine dioxide. In contrast, the k of Aspergillus niger after inactivation with monochloramine ranged from 1.50 to 1.78 min^-1 after addition of melanin which indicated effect of melanin on the inactivation efficiency of monochloramine was negligible. In addition, the extracted fungal melanin exhibited high reactivity with chlorine and chlorine dioxide but very low reactivity with monochloramine. The different inactivation mechanisms of chlorine-based disinfectants and different reactivity of melanin with chlorine-based disinfectants led to the different protective mechanism of melanin for A. niger and A. flavus spores against disinfection with chlorine-based disinfectants. The chlorine and chlorine dioxide appeared to react with functional groups of melanin in cell wall of spores, so sacrificial reactions between melanin and disinfectants decreased the available disinfectants and limited the diffusion of disinfectants to the reactive site on cell membrane, which led to the decrease of the disinfection efficiency for chlorine and chlorine dioxide. The monochloramine could penetrate into cell and damage DNA without the effect of melanin due to its strong penetration and low reactivity with melanin. Our results systematically demonstrate the protective roles of melanin on the fungal spores against chlorine-based disinfectants and the underlying mechanisms in resisting the environmental stress caused by chlorine-based disinfectants, which provides important implications for the control of fungi, especially for fungi producing melanin.

Differentiation of DNA or membrane damage of the cells in disinfection by flow cytometry

Recently, the viabilities changes of fungal spores in the water supply system during different disinfection processes have been revealed. SYBR Green I (SG), a nucleic acid stain, its fluorescence intensity is correlated with the amount of double-stranded DNA. This study established a new method through successive SG-SG-PI staining (PI: Propidium Iodide) with flow cytometry (FCM). It could successfully distinguish DNA damage and membrane damage of fungal spores, clearly elucidating the intrinsic disinfection mechanism during the chemical disinfection. This method was briefly described as follows: firstly, (1) the fungal spores were stained with SG and washed by centrifugation; and then, (2) the washed spores were treated with disinfectants and terminated; after that, (3) the disinfected spores were re-stained with SG and analyzed by FCM; finally, (4) the SG re-stained spores were stained with PI and analyzed by FCM. The percentages of spores with DNA damage and membrane damage were determined by the fluorescence intensity obtained from steps (3) and (4), respectively. The repeatability and applicability of this developed method were confirmed. It was further applied to explore the inactivation mechanism during chlorine-based disinfection, and results demonstrated that chloramine attacked the DNA more seriously than the membrane, while chlorine and chlorine dioxide worked in a reverse way.

Inactivation and subsequent reactivation of Aspergillus species by the combination of UV and monochloramine: Comparisons with UV/chlorine

Ultraviolet (UV)/monochloramine (NH₂Cl) as an advanced oxidation process was firstly applied for Aspergillus spores inactivation. This study aims to: i) clarify the inactivation and photoreactivation characteristics of UV/NH₂Cl process, ii) compared with UV/Cl₂ in inactivation efficiency, photoreactivation and energy consumption. The results illustrated that UV/NH₂Cl showed better inactivation efficiency than that of UV alone and UV/Cl₂, and could effectively control the photoreactivation. For instance, the inactivation rates for Aspergillus flavus, Aspergillus niger and Aspergillus fumigatus in the processes of UV/NH₂Cl (2.0 mg/L) was 0.034, 0.030 and 0.061 cm²/mJ, respectively, which were higher than that of UV alone (0.027, 0.026 and 0.024 cm²/mJ) and UV/Cl₂ (0.023, 0.026 and 0.031 cm²/mJ). However, there was no synergistic effect for Aspergillus flavus and Aspergillus fumigatus. As for Aspergillus niger, the best synergistic effect can reach 1.86-log₁₀. This may be due to their different resistance to disinfectants, which were related to the size, an outer layer of rodlets (hydrophobins) and pigments. After UV/NH₂Cl inactivation, the degree of cell membrane damage and intracellular reactive oxygen species were higher than that of UV alone. UV/NH₂Cl had the advantages of high inactivation efficiency and inhibition of photoreactivation, which provides a new entry point for the disinfection of waterborne fungi.

Association Between Dopaminergic Medications and the Evolution of REM Sleep Behavior Disorder in Parkinson's Disease

REM sleep behavior disorder (RBD) is closely associated with Parkinson's disease (PD), however, the influence of dopaminergic replacement therapy (DRT) on the clinical course of RBD in PD remains less understood. The objective of our study is to investigate how DRTs modify the evolution of RBD in a longitudinal cohort study of initially de novo PD patients. Four hundred and five drug-naive patients with early-stage PD were included. RBD symptoms were assessed using the 10-item RBD Screening Questionnaire (RBDSQ) at baseline and during the 5-year follow-up. A generalized estimating equation was used to examine predictors of the evolution of RBD symptoms. For patients without baseline pRBD, patients on levodopa treatment showed a greater increase in RBDSQ scores than those not on levodopa treatment, and the increase in RBDSQ scores was significantly correlated with the levodopa-LEDD. Moreover, the changes in RBDSQ scores at a given post-baseline visit were significantly associated with the use of levodopa (OR = 1.875, p = 0.008) and the combined use of levodopa and DA (OR = 2.188, p = 0.012), as well as the levodopa-LEDD (OR = 1.001, p = 0.005) at that visit. The use of DA alone or the DA-LEDD was not a significant predictor of changes in RBDSQ scores. Similarly, a conversion from pRBD negative to pRBD positive was significantly associated with levodopa-LEDD (OR = 1.001, p = 0.014) but not DA-LEDD. Together, these finding implicated that the use of levodopa may act as a contributing factor to the increasing prevalence of RBD after the onset of PD, suggesting different mechanisms underlying prodromal RBD and late-onset RBD.

Effective inactivation of fungal spores by the combined UV/PAA: Synergistic effect and mechanisms

Peracetic acid (PAA) can effectively inactivate fungi in water, while may pose a potential risk of regrowth after disinfection. The inactivation kinetic and mechanism of fungal spores by combined UV and PAA (UV/PAA) was investigated in this study. The results showed that synergistic factor of the inactivation of A. niger and A. flavus was 1.44 and 1.37, which indicated significant synergistic effect of UV/PAA. The k of A. niger and A. flavus was similar at pH 5.0 and 7.0, while decreased 60.00% and 39.13% at pH 9.0 compared with that at pH 7.0. The effect of HA concentration on the inactivation efficiency of fungal spores by UV/PAA was negative, while the effect of PAA concentration was positive. The membrane permeabilized cell of A. niger and A. flavus caused by UV/PAA was 17.0% and 31.7%, which was higher than that caused by PAA and UV alone. The changes of morphology of fungal spores and the leakage of intracellular material indicated that the damage of cell structure caused by UV/PAA system was more serious than that of UV or PAA alone. In addition, the four parts that contributed in UV/PAA system was in the following order: UV > radical > PAA > synergistic effect. The inactivation efficiency of combined UV and chlorine (UV/Cl₂) was higher than that of UV/PAA. Furthermore, the typical order of the inactivation efficiency in different matrix was: phosphate buffer solution > surface water > secondary effluent. The regrowth potential of fungal spores after UV/PAA treatment was significantly lower than that by PAA alone, indicating that UV/PAA could decrease the microbial regrowth potential after PAA disinfection alone.

Effect of long-term intensive cholesterol control on the plaque progression in elderly based on CTA cohort study

OBJECTIVES

To investigate the long-term effects of intensive LDL cholesterol-lowering treatments on lumen stenosis severity, plaque calcification, spotty calcifications, percent calcified plaque volume (PCPV), and Agatston coronary artery calcium score (CACS) based on coronary computed tomography angiography (CCTA) in elderly patients.

METHODS

A total of 240 patients over 60 years old (comprising 754 lesions) who underwent serial CCTA were retrospectively enrolled in this 5-year cohort study. Patients were divided into three groups: an intensive lipid-lowering group, a lipid-lowering group, and a control group. The stenosis severity, plaque volume (PV), plaque composition, PCPV, and high-risk plaque (HRP) presence were quantitatively analyzed. The CACS was calculated at baseline and follow-up.

RESULTS

All patients were male with an average age of 66.8 ± 5.8 years old. Over time, increases in the percentages of obstructive coronary lesions (p < 0.001) were observed. Compared with those at baseline, the percentage of obstructive lesions remained unchanged (p = 0.077), and the percentage of spotty calcifications significantly decreased (p < 0.05) at the follow-up CCTA scan in the intensive lipid-lowering group. Patients in the intensive lipid-lowering group demonstrated a higher progression in calcified PV, CACS, and PCPV (all p < 0.05), and a significantly greater attenuation in fibrous-fatty and lipid-rich PV (all p < 0.05) than patients in other groups.

CONCLUSIONS

The PV and contents increased gradually with time in all groups. Intensive LDL-C lowering was associated with slower progression of stenosis severity and reduction of high-risk plaque features, with increased plaque calcification and higher progression in PCPV. Comprehensive serial plaque evaluations by CCTAs may contribute to further refinement of risk stratification and reasonable lipid-lowering treatment in elderly patients.

KEY POINTS

• Intensive LDL-C lowering increased coronary calcification and percent calcified plaque volume progression. • Comprehensive serial plaque evaluations by serial CCTAs may help to refine risk stratification.

Sequential use of UV-LEDs irradiation and chlorine to disinfect waterborne fungal spores: Efficiency, mechanism and photoreactivation

In this work, sequential applications of light-emitting diodes (UV-LEDs) with two wavelengths and chlorine (Cl₂) were performed for fungal spores disinfection: UV-Cl₂, Cl₂-UV, UV/Cl₂-UV, UV-UV/Cl₂, Cl₂-UV/Cl₂-Cl₂. Overall comparisons of the sequential processes with respect to the inhibitory effect on photoreactivation were also evaluated. According to the evaluation of culturability and membrane permeability, inactivation of fungal spores by UV was not enhanced by prior or post exposure to Cl₂, but in the UV/Cl₂ process with pre or post UV treatment, the inactivation efficiency was greatly enhanced. Take P. polonicum for example, pre-treatments by UV₂₆₅ and UV₂₈₀ (40 mJ/cm²) caused the log count reduction (LCR) of 1.05 log and 0.95 log, then the followed UV₂₆₅/Cl₂ and UV₂₈₀/Cl₂ at the same UV fluence caused additional LCR of 1.80 log and 2.00 log. The permeabilization of P. polonicum was also accelerated in the processes of UV/Cl₂-UV and UV-UV/Cl₂, especially at the wavelength of 280 nm. In the sequential processes, especially those containing UV/Cl₂ or at the wavelength of 280 nm, could promote the formation of intracellular reactive oxygen species (ROS), thus leading to more severe damage to the spores as reflected in the culturability reduction, membrane permeability and inhibition of photoreactivation.

Efficacy of UV-LED based advanced disinfection processes in the inactivation of waterborne fungal spores: Kinetics, photoreactivation, mechanism and energy requirements

The contamination of fungi in water supply systems poses great risks to environment and human health. In this work, UV light-emitting diodes (UV-LEDs)-based advanced disinfection processes (ADPs) including UV-LEDs/hydrogen peroxide (H₂O₂), UV-LEDs/persulfate (PS) and UV-LEDs/peroxymonosulfate (PMS), were adopted for waterborne fungal spores inactivation. Overall comparisons of the UV-LEDs-based ADPs with respect to the control efficiency of photoreactivation and energy consumption were also evaluated. Results showed that culturability reduction of the fungal spores treated by UV-LEDs was not enhanced with the addition H₂O₂, PMS, and PS according to the results of heterotrophic plate counts and reaction rate constants; A. niger was expected to have higher UV resistance followed by T. harzianum and P. polonicum. However, UV-LEDs-ADPs inactivation, especially at the wavelengths of 280 and 265/280 nm, could accelerate the permeabilization of fungal spores as characterized by flow cytometry. Take P. polonicum for example, the percentage of membrane permeabilized spores was 98.0%, 98.7%, 97.6% and 82.6% after treatment by UV₂₈₀/H₂O₂, UV₂₈₀/PS, UV₂₈₀/PMS and UV₂₈₀ alone, respectively at the fluence of 100 mJ/cm². The direct attack of free radicals in the processes of UV-LEDs-ADPs further enhanced the membrane damage and lowered the photoreactivation level, thus improved the inactivation efficiency. UV-LEDs/H₂O₂ was considered as an effective process in the disinfection of fungal spores with the advantages of enhancing the damage of membrane, inhibiting photoreactivation and comparable energy consumption compared with UV-LEDs alone.

Effect of Xuezhikang Therapy on Expression of Pulmonary Hypertension Related miR-638 in Patients With Low HDL-C Levels

Objective: Low plasma level of high-density lipoprotein cholesterol (HDL-C) associated with poor outcomes in several cardiovascular diseases, including pulmonary arterial hypertension (PAH). Regulation of miR-638 have been proved to be associated with PAH. The aim of this study was to evaluate the expression of miR-638 after Xuezhikang (XZK) therapy in patients with low HDL-C.

Methods: Plasma levels of miR-638 were quantified by real-time polymerase chain reactions in 20 patients with PAH and 30 healthy controls. A total of 40 subjects with low HDL-C were assigned to receive an XZK therapy for 6 months. The miR-638 expression profiles were detected in PAH patients, XZK-treated subjects and lovastatin treated pulmonary arterial smooth muscle cells (PA-SMCs).

Results: The relative expression level of miR-638 in the plasma was lower in the PAH patients than that in the controls (p < 0.001). An increase of 11.2% from baseline in the HDL-C level was found after XZK therapy (p < 0.001). The relative expression of miR-638 was increased after XZK treatment (p < 0.01). The changes of miR-638 were inversely associated with baseline HDL-C levels. A significantly reduction in miR-638 expression were found in PDGF-BB-treated hPA-SMCs compared to the control cells, and the pre-treatment of the cells with lovastatin significantly re-gain the expression levels in miR-638.

Conclusion: In patients with low HDL-C levels, XZK therapy raised the expression of miR-638, suggesting that the potential therapeutic effect of XZK in PAH patients with low serum HDL-C levels deserves further exploration.

The formation kinetics and control of biofilms by three dominant fungi species isolated from groundwater

Filamentous fungi can enter drinking water supply systems in various ways, and exist in suspended or sessile states which threatens the health of individuals by posing a high risk of invasive infections. In this study, the biofilms formation kinetics of the three genera of fungal spores, Aspergillus niger (A. niger), Penicillium polonicum (P. polonicum) and Trichoderma harzianum (T. harzianum) isolated from the groundwater were reported, as well as the effects of water quality parameters were evaluated. In addition, the efficiency of low- concentrations of chlorine-based disinfectants (chlorine, chlorine dioxide and chloramine) on controlling the formation of fungal biofilms was assessed. The results showed that the biofilms formation of the three genera of fungi could be divided into the following four phases: induction, exponential, stationary and sloughing off. The optimum conditions for fungal biofilms formation were found to be neutral or weakly acidic at 28 °C with rich nutrition. In fact, A. niger, P. polonicum, and T. harzianum were not observed to form mature biofilms in actual groundwater within 120 hr. Carbon was found to have the maximum effect on the fungal biofilms formation in actual groundwater, followed by nitrogen and phosphorus. The resistance of fungal species to disinfectants during the formation of biofilms decreased in the order: A. niger > T. harzianum > P. polonicum. Chlorine dioxide was observed to control the biofilms formation with maximum efficiency, followed by chlorine and chloramine. Consequently, the results of this study will provide a beneficial understanding for the formation and control of fungal biofilms.

Synergistic effect of ozone and chlorine on inactivating fungal spores: Influencing factors and mechanisms

Effective control of fungal contamination in water is vital to provide healthy and safe drinking water for human beings. Although ozone was highly effective in inactivating fungi in water, it was limited by a lack of continuous disinfection ability in water supply system. In present study, the inactivation of fungal spores by combining ozone and chlorine was investigated. The synergistic effects of Aspergillus niger and Trichoderma harzianum spores reached 0.47- and 0.55-log within 10 min, respectively. The inactivation efficiency and the synergistic effect would be affected by disinfectant concentration, pH, and temperature. The combined inactivation caused more violent oxidative stimulation and more severe damage to the fungal spores than the individual inactivation based on the flow cytometry analysis and the scanning electron microscopy observation. The synergistic effect during the combined inactivation process was attributed to the generation of hydroxyl radicals by the reaction between ozone and chlorine and the promotion of chlorine penetration by the destruction of cell wall by ozone. The combined inactivation efficiency in natural water samples was reduced by 26.4-43.8% compared with that in PBS. The results of this study provided an efficient and feasible disinfection method for the control of fungi in drinking water.

The aggregation of Aspergillus spores and the impact on their inactivation by chlorine-based disinfectants

The formation of fungal biofilm goes through some different states, including monodisperse state, aggregated state, germinated state, hyphal and biofilm. The aggregation of spores is a primary step of fungal biofilm development in aquatic systems. Previous studies on the inactivation of fungi were mostly performed in the monodisperse state of fungal spores and biofilm state, however, the inactivation of aggregated fungal spores is still unclear. In this study, the aggregated characteristics of fungal spores (Aspergillus fumigatus and Aspergillus flavus) at different pH values were firstly studied, and the inactivation efficiency of fungal spores at different aggregation degree by chlorine-based disinfectants was also clarified. The results showed that the aggregation degree of Aspergillus fumigatus was the highest at pH 9.0 while it was the lowest at pH 5.0. Aggregation between fungal spores was mainly mediated by occasional adhesin-adhesin interactions and electrostatic interactions. Compared with monodisperse spores, fungal spores were more resistant to chlorine-based disinfectants with the increase of spore aggregation degree. The inactivation rate constants of Aspergillus fumigatus at 30% and 63% aggregation degree were 1.5- and 4-folds lower than that of monodisperse spores, respectively. The lower proportion of membrane damage and higher intracellular reactive oxygen species level for aggregated spores than monodisperse spores was observed according to the flow cytometric results after chlorine-based disinfectants treatment. The reasons for the lower inactivation efficiency of aggregated spores are as following: the protection of outer layer spores and signals between aggregates lead to the increase of resistance for aggregated spores. This study is meaningful for the control of the fungal spores at different states in water.

High-Sensitivity Cardiac Troponin T Is a Risk Factor for Major Adverse Cardiovascular Events and All-Cause Mortality: A 9.5-Year Follow-Up Study

BACKGROUND

The relationship between high-sensitivity cardiac troponin T (hs-cTnT) and different cardiovascular events has been observed in several large community studies, and the results have been controversial. However, there is currently no cross-sectional or longitudinal follow-up study on hs-cTnT in the Chinese population.

METHODS

We analyzed the association of plasma hs-cTnT levels with major adverse cardiovascular events (MACEs) and all-cause mortality in 1325 subjects from a longitudinal follow-up community-based population in Beijing, China.

RESULTS

In the Cox proportional hazards models analysis, the risk of MACEs increased with the increase of hs-cTnT levels (HR, 1.223, 95% CI, 1.054-1.418, P=0.008). Increased hs-cTnT levels were associated with coronary events (HR, 1.391, 95% CI, 1.106-1.749, P=0.005) in Model 4. Cox proportional risk regression model analysis revealed that increased hs-cTnT levels were associated with an increased risk of mortality (HR, 1.763, 95% CI, 1.224-2.540, P=0.002), even after adjusting hs-CRP and NT-proBNP. The area under the ROC curve for predicting MACEs was 0.559 (95% CI, 0.523-0.595, P=0.001). The areas under the ROC curve for predicting coronary events and mortality were 0.629 (95% CI, 0.580-0.678, P < 0.001) and 0.644 (95% CI, 0.564-0.725, P < 0.001), respectively.

CONCLUSIONS

Our findings in the Chinese cohort support that hs-cTnT is a risk factor for major adverse cardiovascular events and all-cause mortality.

Plasma Homocysteine Is a Predictive Factor for Accelerated Renal Function Decline and Chronic Kidney Disease in a Community-Dwelling Population

BACKGROUND

Whether elevated plasma total homocysteine (tHcy) is a risk factor for the progression of kidney disease in general population has not been well established. The purpose of this study was to investigate the prognostic properties of plasma tHcy for renal function decrement and early chronic kidney disease (CKD) in community-dwelling populations with normal renal function at baseline.

METHODS

A total of 1,426 participants were enrolled and followed for a median of 4.8 years (interquartile range, 4.5-5.2), and estimated glomerular filtration rate (eGFR) was evaluated. One main outcome was the rapid eGFR decline defined as a decline in eGFR of >3 mL/min per 1.73 m2 per year; the other was the new incidence of CKD.

RESULTS

At the end of follow-up, the incidence of rapid eGFR decline and new-onset CKD was 20.7 and 5.6%, respectively. In multivariate linear regression analysis, age, central pulse pressure, fasting blood glucose, and concentration of tHcy were independent determinants of the change in eGFR. There was a graded association between tHcy quartiles and eGFR decline. Compared with participants with the lowest quartile of tHcy levels, those with the highest quartile had significantly increased risk for rapid eGFR decline (adjusted odds ratio [aOR] = 1.81; 95% confidence interval [CI]: 1.25-2.94) and new onset of CKD (adjusted hazard ratio = 4.29; 95% CI: 1.42-12.99) after adjusting for various confounders. Similarly, significant associations were also found when baseline tHcy was classified as hyperhomocysteinemia (>15 μmol/L) versus normal tHcy level (≤15 μmol/L). However, there was only association between the change in tHcy levels and new occurrence of CKD but not with rapid eGFR decline (aOR = 0.99, p = 0.613).

CONCLUSIONS

In this prospective cohort of individuals from community-based population, elevated plasma tHcy emerged as an independent predictor of renal function decline and incident CKD, which might support selection of at-risk individuals.

Inactivation of waterborne fungal spores by 1-bromo-3-chloro-5,5-dimethylhydantoin: Kinetics, influencing factors and mechanisms

Fungal contamination in drinking water source has become a problem worth studying, as waterborne fungi may cause deterioration of water quality and outbreak of diseases. Various disinfection methods have been explored to control fungal spores in drinking water, such as chlor(am)ination, ozonation, chlorine dioxide treatment, but these methods are not appropriate for remote areas, owing to the difficulties in preparation, carriage and storage. In this study, a powdery disinfectant of 1-bromo-3-chloro-5,5-dimethylhydantoin (BCDMH), which facilitated transportation and preservation, was firstly chosen to inactivate opportunistic pathogens of Aspergillus niger (A. niger) and Penicillium polonicum (P. polonicum). The results revealed that the inactivation kinetics of fungal spores by BCDMH fitted to Chick-Watson model well, with the inactivation rate constant of 0.011 and 0.034 L mg^-1 min^-1 for A. niger and P. polonicum, respectively. Acidic condition and high temperature promoted the inactivation by BCDMH. Compared with chlorine, BCDMH showed relative weaker ability on inactivation of fungal spores. However, it was demonstrated that the inactivation efficiency of BCDMH was obviously enhanced by adding halide ions, with 11 or 36 folds for A. niger and 4 or 15 folds for P. polonicum by adding 40 μM Br^- or I^-. The inactivation mechanisms were detected by flow cytometry and scanning electron microscope. Fungal spores lost their culturability firstly, then membrane integrity was damaged. Meanwhile, the esterase activity and intracellular reactive oxygen species level changed, and finally intracellular adenosine triphosphate released.

Evaluation of the vital viability and their application in fungal spores' disinfection with flow cytometry

More attention was focused on fungi contamination in drinking water. Most researches about the inactivation of fungal spores has been conducted on disinfection efficiency and the leakage of intracellular substances. However, the specific structural damage of fungal spores treated by different disinfectants is poorly studied. In this study, the viability assessment methods of esterase activities and intracellular reactive oxygen species (ROS) were optimized, and the effects of chlorine-based disinfectants on fungal spores were evaluated by flow cytometry (FCM) and plating. The optimal staining conditions for esterase activity detection were as follows: fungal spores (10⁶ cells/mL) were stained with 10 μM carboxyfluorescein diacetate and 50 mM ethylene diamine tetraacetic acid at 33 °C for 10 min (in dark). The optimal staining conditions for intracellular ROS detection were as follows: dihydroethidium (the final concentration of 2 μg/mL) was added into fungal suspensions (10⁶ cells/mL), and then samples were incubated at 35 °C for 20 min (in dark). The cell culturability, membrane integrity, esterase activities, and intracellular ROS were examined to reveal the structural damage of fungal spores and underlying inactivation mechanisms. Disinfectants would cause the loss of the cell viability via five main steps: altered the morphology of fungal spores; increased the intracellular ROS levels; decreased the culturability, esterase activities and membrane integrity, thus leading to the irreversible death. It is appropriate to assess the effects of disinfectants on fungal spores and investigate their inactivation mechanisms using FCM.

Correlation between small and dense low-density lipoprotein cholesterol and cardiovascular events in Beijing community population

The relationship between small dense low‐density lipoprotein cholesterol (sdLDL‐C) and different cardiovascular events has been observed in several large community studies, and the results have been controversial. However, there is currently no cross‐sectional or longitudinal follow‐up study on sdLDL‐C in the Chinese hypertension population. We analyzed the association of plasma sdLDL‐C levels with major adverse cardiovascular events in 1325 subjects from a longitudinal follow‐up community‐based population in Beijing, China. During the follow‐up period, a total of 191 subjects had MACEs. Cox regression analysis showed that sdLDL‐C is a major risk factor for MACEs independent of sex, age, BMI, hypertension, diabetes, smoking, SBP, DBP, FBG, eGFR in the general community population (1.013 (1.001 −1.025, P < .05)), but the correlation disappeared after adjusting for TC and HDL‐C in Model 3. Cox analysis showed that hypertension combined with high level of sdLDL‐C was still the risk factor for MACEs ((2.079 (1.039‐4.148)). Our findings in the Chinese cohort support that sdLDL‐C is a risk factor for major adverse cardiovascular events in hypertension subjects.

[Diagnosis of adult Philadelphia chromosome-like acute lymphoblastic leukemia by fluorescence in situ hybridization]

目的

建立应用荧光原位杂交技术（FISH）筛查成人Ph样急性淋巴细胞白血病（ALL）的体系。

方法

根据Ph样ALL的遗传学特征，设计了针对ABL1、ABL2、JAK2、EPOR、CRLF2、CSF1R、PDGFRB、P2RY8等基因断裂重排的FISH探针；对BCR-ABL1、ETV6-RUNX1、MLL基因断裂重排和E2A断裂重排均阴性的B-ALL，采用FISH进行Ph样ALL筛查，并结合流式免疫表型、靶向二代测序突变检测和RNA测序进行Ph样ALL诊断分析。

结果

2016年1月至2019年4月，南方医院血液科收治189例成人B-ALL，经FISH和（或）PCR检测，BCR-ABL1、ETV6-RUNX1、MLL断裂重排或E2A断裂重排阳性者共83例；其余106例患者接受Ph样ALL FISH探针筛查，其中，12例（11.3％）检出典型的Ph样ALL特异基因断裂重排，2例检出基因缺失。经RNA测序进一步验证，FISH检测Ph样ALL基因断裂重排结果灵敏度为71.4％，特异度为95.8％。综合免疫表型、靶向二代测序突变检测和RNA测序，共诊断融合基因阳性Ph样ALL 14例（13.2％）。

结论

FISH技术检测Ph样ALL具有较高的特异性，结合免疫表型和测序技术可完善诊断体系。

Mechanical Properties and Degradation Behaviors of Zn-xMg Alloy Fine Wires for Biomedical Applications

Zn and Zn-based alloys exhibit biosafety and biodegradation, considered as candidates for biomedical implants. Zn-0.02 wt.% Mg (Zn-0.02 Mg), Zn-0.05 wt.% Mg (Zn-0.05 Mg), and Zn-0.2 wt.% Mg (Zn-0.2 Mg) wires (Φ 0.3 mm) were prepared for precision biomedical devices in this work. With the addition of Mg in Zn-xMg alloys, the grain size decreased along with the occurrence of Mg₂Zn₁₁ at the grain boundaries. Hot extrusion, cold drawing, and annealing treatment were introduced to further refining the grain size. Besides, the hot extrusion and cold drawing improved the tensile strength of Zn-xMg alloys to 240-270 MPa while elongation also increased but remained under 10%. Annealing treatment could improve the elongation of Zn alloys to 12% -28%, but decrease the tensile strength. Furthermore, Zn-xMg wires displayed an increase in degradation rate with Mg addition. The findings might provide a potential possibility of Zn-xMg alloy wires for biomedical applications.

Bagging cross-validated bandwidths with application to big data

Hall & Robinson (2009) proposed and analysed the use of bagged cross-validation to choose the bandwidth of a kernel density estimator. They established that bagging greatly reduces the noise inherent in ordinary cross-validation, and hence leads to a more efficient bandwidth selector. The asymptotic theory of Hall & Robinson (2009) assumes that $N$, the number of bagged subsamples, is $\infty$. We expand upon their theoretical results by allowing $N$ to be finite, as it is in practice. Our results indicate an important difference in the rate of convergence of the bagged cross-validation bandwidth for the cases $N=\infty$ and $N&lt;\infty$. Simulations quantify the improvement in statistical efficiency and computational speed that can result from using bagged cross-validation as opposed to a binned implementation of ordinary cross-validation. The performance of the bagged bandwidth is also illustrated on a real, very large, dataset. Finally, a byproduct of our study is the correction of errors appearing in the Hall & Robinson (2009) expression for the asymptotic mean squared error of the bagging selector.

Inactivation of fungal spores in water using ozone: Kinetics, influencing factors and mechanisms

Fungal contamination of drinking water sources is increasingly threatening the environment and human health. In this study, the inactivation of three genera of dominant fungi in drinking water sources using ozone was first reported. The inactivation of the fungal spores by ozone could be divided into two distinct stages: first a rapid reduction in survival, and then the inactivation at a slower rate. The secondary stage inactivation fitted the Chick-Watson model well, and there was no significant difference in the second-order inactivation rate constants of the three fungal spores (0.199-0.209 L mg^-1 min^-1). The inactivation rate constants of fungal spores by molecular ozone were much lower than those of viruses, which were equivalent to that of Cryptosporidium. The increase in pH and temperature showed a positive effect on the inactivation rate. Damage to cell membranes, leakage of intracellular compounds, and changes of reactive oxygen species and esterase activity in the spores were detected after inactivation. The results indicated that ozone inactivated fungal spores by firstly destroying cell walls and membranes and then causing the release of intracellular compounds. The fungicidal efficiency of ozone was superior to those of chlorine and chlorine dioxide. In addition, the inactivation efficiency of ozone on fungal spores in real water matrices was reduced to 50.7-91.2% of the efficiency in phosphate buffer. In conclusion, ozone showed high efficiency in the inactivation of fungal spores and could be used as an alternative disinfectant for fungal contamination in drinking water sources.

Simultaneously enhance the inactivation and inhibit the photoreactivation of fungal spores by the combination of UV-LEDs and chlorine: Kinetics and mechanisms

Waterborne fungi have been recognized as an emerging environmental contaminant in recent years. This work was to investigate the inactivation efficiency and mechanisms of ultraviolet light-emitting diodes (UV-LEDs)/chlorine (Cl₂) (265, 280 and 265/280 nm combination) and LPUV/Cl₂ (254 nm) treatments for three fungal species compared with individual disinfection processes. Control of photoreactivation for fungal species inactivated by UV-LEDs/Cl₂ and LPUV/Cl₂ was also evaluated. The results revealed that the combined UV-LEDs/Cl₂ and LPUV/Cl₂ processes, especially UV-LEDs/Cl₂, exhibited better inactivation performance compared to UV alone and Cl₂ alone based on the inactivation rate constants, and an evident synergistic effect was observed. For example, the inactivation rates for Penicillium polonicum in the processes of UV₂₆₅/Cl₂, UV₂₈₀/Cl₂, UV_265/280/Cl₂ and LPUV/Cl₂ was 0.142, 0.168, 0.174 and 0.106 cm²/mJ, respectively, which were all approximately 1.5-fold higher than that of UV alone. The synergistic effect of fungal spores inactivation by UV-LEDs/Cl₂ and LPUV/Cl₂ was due to the high level production of intracellular reactive oxygen species and the reaction of potential extracellular free radicals. Resistance of the tested fungal spores was as follows: Trichoderma harzianum < Penicillium polonicum < Aspergillus niger. In addition, the joint effect of DNA and other cellular damage resulted in the inhibition of photoreactivation of fungal spores inactivated by UV-LEDs/Cl₂ and LPUV/Cl₂ compared with that of fungal spore inactivated by UV alone. This study may provide reference for controlling the dissemination of waterborne fungi utilizing combined UV-LEDs and free chlorine processes.

Circulating Ceramide: A New Cardiometabolic Biomarker in Patients With Comorbid Acute Coronary Syndrome and Type 2 Diabetes Mellitus

Aims

This study investigated the association of circulating ceramides in patients with comorbid acute coronary syndrome and type 2 diabetes mellitus (ACS-DM).

Methods

A total of 761 patients with coronary heart disease who were admitted to the Department of Cardiology at the Chinese PLA General Hospital from March to August 2018 were enrolled in this study. Of these 761 patients, 282 were diagnosed with acute coronary syndrome (ACS). We selected 65 patients with ACS-DM (ACS-DM group; mean age 64.88 years; 38 men) and 65 patients with ACS but without any comorbidities (ACS group; mean age 64.68 years; 38 men); the two groups were matched by age and sex. We determined four circulating ceramides in 130 plasma samples: Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:1), and Cer(d18:1/24:0). The ceramides in plasma samples from patients with ACS and those from patients with ACS-DM were compared. Pearson correlation coefficients between individual ceramides and traditional cardiovascular risk factors for the whole study population were calculated. Multiple logistic regression models were used to evaluate the relativity between the ceramide and ACS-DM.

Results

Compared with the ACS group, the levels of Cer(d18:1/16:0), Cer(d18:1/18:0), and Cer(d18:1/24:1) and their ratios to Cer(d18:1/24:0) were higher in the ACS-DM group and Cer(d18:1/24:0) was lower in the ACS-DM group (P < 0.05). Correlation analysis demonstrated mild-to-moderate correlations of ceramide and traditional cardiovascular risk factors. There were relatively strong correlations of Cer(d18:1/18:0) and Cer(d18:1/24:1) with C-reactive protein, blood lipids, fasting blood glucose, and glycated hemoglobin A₁c. In multiple logistic regression models, Cer(d18:1/18:0) [odds ratio (OR) 2.396; 95% confidence interval (CI) 1.103–5.205; P = 0.027], Cer(d18:1/24:1) (OR 2.826; 95% CI 1.158–6.896; P = 0.023), Cer(d18:1/18:0)/Cer(d18:1/24:0) (OR 2.242; 95% CI 1.103–4.555; P = 0.026), and Cer(d18:1/24:1)/Cer(d18:1/24:0) (OR 2.673; 95% CI 1.225–5.836; P = 0.014) were positively correlated with ACS-DM, and Cer(d18:1/24:0) (OR 0.200; 95% CI 0.051–0.778; P = 0.020) was negatively correlated with ACS-DM.

Conclusion

Circulating ceramides are positively correlated with the risk of ACS-DM comorbidity. These results give a new insight into the pathogenesis of ACS-DM comorbidity and could provide new options for risk estimation.

Rapamycin Promotes Cardiomyocyte Differentiation of Human Induced Pluripotent Stem Cells in a Stage-Dependent Manner

Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) are a promising source for cardiac regenerative therapy, and ideal for in vitro cell modeling of cardiovascular diseases and drug screening. Recent studies have shown that rapamycin can promote cardiomyocyte differentiation in various stem cells. However, how rapamycin affects cardiomyocyte differentiation of iPSCs is still not fully understood. This study aimed to investigate the effect of rapamycin on cardiomyocyte differentiation based on embryoid body (EB) method. First, to determine the autophagy induction protocol, different concentrations of rapamycin were applied in hEBs on day 6. The autophagy was most significant when applying rapamycin at 1 μM for 48 h, demonstrating by the LC3II/LC3I ratio and p62 expression. Then, 1 μM rapamycin was applied for 48 h at different time points of cardiomyocyte differentiation to investigate the role of rapamycin in this process. Compared with control, rapamycin applied on days 0-4 of differentiation significantly decreased the proportion of beating EBs and expression of cardiomyocyte-specific genes, while rapamycin applied on days 4-14 significantly increased them. Among all groups, rapamycin applied on days 4-6 achieved highest cardiomyocyte differentiation efficiency. Furthermore, using autophagy inhibitor NH₄Cl and GSK-3β inhibitor CHIR-99021, we found rapamycin-induced autophagy promoted cardiomyocyte differentiation at middle stage by negatively regulating the Wnt/β-catenin signaling pathway. These results suggest that rapamycin regulates EB-based cardiomyocyte differentiation in a stage-dependent manner, and the negative regulation of Wnt/β-catenin signaling pathway by autophagy was involved in the prodifferentiation effect of rapamycin at middle stage.

Influence of post-core material and cement peculiarities on stress of post-cores under ultrasonic vibration: a three-dimensional finite element analysis

AIM

To analyse the effect of post-core, and cement materials and thickness of the cement lute on the stress in post-core systems under ultrasonic vibration at different frequencies and amplitudes using three-dimensional finite element analysis.

METHODOLOGY

Eight three-dimensional finite element models of a maxillary central incisor with post-cores were established. Two post-core materials (Au and Ni-Cr alloys), two cements (glass ionomer (GI) and zinc phosphate (ZP)) and two cement layer thicknesses (50 and 150 μm) were considered. Vibration loads were applied near the neck on the buccal side of the core at frequencies of 10-40 kHz and amplitudes of 10-50 μm. The maximum shear stress of the cement layer and maximum principal stress of the roots and their distributions were investigated.

RESULTS

The stresses on cements and roots increased with an increase in the frequency and amplitude of the vibration load and elastic modulus of the cements, and decreased with increasing thickness of the cement layer and elastic modulus of the post-core. Maximum cement stress was observed on the contralateral upper part of the loading side, whereas the maximum root stress was found on the ferrule where the load was applied.

CONCLUSIONS

In this simulated model, the frequency and amplitude of ultrasound needed to remove a post-core were positively related to the elastic modulus of the post-core and thickness of the cement layer and negatively related to the elastic modulus of the cements.

Nurses' health beliefs about paper face masks in Japan, Australia and China: a qualitative descriptive study

Aim

To explore the health beliefs of clinical and academic nurses from Japan, Australia and China regarding wearing paper masks to protect themselves and others, and to identify differences in participants' health beliefs regarding masks.

Background

The correct use of face masks and consensus among health professionals across the globe is essential for containing pandemics, and nurses need to act according to policy to protect themselves, educate the public and preserve resources for frontline health workers. Paper masks are worn by health professionals and the general public to avoid the transmission of respiratory infections, such as COVID‐19, but there appear to be differences in health beliefs of nurses within and between countries regarding these.

Methods

This qualitative descriptive study used content analysis with a framework approach.

Findings

There were major differences in nurse participants’ beliefs between and within countries, including how nurses use paper masks and their understanding of their efficacy. In addition, there were cultural differences in the way that nurses use masks in their daily lives and nursing practice contexts.

Conclusion

Nurses from different working environments, countries and areas of practice hold a variety of health beliefs about mask wearing at the personal and professional level.

Implications for nursing policy and health policy

The COVID‐19 pandemic has sparked much discussion about the critical importance of masks for the safety of health professionals, and there has been considerable discussion and disagreement about health policies regarding mask use by the general public. Improper use of masks may have a role in creating mask shortages or transmitting infections. An evidence‐based global policy on mask use for respiratory illnesses for health professionals, including nurses, and the general public needs to be adopted and supported by a wide‐reaching education campaign.

Serial Dopamine Transporter Imaging of Nigrostriatal Function in Parkinson's Disease With Probable REM Sleep Behavior Disorder

The current study aimed to confirm whether probable rapid eye movement sleep behavior disorder (pRBD) is associated with a specific pattern of striatal dopamine depletion in an international, multicenter, prospective cohort of patients with Parkinson's disease (PD). Two hundred and seventy de novo, drug-naïve patients with PD underwent dopamine transporter (DAT) single photon emission computed tomography with ¹²³I-FP-CIT at baseline and 1, 2, and 4 years after the initial scan. The diagnosis of pRBD was based on the 10-item RBD Screening Questionnaire. Striatal DAT binding levels and their rates of decline were compared between patients with pRBD and those without. At baseline, patients in the PD-pRBD+ group showed lower striatal DAT binding in the caudate (which was more pronounced in the less-affected hemisphere) and in the putamen. During the 4-year follow-up, patients in the PD-pRBD+ group consistently exhibited greater DAT loss than patients in the PD-pRBD- group with comparable disease duration in all four striatal subregions. These patients also exhibited a more rapid decrease in DAT binding in the caudate and a less prominent interhemispheric asymmetry in the putamen. The distinct pattern of striatal DAT depletion may contribute to a more malignant phenotype of PD associated with RBD, specifically faster progression of motor symptoms.

Comparison of UV-LEDs and LPUV on inactivation and subsequent reactivation of waterborne fungal spores

Recently, the contamination of fungi in water supply systems has been an area of increasing concern, such as Aspergillus spp. and Penicillium spp. It can cause some waterborne issues such as odor, taste and formation of mycotoxins. Ultraviolet light emitting diodes (UV-LEDs) are considered as a potential alternative to conventional mercury lamps for water disinfection. This study has compared the performance of LPUV (low pressure ultraviolet) and UV-LEDs with emissions at 265, 280 nm and combination emissions at 265/280 nm to test inactivation efficiency, reactivation, viability and electrical energy consumption in the treatment of three water-borne fungal species (Aspergillus niger, Penicillium polonicum, Trichoderma harzianum) at a batch water disinfection system. The results showed that the performances of UV-LEDs were superior for the inactivation of fungal spores compared to the 254 nm (LP), while no statistically differences were observed among the UV-LEDs (p > 0.05). The average photoreactivation rate (k₁) of fungal spores irradiated by UV-LEDs and 254 nm (LP) follows the order: T. harzianum > A. niger > P. polonicum. Compared with LPUV, UV-LEDs irradiation at 280 nm and 265/280 nm more efficiently inhibits photoreactivation, which was attributed to that irradiation of 280 nm and 265/280 nm would cause greater membrane damage and increase intracellular reactive oxygen species level of fungal spores according to the flow cytometric results. The electrical energy consumption of UV-LEDs was higher than that of LPUV, which was due to its lower wall plug efficiency. The results of this study can provide additional and beneficial information for the reasonable exploitation of UV-LEDs in water disinfection.

Development of fungal spore staining methods for flow cytometric quantification and their application in chlorine-based disinfection

Fungal contamination in drinking water has been becoming a hot topic. The routine enumeration method of fungal spores is heterotrophic plate counts (HPC). However, this method is time-consuming and labor-intensive and there is also the difficulty of enumerating viable but non-culturable cells. In this study, a rapid, simple and accurate method for quantifying fungal spores and discriminating their viability in water was established using flow cytometry (FCM) combined with fluorescence dyes. The optimal staining conditions are as follows: spores suspensions are sonicated at 495 W for 5 min as pretreatment, and then 10 μL of SYBR Green I (100×) and 30 mM Ethylene diamine tetraacetic acid are added to a 500 μL water sample, which incubate at 35 °C for 20 min in dark. The concentration of fungal spores measured by FCM was highly correlated with HPC results and microscope observations, with correlation coefficient of 0.996 and 0.988, respectively. This staining method can be widely applied to the enumeration and viability evaluation of fungal spores. In addition, chlorine-based inactivation of three genera of fungal spores was assessed by plating and FCM. The result showed that all three genera of fungal spores lost culturability firstly and then membrane integrity decreased, preliminarily revealing the inactivation mechanism. The inactivation rate constants of membrane damage varied in the following order: chlorine dioxide > chlorine > chloramine. This study concluded that FCM is an appropriate and alternative tool to detect fungal spores' viability and can be used for evaluating the fungal inactivation by disinfectants.

Noninvasive central pulse pressure is an independent determinant of renal function

The purpose of this study was to investigate the prognostic properties of different BP measurements for renal function decrement and early chronic kidney disease (CKD) in community-dwelling populations with normal renal function at baseline. A total of 1426 participants were included and followed for a median of 4.8 years (interquartile range, 4.5-5.2), and central hemodynamic profile and estimated glomerular filtration rate (eGFR) were evaluated. One main outcome was the rapid eGFR decline defined as a decline in eGFR of greater than 3 mL/min per 1.73 m² per year; the other was the new incidence of CKD. At the end of follow-up, mean eGFR decreased from 93.39 ± 13.46 mL/min per 1.73 m² to 85.72 ± 14.81 mL/min per 1.73 m² , and the incidence of rapid eGFR decline and CKD were 20.7% and 5.6%, respectively. In multivariate linear regression analysis, central pulse pressure (PP), age, fasting blood glucose, and concentration of homocysteine were independent determinants of the change in renal function. Not only in the prediction of rapid eGFR decline but also in the incident of CKD, baseline central PP was the only BP component that consistently independently associated with both outcomes after adjustment for various confounders. When compared with subjects in the lowest quartile of central PP, those in the highest quartile demonstrated a significantly increased risk of CKD (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.08-2.96; P = .006). The study showed that central PP emerged as an independent predictor of the decline in renal function.

Ultrasound/Optical Dual-Modality Imaging for Evaluation of Vulnerable Atherosclerotic Plaques with Osteopontin Targeted Nanoparticles

Because of the high mortality of coronary atherosclerotic heart diseases, it is necessary to develop novel early detection methods for vulnerable atherosclerotic plaques. Phenotype transformation of vascular smooth muscle cells (VSMCs) plays a vital role in progressed atherosclerotic plaques. Osteopontin (OPN) is one of the biomarkers for phenotypic conversion of VSMCs. Significant higher OPN expression is found in foam cells along with the aggravating capacity of macrophage recruitment due to its arginine-glycine-aspartate sequence and interaction with CD44. Herein, a dual-modality imaging probe, OPN targeted nanoparticles (Cy5.5-anti-OPN-PEG-PLA-PFOB, denoted as COP-NPs), is constructed to identify the molecular characteristics of high-risk atherosclerosis by ultrasound and optical imaging. Characterization, biocompatibility, good binding sensibility, and specificity are evaluated in vitro. For in vivo study, apolipoprotein E deficien (ApoE^-/- ) mice fed with high fat diet for 20-24 weeks are used as atherosclerotic model. Ultrasound and optical imaging reveal that the nanoparticles are accumulated in the vulnerable atherosclerotic plaques. OPN targeted nanoparticles are demonstrated to be a good contrast agent in molecular imaging of synthetic VSMCs and foam cells, which can be a promising tool to identify the vulnerable atherosclerotic plaques.

Reactivation of fungal spores in water following UV disinfection: Effect of temperature, dark delay, and real water matrices

The occurrence of fungi in water supply systems causes many environmental problems (e.g., odor, taste, turbidity, formation of mycotoxins); it has been an area of increasing concern in recent years. Ultraviolet irradiation can inactivate fungi efficiently. However, its reactivation poses further challenges in water purification. The reactivation characteristics of waterborne fungi under different environmental conditions have rarely been reported. In this study, the effects of temperatures and dark delay on the reactivation of three genera of fungal spores (Trichoderma harzianum, Aspergillus niger, Penicillium polonicum) were evaluated. The reactivation levels among these fungal spores were compared in phosphate buffer solution (PBS) and in real groundwater. It was found that lower temperature can inhibit the photoreactivation of fungi, whereas higher temperatures would promote the process. A long-term dark delay can inhibit the photoreactivation of fungi effectively. The dark repair of fungal spores almost do not occur neither in PBS nor in real groundwater. Finally, the photoreactivation percentage in real groundwater was higher than that in PBS. This study will provide a basis for controlling the reactivation of fungi in water.