Sodium butyrate inhibits oral squamous cell carcinoma proliferation and invasion by regulating the HDAC1/HSPB7 axis.

The study was performed to ascertain the mechanism of sodium butyrate (NaB) mediating the proliferative and invasive properties of oral squamous cell carcinoma (OSCC) cells. The cell proliferative, migrating, and invasive potentials were detected by CCK-8, colony formation, EdU, and Transwell assays. The expression of proliferation- and invasion-related proteins, HDAC1, and HSPB7 in OSCC cells were evaluated by western blot. Immunofluorescence was also performed to evaluate the HDAC1 expression. The enrichment of histone deacetylase HDAC1 in the promoter region of HSPB7 was assessed by the ChIP assay. In vivo growth of OSCC cells was measured by tumorigenesis in nude mice (n=18). The t-test was employed for comparisons of data between the two groups. One-way ANOVA was utilized for comparisons of data among multiple groups, and repeated-measures ANOVA for comparisons of data at different time points among groups, followed by Bonferroni post-hoc test. The data showed that HDAC1 expression was highly upregulated in OSCC cells compared to human normal oral keratinocytes (HNOKs) (p<0.0001), and NaB diminished the HDAC1 expression in OSCC cells. NaB restricted OSCC cell proliferative, migrating, and invasive capabilities by downregulating HDAC1. HSPB7 expression was downregulated in OSCC cells versus HNOKs (p<0.0001). HDAC1 inversely orchestrated the HSPB7 expression in OSCC cells through histone deacetylation modification, and NaB augmented the HSPB7 expression by inhibiting HDAC1. Moreover, NaB inhibited OSCC cell growth in vivo by elevating HSPB7 levels through the HDAC1 repression. In conclusion, NaB restrained cell proliferation and invasion in OSCC cells via HSPB7 upregulation by decreasing the HDAC1 expression.

The optimal range of serum intact parathyroid hormone for a lower risk of mortality in the incident hemodialysis patients.

The serum intact parathyroid hormone (iPTH) is associated with the prognosis of hemodialysis (HD) patients, however, its optimal range for reducing mortality remains inconsistent. We designed a prospective cohort study of 346 incident HD patients to assess the association between different serum iPTH level and mortality. According to the Kidney Disease Outcomes Quality Initiative (K/DOQI) international guidelines (2003), we divided patients into three groups (iPTH < 150 pg/mL, 150-300 pg/mL and >300 pg/mL). During the median follow-up of 58 months, 157 patients (45.38%) died. Multivariate Cox regression analysis showed that iPTH < 150 pg/mL and >300 pg/mL were associated with all-cause and cardiovascular mortality. Then, we performed a sensitivity analysis of patients divided into 6 serum PTH levels groups according to the folds of the K/DOQI target range. Multivariate Cox regression analysis showed that patients with serum iPTH ≥750 pg/mL, 600-749 pg/mL, 450-599 pg/mL had significantly higher risk of all-cause and cardiovascular mortality compared with those with serum iPTH in the range of 150-299 pg/mL. The association between serum iPTH and mortality shows a U-shaped curve. The optimal serum iPTH level which confers the lowest risk of all-cause and cardiovascular mortality could range from 150 pg/mL to 450 pg/mL in this group of incident HD patients.

Molecular characteristics of Staphylococcus aureus isolates from food surveillance in southwest China.

BACKGROUND: Staphylococcal food poisoning (SFP) is one of the most common food-borne diseases in the world. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and spa typing methods were used to characterize Staphylococcus aureus isolates from food surveillance during 2013-2015 in southwest China, and Staphylococcal cassette chromosome mec (SCCmec) typing was used for methicillin-resistant S. aureus (MRSA). Isolates were also examined for their antibiotic resistance and carriage of virulence genes. RESULTS: Isolation rate of S. aureus was 2.60% during the three years' surveillance and 29.50% of them were MRSA. All the S. aureus had hla genes (100%), 14.34% of the strains had tst, and 16.73% had PVL. 163 PFGE-SmaI patterns, 41 ST types and 36 spa types were obtained for all the S. aureus. Among them, ST6-t701 (13.15%), ST7-t091 (12.75%), ST59-t437 (9.96%) and ST5-t002 (7.57%) were the prevalent genotypes. Most of MRSA in this study belonged to SCCmec IV and V, accounted for 74.32% and 20.27% respectively. ST6-SCCmec IV-t701 (36.50%) was the most prevalent clone among isolates from food, followed by ST59-SCCmec V-t437 (20.30%), ST5-SCCmec IV-t002 (12.20%) and ST59-SCCmec IV-t437 (12.20%). Some strains had the identical PFGE patterns, ST and spa types with isolates from patients. CONCLUSIONS: S. aureus isolated from food in southwest China displayed heterogeneity. Isolates had the same genotype profiles with isolates from patients, indicating high homology.

Outbreak of plasmid-mediated NDM-1-producing Klebsiella pneumoniae ST105 among neonatal patients in Yunnan, China.

BACKGROUND: In the past decade, the carbapenemase-producing Enterobacteriaceae (CPE) have been reported worldwide. Emergence of carbapenemase-producing strains among Enterobacteriaceae has been a challenge for treatment of clinical infection. The present study was undertaken to investigate the characteristics of carbapenem-resistant Klebsiella pneumoniae recovered from an outbreak that affected 17 neonatal patients in neonatal intensive care unit (NICU) of Kunming City Maternal and Child health Hospital, which is located in the Kunming city in far southwest of China. METHODS: Minimum inhibitory concentrations (MICs) for antimicrobial agents were determined according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI); Modified Hodge test and Carba-NP test were preformed to identified the phenotypes of carbapenemases producing; To determine whether carbapenem resistance was transferable, a conjugation experiment was carried out in mixed broth cultures; Resistant genes were detected by using PCR and sequencing; Plasmids were typed by PCR-based replicon typing method; Clone relationships were analyzed by using multilocus-sequence typing (MLST) and pulsed field gel electrophoresis (PFGE). RESULTS: Eighteen highly carbapenem-resistant Klebsiella pneumoniae were isolated from patients in NICU and one carbapenem-resistant K. pneumoniae isolate was detected in incubator water. All these isolates harbored bla NDM-1. Moreover, other resistance genes, viz., bla IMP-4 , bla SHV-1 , bla TEM-1 , bla CTX-M-15 , qnrS1, qnrB4, and aacA4 were detected. The bla NDM-1 gene was located on a ca. 50 kb IncFI type plasmid. PFGE analysis showed that NDM-1-producing K. pneumoniae were clonally related and MLST assigned them to sequence type 105. CONCLUSIONS: NDM-1 producing strains present in the hospital environment pose a potential risk and the incubator water may act as a diffusion reservoir of NDM-1- producing bacteria. Nosocomial surveillance system should play a more important role in the infection control to limit the spread of these pathogens.

Association between cerebral blood flow variation and cognitive decline in older patients undergoing hemodialysis.

Background: The mechanism of cognitive impairment in hemodialysis patients is multifactorial. The relationship between cerebral blood flow and the decline of cognitive function is poorly understood. Objective: To investigate the association between cerebral blood flow variation and decline of cognitive function in older patients undergoing hemodialysis. Methods: In this prospective observational cohort study of 121 older patients undergoing hemodialysis, we used transcranial Doppler ultrasound (TCD) to measure cerebral arterial mean flow velocity (MFV) throughout dialysis, assessed cognitive function at baseline and 12-month follow-up, and then analyzed associations between MFV and changes on cognitive scores. Results: TCD recordings demonstrated a significant reduction in MFV throughout dialysis, which were significantly correlated with cumulative ultrafiltration volume (rho 0.356, p < 0.001), ΔSBP (rho 0.251, p = 0.005), and ΔMAP (rho 0.194, p = 0.032). Compared with the baseline assessments, cognitive scores of participants at the 12-month follow-up were significantly worsened in global cognition (MOCA), some tests of memory (CFT-memory), executive function (TMT-B, SCWT-C, and SCWT-T), attention/processing speed (SDMT), and visuospatial function (CFT-copy) (p < 0.05). The worsening scores in global cognition (MOCA) (ß = 0.066, 95% CI 0.018-0.113, p = 0.007) and some tests of memory (AVLT5) (ß = 0.050, 95% CI 0.004-0.097, p = 0.035) and executive function (TMT-B, SCWT-C, SCWT-T) (ß = 1.955, 95% CI 0.457-3.453, p = 0.011; ß = 0.298, 95% CI 0.112-0.484, p = 0.002 and ß = 1.371, 95% CI 0.429-2.303, p = 0.004, respectively) were significantly associated with the reduction of MFV. Conclusion: Hemodialysis may significantly reduce cerebral blood flow in older patients; Repetitive intradialytic decreases in CBF may be one of the mechanisms underlying the decline of cognitive function. Clinical trial registration: https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S000C5B5&selectaction=Edit&uid=U0003QEL&ts=4&cx=-djoi2.

An ultrasensitive electrochemical/colorimetric dual-mode self-powered biosensing platform for lung cancer marker detection by multiple-signal amplification strategy.

BACKGROUND: In recent years, miRNAs have emerged as potentially valuable tumor markers, and their sensitive and accurate detection is crucial for early screening and diagnosis of tumors. However, the analysis of miRNAs faces significant challenges due to their short sequence, susceptibility to degradation, high similarity, low expression level in cells, and stringent requirements for in vitro research environments. Therefore, the development of sensitive and efficient new methods for the detection of tumor markers is crucial for the early intervention of related tumors. RESULTS: An ultrasensitive electrochemical/colorimetric dual-mode self-powered biosensor platform is established to detect microRNA-21 (miR-21) via a multi-signal amplification strategy. Gold nanoparticles (AuNPs) and VS4 nanosheets self-assembled 3D nanorods (VS4-Ns-Nrs) are prepared for constructing a superior performance enzyme biofuel cell (EBFC). The double-signal amplification strategy of Y-shaped DNA nanostructure and catalytic hairpin assembly (CHA) is adopted to further improve enhance the strength and specificity of the output signal. In addition, a capacitor is matched with EBFC to generate an instantaneous current that is amplified several times, and the output detection signal is improved once more. At the same time, electrochemical and colorimetric methods are used for dual-mode strategy to achieve the accuracy of detection. The linear range of detection is from 0.001 pg/mL to 1000 pg/mL, with a relatively low limit of detection (LOD) of 0.16 fg/mL (S/N = 3). SIGNIFICANCE: The established method enables accurate and sensitive detection of markers in patients with lung cancer, providing technical support and data reference for precise identification. It is anticipated to offer a sensitive and practical new technology and approach for early diagnosis, clinical treatment, and drug screening of cancer and other related major diseases.

A convenient research strategy for functional verification of epigenetic regulators during spermatogenesis.

Spermatogenesis is a fundamental process that requires a tightly controlled epigenetic event in spermatogonial stem cells (SSCs). The mechanisms underlying the transition from SSCs to sperm are largely unknown. Most studies utilize gene knockout mice to explain the mechanisms. However, the production of genetically engineered mice is costly and time-consuming. In this study, we presented a convenient research strategy using an RNA interference (RNAi) and testicular transplantation approach. Histone H3 lysine 9 (H3K9) methylation was dynamically regulated during spermatogenesis. As Jumonji domain-containing protein 1A (JMJD1A) and Jumonji domain-containing protein 2C (JMJD2C) demethylases catalyze histone H3 lysine 9 dimethylation (H3K9me2), we firstly analyzed the expression profile of the two demethylases and then investigated their function. Using the convenient research strategy, we showed that normal spermatogenesis is disrupted due to the downregulated expression of both demethylases. These results suggest that this strategy might be a simple and alternative approach for analyzing spermatogenesis relative to the gene knockout mice strategy.

Association between family members of dialysis patients and chronic kidney disease: a multicenter study in China.

BACKGROUND: Family members of patients with end stage renal disease were reported to have an increased prevalence of chronic kidney disease (CKD). However, studies differentiated genetic and non-genetic family members are limited. We sought to investigate the prevalence of CKD among fist-degree relatives and spouses of dialysis patients in China. METHODS: Seventeen dialysis facilities from 4 cities of China including 1062 first-degree relatives and 450 spouses of dialysis patients were enrolled. Sex- and age- matched controls were randomly selected from a representative sample of general population in Beijing. CKD was defined as decreased estimated glomerular (eGFR<60 mL/min/1.73 m2) or albuminuria. RESULTS: The prevalence of eGFR less than 60 mL/min/1.73 m2, albuminuria and the overall prevalence of CKD in dialysis spouses were compared with their counterpart controls, which was 3.8% vs. 7.8% (P<0.01), 16.8% vs. 14.6% (P=0.29) and 18.4% vs. 19.8% (P=0.61), respectively. The prevalence of eGFR less than 60 mL/min/1.73 m2, albuminuria and the overall prevalence of CKD in dialysis relatives were also compared with their counterpart controls, which was 1.5% vs. 2.4% (P=0.12), 14.4% vs. 8.4% (P<0.01) and 14.6% vs. 10.5% (P<0.01), respectively. Multivariable Logistic regression analysis indicated that being spouses of dialysis patients is negatively associated with presence of low eGFR, and being relatives of dialysis patients is positively associated with presence of albuminuria. CONCLUSIONS: The association between being family members of dialysis patients and presence of CKD is different between first-degree relatives and spouses. The underlying mechanisms deserve further investigation.

Abdominal obesity in Chinese patients undergoing hemodialysis and its association with all-cause mortality.

Introduction: Obesity in patients undergoing hemodialysis is common. However, there is limited information on the relationship between obesity types defined by the combined body mass index (BMI) and waist circumference (WC) classification criteria and all-cause mortality in Chinese hemodialysis patients. Our objective was to determine the association between obesity types and all-cause mortality in hemodialysis patients. Methods: We conducted a prospective cohort study including patients from 11 hemodialysis centers in Beijing. According to the World Health Organization's standards, patients were classified into 2 categories with WC and 4 categories with BMI and then followed up for 1 year. Kaplan-Meier survival analysis was used to compare the difference in the cumulative survival rate in different BMI and WC groups. A multivariate Cox regression analysis was used to determine the association between different types of obesity and all-cause mortality. Results: A total of 613 patients were enrolled, the mean age was 63.8 ± 7.1 years old, and 42.1% were women. Based on the baseline BMI, there were 303 (49.4%) patients with normal weight, 227 (37.0%) with overweight, 37(6.0%) with obesity, and 46 (7.5%) with underweight. Based on the baseline WC, 346 (56.4%) patients had abdominal obesity. During a median follow-up of 52 weeks, 69 deaths occurred. Kaplan-Meier plots demonstrated a significant association of BMI categories (log-rank χ2 = 18.574, p<0.001) and WC categories (log-rank χ2 = 5.698, p=0.017) with all-cause death. With normal BMI and non-abdominal obesity as a reference, multivariate Cox regression analysis results showed that obesity (HR 5.36, 95% CI, 2.09-13.76, p<0.001), underweight (HR, 5.29, 95% CI, 2.32-12.07, p<0.001), normal weight combined with abdominal obesity (HR 2.61, 95% CI, 1.20-5.66, p=0.016), and overweight combined with abdominal obesity (HR 1.79, 95% CI, 1.03-3.73, p=0.031, respectively) were significantly associated with higher risks of all-cause mortality. Conclusion: Our study indicated that abdominal obesity is common and associated with all-cause mortality among Chinese hemodialysis patients.

Frailty in Older Patients Undergoing Hemodialysis and Its Association with All-Cause Mortality: A Prospective Cohort Study.

Purpose: The study aimed to determine the prevalence and risk factors of frailty among a Chinese cohort of hemodialysis patients and to assess the degree to which frailty was associated with all-cause mortality. Participants and Methods: We enrolled a group of older adults (≥60 years old) in a prospective cohort study of cognitive impairment in Chinese patients undergoing hemodialysis (registered in Clinical Trials.gov, ID: NCT03251573). We assessed the prevalence of frailty using Fried's definition in the Cardiovascular Health Study, then we evaluated the associated risk factors of frailty using multivariate logistic regression analysis. Finally, we assessed the association of frailty and all-cause mortality with multivariable Cox proportional hazard regression analyses. Results: The prevalence of frailty in these 204 enrolled hemodialysis patients was 72.1%. Patients with frailty were more inclined to have composite abnormal components that included poor physical functioning, exhaustion, low physical activity, and undernutrition. Multivariable logistic regression analysis suggested that increased age, female gender, history of diabetes, longer dialysis vintage, lower Kt/V, lower serum level of albumin concentrations, and increased serum iPTH concentrations were independently associated with frailty. Cox regression analysis indicated that frailty as a dichotomous construct was strongly associated with an increased risk of mortality (HR 6.092, 95% CI 1.886-19.677, P = 0.003) in unadjusted analyses. After adjusting (Model I = no adjusted; II = adjusted for age, gender; III = adjusted for age, gender, history of diabetes; IV = adjusted for all covariates associated at the p ≤ 0.10 level with death in unadjusted analyses, including age, history of diabetes, MoCA<26, single-pool Kt/V, and the levels of albumin and iPTH), the association was slightly affected but observed consistent as before. Conclusion: Frailty is extremely common and is associated with serious clinical outcomes among older hemodialysis patients. Based on those clinical features of frailty, future studies should focus on exploring effective interventions aimed to prevent or attenuate frailty in the older hemodialysis population.

Microbial community succession during crude oil-degrading bacterial enrichment cultivation and construction of a degrading consortium.

Microbial community succession during the enrichment of crude-oil-degrading bacteria was analyzed using Illumina high-throughput sequencing to guide bacterial isolation and construction of a bacterial consortium. Community change occurred in 6 days; the most abundant phylum changed from Proteobacteria to Actinobacteria; the most abundant genera were Dietzia and unspecified_Idiomarinaceae. Two crude oil-degrading strains, Rhodococcus sp. OS62-1 and Dietzia sp. OS33, and one weak-crude-oil-degrading strain, Pseudomonas sp. P35, were isolated. A consortium comprising Rhodococcus sp. OS62-1 and Pseudomonas sp. P35 showed the highest crude-oil-degrading efficiency, reaching 85.72 ± 3.21% within 7 days, over a wide pH range (5-11) and salinity (0-80 g·L-1). Consumption of saturated hydrocarbons, aromatic hydrocarbons, and resins was greater by the consortium than by a single strain, as was degradation of short-chain-alkanes (C13-C17) according to gas-chromatography. The bacterial consortium provides technical support for bioremediation of crude oil pollution.

Surface state dominated and carbon core coordinated red-emitting carbon dots for the detection of Cr2O72- and cell imaging.

Cr(VI) as a toxic heavy metal ion can easily enter into the body through drinking or eating and cause liver and kidney diseases as well as cancer. Considering its high biological toxicity and adverse effects on human body, it is desirable to develop a probe to monitor its level in the environment. Herein, a high-efficiency fluorescent nanoprobe based on red emissive carbon dots (R-CDs) was established through a convenient solvothermal strategy. The as-prepared CDs with excitation-independency had the fixed emission wavelength at 627 nm when the excitation wavelength was 560 nm. Further study manifested that the new surface state formed by nitrogen and sulfur doping and the increased conjugated system established through dehydration and carbonization were the main reasons for the fluorescence redshift. In this system, these R-CDs as a fluorescent probe exhibited high specificity and sensitivity to Cr2O72- with the linear range of 4-40 µΜ and the limit of detection could reach 80.00 nM. The quenching of these CDs by Cr2O72- was efficiently induced through a static quenching process. Meanwhile, the obtained CDs could enter into HeLa cells through endocytosis and exhibit bright red fluorescence in cells under a confocal laser scanning microscope. Thus, this work provided a promising probe not only for detecting Cr(VI) in natural environment but also for imaging in cells.

Cognitive Domain Impairment and All-Cause Mortality in Older Patients Undergoing Hemodialysis.

The highly prevalent cognitive impairment in hemodialysis patients is associated with all-cause mortality; however, the role of different cognitive domain impairments in this association is still not clarified. Our objective was to determine the association between cognitive domain impairment and all-cause mortality in elderly adult patients undergoing hemodialysis. We conducted a prospective cohort study including patients from 11 hemodialysis centers in Beijing. Baseline data were collected, and a series of neuropsychological batteries covering 5 domains of cognitive function were included for the assessment of cognitive function. According to the fifth version of the Diagnostic and Statistical Manual of Mental Disorders criteria (DSM-V), the patients were classified as normal, mild, and major cognitive impairment for global and domain cognitive function, then followed up for 1 year. Kaplan-Meier survival analysis was used to compare the difference in the cumulative survival rate in different cognitive domains. A multivariate Cox proportional hazards regression analysis was used to determine the association between global or domain cognitive impairment and all-cause mortality. A total of 613 patients were enrolled, the mean age was 63.82 ± 7.14 years old, and 42.1% were women. After 49.53 ± 8.42 weeks of follow-up, 69 deaths occurred. Kaplan-Meier plots demonstrated a significant association of cognitive impairment in memory, executive function, attention, and language domains with all-cause death. Multivariate Cox regression analysis showed that mild and major impairment of global cognition (HR = 2.89 (95% CI, 1.01-8.34), p = 0.049 and HR = 4.35 (95% CI, 1.55-12.16), p = 0.005, respectively), executive cognitive domain (HR = 2.51 (95% CI, 1.20-5.24), p = 0.014; HR = 3.91 (95% CI, 1.70-9.03), p = 0.001, respectively), and memory cognitive domain (HR = 2.13 (95% CI, 1.07-4.24), p = 0.031; HR = 3.67 (95% CI, 1.71-7.92), p = 0.001, respectively) were associated with all-cause mortality. Combined impairment of 3, 4, and 5 cognitive domains was associated with all-cause mortality [HR = 5.75 (95% CI, 1.88-17.57), p = 0.002; HR = 12.42 (95% CI, 3.69-41.80), p < 0.001; HR = 13.48 (95% CI, 3.38-53.73), p < 0.001, respectively]. We demonstrate an association between the executive and memory cognitive domain impairment and all-cause mortality in hemodialysis patients. Our data suggest that the impairments in these cognitive domains might help in the early identification of hemodialysis patients at risk of death.

Corrigendum: Association Between Sleep Disorders and Cognitive Impairment in Middle Age and Older Adult Hemodialysis Patients: A Cross-Sectional Study.

[This corrects the article DOI: 10.3389/fnagi.2021.757453.].

Association Between Sleep Disorders and Cognitive Impairment in Middle Age and Older Adult Hemodialysis Patients: A Cross-Sectional Study.

Objective: The aims of the current study were to (1) explore the features of overall poor sleep and specific sleep disorders in Chinese middle age and older adult hemodialysis patients; (2) examine the association between sleep disorders and cognitive impairment (CI) in middle age and older patients undergoing hemodialysis in China. Methods: Data of patients undergoing maintenance hemodialysis were collected from the prospective cohort study of CI in Chinese patients undergoing hemodialysis (Registered in Clinical Trials.gov, ID: NCT03251573). We included 613 patients (mean age = 63.7; SD = 7.8) in this study. We assessed sleep conditions using the Pittsburgh Sleep Quality Index (PSQI) questionnaire and cognitive function by the Chinese Beijing version of the Montreal Cognitive Assessment (MoCA-BJ) scale. Then the association between sleep disorders and CI was evaluated using multivariate logistic regression analysis. Results: The prevalence of sleep disorders in this group of 613 hemodialysis patients was 77.0%. Patients with CI were more inclined to have sleep disorders in specific aspects of sleep latency, habitual sleep efficiency, sleep disturbances, and daytime dysfunction (p < 0.05). In multivariate logistic regression analyses, every 1-point increase in global PSQI score was associated with a 1.2-fold increased risk of CI (adjusted OR = 1.201; 95%CI = 1.123-1.284, p < 0.001). For each specific PSQI, every 1-point increase in sleep disturbances score was associated with a 2.6-fold increased risk of CI (adjusted OR = 2.624; 95%CI = 1.891-3.640, p < 0.001), and every 1-point increase in daytime dysfunction score was associated with a 3.7-fold increased risk of CI (adjusted OR = 3.709; 95%CI = 2.653-5.184, p < 0.001), whereas every 1-point increase in sleep duration score was associated with a decreased risk of CI (adjusted OR = 0.600; 95%CI = 0.434-0.830, p = 0.002). Conclusion: Poor sleep quality especially sleep disturbances, daytime dysfunction, and long sleep duration are associated with CI in middle age and older adult hemodialysis patients. Thus, the early detection of sleep disorders may help identify patients with cognitive impairment among hemodialysis individuals. Clinical Trial Registration: [Clinical Trials.gov], identifier [NCT03251573].

Atomic Oxygen-Resistant Polyimide Composite Films Containing Nanocaged Polyhedral Oligomeric Silsesquioxane Components in Matrix and Fillers.

For the development of spacecraft with long-servicing life in low earth orbit (LEO), high-temperature resistant polymer films with long-term atomic oxygen (AO) resistant features are highly desired. The relatively poor AO resistance of standard polyimide (PI) films greatly limited their applications in LEO spacecraft. In this work, we successfully prepared a series of novel AO resistant PI composite films containing nanocaged polyhedral oligomeric silsesquioxane (POSS) components in both the PI matrix and the fillers. The POSS-containing PI matrix film was prepared from a POSS-substituted aromatic diamine, N-[(heptaisobutyl-POSS)propyl]-3,5-diaminobenzamide (DABA-POSS) and a common aromatic diamine, 4,4'-oxydianline (ODA) and the aromatic dianhydride, pyromellitic dianhydride (PMDA) by a two-step thermal imidization procedure. The POSS-containing filler, trisilanolphenyl POSS (TSP-POSS) was added with the fixed proportion of 20 wt% in the final films. Incorporation of TSP-POSS additive apparently improved the thermal stability, but decreased the high-temperature dimensional stable nature of the PI composite films. The 5% weight loss temperature (T5%) of POSS-PI-20 with 20 wt% of DABA-POSS is 564 °C, and its coefficient of linear thermal expansion (CTE) is 81.0 × 10-6/K. The former is 16 °C lower and the latter was 20.0 × 10-6/K higher than those of the POSS-PI-10 film (T5% = 580 °C, CTE = 61.0 × 10-6/K), respectively. POSS components endowed the PI composite films excellent AO resistance and self-healing characteristics in AO environments. POSS-PI-30 exhibits the lowest AO erosion yield (Es) of 1.64 × 10-26 cm3/atom under AO exposure with a flux of 2.51 × 1021 atoms/cm2, which is more than two orders of magnitude lower than the referenced PI (PMDA-ODA) film. Inert silica or silicate passivation layers were detected on the surface of the PI composite films exposed to AO.

Molecular Relatedness of Salmonella enterica Typhimurium Isolates from Feces and an Infected Surgical Wound.

PURPOSE: Salmonella enterica serovar Typhimurium infection is common in foodborne diseases, but its isolation from surgical incisions is rare. Our aim in this study was to trace the transmission source of a surgical incision infected with S. Typhimurium in a Yunnan Province hospital patient and elucidate the underlying molecular mechanisms of antibiotic resistance. METHODS: Primers were designed to amplify the drug-resistance genes using polymerase chain reaction (PCR). Susceptibility to antibiotics was determined using Etest strips. Macrorestriction profiles were analyzed using pulsed-field gel electrophoresis (PFGE) and XbaI. The two isolates were characterized using agglutination tests and multilocus sequence typing (MLST). RESULTS: MLST analysis revealed that S. Typhimurium isolates SM043 and SM080 belonged to the same genotype, ST34, and PFGE revealed that SM043 and SM080 had high similarity. The isolates were both resistant to third-generation cephalosporins. SM043 harbored the antibiotic resistance genes blaCTX-M-15, blaTEM-1, qnrS-1, qnrB, and acc-3, whereas blaCTX-M-15, blaTEM-1, blaCMY-2, qnrS-1, and acc-3 were detected in SM080. CONCLUSION: The surgical incision infection by S. Typhimurium may have been hospital-acquired. Thus, it is critical to strengthen hospital sanitation by addressing hand hygiene and sterilization of the operational environment to avoid outbreaks of nosocomial Salmonella infections.

The validation of the Beijing version of the Montreal Cognitive Assessment in Chinese patients undergoing hemodialysis.

OBJECTIVE: Cognitive impairment is common among hemodialysis patient, but still lack adequate screening in clinical settings. The Montreal Cognitive Assessment (MoCA) is reportedly to be a sensitive screening tool for cognitive impairment, but its clinical value in patients undergoing hemodialysis is not well established. We aimed to validate the utility of the Beijing version of the MoCA (MoCA-BJ) for detecting cognitive impairment in comparison to a detailed neuropsychological battery as the gold standard. METHODS: We assessed 613 patients undergoing hemodialysis using the MoCA-BJ, the Mini-Mental State Examination (MMSE), and a comprehensive neuropsychological battery. Cognitive dysfunction was defined by the fifth version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). Spearman's correlation and linear regression were used to estimate the performance of the MoCA-BJ and MMSE in predicting cognitive impairment. A receiver operating characteristic (ROC) curve analysis was used to evaluate the utility of various cutoffs of the MoCA-BJ and MMSE for predicting cognitive impairment. RESULTS: Cognitive impairment was diagnosed in 80.91% (496/613), 75.69% (464/613), and 61.34% (376 /613) of the patients using the DSM-V, MoCA-BJ, and MMSE, respectively. Spearman's rank correlation analysis indicated that the MoCA-BJ was significantly correlated with the neuropsychological battery (rs = 0.639, p<0.001), whereas the MMSE had a weaker correlation with the battery. The area under the ROC curve for cognitive impairment diagnosis using the MoCA-BJ was 0.891 (95% confidence interval: 0.859-0.924) while using the MMSE was 0.823 (95% confidence interval: 0.786-0.860). The optimal MoCA-BJ cutoff score in discriminating patients with and without cognitive impairment was 24 points with a sensitivity of 0.877 and specificity of 0.752. CONCLUSION: The MoCA-BJ offers good sensitivity and specificity levels in detecting cognitive impairment in hemodialysis patients. These findings support the utility of the MoCA-BJ as a screening tool for cognitive impairment in Chinese patients undergoing hemodialysis.

Association of atrial fibrillation and clinical outcomes in adults with chronic kidney disease: A propensity score-matched analysis.

OBJECTIVE: Atrial fibrillation (AF) is associated with adverse outcomes in the general population, but its impact on patients with chronic kidney disease (CKD) remains unclear. In this study, we assessed the association between AF and risks of all-cause mortality and stroke in Chinese adults with CKD. METHODS: We enrolled adults aged 45 years or older with CKD (defined as an estimated glomerular filtration rate <60 mL/min per 1.73 m2 and/or proteinuria identified using the urine dipstick method) from the Kailuan study between 2008 and 2014. AF was identified by 12-lead electrocardiography or hospital discharge diagnostic codes. Mortality data were collected from the provincial vital statistics, and physician-diagnosed ischemic or hemorrhagic stroke was confirmed in the biennial interview. RESULTS: Among the 21587 CKD adults, 216 patients were identified with AF, the median follow-up duration was 5.21 years (5.69 ± 1.96 years); During follow-up, there were 70 cases of death, and 16 cases of ischemic stroke and 6 cases of hemorrhagic stroke in the participants with AF in comparison with 2572 cases of death and 656 cases of ischemic stroke and 184 cases of hemorrhagic stroke among the participants without AF. After adjustment for potential confounders, AF was associated with an 86% increase in the rate of death (hazard ratio [HR], 1.86; 95% confidence interval [CI], 1.33-2.59, P<0.001), a 104% (HR, 2.04; 95% CI, 1.09-3.83, P = 0.026) and 325% (HR, 4.25; 95% CI, 1.74-10.36, P = 0.001) increase in the rate of ischemic stroke and hemorrhagic stroke, respectively. These associations were still consistent and strong after propensity score-matched analysis. CONCLUSION: Our study shows that AF is independently associated with increased risk of all-cause mortality, ischemic and hemorrhagic stroke in Chinese CKD adults. Future studies are required to elucidate the physiological mechanisms underlying this association.

Preparation and Properties of Intrinsically Atomic-Oxygen Resistant Polyimide Films Containing Polyhedral Oligomeric Silsesquioxane (POSS) in the Side Chains.

The relatively poor atomic-oxygen (AO) resistance of the standard polyimide (PI) films greatly limits the wide applications in low earth orbit (LEO) environments. The introduction of polyhedral oligomeric silsesquioxane (POSS) units into the molecular structures of the PI films has been proven to be an effective procedure for enhancing the AO resistance of the PI films. In the current work, a series of POSS-substituted poly (pyromellitic anhydride-4,4'-oxydianiline) (PMDA-ODA) films (POSS-PI) with different POSS contents were synthesized via a POSS-containing diamine, N-[(heptaisobutyl-POSS)propyl]-3,5-diaminobenzamide (DABA-POSS). Subsequently, the effects of the molecular structures on the thermal, tensile, optical, and especially the AO-erosion behaviors of the POSS-PI films were investigated. The incorporation of the latent POSS substituents decreased the thermal stability and the high-temperature dimensional stability of the pristine PI-0 (PMDA-ODA) film. For instance, the PI-30 film with the DABA-POSS content of 30 wt% in the film exhibited a 5% weight loss temperature (T5%) of 512 °C and a coefficient of linear thermal expansion (CTE) of 54.6 × 10-6/K in the temperature range of 50-250 °C, respectively, which were all inferior to those of the PI-0 film (T5% = 574 °C; CTE = 28.9 × 10-6/K). In addition, the tensile properties of the POSS-containing PI films were also deteriorated, to some extent, due to the incorporation of the DABA-POSS components. The tensile strength (TS) of the POSS-PI films decreased with the order of PI-0 > PI-10 > PI-15 > PI-20 > PI-25 > PI-30, and so did the tensile modulus (TM) and the elongations at break (Eb). PI-30 showed the TS, TM, and Eb values of 75.0 MPa, 1.55 GPa, and 16.1%, respectively, which were all lower than those of the PI-0 film (TS = 131.0 MPa, TM = 1.88 GPa, Eb = 73.2%). Nevertheless, the incorporation of POSS components obviously increased the AO resistance of the PI films. All of the POSS-PI films survived from the AO exposure with the total fluence of 2.16 × 1021 atoms/cm2, while PI-0 was totally eroded under the same circumstance. The PI-30 film showed an AO erosion yield (Es) of 1.1 × 10-25 cm3/atom, which was approximately 3.67% of the PI-0 film (Es = 3.0 × 10-24 cm3/atom). Inert silica or silicate passivation layers were detected on the surface of the POSS-PI films after AO exposure, which efficiently prevented the further erosion of the under-layer materials.