Naked-Eye LAMP Assay of M. tuberculosis in Sputum by In Situ Au Nanoprobe Identification: For the In Vitro Diagnostics of Tuberculosis.

In spite of the development of diagnostic tests for Mycobacterium tuberculosis (M. tuberculosis), the etiological agent of tuberculosis, there has remained a gap between the established methods and an easily accessible diagnostic test, particularly in developing and resource-poor areas. By combining isothermal amplification of IS6110 as the target gene and recognition by DNA-functionalized Au nanoparticles (DNA-AuNPs), we develop a colorimetric LAMP assay for convenient in vitro diagnostics of tuberculosis with a quick (≤50 min) "yes" or "no" readout. The DNA-AuNPs not only tolerate the interference in the complex LAMP system but also afford in situ identification of the amplicon, allowing for colloidal dispersion via steric effect depending on DNA grafting density. The target-induced stabilization and red appearance of the DNA-AuNPs contrast with the occurrence of gray aggregates in a negative sample. Furthermore, the DNA-AuNPs demonstrate excellent performance after long-term (≥7 months) storage while preserving the unsacrificed sensitivity. The high specificity of the DNA-AuNPs is further demonstrated in the naked-eye LAMP assay of M. tuberculosis in patients' sputum samples. Given the rapidity, cost-effectiveness, and instrument-free characteristics, the naked-eye LAMP assay is particularly beneficial for tuberculosis diagnosis in urgent situations and resource-limited settings and can potentially expedite patient care and treatment initiation.

Association between Sleep Duration and Physical Fitness in Children Aged 3-6 Years: A Cross-Sectional Study from China.

Aim: To explore associations between sleep duration and physical fitness (PF) of children aged 3−6 years. Methods: This study investigated the sleep duration and PF data of children aged 3−6 years by stratified random sampling. The restricted cubic spline model and binary logistic regression analysis were mainly used for the empirical analysis of the correlation effect between sleep duration and PF. The final data had a total of 21,857 children, of which 11,245 (51.45%) were boys and 10,612 (48.55%) were girls. Results: The PF level of the children in this study showed a relatively positive level (pass rate = 93.6%), and 19.7% of them had abnormal sleep duration; the results of the restricted cubic spline showed an inverted U-shaped association between the level of PF and the risk of abnormal sleep duration (X2 = 28.13, p < 0.0001). The results of logistic regression analysis showed that children with abnormal sleep duration were more likely to have a low PF, body morphology and motor ability levels at an OR (95% CI) of 1.077 (1.023−1.133), 1.077 (1.016−1.142) and 1.035 (1.08−1.062), respectively. The results of the bias correlation analysis showed varying degrees of correlation between sleep duration and various components of children's PF. Conclusion: Insufficient or excessive amounts of sleep were significantly associated with PF in children, with abnormal sleep duration leading to reduced levels of PF and its components.

Associations between Fast-Food Restaurants Surrounding Kindergartens and Childhood Obesity: Evidence from China.

The prevalence of obesity among preschool children has risen dramatically due to the influx of Western fast food in China. In this study, we aimed to provide clear evidence on the associations between fast-food restaurants and childhood obesity. We collected and combined three unique cross-sectional datasets: physical fitness data, geographic information, and the financial data of each kindergarten. The two-stage least squares were used for empirical analyses. The final data including 75,730 children were from 785 kindergartens in 82 cities and 23 provinces in China in 2018. The mean age of participants was 4.94 ± 0.87; 34,249 (45.2%) females and 41,481 (54.8%) males. The number of fast-food restaurants within 1, 2, and 3 km radii had a significant and positive correlation with obesity, and this correlation decreased as the radius increased. Furthermore, the distance to the nearest fast-food restaurant had a significant and negative correlation with obesity. Western fast-food restaurants contributed more to obesity than the broader definition of fast-food restaurants. There was marked heterogeneity between urban and rural areas. Our findings documented that fast-food restaurants had a significant and positive association with childhood obesity, thus the restriction of fast-food restaurants surrounding kindergartens might be considered.

Chemically Fueled Plasmon Switching of Gold Nanorods by Single-Base Pairing of Surface-Grafted DNA.

The interactions between metal ions and biomolecules are crucial to various bioprocesses. Development of plasmon switching nanodevices that exploit these molecular interactions is of fundamental and technological interest. Here, we show plasmon switching based on rapid aggregation/dispersion of double-stranded DNA-modified gold nanorods (dsDNA-AuNRs) that exhibit colloidal behaviors depending on pairing/unpairing of the terminal bases. The dsDNA-AuNRs bearing a thymine-thymine (T-T) mismatch at the penultimate position undergo spontaneous non-cross-linking aggregation in the presence of Hg2+ due to T-Hg-T base pairing. Inversely, the subsequent addition of cysteine (Cys) gives rise to the removal of Hg2+ from the T-Hg-T base pair to reproduce the T-T mismatch, resulting in stable dispersion of the dsDNA-AuNRs. The chemical-responsive plasmon switch allows for the rapid and repeatable cycles at room temperature. The validity of the present method is further exemplified by developing another plasmon switch fueled by Ag+ and Cys by installing the Ag+-binding DNA sequence in the dsDNA-AuNR.

Characterization of pore structure in biologically functional poly(2-hydroxyethyl methacrylate)-poly(ethylene glycol) diacrylate (PHEMA-PEGDA).

A copolymer composed of poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(ethylene glycol) diacrylate (PEGDA) (PHEMA-PEGDA) is structurally versatile. Its structure can be adjusted using the following porogens: water, sucrose, and benzyl alcohol. Using phase separation technique, a variety of surface architectures and pore morphologies were developed by adjusting porogen volume and type. The water and sucrose porogens were effective in creating porous and cytocompatible PHEMA-PEGDA scaffolds. When coated with collagen, the PHEMA-PEGDA scaffolds accommodated cell migration. The PHEMA-PEGDA scaffolds are easy to produce, non-toxic, and mechanically stable enough to resist fracture during routine handling. The PHEMA-PEGDA structures presented in this study may expedite the current research effort to engineer tissue scaffolds that provide both structural stability and biological activity.

Engineering copolymeric artificial cornea with salt porogen.

Artificial corneas or keratoprostheses (KPros) are designed to replace diseased or damaged cornea. Although many synthetic KPros have been developed, current products are often inappropriate or inadequate for long term use due to ineffective host integration. This study presents an alternative approach of engineering a KPro that comprises a combination of poly (2-hydroxyethyl methacrylate) (PHEMA), poly (methyl methacrylate) (PMMA), and sodium chloride (NaCl) as porogen. Based on the core-skirt model for KPro, the porous outer portion of artificial cornea (skirt) was engineered by combining NaCl with HEMA and MMA monomers to promote tissue ingrowth from the host. The central optic (core) was designed to provide >85% light transmission in the visible wavelength range and securely attached to the skirt. Mechanical tensile data indicated that our KPro (referred to as salt porogen KPro) is mechanically stable to maintain its structure in the ocular environment and during implantation. Using human corneal fibroblasts (HCFs), we demonstrate that the cells grew into the pores of the skirt and proliferated, suggesting biointegration is adequately achieved. This novel PHEMA-PMMA copolymeric salt porogen KPro may offer a cornea replacement option that leads to minimal risk of corneal melting by permitting sufficient tissue ingrowth and mass transport.