| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Duan, Jiajia, et al.
(författare)
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Histological chorioamnionitis and pathological stages on very preterm infant outcomes
- 2024
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Ingår i: HISTOPATHOLOGY. - 0309-0167 .- 1365-2559.
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Histological chorioamnionitis (HCA) is a condition linked to preterm birth and neonatal infection and its relationship with various pathological stages in extremely preterm neonates, and with their associated short- and long-term consequences, remains a subject of research. This study investigated the connection between different pathological stages of HCA and both short-term complications and long-term outcomes in preterm infants born at or before 32 weeks of gestational age. Methods: Preterm infants born at <= 32 weeks of gestation who underwent placental pathology evaluation and were followed-up at 18-24 months of corrected age were included. Neonates were classified based on their exposure to HCA and were further subdivided into different groups according to maternal inflammatory responses (MIR) and fetal inflammatory responses (FIR) stages. We compared short-term complications during their hospital stay between the HCA-exposed and -unexposed groups and examined the influence of HCA stages on long-term outcomes. Results: The HCA group exhibited distinct characteristics such as higher rates of premature rupture of membranes > 18 h, reduced amniotic fluid, early-onset sepsis, bronchopulmonary dysplasia and intraventricular haemorrhage (IVH) grades III-IV (P < 0.05). The moderate-severe HCA group displayed lower gestational age, lower birth weight and higher incidence of IVH (grades III-IV) and preterm sepsis compared with the mild HCA group (P < 0.05). After adjusting for confounders, the MIR stages 2-3 group showed associations with cognitive impairment and cerebral palsy (P < 0.05), and the FIR stages 2-3 group also showed poor long-term outcomes and cognitive impairment (P < 0.05). Conclusions: Moderate-severe HCA was associated with increased early-onset sepsis, severe IVH and poor long-term outcomes, including cognitive impairment and cerebral palsy. Vigilant prevention strategies are warranted for severe HCA cases in order to mitigate poorer clinical outcomes.
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| 3. |
- Cheng, Ye, et al.
(författare)
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Genetic variants in the HLA region contribute to the risk of cerebral palsy
- 2024
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Ingår i: BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE. - 0925-4439 .- 1879-260X. ; 1870:3
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral palsy (CP) is the most common physical disability in childhood, and genetic factors play an important role in its pathogenesis. However, the genetic contributions remain incompletely elucidated. Here, we conducted a two-stage association study between 1090 CP cases and 1100 healthy controls after whole exome sequencing. The human leukocyte antigen (HLA) allelic predispositions were further analyzed in overall CP and subgroups using multivariate logistic regression. We found a strong signal in the HLA region on chromosome 6, where rs3131787 harbored the most significant association with CP (P = 2.05 x 10-14, OR = 2.22). In comparison to controls, the carrier frequencies of HLA-B*13:02 were significantly higher in children with CP (9.82 % in control vs 19.27 % in CP, P = 1.03 x 10-4, OR = 2.17). Furthermore, the effect of HLA-B*13:02 on increasing the risk of CP mainly existed in cryptogenic CP without exposure to premature birth, low birth weight, birth asphyxia, or periventricular leukomalacia. This study indicated a strong association of HLA variants with CP, which implied that immune dysregulation resulting from immunogenetic variants might underlie the pathogenesis of CP. Our findings provide genetic evidence that an immunomodulator may serve as a promising therapeutic intervention for patients with CP by reinstating the neuroinflammation hemostasis.
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| 4. |
- Gao, Qi, et al.
(författare)
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The Association Between Branched-Chain Amino Acid Concentrations and the Risk of Autism Spectrum Disorder in Preschool-Aged Children
- 2024
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Ingår i: MOLECULAR NEUROBIOLOGY. - 0893-7648 .- 1559-1182.
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have linked branched-chain amino acid (BCAA) metabolism disorders with autism spectrum disorder (ASD), but the results have been inconsistent. The purpose of this study was to explore the association between BCAA concentrations and the risk of ASD. A total of 313 participants were recruited from two tertiary referral hospitals from May 2018 to July 2021. Concentrations of BCAAs in dried blood spots were analyzed using liquid chromatography-tandem mass spectrometry-based analysis. Multivariate analyses and restricted cubic spline models were used to identify the association between BCAAs and the risk of ASD, and a nomogram was developed by using multivariate logistic regression and the risk was determined by receiver operating characteristic curve analysis and calibration curve analysis. Concentrations of total BCAA, valine, and leucine/isoleucine were higher in the ASD group, and all of them were positively and non-linearly associated with the risk of ASD even after adjusting for potential confounding factors such as age, gender, body mass index, and concentrations of BCAAs (P < 0.05). The nomogram integrating total BCAA and valine showed a good discriminant AUC value of 0.756 (95% CI 0.676-0.835). The model could yield net benefits across a reasonable range of risk thresholds. In the stratified analysis, the diagnostic ability of the model was more pronounced in children older than 3 years. We provide evidence that increased levels of BCAAs are associated with the risk of ASD, and the nomogram model of BCAAs presented here can serve as a marker for the early diagnosis of ASD.
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| 5. |
- GUAN, WEN, et al.
(författare)
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Frequency tuning behaviour of terahertz quantum cascade lasers revealed by a laser beating scheme
- 2021
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Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 29:14, s. 21269-21279
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Tidskriftsartikel (refereegranskat)abstract
- In the terahertz frequency range, the commercialized spectrometers, such as the Fourier transform infrared and time domain spectroscopies, show spectral resolutions between a hundred megahertz and a few gigahertz. Therefore, the high precision frequency tuning ability of terahertz lasers cannot be revealed by these traditional spectroscopic techniques. In this work, we demonstrate a laser beating experiment to investigate the frequency tuning characteristics of terahertz quantum cascade lasers (QCLs) induced by temperature or drive current. Two terahertz QCLs emitting around 4.2 THz with identical active regions and laser dimensions (150 μm wide and 6 mm long) are employed in the beating experiment. One laser is operated as a frequency comb and the other one is driven at a lower current to emit a single frequency. To measure the beating signal, the single mode laser is used as a fast detector (laser self-detection). The laser beating scheme allows the high precision measurement of the frequency tuning of the single mode terahertz QCL. The experimental results show that in the investigated temperature and current ranges, the frequency tuning coefficients of the terahertz QCL are 6.1 MHz/0.1 K (temperature tuning) and 2.7 MHz/mA (current tuning) that cannot be revealed by a traditional terahertz spectrometer. The laser beating technique shows potential abilities in high precision linewidth measurements of narrow absorption lines and multi-channel terahertz communications.
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| 6. |
- Li, Kenan, et al.
(författare)
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Sex differences in neonatal mouse brain injury after hypoxia-ischemia and adaptaquin treatment
- 2019
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Ingår i: Journal of Neurochemistry. - : Wiley. - 0022-3042 .- 1471-4159. ; 150:6, s. 759-775
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxia-inducible factor prolyl 4-hydroxylases (HIF-PHDs) are important targets against oxidative stress. We hypothesized that inhibition HIF-PHD by adaptaquin reduces hypoxic-ischemic brain injury in a neonatal mouse model. The pups were treated intraperitoneally immediately with adaptaquin after hypoxia-ischemia (HI) and then every 24 h for 3 days. Adaptaquin treatment reduced infarction volume by an average of 26.3% at 72 h after HI compared to vehicle alone, and this reduction was more pronounced in males (34.8%) than in females (11.7%). The protection was also more pronounced in the cortex. The subcortical white matter injury as measured by tissue loss volume was reduced by 24.4% in the adaptaquin treatment group, and this reduction was also more pronounced in males (28.4%) than in females (18.9%). Cell death was decreased in the cortex as indicated by Fluoro-Jade labeling, but not in other brain regions with adaptaquin treatment. Furthermore, in the brain injury area, adaptaquin did not alter the number of cells positive for caspase-3 activation or translocation of apoptosis-inducing factor to the nuclei. Adaptaquin treatment increased glutathione peroxidase 4 mRNA expression in the cortex but had no impact on 3-nitrotyrosine, 8-hydroxy-2 deoxyguanosine, or malondialdehyde production. Hif1 alpha mRNA expression increased after HI, and adaptaquin treatment also stimulated Hif1 alpha mRNA expression, which was also more pronounced in males than in females. However, nuclear translocation of HIF1 alpha protein was decreased after HI, and adaptaquin treatment had no influence on HIF1 alpha expression in the nucleus. These findings demonstrate that adaptaquin treatment is neuroprotective, but the potential mechanisms need further investigation. Open Science Badges This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at .
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| 7. |
- Li, Tao, et al.
(författare)
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AIF Overexpression Aggravates Oxidative Stress in Neonatal Male Mice After Hypoxia-Ischemia Injury
- 2022
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Ingår i: Molecular Neurobiology. - : Springer Science and Business Media LLC. - 0893-7648 .- 1559-1182. ; 59:11, s. 6613-6631
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Tidskriftsartikel (refereegranskat)abstract
- There are sex differences in the severity, mechanisms, and outcomes of neonatal hypoxia-ischemia (HI) brain injury, and apoptosis-inducing factor (AIF) may play a critical role in this discrepancy. Based on previous findings that AIF over-expression aggravates neonatal HI brain injury, we further investigated potential sex differences in the severity and molecular mechanisms underlying the injury using mice that overexpress AIF from homozygous transgenes. We found that the male sex significantly aggravated AIF-driven brain damage, as indicated by the injury volume in the gray matter (2.25 times greater in males) and by the lost volume of subcortical white matter (1.71 greater in males) after HI. As compared to females, male mice exhibited more severe brain injury, correlating with reduced antioxidant capacities, more pronounced protein carbonylation and nitration, and increased neuronal cell death. Under physiological conditions (without HI), the doublecortin-positive area in the dentate gyrus of females was 1.15 times larger than in males, indicating that AIF upregulation effectively promoted neurogenesis in females in the long term. We also found that AIF stimulated carbohydrate metabolism in young males. Altogether, these findings corroborate earlier studies and further demonstrate that AIF is involved in oxidative stress, which contributes to the sex-specific differences observed in neonatal HI brain injury.
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| 8. |
- Li, Tao, et al.
(författare)
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Overexpression of apoptosis inducing factor aggravates hypoxic-ischemic brain injury in neonatal mice
- 2020
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Ingår i: Cell death & disease. - : Springer Science and Business Media LLC. - 2041-4889. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Apoptosis inducing factor (AIF) has been shown to be a major contributor to neuron loss in the immature brain after hypoxia-ischemia (HI). Indeed, mice bearing a hypomorphic mutation causing reduced AIF expression are protected against neonatal HI. To further investigate the possible molecular mechanisms of this neuroprotection, we generated an AIF knock-in mouse by introduction of a latent transgene coding for flagged AIF protein into the Rosa26 locus, followed by its conditional activation by a ubiquitously expressed Cre recombinase. Such AIF transgenic mice overexpress the pro-apoptotic splice variant of AIF (AIF1) at both the mRNA (5.9 times higher) and protein level (2.4 times higher), but not the brain-specific AIF splice-isoform (AIF2). Excessive AIF did not have any apparent effects on the phenotype or physiological functions of the mice. However, brain injury (both gray and white matter) after neonatal HI was exacerbated in mice overexpressing AIF, coupled to enhanced translocation of mitochondrial AIF to the nucleus as well as enhanced caspase-3 activation in some brain regions, as indicated by immunohistochemistry. Altogether, these findings corroborate earlier studies demonstrating that AIF plays a causal role in neonatal HI brain injury.
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| 9. |
- Li, Yiran, et al.
(författare)
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Photoinduced Radical Emission in a Coassembly System
- 2021
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Ingår i: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 60:44, s. 23842-23848
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Tidskriftsartikel (refereegranskat)abstract
- Developing radical emission at ambient conditions is a challenging task since radical species are unstable in air. In the present work, we overcome this challenge by coassembling a series of tricarbonyl-substituted benzene molecules with polyvinyl alcohol (PVA). The strong hydrogen bonds between the guest dopants and the PVA host matrix protect the free radicals of carbonyl compounds after light irradiation, leading to strong solid state free radical emission. Changing temperature and peripheral functional groups of the tricarbonyl-substituted benzenes can influence the intensity of the radical emission. Quantum-chemical calculations predict that such free radical fluorescence originates from anti-Kasha D-2 -> D-0 vertical emission by the anion radicals. The photoinduced radical emission by the tricarbonyl-substituted benzenes was successfully utilized for information encryption application.
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| 10. |
- Ning, Rui, et al.
(författare)
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Assessing progression limits in different grades of keratoconus from a novel perspective : precision of measurements of the corneal epithelium
- 2024
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Ingår i: Eye and Vision. - 2326-0254. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: To assess repeatability and reproducibility of corneal epithelium thickness (ET) measured by a spectral-domain optical coherence tomographer (SD-OCT)/Placido topographer (MS-39, CSO, Florence, Italy) in keratoconus (KC) population at different stages, as well as to determine the progression limits for evaluating KC progression. Methods: A total of 149 eyes were enrolled in this study, with 29 eyes in the forme fruste keratoconus (FFKC) group, 34 eyes in the mild KC group, 40 eyes in the moderate KC group, and 46 eyes in the severe KC group. Employing the within-subject standard deviation (Sw), test-retest variability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) to evaluate intraoperator repeatability and interoperator reproducibility. Results: The repeatability and reproducibility of MS-39 in patients with KC were acceptable, according to ICC values ranging from 0.732 to 0.954. However, patients with more severe KC and progressive peripheralization of the measurement points had higher TRTs but a thinning trend. The current study tended to set the cut-off values of mild KC, moderate KC, and severe KC to 4.9 µm, 5.2 µm, and 7.4 µm for thinnest epithelium thickness (TET). When differences between follow-ups are higher than those values, progression of the disease is possible. As for center epithelium thickness (CET), cut-off values for mild KC, moderate KC, and severe KC should be 2.8 µm, 4.4 µm, and 5.3 µm. This might be useful in the follow-up and diagnosis of keratoconus. Conclusions: This study demonstrated that the precision of MS-39 was reduced in measuring more severe KC patients and more peripheral corneal points. In determining disease progression, values should be differentiated between disease-related real changes and measurement inaccuracies. Due to the large difference in ET measured by MS-39 between various stages of disease progression, it is necessary to accurately grade KC patients to avoid errors in KC clinical decision-making.
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