Synthesis of N-doped and P-doped silicon quantum dots and their applications for tetracycline detection in the honey samples and antibacterial properties.

The abuse of tetracycline can lead to its residue in animal derived foods, posing many potential hazards to human health. Therefore, rapid and accurate detection of tetracycline is an important means to ensure food safety. Nitrogen doped and phosphorus doped silicon quantum dots (N-SiQDs, P-SiQDs) with remarkable optical stability were fabricated via a one-pot hydrothermal procedure in this study. Upon the excitation at 346 nm, N-SiQDs and P-SiQDs emitted fluorescence at 431 nm and 505 nm, respectively. Two SiQDs had the potential to serve as a probe for detecting low concentrations of tetracycline (TC), employing a mechanism of the static quenching effect. The calibration curves of N-SiQDs and P-SiQDs were linear within the range of 0-0.8 µM and 0-0.4 µM, the limits of detection were low as 5.35 × 10-4 µmol/L and 6.90 × 10-3 µmol/L, respectively. This method could be used successfully to detect TC in honey samples. Moreover, the remarkable antibacterial efficacy of two SiQDs could be attributed to the generation of a large number of intracellular reactive oxygen species. The SEM images showed that the structure of bacterial cell was disrupted and the surface became irregular when treated with both SiQDs. These properties enabled potential usage of SiQDs as excellent antibacterial material for different biomedical applications.

Economic impact of metagenomic next-generation sequencing versus traditional bacterial culture for postoperative central nervous system infections using a decision analysis mode: study protocol for a randomized controlled trial.

IMPORTANCE: Diagnosing and treating postoperative central nervous system infections (PCNSIs) remains challenging due to the low detection rate and time-consuming nature of traditional methods for identifying microorganisms in cerebrospinal fluid. Metagenomic next-generation sequencing (mNGS) technology provides a rapid and comprehensive understanding of microbial composition in PCNSIs by swiftly sequencing and analyzing the microbial genome. The current study aimed to assess the economic impact of using mNGS versus traditional bacterial culture-directed PCNSIs diagnosis and therapy in post-neurosurgical patients from Beijing Tiantan Hospital. mNGS is a relatively expensive test item, and whether it has the corresponding health-economic significance in the clinical application of diagnosing intracranial infection has not been studied clearly. Therefore, the investigators hope to explore the clinical application value of mNGS detection in PCNSIs after neurosurgery.

Logic Control of Directional Long-Range Resonance Energy Transfer On 2D DNA Nanosheet.

By arranging fluorophores in a directional way on a 2D DNA nanosheet that transfers energy from the initial donor to the acceptor through homogeneous Förster resonance energy transfer (homo-FRET), it is found that the photonic wires (PWs) based on cascade long-range resonance energy transfer (LrRET) up to 15.6 nm can be effectively achieved through the rational selection of the fluorophores and the adjustment of their position with different distance. Then, logic control of directional energy transfer is achieved with the blocking of the energy transfer pathway, making two tumor-associated microRNA (miRNA) inputs produce an obvious output with the association of tumor diagnosis only when they present simultaneously. This research provides a new thought for development of PWs on 2D DNA nanosheets and a smart application of LrRET-based DNA AND logic control of intracellular miRNA imaging and tumor cells recognition.

Depression, anxiety and health-related quality of life in paediatric intracranial germ cell tumor survivors.

BACKGROUND: Little is known about depression and anxiety among paediatric intracranial germ cell tumour (iGCT) survivors. We aimed to evaluate the risk factors associated with depression, anxiety and health-related quality of life (HRQoL) in paediatric iGCT survivors. METHODS: We recruited 200 iGCT patients (and their parents) from Beijing Tiantan Hospital and assessed their HRQoL using the Paediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales. The Children's Depression Inventory, Screen for Child Anxiety Related Emotional Disorders, and Symptom Checklist 90 were used to evaluate depression and anxiety. The results were analysed based on disease recurrence, tumour location and treatment strategies. RESULTS: Survivors with recurrent tumours had worse HRQoL scores than those with non-recurrent tumours. Patients with tumours involving both the suprasellar and basal ganglia regions had the worst HRQoL scores. A large proportion of survivors had depression or anxiety. Both depression and anxiety scores were highly correlated with the HRQoL emotional functioning scores. The parent proxy-reports (PPR) and child self-reports were highly correlated in all domains. CONCLUSIONS: This study demonstrated the clinical factors affecting paediatric iGCT survivors' depression, anxiety, and HRQoL. Therefore, psychological interventions should be implemented. It also suggests that the PedsQL PPR would be helpful for routine screening.

Relapse pattern and quality of life in patients with localized basal ganglia germinoma receiving focal radiotherapy, whole-brain radiotherapy, or craniospinal irradiation.

BACKGROUND AND PURPOSE: The optimal target volume in localized basal ganglia (BG) germinoma is still undetermined. Thus, based on the relapse pattern and health-related quality of life (HRQOL), we evaluated three target volumes. MATERIAL AND METHODS: The clinical data of 161 patients with localized BG germinoma were included in this retrospective study. Relapse status and relapse sites after treatment were explored. HRQOL was evaluated using the Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0) (≤15 years) and Short Form-36 (SF-36) (>15 years) questionnaires based on the patients' age at last follow-up. RESULTS: After a median follow-up duration of 83 months (range, 20-214 months), 19 patients experienced relapse, including 15, 4, and 0 patients in the focal radiotherapy (FR) (n = 35), whole-brain radiotherapy (WBRT) plus boost (n = 109), and craniospinal irradiation (CSI) plus boost (n = 17) groups, respectively. The 5-year disease-free survival rates were 74.3%, 97.2%, and 100%, respectively (p < 0.001). Among the 15 patients who relapsed after FR, 14 had positive radiological findings, including seven (50.0%) with lesions in the periventricular area and seven (50.0%) with frontal lobe lesions. Relapse in both these areas were significantly reduced by WBRT or CSI. HRQOL data were available for 69 patients, who generally scored low. Among 38 patients evaluated by SF-36, those receiving CSI had significantly lower mental component scores than those receiving WBRT (p = 0.027) or FR (p = 0.011). CONCLUSIONS: Considering both disease control and HRQOL, WBRT is the optimal target volume in our series. The relapse pattern identified in patients receiving FR is informative for further treatment volume optimization.

Behavior Disorder and Social Function Impairment in Children with Basal Ganglia Germ Cell Tumors.

PURPOSE: Basal ganglia intracranial germ cell tumors (iGCTs) can specifically destroy the basal ganglia network, leading to several cognitive, learning, behavioral, and social impairments. This study aimed to investigate the behavior and social disorders of patients with basal ganglia iGCTs. PATIENTS AND METHODS: We recruited 30 newly diagnosed iGCTs patients (and their parents) for the current study. The Child Behavior Checklist/6-18 was used to evaluate emotional and behavioral problems. The Conner's Parent Rating Scales was used to assess symptoms of hyperactivity/impulsivity and conduct problems. The health-related quality of life (HRQoL) was assessed using the Pediatric Quality of Life Inventory 4.0 Generic Core Scale. Performance status was assessed using the Lansky play-performance scale and Karnofsky performance scale. The effects of basal ganglia lesions on these scores were examined. RESULTS: Patients with basal ganglia iGCTs (n = 10) had more behavioral problems (attention problems, aggressive behavior, learning problems, hyperactivity index), social function impairment, anxiety/depression, and poorer HRQoL compared to patients with non-basal ganglia iGCTs (n = 20). There was no significant difference in the Lansky play-performance/Karnofsky performance scale scores. CONCLUSION: This study demonstrates the effects of basal ganglia lesions on behavioral and emotional outcomes, social functions, and HRQoL of patients with iGCTs. The results may help to understand the function of basal ganglia and provide evidence for the benefit of early psychological intervention to improve the treatment for this rare disease.

Piston error correction of sparse aperture systems using the metaheuristic stochastic parallel gradient descent algorithm.

The next generation of optical telescopes will provide high-resolution imaging of celestial objects by using the aperture synthesis technique. To preserve the quality of the image, fast corrections of the pistons among subapertures have to be applied, namely, the co-phasing of the array. The image-based co-phasing method via an optimization procedure has been newly developed. Despite simplicity and strong commonality, when dealing with large piston errors, this correction method is also faced with a problem in which the metric function easily falls into the local convergence, especially in the case of broadband imaging with many subapertures. In this study, an improved stochastic parallel gradient descent (SPGD) algorithm based on heuristic search is proposed for co-phasing, termed the metaheuristic SPGD algorithm. The heuristic research scheme assists the original SPGD algorithm in getting rid of local extrema. By iterations of this algorithm, the synthetic system can be co-phased without any additional instruments and operations. The effectiveness of the proposed algorithm is verified by means of simulation. Given the efficiency and superiority, it is expected that the method proposed in this study may find wide applications in multi-aperture imaging.

Comparison between Craniospinal Irradiation and Limited-Field Radiation in Patients with Non-metastatic Bifocal Germinoma.

PURPOSE: Whether craniospinal irradiation (CSI) could be replaced by limited-field radiation in non-metastatic bifocal germinoma remains controversial. We addressed the issue based on the data from our series and the literature. MATERIALS AND METHODS: Data from 49 patients diagnosed with non-metastatic bifocal germinoma at our hospital during the last 10 years were collected. The Pediatric Quality of Life Inventory 4.0 was used to evaluate health-related quality of life (HRQOL). Additionally, 81 patients identified from the literature were also analyzed independently. RESULTS: In our cohort, 34 patients had tumors in the sellar/suprasellar (S/SS) plus pineal gland (PG) regions and 15 in the S/SS plus basal ganglia/thalamus (BG/T) regions. The median follow-up period was 52 months (range, 10 to 134 months). Our survival analysis showed that patients treated with CSI (n=12) or whole-brain radiotherapy (WBRT; n=34) had comparable disease-free survival (DFS; p=0.540), but better DFS than those treated with focal radiotherapy (FR; n=3, p=0.016). All 81 patients from the literature had tumors in the S/SS+PG regions. Relapses were documented in 4/45 patients treated with FR, 2/17 treated with whole-ventricle irradiation, 0/4 treated with WBRT, and 1/15 treated with CSI. Survival analysis did not reveal DFS differences between the types of radiation field (p=0.785). HRQOL analysis (n=44) in our cohort found that, compared with S/SS+PG germinoma, patients with BG/T involvement had significantly lower scores in social and school domains. However, HRQOL difference between patients treated with CSI and those not treated with CSI was not significant. CONCLUSION: In patients with non-metastatic bifocal germinoma, it is rational that CSI could be replaced by limited-field radiation. HRQOL in patients with BG/T involvement was poorer.

The Role of Reactive Oxygen Species and Nitric Oxide in the Inhibition of Trichophyton rubrum Growth by HaCaT Cells.

Trichophyton rubrum (T. rubrum) is one of the most important agents of dermatophyte infection in humans. The aim of this experiment was to evaluate the effect of HaCaT cells on T. rubrum, investigate the responsible mechanism of action, and explore the role of reactive oxygen species (ROS) and nitric oxide (NO) in the inhibition of T. rubrum growth by HaCaT cells. The viability of fungi treated with HaCaT cells alone and with HaCaT cells combined with pretreatment with the NADPH oxidase inhibitor (DPI) or the nitric oxide synthase (NOS) inhibitor L-NMMA was determined by enumerating the colony-forming units. NOS, ROS, and NO levels were quantified using fluorescent probes. The levels of the NOS inhibitor asymmetric dimethylarginine (ADMA) were determined by enzyme-linked immunosorbent assay (ELISA). Micromorphology was observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition, fungal keratinase activity was assessed by measuring dye release from keratin azure. In vitro fungal viability, keratinase activity, and ADMA content decreased after HaCaT cell intervention, whereas the levels of ROS, NO, and NOS increased. The micromorphology was abnormal. Fungi pretreated with DPI and L-NMMA exhibited opposite effects. HaCaT cells inhibited the growth and pathogenicity of T. rubrum in vitro. A suggested mechanism is that ROS and NO play an important role in the inhibition of T. rubrum growth by HaCaT cells.

Inhibition of Trichophyton rubrum by 420-nm Intense Pulsed Light: In Vitro Activity and the Role of Nitric Oxide in Fungal Death.

Trichophyton rubrum is a common dermatophyte of the skin. The aim of this experiment was to explore the role of nitric oxide (NO) in the inhibition of T. rubrum growth induced by 420-nm intense pulsed light (IPL). This study found that nitric oxide synthase (NOS) and NO levels were increased, whereas asymmetric dimethylarginine (ADMA) level, keratinase activity, and fungal viability were decreased after IPL treatment compared with the control condition in vitro. Moreover, micromorphology was damaged by IPL treatment. Fungal viability was increased, and the damage to the fungal structure was reduced after pretreatment with an NOS inhibitor (L-NMMA) compared with IPL treatment alone. Compared with IPL alone, pretreatment with L-NMMA decreased NOS expression and NO level and increased keratinase activity. We found that 420-nm IPL treatment can inhibit the growth of T. rubrum by regulating NO in vitro.

Analysis of the Subdivision Errors of Photoelectric Angle Encoders and Improvement of the Tracking Precision of a Telescope Control System.

Photoelectric angle encoders, working as position sensors, have a great influence on the accuracy and stability of telescope control systems (TCS). In order to improve the tracking precision of TCS, a method based on subdivision error compensation for photoelectric angle encoders is proposed. First, a mathematical analysis of six types of subdivision errors (DC error, phase error, amplitude error, harmonic error, noise error, and quantization error) is presented, which is different from the previously used analysis based on the Lissajous figure method. In fact, we believe that a mathematical method is more efficient than the figure method for the expression of subdivision errors. Then, the distribution law and period length of each subdivision error are analyzed. Finally, an error compensation algorithm is presented. In a real TCS, the elevation jittering phenomenon occurs, which indicates that compensating for the amplitude error is necessary. A feed-forward loop is then introduced into the TCS, which is position loop- and velocity loop-closed, leading to a decrease of the tracking error by nearly 54.6%, from 2.31" to 1.05", with a leading speed of 0.25°/s, and by 40.5%, from 3.01" to 1.79", with a leading speed of 1°/s. This method can realize real-time compensation and improve the ability of TCS without any change of the hardware. In addition, independently of the environment and the kind of control strategy used, this method can also improve the tracking precision presumably because it compensates the measuring error inside the photoelectric angle encoder.

Determining the optimal parameters of 420-nm intense pulsed light on Trichophyton rubrum growth in vitro.

The effect of and the optimal parameters for intense pulsed light (IPL) with a 420-nm filter on an isolate of the fungus Trichophyton rubrum (T. rubrum) were examined in vitro. Colonies of T. rubrum were irradiated by using 420-nm IPL with various pulse numbers and energies. Colony areas were photographed and compared with those of untreated colonies to assess growth inhibition. Statistically significant inhibition of T. rubrum growth was detected in colonies treated with 12 pulses of greater than or equal to 12 J/cm2. The optimal parameters of 420-nm IPL were 12 pulses of 12 J/cm2. However, more in vitro and in vivo studies are necessary to investigate and explore this mechanism to determine whether IPL would have a potential use in the treatment of fungal infections of the skin.