Optimisation of monoenergetic images to reduce banding artifacts in the lower cervical spine using dual-layer spectral computed tomography: a retrospective study

AIM

To investigate the application value of dual-layer detector computed tomography (CT) single-energy spectral images for reducing artefacts in the lower cervical spine.

MATERIALS AND METHODS

Sixty-three patients who underwent neck examination using spectral CT between March 2022 and January 2023 were selected as the participants. Conventional mixed-energy images and spectral imaging data at 40-200 KeV were obtained from the spectral CT scans. The standard deviation (SD), signal-to-noise ratio (SNR), |CTdifference| (the difference in CT value between the C6-7 and C3-4 artefact regions), and contrast-to-noise ratio (CNR) of the C6-7 spinal canal were measured. The image quality of the artefact region in the conventional and single images were compared.

RESULTS

The SDintervertebral disc value was highest in the single-level 40 KeV images and lowest in the 120 KeV images (P<0.05). The SNR was lowest in the 40 KeV images (2.07 ± 2.74) and highest in the 120 KeV images (6.20 ± 5.26) (P<0.05). The CTdifference was highest in the 40 KeV images and lowest in the 120 KeV images (108.38 vs. 10.63 ± 8.58). The subjective image quality scores were lowest in the 40 KeV images and highest in the 120 KeV images.

CONCLUSION

Our findings suggest that single-energy 120 KeV images may offer benefits such as low SDintervertebral disc, elevated SNR, higher CNR, and improved image quality.

Evidence for particle acceleration approaching PeV energies in the W51 complex

The γ-ray emission from the W51 complex is widely acknowledged to be attributed to the interaction between the cosmic rays (CRs) accelerated by the shock of supernova remnant (SNR) W51C and the dense molecular clouds in the adjacent star-forming region, W51B. However, the maximum acceleration capability of W51C for CRs remains elusive. Based on observations conducted with the Large High Altitude Air Shower Observatory (LHAASO), we report a significant detection of γ rays emanating from the W51 complex, with energies from 2 to 200 TeV. The LHAASO measurements, for the first time, extend the γ-ray emission from the W51 complex beyond 100 TeV and reveal a significant spectrum bending at tens of TeV. By combining the "π0-decay bump" featured data from Fermi-LAT, the broadband γ-ray spectrum of the W51 region can be well-characterized by a simple pp-collision model. The observed spectral bending feature suggests an exponential cutoff at ∼400 TeV or a power-law break at ∼200 TeV in the CR proton spectrum, most likely providing the first evidence of SNRs serving as CR accelerators approaching the PeV regime. Additionally, two young star clusters within W51B could also be theoretically viable to produce the most energetic γ rays observed by LHAASO. Our findings strongly support the presence of extreme CR accelerators within the W51 complex and provide new insights into the origin of Galactic CRs.

Stringent Tests of Lorentz Invariance Violation from LHAASO Observations of GRB 221009A

On 9 October 2022, the Large High Altitude Air Shower Observatory (LHAASO) reported the observation of the very early TeV afterglow of the brightest-of-all-time gamma-ray burst 221009A, recording the highest photon statistics in the TeV band ever obtained from a gamma-ray burst. We use this unique observation to place stringent constraints on the energy dependence of the speed of light in vacuum, a manifestation of Lorentz invariance violation (LIV) predicted by some quantum gravity (QG) theories. Our results show that the 95% confidence level lower limits on the QG energy scales are E_{QG,1}>10 times the Planck energy E_{Pl} for the linear LIV effect, and E_{QG,2}>6×10^{-8}E_{Pl} for the quadratic LIV effect. Our limits on the quadratic LIV case improve previous best bounds by factors of 5-7.

Constraints on Ultraheavy Dark Matter Properties from Dwarf Spheroidal Galaxies with LHAASO Observations

In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible γ rays by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of the LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter that have low fluxes of astrophysical γ-ray background while having large amount of dark matter. By analyzing more than 700 days of observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultraheavy dark matter annihilation cross section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived.

[Effect of preoperative oral ibuprofen on postoperative pain after dental implantation: a randomized controlled trial]

Objective: To evaluate the effect of preemptive analgesia with ibuprofen on postoperative pain following single posterior tooth implantation, aiming to provide a clinical reference for its application. Methods: A multicenter, randomized, double-blind, placebo-controlled parallel-group trial was conducted. A total of 82 participants were included in the trial, meeting the eligibility criteria from April 2022 to April 2024 at the Capital Medical University School of Stomatology (40 cases), Beijing TianTan Hospital, Capital Medical University (22 cases), Beijing Chao-Yang Hospital, Capital Medical University (20 cases). Participants were randomly assigned in a 1∶1 ratio to either the ibuprofen group or the control group, with each group comprising 41 individuals. Participants in the ibuprofen group received 300 mg of sustained-release ibuprofen capsules orally 15 min before surgery, while the control group received a placebo. Both groups received the same postoperative analgesic regimen for 3 days. Pain scores were assessed using the Numerical rating scale (NRS) at 30 min, 4 h, 6 h, 8 h, 24 h, 48 h, and 72 h postoperatively, and the additional use of analgesic medication was recorded from days 4 to 6 postoperatively. Results: A total of 82 participants were initially enrolled in the study, with 7 dropouts (4 from the control group and 3 from the ibuprofen group), resulting in 75 participants (37 in the control group and 38 in the ibuprofen group) completing the trial. There were no reports of adverse events such as nausea or vomiting among the participants. The ibuprofen group exhibited significantly lower pain scores at 4 h, 6 h and 8 h [1.0 (0.0, 2.0), 1.0 (0.0, 2.0), 1.5 (0.0, 3.0) ] postoperatively compared to the control group 4 h, 6 h and 8 h [2.0 (1.0, 3.0), 3.0 (1.5, 4.0), 2.0 (1.0, 4.0)] (Z=-1.99, P=0.047; Z=-3.01, P=0.003; Z=2.10, P=0.036). The proportions of patients requiring additional analgesic medication between days 4 and 6 post-surgery were 18.4% (7/38) in the ibuprofen group and 27.0% (10/37) in the control group, with no significant difference (χ2=0.79, P=0.373). The median additional medication usage postoperatively was [0.0 (0.0, 0.0) pills] in the ibuprofen group and [0.0 (0.0, 1.0) pills] in the control group, with no significant difference (Z=-0.78, P=0.439). Conclusions: Preemptive analgesia with ibuprofen effectively reduces postoperative pain following tooth implantation, representing a safe and effective perioperative pain management strategy.

Large extracellular vesicles from induced pluripotent stem cell-marrow stem cells enhance limb angiogenesis via ERK/MAPK

Aim: This study aims to investigate the effects of large extracellular vesicles (EVs) induced by pluripotent stem cell-derived mesenchymal stem cells on lower limb ischemic disease and explore its potential mechanisms. Materials & methods: The pathology of muscles was accessed by H&E staining and immunofluorescence staining. In vitro, we conducted wound-healing assay, tube formation assay, RT qPCR, ELISA, RNA sequencing and proteomic analysis. Results: iMSCs-lEVs alleviated the injury of ischemic lower limb and promoted the recovery of lower limb function. In vitro, iMSCs-lEVs promoted the proliferation, migration, and angiogenesis of HMEC-1 cells by regulating the ERK/MAPK signing pathway. Conclusion: This study demonstrated that iMSCs-lEVs promoted endothelial cell angiogenesis via the ERK/MAPK signaling pathway, thereby improving function after lower limb ischemic injury.

Novel data interpretation method for DIII-D divertor retarding field energy analyzer with 3-D particle-in-cell simulations

A novel data interpretation process that utilizes comprehensive particle-in-cell (PIC) simulations is developed for the new retarding field energy analyzer (RFEA) currently being constructed at DIII-D for the lower divertor using the Divertor Material Evaluation System. This probe is expected to survive a heat load of up to 100 MW/m2 for up to 5 s and reliably measure the main ion temperature (Ti) on the divertor target ranging from 10 to 200 eV. These extreme conditions posed significant engineering limitations on the probe geometry, thus extensive validation work has been performed. The conventional fitting method for the RFEA I-V characteristics is based on a simplified 1-D model without considering the ion space charge inside the probe cavity and may not be sufficient for probes designed for the DIII-D divertor environment. In this article, a more realistic description of the particle propagation process within the RFEA cavity is achieved by including both 3-D geometric effects and ion space charge in the PIC simulations, and the capability to reconstruct the ion energy distribution functions is demonstrated with reasonable consistency.

[Interpretation of Chinese guideline for the clinical management of patients with unruptured intracranial aneurysms (2024)]

With the popularization of cerebrovascular imaging technology, the clinical detection rate of unruptured intracranial aneurysm (UIA) is increasing. UIA has a low risk of rupture, but once ruptured, it can seriously affect human health. The treatment of UIA is highly controversial and has attracted widespread clinical attention. The Society of Neurosurgery of the Chinese Medical Association, the Society of Cerebrovascular Surgery of the Chinese Stroke Association, the National Center for Neurological Diseases, and the National Center for Clinical Research on Neurological Diseases jointly formulate "Chinese guideline for the clinical management of patients with unruptured intracranial aneurysm management (2024)", which adopts a modular format, highlighting management recommendations and indicating current research deficiencies and future research directions. It provides comprehensive clinical management recommendations on UIA epidemiology, population screening, clinical imaging and diagnosis, rupture risk assessment, treatment decisions and choices, postoperative follow-up, and long-term management. The evidence sources are divided into the Chinese population and other populations, which helps guide clinical practice in China.

[Semiparametric analysis of nonparametric proportional hazards models with mixed dependent censored data]

OBJECTIVE

To construct a nonparametric proportional hazards (PH) model for mixed informative interval-censored failure time data for predicting the risks in heart transplantation surgeries.

METHODS

Based on the complexity of mixed informative interval-censored failure time data, we considered the interdependent relationship between failure time process and observation time process, constructed a nonparametric proportional hazards (PH) model to describe the nonlinear relationship between the risk factors and heart transplant surgery risks and proposed a two-step sieve estimation maximum likelihood algorithm. An estimation equation was established to estimate frailty variables using the observation process model. Ⅰ-spline and B-spline were used to approximate the unknown baseline hazard function and nonparametric function, respectively, to obtain the working likelihood function in the sieve space. The partial derivative of the model parameters was used to obtain the scoring equation. The maximum likelihood estimation of the parameters was obtained by solving the scoring equation, and a function curve of the impact of risk factors on the risk of heart transplantation surgery was drawn.

RESULTS

Simulation experiment suggested that the estimated values obtained by the proposed method were consistent and asymptotically effective under various settings with good fitting effects. Analysis of heart transplant surgery data showed that the donor's age had a positive linear relationship with the surgical risk. The impact of the recipient's age at disease onset increased at first and then stabilized, but increased against at an older age. The donor-recipient age difference had a positive linear relationship with the surgical risk of heart transplantation.

CONCLUSION

The nonparametric PH model established in this study can be used for predicting the risks in heart transplantation surgery and exploring the functional relationship between the surgery risks and the risk factors.

Application of deep learning in radiation therapy for cancer

In recent years, with the development of artificial intelligence, deep learning has been gradually applied to clinical treatment and research. It has also found its way into the applications in radiotherapy, a crucial method for cancer treatment. This study summarizes the commonly used and latest deep learning algorithms (including transformer, and diffusion models), introduces the workflow of different radiotherapy, and illustrates the application of different algorithms in different radiotherapy modules, as well as the defects and challenges of deep learning in the field of radiotherapy, so as to provide some help for the development of automatic radiotherapy for cancer.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

[Effect of preemptive analgesia with ibuprofen on postoperative pain after mandibular third molar extraction: a randomized controlled trial]

Objective: To evaluate the impact of preemptive analgesia with ibuprofen on postoperative pain following the extraction of impacted mandibular third molars in a Chinese population, aiming to provide a clinical reference for its application. Methods: This multicenter, randomized, double-blind, placebo-controlled parallel-group trial was conducted from April 2022 to October 2023 at the Capital Medical University School of Stomatology (40 cases), Beijing TianTan Hospital, Capital Medical University (22 cases), and Beijing Chao-Yang Hospital, Capital Medical University (20 cases). It included 82 patients with impacted mandibular third molars, with 41 in the ibuprofen group and 41 in the control group. Participants in the ibuprofen group received 300 mg of sustained-release ibuprofen capsules orally 15 min before surgery, while the control group received a placebo. Both groups were instructed to take sustained-release ibuprofen capsules as planned for 3 days post-surgery. Pain intensity was measured using the numerical rating scale at 30 min, 4 h, 6 h, 8 h, 24 h, 48 h, and 72 h after surgery, and the use of additional analgesic medication was recorded during days 4 to 6 postoperatively. Results: All 82 patients completed the study according to the protocol. No adverse events such as nausea, vomiting, or allergies were reported in either group during the trial. The ibuprofen group exhibited significantly lower pain scores at 4 h [2.0 (1.0, 4.0) vs. 4.0 (3.0, 5.0)] (Z=-3.73, P<0.001), 6 h [2.0 (1.0, 4.0) vs. 5.0(2.5, 6.0)] (Z=-3.38, P<0.001), and 8 h [2.0 (1.0, 4.0) vs. 5.0 (2.0, 6.0)] (Z=-2.11, P=0.035) postoperatively compared to the control group. There were no statistically significant differences in pain scores between the groups at 30 min, 24 h, 48 h, and 72 h postoperatively (P>0.05). Additionally, 11 out of 41 patients (26.8%) in the ibuprofen group and 23 out of 41 patients (56.1%) in the control group required extra analgesic medication between days 4 and 6 post-surgery, with the ibuprofen group taking significantly fewer additional pills [0.0 (0.0, 1.0) vs. 1.0 (0.0, 3.0)] (Z=-2.81, P=0.005). Conclusions: A pain management regimen involving 300 mg of oral sustained-release ibuprofen capsules administered 15 minutes before surgery and continued for 3 d postoperatively effectively reduces pain levels and the total amount of analgesic medication used after the extraction of impacted mandibular third molars. Considering its efficacy, safety, and cost-effectiveness, ibuprofen is recommended as a first-line drug for perioperative pain management, enhancing patient comfort during diagnosis and treatment in a feasible manner.

An ultrahigh-energy γ-ray bubble powered by a super PeVatron

We report the detection of a γ-ray bubble spanning at least 100deg2 in ultra-high energy (UHE) up to a few PeV in the direction of the star-forming region Cygnus X, implying the presence super PeVatron(s) accelerating protons to at least 10 PeV. A log-parabola form with the photon index Γ(E)=(2.71±0.02)+(0.11±0.02)×log10(E/10TeV) is found fitting the gamma-ray energy spectrum of the bubble well. UHE sources, "hot spots" correlated with very massive molecular clouds, and a quasi-spherical amorphous γ-ray emitter with a sharp central brightening are observed in the bubble. In the core of ∼0.5°, spatially associating with a region containing massive OB association (Cygnus OB2) and a microquasar (Cygnus X-3), as well as previously reported multi-TeV sources, an enhanced concentration of UHE γ-rays is observed with 2 photons at energies above 1 PeV. The general feature of the bubble, the morphology, and the energy spectrum, are reasonably reproduced by the assumption of a particle accelerator in the core, continuously injecting protons into the ambient medium.

The Effects of Different Exercise Interventions on Patients with Subjective Cognitive Decline: A Systematic Review and Network Meta-Analysis

BACKGROUND AND OBJECTIVE

Exercise is a promising non-pharmacological therapy for subjective cognitive decline, but it is unclear which type of exercise is most effective. The objective was to assess the comparative effects and ranks of all exercise-based interventions on cognitive function in patients with subjective cognitive decline (SCD).

METHOD

In this network meta-analysis, Online databases for Web of Science, PubMed, Embase, Medline, Cochrane Library and PsycINFO were searched from inception to April 30, 2023. The included studies are randomized controlled trials assessing the efficacy of exercise interventions for individuals with SCD. The primary outcome measure is memory, while secondary outcome measures encompass executive function, attention, verbal fluency, and global cognitive function. Represented using Standardized Mean Differences (SMDs) along with their 95% Confidence Intervals (CIs). Bias assessment was conducted in accordance with the 'Cochrane Risk of Bias Assessment Tool, 2nd Edition' (RoB 2). Pairwise meta-analysis was carried out using the 'meta-analysis' module within STATA 14.0, and network meta-analysis was performed using the 'mvmeta' and 'network' packages available in STATA 14.0. Registration number CRD42023289687.

RESULT

This study included a total of 11 randomized controlled trials, encompassing 1,166 patients. Mind-body exercise was found to be efficacious in enhancing or sustaining memory (SMD: 0.58, 95%CI: 0.06 ~ 1.10) and executive function (SMD: 0.41, 95%CI: 0.09 ~ 0.73) in individuals with subjective cognitive decline. Furthermore, mind-body exercise exhibited the highest probability of being the most effective measures for improving or preventing the decline in memory (surface under cumulative ranking curve (SUCRA) value: 90.4) and executive function (SUCRA value: 91.8). The second-ranked moderate-intensity aerobic exercise has also shown a positive effect on the improvement of executive function in patients with subjective cognitive decline (SMD: 0.23, 95%CI: 0.03 ~ 0.43, SUCRA value: 68.2). However, we did not observe a significant effectiveness of exercise interventions on verbal fluency, attention, and overall cognitive function in subjective cognitive decline.

CONCLUSION

Mind-body exercise may potentially be the optimal strategies for enhancing memory and executive function in individuals with subjective cognitive decline. Additionally, moderate-intensity aerobic exercise has shown a modest positive effect on executive function in subjective cognitive decline. When resources permit, practical application of these findings may be considered. Nevertheless, further support for the conclusions of this study is warranted through larger sample sizes and well-designed multicenter trials.

[Clinical and genetic analysis of tyrosine hydroxylase deficiency of six cases]

The clinical and molecular genetic data of 6 patients with genetically confirmed tyrosine hydroxylase deficiency(THD) diagnosed in Department of Neurology, Qilu Hospital of Shandong University from March 2017 to February 2022 were retrospectively collected and analyzed. The 6 patients were from 5 families. Among them, 5 patients had persistent or paroxysmal abnormal walking posture, 4 patients had dystonia of head and face, including spasm of perioral and oculopharyngeal muscles, hyperactivity, and binocular upvision, 4 patients showed obvious morning light and evening heavy phenomenon, 2 patients had postural tremor of limbs, 2 patients had psychomotor retardation from childhood, 1 patient only had limb and cervical muscle weakness, 1 patient had epileptic seizures. Of the 6 patients, only 1 was adult-onset, and the rest were child-onset. Four patients had good response to low-dose dopa preparation, 2 patients from the same family had poor response to dopamine treatment, requiring extremely low dose initiation and multi-frequency titration treatment. However, the long-term treatment effect was poor with obvious abnormalities. Gene testing of 5 families revealed 8 mutations in the TH gene, with c.698G>A (p.R233H) being the hot spot mutation site. The clinical manifestations of THD are complex. Besides paroxysmal or persistent dystonia, it can also be accompanied by eye movement crisis, muscle weakness, epilepsy, and delayed mental and motor development. Most patients respond well to low-dose dopamine preparations, but a small number of patients require titration treatment with extremely low-dose dopamine preparations, and the long-term effect is not satisfactory.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

Fibulin-1 Regulates Initiation of Successional Dental Lamina

In humans, teeth are replaced only once, and the successional dental lamina (SDL) of the permanent tooth is maintained in a quiescent state until adolescence. Recently, we showed that biomechanical stress generated by the rapid growth of the deciduous tooth inhibits SDL development via integrin β1-RUNX2 signaling at embryonic day 60 (E60) in miniature pigs. However, the mechanism by which RUNX2 regulates SDL initiation within the SDL stem cell niche remains unclear. In the current study, we transcriptionally profiled single cells from SDL and surrounding mesenchyme at E60 and identified the landscape of cellular heterogeneity. We then identified a specific fibroblast subtype in the dental follicle mesenchyme between the deciduous tooth and the SDL of the permanent tooth (DFDP), which constitutes the inner part of the niche (deciduous tooth side). Compared with traditional dental follicle cells, the specific expression profile of DFDP was identified and found to be related to biomechanical stress. Subsequently, we found that RUNX2 could bind to the enhancer regions of Fbln1 (gene of fibulin-1), one of the marker genes for DFDP. Through gain- and loss-of-function experiments, we proved that the biomechanical stress-mediated RUNX2-fibulin-1 axis inhibits the initiation of SDL by maintaining SDL niche homeostasis.

Computational explorations of the interaction between laccase and bisphenol A: influence of surfactant and different organic solvents

Bisphenol A (BPA), as an environmental endocrine disruptor can cause damage to the reproductive, nervous and immune systems. Laccase can be used to degrade BPA. However, laccase is easily deactivated, especially in organic solvents, but the specific details are not clear. Molecular dynamics simulations were used to investigate the reasons for changes in laccase activity in acetonitrile (ACN) and dimethyl formamide (DMF) solutions. In addition, the effects of ACN and DMF on the activity of laccase and surfactant rhamnolipid (RL) on the degradation of BPA by laccase were investigated. Results showed that addition of ACN changed the structure of the laccase, not only decreasing the van der Waals interaction that promoted the binding of laccase with BPA, but also increasing the polar solvation free energy that hindered the binding of laccase with BPA, so it weakened the laccase activity. DMF greatly enhanced the van der Waals interaction between laccase and BPA, and played a positive role in their binding. The addition of surfactant RL alleviated the effect of organic solvent on the activity of laccase by changing the polar solvation energy. The mechanism of surfactant RL affecting laccase activity in ACN and DMF is described, providing support for understanding the effect of organic solvents on laccase.

A dual-centre study on the radioprotective effect of a novel X-ray protection device during coronary intervention

AIM

To investigate the shielding efficiency of a novel X-ray protection device (NPD) compared with the traditional lead clothing (TLC) during coronary intervention.

MATERIALS AND METHODS

This study was performed prospectively in two centres. A total of 200 coronary interventions were included and assigned equally into the NPD or TLC group. The NPD is a floor-standing X-ray protection device, which mainly composes of a barrel-like frame and two layers of lead rubber. Thermoluminescent dosimeters (TLDs) were adopted to detect the cumulative absorbed doses, and were attached outside the NPD or TLC or body of the first operator at four different height levels in four directions during the procedure.

RESULTS

The cumulative doses outside the NPD were comparable to that of the TLC (2,398.33 ± 2,341.64 versus 1,624.09 ± 1,732.20 μSv, p=0.366), and the cumulative doses inside the NPD were significantly lower than those inside the TLC (40 ± 0 versus 732.28 ± 919.83 μSv, p<0.001). As the TLC did not cover the calf segment of the operator, the area at 50 cm height from the floor in the TLC group was unshielded. The shielding efficiency of NPD was significantly higher than that of the TLC (98.2 ± 0.63% versus 52.11 ± 38.97%, p=0.021).

CONCLUSION

The NPD has a significantly higher shielding efficacy than that of the TLC, in particular, it protects the operators' lower limb, liberates their lower body from wearing heavy lead apron, and may consequently reduce the radiation or body-load associated complications.

[Characterization of metabotropic glutamate receptor 7 and 8 in rat superior cervical ganglion and their changes following chronic intermittent hypoxia]

OBJECTIVE

To investigate the expression and localization of metabotropic glutamate receptors 7 and 8 (mGluR7/8) in rat superior cervical ganglion (SCG) and their changes in response to chronic intermittent hypoxia (CIH).

METHODS

We detected the expressions of mGluR7 and mGluR8 in the SCG of 8-week-old male SD rats using immunohistochemistry and characterized their distribution with immunofluorescence staining. The expression of mGluR7 and mGluR8 in the cytoplasm and nucleus was detected using Western blotting. A 6-week CIH rat model was established by exposure to intermittent hypoxia (6% oxygen for 30 s followed by normoxia for 4 min) for 8 h daily, and the changes in systolic blood pressure, diastolic blood pressure and mean arterial pressure were measured. The effect of CIH on expression levels of mGluR7 and mGluR8 in the SCG was analyzed using Western blotting.

RESULTS

Positive expressions of mGluR7 and mGluR8 were detected in rat SCG. mGluR7 was distributed in the neurons and small fluorescent (SIF) cells with positive staining in both the cytoplasm and nuclei, but not expressed in satellite glial cells (SGCs), nerve fibers or blood vessels; mGluR8 was localized in the cytoplasm of neurons and SIF cells, but not expressed in SGCs, nerve fibers, or blood vessels. Western blotting of the nuclear and cytoplasmic fractions of rat SCG further confirmed that mGluR7 was expressed in both the cytoplasm and the nucleus, while mGluR8 exists only in the cytoplasm. Exposure to CIH significantly increased systolic blood pressure, diastolic blood pressure and mean arterial pressure of the rats (all P < 0.001) and augmented the protein expressions of mGluR7 and mGluR8 in the SCG (P < 0.05).

CONCLUSION

mGluR7 and mGluR8 are present in rat SCG but with different localization patterns. CIH increases blood pressure of rats and enhanced protein expressions of mGluR7 and mGluR8 in rat SCG.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

[Clinical and genetics characteristics of adult-onset cerebrotendinous xanthomatosis: analysis of a Chinese pedigree]

Objective: Clinical manifestations, imaging findings, pathologic features, and genetic mutations of Chinese adult patients with cerebrotendinous xanthomatosis (CTX) were analyzed in order to achieve a greater understanding of CTX that can improve early detection, diagnosis, and treatment. Methods: Clinical data including medical history, neurologic and auxiliary examinations, imaging findings, and genetic profile were collected for an adult patient with CTX admitted to the Sixth Medical Center of Chinese People's Liberation Army General Hospital in August 2020. Additionally, a systematic review of genetically diagnosed Chinese adult CTX cases reported in major databases in China and other countries was performed and age of onset, first symptoms, common signs and symptoms, pathologic findings, imaging changes, and gene mutations were analyzed. Results: The proband was a 39-year-old female with extensive, early-onset nervous system manifestations including cognitive dysfunction and ataxia. Systemic lesions included juvenile cataract and a tendon mass. Cranial magnetic resonance imaging revealed cerebral atrophy, symmetric white matter changes predominantly in the pyramidal tract, and lesions in the cerebellar dentate nucleus. A novel homozygous mutation in the sterol-27-hydroxylase (CYP27A1) gene (c.1477-2A>C) was identified. There were no family members with similar clinical presentation although some were carriers of the c.1477-2A>C mutation. The patient showed a good response to deoxycholic acid treatment. Totally there were 56 cases of adult CTX patients in China, mostly in East China (31/56, 55.4%), at a male-to-female ratio of 1.8 to 1. Multiple organs and tissues including nervous system, tendon, lens, lung, and skeletal muscle were affected in these cases. The most common neurologic manifestations were cognitive dysfunction (44/52, 84.6%) and ataxia (44/51, 86.3%). The cases were characterized by early onset, chronic progressive damage of multiple systems, long disease course, and delayed diagnosis, making the disease difficult to manage clinically and resulting in poor prognosis. The 2 most common genetic mutations in Chinese adult CTX patients were c.1263+1G>A and c.379C>T. Exon 2 of the CYP27A1 gene was identified as a mutation hot spot. Conclusions: Chinese adult patients with CTX have complex clinical characteristics, a long diagnostic cycle, and various CYP27A1 gene mutations. Early diagnosis and intervention can improve the prognosis of these patients.