Explore the vast range of titles available.

Fast radio bursts (FRBs) are extragalactic astrophysical transients 1 whose brightness requires emitters that are highly energetic yet compact enough to produce the short, millisecond-duration bursts. FRBs have thus far been detected at frequencies from 8 gigahertz (ref. 2 ) down to 300 megahertz (ref. 3 ), but lower-frequency emission has remained elusive. Some FRBs repeat 4 – 6 , and one of the most frequently detected, FRB 20180916B 7 , has a periodicity cycle of 16.35 days (ref. 8 ). Using simultaneous radio data spanning a wide range of wavelengths (a factor of more than 10), here we show that FRB 20180916B emits down to 120 megahertz, and that its activity window is frequency dependent (that is, chromatic). The window is both narrower and earlier at higher frequencies. Binary wind interaction models predict a wider window at higher frequencies, the opposite of our observations. Our full-cycle coverage shows that the 16.3-day periodicity is not aliased. We establish that low-frequency FRB emission can escape the local medium. For bursts of the same fluence, FRB 20180916B is more active below 200 megahertz than at 1.4 gigahertz. Combining our results with previous upper limits on the all-sky FRB rate at 150 megahertz, we find there are 3–450 FRBs in the sky per day above 50 Jy ms. Our chromatic results strongly disfavour scenarios in which absorption from strong stellar winds causes FRB periodicity. We demonstrate that some FRBs are found in ‘clean’ environments that do not absorb or scatter low-frequency radiation. The fast radio burst FRB 20180916B repeats with a periodicity of 16 days, and is now found to emit down to a frequency of 120 MHz, much lower than previously observed.

Fast radio bursts (FRBs) are extragalactic astrophysical transients whose brightness requires emitters that are highly energetic, yet compact enough to produce the short, millisecond-duration bursts. FRBs have thus far been detected between 300 MHz and 8 GHz, but lower-frequency emission has remained elusive. A subset of FRBs is known to repeat, and one of those sources, FRB 20180916B, does so with a 16.3 day activity period. Using simultaneous Apertif and LOFAR data, we show that FRB 20180916B emits down to 120 MHz, and that its activity window is both narrower and earlier at higher frequencies. Binary wind interaction models predict a narrower periodic activity window at lower frequencies, which is the opposite of our observations. Our detections establish that low-frequency FRB emission can escape the local medium. For bursts of the same fluence, FRB 20180916B is more active below 200 MHz than at 1.4 GHz. Combining our results with previous upper-limits on the all-sky FRB rate at 150 MHz, we find that there are 3-450 FRBs/sky/day above 50 Jy ms at 90% confidence. We are able to rule out the scenario in which companion winds cause FRB periodicity. We also demonstrate that some FRBs live in clean environments that do not absorb or scatter low-frequency radiation.

This paper presents the results from one of the first observations of ionospheric scintillation taken using the Low-Frequency Array (LOFAR). The observation was of the strong natural radio source Cas A, taken overnight on 18-19 August 2013, and exhibited moderately strong scattering effects in dynamic spectra of intensity received across an observing bandwidth of 10-80MHz. Delay-Doppler spectra (the 2-D FFT of the dynamic spectrum) from the first hour of observation showed two discrete parabolic arcs, one with a steep curvature and the other shallow, which can be used to provide estimates of the distance to, and velocity of, the scattering plasma. A cross-correlation analysis of data received by the dense array of stations in the LOFAR \"core\" reveals two different velocities in the scintillation pattern: a primary velocity of ~30m/s with a north-west to south-east direction, associated with the steep parabolic arc and a scattering altitude in the F-region or higher, and a secondary velocity of ~110m/s with a north-east to south-west direction, associated with the shallow arc and a scattering altitude in the D-region. Geomagnetic activity was low in the mid-latitudes at the time, but a weak sub-storm at high latitudes reached its peak at the start of the observation. An analysis of Global Navigation Satellite Systems (GNSS) and ionosonde data from the time reveals a larger-scale travelling ionospheric disturbance (TID), possibly the result of the high-latitude activity, travelling in the north-west to south-east direction, and, simultaneously, a smaller--scale TID travelling in a north-east to south-west direction, which could be associated with atmospheric gravity wave activity. The LOFAR observation shows scattering from both TIDs, at different altitudes and propagating in different directions. To the best of our knowledge this is the first time that such a phenomenon has been reported.

The in-hospital treatment of patients with traumatic brain injury (TBI) is considered to be expensive, especially in patients with severe TBI (s-TBI). To improve future treatment decision-making, resource allocation and research initiatives, this study reviewed the in-hospital costs for patients with s-TBI and the quality of study methodology. A systematic search was performed using the following databases: PubMed, MEDLINE, Embase, Web of Science, Cochrane library, CENTRAL, Emcare, PsychINFO, Academic Search Premier and Google Scholar. Articles published before August 2018 reporting in-hospital acute care costs for patients with s-TBI were included. Quality was assessed by using a 19-item checklist based on the CHEERS statement. Twenty-five out of 2372 articles were included. In-hospital costs per patient were generally high and ranged from $2,130 to $401,808. Variation between study results was primarily caused by methodological heterogeneity and variable patient and treatment characteristics. The quality assessment showed variable study quality with a mean total score of 71% (range 48% - 96%). Especially items concerning cost data scored poorly (49%) because data source, cost calculation methodology and outcome reporting were regularly unmentioned or inadequately reported. Healthcare consumption and in-hospital costs for patients with s-TBI were high and varied widely between studies. Costs were primarily driven by the length of stay and surgical intervention and increased with higher TBI severity. However, drawing firm conclusions on the actual in-hospital costs of patients sustaining s-TBI was complicated due to variation and inadequate quality of the included studies. Future economic evaluations should focus on the long-term cost-effectiveness of treatment strategies and use guideline recommendations and common data elements to improve study quality.

Purpose Symptomatic lumbar spondylolisthesis is usually treated with fusion surgery when conservative methods fail. However, traditional open decompression and fusion involves a large skin incision and muscle detachment. Therefore, minimally invasive techniques have been developed to reduce tissue damage, potentially leading to less postoperative pain and earlier resumption of activities. The purpose of this study was to compare percutaneous versus open pedicle screw placement in patients receiving lumbar midline decompression due to symptomatic lumbar spondylolisthesis focusing on short-term low back pain. Methods A randomised controlled trial was conducted in 2 Dutch hospital from 2015 to 2020. Participants with spondylolytic or degenerative lumbar spondylolisthesis were randomised into percutaneous pedicle screw placement with a mini-open decompression (mini-open), or conventional open surgery with instrumented fusion (open). The primary outcome measure was short-term low back pain after 2 weeks, measured by a visual analogue scale. Leg pain, disability and quality of life were recorded at 2 and 6 weeks, 3 and 6 months and 1 year. Surgical variables, including complications, were recorded. Analyses were performed in the intention-to-treat population. Results In total, 169 participants were included and randomised to mini-open ( n  = 81) or standard open surgery ( n  = 88). No statistically or clinically significant differences were found between groups in terms of primary or secondary outcomes. Surgery duration, blood loss, hospital stay, and complications were also similar between groups. Conclusions This study detected no difference in outcome between mini-open compared to open surgery in patients with spondylolisthesis. The hypothetical advantage of reduced short-term low back pain, less blood loss and better clinical outcome could not be confirmed.

Ketoacidosis is a potentially lethal condition caused by the imbalance between hepatic production and extrahepatic utilization of ketone bodies. We performed exome sequencing in a patient with recurrent, severe ketoacidosis and identified a homozygous frameshift mutation in the gene encoding monocarboxylate transporter 1 ( SLC16A1 , also called MCT1 ). Genetic analysis in 96 patients suspected of having ketolytic defects yielded seven additional inactivating mutations in MCT1 , both homozygous and heterozygous. Mutational status was found to be correlated with ketoacidosis severity, MCT1 protein levels, and transport capacity. Thus, MCT1 deficiency is a novel cause of profound ketoacidosis; the present work suggests that MCT1-mediated ketone-body transport is needed to maintain acid–base balance. Ketoacidosis is potentially lethal. The authors of this study found a homozygous frameshift mutation in the gene encoding monocarboxylate transporter 1 ( MCT1 ) in a patient with recurrent, severe ketoacidosis and additional inactivating mutations in MCT1 in 96 other patients. Acetoacetate and 3-hydroxybutyrate are slightly acidic biomolecules that, together with acetone, are called ketone bodies and serve as the major circulating energy source during fasting. Ketone bodies are formed in the liver from the ultimate breakdown product of fatty acids — acetyl coenzyme A (CoA) — by coupling of two acetyl units in a three-step enzymatic process called ketogenesis. Ketone bodies are believed to undergo passive distribution to metabolically active tissues, where they are used as an energy source. 1 Ketoacidosis, a pathologic state, occurs when ketone formation exceeds ketone utilization. The clinical consequences of ketoacidosis are exemplified by diabetic ketoacidosis, . . .

Key Clinical Message This case shows the feasibility of targeted muscle reinnervation (TMR) in a patient with a traumatic neuroma of the medial antebrachial cutaneous nerve (MABCN). TMR was performed by connecting the proximal stump of the MABCN to the branch innervating the accessory epitrochleoanconeus muscle. Postoperatively, the patient reported significantly less pain. Intra‐operative image showing the technique of TMR for the MABCN to EAN.

Abstract Background The treatment of patients with symptomatic spinal metastasis is challenging, and it warrants a multi-disciplinary approach. When surgery is considered, the expected survival time at three months might be an important argument in the discussion. With the advent of new treatment modalities, however, validation of an existing prediction model is warranted. Methods Validation study with inclusion of patients after informed consent from May 2021 through December 2023 in one academic hospital and two large non-academic medical centers. Information was collected on the following variables: sex, primary tumor type, treatment of the primary tumor with curative intention, cervical location of the metastasis, and the highest Karnofsky Performance Score in 24 hours before presentation. The validation set included 378 patients with symptomatic spinal metastasis. The derivation set consisted of 567 patients. The main outcome are C-index, calibration slope, D-statistic, R2D, Brier score, joint test for misspecification Reults The model had a C-index value of 0.68 ± 0.02 (95% CI: 0.64–0.72). Calibration analysis yielded a calibration slope of 0.66 ± 0.09 (95% CI: 0.50–0.83). The D-statistic was 0.92, and the R2D value was 0.17. The model performed well, especially at three months, with a Brier score of 0.44. Although no mismatch was observed graphically, the joint test for misspecification yielded a statistically significant value. The model was therefore adjusted slightly, based on all 945 patients included in the original model and the current study. Conclusion The prediction model performed reasonably well in estimating survival at three months in patients with symptomatic spinal metastasis.

This book presents the proceedings of a conference held near Washington, DC (Airlie, Virginia) to discuss the need for innovative new approaches to rural policy. US Federal Reserve Chairman Alan Greenspan opened the conference by stressing the crucial importance of flexibility in enhancing economic welfare and economic growth, cautioning policy makers to \"be careful when utilisng subsidies as they have exceptionally negative long-term implications\". Other presentations discuss regional partnerships, redefining regions, rural entrepreneurship, rural policy and regional development, federal co-ordination, and the future of rural policy.

Attentional bias for substance-relevant cues has been found to contribute to the persistence of addiction. Attentional bias modification (ABM) interventions might, therefore, increase positive treatment outcome and reduce relapse rates. The current study investigated the effectiveness of a newly developed home-delivered, multi-session, internet-based ABM intervention, the Bouncing Image Training Task (BITT), as an add-on to treatment as usual (TAU). No significant differences were found between conditions with regard to substance use, craving, relapse rates, attentional bias, or physical and psychological complaints. The findings may reflect unsuccessful modification of attentional bias, the BITT not targeting the relevant process (engagement vs. disengagement bias), or may relate to the diverse treatment goals of the current sample (i.e., moderation or abstinence). The current findings provide no support for the efficacy of this ABM approach as an add-on to TAU in alcohol or cannabis use disorder. Future studies need to delineate the role of engagement and disengagement bias in the persistence of addiction, and the role of treatment goal in the effectiveness of ABM interventions.