High-speed Readout System of X-ray CMOS Image Sensor for Time Domain Astronomy

We developed an FPGA-based high-speed readout system for a complementary metal-oxide-semiconductor (CMOS) image sensor to observe soft X-ray transients in future satellite missions, such as HiZ-GUNDAM. Our previous research revealed that the CMOS image sensor has low-energy X-ray detection capability (0.4-4 keV) and strong radiation tolerance, which satisfies the requirements of the HiZ-GUNDAM mission. However, CMOS sensors typically have small pixel sizes (e.g., $\sim$10 ${\rm \mu m}$), resulting in large volumes of image data. GSENSE400BSI has 2048$\times$2048 pixels, producing 6 Mbyte per frame. These large volumes of observed raw image data cannot be stored in a satellite bus system with a limited storage size. Therefore, only X-ray photon events must be extracted from the raw image data. Furthermore, the readout time of CMOS image sensors is approximately ten times faster than that of typical X-ray CCDs, requiring faster event extraction on a timescale of $\sim$0.1 s. To address these issues, we have developed an FPGA-based image signal processing system capable of high-speed X-ray event extraction onboard without storing raw image data. The developed compact system enabled mounting on a CubeSat mission, facilitating early in-orbit operation demonstration. Here, we present the design and results of the performance evaluation tests of the proposed FPGA-based readout system. Utilizing X-ray irradiation experiments, the results of the X-ray event extraction with the onboard and offline processing methods were consistent, validating the functionality of the proposed system

Difference in Spinal Sagittal Alignment and Health-Related Quality of Life between Males and Females with Cervical Deformity

Study DesignLarge cohort study.PurposeTo clarify spinal sagittal alignment and health-related quality of life (HRQOL) according to sex in volunteers aged >50 years with cervical deformity (CD).Overview of LiteratureAdult spinal deformities, especially those associated with lumbosacral lesions, are more frequent in females; however, CD is observed to a greater extent in males.MethodsWe divided 656 volunteers (263 males, 393 females; age, 50–89 years [mean, 73 years]) as follows: males with CD (CDM; 82 patients); males without CD (NCDM, 181); females with CD (CDF, 36); and females without CD (NCDF, 357). CD was defined as C2–7 sagittal vertical axis (SVA) ≥40 mm. We measured pelvic tilt (PT), pelvic incidence minus lumbar lordosis (PI−LL), thoracic kyphosis, T1 slope, cervical lordosis, C7 SVA, and C2–7 SVA. HRQOL was evaluated using EuroQOL five dimensions questionnaire (EQ-5D).ResultsIn CDM, NCDM, CDF, and NCDF groups, the respective parameters were as follows: PT: 15°, 14°, 26°, and 21°; PI−LL: 7°, 5°, 16°, and 10°; C2–7 SVA: 49, 24, 46, and 20 mm; C7 SVA: 61, 40, 75, and 47 mm; and EQ-5D: 0.82, 0.88, 0.78, and 0.81. PT and PI−LL were significantly greater in the CDF group than in the NCDF group (p<0.05) but were not significantly different between CDM and NCDM groups. The CDF group already showed deterioration of spinopelvic alignment, although it was maintained in the CDM group. EQ-5D in showed significantly greater deterioration the CDM group than in the NCDM group; deterioration of lumbopelvic parameters had less influence in males (p<0.05).ConclusionsSagittal spinal deformity may have different mechanisms in males and females. The deterioration of spinal sagittal alignment in males may originate from the cervical spine, and CD may be associated with HRQOL

Transcranial Motor Evoked Potential Monitoring for the Detection of Nerve Root Injury during Adult Spinal Deformity Surgery

Study Design Retrospective study. Purpose We aimed to determine the utility of transcranial motor evoked potential (TcMEP) monitoring for the detection of intraoperative nerve root injury. Overview of Literature Intraoperative neuromonitoring is important for the prediction of neurological injuries or postoperative paralysis. Nerve root injury can develop as a complication of adult spinal deformity (ASD) surgery. Methods We analyzed 295 patients who underwent ASD surgery using multi-channel TcMEP monitoring between 2010 and 2016 (58 men, 237 women; median age, 68 years; follow-up period ≥1 year). We defined the alarm point as a TcMEP amplitude 17.5° in PT (odds ratio, 17.5; 95% confidence interval, 1.994–153.560; p =0.010) was independently associated with intraoperative nerve root injury. Conclusions Multi-channel TcMEP monitoring may be useful for detecting nerve root injuries. A change in PT of >17.5° may be a significant risk factor for neurological events related to intraoperative nerve root injury

Minimum Clinically Important Differences in Oswestry Disability Index Domains and Their Impact on Adult Spinal Deformity Surgery

Study Design Retrospective study. Purpose To calculate the minimum clinically important difference (MCID) for total and individual domains of the Oswestry Disability Index (ODI) and assess score distribution and changes over time in surgically treated adult spinal deformity (ASD) patients. Overview of Literature Despite the common use of ODI for assessing ASD, there are no robust studies defining MCID values for this index. Methods This study included 240 consecutive ASD patients with a minimum of 2 years of follow-up. We calculated MCID values for total and individual ODI domains using all or part of the Scoliosis Research Society-22R questionnaire as anchors. Using current MCID values, we measured the acquisition rates in patients who acquired MCID at follow-up in both total and individual ODI domains. Differences in pathology, age, and locations of the upper and lower instrumented vertebrae were analyzed. Results MCID of the total ODI score was 11%, with an area under the curve of 0.737. Each domain ranged from 0 to 2, with 1 being the most common value. In the pain and standing domains, >60% of the patients acquired MCID, although acquisition rates of the personal care, lifting, sleep, and sexual activity domains were relatively low (20%–35%). Patients with MCID had more radiographic improvement in lumbar lordosis, sagittal vertical axis, and T1 pelvic angle than those without MCID (p<0.05). Conclusions To our knowledge, this is the first study to describe MCID of ODI (11%) after ASD surgery. In the pain and standing domains, most patients acquired MCID although the rates of acquisition of MCID in the personal care, lifting, sleep, and sexual activity domains were low. Spine surgeons should counsel their patients regarding the benefits and setbacks of ASD surgery

Gravitational Wave Physics and Astronomy in the nascent era

The detections of gravitational waves (GW) by the LIGO/Virgo collaborations provide various possibilities for both physics and astronomy. We are quite sure that GW observations will develop a lot, both in precision and in number, thanks to the continuous work on the improvement of detectors, including the expected new detector, KAGRA, and the planned detector, LIGO-India. On this occasion, we review the fundamental outcomes and prospects of gravitational wave physics and astronomy. We survey the development, focusing on representative sources of gravitational waves: binary black holes, binary neutron stars, and supernovae. We also summarize the role of gravitational wave observations as a probe of new physics

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe