17 research outputs found
A CMOS Microelectrode Array System With Reconfigurable Sub-Array Multiplexing Architecture Integrating 24,320 Electrodes and 380 Readout Channels
This article presents a CMOS microelectrode array (MEA) system with a reconfigurable sub-array multiplexing architecture using the time-division multiplexing (TDM) technique. The system consists of 24,320 TiN electrodes with 17.7 ??m-pitch pixels and 380 column-parallel readout channels including a low-noise amplifier, a programmable gain amplifier, and a 10-b successive approximation register analog to digital converter. Readout channels are placed outside the pixel for high spatial resolution, and a flexible structure to acquire neural signals from electrodes selected by configuring in-pixel memory is realized. In this structure, a single channel can handle 8 to 32 electrodes, guaranteeing a temporal resolution from 5kS/s to 20kS/s for each electrode. A 128 ?? 190 MEA system was fabricated in a 110-nm CMOS process, and each readout channel consumes 81 ??W at 1.5-V supply voltage featuring input-referred noise of 1.48 ??Vrms without multiplexing and 5.4 ??Vrms with multiplexing at the action-potential band (300 Hz ??? 10 kHz)
A Reconfigurable Sub-Array Multiplexing Microelectrode Array System with 24,320 Electrodes and 380 Readout Channels for Investigating Neural Communication
Photosensitive Nanodiscs Composed of Human Photoreceptors for Refractive Index Modulation at Selective Wavelengths
A photoreceptor on the retina acts as an optical waveguide to transfer an individual photonic signal to the cell inside, which is determined by the refractive index of internal materials. Under the photoactivation of photoreceptors making conformational and chemical variation in a visual cell, the optical signal modulation is demonstrated using an artificial photoreceptor-based waveguide with a controlling beam refraction. Two types of nanodiscs are made of human photoreceptor proteins, short-wavelength-sensitive opsin and rhodopsin, with spectral sensitivity. The refractive index and nonlinear features of those two photosensitive nanodiscs are investigated as fundamental properties. The photonanodiscs are photoactivated in such a way that allow refractive index tuning over 0.18 according to the biological function of the respective proteins with color-dependent response.N
Evaluation of COVID-19 vaccine effectiveness in different high-risk facility types during a period of Delta variant dominance in the Republic of Korea: a cross-sectional study
Objectives We evaluated the effectiveness of coronavirus disease 2019 vaccination in high-risk facilities in the Republic of Korea during the period when the highly transmissible Delta variant was prevalent. Additionally, we aimed to explore any disparities in vaccine effectiveness (VE) across various types of institutions, specifically distinguishing between non-medical and medical establishments. Methods We examined 8 outbreak clusters covering 243 cases and 895 contacts from 8 high-risk facilities divided into 2 groups: group A (4 non-medical institutions) and group B (4 medical institutions). These clusters were observed from July 27, 2021 to October 16, 2021 for the attack rate (AR) and VE with respect to disease severity. A generalized linear model with a binomial distribution was used to determine the odds ratio (OR) for disease severity and death. Results AR was notably lower in group B (medical institutions). Furthermore, VE analysis revealed that group A exhibited higher effectivity for disease severity and death than group B. The OR for disease severity was 0.24 (95% confidence interval [CI], 0.03â2.16) for group A and 0.27 (95% CI, 0.12â0.64) for group B, with the OR for death at 0.12 (95% CI, 0.01â1.32) in group A and 0.34 (95% CI, 0.14â0.87) in group B. Conclusion Although VE may vary across institutions, our findings underscore the importance of implementing vaccinations in high-risk facilities. Customized vaccination programs, tailored response plans, and competent management personnel are essential for effectively addressing and mitigating public health challenges
Clinical impact of diabetes mellitus on 2-year clinical outcomes following PCI with second-generation drug-eluting stents; Landmark analysis findings from patient registry: Pooled analysis of the Korean multicenter drug-eluting stent registry.
BackgroundPatients with diabetes mellitus are at an increased risk for adverse clinical events following percutaneous coronary interventions (PCI). However, the clinical impact of diabetes mellitus (DM) on second-generation drug-eluting stent (DES) implantation is not well-known. The aim of the current analysis was to examine the clinical impact of DM on clinical outcomes and the time sequence of associated risks in patients treated with second-generation DES.MethodsUsing patient-level data from two stent-specific, all-comer, prospective DES registries, we evaluated 1,913 patients who underwent PCI with second-generation DES between Feb 2009 and Dec 2013. The primary outcomes assessed were two-year major cardiac adverse events (MACE), composite endpoints of death from any cause, myocardial infarction (MI), and any repeat revascularization. We classified 0-1 year as the early period and 1-2 years as the late period. Landmark analyses were performed according to diabetes mellitus status.ResultsThere were 1,913 patients with 2,614 lesions included in the pooled dataset. The median duration of clinical follow-up in the overall population was 2.0 years (interquartile range 1.9-2.1). Patients with DM had more cardiovascular risk factors than patients without DM. In multivariate analyses, the presence of DM and renal failure were strong predictors of MACE and target-vessel revascularization (TVR). After inverse probability of treatment weighting (IPTW) analyses, patients with DM had significantly increased rates of 2-year MACE (HR 2.07, 95% CI; 1.50-2.86; P ConclusionsIn the second-generation DES era, the clinical impact of DM significantly increased the 2-year event rate of MACE, mainly caused by clinical events in the early period (0-1 year). Careful observation of patients with DM is advised in the early period following PCI with second-generation DES
The incidence of left atrial appendage thrombi on transesophageal echocardiography after pretreatment with apixaban for cardioversion in the real-world practice.
The risk of thromboembolisms during the post-cardioversion period is high. For patients with persistent atrial fibrillation (AF), anticoagulation with warfarin (INR 2.0~3.0) is recommended for at least three weeks prior and four weeks after cardioversion. We aimed to evaluate the efficacy of apixaban in preventing thromboembolic events during post-cardioversion. We enrolled 127 consecutive persistent AF patients (83 persistent, 44 longstanding persistent AF), scheduled to undergo cardioversion and were pretreated with apixaban. All patients underwent transesophageal echocardiography (TEE) to rule out thrombi in the left atrium (LA) or LA appendage (LAA) after anticoagulation with apixaban. The median duration of anticoagulation before the TEE was 37 (interquartile range [IQR] 34, 50) days. There were 7 patients (5.5%) with visible thrombi in the LAA. A spontaneous echo contrast was noted in 24 (18.9%) patients. Cardioversion was attempted in 117 patients, and they were prescribed amiodarone before the elective DC cardioversion. Sinus rhythm was achieved in 37 patients (31.6%) by amiodarone itself. DC cardioversion was attempted in 80 patients and was successful in 73 (91.3%). None of the cardioverted patients had any thromboembolic events within one month. Transient ischemic attacks were observed in one patient during a median follow up period of 202 days (IQR 143, 294). In conclusion, apixaban could be used as an anticoagulant for patients scheduled for cardioversion. However, the incidence of thrombi was not negligible. TEE or other imaging modalities should be considered before cardioversion or other invasive procedures
Impact of the Cation Composition on the Electrical Performance of Solution-Processed Zinc Tin Oxide Thin-Film Transistors
This
study examined the structural, chemical, and electrical properties
of solution-processed (Zn,Sn)ÂO<sub>3</sub> (ZTO) films with various
Sn/[Zn+Sn] ratios for potential applications to large-area flat panel
displays. ZTO films with a Zn-rich composition had a polycrystalline
wurtzite structure. On the other hand, the Sn-rich ZTO films exhibited
a rutile structure, where the Zn atom was speculated to replace the
Sn site, thereby acting as an acceptor. In the intermediate composition
regions (Sn/[Zn+Sn] ratio from 0.28 to 0.48), the ZTO films had an
amorphous structure, even after annealing at 450 °C. The electrical
transport properties and photobias stability of ZTO thin film transistors
(TFTs) were also examined according to the Sn/[Zn+Sn] ratio. The optimal
transport property of ZTO TFT was observed for the device with an
amorphous structure at a Sn/[Zn+Sn] ratio of 0.48. The mobility, threshold
voltage, subthreshold swing, and on/off current ratio were 4.3 cm<sup>2</sup>/(V s), 0 V, 0.4 V/decade, and 4.1 Ă 10<sup>7</sup>,
respectively. In contrast, the device performance for the ZTO TFTs
with either a higher or lower Sn concentration suffered from low mobility
and a high off-state current, respectively. The photoelectrical stress
measurements showed that the photobias stability of the ZTO TFTs was
improved substantially when the ZTO semiconducting films had a lower
oxygen vacancy concentration and an amorphous structure. The relevant
rationale is discussed based on the phototransition and subsequent
migration mechanism from neutral to positively charged oxygen vacancies
Performance of MALDI-TOF Mass Spectrometry (VITEK MS) in the Identification of <i>Salmonella</i> Species
Salmonella is a major pathogen causing foodborne infections in humans. Salmonella isolates are identified using biochemical and serological tests, including automated systems such as the VITEK2 system. However, there are few reports on Salmonella identification using VITEK MS. Therefore, we aimed to evaluate the usefulness of MALDI-TOF VITEK MS for Salmonella identification. A total of 1389 Salmonella isolates were identified using VITEK MS ver3.0 or ver3.2. All Salmonella isolates were confirmed by serotyping using the Kauffmann-White scheme, and the results were compared with the VITEK MS results. A total of 1389 Salmonella isolates, including 66 serotypes, were correctly identified at the genus level by VITEK MS. However, these systems failed to correctly identify typhoidal Salmonella. Among the five Salmonella enterica ssp. diarizonae isolates, only one was correctly identified, whereas one and three isolates were partially identified and misidentified, respectively. On the other hand, the VITEK2 system successfully identified all typhoidal Salmonella (Typhi and Paratyphi A) and Salmonella enterica ssp. diarizonae isolates. VITEK MS was useful for identifying Salmonella species isolated from clinical specimens; however, additional biochemical tests, such as the VITEK2 System, should be considered to accurately identify Salmonella ser. Typhi, and Salmonella ser. Paratyphi A
The benefits of the earlier use of sacubitril/valsartan in de novo heart failure with reduced ejection fraction patients
Abstract Aims We evaluated the clinical outcomes and trajectory of cardiac reverse remodelling according to the timing of sacubitril/valsartan (Sac/Val) use in patients with heart failure (HF) with reduced ejection fraction (HFrEF). Methods and results Patients with de novo HFrEF who used Sac/Val between June 2017 and October 2019 were retrospectively enrolled. Patients were grouped into the earlier use group (initiation of Sac/Val < 3 months after the first HFrEF diagnosis) and the later use group (initiation of Sac/Val â„ 3 months after the first HFrEF diagnosis). Primary outcome was a composite of HF hospitalization and cardiac death. Secondary outcomes were HF hospitalization, cardiac death, allâcause death, significant ventricular arrhythmia (ventricular tachycardia or ventricular fibrillation), and echocardiographic evidence of cardiac reverse remodelling including left ventricular ejection fraction (LVEF) change during followâup. Among 115 enrolled patients, 67 were classified in the earlier use group, and 48 were classified in the later use group. Mean period of HFrEF diagnosis to Sac/Val use was 52.1 ± 14.3 days in the earlier use group, and 201.8 ± 127.3 days in the later use group. During the median followâup of 721 days, primary outcome occurred in 21 patients (18.3%). The earlier use group experienced significantly fewer primary outcome than the later use group (10.4% vs. 29.2%, P = 0.010). The KaplanâMeier survival curve showed better eventâfree survival in the earlier use group than in the later use group (log rank = 0.017). There were no significant differences in cardiac death, allâcause death, and ventricular arrhythmia between two groups (1.5% vs. 2.1%, P = 0.811; 1.5% vs. 4.2%, P = 0.375; 3.0% vs. 0%, P = 0.227, respectively). Despite a significantly lower baseline LVEF in the earlier use group (21.3 ± 6.4% vs. 24.8 ± 7.9%, P = 0.012), an early prominent increase of LVEF was noted before 6 months (35.2 ± 11.9% vs. 27.8 ± 8.8%, P = 0.007). A delayed improvement of LVEF in the later use group resulted in similar LVEF at last followâup in both groups (40.7 ± 13.4% vs. 39.4 ± 10.9%, P = 0.686). Although the trajectory of left ventricular remodelling showed similar pattern in two groups, left atrial (LA) reverse remodelling was less prominent in the later use group during the followâup period (final LA volume index: 43.6 ± 14.3 mL/m2 vs. 55.2 ± 17.1 mL/m2, P = 0.011). Conclusions Earlier use of Sac/Val was related with better clinical outcome and earlier left ventricular reverse remodelling. Remodelling of LA was less prominent in the later use group implying delayed response in diastolic function