EEG-Derived Voice Signature for Attended Speaker Detection

\textit{Objective:} Conventional EEG-based auditory attention detection (AAD) is achieved by comparing the time-varying speech stimuli and the elicited EEG signals. However, in order to obtain reliable correlation values, these methods necessitate a long decision window, resulting in a long detection latency. Humans have a remarkable ability to recognize and follow a known speaker, regardless of the spoken content. In this paper, we seek to detect the attended speaker among the pre-enrolled speakers from the elicited EEG signals. In this manner, we avoid relying on the speech stimuli for AAD at run-time. In doing so, we propose a novel EEG-based attended speaker detection (E-ASD) task. \textit{Methods:} We encode a speaker's voice with a fixed dimensional vector, known as speaker embedding, and project it to an audio-derived voice signature, which characterizes the speaker's unique voice regardless of the spoken content. We hypothesize that such a voice signature also exists in the listener's brain that can be decoded from the elicited EEG signals, referred to as EEG-derived voice signature. By comparing the audio-derived voice signature and the EEG-derived voice signature, we are able to effectively detect the attended speaker in the listening brain. \textit{Results:} Experiments show that E-ASD can effectively detect the attended speaker from the 0.5s EEG decision windows, achieving 99.78\% AAD accuracy, 99.94\% AUC, and 0.27\% EER. \textit{Conclusion:} We conclude that it is possible to derive the attended speaker's voice signature from the EEG signals so as to detect the attended speaker in a listening brain. \textit{Significance:} We present the first proof of concept for detecting the attended speaker from the elicited EEG signals in a cocktail party environment. The successful implementation of E-ASD marks a non-trivial, but crucial step towards smart hearing aids.Comment: 8 pages, 2 figure

SGDP: A Stream-Graph Neural Network Based Data Prefetcher

Data prefetching is important for storage system optimization and access performance improvement. Traditional prefetchers work well for mining access patterns of sequential logical block address (LBA) but cannot handle complex non-sequential patterns that commonly exist in real-world applications. The state-of-the-art (SOTA) learning-based prefetchers cover more LBA accesses. However, they do not adequately consider the spatial interdependencies between LBA deltas, which leads to limited performance and robustness. This paper proposes a novel Stream-Graph neural network-based Data Prefetcher (SGDP). Specifically, SGDP models LBA delta streams using a weighted directed graph structure to represent interactive relations among LBA deltas and further extracts hybrid features by graph neural networks for data prefetching. We conduct extensive experiments on eight real-world datasets. Empirical results verify that SGDP outperforms the SOTA methods in terms of the hit ratio by 6.21%, the effective prefetching ratio by 7.00%, and speeds up inference time by 3.13X on average. Besides, we generalize SGDP to different variants by different stream constructions, further expanding its application scenarios and demonstrating its robustness. SGDP offers a novel data prefetching solution and has been verified in commercial hybrid storage systems in the experimental phase. Our codes and appendix are available at https://github.com/yyysjz1997/SGDP/

The influence of delirium on mortality and length of ICU stay and analysis of risk factors for delirium after liver transplantation

ObjectiveTo analyze the incidence, timing, risk factors and prognosis of delirium after liver transplantation (LT).MethodsThe clinical data of 321 patients undergoing LT in the Third Xiangya Hospital of Central South University from January 2018 to December 2022 were collected to investigate the incidence, onset, and risk factors for post-LT delirium and the impact of delirium on LT recipients’ prognosis by statistical analysis.ResultsThe incidence of post-LT delirium was 19.3% (62/321), and the median interval between LT and onset of delirium was 20.1 h. Univariate analysis showed that pre-LT variables (Model for End Stage Liver Disease (MELD) score, hospital stay, hepatic encephalopathy, infection, white blood cell (WBC) count, lymphocyte count, abnormal potassium, lactulose use), intraoperative variables (red blood cell transfusion, remimazolam use, dexmedetomidine use) and post-LT variables (hypernatraemia, acute rejection, reoperation, basiliximab use, tacrolimus concentration) were associated with post-LT delirium. Multivariate logistic regression analysis revealed that MELD score at LT ≥22 [OR = 3.400, 95% CI:1.468–7.876, p = 0.004], pre-LT hepatic encephalopathy [OR = 3.224, 95% CI:1.664–6.244, p = 0.001], infection within 2 months prior to LT [OR = 2.238, 95% CI:1.151–4.351, p = 0.018], acute rejection [OR = 2.974, 95% CI:1.322–6.690, p = 0.008], and reoperation [OR = 11.919, 95% CI:2.938–48.350, p = 0.001] were independent risk factors for post-LT delirium. Post-LT delirium was reduced in LT recipients exposing to intraoperative remimazolam [OR = 0.287, 95% CI: 0.113–0.733, p = 0.009] or ≥ 25 μg of intraoperative dexmedetomidine [OR = 0.441, 95% CI 0.225–0.867, p = 0.018]. As for clinical outcomes, patients with delirium had a higher percentage of staying at the (ICU) ≥7 d after LT than those without delirium [OR = 2.559, 95% CI 1.418–4.617, p = 0.002].ConclusionThe incidence of delirium was high and the onset of delirium was early after LT. Risk factors for post-LT delirium included high MELD score at LT, pre-LT hepatic encephalopathy and infections, acute rejection and reoperation. Intraoperative use of remimazolam or dexmedetomidine reduced post-LT delirium. Delirium had a negative impact on the length of ICU stay

Immunophenotyping in BK Virus Allograft Nephropathy Distinct from Acute Rejection

Differentiating BK virus nephropathy (BKVN) from acute rejection (AR) is crucial in clinical practice, as both of them have interstitial inflammation in the grafts. The purpose of the study is to describe the inflammatory cellular constituents of BKVN and to determine the clinical utility of immunophenotyping findings in distinguishing BKVN from AR. In addition, the expression of the HLA-DR was investigated. Sixty-five renal allograft recipients were included in this study, including 22 cases of BKVN, 31 cases of AR, and 12 cases of stable allograft. Immunostaining for infiltrating lymphocytes showed that the number of CD20 cells (P<0.001) and the percentages of CD3 (P<0.001), CD4 (P=0.004), CD8 (P=0.005), and CD20 (P=0.002) cells were all significantly different between BKVN and AR. Moreover, there were no statistically significant differences in tubule cell HLA-DR expression (P=0.156). This observation suggests that the number of CD20 cells and the percentages of CD3, CD4, CD8, and CD20 cells in renal biopsies would aid the distinction between BKVN and AR. On the other hand, the presence of HLA-DR upregulation may not only be specific for acute rejection but also be a response to BKVN

Autoimmune polyendocrine syndrome type 2 complicated with hyperthyroidism crisis and diabetic acute complications： a case report and literature review

Objective To enhance clinicians’ diagnosis and treatment capability for autoimmune polyendocrine syndrome type 2 （APS-2），and reduce missed diagnosis and misdiagnosis. Methods A 46-year-old female APS-2 patient with polyendocrine crisis was reported. Using the key words of “autoimmune polyendocrine syndrome” “diabetic acute complications” and “hyperthyroidism crisis” ，relevant literatures were searched from PubMed，SinoMed，CNKI，Wanfang Data and China Science and Technology Journal Database. Data of APS patients complicated with diabetic acute complications and hyperthyroidism crisis were collected and analyzed. Results The main manifestations of this patient were repeated polyuria and polydipsia for 18 years. She was admitted due to nausea and vomiting for half a day. Relevant examinations suggested the signs of diabetic ketoacidosis complicated with lactic acidosis and hyperthyroidism crisis，and the diagnosis of APS-2 was confirmed. Only 2 cases of APS-3 combined with acute diabetic complications and hyperthyroidism crisis were found in the literature，no APS-2 or other APS types patient complicated with diabetic acute complications and hyperthyroidism crisis was searched. Conclusions APS-2 patients complicated with diabetic acute complications and hyperthyroidism crisis are rare，which is likely to miss diagnosis and delay the diagnosis and treatment. Clinicians should improve relevant diagnosis and treatment capability. Prompt treatment contributes to favorable prognosis

Mouse Model Established by Early Renal Transplantation After Skin Allograft Sensitization Mimics Clinical Antibody-Mediated Rejection

Antibody-mediated rejection (AMR) is the main barrier to renal graft survival, and mouse renal AMR models are important to study this process. Current mouse models are established by priming the recipient to donor skin for over 7 days before kidney transplantation. The robustness of AMR in these cases is too strong to mimic clinical AMR and it is unclear why altering the priming times ranging from 7 to 91 days fails to reduce the AMR potency in these models. In the present study, we found that the donor-recipient combination and skin graft size were determinants of donor-specific antibody (DSA) development patterns after skin transplantation. DSA-IgG was sustained for over 100 days after skin challenge, accounting for an identical AMR robustness upon different skin priming times over 7 days. However, decreasing the skin priming time within 7 days attenuated the robustness of subsequent renal allograft AMR in C3H to Balb/c mice. Four-day skin priming guaranteed that recipients develop acute renal AMR mixed with a high ratio of graft-infiltrating macrophages, renal grafts survived for a mean of 6.4 ± 2.1 days, characterized by typical AMR histological changes, such as glomerulitis, peritubular capillary (PTC) dilation, and capillaritis, deposition of IgG and C3d in PTCs, but less prevalence of microthrombus, whereas the cellular rejection histological change of tubulitis was absent to mild. With this scheme, we also found that the renal AMR model can be developed using common mouse strains such as C57BL/6 and Balb/c, with mean prolonged renal graft survival times of 14.4 ± 5.0 days. Finally, we proved that donor-matched skin challenge after kidney transplantation did not strongly affect DSA development and kidney graft outcome. These findings may facilitate an understanding and establishment of mouse renal allograft AMR models and promote AMR-associated studies

The Prevalence of Immunologic Injury in Renal Allograft Recipients with De Novo Proteinuria

Post-transplant proteinuria is a common complication after renal transplantation; it is associated with reduced graft and recipient survival. However, the prevalence of histological causes has been reported with considerable variation. A clinico-pathological re-evaluation of post-transplant proteinuria is necessary, especially after dismissal of the term “chronic allograft nephropathy,” which had been considered to be an important cause of proteinuria. Moreover, urinary protein can promote interstitial inflammation in native kidney, whether this occurs in renal allograft remains unknown. Factors that affect the graft outcome in patients with proteinuria also remain unclear. Here we collected 98 cases of renal allograft recipients who developed proteinuria after transplant, histological features were characterized using Banff scoring system. Cox proportional hazard regression models were used for graft survival predictors. We found that transplant glomerulopathy was the leading (40.8%) cause of post-transplant proteinuria. Immunological causes, including transplant glomerulopathy, acute rejection, and chronic rejection accounted for the majority of all pathological causes of proteinuria. Nevertheless, almost all patients that developed proteinuria had immunological lesions in the graft, especially for interstitial inflammation. Intraglomerular C3 deposition was unexpectedly correlated with the severity of proteinuria. Moreover, the severity of interstitial inflammation was an independent risk factor for graft loss, while high level of hemoglobin was a protective factor for graft survival. This study revealed a predominance of immunological parameters in renal allografts with post-transplant proteinuria. These parameters not only correlate with the severity of proteinuria, but also with the outcome of the graft