Oral Simnotrelvir for Adult Patients with Mild-to-Moderate Covid-19.

BACKGROUND: Simnotrelvir is an oral 3-chymotrypsin-like protease inhibitor that has been found to have in vitro activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential efficacy in a phase 1B trial. METHODS: In this phase 2-3, double-blind, randomized, placebo-controlled trial, we assigned patients who had mild-to-moderate coronavirus disease 2019 (Covid-19) and onset of symptoms within the past 3 days in a 1:1 ratio to receive 750 mg of simnotrelvir plus 100 mg of ritonavir or placebo twice daily for 5 days. The primary efficacy end point was the time to sustained resolution of symptoms, defined as the absence of 11 Covid-19-related symptoms for 2 consecutive days. Safety and changes in viral load were also assessed. RESULTS: A total of 1208 patients were enrolled at 35 sites in China; 603 were assigned to receive simnotrelvir and 605 to receive placebo. Among patients in the modified intention-to-treat population who received the first dose of trial drug or placebo within 72 hours after symptom onset, the time to sustained resolution of Covid-19 symptoms was significantly shorter in the simnotrelvir group than in the placebo group (180.1 hours [95% confidence interval {CI}, 162.1 to 201.6] vs. 216.0 hours [95% CI, 203.4 to 228.1]; median difference, -35.8 hours [95% CI, -60.1 to -12.4]; P = 0.006 by Peto-Prentice test). On day 5, the decrease in viral load from baseline was greater in the simnotrelvir group than in the placebo group (mean difference [±SE], -1.51±0.14 log10 copies per milliliter; 95% CI, -1.79 to -1.24). The incidence of adverse events during treatment was higher in the simnotrelvir group than in the placebo group (29.0% vs. 21.6%). Most adverse events were mild or moderate. CONCLUSIONS: Early administration of simnotrelvir plus ritonavir shortened the time to the resolution of symptoms among adult patients with Covid-19, without evident safety concerns. (Funded by Jiangsu Simcere Pharmaceutical; ClinicalTrials.gov number, NCT05506176.).

A model of hybrid speciation process drawn from three new poplar species originating from distant hybridization between sections.

Although numerous studies have been conducted on hybrid speciation, our understanding of this process remains limited. Through an 18-year systematic investigation of all taxa of Populus on the Qinghai-Tibet Plateau, we discovered three new taxa with clear characteristics of sect. Leucoides. Further evidence was gathered from morphology, whole-genome bioinformatics, biogeography, and breeding to demonstrate synthetically that they all originated from distant hybridization between sect. Leucoides and sect. Tacamahaca. P. gonggaensis originated from the hybridization of P. lasiocarpa with P. cathayana, P. butuoensis from the hybridization of P. wilsonii with P. szechuanica, and P. dafengensis from the hybridization of P. lasiocarpa with P. szechuanica. Due to heterosis, the three hybrid taxa possess greater ecological adaptability than their ancestral species. We propose a hybrid speciation process model that incorporates orthogonal, reverse, and backcrossing events. This model can adequately explain some crucial evolutionary concerns, such as the nuclear-cytoplasmic conflict on phylogeny and the extinction of ancestral species within the distribution range of hybrid species.

Vitamin D supplementation for cardiometabolic risk markers in pregnant women based on the gestational diabetes mellitus or obesity status : a randomized clinical trial.

PURPOSE: Women with gestational diabetes mellitus (GDM) or obesity are vulnerable to impaired gestational cardiovascular health (CVH) and cardiovascular disease (CVD) in the future. It is unclear if prenatal vitamin D supplementation improves gestational CVH, especially in women at high risk for developing CVD. Our goal was to find out if vitamin D supplementation could protect against gestational CVH, including the women with GDM or obesity. DESIGN: We randomly assigned women with a serum 25(OH)D concentration < 75 nmol/L to receive 1600 IU/d (intervention group) or 400 IU/d (control group) of vitamin D3 for two months at 24-28 weeks' gestation. The primary outcome was gestational CVH marks (lipids, inflammatory cytokines, endothelial function). RESULTS: There were 1537 participants divided into the intervention (N = 766) and control groups (N = 771). No baseline differences existed among study groups in CVH markers. At the two-month visit, the intervention group's HDL-C levels (2.01 ± 0.39 VS 1.96 ± 0.39 mmol/L) were significantly higher than those of the control group, while the hs-CRP levels were significantly lower (3.28 ± 2.02 VS 3.64 ± 2.42 mg/L). Subgroup analysis found that HDL-C, TC, hs-CRP, E-Selectin, and SBP were improved in the intervention group among women with GDM or overweight/obesity, and the improvement was not found in women without GDM or overweight/obesity. Vitamin D supplementation significantly decreased the mean triglyceride-glucose index at the two-month visit in women with GDM. CONCLUSIONS: Vitamin D supplementation at mid-gestation might optimize the gestational CVH status for pregnant women, particularly the women with GDM or obesity, which is advantageous for later-life primary prevention of CVD. CLINICAL TRIAL REGISTRATION: The Chinese Clinical Trial Registry (ChiCTR2100051914, 10/9/2021, Prospective registered, https://www.chictr.org.cn/showproj.aspx?proj=134700 ).

Associations between dietary patterns and renal impairment in individuals with diabetes: a cross-sectional study.

BACKGROUND: A variety of chronic diseases are affected by diet. To our knowledge, few studies have investigated the relationship between dietary patterns and renal impairment in individuals with diabetes within an Asian population. This study aimed to assess the relationship between renal impairment and dietary patterns in individuals with diabetes within a Chinese population. METHODS: In this cross-sectional survey, we analysed data on 1522 participants with diabetes aged 18 years or older who took part in the China National Diabetic Chronic Complications Study. We utilised the Chinese Diabetes Complications Questionnaire, including the semiquantitative food frequency questionnaire (SQFFQ). We identified three dietary patterns using factor analysis: Chinese traditional, healthy and plant-based dietary patterns, and these dietary patterns were used to classify participants into four groups based on the quartiles of their scores. A decrease in the estimated glomerular filtration rate (eGFR; <60 mL/min/1.73 m2 ) and an increase in the albumin-to-creatinine ratio (ACR; ≥3 mg/mmol) were used as indicators of renal impairment. Binary logistic regression models were used to estimate the odds ratio (OR) of the highest quartile (Q4: high intake levels of each dietary pattern) for renal impairment compared to the lowest quartile (Q1: low intake levels of each dietary pattern). RESULTS: Among the 1522 participants, there was a 5.5% prevalence of low eGFR, with prevalence rates of 5.2% in men and 5.9% in women, yet the prevalence of albuminuria was as high as 47.9%. After adjusting for confounders, participants in Q4 of the plant-based dietary pattern had a smaller OR for renal impairment than those in Q1. CONCLUSIONS: Our findings demonstrated that a plant-based dietary pattern is associated with a reduced risk of renal impairment in a population with diabetes.

Comparative Study on the Effects of Four Plant Protein Sources on the Liver and Intestinal Health of Largemouth Bass, Micropterus salmoides.

The effects of plant protein sources (PPSs) on the health of the liver and intestine of the largemouth bass, Micropterus salmoides, were compared to verify the potential damaging effects of dietary fiber (DF). A diet containing 55% fish meal (FM) was used as the control. The test diets contained 25% soybean meal (SBM), rapeseed meal (RSM), cottonseed meal, or peanut meal, and the FM content was decreased to 30%. The protein and lipid contents of these five diets were balanced by casein and oil. Fish were raised for 8 weeks. The fish fed the diet containing PPS showed a trend of decreasing growth and apparent digestibility coefficients. The contents of total bile acid, lipid, and collagen in the liver were increased, and the mRNA expression levels of genes encoding inflammatory factors and enzymes involved in de novo fatty acid synthesis and bile acid synthesis were upregulated. Both the lipid and collagen contents in the liver were positively correlated with the DF content in the diet significantly. Morphology and histology showed reduced liver size, hepatic steatosis, and fibrosis in fish fed diets containing PPS. The lowest hepatosomatic index was observed in fish fed the SBM diet, and the most severe damage was observed in fish fed the RSM diet. No obvious histological abnormalities were observed in the hindgut. The bile acid profile in the liver could be used to distinguish the types of PPS very well by Fisher discriminant analysis. These results indicated that 25% of each of the four PPSs in the diet exceeded the tolerance range of largemouth bass and caused liver damage, which might be mediated by bile acid. DF in PPS might be an important agent contributing to liver damage.

The Effect of Diabetes Management Shared Care Clinic on Glycated Hemoglobin A1c Compliance and Self-Management Abilities in Patients with Type 2 Diabetes Mellitus.

Objective: We aim to evaluate the impact of diabetes management shared care clinic (DMSCC) on glycated hemoglobin A1c (HbA1c) compliance and self-management abilities in patients with type 2 diabetes mellitus (T2DM). Methods: This study was a prospective cohort study of patients with T2DM participating in the DMSCC. At baseline and after management, the HbA1c levels were measured, the HbA1c compliance rate were calculated, and the Summary of Diabetes Self-Care Activities-6 (SDSCA-6), Diabetes Empowerment Scale-DAWN Short Form (DES-DSF), and Problem Areas in Diabetes Scale-Five-item Short Form (PAID-5) were completed. These pre- and post-management data were compared. Results: A total of 124 eligible patients were enrolled. After the diabetes management of DMSCC, the average HbA1c decreased and the HbA1c compliance rate increased significantly (P < 0.01). SDSCA-6 showed significant improvement in physical activity, glycemic monitoring, smoking (P < 0.01), and taking medication (P < 0.05). DES-DSF suggested a greater willingness to try to effectively treat diabetes (P < 0.05). PAID-5 indicated significant improvement in diabetes-related emotional distress. Conclusion: DMSCC can help patients with T2DM reduce HbA1c, increase HbA1c compliance, improve diabetes self-management behaviors, empowerment, and diabetes-related emotional distress and serve as an effective exploration and practice of diabetes self-management education and support.

Remote Interference Discrimination Testbed Employing AI Ensemble Algorithms for 6G TDD Networks.

The Internet-of-Things (IoT) massive access is a significant scenario for sixth-generation (6G) communications. However, low-power IoT devices easily suffer from remote interference caused by the atmospheric duct under the 6G time-division duplex (TDD) mode. It causes distant downlink wireless signals to propagate beyond the designed protection distance and interfere with local uplink signals, leading to a large outage probability. In this paper, a remote interference discrimination testbed is originally proposed to detect interference, which supports the comparison of different types of algorithms on the testbed. Specifically, 5,520,000 TDD network-side data collected by real sensors are used to validate the interference discrimination capabilities of nine promising AI algorithms. Moreover, a consistent comparison of the testbed shows that the ensemble algorithm achieves an average accuracy of 12% higher than the single model algorithm.

A Sliced Parabolic Equation Method to Characterize Maritime Radio Propagation.

For maritime broadband communications, atmospheric ducts can enable beyond line-of-sight communications or cause severe interference. Due to the strong spatial-temporal variability of atmospheric conditions in near-shore areas, atmospheric ducts have inherent spatial heterogeneity and suddenness. This paper aims to evaluate the effect of horizontally inhomogeneous ducts on maritime radio propagation through theoretical analysis and measurement validation. To make better use of meteorological reanalysis data, we design a range-dependent atmospheric duct model. Then, a sliced parabolic equation algorithm is proposed to improve the prediction accuracy of path loss. We derive the corresponding numerical solution and analyze the feasibility of the proposed algorithm under the range-dependent duct conditions. A 3.5 GHz long-distance radio propagation measurement is utilized to verify the algorithm. The spatial distribution characteristics of atmospheric ducts in the measurements are analyzed. Based on actual duct conditions, the simulation results are consistent with the measured path loss. The proposed algorithm outperforms the existing method during the multiple duct periods. We further investigate the influence of different duct horizontal characteristics on the received signal strength.

Protective effect of omega-3 polyunsaturated fatty acids on sepsis via the AMPK/mTOR pathway.

CONTEXT: Sepsis is a systemic inflammatory response caused by infection, with high morbidity and mortality. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have reported biological activities. OBJECTIVE: This study explored the signaling pathways through which ω-3 PUFAs protect against sepsis-induced multiorgan failure. MATERIALS AND METHODS: Septic Sprague-Dawley (SD) rat model was established by the cecum ligation perforation (CLP) method. Rats were divided into control, sham, model, parenteral ω-3 PUFAs (0.5 g/kg) treatment, ω-3 PUFAs (0.5 g/kg) + AMPK inhibitor Compound C (30 mg/kg) treatment, and ω-3 PUFAs (0.5 g/kg) + mTOR activator MHY1485 (10 mg/kg) treatment groups. The serum inflammatory cytokines were measured using ELISA. Organ damage-related markers cTnI, CK, CK-MB, Cr, BUN, ALT, and AST were measured using an automated chemical analyzer. The AMPK/mTOR pathway in liver, kidney, and myocardial tissues was detected using western blot and qRT-PCR methods. RESULTS: CLP treatment enhanced the secretion of pro-inflammatory cytokines and multi-organ related markers, along with increased p-AMPK/AMPK ratio (from 0.47 to 0.87) and decreased p-mTOR/mTOR ratio (from 0.33 to 0.12) in rats. The inflammation response and multi-organ injury induced by CLP treatment could be partially counteracted by 0.5 g/kg parenteral ω-3 PUFA treatment. The activated AMPK/mTOR pathway in CLP-induced rats was further promoted. Finally, Compound C and MHY1485 could reverse the effects of parenteral ω-3 PUFA treatment on sepsis rats. DISCUSSION AND CONCLUSION: ω-3 PUFAs ameliorated sepsis development by activating the AMPK/mTOR pathway, serving as a potent therapeutic agent for sepsis. Further in vivo studies may validate potential clinical use.

Joint User Association and Deployment Optimization for Energy-Efficient Heterogeneous UAV-Enabled MEC Networks.

Unmanned aerial vehicles (UAVs) providing additional on-demand communication and computing services have become a promising technology. However, the limited energy supply of UAVs, which constrains their service duration, has emerged as an obstacle in UAV-enabled networks. In this context, a novel task offloading framework is proposed in UAV-enabled mobile edge computing (MEC) networks. Specifically, heterogeneous UAVs with different communication and computing capabilities are considered and the energy consumption of UAVs is minimized via jointly optimizing user association and UAV deployment. The optimal transport theory is introduced to analyze the user association sub-problem, and the UAV deployment for each sub-region is determined by a dragonfly algorithm (DA). Simulation results show that the energy consumption performance is significantly improved by the proposed algorithm.

FAT10 promotes the progression of bladder cancer by upregulating HK2 through the EGFR/AKT pathway.

The ubiquitin-like protein FAT10 and the hexokinase protein HK2 play vital regulatory roles in several cellular processes. However, the relationship between these two proteins and their role in the pathogenesis of bladder cancer are not well understood. Here, we found that FAT10 and HK2 protein levels were markedly higher in bladder cancer tissues than in normal adjacent tissues. In addition, RNAi-mediated silencing of FAT10 led to reduced HK2 levels and suppressed bladder cancer progression in vivo and in vitro. The results of our in vivo and in vitro experiments revealed that HK2 is critical for FAT10-mediated progression of bladder cancer. The current study demonstrated that FAT10 enhanced the progression of bladder cancer by positively regulating HK2 via the EGFR/AKT pathway. Based on our findings, FAT10 is believed to stabilize EGFR expression by modulating its degradation and ubiquitination. The results of the current study indicate that there is a correlation between FAT10 and HK2 in the progression of bladder cancer. In addition, we identified a new pathway that may be involved in the regulation of HK2. These findings implicate dysfunction of the FAT10, EGFR/AKT, and HK2 regulatory circuit in the progression of bladder cancer.

Management of medically inoperable and tyrosine kinase inhibitor-naïve early-stage lung adenocarcinoma with epidermal growth factor receptor mutations: a retrospective multi-institutional analysis.

BACKGROUND: The clinical value of combined local radiation and epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) for medically inoperable and TKI-naïve early-stage lung adenocarcinoma patients with EGFR mutations has not yet been determined. In this study, we aimed to pool multi-institutional data to compare the therapeutic effect of EGFR-TKI treatment alone and combined radiation and TKI treatment on the survival outcomes in this patient subgroup. METHODS: A total of 132 cases of medically inoperable stage I to III EGFR mutant lung adenocarcinoma were retrospectively reviewed based on data from 5 centers. Among these patients, 65 received combined radiation and EGFR-TKI therapy (R + TKI) (49.2%), while 67 received EGFR-TKI (50.8%) treatment alone. All patients were followed until death. RESULTS: For the R + TKI group, the median overall survival (OS) after primary therapy was 42.6 months, while that of the TKI alone group was 29.4 months (log-rank p < 0.001). In terms of progression-free survival (PFS), the median PFS in these two treatment groups was 24 months and 14.7 months respectively (log-rank p < 0.001). Multivariate analysis showed that R + TKI was independently associated with improved OS (adjusted HR 0.420; 95% CI 0.287 to 0.614; p < 0.001) and PFS (adjusted HR 0.420; 95% CI 0.291 to 0.605; p < 0.001) compared to TKI alone. Subgroup analysis confirmed the significant OS benefits in stage III patients and RFS benefits in stage II/III patients. CONCLUSIONS: Upfront radiation to primary sites with subsequent TKI treatment is a feasible option for patients with medically inoperable EGFR-mutant non-small-cell lung carcinoma (NSCLC) during first-line EGFR-TKI treatment, with significantly improved PFS and OS compared with those yielded by TKI treatment alone.

The role of parathyroid hormone during pregnancy on the relationship between maternal vitamin D deficiency and fetal growth restriction: a prospective birth cohort study.

Previous studies have shown conflicting findings regarding the relationship between maternal vitamin D deficiency (VDD) and fetal growth restriction (FGR). We hypothesised that parathyroid hormone (PTH) may be an underlying factor relevant to this potential association. In a prospective birth cohort study, descriptive statistics were evaluated for the demographic characteristics of 3407 pregnancies in the second trimester from three antenatal clinics in Hefei, China. The association of the combined status of vitamin D and PTH with birth weight and the risk of small for gestational age (SGA) was assessed by a multivariate linear and binary logistic regression. We found that declined status of 25-hydroxyvitamin D is associated with lower birth weight (for moderate VDD: adjusted ß = -49·4 g, 95 % CI -91·1, -7·8, P < 0·05; for severe VDD: adjusted ß = -79·8 g, 95 % CI -127·2, -32·5, P < 0·01), as well as ascended levels of PTH (for elevated PTH: adjusted ß = -44·5 g, 95 % CI -82·6, -6·4, P < 0·05). Compared with the non-VDD group with non-elevated PTH, pregnancies with severe VDD and elevated PTH had the lowest neonatal birth weight (adjusted ß = -124·7 g, 95 % CI -194·6, -54·8, P < 0·001) and the highest risk of SGA (adjusted risk ratio (RR) = 3·36, 95 % CI 1·41, 8·03, P < 0·01). Notably, the highest risk of less Ca supplementation was founded in severe VDD group with elevated PTH (adjusted RR = 4·67, 95 % CI 2·78, 7·85, P < 0·001). In conclusion, elevated PTH induced by less Ca supplementation would further aggravate the risk of FGR in pregnancies with severe VDD through impaired maternal Ca metabolism homoeostasis.

rs11671784 G/A variation in miR-27a decreases chemo-sensitivity of bladder cancer by decreasing miR-27a and increasing the target RUNX-1 expression.

Single nucleotide polymorphism (SNP) rs11671784 is in the loop of pre-miR-27a and the G/A variation can significantly decrease mature miR-27a expression. This study explored the role of miR-27a in chemo-sensitivity of bladder cancer and how rs11671784 G/A variation affects the sensitivity. Blood and tumor samples from 89 bladder cancer cases were analyzed. In-vitro study was performed to explore the mechanism of chemo-sensitivity and the downstream target of miR-27a by using bladder cancer cell lines. This study identified a causative relationship between rs11671784 G/A variation, lowered miR-27a expression, increased RUNX-1 expression and following weakened chemo-sensitivity. rs11671784 G allele has significantly stronger effect over A allele in promoting chemo-sensitivity in bladder cancer. miR-27a mediates chemotherapy at least partially through reducing P-gp expression and increasing apoptosis. In addition, RUNX-1 is a novel direct target of miR-27a, which is involved in its regulation of chemo-sensitivity in bladder cancer.

[Expression and clinical significance of CIP2A in small cell lung cancer patients].

OBJECTIVE: To explore the expression of cancerous inhibitor of phosphatase 2A (CIP2A) protein in small cell lung cancer and their relationship with clinicpathological features and prognosis. METHODS: A total of 112 cases of surgical specimens or bronchoscopic biopsies of small cell lung cancer were collected. There were specimens of 94 cases of SCLC tissues and 40 cases of paracancerous lung tissues. Quantitative RT-PCR and immunohistochemistry analysis were performed to determine the CIP2A expression in SCLC tissues. Kaplan-Meier curves were used to estimate the association between CIP2A expression and clinicopathological characteristics and prognosis of the patients. RESULTS: The expression of CIP2A in SCLC tissue was 7.605 ± 1.893, significantly higher than that in the paracancerous tissues (1.041 ± 0.786) (P < 0.01). The positive rate of CIP2A expression in cancer tissues was 82.8%, significantly higher than that in the paracancerous tissues (13.3%) (P < 0.01). The median disease-free survival was 9.88 months in the CIP2A-high expressing patients, significantly shorter than the 20.92 months in CIP2A-low expressing patients (P < 0.001). CIP2A expression was significantly correlated with the tumor stage, chemotherapeutic sensitivity, and survival (P < 0.05 for all). CONCLUSIONS: CIP2A expression is associated with the pathogenesis of SCLC, and may become a potential prognostic indicator of SCLC.

MicroRNA-21 attenuates renal ischemia reperfusion injury via targeting caspase signaling in mice.

BACKGROUND: MicroRNAs (miR) have come into focus as powerful regulators of gene expression and potential diagnostic tools during renal ischemia reperfusion injury (IRI). The aim of this study was to investigate the molecular regulation and function of miR-21, and to analyze the relationship between caspases and miR-21 expression levels in an experimental model of renal IRI. METHODS: IRI was induced by bilateral renal ischemia for 45 min followed by reperfusion. The male BALB/c mice were randomly assigned to the following groups: pre-miR-21 + IRI group, antagomiR-21 + IRI group, PBS + IRI group, pre-miR-21 + sham operation group, antagomiR-21 + sham operation group, PBS + sham operation group. The pre-miR-21 or antagomiR-21 was administered intraperitoneally (200 ng/kg weight) 24 and 6 h before induction of ischemia. Renal function, histological damage, renal cell apoptosis proteins were evaluated at 24 h after reperfusion. RESULTS: Mice upregulated miR-21 had lower plasma levels of blood urea nitrogen (BUN) and creatinine, lower histopathological scores and a decrease in programmed cell death 4 (PDCD4) mRNA and active caspase-3, caspase-8 proteins expressions. CONCLUSIONS: miR-21 is endowed with anti-apoptotic properties by suppressing the expression of PDCD4 gene and active caspase 3/8 fragments in the condition of renal IRI. miR-21 exerts significant functional protection in our renal murine model of IRI.

Role of mitochondria in renal ischemia-reperfusion injury.

Acute kidney injury (AKI) induced by renal ischemia-reperfusion injury (IRI) has a high morbidity and mortality, representing a worldwide problem. The kidney is an essential organ of metabolism that has high blood perfusion and is the second most mitochondria-rich organ after the heart because of the high ATP demands of its essential functions of nutrient reabsorption, acid-base and electrolyte balance, and hemodynamics. Thus, these energy-intensive cells are particularly vulnerable to mitochondrial dysfunction. As the bulk of glomerular ultrafiltrate reabsorption by proximal tubules occurs via active transport, the mitochondria of proximal tubules must be equipped for detecting and responding to fluctuations in energy availability to guarantee efficient basal metabolism. Any insults to mitochondrial quality control mechanisms may lead to biological disruption, blocking the clearance of damaged mitochondria and resulting in morphological change and tissue dysfunction. Extensive research has shown that mitochondria have pivotal roles in acute kidney disease, so in this article, we discuss the role of mitochondria, their dynamics and mitophagy in renal ischemia-reperfusion injury.

Average Time Consumption Per Character - a Practical Performance Metric for Generic Synchronous BCI Spellers.

OBJECTIVE: The information transfer rate (ITR) is widely accepted as a performance metric for generic brain-computer interface (BCI) spellers, while it is noticeable that the communication speed given by ITR is actually an upper bound which however can never be reached in real systems. A new performance metric is therefore needed. METHODS: In this paper, a new metric named average time consumption per character (ATCPC) is proposed. It quantifies how long it takes on average to type one character using a typical synchronous BCI speller. To analytically derive ATCPC, the real typing process is modelled with a random walk on a graph. Misclassification and backspace are carefully characterized. A close-form formula of ATCPC is obtained through computing the hitting time of the random walk. The new metric is validated through simulated typing experiments and compared with ITR. RESULTS: Firstly, the formula and simulation show a good consistency. Secondly, ITR always tends to overestimate the communication speed, while ATCPC is more realistic. CONCLUSION: The proposed ATCPC metric is valid. SIGNIFICANCE: ATCPC is a qualified substitute for ITR. ATCPC also reveals the great potential of keyboard optimization to further enhance the performance of BCI spellers, which was hardly investigated before.