[Objective] To retrospectively analyze the detection results of alanine aminotransferase (ALT) unqualified repeat blood donors in Guangzhou, so as to provide evidence for further expanding the repeat blood donor pool, reducing the rate of blood discarding and improving the qualified rate of blood test. [Methods] Blood donors with unqualified ALT in Guangzhou Blood Center from January 2018 to April 2024 were selected as the research objects. The past blood donation and population characteristics were analyzed according to the number of blood donations and ALT unqualified times. [Results] Among repeat blood donors with previous ALT disqualification, 99.5% to 99.7% did not have reactive markers for transfusion-transmitted diseases (TTD), which was higher than the rate among first-time blood donors with unqualified ALT (95.8%) (P<0.05). The rate of single-item ALT disqualification in repeat blood donors was higher in males than in females (P<0.05); it also varied by age (18-25 years > 26-35 years > 36-45 years > over 45 years) (P<0.05); and by quarter (third and fourth quarters > first and second quarters) (P<0.05). The ALT unqualified rate was significantly higher whole blood donors than that of platelet donors and returning blood donors (P<0.05). The overall ALT level (51.0 U/L), individual ALT level (56.0 U/L) and individual ALT unqualified rate (66.7%) of repeat blood donors with multiple ALT disqualifications were higher than those of repeat blood donors with single-item ALT disqualifications (26.0 U/L, 38.5 U/L, and 33.3%, respectively) (P<0.05). Moreover, as the number of ALT disqualifications increased, the overall level of ALT in repeat blood donors also increased (P<0.05), and the average level of individual ALT and individual ALT unqualified ratio tended to increase. Repeat blood donors with frequent ALT disqualifications had higher ALT levels (69.0 U/L). [Conclusion] The ALT unqualified rates of repeat blood donors were mostly non-specific elevation without TTD. Repeat blood donors with multiple ALT disqualifications tend to have continuous high ALT. Moreover, and with the increase of ALT disqualifications times, the overall ALT levels the average individual ALT levels and individual ALT unqualified rates showed an increasing trend.

In order to accurately capture the respiratory muscle movement and extract the synchronization signals corresponding to the breathing phases, a comprehensive signal sensing system for sensing the movement of the respiratory muscle was developed with applying the thin-film varistor FSR402 IMS-C07A in this paper. The system integrated a sensor, a signal processing circuit, and an application program to collect, amplify and denoise electronic signals. Based on the respiratory muscle movement sensor and a STM32F107 development board, an experimental platform was designed to conduct experiments. The respiratory muscle movement data and respiratory airflow data were collected from 3 healthy adults for comparative analysis. In this paper, the results demonstrated that the method for determining respiratory phase based on the sensing the respiratory muscle movement exhibited strong real-time performance. Compared to traditional airflow-based respiratory phase detection, the proposed method showed a lead times ranging from 33 to 210 ms [(88.3 ± 47.9) ms] for expiration switched into inspiration and 17 to 222 ms [(92.9 ± 63.8) ms] for inspiration switched into expiration, respectively. When this system is applied to trigger the output of the ventilator, it will effectively improve the patient-ventilator synchrony and facilitate the ventilation treatment for patients with respiratory diseases.
Humans ; Respiratory Muscles/physiology* ; Signal Processing, Computer-Assisted ; Movement/physiology* ; Respiration ; Monitoring, Physiologic/methods* ; Adult

【Objective】 To investigate the distribution of ABO and RhD blood groups among voluntary blood donors in Guangzhou, in order to ensure clinical blood safety and better serve blood donors. 【Methods】 Routine ABO and RhD blood group screening tests were carried out among voluntary blood donors from January 2021 to December 2022. The composition ratio of ABO blood group was statistically analyzed. The samples with discrepancy between forward and reverse blood grouping and negative RhD blood group samples were further verified by serological test to analyze the ABO subtypes and the reasons for missed detection. 【Results】 A total of 749 123 blood samples were screened from January 2021 to December 2022, and 513 291 samples were collected after excluding repeat blood donors, with the ABO blood groups as 208 126(40.55%) of O type, 138 859(27.05%) of A type, 130 987(25.52%) of B type and 35 319(6.88%) of AB type. The screening results showed discrepancy between forward and reverse blood grouping in 506 samples, of which 58 were with weak/non-erythrocyte reaction, 16 with erythrocyte reaction, 215 with weak/non-serum reaction, and 217 with serum reaction. Further serological test indicated that 44 samples were ABO subtypes, among which 13 were subtype A, 26 subtype B, 5 subtype AB and 3 B (A) and 14 Bombay-like blood group. The blood group with the highest missed detection rate in repeat blood donors were A3/B3 subtype (68.42%). A total of 128 unexpected antibody positive samples were detected among 513 291 samples A total of 2 277 samples were screened negative for RhD blood type, of which 2 188 were confirmed to be Rh negative (2 188/513 291, 0.43%), 89 were D variants (89/513 291, 0.02%, ) and 30 were detected with unexpected antibodies (30/2 188, 1.37%). 【Conclusion】 The ABO blood group distribution of blood donors in Guangzhou is O>A>B>AB, and the proportion of RhD negative population is 0.43%, slightly highter than 0.3%-0.4% of Han population nationwide. The ABO blood group subtype is dominated by B subtype. The detection rate and missed detection rate of A3/B3 subtypes in routine blood group tests are the highest.

【Objective】 To investigate the population data of human immunodeficiency virus (HIV) infections among voluntary blood donors in Guangzhou between 2012 and 2022, and analyze its characteristics and trends, so as to provide valuable data for formulating targeted prevention and ensuring blood safety. 【Methods】 Voluntary blood donors samples from 2012 to 2022 were screened for p24 antigen and anti-HIV by two ELISA diagnostic kits and HIV RNA by nucleic acid test(NAT). The reactive blood samples were sent to the Disease Control and Prevention Center of Guangzhou for anti-HIV confirmatory test by Western blot. The population characteristics of blood donors with confirmed-positive HIV were subsequently analyzed. 【Results】 There were a total of 3 351 596 blood samples from voluntary blood donors in Guangzhou from 2012 to 2022, of which 708 samples were confirmed-positive of anti-HIV, with a total positive rate of 21.12/100 000, showing a decreasing trend (P<0.05). 1) The positive rates of age groups from high to low were 25-34 year old group, 35-44 year old group, 18-24 year old group, and≥45 year old group. The differences among various groups are statistically significant; 2) The anti-HIV positive rate of first-time blood donors (39.23/100 000) was significantly higher than that of repeat blood donors (10.78/100 000) (P<0.05); 3) The anti-HIV positive rate of male blood donors was 30.45/100 000, which was significantly higher than that of female blood donors (3.46/100 000); 4) The anti-HIV positive rate of individual blood donors (32.18/100 000) was higher than that of group blood donors (9.10/100 000) (P<0.05). 【Conclusion】 From 2012 to 2022, the confirmed-positive rate of anti-HIV among voluntary blood donors in Guangzhou showed a downward trend, which was significantly correlated with the implementation of voluntary blood donation and AIDS prevention policies. Young blood donors are of high risk of HIV, and it is necessary to enhance publicity and education on AIDS prevention through multiple channels among young population. Given that the anti-HIV positive rate of first-time blood donors is much higher than that of repeat blood donors, it is recommended to further optimize the health consultation and physical examination process before blood donation, and take multiple measures to screen high-risk behavior groups. Besides, more efforts should be made to promote publicity and education on AIDS prevention among regular blood donors. It is also important to recruit blood donors from low-risk groups and inform the donors about confidential unit exclusion.

【Objective】 To explore the correlation between serological screening of human T-lymphotropic virus antibodies (anti HTLV) and Western blot(WB) confirmatory tests among blood donors, so as to explore the infection status of HTLV Ⅰ/Ⅱ in Guangzhou. 【Methods】 The anti HTLV Ⅰ/Ⅱ enzyme-linked immunosorbent assay(ELISA) kit was used to screen voluntary blood donors from Guangzhou Blood Center from July 2016 to August 2022. WB was used to confirm 395 reactive blood samples by ELISA. The correlation between the S/CO values of anti HTLV Ⅰ/Ⅱ ELISA reagents and the confirmatory test was analyzed using ROC curves. 【Results】 The results showed that 25 out of 395 initially screened reactive blood donor samples were confirmed as HTLV positive by WB, while 16 were uncertain. ROC curve analysis showed a correlation between the S/CO values by ELISA and the confirmatory test results: the S/CO value at the highest Youden index was 3.789, which was the optimal threshold. The S/CO value had a certain correlation with the predicted positive rate of confirmatory results (P<0.05): the larger the S/CO value, the higher the predicted positive value. The overall prevalence of HTLV in Guangzhou is relatively low. 【Conclusion】 The prevalence of HTLV among blood donors in Guangzhou is low.Since the false positive rate of HTLV Ⅰ/Ⅱ antibody by ELISA serological screening is high, the confirmatory testing is particularly important.

【Objective】 To analyze the reasons for the invalidity of blood nucleic acid test results, and to explore the countermeasures to reduce the invalidity of the test. 【Methods】 From 2019 to 2021, the number of tests performed in our laboratory for Cobas s201 blood nucleic acid screening system and the number of batches and tests with invalid results were counted, and the types and reasons of invalid results were analyzed. 【Results】 From 2019 to 2021, the Cobas s201 nucleic acid detection system detected a total of 5, 420 batches and 127, 950 pools, and the invalid rate of batches and pools were 1.83% and 1.97%, respectively. The types of invalid results can be summarized as improper operation, sample quality problems, invalid quality control (IQC), equipment failure and others. Among them, IQC and equipment failure were the main reasons for invalid results, accounting for 44.51% and 39.96%, respectively. IQC was mainly related to cross-contamination of samples and insufficient mixing of quality control products. Equipment failures mostly occurred in the robotic arm gripper of the nucleic acid extraction instrument and the TC module of the amplification instrument. 【Conclusion】 The laboratory should conduct quality monitoring for invalid results, and take targeted improvement measures, especially to reduce invalid results caused by invalid quality control and instrument failure.

【Objective】 To assess the trend of hepatitis B virus (HBV) prevalence and associated risk factors among voluntary blood donors in Guangzhou area from 2011 to 2020, and to explore the impact of hepatitis B vaccination in neonates on the risk of HBV infection. 【Methods】 Blood samples of 2 624 434 voluntary blood donors from 2011 to 2020 in Guangzhou were tested by HBV surface antigen (HBsAg) enzyme-linked immunosorbent assay (ELISA) reagents twice and nucleic acid test (NAT) reagent once. Samples reactive to ELISA twice, or ELISA once + NAT were considered as HBV infection. The gender, age, ethnicity and region of HBV infected blood donors were collected, and the incidence of HBV infection in blood donors born before and after 1992 (when HBV vaccination was conducted in neonates) was compared. The trend and risk factors of HBV infection in blood donors in Guangzhou from 2011 to 2020 were analyzed. 【Results】 An overall HBV prevalence of 0.75% was found in voluntary blood donors in Guangzhou area from 2010 to 2020, showing an overall downward trend(P<0.05). HBV prevalence was lower in blood donors born after 1992 (0.49 %, 4 825/98 5362) than prior to 1992 (P<0.05). HBV prevalence in male blood donors (0.89%, 15 049/1 695 062) was significantly higher than that in female blood donors (P<0.05). HBV prevalence in blood donors aged 18~25(0.52%, 6 337/1 219 282)was lower than that in other age groups (P<0.05). HBV prevalence was similar in donors resident in Guangdong and other provinces(P>0.05), but both were significantly higher than that in Hong Kong, Macao, Taiwan and foreign countries (P<0.05). HBV prevalence in Han nationality donors was significantly higher than the ethnic minority donors (P<0.05). Gender, age, ethnicity and birth vaccination are the main risk factors for HBV infection among blood donors. 【Conclusion】 The overall HBV prevalence among voluntary blood donors in Guangzhou area from 2011 to 2020 has shown a decreasing trend, and differences have been found in gender, age, region, ethnicity and birth vaccination, which is helpful to formulate targeted recruitment strategies, thus reducing the risk of transfusion transmitted HBV.

Objective:To explore the clinical characteristics and establish a corresponding prognostic scoring model in patients with early-stage clinical features of hepatitis B-induced acute-on-chronic liver failure (HBV-ACLF).Methods:Clinical characteristics of 725 cases with hepatitis B-related acute-on-chronic hepatic dysfunction (HBV-ACHD) were retrospectively analyzed using Chinese group on the study of severe hepatitis B (COSSH). The independent risk factors associated with 90-day prognosis to establish a prognostic scoring model was analyzed by multivariate Cox regression, and was validated by 500 internal and 390 external HBV-ACHD patients.Results:Among 725 cases with HBV-ACHD, 76.8% were male, 96.8% had cirrhosis base,66.5% had complications of ascites, 4.1% had coagulation failure in respect to organ failure, and 9.2% had 90-day mortality rate. Multivariate Cox regression analysis showed that TBil, WBC and ALP were the best predictors of 90-day mortality rate in HBV-ACHD patients. The established scoring model was COSS-HACHADs = 0.75 × ln(WBC) + 0.57 × ln(TBil)-0.94 × ln(ALP) +10. The area under the receiver operating characteristic curve (AUROC) of subjects was significantly higher than MELD, MELD-Na, CTP and CLIF-C ADs( P < 0.05). An analysis of 500 and 390 cases of internal random selection group and external group had similar verified results. Conclusion:HBV-ACHD patients are a group of people with decompensated cirrhosis combined with small number of organ failure, and the 90-day mortality rate is 9.2%. COSSH-ACHDs have a higher predictive effect on HBV-ACHD patients' 90-day prognosis, and thus provide evidence-based medicine for early clinical diagnosis and treatment.

Objective To analyze the biological characteristics of clinical isolates of coxsackievir-us A6 (CVA6), a pathogen of hand,foot and mouth disease (HFMD), and to provide reference for vaccine development. Methods CVA6 strains were isolated from 21 stool and throat swab specimens of patients with HFMD in Yunnan Province and then identified. Their growth characteristics, plaque morphology and virulence to suckling mice were analyzed. Results Five CVA6 strains, named CVA6-129, CVA6-113, CVA6-57, CVA6-94 and CVA6-162, were isolated and all belonged to D3 subtype. Only the CVA6-129 strain could proliferate rapidly in Vero and KMB17 cells and the proliferation peaked 30 h after inoculation. The infectious titer of the CVA6-129 strain was 7. 54 lgCCID50 (50％ cell culture infective dose) / ml in KMB17 cells. Different morphologies of plaques were formed by the CVA6-129 strain in Vero and KMB17 cells at the same time points, which were small and round with clear edges in Vero cells, and large and irregular with blurry edges in KMB17 cells. Suckling mice were susceptible to CVA6 via intramuscular and intraperito-neal injection. The most common symptoms in infected suckling mice were reduced mobility, hind limb pa-ralysis and quadriplegia. CVA6 infection could result in death in severe cases. Conclusions This study isolated five CVA6 strains from a number of clinical samples of suspected HFMD cases, of which the CVA6-129 strain showed potential as a vaccine candidate.

Objective: To evaluate the efficacy and safety of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) 25/150/100 mg once daily and dasabuvir (DSV) 250 mg twice daily combined with ribavirin in adult patients of Mainland China with chronic HCV genotype 1b infection and compensated cirrhosis. Methods: An open-label, multicenter, phase 3 clinical trial study was conducted in mainland China, Taiwan, and South Korea. Adult patients with compensated cirrhosis (Metavir score =F4) who were newly diagnosed and treated for hepatitis C virus genotype 1b infection with ombitasvir/paritaprevir/ritonavir and dasabuvir combined with ribavirin for 12 weeks were included. Assessed SVR rate of patients obtained at 12 and 24 weeks after drug withdrawal. Efficacy and safety were evaluated in patients who received at least one time study drugs. Results: A total of 63 patients from mainland China were enrolled, 62 of whom (98.4%) had a baseline Child-Pugh score of 5 points. The overall rate of SVR12 and SVR24 in patients was 100% (95% CI: 94.3% to 100.0%). Most of the adverse events that occurred were mild. The incidence of common (≥10%) adverse events and laboratory abnormalities included elevated total bilirubin (36.5%), weakness (19.0%), elevated unconjugated bilirubin (19.0%) and conjugated bilirubin (17.5%), and anemia (14.3%). Three cases (4.8%) of patients experienced Grade ≥ 3 adverse events that were considered by the investigators to be unrelated to the study drug. None patients had adverse events leading to premature drug withdrawal. Conclusion Mainland Chinese patients with chronic HCV genotype 1b infection and compensated cirrhosis who were treated with OBV/PTV/r plus DSV combined with RBV for 12 weeks achieved 100 % SVR at 12 and 24 weeks after drug withdrawal. Tolerability and safety were good, and majority of adverse events were mild.