Objective To observe the feasibility of cardiac MR tissue tracking(CMR-TT)technique for quantitatively evaluating myocardial strain of patients with myocardial amyloidosis(CA).Methods Cardiac MRI were collected from 20 patients of immunoglobulin amyloid light-chain CA(AL-CA,group A),20 cases of transthyretin CA(ATTR-CA,group B)and 20 healthy subjects(group C),and myocardial strain parameters were obtained using CMR-TT technique.Left ventricular cardiac function parameters were compared among 3 groups,so were strain parameters of each myocardial segment of left ventricle and global myocardium,including 3D longitudinal strain(LS),3D radial strain(RS)and 3D circumferential strain(CS).Results Compared with those in group C,significant differences of left ventricular cardiac function parameters were found in both group A and B(all P＜0.01),while no statistical difference was found between group A and B(all P＞0.05).Except for apical segment RS(P=0.81),strain parameters in group A and B were both lower than those in group C(all P＜0.01),while no significant difference was detected between group A and B(all P＞0.05).Conclusion CMR-TT technique could be used to quantitatively evaluate left ventricular myocardial strain of CA patients.

Objective:To investigate the impact of age,various hormonal levels,and biochemical markers on penile cavernous body vascular function in patients with erectile dysfunction(ED).Me-thods:A retrospective analysis of clinical data from male patients with ED who underwent color duplex Doppler ultrasonography(CDDU)and intracavernosal injection test(ICI)at the Reproductive Medicine Center of Peking University Third Hospital from January 2020 to August 2023.Data were managed and processed using SPSS 29.0,and a multivariable Logistic regression analysis was conducted.Results:A total of 700 ED patients were included,with 380 showing negative ICI results and 320 positive.In the study,84 patients had a peak systolic velocity(PSV)＜25 cm/s,while 616 had PSV ≥ 25 cm/s;202 patients had end-diastolic velocity(EDV)＞5 cm/s,and 498 had EDV ≤5 cm/s.264 patients had ab-normal PSV and/or EDV results,and 436 had normal results for both.Patients with vascular ED had sig-nificantly lower estrogen levels(t=-3.546,P＜0.001),lower testosterone levels(t=-2.089,P=0.037),and a higher rate of hyperglycemia(x2=12.772,P=0.002)compared with those with non-vascular ED.The patients with arterial ED were older(t=3.953,P＜0.001),had a higher rate of hyperglycemia(x2=9.518,P=0.009),and a higher estrogen/testosterone ratio(t=2.330,P=0.020)compared with those with non-arterial ED.The patients with mixed arteriovenous ED had higher age(t=3.567,P＜0.001),lower testosterone levels(t=-2.288,P=0.022),a higher rate of hyperglycemia(x2=12.877,P=0.002),and a larger estrogen/testosterone ratio(t=2.096,P=0.037)compared with those with normal findings.Multifactorial Logistic regression analysis indicated that higher levels of estrogen were a protective factor for vascular ED(OR=1.009,95％CI:1.004-1.014),and glucose 7.0 mmol/L was a risk factor(OR=0.381,95％CI:0.219-0.661).Older age was a risk factor for arte-rial ED(OR=0.960,95％CI:0.938-0.982).Additionally,older age(OR=0.976,95％CI:0.958-0.993)and glucose levels of 5.6-6.9 mmol/L(OR=0.591,95％CI:0.399-0.876)were also risk fac-tors for mixed arterio-venous ED.Conclusion:Hyperglycemia and aging may impair penile cavernous body vascular function,while higher levels of estrogen may have a protective effect on it.

In this paper, we propose a multi-scale mel domain feature map extraction algorithm to solve the problem that the speech recognition rate of dysarthria is difficult to improve. We used the empirical mode decomposition method to decompose speech signals and extracted Fbank features and their first-order differences for each of the three effective components to construct a new feature map, which could capture details in the frequency domain. Secondly, due to the problems of effective feature loss and high computational complexity in the training process of single channel neural network, we proposed a speech recognition network model in this paper. Finally, training and decoding were performed on the public UA-Speech dataset. The experimental results showed that the accuracy of the speech recognition model of this method reached 92.77%. Therefore, the algorithm proposed in this paper can effectively improve the speech recognition rate of dysarthria.
Humans ; Dysarthria/diagnosis* ; Speech ; Speech Perception ; Algorithms ; Neural Networks, Computer

Humans ; Neoplasms, Second Primary/epidemiology* ; Neoplasms/epidemiology* ; Risk Factors ; Prognosis

Objective:To investigate the feasibility of single breath-hold TFE-EPI in non-contrast coronary MRA on 3.0 T MRI.Methods:Both single breath-hold TFE-EPI and free breathing TFE were conducted in 23 healthy volunteers. Acquisition time between the two sequences were compared by paired- t-test analysis. Signal-noise-ratio (SNR), contrast-noise-ratio (CNR),image artifacts and distortion,vessel acuity were evaluated on the aorta(Ao), right coronary artery proximal(RCA-pro), right coronary artery middle (RCA-mid), left anterior descending proximal(LAD-pro) and left circumflex proximal(LCX-pro). Nonparametric analyses were conducted for the comparison. Results:The acquisition time decreased 96.51% in TFE-EPI compared with TFE [(16.3±2.2)s vs.(466.9±101.3)s, t=21.49, P<0.01]. There was no statistical significance in SNR comparison in all the vessel evaluation (all the P>0.05). TFE-EPI showed better CNR in RCA-mid than TFE ( Z=2.65, P=0.008). TFE-EPI showed less image artifacts and distortion in RCA-mid than TFE ( Z=2.00, P=0.046). TFE-EPI also showed better vessel acuity in both RCA-pro and RCA-mid than TFE ( Z=3.88, P<0.001; Z=3.42, P=0.001). Conclusion:Single breath-hold TFE-EPI could greatly shorten scan time while ensuring image quality in coronal artery imaging and has a broad application in future.

To evaluate the effectiveness and safety of self-prepared absorbable hemostatic fibrils.A kind of absorbable hemostatic fibrils were prepared by self-developed patent technique. The physical form and molecular structure of the fibrils and a marketed product Surgicel were characterized by general observation and infrared spectroscopy; the carboxyl content, pH value and relative molecular mass of fibrils were determined by potentiometric titration method, pH meter and copper ethylenediamine method, respectively. The behavior of the fibrils and Surgicel in contact with blood was observed by inverted microscope, the cytotoxicity was evaluated by agarose diffusion cell assay . The external iliac artery hemorrhage model and the back muscle infiltration model in rats were established. The hemostatic effectiveness of the fibrils was investigated by hemostasis time and blood weight, and the degradation and biosafety of fibrils were investigated by observation photography, immune organ weighing, hematology and coagulation index measuring, and histopathological examination. The fibrils and Surgicel had similar molecular structures. Compared with the raw material regenerated cellulose, the typical carboxyl stretching vibration absorption peak of -COOH appeared near in both fibrils and Surgicel. The carboxyl content of the two materials was about 20%, and the pH value was about 3. The relative molecular mass of the fibers after oxidation was 4466±79, which was close to that of Surgicel(>0.05). After contacting with blood, the volume of fibrils and Surgicel expanded, and absorbed blood of dozens of times as their own weight. The results of agar diffusion test showed that the fibrils had no cytotoxicity. The results of animal experiments showed that the hemostasis completed within and there was no significant difference in blood weight and speed of hemostasis between two products (both >0.05). The fibrils could be degraded 1 week after being implanted to the bleeding sites of the muscle. There were no pathological effects on the appearance, body weight, food intake, immunological tissue thymus, spleen, lymph nodes, hematology and coagulation indexes of the rats, and no obvious abnormality found in the histopathological examination. The prepared absorbable hemostatic fibrils have excellent biological safety and effectiveness.
Animals ; Cellulose/pharmacology* ; Hemostasis ; Hemostatics/pharmacology* ; Rats ; Spleen

Domestic and foreign literatures related to the persistence of SARS-CoV-2 and the re-positive cases infected with SARS-CoV-2 were reviewed, and the characteristics and infectivity of the re-positive cases were analyzed to provide scientific evidence for the improvement of case management and the development of measures to stop the spread of SARS-CoV-2. Existing studies have shown that re-positive rate of SARS-CoV-2 ranged from 2.4% to 19.8%, the median of interval between re-positive detection and discharge was 4-15 days. Following the second course of the disease, the anti-SARS-CoV-2 IgM, IgG and IgA positive rates of the cases were 11.11%-86.08%, 52.00%-100.00% and 61.54%-100.00% respectively, the total antibody and neutralizing antibody positive rates were 98.72% and 88.46%. The viral load of the re-positive cases was lower than that in the initial infection. At least 3 380 re-positive cases have been reported globally. SARS-CoV-2 strains were isolated from the samples of 3 re-positive cases (1 immunodeficiency case and 2 cases with abnormal pulmonary imaging). There were close contacts that were infected by an asymptomatic case taking immunosuppressive agents. In conclusion, the infectivity of re-positive cases infected with SARS-CoV-2 is generally very low. Rare re-positive cases infected with SARS-CoV-2 might cause further transmission. The management approach for the re-positive cases can be based on the assessment of the individual transmission risk according to the pathogen detection results.
Antibodies, Neutralizing ; Antibodies, Viral ; COVID-19 ; Humans ; Immunoglobulin M ; SARS-CoV-2

COVID-19 is an emerging infectious disease caused by SARS-CoV-2. After the infection of the virus, the host immune system is stimulated to produce multifarious specific antibodies to decrease or eliminate effects of the pathogen. Study of the specific antibodies dynamic characteristics in patients with COVID-19 is very important for the understanding and diagnosis of the disease, research and development of vaccine, and planning of prevention and control strategy. This paper reviews and summarizes the domestic and oversea research on dynamic characteristics of specific antibodies of COVID-19 patients, including the antibody producing, duration and level, and its possible influencing factors in order to improve the understanding of the immunological characteristics of COVID-19.

The studies on infectiousness of person infected with SARS-CoV-2 at different stages of illness are an important basis for making effective prevention and control measures such as investigating the infectious source, determining the scope of close contacts and the timing of case isolation. This review discusses the infectiousness of cases infected with SARS-CoV-2 in the incubation period, symptomatic period and convalescent period by reviewing national and international literatures, technical and professional guidelines. Existing researches suggest that the infectious viruses could be isolated at the end of the incubation period as well as since illness onset, and viral load in upper respiratory tract swabs reached the peak on day 4-6 after illness onset and thereafter began to decline, implying the infectiousness was relatively strong at the end of incubation period and within one week after illness onset. Although there were a few cases who tested positive for SARS-CoV-2 after recovery, no evidence was found to indicate these cases can cause the transmission.

Objective:To analyze the incidence of acute respiratory infection (ARI) and related healthcare seeking behaviors in population in the period of COVID-19 epidemic in China.Methods:According to the province specific cumulative incidence rates of COVID-19 reported as of March 31, 2020, the low, medium and high-risk areas were classified. In these areas, a stratified two stage cluster random sampling method was used to select participants for face-to-face questionnaire surveys. Data on the incidence of ARI and related healthcare seeking behaviors in community residents during COVID-19 epidemic period were collected to calculate the attack rate of ARI and related healthcare seeking rate. Logistic regression method was used to explore the influencing factors for ARI incidence and healthcare seeking behavior.Results:A total of 34 857 community residents were surveyed, in whom 647 (1.9%) reported that they had ARI symptoms during the COVID-19 epidemic period, and 241 (37.2%) had healthcare seeking behaviors. In terms of the incidence of COVID-19-related ARI, in high-risk area, the risk of COVID-19-related ARI was 1.36 times (95% CI: 1.12-1.65) than that in low-risk area; among different age groups, the risk of COVID-19-related ARI in age groups 20-39 years, ≥60 years was 1.80 times (95% CI: 1.29-2.59) and 1.63 times (95% CI: 1.14-2.40) than that in age group 1-9 years; the risk of COVID-19-related ARI in people with underlying diseases was 1.53 times (95% CI: 1.23-1.89) than that in those without underlying diseases; the risk of COVID-19-related ARI in people with contacts with confirmed cases of COVID-19 and people with fever or respiratory symptoms was 1.53 times (95% CI: 1.01-2.27) and 6.60 times (95% CI: 5.05-8.53) than those in people without these contacts. The healthcare seeking rate in COVID-19-related ARI patients with exposures to those with fever or respiratory symptoms was 1.68 times (95% CI: 1.05-2.70) than that in such patients without the exposures. Conclusions:The attack rate of COVID-19-related ARI was affected by the local epidemic level of COVID-19, and in high-risk area, the attack rate of COVID-19-related ARI was also high. The healthcare seeking rate in patients with COVID-19-related ARI was low. Therefore, it is necessary to encourage the healthcare seeking in people with ARI in COVID-19 pandemic period.