Compact step-added T-type PAC for enhanced hydrogen detection: A photoacoustic frequency shift approach.

In this study, we introduce an innovative photoacoustic frequency shift (PAFS) technique for hydrogen (H2) detection, complemented by both theoretical models and practical experiments. To mitigate cross-sensitivity, we analyzed the sound speeds of six different gases, confirming minimal interference with H2 due to significant velocity disparities. Central to our approach is the design of a miniaturized step-added T-type Photoacoustic Cell (PAC), with parameters meticulously optimized for enhanced performance. Using COMSOL Multiphysics' Thermal Viscous Acoustics module, we conducted simulations to evaluate the quality factor and acoustic pressure, both crucial for the sensor's efficiency. Additionally, we assessed the system's stability, influenced by gas flow, through gas velocity distribution analyses using the Computational Fluid Dynamics module. Experimental investigations focused on the system's sensing performance, revealing a distinct frequency shift of âˆ¼45 Hz for every 1 % change in H2 concentration, with a high linear correlation (R2 = 0.99825). The system's response and recovery times were measured at 1.09 s and 1.25 s, respectively. Long-term stability, evaluated over 3000 s using Allan deviation, indicated a minimum detection limit (MDL) of 102.47 ppm at an integration time of 375 s. These findings validate the efficacy of the step-added T-type PAC in H2 detection.

Association between obesity and clinical prognosis in patients infected with SARS-CoV-2.

BACKGROUND: It is well established that obesity is a disease of sustained low-grade inflammation. However, it is currently unknown if obesity plays a role in the clinical manifestations and prognosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients. In this study, we aimed to investigate whether obesity played a role in clinical manifestations and prognosis in patients infected with SARS-CoV-2. METHODS: This is a retrospective multicenter clinical study. A total of 96 patients hospitalized with SARS-CoV-2 infection were enrolled from Dongguan People's Hospital, Nanfang hospital and the First Affiliated Hospital of Xiamen University between 23 January and 14 February 2020. Demographic and clinical data were extracted from medical records. Acute respiratory distress syndrome (ARDS) was defined as oxygenation index (PaO2/FiO2) ≤ 300 mmHg. We grouped patients through the body mass index (BMI). Associations were examined using the t test, χ2 test and multivariate logistic forward regression test. RESULTS: Patients with BMI <  24 were significantly younger (P = 0.025) with lower creatine kinase (P = 0.013), lower diastolic pressure blood (P = 0.035), lower serum creatinine (P = 0.012), lower lactate dehydrogenase (P = 0.001) and higher platelet count (P = 0.002). The BMI level was 20.78 ± 3.15 in patients without pneumonia compared with the patients with pneumonia (23.81 ± 3.49, P = 0.001). For patients without ARDS, an average BMI level of 22.65 ± 3.53 was observed, significantly lower than patients with ARDS (24.57 ± 3.59, P = 0.022). The mean BMI was 22.35 ± 3.56 in patients experienced with relieving the clinical symptoms or stable condition by radiographic tests, lower than patients with disease exacerbation with 24.89 ± 3.17 (P = 0.001). In addition, lymphocyte count (r = - 0.23, P = 0.027) and platelet count (r = - 0.44, P < 0.001) were negatively correlated with BMI. While hemoglobin (r = 0.267, P = 0.008), creatine kinase (r = 0.331, P = 0.001), serum creatinine (r = 0.424, P < 0.001) and lactate dehydrogenase (r = 0.343, P = 0.001) were significantly positive correlated with BMI. Multivariate analysis showed that older age (OR = 1.046, P = 0.009) and BMI ≥ 24 (OR = 1.258, P = 0.005) were independent risk factors associated ICU admission while BMI ≥ 24 (OR = 4.219, P = 0.007) was independent risk factor associated with radiographic disease exacerbation. CONCLUSIONS: Our study found BMI was significantly associated with clinical manifestations and prognosis of patients with SARS-CoV-2 infection. For patients with increased risk, clinicians should intervene promptly to avoid disease progression.

Association Between Clinical Manifestations and Prognosis in Patients with COVID-19.

PURPOSE: The purpose of this study was to determine the risk factors associated with pneumonia, acute respiratory distress syndrome (ARDS), and clinical outcome among patients with novel coronavirus disease 2019 (COVID-19). METHODS: This was a cross-sectional multicenter clinical study. A total of 95 patients infected with COVID-19 were enrolled. The COVID-19 diagnostic standard was polymerase chain reaction detection of target genes of 2019 novel coronavirus (2019-nCoV). Clinical, laboratory, and radiologic results, as well as treatment outcome data, were obtained. ARDS was defined as an oxygenation index (arterial partial pressure of oxygen/fraction of inspired oxygen) ≤300 mm Hg. FINDINGS: Multivariate analysis showed that older age (odds ratio [OR], 1.078; p = 0.008) and high body mass index (OR, 1.327; p = 0.024) were independent risk factors associated with patients with pneumonia. For patients with ARDS, multivariate analysis showed that only high systolic blood pressure (OR, 1.046; p = 0.025) and high lactate dehydrogenase level (OR, 1.010; p = 0.021) were independent risk factors associated with ARDS. A total of 70 patients underwent CT imaging repeatedly after treatment. Patients were divided in a disease exacerbation group (n = 19) and a disease relief group (n = 51). High body mass index (OR, 1.285; p = 0.017) and tobacco smoking (OR, 16.13; p = 0.032) were independent risk factors associated with disease exacerbation after treatment. IMPLICATIONS: These study results help in the risk stratification of patients with 2019-nCoV infection. Patients with risk factors should be given timely intervention to avoid disease progression.

Effect of nucleos(t)ide analogue on serum HBsAg level in chronic hepatitis B patients: A 3-years study.

AIM: We aim to explore the effects of nucleos(t)ide analogues (NUCs) on the changes of HBsAg in chronic hepatitis B (CHB) patients. METHODS: A total of 264 CHB patients were enrolled in our study. All of them were treated with NUCs for at least three years. Quantification of HBsAg levels were measured by Elecsys HBsAg II. RESULTS: Although HBsAg levels were significantly higher in HBeAg seropositive CHB patients at baseline than in HBeAg seronegative CHB patients (3.84 ±â€¯0.82 vs 3.21 ±â€¯0.59 IU/mL), HBsAg levels declined more rapidly in the HBeAg seropositive group (P < 0.001). In HBeAg-positive CHB patients, HBsAg level in the telbivudine (LDT)-treated group was 3.68 ±â€¯0.56 IU/mL after 52-week of treatment, which was significantly higher than that in lamivudine (LAM)-treated group (P = 0.009). Multivariable analyses showed that baseline HBV DNA viral load (OR = 0.75, P = 0.018), baseline ALT level (OR = 0.99, P = 0.015), and baseline HBsAg level (OR = 0.188, P < 0.001) were independent factors that affected HBsAg decline in HBeAg seropositive CHB patients. For HBeAg seronegative CHB patients, the average of serum HBsAg levels in LAM-, LdT-, adefovir (ADV)-, and entecavir (ETV)-treated groups at baseline, 52 weeks, 104 weeks, and 156 weeks were similar. Multivariable analyses showed that only baseline HBV DNA level (OR = 0.56, P = 0.020) and baseline HBsAg level (OR = 0.57, P = 0.012) were independent factors that affected HBsAg decline in HBeAg seronegative patients with CHB. Baseline HBV DNA level (OR = 0.72, P = 0.010) and baseline HBsAg level (OR = 0.19, P < 0.001) were independent factors that affected all CHB patients. CONCLUSIONS: CHB Patients who had received NUCs antiviral treatment showed a slow but significant decrease in serum HBsAg level. Long-term monitoring and continuous antiviral treatment are necessary, especially for those patients with risk factors associated with HBsAg decline.

Risk factors associated with fatigue in chronic hepatitis B patients.

AIM: To evaluate fatigue in chronic hepatitis B patients and its related independent factors, as well as the relationship between fatigue and health-related quality of life (HRQoL). MATERIALS AND METHODS: The study enrolled 400 patients who met the selection criteria, and their sociodemographic information was collected. The 36-item Short-Form Health Survey (SF-36) and Multidimensional fatigue inventory 20 (MFI-20) were adopted to evaluate HRQoL and fatigue level. RESULTS: Significant differences between the fatigue group and non-fatigue group were observed for the female proportion (p=0.021), height (p=0.003), and weight (p=0.010), with or without regular exercise (p=0.001). We further determined the dimensions of fatigue that were affected by these factors and found that male patients showed significantly lower results than female patients in terms of physical fatigue (p=0.048), mental fatigue (p=0.017), and reduced motivation (p=0.025). In patients who exercised regularly, the fatigue scores for the three dimensions of general fatigue (p<0.001), physical fatigue (p=0.046), and reduced activity (p=0.008) were significantly better than in those without exercise habits. Multivariate analysis was conducted, which suggested that only height and regular exercise habits were the independent factors affecting the patients' fatigue levels. We further analyzed the relationship between quality of life and fatigue. With respect to physiological HRQoL, the average fatigue score of patients with high HRQoL was 41.91, which was significantly lower than that of patients with low physiological HRQoL (56.18, p<0.001). Moreover, the average fatigue score in patients with low psychological HRQoL was 55.25, which was significantly higher than that of patients with high psychological HRQoL (41.23, p<0.001). Correlation analysis showed that the physiological HRQoL and psychological HRQoL scores were negatively correlated with fatigue score (r = -0.639, p<0.001 and r= -0.655, p<0.001, respectively). CONCLUSIONS: In this study, we found that the fatigue dimensions of chronic hepatitis B patients differed between various subpopulations. Height and regular exercise habits were the independent factors that affected the patients' fatigue levels. Moreover, HRQoL was correlated with fatigue level. For patients with risk factors of fatigue, target intervention is advised in order to decrease fatigue and increase HRQoL.

[Quality evaluation and clinical applicability of pyrosequencing assay kit for detecting hepatitis B virus resistance].

OBJECTIVE: To evaluate the quality and clinical applicability of pyrosequencing assay kit for detecting hepatitis B virus resistance (HBV DRT). METHODS: Serial dilutions of the International Standard for HBV DNA were used to test the detection limit of the PCR for HBV DRT. Plasmids containing the either a wild-type (WT) copy or one of 10 mutant (MT) copies of the HBV RT gene were used to prepare a series of samples with various mutation ratios. To construct the linear relationship between the true mutation rate and the detected mutation rate, each sample was repeated at least 10 times. A total of 102 clinical samples were analyzed by Sanger sequencing and retested by the PCR for HBV DRT to determine the concordance of these two methods. RESULTS: The lower detection limit of the PCR for HBV DRT was 50 IU/ml. Except for the RT236 MT, the correlation between the true mutation rate and the detected mutation rate for the other nine resistance-related mutation sites were excellent, with R² more than 0.98 (P less than 0.001). Among the 102 clinical samples, four were not amplified successfully by PCR. The results were significantly different between the PCR for HBV DRT method and the Sanger sequencing method (x² = 71.2, P less than 0.001), and concordance was observed for 897/969 (92.6%) amino acid positions in 98 samples. Concordant results were achieved in 46/98 (46.9%) samples at all 10 mutation sites. For detection of a single mutation site, concordance rates ranged from 71.5% to 100% at the 10 mutation sites, respectively. Analysis of discordant samples showed that in 87.5% (63/72), Sanger sequencing detected WT and the PCR for HBV DRT detected WT/MT. In 5.6% (4/72) of samples, Sanger sequencing detected WT/MT and the PCR for HBV DRT detected WT. In the remaining 6.9% (5/72) of samples, Sanger sequencing detected WT but PCR for HBV DRT detected MT. CONCLUSION: The PCR for HBV DRT showed high sensitivity and accuracy in detecting antiviral drug-resistant mutations. The method is superior to Sanger sequencing for detecting minor mutations and can be used for early detection of a resistance mutation.

Association between vitamin D level and viral load or fibrosis stage in chronic hepatitis B patients from Southern China.

BACKGROUND AND AIM: The role of vitamin D playing in patients with chronic hepatitis C has been intensively studied. However, studies on the potential interaction between vitamin D level and chronic hepatitis B are still limited. This study aimed to explore whether any association existed between serum vitamin D level and liver histology or virological parameters in patients with chronic hepatitis B infection in Southern China. METHODS: 25-Hydroxyvitamin D serum levels were determined in a cohort of 242 treatment-naïve chronic hepatitis B patients. Histologic assessment was based on Knodell histologic activity index and Ishak fibrosis staging. Predictors of vitamin D insufficiency were identified using multivariate analysis. RESULTS: Mean 25-hydroxyvitamin D value was 33.90 ng/mL. The percentage of patients with different concentration of 25-hydroxyvitamin D (≥ 30 ng/mL, 20-30 ng/mL, < 20 ng/mL) were 59.9%, 31.4%, and 8.7%, respectively. Gender, season, age, and viral genotype were independent predictors of vitamin D insufficiency (< 30 ng/mL). Patients with genotype B virus infection had a lower mean 25-hydroxyvitamin D level (P = 0.023) and higher prevalence of vitamin D insufficiency than those with genotype C (P = 0.021), while no association was found between vitamin D status and viral load. In addition, 25-hydroxyvitamin D level did not significantly vary according to activity grade or fibrosis stage. CONCLUSIONS: The prevalence of vitamin D insufficiency is relatively low in our cohort. Patients infected with genotype B had a higher prevalence of vitamin D insufficiency than genotype C. 25-Hydroxyvitamin D serum level is not associated with viral load or fibrosis stage in chronic hepatitis B patients.

[Assessment of renal function and risk factors for renal impairment in patients with hepatitis B virus-related liver cirrhosis].

OBJECTIVE: To evaluate the renal function in treatment-naive patients with hepatitis B virus (HBV) related cirrhosis and to identify the risk factors for renal impairment. METHODS: We collected the data of 860 HBV-related cirrhosis patients hospitalized in our unit between Jan 1, 2011 and Dec 31, 2011. Liver function of the patients was assessed with Child-Pugh score system, and the renal function with estimated glomerular filtration rate (eGFR) calculated by Modification of Diet in Renal Disease (MDRD) equation recommended by Kidney Disease Outcomes Quality Initiative (K/DOQI). We investigated the prevalence of renal impairment (eGFR>60 ml/min/1.73 m(2)) among these patients and explored the risk factors for renal impairment. RESULTS: Of the 860 patients, 296 had complete clinical data and were included in our analysis. The overall incidence of renal impairment among the enrolled patients was 8.45% (25/296). Patients with Child-Pugh stage C showed a significantly higher incidence of renal impairment than those with stages B and A (17.17% [17/99] vs 6.67%[7/105] vs 1.09% [1/92], P<0.001). Age, history of hyperuricemia, and Child-Pugh score were identified as the risk factors for renal impairment in these patients. CONCLUSION: In patients with HBV-related liver cirrhosis, the incidence of renal impairment increases significantly with deterioration of the liver function, and renal function should be regularly monitored in these patients for appropriate antiviral treatment.