ObjectiveTo analyze the evolutionary characteristics and genetic variations of the HA (hemagglutinin) and NA (neuraminidase) genes of influenza A(H1N1) viruses in Shanghai during 2024, to investigate their transmission patterns, and to evaluate their potential impact on vaccine effectiveness. MethodsFrom January to October 2024, throat swab specimens were collected from influenza like illness (ILI) patients at 4 hospitals in Shanghai. Real-time fluorescence ploymerase chain reaction (RT-PCR) was used for virus detection and isolation of H1N1 influenza viruses. Forty influenza A(H1N1) virus strains were sequenced using Illumina NovaSeq 6000 platform, followed by phylogenetic analyses, genetic distance analysis, and amino acid variation analyses of HA and NA genes. ResultsPhylogenetic tree of the HA and NA genes revealed that the 40 influenza A(H1N1) virus strains circulating in Shanghai in 2024 exhibited no significant geographic clustering, with a broad origin of strains and complex transmission chains. Genetic distance analyses demonstrated that the average intra-group genetic distances of HA and NA genes among the Shanghai strains were 0.005 1±0.000 6 and 0.004 6±0.000 6, respectively, which were comparable to or higher than those observed in global surveillance strains. Both HA and NA genes displayed frequent mutations. Compared to the 2023‒2024 and 2024‒2025 Northern Hemisphere A(H1N1) vaccine strains (WHO-recommended), the HA proteins of 40 Shanghai strains exhibited amino acid substitutions at positions 120, 137, 142, 169, 216, 223, 260, 277, 356 and 451, with critical mutations at positions 137 and 142 located within the Ca2 antigenic determinant. Furthermore, mutations in the NA protein were observed at positions 13, 50, 200, 257, 264, 339 and 382. ConclusionThe genetic background of the 2024 Shanghai influenza A(H1N1) virus strains is complex and diverse, and antigenic variation may affect vaccine effectiveness. Therefore, it is recommended to enhance genomic surveillance of influenza viruses, evaluate vaccine suitability, and implement more targeted prevention and control strategies against imported influenza viruses.

Objective:To quantitatively analyze the plaque components of carotid artery through energy spectrum computed tomography angiography(CTA),and to measure the blood flow perfusion in the blood-supply area of carotid artery through CT perfusion(CTP),so as to explore the relationship among plaque component,the degree of luminal stenosis and cerebral blood flow perfusion.Methods:A total of 68 patients with unilateral plaques of carotid artery and severe vascular stenosis who were screened and diagnosed by ultrasound and CTA in Xiyuan Hospital from December 2017 to July 2019 were selected,and all patients underwent CTA examination and CTP examination.North American symptomatic carotid endarterectomy test(NASCET)method was used to measure the degree of carotid stenosis.The GE AW 4.7 post-process workstation was used to conduct analyses of energy spectrum and cerebral perfusion for the plaque component.And then,the slope of energy spectrum curve and the effective atomic number were obtained.At the same time,the cerebral blood volume(CBV),cerebral blood flow(CBF),time to peak(TTP)and mean transit time(MTT)of contrast agent in blood-supplying area of anterior cerebral artery(ACA)and middle cerebral artery(MCA)at the side of lesion were measured.Results:A total of 68 measured plaques of 68 patients met the condition,including 44 vulnerable plaques(including lipid plaques and mixed plaques)and 24 stable plaques(fibrous plaques).The average slopes of the energy spectrum curves of vulnerable plaque and stable plaque were respectively 0.45±0.45 and 1.15±0.39,and the differences were significant(t=2.413,P<0.05).The averagely effective atomic numbers of vulnerable plaques and stable plaques were respectively 7.21±1.06 and 8.01±0.63,and the difference were significant(t=2.548,P<0.05).The average TTP values of the ACA at the side of lesion of vulnerable plaques and stable plaques were respectively(12.20±1.61)S and(13.59±2.79)S,and the difference was significant(t=-2.607,P<0.05).The mean MTT values of the ACA at the side of lesion of vulnerable plaques and stable plaques were respectively(5.07±1.66)S and(6.09±2.19)S,and the difference was significant(t=-2.177,P<0.05).The degree of vascular stenosis at the side of lesion was positively correlated with TTP and MTT in blood-supplying area of middle cerebral artery(MCA)at the side of lesion(r=0.537,0.465,P<0.05),and that was negatively correlated with CBF values in blood-supplying areas of ACA and MCA at the side of lesion(r=-0.281,-0.569,P<0.05),respectively.The slope of the energy spectrum curve of carotid plaque was positively correlated with the TTP values in blood-supplying areas of ACA and MCA at the side of lesion(r=0.242,0.246,P<0.05),respectively.Conclusion:CT spectral imaging can quantitatively analyze the displayed components of carotid atherosclerotic plaque,and the degree of vascular stenosis can affect the blood flow perfusion of cerebral tissue,and the delays of TTP and MTT are more easily caused by vulnerable plaque,and the TTP of them is more sensitivity.

BACKGROUND:Most of the biomechanical studies on kyphosis have focused on trunk muscle strength and sagittal plane balance,and little has been reported on the biomechanical response within the spine during kyphosis. OBJECTIVE:To investigate the biomechanical response of the spine during postural kyphosis by simulating the process of postural kyphosis. METHODS:A three-dimensional finite element model of the normal thoracolumbar segment(T1-S1 segment)was established by using the finite element method.10 groups of pure bending loads from 1.15-11.52 N·m were applied using a three-point force system on T1,T6,and T12 vertebrae to simulate the process of postural kyphosis in normal humans.The relationship between the loads and Cobb angle and the biomechanical responses of vertebrae,ribs,and intervertebral discs were analyzed. RESULTS AND CONCLUSION:(1)During postural kyphosis,the Cobb angle size of T1-T12 segments was linearly related to the load size.(2)The maximum stresses on the vertebrae,ribs,and intervertebral discs increased with increasing load.(3)Under the action of 11.52 N·m moment,the maximum stresses on the vertebral body,ribs,and intervertebral disc were found in the front of the T6 vertebral body,the rib head of the 10th pair of ribs,and the right posterior side of the intervertebral disc of the T5-T6 segments.(4)The results of this study suggest that postural kyphosis leads to increased stress on the vertebrae,ribs,and discs,with the most significant increase in stress on the anterior side of the T6 vertebrae,at the rib head of the 10th pair of ribs,and on the anterior side of the disc at the T5-T6 segment,as well as on the posterior side,which may increase the risk of injury to the vertebrae,ribs,and discs,which provides a biomechanical basis for the design of kyphosis orthoses.

Objective To investigate the advantages and efficacy of traction with titanium clips in endoscopic submucosal dissection(ESD)for large laterally spreading tumor(LST)in rectum and sigmoid colon.Methods 67 patients with large sigmoid or rectal LST underwent ESD from January 2018 to June 2022 were analyzed retrospectively,including 32 patients in Group A and 35 patients in Group B.Group A was treated with clip-line traction and group B was treated with traditional ESD.The size of lesion,the total operation time,the submucosal dissection time,submucosal dissection rate,submucosal injection number,en bloc resection rate,R0 resection rate,curative resection rate and complications of the two groups were compared.Results LST-G-M was the most common type and villous adenoma was the main pathology in both groups.There were no differences in en bloc resection rate,R0 resection rate and incidence of complications between the two groups.The average size of group A was(13.6±8.4)cm2,significantly larger than that in group B(9.3±4.7)cm2,the total operation time was(42.3±10.3)min in group A,significantly shorter than that in group B(47.9±10.1)min,submucosal dissection time was(30.7±8.2)min in group A,significantly shorter than that in group B(36.1±7.6)min,submucosal injection number was(2.7±1.1)times in group A,significantly less than that in group B(3.5±1.2)times,submucosal dissection rate was(0.4±0.2)cm2/min in group A,significantly faster than that in group B(0.2±0.1)cm2/min,the differences were statistically significant(P<0.05).Conclusion Compared with traditional ESD,clip-line traction can provide a better surgical field and more effective dissection for large LST in rectum and sigmoid colon.

Objective:To investigate the feasibility of predicting the risk of spontaneous preterm birth in singleton pregnancy women with low risk of preterm birth by transabdominal-transvaginal ultrasound cervical length sequential screening in the second trimester.Methods:This prospective longitudinal cohort study included singleton pregnant women at 11-13 +6 gestational weeks who were admitted to Nanjing Drum Tower Hospital from January 2023 to September 2023. Transabdominal and transvaginal cervical lengths were measured during the mid-trimester fetal ultrasound scan at 18-24 weeks, and pregnancy outcomes were obtained after delivery. A short cervix was defined as a transvaginal cervical length of ≤25 mm, and the outcomes were defined as spontaneous preterm birth occurs between 20 and 36 +6 weeks and extremely preterm birth before 32 weeks. The area under the receiver operating characteristic (ROC) curve was used to evaluate the effectiveness of predicting spontaneous preterm birth by transabdominal and transvaginal cervix length, as well as the effectiveness of predicting short cervix by transabdominal cervical length. The relationship between transabdominal and transvaginal cervical length was evaluated using a scatter plot. Results:A total of 562 cases were included in this study, comprising 33 cases of spontaneous preterm birth (7 cases occurring before 32 weeks) and 529 cases of term birth. (1) Compared to the term birth group, transabdominal cervical length (median: 37.6 vs 33.2 mm; Z=-3.838, P<0.001) and transvaginal cervical length (median: 34.0 vs 29.9 mm, Z=-3.030, P=0.002) in the spontaneous preterm birth group were significantly shorter. (2) The areas under the ROC curve for predicting spontaneous preterm birth by transabdominal and transvaginal cervical length were 0.699 (95% CI: 0.588-0.809) and 0.657 (95% CI: 0.540-0.774), respectively. The sensitivity, specificity and positive predictive value of transvaginal cervical length Conclusions:In singleton pregnancy women with low risk of preterm birth, transabdominal-transvaginal cervical length sequential screening can reduce unnecessary transvaginal ultrasounds by approximately 41% without missing the diagnosis of pregnant women with a short cervix. This method also enhances the effectiveness of transvaginal cervical length to spontaneous preterm birth.

Objective:To investigate the clinical characteristics of cases with different congenital pulmonary airway malformations (CPAM) volume ratios (CVR) and the effect of maternal glucocorticoid treatment during pregnancy on CPAM.Methods:A retrospective study was conducted on 56 singleton pregnant women with fetal CPAM diagnosed prenatally in the Department of Obstetrics and Gynecology at Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, from September 2020 to May 2023. Among these, three cases received maternal glucocorticoid treatment during pregnancy and clinical conditions were reported in detail. Statistical analyses were performed using independent sample t-tests, non-parametric tests, Chi-square tests, or Fisher's exact test. Results:(1) General information: The average age of the 56 pregnant women with CPAM fetuses was (32.0±0.7) years. All fetuses had unilateral lesions, with 25 cases (44.6%) on the left side. Types Ⅰ, Ⅱ, and Ⅲ CPAM accounted for 5.4% (3/56), 50.0% (28/56), and 44.6% (25/56), respectively. Fetal hydrops occurred in two cases, and the maximum CVR during the fetal period for the other 54 non-hydropic fetuses was 0.79±0.66. (2) The CVR threshold for the risk of fetal hydrops was set as the mean maximum CVR of non-hydropic CPAM fetuses plus 2 standard deviations (0.79+2×0.66=2.1). The subjects were divided into two groups based on the maximum CVR during the fetal period: CVR≤2.0 group ( n=50) and CVR>2.0 group ( n=6). Comparison between the CVR>2.0 group and CVR≤2.0 group: The CVR>2.0 group had significantly higher rates of fetal hydrops [2/6 vs. 0.0% (0/50), Fisher's exact test], mediastinal shift [5/6 vs. 32.0% (16/50), χ 2=4.03], polyhydramnios [6/6 vs. 4.0% (2/50), Fisher's exact test], and postnatal surgery [4/5 vs. 22.2% (10/45), continuity correction χ 2=4.86] (all P<0.05). None of the fetuses with CVR≤2.0 had hydrops or received intrauterine intervention. The overall live birth rate was 89.3% (50/56). (3) Maternal glucocorticoid treatment during pregnancy: three of six fetuses with CVR>2.0 were treated with maternal glucocorticoid during pregnancy, and all were delivered alive at term after the intervention with resolution of edema and/or reduction in mass size. Two of them were treated with postnatal thoracoscopic surgery and were followed up to 5 and 14 months of age, respectively, with no abnormalities in feeding and development; the other was not treated surgically until 3 months of age, with no respiratory-related symptoms and no abnormalities in feeding and development. Conclusions:Prenatal ultrasound indicating CVR>2.0 is associated with increased rates of fetal hydrops, mediastinal shift, and polyhydramnios. Maternal glucocorticoid treatment during pregnancy may lead to favorable pregnancy outcomes for these CPAM fetuses.

Objective:To investigate the effectiveness and prognosis of using improved domestic neonatal ureteral stents (referred to as improved double-J stents) for thoraco-amniotic shunting (TAS) in treating fetal chylothorax.Methods:A retrospective analysis was conducted on the clinical data of 21 cases of fetal chylothorax treated with TAS using improved double-J stents at Nanjing Drum Tower Hospital, Nanjing University Medical School from April 1, 2018, to September 30, 2023. Surgical complications and perinatal outcomes were summarized, and the development of surviving infants in five domains (communication, gross motor, fine motor, problem-solving, and personal-social) was assessed using the Ages and Stages Questionnaires-Third Edition (ASQ-3). Descriptive statistical analysis was used. Results:(1) The median gestational age at prenatal diagnosis was 28.7 weeks (27.3-30.4 weeks), with 85.7% (18/21) of cases complicated by fetal hydrops, 90.5% (19/21) by polyhydramnios, and 85.7% (18/21) by bilateral pleural effusion. (2) The median gestational age at the first TAS was 30.9 weeks (29.7-32.7 weeks). Of the 21 cases, 10 required repeat stent placement due to dislodgement or blockage, with a total of 49 stent placements. The dislodgement rate within 7 days was 24.5% (12/49), and the blockage rate was 16.3% (8/49). The rate of premature rupture of membranes within one week post-stent placement was 9.5% (2/21), with an overall preterm premature rupture of membranes rate of 28.6% (6/21). The median interval from the first TAS to delivery was 30.0 d (19.8-40.0 d). Of the 21 cases, three opted for selective termination of pregnancy; the remaining 18 cases resulted in live births, with a median gestational age at delivery of 35.6 weeks (34.1-37.1 weeks), and three neonatal deaths. The overall neonatal survival rate was 15/18. Surviving infants were followed up to a median age of 30 months (7-48 months), with 13 showing normal development and two scoring below the ASQ-3 threshold.Conclusion:The improved double-J stent can be used for TAS in the treatment of fetal chylothorax, with generally favorable outcomes.

Objective:To explore the clinical significance of cervical length (CL) measured by transabdominal ultrasound during fetal structural anomalies screeing at 20-24 +6 weeks of gestation. Methods:This was a retrospective nested case-control study based on a prospective longitudinal cohort of "Prediction and Prevention of Early-onset Preeclampsia", which recruited 4 995 singleton pregnant women at the gestational age of 11-13 +6 weeks in Nanjing Drum Tower Hospital from April 2019 to August 2022. All the subjects underwent second-trimester ultrasound screening for fetal structural anomalies in our hospital with image records. This study excluded the women who were lost to follow-up, underwent cervical cerclage, terminated the pregnancy due to personal or social factors, or had miscarriage before 20 weeks of gestation, and those with iatrogenic preterm births, intrauterine fetal death or no second-trimester cervical sonography images. Propensity score matching was used to match pregnant women with spontaneous preterm birth ( n=101) and those with full-term delivery ( n=101) in a 1∶1 ratio, with factors of maternal age, body mass index, preterm birth history, cesarean section history, and pregnancy interval ≥5 years. CL was measured based on the retained ultrasound images. Nonparametric test or Chi-square test were used for statistical analysis. Receiver operating characteristic (ROC) curve was used to evaluate the correlation between CL measured by transabdominal ultrasound in the second trimester and spontaneous preterm birth. Results:The CL measured by transabdominal ultrasound at 20-24 +6 weeks of gestation was significantly shorter in the spontaneous preterm birth group than that in the full-term group [2.8 cm (2.5-3.3 cm) vs. 3.4 cm (3.0-3.9 cm), Z=－5.85, P<0.001]. If CL<3.4 cm was used as the cut-off value for predicting spontaneous preterm birth (20-36 +6 weeks), the specificity and the sensitivity were 0.50 and 0.77, respectively, and the sensitivity reached 0.92 for predicting preterm birth before 32 weeks and 1.00 for predicting preterm birth before 28 weeks. If CL<3.7 cm was used as the cut-off value, the specificity and the sensitivity were 0.36 and 0.87, respectively, and the sensitivity was 1.00 for predicting preterm birth before 32 weeks. The efficacy of preterm birth screening at 28-36 +6 weeks of gestation was comparable to that at 20-36 +6 weeks, if CL<3.4 cm and CL<3.7 cm were used as the cut-off value, the sensitivity were 0.76 and 0.86, respectively. Conclusion:Transabdominal ultrasound measurement of CL in the second trimester can be a preliminary screening to determine whether further transvaginal ultrasound measurement of CL is needed for women without a history of preterm birth or late spontaneous abortion.

Influenza has caused high morbidity and mortality worldwide, seriously endangering human health and life. The continuous mutation of influenza virus has brought new challenges to the prevention and treatment of influenza. Animal models provide convenience for a comprehensive understanding of influenza virus pathogenesis, transmission mechanism, vaccine development, and evaluation of therapeutic effects. The construction and use of animal models of influenza virus infection vary in different studies, and the application of different animal models also has its own characteristics. This article reviewed the current status of the construction and use of various animal models, and summarized the advantages and limitations of animal models in evaluating the efficacy of antibodies, drugs and vaccines, with the aim of providing reference for the selection and optimization of animal models in the future.