Background: Influenza A virus (IAV) is a negative-sense RNA virus of the Orthomyxoviridae family and is the etiological agent of a highly contagious acute respiratory disease that can lead to acute lung injury. Objective: To elucidate the molecular mechanisms of IAV infection, an integrative research approach combining gene expression profiling, multinetwork analysis, and in vivo experimental validations was employed. Methods: First, a series of network-based analyses were performed, including protein-protein interaction network construction, weighted gene co-expression network analysis, and subsequent gene set enrichment analysis, to identify the major underlying mechanisms of IAV infection. Following gene expression analysis, core targets, both direct and indirect regulators, were screened. An IAV (H1N1) strain A/PR/8/34-induced acute lung injury mouse model was constructed for in vivo validations. Batch one included two groups to evaluate findings from the multi-network analysis: Mock (n = 10; 5 males and 5 females) and IAV (n = 10; 5 males and 5 females). Batch two included three groups to assess the role of toll-like receptor 3 (TLR3) in IAV infection: Mock (n = 6; 3 males and 3 females), IAV (n = 6; 3 males and 3 females), and TLR3 inhibitor (n = 6; 3 males and 3 females). Body weight was measured on days 0, 3, and 5 after infection. On day 5, lung tissues were collected to assess viral load and histopathological changes. Key targets were examined using enzyme-linked immunosorbent assay, Western blotting, and immunofluorescence staining, both in sera and lung tissues. Results: IAV infection was significantly associated with dysregulation of the immune-inflammation system, such as the LTR, nucle-otide-binding oligomerization domain-(NOD) like receptor, retinoic acid-inducible gene I-like receptor, and nuclear factor kappa-B signaling pathways. Gene set enrichment analysis further indicated that the TLR and necroptosis signaling pathways played crucial roles in the progression of IAV infection (TLR signaling pathway normalized enrichment score = 2.3941, P = 1.00 × 10 ⁻¹⁰; necroptosis normalized enrichment score = 1.9421, P = 6.21 × 10 ⁻⁷). Among the core targets, TLR3 and mixed lineage kinase domain-like protein (MLKL) may regulate gene expression at the transcriptional level (all P < 0.05). In vivo validation using an IAV (PR8) infected acute lung injury mouse model demonstrated increased viral load and lung index, alveolar structural damage, and inflammatory cell infiltration. Immunofluorescence staining exhibited large gaps in Lamin B1 staining and breaches in Emerin signals following IAV-PR8 infection. Expression levels of TLR3, p-receptor-interacting serine/threonine-protein kinase 3 (RIPK3)/RIPK3, and p-mixed lineage kinase domain-like protein (MLKL)/MLKL proteins in lung tissues, as well as proinflammatory factors and mediators in sera, were significantly elevated after IAV infection. Moreover, enhanced neutrophil infiltration (myeloperoxidase) and citrullinated histone H3 (a neutrophil extracellular trap-specific marker), both established indicators of neutrophil extracellular trap formation, were observed. Notably, treatment with a TLR3 inhibitor significantly ameliorated IAV-induced acute lung injury by regulating necroptosis-related targets. Conclusion: Our study provides network-based in vivo evidence that TLR3-receptor-interacting serine/threonine-protein kinase 3-MLKL-mediated necroptosis may underlie IAV-induced acute lung injury and could serve as a potential therapeutic target in severe influenza cases.

Objective To explore the feasibility of phase-contrast CT for three-dimensional visualization of in vitro intrahepatic vessels and necrotic foci in mouse model of acute liver injury(ALI).Methods Six clean grade male wild-type C57BL/6 mice were randomly divided into model group and control group(each n=3).The mice in model group were fed with overdose of acetaminophen to induce ALI,while those in control group were fed with the same amount of distilled water.After 24 h,the mice were all sacrificed,the livers were harvested and then fixed and dehydrated.Phase-contrast CT images of in vitro liver were acquired,sectional and three-dimensional images were reconstructed.The effect of phase-contrast CT for displaying the outline of liver and internal vessels and necrotic foci were observed,the maximum diameter and volume of necrotic foci were quantitatively analyzed,and the results of phase-contrast CT were compared with pathological findings.Results The original projection and sectional images of phase-contrast CT clearly showed the outline of in vitro liver and internal vasculatures.Necrotic foci within the liver were found in model group,but not in control group.The findings of phase-contrast CT corresponded accurately to those of pathology.Three-dimensional reconstruction images of phase-contrast CT clearly displayed intrahepatic portal vein system and hepatic vein system in both groups,and discontinuous punctate necrotic foci within the liver were found in model group,mainly distributed around hepatic vein,with a median maximum diameter of 18.50 μm and a median volume of 5 870.11 μm3,but was not observed in control group.Conclusion Phase-contrast CT could be used in three-dimensional visualization of intrahepatic vessels and necrotic foci of in vitro liver in mouse model of ALI.

Objective: To analyze the differences in bile acid profiles during different pregnancy durations of patients with intrahepatic cholestasis of pregnancy (ICP), so as to provide a reference for early prevention and treatment of ICP and optimization of maternal-infant health outcomes. Methods: Pregnant women who underwent routine prenatal examinations and delivered at Hangzhou Obstetrics and Gynecology Hospital from 2021 to 2023 were selected as study subjects. According to the ICP guidelines (2020), pregnant women were categorized into normal group, mild ICP group, and moderate/severe ICP group. Age, parity, and gravidity were collected through the obstetric electronic medical record system, liver function indicators and seven bile acid levels were collected through the hospital's laboratory information system. Differences in bile acid profiles across pregnancy durations among the three groups were compared. Results: A total of 238 pregnant women were enrolled, including 57 cases (23.95%) in the normal group, 136 cases (57.14%) in the mild ICP group, and 45 cases (18.91%) in the moderate/severe ICP group. There were statistically significant differences between the three groups in total bile acid (TBA), cholic acid (CA), chenodeoxycholic acid (CDCA), glycochenodeoxycholic acid (GCDCA), glycocholic acid (GCA), taurocholic acid (TCA) levels (all P<0.05). Compared with the normal group, CA, GCDCA and GCA, and TCA were higher in the mild and moderate/severe ICP groups; compared with the mild ICP group, GCA was higher in the moderate/severe ICP group (all P<0.05). Significant differences were observed in the levels of GCDCA, GCA, and TCA among three groups pregnant women in the early, mid, and late pregnancy (all P<0.05). Compared with the normal group, mild ICP group had higher GCDCA and GCA in the early and mid pregnancy; moderate/severe ICP group had higher TCA in the early pregnancy and higher GCDCA and GCA in the late pregnancy. Compared with the mild ICP group, mild ICP group had higher TCA in the early pregnancy and the moderate/severe ICP group had higher GCA in the late pregnancy. Conclusions GCDCA, GCA, and TCA levels remain higher in ICP patients than in normal pregnant women across all pregnancy durations. Personalized perinatal management plans can be developed based on bile acid profile dynamics to optimize maternal-fetal outcomes.

Objective To explore the feasibility of phase-contrast CT for three-dimensional visualization of in vitro intrahepatic vessels and necrotic foci in mouse model of acute liver injury(ALI).Methods Six clean grade male wild-type C57BL/6 mice were randomly divided into model group and control group(each n=3).The mice in model group were fed with overdose of acetaminophen to induce ALI,while those in control group were fed with the same amount of distilled water.After 24 h,the mice were all sacrificed,the livers were harvested and then fixed and dehydrated.Phase-contrast CT images of in vitro liver were acquired,sectional and three-dimensional images were reconstructed.The effect of phase-contrast CT for displaying the outline of liver and internal vessels and necrotic foci were observed,the maximum diameter and volume of necrotic foci were quantitatively analyzed,and the results of phase-contrast CT were compared with pathological findings.Results The original projection and sectional images of phase-contrast CT clearly showed the outline of in vitro liver and internal vasculatures.Necrotic foci within the liver were found in model group,but not in control group.The findings of phase-contrast CT corresponded accurately to those of pathology.Three-dimensional reconstruction images of phase-contrast CT clearly displayed intrahepatic portal vein system and hepatic vein system in both groups,and discontinuous punctate necrotic foci within the liver were found in model group,mainly distributed around hepatic vein,with a median maximum diameter of 18.50 μm and a median volume of 5 870.11 μm3,but was not observed in control group.Conclusion Phase-contrast CT could be used in three-dimensional visualization of intrahepatic vessels and necrotic foci of in vitro liver in mouse model of ALI.

Objective To analyze the antiviral effect of molnupiravir against influenza virus in vitro and in vivo.Methods The antiviral ability of molnupiravir against influenza virus strain H1N1 PR8 was detected in vitro and in vivo.H uman non-small cell lung cancer cell line(A549 cells)was used as an in vitro model of PR8 infection.The antiviral effects of molnupiravir on virus replication,protein synthesis,and viral particle formation were analyzed using real-time fluorescence quantitative polymerase chain reaction(qRT-PCR),Western blot(WB)assay,and plaque assay.PR8 nose-dripping infected C57BL/6 female mice were used as an in vivo infection model.The antivi-ral ability of molnupiravir was evaluated by detecting viral load,pathological changes,and immunohistochemistry in the control group,administration group,inoculation group,and inoculation-administration group.Results In vitro test results showed that molnupiravir had no significant inhibitory effect on influenza virus replication,protein syn-thesis,and virus particle formation(all P＞0.05).In vivo test results showed that compared with mice infected with H1N1 alone,the viral load in the lung tissue of mice treated with molnupiravir declined significantly,and the extent of pathological changes was milder.Immunohistochemical detection showed a significant weakening in nuclear protein(NP)antigen signal,and the expression levels of interferon(IFN)-α,interleukin(IL)-4,and IL-6 in the lungs were lower(all P＜0.01).Conclusion As a precursor with antiviral activity,molnupiravir can not exert anti-viral activity in lung-derived cells cultured in vitro,but can be transformed into an active form in the host,which significantly decreases the ability of H1N1 influenza virus to proliferate in the lungs and thereby alleviates the da-mage of virus to lung tissue.

Objective:To evaluate the epidemiological characteristics and influencing factors of out-of-hospital sudden cardiac death (SCD) in Hangzhou from 2016 to 2019.Methods:SCD events recorded by Hangzhou Emergency Center from January 1, 2016 to December 31, 2019 were reviewed. Demographic and mortality data were recorded, and the distribution patterns of SCD events in terms of date, time, and population with different characteristics were observed. Time series analysis method and a distributed lag nonlinear model based on quasi-Poisson distribution were used to explore the possible nonlinear association between ambient temperature and SCD incidence.Results:A total of 4 744 out-of-hospital sudden death events were recorded by Hangzhou Emergency Center from January 1, 2016 to December 31, 2019. After excluding non-SCD events and observed events with missing items, 3 743 SCD events were finally included in the study. The survey results showed that the incidence of out-of-hospital SCD in Hangzhou was 96.5 cases per 100 000 person-years. Most of the people who experienced SCD were aged ≥60 years. The incidence in males (2 462 cases, 66%) was significantly higher than that in females (1 281 cases, 34%), and the proportion of events occurring during the day (2 737 cases, 73%) was significantly higher than that at night (1 006 cases, 27%), mainly occurring between 7: 00 and 9: 00. High temperature was associated with an increased risk of SCD. When the average daily temperature was higher than 25.5 ℃, the risk of SCD increased with the further increase of average daily temperature.Conclusions:SCD events mainly occur in the elderly population aged ≥60 years, with a significantly higher incidence in males than in females, and more frequently during the day than at night, mainly between 7: 00 and 9: 00 in the morning. High temperature is closely related to the risk of SCD. It is particularly important to carry out targeted SCD screening and prevention for different populations and implement appropriate prevention strategies for high-risk groups of SCD in high-temperature weather.

Objective To analyze the antiviral effect of molnupiravir against influenza virus in vitro and in vivo.Methods The antiviral ability of molnupiravir against influenza virus strain H1N1 PR8 was detected in vitro and in vivo.H uman non-small cell lung cancer cell line(A549 cells)was used as an in vitro model of PR8 infection.The antiviral effects of molnupiravir on virus replication,protein synthesis,and viral particle formation were analyzed using real-time fluorescence quantitative polymerase chain reaction(qRT-PCR),Western blot(WB)assay,and plaque assay.PR8 nose-dripping infected C57BL/6 female mice were used as an in vivo infection model.The antivi-ral ability of molnupiravir was evaluated by detecting viral load,pathological changes,and immunohistochemistry in the control group,administration group,inoculation group,and inoculation-administration group.Results In vitro test results showed that molnupiravir had no significant inhibitory effect on influenza virus replication,protein syn-thesis,and virus particle formation(all P＞0.05).In vivo test results showed that compared with mice infected with H1N1 alone,the viral load in the lung tissue of mice treated with molnupiravir declined significantly,and the extent of pathological changes was milder.Immunohistochemical detection showed a significant weakening in nuclear protein(NP)antigen signal,and the expression levels of interferon(IFN)-α,interleukin(IL)-4,and IL-6 in the lungs were lower(all P＜0.01).Conclusion As a precursor with antiviral activity,molnupiravir can not exert anti-viral activity in lung-derived cells cultured in vitro,but can be transformed into an active form in the host,which significantly decreases the ability of H1N1 influenza virus to proliferate in the lungs and thereby alleviates the da-mage of virus to lung tissue.

Objective:To evaluate the epidemiological characteristics and influencing factors of out-of-hospital sudden cardiac death (SCD) in Hangzhou from 2016 to 2019.Methods:SCD events recorded by Hangzhou Emergency Center from January 1, 2016 to December 31, 2019 were reviewed. Demographic and mortality data were recorded, and the distribution patterns of SCD events in terms of date, time, and population with different characteristics were observed. Time series analysis method and a distributed lag nonlinear model based on quasi-Poisson distribution were used to explore the possible nonlinear association between ambient temperature and SCD incidence.Results:A total of 4 744 out-of-hospital sudden death events were recorded by Hangzhou Emergency Center from January 1, 2016 to December 31, 2019. After excluding non-SCD events and observed events with missing items, 3 743 SCD events were finally included in the study. The survey results showed that the incidence of out-of-hospital SCD in Hangzhou was 96.5 cases per 100 000 person-years. Most of the people who experienced SCD were aged ≥60 years. The incidence in males (2 462 cases, 66%) was significantly higher than that in females (1 281 cases, 34%), and the proportion of events occurring during the day (2 737 cases, 73%) was significantly higher than that at night (1 006 cases, 27%), mainly occurring between 7: 00 and 9: 00. High temperature was associated with an increased risk of SCD. When the average daily temperature was higher than 25.5 ℃, the risk of SCD increased with the further increase of average daily temperature.Conclusions:SCD events mainly occur in the elderly population aged ≥60 years, with a significantly higher incidence in males than in females, and more frequently during the day than at night, mainly between 7: 00 and 9: 00 in the morning. High temperature is closely related to the risk of SCD. It is particularly important to carry out targeted SCD screening and prevention for different populations and implement appropriate prevention strategies for high-risk groups of SCD in high-temperature weather.

Objective To evaluate the effect of red-blue light photon assisted therapy on wound healing after flap reconstruction of limb traumatic defects.Methods A total of 146 patients who were admitted to the Ward of Microsurgery of ⅢA hospital of Shanghai from January 2020 to December 2021 and received flap reconstruction surgery for soft tissue defects of limbs were included in this prospective observational study.According to the order of admission,patients were divided into a control group(n=70)and an trial group(n=76).In the control group,a 60W thermal lamp was offered to the patients for locally heating the flaps,with continuous irradiation for 24 hours with a maintaining power of 1-2W,at an approximately 30-45 cm in distance from the flap.In the trial group,based on the thermal irradiation applied to the control group,a combined red and blue light photon irradiation therapy was offered as an additional measure,by twice a day at 20 minutes per session of blue-red light photon irradiation,at 8-12cm in distance from the flap.The two groups were compared in terms of tension of tissues around flap,incidence of infection within 7 days after surgery and the survival of flap within 2 weeks after surgery.Results The two groups showed no significant difference in terms of tissue tension between the 1st and 3rd day after surgery(P<0.05),but with significant differences on the 5th and 7th day after surgery(P>0.05).The trial group exhibited significantly lower incidence of infection within 7 days after surgery compared to that of the control group(P<0.05),and with a significantly higher flap survival rate at 2 weeks after surgery(P<0.05).Conclusion After the flap reconstruction of soft tissue defects of limbs,a red-blue light assisted photon irradiation therapy can effectively improve postoperative tissue tension around a flap,reduce infection rate and improve the survival rate of a flap.It provides an effective and safe interventional measures for postoperative care of the transferred flap.

Objective To establish a risk prediction model,and to observe its value for predicting retained cesarean scar pregnancy(CSP)after ultrasound-guided curettage.Methods Data of 401 CSP patients who received ultrasound-guided curettage were retrospectively analyzed.The patients were randomly divided into training set(n=264)or validation set(n=137)at a ratio of 7:3.According to whether there was retained CSP at the lower segmental scar of uterine after ultrasound-guided curettage,the patients were divided into retained group or non-retained group.The variables with the biggest predictive value for retained CSP after ultrasound-guided curettage were selected with LASSO regression,and the independent risk factors were screened using multivariate logistic regression,and then a nomogram model was established.Results The results of LASSO regression and multivariate logistic regression indicated that embedded depth of gestational sac in cesarean scar more than 1.13 cm,convexity of gestational sac,rich blood supply(Adler degree Ⅱ-Ⅲ),and pre-curettage serum β-human chorionic gonadotropin(HCG)more than 33 063.50 U/L were all independent risk factors for retained CSP after curettage(all P＜0.05).The calibration curve of nomogram predictive model established based on the above indexes was basically consistent with the ideal curve,and the model had good clinical benefits.Conclusion The established nomogram predictive model had good predictive ability for retained CSP after curettage.