End-tidal carbon dioxide monitoring is an important means of evaluating human lung function and is widely used in fields such as clinical emergency treatment and cardiopulmonary resuscitation. This paper develops a microstream end-tidal carbon dioxide monitoring system. It adopts an integrated gas circuit design to further reduce the size of the equipment. The system uses the method of calculating the root mean square (RMS) of differential pressure signals to regulate the gas circuit flow, enabling the system to stably operate at a flow state of 30 mL/min. In addition, by simultaneously detecting multiple environmental parameters such as temperature and pressure, the system realizes system state monitoring and gas parameter compensation. The test results show that various indicators of the system meet the requirements of relevant standards, laying a good foundation for subsequent engineering applications.
Carbon Dioxide/analysis* ; Equipment Design ; Monitoring, Physiologic/methods* ; Humans

Objective:To investigate the value of the five-sectional screening method of the central nervous system（CNS）in early detection of fetal CNS abnormalities during the first trimester.Methods:The data of pregnant women who underwent nuchal translucency（NT）screening at the Affiliated Suzhou Hospital of Nanjing Medical University from September 2018 to September 2023 were retrospectively analyzed. And a five-sectional screening method of CNS was performed in all fetuses at the meantime. The five-sectional screening protocol in the first trimester consists of the mid-sagittal plane of the fetal head，trans-ventricular plane，trans-thalamus plane，axial plane of the fetal head at the posterior fossa level，and the sagittal plane of the fetal spine. All fetuses underwent ultrasound screening during the second trimester and the third trimester sequentially after NT screening. All the ultrasound findings were tracked，and all fetuses were followed up until delivery or after induction. Fetuses with CNS abnormalities found or suspected in the first trimester were reviewed by at least one senior physician，and follow-up examinations were routinely performed after 2 weeks to further confirm the diagnosis or find other abnormalities that may be present.Results:A total of 13 679 fetuses were screened，included 11 415 singleton pregnancies and 1 132 twin pregnancies. Among them，there were 289 cases of missed follow-up and unexplained fetal death，included 263 singleton pregnancies and 13 twin pregnancies. A total of 13 390 fetuses were finally included，among which，35 cases developed CNS abnormalities with 34 cases detected by prenatal ultrasound and 1 case of closed spina bifida missed in prenatal diagnosis，and the detection rate of CNS malformation by prenatal ultrasound was 97.14%（34/35）. Of the 35 fetuses with CNS abnormalities，24 were detected by the CNS five-sectional screening method in the first trimester，with a sensitivity of 68.57%，a specificity of 100%，a positive predictive value of 100%，and a negative predictive value of 99.92%. Among them，there were 2 cases of anencephaly，3 cases of exencephaly and 6 cases of encephalocele were all detected in the first trimester. In addition，6 cases of holoprosencephaly，3 cases of severe ventriculomegaly，2 cases of open spina bifida，and 2 cases of Dandy-Walker malformation were detected in the first trimester. In this study，1 case of agenesis of corpus callosum（ACC），1 case of arachnoid cyst，1 case of lissencephaly，1 case of schizencephaly，and 1 case of mega cisterna magna were not detected in early pregnancy.Conclusions:The fetal five-sectional screening method of CNS in the first trimester has high specificity，positive predictive value and negative predictive value for the detection of fetal CNS abnormalities，but the sensitivity is moderate. The five-sectional screening method for CNS in early pregnancy may be an effective method for early detection of fetal CNS abnormalities.

Objective:To explore the clinical application value of artificial intelligence（AI）-assisted training in enhancing the accuracy of nuchal translucency（NT）identification，standardization of measurement，and diagnostic efficacy for abnormalities among ultrasound residents.Methods:A retrospective collection of 300 standard fetal NT ultrasound images was conducted at the Center for Medical Ultrasound，Suzhou Hospital Affiliated of Nanjing Medical University from January 2018 to June 2024. The AI model performed NT measurements and diagnoses once. Four sonographers of different seniority levels（including two resident physicians）independently conducted NT measurements and diagnoses twice. Prior to the experiment，the middle-age and resident sonographers had uniformly completed traditional theory training. Following the first independent measurements，the two resident sonographers received additional AI-assisted training，after which all 4 sonographers performed the second independent measurements. A fetal medicine expert evaluated blindly all the results and compared the differences in NT recognition accuracy，measurement standard rate and diagnosis accuracy between the middle-age sonographer（traditional training only）and two resident sonographers（traditional + AI-assisted training）.Results:For the middle-aged sonographer who only received traditional lecture-based training，the accuracy of NT recognition，standardization rate of measurement，or diagnostic accuracy were not significantly improved befroe and after the training，and the diffrence was not statistically significant（ χ2=0.189，1.887，0.326；all P>0.05）. In contrast，the second-year resident（Resident 2）and first-year resident（Resident 1），who received both traditional lecture-based training and AI training，demonstrated some improvements in the accuracy of NT measurement site recognition，though the differences were not statistically significant（ χ2=1.301，2.418；all P>0.05）. However，both residents did significant improvements in the standardization rate of NT measurement（ χ2=25.768，17.035；all P<0.05）. In terms of diagnostic accuracy，Resident 1 did significant improvement（ χ2=10.180， P<0.05），while Resident 2 also did some improvement，though the difference was not statistically significant（ χ2=2.573， P>0.05）. Conclusions:The AI-assisted training system enhances the ability of ultrasound resident sonographers to recognize，measure，and diagnose NT，providing a novel and efficient training model for standardized residency training in ultrasound specialties.

Objective:To investigate the diagnostic value of fetal cardiac ultrasound view visualization in the first trimester for congenital heart disease（CHD）.Methods:A retrospective analysis was performed on 13 323 singleton fetuses who underwent first-trimester（11-13 +6 weeks）ultrasound screening at the Ultrasound Medicine Center，the Affiliated Suzhou Hospital of Nanjing Medical University from January 2018 to June 2024. Cardiac views including the four-chamber view（4CV），left ventricular outflow tract view（LVOT），and Results:The study group showed significantly higher rates of "poorly visualized" 4CV，LVOT，and 3VT than the control group（2.70% vs. 0.14%， P=0.005；36.49% vs. 4.76%， P<0.001；36.49% vs.2.46%， P<0.001）. The efficacies of combination 1（any view abnormal）and combination 2（any view "poorly visualized" or "abnormal"）were comparable，with AUCs of 0.86 and 0.85（ P=0.424）. The AUCs of combination 3（3VT "poorly visualized" or any view "abnormal"）and combination 4（4CV "poorly visualized" or any view "abnormal"）were 0.88 and 0.86（ P=0.424），all significantly higher than combination 5（LVOT "poorly visualized" or any view "abnormal"，AUC=0.84，all P<0.05）. Conclusions:"Poorly visualized" cardiac views in the first trimester demonstrate good diagnostic efficacy for CHD，particularly when 3VT or 4CV are affected，warranting heightened clinical vigilance for fetal cardiac anomalies.

Objective:To investigate the value of the five-sectional screening method of the central nervous system（CNS）in early detection of fetal CNS abnormalities during the first trimester.Methods:The data of pregnant women who underwent nuchal translucency（NT）screening at the Affiliated Suzhou Hospital of Nanjing Medical University from September 2018 to September 2023 were retrospectively analyzed. And a five-sectional screening method of CNS was performed in all fetuses at the meantime. The five-sectional screening protocol in the first trimester consists of the mid-sagittal plane of the fetal head，trans-ventricular plane，trans-thalamus plane，axial plane of the fetal head at the posterior fossa level，and the sagittal plane of the fetal spine. All fetuses underwent ultrasound screening during the second trimester and the third trimester sequentially after NT screening. All the ultrasound findings were tracked，and all fetuses were followed up until delivery or after induction. Fetuses with CNS abnormalities found or suspected in the first trimester were reviewed by at least one senior physician，and follow-up examinations were routinely performed after 2 weeks to further confirm the diagnosis or find other abnormalities that may be present.Results:A total of 13 679 fetuses were screened，included 11 415 singleton pregnancies and 1 132 twin pregnancies. Among them，there were 289 cases of missed follow-up and unexplained fetal death，included 263 singleton pregnancies and 13 twin pregnancies. A total of 13 390 fetuses were finally included，among which，35 cases developed CNS abnormalities with 34 cases detected by prenatal ultrasound and 1 case of closed spina bifida missed in prenatal diagnosis，and the detection rate of CNS malformation by prenatal ultrasound was 97.14%（34/35）. Of the 35 fetuses with CNS abnormalities，24 were detected by the CNS five-sectional screening method in the first trimester，with a sensitivity of 68.57%，a specificity of 100%，a positive predictive value of 100%，and a negative predictive value of 99.92%. Among them，there were 2 cases of anencephaly，3 cases of exencephaly and 6 cases of encephalocele were all detected in the first trimester. In addition，6 cases of holoprosencephaly，3 cases of severe ventriculomegaly，2 cases of open spina bifida，and 2 cases of Dandy-Walker malformation were detected in the first trimester. In this study，1 case of agenesis of corpus callosum（ACC），1 case of arachnoid cyst，1 case of lissencephaly，1 case of schizencephaly，and 1 case of mega cisterna magna were not detected in early pregnancy.Conclusions:The fetal five-sectional screening method of CNS in the first trimester has high specificity，positive predictive value and negative predictive value for the detection of fetal CNS abnormalities，but the sensitivity is moderate. The five-sectional screening method for CNS in early pregnancy may be an effective method for early detection of fetal CNS abnormalities.

Objective:To explore the clinical application value of artificial intelligence（AI）-assisted training in enhancing the accuracy of nuchal translucency（NT）identification，standardization of measurement，and diagnostic efficacy for abnormalities among ultrasound residents.Methods:A retrospective collection of 300 standard fetal NT ultrasound images was conducted at the Center for Medical Ultrasound，Suzhou Hospital Affiliated of Nanjing Medical University from January 2018 to June 2024. The AI model performed NT measurements and diagnoses once. Four sonographers of different seniority levels（including two resident physicians）independently conducted NT measurements and diagnoses twice. Prior to the experiment，the middle-age and resident sonographers had uniformly completed traditional theory training. Following the first independent measurements，the two resident sonographers received additional AI-assisted training，after which all 4 sonographers performed the second independent measurements. A fetal medicine expert evaluated blindly all the results and compared the differences in NT recognition accuracy，measurement standard rate and diagnosis accuracy between the middle-age sonographer（traditional training only）and two resident sonographers（traditional + AI-assisted training）.Results:For the middle-aged sonographer who only received traditional lecture-based training，the accuracy of NT recognition，standardization rate of measurement，or diagnostic accuracy were not significantly improved befroe and after the training，and the diffrence was not statistically significant（ χ2=0.189，1.887，0.326；all P>0.05）. In contrast，the second-year resident（Resident 2）and first-year resident（Resident 1），who received both traditional lecture-based training and AI training，demonstrated some improvements in the accuracy of NT measurement site recognition，though the differences were not statistically significant（ χ2=1.301，2.418；all P>0.05）. However，both residents did significant improvements in the standardization rate of NT measurement（ χ2=25.768，17.035；all P<0.05）. In terms of diagnostic accuracy，Resident 1 did significant improvement（ χ2=10.180， P<0.05），while Resident 2 also did some improvement，though the difference was not statistically significant（ χ2=2.573， P>0.05）. Conclusions:The AI-assisted training system enhances the ability of ultrasound resident sonographers to recognize，measure，and diagnose NT，providing a novel and efficient training model for standardized residency training in ultrasound specialties.

Objective:To investigate the diagnostic value of fetal cardiac ultrasound view visualization in the first trimester for congenital heart disease（CHD）.Methods:A retrospective analysis was performed on 13 323 singleton fetuses who underwent first-trimester（11-13 +6 weeks）ultrasound screening at the Ultrasound Medicine Center，the Affiliated Suzhou Hospital of Nanjing Medical University from January 2018 to June 2024. Cardiac views including the four-chamber view（4CV），left ventricular outflow tract view（LVOT），and Results:The study group showed significantly higher rates of "poorly visualized" 4CV，LVOT，and 3VT than the control group（2.70% vs. 0.14%， P=0.005；36.49% vs. 4.76%， P<0.001；36.49% vs.2.46%， P<0.001）. The efficacies of combination 1（any view abnormal）and combination 2（any view "poorly visualized" or "abnormal"）were comparable，with AUCs of 0.86 and 0.85（ P=0.424）. The AUCs of combination 3（3VT "poorly visualized" or any view "abnormal"）and combination 4（4CV "poorly visualized" or any view "abnormal"）were 0.88 and 0.86（ P=0.424），all significantly higher than combination 5（LVOT "poorly visualized" or any view "abnormal"，AUC=0.84，all P<0.05）. Conclusions:"Poorly visualized" cardiac views in the first trimester demonstrate good diagnostic efficacy for CHD，particularly when 3VT or 4CV are affected，warranting heightened clinical vigilance for fetal cardiac anomalies.

Objective:To investigate the association between serum levels of thyroglobulin (Tg), thyroid stimulating hormone (TSH) and antibodies and lymph node metastasis (LNM) in papillary thyroid cancer (PTC) .Methods:A total of 1 502 patients with PTC who were admitted to the Department of Breast and Thyroid Surgery of the First Affiliated Hospital of Chongqing Medical University from Jan. 2019 to Jan. 2022 were retrospectively enrolled, including males ( n=431), females ( n=1 071), aged < 55 years ( n=1 271), and ≥ 55 years old ( n=231). All patients were pathologically confirmed to have PTC after surgery. Univariate analysis was performed on the general data of patients and the indexes in the postoperative pathology report and the LNM group, and the data of P<0.05 in the analysis were included in the regression analysis to determine the independent risk factors of cervical LNM in PTC patients. Patients were divided into 8 subgroups according to the different statuses of the three thyroid antibodies (TGAb, TPOAb, TRAb) : [ (+) indicates positive; (-) indicates negative]. According to the order of TGAb, TPOAb, and TRAb, there are the following 8 states, 1 (+++) ; 2 (---) ; 3 (++-) ; 4 (+--) ; 5 (+-+) ; 6 (-+-) ; 7 (-++) ; 8 (--+). The differences in general clinical information, Tg and TSH between the two groups were compared, and the receiver operating characteristic curve (ROC) curve of Tg in the diagnosis of PTC lymph node metastasis was constructed, and regression analysis was used to explore the diagnostic value of serological indicators in the diagnosis of cervical LNM in PTC. Results:In this study, compared with the non-metastasis group, there were 308 males (33.2%) and 225 patients (24.3%) with bilateral PTC in metastasis group. The mean serum Tg value was (25.5±2.1) ng/mL and the TSH level was significantly increased ( P<0.05), and the results of binary logistic regression analysis showed that males ( OR=1.57, P<0.001), bilateral PTC ( OR=1.448, P<0.001), non-papillary carcinoma (>10 mm) ( OR=1.745, P<0.001) and increased Tg level ( OR=1.007, P=0.002) were independent risk factors for cervical lymph node metastasis in PTC patients, and the area under the ROC curve of Tg in the evaluation of cervical lymph node metastasis was 0.634 [95% CI (0.636, 0.691), P<0.05], while the TSH status was 0.56-1.39 ( OR=0.375, P=0.013). 1.40-2.29 ( OR=0.422, P=0.003) ; 2.30-5.91 ( OR=0.466, P=0.004) ; ≥5.91 ( OR=0.41, P=0.001) was not a risk factor. Conclusion:Male sex, bilateral thyroid cancer, non-papillary carcinoma (>10 mm), and preoperative serum Tg>29.8 ng/mL are the influencing factors of LNM in PTC patients.

Objective:To establish reference ranges of central nervous system-related fetal intracranial markers during the first trimester in a local population of Suzhou.Methods:Ultrasound images of fetuses with normal birth outcomes in singleton pregnancies who underwent nuchal translucency(NT) screening during the first trimester (11-13 + 6 gestational weeks) from January 2021 to July 2022 at the Affiliated Suzhou Hospital of Nanjing Medical University were retrospectively selected. The images including 3 planes: the midsagittal plane of the fetal head, also known as the plane for NT measurement, the trans-ventricular plane of the fetal head, and the axial plane of the fetal head at the posterior fossa level. The brainstem (BS) thickness, brainstem to occipital bone distance (BSOB), the ratio of BS to BSOB (BS/BSOB), intracranial translucency (IT) thickness, cisterna magna (CM) width, and the midbrain (MB) to falx (F) ratio MB/F were measured in the mid-sagittal plane of the fetal head. Choroid plexus length (CPL) to occipital frontal diameter (OFD) ratio CPL/OFD, and choroid plexus area (CPA) to head area (HA) ratio CPA/HA were measured in the trans-ventricular plane of the fetal head. Anteroposterior diameter of the fourth ventricle (4V) and CM were measured in the axial plane of the fetal head at the posterior fossa level.Statistical analysis was performed to obtain the corresponding normal reference range.Intra-class correlation coefficient (ICC) was used to analyze intra-observer and inter-observer consistency. Pearson correlation analysis and linear correlation analysis were used to study the correlations between crown-lump length (CRL) and intracranial markers, and the regression equation was derived. Results:A total of 2 331 fetuses were enrolled, providing 1 023 images of the midsagittal plane, 817 images of the trans-ventricular plane, and 567 images of the axial plane of the fetal head at the posterior fossa level. The intra-observer and inter-observer ICCs of intracranial markers BS, BSOB, BS/BSOB, IT thickness, CM width, MB/F in the mid-sagittal plane, the intracranial markers CPL/OFD, CPA/HA on the trans-ventricular plane, and the intracranial markers 4V and CM width in the axial plane at the posterior fossa level were all >0.75. Fetal intracranial markers were linearly correlated with CRL. The midsagittal plane: BS, BSOB, BS/BSOB, IT thickness, CM width, MB/F were linearly correlated with CRL ( r=0.508, 0.626, -0.234, 0.105, 0.508, -0.493; all P<0.05); the trans-ventricular plane: CPL/OFD, CPA/HA were linearly correlated with CRL( r=-0.324, -0.268; all P<0.001); the axial plane of the fetal head at the posterior fossa level: 4V, CM width were linearly correlated with CRL ( r=0.246, 0.467; all P<0.001). Conclusions:Quantitative analysis of fetal intracranial markers in the first trimester is feasible. This study constructed a normal reference range of multiple intracranial markers related to central nervous system in the first trimester with a local population of Suzhou. And the construction of this normal range can provide an objective basis for the detection of fetal central nervous system malformations in the first trimester.

The emerging and re-emerging arthropod-borne infectious diseases pose a serious threat to global public health security. Field and laboratory studies of arthropods of medical importance are essential and critical for the prevention and control of arthropod-borne infectious diseases. Various institutions or universities in China have been conducting research in the field or laboratory study of arthropods of medical importance, but up to 2023, it is still lacking detailed biosafety guidelines or recommendations that can guide the related work for arthropods of medical importance. In order to proactively address potential biosafety issues in the field or laboratory activities related to arthropods of medical importance, improve the standardization of arthropod biosafety classification, operations, and protection, and ensure the safety of practitioners, an expert consensus on the biosafety recommendation of arthropods of medical importance in field and laboratory has been developed, aiming to guide the future work of arthropods and ensure the national biosafety and biosecurity of China.