Objective To investigate the effects of increasing the ejection seat backrest angle on the body pressure distribution of pilots of different body types,and to provide a basis for the design of ejection seats,flight training,and the development of strategies to alleviate muscle fatigue.Methods Male fighter pilots were divided into normal and overweight groups according to their body mass index(BMI),and a total of 40 pilots were tested for the distribution of sitting pressure under the two seat inclination angles of 20°and 33°by using the body pressure distribution measurement system.The effects of different seat inclination angles on sitting comfort were also analyzed.Results The pressure distributions of pilots with different body types were significantly different at different seat inclination angles.Compared with the 20°seat,the 33°seat condition had a larger cushion contact area[F(1,78)=40.281,P<0.001],a smaller average pressure and average pressure gradient[F(1,78)=32.030,P<0.001;F(1,78)=12.594,P<0.001],and significantly reduced average,maximum pressure,and maximal pressure gradients for the backrest[F(1,78)=10.516,P=0.002;F(1,78)=26.803,P<0.001;F(1,78)=4.918,P=0.029,respectively].In addition,overweight individuals with BMI had a notable increase in the cushion contact area[F(1,78)=21.038,P<0.001]and the backrest contact area[F(1,78)=8.301,P=0.005].No significant interaction was observed for angle and BMI.Conclusion An increased seat inclination angle results in a more uniform distribution of pressure across the human body,thereby increasing comfort.Moreover,the disparities in pressure and backrest distribution across disparate body types at varying seat angles provide a vital foundation for the optimized design of seating.

Objective To explore the application value of Auto-prescription combined with low-dose contrast and adaptive statisti-cal iterative reconstruction-Veo(ASIR-V)algorithm in the computed tomography angiography(CTA)of thoracodorsal artery(TDA).Methods A total of 100 patients who underwent TDA CTA examination were prospectively selected.A tube voltage of 120 kVp and contrast agent of 1.5 mL/kg were used for group A(50 cases),and images were reconstructed with 40％ post-set ASIR-V.The Auto-prescription for tube voltage and contrast agent of 1.2 mL/kg were used for group B(50 cases),while images were reconstruc-ted with 40％,60％,and 80％ post-set ASIR-V,labeled as subgroups B1 to B3.The objective and subjective evaluation results of the images were compared between and within groups.Results Group A had an effective dose(ED)of 2.98(2.65,4.03)mSv,while group B had an ED of 1.92(1.44,3.33)mSv.The iodine intake in group B was lower than that in group A,and the CT value of the axillary artery in group B was significantly higher than that in group A(P＜0.001).With the increased of ASIR-V level in group B,the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the images gradually increased(P＜0.05).In terms of subjec-tive scores on axial images,both subgroups B2 and B3 were superior to group A(P＜0.001);with the increased of ASIR-V level in group B,subjective scores of axial images increased first and then decreased,among which subjective score of subgroup B2 was the highest and the differences were statistically significant(P＜0.001).In terms of subjective scores on three-dimensional image quality,subgroups B1 to B3 were superior to group A(P＜0.001).Conclusion The use of Auto-prescription combined with low-dose con-trast and 60％ ASIR-V can significantly optimize the display of TDA,and reduce the radiation dose and contrast agent dose to a certain extent.

Objective To explore the application value of deep learning image reconstruction(DLIR)algorithm combined with a large reconstruction matrix in lung nodules screening using low-dose computed tomography(LDCT)of the chest.Methods Patients who underwent LDCT scans were prospectively enrolled.The control group(group A)used the iterative reconstruction(IR)algorithm(Karl)with a reconstruction level of Karl 5,reconstructed images of 512×512(group A1)matrix,and 1 024 × 1 024(group A2)matrix.The experimental group employed DLIR combined with 512×512(group B)matrix and 1 024 × 1 024(group C)matrix for image reconstruction at levels 1-5,which were recorded as groups B1-5 and groups C1-5.The CT values and standard deviation(SD)values of the lung parenchyma and tracheal air were measured,and the signal-to-noise ratio(SNR)was calculated.The overall lung image quality was scored on a Likert 5-point scale,and the subgroup with the best lung image quality was selected.The lung nodule detec-tion rate and clarity were compared with group A1.Results Under the same reconstruction matrix,the CT values of the tracheal air and lung parenchyma in the experimental group showed no significant difference compared to the control group,while the SD values were lower and SNR were higher(P＜0.05).Within groups B and C,as the DLIR level increased,the SD values of the tracheal air and lung paren-chyma gradually decreased,and SNR gradually improved(P＜0.05).Subjective scores for the image quality in groups B and C initially increased and then decreased,with group B3 and group C4 showed the best image quality.No difference was observed in objective eval-uation between the two groups,but the subjective image quality score of group C4 was superior to group B3(P＜0.05).Subjective eval-uation of lung nodule display in group C4 was better than in group A1(P＜0.05).Conclusion DLIR algorithm combined with a large reconstruction matrix is feasible for lung nodules screening in chest LDCT,reducing image noise while improving lung nodules clarity,demonstrating significant clinical value.

Objective:To characterize the vaginal flora of pregnant women during the second trimester using full-length 16S rRNA sequencing.Methods:A total of 142 pregnant women were systematically sampled from a pregnancy cohort. Vaginal swabs were collected for full-length 16S rRNA gene sequencing，and bioinformatics analysis was performed to characterize the vaginal microbiota and identify associated influencing factors.Results:Among the 142 pregnant women，the most frequently detected species were Lactobacillus iners（83.10%，118/142）and Lactobacillus crispatus（49.30%，70/142）. The majority of samples（90.85%，129/142）were classified as Lactobacillus-dominant vagitypes，with the Lactobacillus iners vagitype accounting for 48.59%（69/142）and the Lactobacillus crispatus vagitype accounting for 38.73%（55/142）. The vaginal microbiota was clustered into five community state types（CSTs）：Ⅰa，Ⅰb，Ⅲa，Ⅲb，and Ⅳ. The most prevalent CSTs were Lactobacillus iners-dominated CST-Ⅲ（51.41%，73/142）and Lactobacillus crispatus-dominated CST-Ⅰ（24.65%，35/142）. No samples were classified as CST-Ⅱ or CST-Ⅴ. A significant negative correlation was observed between Lactobacill and vaginosis-associated bacteria. Age，alcohol consumption，smoking，and vaginal treatments showed significant associations or trends toward significance with various Alpha diversity indices. Vaginal douching was associated with CST clustering，while obstetric history（primiparity，previous miscarriage history）was associated with vagitype classification. However，no significant associations were identified between maternal baseline characteristics and Beta diversity indices. Conclusions:Full-length 16S rRNA gene sequencing reveals that the vaginal microbiota of pregnant women is dominated by Lactobacillus iners and Lactobacillus crispatus. Maternal age，lifestyle factors such as smoking and alcohol consumption，and obstetric history are significantly associated with variations in vaginal microbiota composition.

Objective:To develop a camelid single-domain antibody (SdAb) recognizing linear B-cell epitopes in glutamate dehydrogenase of Clostridium difficile(CD-GDH), and to apply it in Western blot and ELISA. Methods:Purified recombinant CD-GDH was used as bait to screen phage-displayed camelid SdAb library and obtain positive clones. Then those clones were confirmed by Western blot, and their variable domain of heavy chain of heavy chain antibody(VHH) nucleotide sequence were determined. The VHH sequence was synthesized after codon optimization and cloned into the expression vector pET28a. The SdAb was then expressed and purified, and its ability to detect CD-GDH protein in multiple assays was further explored.Results:Six positive clones were obtained, among which clone GA4 was chosen for recombinant expression in Escherichia coli and further purification. The purified GA4 binded well with CD-GDH with a Kd value of 3 nmol/L. In Western blot and ELISA, GA4 was proven to be able to selectively detect both recombinant and endogenous CD-GDH. Conclusions:A camelid SdAb targeting a linear B-cell epitope in CD-GDH is successfully developed, which provides a very useful tool for detecting CD-GDH.

Objective:To explore the application value of the double-low technique of auto-prescription technique combined with iterative reconstruction algorithm in CT pulmonary angiography (CTPA).Methods:A total of 86 patients who were clinically suspected of having pulmonary embolism and underwent CTPA examination in the First Affiliated Hospital of Dalian Medical University were prospectively collected and randomly assigned to a control group ( n = 45) and an observation group ( n = 41) according to the random number table method. In the control group, a tube voltage of 120 kVp was used with a standard iodine contrast agent dose of 60 ml, and images were reconstructed using the 40% adaptive statistical iterative reconstruction algorithm (ASIR-V). In the observation group, the tube voltage was set by auto-prescription technique, and 0.4 ml/kg of personalized low iodine contrast agent was used. Images were reconstructed with 40%, 60%, and 80% ASIR-V, respectively, and designated as observation 1, observation 2, and observation 3 respectively. The volume CT dose index (CTDI vol), dose-length product (DLP), and effective dose ( E) were recorded and compared among the four groups. The CT values and standard deviation (SD) of the main pulmonary artery, left and right pulmonary arteries, as well as the left and right pulmonary lobe arteries were measured, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of these arteries were calculated. Additionally, the SD value at the contrast medium concentration in the superior vena cava was measured, and the artifact index (AI) was subsequently calculated. Two observers independently assessed the visibility of the pulmonary arteries, image noise, and sclerosis artifacts in the superior vena cava using a blinded method. Results:The E in the observation group was 3.28 (2.08, 3.93) mSv, which was significantly lower than that in the control group [5.03 (4.86, 5.20)] mSv, and the difference was statistically significant ( Z = 174.00, P < 0.05). The contrast agent dosage in the observation group was 28 (25, 30) ml, which was lower than that in the control group (60 ml), and the difference was statistically significant ( Z = 0, P < 0.05). The CT values for the main pulmonary artery and the left and right pulmonary lobe arteries in the observation group were higher than those in the control group, and the differences were all statistically significant ( t = -3.65 to -3.89, P < 0.05). The SNR and CNR of the observation groups 2 and 3 were greater than those of the control group ( t = -9.20 to -2.98, P < 0.05). The consistency of subjective evaluations between the two observers was good ( Kappa = 0.729 - 0.879, P < 0.05). There was no statistically significant difference in the subjective score of pulmonary artery visibility between the control and observation group ( P > 0.05). The subjective scores for image noise in observation group 2 and group 3 were higher than those in the control group ( U =598.50, 654.00, P < 0.05). The presence of artifacts due to sclerosis in the superior vena cava was significantly lower in the observation group compared to the control group ( χ2 = 46.09, P < 0.001). Conclusions:The combination of auto-prescription technique with ASIR-V reconstruction algorithm and low contrast agent imaging protocol can reduce the radiation dose and contrast agent dose without compromising image quality, and enable personalized double low CTPA imaging.

Objective:To characterize the vaginal flora of pregnant women during the second trimester using full-length 16S rRNA sequencing.Methods:A total of 142 pregnant women were systematically sampled from a pregnancy cohort. Vaginal swabs were collected for full-length 16S rRNA gene sequencing，and bioinformatics analysis was performed to characterize the vaginal microbiota and identify associated influencing factors.Results:Among the 142 pregnant women，the most frequently detected species were Lactobacillus iners（83.10%，118/142）and Lactobacillus crispatus（49.30%，70/142）. The majority of samples（90.85%，129/142）were classified as Lactobacillus-dominant vagitypes，with the Lactobacillus iners vagitype accounting for 48.59%（69/142）and the Lactobacillus crispatus vagitype accounting for 38.73%（55/142）. The vaginal microbiota was clustered into five community state types（CSTs）：Ⅰa，Ⅰb，Ⅲa，Ⅲb，and Ⅳ. The most prevalent CSTs were Lactobacillus iners-dominated CST-Ⅲ（51.41%，73/142）and Lactobacillus crispatus-dominated CST-Ⅰ（24.65%，35/142）. No samples were classified as CST-Ⅱ or CST-Ⅴ. A significant negative correlation was observed between Lactobacill and vaginosis-associated bacteria. Age，alcohol consumption，smoking，and vaginal treatments showed significant associations or trends toward significance with various Alpha diversity indices. Vaginal douching was associated with CST clustering，while obstetric history（primiparity，previous miscarriage history）was associated with vagitype classification. However，no significant associations were identified between maternal baseline characteristics and Beta diversity indices. Conclusions:Full-length 16S rRNA gene sequencing reveals that the vaginal microbiota of pregnant women is dominated by Lactobacillus iners and Lactobacillus crispatus. Maternal age，lifestyle factors such as smoking and alcohol consumption，and obstetric history are significantly associated with variations in vaginal microbiota composition.

Objective:To develop a camelid single-domain antibody (SdAb) recognizing linear B-cell epitopes in glutamate dehydrogenase of Clostridium difficile(CD-GDH), and to apply it in Western blot and ELISA. Methods:Purified recombinant CD-GDH was used as bait to screen phage-displayed camelid SdAb library and obtain positive clones. Then those clones were confirmed by Western blot, and their variable domain of heavy chain of heavy chain antibody(VHH) nucleotide sequence were determined. The VHH sequence was synthesized after codon optimization and cloned into the expression vector pET28a. The SdAb was then expressed and purified, and its ability to detect CD-GDH protein in multiple assays was further explored.Results:Six positive clones were obtained, among which clone GA4 was chosen for recombinant expression in Escherichia coli and further purification. The purified GA4 binded well with CD-GDH with a Kd value of 3 nmol/L. In Western blot and ELISA, GA4 was proven to be able to selectively detect both recombinant and endogenous CD-GDH. Conclusions:A camelid SdAb targeting a linear B-cell epitope in CD-GDH is successfully developed, which provides a very useful tool for detecting CD-GDH.

Objective:To explore the application value of the double-low technique of auto-prescription technique combined with iterative reconstruction algorithm in CT pulmonary angiography (CTPA).Methods:A total of 86 patients who were clinically suspected of having pulmonary embolism and underwent CTPA examination in the First Affiliated Hospital of Dalian Medical University were prospectively collected and randomly assigned to a control group ( n = 45) and an observation group ( n = 41) according to the random number table method. In the control group, a tube voltage of 120 kVp was used with a standard iodine contrast agent dose of 60 ml, and images were reconstructed using the 40% adaptive statistical iterative reconstruction algorithm (ASIR-V). In the observation group, the tube voltage was set by auto-prescription technique, and 0.4 ml/kg of personalized low iodine contrast agent was used. Images were reconstructed with 40%, 60%, and 80% ASIR-V, respectively, and designated as observation 1, observation 2, and observation 3 respectively. The volume CT dose index (CTDI vol), dose-length product (DLP), and effective dose ( E) were recorded and compared among the four groups. The CT values and standard deviation (SD) of the main pulmonary artery, left and right pulmonary arteries, as well as the left and right pulmonary lobe arteries were measured, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of these arteries were calculated. Additionally, the SD value at the contrast medium concentration in the superior vena cava was measured, and the artifact index (AI) was subsequently calculated. Two observers independently assessed the visibility of the pulmonary arteries, image noise, and sclerosis artifacts in the superior vena cava using a blinded method. Results:The E in the observation group was 3.28 (2.08, 3.93) mSv, which was significantly lower than that in the control group [5.03 (4.86, 5.20)] mSv, and the difference was statistically significant ( Z = 174.00, P < 0.05). The contrast agent dosage in the observation group was 28 (25, 30) ml, which was lower than that in the control group (60 ml), and the difference was statistically significant ( Z = 0, P < 0.05). The CT values for the main pulmonary artery and the left and right pulmonary lobe arteries in the observation group were higher than those in the control group, and the differences were all statistically significant ( t = -3.65 to -3.89, P < 0.05). The SNR and CNR of the observation groups 2 and 3 were greater than those of the control group ( t = -9.20 to -2.98, P < 0.05). The consistency of subjective evaluations between the two observers was good ( Kappa = 0.729 - 0.879, P < 0.05). There was no statistically significant difference in the subjective score of pulmonary artery visibility between the control and observation group ( P > 0.05). The subjective scores for image noise in observation group 2 and group 3 were higher than those in the control group ( U =598.50, 654.00, P < 0.05). The presence of artifacts due to sclerosis in the superior vena cava was significantly lower in the observation group compared to the control group ( χ2 = 46.09, P < 0.001). Conclusions:The combination of auto-prescription technique with ASIR-V reconstruction algorithm and low contrast agent imaging protocol can reduce the radiation dose and contrast agent dose without compromising image quality, and enable personalized double low CTPA imaging.

Following the evidence-based diagnosis and treatment guideline development method for common pediatric diseases,the The Guideline for the Diagnosis and Treatment of Pediatric Food Accumulation and Stagnation in Chinese Medicine was formed through literature retrieval,expert questionnaire survey,expert discussion meeting,and solicitation of opinions.The revised content includes the scope of the guideline,normative reference documents,terms and definitions,diagnosis,syndrome differentiation,treatment,pre-vention and nursing suggestions,etc.,aiming to update the clinical diagnosis and treatment plan of Chinese medicine for accumulation and provide important clinical decision-making references for clinical physicians to rationally apply the diagnosis and treatment plan of Chinese medicine in the prevention and treatment of accumulation and stagnation in Children.