Meconium is changed from defoliated intestinal villi with apoptosis. A meconium corpuscle is a limited architecture in the meconium at the light microscopic level. In histological and immunohistochemical sections of the abdomen from 40 fetuses at 20–31 weeks of gestation, we found 12 fetuses with meconium and examined the architecture.A solid or loose meconium was seen depending on sites. The solid meconium in the colon and rectum contained numerous spherical or rugby ball-like corpuscles comprising of a core with tightly-packed atrophied cells and a laminar fibrous sheath.The solid meconium surrounded and incorporated villi that maintained the original architecture. The loose meconium was seen not only in the stomach and duodenum but also, depending on specimens, in the colon and rectum. It was composed of a large mucosal fold, a single small villus and/or fragmented epithelia. Notably, these mucosal tissues still contained chromogranin-positive gastrointestinal cells and cytokeratin-positive epithelia. A large ring-like meconium was composed of the entirely circular mucosa or epithelia that seemed to be detached along the muscularis mucosae or the basal lamina.A sheath-like fibrous structure in meconium seemed to originate from the lamina propria and basal lamina of villi. A defoliation of villi with apoptosis seemed difficult to explain a detachment of the entirely circular mucosa or epithelia in large fetuses examined. The latter event might require a specific mechanism such as an in utero intussusception in which a proximal side of the colon was invaginated into the distal lumen.

Objective To analyze the effects of left bundle branch area pacing(LBBaP)on atrial fibrillation occurrence after dual-chamber pacemaker implantation.Methods The medical records of 87 patients who underwent dual-chamber pacemaker implantation at People's Hospital between May 2021 and September 2022 were retrospectively analyzed.According to different implantation methods,the patients were divided into an observation group(n=45)and a control group(n=42).The control group received traditional right ventricular pacing(RVP),while the observation group received LBBaP.Serum N-terminal pro B-type natriuretic peptide(NT-proBNP),QRS onset-to-end duration(QRSd),echocardiographic parameters,cardiac pacing parameters,complications,atrial high-rate events,and atrial fibrillation incidence were compared between the two groups.Results Twelve months after surgery,serum NT-proBNP levels in the observation group were significantly lower than those in the control group(P＜0.05),and QRS duration(QRSd)was shorter in the observation group than in the control group(P＜0.05).There were no significant differences in left ventricular ejection fraction(LVEF)or left ventricular end-systolic diameter(LVESD)between the two groups at 12 months postoperatively(P＞0.05).Left atrial diameter(LAD)was smaller in the observation group than in the control group at 12 months postoperatively(P＜0.05).No significant differences were observed in sensing levels or the proportion of cardiac pacing between the two groups(P＞0.05).However,the proportion of ventricular pacing was higher in the observation group than in the control group(P＜0.05).Intraoperatively and at 12 months postoperatively,impedance levels were lower in the observation group than in the control group(P＜0.05),while threshold values were higher in the observation group(P＜0.05).Total complication rates did not differ significantly between the two groups(P＞0.05).At 12 months postoperatively,the incidence of atrial fibrillation was similar between the two groups(P＞0.05),but the incidence of atrial high-rate events was lower in the observation group than in the control group(P＜0.05).At 24 months postoperatively,both the incidence of atrial high-rate events and atrial fibrillation were lower in the observation group than in the control group(P＜0.05).Conclusion Compared with traditional RVP implantation,LBBaP implantation can significantly improve left heart function,provide more stable pacing parameters,and reduce the risk of long-term atrial high-rate events and atrial fibrillation.The risk of complications is similar for both groups,but LBBaP implantation increases the pacing threshold.

Objective To analyze the effect of dronedarone and propafenone in preventing postoperative recurrence in patients with atrial fibrillation(AF)and to discuss its influence on inflammatory response and myocardial injury.Methods A total of 113 patients with AF,who were admitted to the Qiandongnan People's Hospital of China from July 2022 to March 2024,were enrolled in this study.By using random number table method,the patients were divided into control group(n=56)and study group(n=57).All patients received circumpulmonary vein electrical isolation.After treatment,the patients of control group were given propafenone orally for three months,while the patients of study group received dronedarone orally for three months.Both the preoperative and postoperative 3-month inflammatory response indicators including hypersensitive C-reactive protein(Hs-CRP),leucolipin,nucleotide-bound oligomeric domain-like receptor protein 3(NLRP3)inflammasome,and tumor necrosis factor α(TNF-α),the echocardiographic indicators including left atrial maximum volume(LAMV),left ventricular end-systolic diameter(LVESD),and left ventricular ejection fraction(LVEF),the myocardial injury markers including creatine kinase(CK),cardiac troponin I(cTn I),the central nervous specific protein β(S100β),the creatine kinase isoenzyme(CK-MB),the adverse reactions,and the recurrence of AF were compared between the two groups.Results At 3 months after treatment,the serum levels of hs-CRP,leucolipin,NLRP3 inflammasome and TNF-α were decreased in both groups(all P＜0.01),which in the study group were obviously lower than those in the control group(all P＜0.001);the levels of LAMV and LVESD were decreased in both groups(both P＜0.01),which in the study group were remarkably lower than those in the control group(both P＜0.001);the level of LVEF was increased in both groups(P＜0.01),which in the study group was significantly higher than that in the control group(P＜0.001);the levels of CK,cTn I,S100β,and CK-MB were decreased in both groups(all P＜0.01),which in the study group were strikingly lower than those in the control group(all P＜0.001).The incidence of adverse drug reactions in control group and in the study group was 5.36％(3/56)and 7.02％(4/57 cases)respectively,and the difference was not statistically significant(P＞0.05).Within 3 months after treatment,the recurrence rate in the study group was 5.26％(3/57),which was lower than 19.64％(11/56)in the control group,and the difference was statistically significant(P＜0.05).Conclusion Compared with propafenone,the use of dronedarone after circumferential pulmonary vein electrical isolation in patients with AF can improve the cardiac functions,reduce myocardial injury and inflammatory responses,and lower the risk of postoperative recurrence of AF.

Objective To investigate the status of population dynamics and distribution changes of Aedes aegypti in Guangdong Province.Methods Continuous monitoring was conducted from May 2018 to July 2024 in Wushi Town and Qishui Town,Leizhou City,Zhanjiang City,Guangdong Province.Additionally,a survey of the distribution of Ae.aegypti along the Leizhou Peninsula coast was carried out.Results The density of Ae.aegypti in Zhanjiang showed a gradual decline from 2018 to 2024.The last detection of adult Ae.aegypti in Wushi Town was in September 2021,and the last larva was found in October 2023.No Ae.aegypti was detected in Qishui Town during surveys from 2021 to 2024.A survey of 18 coastal villages in the Leizhou Peninsula revealed no detections of Ae.aegypti.Conclusions This study provides a basis for understanding the distribution and population density fluctuations of Ae.aegypti,assessing its invasion risk,and scientifically conducting relevant prevention and control efforts.

Objective This study aimed to provide an effective scientific basis for prevention and control of cockroaches on aircrafts by identifying cockroach-carried pathogens,and assess the insecticidal efficacy of gel bait mediated cockroach control on aircrafts,to provide technical guidance for aircraft disinsection.Methods Cassette-trapping was used to trap cockroaches,and the carried pathogens were detected using bacterial cultivation techniques.The gel bait mediated killing rate was calculated after 1,7,and 30 d by field application of gel bait.Results A total of 411 cockroaches were captured,and all were identified as Blattella germanica.26 strains of pathogenic bacteria were isolated from the trapped cockroaches.The killing rates of cockroaches were 58.8％-96.3％with 1-30 day application of gel bait.Statistically significant differences were observed in cockroach killing rates on different days(χ2=58.95,P<0.01).Conclusions B.germanica carry a large variety of pathogenic bacteria and opportunistic pathogens and are thus important infectious disease carriers.Gel bait agents have proven to be very effective against cockroaches on aircrafts.

Objective To propose a low-dose CT image denoising method based on an improved Corediff model to recover the detailed features of the image and enhance the image quality.Methods An RS-Corediff model was established by modifying the key component U-Net network of the Corediff model.Firstly,the residual module was introduced in the network input stage for feature extraction;secondly,a new downsampling module was designed in the U-Net network encoder,which learned the semantic information of the feature map by convolution and maintained the learning state during the downsampling process so as to fully extract the image features;thirdly,the feature splicing processing was used to further enhance the learning effect during the upsampling process of the U-Net network decoder;finally,the convolutional kernel size was modified to adjust the sensory field during the convolutional process of the whole U-Net network structure so as to obtain rich features.The RS-Corediff model was compared with the residual encoder-decoder convolutional neural network(RED-CNN)model and the Corediff model on the public dataset AAPM 2016 in order to verify its effectiveness for low-dose CT image denoising.Results The RS-Corediff model gained advantages over the RED-CNN and Corediff models with a peak signal-to-noise ratio(PSNR)of 41.269 8,structural similarity(SSIM)of 0.953 4 and root mean square error(RMSE)of 17.568 7.Conclusion The proposed method effectively preserves the texture and details of low-dose CT images during the denoising process to improve the overall quality of the images.[Chinese Medical Equipment Journal,2025,46(5):9-13]

Objective:To explore the application effects of improved case-based learning (CBL) combined with hierarchical and progressive teaching in the standardized training of nuclear medicine resident physicians.Methods:A total of 43 resident physicians who rotated in the nuclear medicine base of our hospital between 2018 and 2023 were selected as the research subjects and divided into an experimental group ( n=22) and a control group ( n=21) according to the order of enrollment. The control group received the traditional teacher-centered teaching model and was divided into junior and senior subgroups according to the training years. The experimental group received the improved CBL combined with hierarchical and progressive teaching. First, through multidimensional evaluation (theoretical testing + standardized case analysis), the students were scientifically divided into preliminary, intermediate, and advanced levels. Subsequently, progressive teaching objectives were set for different levels, and real clinical cases embedded with hierarchical learning tasks were published. During the teaching process, a dynamic discussion mode combining homogeneous and heterogeneous grouping was adopted, and personalized guidance was provided by the teachers. Finally, dynamic hierarchical adjustment was implemented through process evaluation. After the training, the two groups were compared in terms of exit assessment performance (including professional basic theory and practical skills) and teaching satisfaction. Results:The total score of the exit assessment of the experimental group was higher than that of the control group [(86.90±6.78) vs. (75.09±8.45)], and the difference was statistically significant. In terms of practical skill assessment, the experimental group scored higher than the control group in modules such as imaging symptom description [(22.34±2.56) vs. (19.85±3.12)], localization diagnosis [(23.01±2.11) vs. (20.12±2.98)], qualitative diagnosis [(22.89±2.67 vs. 18.67±3.45)], and differential diagnosis [(21.56±2.89) vs. (17.23±3.78)] ( P<0.01). The teaching satisfaction survey showed that the satisfaction scores of the experimental group were higher than those of the control group in nine domains, including theoretical knowledge mastery, clinical thinking, image interpretation, and learning initiative ( P<0.05). Conclusions:The improved CBL combined with hierarchical and progressive teaching can effectively improve the exit assessment performance, clinical practice skills, and teaching satisfaction of nuclear medicine resident trainees, and is worthy of promotion.

Transoral endoscopic thyroidectomy vestibular approach(TOETVA)has become a research hotspot because of its cosmetic advantages of no scar on the body surface,but there is still a risk of unique complications,among which mandibular sensory dysfunction is the most common,mainly related to mental nerve injury.This review focuses on the key anatomical structures closely related to the establishment of TOETVA space and the occurrence of complications.A deep understanding of the related anatomical structures of maxillofacial region and neck,especially the location and variation of mental nerve,the course of mandibular marginal branches of facial nerve,the level of mandibular muscles and the adjacent relationship of blood vessels,is the key to safely implement TOETVA and reduce postoperative complications.Preoperative image evaluation,intraoperative precise anatomy,following the design of safe area and improving the operation method in the future will contribute to the further promotion of this operation.

ObjectiveTo investigate the therapeutic effects and mechanism of Shenqi Dihuang decoction （SQDHD） on diabetic kidney disease （DKD）， with a focus on its impact on arachidonic acid-related ferroptosis. MethodsSixty C57BL/6 mice were allocated into a normal group （n=10） and a modeling group （n=50）， with 43 mice successfully modeled. The successfully modeled mice were further allocated into model， low-， medium-， and high-dose （4.68， 9.36， and 18.72 g·kg^-1， respectively） SQDHD， and dapagliflozin （0.13 mg·kg^-1） groups. The drug treatment groups were administrated with corresponding agents by gavage， and the normal and model groups were administrated with equal volumes of normal saline by gavage. An electronic balance and a glucometer were used to monitor the body weight and fasting blood glucose level from the tail tip， respectively. Serum creatinine （Scr） and blood urea nitrogen （BUN） levels were measured by enzyme-linked immunosorbent assay （ELISA）. Histopathological changes in the renal tissue were assessed by hematoxylin-eosin staining， Masson staining， and periodic acid-Schiff （PAS） staining. The fluorescence intensity of reactive oxygen species （ROS） in frozen sections was observed by an inverted fluorescence microscope to evaluate the levels of ferrous ions （Fe²⁺） and lipid peroxidation in the renal tissue. Immunofluorescence staining of glutathione peroxidase 4 （GPX4） and acyl-CoA synthetase long-chain family member 4 （ACSL4） in the renal tissue was performed to detect their localization and expression. Western blot was employed to assess the expression levels of key ferroptosis proteins such as GPX4 and cystine/glutamate antiporter （xCT）， as well as the arachidonic acid metabolic pathway-related proteins， including ACSL4， lysophosphatidylcholine acyltransferase 3 （LPCAT3）， and arachidonate 15-lipoxygenase （ALOX15）. Real-time PCR was employed to measure the mRNA levels of key ferroptosis proteins， including solute carrier family 7 member 11 （SLC7A11） and GPX4， as well as arachidonic acid metabolism-related factors （ACSL4， LPCAT3， and ALOX15） in the renal tissue. ResultsCompared with the normal group， DKD model mice exhibited a decrease in body weight （P<0.01）， increases in levels of blood glucose （P<0.01）， 24-hour urinary protein， Scr， and BUN （P<0.01）， along with severe pathological changes， such as mesangial cell proliferation， basement membrane thickening， tubular atrophy， and interstitial inflammatory cell infiltration. In addition， the modeling elevated the levels of Fe²⁺， MDA， LPO， and ROS （P<0.01）， lowered the GPX4 and xCT levels （P<0.01）， raised the ACSL4， LPCAT3， and ALOX15 levels （P<0.01）， down-regulated the mRNA levels of GPX4 and SLC7A11 （P<0.01）， and up-regulated the mRNA levels of ACSL4， LPCAT3， and ALOX15 （P<0.01） in the renal tissue. Compared with the model group， low-， medium-， and high-dose SQDHD groups and the dapagliflozin group showed an increase in body weight （P<0.01）， decreases in levels of blood glucose （P<0.01）， 24-hour urinary protein， and Scr （P<0.01）， alleviated pathological changes in glomeruli and tubules， and reduced degree of glomerular and tubular fibrosis. The high-dose SQDHD group and the dapagliflozin group showed reductions in Fe²⁺， MDA， LPO， and ROS levels （P<0.01）. The medium- and high-dose SQDHD groups and the dapagliflozin group exhibited increased levels of GPX4 and xCT （P<0.01）， decreased levels of ACSL4， LPCAT3， and ALOX15 （P<0.05， P<0.01）， and down-regulated mRNA levels of ACSL4， LPCAT3， and ALOX15 （P<0.01）. ConclusionSQDHD ameliorates DKD by inhibiting ferroptosis potentially by reducing iron ion levels， inhibiting lipid peroxidation， up-regulating GPX4 expression， and down-regulating ACSL4 expression. This study provides new insights and a theoretical basis for the treatment of DKD with traditional Chinese medicine and identifies potential targets for developing novel therapeutics for DKD.

ObjectiveTo investigate the therapeutic effects and mechanism of Shenqi Dihuang decoction （SQDHD） on diabetic kidney disease （DKD）， with a focus on its impact on arachidonic acid-related ferroptosis. MethodsSixty C57BL/6 mice were allocated into a normal group （n=10） and a modeling group （n=50）， with 43 mice successfully modeled. The successfully modeled mice were further allocated into model， low-， medium-， and high-dose （4.68， 9.36， and 18.72 g·kg^-1， respectively） SQDHD， and dapagliflozin （0.13 mg·kg^-1） groups. The drug treatment groups were administrated with corresponding agents by gavage， and the normal and model groups were administrated with equal volumes of normal saline by gavage. An electronic balance and a glucometer were used to monitor the body weight and fasting blood glucose level from the tail tip， respectively. Serum creatinine （Scr） and blood urea nitrogen （BUN） levels were measured by enzyme-linked immunosorbent assay （ELISA）. Histopathological changes in the renal tissue were assessed by hematoxylin-eosin staining， Masson staining， and periodic acid-Schiff （PAS） staining. The fluorescence intensity of reactive oxygen species （ROS） in frozen sections was observed by an inverted fluorescence microscope to evaluate the levels of ferrous ions （Fe²⁺） and lipid peroxidation in the renal tissue. Immunofluorescence staining of glutathione peroxidase 4 （GPX4） and acyl-CoA synthetase long-chain family member 4 （ACSL4） in the renal tissue was performed to detect their localization and expression. Western blot was employed to assess the expression levels of key ferroptosis proteins such as GPX4 and cystine/glutamate antiporter （xCT）， as well as the arachidonic acid metabolic pathway-related proteins， including ACSL4， lysophosphatidylcholine acyltransferase 3 （LPCAT3）， and arachidonate 15-lipoxygenase （ALOX15）. Real-time PCR was employed to measure the mRNA levels of key ferroptosis proteins， including solute carrier family 7 member 11 （SLC7A11） and GPX4， as well as arachidonic acid metabolism-related factors （ACSL4， LPCAT3， and ALOX15） in the renal tissue. ResultsCompared with the normal group， DKD model mice exhibited a decrease in body weight （P<0.01）， increases in levels of blood glucose （P<0.01）， 24-hour urinary protein， Scr， and BUN （P<0.01）， along with severe pathological changes， such as mesangial cell proliferation， basement membrane thickening， tubular atrophy， and interstitial inflammatory cell infiltration. In addition， the modeling elevated the levels of Fe²⁺， MDA， LPO， and ROS （P<0.01）， lowered the GPX4 and xCT levels （P<0.01）， raised the ACSL4， LPCAT3， and ALOX15 levels （P<0.01）， down-regulated the mRNA levels of GPX4 and SLC7A11 （P<0.01）， and up-regulated the mRNA levels of ACSL4， LPCAT3， and ALOX15 （P<0.01） in the renal tissue. Compared with the model group， low-， medium-， and high-dose SQDHD groups and the dapagliflozin group showed an increase in body weight （P<0.01）， decreases in levels of blood glucose （P<0.01）， 24-hour urinary protein， and Scr （P<0.01）， alleviated pathological changes in glomeruli and tubules， and reduced degree of glomerular and tubular fibrosis. The high-dose SQDHD group and the dapagliflozin group showed reductions in Fe²⁺， MDA， LPO， and ROS levels （P<0.01）. The medium- and high-dose SQDHD groups and the dapagliflozin group exhibited increased levels of GPX4 and xCT （P<0.01）， decreased levels of ACSL4， LPCAT3， and ALOX15 （P<0.05， P<0.01）， and down-regulated mRNA levels of ACSL4， LPCAT3， and ALOX15 （P<0.01）. ConclusionSQDHD ameliorates DKD by inhibiting ferroptosis potentially by reducing iron ion levels， inhibiting lipid peroxidation， up-regulating GPX4 expression， and down-regulating ACSL4 expression. This study provides new insights and a theoretical basis for the treatment of DKD with traditional Chinese medicine and identifies potential targets for developing novel therapeutics for DKD.