BACKGROUND:Heart rate variability biofeedback is a respiratory training method that uses slow and deep breathing at the resonant frequency to induce rhythmic,high-amplitude oscillations in the cardiovascular system,thereby stimulating and exercising the autonomic and baroreflex.However,current studies have not systematically reviewed how heart rate variability biofeedback modulates the autonomic function and produces effects.There is a lack of public understanding of the mechanism of heart rate variability biofeedback,and its application progress and scheme are not fully understood. OBJECTIVE:To review the existing experimental studies on the effects of heart rate variability biofeedback on symptoms in different populations at home and abroad and to introduce the mechanisms and advances in the application of heart rate variability biofeedback to modulate the autonomic nervous system. METHODS:"Heart rate variability biofeedback,resonance breathing,heart rate variability,autonomic nerve,breathing training,chronic diseases,mental illness,biofeedback"were used as Chinese or English keywords to search in CNKI,WanFang Database,PubMed,and Web of Science.A total of 72 core related papers were included according to the inclusion and exclusion criteria. RESULTS AND CONCLUSION:The body's oscillation system and resonance system are essential for the effectiveness of heart rate variability biofeedback.Oscillations reflect the response to external stimuli and self-regulating reflex systems,while resonances involve synchronous oscillations that result in higher amplitude operations.The balance between sympathetic and parasympathetic nerves is crucial for maintaining a stable internal environment.Autonomic nervous system disorders are associated with reduced heart rate variability and are closely linked to the progression of related diseases.Heart rate variability biofeedback utilizes the resonance characteristics of the cardiovascular system,inducing rhythmic high-amplitude oscillations by employing deep slow breathing at the resonance frequency.This method improves the regulatory function of the sympathetic and parasympathetic system reflexes and enhances the balance regulation between the two systems.Two major mechanisms of cardiovascular system resonance are the baroreflex closed-loop pathway and respiratory sinus arrhythmia.These mechanisms,along with the unique delay of baroreflex,result in a 0° phase angle oscillation between heart rate and respiration and a 180° phase angle oscillation between blood pressure and respiration during breathing at the resonant frequency rhythm.Periodically stimulating the human cardiovascular oscillation system through this method is an easy-to-operate and effective training approach.Currently,heart rate variability biofeedback is mainly applied in the fields of mental illness,chronic disease,and sports.However,the intervention mechanism and efficacy are unclear,the intervention content,frequency and duration are varied,and there are limited review studies on the intervention methods tailored to different types of individuals.As a non-drug and non-invasive intervention,heart rate variability biofeedback can significantly increase heart rate variability,regulate the balance between sympathetic and parasympathetic nerves,and improve the stability and adaptability of the autonomic nervous system.In the future,it is suggested to investigate the mechanisms and potential applications of the pathways of the heart rate variability biofeedback that induce cardiovascular resonance.It is also recommended to incorporate long-term follow-ups to assess the sustained value of heart rate variability biofeedback in various fields.This would provide new directions and strategies for the comprehensive treatment of complex diseases.

Objective To observe the influence of different energy windows of the medium-energy general-purpose(MEGP)collimator on image quality,so as to optimize the energy window of yttrium-90(90Y)bremsstrahlung SPECT imaging.Methods 90Y bremsstrahlung spectrum was acquired,and the sensitivity,percentage of the source counts in useful field of view(S/FOV%)and signal-to-background ratio(S/B)of 90Y bremsstrahlung SPECT imaging at MEGP under different energy windows were compared.Results The energy spectrum of 90Y bremsstrahlung was a continuous curve,with the peak of 76.2 keV with MEGP collimator.The images obtained with MEGP collimator were clear,and no significant differences of S/FOV%nor S/B was found between 10%and 20%window width groups(both P＞0.05),but the sensitivities of the latter was higher than the former(P＜0.05).The sensitivity of 70-90 keV images was relatively high,while the S/FOV%and S/B had decreased.The S/FOV%and S/B of images ranging from 40-60 keV were high,but the sensitivity was low.Images acquired with 100 keV±20%showed fairly high sensitivity,S/FOV%and S/B,which was 69.73%,0.62 and 1.64,respectively.Conclusion When performing 90Y bremsstrahlung SPECT with MEGP collimator,the image quality at 20%window width was better than at 10%window width,and 100 keV±20%showed fairly high sensitivity and not significantly decreased S/FOV%and S/B.

China prospective multicenter birth cohort (Prospective Omics Health Atlas birth cohort, POHA birth cohort) study was officially launched in 2022. This study, in collaboration with 12 participating units, aims to establish a high-quality, multidimensional cohort comprising 20 000 naturally conceived families and assisted reproductive families. The study involves long-term follow-up of parents and offspring, with corresponding biological samples collected at key time points. Through multi-omics testing and analysis, the study aims to conduct multi-omics big data research across the entire maternal and infant life cycle. The goal is to identify new biomarkers for maternal and infant diseases and provide scientific evidence for risk prediction related to maternal diseases and neonatal health.

AIM:This study investigates the effect of fibroblast growth factor 21(FGF21)long-acting ana-logue PF-05231023 on promoting the"browning"of white adipose tissue(WAT)by inhibiting mitophagy in WAT and the molecular mechanisms involved.METHODS:Using a high-fat diet(HFD)to replicate an obesity model in mice,18 C57BL/6J mice were divided into three groups:normal control(NC)group,HFD group,and PF-05231023 intervention(PF+HFD)group,each consisting of 6 mice.After 12 weeks of feeding,the mice were anaesthetized,their eyeballs were removed to collect blood samples,and serum was separated to measure levels of total cholesterol(TC),triglycerides(TG),low-density lipoprotein cholesterol(LDL-C)、alanine aminotransferase(ALT),and aspartate aminotransferase(AST)in mouse serum.The inguinal WAT(iWAT),epididymal WAT(eWAT)and liver were collected.Part of the tis-sues were used for Western blot experiments to measure the protein levels of"browning"related markers uncoupling pro-tein-1(Ucp-1)and peroxisome proliferator-activated receptor γ coactivator-1α(PGC-1α),as well as mitophagy-related markers PTEN-induced kinase 1(Pink1),parkin,beclin-1 and microtubule-associated protein 1 light chain 3-Ⅱ(LC3-Ⅱ).Another part of the tissues was fixed in paraformaldehyde for subsequent HE and immunohistochemical staining.3T3-L1 cells were induced to mature adipocytes using the classic"cocktail"method.The CCK-8 assay was used to assess the impact of different concentrations of PF-05231023 intervention on cell viability.After 48 h of PF-05231023 intervention,the 3T3-L1 cell clumps were collected for Western blot experiments to measure the expression levels of"browning"related markers Ucp-1 and PGC-1α,as well as mitochondrial autophagy-related markers Pink1,parkin,beclin-1,and LC3-Ⅱ proteins.Oil red O staining was performed to detect cell accumulation,and immunofluorescence staining was used to mea-sure Ucp-1 protein content.Subsequently,3T3-L1 cells were divided into the normal group,PF-05231023 intervention group,Pink1 agonist MTK458 intervention group,and MTK458+PF-05231023 intervention group.Cell clumps were col-lected for Western blot experiments to measure the markers as mentioned above.RESULTS:The key findings of our study indicate that the PF-05231023 intervention did not affect energy intake in mice but significantly reduced the weight,liver weight,and fat weight of mice induced by a high-fat diet(P<0.05).The intervention also decreased lipid accumula-tion(TC,TG、LDL-C)and liver damage(ALT,AST)and alleviated hepatocyte vacuolization and adipocyte size(P<0.05).Compared with the HFD group,the PF-05231023 intervention increased the levels of Ucp-1 and PGC-1α protein expression in iWAT and eWAT(P<0.01).Immunohistochemical staining showed higher Ucp-1 protein content in the PF-05231023 intervention group than in the HFD group.The PF-05231023 intervention dose-dependently increased Ucp-1 and PGC-1α protein expression levels in mature 3T3-L1 cells(P<0.01),reduced cellular lipid accumulation,and immu-nofluorescence staining showed increased Ucp-1 protein content in mature 3T3-L1 cells after PF-05231023 intervention.The PF-05231023 intervention inhibited mitochondrial autophagy-related indicators Pink1,parkin,beclin-1,and LC3-Ⅱ protein expression levels in iWAT,eWAT,and induced mature 3T3-L1 cells(P<0.05).The MTK intervention increased Pink1,parkin,beclin-1,and LC3-Ⅱ protein expression levels,increased Ucp-1 protein expression level,compared with the MTK intervention group,after MTK and PF-05231023 co-intervention,partially decreased Pink1,parkin,beclin-1,and LC3-Ⅱ protein expression levels,and partially restored Ucp-1 protein expression level(P<0.01).CONCLUSION:(1)Intervention with PF-05231023 can improve obesity and related metabolic disorders induced by a high-fat diet in mice;(2)PF-05231023 intervention can inhibit white adipose tissue(WAT)and induce mature 3T3-L1 cell mitochondria autophagy,promoting"browning"by inhibiting mitochondrial autophagy;(3)Its mechanism may be related to the inhibi-tion of the Pink1-parkin signalling pathway.

Cardiovascular and cerebrovascular diseases are one of the diseases with the highest mortality rate in the world, seriously affecting human health. Clinically, the abnormal values of myocardial injury markers are often detected to reflect the severity of myocardial injury and used as a reference index for screening, diagnosis, and prognosis of myocardial injury (abnormality). In this paper, the classification of metal-organic frameworks (MOFs) and their composites were introduced, and the research progress of electrochemical protein sensors, electrochemical immunosensors, and electrochemical aptamer sensors based on MOF composites for the detection of markers of myocardial injury was reviewed.

Objective:To study the clinical characteristics，diagnosis，treatment and prognosis of neonatal appendicitis.Methods:From January 2019 to December 2022，19 neonates with appendicitis（appendicitis group）and 38 neonates with sepsis（sepsis group）admitted to the Neonatal Department of Xi'an Children's Hospital Affiliated to Xi'an Jiaotong University were studied.The characteristics of clinical manifestation，imaging，treatment and prognosis of neonates in two groups were analyzed,retrospectively.Results:Among 19 neonates with appendicitis，31.6% were premature，the mean birth weight was（2 927.9±796.2）g，male∶female=2.17∶1.Abdominal distention（8/19，42.1%）and fever（8/19，42.1%）were the first symptoms of appendicitis，and the first symptoms of sepsis were mainly fever（20/38，52.6%）and poor reaction（7/38，18.4%）.In the appendicitis group，the proportions of abdominal distension（89.5% vs. 5.3%），vomiting（36.8% vs. 2.6%），breast resistance（84.2% vs. 39.5%），mental reaction changing（94.7% vs. 71.1%）and abdominal positive signs（84.2% vs. 5.3%）were significantly higher than those in sepsis group（ P<0.05）.C-reactive protein（CRP）was elevated in 16 neonates with appendicitis and 13 neonates with sepsis，and elevated gradually in 14 neonates with appendicitis. Compared with sepsis group，CRP was higher in appendicitis group（ P<0.05）.Fifteen（78.9%）neonates with appendicitis were diagnosed only by ultrasound，mainly manifested as low echo area or liquid dark area in the right abdomen，thickening of the appendix wall or effusion in the cavity，and liquid exudation.Three（15.8%）neonates with appendicitis were diagnosed by ultrasound and CT.Eight（42.1%）neonates with appendicitis were complicated appendiceal perforation.Fifteen neonates with appendicitis were treated by conservative treatment，four cases were treated by operation，and all of them were cured and discharged. Conclusion:Abdominal ultrasonography should be improved as soon as possible in neonates with fever and septicemia，especially those with abdominal symptoms or signs，or CRP increased during treatment，and CT or surgical exploration if necessary,to confirm the diagnosis of neonatal appenditis and early treatment.

Objective:To explore the prognosis of umbilical cord cysts in fetuses with structural abnormalities diagnosed by prenatal ultrasonography.Methods:This retrospective study involved 109 cases of umbilical cord cysts diagnosed by ultrasound at Beijing Obstetrics and Gynecology Hospital from January 2016 to December 2020. According to the ultrasound findings, these cases were divided into the isolated umbilical cord cyst, umbilical cord cyst with soft ultrasound markers, and umbilical cord cyst with fetal malformation groups. Chi-square was performed for statistical analysis to compare the prognosis. Results:(1) Among 109 cases of umbilical cord cysts, 55 cases (50.5%) were isolated, 20 (18.3%) were complicated by soft ultrasound markers, and 34 (31.2%) cases were complicated by fetal malformation. After excluding two cases of multiple cysts at different locations, the incidence of umbilical cord cysts at the placental end, free segment, and fetal terminal with other ultrasound abnormalities in the remaining 107 cases increased sequentially [27.5% (14/51), 10/17, and 76.9% (30/39), χ2=22.20, P<0.001]. The incidence of umbilical cord cysts with other ultrasound abnormalities at the fetal end was higher than at the placental end ( χ2=21.65, P<0.001). (2) A total of 60 fetal malformations were detected, dominated by fetal ventricular septal defect, omphalocele, giant bladder, fetal edema, and nuchal cystic hygroma, et al., mainly involving the cardiovascular system, urogenital system, anterior abdominal wall, and skeletal system. (3) Eighty-nine cases were followed up to the end of the pregnancy, and 21 (23.6%) of them had adverse outcomes. The prognoses of isolated umbilical cord cyst cases were all good. Two pregnancies (2/18) were terminated in the umbilical cord cyst with ultrasound soft markers group. In the group of umbilical cord cyst with fetal malformation, 19 pregnancies (19/26, 73.1%) had adverse outcomes, including pregnancy termination, intrauterine fetal demise, and perinatal death. Conclusions:The prognosis of isolated umbilical cord cysts is generally good. The umbilical cord cyst complicated by soft ultrasound marker and fetal malformation can have adverse outcomes, while conditions might be worse in those with fetal malformation. When an umbilical cord cyst is revealed, a systematical examination is recommended to identify whether it is combined with other ultrasound abnormalities.

Objective:To investigate the clinical characteristics of neonatal congenital tongue base cyst.Methods:This retrospective study involved 35 neonates with congenital tongue base cyst diagnosed in the neonatal intensive care unit (NICU) of Xi'an Children's Hospital from June 2013 to December 2019. General information, clinical manifestations, supplementary results, treatment and prognosis of these babies were described.Results:(1) The median age at the onset of the disease was 12.5 (0~28) d and the median age at admission was 15 (0~28) d for these babies. The main clinical manifestations were laryngeal stridor (28/35, 80.0%), inspiratory dyspnea and crying, especially when feeding (26/35, 74.3%) and choking and spitting with feeding (23/35, 65.7%). (2) Among the 35 cases, 15 (42.9%) required emergency endotracheal intubation due to significant dyspnea when were admitted to the NICU and five out of them were considered for having tongue base mass under laryngoscopy, while the other 10 cases underwent bedside electronic laryngoscopy after endotracheal intubation, in which space-occupying lesions were found. Tongue base cyst was considered in seven cases with laryngeal stridor complicated by protracted pneumonia using fiberoptic bronchoscopy. The other 13 cases were examined by electronic laryngoscope and considered as tongue base cyst. Thirty-five cases underwent cervical ultrasound and only five of them were considered as tongue base tumor. Thirty-two cases underwent cervical CT scan and only two of them were normal. Three cases were found to have tongue base cyst by cranial MRI. (3) Thirty-four cases were treated by radiofrequency ablation assisted with self-retaining microlaryngoscope and general anesthesia, while the other one firstly received puncture and drainage under direct laryngoscope due to the difficult intubation because of the huge tongue base cyst and then underwent surgery when stable. Only one case (2.9%) relapsed after surgical treatment during regular follow-up.Conclusions:Neonatal congenital tongue base cyst has an early onset and atypical clinical manifestations. Electronic laryngoscopy/fiberoptic bronchoscopy combined with neck CT or MRI examination should be performed promptly in patients with laryngeal stridor and inspiratory dyspnea to facilitate the accurate diagnosis and timely surgery is required for.

Objective:To explore the effects of acute paraquat poisoning on cognitive function of patients through neuropsychologic test.Methods:In June 2019, 36 patients with acute paraquat poisoning in the emergency department of a provincial hospital in Hebei Province were selected as the case group. 36 healthy individuals were selected as control group. The cognitive function and depressive state were assessed by mini mental state scale, auditory word learning test, digit span test, connection test, Boston Naming Test and geriatric depression scale.Results:The results of Mini-Mental State examination showed that the total score of the case group was lower than that of the control group, the difference was statistically significant ( P<0.05) . The results of the Auditory Vocabulary Learning test showed that the scores of delayed recall, clue recall, corrective ability and semantic learning strategies of the case group were significantly lower than those in the control group ( P<0.05) . There was no significant difference in the scores of immediate memory between the two groups ( P>0.05) . The scores of Digit Span test and Boston Naming test in the control group were higher than those in the case group, the Trail Making test time in the control group was shorter than that in the case group, and the differences were statistically significant ( P<0.05) . Conclusion:Acute paraquat poisoning can impair human cognitive ability to a certain extent.

Objective:To explore the effects of acute paraquat poisoning on cognitive function of patients through neuropsychologic test.Methods:In June 2019, 36 patients with acute paraquat poisoning in the emergency department of a provincial hospital in Hebei Province were selected as the case group. 36 healthy individuals were selected as control group. The cognitive function and depressive state were assessed by mini mental state scale, auditory word learning test, digit span test, connection test, Boston Naming Test and geriatric depression scale.Results:The results of Mini-Mental State examination showed that the total score of the case group was lower than that of the control group, the difference was statistically significant ( P<0.05) . The results of the Auditory Vocabulary Learning test showed that the scores of delayed recall, clue recall, corrective ability and semantic learning strategies of the case group were significantly lower than those in the control group ( P<0.05) . There was no significant difference in the scores of immediate memory between the two groups ( P>0.05) . The scores of Digit Span test and Boston Naming test in the control group were higher than those in the case group, the Trail Making test time in the control group was shorter than that in the case group, and the differences were statistically significant ( P<0.05) . Conclusion:Acute paraquat poisoning can impair human cognitive ability to a certain extent.