[Evaluation of semicircular canal and otolith graviceptive pathway function in patients diagnosed with motion sickness disorder based on the diagnostic criteria of the Bárány society].

Objective: To investigate the altered function of the semicircular canal and otolith graviceptive pathway in patients diagnosed with motion sickness disorder (MSD) based on the diagnostic criteria of the Bárány society, and explore its relevance to the pathogenesis of MSD. Methods: This is a case-control study. Twenty patients with MSD and age-and sex-matched healthy controls without a history of MSD from the Department of Neurology of Aerospace Center Hospital between March and August 2022 were recruited. All subjects completed the motion sickness susceptibility questionnaire-short version (MSSQ-short) and the motion sickness assessment questionnaire (MSAQ). Canal function was evaluated using caloric stimulation test and video head impulse test (vHIT), and subjective visual vertical/horizontal (SVV/SVH) and vestibular evoked myogenic potential (VEMP) were employed to assess otolith graviceptive function. Differences in vestibular function and correlations between the two groups were analyzed. Results: Each group consisted of 20 cases (9 males and 11 females). The mean age of the MSD and control groups was (26.9±3.9) years and (27.0±3.4) years, respectively. The scores of MSSQ-short [27.0 (22.5, 38.8) vs 1.2 (0, 3.2), P<0.001] and MSAQ [70.1 (54.5, 78.1) vs 11.8 (11.1, 13.9), P<0.001] were significantly higher in the MSD group compared with those of the control group. Evaluation of canal function revealed a significantly higher incidence of caloric stimulation intolerance in MSD patients (60.0%, 12/20) compared with that of the control group (20.0%, 4/20) (P=0.010). Evaluation of otolith graviceptive pathway indicated no significant difference in SVV, SVH and cervical VEMP (cVEMP) abnormality rates between the two groups (all P>0.05). The ocular VEMP (oVEMP) abnormality rate was significantly higher in the MSD group (55.0%, 11/20) than that of the control group (10.0%, 2/20) (P=0.002), with a delayed P1-wave latency compared with the control group [(18.4±1.2) ms vs (17.6±0.8) ms, P=0.018]. Further correlation analysis revealed that P1-wave latency in oVEMP was positively correlated with MSSQ-short (r=0.486, P=0.002) and MSAQ (r=0.391, P=0.015) scores, and duration of caloric intolerance symptoms (r=0.377, P=0.004). Conclusion: The presence of hypersensitivity to caloric stimulation and delayed latency of otolith function in patients with MSD suggests a "separation" between semicircular canal and otolithic function, which may be related to sensory conflict.

[Short-term outcomes of the TRIANGLE operation after neoadjuvant chemotherapy in locally advanced pancreatic cancer].

Objective: To investigate the safety and efficacy of the TRIANGLE operation after neoadjuvant chemotherapy in locally advanced pancreatic cancer(LAPC). Methods: This study is a retrospective case series analysis. Between January 2020 and December 2022, a total of 103 patients were diagnosed as LAPC who underwent neoadjuvant chemotherapy at the Pancreas Center, the First Affiliated Hospital of Nanjing Medical University. Among them, 26 patients (25.2%) underwent the TRIANGLE operation. There were 15 males and 11 females,with a age of (59±7) years (range: 49 to 74 years). The pre-treatment serum CA19-9(M(IQR)) was 248.8(391.6)U/ml (range: 0 to 1 428 U/ml),and the serum carcinoembryonic antigen was 4.1(3.8)µg/L(range: 1.4 to 13.4 µg/L). The neoadjuvant chemotherapy regimens included: mFOLFIRINOX regimen in 6 cases(23.1%), GnP regimen in 14 cases(53.8%), and mFOLFIRINOX+GnP regimen in 6 cases(23.1%). The follow-up duration extended until June 2023 or until the occurrence of the patient's death or loss to follow-up. The Kaplan-Meier method was employed to estimate the 1-year and 3-year overall survival rates. Results: After neoadjuvant chemotherapy,CA19-9 levels decreased by 92.3(40.1)%(range:2.1% to 97.7%). Evaluation of the response to treatment revealed 13 cases(50.0%) of stable disease,11 cases(42.3%) of partial response,and 2 cases(7.7%) of complete response. The surgical operation consisted of 12 cases(46.2%) of pancreaticoduodenectomy,12 cases(46.2%) of distal pancreatectomy,and 2 cases(7.7%) of total pancreatectomy. Margin determination was based on the "standardised pathology protocol" and the "1 mm" principle. No R2 and R1(direct) resections were observed,while the R0 resection rate was 61.5%(16/26), and the R1(1 mm) resection rate was 38.5%(10/26).The R1(1 mm) resection rates for the anterior margin,posterior margin,transected margin,portal vein groove margin,and uncinate margin were 23.1%(6/26),19.2%(5/26),12.5%(3/24),2/14, and 1/12, respectively. The overall postoperative complication rate was 57.8%(15/26),with major complications including grade B/C pancreatic fistula 25.0%(6/24,excluding 2 cases of total pancreatectomy),delayed gastric emptying in 23.1%(6/26),wound complications 11.5%(3/26),postoperative hemorrhage 7.7%(2/26), chylous fistula 7.7%(2/26) and bile fistula 3.8%(1/26). No reoperation was performed during the perioperative period(<90 days). One patient died on the 32nd day postoperatively due to a ruptured pseudoaneurysm. A total of 25 patients were followed up,with a follow-up time of 21(24)months(range: 8 to 42 months). During the follow-up period,8 cases(32.0%) died due to tumor recurrence and metastasis,while 17 patients(68.0%) remained alive,including 11 cases of disease-free survival,5 cases of distant metastasis,and 1 case of local recurrence. The overall survival rates at 1- and 3-year after the initiation of neoadjuvant chemotherapy were 95.8% and 58.9%, respectively. The overall survival rates at 1- and 3-year after surgery were 77.7% and 57.8%, respectively. Conclusion: Performing pancreatoduodenectomy according to the Heidelberg triangle protocol in LAPC patients after neoadjuvant chemotherapy might increase the R0 resection rate without increasing perioperative mortality or the incidence of major postoperative complications.

[Benchmark dose estimation of polycyclic aromatic hydrocarbons exposure base on Bayesian kernel machine regression].

Objective: To explore benchmark dose (BMD) estimations of polycyclic aromatic hydrocarbons (PAHs) based on Bayesian kernel machine regression (BKMR) . Methods: A total of 155 adult residents of a coking plant in Shanxi Province who were surveyed in summer (June to August) from 2014 to 2019 were selected as the research objects. Fasting elbow vein blood of the subjects was collected in the morning for automatic analysis and detection of blood routine. Morning urine samples were collected for automatic analysis and detection of urine routine and urine creatinine detection. BKMR model combined with BMD method was used to calculate the acceptable doses of PAHs exposure on red blood cell damage in non-occupational population. Results: The concentration of hydroxylpolycyclic aromatic hydrocarbons (OH-PAHs) in the red blood cells abnormal group (n=117) was significantly higher than that in the normal group (n=38) (P<0.01). In the combined effect of OH-PAHs, 2-hydrol-naphthalene contributed the most, and the posterior inclusion probability (PIP) value was 0.9354. When OH-PAHs ≥P(55) concentration, the joint effect on the risk of red blood cell abnormalities increased as the concentration of the OH-PAHs mixture increased. When OH-PAHs were at P(65) and P(75) concentrations, respectively, the risk of red blood cell abnormalities in adults were 3.09 and 4.98 times that of OH-PAHs at P(50) concentrations, respectively. Compared with high concentration, low concentration of OH-PAHs exposure was more sensitive to red blood cell darmage. The acceptable doses of 8 kinds of OH-PAHs were 1.010 µmol/mol Cr (2-hydrol-naphthalene), 0.743 µmol/mol Cr (1-hydrol-naphthalene), 0.901 µmol/mol Cr (2-hydroxy-fluorene) and 0.775 µmol/mol Cr (1-hydroxy-phenanthrene), 0.737 µmol/mol Cr (1-hydroxy-pyrene), 0.607 µmol/mol Cr (9-hydroxy-fluorene), 0.713 µmol/mol Cr (2-hydroxy-phenanthrene) and 0.628 µmol/mol Cr (3-hydroxybenzo[a] pyrene), respectively. Conclusion: OH-PAHs mixture has positive combined effect on red blood cell damage in non-occupational population, and low concentration of OH-PAHs exposure is more sensitive to red blood cell damage. It is recommended that the exposure dose of PAHs should be controlled within 1 µmol/mol Cr.

Corrigendum: Use of autologous cord blood mononuclear cells infusion for the prevention of bronchopulmonary dysplasia in extremely preterm neonates: a study protocol for a placebo-controlled randomized multicenter trial [NCT03053076].

[This corrects the article DOI: 10.3389/fped.2020.00136.].

Auto interpretable depth learning model to analyze the hemodynamic changes and pulmonary complications in laparoscopic gynecologic tumor surgery with nalmefene hydrochloride combined with general anesthesia.

OBJECTIVE: In this work, based on intelligent computing, the biological signals of patients were analyzed to investigate the hemodynamic changes and pulmonary complications of Nalmefene Hcl combined with general anesthesia (GA) in laparoscopic gynecological tumor surgery (GTS). PATIENTS AND METHODS: Eighty computer-aided GTS patients were randomly divided into a control group (n = 40) and an observation group (n = 40). Biomedical electrocardiogram (ECG) signals were detected by wavelet neural network in all patients undergoing laparoscopic gynecological tumor surgery and were computerized according to the android interface definition language model (AIDL). GA was used during surgery. The observation group was injected intravenously with 0.2 µg/kg naproxenacin hydrochloride after operation. The control group was given 1 mL 0.9% sodium chloride solution after operation. Mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), pulse oxygen saturation (SPO), coma score, and adverse reactions (AR) were compared between the two groups at 10, 20, and 30 minutes after wakefulness. The hemodynamic parameters between the two groups were compared. Serum urocholine (URO) and creatinine (Cre) levels were analyzed in patients without complications. RESULTS: ECG waveform based on wavelet neural network has a high recognition rate and strong generalization ability. 37 patients in the observation group recovered within 10 minutes after surgery, and the recovery rate at 30 minutes was 95%. 30 patients in the control group awoke 10 minutes after the operation, and the recovery rate at 30 minutes m-AR was 75%. The average abstract windows toolkit (AWT) of the observation group and control group was 11.87 ± 5.78 min and 16.46 ± 5.32 min, respectively, and the difference was significant (p < 0.05). There were significant differences in HR, systolic blood pressure (SBP), and diastolic blood pressure (DBP) between the observation group and the control group during the extubation (p < 0.05). Blood gas indexes PaO2, PvO2, PaCO2, and PvCO2 in the observation group were significantly different from those in the control group half an hour after the operation and half an hour after pneumoperitoneum (p > 0.05). CONCLUSIONS: Intelligent computational biological signal detection was beneficial to the development of surgery. Nalmefene Hcl combined with GA on the basis of the AIDL model has a significant effect on the awakening of GTS patients and can shorten sleep time. Patients with underlying cardiac disease were more likely to develop postoperative lung complications.

[Phenotype-genotype analysis of the autosomal recessive hereditary hearing loss caused by OTOA variations].

Objective: To analyze the phenotypic-genotypic characteristics of hereditary deafness caused by OTOA gene variations. Methods: Family histories, clinical phenotypes and gene variations of six pedigrees were analyzed, which were diagnosed with hearing loss caused by OTOA gene variations at the PLA General Hospital from September 2015 to January 2022. The sequence variations were verified by Sanger sequencing and the copy number variations were validated by multiplex ligation-dependent probe amplification (MLPA) in the family members. Results: The hearing loss phenotype caused by OTOA variations ranged from mild to moderate in the low frequencies, and from moderate to severe in the high frequencies in the probands, which came from six sporadic pedigrees, among which a proband was diagnosed as congenital deafness and five were diagnosed as postlingual deafness. One proband carried homozygous variations and five probands carried compound heterozygous variations in OTOA gene. Nine pathogenic variations (six copy number variations, two deletion variations and one missense variation) and two variations with uncertain significance in OTOA were identified in total, including six copy number variations and five single nucleotide variants, and three of the five single nucleotide variants were firstly reported [c.1265G>T(p.Gly422Val),c.1534delG(p.Ala513Leufs*11) and c.3292C>T(p.Gln1098fs*)]. Conclusions: OTOA gene variations can lead to autosomal recessive nonsyndromic hearing loss. In this study, the hearing loss caused by OTOA defects mostly presents as bilateral, symmetrical, and postlingual, and that of a few presents as congenital. The pathogenic variations of OTOA gene are mainly copy number variations followed by deletion variations and missense variations.

[Effects of surgical procedures and general anesthesia exposure within 2 hours in early childhood on neurodevelopmental outcomes in school-age].

Objective: To observe the effect of surgical procedures and general anesthesia exposure (<2 h) in early childhood on neurodevelopmental outcomes in school-age. Methods: A total of 147 children aged 6-12 years old, who received surgery under general anesthesia (<2 h) at the age of 0-2 years in Children's Hospital of Nanjing Medical Universityfrom June 2009 to December 2012 were retrospectively enrolled in this study (from June 2018 to December 2021) as exposure group, including 76 males and 71 females, with a mean age of (8.8±1.6) years. All the cases were divided into single-exposure group (n=65) and multiple-exposure group (≥2 times, n=82) according to different times of anesthesia exposure. According to the cohort of exposure group, 160 healthy children of the same age with no history of surgery under general anesthesia were recruited from the community from June 2018 to December 2021 as the control group, including 87 males and 73 females, and aged (8.6±1.9) years. A variety of standardized neurological tests including Wechsler intelligence scale for children fourth edition (WSC-Ⅳ), integrated visual and auditory continuous performance test (IVA-CPT), Swanson Nolan and Pelham, version Ⅳ (SNAP-Ⅳ), children sensory integration capacity development rating scale (CSIC), and social living ability scale were performed in all subjects by a child health specialist who failed to know the details. The primary outcome was the full-scale IQ (FSIQ) in WISC-Ⅳ, and the secondary outcomes were IVA-CPT, SNAP-Ⅳ, CSIC, and social living ability scale. Results: The FSIQ of single-exposure, multiple-exposure and control groups was 105.4±14.1, 100.9±10.2 and 103.6±13.5, respectively, with no statistically significant difference (F=2.37, P=0.095). The FSIQ of different first age exposure groups (aged 0-6 months, 7-12 months and 1-2 years) was 99.8±10.2, 104.5±10.5 and 104.4±14.5, respectively, with no statistically significant difference (F=2.39, P=0.095). The FSIQ of different exposure duration groups (0-59 min, 60-119 min and control group) was 102.8±11.3, 103.0±13.7 and 103.6±13.5, respectively, with no statistically significant difference (F=0.13, P=0.882). As for the secondary outcomes, the scores of visual persistence quotient in single-exposure, multiple-exposure and control groups were 94.8±10.5, 94.0±10.9 and 100.6±17.7, with a statistically significant difference (F=6.96, P=0.001). In terms of locomotion in social living ability scale, the score of the three groups was 10.0±0.2, 10.2±0.6 and 10.4±0.7, respectively, with a statistically significant difference (F=10.61, P<0.001), but all were within the standard range. Conclusions: The surgical procedures and general anesthesia exposure within 2 hours in early childhood has no effect on the overall FSIQ in school age, but has a slight impacts on the visual persistence quotient of IVA-CPT and the locomotion score of social living ability scale.

[Comparison of time series and case-crossover analyses in environmental epidemiology].

Time-series and case-crossover are two main study designs in environmental epidemiology. However, due to the differences in design principles and model construction between the two analyses, the results of the two analyses may not be consistent. Herein, we examined the short-term effect of cold spells on cardiovascular mortality in Nanjing using both time series and case-crossover analyses, aiming to provide a basis for the selection of appropriate research design in environmental epidemiology.

Assembly of Ultralong Hydroxyapatite Nanowires into Enamel-like Materials.

To develop dental restorative materials with enamel-like structures, ultralong hydroxyapatite (HA) nanowires were synthesized by a hydrothermal method, followed by functionalization with 3-methacryloxypropyltrimethoxysilane (KH-570). The mixture of HA nanowires, KH-570, and light initiator was stirred and centrifuged. The precipitate was vacuum filtered to remove excessive KH-570 and then pressured under cold isostatic pressing (10 MPa × 24 h). Finally, the block was polymerized by lighting. Scanning electron microscopy and transmission electron microscopy showed that HA nanowires with aspect ratios >1,000 were assembled into enamel rod-like microstructures and evenly dispersed in the polymerized KH-570 silane matrix to form enamel-like structures. Thermogravimetric analysis demonstrated that the content of HA nanowires reached 72 wt% in the composite. The enamel-like composite showed a similar hardness, frictional property, and acid-etching property to those of enamel and a comparable or even better diametral tensile strength and compressive strength than some commercial composite resins in mechanical tests in vitro. In addition, the enamel-like composite had good cytocompatibility. Such enamel-like composites may have the potential to be used in biomimetic tooth restorations in the future.

[Spatiotemporal evolution of COVID-19 epidemic in the early phase in China].

Objective: Based on the geographic information systems, we exploreed the spatiotemporal clustering and the development and evolution of COVID-19 epidemic at prefectural level in China from the time when the epidemic was discovered to the time when the lockdown ended in Wuhan. Methods: The information and data of the confirmed COVID-19 cases from December 8, 2019 to April 8, 2020 were collected from 367 prefectures in China for a spatial autocorrelation analysis with software GeoDa, and software ArcGIS was used to visualize the results. Software SatScan was used for spatiotemporal scanning analysis to visualize the hot-spot areas of the epidemic. Results: The incidence of new cases of COVID-19 had obvious global autocorrelation and the partial autocorrelation results showed that incidence of COVID-19 had different spatial distribution at different times from December 8, 2019 to March 4, 2020. There was no significant difference in global autocorrelation coefficient from March 5, 2020 to April 8, 2020. The statistical analysis of spatiotemporal scanning identified two kinds of spatiotemporal clustering areas, the first class clustering areas included 10 prefectures, mainly distributed in Hubei, from January 13 to February 25, 2020. The secondary class clustering areas included 142 prefectures, mainly distributed in provinces in the north and east of Hubei, from January 23 to February 1, 2020. Conclusions: There was a clear spatiotemporal correlation in the distribution of the outbreaks in the early phase of COVID-19 epidemic (December 8, 2019-March 4, 2020) in China. With the decrease of the case and effective prevention and control measures, the epidemics had no longer significant correlations among areas from March 5 to April 8. The study results showed relationship with time points of start and adjustment of emergency response at different degree in provinces. Furthermore, improving the early detection of new outbreaks and taking timely and effective prevention and control measures played an important role in blocking the transmission.

[Efficacy and safety of lenalidomide combined with bortezomib and dexamethasone induction therapy in newly diagnosed patients with multiple myeloma].

Objective: This study aimed to evaluate the efficacy and safety of lenalidomide combined with bortezomib and dexamethasone (VRD) in the treatment of newly diagnosed multiple myeloma (MM) . Methods: A total of 150 newly diagnosed patients with MM diagnosed in The First Affiliated Hospital of Soochow University from November 2018 to February 2021 and received VRD as the induction regimen were included to evaluate the safety and efficacy of VRD induction therapy for newly diagnosed MM. Results: The median follow-up was 22 months, two patients (1.3%) died early after treatment, and 148 patients (98.7%) completed induction therapy. 116 patients (77.3%) were mobilized to collect autologous hematopoietic stem cells, 101 cases (87.1%) were qualified in the collection, of which 48 cases (41.4%) were excellent in the collection. The 3-year progression-free survival (PFS) rate was 59%, and the 3-year overall survival (OS) rate was 83%. After induction, complete remission (CR) /stringent CR rate was 54.4%, ≥ very good partial remission rate was 77.3%, overall response rate was 86.0%, and minimal residual disease negative rate was 46.0%. There was no statistically significant difference in the efficacy of cytogenetic high-risk patients compared with standard risk patients (P=0.456) . The median PFS time of cytogenetic high-risk patients was shorter than that of standard risk patients (not reached vs 33 months, P=0.014) . There was no statistically significant difference in the median OS time (not reached vs not reached, P=0.072) . The highest incidence of hematological adverse events was thrombocytopenia (72%) , followed by neutropenia (42%) and anemia (20%) . The highest incidence of non-hematological adverse events was peripheral neuritis (56.7%) . The main digestive tract symptoms include constipation (30.0%) and diarrhea (17.3%) . Upper respiratory tract infection (23.3%) and lung infection (7.3%) are the main infections. The incidence of adverse thrombocytopenia (90.0% vs 63.7%, P=0.001) , neutropenia (54.2% vs 36.3%, P=0.038) , anemia (33.3% vs 13.7%, P=0.005) , diarrhea (27.1% vs 12.7%, P=0.030) , limb edema (20.8% vs 3.9%, P=0.030) , fever (20.8% vs 4.9%, P=0.006) , thrombosis (8.3% vs 0, P=0.016) , and renal function deterioration (20.8% vs 3.9%, P=0.030) in patients with renal insufficiency was higher than that in patients with normal renal function. Conclusion: The VRD regimen has a significant effect on newly diagnosed MM, does not affect the hematopoietic stem cell collection, and has controllable adverse events; however, the incidence of adverse events was higher in patients with renal insufficiency.

[Gene transcriptome analysis of nasal epithelial cells in chronic rhinosinusitis with nasal polyps].

Objective: To identify the differentially expressed genes in nasal epithelial cells from chronic rhinosinusitis with nasal polyps (CRSwNP), and to analyze related genes which are involved in deficiency of nasal epithelial barrier in CRSwNP patients by analyzing the datasets download from the gene expression omnibus(GEO) database. Methods: The mRNA expression microarray data numbered GSE107624 (7 CRSwNP and 7 controls) and GSE69093 (13 CRSwNP and 11 controls) were downloaded from the publicly available GEO database. These two datasets were jointly analyzed to screen the differentially expressed genes in nasal epithelial cells of controls and CRSwNP patients. In the meanwhile, we further evaluated the function annotation and regulatory pathways of the differentially expressed genes. To further confirmed what we have observed, sinus tissues were collected from patients with CRSwNP (14 cases, 46.8±17.9 years) and uncinate process tissues were collected from patients with nasal septum deviation (7 cases, 23.4±2.3 years) as control group. The primary epithelial cells of nasal mucosa were cultured and the mRNA level of screened genes were measured by Q-PCR. SPSS 22.0 software was used to for statistical analysis. Results: GSE107624 dataset showed that there were 3 856 differentially genes in nasal epithelial cells between CRSwNP and control group, while there were 771 differentially expressed genes in GSE69093 dataset. Finally, 55 up-regulated genes and 3 down-regulated genes were noticed in nasal epithelial cells of CRSwNP patients in the two datasets. GO gene functional annotation analysis showed that SPTBN1, FNBP1L, VAPB and SNX1 were involved in cell adhesion function, MAP1B was participated in the formation of microtubule related complex. KEGG pathway enrichment analysis indicated that BAMBI and SIAH1 were involved in regulation of Wnt pathway, COL6A1 and EIF4E were involved in the regulation of PI3K-AKT pathway. String protein interaction network analysis assumed that MAP1B and VAPB were the core functional proteins. Among top 3 differentially expressed genes COL6A1, MAP1B and BAMBI, only MAP1B gene was increased in nasal epithelial cells of CRSwNP patients in comparison to controls. Conclusion: The increased MAP1B gene in epithelial cells of CRSwNP, as well as abnormal regulation of Wnt and PI3K-AKT signal pathways may mediate the barrier dysfunction in CRSwNP.

Use of Autologous Cord Blood Mononuclear Cells Infusion for the Prevention of Bronchopulmonary Dysplasia in Extremely Preterm Neonates: A Study Protocol for a Placebo-Controlled Randomized Multicenter Trial [NCT03053076].

Background: Despite the rapid advance of neonatal care, bronchopulmonary dysplasia (BPD) remains a significant burden for the preterm population, and there is a lack of effective intervention. Stem cell depletion because of preterm birth is regarded as one of the underlying pathological mechanisms for the arrest of alveolar and vascular development. Preclinical and small-sample clinical studies have proven the efficacy and safety of stem cells in treating and preventing lung injury. However, there are currently no randomized clinical trials (RCTs) investigating the use of autologous cord blood mononuclear cells (ACBMNC) for the prevention of BPD in premature infants. The purpose of this study is to investigate the effects of infusion of ACBMNC for the prevention of BPD in preterm neonates <28 weeks. Methods: In this prospective, randomized controlled double-blind multi-center clinical trial, 200 preterm neonates <28 weeks gestation will be randomly assigned to receive intravenous ACBMNC infusion (5 × 107 cells/kg) or placebo (normal saline) within 24 h after birth in a 1:1 ratio using a central randomization system. The primary outcome will be survival without BPD at 36 weeks of postmenstrual age or at discharge, whichever comes first. The secondary outcomes will include the mortality rate, other common preterm complication rates, respiratory support duration, length, and cost of hospitalization, and long-term outcomes after a 2-year follow-up. Conclusion: This will be the first randomized, controlled, blinded trial to evaluate the efficacy of ACBMNC infusion as a prevention therapy for BPD. The results of this trial will provide valuable clinical evidence for recommendations on the management of BPD in extremely preterm infants. Clinical Trial Registration: ClinicalTrials.gov, NCT03053076, registered 02/14/2017, retrospectively registered, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0006WN4&selectaction=Edit&uid=U0002PLA&ts=2&cx=9y23d4 (Additional File 2).

[Multiple linear regression models with natural logarithmic transformations of variables].

In general, the application conditions of linear regression models could be met after the natural logarithmic transformation of data. From the practical perspective, this paper introduced the linear regression models with natural logarithmic transformation of independent variable, dependent variable, and both independent and dependent variables in detail. The paper illustrated why the equation and coefficients could not be directly explained after the natural logarithmic transformation of data. The percentage changes of X and/or Y were applied to elaborate the principle and method for the explanation of the equation and coefficients. Three examples were used to fit simple linear models with natural logarithmic transformation of independent, dependent, and both independent and dependent variables and the results of theses models were explained in detail.