Human angiotensin converting enzyme 2 specific antisense oligonucleotides reduce infection with SARS-CoV-2 variants.

BACKGROUND: The Spike protein mutation of SARS-CoV-2 led to decreased protective effect of various vaccines and monoclonal antibodies, suggesting that blocking SARS-CoV-2 infection by targeting host factors would make the therapy more resilient against virus mutations. Angiotensin converting enzyme 2 (ACE2) is the host receptor of SARS-CoV-2 and its variants, as well as many other coronaviruses. Down-regulation of ACE2 expression in the respiratory tract may prevent viral infection. Antisense oligonucleotides (ASOs) can be rationally designed based on sequence data, require no delivery system, and can be administered locally. OBJECTIVE: We sought to design ASOs that can block SARS-CoV-2 by down-regulating ACE2 in human airway. METHODS: ACE2-targeting ASOs were designed using a bioinformatic method and screened in cell lines. Human primary nasal epithelial cells cultured at the air-liquid interface and humanized ACE2 mice were used to detect the ACE2 reduction levels and the safety of ASOs. ASOs pretreated nasal epithelial cells and mice were infected and then used to detect the viral infection levels. RESULTS: ASOs reduced ACE2 expression on mRNA and protein level in cell lines and in human nasal epithelial cells. Furthermore they efficiently suppressed virus replication of three different SARS-CoV-2 variants in human nasal epithelial cells. In vivo, ASOs also down-regulated human ACE2 in humanized ACE2 mice and thereby reduced viral load, histopathological changes in lungs, and they increased survival of mice. CONCLUSION: ACE2-targeting ASOs can effectively block SARS-COV-2 infection. Our study provides a new approach for blocking SARS-CoV-2 and other ACE2-targeting virus in high-risk populations.

Comparing Protein and Gene Expression Signature between Nasal Polyps and Nasal Fluids in Chronic Rhinosinusitis.

INTRODUCTION: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a serious inflammatory condition. Nasal fluids (NFs) present a noninvasive alternative to nasal biopsy for studying CRSwNP pathogenesis. We aimed to compare the protein and mRNA inflammation signature between nasal polyps (NPs) and NFs. METHOD: The performance of polyvinyl alcohol (PVA) sponges and NFs absorbable device (NFAD) for collecting NFs from 20 patients with CRSwNP was compared using the Luminex assay. The other group consisted of four healthy controls and an additional 21 CRSwNP patients (including eosinophilic CRSwNP [ECRSwNP] and non-eosinophilic CRSwNP [NECRSwNP]) for protein quantification by Olink platform and gene expression evaluation by RNA-sequencing. Spearman's analysis was performed to detect correlations between protein expression levels in NFs and clinical assessment variables. RESULTS: NFAD-collected NFs contained at least a 2-fold higher concentration of cytokines than that obtained using PVA sponge, and these cytokines levels are significantly associated with NPs (ρ > 0.45, p < 0.05). Differentially expressed proteins between NFs and NPs were significantly correlated in the ECRSwNP subgroup compared with controls (ρ = 0.41, p < 0.01). Levels of Th2/IL-13, MCP4, and CCL4, characteristic of eosinophilic infiltration, were increased in ECRSwNP patients. A significant correlation between gene and protein expression was observed (ρ = 0.34, p < 0.01). PDL2 levels in NFs were positively correlated with ECRSwNP postoperative recurrence, the nasal VAS, and SNOT-22 scores (ρ > 0.68, p < 0.05 for all). CONCLUSION: Our study revealed similarities and discrepancies in inflammatory signatures between NPs and NFs in the same CRSwNP patient.

Factors for predicting the outcome of surgery for non-eosinophilic chronic rhinosinusitis with nasal polyps.

BACKGROUND: Despite the large patient base in Asia, the prognostic factors of patients with non-eosinophilic chronic rhinosinusitis with nasal polyps (CRSwNP) remain largely undetermined. OBJECTIVE: We aimed to systematically investigate the predictive value of clinical and biological variables for non-eosinophilic CRSwNP. METHODS: Fifty-one patients with non-eosinophilic CRSwNP who underwent functional endoscopic surgery were recruited. Clinical information and assessment were comprehensively collected before and after surgery. A broad spectrum of biomarkers was measured in tissue homogenates using multiple assays. A random forest algorithm and stepwise logistic regression were used to construct clinical, biological, and combined models. RESULTS: A total of 41.2% of non-eosinophilic CRSwNP patients were uncontrolled more than 6 months after surgery. We identified one clinical variable (22-item Sino-Nasal Outcome Test score) and four biomarkers (programmed cell death ligand 1, platelet-derived growth factor subunit B [PDGF-ß], macrophage inflammatory protein-3b, and PDGF-α) that were significantly predictive of the surgical outcome. The clinical, biological, and combined models showed predictive ability with areas under the curve of 0.78, 0.83, and 0.89, respectively. PDGF-ß and programmed cell death ligand 1 were identified as independent biomarkers for the prognosis of patients with CRSwNP without considerable eosinophilic infiltration. CONCLUSION: This study shows that clinical and biological factors, such as the 22-item Sino-Nasal Outcome Test score and PDGF-ß, are predictive of the post-functional endoscopic surgical prognosis of non-eosinophilic CRSwNP patients.

The SMYD3-dependent H3K4me3 status of IGF2 intensifies local Th2 differentiation in CRSwNP via positive feedback.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous and common upper airway disease divided into various inflammatory endotypes. Recent epidemiological findings showed a T helper 2 (Th2)-skewed dominance in CRSwNP patients. Histone modification alterations can regulate transcriptional and translational expression, resulting in abnormal pathogenic changes and the occurrence of diseases. Trimethylation of histone H3 lysine 4 (H3K4me3) is considered an activator of gene expression through modulation of accessibility for transcription, which is closely related to CRSwNP. H3K4me3 levels in the human nasal epithelium may change under Th2-biased inflammatory conditions, resulting in exaggerated local nasal Th2 responses via the regulation of naïve CD4+ T-cell differentiation. Here, we revealed that the level of SET and MYND domain-containing protein 3 (SMYD3)-mediated H3K4me3 was increased in NPs from Th2 CRSwNP patients compared with those from healthy controls. We demonstrated that SMYD3-mediated H3K4me3 is increased in human nasal epithelial cells under Th2-biased inflammatory conditions via S-adenosyl-L-methionine (SAM) production and further found that the H3K4me3high status of insulin-like growth factor 2 (IGF2) produced in primary human nasal epithelial cells could promote naïve CD4+ T-cell differentiation into Th2 cells. Moreover, we found that SAM production was dependent on the c-Myc/methionine adenosyltransferase 2A (MAT2A) axis in the nasal epithelium. Understanding histone modifications in the nasal epithelium has immense potential utility in the development of novel classes of therapeutics targeting Th2 polarization in Th2 CRSwNP. Video Abstract.

Impact of obstructive sleep apnea on cancer risk: a systematic review and meta-analysis.

PURPOSE: We aimed to study the effect of obstructive sleep apnea (OSA) on cancer risk. METHODS: We searched PubMed, Embase, and Cochrane databases for relevant studies. The qualities of included studies were assessed using Newcastle-Ottawa Scale (NOS). Unadjusted and adjusted analyses were performed. We also conducted subgroup analyses stratified by gender, severity of OSA, study design, and cancer type. RESULTS: After literatures search, 18 studies were included in the present study. In the unadjusted analysis, we discovered an increased cancer risk in patients with OSA with a pooled relative risk (RR) in the OSA group of 1.49 (95% confidence interval (CI): 1.32-1.69, I2 = 32%, P = 0.15). In adjusted analysis, OSA correlated with cancer risk (RR: 1.36, 95% CI: 1.18-1.56, I2 = 54%, P < 0.01). In subgroup stratified by gender and OSA severity, OSA statistically with cancer risk in females (RR: 1.27, 95% CI: 1.06-1.51) and moderate to severe OSA groups (RR: 2.62, 95% CI: 1.64; 4.19). In subgroup stratified by study design, a trend toward statistically significant differences was observed in prospective studies (RR: 1.21, 95% CI: 0.99-1.48) and cross-sectional studies (RR: 1.81, 95% CI: 0.96-3.41). Patients with OSA in the retrospective study group had a statistically higher chance of developing cancer (RR: 1.41, 95% CI: 1.11-1.79). When stratified by cancer group, statistically significant differences was observed in many types of cancer (breast cancer: RR: 1.32, 95% CI: 1.03-1.70; central nervous system cancer: RR: 1.71, 95% CI: 1.06-2.75; kidney cancer: RR: 1.81, 95% CI: 1.20-2.74; liver cancer: RR: 1.19, 95% CI: 1.10-1.29; and pancreatic cancer: RR: 1.23, 95% CI: 1.14-1.33). CONCLUSIONS: This systematic review and meta-analysis suggests that obstructive sleep apnea may increase risk of cancer.

Redox-Induced Structural Change in Artificial Heterometallic-Oxide Cluster Mimicking the Photosynthetic Oxygen-Evolving Center.

The oxygen-evolving center (OEC) in photosynthesis is a unique Mn4 CaO5 -cluster that catalyzes the water-splitting reaction in nature. Understanding its catalytic mechanism for the O=O bond formation is of great challenge and long-standing issue, which is severely restricted by the lack of precise structure and mechanism mimics of this heterometallic-oxide cluster. Herein, we report two synthetic (Mn3 XO4 )2 O-clusters (X=Sr2+ , La3+ ) that closely mimic the heterometallic-oxide Mn3 XO4 cubane and three different types of µ-oxide bridges (µ2 -O2- , µ3 -O2- , and µ4 -O2- ) simultaneously as seen in the OEC. By resolving the crystal structures of both oxidized and reduced forms of the cluster, we have identified significant redox-induced structural changes that take place on the µ2 -oxide bridge, rather than the µ4 -oxide or µ3 -oxide bridges. Our results provide chemical insights into understanding the reactivity of three different types of oxide bridges in the biological Mn4 CaO5 -cluster in PSII.

Identification and molecular epidemiology of routinely determined Streptococcus pneumoniae with negative Quellung reaction results.

BACKGROUND: Some streptococci strains identified as Streptococcus pneumoniae (S. pneumoniae) by routine clinical methods exhibiting negative Quellung reaction results may belong to other species of viridans group streptococci or non-typeable S. pneumoniae. The purpose of this study was to investigate the identification and molecular characteristics of S. pneumoniae with negative Quellung reaction results. METHODS: One hundred and five isolates identified as S. pneumoniae using routine microbiological methods with negative Quellung reaction results were included. Multilocus sequence analysis (MLSA) was used as a gold standard in species identification, and the capacity of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) in identification was evaluated. Capsular genes and sequence types of S. pneumoniae isolates were determined by sequential multiplex PCR and multilocus sequence typing. Antimicrobial susceptibility patterns were determined via broth microdilution with a commercialized 96-well plate. RESULTS: Among the isolates, 81 were identified as S. pneumoniae and 24 were S. pseudopneumoniae by MLSA. MALDI-TOF MS misidentified six S. pneumoniae isolates as S. pseudopneumoniae and nine S. pseudopneumoniae isolates as S. pneumoniae or S. mitis/S. oralis. Thirty-one sequence types (STs) were detected for these 81 S. pneumoniae isolates, and the dominant ST was ST-bj12 (16, 19.8%). The non-susceptibility rates of S. pseudopneumoniae were comparable to those of NESp strains. CONCLUSIONS: Some S. pneumoniae isolates identified by routine methods were S. pseudopneumoniae. Most NESp strains have a different genetic background compared with capsulated S. pneumoniae strains. The resistance patterns of S. pseudopneumoniae against common antibiotics were comparable to those of NESp.

Rare-Earth Elements Can Structurally and Energetically Replace the Calcium in a Synthetic Mn4CaO4-Cluster Mimicking the Oxygen-Evolving Center in Photosynthesis.

The oxygen-evolving center (OEC) in photosynthesis is a unique biological Mn4CaO5 cluster catalyzing the water-splitting reaction. A great current challenge is to achieve a robust and precise mimic of the OEC in the laboratory. Herein, we report synthetic Mn4XO4 clusters (X = calcium, yttrium, gadolinium) that closely resemble the OEC with regard to the main metal-oxide core and peripheral ligands, as well as the oxidation states of the four Mn ions and the redox potential of the cluster. We demonstrate that rare-earth elements can structurally replace the calcium in neutral Mn4XO4 clusters. All three Mn4XO4 clusters with different redox-inactive metal ions display essentially the same redox properties, challenging the conventional view that the Lewis acidity of the redox-inactive metal ions could modulate the redox potential of the heteronuclear-oxide clusters. The new synthetic rare-earth element-containing Mn4XO4 clusters reported here provide robust and structurally well-defined chemical models and shed new light on the design of new water-splitting catalysts in artificial photosynthesis.

[RCT of Reduction in Catheter-Related Complications by Using Intracavitary Electrocardiogram-Assisted Guidance in Neonatal PICC Placement].

OBJECTIVE: To investigate the effect of intracavitary electrocardiogram (IC-ECG) guidance on peripherally inserted central catheter (PICC) related complications in neonatal patients. METHODS: A total of 210 neonatal patients were included in the study. They were admitted to the Neonatal Intensive Care Unit, Sichuan Provincial People's Hosptial between January, 2017 and December, 2019 and had PICC lines were placed in their upper limbs. The patients were randomly assigned to the observation group, which had PICC placement through conventional anatomical landmark guidance combined with IC-ECG guidance ( n=105) or to the control group, which had PICC placement through only conventional anatomical landmark guidance ( n=105) for PICC catheter tip positioning. Patient baseline data and data on subsequent catheter-related complications of the two groups were collected and compared. RESULTS: There were no significant difference between the two groups in sex composition, gestational age, postnatal days on the day of PICC placement, duration of PICC placement, disease profile, and the site of puncture ( P>0.05). The observation group showed a significantly lower overall incidence of catheter-related complications (3.8%), compared to that of the control group (21.9%) ( P<0.05). The observation group showed significantly lower incidence of phlebitis and arrhthmia compared to that of the control group ( P<0.05). CONCLUSION: A combination of anatomical landmark guidance and IC-ECG guidance to assist the placement of PICC decreases catheter-related complications.

Widespread of non-typeable Haemophilus influenzae with high genetic diversity after two decades use of Hib vaccine in China.

BACKGROUND: The aim of this study was to analyze the microbiological characteristics of nasopharyngeal carriage Haemophilus influenzae isolates collected from children with respiratory infections in Beijing hospital and Youyang Hospital of China. METHODS: The serotypes of all isolates were determined using latex agglutinated antisera (a-f). The minimum inhibitory concentrations (MICs) of 11 antibiotics were determined using E-test strips. For the beta-lactamase-negative ampicillin-resistant (BLNAR) isolates, ftsI gene was sequenced based on fragments amplified by PCR. STs of H influenzae isolates were determined by multi-locus sequence typing. RESULTS: The overall carriage rate of H influenzae in the study population was 9.1% (362/3984). One hundred and ninety H influenzae isolates which were selected in our study were non-typeable (NTHi) and 44 (23.2%) of them were positive for ß-lactamase. All isolates were susceptible to ceftriaxone and levofloxacin. Susceptibility rates to erythromycin and sulfamethoxazole-trimethoprim in Beijing were significantly higher than Youyang (P < .05). Thirty-six BLNAR isolates were identified. The MLST analysis showed 108 STs in 190 isolates, the most common of which were ST408 (11, 5.8%), ST914 (10, 5.3%), ST57 (9, 4.7%), and ST834 (6, 3.2%). Twelve STs were detected in both of the study sites, which covered 63 isolates. CONCLUSIONS: All isolates in the present study were NTHi, which suggested widespread of this type in China. The BLNAR isolates were detected more frequently than before. Because high genetic diversity of NTHi isolates of H influenzae exists worldwide, it is important to continuously monitor these bacteria in the future.

Multi-charged bis(p-calixarene)/pillararene functionalized gold nanoparticles for ultra-sensitive sensing of butyrylcholinesterase.

A series of supramolecular assemblies based on multi-charged calixarene (SC4A), bis(p-calixarene) (BSC4A) and pillararene (CP5A) modified gold nanoparticles (AuNP) was constructed to realize colorimetric sensing of both succinylcholine (SuCh) and butyrylcholinesterase (BChE). With the high binding affinity of BSC4A and CP5A towards SuCh, BSC4A-AuNPs and CP5A-AuNPs could assemble with micromolar level SuCh as SuCh-BSC4A/CP5A-AuNPs. More interestingly, the enzymatic hydrolysis of SuCh by BChE could lead to the disassembly of SuCh-BSC4A/CP5A-AuNPs and provide a sensitive time-dependent color change from blue to red which could be observed by the naked eye and used to monitor BChE activity. As BChE activity is an important biomarker for diseases and poor health conditions, this novel supramolecular tandem colorimetric sensing strategy may have potential use for early diagnosis of diseases.

Artificial Mn4 Ca Clusters with Exchangeable Solvent Molecules Mimicking the Oxygen-Evolving Center in Photosynthesis.

The natural Mn4 Ca cluster in photosystem II serves as a blueprint to develop artificial water-splitting catalysts for the generation of solar fuel in artificial photosynthesis. Although significant advances have recently been achieved, it remains a great challenge to prepare robust artificial Mn4 Ca clusters that precisely mimic the structure and function of the biological catalyst. Herein, we report the isolation and structural characterization of two Mn4 CaO4 complexes with polar solvent molecules, acetonitrile or N,N-dimethylformamide, which closely mimics the two water molecules on the calcium ion, as well as the oxidation states of the four manganese ions and the main geometric structure of the natural Mn4 Ca cluster. These new artificial Mn4 Ca complexes provide important chemical clues to understand the structure and mechanism of the biological system.

ß-Lactamase production and antibiotic susceptibility pattern of Moraxella catarrhalis isolates collected from two county hospitals in China.

BACKGROUND: Moraxella catarrhalis (M. catarrhalis) is an important bacterial pathogen. However, its antibiotic susceptibility patterns in different areas are difficult to compare because of the use of different methods and judgement criteria. This study aimed to determine antimicrobial susceptibility and ß-lactamase activity characteristics of M. catarrhalis isolates collected from two county hospitals in China, and to express the results with reference to three commonly used judgement criteria. RESULTS: Nasopharyngeal swabs were obtained from child inpatients with respiratory tract infections at the People's Hospital of Zhongjiang County and Youyang County from January to December 2015. M. catarrhalis strains were isolated and identified from the swabs, and susceptibility against 11 antimicrobials was determined using the E-test method or disc diffusion. Test results were interpreted with reference to the standards of the European Committee on Antimicrobial Susceptibility Testing (EUCAST), the Clinical and Laboratory Standards Institute (CLSI), and the British Society for Antimicrobial Chemotherapy (BSAC). Detection of ß-lactamase activity was determined by the chromogenic cephalosporin nitrocefin. M. catarrhalis yield rates were 7.12 and 9.58% (Zhongjiang County, 77/1082 cases; Youyang County, 101/1054 cases, respectively). All isolates were susceptible to amoxicillin-clavulanic acid. The susceptibility rate to meropenem was 100% according to EUCAST; no breakpoints were listed in CLSI or BSAC. The non-susceptibility rate to sulfamethoxazole-trimethoprim differed significantly between the two hospitals regardless of the judgemnet criteria used, with isolates from Zhongjiang showing higher susceptibility to those from Youyang (Fisher's exact test, P < 0.05). According to CLSI, the total non-susceptibility rate to erythromycin was 70.8% (Zhongjiang County, 79.2%; Youyang County, 64.3%), and the rate reached 92.1% (Zhongjiang County, 90.9%; Youyang County, 93.1%) on the basis of EUCAST or BSAC. The total positive rate of ß-lactamase was 99.4% (177/178 cases) (Zhongjiang County, 100%, 77/77 cases; Youyang County, 99.0%, 100/101 cases). CONCLUSIONS: Ninety nine percent of M. catarrhalis isolates produce ß-lactamase. The isolates showed poor susceptibility to ampicillin and erythromycin, and high susceptibility to the third- and fourth-generation cephalosporins and amoxicillin-clavulanic. Significant discrepancies between different antimicrobial susceptibility judgemnet criteria were noted.

An in vivo study of hypoxia-inducible factor-1α signaling in ginsenoside Rg1-mediated brain repair after hypoxia/ischemia brain injury.

BACKGROUND: Hypoxia/ischemia (HI) brain injury is a common central nervous system insult in newborns. Studies have demonstrated bioactivity of ginsenoside Rg1 in increasing neural viability and promoting angiogenesis. However, there are few reports on roles of Rg1 in brain repair of neonatal HI, and the mechanisms involved are unclear. METHODS: a neonatal HI model was established by a modified Rice-Vannucci model (RVM) and pups received ginsenoside Rg1 or monosialotetrahexosyl ganglioside (GM1) treatment. Neurological function and pathologic damage of rats were evaluated. Cellular apoptosis was detected with Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Immunohistochemistry for von willebrand factor (vwf) was used to label micro vessels. Expression levels of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), and cleaved caspase 3 (CC3) were detected by western blot. RESULTS: Both Rg1 and GM1 reduced neurological impairment and pathologic damage after HI by enhancing neural survival. Rg1, but not GM1, could also facilitate angiogenesis after HI. These pharmacological effects of Rg1 may be attributed to regulation of expression level of VEGF and CC3 and HIF-1α signaling pathway was involved. CONCLUSION: Rg1 plays a neuroprotective role in brain repair following neonatal HI, and HIF-1α is a potential target for therapeutic intervention in neonates with HI brain injury.

Epidemiological study on the penicillin resistance of clinical Streptococcus pneumoniae isolates identified as the common sequence types.

There were some limitation in the current interpretation about the penicillin resistance mechanism of clinical Streptococcus pneumoniae isolates at the strain level. To explore the possibilities of studying the mechanism based on the sequence types (ST) of this bacteria, 488 isolates collected in Beijing from 1997-2014 and 88 isolates collected in Youyang County, Chongqing and Zhongjiang County, Sichuan in 2015 were analyzed by penicillin minimum inhibitory concentration (MIC) distribution and annual distribution. The results showed that the penicillin MICs of the all isolates covering by the given ST in Beijing have a defined range, either <0.25 mg/L or≥0.25 mg/L, except for the ST342. The isolates with penicillin MIC <0.25 mg/L were mainly collected before 2001, after which the isolates with MIC≥0.25 mg/L occurred and became the major population gradually. This law of year distribution, however, was not obvious for any specific ST. The isolates covering by any given ST could be determined with different penicillin MICs in the first few years after it was identified. The penicillin MIC of isolates identified as common STs and collected in Youyang County, Chongqing and Sichuan Zhongjiang County, including the ST271, ST320 and ST81, was around 0.25~2 mg/L (≥0.25 mg/L). Our study revealed the epidemiological distribution of penicillin MICs of the given STs determined in clinical S. pneumoniae isolates, suggesting that it is reasonable to research the penicillin resistance mechanism based on the STs of this bacteria.

[Application of ultrasonic cardiac output monitor in evaluation of cardiac function in children with severe pneumonia].

OBJECTIVE: To study the clinical application of ultrasonic cardiac output monitor (USCOM) in evaluation of cardiac function in children with severe pneumonia. METHODS: Twenty-nine children with severe pneumonia were enrolled in the observation group and forty-three children with common pneumonia were enrolled in the control group. The USCOM was used to measure the cardiac function indices in the two groups. The results were compared between the two groups. The changes in cardiac function indices after treatment were evaluated in the observation group. ESULTS: The observation group had a significantly higher heart rate and significantly lower cardiac output, systolic volume, and aortic peak velocity than the control group (P<0.05). There were no significant differences in cardiac index or systemic vascular resistance between the two groups (P>0.05). In the observation group, the heart rate, cardiac output, systolic volume, aortic peak velocity, cardiac index, and systemic vascular resistance were significantly improved after treatment (P<0.05). CONCLUSIONS: The USCOM is a fast, convenient, and accurate approach for dynamic measurement of cardiac function and overall circulation state in children with severe pneumonia. The USCOM can provide a basis for diagnosis, treatment, and evaluation of the disease, which is quite useful in clinical practice.

[Clinical features of respiratory distress syndrome in neonates of different gestational ages].

OBJECTIVE: To study clinical features of respiratory distress syndrome (RDS) in neonates of different gestational ages (GA). METHODS: According to GA, 133 neonates with RDS were classified into GA <34 weeks group (n=66), GA 34-36 weeks group (late preterm neonates; n=31), and GA ≥37 weeks group (full-term neonates; n=36). The mothers' medical history during pregnancy and the condition of the neonates at birth were retrospectively analyzed, and the clinical data were compared between groups. RESULTS: Prenatal corticosteroids supplementation in the GA <34 weeks group was more common than that in the GA 34-36 weeks group (P<0.05). Compared with the GA ≥37 weeks group and the GA 34-36 weeks group, the GA <34 weeks group showed a significantly lower rate of primary diseases, a significantly later time of the development of dyspnea (P<0.05), and a higher rate of intraventricular hemorrhage (P<0.05). Serum albumin levels in the GA <34 weeks group were significantly lower than in the GA ≥37 weeks group (P<0.05). The GA ≥37 weeks group and the GA 34-36 weeks group showed a significantly higher reuse rate of pulmonary surfactant (P<0.05). Use of high-frequency oscillatory ventilation was more common in the GA ≥37 weeks group compared with the GA <34 weeks group (P<0.05). CONCLUSIONS: The clinical features of RDS are different across neonates of different GA, suggesting that the pathogenesis of RDS may be different in neonates of different GA.

[Suggestions for standardized management of nomenclature and classification of neonatal diseases].

Nomenclature and classification of diseases are not only related to clinical diagnosis and treatment, but also involved in the fields such as management and exchange of medical information, medical expense payments, and medical insurance payment. In order to standardize clinical physicians' diagnostic and treatment activities, medical records, and the first page of medical records, this article elaborates on the basic principles and methods for nomenclature and classification of diseases with reference to international nomenclature of diseases and international classification of diseases. Meanwhile, in view of the problems in clinical practice, this article proposes the classification of neonatal diseases, the basic procedure and writing rules in the diagnosis of neonatal diseases, and death diagnosis principles.

Voltammetric Scanning Electrochemical Cell Microscopy: Dynamic Imaging of Hydrazine Electro-oxidation on Platinum Electrodes.

Voltammetric scanning electrochemical cell microscopy (SECCM) incorporates cyclic voltammetry measurements in the SECCM imaging protocol, by recording electrochemical currents in a wide potential window at each pixel in a map. This provides much more information compared to traditional fixed potential imaging. Data can be represented as movies (hundreds of frames) of current (over a surface region) at a series of potentials and are highly revealing of subtle variations in electrode activity. Furthermore, by combining SECCM data with other forms of microscopy, e.g. scanning electron microscopy and electron backscatter diffraction data, it is possible to directly relate the current-voltage characteristics to spatial position and surface structure. In this work we use a "hopping mode", where the SECCM pipet probe is translated toward the surface at a series of positions until meniscus contact. Small amounts of residue left on the surface, upon probe retraction, demark the precise area of each measurement. We use these techniques to study hydrazine oxidation on a polycrystalline platinum substrate both in air and in a deaerated environment. In both cases, the detected faradaic current shows a structural dependence on the surface crystallographic orientation. Significantly, in the presence of oxygen (aerated solution) the electrochemical current decreases strongly for almost all grains (crystallographic orientations). The results highlight the flexibility of voltammetric SECCM for electrochemical imaging and present important implications for hydrazine electroanalysis.

Impact of Surface Chemistry on Nanoparticle-Electrode Interactions in the Electrochemical Detection of Nanoparticle Collisions.

The electrochemical detection of a single nanoparticle (NP) at a support electrode can provide key information on surface chemistry and fundamental electron transfer (ET) properties at the nanoscale. This study employs scanning electrochemical cell microscopy (SECCM) as a fluidic device to both deliver individual citrate-capped gold nanoparticles (AuNPs) and study the interactions between them and a range of alkanethiol-modified Au electrodes with different terminal groups, namely, -COOH, -OH, and -CH3. Single NP collisions were detected through the AuNP-mediated ET reaction of Fe(CN)6(4-/3-) in aqueous solution. The collision frequency, residence time, and current-time characteristics of AuNPs are greatly affected by the terminal groups of the alkanethiol. Methods to determine these parameters, including the effect of the instrument response function, and derive ET kinetics are outlined. To further understand the interactions of AuNPs with these surfaces, atomic force microscopy (AFM) force measurements were performed using citrate-modified Au-coated AFM tips and the same alkanethiol-modified Au substrates in aqueous solution at the same potential bias as for the AuNP collision experiments. Force curves on OH-terminated surfaces showed no repulsion and negligible adhesion force. In contrast, a clear repulsion (on approach) was seen for COOH-terminated surface and adhesion forces (on retract) were observed for both COOH- and CH3-terminated surfaces. These interactions help to explain the residence times and collision frequencies in AuNP collisions. More generally, as the interfacial properties probed by AFM appear to be amplified in NP collision experiments, and new features also become evident, it is suggested that such experiments provide a new means of probing surface chemistry at the nanoscale.