Tuning iron spin states in single-atom nanozymes enables efficient peroxidase mimicking

The large-scale application of nanozymes remains a significant challenge owing to their unsatisfactory catalytic performances. Featuring a unique electronic structure and coordination environment, single-atom nanozymes provide great opportunities to vividly mimic the specific metal catalytic center of natural enzymes and achieve superior enzyme-like activity. In this study, the spin state engineering of Fe single-atom nanozymes (FeNC) is employed to enhance their peroxidase-like activity. Pd nanoclusters (PdNC) are introduced into FeNC, whose electron-withdrawing properties rearrange the spin electron occupation in Fe(ii) of FeNC-PdNC from low spin to medium spin, facilitating the heterolysis of H2O2 and timely desorption of H2O. The spin-rearranged FeNC-PdNC exhibits greater H2O2 activation activity and rapid reaction kinetics compared to those of FeNC. As a proof of concept, FeNC-PdNC is used in the immunosorbent assay for the colorimetric detection of prostate-specific antigen and achieves an ultralow detection limit of 0.38 pg mL-1. Our spin-state engineering strategy provides a fundamental understanding of the catalytic mechanism of nanozymes and facilitates the design of advanced enzyme mimics.

[Clinical characteristics of digestive system cancers metastatic to the heart]

Objective: To investigate the clinical features of patients with cardiac metastases from digestive system tumors. Methods: This retrospective study collected and analyzed the medical records of patients with cardiac metastases from digestive system tumors who received treatments in the Cancer Hospital, Chinese Academy of Medical Sciences between January 1999 and January 2021. Kaplan-Meier method was used for survival analysis. Results: A total of 19 patients were identified. The primary tumors were esophageal squamous cell carcinoma (n=7), gastric or gastroesophageal junction adenocarcinoma (n=6), hepatobiliary cancers (n=3) and colorectal cancers (n=3). 16 patients had pericardial metastases, 2 patients had right atrium metastases, and 1 patient had left ventricle metastasis. The most common symptom was dyspnea, which was present in 8 cases. 7 patients received locoregional treatment, while 11 patients underwent systemic therapies. The median overall survival from diagnosis of primary cancer was 31.4 months, and the median overall survival time from diagnosis of cardiac metastasis was 4.7 months. Conclusion: Cardiac metastasis from digestive system tumors is associated with low incidence and a poor prognosis. Systemic treatment remains the cornerstone of management, while novel anti-tumor drugs may improve therapeutic efficacy.

Quality Improvement at the Laboratory’s Specimen Reception Station

Introduction/Objective

In our 1000-bed acute care tertiary hospital, physicians order laboratory tests via the computerized-provider-order-entry (CPOE) system and print barcode labels (patient demographics/tests ordered) at the computer-on-wheel printer. When tubes with unsuitable barcodes (misaligned, poor quality) are received at the laboratory specimen reception area a fresh barcode is re-printed by our laboratory staff. An incident involving a re- printed barcode label pasted on the wrong blood tube prompted an investigation into the quality of barcodes.

Methods/Case Report

We initiated ‘an opportunity for improvement (OFI) project’ at the laboratory specimen reception station. The OFI team involved Nursing, Information Technology (IT) and Pathology departments aimed to eliminate re-printing of barcode labels by 75% within 6 months. We collated and analyzed reasons for re-printing of barcodes on 3 separate 48-hour periods (27-28 April 2020, 24-25 June 2020, and 13-14 June 2022). A series of interventions and initiatives were implemented.

Results (if a Case Study enter NA)

Re-printed barcodes were from the Emergency Department (56%), Out-patient clinics (7%) and Wards (57%). Root cause analysis(RCA) using the “5 whys” technique categorized re-print causes into staff-related (misaligned barcodes) and printer-related (faint barcodes lines/truncated un-verifiable patient demographics). The team mass-emailed clinicians an educational “Do-You-Know” guide on proper pasting of barcodes on blood tubes and instructions on how to obtain help for printer rectification. These guide documents were placed in the hospital-wide document-sharing portal - Docupedia. Immediate close follow-up with sites that had poor barcodes was done in real-time. Barcode reprints decreased 83% within 2 months - from 174 (27-28 Apr 2020) to 30 (24-25 Jun 2020). A recent audit showed sustained elimination of barcode re-printing: 25 cases (13-14 Jun 2022).

Conclusion

The OFI project has successfully raised the quality of CPOE labels on specimen tubes contributing to process efficiency and safer patient care. Close communication with all care sites and their representatives on the OFI team are critical success factors.

The comparative burden of brain and central nervous system cancers from 1990 to 2019 between China and the United States and predicting the future burden

Background

Brain and central nervous system (CNS) cancers represent a major source of cancer burden in China and the United States. Comparing the two countries' epidemiological features for brain and CNS cancers can help plan interventions and draw lessons.

Methods

Data were extracted from the Global Burden of Disease repository. The average annual percentage change (AAPC) and relative risks of cancer burdens were calculated using joinpoint regression analysis and age-period-cohort (APC) models, respectively. Moreover, a Bayesian APC model was employed to predict the disease burden over the next decade.

Results

From 1990 to 2019, the number of incidences, deaths, and disability-adjusted life-years (DALYs) increased in China and the US, with a larger increase in China. Age-standardized incidence rates in China and the United States have shown an increasing trend over the past three decades, with AAPCs of 0.84 and 0.16%, respectively. However, the rates of age-standardized mortality and age-standardized DALYs decreased in both countries, with a greater decrease in China. Overall, age trends in cancer burden were similar for males and females, with two peaks in the childhood and elderly groups, respectively. The period and cohort effects on incidence showed an overall increasing trend in China and limited change in the US. However, the period effects for mortality and DALY were decreasing in both countries, while the cohort effects tended to increase and then decrease. Moreover, we predicted that the cancer burdens would continue to rise in China over the next decade.

Conclusion

The burden of brain and CNS cancers is substantial and will continue to increase in China. Comprehensive policy and control measures need to be implemented to reduce the burden.

Evaluation of 2 Novel Ratio-Based Metrics for Lumbar Spinal Stenosis

BACKGROUND AND PURPOSE

Quantitative metrics of the dural sac such as the cross-sectional area are commonly used to evaluate central canal stenosis. The aim of this study was to analyze 2 new metrics to measure spinal stenosis on the basis of the ratio between the dural sac and disc cross-sectional areas (DDRCA) and the dural sac and disc anterior-posterior diameters (DDRDIA) and compare them with established quantitative metrics of the dural sac.

MATERIALS AND METHODS

T2-weighted axial MR images (n = 260 patients) were retrospectively evaluated, graded for central canal stenosis as normal (no stenosis), mild, moderate, or severe from L1/L2 through L5/S1 with 1 grade per spinal level and annotated to measure the DDRCA and DDRDIA. Thresholds were obtained using a decision tree classifier on a subset of patients (n = 130) and evaluated on the remaining patients (n = 130) for accuracy and consistency across demographics, anatomic variation, and clinical outcomes.

RESULTS

DDRCA and DDRDIA had areas under the receiver operating characteristic curve of 98.6 (97.4-99.3) and 98.0 (96.7-98.9) compared with dural sac cross-sectional area at 96.5 (95.0-97.7) for binary classification. DDRDIA and DDRCA had κ scores of 0.75 (0.71-0.79) and 0.80 (0.75-0.83) compared with dural sac cross-sectional area at 0.62 (0.57-0.66) for multigrade classification. No significant differences (P > .1) in the area under the receiver operating characteristic curve were observed for the DDRDIA across variations in the body mass index. The DDRDIA also had the highest area under the receiver operating characteristic curve among symptomatic patients (visual analog scale ≥ 7) or patients who underwent surgery.

CONCLUSIONS

Ratio-based metrics (DDRDIA and DDRCA) are accurate and robust to anatomic and demographic variability compared with quantitative metrics of the dural sac and better correlated with symptomatology and surgical outcomes.

[Efficacy of in-situ full-left/full-right split liver transplantation for adult recipients using the living donor liver transplantation technique:a single-center report of 25 cases]

Objective: To evaluate the efficacy of in-situ full size split liver transplantation(fSLT) for adult recipients using the living donor liver transplantation(LDLT) technique and to compare the characteristics of the left hemiliver graft (LHG) and the right hemiliver graft(RHG)transplantation. Methods: Deceased donor and recipient data of 25 consecutive cases of fSLT at Department of Hepatopancreatobiliary Surgery, Ningbo Medical Center Lihuili Hospital from March to December 2021 was retrieved and the patients divided into two groups:LHG group and RHG group. Among the 13 donors,11 were male and 2 were female,aged (M(IQR))38(19) years(range: 25 to 56 years),with height of 168(5) cm(range:160 to 175 cm) and weight of 65(9) kg(range: 50 to 75 kg). The median age of the 25 recipients was 52(14) years(range:35 to 71 years),17 were male and 8 were female,15 had primary liver cancer and 10 had benign end-stage liver disease,model for end-stage liver disease score was 10(9) points(range:7 to 23 points). Of the 25 recipients,10 recipients had previously undergone hepatobiliary surgery. The follow-up period was to January 2022. Demographic,clinicopathological,surgical outcomes and postoperative complications were evaluated and compared between the two groups. Continuous quantitative data were compared using Mann-Whitney U test. Classification data were expressed as frequencies,and were compared between groups using χ² test or Fisher exact probability method. Results: Using LDLT technique,in-situ full-left/full-right liver splitting was performed and 13 viable pairs of hemiliver grafts were harvested with acquisition time of 230(53) minutes(range:125 to 352 minutes) and blood loss of 250(100) ml(range:150 to 1 000 ml). A total of 25 hemiliver grafts(13 LHG and 12 RHG) were allocated to patients listed for liver transplantation in our center by China Organ Transplant Response System. In the LHG group(13 cases),there were more females and more patients with benign end-stage liver disease than in the RHG group(12 cases)(P<0.05). The body weight and graft weight of recipients in the LHG group were lower than that in RHG group(both P<0.05). There were no significant differences in other baseline data between the two groups(all P>0.05). The graft to recipient weight ratio(GRWR) was 1.2(0.4)%(range:0.7% to 1.9%) for 25 recipients,1.1(0.5)%(range:0.7% to 1.6%)for the LHG group and 1.3(0.5)%(range:0.9% to 1.9%)for the RHG group. There was no significant difference between the two groups (P>0.05). Sharing patterns of hepatic vessels and the common bile duct are as follows:all the trunk of middle hepatic vein were allocated to the LHG group. The proportion of celiac trunk,main portal vein and common bile duct assigned to LHG and RHG was 10∶3 (P=0.009), 9∶4 (P>0.05) and 4∶9 (P=0.027),respectively. The vena cava of 12 donors in early stage retained in LHG and that of last one was shared between LHG and RHG (P<0.01). The median cold ischemia time of 25 hemiliver grafts was 240(90) minutes(range:138 to 420 minutes). For the total of 25 fSLT,the median anhepatic phase was 50(16) minutes(range:31 to 98 minutes) and the operation time was 474(138)minutes(range:294 to 680 minutes) with blood loss of 800(640) ml(range:200 to 5 000 ml). There were no significant differences in all of operation data between two groups. In the LHG group,3 patients with GRWR≤0.8% had postoperative small-for-size syndrome which improved after treatment. Postoperative Clavien-Dindo grade≥Ⅲ complications were observed in 6 cases(24.0%),4 cases(4/13) in the LHG group and 2 cases(2/12) in the RHG group,respectively. The difference was not statistically significant. Among them,5 cases improved after re-operation and intervention,1 case in LHG group died of secondary infection 2 weeks after operation,and the mortality was 4.0%. Analysis of serious postoperative complications and death has suggested that conventional caval interposition should not be used for LHG transplantation. Conclusion: Relying on accurate donor-recipient evaluation and the apply of LDLT technique,the morbidity and mortality of in-situ fSLT in adults is acceptable.

Semicrystalline Conjugated Polymers with Well-Defined Active Sites for Nitrogen Fixation in a Seawater Electrolyte

Faradaic efficiency for the nitrogen reduction reaction (NRR) is often limited by low N₂ solubility in the electrolyte, while a large number of intimate contacts between the electrolyte and solid catalyst can also inevitably sacrifice many active sites for the NRR. Here, it is reported that a "quasi-gas-solid" interface formed in donor-acceptor-based conjugated polymers (CPs) is beneficial to boosting the NRR process and at the same time suppressing the competing hydrogen evolution reaction. Of particular interest, it is found that a semicrystalline CP catalyst, SC-PBDT-TT, exhibits a high Faradaic efficiency of up to 60.5% with a maximum NH₃ production rate of 16.8 µg h^-1 mg^-1 in a neutral-buffered seawater electrolyte. Molecular dynamics and COMSOL Multiphysics simulations reveal the origin of the observed high NRR performance arising from the presence of desirable crystal regions to resist the penetration of H₂ O molecules, leading to the formation of a "quasi-gas-solid" interface inside the catalyst for a favorable direct-contact between the catalyst and N₂ molecules. Furthermore, high-throughput computations, based on density functional theory, reveal the actual real active site for N₂ adsorption and reduction in SC-PBDT-TT. This work provides a new framework for optimizing NRR performance of metal-free catalysts by controlling their crystallinities.

[Outcomes at discharge of preterm infants born <34 weeks' gestation]

Objective: To investigate the incidence and trend of short-term outcomes among preterm infants born <34 weeks' gestation. Methods: A secondary analysis of data from the standardized database established by a multicenter cluster-randomized controlled study "reduction of infection in neonatal intensive care units (NICU) using the evidence-based practice for improving quality (REIN-EPIQ) study". This study was conducted in 25 tertiary NICU. A total of 27 192 infants with gestational age <34 weeks at birth and admitted to NICU within the first 7 days of life from May 2015 to April 2018 were enrolled. Infants with severe congenital malformation were excluded. Descriptive analyses were used to describe the mortality and major morbidities of preterm infants by gestational age groups and different admission year groups. Cochran-Armitage test and Jonckheere-Terpstra test were used to analyze the trend of incidences of mortality and morbidities in 3 study-years. Multiple Logistic regression model was constructed to analyze the differences of outcomes in 3 study-years adjusting for confounders. Results: A total of 27 192 preterm infants were enrolled with gestational age of (31.3±2.0) weeks at birth and weight of (1 617±415) g at birth. Overall, 9.5% (2 594/27 192) of infants were discharged against medical advice, and the overall mortality rate was 10.7% (2 907/27 192). Mortality for infants who received complete care was 4.7% (1 147/24 598), and mortality or any major morbidity was 26.2% (6 452/24 598). The incidences of moderate to severe bronchopulmonary dysplasia, sepsis, severe intraventricular hemorrhage or periventricular leukomalacia, proven necrotizing enterocolitis, and severe retinopathy of prematurity were 16.0% (4 342/27 192), 11.9% (3 225/27 192), 6.8% (1 641/24 206), 3.6% (939/25 762) and 1.5% (214/13 868), respectively. There was a decreasing of the overall mortality (P<0.001) during the 3 years. Also, the incidences for sepsis and severe retinopathy of prematurity both decreased (both P<0.001). However, there were no significant differences in the major morbidity in preterm infants who received complete care during the 3-year study period (P=0.230). After adjusting for confounders, infants admitted during the third study year showed significantly lower risk of overall mortality (adjust OR=0.62, 95%CI 0.55-0.69, P<0.001), mortality or major morbidity, moderate to severe bronchopulmonary dysplasia, sepsis and severe retinopathy of prematurity, compared to those admitted in the first study year (all P<0.05). Conclusions: From 2015 to 2018, the mortality and major morbidities among preterm infants in Chinese NICU decreased, but there is still space for further efforts. Further targeted quality improvement is needed to improve the overall outcome of preterm infants.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Clinical and Pulmonary CT Characteristics of Patients Infected With the SARS-CoV-2 Omicron Variant Compared With Those of Patients Infected With the Alpha Viral Strain

Background

Omicron has become the dominant variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) globally. We aimed to compare the clinical and pulmonary computed tomography (CT) characteristics of the patients infected with SARS-CoV-2 Omicron with those of patients infected with the Alpha viral strain.

Methods

Clinical profiles and pulmonary CT images of 420 patients diagnosed with coronavirus disease-2019 (COVID-19) at Ningbo First Hospital between January 2020 and April 2022 were collected. Demographic characteristics, symptoms, and imaging manifestations of patients infected with the SARS-CoV-2 Omicron variant were compared with those of patients infected with the Alpha strain.

Results

A total of 38 patients were diagnosed to be infected with the Alpha strain of SARS-CoV-2, whereas 382 patients were thought to be infected with the Omicron variant. Compared with patients infected with the Alpha strain, those infected with the Omicron variant were younger, and a higher proportion of men were infected (P < 0.001). Notably, 93 (24.3%) of the patients infected with Omicron were asymptomatic, whereas only two (5.3%) of the patients infected with the Alpha strain were asymptomatic. Fever (65.8%), cough (63.2%), shortness of breath (21.1%), and diarrhea (21.1%) were more common in patients infected with the SARS-CoV-2 Alpha strain, while runny nose (24.1%), sore throat (31.9%), body aches (13.6%), and headache (12.3%) were more common in patients with the Omicron variant. Compared with 33 (86.84%) of 38 patients infected with the Alpha strain, who had viral pneumonia on pulmonary CT images, only 5 (1.3%) of 382 patients infected with the Omicron variant had mild foci. In addition, the distribution of opacities in the five patients was unilateral and centrilobular, whereas most patients infected with the Alpha strain had bilateral involvement and multiple lesions in the peripheral zones of the lung.

Conclusion

The SARS-CoV-2 Alpha strain mainly affects the lungs, while Omicron is confined to the upper respiratory tract in patients with COVID-19.

The SARS-CoV-2 rS1-E-PLGA nanovaccine and evaluation of its immune effect in BALB/c mice

OBJECTIVE

Vaccination is an important method for preventing COVID-19 infection. However, certain vaccines do not meet the current needs. To improve the vaccine effect, discard ineffective antigens, and focus on high-quality antigenic clusters, S1-E bivalent antigens were designed.

MATERIALS AND METHODS

Vaccine delivery is performed using poly (lactic-co-glycolic acid) (PLGA). Here, the recombinant S1-E (rS1-E) was covered on PLGA and injected intramuscularly into mice. In total, 48 BALB/c mice were randomly divided into six groups with 8 mice in each group. The mice received intramuscular injections. Prior to vaccination, the hydrophobicity of the rS1-E and the antigenic site of the E protein were both analysed. The morphology, zeta potential, and particle size distribution of rS1-E-PLGA were examined. Anti-S1 and anti-E antibodies were detected in mouse serum by ELISA. Neutralising an-tibodies were detected by co-incubating the pseudovirus with the obtained serum. IL-2 and TNF-α levels were also measured.

RESULTS

The designed recombinant S1-E protein was successfully coated on PLGA nanoparticles. rS1-E-PLGA nanovaccine has suitable size, shape, good stability, sustained release and other characteristics. Importantly, mice were stimulated with rS1-E-PLGA nanovaccines to produce high-titre antibodies and a good cellular immune response.

CONCLUSIONS

Our results indicate that rS1-E-PLGA nanovaccine may provide a good protective effect, and the vaccine should be further investigated in human clinical trials for use in vaccination or as a booster.

HLA class II immunogenic mutation burden predicts response to immune checkpoint blockade

BACKGROUND

Whereas human leukocyte antigen (HLA) class I mutation-associated neoantigen burden has been linked with response to immune checkpoint blockade (ICB), the role of HLA class II-restricted neoantigens in clinical responses to ICB is less studied. We used computational approaches to assess HLA class II immunogenic mutation (IMM) burden in patients with melanoma and lung cancer treated with ICB.

PATIENTS AND METHODS

We analyzed whole-exome sequence data from four cohorts of ICB-treated patients with melanoma (n = 110) and non-small-cell lung cancer (NSCLC) (n = 123). MHCnuggets, a neural network-based model, was applied to estimate HLA class II IMM burdens and cellular fractions of IMMs were calculated to assess mutation clonality. We evaluated the combined impact of HLA class II germline genetic variation and class II IMM burden on clinical outcomes. Correlations between HLA class II IMM burden and density of tumor-infiltrating lymphocytes were computed from expression data.

RESULTS

Responding tumors harbored a significantly higher HLA class II IMM burden for both melanoma and NSCLC (P ≤ 9.6e-3). HLA class II IMM burden was correlated with longer survival, particularly in the NSCLC cohort and in the context of low intratumoral IMM heterogeneity (P < 0.001). HLA class I and II IMM landscapes were largely distinct suggesting a complementary role for class II IMMs in tumor rejection. A higher HLA class II IMM burden was associated with CD4+ T-cell infiltration and programmed death-ligand 1 expression. Transcriptomic analyses revealed an inflamed tumor microenvironment for tumors harboring a high HLA class II IMM burden.

CONCLUSIONS

HLA class II IMM burden identified patients with NSCLC and melanoma that attained longer survival after ICB treatment. Our findings suggest that HLA class II IMMs may impact responses to ICB in a manner that is distinct and complementary to HLA class I-mediated responses.

Theoretical study on Y-doped Na2ZrO3 as a high-capacity Na-rich cathode material based on anionic redox

First-principles calculations based on density functional theory were utilized to study the performance of Na₂ZrO₃ (NZO) and yttrium-doped Na₂ZrO₃ (Y-NZO) as cathode materials for sodium ion batteries (SIBs), including the stability of the desodiated structures, desodiation energy, redox mechanism, and the diffusion of Na. When 62.5% sodium is removed from NZO, its structure and volume change little and the layered structure is retained, whereas the structure starts to distort and shift to the ZrO₃ phase with the extraction of more than 62.5% sodium. As desodiation proceeds, oxygen anions act as the only redox center for charge compensation, yielding a high initial voltage of 4.03 eV vs. Na/Na⁺ by PBE + U-D3 functional and 4.82 eV vs. Na/Na⁺ by HSE06-D3 functional. When the desodiation content is less than 31.25%, O₂^3- is formed with an O-O distance of 2.38 Å. At the desodiation content of 31.25%, peroxide dimer O₂^2- starts to form; at the desodiation content of 56.25%, the O-O bond distance is further shortened to 1.3 Å, corresponding to the formation of superoxide O₂^-. However, for Y-NZO, the redox reaction firstly involves O^2-/O^1-, which does not occur in NZO. Peroxides and superoxides appear when the sodium removal concentration is 59.38% and 75%, respectively. This indicates that the O-O dimers appear in Y-NZO at much deeper sodium removal. The calculations of diffusion paths and barriers of Na ions in NZO by PBE + U-D3 predict that the barrier of Na escaping from the mixed layer to the Na layer in NZO is 0.48 eV (the reverse barrier is 0.76 eV), smaller than those of other O3-type layered transition metal compounds, such as Na₂IrO₃ and Na₂RuO₃. After yttrium doping, the diffusion of Na ions becomes easier, indicating that the Y-doping improves the diffusion ability. This investigation interprets the mechanism of oxygen oxidation of NZO as a cathode for SIBs, and provides theoretical support for a better design of Na-rich layered oxide Na₂MO₃ (M represents the transition metal element) in the future research.

Single-Atom Iron Enables Strong Low-Triggering-Potential Luminol Cathodic Electrochemiluminescence

The conventional cathodic electrochemiluminescence (ECL) always requires a more negative potential to trigger strong emission, which inevitably damages the bioactivity of targets and decreases the sensitivity and specificity. In this work, iron single-atom catalysts (Fe-N-C SACs) were employed as an efficient co-reaction accelerator for the first time to achieve the impressively cathodic emission of a luminol-H₂O₂ ECL system at an ultralow potential. Benefiting from the distinct electronic structure, Fe-N-C SACs exhibit remarkable properties for the activation of H₂O₂ to produce massive reactive oxygen species (ROS) under a negative scanning potential from 0 to -0.2 V. The ROS can oxidize the luminol anions into luminol anion radicals, avoiding the tedious electrochemical oxidation process of luminol. Then, the in situ-formed luminol anion radicals will directly react with ROS for the strong ECL emission. As a proof of concept, sensitive detection of the carcinoembryonic antigen was realized by glucose oxidase-mediated ECL immunoassay, shedding light on the superiority of SACs to construct efficient cathodic ECL systems with low triggering potential.

[Inhibition of Sonic Hedgehog signaling inhibits fibrous scar formation and adversely affects functional outcome after ischemic brain injury in rats]

OBJECTIVE

To investigate the effects of inhibiting Sonic Hedgehog (Shh) signaling on fibrous scar formation and functional outcome after ischemic brain injury.

METHODS

Adult SD rats were randomized into sham-operated group, middle cerebral artery occlusion (MCAO) and reperfusion (I/R) group, I/R with intraventricular empty adenoviral vector (rAd-NC) injection group, and I/R with adenovirus-mediated Shh knockdown (rAd-ShShh) group. After the treatments, the neurological deficits of the rats were assessed, and the protein and mRNA expressions of fibronectin (Fn), α-SMA, and Shh in the ischemic hemisphere were detected with immunofluorescence assay and qPCR; TUNEL staining was used for detecting neural cell apoptosis. In the cell experiment, primary meningeal fibroblasts isolated from neonatal SD rats were pretreated for 24 h with TGF-β1 or TGF-β1 plus cyclopamine (CYC) before oxygen-glucose deprivation for 150 min followed by reoxygenation for 72 h (OGD/R). CCK-8 assay and scratch test were performed to examine the changes in cell proliferation and migration, and immunofluorescence assay, qPCR and Western blotting were used for detecting cell transformation and the expressions of Shh, α-SMA, and Fn.

RESULTS

Cerebral I/R injury significantly increased the protein and mRNA expressions of Shh, α-SMA, and Fn in the ischemic hemisphere of the rats, but their expression levels were significantly lowered by intraventricular injection of rAd-Shshh (P < 0.05), which obviously increased cell apoptosis in the ischemic hemisphere (P < 0.05) and improved modified mNSS and modified Bederson scores of the rats (P < 0.05). In the cell experiment, pretreatment with TGF-β1 and TGF-β1+CYC both increased the viability of the primary meningeal fibroblasts after OGD/R. TGF-β1 significantly enhanced the migration ability and induced obvious transformation of the exposed cells (P < 0.05), but these effects were significantly attenuated by co-treatment with CYC (P < 0.05). The expressions of Shh, α-SMA and Fn in the TGF-β1 group were all significantly higher in TGF-β1-treated cells (P < 0.05) and were obviously lowered by co-treatment with CYC (P < 0.05).

CONCLUSION

Inhibition of Shh signaling may inhibit fibrous scar formation and functional recovery in rats after ischemic brain injury.

[A cross-sectional investigation and analysis of early treatment of partial-thickness burn wounds by professional burn medical staff in China]

Objective: To assess the current situation of early treatment of partial-thickness burn wounds by professional burn medical staff in China, and to further promote the standardized early clinical treatment of partial-thickness burn wounds. Methods: A cross-sectional investigation was conducted. From November 2020 to February 2021, the self-designed questionnaire for the early treatment of partial-thickness burn wounds was published through the "questionnaire star" website and shared through WeChat to conduct a convenient sampling survey of domestic medical staff engaged in burn specialty who met the inclusion criteria. The number, region, and grade of the affiliated hospital, the age, gender, occupation, and seniority of the respondents were recorded. The respondents were divided into physician group and nurse group, senior group and junior group, eastern region group and non-eastern region group, primary and secondary hospital group and tertiary hospital group. Then the seniority, grade of the affiliated hospital, region of the affiliated hospital of the respondents in physician group and nurse group, conventional treatment of partial-thickness burn blisters, reasons for retaining vesicular skin, reasons for removing vesicular skin, and the conventional selection and optimal solution recommendation of topical drugs or dressings for partial-thickness burn wounds in the early stage of respondents in each of all the groups were recorded. Data were statistically analyzed with chi-square test. Results: The survey covered 31 provinces, municipalities, and autonomous regions in China (except for Hong Kong, Macau, and Taiwan regions). A total of 979 questionnaires were recovered, which were all valid. The 979 respondents came from 449 hospitals across the country, including 203 hospitals in the eastern region, 116 hospitals in the western region, 99 hospitals in the central region, and 31 hospitals in the northeast region, 348 tertiary hospitals, 79 secondary hospitals, and 22 primary hospitals. The age of the respondents was (39±10) years. There were 543 males and 436 females, 656 physicians and 323 nurses, 473 juniors and 506 seniors, 460 in the eastern regions and 519 in the non-eastern regions, 818 in tertiary hospitals and 161 in primary and secondary hospitals. There were statistically significant differences in the composition of different seniority in the respondents between physician group and nurse group (χ2=44.32, P<0.01), while there were no statistically significant differences in grade or region of the affiliated hospital of the respondents between physician group and nurse group (P>0.05). There were no statistically significant differences in the conventional treatment of partial-thickness burn blisters among respondents between different occupational groups, seniority groups, and region of the affiliated hospital groups (P>0.05).The respondents in different grade of the affiliated hospital groups differed significantly in the conventional treatment of partial-thickness burn blisters (χ2=6.24, P<0.05). Compared with respondents in nurse group, larger percentage of respondents in physician group chose to retain vesicular skin for protecting the wounds and providing a moist environment, and alleviating the pain of dressing change (with χ2 values of 21.22 and 19.96, respectively, P values below 0.01), and smaller percentage of respondents in physician group chose to retain vesicular skin for prevention of wound infection (χ2=23.55, P<0.01). The reasons for retaining vesicular skin of respondents between physician group and nurse group were similar in accelerating wound healing, alleviating pigmentation and scar hyperplasia post wound healing (P>0.05). Compared with respondents in junior group, larger percentage of respondents in senior group chose to retain vesicular skin for protecting the wounds and providing a moist environment and alleviating the pain of dressing change (with χ2 values of 10.36 and 4.60, respectively, P<0.05 or P<0.01), and smaller percentage of respondents in senior group chose to retain vesicular skin for prevention of wound infection (χ2=8.20, P<0.01). The reasons for retaining vesicular skin of respondents in senior group and junior group were similar in accelerating wound healing, alleviating pigmentation and scar hyperplasia post wound healing (P>0.05). The 5 reasons for the respondents between eastern region group and non-eastern region group, primary and secondary hospital group and tertiary hospital group chose to retain vesicular skin were all similar (P>0.05). Compared with those in physician group, significantly higher percentage of respondents in nurse group were in favor of the following 6 reasons for removing the vesicular skin, including convenience for using more ideal dressings to protect the wounds, prevention of wound infection, facilitating the effect of topical drugs on the wounds, the likely rupture of blisters and wound contamination, accelerating wound healing, and alleviating pigmentation and scar hyperplasia post wound healing (with χ2 values of 4.35, 25.59, 11.83, 16.76, 46.31, and 17.54, respectively, P<0.05 or P<0.01). Compared with respondents in senior group, larger percentage of respondents in junior group chose to remove vesicular skin for the reasons such as the likely blister rupture and wound contamination, preventing wound infection, accelerating wound healing, and alleviating pigmentation and scar hyperplasia post wound healing (with χ2 values of 17.25, 18.63, 14.83, and 10.23, respectively, P values below 0.01). Compared with respondents in non-eastern region group, larger percentage of respondents in eastern region group chose to remove vesicular skin for preventing wound infection and the likely rupture of blisters and wound contamination (with χ2 values of 9.30 and 8.65, respectively, P values below 0.01). The 6 reasons for the respondents between tertiary hospital group and primary and secondary hospital group choose to remove vesicular skin were similar (P>0.05). Compared with respondents in physician group, larger percentage of respondents in nurse group chose to use moisturizing materials for partial-thickness burn wounds in the early stage (χ2=6.18, P<0.05), and smaller percentage of respondents in nurse group chose other topical drugs or dressings (χ2=5.20, P<0.05). Compared with respondents in junior group, larger percentage of respondents in senior group chose to use moisturizing materials and other topical drugs or dressings for partial-thickness burn wounds in the early stage (with χ2 values of 4.97 and 21.80, respectively, P<0.05 or P<0.01). Compared with respondents in non-eastern region group, larger percentage of respondents in eastern region group chose to use topical antimicrobial drugs for partial-thickness burn wounds in the early stage (χ2=4.09, P<0.05), and smaller percentage of respondents in eastern region group chose to use other topical drugs or dressings for the partial-thickness burn wounds in the early stage (χ2=5.63, P<0.05). Compared with respondents in primary and secondary hospital group, larger percentage of respondents in tertiary hospital group chose to use biological dressings for partial-thickness burn wounds in the early stage (χ2=9.38, P<0.01). The optimal solution recommendation of topical drugs or dressings for partial-thickness burn wounds in the early stage varied significantly among the respondents between different occupational groups and seniority groups (with χ2 values of 39.58 and 19.93, respectively, P values below 0.01). There were no statistically significant differences between eastern and non-eastern region groups, tertiary hospital group and primary and secondary hospital groups in optimal solution recommendation of topical drugs or dressings for partial-thickness burn wounds in the early stage (P>0.05). Conclusions: The conventional treatment measures of partial-thickness burn blisters and reasons for preserving blister skin by professional burn medical staff in China are relatively consistent, but there are great differences in the selection of reasons for removing blister skin, the conventional selection and optimal solution recommendation of topical drugs or dressings for partial-thickness burn wounds in the early stage. Therefore, it is urgent to establish a clinical treatment standard for partial-thickness burn wounds.

Amorphous metal-organic frameworks on PtCu hydrogels: Enzyme immobilization platform with boosted activity and stability for sensitive biosensing

Cell-free enzymatic catalysis (CFEC) is emerging biotechnology that simulates biological transformations without living cells. However, the high cost of separation and preparation of the enzyme has hindered the practical application of the CFEC. Enzyme immobilization technologies using solid supports to stabilize enzymes have been regarded as an efficient strategy to address this issue. Nevertheless, the activity and stability of the immobilized enzymes are still crucial challenges for working in vitro. Herein, an enzyme immobilization platform is developed by using PtCu hydrogels coated with amorphous metallic-organic frameworks (MOFs) as multifunctional carriers to encapsulate horseradish peroxidase (HRP). Specifically, PtCu hydrogels acting as a "reservoir of metal ions" can interact with the immobilized enzyme and facilitate electron transfer, leading to the boosted enzyme catalytic performances. Furthermore, amorphous MOFs on the surface of PtCu hydrogels serve as an "armor" to protect the internal enzymes from various perturbation environments. The resultant enzyme immobilization platform (PtCu@HRP@ZIF-8) not only shows an approximately 2.4-fold enhanced activity compared with free enzyme but also exhibits improved stability against harsh conditions. The PtCu@HRP@ZIF-8-based biosensor is constructed for sensitive sensing of organophosphorus pesticides (OPs). The proposed biosensor exhibits a favorable linear relationship with the concentration of paraoxon-ethyl from 6 to 800 ng/mL, with a low detection limit of 1.8 ng/mL. This work reveals the promising potential of our proposed enzyme immobilization platform in practical applications.

A pharmacokinetic-pharmacodynamic (PKPD) model-based analysis of tedizolid against enterococci using the hollow-fibre infection model

BACKGROUND

Tedizolid is a novel oxazolidinone antibiotic. Considering the higher antibacterial effect in immunocompetent compared with immunosuppressed animals, it is not recommended in immunocompromised patients.

OBJECTIVES

In this study, we assessed the 'pure' pharmacokinetic-pharmacodynamic (PKPD) relationship for tedizolid against Enterococcus in the hollow-fibre infection model (HFIM).

METHODS

Unbound plasma concentration time profiles (200-5000 mg/day IV) were simulated in the HFIM over 120 h against an Enterococcus faecalis strain and two clinical isolates of Enterococcus faecium (VRE-vanB and VRE-vanA). Next, a PKPD model describing tedizolid efficacy against bacterial isolates was developed. A population PK model was linked to the developed PKPD model and utilized to predict the bacterial kinetics in plasma and in target tissues [adipose, muscle, epithelial lining fluid (ELF) and sputum] over 120 h of therapy.

RESULTS

The PKPD model adequately described the bacterial kill kinetics for all bacterial populations. At the human recommended dose of 200 mg/day, bacterial growth was predicted in plasma and all tissues, except for ELF. Bacteriostasis was observed only at a higher dose of 1200 mg/day over 120 h. An fAUC/MIC of 80 related to stasis over 120 h. Subpopulations resistant to 3 × MIC were amplified in plasma and target tissues, except for ELF, at doses of 200-800 mg/day.

CONCLUSIONS

The human dose of 200 mg/day was insufficient to suppress bacterial growth in the HFIM, indicating that further components contribute to the clinical effect of tedizolid. This study supports the warning/precaution for tedizolid to limit its use in immunocompromised patients.

Hemodynamic changes associated with neuraxial anesthesia in pregnant women with covid 19 disease: a retrospective case-control study

Background

Neuraxial blocks is the recommended mode of analgesia and anesthesia in parturients with Coronavirus 19 (COVID-19). There is limited data on the hemodynamic responses to neuraxial blocks in COVID-19 patients. We aim to compare the hemodynamic responses to neuraxial blocks in COVID-19 positive and propensity-matched COVID-19 negative parturients.

Methods

We conducted retrospective, cross-sectional case–control study of hemodynamic changes associated with neuraxial blocks in COVID-19 positive parturients in a Tertiary care academic medical center. Fifty-one COVID-19 positive women confirmed by nasopharyngeal reverse transcription–polymerase chain reaction (RT-PCR), were compared with propensity-matched COVID negative controls (n = 51). Hemodynamic changes after neuraxial block were recorded by electronic medical recording system and analyzed using paired and unpaired T- test and Wilcoxon-Mann–Whitney Rank Sum tests. The primary outcome was ≥ 20% change in MAP and HR after neuraxial block placement.

Results

In the epidural group, 7% COVID-19 positive parturients had > 20% decrease in mean arterial pressure (MAP) from baseline compared to 15% COVID-19 negative parturients (P = 0.66). In the spinal group, 83% of COVID-19 positive parturients had a decrease in MAP more than 20% from baseline compared to 71% in control (P = 0.49). MAP drop of more than 40% occurred in 29% COVID positive parturients in the spinal group versus 17% in COVID-19 negative parturients (P = 0.5465). In COVID-19 positive spinal group, 54% required vasopressors whereas 38% in COVID-19 negative spinal group required vasopressors (P = 0.387). We found a significant correlation between body mass index (BMI) > 30 and hypotension in COVID ( +) parturient with odds ratio (8.63; 95% CI-1.93 – 37.21) (P = 0.007).

Conclusion

Incidence and severity of hypotension after neuraxial blocks were similar between COVID-19 positive and COVID-19 negative parturients. BMI > 30 was a significant risk factor for hypotension as described in preexisting literature, this correlation was seen in COVID-19 positive parturients. The likely reason for parturients with BMI > 30 in COVID negative patients not showing similar correlation, is that the sample size was small.

Supplementary information

The online version contains supplementary material available at 10.1186/s12871-022-01719-0.

[Clinical phenotype and genotype of Gaucher disease in 14 children]

Objective: To analyze the clinical and genetical characteristics of children with Gaucher disease and to explore the relationship between genotype and phenotype. Methods: In this retrospective study, the clinical data of 14 children with Gaucher disease diagnosed in Children's Hospital of Nanjing Medical University from August 2016 to October 2021 were analyzed. Their general conditions, clinical manifestations, laboratory tests and gene variations were collected, followed by the analysis of the clinical phenotypes and genotypes. Results: Among 14 children diagnosed with Gaucher disease, 9 were males and 5 were females, with the age of diagnosis ranging from 0.7 to 15.8 years. There were 10 patients with type 1 Gaucher disease, 2 patients with type 2, and 2 patients with type 3. The most common clinical manifestations were splenomegaly, thrombocytopenia (14 cases), hepatomegaly (8 cases) and anemia (8 cases). There were 6 patients with growth retardation, and 5 patients lag in height compared with their peers. Bone abnormalities were revealed by magnetic resonance imaging in 7 type 1 Gaucher disease patients, but only 1 patient experienced bone pain. Patients with type 2 and type 3 Gaucher disease also presented with convulsions, nystagmus and hearing loss. Gaucher cells were found in bone marrow smears in 12 patients. The glucocerebrosidase gene variations identified in 13 patients were heterozygous and in 1 type 1 patient was homozygous of L483P. L483P variation accounted for 33%(10/30) of the variation alleles, followed by V414L, D448H and R159W. The variation alleles were L483P and L422R, F252I and L483P in 2 children with severe neurological manifestations of Gaucher disease. A novel variation c.22A>G was detected. Conclusions: Splenomegaly and thrombocytopenia are the main clinical presentations of Gaucher disease in children and bone lesions revealed by radiologic imaging appear prior to the occurrence of bone diseases, type 2 and type 3 Gaucher disease also present growth retardation and neurological manifestation. The most frequent variant allele is L483P, which are detected in all 3 subtypes of Gaucher disease. The L422R, F252I gene variants correlated with the neuronopathic phenotype.

Neuroprotective effects of visnagin on cerebral ischemia-reperfusion injury rats and the underlying mechanisms

OBJECTIVE

Cerebral ischemia-reperfusion (I/R), caused by the treatments of ischemic stroke, usually leads to brain injury. Inflammation, oxidative stress, and autophagy play pivotal roles in the pathology. Visnagin presents a protective effect on I/R injured animal models of the heart, liver, kidney, and other organs. In our research, we identified the neuroprotective effects and the underlying mechanisms of visnagin in cerebral I/R injured models.

MATERIALS AND METHODS

We constructed rat models of cerebral I/R injury and categorized them into 5 groups: sham operation group, I/R model group, and visnagin treatment I/R group (10, 30, 60 mg/kg). The neurological deficits of the rats were analyzed after 24 hours of reperfusion, then, the contents of glutathione peroxidase, malondialdehyde, superoxide dismutase catalase, caspase-3, nuclear factor kappa-B p65 unit, tumor necrosis factor-α, interleukin-1β, and interleukin6 were measured in rat models. The expressions of Bcl-2 and Bax were detected by Western blot analysis.

RESULTS

Our results suggested that the administration of visnagin alleviated the cognitive dysfunction, reduced the activities of inflammatory factors, promoted the protein expression of Bcl-2, and downregulated the expression of Bax in the I/R injured rat model.

CONCLUSIONS

Visnagin exerts a neuroprotective effect during I/R injury in rats, the underlying mechanisms may be the effect of attenuating neuroinflammation, anti-oxidative and inhibition of apoptosis.

[A nonlocal spectral similarity-induced material decomposition method for noise reduction of dual-energy CT images]

OBJECTIVE

To propose a nonlocal spectral similarity-induced material decomposition network (NSSD-Net) to reduce the correlation noise in the low-dose spectral CT decomposed images.

METHODS

We first built a model-driven iterative decomposition model for dual-energy CT, optimized the objective function solving process using the iterative shrinking threshold algorithm (ISTA), and cast the ISTA decomposition model into the deep learning network. We then developed a novel cost function based on the nonlocal spectral similarity to constrain the training process. To validate the decomposition performance, we established a material decomposition dataset by real patient dual-energy CT data. The NSSD-Net was compared with two traditional model-driven material decomposition methods, one data-based material decomposition method and one data-model coupling-driven material decomposition supervised learning method.

RESULTS

The quantitative results showed that compared with the two traditional methods, the NSSD-Net method obtained the highest PNSR values (31.383 and 31.444) and SSIM values (0.970 and 0.963) and the lowest RMSE values (2.901 and 1.633). Compared with the datamodel coupling-driven supervised decomposition method, the NSSD-Net method obtained the highest SSIM values on water and bone decomposed results. The results of subjective image quality assessment by clinical experts showed that the NSSD-Net achieved the highest image quality assessment scores on water and bone basis material (8.625 and 8.250), showing significant differences from the other 4 decomposition methods (P < 0.001).

CONCLUSION

The proposed method can achieve high-precision material decomposition and avoid training data quality issues and model unexplainable issues.

[Metformin inhibits proliferation and promotes apoptosis of HER-2 positive breast cancer cells possibly through the Hippo-YAP pathway]

OBJECTIVE

To investigate the effect of metformin on the proliferation and apoptosis of HER-2-positive breast cancer cell line SKBR3 and explore the possible mechanism of its action.

METHODS

SKBR3 cells were treated with different concentrations (20-120 μmol/L) of metformin, and the changes in cell proliferation and colony formation ability were assessed using CCK-8 assay and crystal violet staining, respectively. Flow cytometry was performed to analyze cell apoptosis and cell cycle changes. Real-time fluorescent quantitative PCR (qRT-PCR) was used to detect mRNA expressions of YAP, TAZ, EGFR, CTGF, CYR61, E-cadherin, N-cadherin, vimentin and fibronectin in the treated cells, and the protein expressions of YAP and TAZ were detected using Western blotting; immunofluorescence assay was used to observe YAP/TAZ nuclear translocation in the cells.

RESULTS

Metformin treatment significantly inhibited the proliferation of SKBR3 cells (P < 0.05) in a concentration- and time-dependent manner. The results of flow cytometry showed that metformin significantly promoted apoptosis and caused cell cycle arrest at G1 phase in SKBR3 cells. Metformin treatment significantly down-regulated the mRNA expressions of YAP, TAZ, EGFR, CTGF and CYR61, N-cadherin, vimentin and fibronectin (P < 0.05) and up-regulated the expression of E-cadherin (P < 0.05); Western blotting results showed that YAP and TAZ protein expressions were significantly down-regulated in the cells after metformin treatment (P < 0.05). Immunofluorescence assay revealed that metformin treatment caused the concentration of YAP and TAZ in the cytoplasm, and significantly reduced their amount in the cell nucleus.

CONCLUSION

Metformin can inhibit proliferation and promote apoptosis and epithelal-mesenchymal transition of HER-2 positive breast cancer cells possibly by that inhibing YAP and TAZ expression and their nuclear localization.

Pre-diabetes increases the risk of heart failure among patients with nonvalvular atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Heart failure (HF) is common in patients with nonvalvular atrial fibrillation (NVAF) which is associated with excess morbidity and mortality. Notably, the presence of diabetes increases risk of HF in patients with NVAF. The association between pre-diabetes and risk of HF was nonetheless unexplored in this population.

Purpose

The present study aimed to evaluate whether pre-diabetes was associated with an increased risk of HF in patients with NVAF.

Methods

Using a previously validated territory-wide electronic health record database, patients with newly diagnosed NVAF from 2010 to 2018 were included to evaluate for risk of HF upon competing risk regression with Cox proportional-hazard model adjustment. Patients were divided into 3 groups according to their baseline glycemic status: (1) type 2 diabetes, (2) pre-diabetes, and (3) normoglycemia. In the pre-diabetes group, the subsequent risk of HF was further evaluated according to the changes of glycemic status at two years following index date.

Results

Among 65,994 NVAF patients (mean age 75.7 years, 48.5% female), 27,706 (42.0%) were normoglycemic, 10,926 (16.6%) had pre-diabetes, and 27,312 (41.4%) had diabetes at baseline. Over a median follow-up of 7.1 years, 7,203 (26%) normoglycemic patients, 3,168 (29%) pre-diabetic patients, and 8,745 (32%) diabetic patients developed HF (Log rank test, P&lt;0.001). Pre-diabetes was associated with an increased risk of HF compared with normoglycemic patients (subdistribution Hazard Ratio (SHR) = 1.09, 95% confidence interval (CI): 1.04-1.14) and diabetes conferred the highest risk amongst three groups (SHR=1.19, 95%CI: 1.15-1.24). In patients with pre-diabetes at baseline, 873 (8.0%) progressed to diabetes and 1204 (11%) resolved to normoglycemia at 2 years. Compared to those who remained pre-diabetic, patients who progressed to diabetes had a higher risk of HF (SHR = 1.23, 95% CI :1.05-1.44), whereas those who resolved to normoglycemia incurred a lower risk (SHR = 0.80, 95% CI :0.68-0.94).

Conclusion(s)

Pre-diabetes was independently associated with an increased risk of HF in patients with NVAF. Pre-diabetic patients who progressed to diabetes at 2 years experienced an increased risk of HF, whereas those who resolved to normoglycemia reduced risk of HF, as compared to those who remained pre-diabetic. These findings highlight the importance of strict blood glucose control in reducing the risk of HF in patients with atrial fibrillation.

Investigating the effect of graphene oxide in chitosan/alginate-based foams on the release and antifungal activity of clotrimazole in vitro

Polyelectrolyte complexes (PECs) have been used as the matrix of solid foams for drug delivery. This study aimed at investigating the effect of graphene oxide (GO) and the composition of excipients in chitosan/alginate-based buccal foams on the clotrimazole release and antifungal activities. The investigation has been focused on the interactions of the drug with excipients in the foams, and the changes of ionization degree upon exposure to various media are discussed. The solid foams were prepared by mixing the excipients and clotrimazole via probe sonication, followed by a freeze-drying method. The pH values of the formulations were measured during the foam preparation process to estimate the ionization degree of clotrimazole and the other excipients. The foam matrix was the PECs between the cationic chitosan and anionic alginate. The mechanical strength of clotrimazole-loaded foams was lower than that of drug-free foams due to the positively charged clotrimazole interacting with the anionic alginate and interfering the PECs between chitosan and alginate. Addition of GO in the clotrimazole-loaded matrix made the foams mechanically stronger and contributed to a faster release of clotrimazole from the buccal foams by disrupting the electrostatic interactions between alginate and clotrimazole. However, addition of 1 wt% GO in the formulations didn't affect the antifungal activity of clotrimazole-loaded foams significantly. A lower amount GO in the formulation may be required for enhancing the antifungal effect, which should be further investigated in future.

[Application values of right atrial volume, myocardial strain and strain rate in evaluating right atrial function in patients with essential hypertension with normal left ventricular ejection fraction]

Objective: To explore the application values of right atrial (RA) volume, myocardial strain and strain rate in evaluating right atrial functions in patients with essential hypertension (EHT) with normal left ventricular ejection fraction (LVEF). Methods: We retrospectively collected a total of 126 EHT patients with normal LVEF, including 66 males and 60 females, age from 18 to 83(48±15) years from the Affiliated Changzhou No.2 People's Hospital with Nanjing Medical University from March, 2018 to May, 2020. According to the left ventricular mass index, those patients were divided into without left ventricle hypertrophy (LVH) group (n=66) and LVH group (n=60), and 83 healthy volunteers were enrolled as control group, which including 42 males and 41 females, age from 14 to 88 (48±16) years. The total, passive and active RA emptying fraction (total RAEF, passive RAEF and active RAEF) were measured by using RA volumes method. The RA strain (S-reservoir, S-conduit, S-booster pump) and the strain rate (SR-reservoir, SR-conduit, SR-booster pump) were measured by two-dimensional speckle tracking echocardiography. Total RAEF, S-reservoir, and Sr-reservoir represented the reservoir function, while passive RAEF, S-conduit, and Sr-conduit represented the conduit function, and active RAEF, S-booster pump and Sr-booster pump represented the booster pump function, respectively. Than the values between the EHT patients and normal subjects, and the values among the EHT patients without LVH, EHT patients without LVH and normal subjects were compared. Results: The value of active RAEF was significantly lower in EHT patient than normal controls (40.1%±10.5% vs 45.4%±11.1%,P=0.001). There were significant differences among EHT patients without LVH, EHT patients with LVH and normal subjects in passive RAEF and active RAEF (passive RAEF: 40.2%±9.3% vs 36.4%±10.7% vs 36.5%±9.4%, P=0.038, active RAEF: 39.8%±10.6% vs 40.4%±10.4% vs 45.4%±11.1%, P=0.002). There were significant differences in S-reservoir, S-conduit, S-booster pump, SR-reservoir, SR-conduit and SR-booster pump between EHT patients and normal subjects [S-reservoir: 34.8%±13.7% vs 45.0%±13.3%, S-conduit: 18.3%±9.4% vs 26.5%±9.6%, S-booster pump: 16.4%±7.3% vs 18.6%±7.1%, SR-reservoir: (1.6±0.6)/s vs (2.0±0.6)/s, SR-conduit: (-1.2±0.5)/s vs (-1.6±0.6)/s, SR-booster pump: (-1.7±0.6)/s vs (-2.3±0.6)/s; all P<0.05]. The trend tests showed normal controls achieved the largest the absolute values of S-reservoir, S-conduit, SR-reservoir, SR-conduit, SR-booster pump, followed by EHT patients without LVH and EHT patients with LVH(all P<0.001). Conclusions: Using RA volume, myocardial strain and strain rate can detect the RA impaired reservoir, conduit, and the booster pump functions in EHT patients with normal LVEF, and the RA functions were damaged more significantly in EHT patients with LVH.