A platinum glutamate acid complex as a peroxidase mimic: high activity, controllable chemical modification, and application in biosensors

Recent strides in nanotechnology have given rise to nanozymes, nanomaterials designed to emulate enzymatic functions. Despite their promise, challenges such as batch-to-batch variability and limited atomic utilization persist. This study introduces Pt(Glu)2, a platinum glutamic acid complex, as a versatile small-molecule peroxidase mimic. Synthesized through a straightforward method, Pt(Glu)2 exhibits robust catalytic activity and stability. Steady-state kinetics reveal a lower Km value compared to that of natural enzymes, signifying strong substrate affinity. Pt(Glu)2 was explored for controllable chemical modification and integration into cascade reactions with natural enzymes, surpassing other nanomaterials. Its facile synthesis and seamless integration enhance cascade reactions beyond the capabilities of nanozymes. In biosensing applications, Pt(Glu)2 enabled simultaneous detection of cholesterol and alkaline phosphatase in human serum with high selectivity and sensitivity. These findings illustrate the potential of small molecule mimetics in catalysis and biosensing, paving the way for their broader applications.

Economic burden attributable to healthcare-associated infections at western China hospitals: 6 Year, prospective cohort study

OBJECTIVES

Healthcare-associated infections (HAIs) represent a major threat to patient safety and are associated with significant economic burden. Calculating the costs attributable to HAIs is challenging given the various sources of bias. Although HAIs as a reasonably preventable medical harm should have been closely linked to medical insurance incentives, there was little linkage between HAIs and medicare in western China owing to the lack of economic evaluation data. The present study aimed to generate estimates of the attributable costs associated with HAIs and the magnitude of costs growth.

METHODS

In this cohort study designed horizontally and vertically from 2016 to 2022, we compared outcomes of randomly sampling patients with HAIs and individually matched patients without HAIs in two cohorts at a 6-year interval at 34 hospitals in western China. The primary outcome was the direct medical cost for the entire hospital stay, converted to US dollars ($ for the benchmark year), discounted at 3% annually, and estimated separately in the full analysis set (FAS) and the per protocol set (PPS). We used multiple linear regression to adjust the discounted costs and to assess subgroups effects within each cohort. We nested a dynamic vertical comparison of costs attributable to HAIs between the front and rear cohorts.

RESULTS

A total of 230 patients with HAIs in 2016 and 204 patients with HAIs in 2022 were enrolled. After a 1:1 match, all 431 pairs were recruited as FAS, of which 332 pairs as PPS met all matching restrictions. Compared to the 2016 cohort in FAS, the patients with HAIs in 2022 had a significantly older age (64.40 ± 16.45 years), higher repeat hospitalization rate (65 [32.02%] of 203), and lower immune function (69 [33.99%] of 203). The discounted costs and adjusted-discounted costs for patients with HAIs in the 2022 cohort were found to be significantly higher than those of patients without HAIs (discounted costs: $5484.60 [IQR 8426.03] vs $2554.04(4530.82), P < 0.001; adjusted-discounted costs: $5235.90 [3772.12] vs $3040.21(1823.36), P < 0.001, respectively), and also higher than those of patients with HAIs in the 2016 cohort (discounted costs: $5484.60 [8426.03] vs $3553.00 [6127.79], P < 0.001; adjusted-discounted costs: $5235.90 [3772.12] vs $3703.82 [3159.14], P < 0.001, respectively). In vertical comparison of PPS, the incremental costs of the 2022 cohort are 1.48 times higher than those of the 2016 cohort ($964.63(4076.15) vs $652.43 [2533.44], P = 0.084).

CONCLUSIONS

This meticulously designed study in western China has successfully and accurately examined the economic burden attributable to HAIs. Their rapidly increasing tendency poses a serious challenge to patients, hospitals, and the medical insurance. A closer linkage between HAIs and ongoing motivating system changes is urgently needed in western China.

Enhancement and inactivation effect of CRISPR/Cas12a via extending hairpin activators for detection of transcription factors

An enhancement effect for the activation of CRISPR/Cas12a (CRISPR = clustered regularly interspaced short palindromic repeats; Cas = CRISPR-associated) was discovered. That was, a hairpin model with dangling 5' end complementary to crRNA (CRISPR RNA) greatly improved the activity of CRISPR/Cas12a after extention of two random sequences. But, the corresponding intact hairpin without PAM (protospacer adjacent motif) or suboptimal PAM sequences was completely inactive to CRISPR/Cas12a because of the superhigh stability of intact hairpin. According to the finding, a CRISPR/Cas12a-based strategy coupled with a signal reported system was designed for transcription factors detection. By using mono-labeled ssDNA (single-stranded DNA) as reporter and two newly synthesized N-C (nitrogen-doped carbon) nanosheets as scavenger to eliminate the fluorescent background, the strategy realized the detection of NF-ĸB p50 (p50 subunit of nuclear factor kappa-B) with a linear detection range of 0.8 - 2000.0 pM and a LOD of 0.5 pM. The discovery of "enhancement and inactivation effect" not only deepened insight into CRISPR/Cas12a but also broadened the practical application of CRISPR/Cas systems for the molecular detection and disease diagnostics.

A dual-mode strategy based on β-galactosidase and target-induced DNA polymerase protection for transcription factor detection using colorimetry and a glucose meter

In this work, we report a novel dual-mode method for the highly specific and sensitive detection of transcription factors (TFs) via the integration of Klenow polymerase protection induced by target-specific recognition, cascade-signal amplification using the hybridization chain reaction (HCR) and CRISPR/Cas12a system, and dual-signal transduction mediated by β-galactosidase (β-gal) and two substrates. A dual-mode signal-sensing interface was constructed by immobilizing the oligo DNA probe (P1) tethered β-gal in a 96-well plate. A hairpin H1 with the ability to initiate HCRs was designed to contain the TF binding site. The binding between the TF and H1 protected the H1 from being extended by the Klenow fragment. After thermal denaturation, the reserved H1 launched the HCR and the HCR products activated CRISPR/Cas12a to cleave P1 and reduce the β-gal on the sensing interface, and thus the contents of the TFs and the corresponding signals mediated by the catalysis of β-gal showed a correlation. This work was the first attempt at utilizing β-gal for dual-signal transduction. It is a pioneering study to utilize the HCR-CRISPR/Cas12a system for dual-mode TF sensors. It revealed that DNA polymerase protection through the binding of TF and DNA could be applied as a new pattern to develop TF sensors.

Multifunctional Gold-Silver-Carbon Quantum Dots Nano-Hybrid Composite: Advancing Antibacterial Wound Healing and Cell Proliferation

The urgent need for innovative materials that effectively eliminate bacteria while promoting cell growth to accelerate wound healing has led to the exploration of new options, as current antimicrobial nanoparticles often exhibit high cytotoxicity, which hinders wound closure. In this study, a nano-hybrid composite, named gold-silver-carbon quantum dots (AuAg-CDs), was prepared by embedding gold and silver nanoclusters into carbon dots. The AuAg-CDs nano-hybrid composite demonstrates remarkable biocompatibility, displays potent antibacterial activity, and possesses a unique capability to promote cell proliferation. By physically disrupting bacterial membranes and promoting mammalian cell proliferation, this composite emerges as a highly promising material for wound healing applications. The underlying mechanism of the multifunctional AuAg-CDs was investigated through comprehensive analyses encompassing cell morphology, bacterial membrane potential, levels of reactive oxygen species (ROS), and adenosine triphosphate (ATP) production in both bacterial and mammalian cells. Additionally, AuAg-CDs were incorporated into alginate to create a hydrogel wound dressing, which underwent evaluation using animal models. The results underscore the remarkable potential of the AuAg-CDs wound dressing in facilitating the proliferation of wound fibroblasts and combating bacterial infections. The significance of designing multifunctional nanomaterials to address the challenges associated with pathogenic bacterial infections and regenerative medicine is highlighted by this study, paving the way for future advancements in these fields.

The composite of bismuth oxyiodide-bismuth/nitrogen-doped carbon for photoreduction and electrochemical/photoelectrochemical dual-model sensing of Cr(VI)

A porous bismuth oxyiodide-metal bismuth/nitrogen-doped carbon (BiOI-Bi/N-C) composite composed of BiOI nanosheets, N-C sheets, and metallic Bi nanoparticles was prepared. BiOI-Bi/N-C exhibited remarkable cathodic photoelectrochemical activity and rapid adsorption capacity for Cr(VI) ions. Interestingly, the photocatalytic process of BiOI-Bi/N-C toward Cr(VI) was pH dependent. Under acidic medium, the synthesized material displayed efficient photocatalysis and achieved 95.0% photoreduction efficacy for Cr(VI) ions to Cr³⁺ within 30 min under visible light irradiation. Under neutral medium, Cr(VI) state showed a different photocatalytic process, and Cr(OH)₃ as a product covered on BiOI-Bi/N-C, which decreased the electrochemical (EC) and photoelectrochemical (PEC) performance of BiOI-Bi/N-C. Based on the findings, BiOI-Bi/N-C was utilized as EC/PEC dual-model sensing interface for the detection of Cr(VI) ions. The presented dual-model sensing method displayed an ultralow limit of detection down to 6.8 pM for EC and 3.2 pM for PEC. It demonstrated the practical application potential for the assay of Cr(VI) in real samples.

Radiomics model and clinical scale for the preoperative diagnosis of silent corticotroph adenomas

OBJECTIVE

Silent corticotroph adenomas (SCAs) are a subtype of nonfunctioning pituitary adenomas that exhibit more aggressive behavior. However, rapid and accurate preoperative diagnostic methods are currently lacking.

DESIGN

The purpose of this study was to examine the differences between SCA and non-SCA features and to establish radiomics models and a clinical scale for rapid and accurate prediction.

METHODS

A total of 260 patients (72 SCAs vs. 188 NSCAs) with nonfunctioning adenomas from Peking Union Medical College Hospital were enrolled in the study as the internal dataset. Thirty-five patients (6 SCAs vs. 29 NSCAs) from Fuzhou General Hospital were enrolled as the external dataset. Radiomics models and an SCA scale to preoperatively diagnose SCAs were established based on MR images and clinical features.

RESULTS

There were more female patients (internal dataset: p < 0.001; external dataset: p = 0.028) and more multiple microcystic changes (internal dataset: p < 0.001; external dataset: p = 0.012) in the SCA group. MRI showed more invasiveness (higher Knosp grades, p ≤ 0.001). The radiomics model achieved AUCs of 0.931 and 0.937 in the internal and external datasets, respectively. The clinical scale achieved an AUC of 0.877 and a sensitivity of 0.952 in the internal dataset and an AUC of 0.899 and a sensitivity of 1.0 in the external dataset.

CONCLUSIONS

Based on clinical information and imaging characteristics, the constructed radiomics model achieved high preoperative diagnostic ability. The SCA scale achieved the purpose of rapidity and practicality while ensuring sensitivity, which is conducive to simplifying clinical work.

Base MRI Imaging Characteristics of Meningioma Patients to Discuss the WHO Classification of Brain Invasion Otherwise Benign Meningiomas

PURPOSE

Compared and analyzed the MRI imaging features of brain invasion otherwise benign (BIOB) meningiomas and WHO grade 1, grade 2 meningiomas, discussed the WHO grading of BIOB from the perspective of imaging.

MATERIALS AND METHODS

A retrospective analysis was performed on 675 meningiomas patients who carried on MRI examination from January 2006 to February 2022. Setting the 2022 Central nervous system (CNS) WHO Guidelines as the gold standard for pathological diagnosis. Statistical analysis of age, gender, and MRI features of meningiomas in relation to WHO grade and brain invasion.

RESULTS

Among 675 cases meningiomas, 543 (80.4%) were WHO grade 1, 123 (18.2%) were WHO grade 2, and 9 (1.3%) were WHO grade 3. There were 108 cases meningiomas with brain invasion (BI) (16.0%) and 567 cases without BI (84.0%). Among BI cases, 67 cases were BIOB. Compared the MRI features between BIOB and WHO grade 1 meningiomas, multivariate analysis demonstrated that the most strongly factors associated with distinguish them were enhancement degree, peritumoral edema, tumor-brain interface, fingerlike protrusion, mushroom sign, and bone invasion (AUC: 0.925 (0.901∼0.945), sensitivity: 0.925, specificity: 0.801). Compared the MRI features between BIOB and WHO grade 2 meningiomas, multivariate analysis demonstrated that the most strongly factors associated with distinguish them were enhancement degree and the tumor-brain interface (AUC: 0.779 (0.686∼0.841), sensitivity: 0.746, specificity: 0.732), their efficacy was slightly weaker.

CONCLUSIONS

BIOB is more similar to WHO grade 2 meningiomas in clinical and imaging features than WHO grade 1, so we think that it may be reasonable to classify BIOB as WHO Grade 2 meningiomas in the guidelines.

Dual-mode photoelectrochemical/electrochemical sensor based on Z-scheme AgBr/AgI-Ag-CNTs and aptamer structure switch for the determination of kanamycin

A "signal-on" dual-mode aptasensor based on photoelectrochemical (PEC) and electrochemical (EC) signals was established for kanamycin (Kana) assay by using a novel Z-scheme AgBr/AgI-Ag-CNTs composite as sensing platform, an aptamer structure switch, and K₃[Fe(CN)₆] as photoelectron acceptor and electrochemical signal indicator. The aptamer structure switch was designed to obtain a "signal-off" state, which included an extended Kana aptamer (APT), one immobilized probe (P1), and one blocking probe (P2) covalently linked with graphdiyne oxide (GDYO) nanosheets. P1, P2, and aptamer formed the double helix structure, which resulted in the inhibited photocurrent intensity because of the weak conductivity of double helix layer and serious electrostatic repulsion of GDYO towards K₃[Fe(CN)₆]. In the presence of Kana, APT specifically bound to the target and dissociated from P1 and P2, and thus, a "signal-on" state was initiated by releasing P2-GDYO from the platform. Based on the sensing platform and the aptamer structure switch, the dual-mode aptasensor realized the linear determination ranges of 1.0 pM-2.0 μM with a detection limit (LOD) of 0.4 pM (for PEC method) and 10 pM-5.0 μM with a LOD of 5 pM (for EC method). The aptasensor displayed good application potential for Kana test in real samples.

A study on serum pro-neurotensin (PNT), furin, and zinc alpha-2-glycoprotein (ZAG) levels in patients with acromegaly

PURPOSE

Acromegaly caused by growth hormone cell adenoma is commonly associated with abnormal glucolipid metabolism, which may result from changes in adipocytokine secretion. This study aims to investigate serum adipokine levels, including pro-neurotensin (PNT), furin, and zinc alpha-2-glycoprotein (ZAG), in acromegalic patients and the correlation between the levels of these three adipokines and GH levels and glucolipid metabolism indices.

METHODS

Sixty-eight acromegalic patients and 121 controls were included, and their clinical data were recorded from electronic medical record system. Serum PNT, furin and ZAG levels were measured by ELISA.

RESULTS

Serum PNT levels in acromegalic patients were significantly higher than controls (66.60 ± 12.36 vs. 46.68 ± 20.54 pg/ml, P < 0.001), and acromegaly was an independent influencing factor of PNT levels (P < 0.001). Moreover, subjects with the highest tertile of PNT levels had a close correlation with acromegaly (OR = 22.200, 95% CI 7.156 ~ 68.875, P < 0.001), even in Model 1 adjusted for gender and age and Model 2 adjusted for gender, age and BMI. Additionally, serum PNT levels were positively correlated with BMI (r = 0.220, P = 0.002) and triglycerides (TGs, r = 0.295, P < 0.001), and TGs were an independent influencing factor of serum PNT levels in acromegalic subjects (P < 0.001). Furthermore, serum PNT levels in obese acromegalic patients were significantly higher than those with normal BMI (P < 0.05). However, serum furin levels were lower in acromegalic patients than controls (0.184 ± 0.036 vs. 0.204 ± 0.061 ng/ml, P < 0.001).

CONCLUSION

This study is the first to demonstrate that acromegalic patients have increased serum PNT levels. Moreover, serum PNT plays a potential role in abnormal lipid metabolism of acromegalic patients.

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.

Analysis of contrast-enhanced spectral chest CT optimal monochromatic imaging combined with ASIR and ASIR-V

OBJECTIVE

The aim of the study was to explore the application of spectral chest CT optimal monochromatic imaging combined with ASIR and ASIR-V to optimize the image quality in the arterial phase.

PATIENTS AND METHODS

62 patients who had undergone contrast-enhanced chest CT examination using spectral CT were included. Twelve sets of arterial phase images were acquired using GSI mode. The CNR, BHA values and subjective scores were statistically analysed. Thus, optimal monochromatic images were obtained. Then, the images were acquired by reconstruction using ASIR and ASIR-V at 30%, 50% and 70% levels. Six sets of images were obtained and compared with QC and the monochromatic image under FBP mode.

RESULTS

In FBP mode, the CNR of 80-keV images was 7.7±2.0, showing no significant difference with QC images (p > 0.05). The BHA value in the blood vessels was 45.2±23.1, which was lower than that in QC images (p < 0.05). The subjective image quality score of 80-keV images was 4.50±0.62. No significant difference was found in QC images (p > 0.05). The subjective score of the artefacts was 2.45±0.62, which was lower than that of QC images (p < 0.05). Thus, 80 keV was chosen as the optimal monochromatic energy to be reconstructed with ASIR and ASIR-V. The CNR of the 80keV+50% ASIR-V group was 13.9±4.3, which was higher than those of 140-kVp and 80-keV images in FBP (p < 0.05). The subjective score was 4.90±0.298, which was higher than that of other groups (p < 0.05).

CONCLUSIONS

Compared with conventional chest CT images in the arterial phase, 80keV+50% ASIR-V images can effectively eliminate beam-hardening artefacts and improve image quality.

fs laser-induced filament study of aliphatic nitroalkanes: correlation between molecular structure and spectroscopic evolution of the filament

fs laser-induced filament and breakdown spectroscopy can be used for studying the correlation between the molecular structure and spectroscopic evolution of the filament.

The damping properties of the foam-filled shaft of primary feathers of the pigeon Columba livia

The avian feather combines mechanical properties of robustness and flexibility while maintaining a low weight. Under periodic and random dynamic loading, the feathers sustain bending forces and vibrations during flight. Excessive vibrations can increase noise, energy consumption, and negatively impact flight stability. However, damping can alter the system response, and result in increased stability and reduced noise. Although the structure of feathers has already been studied, little is known about their damping properties. In particular, the link between the structure of shafts and their damping is unknown. This study aims at understanding the structure-damping relationship of the shafts. For this purpose, laser Doppler vibrometry (LDV) was used to measure the damping properties of the feather shaft in three segments selected from the base, middle, and tip. A combination of scanning electron microscopy (SEM) and micro-computed tomography (µCT) was used to investigate the gradient microstructure of the shaft. The results showed the presence of two fundamental vibration modes, when mechanically excited in the horizontal and vertical directions. It was also found that the base and middle parts of the shaft have higher damping ratios than the tip, which could be attributed to their larger foam cells, higher foam/cortex ratio, and higher percentage of foam. This study provides the first indication of graded damping properties in feathers.

Visual Quantitative Detection of Glutathione and Cholesterol in Human Blood Based on the Thiol-Ene Click Reaction-Triggered Wettability Change of the Interface

Herein, we proposed an innovative visual quantitative sensing strategy based on thiol-ene click chemistry and the capillary action principle. A triethoxyvinylsilane (VTEO)- or mercaptopropylsilatrane (MPS)-modified interface was prepared for analyte recognition. Target analyte molecules containing thiol groups or C═C double bonds are coupled to the VTEO- or MPS-modified inner surface of the glass capillary tube via a thiol-ene click reaction, respectively. Then, the molecular recognition events were transformed into the wettability change of the inner wall of the glass capillary. The concentration of the target molecules was quantified by reading the height change of the water column in the capillary tube. As a proof of concept, this strategy was successfully used to build visual quantitative sensors for detecting glutathione and cholesterol. In addition, this strategy showed a good anti-interference ability to complex biological fluids and realized sensitive glutathione (GSH) and cholesterol detection in real human blood samples.

De Novo Development of a Universal Biosensing Platform by Rapid Direct Native Protein Modification

An innovative biosensing assay was developed for simplified, cost-effective, and sensitive detection. By rapid, direct treatment of target proteins with iron porphyrin (TPPFe) in situ, a carboxyl group of amino acid conjugates with an Fe atom of the TPPFe molecule, forming a stable protein complex. We have shown that this complex not only maintains the integrity and functions of original proteins but also acquires peroxidase activity that can turn TMB to a comparably visible signal like that in ELISA. This study is unique since such conversion is difficult to achieve with standard chemical modification or molecular biology methods. In addition, the proposed immunoassay is superior to traditional ELISA as it eliminates an expensive and complicated cross-linking process of an enzyme-labeled antibody. From a practical point of view, we extended this assay to rapid detection of clinically relevant proteins and glucose in blood samples. The results show that this simple immunoassay provides clinical diagnosis, food safety, and environmental monitoring in an easy-to-implement manner.

In Situ Measurement of Vacuum Window Birefringence using 25Mg+ Fluorescence

Accurate control of the polarization states of laser light is important in precision measurement experiments. In experiments involving the use of a vacuum environment, the stress-induced birefringence effect of the vacuum windows will affect the polarization states of laser light inside the vacuum system, and it is very difficult to measure and optimize the polarization states of the laser light in situ. The purpose of this protocol is to demonstrate how to optimize the polarization states of the laser light based on the fluorescence of ions in the vacuum system, and how to calculate the birefringence of vacuum windows based on azimuthal angles of external wave plates with Mueller matrix. The fluorescence of ²⁵Mg⁺ ions induced by laser light that is resonant with the transition of |3²P3/2,F = 4, mF = 4 → |3²S1/2,F = 3, mF = 3 is sensitive to the polarization state of the laser light, and maximum fluorescence will be observed with pure circularly polarized light. A combination of half-wave plate (HWP) and quarter-wave plate (QWP) can achieve arbitrary phase retardation and is used for compensating the birefringence of the vacuum window. In this experiment, the polarization state of the laser light is optimized based on the fluorescence of ²⁵Mg⁺ ion with a pair of HWP and QWP outside the vacuum chamber. By adjusting the azimuthal angles of the HWP and QWP to obtain maximum ion fluorescence, one can obtain a pure circularly polarized light inside the vacuum chamber. With the information on the azimuthal angles of the external HWP and QWP, the birefringence of the vacuum window can be determined.

miR-27a is an important adipogenesis regulator associated with differential lipid accumulation between intramuscular and subcutaneous adipose tissues of sheep

Micro ribonucleic acids (miRNAs) are crucial regulators for various biological processes. Despite important function in the proliferation and differentiation of preadipocytes, miRNA studies are limited in regional differences in adipogenesis. Here, we show that miR-27a plays an important role in regulating differential lipid accumulation between intramuscular (IM) and subcutaneous (SC) adipose tissues in sheep. Invivo, we observed that miR-27a expression in IM adipose tissue is more abundant than in SC adipose tissue. However, the expression of Peroxisome Proliferator-Activated Receptor Gamma (PPARG) and retinoid X receptor alpha (RXR alpha) in IM adipose tissue was significantly lower than that in SC adipose tissue. In the ovine preadipocyte differentiation model, we found that the expression of miR-27a was significantly decreased in differentiated ovine adipocytes. Overexpression of miR-27a significantly downregulated the expression of PPARG and RXR alpha and suppressed the accumulation of triglyceride but promoted the proliferation of ovine preadipocytes. Whereas, inhibition of miR-27a suppressed preadipocyte proliferation but enhanced PPARG and RXR alpha expression and lipid droplet formation. In addition, dual-luciferase activity assays showed that RXR alpha was a direct target of miR-27a. Thus, miR-27a enhances ovine preadipocytes proliferation and inhibits ovine preadipocytes differentiation through regulating the expression of target RXR alpha. Collectively, our study demonstrates the functional importance of miR-27a in ovine adipogenesis and provides novel insights into exploring regional differences in adipogenesis.

A simple method for in situ measurement of vacuum window birefringence

We present a simple method to measure the degrees of circular polarization (DoCP) of laser light inside a vacuum chamber and the birefringence of a vacuum window by detecting the fluorescence emitted by Doppler cooled ions in an ion trap. Imperfect laser polarization will cause ions to be pumped to the dark state which will decrease the fluorescence rates of the ions. With a simulation based on the rate equations of the relevant energy levels of ²⁵Mg⁺ ions, we find that the fluorescence rate is sensitive to the DoCP of the laser. Based on the simulation result, we present a new method to optimize the DoCP of the laser inside the vacuum chamber by adjusting fast axis azimuthal angles of a half-wave plate and a quarter-wave plate outside the vacuum chamber. The laser light is optimized to be circularly polarized with an uncertainty of the DoCP of 7.8 × 10^-5. With the obtained polarization information on both sides of the vacuum window and treating the vacuum window as an unknown wave plate, the phase delay and the fast axis azimuthal angle of the vacuum window can be determined in the form of Mueller matrix. The phase delay is determined to be 197.60(39)°, and the fast axis azimuthal angle is determined to be 104.00(5)°.

Selectively monitoring glutathione in human serum and growth-associated living cells using gold nanoclusters

Glutathione (GSH) plays a variety of vital functions in biological systems. Growth-associated change of GSH level in cells might be critical for cell survival and monitoring of GSH in living cells are of great significance for understanding the dynamic link between GSH and some diseases. In this work, chitason micelles templated gold nanoclusters (CM-Au NCs) emitting red fluorescence were prepared with a simple and rapid method, which shows interesting phenomenon of aggregation induced emission (AIE) affected by the size of the chitosan micelles. The unique CM-Au NCs can be used to develop turn-off fluorescent probe for detecting GSH in human serum and living cells based on the reverse process of AIE of CM-Au NCs, completely different from the principle of aggregation caused quenching (ACQ) effect, which can distinguish GSH from other biothiols (cysteine and homocysteine) and quantitatively detect GSH concentration of human serum in healthy people and cancer patients with high sensitivity. The practical application of fluorescent CM-Au NCs for cellular imaging and detecting GSH level indicates ultra-trace changes of GSH levels in normal and cancer cells could be monitored at different growth stages, which reveals that the levels of GSH in cancer cells was always higher than that of normal cells. Compared with commercial GSH assay kits for detection GSH in human serum and living cells, the proposed method was verified to be accuracy and precision. The results not only reflect the changes of GSH during cell growth at different stages, but also demonstrate the feasibility of reverse process of AIE of CM-Au NCs for detection GSH. This strategy would provide a platform to understand the dynamic link between GSH and disease to clarify the disease mechanism.

Enhanced Mimetic Enzyme Activity of Phosphorylated Porphyrin Nanocomposite Induced by Localized Surface Plasmon Resonance for Colorimetric Assay

Plasmon-enhanced light harvesting has been of great interest to enhance the catalytic efficiency of some composites or hybrids. The enhanced peroxidase-like activity of phosphorylated iron(III) porphyrin (TPPFe(III))-based nanocomposite, induced by localized surface plasmon resonance for a colorimetric assay, was developed in this study. Firstly, a phosphate group modification strategy was adopted to synthesize water-soluble iron(III) porphyrin materials. Then, the as-synthesized TPPFe(III) was covalently attached to core-shell gold nanorods (GNRs), GNR@Au₂S/AuAgS, to form TPPFe(III)-GNR@Au₂S/AuAgS nanocomposite, which shows greatly enhanced peroxidase-like activity compared to TPPFe(III). A mechanism for the enhanced peroxidase-like activity of TPPFe(III)-GNR@Au₂S/AuAgS was proposed, which results from a synergic effect of hot electrons excited by localized surface plasmon resonance and photogenerated electrons of the TPPFe(III), verified by experiments. Furthermore, a fast colorimetric assay for the detection of H₂O₂ and glucose was established based on the unique property of TPPFe(III)-GNR@Au₂S/AuAgS. This colorimetric assay was applied to determine practical human serum samples; satisfactory results demonstrate this method has high accuracy. The present study would not only provide some insights into the mechanism of plasmon-activated enzyme-like reactions, but also offer new strategies for improving the catalytic activity of a mimetic enzyme.

Prompting peroxidase-like activity of gold nanorod composites by localized surface plasmon resonance for fast colorimetric detection of prostate specific antigen

The interaction between incident light and surface electrons in conductive nanoparticles produces localized plasmon oscillations with a resonant frequency that strongly depends on the composition, size, geometry, and dielectric environment. Hybrid heterostructure materials combining two or more materials in one structure represent a powerful way to achieve unique properties and multifunctionality compared to those of the individual nanoparticle components. Hybrid gold nanorods and gold nanoclusters (GNR/AuNCs) heterostructures prepared by intimate integration of GNRs with AuNCs exhibit both localized surface plasmon resonance (LSPR) property and peroxidase-like activity. It is found that the catalytic activity of the AuNC/GNR heterostructure could be remarkably enhanced by LSPR induced by photon-plasmon coupling in the visible to near-infrared (NIR) region. Meanwhile, the catalytic activity of enzyme-like AuNC/GNRs may be regulated by immunoreactions to realize specific recognition of a target analyte. Accordingly, a fast colorimetric assay within 5 min for the detection of prostate specific antigen (PSA) was developed based on a AuNC/GNRs heterostructure mask regulated by the target molecule under photon-plasmon coupling. The color intensity is inversely proportional to the PSA concentration, and quantitative analysis may be achieved in a range of 10 and 200 pg mL-1. This sensor was practically applied to detect PSA levels in prostate cancer serum samples and the determined values agreed well with those measured by the hospital using standard methods. This indicates that the AuNC/GNRs heterostructure-based assay has high accuracy for the analysis of practical samples. Moreover, the new method has the advantages of very fast determination and low sample volume requirements.

Fabricating and regulating peroxidase-like activity of eggshell membrane-templated gold nanoclusters for colorimetric detection of staphylococcal enterotoxin B

Fluorescent eggshell membrane-templated gold nanoclusters (Au-ESM) can be obtained in a facile and low-cost manner in this study. The fluorescence of the Au-ESM may be significantly quenched by mercapto-compounds and peroxidase-like activity of Au-ESM could be regulated by the reaction process with glutathione. Moreover, the catalytic activity of the mimetic enzyme membrane could be modulated by immunoreactions. An immunoassay for colorimetric determination of staphylococcal enterotoxins B (SE-B) using colored gold nanoparticles was established based on the catalytic activity adjusted by the target molecules. This colorimetric assay can detect SE-B at the concentration range of 0.4-20 ng/mL and the limit of detection (LOD) is 0.12 ng/mL. As a practical application, the proposed colorimetric assay was further utilized to detect SE-B in food samples such as flour, corn and rice, requiring very low volume of sample and exhibiting great sensitivity and high accuracy, which provides promising platform for development of point-of-care diagnostic devices with biomedical and food safety applications.

Thermal-noise-limited higher-order mode locking of a reference cavity

Higher-order mode locking has been proposed to reduce the thermal noise limit of reference cavities. By locking a laser to the HG₀₂ mode of a 10-cm long all ultra-low expansion (ULE) cavity and measuring its performance with the three-cornered-hat method among three independently stabilized lasers, we demonstrate a thermal-noise-limited performance of a fractional frequency instability of 4.9×10^-16. The results match the theoretical models with higher-order optical modes. The achieved laser instability improves the all ULE short cavity results to a new low level.

Approaches toward Identification of Surrogates To Validate Antimicrobial Washes as Preventive Controls for Fresh-Cut Leafy Greens

In fresh-cut produce production, antimicrobials may be used during washing to control the risk of cross-contamination by microbial hazards. Surrogate microorganisms have long been used to validate processes, but none have been identified for validating the efficacy of antimicrobial washing of fresh-cut produce. The objective of this study was to develop procedures by which surrogates may be identified for use in validating the control of cross-contamination for fresh-cut lettuce operations. Four microbial characteristics, which may be important factors in cross-contamination events, were quantitatively evaluated in potential surrogate microorganisms for comparison to a reasonably foreseeable hazard, Escherichia coli O157:H7: sensitivity to chlorine in solution, sensitivity to chlorine on lettuce leaf surfaces, shedding from contaminated lettuce leaves into the water during washing, and cross-contamination from inoculated to uninoculated lettuce leaves during chorine washing. A procedure of practical quantitative experiments for comparing the characteristics reduced the original pool of 80 potential strains, which consisted of lactic acid bacteria, probiotics, and isolates obtained from lettuce enrichment cultures, to five strains: Lactobacillus plantarum, Pediococcus pentosaceus, probiotic 22C, and two lettuce enrichment isolates. These strains may be evaluated in additional studies involving comparisons to other reasonably foreseeable hazards and including other potential process variables that should be understood and controlled to prevent cross-contamination in fresh-cut lettuce operations.

[Minimally invasive tarsal sinus incision combined with manipulative reduction and internal fixation for calcaneal fractures of Sanders typeⅡ and Ⅲ]

Objective: To evaluate the method and curative effect of plate fixation or percutaneous screws for the treatment of calcaneal fractures of Sanders type Ⅱ and Ⅲ via a minimally invasive sinus tarsi incision combined with a variety of manipulative reduction methods. Methods: Twenty-one patients with closed calcaneal fractures treated in the Department of Orthopedics, the First Affiliated Hospital of Nanchang University from January 2014 to January 2016 were collected. There were 15 men and 6 women, with an average age of 39.3 years(from 25 to 63 years). According to the Sanders classification, 16 cases were type Ⅱ and 5 were type Ⅲ.All cases were treated with internal fixation with plate and percutaneous screws via the mini-open sinus tarsi approach following reduction of the posterior articular surface of the subtalar joint and calcaneal length, width and height.Statistical analysis was performed on calcaneal width and Böhler angle, Gissane angle preoperatively and postoperatively (3 days and 3 months). All data were analyzed by ANOVA, functional recovery was evaluated according to the Ankle and Hind-foot Score of American Orthopedic Foot and Ankle Society (AOFAS). Results: Twenty one patients were followed up for a mean duration of 13.4 months(6 to 24 months). All cases gained primary incision healing, without complications such as skin necrosis, wound infection, tenosynovitis of peroneus longus and brevis muscles, or fracture displacement and hardware failure.Bone union was achieved at an average of 10.5 weeks(9 to 11 weeks). No obvious malunion occurred by the last follow-up. Compared to preoperative, calcaneal width(F=25.62, 38.90) were significantly improved 3 days and 3 months after surgery, Böhler angle(F=440.24, 272.42) and Gissane angle(F=91.86, 43.74) were normal, the differences were statistically significant (all P<0.05). Compared to 3 days after surgery, calcaneal width, Böhler angle and Gissane angle kept normal 3 months after surgery, there were no statistically differences (F=0.26, 1.35, 2.60, all P>0.05). By the AOFAS scoring, 10 cases were rated as excellent, 7 were good and 4 were fair. Conclusions: Fixation with plate and percutaneous screws via the mini-open sinus tarsi approach is an effective treatment for Sanders types Ⅱ and Ⅲ calcaneal fractures, which with the advantages of small wound, simple operation, reliable fixation, no incision complication, especially suitable for elderly patients and the patients with severe injury of local soft tissue.

[Analysis of outcomes and learning curve of endoscopic transsphenoidal surgeries for 124 patients with pituitary adenomas]

OBJECTIVE

To investigate the outcomes of the Endoscopic transsphenoidal surgery for patients with pituitary adenomas, analyze the learning curve and provide reference for future surgeries.

METHODS

Retrospective analysis was carried out on 124 patients by endoscopic transsphenoidal surgery with a single neurosurgeon over a period spanning from January 2010 to January 2014 at Peking Union Medical College Hospital.The changes of endocrine and tumor imaging before and after surgery were analysed. Operative time and complication rates of one surgeon in the early period of learning curve were compared with that in later period.

RESULTS

There were significant differences in Gross total resection (GTR) rate of pituitary adenomas with different sizes and different Knosp classifications (P<0.01, P<0.01). GTR rate of huge adenomas was significantly lower than that of macroadenoma and adenomas (P<0.05). GTR rate of Knosp 4 grade adenoma was significantly lower than that of Knosp 0-3 level (P<0.05). No significant difference in GTR among all types of functional pituitary adenomas and hormone levels after surgery was observed (P>0.05). In addition, no significant difference (P>0.05) in complications among different sizes, Knosp grade and type of pituitary adenomas was observed.GTR of Knosp 4 adenoma in later period of the learning curve was significantly higher than that in early period (P<0.05). Meanwhile the operative time was significantly lower than early period (P<0.05).

CONCLUSIONS

Endoscopic transsphenoidal pituitary adenoma resection has the advantages of wider surgical field, higher GTR rate, less trauma, fewer complications and better life quality of patients.Through standardized learning, the GTR rate of the invasive pituitary adenomas can be improved.

[Treatment effects analysis of preoperative long-acting somatostatin analogs combined trans-sphenoidal endoscopic surgery for patients with growth hormone secreting pituitary macroadenomas]

Objective: To evaluate the treatment effects of preoperative long-acting somatostatin analogue (SSA) combined trans-sphenoidal endoscopic surgery for patients with growth hormone (GH)-secreting pituitary macroadenomas. Methods: Retrospective analysis was carried out on 20 patients with GH-secreting pituitary macroadenomas who were treated with preoperative SSA and trans-sphenoidal endoscopic surgery in our apartment from January 2010 to January 2016. We also selected 20 patients with only trans-sphenoidal endoscopic surgery treatment and 20 patients with preoperative SSA and non-trans-sphenoidal endoscopic surgery treatment. The changes of tumor imaging, endocrine and blood pressure before and after treatment were analysed. Results: The Gross total resection (GTR) rate of invasive GH-secreting pituitary macroadenomas of preoperative SSA combined trans-sphenoidal endoscopic surgery group (8/13) were higher than that if only trans-sphenoidal endoscopic surgery group (4/16) and preoperative SSA combined non endoscopic surgery group (1/8) (P<0.05). Meanwhile, preoperative SSA combined trans-sphenoidal endoscopic surgery group had significantly improved the GH levels, blood glucose, lipid metabolism and blood pressure levels (P<0.05). Conclusion: The trans-sphenoidal endoscopic surgery on patients with GH-secreting pituitary macroadenomas has a significant improvement on GH levels, blood glucose, lipid metabolism and blood pressure levels. Through the treatment of preoperative long-acting SSA, the gross total resection rate is higher than other two groups.

Guidelines To Validate Control of Cross-Contamination during Washing of Fresh-Cut Leafy Vegetables

The U.S. Food and Drug Administration requires food processors to implement and validate processes that will result in significantly minimizing or preventing the occurrence of hazards that are reasonably foreseeable in food production. During production of fresh-cut leafy vegetables, microbial contamination that may be present on the product can spread throughout the production batch when the product is washed, thus increasing the risk of illnesses. The use of antimicrobials in the wash water is a critical step in preventing such water-mediated cross-contamination; however, many factors can affect antimicrobial efficacy in the production of fresh-cut leafy vegetables, and the procedures for validating this key preventive control have not been articulated. Producers may consider three options for validating antimicrobial washing as a preventive control for cross-contamination. Option 1 involves the use of a surrogate for the microbial hazard and the demonstration that cross-contamination is prevented by the antimicrobial wash. Option 2 involves the use of antimicrobial sensors and the demonstration that a critical antimicrobial level is maintained during worst-case operating conditions. Option 3 validates the placement of the sensors in the processing equipment with the demonstration that a critical antimicrobial level is maintained at all locations, regardless of operating conditions. These validation options developed for fresh-cut leafy vegetables may serve as examples for validating processes that prevent cross-contamination during washing of other fresh produce commodities.

[The value and comparison of plasma adrenocorticotropic hormone and urinary free cortisol in predicting long-term outcome after operation of Cushing's disease]

Objective: To study and the value of morning plasma adrenocorticotropic hormone (ACTH) and urinary free cortisol (24 h UFC) within 3 days after operation in patients with Cushing's disease in predicting the long-term outcome. Methods: The clinical data of 140 patients with Cushing's disease who were treated in Department of Neurosurgery of PUMCH from 2012 to 2014 were analyzed retrospectively.The univariate analysis, multivariate Logistic analysis, ROC curve analysis and other statistical methods were used to study the predicting value of morning plasma ACTH and 24 h UFC in 3 days post operation. Results: Univariate analysis showed that in the two groups of the early remission and no remission, there was significant statistical difference between the preoperative ACTH, preoperative 24 h UFC, postoperative ACTH and postoperative 24 h UFC (P<0.05, <0.01, <0.01). Logistic analysis showed that ACTH and 24 h UFC after operation of two groups had significant difference (P<0.01, <0.05). ROC curve analysis showed that postoperative cutoff values of ACTH and 24 h UFC were 4.11 pmol/L (18.7 pg/ml) and 281.42 nmol (102 μg)/24 h. ROC analysis was performed to evaluate the predicting performance of postoperative ACTH, resulting in an area under the curve (AUC) of 0.917 (95%CI: 0.858-0.957, P<0.01). In comparison, 24 h UFC had an AUC of 0.814 (95%CI: 0.739-0.875, P<0.01). The predicting value of ACTH is significantly better than that of 24 h UFC (P=0.005). Conclusion: Early morning 24 h UFC and ACTH within 3 days after operation both showed considerable accuracy in predicting the long-term outcome of Cushing's disease, and the significance of ACTH was even greater than that of 24 h UFC.

Characterization of electrical noise limits in ultra-stable laser systems

We demonstrate thermal noise limited and shot noise limited performance of ultra-stable diode laser systems. The measured heterodyne beat linewidth between such two independent diode lasers reaches 0.74 Hz. The frequency instability of one single laser approaches 1.0 × 10^-15 for averaging time between 0.3 s and 10 s, which is close to the thermal noise limit of the reference cavity. Taking advantage of these two ultra-stable laser systems, we systematically investigate the ultimate electrical noise contributions, and derive expressions for the closed-loop spectral density of laser frequency noise. The measured power spectral density of the beat frequency is compared with the theoretically calculated closed-loop spectral density of the laser frequency noise, and they agree very well. It illustrates the power and generality of the derived closed-loop spectral density formula of the laser frequency noise. Our result demonstrates that a 10^-17 level locking in a wide frequency range is feasible with careful design.

[Use early morning serum cortisollevel to evaluate the effect of Cushing's disease after transsphenoidal surgery]

OBJECTIVE

To predict the therapeutic effect of Cushing's disease after transsphenoidal surgery by using morning serum cortisol level.

METHODS

The clinical data of 275 cases that had transsphenoidal surgery in Peking Union Medical College Hospital from 2010 to 2014 were analyzed retrospectively.Early morning serum cortisol level less than 140 nmol/L 3 days postoperation was usedto predict endocrinological remission. And long-term efficacy was evaluated by follow-up.

RESULTS

Of the 275 patients, there were 49 males and 226 females; average age was 36.5 years old.Remission wasconfirmed in 201 cases, the remission rate was 73.1%, and 8 cases recurrent duringfollow-up.There were 17 macroadenomas, theremission rate was 47.1%; 258 microadenomas and MRI negative adenomas, the remission rate was 74.8%.And 43 recurrent cases had reoperations; the remission rate was 46.5%.

CONCLUSION

Early morningserum cortisol 3 days post operation can evaluate the effectof transsphenoidal surgery, but even if the level of cortisol is less than 140 nmol/L, there is still tumor recurrence.Patients should be follow-up for a lifetime.

[Simultaneous Determination of Three Kinds of Effective Constituents in Cannabis Plants by Reversed-phase HPLC]

OBJECTIVES

To establish a high performance liquid chromatographic （HPLC） method for simultaneous determination of three effective constituents, including tetrahydrocannabinol （THC）, cannabidiol （CBD） and cannabinol （CBN） in Cannabis plants.

METHODS

A C₁₈ column was used in this study, and acetonitrile-phosphate buffer （0.015 mol/L KH₂PO₄） was used as mobile phase at a flow rate of 1.0 mL/min. At a detection wavelength of 220 mm, UV absorption spectra were collected at the wavelength range of 190-400 nm, and the spectra and retention time were counted as qualitative evidence.

RESULTS

THC, CBD and CBN could be well separated by this method. Three components had good linear relationship in the range of 0.4-40 μg/mL （R²≥0.999 3）. The recoveries were over 87%. The limits of detection were 1.8 ng, 2.0 ng and 1.3 ng, respectively. The relative standard deviation （RSD） were less than 5% for both inter-day and intra-day precisions.

CONCLUSIONS

Reversed-phase HPLC method is simple, rapid and accurate, and it is suitable for the qualitative and quantitative detection of THC, CBD and CBN in Cannabis plants.

Effects of Inulin Supplementation in Low- or High-Fat Diets on Reproductive Performance of Sows and Antioxidant Defence Capacity in Sows and Offspring

This experiment was conducted to investigate the effects of inulin supplementation in low- or high-fat diets on both the reproductive performance of sow and the antioxidant defence capacity in sows and offspring. Sixty Landrace × Yorkshire sows were randomly allocated to four treatments with low-fat diet (L), low-fat diet containing 1.5% inulin (LI), high-fat diet (H) and high-fat diet containing 1.5% inulin (HI). Inulin-rich diets lowered the within-litter birth weight coefficient of variation (CV, p = 0.05) of piglets, increased the proportion of piglets weighing 1.0-1.5 kg at farrowing (p < 0.01), reduced the loss of body weight (BW) and backfat thickness (BF) during lactation (p < 0.05) and decreased the duration of farrowing as well as improved sow constipation (p < 0.05). Sows fed fat-rich diets gained more BW during gestation (p < 0.01), farrowed a greater number of total (+1.65 pigs, p < 0.05) and alive (+1.52 pigs p < 0.05) piglets and had a heavier (+2.06 kg, p < 0.05) litter weight at birth as well as a decreased weaning-to-oestrous interval (WEI, p < 0.01) compared with sows fed low-fat diets. However, it is worth noting that the H diet significantly decreased the serum activities of superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) and increased the serum malondialdehyde (MDA) levels in sows and piglets (p < 0.05). In contrast, HI diet enhanced the activities of T-SOD and GSH-Px and decreased the serum MDA concentrations (p < 0.05) in sows and piglets. In summary, the fat-rich diets fed to sows during gestation had beneficial effects on reproductive performance, but aggravated the oxidative stress in sow and piglets. Inulin-rich diets fed to sow during gestation had beneficial effects on within-litter uniformity of piglet birthweight and enhanced the antioxidant defence capacity of sows and piglets.

Preparation of Gold-Carbon Dots and Ratiometric Fluorescence Cellular Imaging

In this study, we synthesized novel gold-carbon dots (GCDs) with unique properties by microwave-assisted method. The characterization of high-resolution transmission electron microscope (HRTEM), XRD, high-angle annular dark field scanning transmission electron microscope (HAADF-STEM), and energy dispersive spectrometer demonstrates that GCDs are composed of carbon and Au. Tiny Au clusters are dispersed in a 2 nm-size carbon skeleton, which integrates the properties of typical CDs and gold nanoclusters (AuNCs), displaying fascinating peroxidase-like activity and single excitation/dual emission. Dual emission of the GCDs exhibits different fluorescent response to the target species and enables the GCDs to be exploited for sensing and bioimaging. The highly photostable and biocompatible GCDs were applied to dual fluorescent imaging for breast cancer cells and normal rat osteoblast cells under a single excitation. Moreover, ratiometric fluorescence imaging was used to monitor Fe(3+) level in normal rat osteoblast cells.

Correlation between vascular endothelial growth factor and quantitative dual-energy spectral CT in non-small-cell lung cancer

AIM

To explore the correlation between the expression level of vascular endothelial growth factor (VEGF) in non-small-cell lung cancer (NSCLC) tissue and quantitative parameters of spectral computed tomography (CT) imaging.

MATERIALS AND METHODS

Forty-eight patients with NSCLC underwent a spectral CT imaging protocol before surgical tumour resection. The repetition of iodine concentration, water concentration, and CT values at 40 keV in the region of interest were measured. The slopes of spectral attenuation curves (λHU) in the region were also calculated. The level of VEGF expression in the tumour tissue was measured using an immunohistochemical method (MaxVision method). The quantitative parameters of spectral CT imaging were compared among different levels of VEGF expression using one-way analysis of variance (ANOVA) and least significant difference (SLD) test. The correlation between VEGF expression and spectral CT imaging was estimated through Spearman's rank correlation analysis.

RESULTS

There were significant differences in iodine concentrations, λHU, and CT values at 40 KeV in NSCLC between the groups showing negative and moderately positive expression of VEGF (p=0.001, 0.000, and 0.001, respectively) as well as between those showing mildly and moderately positive expression of VEGF (p=0.047, 0.005, and 0.002, respectively). In addition, all of the iodine concentrations, λHU values, and CT values at 40 KeV displayed a significant and positive correlation with the level of VEGF expression (r=0.413, 0.458, and 0.393, respectively, p<0.05).

CONCLUSIONS

Quantitative parameters of spectral CT imaging may be helpful for evaluating the status of angiogenesis in NSCLC.