Theoretical study of the nitrogen reduction reaction catalyzed by a B-doped MoO2 six-membered ring.

In this study, two potential catalysts with double-B atom-doped atomic MoO2 (B2/MoO2) and single-B atom-doped atomic MoO2 (B/MoO2) were designed and constructed. The thermodynamics and selectivity of two catalysts in the nitrogen fixation reaction were analyzed by a DFT calculation method. The results show that B2/MoO2 shows better adsorption activation and reduction and can effectively activate nitrogen molecules by two adjacent boron atoms. It achieves an extremely low overpotential of -0.18 V and rapid NRR kinetics through an enzymatic mechanism. Therefore, B2/MoO2 is a very promising NRR candidate catalyst. This research shows that doping with diatomic B (as an active site) results in an excellent NRR catalytic activity, which provides a certain theoretical basis for the preparation of high-performance NRR catalysts.

Three-dimensional ultrasound-based radiomics nomogram for the prediction of extrathyroidal extension features in papillary thyroid cancer.

Purpose: To develop and validate a three-dimensional ultrasound (3D US) radiomics nomogram for the preoperative prediction of extrathyroidal extension (ETE) in papillary thyroid cancer (PTC). Methods: This retrospective study included 168 patients with surgically proven PTC (non-ETE, n = 90; ETE, n = 78) who were divided into training (n = 117) and validation (n = 51) cohorts by a random stratified sampling strategy. The regions of interest (ROIs) were obtained manually from 3D US images. A larger number of radiomic features were automatically extracted. Finally, a nomogram was built, incorporating the radiomics scores and selected clinical predictors. Receiver operating characteristic (ROC) curves were performed to validate the capability of the nomogram on both the training and validation sets. The nomogram models were compared with conventional US models. The DeLong test was adopted to compare different ROC curves. Results: The area under the receiver operating characteristic curve (AUC) of the radiologist was 0.67 [95% confidence interval (CI), 0.580-0.757] in the training cohort and 0.62 (95% CI, 0.467-0.746) in the validation cohort. Sixteen features from 3D US images were used to build the radiomics signature. The radiomics nomogram, which incorporated the radiomics signature, tumor location, and tumor size showed good calibration and discrimination in the training cohort (AUC, 0.810; 95% CI, 0.727-0.876) and the validation cohort (AUC, 0.798; 95% CI, 0.662-0.897). The result suggested that the diagnostic efficiency of the 3D US-based radiomics nomogram was better than that of the radiologist and it had a favorable discriminate performance with a higher AUC (DeLong test: p < 0.05). Conclusions: The 3D US-based radiomics signature nomogram, a noninvasive preoperative prediction method that incorporates tumor location and tumor size, presented more advantages over radiologist-reported ETE statuses for PTC.

Development and Validation of a Radiomics Model Based on 3-Dimensional Endoanal Rectal Ultrasound of Rectal Cancer for Predicting Lymph Node Metastasis.

BACKGROUND: Development of a radiomics model for predicting lymph node metastasis status in rectal cancer patients based on 3-dimensional endoanal rectal ultrasound images. METHODS: This study retrospectively included 79 patients (41 with lymph node metastasis positive and 38 with lymph node metastasis negative) diagnosed with rectal cancer in our hospital from January 2018 to February 2022. The tumor's region of interest is first delineated by radiologists, from which radiomics features are extracted. Radiomics features were then selected by independent samples t-test, correlation coefficient analysis between features, and least absolute shrinkage and regression with selection operator. Finally, a multilayer neural network model is developed using the selected radiomics features, and nested cross-validation is performed on it. These models were validated by assessing their diagnostic performance and comparing the areas under the curve and recall rate curve in the test set. RESULTS: The areas under the curve of radiologist was 0.662 and the F1 score was 0.632. Thirty-four radiomics features were significantly associated with lymph node metastasis (P < .05), and 10 features were finally selected for developing multilayer neural network models. The areas under the curve of the multilayer neural network models were 0.787, 0.761, 0.853, and the mean areas under the curve was 0.800. The F1 scores of the multilayer neural network models were 0.738, 0.740, and 0.818, and the mean F1 score was 0.771. CONCLUSIONS: Radiomics models based on 3-dimensional endoanal rectal ultrasound can be used to identify lymph node metastasis status in rectal cancer patient with good diagnostic performance.

The stiffness of transplanted kidneys changes with time after renal transplantation.

BACKGROUND: Kidney transplantation is one of the most effective ways to treat end-stage kidney disease. However, 5000 renal transplant recipients start or restart dialysis because of chronic allograft nephropathy (CAN) every year in the United States. Detecting changes in the stiffness of transplanted kidneys can help diagnose transplanted kidney disease. PURPOSE: To explore changes in the stiffness of transplanted kidneys after renal transplantation using shear wave elastography (SWE). MATERIAL AND METHODS: This study conducted consecutive follow-up observations on 10 patients after kidney transplantation. SWE examination was performed in the first week, second week, first month, second month, third month, fourth month, fifth month, and sixth month after surgery. This study also analyzed the graft stiffness of 86 patients with stable renal function recovery one month after surgery. RESULTS: The results show that there is a change in the stiffness of the transplanted kidney over time after renal transplantation. It decreases rapidly within one month after renal transplantation and tends to be stable after one month. The mean renal cortical and pyramidal stiffness of patients with stable renal function were 28.48 ± 4.27 kPa and 21.97 ± 3.90 kPa, respectively. CONCLUSION: Consecutive stiffness measurement of transplanted kidneys is an effective method for monitoring the function of transplanted kidneys. According to the change in transplanted kidney stiffness, we can designate a more scientific review plan to determine the functional status of the transplanted kidney.

Diagnostic Accuracy of Three-Dimensional Endoanal Ultrasound for Anal Fistula: A Systematic Review and Meta-analysis.

BACKGROUND: Anal fistula is a relatively common anorectal disease. An accurate assessment of the main anal fistula type and the anatomy of the internal opening before surgery is necessary to obtain the best surgical results. Whether three-dimensional endoanal ultrasound (3D-EAUS) should be used as the first-line diagnostic tool for anal fistula is still controversial. The purpose of this study is to conduct a meta-analysis of the published literature on 3D-EAUS and anal fistula, and compare the results of 3D-EAUS and surgery to evaluate the diagnostic value of 3D-EAUS for anal fistula. METHODS: An online search of databases in English included PubMed, Embase, and Cochrane Library. After the diagnostic accuracy of 3D-EAUS of all anal fistula types was integrated, a single-group rate meta-analysis was performed; we analyzed 3D-EAUS separately for the diagnosis of different anal fistula types, and conducted a meta-analysis of test accuracy. The analysis combined sensitivity, specificity, and the respective 95% CI, to draw a summary receiver operating characteristic curve (SROC), and estimate the area under curve (AUC). RESULTS: Based on the inclusion criteria, we selected 8 studies covering 1057 cases of anal fistula and 548 cases of internal opening. The meta-analysis data show that 3D-EAUS has a total accuracy rate of 91% (95% CI, 88-94%). It has high sensitivity and specificity for different anal fistula classifications. The SROC curves for anal fistula internal openings were plotted, and the AUC was calculated to be 0.86 (95% CI, 0.83-0.89). CONCLUSIONS: 3D-EAUS can be used as the first-line diagnostic tool for anal fistula, because it has a high diagnostic accuracy for most anal fistulas. However, due to the insufficient diagnostic accuracy of 3D-EAUS for complex fistulas, 3D-EAUS combined with MRI examination can be used to more accurately detect the secondary extension of complex fistulas, so as to describe the complete anatomy of the fistula in more detail.

Effects of continuing nursing care under cognitive behavioral intervention on psychological state and living quality in patients with double J catheter after ureterolithiasis surgery.

OBJECTIVE: The effects of continuing nursing care under cognitive behavioral intervention on the psychological state and living quality of patients with double J catheter after ureterolithiasis surgery were analyzed in this research. METHODS: The research subjects in this study were 142 patients who were discharged from our hospital with a double J tube after ureterolithiasis surgeries from June 2019 to June 2020. According to the patient care plan, the subjects were divided into the control group (n=71) and the observation group (n=71) and respectively treated with routine basic nursing measures and continuing nursing care under cognitive-behavior intervention. Subsequently, the psychological state, living quality and the complications that occurred were compared between the two groups. RESULTS: The depression and anxiety scores of the two groups after 4 weeks of intervention, comparing to thoes before intervention, were seen with remarkably decreased significance (P<0.05). The scores of living quality and self-care quality of patients in the observation group were obviously higher than those in the control group (P<0.05). In addition, the incidence of complications in the observation group was critically lower than that in control group (P<0.05). CONCLUSION: Continuous nursing care under cognitive behavioral intervention can substantially improve the psychological state, living quality and self-care ability of patients with double J tube after ureterolithiasis surgery, and reduce the incidence of complications, which is worthy of clinic promotion.

The Neural Correlate Difference Between Positive and Negative Awe.

Awe is an emotional response to perceptually vast stimuli that transcend current frames of reference. Narrative and experimental work has characterized two distinct variants of awe: positive and negative; however, little is known about the structural neural basis associated with the differences of these two variants of awe. In this study, we investigated the structural neural basis of positive and negative awe underlying individual differences among 62 young healthy adults. Specifically, we assessed the association between regional gray matter volume (rGMV) and the two different variants of awe using the voxel-based morphometry (VBM). A partial correlation analysis was conducted to examine the relationship between rGMV and behavioral positive and negative awe, while controlling for sex, age and total GMV. VBM indicated that positive awe was positively correlated with GMV in the precuneus, and negatively correlated with GMV in the left fusiform and the right calcarine. Negative awe was negatively correlated with GMV in the left and right insula, and the left superior temporal gyrus. These results provide a neural explanation for the differences of these two variants of awe.

Synthesis of graphene quantum dot-stabilized gold nanoparticles and their application.

Herein, we report an in situ synthesis of graphene quantum dots (GQDs), which have been synthesized from only starch and water and stabilize AuNPs in water. The construction of six gold nanocomposites, i.e. AuNPs 1-6, with sizes ranging from 13.4 nm to 32.6 nm, was accomplished by only mixing the GQDs and chloroauric acid in different amounts without any additional reductants and surfactants. HRTEM has confirmed that the AuNPs have been stabilized by the GQDs, and a core/shell AuNPs@GQD structure has formed. In addition, the as-synthesized AuNPs show excellent catalytic performance in the reduction of 4-nitrophenol, a pertinacious pollutant occurring in industrial wastewater.

Non-invasive Assessment of Changes in Muscle Injury by Ultrasound Shear Wave Elastography: An Experimental Study in Contusion Model.

The present study investigated the potential of ultrasound shear wave elastography (SWE) in assessment of muscle stiffness in muscle injury. SWE was performed on the injured muscle in 30 New Zealand rabbits that were randomly assigned to three groups: the contusion group, which was not treated with an efficient therapeutic strategy after muscle injury; the treatment group, which was treated with a therapeutic scheme after muscle injury; and the healthy group, which was not injured and served as a control. Both the mean Young's modulus (Emean) and the maximum Young's modulus (Emax) were obtained pre-injury and 0.5, 1, 3, 5, 7, 14 and 28 d post-injury. At these time points, a rabbit in each group was randomly selected for biopsy for histopathological observation as well as comparison with Young's modulus. Eventually, all muscle tissues were collected for histologic analysis of collagen fiber formation. The contusion group had the highest Young's modulus, followed by the treatment group and then the healthy group (p < 0.05). In both the contusion and treatment groups, Emean and Emax gradually increased within 1-3 d after injury, followed by a gradual decrease. Compared with the healthy group, histopathologic analysis of the contusion and treatment groups revealed the myofibril destruction process, inflammatory reaction and myofibril regeneration. The amount of collagen fibers in the contusion group was maximal compared with the treated and healthy groups (p = 0.001 and p < 0.001, respectively). There were more collagen fibers in the treatment group than in the healthy group (p = 0.003). The abundance of collagen fibers was positively correlated with the value of Young's modulus (Emean: r = 0.706, p < 0.001; Emax: r = 0.761, p < 0.001). Thus, SWE can be used to detect pathologic changes in injured muscle and to monitor therapeutic effects.

Rapid and sensitive biomarker detection using molecular imprinting polymer hydrogel and surface-enhanced Raman scattering.

Biomarkers are important biochemical indicators, which could be used for identification, early diagnosis and monitoring of diseases during the course of treatment. However, biomarker diagnosis has some shortcomings such as requiring a large amount of samples, long test time and high cost, which seriously influences the correctness and timely treatment to patients. Here, a relatively fast and efficient plasmonic hot spot-localized surface imprinting of Ag spheres using biomarker template immobilization and hydrogel copolymerization is described. The technique takes a fine control of the imprinting process at the nanometre scale and provides a biosensor with high sensitivity. Proof of the opinion is established by detection of biomarker using surface-enhanced Raman scattering (SERS) spectroscopy. This work represents a valuable step towards SERS with biomarkers for cost-saving and time-saving diagnostic assay. It is expected that the new surface imprinted hydrogel plasmonic material can drive possibilities in advancing application of biomarkers in plasmonic biosensors.

A Ag-molecularly imprinted polymer composite for efficient surface-enhanced Raman scattering activities under a low-energy laser.

In this work, we have fabricated flower-shaped Ag particles coated with a molecularly imprinted polymer (Ag@MIP) based on the molecular imprinting technique and SERS technology. Although Raman signals decrease with the reducing laser power, Ag@MIP could sensitively detect the target molecules even at a laser power as low as 0.14 µW. As a new SERS substrate, Ag@MIP shows high enhancement under low irradiation effectively, which limits the possible laser induced effects in the measurement process, improving the signal-to-noise ratio and repeatability. This platform has potential for the development of next-generation SERS spectroscopy.

High performance surface-enhanced Raman scattering from molecular imprinting polymer capsulated silver spheres.

Driven by the ultrasensitivity of the surface-enhanced Raman scattering (SERS) technique and the directive selection of molecular imprinting polymers (MIPs), core-shell silver-molecularly imprinted polymer (Ag@MIP) hybrid structure was synthesized to serve as a novel SERS platform. The results show that as prepared Ag@MIPs wrapped over a thin shell of MIPs are sensitive to the template molecule (Rhodamine 6G). To investigate the selectivity of Ag@MIPs, the structurally related molecules, such as Rhodamine B and crystal violet, were chosen as controls. Notably, the high sensitivity of Ag@MIPs is restrained by the non-specific recognition of Rhodamine B and crystal violet. This high SERS enhancement of the template molecule can be interpreted by the "gate effect" and/or "dummy hot spots". We believe that the sensitivity of SERS coupled with the selectivity of MIPs could induce a promising chemosensor or biosensor for practical applications.

High performance surface-enhanced Raman scattering via dummy molecular imprinting onto silver microspheres.

A new strategy for achieving high performance SERS was proposed by using the dummy molecular imprinting technique. The obtained core-shell composite can effectively improve the signal-to-noise ratio and the veracity of trace analysis in SERS detection.

Synthesis of multifunctional fluorescent magnetic graphene oxide hybrid materials.

Fluorescent magnetic graphene oxide hybrid materials have been fabricated by a multistep method. X-ray diffraction, transmission and scanning electron microscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, vibration sample magnetometry, and energy dispersive spectroscopy were used to characterize the resulting material. The results showed that the materials have a saturation magnetization value of 22.0 emu/g at room temperature and exhibit a symmetrical and narrow emission peak at 544 nm. The resultant materials are able to carry an anti-cancer drug, 5-fluorouracil, with a load capacity of 0.24 mg/mg.