Fluoride-Free Synthesis of 2D Titanium Carbide (MXenes) Assisted by scCO2 -Based Ternary Solution.

2D MXene-Ti3 C2 Tx holds great promise in various electronic applications, especially for electromagnetic interference (EMI) shielding devices and supercapacitors. Ti3 C2 Tx synthesis typically involves the use of hazardous fluorine-containing chemicals that can result in the formation of inert fluoride functional groups on the surface of Ti3 C2 Tx , severely degrading its properties and posing a threat to the performance of electron transfer among electrical devices. Herein, a supercritical carbon dioxide-based ternary solution (scCO2 /DMSO/HCl) to produce fluoride-free Ti3 C2 Tx in mild conditions (via 0.5 m HCl, 20 MPa, 32 °C) is reported. The fluorine-free Ti3 C2 Tx films electrode presents an excellent gravimetric capacitance of 320 F g-1 at 2 mV s-1 in 1 m H2 SO4 . Besides, it is demonstrated that fluorine-free Ti3 C2 Tx films exhibit outstanding EMI shielding efficiency of 53.12 dB at 2.5 µm thickness. The findings offer a mild and practical approach to producing fluoride-free Ti3 C2 Tx and open opportunities for exploring MXenes' potential applications in various fields.

Biosensing of Cysteine through the Induction of Oxygen Vacancies in a Cu/Zr Heterostructure Prepared by Supercritical Antisolvent Technique.

There has been a growing emphasis on facile preparation of binary heterogeneous composite materials. Leveraging the eco-friendly efficiency of supercritical CO2 technology, we achieved precise control over the influencing factors of mass transfer, enabling the accurate modulation of the resulting product morphology and properties. In the current study, CuxO/ZrOy composite materials were prepared using this technology and calcined to obtain electrode materials for the detection of cysteine (Cys). Essential comprehensive characterization techniques were employed to elucidate the heterojunction. The resulting electrode demonstrated a linear response to Cys within a concentration range of 0.5 nM to 1 µM, featuring a high sensitivity of 1035 µA·cm-2·µM-1 and a low detection limit of 97.3 nM. Thus, establishing a novel avenue for nonenzyme-based electrochemical sensors tailored for biologically active Cys detection through the implementation of a heterogeneous structure.

NIR-II light triggered burst-release cascade nanoreactor for precise cancer chemotherapy.

The current strategy of co-delivering copper ions and disulfiram (DSF) to generate cytotoxic CuET faces limitations in achieving rapid and substantial CuET production, specifically in tumor lesions. To overcome this challenge, we introduce a novel burst-release cascade reactor composed of phase change materials (PCMs) encapsulating ultrasmall Cu2-xSe nanoparticles (NPs) and DSF (DSF/Cu2-xSe@PCM). Once triggered by second near-infrared (NIR-II) light irradiation, the reactor swiftly releases Cu2-xSe NPs and DSF, enabling catalytic reactions that lead to the rapid and massive production of Cu2-xSe-ET complexes, thereby achieving in situ chemotherapy. The mechanism of the burst reaction is due to the unique properties of ultrasmall Cu2-xSe NPs, including their small size, multiple defects, and high surface activity. These characteristics allow DSF to be directly reduced and chelated on the surface defect sites of Cu2-xSe, forming Cu2-xSe-ET complexes without the need for copper ion release. Additionally, Cu2-xSe-ET has demonstrated a similar (to CuET) anti-tumor activity through increased autophagy, but with even greater potency due to its unique two-dimensional-like structure. The light-triggered cascade of interlocking reactions, coupled with in situ explosive generation of tumor-suppressive substances mediated by the size and valence of Cu2-xSe, presents a promising approach for the development of innovative nanoplatforms in the field of precise tumor chemotherapy.

Feasibility and Diagnostic Accuracy for Assessment of Coronary Artery Stenosis of Prospectively Electrocardiogram-gated High-pitch Spiral Acquisition Mode Dual-source CT Coronary Angiography in Patients with Relatively Higher Heart Rates: in Comparison with Catheter Coronary Angiography.

Objective To prospectively investigate the diagnostic accuracy for coronary artery stenosis of prospectively electrocardiogram-triggered spiral acquisition mode (high pitch mode) dual-source computed tomography coronary angiography (CTCA) in patients with relatively higher heart rates (HR) compared with catheter coronary angiography (CCA). Methods Forty-seven consecutive patients with relatively higher HR (>65 and <100 bpm) (20 male, 27 female; age 55±10 years) who both underwent dual-source CTCA and CCA were prospectively included in this study. All patients were performed CTCA using high pitch mode setting at 20%-30% of the R-R interval for the image acquisition. All coronary segments were evaluated by two blinded and independent observers with regard to image quality on a three-point scale (1: excellent to 3: non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%). Considered CCA as the standard of reference, the sensitivity, specificity, positive predictive value and negative predictive value were calculated. Radiation dose values were calculated using the dose-length product. Results Image quality was rated as being score 1 in 92.4% of segments, score 2 in 6.1% of segmentsand score 3 in 1.5% of segments. The average image quality score per segment was 1.064±0.306. The HR variability of patients with image score 1, 2 and 3 were 2.29±1.06 bpm, 5.17±1.37 bpm, 8.88±1.53 bpm, respectively. The average HR variability of patients with different image scores were significantly different (F=170.402, P=0.001). The sensitivity, specificity, positive and negative predictive values were 92.6%, 97.0%, 87.6%, 98.3%, respectively, per segment and 90.0%, 95.2%, 85.3%, 96.9%, respectively, per vessel and 100%, 63.6%, 90.0%, 100%, respectively, per patient. The effective radiation dose was on average 0.86±0.16 mSv. Conclusion In patients with HR more than 65 bpm and below 100 bpm without cardiac arrhythmia, the prospectively electrocardiogram-gated high-pitch spiral acquisition mode with image acquired timing set at 20%-30% of the R-R interval provides a high diagnostic accuracy for the assessment of coronary stenoses combined with a 1.5% of non-diagnostic coronary segments and a radiation dose below 1 mSv.

Intravenous Contrast Material Administration at High-pitch Dual-source CT Coronary Angiography: Bolus-tracking Technique with Shortened Time of Respiratory Instruction Versus Test Bolus Technique.

Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv, P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.

Hyaluronic Acid-Based Nanocarriers for Anticancer Drug Delivery.

Hyaluronic acid (HA), a main component of the extracellular matrix, is widely utilized to deliver anticancer drugs due to its biocompatibility, biodegradability, non-toxicity, non-immunogenicity and numerous modification sites, such as carboxyl and hydroxyl groups. Moreover, HA serves as a natural ligand for tumor-targeted drug delivery systems, as it contains the endocytic HA receptor, CD44, which is overexpressed in many cancer cells. Therefore, HA-based nanocarriers have been developed to improve drug delivery efficiency and distinguish between healthy and cancerous tissues, resulting in reduced residual toxicity and off-target accumulation. This article comprehensively reviews the fabrication of anticancer drug nanocarriers based on HA in the context of prodrugs, organic carrier materials (micelles, liposomes, nanoparticles, microbubbles and hydrogels) and inorganic composite nanocarriers (gold nanoparticles, quantum dots, carbon nanotubes and silicon dioxide). Additionally, the progress achieved in the design and optimization of these nanocarriers and their effects on cancer therapy are discussed. Finally, the review provides a summary of the perspectives, the lessons learned so far and the outlook towards further developments in this field.

Intra-articular injection of human umbilical cord mesenchymal stem cells ameliorates monosodium iodoacetate-induced osteoarthritis in rats by inhibiting cartilage degradation and inflammation.

AIMS: This study aimed to investigate whether human umbilical cord mesenchymal stem cells (UC-MSCs) can prevent articular cartilage degradation and explore the underlying mechanisms in a rat osteoarthritis (OA) model induced by monosodium iodoacetate (MIA). METHODS: Human UC-MSCs were characterized by their phenotype and multilineage differentiation potential. Two weeks after MIA induction in rats, human UC-MSCs were intra-articularly injected once a week for three weeks. The therapeutic effect of human UC-MSCs was evaluated by haematoxylin and eosin, toluidine blue, Safranin-O/Fast green staining, and Mankin scores. Markers of joint cartilage injury and pro- and anti-inflammatory markers were detected by immunohistochemistry. RESULTS: Histopathological analysis showed that intra-articular injection of human UC-MSCs significantly inhibited the progression of OA, as demonstrated by reduced cartilage degradation, increased Safranin-O staining, and lower Mankin scores. Immunohistochemistry showed that human UC-MSC treatment down-regulated the expression of matrix metalloproteinase-13 (MMP13) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), and enhanced the expression of type II collagen and ki67 in the articular cartilage. Furthermore, human UC-MSCs significantly decreased the expression of interleukin (IL)-1ß and tumour necrosis factor-α (TNF-α), while increasing TNF-α-induced protein 6 and IL-1 receptor antagonist. CONCLUSION: Our results demonstrated that human UC-MSCs ameliorate MIA-induced OA by preventing cartilage degradation, restoring the proliferation of chondrocytes, and inhibiting the inflammatory response, which implies that human UC-MSCs may be a promising strategy for the treatment of OA. Cite this article: Bone Joint Res 2021;10(3):226-236.

[Genetic polymorphism of 15 STR loci in Tibetan population].

The polymorphism distributions of 15 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818, and FGA) were investigated in a Tibetan population by multiplex PCR amplification using five fluorochromes (6FAM, VIC, NED, PET, LIZ). Gene frequency, discrimination power (DP), heterozygosity (H), polymorphism information content (PIC) and probability of paternity exclusion (EPP) were calculated, and all loci were tested for Hardy-Weinberg equilibrium. Results indicate that the gene frequency of these 15 STR loci is in Hardy-Weinberg equilibrium. The DP is at 0.7555-0.9602, H is at 0.5651-0.8530, PIC is at 0.5528-0.8456, and EPP is at 0.3811-0.8549. Cumulative DP of the 15 STR is 0.99999999, and cumulative EPP is 0.999999997. Therefore, these 15 STR loci can be used as genetic markers of Tibetan populations in anthropological studies, linkage analysis of genetic diseases, individual identification and paternity testing in forensic medicine.

[Experimental study on harmonic detection of methane by use of a digital lock-in amplifier].

The harmonic detection of methane at 6105.3694 cm(-1) was measured by use of a digital lock-in amplifier (SR830) remotely controlled by a computer. The programme was written by Visual Basic 6.0 because it has strong function and a friendly appearance. The experimental results are in agreement with theoretical analysis, which fully confirms that a better signal-to-noise ratio (SNR) can be achieved in the high-harmonics detection of trace gases by the digital lock-in amplifier. The method can be applicable to the highly sensitive detection of pollution gases.

Transcatheter closure of medium and large congenital coronary artery fistula using wire-maintaining technique.

BACKGROUND: For medium and large coronary artery fistula (CAF), the initially selected device sometimes has to be exchanged by reconstruction of track wire loop due to the complexity of CAF. OBJECTIVES: We sought to evaluate the feasibility and safety of transcatheter closure of medium and large CAF by using the wire-maintaining technique (WMT). METHODS: A total of 18 patients aged 15-56 years with congenital CAF underwent percutaneous transcatheter closure by WMT between April 2006 and October 2012. The immediate and long-term outcomes were evaluated. RESULTS: Of the 18 patients (11 females), 16 (88%) underwent successful transcatheter closure of fistula using WMT. The CAFs originated from the right coronary artery (67%), the left circumflex coronary artery (28%), and the left anterior descending coronary artery (5%). The drainage sites were the right ventricle (56%), right atrium (22%), left ventricle (11%), and coronary sinus (11%). The mean diameter of fistulas was 9.5±1.71mm and mean size of the devices was 13.6±3.03mm. An angiogram following device deployment showed complete occlusion in 11 patients, mild residual shunt in 2 patients, and trivial residual shunt in 3 patients. One patient had transient ST-T wave changes, and one patient had hemolysis after the procedure. Follow-up ranged from 1 month to 54 months (median 39 months). Echocardiogram showed trivial residual shunt in 3 patients at 6-month follow-up and in 1 patient at 12-month follow-up. Coronary artery thrombosis was observed in 1 patient by multislice computed tomography at 12-month follow-up. CONCLUSION: For those patients with medium and large complex fistula, transcatheter closure of CAF can be performed by using the wire-maintaining technique.

Complete atrioventricular block after percutaneous device closure of perimembranous ventricular septal defect: A single-center experience on 1046 cases.

BACKGROUND: Complete atrioventricular block (cAVB) has been deemed a rare complication after transcatheter closure for ventricular septal defect (VSD). However, this serious event appears to be underrecognized and is worth being investigated further. OBJECTIVES: To determine the incidence and predisposing factors of cAVB associated with closure of VSD using a modified double-disk occluder (MDO). METHODS: From December 21, 2001 to December 31, 2014, 1046 patients with perimembranous ventricular septal defect underwent percutaneous closure using the MDO. Electrocardiography was evaluated before the procedure, within 1 week after the procedure, and then at 1, 3, 6, and 12 months and every year thereafter. Other baseline and procedural parameters were also evaluated and a comparison between patients requiring pacemakers and those not suffering from cAVB was done. RESULTS: cAVB occurred in 17 patients (1.63%) after the procedure. Of the 17 patients, 8 underwent permanent pacemaker (PPM) implantation. The cAVB occurred within 30 days after the procedure in 14 patients and after 1 year in 3 patients. In comparison patients aged ≤18 years, patients aged >18 years were more prone to cAVB (P = .025). Logistic regression revealed no significant parameter to predict later requirement for PPM. CONCLUSIONS: The incidence of cAVB after transcatheter closure of VSD was acceptable, as part of the cAVB population recovered after administration of corticosteroid and application of a temporary pacemaker. Late cAVB (>1 year) appears to make it more difficult to restore normal conduction block. Because of the recurrence of cAVB, life-long follow-up with periodic electrocardiography examination may be mandatory.

[Analysis of gas absorption coefficient at various pressures].

The absorption coefficient alpha(v) of gas plays an important role in quantitative analysis of pollution gases and theoretical investigation of molecular parameter. In this paper we first analyze alpha(v) theoretically and present a calculation method. Then we analyze 2v3 band R3 manifold of pure CH4 and draw a conclusion that alpha(v0) decreases and the peak absorption kappa(v0) increases with increasing the pressure. When the pressure is <0.03 and >2 atm, we can calculate alpha(v0) using the Gaussian profile and Lorentzian profile respectively, and then analyze the relative error. Finally we analyze the peak absorption kappa(v0) at various pressures, then define the high-resolution area and high-sensitive area respectively when the pressure is <0.01 and >1 atm.