Label-free detection of kidney stones urine combined with SERS and multivariate statistical algorithm.

Kidney stones are a common urological disease with an increasing incidence worldwide. Traditional diagnostic methods for kidney stones are relatively complex and time-consuming, thus necessitating the development of a quicker and simpler diagnostic approach. This study investigates the clinical screening of kidney stones using Surface-Enhanced Raman Scattering (SERS) technology combined with multivariate statistical algorithms, comparing the classification performance of three algorithms (PCA-LDA, PCA-LR, PCA-SVM). Urine samples from 32 kidney stone patients, 30 patients with other urinary stones, and 36 healthy individuals were analyzed. SERS spectra data were collected in the range of 450-1800 cm-1 and analyzed. The results showed that the PCA-SVM algorithm had the highest classification accuracy, with 92.9 % for distinguishing kidney stone patients from healthy individuals and 92 % for distinguishing kidney stone patients from those with other urinary stones. In comparison, the classification accuracy of PCA-LR and PCA-LDA was slightly lower. The findings indicate that SERS combined with PCA-SVM demonstrates excellent performance in the clinical screening of kidney stones and has potential for practical clinical application. Future research can further optimize SERS technology and algorithms to enhance their stability and accuracy, and expand the sample size to verify their applicability across different populations. Overall, this study provides a new method for the rapid diagnosis of kidney stones, which is expected to play an important role in clinical diagnostics.

Interpretable GWAS by linking clinical phenotypes to quantifiable immune repertoire components.

Bridging the gap between genotype and phenotype in GWAS studies is challenging. A multitude of genetic variants have been associated with immune-related diseases, including cancer, yet the interpretability of most variants remains low. Here, we investigate the quantitative components in the T cell receptor (TCR) repertoire, the frequency of clusters of TCR sequences predicted to have common antigen specificity, to interpret the genetic associations of diverse human diseases. We first developed a statistical model to predict the TCR components using variants in the TRB and HLA loci. Applying this model to over 300,000 individuals in the UK Biobank data, we identified 2309 associations between TCR abundances and various immune diseases. TCR clusters predicted to be pathogenic for autoimmune diseases were significantly enriched for predicted autoantigen-specificity. Moreover, four TCR clusters were associated with better outcomes in distinct cancers, where conventional GWAS cannot identify any significant locus. Collectively, our results highlight the integral role of adaptive immune responses in explaining the associations between genotype and phenotype.

Unravelling the object-based nature of visual working memory: insight from pointers.

Visual working memory (VWM) plays a crucial role in temporarily storing and processing visual information, but the nature of stored representations and their interaction with new inputs has long been unclear. The pointer system refers to how VWM links new sensory inputs to stored information using specific cues. This study aimed to investigate whether the pointer system is based on spatial, feature-based, or object-based cues by employing the repetition benefit effect, where memory performance improves with repeated memory items. Across three experiments, we manipulated spatial positions, shapes, and colors as pointer cues to determine how these features affect VWM consolidation and updating. The results showed that while spatial location serves as a strong pointer cue, shape and color features can also effectively reestablish object correspondence in VWM. These findings support the view that the pointer system in VWM is flexible and object-based, utilizing various feature cues to maintain memory continuity. This study provides new insights into how VWM connects new inputs with stored information through the pointer system.

Using the Ethaline Electropolishing Method on the Internal Surface of Additive Manufactured Tubes.

Electropolishing is a widely used technique for polishing additive manufactured (AM) components, while complex internal surface polishing remains a challenge. In this study, we explore the use of ethaline as an electrolyte and investigate the effects of temperature, time, stirring speed, and voltage on the electropolishing effectiveness for AM tubes without pre-treatment through orthogonal experiments. The optimal combination of these factors is then applied in further electropolishing experiments on straight tubes with large length-to-diameter ratios and an angled tube. Our results indicate that temperature has the most significant impact on internal surface electropolishing performance, and other factors' effects are also analyzed. Ethaline can be a promising electrolyte for internal surface electropolishing of AM components because of its high viscosity, which is validated by flow field simulation of the hydrodynamic conditions inside the tubes.

Protein P5 of pear chlorotic leaf spot-associated virus is a pathogenic factor that suppresses RNA silencing and enhances virus movement.

Pear chlorotic leaf spot-associated virus (PCLSaV) is a newly described emaravirus that infects pear trees. The virus genome consists of at least five single-stranded, negative-sense RNAs. The P5 encoded by RNA5 is unique to PCLSaV. In this study, the RNA silencing suppression (RSS) activity of P5 and its subcellular localization were determined in Nicotiana benthamiana plants by Agrobacterium tumefaciens-mediated expression assays and green fluorescent protein RNA silencing induction. Protein P5 partially suppressed local RNA silencing, strongly suppressed systemic RNA silencing and triggered reactive oxygen species accumulation. The P5 self-interacted and showed subcellular locations in plasmodesmata, endoplasmic reticulum and nucleus. Furthermore, P5 rescued the cell-to-cell movement of a movement defective mutant PVXΔP25 of potato virus X (PVX) and enhanced the pathogenicity of PVX. The N-terminal 1-89 amino acids of the P5 were responsible for the self-interaction ability and RSS activity, for which the signal peptide at positions 1-19 was indispensable. This study demonstrated the function of an emaravirus protein as a pathogenic factor suppressing plant RNA silencing to enhance virus infection and as an enhancer of virus movement.

Combination Therapy With CGF and Microneedling-Assisted Compound Betamethasone for Resistant Alopecia Areata: APilot Study.

BACKGROUND: Alopecia areata (AA), an autoimmune disorder characterized by hair loss, can be particularly difficult to manage when patients do not respond to standard therapeutic approaches such as topical or injectable corticosteroids, contact immunotherapy, and systemic treatments. In instances where these conventional therapies prove ineffective, alternative or adjunctive treatments are sought. Concentrated growth factor (CGF) and microneedling (MN)-assisted drug delivery are promising methods for the treatment of different dermatological diseases. OBJECTIVE: This study aimed to assess the practical benefits and the safety aspects of utilizing a dual treatment approach involving CGF and MN-assisted compound betamethasone for patients suffering from resistant AA that are unresponsive to conventional medical interventions. MATERIAL AND METHODS: This retrospective study was based on evaluations of seven patients with refractory AA treated with CGF and MN-assisted compound betamethasone from July 2021 to December 2023. The efficacy of treatment was assessed by extents of hair regrowth percentages of involved areas. RESULTS: Among the seven enrolled patients with refractory AA, a notable outcome was observed where one patient (14.3%) achieved a regrowth of hair by over 50%, while six patients (85.7%) exhibited complete recovery without any systemic or local adverse effects. Furthermore, the difference in SALT scores between baseline, and the final visit for all patients was found to be statistically significant, substantiating the therapeutic efficacy of the intervention employed. CONCLUSION: The present study demonstrated that the synergistic application of CGF in conjunction with MN-assisted compound betamethasone may constitute a promising and well-tolerated therapeutic modality for refractory AA, offering a potentially efficacious and safe treatment alternative.

Aquaporin CmPIP2; 3 links H2O2 signal and antioxidation to modulate trehalose-induced cold tolerance in melon seedlings.

Cold stress severely restricts the growth and development of cold-sensitive crops. Trehalose (Tre), known as the 'sugar of life', plays key roles in regulating plant cold tolerance by triggering antioxidation. However, the relevant regulatory mechanism remains unclear. Here, we confirmed that Tre triggers apoplastic hydrogen peroxide (H2O2) production and thus plays key roles in improving the cold tolerance of melon (Cucumis melo var. makuwa Makino) seedlings. Moreover, Tre treatment can promote the transport of apoplastic H2O2 to the cytoplasm. This physiological process may depend on aquaporins. Further studies showed that a Tre-responsive plasma membrane intrinsic protein 2; 3 (CmPIP2; 3) had strong H2O2 transport function and that silencing CmPIP2; 3 significantly weakened apoplastic H2O2 transport and reduced the cold tolerance of melon seedlings. Yeast library and protein-DNA interaction technology were then used to screen two Tre-responsive transcription factors, abscisic acid responsive element (ABRE)-binding factor 2 (CmABF2) and abscisic acid responsive element (ABRE)-binding factor 3 (CmABF3), which can bind to the ABRE motif of the CmPIP2; 3 promoter and activate its expression. Silencing of CmABF2 and CmABF3 further dramatically increased the ratio of apoplastic H2O2/cytoplasm H2O2 and reduced the cold tolerance of melon seedlings. This study uncovered that Tre treatment induces CmABF2/3 to positively regulate CmPIP2; 3 expression. CmPIP2; 3 subsequently enhances the cold tolerance of melon seedlings by promoting the transport of apoplastic H2O2 into the cytoplasm for conducting redox signals and stimulating downstream antioxidation.

Lipocalin-2 promotes breast cancer brain metastasis by enhancing tumor invasion and modulating brain microenvironment.

Breast cancer is the leading cancer diagnosed in women globally, with brain metastasis emerging as a major cause of death, particularly in human epidermal growth factor receptor 2 positive and triple-negative breast cancer subtypes. Comprehensive understanding of the molecular foundations of central nervous system metastases is imperative for the evolution of efficacious treatment strategies. Lipocalin-2 (LCN2), a secreted iron transport protein with multiple functions, has been linked to the progression of breast cancer brain metastasis (BCBM). In primary tumors, LCN2 promotes the proliferation and angiogenesis of breast cancer cells, triggers the epithelial-mesenchymal transition, interacts with matrix metalloproteinase-9, thereby facilitating the reorganization of the extracellular matrix and enhancing cancer cell invasion and migration. In brain microenvironment, LCN2 undermines the blood-brain barrier and facilitates tumor seeding in the brain by modulating the behavior of key cellular components. In summary, this review meticulously examines the fuel role of LCN2 in BCBM cascade, and investigates the potential mechanisms involved. It highlights the potential of LCN2 as both a therapeutic target and biomarker, indicating that interventions targeting LCN2 may offer improved outcomes for patients afflicted with BCBM.

A bibliometric analysis of global research on microbial immune microenvironment in melanoma from 2012 to 2022.

BACKGROUND: Melanoma is an aggressive malignancy primarily impacting the skin, mucous membranes, and pigment epithelium. The tumor microbial microenvironment encompasses both the microorganisms inhabiting the tumor vicinity and the environmental factors influencing their interactions. Emerging evidence highlights the pivotal role of the microbial immune microenvironment in melanoma. METHODS: We conducted an extensive review of scholarly works published from 2012 to 2022, utilizing The Web of Science Core Collection. Subsequently, we employed analytical tools such as VOSviewer, CiteSpace, and the R programming language to scrutinize prevailing research patterns within this domain. RESULTS: A sum of 513 articles were pinpointed, with notable input coming from the United States and China. Harvard University stood out as the top-contributing institution, while the journal Science received the most citations. Current research within this sphere chiefly focuses on two principal domains: the gut microbiota and the PD-L1 pathway concerning melanoma treatment. CONCLUSION: The study offers an extensive analysis and overview of the worldwide research landscape concerning the immune microenvironment with a focus on microbes in melanoma. It underscores the promising prospects for harnessing the microbial immune microenvironment's potential in melanoma. These findings furnish valuable insights and guidance for advancing scientific inquiry and refining clinical approaches within this dynamic field.

Non-alcoholic fatty liver disease increases the risk of biochemical recurrence in high-grade metastatic prostate cancer patients.

INTRODUCTION: Non-alcoholic fatty liver disease (NAFLD) has been reported to be helpful to identify high-risk individuals of developing prostate cancer. Our aim is to investigate the relationship between NAFLD and biochemical recurrence in metastatic prostate cancer patients. METHODS: We retrospectively investigated 602 patients with metastatic prostate cancer receiving the androgen deprivation therapy. Liver fat was estimated with liver-to-spleen ratio by computed tomography (CT) scans. The relationship between NAFLD and biochemical recurrence was investigated with Cox models. The model for biochemical recurrence was adjusted for multiple variables. RESULTS: NAFLD was significantly associated with biochemical recurrence in patients with Gleason score ≥4+3 when adjusting for each of body mass index (hazards ratio [HR] = 1.38; 95% confidence interval [CI] = 1.08-1.77; p = 0.01), visceral adipose tissue (HR = 1.36; 95% CI = 1.07-1.74; p = 0.01), hypertension (HR = 1.41; 95% CI = 1.10-1.80; p = 0.01), and diabetes mellitus (HR = 1.42; 95% CI = 1.11-1.82; p = 0.01), using age and prostate-specific antigen level as potential confounder. The 2-year biochemical recurrence rate in the Gleason score ≥4+3 patients with and without NAFLD was 84.0% (100/119) and 72.2% (130/180), respectively (p = 0.018). The median biochemical recurrence free survival of the Gleason score ≥4+3 patients with and without NAFLD were 17 and 21 months, respectively (p = 0.005). CONCLUSIONS: NAFLD is an independent risk factor for biochemical recurrence in patients with high-grade metastatic prostate cancer. If validated in prospective studies, future research should test whether treatment of NAFLD can lead to better prognosis.

Fusing Ta-doped Li7La3Zr2O12 grains using nanoscale Y2O3 sintering aids for high-performance solid-state lithium batteries.

Solid-state lithium batteries have advantages of high energy density and usage safety and are considered as promising next-generation power sources. Among them, the garnet-type oxide electrolyte has become a widely studied inorganic electrolyte due to its high ionic conductivity and chemical stability. In this paper, nanoscale Y2O3 (NYO) particles are introduced as sintering aids for fabricating Ta-doped Li7La3Zr2O12 (LLZTO) ceramics, and the sintering effects of various NYO ratios on the properties of LLZTO are investigated. Among the samples, the LLZTO-5%NYO sample exhibits the highest ionic conductivity (7.39 × 10-4 S cm-1) and the lowest activation energy (0.17 eV). At various current densities, the polarization voltage of LLZTO-5%NYO is also the lowest without a short circuit. The full cells of LFP|LLZTO-5%NYO|Li exhibit a high capacity of 163.9 mA h g-1 with a high initial coulombic efficiency of 97.4%, and the capacity retention rate is up to 98.1% after 50 cycles. This work may inspire the development of analogous solid-state electrolytes and lithium batteries.

S3T-Net: A novel electroencephalogram signals-oriented emotion recognition model.

In this paper, a novel skipping spatial-spectral-temporal network (S3T-Net) is developed to handle intra-individual differences in electroencephalogram (EEG) signals for accurate, robust, and generalized emotion recognition. In particular, aiming at the 4D features extracted from the raw EEG signals, a multi-branch architecture is proposed to learn spatial-spectral cross-domain representations, which benefits enhancing the model generalization ability. Time dependency among different spatial-spectral features is further captured via a bi-directional long-short term memory module, which employs an attention mechanism to integrate context information. Moreover, a skip-change unit is designed to add another auxiliary pathway for updating model parameters, which alleviates the vanishing gradient problem in complex spatial-temporal network. Evaluation results show that the proposed S3T-Net outperforms other advanced models in terms of the emotion recognition accuracy, which yields an performance improvement of 0.23% , 0.13%, and 0.43% as compared to the sub-optimal model in three test scenes, respectively. In addition, the effectiveness and superiority of the key components of S3T-Net are demonstrated from various experiments. As a reliable and competent emotion recognition model, the proposed S3T-Net contributes to the development of intelligent sentiment analysis in human-computer interaction (HCI) realm.

A cryogenic on-chip microwave pulse generator for large-scale superconducting quantum computing.

For superconducting quantum processors, microwave signals are delivered to each qubit from room-temperature electronics to the cryogenic environment through coaxial cables. Limited by the heat load of cabling and the massive cost of electronics, such an architecture is not viable for millions of qubits required for fault-tolerant quantum computing. Monolithic integration of the control electronics and the qubits provides a promising solution, which, however, requires a coherent cryogenic microwave pulse generator that is compatible with superconducting quantum circuits. Here, we report such a signal source driven by digital-like signals, generating pulsed microwave emission with well-controlled phase, intensity, and frequency directly at millikelvin temperatures. We showcase high-fidelity readout of superconducting qubits with the microwave pulse generator. The device demonstrated here has a small footprint, negligible heat load, great flexibility to operate, and is fully compatible with today's superconducting quantum circuits, thus providing an enabling technology for large-scale superconducting quantum computers.

Efficacy and safety of percutaneous transhepatic biliary radiofrequency ablation in patients with malignant obstructive jaundice.

BACKGROUND: Percutaneous transhepatic cholangiodrainage (PTCD) and endoscopic retrograde cholangiopancreatography/endoscopic nasobiliary drainage are the most common clinical procedures for jaundice control in patients with unresectable malignant obstructive jaundice, yet the safety and effect of endobiliary radiofrequency ablation (EB-RFA) combined PTCD is rarely reported, in this article, we report our experience of EB-RFA combined PTCD in such patients. AIM: To retrospectively study the efficacy and safety of EB-RFA combined PTCD in patients with unresectable malignant obstructive jaundice. METHODS: Patients with unresectable malignant obstructive jaundice treated with EB-RFA under PTCD were selected, the bile ducts of the right posterior lobe was selected as the target bile ducts in all cases. The general conditions of all patients, preoperative tumour markers, total bilirubin (TBIL), direct bilirubin (DBIL), albumin (ALB), alkaline phosphatase (ALP), and glutamyl transferase (GGT) before and on the 7th day after the procedure, as well as perioperative complications, stent patency time and patient survival were recorded. RESULTS: All patients successfully completed the operation, TBIL and DBIL decreased significantly in all patients at the 7th postoperative day (P = 0.009 and 0.006, respectively); the values of ALB, ALP and GGT also decreased compared with the preoperative period, but the difference was not statistically significant. Perioperative biliary bleeding occurred in 2 patients, which was improved after transfusion of blood and other conservative treatments, pancreatitis appeared in 1 patient after the operation, no serious complication and death happened after operation. Except for 3 patients with loss of visits, the stent patency rate of the remaining 14 patients was 100% 71% and 29% at the 1st, 3rd, and 6th postoperative months respectively, with a median survival of 4 months. CONCLUSION: EB-RFA under PTCD in patients with unresectable malignant obstructive jaundice has a satisfactory therapeutic effect and high safety, which is worthy of further clinical practice.

A highly sensitive SERS substrate of porous membrane-Ag NPs for kidney cancer detection.

BACKGROUND: The substrate employed in surface-enhanced Raman spectroscopy (SERS) constitutes an essential element in the cancer detection methodology. In this research, we introduce a three-dimensional (3D) structured SERS substrate that integrates a porous membrane with silver nanoparticles to enhance SERS spectral signals through the utilization of the aggregation effect of silver nanoparticles. This enhancement is crucial because accurate detection results strongly depend on the intensity of specific peaks in Raman spectroscopy. A highly sensitive SERS substrate can significantly improve the accuracy of detection results. RESULTS: We collected 66 plasma samples from individuals with kidney cancer and control individuals, including both bladder cancer patients and healthy individuals. Then, we utilized substrates with and without porous membranes to acquire the SERS spectra of the samples, enabling us to evaluate the enhancement effect of our SERS substrate. The spectral analysis demonstrated enhanced peak intensities in the experimental group (with porous substrate) compared to the control group (without porous substrate). The uniformity and reproducibility of the SERS substrate are also significantly enhanced, which is very helpful for improving the accuracy of detection results. Additionally, the Principal Component Analysis-Linear Discriminant Analysis algorithm (PCA-LDA) was employed to classify the SERS spectra of both groups. In the experimental group, the classification accuracy was 98.5 % for kidney cancer, and 83.3 % for kidney and bladder cancer. Compared to the control group, it improved by 3 % and 12.6 % respectively. SIGNIFICANT: This indicates that our 3D structured SERS substrate combined with multivariate statistical algorithms PCA-LDA can not only improve the accuracy of SERS detection technology in single cancer detection, but also has great potential in multiple cancer detection. This 3D structured SERS substrate is expected to become a new auxiliary means for cancer detection.

An enhanced multimode phase imaging method based on the transport of intensity equation.

Label-free biological cell imaging relies on rapid multimode phase imaging of biological samples in natural settings. To improve image contrast, phase is encoded into intensity information using the differential interference contrast (DIC) and Zernike phase contrast (ZPC) techniques. To enable multimode contrast-enhanced observation of unstained specimens, this paper proposes an improved multimode phase imaging method based on the transport of intensity equation (TIE), which combines conventional microscopy with computational imaging. The ZPC imaging module based on adaptive aperture adjustment is applied when the quantitative phase results of biological samples have been obtained by solving the TIE. Simultaneously, a rotationally symmetric shear-based technique is used that can yield isotropic DIC. In this paper, we describe numerical simulation and optical experiments carried out to validate the accuracy and viability of this technology. The calculated Michelson contrast of the ZPC image in the resolution plate experiment increased from 0.196 to 0.394.

Influence of microorganisms on flavor substances and functional components of sojae semen praeparatum during fermentation: A study integrating comparative metabolomics and high-throughput sequencing.

Sojae semen praeparatum (SSP), a fermented product known for its distinctive flavor and medicinal properties, undergoes a complex fermentation process due to the action of various microorganisms. Despite its widespread use, the effect of these microorganisms on the flavor compounds and functional components of SSP remains poorly understood. This study aimed to shed light on this aspect by identifying 20 metabolites as potential key flavor substances in SSP. Moreover, glycine and lysine were identified as crucial flavor substances. Additionally, 24 metabolites were identified as key functional components. The dominant microorganisms involved in the fermentation process were examined, revealing six genera of fungi and 12 genera of bacteria. At the species level, 16 microorganisms were identified as dominant through metagenome sequencing. Spearman correlation analysis demonstrated a strong association between dominant microorganisms and both flavor substances and functional components. Furthermore, the study validated the significance of four core functional microorganisms in improving the flavor and quality of SSP. This comprehensive exploration of functional microorganisms of SSP on key flavor substances/functional components during SSP fermentation. The study findings serve as a valuable reference for enhancing the overall flavor and quality of SSP.

A Single Component, Single Layer Flexile Foam Evaporator with the Higher Efficiency for Water Generation.

One of the greenest and promising ways to solve the problem of freshwater crisis is surface solar steam generation from seawater. A great number of photothermal materials with multi-component and multi-layered delicate yet complex structures often suffer from either low evaporation rate or high energy loss. Here, this work presents a single component foam evaporator with steam generation rate of up to 4.32 kg m-2 h-1 under 1 sun irradiation. The evaporator is constructed from an aniline oligomer as a single light-absorbing component, covalent linked with polyethylene glycol to form a monolithic polymer foam. Floating on the seawater, the foam has absorbance of 99.5% over the entire solar spectral range and low thermal conductivity (0.0077 W K-1m-1) that effectively retains heat in the material and at the interface. After 3 months of continuous outdoor natural sunlight irradiation, the evaporator maintains a stable and durable evaporation rate. Moreover, the materials have good mechanical properties (7.48 MPa young's modulus and 57.38% elongation at break) and excellent chemical resistance in 10 common organic solvents and aqueous solutions of pH = 1 to 14. This study provides a new system and strategy for desalination, steam power generation, treatment of polluted water and sewage, etc.

First-Principles Study of Discharge Products and Their Stability for Lithium-Nitrogen Batteries.

Li-N2 batteries present a relatively novel approach to N2 immobilization, and an advanced N2/Li3N cycling method is introduced in this study. The low operating overpotential of metal-air batteries is quite favorable to their stable cycling performance, providing a prospect for the development of a new type of battery with extreme voltage. The battery system of Li-N2 uses N2 as the positive electrode, lithium metal as the negative electrode, and a conductive medium containing soluble lithium salts as the electrolyte. In accordance with its voltage-distribution trend, a variety of lithium-nitrogen molecule intermediates are produced during the discharge process. There is a lack of theoretical description of material changes at the microscopic level during the discharge process. In this paper, the first-principles approach is used to simulate and analyze possible material changes during the discharge process of Li-N2 batteries. The discharge process is simulated on a 4N-graphene anode substrate model, and simulations of its electrostatic potential, Density of States (DOS), HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) aspects confirm that the experimentally found Li3N becomes the final stabilized product of the Li-N2 battery. It can also be seen in the density of states that graphene with adsorption of 4N transforms from semiconducting to metallic properties. In addition, the differential charge also indicates that the Li-N2 material has a strong adsorption effect on the substrate, which can play the dual role of electricity storage and nitrogen fixation.

[Rapid determination of 15 N-nitrosamines in air-dried yak meat using one-step QuEChERS-gas chromatography-triple quadrupole mass spectrometry].

A method based on gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) coupled with one-step QuEChERS technique was developed for the simultaneous determination of 15 N-nitrosamines in air-dried yak meat. The hydration volume, extraction solvent, extracting salt, and cleaning material were optimized according to the characteristics of the N-nitrosamines and sample matrix. The optimized conditions were as follows: 10 mL of purified water for sample hydration, acetonitrile as the extraction solvent for the sample after hydration, 4.0 g of anhydrous MgSO4 and 1.0 g of NaCl as extracting salts, 500 mg of MgSO4+25 mg of C18+50 mg of PSA as cleaning materials. Favorable recoveries of the 15 N-nitrosamines were obtained when the extraction solution was incompletely dried. Thus, the final extract was dried to below 0.5 mL under a mild nitrogen stream and then redissolved to 0.5 mL with acetonitrile. After filtration, 200 µL of the sample was transferred to an autosampler vial for GC-MS/MS analysis. The 15 N-nitrosamines were determined using GC-MS/MS on a DB-HeavyWAX column (30 m×0.25 mm×0.25 µm) with an electron impact ion source in multiple-reaction monitoring (MRM) mode, and quantified using an external standard method. Under the optimized experimental conditions, the results showed that the calibration curves exhibited good linearities for the 15 N-nitrosamines, with correlation coefficients (r2) greater than 0.9990. The limits of detection (LODs) and the limits of quantification (LOQs) ranged from 0.05 to 0.20 µg/kg and from 0.10 to 0.50 µg/kg, respectively. At spiked levels of 1LOQ, 2LOQ, and 10LOQ, the average recoveries were 79.4%-102.1%, 80.6%-109.5%, and 83.0%-110.6%, respectively, and the relative standard deviations were in the range of 0.8%-16.0%. The low matrix effects of the 15 N-nitrosamines indicated the high sensitivity of the proposed method. The method was applied to detect representative commercial air-dried yak meat samples obtained using different processing techniques. Seven N-nitrosamines, including N-nitrosodimethylamine, N-nitrosodiisobutylamine, N-nitrosodibutylamine, N-methyl-N-phenylnitrous amide, N-ethyl-N-nitrosoaniline, N-nitrosopyrrolidine, and N-nitrosodiphenylamine were detected in all samples. The average contents of the seven N-nitrosamines was 0.08-20.18 µg/kg. The detection rates and average contents of the N-nitrosamines in cooked air-dried yak meat samples were higher than those in traditional raw air-dried yak meat samples. Compared with the manual QuEChERS method, the one-step QuEChERS method developed integrated the extraction and clean-up procedures into one single run, and the detection efficiency was considerably improved. The developed method is simple, rapid, highly sensitive, and insusceptible to human errors. Thus, it is useful for the determination of N-nitrosamines in air-dried yak meat and can be extended to the qualitative and quantitative analysis of N-nitrosamines in other meat products. It also provides method support and a data reference for the general determination of N-nitrosamines, which is of great significance for food safety.