Matching actions to needs: shifting policy responses to the changing health needs of Chinese children and adolescents.

China is home to the second largest population of children and adolescents in the world. Yet demographic shifts mean that the government must manage the challenge of fewer children with the needs of an ageing population, while considering the delicate tension between economic growth and environmental sustainability. We mapped the health problems and risks of contemporary school-aged children and adolescents in China against current national health policies. We involved multidisciplinary experts, including young people, with the aim of identifying actionable strategies and specific recommendations to promote child and adolescent health and wellbeing. Notwithstanding major improvements in their health over the past few decades, contemporary Chinese children and adolescents face distinct social challenges, including high academic pressures and youth unemployment, and new health concerns including obesity, mental health issues, and sexually transmitted infections. Inequality by gender, geography, and ethnicity remains a feature of health risks and outcomes. We identified a mismatch between current health determinants, risks and outcomes, and government policies. To promote the health of children and adolescents in China, we recommend a set of strategies that target government-led initiatives across the health, education, and community sectors, which aim to build supportive and responsive families, safe communities, and engaging and respectful learning environments. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Effector MoSDT1 enhances Magnaporthe oryzae virulence and plays a dual role in regulating rice defense.

C2H2 zinc effectors are a class of pathogen proteins that play a dual role in plant-pathogen interactions, promoting pathogenicity and enhancing plant defense. In our previous research, we identified Magnaporthe oryzae Systemic Defense Trigger 1 (MoSDT1) as a C2H2 zinc effector that activates rice (Oryza sativa) defense when overexpressed in rice. However, its regulatory roles in pathogenicity and defense require further investigation. In this study, we generated an MoSDT1 overexpressing strain and 2 knockout strains of M. oryzae to assess the impact of MoSDT1 on pathogenicity, rice defense, and phenotypic characteristics. Our analyses revealed that MoSDT1 substantially influenced vegetative growth, conidia size, and conidiation, and was crucial for the virulence of M. oryzae while suppressing rice defense. MoSDT1 localized to the nucleus and cytoplasm of rice, either dependent or independent of M. oryzae delivery. Through RNA-seq, scRNA-seq, and ChIP-seq, we identified that MoSDT1 modulates rice defense by regulating the phosphorylation and ubiquitination of various rice signaling proteins, including transcription factors, transcription repressors, kinases, phosphatases, and the ubiquitin system. These findings provide valuable insights into the regulatory mechanisms of C2H2 zinc finger effector proteins and offer important foundational information for utilizing their target genes in disease resistance breeding and the design of targets for disease management.

Compound heterozygous variants in SLC45A1 might cause syndromic intellectual disability by localization failure and activity attenuation in cells.

Intellectual disability (ID) is a kind of nervous developmental disorder and affects more than 1% of people worldwide. SLC45A1 as a transmembrane protein is implicated in the regulation of glucose homoeostasis. Through trio-based exome sequencing, the missense mutations of SLC45A1 c.103G>A (p.V35M) and c.1211T>G (p.F404C) were identified in the proband with syndromic ID. The distribution, expression and activity of SLC45A1 wild-type (WT) and variants were assayed in transfected COS7 cells. In SLC45A1 variants, the hydrogen bonds surrounding the 35th and 404th amino acid were changed, location on the cytomembrane was failed, their activity to transport glucose was also significantly decreased to contrast with SLC45A1-WT. No difference was observed at the mRNA and protein level. In conclusion, the compound heterozygous variants of SLC45A1 might be the genetic etiology for syndromic ID. These novel mutations probably attenuated its activity to transport glucose by the alteration of tertiary structure and failure of intracellular location.

The cyclic AMP (cAMP) phosphodiesterase CpdA required for growth, biofilm formation, motility and pathogenicity of Edwardsiella piscicida.

Edwardsiella piscicida is a severe fish pathogen with wide host range, causing the huge economic losses in the aquaculture industry. Cyclic adenosine monophosphate (cAMP) as an important second messenger regulates the physiological and behavioral responses to environmental cues in eukaryotic and prokaryotic. The intracellular level of cAMP for effective activity is tightly controlled by the synthesis of adenylate cyclase, excretion and degradation of phosphodiesterase. In this study, we identified and characterized a class III cAMP phosphodiesterase, named as CpdA, in the E. piscicida. To investigate the role of CpdA in the physiology and pathogenicity, we constructed the in-frame deletion mutant of cpdA of E. piscicida, TX01ΔcpdA. The results showed that TX01ΔcpdA accumulated the higher intracellular cAMP concentration than TX01, indicating that CpdA exerted the hydrolysis of cAMP. In addition, compared to the TX01, the TX01ΔcpdA slowed growth rate, diminished biofilm formation and lost motility. More importantly, pathogenicity analysis confirmed that TX01ΔcpdA significantly impaired the ability of invading the epithelial cells, reproduction in macrophages, tissues dissemination and lethality for healthy tilapias. The most of lost properties of TX01ΔcpdA were restored partially or fully by the introduction of cpdA gene. These results suggest that cpdA is required for regulation of the physiology and virulence of E. piscicida.

Thermal and Coherent Spin Pumping by Noncollinear Antiferromagnets.

Antiferromagnets attract much interest because of their potential for spintronic applications and open fundamental physics questions, but especially noncollinear antiferromagnets remain relatively unexplored. Here, we formulate the thermal and coherent pumping of spins in noncollinear antiferromagnets|normal metal bilayers. We find that the spin current polarization is a vector with components along both the Néel vector and net magnetic moment. The spin mixing conductance for the coherent spin pumping is a tensor with elements depending on the degree of noncollinearity and interface spin configuration. We explain the controversial sign problem of the antiferromagnetic spin Seebeck effect by interface effects and suggest that interface engineering may enhance the spin pumping efficiency.

Understanding the application of covalent adaptable networks in self-repair materials based on molecular simulation.

Covalent adaptable networks (CANs) are widely used in the field of self-repair materials. They are a group of covalently cross-linked associative polymers that undergo reversible chemical reactions, and can be further divided into dissociative CANs (Diss-CANs) and associative CANs (Asso-CANs). Self-repair refers to the ability of a material to repair itself without external intervention, and can be classified into self-adhesion and self-healing according to the utilization of open stickers. Unlike conventional materials, the viscoelastic properties of CANs are influenced by both the molecular structure and reaction kinetics, ultimately affecting their repair performance. To gain deeper insight into the repair mechanism of CANs, we conducted simulations by using the hybrid MC/MD algorithm, as previously proposed in our research. Interestingly, we observed a significant correlation between reaction kinetics and repair behavior. Asso-CANs exhibited strong mechanical strength and high creep resistance, rendering them suitable as self-adhesion materials. On the other hand, Diss-CANs formed open stickers that facilitated local relaxation, aligning perfectly with self-healing processes. Moreover, the introduction of crosslinkers in the form of small molecules enhanced the repair efficiency. Theoretically, it was found that the repair timescale of Asso-CANs is slower than that of Diss-CANs with identical molecular structures. Our study not only clarifies the similarities and differences between Diss-CANs and Asso-CANs in terms of their self-repairing capabilities, but more importantly, it provides valuable insights guiding the effective utilization of CANs in the development of self-repair materials.

Mandarin-speaking Children With Cochlear Implants Face Challenges in Using F0 Expansion to Express Contrastive Focus.

OBJECTIVES: Children with cochlear implants (CIs) face challenges in perceiving fundamental frequency (F0) information because CIs do not transmit F0 effectively. In Mandarin, F0 can contrast meanings at the word level, that is, via lexical tones with distinct F0 contours, and signal contrastive relations between words at the utterance-level, that is, via contrastive focus with expanded F0 range and longer duration. Mandarin-speaking children with CIs have been reported to face challenges in producing distinct F0 contours across tones, but early implantation facilitates tonal acquisition. However, it is still unclear if utterance-level prosody, such as contrastive focus, is also challenging for these children, and if early implantation also offers benefits for focus production. Therefore, this study asked how accurately children with CIs can produce contrastive focus, and if early implantation leads to more accurate focus production, with acoustic patterns approaching that of children with typical hearing (TH). DESIGN: Participants included 55 Mandarin-speaking children (3 to 7 years) with CIs and 55 age-matched children with TH. Children produced noun phrases with and without contrastive focus, such as RED-COLORED cat versus red-colored cat . Three adult native listeners perceptually scored the productions as correct or incorrect. The "correct" productions were then acoustically analyzed in terms of F0 range and duration. RESULTS: Based on the perceptual scores, children with CIs produced focus with significantly lower accuracy (38%) than their TH peers (84%). The acoustic analysis on their "correct" productions showed that children with TH used both F0 and duration to mark focus, producing focal syllables with an expanded F0 range and long duration, and postfocal syllables with a reduced F0 range and short duration. However, children with CIs differed from children with TH in that they produced focal syllables with long duration but not an expanded F0 range, although they produced postfocal syllables with a reduced F0 range and short duration like their TH peers. In addition, early implantation correlated with the percept of more accurate focus productions and better use of F0 range in focal marking. CONCLUSIONS: This study finds that Mandarin-speaking children with CIs are still learning to apply appropriate acoustic cues to contrastive focus. The challenge appears to lie in the use of an expanded F0 range to mark focus, probably related to the limited transmission of F0 information through the CI devices. These findings thus have implications for parents and those working with children with CIs, showing that utterance-level prosody also requires speech remediation, and underscores the critical role of identifying problems early in the acquisition of F0 functions in Mandarin, not only at the word level but also at the utterance-level.

THBru attenuates diabetic cardiomyopathy by inhibiting RAGE-dependent inflammation.

Diabetic cardiomyopathy (DCM) is a complication of diabetes mellitus characterized by heart failure and cardiac remodeling. Previous studies show that tetrahydroberberrubine (THBru) retrogrades cardiac aging by promoting PHB2-mediated mitochondrial autophagy and prevents peritoneal adhesion by suppressing inflammation. In this study we investigated whether THBru exerted protective effect against DCM in db/db mice and potential mechanisms. Eight-week-old male db/db mice were administered THBru (25, 50 mg·kg-1·d-1, i.g.) for 12 weeks. Cardiac function was assessed using echocardiography. We showed that THBru administration significantly improved both cardiac systolic and diastolic function, as well as attenuated cardiac remodeling in db/db mice. In primary neonatal mouse cardiomyocytes (NMCMs), THBru (20, 40 µM) dose-dependently ameliorated high glucose (HG)-induced cell damage, hypertrophy, inflammatory cytokines release, and reactive oxygen species (ROS) production. Using Autodock, surface plasmon resonance (SPR) and DARTS analyses, we revealed that THBru bound to the domain of the receptor for advanced glycosylation end products (RAGE), subsequently leading to inactivation of the PI3K/AKT/NF-κB pathway. Importantly, overexpression of RAGE in NMCMs reversed HG-induced inactivation of the PI3K/AKT/NF-κB pathway and subsequently counteracted the beneficial effects mediated by THBru. We conclude that THBru acts as an inhibitor of RAGE, leading to inactivation of the PI3K/AKT/NF-κB pathway. This action effectively alleviates the inflammatory responses and oxidative stress in cardiomyocytes, ultimately leading to ameliorated DCM.

Endoscopic resection for the treatment of gastric gastrointestinal stromal tumors: a retrospective study from a large tertiary hospital in China.

BACKGROUND AND AIMS: With the continuous development of endoscopic technology, endoscopic resection (ER) has gradually become an optional method for the treatment of gastric gastrointestinal stromal tumors (GISTs). However, studies with a large sample or a long follow-up are lacking. Therefore, this research aims to evaluate the efficacy and safety of ER for gastric GISTs in the real-world setting with more than 300 enrolled patients and a follow-up period longer than 45 months. METHODS: From January 2013 to February 2023, 409 patients with a pathological diagnosis of GISTs after ER were retrospectively enrolled in this study. After excluding 86 patients with non-gastric GISTs, we assessed 323 patients with gastric GISTs. The main outcome measures were en bloc resection, complete resection, residual disease, recurrence, and complications. RESULTS: There were 194 (60.06%) females and 129 (39.94%) males, and the median age of the included patients was 58 years (51, 63). The median tumor size was 15.0 (10.0, 20.0) mm. According to the modified NIH criteria, 246 (75.85%) patients were classified as very low risk, 62 (19.20%) were classified as low risk, 12 (3.72%) were classified as moderate risk, and 3 (0.93%) were classified as high risk. A total of 287 (88.85%) patients achieved en bloc resection, and 287 (88.85%) also achieved complete resection. Only one patient showed residual and no recurrent lesions were noted during the follow-up. Regarding complications, three patients had complications, with a complication rate of 0.93%, and no severe complications requiring surgical intervention occurred. CONCLUSION: ER is an appropriate alternative method for the treatment of gastric GISTs, with an en bloc resection rate of 88.85% and a complication rate of 0.93%. No recurrence was noted during follow-up, even for GISTs with piecemeal resection.

Prosodic and Visual Cues Facilitate Irony Comprehension by Mandarin-Speaking Children With Cochlear Implants.

PURPOSE: This study investigated irony comprehension by Mandarin-speaking children with cochlear implants, focusing on how prosodic and visual cues contribute to their comprehension, and whether second-order Theory of Mind is required for using these cues. METHOD: We tested 52 Mandarin-speaking children with cochlear implants (aged 3-7 years) and 52 age- and gender-matched children with normal hearing. All children completed a Theory of Mind test and a story comprehension test. Ironic stories were presented in three conditions, each providing different cues: (a) context-only, (b) context and prosody, and (c) context, prosody, and visual cues. Comparisons were conducted on the accuracy of story understanding across the three conditions to examine the role of prosodic and visual cues. RESULTS: The results showed that, compared to the context-only condition, the additional prosodic and visual cues both improved the accuracy of irony comprehension for children with cochlear implants, similar to their normal-hearing peers. Furthermore, such improvements were observed for all children, regardless of whether they passed the second-order Theory of Mind test or not. CONCLUSIONS: This study is the first to demonstrate the benefits of prosodic and visual cues in irony comprehension, without reliance on second-order Theory of Mind, for Mandarin-speaking children with cochlear implants. It implies potential insights for utilizing prosodic and visual cues in intervention strategies to promote irony comprehension.

Enhancing scanning electron microscopy imaging quality of weakly conductive samples through unsupervised learning.

Scanning electron microscopy (SEM) is a crucial tool for analyzing submicron-scale structures. However, the attainment of high-quality SEM images is contingent upon the high conductivity of the material due to constraints imposed by its imaging principles. For weakly conductive materials or structures induced by intrinsic properties or organic doping, the SEM imaging quality is significantly compromised, thereby impeding the accuracy of subsequent structure-related analyses. Moreover, the unavailability of paired high-low quality images in this context renders the supervised-based image processing methods ineffective in addressing this challenge. Here, an unsupervised method based on Cycle-consistent Generative Adversarial Network (CycleGAN) was proposed to enhance the quality of SEM images for weakly conductive samples. The unsupervised model can perform end-to-end learning using unpaired blurred and clear SEM images from weakly and well-conductive samples, respectively. To address the requirements of material structure analysis, an edge loss function was further introduced to recover finer details in the network-generated images. Various quantitative evaluations substantiate the efficacy of the proposed method in SEM image quality improvement with better performance than the traditional methods. Our framework broadens the application of artificial intelligence in materials analysis, holding significant implications in fields such as materials science and image restoration.

The Effect of Visual Articulatory Cues on the Identification of Mandarin Tones by Children With Cochlear Implants.

PURPOSE: This study explored the facilitatory effect of visual articulatory cues on the identification of Mandarin lexical tones by children with cochlear implants (CIs) in both quiet and noisy environments. It also explored whether early implantation is associated with better use of visual cues in tonal identification. METHOD: Participants included 106 children with CIs and 100 normal-hearing (NH) controls. A tonal identification task was employed using a two-alternative forced-choice picture-pointing paradigm. Participants' tonal identification accuracies were compared between audio-only (AO) and audiovisual (AV) modalities. Correlations between implantation ages and visual benefits (accuracy differences between AO and AV modalities) were also examined. RESULTS: Children with CIs demonstrated an improved identification accuracy from AO to AV modalities in the noisy environment. Additionally, earlier implantation was significantly correlated with a greater visual benefit in noise. CONCLUSIONS: These findings indicated that children with CIs benefited from visual cues on tonal identification in noise, and early implantation enhanced the visual benefit. These results thus have practical implications on tonal perception interventions for Mandarin-speaking children with CIs.

Highly Sensitive Qualitative and Quantitative Identification of Cashmere and Wool Based on Terahertz Electromagnetically Induced Transparent Metasurface Biosensor.

Cashmere and wool are both natural animal fibers used in the textile industry, but cashmere is of superior quality, is rarer, and more precious. It is therefore important to distinguish the two fibers accurately and effectively. However, challenges due to their similar appearance, morphology, and physical and chemical properties remain. Herein, a terahertz electromagnetic inductive transparency (EIT) metasurface biosensor is introduced for qualitative and quantitative identification of cashmere and wool. The periodic unit structure of the metasurface consists of four rotationally symmetric resonators and two cross-arranged metal secants to form toroidal dipoles and electric dipoles, respectively, so that its effective sensing area can be greatly improved by 1075% compared to the traditional dipole mode, and the sensitivity will be up to 342 GHz/RIU. The amplitude and frequency shift changes of the terahertz transmission spectra caused by the different refractive indices of cashmere/wool can achieve highly sensitive label-free qualitative and quantitative identification of both. The experimental results show that the terahertz metasurface biosensor can work at a concentration of 0.02 mg/mL. It provides a new way to achieve high sensitivity, precision, and trace detection of cashmere/wool, and would be a valuable application for the cashmere industry.

Spatiotemporal heterogeneity of the association between short-term exposure to carbon monoxide and COVID-19 incidence: A multistage time-series study in the continental United States.

Background: Previous research has established carbon monoxide (CO) as a significant air pollutant contributing to coronavirus disease 2019 (COVID-19) transmission. The spatiotemporal heterogeneity in the relationship between short-duration CO exposure and COVID-19 incidence remain underexplored. Investigating such heterogeneity plays a crucial role in designing region-specific cost-effective public health policies, exploring the reasons for heterogeneity, and understanding the temporal trends in the association between CO and an emerging infectious disease such as COVID-19. Methods: The 49 states of the continental United States (U.S.) were examined in this study. Initially, we developed time-series generalized additive models (GAMs) for each state to assess the preliminary correlation between daily COVID-19 cases and short-term CO exposure from April 1, 2020, to December 31, 2021. Subsequently, the correlations were compiled utilizing Leroux-prior-based conditional autoregression (LCAR) to achieve a smoothed spatial distribution. Finally, we integrated a time-varying component into the GAM and LCAR to analyze temporal correlations and illuminate the factors contributing to spatiotemporal heterogeneity. Results: Our analysis revealed that, across the 49 states, a 10-ppb increase in CO concentration was associated with a 1.33 % (95%CI: 0.86%-1.81 %) increase in COVID-19 cases on average. Furthermore, spatial variability was noted, with weaker correlations observed in the central and southeastern regions, stronger associations in the northeastern regions, and negligible associations in the western regions. Temporally, the correlation was not significant from April 2020 to June 2021, but began to increase steadily thereafter until the end of 2021. Additionally, vaccination and temperature were determined to be potential causes contributing to the heterogeneity, indicating stronger positive associations in areas with higher vaccination rates and temperatures. Conclusion: The findings of this study underscore the importance of monitoring CO pollution in the central and northeastern US, especially in the aftermath of the pandemic.

Bacterial cellulose/multi-walled carbon nanotube composite films for moist-electric energy harvesting.

Generation of renewable and clean electricity energy from ubiquitous moisture for the power supply of portable electronic devices has become one of the most promising energy collection methods. However, the modest electrical output and transient power supply characteristics of existing moist-electric generator (MEG) severely limit its commercial application, leading to an urgent demand of developing a MEG with high electrical output and continuous power generation capacity. In this work, it is demonstrated that a flexible bacterial cellulose (BC)/Multi-walled carbon nanotube (MWCNT) double-layer (BM-dl) film prepared by vacuum filtration can maintain the moisture concentration difference in the film MEG. Unlike previous studies on cellulose based MEG, BM-dl film has a heterogeneous structure, resulting in a maximum output power density of 0.163 µW/cm2, an extreme voltage of 0.84 V, and current of 2.21 µA at RH = 90 %. BM-dl MEG can generate a voltage of 0.55 V continuously for 45 h in a natural environment (RH = 63-77 %, T = 26-27 °C), which is in a leading level among existing reported cellulose-based MEGs. In summary, this study provides new ideas for innovative design of MEG, which is highly competitive in terms of energy supply for the Internet of Things and wearable devices.

A Multi-foci Sparse-Aperture Metalens.

Multi-foci lenses are essential components for optical communications, virtual reality display and microscopy, yet the bulkiness of conventional counterparts has significantly hindered their widespread applications. Benefiting from the unprecedented capability of metasurfaces in light modulation, metalenses are able to provide multi-foci functionality with a more compact footprint. However, achieving imaging quality comparable to that of corresponding single-foci metalenses at each focal point poses a challenge for existing multi-foci metalenses. Here, a polarization-independent all-dielectric multi-foci metalens is proposed and experimentally demonstrated by spatially integrating single-foci optical sparse-aperture sub-metalenses. Such design enables the metalens to generate multiple focal points, while maintaining the ability to capture target information comparable to that of a single-foci metalens. The proposed multi-foci metalens is composed of square-nanohole units array fabricated by two-photon polymerization. The focusing characteristic and imaging capability are demonstrated upon the illumination of an unpolarized light beam. This work finds a novel route toward multi-foci metalenses and may open a new avenue for dealing with the trade-off between multi-foci functionality and high-quality imaging performance.

Application of CT and MRI images based on artificial intelligence to predict lymph node metastases in patients with oral squamous cell carcinoma: a subgroup meta-analysis.

Background: The performance of artificial intelligence (AI) in the prediction of lymph node (LN) metastasis in patients with oral squamous cell carcinoma (OSCC) has not been quantitatively evaluated. The purpose of this study was to conduct a systematic review and meta-analysis of published data on the diagnostic performance of CT and MRI based on AI algorithms for predicting LN metastases in patients with OSCC. Methods: We searched the Embase, PubMed (Medline), Web of Science, and Cochrane databases for studies on the use of AI in predicting LN metastasis in OSCC. Binary diagnostic accuracy data were extracted to obtain the outcomes of interest, namely, the area under the curve (AUC), sensitivity, and specificity, and compared the diagnostic performance of AI with that of radiologists. Subgroup analyses were performed with regard to different types of AI algorithms and imaging modalities. Results: Fourteen eligible studies were included in the meta-analysis. The AUC, sensitivity, and specificity of the AI models for the diagnosis of LN metastases were 0.92 (95% CI 0.89-0.94), 0.79 (95% CI 0.72-0.85), and 0.90 (95% CI 0.86-0.93), respectively. Promising diagnostic performance was observed in the subgroup analyses based on algorithm types [machine learning (ML) or deep learning (DL)] and imaging modalities (CT vs. MRI). The pooled diagnostic performance of AI was significantly better than that of experienced radiologists. Discussion: In conclusion, AI based on CT and MRI imaging has good diagnostic accuracy in predicting LN metastasis in patients with OSCC and thus has the potential for clinical application. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#recordDetails, PROSPERO (No. CRD42024506159).

Highly sensitive humidity sensor based on composite film of partially reduced graphene oxide and bacterial cellulose.

Breathing is an important physiological activity of human body, which not only reflects the state of human movement, but also is one of the important health indicators. Breathing can change the concentration of water molecules, so monitoring humidity has gradually become a hot topic in modern research. In this study, a humidity sensing composite film with high sensitivity and short response time was made by using the mixture of graphene oxide (GO) and bacterial cellulose (BC) with simple dry film-forming method. L-ascorbic acid was used as reducing agent to reduce GO and improve the conductivity of GO/BC composite film (BG). The influence of different BC contents and the different reduction degree on the resistance change rate of composite film was investigated in details. The maximum resistance change rate of partially reduced BG humidity sensitive composite film reached up to 94%, and the response and recovery time were 13 s and 47 s respectively. Furthermore, the sensor shows obvious resistance change in noncontact sensing test and different breathing states. This kind of humidity sensitive film with fast response and high sensitivity has great potential in human health monitoring and noncontact sensing, and is of great significance in promoting health detection and intelligent life.

Rapid and accurate identification of stem cell differentiation stages via SERS and convolutional neural networks.

Monitoring the transition of cell states during induced pluripotent stem cell (iPSC) differentiation is crucial for clinical medicine and basic research. However, both identification category and prediction accuracy need further improvement. Here, we propose a method combining surface-enhanced Raman spectroscopy (SERS) with convolutional neural networks (CNN) to precisely identify and distinguish cell states during stem cell differentiation. First, mitochondria-targeted probes were synthesized by combining AuNRs and mitochondrial localization signal (MLS) peptides to obtain effective and stable SERS spectra signals at various stages of cell differentiation. Then, the SERS spectra served as input datasets, and their distinctive features were learned and distinguished by CNN. As a result, rapid and accurate identification of six different cell states, including the embryoid body (EB) stage, was successfully achieved throughout the stem cell differentiation process with an impressive prediction accuracy of 98.5%. Furthermore, the impact of different spectral feature peaks on the identification results was investigated, which provides a valuable reference for selecting appropriate spectral bands to identify cell states. This is also beneficial for shortening the spectral acquisition region to enhance spectral acquisition speed. These results suggest the potential for SERS-CNN models in quality monitoring of stem cells, advancing the practical applications of stem cells.

Raman signal optimization based on residual network adaptive focusing.

Due to its high sensitivity and specificity, Micro-Raman spectroscopy has emerged as a vital technique for molecular recognition and identification. As a weakly scattered signal, ensuring the accurate focus of the sample is essential for acquiring high quality Raman spectral signal and its analysis, especially in some complex microenvironments such as intracellular settings. Traditional autofocus methods are often time consuming or necessitate additional hardware, limiting real-time sample observation and device compatibility. Here, we propose an adaptive focusing method based on residual network to realize rapid and accurate focusing on Micro-Raman measurements. Using only a bright field image of the sample acquired on any image plane, we can predict the defocus distance with a residual network trained by Resnet50, in which the focus position is determined by combining the gradient and discrete cosine transform. Further, detailed regional division of the bright field map used for characterizing the height variation of actual sample surface is performed. As a result, a focus prediction map with 1µm accuracy is obtained from a bright field image in 120 ms. Based on this method, we successfully realize Raman signal optimization and the necessary correction of spectral information. This adaptive focusing method based on residual network is beneficial to further enhance the sensitivity and accuracy of Micro-Raman spectroscopy technology, which is of great significance in promoting the wide application of Raman spectroscopy.