Spatial consistency of co-exposure to air and surface water pollution and cancer in China.

Humans can be exposed to multiple pollutants in the air and surface water. These environments are non-static, trans-boundary and correlated, creating a complex network, and significant challenges for research on environmental hazards, especially in real-world cancer research. This article reports on a large study (377 million people in 30 provinces of China) that evaluated the combined impact of air and surface water pollution on cancer. We formulate a spatial evaluation system and a common grading scale for co-pollution measurement, and validate assumptions that air and surface water environments are spatially connected and that cancers of different types tend to cluster in areas where these environments are poorer. We observe "dose-response" relationships in both the number of affected cancer types and the cancer incidence with an increase in degree of co-pollution. We estimate that 62,847 (7.4%) new cases of cancer registered in China in 2016 were attributable to air and surface water pollution, and the majority (69.7%) of these excess cases occurred in areas with the highest level of co-pollution. The findings clearly show that the environment cannot be considered as a set of separate entities. They also support the development of policies for cooperative environmental governance and disease prevention.

Injectable polypeptide-polysaccharide depot for preventing postoperative tumor recurrence by concurrent in situ chemotherapy and brachytherapy.

Chemotherapy and radiotherapy in combination with sequence regimens are recognized as the current major strategy for suppressing postoperative tumor recurrence. However, systemic side effects and poor in-field cooperation of the two therapies seriously impair the therapeutic efficacy of patients. The combination of brachytherapy and chemotherapy through innovative biomaterials has proven to be an important strategy to achieve synergistic effects of radiotherapy and chemotherapy in-time and in-field. However, for postoperative chemoradiotherapy, as far as we know, there are few relevant reports. Herein, an injectable pH-responsive polypeptide-polysaccharide depot for concurrent in situ chemotherapy and brachytherapy was developed by encapsulating vincristine into iodine-125 radionuclide labeled hydrogel. This depot hydrogel was prepared by dynamic covalent bonds of Schiff base between aldehydeated hyaluronic acid and polyethylene glycol-polytyrosine. Therefore, this hydrogel enables smart response to tumor acidic microenvironment, rapid release of the encapsulated vincristine and an enhanced uptake effect by tumor cells, which significantly reduces IC50 of vincristine for the anaplasia Wilms' tumor cells in vitro. This depot hydrogel shows excellent stability and biocompatibility, and maintains for 14 days after in situ injection in a postoperative model of anaplasia Wilms' tumor. After injection at the cavity of tumor excision, responsively-released vincristine and the radioactive iodine-125 exerted excellent killing effects on residual tumor cells, inhibiting tumor relapse and liver metastasis of the recurrent tumor. Hence, this study proposes an effective therapeutic strategy for inhibiting anaplasia Wilms' tumor recurrence, which provides a new approach for concurrent postoperative chemo-radiotherapy and a desirable guidance in regimen execution of pediatric refractory tumors.

Mono-2-ethylhexyl phthalate-induced downregulation of MMP11 in foreskin fibroblasts contributes to the pathogenesis of hypospadias.

Hypospadias is one of the most common congenital anomalies of the male urogenital system, and di(2-ethylhexyl) phthalate (DEHP), a widely used endocrine-disrupting chemical (EDC), is considered a significant risk factor for this condition. Mono-2-ethylhexyl phthalate (MEHP), the toxic active metabolite of DEHP, has been proven to affect penile development and ultimately result in the hypospadias phenotype. However, while it is acknowledged that hypospadias arises from the aberrant development of multiple penile tissues, the specific impact of MEHP on human foreskin tissue development and its underlying molecular mechanisms of action remain unclear. In this study, we constructed an in vitro toxicity assay for MEHP using human foreskin fibroblasts and employed high-throughput RNA sequencing to investigate the molecular mechanisms subserving the defects in cellular function. We subsequently conducted multi-omics data analysis using public databases to analyze key target genes, and identified MMP11 as a chief downstream gene responsible for the effects of MEHP on HFF-1 cell migration. Through molecular docking analysis and molecular biology experiments, we further demonstrated that the nuclear receptor PPAR-gamma was activated upon binding with MEHP, leading to the suppression of MMP11 expression. Additionally, we found that epigenetic modifications induced by MEHP were also involved in its pathogenic effects on hypospadias. Our research highlights the crucial role of impaired cellular proliferation and migration in MEHP-induced hypospadias. We identified the MEHP/PPAR-gamma/MMP11 pathway as a novel pathogenic mechanism, providing important potential targets for future preventive strategies with respect to hypospadias.

Recent progress in quantitative analysis of self-assembled peptides.

Self-assembled peptides have been among the important biomaterials due to its excellent biocompatibility and diverse functions. Over the past decades, substantial progress and breakthroughs have been made in designing self-assembled peptides with multifaceted biomedical applications. The techniques for quantitative analysis, including imaging-based quantitative techniques, chromatographic technique and computational approach (molecular dynamics simulation), are becoming powerful tools for exploring the structure, properties, biomedical applications, and even supramolecular assembly processes of self-assembled peptides. However, a comprehensive review concerning these quantitative techniques remains scarce. In this review, recent progress in techniques for quantitative investigation of biostability, cellular uptake, biodistribution, self-assembly behaviors of self-assembled peptide etc., are summarized. Specific applications and roles of these techniques are highlighted in detail. Finally, challenges and outlook in this field are concluded. It is believed that this review will provide technical guidance for researchers in the field of peptide-based materials and pharmaceuticals, and facilitate related research for newcomers in this field.

Glucopeptide Superstructure Hydrogel Promotes Surgical Wound Healing Following Neoadjuvant Radiotherapy by Producing NO and Anticellular Senescence.

Neoadjuvant radiotherapy, a preoperative intervention regimen for reducing the stage of primary tumors and surgical margins, has gained increasing attention in the past decade. However, radiation-induced skin damage during neoadjuvant radiotherapy exacerbates surgical injury, remarkably increasing the risk of refractory wounds and compromising the therapeutic effects. Radiation impedes wound healing by increasing the production of reactive oxygen species and inducing cell apoptosis and senescence. Here, a self-assembling peptide (R-peptide) and hyaluronic-acid (HA)-based and cordycepin-loaded superstructure hydrogel is prepared for surgical incision healing after neoadjuvant radiotherapy. Results show that i) R-peptide coassembles with HA to form biomimetic fiber bundle microstructure, in which R-peptide drives the assembly of single fiber through π-π stacking and other forces and HA, as a single fiber adhesive, facilitates bunching through electrostatic interactions. ii) The biomimetic superstructure contributes to the adhesion and proliferation of cells in the surgical wound. iii) Aldehyde-modified HA provides dynamic covalent binding sites for cordycepin to achieve responsive release, inhibiting radiation-induced cellular senescence. iv) Arginine in the peptides provides antioxidant capacity and a substrate for the endogenous production of nitric oxide to promote wound healing and angiogenesis of surgical wounds after neoadjuvant radiotherapy.

Terahertz wave radiation simulation in the Fe thin film.

Femtosecond laser (FL) induced terahertz (THz) source is a new type of THz source based on injecting FL beams into ferromagnetic thin films by nonlinear effects to generate THz wave. It has a wider bandwidth compared to the traditional THz source, which provides higher flexibility and tunability in the application. In this paper, the three-temperature model and the stochastic Landau Lifshitz Gilbert equation at the atomic level are applied to simulate THz wave generation in Fe thin film induced by FL. Simulation results show that under a FL irradiance of 2 J m-2, the maximum demagnetization of the Fe thin film reaches 8.7%. The electromagnetic waves generated completely cover the THz band (0.1-10 THz), which fully satisfied the application requirements of the THz technology, verifying the feasibility of FL inducing the Fe thin film as a THz source. However, when the Fe thin film is overheated, it will be difficult for FL to excite valuable THz waves. Therefore, additional cooling devices are needed to keep the THz source in a workable temperature state, or to use ferromagnetic materials with magnetic moments that can quickly recover to saturation.

Analyzing Xinjiang's Sports Exports: A Comparative Advantage Perspective from the Sports Sector / Análisis de las exportaciones deportivas de Xinjiang: una perspectiva de ventaja comparativa desde el sector deportivo

This study explores the comparative advantage of Xinjiang's sports exports from the perspective of the sports sector. Xinjiang, a region in western China, has been gaining recognition for its growing sports industry, encompassing various disciplines such as basketball, soccer, and traditional sports like Uyghur wrestling. Leveraging the framework of comparative advantage, this research delves into the unique strengths and opportunities that Xinjiang possesses in the global sports market. This study uncovers the region's competitive edge in sports exports through a comprehensive analysis of Xinjiang's sports industry, including its infrastructure, talent development, and cultural heritage. By examining the factors contributing to this comparative advantage, such as the region's strategic location along the Silk Road Economic Belt and its rich cultural diversity, this research sheds light on how Xinjiang can further capitalize on its sports sector to bolster economic development and international engagement. The findings of this study not only provide insights into Xinjiang's potential as a sports export hub but also offer valuable lessons for policymakers, business leaders, and sports enthusiasts interested in harnessing the economic and cultural potential of this dynamic region.(AU)

[Advances on the treatment of Fusobacterium nucleatum-promoted colorectal cancers using nanomaterials].

Fusobacterium nucleatum (Fn) is an oral anaerobic bacterium that has recently been found to colonize on the surface of colorectal cancer cells in humans, and its degree of enrichment is highly negatively correlated with the prognosis of tumor treatment. Numerous studies have shown that Fn is involved in the occurrence and development of colorectal cancer (CRC), and Fn interacts with multiple components in the tumor microenvironment to increase tumor resistance. In recent years, researchers have begun using nanomedicine to inhibit Fn's proliferation at the tumor site or directly target Fn to treat CRC. This review summarizes the mechanism of Fn in promoting CRC and the latest research progress on Fn-related CRC therapy using different nanomaterials. Finally, the applications perspective of nanomaterials in Fn-promoted CRC therapy was prospected.

EISA in Tandem with ICD to Form In Situ Nanofiber Vaccine for Enhanced Tumor Radioimmunotherapy.

Radiotherapy (RT) can produce a vaccine effect and remodel a tumor microenvironment (TME) by inducing immunogenic cell death (ICD) and inflammation in tumors. However, RT alone is insufficient to elicit a systemic antitumor immune response owing to limited antigen presentation, immunosuppressive microenvironment, and chronic inflammation within the tumor. Here, a novel strategy is reported for the generation of in situ peptide-based nanovaccines via enzyme-induced self-assembly (EISA) in tandem with ICD. As ICD progresses, the peptide Fbp-GD FD FD pY (Fbp-pY), dephosphorylated by alkaline phosphatase (ALP) forms a fibrous nanostructure around the tumor cells, resulting in the capture and encapsulation of the autologous antigens produced by radiation. Utilizing the adjuvant and controlled-release advantages of self-assembling peptides, this nanofiber vaccine effectively increases antigen accumulation in the lymph nodes and cross-presentation by antigen-presenting cells (APCs). In addition, the inhibition of cyclooxygenase 2 (COX-2) expression by the nanofibers promotes the repolarization of M2-macrophages into M1 and reduces the number of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) required for TME remodeling. As a result, the combination of nanovaccines and RT significantly enhances the therapeutic effect on 4T1 tumors compared with RT alone, suggesting a promising treatment strategy for tumor radioimmunotherapy.

China's domestic industry redistribution facilitates carbon emissions mitigation.

Industry redistribution is a common economic phenomenon that involves a dynamic configuration of the production location across a region, country, or the world. However, measurements of the associated pollutant emission effects have not been well conducted at the domestically regional level. Here, we calculate the CO2 emission changes induced by China's domestic inter-provincial industry redistribution during 2002-2017 using a counterfactual approach in the multi-regional input-output framework. We find that China's domestic industry redistribution decreased CO2 emissions during 2002-2017 and has considerable potential to continuously mitigate CO2 emissions in the future. We emphasize that the pollution haven effect may accompany the process of industry redistribution but can be weakened by effective policies, including stringent access thresholds in the regions undertaking industry relocation and regional industry structural upgrading. This paper provides policy recommendations for strengthening regional coordination to achieve China's transformation to carbon neutrality.

Supramolecular nanofibers co-loaded with dabrafenib and doxorubicin for targeted and synergistic therapy of differentiated thyroid carcinoma.

Rationale: Although surgery, radioiodine therapy, and thyroid hormone therapy are the primary clinical treatments for differentiated thyroid carcinoma (DTC), effective therapy for locally advanced or progressive DTC remains challenging. BRAF V600E, the most common BRAF mutation subtype, is highly related to DTC. Previous studies prove that combination of kinase inhibitors and chemotherapeutic drugs may be a potential approach for DTC treatment. In this study, a supramolecular peptide nanofiber (SPNs) co-loaded with dabrafenib (Da) and doxorubicin (Dox) was constructed for targeted and synergistic therapy with BRAF V600E+ DTC. Methods: A self-assembling peptide nanofiber (Biotin-GDFDFDYGRGD, termed SPNs) bearing biotin at the N-terminus and a cancer-targeting ligand RGD at the C-terminus was used as a carrier for co-loading Da and Dox. D-phenylalanine and D-tyrosine (DFDFDY) are used to improve the stability of peptides in vivo. Under multiple non-covalent interactions, SPNs/Da/Dox assembled into longer and denser nanofibers. RGD ligand endows self-assembled nanofibers with targeting cancer cells and co-delivery, thereby improving cellular uptake of payloads. Results: Both Da and Dox indicated decreased IC50 values upon encapsulation in SPNs. Co-delivery of Da and Dox by SPNs exhibited the strongest therapeutic effect in vitro and in vivo by inhibiting ERK phosphorylation in BRAF V600E mutant thyroid cancer cells. Moreover, SPNs enable efficient drug delivery and lower Dox dosage, thereby significantly reducing its side effects. Conclusion: This study proposes a promising paradigm for the synergistic treatment of DTC with Da and Dox using supramolecular self-assembled peptides as carriers.

Tumor-Specific Peroxynitrite Overproduction Disrupts Metabolic Homeostasis for Sensitizing Melanoma Immunotherapy.

Tumor cells elicit metabolic reprogramming to establish an immunosuppressive tumor microenvironment (TME) for escaping from immunosurveillance. Therefore, interrupting the metabolic adaptation of tumor cells may be a promising strategy for TME immunomodulation, favoring immunotherapy. In this work, a tumor-specific peroxynitrite nanogenerator APAP-P-NO is constructed that can selectively disrupt metabolic homeostasis in melanoma cells. Stimulated by melanoma-characteristic acid, glutathione, and tyrosinase, APAP-P-NO can efficiently generate peroxynitrite through the in situ coupling of the produced superoxide anion and released nitric oxide. Metabolomics profiling reveals that the accumulated peroxynitrite induces a great decrease in metabolites in the tricarboxylic acid cycle. Meanwhile, the glycolysis-produced lactate drops sharply both intracellularly and extracellularly under peroxynitrite stress. Mechanistically, peroxynitrite impairs the activity of glyceraldehyde-3-phosphate dehydrogenase in glucose metabolism through S-nitrosylation. The metabolic alterations effectively reverse the immunosuppressive TME to evoke potent antitumor immune responses, including polarization of M2-like macrophages to M1phenotype, reduction of myeloid-derived suppressor cells and regulatory T cells, and restoration of CD8+ T cell infiltration. Combining APAP-P-NO with anti-PD-L1 achieves a significant inhibition against both primary and metastatic melanomas without systemic toxicities. Collectively, a tumor-specific peroxynitrite overproduction approach is developed and the possible mechanism of peroxynitrite-mediated TME immunomodulation is explored, providing a new strategy for facilitating immunotherapy sensitivity.

Achieving higher hierarchical structures by cooperative assembly of tripeptides with reverse sequences.

Hierarchical self-assembly based on peptides in nature is a multi-component interaction process, providing a broad platform for various bionanotechnological applications. However, the study of controlling the hierarchical structure transformation via the cooperation rules of different sequences is still rarely reported. Herein, we report a novel strategy of achieving higher hierarchical structures through cooperative self-assembly of hydrophobic tripeptides with reverse sequences. We unexpectedly found that Nap-FVY and its reverse sequence Nap-YVF self-assembled into nanospheres, respectively, while their mixture formed nanofibers, obviously exhibiting a low-to-high hierarchical structure transformation. Further, this phenomenon was demonstrated by the other two collocations. The cooperation of Nap-VYF and Nap-FYV afforded the transformation from nanofibers to twisted nanoribbons, and the cooperation of Nap-VFY and Nap-YFV realized the transformation from nanoribbons to nanotubes. The reason may be that the cooperative systems in the anti-parallel ß-sheet conformation created more hydrogen bond interactions and in-register π-π stacking, promoting a more compact molecular arrangement. This work provides a handy approach for controlled hierarchical assembly and the development of various functional bionanomaterials.

Serum vitamin D3 deficiency can affect the efficacy of sublingual immunotherapy in children with allergic rhinitis: a retrospective cohort study.

Background: Sublingual immunotherapy (SLIT) is effective and convenient for many allergic patients but it is still ineffective for many children with allergic rhinitis (AR). In previous studies, most of the patients with poor efficacy of SLIT used the method of individualized adjustment of drug dosage. Currently, there are few reports on the relationship between serum vitamin D3 level and the efficacy of SLIT. Methods: In this study, 153 patients with AR who received SLIT were selected as the study objects. All patients collected serum for vitamin D3 test before treatment. The clinical characteristics of the patients were collected, and all patients were regularly followed up for at least 6 months. The improvement rates were assessed according to the combined symptom medication score (CSMS). A receiver operating characteristic (ROC) curve was drawn, and the optimal cut-off point was determined according to the Youden index. Univariate and multivariate logistic regression were used to analyze the relationship between serum vitamin D3 and SLIT efficacy. The odds ratios (ORs) and 95% confidence intervals (CIs) were computed by logistic regression. Results: Of 153 AR patients, 101 patients entered the final statistical analysis. According to CSMS, 29.7% of patients in low response (LR) group. The mean vitamin D3 level was (20.42±7.48) ng/mL. The optimal cutoff point for vitamin D3 was 22.25 ng/mL. Univariate logistic regression analysis of SLIT efficacy showed that whether the patient also had a food allergy (P<0.001) or asthma (P=0.011), whether they used acarid products (P=0.002), and whether vitamin D3 is sufficient (P=0.001) were significantly related to the efficacy of SLIT. Multivariate logistic regression analysis showed that after adjusting for whether the patient also had asthma and whether they had used acarid products, whether the patient also had a food allergy (OR: 12.13, 95% CI: 3.57-41.18, P<0.001) and whether vitamin D3 is sufficient (OR: 22.21, 95% CI: 4.04-122.30, P<0.001) were independent factors affecting the efficacy of SLIT. Conclusions: Serum Vitamin D3 deficiency can affect the efficacy of SLIT in children with AR. This study provided a new therapeutic approach for SLIT patients with poor efficacy.

Internet follow-up can improve the compliance of sublingual immunotherapy in children with allergic rhinitis: a retrospective cohort study.

Background: Sublingual immunotherapy (SLIT) is an effective approach for treating allergic rhinitis in children. Although the curative effect of SLIT is significant, the compliance of patients is poor because of the long treatment time. How to improve patients' compliance with SLIT is an important clinical problem faced by otolaryngology clinicians. At present, there are few studies on SLIT compliance. The present study aimed to analyze the related factors affecting SLIT compliance in children with allergic rhinitis (AR). Methods: In total, 153 patients with AR who received SLIT were selected as the study objects. Seventeen patients were excluded from this study.The patients' demographic, follow-up methods, complications efficacy, compliance data, etc. were collected, and all patients were followed-up regularly. Patients were considered to have poor compliance when they stop taking medication of SLIT. Univariate and multivariable regression analyses were performed to analyze the independent factors influencing SLIT compliance. The odds ratios (ORs) and 95% confidence intervals (CIs) were computed by logistic regression. Results: A total of 136 patients were enrolled in this study. The baseline clinical factors of the two groups of follow-up methods were balanced and comparable. Among these, 35 patients (25.7%) ceased SLIT. There was a significant difference in compliance between the Internet follow-up group and the traditional follow-up group (P<0.001). Univariate logistic regression analysis showed that SLIT compliance was significantly related to residence (P<0.001), the caregiver's education level (P<0.001), follow-up methods (P<0.001), and whether the patient also had asthma (P<0.002). In the multivariate regression analysis, it was found that the follow-up methods (OR =7.60, 95% CI: 2.20-26.21, P=0.001) and caregiver's education level (OR =8.54, 95% CI: 3.04-23.95, P<0.001) were independent factors influencing SLIT compliance after adjusting for residence and whether the patient also had asthma. Conclusions: Our study found that the follow-up methods and the education level of caregivers were independent factors affecting SLIT compliance in children with AR. This study suggested that we should use the Internet follow-up method for children treated with SLIT in the future, and provides a basis for how to improve the compliance of SLIT in children with AR.

Learning from human metabolism for nanomedicine: a convertible bismuth-agent for tumour-selective theranostics.

Tumour-selective theranostic agents have attracted considerable interest over the past decade in oncology owing to their extraordinary anticancer efficacy. However, it still remains a challenge to develop theranostic agents balancing biocompatibility, multidimensional theranostics, tumour-selectivity, and simple components. Inspired by the metabolic pathways of exogenous sodium selenite against selenium-deficient diseases, reported here is the first convertible bismuth-based agent for tumour-selective theranostic functionalities. The specifically overexpressed substances in tumour tissue enable it to act as a natural reactor for the conversion from bismuth selenite to bismuth selenide, activating the theranostic functionalities specifically in tumour tissues. The converted product exhibits excellent multidimensional imaging-guided therapy. This study not only demonstrates a simple agent with both biocompatibility and sophisticated tumour-selective theranostic functionalities, but also pioneers a new approach from emulating nature towards oncological theranostic applications.

Bio-Inspired Antioxidant Heparin-Mimetic Peptide Hydrogel for Radiation-Induced Skin Injury Repair.

Radiotherapy is one of the most important means of cancer treatment, however, radiation can also cause adverse reactions and even serious injuries to the skin. Radiation-induced excess reactive oxygen species (ROS) production and inflammatory infiltration make skin wounds difficult to heal compared to normal skin injuries. Herein, an antioxidant heparin-mimetic peptide hydrogel (K16, KYKYEYEYAGEGDSS-4Sa) is designed for radiation-induced skin injury (RISI) repair. First, the K16 peptide can self-assemble into a hydrogel with a 3D mesh-like porous nanofiber structure, which can provide certain physical support for skin repair like extracellular matrix (ECM). Then, K16 hydrogel not only scavenges ROS and prevents radiation damage to cellular DNA, but also promotes cell proliferation, migration, and angiogenesis. Meanwhile, 4-sulfobenzoic acid (4Sa) modified at the N-terminal end of the K16 peptide can adsorb inflammatory cytokines, thus acting to eliminate inflammation at the wound site. In vivo experiments showed that K16 hydrogel can inhibit early wound degradation, reduce inflammatory infiltration, and promote angiogenesis and collagen deposition, thus promoting wound healing. Therefore, the K16 hydrogel designed in this study has good potential for application in the field of radiation-induced skin injury repair.

Smoking-related cancer death among men and women in an ageing society (China 2020-2040): a population-based modelling study.

BACKGROUND: China is experiencing a postpeak smoking epidemic with accelerating population ageing. Understanding the impacts of these factors on the future cancer burden has widespread implications. METHODS: We developed predictive models to estimate smoking-related cancer deaths among men and women aged ≥35 years in China during 2020-2040. Data sources for model parameters included the United Nations World Population Prospects, China Death Surveillance Database, national adult tobacco surveys and the largest national survey of smoking and all causes of death to date. The main assumptions included stable sex-specific and age-specific cancer mortality rates and carcinogenic risks of smoking over time. RESULTS: In a base-case scenario of continuing trends in current smoking prevalence (men: 57.4%-50.5%; women: 2.6%-2.1% during 2002-2018), the smoking-related cancer mortality rate with population ageing during 2020-2040 would rise by 44.0% (from 337.2/100 000 to 485.6/100 000) among men and 52.8% (from 157.3/100 000 to 240.4/100 000) among women; over 20 years, there would be 8.6 million excess deaths (0.5 million more considering former smoking), and a total of 117.3 million smoking-attributable years of life lost (110.3 million (94.0%) in men; 54.1 million (46.1%) in working-age (35-64 years) adults). An inflection point may occur in 2030 if smoking prevalence were reduced to 20% (Healthy China 2030 goal), and 1.4 million deaths would be averted relative to the base-case scenario if the trend were maintained through 2040. CONCLUSIONS: Coordinated efforts are urgently needed to curtail a rising tide of cancer deaths in China, with intensified tobacco control being key.

Tunable type-II lateral MoSi2N4/WSi2N4 heterostructures for photocatalytic applications.

Combining various two-dimensional crystals has emerged as an exciting way to tailor the properties of lateral heterostructures for new-generation optoelectronic devices. Herein, a seamless lateral heterostructure based on MoSi2N4 and MoSi2N4 monolayers along armchair interfaces is predicted, and its electronic and optical properties are investigated by using first principles calculations. Our calculations indicate that the MoSi2N4/WSi2N4 lateral heterostructures (HSs) possess excellent stability due to the very small lattice mismatch. In contrast to their parent monolayers with wide indirect band gaps, all (MoSi2N4)m(WSi2N4)n lateral HSs are direct gap semiconductors, and their direct gap nature is independent of compositions and strains. The band alignment of (MoSi2N4)m(WSi2N4)16-m lateral HSs undergoes a quasi-type-I to type-II to quasi-type-II to quasi-type-I band transition with an increase in m. (MoSi2N4)8(WSi2N4)8 is a type-II semiconductor, and the band arrangement changes from type-II to quasi-type-I upon applying tensile strain. Compared with pristine materials, the band edges of MoSi2N4/WSi2N4 lateral HSs are more favorable for photocatalytic water splitting. Furthermore, MoSi2N4/WSi2N4 lateral HSs exhibit higher visible light absorption. These results greatly expand the optoelectronic applications of Mxenes in the 2D realm.