Low-loss and flexible terahertz bandpass frequency selective surface based on cyclic olefin copolymer substrate via solvent-free synthesis.

This study investigates a low-loss and flexible terahertz frequency selective surface (FSS) based on cyclic olefin copolymer (COC) film substrate, which is fabricated via a simple temperature-control method without the use of solvent. The measured frequency response of the proof-of-concept COC-based THz bandpass FSS matches well with the numerical results. Due to the ultra-low COC dielectric dissipation factor (order of 0.0001) in the THz band, the measured passband insertion loss at 559 GHz reaches 1.22 dB, which is much better than that of previously reported THz bandpass filters. This work indicates that the remarkable characteristics (small dielectric constant, low frequency dispersion, low dissipation factor, good flexibility, etc.) of the proposed COC material make it a great application prospect in the THz field.

Freestanding narrowband terahertz filters based on aluminum foil.

Terahertz (THz) filters with high transmission coefficient (T) in the passband and frequency selectivity are critical in numerous applications such as astronomical detection and next-generation wireless communication. Freestanding bandpass filters eliminate the Fabry-Pérot effect of substrate, thus providing a promising choice for cascaded THz metasurfaces. However, the freestanding bandpass filters (BPFs) using the traditional fabrication process are costly and fragile. Here, we demonstrate a methodology to fabricate THz BPFs using aluminum (Al) foils. We designed a series of filters with center frequencies below 2 THz and manufacture them on 2-inch Al foils with various thicknesses. By optimizing the geometry, T of the filter at the center frequency is over 92%, and the relative full-width half maxima (FWHM) is as narrow as 9%. The responses of BPFs show that "cross-shaped" structures are insensitive to the polarization direction. The simple and low-cost fabrication process of the freestanding BPFs promise their widespread applications in THz systems.

Flexible bilayer terahertz metasurface for the manipulation of orbital angular momentum states.

Metasurfaces employed for generating orbital angular momentum (OAM) beams have drawn tremendous interest since they can offer extensive applications ranging from quantum optics to information processing over the subwavelength scale. In this study, a flexible bilayer metasurface is proposed and experimentally verified in the terahertz (THz) region. Based on Pancharatnam-Berry (P-B) phase, the proposed meta-atom satisfies perfect polarization-flipping at the design frequency and is implemented for the generation of vortex beams under circularly polarized (CP) illumination. Two metasurfaces are designed, fabricated and experimentally characterized with a THz spectral imaging system for linearly polarized (LP) illumination. The transmitted field intensity distribution of y component is petal-shaped of gradually varied pieces with the frequency due to the complementary symmetric structure, indicating OAM state transition between a single vortex beam and superposition of two vortex beams. The measured spectral imaging distributions of amplitude and phase show good agreement with the simulation results. Such designs open a pathway for modulation of THz OAM states and bring more possibilities for flexible metasurfaces in a THz application.

Coordinated regulation of immune contexture: crosstalk between STAT3 and immune cells during breast cancer progression.

Recent insights into the molecular and cellular mechanisms underlying cancer development have revealed the tumor microenvironment (TME) immune cells to functionally affect the development and progression of breast cancer. However, insufficient evidence of TME immune modulators limit the clinical application of immunotherapy for advanced and metastatic breast cancers. Intercellular STAT3 activation of immune cells plays a central role in breast cancer TME immunosuppression and distant metastasis. Accumulating evidence suggests that targeting STAT3 and/or in combination with radiotherapy may enhance anti-cancer immune responses and rescue the systemic immunologic microenvironment in breast cancer. Indeed, apart from its oncogenic role in tumor cells, the functions of STAT3 in TME of breast cancer involve multiple types of immunosuppression and is associated with tumor cell metastasis. In this review, we summarize the available information on the functions of STAT3-related immune cells in TME of breast cancer, as well as the specific upstream and downstream targets. Additionally, we provide insights about the potential immunosuppression mechanisms of each type of evaluated immune cells. Video abstract.

Molecular Precursor Route to CuCo2S4 Nanosheets: A High-Performance Pre-Catalyst for Oxygen Evolution and Its Application in Zn-Air Batteries.

Development of high-efficiency non-precious metal-based electrocatalysts to drive the complex four-electron process of the oxygen evolution reaction (OER) is crucial for production of hydrogen and energy storage components. Herein, bimetallic CuCo2S4 nanosheets were created by a new molecular precursor route. The optimal CuCo2S4 catalyst demonstrates superior performance to catalyze the OER with excellent stability, which was confirmed by the low overpotential of 290 mV at 10 mA cm-2 in 1 M KOH. The catalytic activity can be maintained for at least 40 h. The catalyst after the OER was then detected. The results indicate that S-doped CoOOH/CuO nanosheets formed on the catalyst surface during the OER may act as the catalytic active substance. Furthermore, when employed as an air cathode in a Zn-air battery, it reveals a high open-cycle potential of 1.38 V and a peak power density of 123.9 mW cm-2. The performance of the rechargeable Zn-air battery is close to that fabricated with commercial precious metal-based electrocatalysts. These findings would furnish some guidelines for the design, development, and applications of bimetallic sulfide electrocatalysts for the OER.

Smooth muscle tumors of the gastrointestinal tract: an analysis of prognostic features in 407 cases.

Smooth muscle tumors represent the second most common mural mesenchymal neoplasm in the gastrointestinal tract, but established criteria for prognostic assessment of these tumors are lacking. A large cohort of surgically resected intramural gastrointestinal smooth muscle tumors from 31 institutions was analyzed to identify potential prognostic features. Pathologic features were assessed by expert gastrointestinal and/or soft tissue pathologists at each center. Immunohistochemical confirmation was required. A total of 407 cases from the esophagus (n = 97, 24%), stomach (n = 180, 44%), small bowel (n = 74, 18%), and colorectum (n = 56, 14%) were identified. Patients ranged in age from 19 to 92 years (mean 55 years), with a slight female predominance (57%). Mean tumor size was 5.4 cm, with the largest tumor measuring 29 cm. Disease progression following surgery, defined as local recurrence, metastasis, or disease-related death, occurred in 56 patients (14%). Colorectal tumors were most likely to progress, followed by small bowel and gastric tumors. None of the esophageal tumors in this series progressed. Receiver operator characteristic analysis identified optimal cutoffs of 9.8 cm and 3 mitoses/5 mm2 for discriminating between progressive and non-progressive tumors. Histologic features strongly associated with progression by univariate analysis included moderate-to-severe atypia, high cellularity, abnormal differentiation (defined as differentiation not closely resembling that of normal smooth muscle), tumor necrosis, mucosal ulceration, lamina propria involvement, and serosal involvement (P < 0.0001 for all features). Age, sex, and margin status were not significantly associated with progression (P = 0.23, 0.82, and 0.07, respectively). A risk assessment table was created based on tumor site, size, and mitotic count, and Kaplan-Meier plots of progression-free survival for each subgroup revealed progression-based tiers. Based on our findings, it appears that nonesophageal gastrointestinal smooth muscle tumors measuring >10 cm and/or showing ≥3 mitoses/5 mm2 may behave aggressively, and therefore close clinical follow-up is recommended in these cases.

Nutritional outcomes after radiotherapy target volume reduction for nasopharyngeal cancer: a Phase III trial.

Aim: This study aimed to assess the nutritional status of patients with locoregionally advanced nasopharyngeal cancer, for whom intensity-modulated radiotherapy (IMRT) was planned using their pre- or post-induction chemotherapy (IC) nasopharyngeal gross tumor volume. Materials & methods: 212 cases of stage III-IVb nasopharyngeal cancer were randomized into groups A (n = 97) and B (n = 115). IMRT was planned for groups A and B using pre-IC and post-IC images, respectively. Results: There was a significant decrease in the nutritional parameters of group B compared with those of group A during radiotherapy. Multivariate analysis indicated that the T stage and nasopharyngeal gross tumor volume IMRT-planning protocol were prognostic factors of poor nutritional status. Conclusion: Decreasing the IMRT target volume through IC can improve nutritional status.

Synergistic effect and reduced toxicity by intratumoral injection of cytarabine-loaded hyaluronic acid hydrogel conjugates combined with radiotherapy on lung cancer.

The aim of this study was to explore the synergistic anti-tumor effects of cytarabine hyaluronic acid-tyramine (Ara-HA-Tyr) hydrogel conjugates and radiotherapy (RT) in the Lewis lung cancer (LLC) xenograft model, and the mechanisms involved. The radiotherapy sensitization ratio (SER) of 0.5 µg cytarabine (Ara-C) was 1.619 in the LLC cells. Ara-HA-Tyr was prepared by encapsulating Ara-C into hyaluronic acid-tyramine (HA-Tyr) conjugates. The hydrogels were formed through the oxidative coupling of tyramines by hydrogen peroxide (H2O2) and horseradish peroxidase (HRP). Mice engrafted with the LLC cells were given intra-tumoral injections of saline, Ara-C or Ara-HA-Tyr, with or without RT. The combination of Ara-HA-Tyr and RT increased survival compared to free Ara-C and RT (p < 0.05), and prolonged tumor growth delay (TGD). Furthermore, the RT + Ara-HA-Tyr combination therapy significantly reduced 18F-FDG uptake, induced cell cycle arrest at G2/M-phase, increased apoptosis and histone H2AX phosphorylation (γ-H2AX), and decreased the proliferation index (Ki67) in tumor cells compared to either monotherapy. Taken together, Ara-C encapsulated with HA-Tyr effectively sensitized tumor xenografts to RT and showed significantly less systemic toxicity. Graphical abstract In this work, Ara-C encapsulated with hyaluronic acid-tyramine conjugates (HA-Tyr) was prepared and used to investigate its synergistic anti-tumor efficacy by combination with radiotherapy in the Lewis lung cancer xenograft model. The synergistic mechanism may be related to tumor cell cycle redistribution, apoptosis and expression of histone H2AX phosphorylation.

Preliminary report of a single-channel applicator in high dose rate afterloading brachytherapy for cervical cancer.

The aim of this study was to evaluate whether a patented single-channel applicator, which was modified from the traditional tandem applicator and wrapped with an oval-shield alloy around the source channel, has the same clinical efficacy and safety as the standard Fletcher-type applicator in high dose rate (HDR) brachytherapy for carcinoma of the cervix. Between December 2011 and February 2017, 299 patients with pathologically confirmed International Federation of Gynecology and Obstetrics (2009) stage Ib2-IVa cervical cancer were recruited to the trial and finished the allocated intervention. Of the first 151 patients, 71 were allocated to the Fletcher group and 80 to the single-channel group, satisfying the criteria for a preliminary analysis. All but 3 patients were treated with concurrent cisplatin chemotherapy and external beam radiotherapy followed by HDR brachytherapy. The 2-year overall survival, progression-free survival, and locoregional failure-free survival was 80.3%, 77.5%, and 78.9%, respectively, for the Fletcher group, and 86.3%, 82.5%, and 83.8%, respectively, for the single-channel group. The seriousness of acute treatment-related toxicities was similar in the 2 groups. The cumulative rate of late rectal complications of grade 3-4 in the Fletcher group and the single-channel group was 2.8% and 2.5%, respectively. The cumulative rate of grade 3 bladder complications was 2.8% for the Fletcher group and 1.3% for the single-channel group. The preliminary results of our study show that the patented single-channel intracavitary applicator might be able to provide protection for the rectum and bladder and seems to have the same clinical efficacy as the standard Fletcher-type 3-channel applicator in HDR brachytherapy for carcinoma of the cervix. This trial was registered with the Chinese Clinical Trial Registry (registration no. ChiCTR-TRC-12002321).

A quality control method for intensity-modulated radiation therapy planning based on generalized equivalent uniform dose.

To ensure good quality intensity-modulated radiation therapy (IMRT) planning, we proposed the use of a quality control method based on generalized equivalent uniform dose (gEUD) that predicts absorbed radiation doses in organs at risk (OAR). We conducted a retrospective analysis of patients who underwent IMRT for the treatment of cervical carcinoma, nasopharyngeal carcinoma (NPC), or non-small cell lung cancer (NSCLC). IMRT plans were randomly divided into data acquisition and data verification groups. OAR in the data acquisition group for cervical carcinoma and NPC were further classified as sub-organs at risk (sOAR). The normalized volume of sOAR and normalized gEUD (a = 1) were analyzed using multiple linear regression to establish a fitting formula. For NSCLC, the normalized intersection volume of the planning target volume (PTV) and lung, the maximum diameter of the PTV (left-right, anterior-posterior, and superior-inferior), and the normalized gEUD (a = 1) were analyzed using multiple linear regression to establish a fitting formula for the lung gEUD (a = 1). The r-squared and P values indicated that the fitting formula was a good fit. In the data verification group, IMRT plans verified the accuracy of the fitting formula, and compared the gEUD (a = 1) for each OAR between the subjective method and the gEUD-based method. In conclusion, the gEUD-based method can be used effectively for quality control and can reduce the influence of subjective factors on IMRT planning optimization.

Broadband and high modulation-depth THz modulator using low bias controlled VO2-integrated metasurface.

An active vanadium dioxide integrated metasurface offering broadband transmitted terahertz wave modulation with large modulation-depth under electrical control is demonstrated. The device consists of metal bias-lines arranged with grid-structure patterned vanadium dioxide (VO2) film on sapphire substrate. Amplitude transmission is continuously tuned from more than 78% to 28% or lower in the frequency range from 0.3 THz to 1.0 THz, by means of electrical bias at temperature of 68 °C. The physical mechanism underlying the device's electrical tunability is investigated and found to be attributed to the ohmic heating. The developed device possessing over 87% modulation depth with 0.7 THz frequency band is expected to have many potential applications in THz regime such as tunable THz attenuator.

[Design of an adaptive radiation therapy system for target movement compensation].

In order to decrease the radiotherapy error caused by target motion, an adaptive radiation therapy system for target movement compensation has been designed and passed by simulation test. The real-time position of the target labelled by a mark was captured by the control system and compared with the reference point. Then the treatment couch was controlled to move in the opposite direction for compensation according to that position information. The three dimensional movement of the treatment bed relied on three independent stepping motors which were controlled by a control system. Experiments showed that the adaptive radiation therapy system was able to reduce the therapy error caused by target movement. It would be useful in radiotherapy clinical practice with high real-time position precision.

MicroRNA-183 promotes migration and invasion of CD133(+)/CD326(+) lung adenocarcinoma initiating cells via PTPN4 inhibition.

Non-small cell lung cancer (NSCLC) is the most common cancer worldwide and is a leading cause of lung cancer mortality due to early stage metastases. Cancer stem-like cells (CSLCs) or tumor-initiating cells (TICs) are rare subpopulation cells that are responsible for maintaining tumor growth and invasion leading to recurrence and metastasis. Previous studies revealed that miR-183 can mediate the invasiveness and growth of NSCLC. However, the exact role of miR-183 in regulating the biological behavior of CSLCs in NSCLC remains unclear. In the present study, we explored the regulation of protein tyrosine phosphatase non-receptor type 4 (PTPN4) by miR-183 in vitro using luciferase reporter assays, and we further analyzed the effects of miR-183 on the invasiveness of CSLCs in vitro and in vivo using transwell and bioluminescence assays. Following our finding that miR-183 binds to PTPN4 messenger RNA (mRNA) to prevent its translation through the 3'-untranslated region (UTR), we found that overexpression of miR-183 in CSLCs decreased PTPN4 protein levels while inhibition of miR-183 increased PTPN4 protein levels. The suppression of PTPN4 levels in CSLCs by miR-183 paralleled with a significant promotion in their motility in vitro and in vivo, while anti-sense miR-183 increased PTPN4 levels in CSLCs, which paralleled with a significant decrease in their invasiveness. Furthermore, correlation analysis between miR-183 and PTPN4 in clinical samples demonstrated a statistically significant inverse correlation between PTPN4 mRNA levels and miR-183. In brief, our data indicate that miR-183 plays a pro-invasive role by inverse regulation of PTPN4, and this axis may be a new therapeutic target for suppressing the metastatic capability of CSLCs in NSCLC.

Development of a sensitive molecular detection assay for mango malformation disease caused by Fusarium mangiferae.

OBJECTIVES: To develop a sensitive and specific molecular assay for detection of mango malformation disease (MMD), which is caused primarily by Fusarium mangiferae. RESULTS: We screened 100 ISSR primers and identified one (UBC888) that directed the stable amplification of a specific gene fragment of 479 bp (GenBank accession number KJ526382). Based on the DNA sequence of this fragment, a pair of SCAR primers (W342 and W1772) were designed to amplify another gene fragment of 1376 bp (GenBank accession number KJ526383), demonstrating the successful conversion of an ISSR marker to a SCAR marker. An effective and simple detection assay for MMD was established based on this pair of PCR primers, with a high level of specificity and sensitivity to the DNA of F. mangiferae and other species of Fusarium both in vitro and in vivo. It can detect as little as 10 pg fungal DNA from the DNA of mango's tissues. CONCLUSIONS: Our assay provides a practical method for the early diagnosis so that proper prevention of the mango malformation disease can be developed.

Potential risk of blood transfusion-transmitted brucellosis in an endemic area of China.

BACKGROUND: Brucellosis is a severe zoonotic disease that is increasingly prevalent in north China. A study evaluating Brucella infection in blood donors was conducted at Kashi central blood station, Xinjiang, China. STUDY DESIGN AND METHODS: Four serologic and two molecular methods of detection of Brucella infection were used in plasma samples from blood donations collected from Kashi in northwest China, considered a brucellosis-endemic area. Blood donor samples collected in Shenzhen, southern China, a brucellosis-nonendemic area, were tested as a negative control group. RESULTS: In 3896 plasma samples collected from Kashi central blood station, 135 (3.5%) plasma samples were reactive by the Rose Bengal plate test (RBPT), and 120 (3.1%) of the 135 RBPT-reactive sample were also reactive with the standard tube agglutination test (SAT), respectively. All samples of the control group of 399 blood samples from Shenzhen blood center tested negative with RBPT and SAT. Of 135 seroreactive plasma samples, 39 (1.0%) reacted with B. melitensis membrane protein extracts by enzyme-linked immunosorbent assay and 25 were reactive to either rBP26 or rOMP31 by Western blot. Thirteen plasma samples and two follow-up blood samples were identified as carrying Brucella DNA by quantitative polymerase chain reaction (PCR) and nested PCR. Overall 15 (1:300) Kashi blood donations were found positive by nucleic acid testing, confirmed specific by DNA sequencing. CONCLUSIONS: The data indicate a probable high rate of Brucella bacteremia, suggesting a potential risk of transfusion-transmitted brucellosis. Blood donation screening for Brucella infection may be considered in the high Brucella-endemic areas of China.

Sorption of heavy metal ions onto carboxylate chitosan derivatives--a mini-review.

Chitosan is of importance for the elimination of heavy metals due to their outstanding characteristics such as the presence of NH2 and -OH functional groups, non-toxicity, low cost and, large available quantities. Modifying a chitosan structure with -COOH group improves it in terms of solubility at pH ≤7 without affecting the aforementioned characteristics. Chitosan modified with a carboxylic group possess carboxyl, amino and hydroxyl multifunctional groups which are good for elimination of metal ions. The focal point of this mini-review will be on the preparation and characterization of some carboxylate chitosan derivatives as a sorbent for heavy metal sorption.

A biomechanical analysis of novel endovascular implants for aortic valve replacement and ascending aortic repair.

Advances in medical technology have enabled minimally invasive treatment of type A aortic dissection with accompanying aortic regurgitation. Implants include endovascular stent grafts (ESG) and heart valve substitute (HVS) modules. Traditional implants can be divided into two types based on the assembly relationship between ESG and HVS: separated z-shaped implants (SZ) and separated diamond-shaped implants (SD). This study proposes a novel linked diamond-shaped implant (LD). To evaluate the safety and effectiveness of this new implant, finite element simulation models were created to assess the risks of endoleak, migration, and vascular wall rupture under annulus displacement load. After the SZ, SD, and LD implants were grafted in virtual release method, all the implants can cover tear-entry located in the ascending aorta, but space distance (δ) which exposed to blood was 14.5, 13.1, and 7.4 mm, respectively; the maximum areas of contact gap was 76.5, 51.5 and 6.3 mm2; the maximum migration distance (ΔL1) were 1.27, 1.06, and 0.1 mm; the maximum stress on ascending aorta was 0.19, 0.24, and 0.51 MPa, which were lower than failure stress (0.9 MPa). This study showed that both SZ and SD implants had minimal effects on the ascending aorta; however, higher risks were associated with implant migration and proximal endoleak. In contrast, the LD implant can simplify the surgical procedure, has a lower risk of endoleak and migration, and limited stress stimulation of the aorta. This study validated the feasibility and effectiveness of this novel implant using the finite element method, indicating its potential as a secure and reliable treatment option.

Targeted modulation of gut and intra-tumor microbiota to improve the quality of immune checkpoint inhibitor responses.

Immune checkpoint inhibitor (ICI) therapies, such as those blocking the interaction of PD-1 with its ligands, can restore the immune-killing function of T cells. However, ICI therapy is clinically beneficial in only a small number of patients, and it is difficult to predict post-treatment outcomes, thereby limiting its widespread clinical use. Research suggests that gut microbiota can regulate the host immune system and affect cancer progression and treatment. Moreover, the effectiveness of immunotherapy is related to the composition of the patient's gut microbiota; different gut microbial strains can either activate or inhibit the immune response. However, the importance of the microbial composition within the tumor has not been explored until recently. This study describes recent advances in the crosstalk between microbes in tumors and gut microbiota, which can modulate the tumor microbiome by directly translocating into the tumor and altering the tumor microenvironment. This study focused on the potential manipulation of the tumor and gut microbiota using fecal microbiota transplantation (FMT), probiotics, antimicrobials, prebiotics, and postbiotics to enrich immune-boosting bacteria while decreasing unfavorable bacteria to proactively improve the efficacy of ICI treatments. In addition, the use of genetic technologies and nanomaterials to modify microorganisms can largely optimize tumor immunotherapy and advance personalized and precise cancer treatment.

Indium oxide-based Z-scheme hollow core-shell heterostructure with rich sulfur-vacancy for highly efficient light-driven splitting of water to produce clean energy.

Crafting an inorganic semiconductor heterojunction with defect engineering and morphology modulation is a strategic approach to produce clean energy by the highly efficient light-driven splitting of water. In this paper, a novel Z-scheme sulfur-vacancy containing Zn3In2S6 (Vs-Zn3In2S6) nanosheets/In2O3 hollow hexagonal prisms heterostructrue (Vs-ZIS6INO) was firstly constructed by an oil bath method, in which Vs-Zn3In2S6 nanosheets grew on the surfaces of In2O3 hollow hexagonal prisms to form a hollow core-shell structure. The obtained Vs-ZIS6INO heterostructrue exhibited much enhanced activity of the production of H2 and H2O2 by the light-driven water splitting. In particular, under visible light irradiation (λ > 420 nm), the rate of generation of H2 of Vs-ZIS6INO sample containing 30 wt% Vs-Zn3In2S6 (30Vs-ZIS6INO) could reach 3721 µmol g-1h-1, which was 87 and 6 times higher than those of Zn3In2S6 (43 µmol g-1h-1) and Vs-Zn3In2S6 (586 µmol g-1h-1), respectively. Meanwhile, 30Vs-ZIS6INO could exhibit the rate of H2O2 production of 483 µmol g-1h-1 through the dual pathways of indirect 2e- oxygen reduction (ORR) and water oxidation (WOR) without adding any sacrifice agents, far exceeding In2O3 (7 µmol g-1h-1) and Vs-Zn3In2S6 (58 µmol g-1h-1). The excellent photocatalytic activities of H2 and H2O2 generations of Vs-ZIS6INO sample might result from the synergistic effect of the sulfur vacancy, hollow core-shell structure, and Z-scheme heterostructure, which accelerated the electron delocalization, enhanced the absorption and conversion of solar energy, reduced the carrier diffusion distance, and ensured high REDOX ability. In addition, the possible photocatalytic mechanisms for the production of H2 and H2O2 were discussed in detail. This study provided a new idea and reference for constructing the novel and efficient inorganic semiconductor heterostructures by coordinating vacancy defect and morphology design to adequately utilize water splitting for the production of clean energy.

Linear and phase controllable terahertz frequency conversion via ultrafast breaking the bond of a meta-molecule.

The metasurface platform with time-varying characteristics has emerged as a promising avenue for exploring exotic physics associated with Floquet materials and for designing photonic devices like linear frequency converters. However, the limited availability of materials with ultrafast responses hinders their applications in the terahertz range. Here we present a time-varying metasurface comprising an array of superconductor-metal hybrid meta-molecules. Each meta-molecule consists of two meta-atoms that are "bonded" together by double superconducting microbridges. Through experimental investigations, we demonstrate high-efficiency linear terahertz frequency conversion by rapidly breaking the bond using a coherent ultrashort terahertz pump pulse. The frequency and relative phase of the converted wave exhibit strong dependence on the pump-probe delay, indicating phase controllable wave conversion. The dynamics of the meta-molecules during the frequency conversion process are comprehensively understood using a time-varying coupled mode model. This research not only opens up new possibilities for developing innovative terahertz sources but also provides opportunities for exploring topological dynamics and Floquet physics within metasurfaces.