Depolymerization and Re/Upcycling of Biodegradable PLA Plastics.

With the escalating utilization of plastic products, global attention has been increasingly drawn to environmental pollution and recycling challenges stemming from plastic waste. Against this backdrop, biodegradable plastics have emerged as viable alternatives owing to their sustainability and capacity for biodegradation. Polylactic acid (PLA) presently commands the largest market share among biodegradable plastics, finding extensive application in products such as thin films, medical materials, and biodegradable straws. However, the widespread adoption of PLA is hindered by challenges such as high cost, low recycling rates, and complete degradation to H2O and CO2 in natural conditions. Therefore, it is imperative and time-sensitive to explore solutions for the depolymerization and re/upcycling of PLA waste plastics. This review comprehensively outlines the current landscape of PLA recycling methods, emphasizing the advantages and significance of chemical re/upcycling. The subsequent exploration encompasses recent breakthroughs and technical obstacles inherent in diverse chemical depolymerization methods. Ultimately, this review accentuates the impediments and forthcoming possibilities in the realm of PLA plastics, emphasizing the pursuit of closed-loop recycling and upcycling.

A new classification for surgical NEC during exploratory laparotomy: introduction and reproducibility assessment.

PURPOSE: Variability in necrosis patterns and operative techniques in surgical necrotizing enterocolitis (NEC) necessitates a standardized classification system for consistent assessment and comparison. This study introduces a novel intraoperative reporting system for surgical NEC, focusing on reliability and reproducibility. METHODS: Analyzing surgical NEC cases from January 2018 to June 2023 at two tertiary neonatal and pediatric surgery units, a new classification system incorporating anatomical details and intestinal involvement extent was developed. Its reproducibility was quantified using kappa coefficients (κ) for interobserver and intraobserver reliability, assessed by four specialists. Furthermore, following surgery, the occurrence of mortality and enteric autonomy were evaluated on the basis of surgical decision-making of the novel intraoperative classification system for surgical NEC. RESULTS: In total, 95 patients with surgical NEC were included in this analysis. The mean κ value of the intra-observer reliability was 0.889 (range, 0.790-0.941) for the new classification, indicating excellent agreement and the inter-observer reliability was 0.806 (range, 0.718-0.883), indicating substantial agreement. CONCLUSION: The introduced classification system for surgical NEC shows high reliability, deepening the understanding of NEC's intraoperative exploration aspects. It promises to indicate operative strategies, enhance prognosis prediction, and substantially facilitate scholarly communication in pediatric surgery. Importantly, it explores the potential for a standardized report and may represent a step forward in classifying surgical NEC, if pediatric surgeons are open to change.

Natural Amino Acid-Bearing Carbamate Prodrugs of Daidzein Increase Water Solubility and Improve Phase II Metabolic Stability for Enhanced Oral Bioavailability.

Daidzein (DAN) is an isoflavone, and it is often found in its natural form in soybean and food supplements. DAN has poor bioavailability owing to its extremely low water solubility and first-pass metabolism. Herein, we hypothesized that a bioactivatable natural amino acid-bearing carbamate prodrug strategy could increase the water solubility and metabolic stability of DAN. To test our hypothesis, nine amino acid prodrugs of DAN were designed and synthesized. Compared with DAN, the optimal prodrug (daidzein-4'-O-CO-N-isoleucine, D-4'-I) demonstrated enhanced water solubility and improved phase II metabolic stability and activation to DAN in plasma. In addition, unlike the passive transport of DAN, D-4'-I maintained high permeability via organic anion-transporting polypeptide 2B1 (OATP2B1)-mediated transport. Importantly, D-4'-I increased the oral bioavailability by 15.5-fold, reduced the gender difference, and extended the linear absorption capacity in the pharmacokinetics of DAN in rats. Furthermore, D-4'-I exhibited dose-dependent protection against liver injury. Thus, the natural amino acid-bearing carbamate prodrug strategy shows potential in increasing water solubility and improving phase II metabolic stability to enhance the oral bioavailability of DAN.

Guiding function of positron emission tomography-computed tomography examination in the diagnosis and treatment of ocular adnexal mucosa associated lymphoid tissue lymphoma.

AIM: To explore the role of positron emission tomography-computed tomography (PET-CT) examination in the diagnosis and treatment of ocular adnexal mucosa associated lymphoid tissue lymphoma (OAML). METHODS: The general clinical data, postoperative PET-CT results, treatment regimens, and the prognosis of 21 histopathologically confirmed OAML patients between October 2017 and September 2021 were collected. Among the 21 patients, five patients underwent surgical treatment alone, 13 patients underwent surgical treatment combined with radiotherapy, and three patients underwent surgical treatment combined with chemotherapy. RESULTS: The follow-up period ranged from 8 to 79mo, with four cases of recurrence and no deaths. Through PET-CT examination, two patients exhibited both local ocular metabolic elevation and systemic metastasis, and one of these patients had cervical lymph node metastasis, while the other had submandibular and parotid gland metastasis. Nine patients showed only local ocular metabolic elevation, while 10 patients had no abnormal metabolic activity locally. CONCLUSION: PET-CT examination plays a crucial role in detecting residual lesions and recurrence following tumor resection, aiding in precise disease staging, and facilitating the development of personalized treatment plans, ultimately improving patient prognosis.

Effect of Body Mass Index on Cecal Intubation Time During Unsedated Colonoscopy: Variation Across the Learning Stages of an Endoscopist.

BACKGROUND Body mass index (BMI) and endoscopists' experiences can be associated with cecal intubation time (CIT), but such associations are controversial. This study aimed to clarify the association between BMI and CIT during unsedated colonoscopy at 3 learning stages of a single endoscopist. MATERIAL AND METHODS A total of 1500 consecutive patients undergoing unsedated colonoscopy by 1 endoscopist at our department from December 11, 2020, to August 21, 2022, were reviewed. They were divided into 3 learning stages according to the number of colonoscopies performed by 1 endoscopist, including intermediate (501-1000 colonoscopies), experienced (1001-1500 colonoscopies), and senior stages (1501-2000 colonoscopies). Variables that significantly correlated with CIT were identified by Spearman rank correlation analyses and then included in multiple linear regression analysis. RESULTS Overall, 1233 patients were included. Among them, 392, 420, and 421 patients were divided into intermediate, experienced, and senior stages, respectively. Median CIT was 7.83, 6.38, and 5.58 min at intermediate, experienced, and senior stages, respectively (P.

Cycloalkane degradation by an uncultivated novel genus of Gammaproteobacteria derived from China's marginal seas.

The consumption of cycloalkanes is prevalent in low-temperature marine environments, likely influenced by psychrophilic microorganisms. Despite their significance, the primary active species responsible for marine cycloalkane degradation remain largely unidentified due to cultivation challenges. In this study, we provide compelling evidence indicating that the uncultured genus C1-B045 of Gammaproteobacteria is a pivotal participant in cycloalkane decomposition within China's marginal seas. Notably, the relative abundance of C1-B045 surged from 15.9% in the methylcyclohexane (MCH)-consuming starter culture to as high as 97.5% in MCH-utilizing extinction cultures following successive dilution-to-extinction and incubation cycles. We used stable isotope probing, Raman-activated gravity-driven encapsulation, and 16 S rRNA gene sequencing to link cycloalkane-metabolizing phenotype to genotype at the single-cell level. By annotating key enzymes (e.g., alkane monooxygenase, cyclohexanone monooxygenase, and 6-hexanolactone hydrolase) involved in MCH metabolism within C1-B045's representative metagenome-assembled genome, we developed a putative MCH degradation pathway.

Excellent Bowel Preparation Quality Is Not Superior to Good Bowel Preparation Quality for Improving Adenoma/Polyp Detection Rate.

Background: Adequate bowel preparation quality is essential for high-quality colonoscopy according to the current guidelines. However, the excellent effect of bowel preparation on adenoma/polyp detection rate (ADR/PDR) remained controversial. Methods: During the period from December 2020 to August 2022, a total of 1566 consecutive patients underwent colonoscopy by an endoscopist. Their medical records were reviewed. According to the Boston bowel preparation scale, patients were divided into excellent, good, and poor bowel preparation quality groups. ADR/PDR, diminutive ADR/PDR, small ADR/PDR, intermediate ADR/PDR, large ADR/PDR, and number of adenomas/polyps were compared among them. Logistic regression analyses were performed to identify the factors that were significantly associated with ADR/PDR. Results: Overall, 1232 patients were included, of whom 463, 636, and 133 were assigned to the excellent, good, and poor groups, respectively. The good group had a significantly higher ADR/PDR (63% vs 55%, P = .015) and a larger number of adenomas/polyps (2.5 ± 3.2 vs 2.0 ± 2.8, P = .030) than the poor group. Both ADR/PDR (63% vs 55%, P = .097) and number of adenomas/polyps (2.2 ± 2.8 vs 2.0 ± 2.8, P = .219) were not significantly different between excellent and poor groups. The excellent (9% vs 4%, P = .045) and good (9% vs 4%, P = .040) groups had a significantly higher intermediate ADR/PDR than the poor group. Logistic regression analyses showed that either good (odds ratio [OR] = 1.786, 95% CI = 1.046-3.047, P = .034) or excellent (OR = 2.179, 95% CI = 1.241-3.826, P = .007) bowel preparation quality was independently associated with a higher ADR/PDR compared with poor bowel preparation quality. Excellent (OR = 1.202, 95% CI = 0.848-1.704, P = .302) bowel preparation quality was not independently associated with a higher ADR/PDR compared with good bowel preparation quality. Conclusions: The pursuit of excellence in bowel preparation does not show an association with increased ADR/PDR and number of adenomas/polyps compared with a good level. In addition, our study further contributes to the existing evidence that poor bowel preparation compromises ADR/PDR and number of adenomas/polyps.

Analysis of multispectral polarization imaging image information based on micro-polarizer array.

As a new detection technology, polarization imaging is of great significance in the field of target detection. At present, polarization imaging technology usually adopts visible light polarization imaging. The technique is difficult to image the target in complex background due to its narrow working spectrum and short detection distance. Therefore, based on the principle of full Stokes micro-polarizer array, this paper proposes a multi-spectral polarization imaging scheme and designs a multi-spectral polarization imaging detection system penetrating haze. Conducting indoor and outdoor polarized imaging experiments. Finally, image quality was assessed using metrics such as information entropy (EN), average gradient (AG), and standard deviation (STD). The results show that compared with traditional strength detection, the imaging system has significantly improved detection distance and imaging quality in smoky environments. The imaging system can effectively enhance the contours and details of the target object and improve detection and recognition capabilities.

Improved target detection method for space-based optoelectronic systems.

The detection of faint and small targets by space-based surveillance systems is difficult owing to the long distances, low energies, high speeds, high false alarm rates, and low algorithmic efficiencies involved in the process. To improve space object detection and help prevent collisions with critical facilities such as satellites, this study proposes an improved method for the detection of faint and small space-based targets. The proposed method consists of two components: star atlas preprocessing and space-based target detection. The star atlas preprocessing step applies multi-exposure image pyramidal weighted fusion to the original image containing the faint and small space-based target. After obtaining the image pyramidal weighted fusion result atlas, the algorithm employs threshold segmentation to improve the overall image clarity, highlight image details, and provide additional information for target detection. The detection of targets partially relies on the local symmetry of the image. Accordingly, a diffusion function describing the local symmetry is established to precisely locate stars by measuring the symmetry factor in a small area surrounding each pixel in the star atlas. This effectively removes the background stars while retaining high-definition and high-contrast images. The efficacy of the algorithm is validated using simulated datasets consisting of space-based and real images. The results demonstrate that the proposed technique improves the applicability of the multistage hypothesis testing (MHT) method in the context of a complex space environment, thus improving the performance of the space-based electro-optical detection system to better catalogue, identify, and track space targets.

Current targeting strategies and advanced nanoplatforms for atherosclerosis therapy.

Atherosclerosis is one of the major causes of death worldwide, and it is closely related to many cardiovascular diseases, such as stroke, myocardial infraction and angina. Although traditional surgical and pharmacological interventions can effectively retard or slow down the progression of atherosclerosis, it is very difficult to prevent or even reverse this disease. In recent years, with the rapid development of nanotechnology, various nanoagents have been designed and applied to different diseases including atherosclerosis. The unique atherosclerotic microenvironment with signature biological components allows nanoplatforms to distinguish atherosclerotic lesions from normal tissue and to approach plaques specifically. Based on the process of atherosclerotic plaque formation, this review summarises the nanodrug delivery strategies for atherosclerotic therapy, trying to provide help for researchers to understand the existing atherosclerosis management approaches as well as challenges and to reasonably design anti-atherosclerotic nanoplatforms.

Neurodevelopmental impairment following surgical necrotizing enterocolitis with gestational age ≥ 28 weeks: who is at risk?

PURPOSE: Surgical necrotizing enterocolitis (NEC) is a severe medical condition that, even after surgery, a portion of the survival infants may still have neurological sequelae. The objective of this study was to identify the risk factors associated with the development of permanent neurodevelopmental impairment (NDI) in neonates with surgical NEC. METHODS: Between January 2016 and June 2022, a retrospective data collection was conducted on 98 individuals who experienced surgical NEC with gestational age ≥ 28 weeks. Among these patients, 27 patients were diagnosed with NDI, while the remaining 71 patients did not have NDI. Based on this division, the patients were categorized into the NDI group and the Non-NDI group. Demographics, comorbidities, and admission lab results were analyzed using univariate and logistic regression analyses. RESULTS: Of the 98 neonates following surgical NEC, 27(27.6%) developed permanent neurodevelopmental impairment (NDI). Predictors of NDI were identified through the final multivariable logistic regression analysis, which revealed that gestational age ≤ 32 weeks (p = 0.032; odds ratio [OR], 5.673), assisted mechanical ventilation after NEC onset (p = 0.047; OR, 5.299), postoperative acute kidney injury (p = 0.040; OR, 5.106), CRP day 3 after NEC onset (p = 0.049; OR, 1.037), time from presentation to surgery (p = 0.003; OR, 1.047) were significant risk factors. CONCLUSIONS: Our study identified gestational age ≤ 32 weeks, assisted mechanical ventilation after NEC onset, postoperative acute kidney injury, CRP day 3 after NEC onset, and time from presentation to surgery as significant risk factors for NDI in neonates with surgical NEC. These factors would be helpful to refine treatment modalities for better disease outcomes. We also determined the cut-off values of CRP day 3 after NEC onset and time from presentation to surgery, allowing for the individualized evaluation of NDI risk and the implementation of earlier targeted laparotomy.

The association between Helicobacter pylori and gastrointestinal disorders during pregnancy: A Multicenter retrospective study.

BACKGROUND: Some gastrointestinal disorders may be associated with Helicobacter pylori infection, which not only affect maternal health, but may also lead to adverse pregnancy outcomes. We aim to explore the association between H. pylori and gastrointestinal disorders in pregnant women. MATERIALS AND METHODS: In total, 503 patients were retrospectively analyzed and divided into the H. pylori-uninfected group, the H. pylori-infected group, or the H. pylori-eradicated group. We analyzed the influence of H. pylori on gastrointestinal diseases during pregnancy among the groups, as well as the severity, symptoms, laboratory tests of the H. pylori-related diseases. RESULTS: Pregnant women with H. pylori infection had higher risk of nausea and vomiting of pregnancy (NVP) (p < 0.001), severe NVP(p = 0.012), hyperemesis gravidarum (p = 0.027), hematemesis (p = 0.018), hyponatremia (p = 0.033), as well as functional dyspepsia symptoms including epigastric pain (p = 0.004), bloating (p = 0.024), and feeling full quickly in a meal (p = 0.031) compared with those without H. pylori infection. While the prevalence of NVP (p = 0.024), severe NVP (p = 0.009), epigastric pain (p = 0.037), and bloating (p = 0.032) were lower in H. pylori-eradicated pregnant women than in H. pylori-infected women. In addition, pregnant women with H. pylori infection had higher risk of spontaneous preterm birth than whom without H. pylori infection (p = 0.033). CONCLUSIONS: Helicobacter pylori infection was associated with higher risks of NVP, severe NVP, hyperemesis gravidarum, functional dyspepsia, and spontaneous preterm birth in pregnant women.

Detection and identification of oil spill species based on polarization information.

Aiming at the problem of poor oil identification accuracy in existing oil spill detection technologies, the polarization degree model of oil spill on rough sea surface under different azimuths and zenith angles was established based on Fresnel theory. The analytical expressions of visible light polarization degree in calm and fluctuating water surface were derived respectively, and the polarization degree model of oil spill in reflection space was constructed. The effectiveness of the method and its influence on the polarization distribution of oil spill were analyzed by simulation. A portable turntable was designed to test the polarization characteristics of the experiment, and the visible light polarization detection experiment was carried out. The visible light polarization images of five typical oil spills at different observation azimuth and zenth angles were obtained. The differences in the polarization degrees of different oil species were analyzed, and the correctness of the theoretical model was proved by experiments. The polarization detection experiment of visible light pBRDF was completed, which more intuitively showed the variation law of the polarization characteristics of light reflected by different oil spills in different spatial positions. Using polarization information to distinguish oil species is a useful supplement to the traditional oil spill detection method and has important significance to improve the marine pollution control ability.

The variation characteristics of fecal microbiota in remission UC patients with anxiety and depression.

Background: Ulcerative colitis (UC) patients with relapsed disease are most likely to suffer from anxiety and depression. Increasing data indicates that psychological issues can change the composition of intestinal flora. Thus, we aim to seek the variation of intestinal microbiota composition in remission UC patients with anxiety and depression in Northwest China. Results: In this study, 45 UC patients in remission were enrolled. The incidence of anxiety was 33.3%, and the prevalence of depression was 22.2%. There was no statistical difference in the alpha diversity of fecal microbiota, while beta diversity had a significant difference between the anxiety group and the non-anxiety group and the depression group and the non-depression group. Species composition analysis results showed that the ratio of Bifidobacterium and Lactobacilales significantly decreased. At the same time, the proportion of Escherichia-Shigella and Proteus_mirabilis increased in the anxiety group, and the ratio of Faecalibacterium and Bifidobacterium significantly decreased. In contrast, Escherichia-Shigella increased in the depression group at the gene levels. Conclusion: Anxiety and depression still exist in UC patients even in the remission period. We first identify that the proportion of probiotics decreases while the proportion of pathogens increases in UC patients with anxiety and depression. These findings may provide a new pathophysiological mechanism for the recurrence of disease caused by impaired psychological function and a new method for the treatment strategy of UC patients with psychological issues.

Soil-root interface hydraulic conductance determines responses of photosynthesis to drought in rice and wheat.

Rice (Oryza sativa) production consumes a huge amount of fresh water, and improvement of drought tolerance in rice is important to conserve water resources and minimize yield loss under drought. However, processes to improve drought tolerance in rice have not been fully explored, and a comparative study between rice and wheat (Triticum aestivum) is an effective method to understand the mechanisms determining drought tolerance capacity. In the present study, we applied short-term drought stress to Shanyou 63 rice and Yannong 19 wheat to create a range of water potentials and investigated the responses of gas exchange, plant hydraulic conductance, and root morphological and anatomical traits to soil drought. We found that photosynthesis in rice was more sensitive to drought stress than that in wheat, which was related to differences in the decline of stomatal conductance and plant hydraulic conductance (Kplant). The decline of Kplant under drought was mainly driven by the decrease of soil-root interface hydraulic conductance (Ki) because Ki was more sensitive to drought than root and shoot hydraulic conductance and the soil-root interface contributed to >40% of whole-plant hydraulic resistance in both crops. Root shrinkage in response to drought was more severe in rice than that in wheat, which explains the larger depression of Ki and Kplant under drought stress in rice. We concluded that the decline of Ki drives the depression of Kplant and photosynthesis in both crops, and the plasticity of root morphology and anatomy is important in determining drought tolerance capacity.

Improvement of coated aluminum sheet pBRDF model based on scattering and phase function optimization.

The pBRDF model is able to relate the properties of target materials to the polarization information of incident and reflected light, and is an important basis for obtaining polarization information of targets in space. It is an important basis for obtaining target polarization information and polarization detection of space targets. P-G model is the first strictly pBRDF model officially released, but there are still deficiencies. In this paper, we first analyze the assumption framework of the P-G model, derive the imperfections in the framework through the analysis of the assumption framework, and add scattering and phase function to enhance the existing model. On the basis of the existing P-G model and parameter inversion, the output results of the model are compared with the experimental data through simulation, and the results show that the relative error of the target's linear polarizability is reduced under the improved model, which proves the accuracy and precision of the improved model.

Severity assessment to guide empiric antibiotic therapy for cholangitis in children after Kasai portoenterostomy: a multicenter prospective randomized control trial in China.

BACKGROUND: Cholangitis is common in patients with biliary atresia following Kasai portoenterostomy (KPE). The prompt use of empiric antibiotics is essential due to the lack of identified microorganisms. The authors aimed to validate a severity grading system to guide empiric antibiotic therapy in the management of post-KPE cholangitis. MATERIALS AND METHODS: This multicenter, prospective, randomized, open-label study recruited patients with post-KPE cholangitis and was conducted from January 2018 to December 2019. On admission, patients were categorized into mild, moderate, and severe cholangitis according to the severity grading system. Patients in the mild cholangitis group were randomized to receive cefoperazone sodium tazobactam sodium (CSTS) or meropenem (MEPM). Patients with severe cholangitis were randomized to treatment with MEPM or a combination of MEPM plus immunoglobulin (MEPM+IVIG). Patients with moderate cholangitis received MEPM. RESULTS: The primary endpoint was duration of fever (DOF). Secondary outcomes included blood culture, length of hospital stay, incidence of recurrent cholangitis, jaundice clearance rate, and native liver survival (NLS). For mild cholangitis, DOF, and length of hospital stay were similar between those treated with CSTS or MEPM (all P >0.05). In addition, no significant difference in recurrence rate, jaundice clearance rate, and NLS was observed between patients treated with CSTS and MEPM at 1-month, 3-month, and 6-month follow-up. In patients with moderate cholangitis, the DOF was 36.00 (interquartile range: 24.00-48.00) h. In severe cholangitis, compared with MEPM, MEPM+IVIG decreased DOF and improved liver function by reducing alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and direct bilirubin at 1-month follow-up. However, recurrence rate, jaundice clearance rate, and NLS did not differ significantly between MEPM+IVIG and MEPM at 1-month, 3-month, and 6-month follow-up. CONCLUSIONS: In patients with post-KPE cholangitis, MEPM is not superior to CSTS for the treatment of mild cholangitis. However, MEPM+IVIG treatment was associated with better short-term clinical outcomes in patients with severe cholangitis.

Infrared Image-Enhancement Algorithm for Weak Targets in Complex Backgrounds.

Infrared small-target enhancement in complex contexts is one of the key technologies for infrared search and tracking systems. The effect of enhancement directly determines the reliability of the monitoring equipment. To address the problem of the low signal-to-noise ratio of small infrared moving targets in complex backgrounds and the poor effect of traditional enhancement algorithms, an accurate enhancement method for small infrared moving targets based on two-channel information is proposed. For a single frame, a modified curvature filter is used in the A channel to weaken the background while an improved PM model is used to enhance the target, and a modified band-pass filter is used in the B channel for coarse enhancement followed by a local contrast algorithm for fine enhancement, based on which a weighted superposition algorithm is used to extract a single-frame candidate target. The results of the experimental data analysis prove that the method has a good enhancement effect and robustness for small IR motion target enhancement in complex backgrounds, and it outperforms other advanced algorithms by about 43.7% in ROC.

Compressive space-dimensional dual-coded hyperspectral polarimeter (CSDHP) and interactive design method.

A compressive space-dimensional dual-coded hyperspectral polarimeter (CSDHP) and interactive design method are introduced. A digital micromirror device (DMD), a micro polarizer array detector (MPA), and a prism grating prism (PGP) are combined to achieve single-shot hyperspectral polarization imaging. The longitudinal chromatic aberration (LCA) and spectral smile of the system are both eliminated to guarantee the matching accuracy of DMD and MPA pixels. A 4D data cube with 100 channels and 3 Stocks parameters is reconstructed in the experiment. The feasibility and fidelity are verified from the image and spectral reconstruction evaluations. It is demonstrated that the target material can be distinguished by CSDHP.

Topologically optimized concentric-nanoring metalens with 1 mm diameter, 0.8†NA and 600†nm imaging resolution in the visible.

Metalenses can achieve diffraction-limited focusing via localized phase modification of the incoming light beam. However, the current metalenses face to the restrictions on simultaneously achieving large diameter, large numerical aperture, broad working bandwidth and the structure manufacturability. Herein, we present a kind of metalenses composed of concentric nanorings that can address these restrictions using topology optimization approach. Compared to existing inverse design approaches, the computational cost of our optimization method is greatly reduced for large-size metalenses. With its design flexibility, the achieved metalens can work in the whole visible range with millimeter size and a numerical aperture of 0.8 without involving high-aspect ratio structures and large refractive index materials. Electron-beam resist PMMA with a low refractive index is directly used as the material of the metalens, enabling a much more simplified manufacturing process. Experimental results show that the imaging performance of the fabricated metalens has a resolution better than 600 nm corresponding to the measured FWHM of 745 nm.