Macromolecular bioscience最新文献_第6页

Mechanically Stable and Biocompatible Polymer Brush Coated Dental Materials with Lubricious and Antifouling Properties 具有润滑和防污特性的机械稳定且生物兼容的聚合物刷涂牙科材料

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-11-15 DOI: 10.1002/mabi.202470026

Rong Mu, Ling Yang, Xinyue Wang, Binrui Yang, Jia Li, Aijun Wang, Guorui Zhang, Chufeng Sun, Yang Wu, Bo Yu, Bin Li

引用次数: 0

In Situ Forming Injectable Gelatin-Based Antibacterial Bioadhesives for Preventing Postoperative Leakage and Abdominal Adhesions. 用于防止术后渗漏和腹部粘连的原位成型明胶基抗菌生物粘合剂。

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-11-08 DOI: 10.1002/mabi.202400372

Shibo Hu, Wanglin Duan, Xianzhen Jin, Chaowei Li, Bin Zhu, Yurong Chen, Ye Zhu, Peihai Cao, Zepeng Dong, Luyao Feng, Junhui Yu, Xuejun Sun, Zeshaan Yahaya Haji Mahmood, Yazhong Bu, Baoji Du, Jianbao Zheng

{"title":"In Situ Forming Injectable Gelatin-Based Antibacterial Bioadhesives for Preventing Postoperative Leakage and Abdominal Adhesions.","authors":"Shibo Hu, Wanglin Duan, Xianzhen Jin, Chaowei Li, Bin Zhu, Yurong Chen, Ye Zhu, Peihai Cao, Zepeng Dong, Luyao Feng, Junhui Yu, Xuejun Sun, Zeshaan Yahaya Haji Mahmood, Yazhong Bu, Baoji Du, Jianbao Zheng","doi":"10.1002/mabi.202400372","DOIUrl":"https://doi.org/10.1002/mabi.202400372","url":null,"abstract":"Postoperative anastomotic leakage (AL) and abdominal adhesions are two major complications after intestinal surgery, with an incidence of 2-25% for AL and 93% for adhesion. Until now, there is no method addressing AL and abdominal adhesions simultaneously. In this work, Bi-PEG-succinimidyl succinate (PEG-NHS), amino-gelatin (Agel) is combined with cefoperazone-sulbactam (SCF) to prepare a multifunctional bioadhesive (SCF/SEAgel) for the postoperative leakage and adhesion prevention. SCF/SEAgel possesses a great sealing capability for tissue, with a bursting pressure of 54 kPa. The loaded SCF endows the systems with good antibacterial properties. The in vivo antiadhesion experiments show that SCF/SEAgel possesses better anti-adhesion properties than the commercially used sodium hyaluronate gel. In the cecum leakage model, the SCF/SEAgel effectively seals the leakage with a survival rate of 100%, superior to commercial products (Sainaoning). Meanwhile, it significantly reduces tissue adhesion. Finally, the laparoscopic surgery with dogs shows that the SCF/SEAgel can be injected through minimally invasive surgery, demonstrating its ease of use. Combined with its great biocompatibility, SCF/SEAgel is very promising in intestinal surgery.","PeriodicalId":18103,"journal":{"name":"Macromolecular bioscience","volume":" ","pages":"e2400372"},"PeriodicalIF":4.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142604961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Polyamino Acid Based Zwitterionic Coating can Inhibit Coagulation and Inflammation Through Anti-Fouling and Restoring Microenvironment 聚氨基酸型聚合离子涂层可通过防污和恢复微环境来抑制凝血和炎症。

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-11-08 DOI: 10.1002/mabi.202400336

Zehong Xiang, Honghong Chen, Feng Wu, Haobo Pan

{"title":"Polyamino Acid Based Zwitterionic Coating can Inhibit Coagulation and Inflammation Through Anti-Fouling and Restoring Microenvironment","authors":"Zehong Xiang, Honghong Chen, Feng Wu, Haobo Pan","doi":"10.1002/mabi.202400336","DOIUrl":"10.1002/mabi.202400336","url":null,"abstract":"Protein adhesion and thrombosis formation caused by limited surface properties pose great challenges to biomedical implants. Although various hydrophilic coating or drug release coatings are reported, the single coating cannot cope with cases under the condition of complex physiological environment, which causes the coating effect is limited. In this study, a polyamino acid-derived zwitterionic coating is constructed to eliminate reactive oxygen species (ROS) in the microenvironment. It is demonstrated that the coating has excellent hydrophilicity, stability, and lubricity, and can obviously prevent protein adhesion. At the same time, the coating can eliminate hydrogen peroxide and maintain the stability of the microenvironment. The in vivo and in vitro experiments show that the coating has good biocompatibility, and inhibits thrombus. Amino acid zwitterion coating prevents protein deposition, alleviates the inflammatory process, inhibit of thrombosis, reduces the risk of implantable medical devices, and prolongs their service time. Hence, the work paves a new way to develop amino acid based zwitterionic polymer coating that can reduce the implant complications.","PeriodicalId":18103,"journal":{"name":"Macromolecular bioscience","volume":"25 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142604963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Surface Coating of ZIF-8 Nanoparticles with Polyacrylic Acid: A Facile Approach to Enhance Chemical Stability for Biomedical Applications 用聚丙烯酸对 ZIF-8 纳米粒子进行表面涂层：增强生物医学应用中化学稳定性的简便方法。

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-11-03 DOI: 10.1002/mabi.202400382

Setsuko Yamane, Abdul Hadi Bin Yusri, Po-yu Chen, André J. van der Vlies, Amira Ben Mabrouk, Isabelle Fetzer, Urara Hasegawa

{"title":"Surface Coating of ZIF-8 Nanoparticles with Polyacrylic Acid: A Facile Approach to Enhance Chemical Stability for Biomedical Applications","authors":"Setsuko Yamane, Abdul Hadi Bin Yusri, Po-yu Chen, André J. van der Vlies, Amira Ben Mabrouk, Isabelle Fetzer, Urara Hasegawa","doi":"10.1002/mabi.202400382","DOIUrl":"10.1002/mabi.202400382","url":null,"abstract":"Nanoparticles of zeolitic imidazole framework-8 (ZIF-8 NPs), which are the subclass of metal-organic frameworks consisting of Zn ion and 2-methylimidazole, have been identified as promising drug carriers since their large microporous structure is suited for encapsulating hydrophobic drug molecules. However, one of the limitations of ZIF-8 NPs is their low stability in physiological solutions, especially in the presence of water and phosphate anions. These molecules can interact with the coordinatively unsaturated Zn sites at the external surface to induce the degradation of ZIF-8 NPs. In this study, herein a facile approach is reported to enhance the chemical stability of ZIF-8 NPs by surface coating with polyacrylic acid (PAA). The PAA-coated ZIF-8 (PAA-ZIF-8) NPs are prepared by mixing ZIF-8 NPs and PAA in water. PAA coating inhibits the degradation of ZIF-8 NPs in water as well as phosphate-buffered saline over 6 days, which seems to be due to the coordination of carboxyl groups of PAA to the reactive Zn sites. Furthermore, the PAA-ZIF-8 NPs loaded with the anticancer drug doxorubicin (Dox) show cytotoxicity in human colon cancer cells. These results clearly show the feasibility of the PAA coating approach to improve the chemical stability of ZIF-8 NPs without impairing their drug delivery capability.","PeriodicalId":18103,"journal":{"name":"Macromolecular bioscience","volume":"25 2","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mabi.202400382","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Application of Biomaterial-Based Spinal Cord Tissue Engineering. 基于生物材料的脊髓组织工程的应用。

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-10-29 DOI: 10.1002/mabi.202400444

Liang Ma, Zhen Zhang, Yulei Mu, Bangheng Liu, Huiqun Zhou, Dong-An Wang

{"title":"The Application of Biomaterial-Based Spinal Cord Tissue Engineering.","authors":"Liang Ma, Zhen Zhang, Yulei Mu, Bangheng Liu, Huiqun Zhou, Dong-An Wang","doi":"10.1002/mabi.202400444","DOIUrl":"https://doi.org/10.1002/mabi.202400444","url":null,"abstract":"Advancements in biomaterial-based spinal cord tissue engineering technology have profoundly influenced regenerative medicine, providing innovative solutions for both spinal cord organoid development and engineered spinal cord injury (SCI) repair. In spinal cord organoids, biomaterials offer a supportive microenvironment that mimics the natural extracellular matrix, facilitating cell differentiation and organization and advancing the understanding of spinal cord development and pathophysiology. Furthermore, biomaterials are essential in constructing engineered spinal cords for SCI repair. The incorporation of biomaterials with growth factors, fabrication of ordered scaffold structures, and artificial spinal cord assemblies are critical insights for SCI to ensure structural integrity, enhance cell viability, and promote neural regeneration in transplantation. In summary, this review summarizes the contribution of biomaterials to the spinal cord organoids progression and discusses strategies for biomaterial-based spinal cord engineering in SCI therapy. These achievements underscore the transformative potential of biomaterials to improve treatment options for SCI and accelerate future clinical applications.","PeriodicalId":18103,"journal":{"name":"Macromolecular bioscience","volume":" ","pages":"e2400444"},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biocompatible Zn-Phthalocyanine/Gelatin Nanofiber Membrane for Antibacterial Therapy 用于抗菌治疗的生物相容性锌-酞菁/明胶纳米纤维膜

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-10-29 DOI: 10.1002/mabi.202400334

Romina Clementi, Maria Angela Vargas, Mariana Cid, Nancy Salvatierra, Romina Comín, Tomas Tempesti

{"title":"Biocompatible Zn-Phthalocyanine/Gelatin Nanofiber Membrane for Antibacterial Therapy","authors":"Romina Clementi, Maria Angela Vargas, Mariana Cid, Nancy Salvatierra, Romina Comín, Tomas Tempesti","doi":"10.1002/mabi.202400334","DOIUrl":"10.1002/mabi.202400334","url":null,"abstract":"In this study, the fabrication and characterization of Zn-phthalocyanine/gelatin nanofibrous membranes is reported using the electrospinning technique. The membranes exhibit a homogeneous distribution of Zn-phthalocyanine within the gelatin matrix, maintaining the structural integrity and photosensitizing properties of the phthalocyanine. Scanning electron microscopy revealed that the electrospun fibers possess diameters ranging results as 100–300, 200–700, and 300–800 nm for Gel, ZnPc/Gel 1, and ZnPc/Gel 2, respectively. The addition of ZnPc does not decrease the hydrophilicity of the Gel membrane. The nanofibrous membranes showed good cytocompatibility, as indicated by the high viability of Vero cells exposed to membrane extracts. Furthermore, these composites supported cell adhesion and proliferation on their surfaces. The two Zn-phthalocyanine/gelatin nanofiber formulations exhibited significant antimicrobial activity toward Escherichia Coli (E. Coli) and Staphylococcus Aureus (S. Aureus) under visible light illumination, achieving reductions of 3.4 log10 and 3.6 log10 CFU mL−1 for E. coli, and 3.9 log10 and 4.1 log10 CFU mL−1 for S. aureus. These results demonstrate the potential of Zn-phthalocyanine/gelatin nanofibrous membranes as effective agents in antibacterial photodynamic therapy, providing a promising solution to control bacterial infections and antibiotic resistance.","PeriodicalId":18103,"journal":{"name":"Macromolecular bioscience","volume":"25 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142522275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Applications of Diels–Alder Chemistry in Biomaterials and Drug Delivery Diels-Alder 化学在生物材料和药物输送中的应用。

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-10-26 DOI: 10.1002/mabi.202400274

Tyus J. Yeingst, Angelica M. Helton, Daniel J. Hayes

引用次数: 0

Manufacturing Radially Aligned PCL Nanofibers Reinforced With Sulfated Levan and Evaluation of its Biological Activity for Healing Tympanic Membrane Perforations 用硫酸化莱凡制造径向排列的 PCL 纳米纤维并评估其愈合鼓膜穿孔的生物活性。

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-10-26 DOI: 10.1002/mabi.202400291

Busra Akgul, Cansu Gulcan, Selay Tornaci, Merve Erginer, Ebru Toksoy Oner, Emrah Sefik Abamor, Serap Acar, Adil M. Allahverdiyev

{"title":"Manufacturing Radially Aligned PCL Nanofibers Reinforced With Sulfated Levan and Evaluation of its Biological Activity for Healing Tympanic Membrane Perforations","authors":"Busra Akgul, Cansu Gulcan, Selay Tornaci, Merve Erginer, Ebru Toksoy Oner, Emrah Sefik Abamor, Serap Acar, Adil M. Allahverdiyev","doi":"10.1002/mabi.202400291","DOIUrl":"10.1002/mabi.202400291","url":null,"abstract":"The main objective of this study is to construct radially aligned PCL nanofibers reinforced with levan polymer and investigate their in vitro biological activities thoroughly. First Halomonas levan (HL) polysaccharide is hydrolyzed (hHL) and subjected to sulfation to attain Sulfated hydrolyzed Halomonas levan (ShHL)-based material indicating heparin mimetic properties. Then, optimization studies are carried out to produce coaxially generated radially aligned Poly(caprolactone) (PCL) -ShHL nanofibers via electrospinning. The obtained nanofibers are characterized with Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray (FESEM-EDX) analysis, and mechanical, contact angle measurement, biodegradability, and swelling tests as well. Afterward, cytotoxicity of artificial tympanic membranes is analyzed by MTT (3-(4,5-Dimethylthiazol-2-yl) -2,5 Diphenyltetrazolium Bromide) test, and their impacts on cell proliferation, cellular adhesion, wound healing processes are explored. Furthermore, an additional FESEM imaging is performed to manifest the interactions between fibroblasts and nanofibers. According to analytical measurements it is detected that PCL-ShHL nanofibers i) are smaller in fiber diameter, ii) are more biodegradable, iii) are more hydrophilic, and iv) demonstrated superior mechanical properties compared to PCL nanofibers. Moreover, it is also deciphered that PCL-ShHL nanofibers strongly elevated cellular adhesion, proliferation, and in vitro wound healing features compared to PCL nanofibers. According to obtained results it is assumed that newly synthetized levan and PCL mediated nanofibers are very encouraging for healing tympanic membrane perforations.","PeriodicalId":18103,"journal":{"name":"Macromolecular bioscience","volume":"25 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11727819/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring Morphological and Molecular Properties of Different Adipose Cell Models: Monolayer, Spheroids, Gellan Gum-Based Hydrogels, and Explants. 探索不同脂肪细胞模型的形态和分子特性：单层、球形、结冷胶水凝胶和外植体

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-10-25 DOI: 10.1002/mabi.202400320

Franziska B Albrecht, Ann-Kathrin Schick, Annemarie Klatt, Freia F Schmidt, Svenja Nellinger, Petra J Kluger

{"title":"Exploring Morphological and Molecular Properties of Different Adipose Cell Models: Monolayer, Spheroids, Gellan Gum-Based Hydrogels, and Explants.","authors":"Franziska B Albrecht, Ann-Kathrin Schick, Annemarie Klatt, Freia F Schmidt, Svenja Nellinger, Petra J Kluger","doi":"10.1002/mabi.202400320","DOIUrl":"https://doi.org/10.1002/mabi.202400320","url":null,"abstract":"White adipose tissue (WAT) plays a crucial role in energy homeostasis and secretes numerous adipokines with far-reaching effects. WAT is linked to diseases such as diabetes, cardiovascular disease, and cancer. There is a high demand for suitable in vitro models to study diseases and tissue metabolism. Most of these models are covered by 2D-monolayer cultures. This study aims to evaluate the performance of different WAT models to better derive potential applications. The stability of adipocyte characteristics in spheroids and two 3D gellan gum hydrogels with ex situ lobules and 2D-monolayer culture is analyzed. First, the differentiation to achieve adipocyte-like characteristics is determined. Second, to evaluate the maintenance of differentiated ASC-based models, an adipocyte-based model, and explants over 3 weeks, viability, intracellular lipid content, perilipin A expression, adipokine, and gene expression are analyzed. Several advantages are supported using each of the models. Including, but not limited to, the strong differentiation in 2D-monolayers, the self-assembling within spheroids, the long-term stability of the stem cell-containing hydrogels, and the mature phenotype within adipocyte-containing hydrogels and the lobules. This study highlights the advantages of 3D models due to their more in vivo-like behavior and provides an overview of the different adipose cell models.","PeriodicalId":18103,"journal":{"name":"Macromolecular bioscience","volume":" ","pages":"e2400320"},"PeriodicalIF":4.4,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Viscosity Characteristics of Ideal Lubricants to Reduce Stress on Intestinal Mucosa During Balloon-Assisted Enteroscopy 理想润滑剂的粘度特性，以减轻球囊辅助肠镜检查过程中对肠道粘膜的压力。

IF 4.4 4区医学

Macromolecular bioscience Pub Date : 2024-10-22 DOI: 10.1002/mabi.202400285

Katsuma Yamauchi, Ryohei Hirose, Hiroshi Ikegaya, Hiroki Mukai, Hajime Miyazaki, Naoto Watanabe, Takuma Yoshida, Risa Bandou, Ken Inoue, Osamu Dohi, Naohisa Yoshida, Takaaki Nakaya, Yoshito Itoh

{"title":"Viscosity Characteristics of Ideal Lubricants to Reduce Stress on Intestinal Mucosa During Balloon-Assisted Enteroscopy","authors":"Katsuma Yamauchi, Ryohei Hirose, Hiroshi Ikegaya, Hiroki Mukai, Hajime Miyazaki, Naoto Watanabe, Takuma Yoshida, Risa Bandou, Ken Inoue, Osamu Dohi, Naohisa Yoshida, Takaaki Nakaya, Yoshito Itoh","doi":"10.1002/mabi.202400285","DOIUrl":"10.1002/mabi.202400285","url":null,"abstract":"Balloon-assisted enteroscopy (BAE) is highly invasive and carries a higher risk of complications such as pain and perforation during enteroscope insertion. Applying lubricants to the small intestinal mucosa and reducing the dynamic friction coefficient (DFC) between the small intestinal mucosa and endoscopic shaft (ES) (or overtube (OT)) can minimize the invasiveness of BAE. However, the ideal viscosity characteristics of these lubricants remain unknown. In this study, a model is developed to measure the DFC using human small intestines from forensic autopsies and determine the ideal viscosity of low-friction lubricants that exhibit a minimal DFC, thus reducing the pressure on the intestinal lining during the procedure. The results reveal that the DFC is strongly correlated to the lubricant's viscosity rather than its chemical composition. Low-friction lubricants with viscosities within 0.20–0.32 and 0.35–0.58 Pa·s (at shear rates of 10 s−1) for the OT and ES, respectively, can significantly reduce the DFC, yielding optimal results. These findings highlight the role of viscosity in minimizing the friction between the equipment and small intestinal mucosa. The ideal low-friction lubricants satisfying the aforementioned viscosity ranges can minimize the invasiveness of BAE by decreasing the friction between the equipment and intestinal lining.","PeriodicalId":18103,"journal":{"name":"Macromolecular bioscience","volume":"24 12","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0