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find Keyword "modification" 36 results
  • Research progress on 3D printing ceramic-polymer composite for bone repair

    Traditional bone repair materials, such as titanium, polyetheretherketone, and calcium phosphate, exhibit limitations, including poor biocompatibility and incongruent mechanical properties. In contrast, ceramic-polymer composite materials combine the robust mechanical strength of ceramics with the flexibility of polymers, resulting in enhanced biocompatibility and mechanical performance. In recent years, researchers worldwide have conducted extensive studies to develop innovative composite materials and manufacturing processes, with the aim of enhancing the bone repair capabilities of implants. This article provides a comprehensive overview of the advancements in ceramic-polymer composite materials, as well as in 3D printing and surface modification techniques for composite materials, with the objective of offering valuable insights to improve and facilitate the clinical application of ceramic-polymer composite materials in the future.

    Release date:2023-10-24 03:04 Export PDF Favorites Scan
  • Relationship Between Histone Modifications and Gastrointestinal Cancer

    Objective To review the relationship between histone modifications and gastrointestinal cancer. Methods Literatures on histone modifications and the relationship between histone modifications and gastrointestinal cancer were collected and reviewed. Results Histone modifications played an important role in the establishment of gene silencing during tumorgenesis. DNA methylation and histone modifications might interact with each other and form a complex network to establish and maintain gene silencing. Restoring gene function silenced by epigenetic changes in cancer had the potential of ‘normalizing’ cancer cells, which was named epigenetic therapy. Epigenetic therapy was very promising in prevention and treatment of gastrointestinal cancer, but many unsolved issues remain which need to be addressed in future studies. Conclusion Histone modifications are associated with the pathogenesis of gastrointestinal cancer. Restoring gene function silenced by epigenetic changes may have a great role in the prevention and treatment of gastrointestinal cancer.

    Release date:2016-09-08 11:49 Export PDF Favorites Scan
  • STUDY ON IMPROVEMENT OF CELL AFFINITY OF POLYMER MATERIALS--MODIFIED POLY(D,L-LACTIDE) BY ANHYDROUS AMMONIA GASEOUS PLASMA

    OBJECTIVE: To modify the surface of poly(D,L-lactide) film by anhydrous ammonia gaseous plasma treatment. METHODS: The changes of contact angles were measured and surface energy were calculated. Mouse 3T3 fibroblast cells were cultured on plasma modified and control poly(D,L-lactide) films. RESULTS: It was found that the hydrophilicity and surface energy of the materials have been increased after plasma treatment. Cell culture results showed that ammonia plasma treatment could promote the cell attachment and cells growth. After 4 days culture, the cells on the plasma treated films were 2-folds quantitatively compared with that of the control films. CONCLUSION: Ammonia plasma treatment can improve the cell affinity to poly(D,L-lactide).

    Release date:2016-09-01 10:21 Export PDF Favorites Scan
  • Complex and diverse RNA modifications and cancer

    RNA can be labeled by more than 170 chemical modifications after transcription, and these chemical modifications are collectively referred to as RNA modifications. It opened a new chapter of epigenetic research and became a major research hotspot in recent years. RNA modification regulates the expression of genes from the transcriptome level by regulating the fate of RNA, thus participating in many biological processes and disease occurrence and development. With the deepening of research, the diversity and complexity of RNA modification, as well as its physiological significance and potential as a therapeutic target, can not be ignored.

    Release date:2022-11-24 03:20 Export PDF Favorites Scan
  • Research on Molecular Biological Characteristics of Proto-oncogene pim-2

    The purpose of this paper is to present the research on the molecular biological characteristics of proto-oncogene pim-2 and to analyze the related mechanism. Proto-oncogene pim-2 was studied and analyzed by the bioinformatics method and technology. With an online server, the chromosomal localization of pim-2 gene was analyzed, and the exon, open reading frame, CpG island and miRNAs complementary fragments and the like were predicted. With bioinformatics software, the physicochemical property of transcription protein of proto-oncogene pim-2 and various modification sites of protein sequence, such as ubiquitination and glycosylation, were predicted, the antigenic index was calculated, and the spatial structural was modeled. The research findings showed that the proto-oncogene pim-2 comprised six exons, the CDS (coding sequence) transcribed a section of peptide chain including 311 amino acids, a gene promoter has a CpG island, and the 3'UTR region contains an miRNA gene. The molecular weight of the Pim-2 protein was 34, 188.47, the isoelectric point was 5.78, the instability index was 45.87, and the extinction coefficient was 279nm. A plurality of covalent modification sites, two ubiquitination sites, four glycosylation sites, an SUMO sumoylation site, a nitrosation site, two palmitoylation sites and sixteen regions with higher antigenic index were distributed in the protein sequence. This research showed that the related regions and modification sites distributed on the sequence of proto-oncogene pim-2 were closely related to the carcinogenic effect thereof.

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  • Progress in biocompatibility and surface modification of nickel titanium shape memory alloys

    Objective To summarize the research progress of biocompatibility and surface modification of nickel titanium shape memory alloys (Ni-Ti SMA). Methods The relative researches about Ni-Ti SMA at home and abroad were reviewed, collated, analyzed, and summarized. Results At present, Ni-Ti SMA as an internal fixation material has been widely used in clinic. It has the following advantages: the super elasticity, the shape memory characteristic, the good wear resistance, and the strong corrosion resistance. It also can effectively avoid the internal fixator rupture caused by stress shielding. After surface modification, the biocompatibility of Ni-Ti SMA has been improved. Conclusion The Ni-Ti SMA is the most promising alloy material for the long-term internal fixator because of its excellent material properties.

    Release date:2018-07-30 05:33 Export PDF Favorites Scan
  • Advances in anti-thrombogenetic strategies of biomaterials

    The presence of thrombus on the surface of blood-contacting biomaterials in clinical practice can significantly impact both the longevity of the biomaterials and the overall survival prognosis of patients. The administration of anticoagulant and antiplatelet medications may heighten the risk of systemic bleeding. Developing biomaterials with anti-thrombogenetic properties and enabling localized anti-thrombosis may offer a solution to these challenges. The development strategies for anti-thrombogenetic biomaterials can be categorized into three main approaches based on the mechanisms of thrombus formation on biomaterial surfaces: altering physical and chemical properties, designing coatings containing or releasing active substances, and promoting endothelialization. However, due to the intricate and interconnected nature of these mechanisms, biomaterials constructed using a single approach may not effectively prevent thrombus formation. The collaborative intervention of various mechanisms can facilitate the development of biomaterials with enhanced blood compatibility.

    Release date:2024-08-21 02:11 Export PDF Favorites Scan
  • Standardization and surgical modification of sleeve gastrectomy with jejunojejunal bypass

    ObjectiveTo analyze why sleeve gastrectomy (SG) with jejunojejunal bypass (SG-JJB), despite being the second most common bariatric procedure in China, has not been recommended in national and international guidelines nor endorsed by expert consensus; to investigate the primary obstacles to its standardization and widespread adoption; and to propose strategies leveraging China’s extensive clinical experience to refine the technique, establish standardized protocols, and address existing challenges, thereby defining its future role in metabolic surgery. MethodsBy systematically reviewing the evolution, current evidence profile, and distinctive features of SG-JJB compared to other SG-Plus procedures, this study aimed to identify constraints hindering its adoption. Concurrently, considering the characteristics of domestic healthcare resources, we explored the feasibility of procedural refinements, key steps for standardization, and solutions to potential challenges, thereby facilitating the optimization and standardization of SG-JJB. ResultsThe three key constraints hindering SG-JJB development were: risks of blind loop syndrome, uncertainty regarding optimal bypass limb length, and limited evidence on long-term efficacy. To address these issues, this study proposed leveraging China’s clinical and multi-center collaboration strengths to: conduct high-quality studies defining the impact of bypass length on outcomes, establish unified diagnostic and monitoring protocols for blind loop syndrome, and systematically collect longitudinal data to evaluate long-term efficacy, thereby informing evidence-based surgical standardization. ConclusionsSG-JJB holds significant potential in Chinese bariatric-metabolic practice, yet its standardization faces persistent challenges. Addressing concerns about blind loop syndrome, defining optimal bypass limb length, and accumulating robust long-term efficacy data are pivotal for advancing SG-JJB standardization and adoption. Leveraging domestic clinical resources through multi-center collaborations, high-quality research, and evidence-based protocol development is the essential pathway to overcoming these barriers, achieving standardized implementation, and securing recognition in authoritative guidelines.

    Release date:2025-09-22 03:59 Export PDF Favorites Scan
  • Clinical study of modified technique to reduce partial necrosis rate of distally pedicled sural flap

    ObjectiveTo investigate whether the technical modifications regarding the risk factors related to the partial necrosis of the distally pedicled sural flap could reduce the partial necrosis rate of the flap.MethodsA clinical data of 254 patients (256 sites) (modified group), who used modified technique to design and cut distally pedicled sural flaps to repair the distal soft tissue defects of the lower limbs between April 2010 and December 2019, was retrospectively analyzed. Between April 2001 and March 2010, 175 patients (179 sites) (control group) who used the traditional method to design and cut the skin flap to repair the distal soft tissue defects of the lower limbs were compared. Various technical modifications were used to lower the top-edge of the flap, reduce the length-width ratio (LWR) of the flap and width of the skin island. There was no significant difference in gender, age, etiology, duration from injury to operation, site and area of the soft tissue defect between groups (P>0.05). The length and width of the skin island and adipofascial pedicle, the total length of the flap and LWR, and the pivot point position were measured and recorded. The top-edge of the flap was determined according to the division of 9 zones in the posterior aspect of the lower limb. The occurrence of partial necrosis of the flap and the success rate of defect reconstruction were observed postoperatively.ResultsThere was no significant difference in the length and width of the skin island, the length of the adipofascial pedicle, total length and LWR of the flap, and pivot point position of the flap between groups (P>0.05). The width of the adipofasical pedicle in modified group was significant higher than that in control group (t=–2.019, P=0.044). The top-edge of 32 flaps (17.88%) in control group and 31 flaps (12.11%) in modified group were located at the 9th zone; the constituent ratio of the LWR more than 5∶1 in modified group (42.58%, 109/256) was higher than that in control group (42.46%, 76/179); and the constituent ratio of width of skin island more than 8 cm in control group (59.78%, 107/179) was higher than that in modified group (57.42%, 147/256). There was no significant difference in the above indicators between groups (P>0.05). In control group, 155 flaps (86.59%) survived completely, 24 flaps (13.41%) exhibited partial necrosis. Among them, 21 wounds healed after symptomatic treatments, 3 cases were amputated. The success rate of defects reconstruction was 98.32% (176/179). In modified group, 241 flaps (94.14%) survived completely, 15 flaps (5.86%) exhibited partial necrosis. Among them, 14 wounds healed after symptomatic treatments, 1 case was amputated. The success rate of defect reconstruction was 99.61% (255/256). The partial necrosis rate in modified group was significantly lower than that in control group (χ2=7.354, P=0.007). There was no significant difference in the success rate between the two groups (P=0.310). All patients in both groups were followed up 1 to 131 months (median, 9.5 months). All wounds in the donor and recipient sites healed well.ConclusionThe partial necrosis rate of the distally based sural flap can be decreased effectively by applying personalized modified technical for specific patients.

    Release date:2021-06-30 03:55 Export PDF Favorites Scan
  • EXPERIMENTAL STUDY ON VASCULAR ENDOTHELIAL GROWTH FACTOR 165 GENE-MODIFIED RAT HAIR FOLLICLE STEM CELLS MEDIATED BY LENTIVIRAL VECTOR

    ObjectiveTo obtain rat hair follicle stem cells (rHFSCs) which can constantly and highly express vascular endothelial growth factor 165 (VEGF165), and to observe the expression of VEGF165 gene in rat HFSCs. MethodsThe cirri skin of 1-week-old Sprague Dawley rat was harvested and digested by using combination of Dispase and type IV collagenases. The bulge was isolated under microscope. The rHFSCs were cultured by tissue block method. After purified by rapid adhering on collagen type IV, the growth curve of different generations rHFSCs was drawn. The cells were identified by immunofluorescence staining and real time quantitative PCR (RT-qPCR) analysis that tested the expression level of correlated genes. Lentivirus of pLV-internal ribosome entry site (IRES)-VEGF165-enhanced green fluorescent protein (EGFP) (experimental group) and pLV-IRES-EGFP empty vector (control group) was packaged by calcium transfected method and the rHFSCs were transfected. The green fluorescent protein expression was observed by inverted fluorescence microscope, and VEGF165 mRNA and protein expressions were detected using RT-PCR and Western blot. ResultsThe rHFSCs which were isolated, cultured, and purified were like the "slabstone", and had strong adhesion ability and colony formation ability. The purified cells were in latent growth phase at 2-3 days; they were in exponential growth phase at 5-6 days. The expressions of cytokeration 15 (CK15), integrin α6, and integrin β1 (markers of HFSCs) were positive by immunocytochemistry. The RT-qPCR analysis showed that CK15, CK19, integrin α6, and integrin β1 expressed highly, but CD34 (a marker of epidermal stem cells) and CK10 (a marker of keratinocyte) expressed lowly. After 14 days, the transfection efficiency was up to 85.76%±1.91%. RT-PCR analysis and Western blot showed that VEGF165 mRNA and protein expressions were positive in experimental group, and were negative in control group. ConclusionThe rHFSCs with high purity and strong proliferation ability can be obtained by using microscope combined with tissue cultivation and rapid cell adhesion on collagen type IV. The rHFSCs with high expression of VEGF165 can be successfully obtained by lentiviral transfection. This method provides good seeding cells for tissue engineering to construct artificial hair follicles, blood vessels, and skins.

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