Chronic infections caused by the pathogenic biofilms on implantable medical devices pose an increasing challenge. To combat long-term biofilm-associated infections, we developed a novel dual-functional polymer coating with antibacterial and antifouling properties. The coating consists of N-vinylpyrrolidone (NVP) and 3-(acrylamido)phenylboronic acid (APBA) copolymer brushes, which bind to curcumin (Cur) as antibacterial molecules through acid-responsive boronate ester bonds. In this surface design, the hydrophilic poly (N-vinylpyrrolidone) (PVP) component improved antifouling performance and effectively prevented bacterial adhesion and aggregation during the initial phases. The poly (3-(acrylamido) phenylboronic acid) (PAPBA, abbreviated PB) component provided binding sites for Cur by forming acid-responsive boronate ester bonds. When fewer bacteria overcame the anti-adhesion barrier and colonized, the surface responded to the decreased microenvironmental pH by breaking the boronate ester bonds and releasing curcumin. This responsive mechanism enabled Cur to interfere with biofilm formation and provide a multilayer anti-biofilm protection system. The coating showed excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, preventing biofilm formation for up to 7 days. The coating also inhibited protein adsorption and platelet adhesion significantly. This coating also exhibited high biocompatibility with animal erythrocytes and pre-osteoblasts. This research offers a promising approach for developing novel smart anti-biofilm coating materials.
Anti-Bacterial Agents , Biofilms , Curcumin , Escherichia coli , Polymers , Staphylococcus aureus , Biofilms/drug effects , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Escherichia coli/drug effects , Staphylococcus aureus/drug effects , Polymers/chemistry , Polymers/pharmacology , Curcumin/pharmacology , Curcumin/chemistry , Bacterial Adhesion/drug effects , Coated Materials, Biocompatible/chemistry , Coated Materials, Biocompatible/pharmacology , Animals , Microbial Sensitivity Tests , Boronic Acids/chemistry , Boronic Acids/pharmacology , Surface Properties , Humans , Biofouling/prevention & control , Hydrogen-Ion Concentration
Background: There has been limited literature synthesizing the therapeutic effects of surgical procedures for fungal periprosthetic joint infection (PJI) following hip arthroplasty. The authors' current study aims to comprehensively review and analyze those relevant literature, and carefully make recommendations for future clinical practices. Methods: Our current study was carried out in accordance with the PRISMA 2020 statement. Studies regarding the surgical management of fungal PJI following hip arthroplasty were collected via a thorough search of PubMed, Embase and Google scholar databases. The search was lastly performed in March 2023. Non-English language, reviews, articles with duplicated data, and articles without clear information about the type of fungal pathogens and treatment options were excluded. The authors evaluated their systematic review compliance by using AMSTAR 2 criteria and fell in moderate quality. Clinical outcomes of different surgical procedures were evaluated, and a binary logistic regression model was used to identify the risks associated with treatment failure. Data analyses were performed using the SPSS version 19.0. Results: A total of 33 articles encompassing 80 patients with fungal PJI following hip arthroplasty were identified. Candida albicans was the most frequently isolated fungus (56.3%, 45/80). The overall treatment success was achieved in 71.1% (54/76) of the reported cases. Univariate analysis showed that the differences of success rate were not significant between publication periods, genders, ages, specimen collection methods, and fungal pathogens. Treatment success rate was 47.4% (9/19) in fungal PJI cases with bacterial co-infection, significantly lower than those without [vs. 79.0% (45/57), P=0.017]. The pooled success rate for surgical debridement, spacer implantation, resection arthroplasty, one-stage revision, and two-stage revision was 50.0% (4/8), 42.9% (3/7), 55.0% (11/20), 86.7% (13/15), and 88.5% (23/26), respectively, with significant differences between them (P=0.009). A binary logistic regression model showed that bacterial co-infection and surgical option were the two significant risk factors associated with treatment failure for fungal PJI following hip arthroplasty. Discussion: Regarding the surgical treatment of fungal PJI following hip arthroplasty, patients with bacterial co-infection, and those treated with surgical procedures such as debridement, spacer implantation, and resection arthroplasty should be aware of the higher risks of failure. Nonetheless, future multiple-centre cohort studies are required to establish the optimal treatment.
Dialogic reading promotes early language and literacy development, but high-quality interactions may be inaccessible to disadvantaged children. This study examined whether a chatbot could deliver dialogic reading support comparable to a human partner for Chinese kindergarteners. Using a 2 × 2 factorial design, 148 children (83 girls; Mage = 70.07 months, SD = 7.64) from less resourced families in Beijing, China, were randomly assigned to one of four conditions: dialogic or non-dialogic reading techniques with either a chatbot or human partner. The chatbot provided comparable dialogic support to the human partner, enhancing story comprehension and word learning. Critically, the chatbot's effect on story comprehension was moderated by children's language proficiency rather than age or reading ability. This demonstrates that chatbots can facilitate dialogic reading and highlights the importance of considering children's language skills when implementing chatbot dialogic interventions.
Comprehension , Reading , Child , Female , Humans , Child, Preschool , Vocabulary , Verbal Learning , China
Photonic generation of microwave waveforms is currently an interesting topic due to the advantages of large bandwidth and immunity to electromagnetic interference. In this paper, a photonic microwave waveform generator with tunable waveforms and repetition rates is proposed and experimentally demonstrated. A continuous-wave (CW) light is phase modulated by a local oscillator (LO) signal to generate optical sidebands. By locating the phase modulator (PM) in a Sagnac loop, we can control the intensity and phase of the carrier of the phase modulated signal. Then a compact tunable dispersion compensation module is used to introduce phase shifts to the optical sidebands. Thanks to the flexible controlling of the optical signal, the generation of microwave waveforms with tunable shapes and repetition rates can be realized. In the demonstration experiment, full-duty-cycle triangular and square waveforms with repetition rates of 5 and 10 GHz (bandwidths of 15 and 30 GHz) are successfully generated, respectively. The bandwidths are expected to be improved to above 120 GHz if larger-bandwidth measurement instruments are used. In addition to the flexible tunability, the proposed scheme also features the advantages of easy implementation and free from bias drift.
