RESUMEN
To providing evidence-based recommendations for surgery in patients with femoral neck fractures, a meta-analysis was conducted to comprehensively evaluate the effects of cemented and uncemented prostheses on postoperative surgical site wound infection and pain in these patients. Relevant studies on the use of cemented prostheses in femoral neck fractures were retrieved from PubMed, EMBASE, Cochrane Library, Ovid, CNKI, and Wanfang databases from the time of their establishment until March 2023. Two authors independently screened and extracted data from the included and excluded literature according to predetermined criteria. Review Manager 5.4 software was used to perform meta-analyses on the collected data. A total of 27 articles comprising 34 210 patients (24 646 cases in the cemented group and 9564 cases in the uncemented group) were included in the final analysis. The results of the meta-analysis showed that, compared with the uncemented group, cemented prostheses significantly reduced the incidence of surgical site wound infections (odds ratio [OR]: 0.75, 95% confidence interval [CI]: 0.64-0.88, p < 0.001) and relieved surgical site wound pain (standardised mean difference: -0.76, 95% CI: -1.12-0.40, p < 0.001), but did not reduce the incidence of pressure ulcers after surgery (OR: 0.50, 95% CI: 0.20-1.26, p = 0.140). Therefore, existing evidence suggests that the use of cemented prostheses in femoral neck fracture surgery can significantly reduce the incidence of surgical site wound infections and relieve surgical site wound pain, which is worthy of clinical recommendation.
Asunto(s)
Fracturas del Cuello Femoral , Hemiartroplastia , Humanos , Cementos para Huesos/uso terapéutico , Hemiartroplastia/métodos , Dolor , Prótesis e Implantes , Infección de la Herida Quirúrgica/etiología , Infección de la Herida Quirúrgica/cirugía , Fracturas del Cuello Femoral/cirugía , Resultado del TratamientoRESUMEN
Plastic waste can exist naturally for hundreds of thousands of years and harm humans, animals, and the environment. In this study, the energy and exergy performances (absorbed energy, energy efficiency, absorbed exergy, and exergy efficiency) of LDPE (low-density polyethylene) plastic particles assisted by microwave heating based on the experimental data as affected by microwave power, feeding load, and chamber volume were evaluated and analyzed. The results showed that as the microwave power raised from 500 to 900 W, the feeding load changed from 10 to 30 g, and the chamber volume decreased from 200 to 100 ml, (a) the absorbed energy at the heating time of 60 min increased from 19.73 kJ, 5.84 kJ, and 22.71 kJ to 37.69 kJ; (b) the energy efficiency for the whole heating process increased from 1.10%, 0.32%, and 1.26% to 2.09%; (c) the absorbed exergy at the heating time of 60 min increased from 0.308, 0.091, and 0.091 to 0.724 kJ; and (d) the exergy efficiency for the whole heating process increased from 0.017, 0.005, and 0.023 to 0.040%, respectively.
Asunto(s)
Microondas , Polietileno , Polietileno/química , Calefacción , PlásticosRESUMEN
Addressing the mounting environmental challenge of non-degradable polymeric waste, the world grapples with escalating production driven by population growth, modernization, and industrialization. Pyrolysis has emerged as a promising and strategic solution for transforming non-degradable polymeric waste into valuable fuels and other chemical products. This study detailed the high-quality oil recovery from microwave co-pyrolysis of polystyrene (PS) and polypropylene (PP) mixtures. The effects of PS/PP ratio (30:0, 10:20, 15:15, 20:10, and 30:0 g), microwave power (400, 500, 600, 700, and 800 W), and pyrolysis temperature (450, 500, 550, 600, and 650 °C) on oil yield and components were studied, and the synergistic effect, higher heating value (HHV) and thermal efficiency were also detailed. The results revealed that the highest oil yield was 93.84 wt% when PS/PP ratio, microwave power, and pyrolysis temperature were adjusted at 20:10 g, 600 W, and 550 °C, respectively. And the maximum higher heating value and thermal efficiency were 45.67 MJ/kg and 56.53%, respectively. The contents of aromatic hydrocarbons, cyclic hydrocarbons, and oxygenated hydrocarbons varied in the ranges of 1.92-58.88 area%, 10.47-41.76 area%, and 5.06-24.36 area%, respectively. The contents of the major carbon numbers were C8 and C9, and they varied in 2.51-43.66 area% and 7.31-20.09 area%, respectively. The results presented in this study showed that high-quality oil can be recovered from polystyrene and polypropylene plastics by using microwave irradiation, contributing to cleaner ways for plastics recycling.
Asunto(s)
Microondas , Plásticos , Polipropilenos , Poliestirenos , Pirólisis , Polipropilenos/química , Poliestirenos/química , Reciclaje/métodosRESUMEN
The activation of multiple Pattern Recognition Receptors (PRRs) has been demonstrated to trigger inflammatory responses and coordinate the host's adaptive immunity during pathogen infections. The use of PRR agonists as vaccine adjuvants has been reported to synergistically induce specific humoral and cellular immune responses. However, incorporating multiple PRR agonists as adjuvants increases the complexity of vaccine design and manufacturing. In this study, we discovered a polymer that can activate both the Toll-like receptor (TLR) pathway and cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway. The polymer was then conjugated to protein antigens, creating an antigen delivery system for subunit vaccines. Without additional adjuvants, the antigen-polymer conjugates elicited strong antigen-specific humoral and cellular immune responses. Furthermore, the antigen-polymer conjugates, containing the Receptor Binding Domain (RBD) of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Spike Protein or the Monkeypox Antigen M1R as the antigens, were found to induce potent antigen-specific antibodies, neutralizing antibodies, and cytotoxic T cells. Immunization with M1R-polymer also resulted in effective protection in a lethal challenge model. In conclusion, this vaccine delivery platform offers an effective, safe, and simple strategy for inducing antigen-specific immunity against infectious diseases.
Asunto(s)
Adyuvantes Inmunológicos , Polímeros , Adyuvantes Inmunológicos/farmacología , Antígenos , Inmunidad Celular , Vacunas de Subunidad , Anticuerpos Neutralizantes , Inmunidad Innata , Anticuerpos AntiviralesRESUMEN
The minimally invasive injection of bone cement (MIIBC) is an effective way to treat senile osteoporotic spinal fractures (OSF) in clinical practice. However, the intraspinal dura and nerves may be damaged when the puncture needle passes through the pedicle. Therefore, in this protocol, the puncture site was optimized during the surgery, selecting the same 1-2 cm away from the surface projection of the diseased vertebra. The needle was punctured along the lateral cortex of the pedicle from the junction of the pedicle and the vertebral body into the vertebral body. Meanwhile, bone cement was used as a filling material, and the MIIBC was performed by a percutaneous puncture at the external edge of the pedicle under C-arm fluoroscopy. This modified puncture site is far away from the spinal canal as possible, thereby reducing the risk of the puncture needles penetrating the spinal canal and damaging the nerves and dura mater. In conclusion, a modified MIIBC by percutaneous lateral pedicle puncture can effectively relieve pain in elderly patients with OSF.
Asunto(s)
Fracturas Osteoporóticas , Fracturas de la Columna Vertebral , Humanos , Anciano , Cementos para Huesos/uso terapéutico , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fracturas de la Columna Vertebral/cirugía , Punción Espinal , Columna Vertebral , Fracturas Osteoporóticas/cirugía , Resultado del Tratamiento , Estudios RetrospectivosRESUMEN
In-situ and ex-situ catalytic upgrading with HZSM-5 of vapors from microwave-assisted pyrolysis of lignin were studied. The in-situ process produced higher bio-oil and less char than ex-situ process. The gas yield was similar for both processes. The ex-situ process had higher selectivity to aromatics and produced more syngas and less CO2 than the in-situ process. Additional experiments on ex-situ process found that the bio-oil yield and coke deposition decreased while the gas yield increased at higher catalyst-to-lignin ratios and catalytic upgrading temperatures. The increased catalyst-to-lignin ratio from 0 to 0.3 reduced the selectivity of methoxy phenols from 73.7% to 22.6% while increased that of aromatics from 1.1% to 41.4%. The highest selectivity of alkyl phenols (31.9%) was obtained at 0.2 of catalyst-to-lignin ratio. Higher catalytic temperatures favored greater conversion of methoxy phenols to alkyl phenols and aromatics. Appropriate catalyst-to-lignin ratio (0.3) together with higher catalytic temperatures favored syngas formation.
Asunto(s)
Lignina , Microondas , Biocombustibles , Catálisis , Calor , Eliminación de ResiduosRESUMEN
Fast microwave-assisted catalytic co-pyrolysis of lignin and low-density polyethylene (LDPE) with HZSM-5 and MgO was investigated. Effects of pyrolysis temperature, lignin to LDPE ratio, MgO to HZSM-5 ratio, and feedstock to catalyst ratio on the products yields and chemical profiles were examined. 500°C was the optimal co-pyrolysis temperature in terms of the maximum bio-oil yield. The proportion of aromatics increased with increasing LDPE content. In addition, with the addition of LDPE (lignin/LDPE=1/2), methoxyl group in the phenols was completely removed. A synergistic effect was found between lignin and LDPE. The proportion of aromatics increased and alkylated phenols decreased with increasing HZSM-5 to MgO ratio. The bio-oil yield increased with the addition of appropriate amount of catalyst and the proportion of alkylated phenols increased with increasing catalyst to feedstock ratio.
Asunto(s)
Biocombustibles , Lignina/química , Microondas , Polietileno/química , Calor , Eliminación de ResiduosRESUMEN
Effects of process parameters on the yield and chemical profile of bio-oil from fast pyrolysis of lignin and the processes for lignin-derived bio-oil upgrading were reviewed. Various process parameters including pyrolysis temperature, reactor types, lignin characteristics, residence time, and feeding rate were discussed and the optimal parameter conditions for improved bio-oil yield and quality were concluded. In terms of lignin-derived bio-oil upgrading, three routes including pretreatment of lignin, catalytic upgrading, and co-pyrolysis of hydrogen-rich materials have been investigated. Zeolite cracking and hydrodeoxygenation (HDO) treatment are two main methods for catalytic upgrading of lignin-derived bio-oil. Factors affecting zeolite activity and the main zeolite catalytic mechanisms for lignin conversion were analyzed. Noble metal-based catalysts and metal sulfide catalysts are normally used as the HDO catalysts and the conversion mechanisms associated with a series of reactions have been proposed.