Effect of a Cationic Polymer on the Rheology of Cement Pastes Containing Na-Bentonite.

This paper studies how a cationic polymer affects the rheological properties of cement pastes containing Na-bentonite in the presence of a polycarboxylate superplasticizer (PCE), and the fluidity was also investigated. The Herschel-Bulkley model was applied to fit the rheological data of cement pastes at the beginning and after 1 and 3 h. The results show that the cement pastes exhibit a significant increase in fluidity and turn to be a shear-thickening fluid with the addition of the cationic polymer KN, as indicated by the pseudoplastic index n. The yield stress and plastic viscosity of cement pastes containing Na-bentonite obviously decrease with the addition of KN. Statistical analysis was performed to evaluate the impact of KN and PCE on the rheological properties. PCE exhibits a significant influence on both yield stress and plastic viscosity, while KN also exerts an obvious effect on the yield stress for cement pastes containing minor amounts of PCE. The equations for yield stress and plastic viscosity are obtained, which will allow us to predict the yield stress and plastic viscosity of cement pastes containing various contents of PCE and KN.

Study on the Impact of Na/Ca Bentonites on the Dispersion Performance of Conventional and Modified Phosphate Polycarboxylate Superplasticizers in Cement Mortar.

Through molecular structure design, modified polycarboxylate superplasticizers (PCEs) were synthesized via copolymerization using isoprenyl oxy poly(ethylene glycol) ether (TPEG), acrylic acid, and hydroxyethyl methacrylate phosphate. TPEG-PCEs were selected as potential dispersants for Na/Ca-bentonite containing cement mortar. Other two kinds of commercial PCE that were obtained based on methallyl ether (HPEG) and ethylene-glycol monovinyl polyethylene glycol (EPEG) as macromonomers were also applied in the mortar. The effects of the type of bentonite and its dosage, as well as the monomer structure of PCEs and the type of cement, on the dispersion properties of the bentonite-containing mortar were studied. According to the findings, the initial fluidity of the mortar was reduced by about 20 mm when two kinds of bentonite were used. Applying 3% Ca-bentonite resulted in 40% flow loss in the mortar after 1 h. The fluidity of the mortar with Na-bentonite exhibited lower dispersion ability than that with Ca-bentonite when HPEG-PCE and EPEG-PCE were chosen as dispersants. The TPEG-PCE exhibited superior dispersing performance over HPEG-PCE and EPEG-PCE and exerted a retarding effect on cement, being also weakly sensitive to clay content. Thus, TPEG-PCEs with phosphate groups present a viable alternative to conventional PCEs.

Incidence and risk factors associated with surgical site infection after surgically treated hip fractures in older adults: a retrospective cohort study.

BACKGROUND: Surgical site infection (SSI) is one of the most common complications in the traumatic orthopedics field, but remains not adequately studied after hip fractures. AIMS: This study aims to investigate the incidence and risk factors associated with SSI after surgically treated hip fractures in older adults. METHODS: A retrospective cohort study including 2932 older adult patients (1416 with femoral neck fracture and 1516 with intertrochanteric fracture) surgically treated from Jan 2015 to Dec 2019 due to hip fractures was performed. Their data on demographics, injury-related data, surgery-related data, and preoperative laboratory test results were collected from hospitalization medical records. Univariate analyses were used to compare between the patients with and without SSI, and multivariate logistic regression analyses were used to identify the risk factors. RESULTS: A total of 89 patients developed SSI, with an accumulated incidence rate of 3.04% (95%CI 2.41-3.66). Staphylococcus aureus was the most common source of infection. In univariate analysis, 11 items were found to be significant in femoral neck fractures and 5 items were found to be significant in intertrochanteric fracture. In the multivariable logistic regression model, cerebrovascular disease (OR 2.17, 95%CI 1.14-4.15) and hematocrit (HCT) (< Lower limit) (OR 3.46, 95%CI 1.13-10.56) were independent risk factors for SSI in femoral neck fracture. Heart disease (OR 2.13, 95%CI 1.18-3.85) was a risk factor for SSI, while LDH (> 250 U/L) (OR 0.44, 95%CI 0.20-0.95) was a protective factor for SSI in intertrochanteric fracture. DISCUSSION: We observed 89 cases (3.04%) of SSI in 2932 older adult patients with hip fractures in this study. Cerebrovascular disease and lower HCT were two independent risk factors for SSI in femoral neck fracture, whereas heart disease was a risk factor and LDH was a protective factor for SSI in intertrochanteric fracture. CONCLUSIONS: Targeted preoperative management, such as predicting the probability of SSI and taking appropriate measures accordingly is essential and highly regarded. Future multicentric studies with more patients evaluated are expected to better address the risk factors for SSI in older hip fracture patients.

Incidence and risk factors associated with postoperative surgical site infection in younger adults with hip fractures: a case-control study.

PURPOSE: Hip fracture is associated with high morbidity and mortality. The most common complication after hip fracture is surgical site infection (SSI). The goal was to investigate risks associated with SSI in young adults who underwent surgery for hip fractures. METHODS: We conducted a case-control study enrolling 1243 patients from Jan 2015 to Dec 2019. This study investigated the multifaceted factors including demographics, lifestyles, comorbidities, surgical variables, and laboratory test results. Patients were divided into the case group (developed SSI) and control group (not developed SSI). Univariate analyses and multivariate logistic regression analyses were used to identify the risk factors independently associated with SSI. RESULTS: A total of 25 patients including 16 (1.8%) in femoral neck fracture and nine (2.5%) in intertrochanteric fracture developed SSI post-operatively, with an accumulated incidence rate of 2.0%. Among them, four cases (1.6%) were deep SSI and 21 cases (98.4%) were superficial SSI. In most cases, Staphylococcus aureus caused the infections. Diabetes mellitus (OR 4.05, 95%CI: 1.08-15.23, P = 0.038), cerebrovascular disease (OR 3.71, 95%CI: 1.14-12.03, P = 0.029), heart disease (OR 6.23, 95%CI: 1.81-21.48, P = 0.004), and operative time (OR 1.01, 95%CI: 1.01-1.02, P = 0.002) in femoral neck fractures while ALP (> upper limit) (OR 33.39, 95%CI: 2.21-504.89, P = 0.011) and CK (> upper limit) (OR 40.97, 95%CI: 1.70-989.31, P = 0.022) in intertrochanteric fractures were found to be significantly associated with SSI. CONCLUSION: Targeted pre-operative management, depending on the patients' fracture type and risk factors, should be developed to reduce post-operative SSI rates of younger adults with hip fracture.

The second cutaneous anthrax infection diagnosed by metagenomic next-generation sequencing: A case report.

RATIONALE: Anthrax is a severe zoonotic infectious disease caused by Bacillus anthracis. Most reported cases were traditionally diagnosed through culture and microscopy. We reported here the second case of cutaneous anthrax diagnosed by metagenomic next-generation sequencing (mNGS). PATIENT CONCERNS: A 63-year-old man had a history of contact with an unwell sheep, developing local redness and swelling on wrist. The dorsal side of the left hand and forearm, with tension blisters on the back of the left. DIAGNOSIS: B anthracis was detected from culturing and mNGS of tension blisters. INTERVENTIONS: On the second day of admission, the patient was administered 3.2 million units of penicillin every 6 hours, and isolated and closely observed. OUTCOMES: The patient improves and is discharged. LESSONS: Traditional bacterial cultures are time-consuming, while mNGS offers the advantage of accurate, quick, high-throughput, unbiased sequencing of all genetic material in a sample, which is a good technical tool for assisting in the diagnosis of rare pathogen infections.

Rare occurrence of pulmonary coinfection involving Aspergillus fumigatus and Nocardia cyriacigeorgica in immunocompetent patients based on NGS: A case report and literature review.

RATIONALE: In our search on PubMed, we found that reports of co-infections involving Aspergillus fumigatus and Nocardia cyriacigeorgica in the literature are notably scarce. Most cases have been documented in patients with compromised immune systems or underlying pulmonary conditions. In contrast, our patient did not present with any of these risk factors. Furthermore, there have been no recent incidents such as near-drowning or other accidents in the patient history. To the best of our knowledge, this case represents a hitherto unreported clinical scenario. To enhance comprehension, we conducted a comprehensive literature review by compiling a total of 20 case reports (spanning from 1984 to 2023) on co-infections involving Aspergillus and Nocardia species, retrieved from PubMed. PATIENT CONCERNS AND DIAGNOSIS: Chest CT revealed the presence of multiple nodules and clustered high-density shadows in both lungs. Bronchoscopy revealed mucosal congestion and edema in the apical segment of the right upper lobe of the lung, along with the presence of 2 spherical polypoid new organisms. The pathological analysis reported severe chronic inflammation with evidence of Aspergillus within the tissue. Next-Generation Sequencing of bronchoalveolar lavage fluid revealed the presence of reads corresponding to A fumigatus and N cyriacigeorgica. Positive cultures for A fumigatus and the Nocardia genus were yielded by prolonging the incubation of samples in the microbiology laboratory. INTERVENTIONS: Treatment with voriconazole for A fumigatus and sulfamethoxazole-trimethoprim for N cyriacigeorgica infection was given. OUTCOMES: The patient improved and was discharged. After 6 months of telephone follow-up, the patient reported no clinical symptoms, discontinued the medication on his own. LESSONS: A fumigatus and N cyriacigeorgica can manifest as a co-infection in immunocompetent patients. Clinicians should prioritize the significant advantages and value of NGS in detecting rare and mixed pathogens associated with pulmonary infections.

Association of rs2075876 polymorphism of AIRE gene with rheumatoid arthritis risk.

BACKGROUND: Autoimmune regulator (AIRE), a protein encoded by AIRE gene, is a transcriptional factor primarily expressed in medullary thymic epithelial cells (mTECs). It has pivotal role in regulation of human immunology. The mutations of AIRE gene or protein level changes would alter the status of body immunity and therefore onset of diseases. Therefore we aimed at investigating the association of AIRE gene with the risk of rheumatoid arthritis (RA). METHODS: We genotyped 9 SNPs of AIRE gene of recruited 691 patients of rheumatoid arthritis and 800 healthy people in Chinese Han population. RESULTS: Our results indicated that a variant rs2075876 with minor allele A increased the risk of rheumatoid arthritis (pa=0.008, OR=1.991, 95%CI 1.214-2.919). Other two SNPs rs933150 and rs760426 were borderline-associated with rheumatoid arthritis risk (pa=0.055; pa=0.074, respectively). Furthermore, in correlation analysis of SNPs in AIRE gene with clinical characteristics of rheumatoid arthritis, we found the SNP rs2075876 had significant correlation with CRP concentration (pa=0.020). CONCLUSION: We might provide a new inside look into the AIRE gene variants in development and progression of rheumatoid arthritis.