Effects of waste oyster shell replacing fine aggregate on the dynamic mechanical characteristics of concrete.

Waste oyster shells (WOS) have the potential to serve as a construction material, offering a sustainable alternative to traditional fine aggregates in the production of WOS concrete. This can play a critical role in reducing environmental issues resulting from the overexploitation of river sand and the haphazard disposal of WOS. Although existing research has predominantly focused on understanding the static mechanical characteristics of concrete when WOS is employed, the dynamic mechanical properties have still received less attention. To understand the impact of WOS as a substitute for fine aggregates on the dynamic mechanical properties of concrete, a series of tests employing Split Hopkinson Pressure Bar (SHPB) were carried out. The findings demonstrate that the peak stress and elastic modulus increase as the WOS substitution ratio (Sr) increases from 0 to 20% but exhibit an exponential decline as Sr increases from 20 to 100%. This response can be explained by the joint effects of the pore-filling effect caused by WOS sand and the increasing air content caused by WOS sand. As Sr increases from 0 to 20%, the pore-filling mechanism becomes predominant as the water absorption rate decreases slightly from 4.31 to 3.83%. However, for Sr increasing from 20 to 100%, the negative influence of the air content becomes the primary contributing factor, where the water absorption rate increases from 3.83 to 14.68%. Furthermore, under the same impact pressure, the concrete with Sr = 20% absorbed the most energy, providing the best dynamic mechanical performance. These findings highlight the potential use of WOS in concrete for improving its dynamic characteristics, promoting both sustainable construction and enhancing the material properties in impact-resistant structures.

Long-Acting Lipoglycopeptides for the Treatment of Bone and Joint Infections.

Background: The long-acting lipoglycopeptides dalbavancin and oritavancin possess excellent microbiologic activity against gram-positive bacteria and provide prolonged tissue exposure at sites of infection. Moreover, these antibiotics are well tolerated and do not require therapeutic drug monitoring. Methods: Pharmacokinetic/pharmacodynamic experiments ascertained that one to two doses of these long-acting agents can provide an extended period (≥6 weeks) of antimicrobial therapy. Results: Clinical studies subsequently found that microbiologic and clinical response rates with these agents were comparable to standard antibiotic agents used in the treatment of bone and joint infections. In addition, pharmacoeconomic analyses have discovered cost savings with the use of these antimicrobial agents in the treatment of serious deep-seated bacterial infections. Conclusions: Thus, these long-acting lipoglycopeptides offer potential for cost-effective outpatient parenteral antibiotic therapy of difficult to treat infections, such as osteomyelitis.

Invasive, aggressive mastoid bone eumycetoma: a treatment challenge.

Mycetoma is a chronic granulomatous disease that significant affects the subcutaneous tissue and deep structures. Mycetoma is caused by certain fungi (eumycetoma) or higher bacteria (actinomycetoma). The clinical presentation is variable and depends on the causative agent. For proper treatment and patient management, an accurate diagnosis of the species is mandatory. The disease mainly involves the extremities and it is rarely seen in the head and neck or other sites. In this communication, we present an interesting case of both invasive and aggressive mastoid bone eumycetoma caused by Madurella mycetomatis. Such cases are defied by complex challenges in finding effective surgical and medical treatments when the patient does not respond to both prolonged and different antifungal therapies.

Secondary pulmonary alveolar proteinosis in GATA-2 deficiency (MonoMAC syndrome).

We present here a case of a 29-year-old woman with a medical history of GATA-2 deficiency, who was under treatment for Mycobacterium avium intracellulare pneumonia. She presented with worsening dyspnoea with cough and fever. It was initially thought she had pneumonia but she was later diagnosed with Pulmonary Alveolar Proteinosis (PAP).

Immunohistochemical expression of PAX-8 in Sudanese patients diagnosed with malignant female reproductive tract tumors.

OBJECTIVES: Paired box protein-8 (PAX-8) immunohistochemical expression can be used as a diagnostic marker for epithelial cells tumors. This study aimed at investigating the immunohistochemical expression of PAX-8 among Sudanese females diagnosed with cervical, endometrial, and ovarian cancers between December 2017 and May 2019 by studying their Formalin-fixed paraffin embedded blocks. RESULTS: Sixty patients diagnosed with female reproductive tract cancers were included who aged 58.7 ± 6.9 years (range, 43-71). Cervix was the most common cancer site in 51/60 (85%) patients. Regarding cancer stage, there was 17 (28%) and 14 (23%) of the study population had stage 3B and 2B, respectively. The histopathological diagnosis included 20 (44%), 13 (29%), and 12 (27%) poorly, moderately, and well differentiated cervical squamous cell carcinoma (SCC) as well as 11 (73%), 2 (13%), 1 (7%), and 1 (7%) endometrial adenocarcinoma, metastatic adenocarcinoma, endocervical adenocarcinoma, and ovarian mucinous cyst adenocarcinoma, respectively. PAX-8 was positively expressed in 9 endometrial adenocarcinoma, 1 endocervical adenocarcinoma and 1 ovarian mucinous cyst adenocarcinoma, 2 poorly, and 1 moderately differentiated SCC. All patients diagnosed with well differentiated SCC and metastatic adenocarcinoma showed no expression of PAX-8. A statistically significant was seen for PAX-8 expression and the different histopathological diagnosis, P value < 0.001.

The disabling consequences of Mycetoma.

Mycetoma is a neglected tropical disease endemic in tropical and subtropical countries, particularly Sudan. The disease is characterised by the triad of painless subcutaneous mass, multiple sinuses and discharge that contain grains. It is a chronic, debilitating disease most commonly affecting the feet or hands and leads to substantial morbidity, loss of function and even amputation. It predominantly affects poor, rural populations and patients typically present late with advanced disease and complications. In this descriptive cross-sectional study, we characterise the disabling consequences of mycetoma. The study included 300 patients; 228 (76%) male and 72 (24%) female with confirmed mycetoma seen at the Mycetoma Research Centre, University of Khartoum, Sudan in the period May 2016 and January 2017. The study design was based upon the International Classification of Functioning, Disability and Health, examining the impact of mycetoma on eight life domains. Our major finding is that mycetoma is a significantly disabling disease. Over 60% of the study population (181 patients) had moderate impairment or difficulty in at least one domain variable. The important disability was mobility impairment and walking difficulty that was reported in 119 patients (39.7%). There was significant pain associated with mycetoma lesions in 103 patients (34%), challenging the traditional view of mycetoma as a painless disease. The economic burden was also found to be substantial, with 126 patients (46.7%) reporting barriers to their ability to sustain themselves. This is the first study evaluating the disabling consequences of mycetoma and shows clear areas for intervention and further research. Options for mitigating social and economic impacts include routine integration of analgesia and physiotherapy into treatment protocols, and adapting educational provision and working practices based on disability assessment. Our data show that mycetoma is a public health issue with direct implications on quality of life.

Acute Bacterial Meningitis in Qatar: A Hospital-Based Study from 2009 to 2013.

BACKGROUND AND OBJECTIVES: Bacterial meningitis is a common medical condition in Qatar. The aim of this study was to describe the clinical characteristics of bacterial meningitis, the frequency of each pathogen, and its sensitivity to antibiotics and risk factors for death. PATIENTS AND METHODS: This retrospective study was conducted at Hamad General Hospital between January 1, 2009, and December 31, 2013. RESULTS: We identified 117 episodes of acute bacterial meningitis in 110 patients. Their mean age was 26.4 ± 22.3 years (range: 2-74) and 81 (69.2%) of them were male patients. Fifty-nine episodes (50.4%) were community-acquired infection and fever was the most frequent symptom (94%), whereas neurosurgery is the most common underlying condition. Coagulase-negative staphylococci were the most common causative agent, of which 95% were oxacillin-resistant, while 63.3% of Acinetobacter spp. showed resistance to meropenem. The in-hospital mortality was 14 (12%). Only the presence of underlying diseases, hypotension, and inappropriate treatment were found to be independent predictors of mortality. CONCLUSION: Acute bacterial meningitis predominantly affected adults and coagulase-negative staphylococci species were the common causative agent in Qatar with majority of infections occurring nosocomially. More than 90% of all implicated coagulase-negative staphylococci strains were oxacillin-resistant.