The balance control of neutral-point voltage (NPV) is important in the three-level converter. In this paper, problem studied by taking VIENNA circuit as an example. deviation NPV essentially caused mismatch between charging and discharging time two series capacitors current flowing into or out DC side. unbalanced will lead to stress power switches may cause overvoltage damage both also increase...

BACKGROUND Cervical cancer poses a substantial burden in terms of morbidity, mortality, and economic losses, especially in low/middle-income countries. HPV vaccination and/or cervical cancer screening among females may reduce the burden of HPV-related diseases, including cervical cancer. However, limited funds may impede the implementation of population-based programmes. Governmental investment...

OBJECTIVE We systematically reviewed the performance of 2010 WHO immunologic and clinical criteria for predicting virologic failure in HIV-infected patients on antiretroviral therapy (ART). DESIGN Systematic review. METHODS We used Cochrane Collaboration methods. We calculated unweighted sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of immuno...

BACKGROUND The absence of commercially available penicilloyl-polylysine (PPL) for most of the last decade severely hampered the practice of penicillin allergy evaluation because skin testing without PPL is reported to have a poor negative predictive value (NPV). OBJECTIVE To determine the safety and NPV of skin testing without PPL using only penicillin G followed by a 3-dose graded challenge ...

AIM To evaluate the accuracy of the elastography score combined to the strain ratio in the diagnosis of solid pancreatic lesions (SPL). METHODS A total of 172 patients with SPL identified by endoscopic ultrasound were enrolled in the study to evaluate the efficacy of elastography and strain ratio in differentiating malignant from benign lesions. The semi quantitative score of elastography was...

BACKGROUND Paracetamol is a major cause of poisoning. Treatment decisions are predominately based on the dose ingested and a timed blood paracetamol concentration because most patients present to hospital soon after overdose, before hepatotoxicity can be confirmed/excluded using serum alanine transaminase (ALT). Nonetheless, ALT is measured at hospital presentation; we investigated its value in...

OBJECTIVE To evaluate the validity of MRI, in the assessment of the meniscal and cruciate ligamenteous injuries of the knee joint and comparison with arthroscopic findings. METHODS A one year prospective cross-sectional study from January 2006 to January 2007, was performed on 50 patients (32 males & 18 females) with knee injury presenting at the orthopedic unit of AKUH. The patients were ref...

Background We are evaluating the immunogenicity and efficacy of a nanoparticle vaccine (NPV) targeting the tumor marker human aspartyl (asparaginyl) b-hydroxylase (HAAH). HAAH is an embryonic protein that is over-expressed on the surface of cancer cells, is demonstrated to be responsible for cell proliferation, motility and invasiveness, processes which can be inhibited by anti-HAAH antibodies ...