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This paper aims to investigate and document the effects of copper-clad laminate (CCL) inorganic filler on the hole performance in printed circuit boards drilling process.

Drilling of brittle laminates can result in hole cracking, layer-to-layer delamination and drill-bit wear and tool breakage. Adding large amount of fillers not only shortens the life of the drilling tool but also affects the drilling properties significantly regarding hole quality. This paper introduces the influence of filler content, type, hardness, particle size and the compounding method in the manufacture of the CCL on the drilling performance.

The filler content, filler type, hardness of filler, particle size of filler and the compounding method used for the filler have a great influence on the drilling properties of CCL. The higher the filler content, the larger the particle size and the more the hardness of the filler, the worse the drilling properties. The combination of hard particles like silica with softer particles can improve the drilling performance of CCL.

The paper describes what affects the drilling performance of CCL and how this knowledge can be used to design CCL with good drilling performance.

Bacterial vaginosis (BV) is quite common and linked with serious public health issues such as premature delivery and spread of sexually transmitted infections. The study aims to identify different genital mycoplasmas (GM) in high vaginal swabs (HVS) from adult females in Bahrain.

In total, 401 HVS were collected and cultured on MYCOFAST^® RevolutioN 2 test for identification and antibiotic susceptibility. Polymerase chain reaction (PCR) was performed for detection of Mycoplasma genitalium (Mg), Mycoplasma hominis (Mh) and Ureaplasma species. DNA-probe based detection for Gardnerella, Candida and Trichomonas was performed by BD Affirm Assay. Representative PCR amplicons were sequenced by Sanger sequencing.

In PCR, Ureaplasma sp. was the most common GM, followed by Mg and Mh; the prevalence being 21.2, 5.2 and 1.5%, respectively. On the contrary, 10.7% samples showed positivity for Ureaplasma urealyticum (Uu) and 1.7% for Mh in MYCOFAST^® RevolutioN 2. The concordance rates between MYCOFAST^® RevolutioN 2 and PCR for Mh and Ureaplasma sp. were 97.7 and 84%, respectively. Considering PCR as gold standard, sensitivity, specificity, positive predictive value, and negative predictive value of MYCOFAST^® RevolutioN 2 were 33.3, 98.8, 28.6, 98.9 and 37.7, 96.5, 74.4, 85.2% for Mh and Ureaplasma sp., respectively. The Uu and Mh isolates showed antibiotic-resistance ranging from 53%–58% and 71%–86%, respectively.

The prevalence of Ureaplasma sp. was high. Significant co-occurrence of GM was noticed with BV. MYCOFAST^® RevolutioN 2 had lower detection-rate than PCR, so a combination is suggested for wider diagnostic coverage.

The research reflects on status of prevalence of GM in adult females in Bahrain, and their co-occurrence with bacterial vaginosis. Diagnostic approach with combination of tests is suggested for wider coverage. The research has epidemiologic, diagnostic, and therapeutic implications.

This is the first report from the Kingdom of Bahrain reflecting on burden of GM from this geographic location. The diagnostic efficacy of MYCOFAST^® RevolutionN 2 test and polymerase chain reaction was evaluated for GM detection.