TEM-154, identified in Portugal in 2004, associated the substitutions observed in the extended-spectrum β-lactamase (ESBL) TEM-12 and in the inhibitor-resistant penicillinase (IRT) TEM-33. This enzyme exhibited hydrolytic activity against ceftazidime and a low level of resistance to clavulanic acid. Surprisingly, the substitution Met69Leu enhanced the catalytic efficiency of oxyimino β-lactams ...

Using an isogenic system, we have determined the impact that the four promoters known to control bla(TEM) gene expression have on beta-lactamase activity. For both TEM-1 and TEM-30, this activity gradually increased in relation to the presence of promoters P3, Pa/Pb, and P4 upstream of the corresponding gene. Promoter P5, only found upstream of the bla(TEM-1B) gene, was related to the highest e...

Characterization of the structure of surfaces is very important in order to develop a fundamental understanding of the electronic, mechanical and chemical properties of a material. While transmission electron microscopy imaging (TEM) and diffraction (TED) techniques are capable of providing surface structural information at the atomic level, such data would be suspect if obtained under conventi...

The overall outcome of patients with hepatocellular carcinoma (HCC) is still very poor due to its high metastasis and recurrence rate. During metastasis, trans-endothelial migration (TEM) of HCC cells is a key step. Heparanase (HPSE) is an endo-beta-glucuronidase and exerts prometastatic properties for normal and tumor-derived cells. However, it is remains unclear that HPSE contributes to TEM o...

Specimen quality is vital to (scanning) transmission electron microscopy (TEM) investigations. In particular, thin specimens are required to obtain excellent high-resolution TEM images. Conventional focused ion beam (FIB) preparation methods cannot be employed to reliably create high quality specimens much thinner than 20 nm. We have developed a method for in situ target preparation of ultrathi...