Erratum: Capek et al. On the Weldability of Thick P355NL1 Pressure Vessel Steel Plates Using Laser Welding. Materials 2021, 14, 131.

The authors would like to correct the sentence in the "Materials and Methods" section of their article [...].

On the Weldability of Thick P355NL1 Pressure Vessel Steel Plates Using Laser Welding.

Pipeline transport uses millions of kilometers of pipes worldwide to transport liquid or gas over long distances to the point of consumption. High demands are placed, especially on the transport of hazardous substances under high pressure (gas, oil, etc.). Mostly seamless steel pipes of various diameters are used, but their production is expensive. The use of laser-welded pipes could significantly reduce the cost of building new pipelines. However, sufficient mechanical properties need to be ensured for welded pipes to meet stringent requirements. Therefore, laser-welded 10 mm thick pressure vessel steel plates were subjected to various mechanical tests, including high-cycle fatigue tests. Furthermore, the microstructural parameters and the state of residual stresses were determined using X-ray and neutron diffraction, which could affect fatigue life, too. The critical areas for possible crack initialization, especially in and near the heat-affected zone, were found using different tests. The presented results outline the promising application potential of laser welding for the production of pipes for high-pressure pipelines.

The changes of peripheral nerve microstructure after surgical manipulation--experiment on rat model.

The aim of our study was to describe histopathology of the peripheral nerve after its circular release followed by embedding in different environs. We operated on 18 male rats divided into 3 groups. In the first group right femoral nerve was surgically released. In the second group the nerve was enveloped by the subcutaneous fat flap. In the third one the nerve was wrapped up by the skeletal muscle. Six weeks later the animals were killed by exsanguination. The femoral nerve, in the first group, did not show any pathological changes. In the second group 3 animals appeared normal or nearly normal, nevertheless in 3 of them perineural fibrosis and axonal degeneration were observed. Histological reaction in the third group disclosed dispersed axonal injury. Our experiments using rat model imitate situation in humans. The results obtained will help us in making meaningful decision when performing peripheral nerve injury.

Prognostic impact of hemoglobin level prior to radiotherapy on survival in patients with glioblastoma.

PURPOSE: To evaluate prognostic factors in patients with glioblastoma treated with postoperative or primary radiotherapy. PATIENTS AND METHODS: From 1989 to 2000, a total of 100 patients underwent irradiation as part of their initial treatment for glioblastoma. All patients had undergone surgery or biopsy followed by conventional external-beam radiotherapy. 85 patients who received the planned dose of irradiation (60 Gy in 30 fractions) were analyzed for the influence of prognostic factors. 73/85 (86%) of patients were given postoperative irradiation, while 12/85 (14%) of patients were primarily treated with radiotherapy after biopsy. RESULTS: The median overall survival was 10.1 months (range, 3.7-49.8 months), the 1- and 2-year survival rates were 41% and 5%, respectively. Univariate analysis revealed age < or = 55 years (p < 0.001), pre-radiotherapy hemoglobin (Hb) level > 12 g/dl (p = 0.009), and pre-radiotherapy dose of dexamethasone < or = 2 mg/day (p = 0.005) to be associated with prolonged survival. At multivariate analysis, younger age (p < 0.001), higher Hb level (p = 0.002), lower dose of dexamethasone (p = 0.026), and a hemispheric tumor location (p = 0.019) were identified as independent prognostic factors for longer survival. The median survival for patients with an Hb level > 12 g/dl was 12.1 months compared to 7.9 months for those with a lower Hb level. Contingency-table statistics showed no significant differences for the two Hb groups in the distribution of other prognostic factors. CONCLUSION: The results indicate that lower Hb level prior to radiotherapy for glioblastoma can adversely influence prognosis. This finding deserves further evaluation.

The influence of treatment with somatostatin analogues on morphology, proliferative and apoptotic activity in GH-secreting pituitary adenomas.

With the aim to investigate histopathological changes and proliferative and apoptotic activity in GH-secreting adenomas we compared 14 cases pre-treated with somatostatin analogues before surgery with a reference group of 17 un-pretreated ones. Besides routine histology, immunocytochemical detection of all pituitary hormones, caspase-3, cytokeratin-18, and "M30 antigen", its apoptosis-specific fragment was performed. Proliferation activity of the tumour was determined by the Ki-67 antigen expression. In treated adenomas more prominent regressive changes were found accompanied by compensatory increase in perivascular fibrosis. The Ki-67 labelling index was lower in treated group (mean 2.5, median 1.6 per mille) than in untreated patients (mean 9.4, median 5.0 per mille). The difference was statistically significant (p=0.049 using Mann-Whitney Rank Sum Test). Apoptosis was detected in only 2 of the 14 pre-treated adenomas, and it was more frequent (9/17) and more prominent in the untreated group.

The role of apoptosis in pituitary adenomas in the field of conventionally used therapeutic approaches.

The aim of the study was to investigate the mechanism of action of somatostatin analogues (SSA), ionizing radiation, and their combination on pituitary adenoma cells with special emphasis on proliferative and apoptotic activity. In the 14 GH-secreting adenomas pretreated with SSA before surgery, more prominent regressive changes were found accompanied by compensatory increase in perivascular fibrosis than in the reference group of 17 unpretreated adenomas. The proliferative Ki-67 labeling index was significantly lower in the treated group (median 1.6 per 1000) than in the untreated patients (median 5.0 per 1000). Apoptosis was detected in only 2 of the 14 pretreated adenomas, and it was more frequent (9/17) and more prominent in the untreated group. In cell lines, the SSA had minimal antiproliferative effect, and they were unable to induce apoptosis. Ionizing radiation at doses of 5-20 Gy induced apoptosis in the corticotroph cell line AtT20 with no cell-cycle block. In the somatotroph GH3 cell line, the early (premitotic) apoptosis was detectable using only a high dose of 200 Gy; after irradiation with doses of 20-50 Gy, apoptosis appeared with the latency of 48-72 hours, and was preceded by cell-cycle arrest in the G(2)/M phase. The treatment with somatostatin-14 during irradiation increased the percentage of apoptotic cells in culture 10 days after irradiation (11% versus 3% using 20 Gy).