Quality Evaluation of New Types of Layered Composites for Flooring Materials

The need, or even the obligation, to take care of the natural environment compels a search for new technological solutions, or for known solutions to be adapted to new applications. The maxim is 'don't harm, but improve the world for future generations'. In the wood industry in particular, given that it is based on a natural raw material, we must look for ecological solutions. Trees grow, but the demand for wood exceeds the volume of tree growth. In industrial manufacturing, one of the ways to make full use of wood is through chipless processing, which occurs during rotary cutting (peeling). In addition, wood is a natural material, each fragment of which has a range of properties. In addition, wood defects in quality manipulation generate a lot of waste. The aim of this study was to analyse the quality effect of the tested layered composites for flooring materials on production application. The practical purpose was to exchange actual sawing-based production for chipless production. The composite base layers were made of pine wood (Pinus L.) veneers with differing quality classes. The samples were subjected to three-point bending tests to calculate the moduli of elasticity and stiffness, which are the most important parameters. Because both analysed parameters describe product quality, the analyses were based on the creation of Shewhart control charts for each parameter. In theory, these control charts are tools for analysing whether the production process is stable and yields predictable results. To have full control over the process, five elements have to be applied: central line (target), two types of control lines (upper and lower) and two types of specification lines (upper and lower). New types of layered composites for flooring may be applied to production once verified using Shewhart control charts. It turns out that it is possible to produce the base layer of the flooring materials using the rotary cutting (peeling) method without having to analyse the quality of the raw material. This is a way to significantly increase the efficiency of production in every element of manufacturing.

Selected Properties of Single and Multi-Layered Particleboards with the Structure Modified by Fibers Implication

One of the ways of potential improvement of the particleboard properties, especially surface quality, can be the incorporation of wood fibers to face layers. This study aimed to evaluate the selected mechanical and physical parameters of single and multi-layered particleboards with the structure modified by the incorporation of various types and amounts of wood fibers. Single, 3- and 5-layers particleboards were produced with two different types of wood fibers added to the face and core layers. The basic mechanical parameters (modulus of rupture, modulus of elasticity, internal bond, surface soundness), as well as density profile and surface roughness, have been investigated. The results have shown that the single-layer panels with fibers did not meet the standard requirements due to unsatisfactory unstable parameters, probably caused by uneven resination. The remaining panels, 3- and 5-layer, met the standard requirements, and, due to fiber incorporation, there is also potential to reduce the panel density, still meeting standard requirements. The addition of fibers from 0% to 75% in face layers leads to an increase in the modulus of rupture from 10.6 N mm^-2 to 15.6 N mm^-2. Depending on the fibers' type, the surface soundness can vary between 0.7 N mm^-2 and 1.2 N mm^-2. Five-layer panels were of similar or even higher parameters, but due to much-complicated technology, it seems unreasonable to develop this type of composite. The novelty of the conducted research is the attempt to modify the structure of particleboards by adding various amounts of two different types of fibers by mixing them with particles or adding them as separate layers and producing panels of different densities.

Near-infrared fluorescent image-guided lymph node dissection compared with locoregional lymphadenectomies in dogs with mast cell tumours

Objectives

Near‐infrared fluorescent imaging has been described for intraoperative mapping of the draining lymph nodes in human cancer and canine oral tumours. The aim of this study was to retrospectively describe the results of lymphadenectomies in dogs with mast cell tumours treated either by standard unguided locoregional lymph node dissection or near‐infrared fluorescent image‐guided lymph node dissection.

Methods

Medical records between 2012 and 2020 were reviewed for dogs that were presented for surgical resection of mast cell tumours with concurrent lymphadenectomy either with (near‐infrared fluorescent image‐guided lymph node dissection) or without near‐infrared fluorescence image guidance (lymph node dissection). The number and location of lymph nodes planned for surgical dissection and actually dissected nodes, presence of metastases and perioperative complications were recorded.

Results

Thirty‐five patients underwent near‐infrared fluorescent image‐guided lymph node dissection, and 43 lymph node dissections. The number of nodes preoperatively planned for resection were 70 and 68, respectively. Fifty‐eight of those (83%) were identified during near‐infrared fluorescent image‐guided lymph node dissection procedures, compared with 50 (74%) during lymph node dissection. near‐infrared fluorescent image‐guided lymph node dissection resulted in resection of additional fluorescent nodes not corresponding to locoregional nodes in 15 of 35 dogs. Using near‐infrared fluorescent image‐guided lymph node dissection, we identified at least one metastatic node in 68% of dogs (24 of 35) compared with 33% (14 of 43) when lymph node dissection was used without imaging. No complications related to near‐infrared fluorescent imaging were reported.

Clinical Significance

The present study suggests that near‐infrared imaging is a promising technique for intraoperative detection of the draining lymph nodes in dogs with mast cell tumours. Further validation of the technique is required to assess if near‐infrared fluorescent imaging can detect the true sentinel lymph node.

Aligning tumor mutational burden (TMB) quantification across diagnostic platforms: phase II of the Friends of Cancer Research TMB Harmonization Project

BACKGROUND

Tumor mutational burden (TMB) measurements aid in identifying patients who are likely to benefit from immunotherapy; however, there is empirical variability across panel assays and factors contributing to this variability have not been comprehensively investigated. Identifying sources of variability can help facilitate comparability across different panel assays, which may aid in broader adoption of panel assays and development of clinical applications.

MATERIALS AND METHODS

Twenty-nine tumor samples and 10 human-derived cell lines were processed and distributed to 16 laboratories; each used their own bioinformatics pipelines to calculate TMB and compare to whole exome results. Additionally, theoretical positive percent agreement (PPA) and negative percent agreement (NPA) of TMB were estimated. The impact of filtering pathogenic and germline variants on TMB estimates was assessed. Calibration curves specific to each panel assay were developed to facilitate translation of panel TMB values to whole exome sequencing (WES) TMB values.

RESULTS

Panel sizes >667 Kb are necessary to maintain adequate PPA and NPA for calling TMB high versus TMB low across the range of cut-offs used in practice. Failure to filter out pathogenic variants when estimating panel TMB resulted in overestimating TMB relative to WES for all assays. Filtering out potential germline variants at >0% population minor allele frequency resulted in the strongest correlation to WES TMB. Application of a calibration approach derived from The Cancer Genome Atlas data, tailored to each panel assay, reduced the spread of panel TMB values around the WES TMB as reflected in lower root mean squared error (RMSE) for 26/29 (90%) of the clinical samples.

CONCLUSIONS

Estimation of TMB varies across different panels, with panel size, gene content, and bioinformatics pipelines contributing to empirical variability. Statistical calibration can achieve more consistent results across panels and allows for comparison of TMB values across various panel assays. To promote reproducibility and comparability across assays, a software tool was developed and made publicly available.

Cardiovascular and pupillary autonomic nervous dysfunction in patients with rheumatoid arthritis - a cross-sectional and longitudinal study

OBJECTIVES

Patients with inflammatory diseases often demonstrate autonomic nervous dysfunction. This study was initiated to investigate cardiovascular (CAD) or pupillary autonomic dysfunction (PAD) in patients with rheumatoid arthritis (RA).

METHODS

Between 1997 and 1998, 33 RA patients were examined for characteristics, and parameters of CAD and PAD. In a longitudinal part of this study, thirty patients have been re-evaluated 8.3 +/- 0.1 yr later (response rate = 91%).

RESULTS

A total of 18 patients (60%) demonstrated either CAD or PAD. The prevalence of CAD was 6/30 (20%) and the prevalence of PAD was 15/30 (50%). Of all cardiovascular tests, the Ewing test demonstrated the worst results (13/30 patients were below the 5th percentile). Similar as in other diseases, several RA patients demonstrated autonomic nervous hyperreflexia with values above the 95 th percentile (relative variation coefficient: 7/30; respiratory sinus arrhythmia measure: 12/30; Valsalva measure: 1/30; Ewing measure: 0/30; latency time of pupillary light reflex: 5/30; maximal pupillary area: 0/30). During the 8-year observation period, 4/30 RA patients died. Non-survivors as compared to survivors had increased heart rate variation in the respiratory arrhythmia test (p= 0.038, hyperreflexia) but largely decreased heart rate variation in the Ewing test (p= 0.009, hyporeflexia). Non-survivors as compared to survivors demonstrated more frequent pupillary autonomic dysfunction (100% vs. 42%, p= 0.035).

CONCLUSION

This study demonstrates that CAD and PAD were frequent in patients with RA. Patients with a poor test result in the Ewing test and PAD might have an increased risk of death. This study in RA patients demonstrates similar results as in patients with diabetes mellitus.

[Acute pseudo-obstruction of the colon (Ogilvie syndrome) after Cesarean section]

In a 27-year-old woman a spontaneous perforation of the bowel developed after cesarean section. The clinical picture, pathophysiological aspects and prophylactic treatment of Ogilvie's syndrome are discussed. This rare but serious complication could have been avoided if the clinical picture and its simple conservative treatment had been known.

[Changes in indications for obstetric peridural anesthesia in our clinic]

In relation to the Swiss average our hospital has had a constant high rate of spontaneous deliveries and a low rate of cesarean sections. On the other hand the rate of obstetrical peridural anesthesia has been increasing significantly since 1986. This is above all related to its more frequent usage in cases of cervical dystocia and intolerable birth pain. Exactly in these indications peridural anesthesia has been very successful. In almost three quarters of the above-mentioned cases a cesarean section can be avoided due to peridural anesthesia.

[Adenosarcoma of the uterus]

A case of a 67-year old woman with adenosarcoma of the uterus is reported. Adenosarcoma is a mixed mesodermal tumour with a low malignant potential. It is characterised by a benign glandular and a malignant stromal component. Adenosarcomas are usually treated by hysterectomy with bilateral salpingo-oophorectomy. Patients with myometrial invasion have an increased risk of recurrence. It may be appropriate, to consider adjuvant chemotherapy or radiation treatment for these patients.

Mütterliches Lungenödem als Narkosekomplikation bei Status nach intravenöser Tokolyse und LungenreIfungsstimulation

Maternal lung edema due to the use of beta-mimetic tocolytic agents is a well-documented complication. The risk increases if several other factors are present: infectious diseases, the use of inhaled anesthetics, EPH gestosis, hydramnios, twin gestation and preexisting cardiovascular disease. The complications induced by beta-mimetic tocolytic agents can be reduced by remembering their side effects and contraindications and restricting fluid intake. During obstetric general anesthesia in patients undergoing tocolysis, the infusion of large amounts of saline, as is widely practised today, is strictly contraindicated.

[Comparative studies of thresholds after implantation of pacemaker leads of different size (author's transl)]

Within the first 14 days after implantation, thresholds were measured at three transvenous pacemaker electrodes with different surface areas. It should be verified, 1. to what extent a correlation existed between maximal threshold increase and electrode surface, 2. how electrode impedance and 3. how the amplitudes of the R-wave voltages developed. The results were: At initial implantation, thresholds were all the lower the smaller the electrode-surface area was. On overage, 9-10 days after implantation the highest thresholds were reached. Thereby, in small surface area electrodes the threshold-increase factor was greater than in larger ones. In all cases the current threshold increase exceeded that one for voltage thresholds. 14 days later, thresholds had dropped again compared to the maximum. And this decrease was depending on the electrode-surface area also. The electrode impedance decreased after implantation to rise later on once more to 80-88% of the original value. The magnitude of the detected R-wave was independent on electrode-surface area. Indeed, using small surface electrodes, signal reductions up to 50% could be found. But 14 days later they reached again 80-95% of the initial amplitude. The key finding there is that when applying small surface-area electrodes and presuming suitable initial thresholds it seems to be possible to connect low-output pacemakers (output 5,4 V and impluse duration 0.25 ms or 4 V at 0.5 ms) to those electrodes. By this reduction of the safety margin, a considerable increase in pacemaker lifetime could be achieved.

[Possibilities of pacing the heart by transmediastinal retrocardially inserted leads (author's transl)]

Based upon experiences with 14 patients the clinical feasibility of transmediastinal retrocardial stimulation of the heart, of the left atrium as well as in one case of the left ventricle, is reported. Principally both can be stimulated by thus introduced pacemaker electodes. Thus on the one hand thresholds and consequently pulse effectivity appear to be a function of the electrode distance from the myocardium, whilst on the other hand the transmediastinal retrocardial thresholds are initially rather high in analogy to the majority taken from the atrial endocardial surface. Nevertheless, the transmediastinal retrocardial technique is possibly applicable for permanent cardiac pacing. However, additional tests about this are still necessary.

[Experiences with 87 permanent atrial electrodes of various types and emplacement technics]

Between March 1972 and December 1975 87 atrial leads were implanted into 85 patients. In 37 cases the transmediastinal retrocardial approach was preferred. In all the other cases the electrodes were introduced transvenous endocardially. The results showed: 1. There exist techniques of atrial lead emplacement which, when applying suitable lead designs, guarantee an anatomic stable positioning either on the left or in the right atrium. Especially the new transvenous J-shaped electrodes of type Medtronic TJL can be positioned easily. The dislodgement ratio of these leads amounts of only 6%. 2. Retro- as well as intracardially very high action voltages were found. The ones sensed by the J-tip-electrodes from the endocardial surface of the right appendage even run up to 5,4 mV. 3. In spite of relatively high initial thresholds, no exit block was seen in any of the 34 cases, in whom atrial leads were inserted transvenous endocardially for permanent atrial pacing.

Special pacemaker catheter techniques. The transmediastinal placement of sensing electrodes

The clinical utilization of atrial programmed pacemakers is limited by the lead systems available for sensing of atrial activity. The endocardial method of lead placement is burdened by a dislodgement rate of up to 30 per cent. Alternatively, the patient must submit to the risks of a thoracotomy. Thirty-one patients have been treated with a transmediastinally, retrocardially positioned atrial detector electrode. In 20 patients (65 per cent) the detector performed as desired with no postimplant revision. In 11 patients (35 per cent) corrective measures were required primarily to correct lead placement; seven of these were corrected under local anesthesia merely by pulling the catheter. Spontaneous lead dislocation occurred in four patients. Four patients (13 per cent) underwent remediastinoscopy due to cranial displacement of the detector electrode with a resulting decrease in atrial potential to less than 0.5 mV. For technical reasons, the lead placements were performed without the benefit of x-ray illumination, with only an ECG check of the posterior atrial wall, and this may account for the relatively high incidence of revision. Transmediastinal placement of sensing electrodes presents a practicable alternative to methods presently used.