Modeling and simulation of the lateral photovoltage scanning method

The fast, cheap and nondestructive lateral photovoltage scanning (LPS) method detects inhomogeneities in semiconductors crystals. The goal of this paper is to model and simulate this technique for a given doping profile. Our model is based on the semiconductor device equations combined with a nonlinear boundary condition, modelling a volt meter. To validate our 2D and 3D finite volume simulations, we use theory developed by Tauc [21] to derive three analytical predictions which our simulation results corroborate, even for anisotropic 2D and 3D meshes. Our code runs about two orders of magnitudes faster than earlier implementations based on commercial software [15]. It also performs well for small doping concentrations which previously could not be simulated at all due to numerical instabilities. Our simulations provide experimentalists with reference laser powers for which meaningful voltages can still be measured. For higher laser power the screening effect does not allow this anymore

Detecting striations via the lateral photovoltage scanning method without screening effect

The lateral photovoltage scanning method (LPS) detects doping inhomogeneities in semiconductors such as Si, Ge and Si(x)Ge(1-x) in a cheap, fast and nondestructive manner. LPS relies on the bulk photovoltaic effect and thus can detect any physical quantity affecting the band profiles of the sample. LPS finite volume simulation using commercial software suffer from long simulation times and convergence instabilities. We present here an open-source finite volume simulation for a 2D Si sample using the ddfermi simulator. For low injection conditions we show that the LPS voltage is proportional to the doping gradient as previous theory suggested under certain conditions. For higher injection conditions we directly show how the LPS voltage and the doping gradient differ and link the physical effect of lower local resolution to the screening effect. Previously, the loss of local resolution was assumed to be only connected to the enlargement of the excess charge carrier distribution

C-Reactive Protein Triggers Cell Death in Ischemic Cells

C-reactive protein (CRP) is the best-known acute phase protein. In humans, almost every type of inflammation is accompanied by an increase of CRP concentration. Until recently, the only known physiological function of CRP was the marking of cells to initiate their phagocytosis. This triggers the classical complement pathway up to C4, which helps to eliminate pathogens and dead cells. However, vital cells with reduced energy supply are also marked, which is useful in the case of a classical external wound because an important substrate for pathogens is disposed of, but is counterproductive at internal wounds (e.g., heart attack or stroke). This mechanism negatively affects clinical outcomes since it is established that CRP levels correlate with the prognosis of these indications. Here, we summarize what we can learn from a clinical study in which CRP was adsorbed from the bloodstream by CRP-apheresis. Recently, it was shown that CRP can have a direct effect on blood pressure in rabbits. This is interesting in regard to patients with high inflammation, as they often become tachycardic and need catecholamines. These two physiological effects of CRP apparently also occur in COVID-19. Parts of the lung become ischemic due to intra-alveolar edema and hemorrhage and in parallel CRP increases dramatically, hence it is assumed that CRP is also involved in this ischemic condition. It is meanwhile considered that most of the damage in COVID-19 is caused by the immune system. The high amounts of CRP could have an additional influence on blood pressure in severe COVID-19

Small Pulmonary Lesions -A Challenge for Thoracic Surgery?

We analyzed the diagnosis, the potentially associated external and clinical features, and the surgical procedures of small pulmonary lesions, especially hamartomas (in relation to peripheral T1 lung carcinomas and lymphoid hyperplasia) in 103 patients who experienced enucleation or resection of pulmonary hamartomas between March 1, 1995 and December 31, 2000. The causes of surgical intervention, presurgical diagnoses, surgical procedures, location, size, and histological compartments were analyzed, as well as clinical features potentially associated with the tumors (alcohol, asbestos, smoking, and chronic lung diseases). Follow up of patients lasted for 5.5 years at maximum. For comparison, 36 patients with peripheral T1 lung carcinomas are included as well as 50 patients with lymphoid hyperplasia. The sex and age distribution of the patients with hamartomas was comparable to that of patients with lymphoid hyperplasia. About 75% of men and 55% of women were heavy smokers, with an average history of 30 and 17 pack years, respectively. In 84% of patients, the lesions were incidentally detected in chest radiographs, whereas 12% of patients underwent thoracic surgery suspicious for intrapulmonary metastases of known extrapulmonary malignancies. Enucleation was performed in 21%, and wedge resection in 77% of patients. At average, hamartomas were smaller than T1 lung carcinomas, but considerably larger in comparison to lymphoid hyperplasia. No recurrent tumors or additionally detected hamartomas were noted during the follow up, and both surgical procedures (enucleation or wedge resection) were identical in curative treatment. All patients with peripherally localized T1 tumors underwent lobectomy. The 3/5 year survival rate was calculated to 69/52%. Lymphoid hyperplasia is of clinical importance for the estimation of prognosis in patients with metastatic disease, as the number of radiologically suggestive metastatic nodules can often be significantly changed due to this entity. Pulmonary hamartomas are benign lesions that display certain clinical associations with malignant lung carcinomas in respect to external risk factors, and to lymphoid hyperplasia. Both surgical procedures (enucleation or wedge resection) can be performed, giving identical results in respect to treatment. KEY WORDS: pulmonary hamartoma, T1 carcinoma, lymphoid hyperplasia, diagnosis, surgical treatment, prognosis DOMAINS: pulmonology, clinical trials, cancer Kayser et al.: Thoracic Surgery for Pulmonary Lesions TheScientificWorld (2001) 1, 906-913 907 INTRODUCTION Benign tumors of the lung are rare, comprising only about 5% of all intrapulmonary tumors Hamartomas seem not to possess striking clinical or surgical features at a first glance; however, they are interesting lesions in respect to their origin and their biological behavior. It is still in question whether these lesions are of neoplastic origin, or whether they are just chronic inflammatory lesions with some specific abnormalities mimicking a neoplasm Our prospective study was designed primarily to contribute to chromosome analysis of deepfrozen hamartomatous tissue. It soon became clear that clinical features, patient behavior, and prognosis might make an equally important, if not superior, contribution to the increase of knowledge of this rare entity of a benign lung lesion. MATERIAL AND METHODS This prospective study started March 1, 1995 and includes all patients with surgically excised pulmonary hamartomas treated at the Thoraxklinik, Heidelberg, until December 31, 2000. A total of 103 patients were included, of whom 45 underwent a preoperative transbronchial biopsy. A definitive diagnosis could not be obtained by these preoperative investigations, probably due to sampling errors (i.e., missing the lesion). For comparison, a contemporary prospective study including 36 patients with radiologically comparable lesions (staged T1 N0) resulting in histologically proven primary lung carcinomas was included in this analysis. The third cohort comprises 50 patients with peripheral lesions suspicious for malignancy or metastatic growth, and histologically confirmed as lymphoid hyperplasia. The diagnosis in all cohorts is based on Kayser et al.: Thoracic Surgery for Pulmonary Lesions TheScientificWorld (2001) 1, 906-913 surgical specimens only, and includes common HE stains, PAS, and Feulgen stains. The history of the patients was analyzed, with specific attention given to smoking and alcohol consumption. Information about surgical procedures, potential side symptoms, and the presence of other diseases was obtained from the intraoperative reports. The clinical trial was determined January 31, 2001. Survival was evaluated by repeated questionnaires sent to the house physicians. The statistical analysis was performed using a commercially available package (Number Cruncher Statistical System, NCSS, Kaysville, UT). 908 RESULTS A total of 103 patients with hamartomas were included in this study, including 61 men and 42 women

Clinical decision making is improved by BioFire Pneumonia Plus in suspected lower respiratory tract infection after lung transplantation: Results of the prospective DBATE‐IT * study

Background: Lower respiratory tract infections (LRTIs) are a significant cause of morbidity and mortality in lung transplant (LTx) recipients. Timely and precise pathogen detection is vital to successful treatment. Multiplex PCR kits with short turnover times like the BioFire Pneumonia Plus (BFPPp) (manufactured by bioMérieux) may be a valuable addition to conventional tests. Methods: We performed a prospective observational cohort study in 60 LTx recipients with suspected LRTI. All patients received BFPPp testing of bronchoalveolar lavage fluid in addition to conventional tests including microbiological cultures and conventional diagnostics for respiratory viruses. Primary outcome was time‐to‐test‐result; secondary outcomes included time‐to‐clinical‐decision and BFPPp test accuracy compared to conventional tests. Results: BFPPp provided results faster than conventional tests (2.3 h [2–2.8] vs. 23.4 h [21–62], p < 0.001), allowing for faster clinical decisions (2.8 [2.2–44] vs. virology 28.1 h [23.1–70.6] and microbiology 32.6 h [4.6–70.9], both p < 0.001). Based on all available diagnostic modalities, 26 (43%) patients were diagnosed with viral LRTI, nine (15 %) with non‐viral LRTI, and five (8 %) with combined viral and non‐viral LRTI. These diagnoses were established by BFPPp in 92%, 78%, and 100%, respectively. The remaining 20 patients (33 %) received a diagnosis other than LRTI. Preliminary therapies based on BFPPp results were upheld in 90% of cases. There were six treatment modifications based on pathogen‐isolation by conventional testing missed by BFPPp, including three due to fungal pathogens not covered by the BFPPp. Conclusion: BFPPp offered faster test results compared to conventional tests with good concordance. The absence of fungal pathogens from the panel is a potential weakness in a severely immunosuppressed population

Proceedings of the Linux Audio Conference 2018

These proceedings contain all papers presented at the Linux Audio Conference 2018. The conference took place at c-base, Berlin, from June 7th - 10th, 2018 and was organized in cooperation with the Electronic Music Studio at TU Berlin