Publications by authors named "Martin Koch"

187 Publications

Broadband wide-angle terahertz antenna based on the application of transformation optics to a Luneburg lens.

Sci Rep 2021 Mar 4;11(1):5230. Epub 2021 Mar 4.

School of Engineering, Brown University, Providence, RI, 02912, USA.

The design of antennas for terahertz systems remains a significant challenge. These antennas must provide very high gain to overcome significant free-space path loss, which limits their ability to broadcast or receive a beam over a wide angular range. To circumvent this limitation, here we describe a new device concept, based on the application of quasi-conformal transformation optics to the traditional Luneburg lens. This device offers the possibility for wide-angle beam steering and beam reception over a broad bandwidth, scalable to any frequency band in the THz range.
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http://dx.doi.org/10.1038/s41598-021-84849-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7970861PMC
March 2021

The performance of a fertility tracking device.

Eur J Contracept Reprod Health Care 2021 Apr 8;26(2):111-118. Epub 2021 Feb 8.

Gynaecological Clinic, Ansbach Hospital, Ansbach, Germany.

Objective: Fertility tracking devices offer women direct-to-user information about their fertility. The objective of this study is to understand how a fertility tracking device algorithm adjusts to changes of the individual menstrual cycle and under different conditions.

Methods: A retrospective analysis was conducted on a cohort of women who were using the device between January 2004 and November 2014. Available temperature and menstruation inputs were processed through the Daysy 1.0.7 firmware to determine fertility outputs. Sensitivity analyses on temperature noise, skipped measurements, and various characteristics were conducted.

Results: A cohort of 5328 women from Germany and Switzerland contributed 107,020 cycles. Mean age of the sample was 30.77 [SD 5.1] years, with a BMI of 22.07 kg/m^2 [SD 2.4]. The mean cycle length reported was 29.54 [SD 3.0] days. The majority of women were using the device 80-100% of the time during the cycle (53.1%). For this subset of women, the fertility device identified on average 41.4% [SD 6.4] possibly fertile (red) days, 42.4% [SD 8.7] infertile (green) days and 15.9% [SD 7.3] yellow days. The number of infertile (green) days decreases proportionally to the number of measured days, whereas the number of undefined (yellow) days increases.

Conclusion: Overall, these results showed that the fertility tracker algorithm was able to distinguish biphasic cycles and provide personalised fertility statuses for users based on daily basal body temperature readings and menstruation data. We identified a direct linear relationship between the number of measurements and output of the fertility tracker.
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http://dx.doi.org/10.1080/13625187.2021.1871599DOI Listing
April 2021

Human papilloma virus genotype distribution in women with premalignant or malignant lesions of the uterine cervix.

Arch Gynecol Obstet 2021 Feb 4. Epub 2021 Feb 4.

Department of Gynecology and Obstetrics, Comprehensive Cancer Center Erlangen-European Metropolitan Area of Nuremberg (CCC ER-EMN), Erlangen University Hospital, Universitätsstrasse 21-23, 91054, Erlangen, Germany.

Objective: Cervical cancer is caused by persistent infection with high-risk human papillomavirus (hrHPV). Cytology-based national screening programs have reduced the incidence and mortality of cervical cancer. Different hrHPV subtypes have different carcinogenic potentials. This study evaluated the distribution of different types of hrHPV relative to age in cervical cancer and its precursor lesions.

Methods: HPV testing was performed between November 2018 and February 2020 using the Abbott RealTime high-risk HPV assay on an Abbott m2000sp instrument. This assay separately detects HPV-16, HPV-18, and a pool of 12 additional hrHPV types (HPV-31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -66, and -68).

Results: The study included 652 women with HPV samples and biopsies of the cervix or histology samples obtained during surgery. In all, 30.8% (95% CI, 27.3-34.6%) were HPV-negative. Among HPV-positive women, HPV-16, HPV-18, and "HPV other" types were found in 33.5, 4.4, and 49.4%, respectively. Cervical intraepithelial neoplasia (CIN) 3/high-grade squamous intraepithelial lesions (HSILs) in women ≤ 34 years were positive for HPV-16 in 54.5% of cases and in those ≥ 35 years in 45.4% of cases. Among women with cervical cancer, 75.8% were infected with HPV-16 or had coinfection with HPV-16 and "HPV other".

Conclusions: HPV-16 is the most common type of hrHPV in HSIL + lesions. It is more common in women diagnosed with CIN 3/HSIL who are aged ≤ 35 and is decreasing with age. Therefore, women age ≥ 35 with persistent infection with this type of hrHPV need careful surveillance, as they are at high risk of progression to cervical cancer.
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http://dx.doi.org/10.1007/s00404-021-05986-zDOI Listing
February 2021

Lensless digital holographic microscopy as an efficient method to monitor enzymatic plastic degradation.

Mar Pollut Bull 2021 Feb 11;163:111950. Epub 2021 Jan 11.

SYNMIKRO Research Center, Hans-Meerwein-Str. 6, 35043 Marburg, Germany; Laboratory for Cell Biology, Department of Biology, University of Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany. Electronic address:

A big challenge of the 21st century is to cope with the huge amounts of plastic waste on Earth. Especially the oceans are heavily polluted with plastics. To counteract this issue, biological (enzymatic) plastic decomposition is increasingly gaining attention. Recently it was shown that polyethylene terephthalate (PET) can be degraded in a saltwater-based environment using bacterial PETase produced by a marine diatom. At moderate temperatures, plastic biodegradation is slow and requires sensitive methods for detection, at least at initial stages. However, conventional methods for verifying the plastic degradation are either complex, expensive, time-consuming or they interfere with the degradation process. Here, we adapt lensless digital holographic microscopy (LDHM) as a new application for efficiently monitoring enzymatic degradation of a PET glycol copolymer (PETG). LDHM is a cost-effective, compact and sensitive optical method. We demonstrate enzymatic PETG degradation over a time course of 43 days employing numerical analysis of LDHM images.
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http://dx.doi.org/10.1016/j.marpolbul.2020.111950DOI Listing
February 2021

Recognition of coal from other minerals in powder form using terahertz spectroscopy.

Opt Express 2020 Oct;28(21):30943-30951

Currently a significant fraction of the world energy is still produced from the combustion of mineral coal. The extraction of coal from mines is a relatively complex and dangerous activity that still requires the intervention of human miners, and therefore in order to minimize risks, automation of the coal mining process is desirable. An aspect that is still under investigation is potential techniques that can recognize on-line if the mineral being extracted from the mine is coal or if it is the surrounding rock. In this contribution we present the proof of concept of a method that has potential for recognition of the extraction debris from mining based on their terahertz transmission.
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http://dx.doi.org/10.1364/OE.405438DOI Listing
October 2020

Repeatability of material parameter extraction of liquids from transmission terahertz time-domain measurements.

Opt Express 2020 Sep;28(19):28178-28189

Recently, many research groups worldwide have reported on the THz properties of liquids. Often these parameters, i.e., refractive index and absorption coefficient, are determined using liquids in cuvettes and terahertz time-domain spectroscopy. Here, we discuss the measurement process and determine how repeatable such measurements and the data extraction are using rapeseed oil as a sample. We address system stability, cuvette positioning, cuvette cleaning and cuvette assembly as sources affecting the repeatability. The results show that system stability and cuvette assembly are the most prominent factors limiting the repeatability of the THz measurements. These findings suggest that a single cuvette with precise positioning and thorough cleaning of the cuvette delivers the best discrimination among different liquid samples. Furthermore, when using a single cuvette and measurement systems of similar stability, the repeatability calculated based on several consecutive measurements is a good estimate to tell whether samples can be discriminated.
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http://dx.doi.org/10.1364/OE.403159DOI Listing
September 2020

Monitoring Intracranial Cerebral Hemorrhage Using Multicontrast Real-Time Magnetic Particle Imaging.

ACS Nano 2020 10 25;14(10):13913-13923. Epub 2020 Sep 25.

Institute for Biomedical Imaging, Hamburg University of Technology, Hamburg, DE 21073, Germany.

Magnetic particle imaging (MPI) is an innovative radiation-free tomographic imaging method providing excellent temporal resolution, contrast, sensitivity, and safety. Mobile human MPI prototypes suitable for continuous bedside monitoring of whole-brain perfusion have been developed. However, for the clinical translation of MPI, a crucial gap in knowledge still remains: while MPI can visualize the reduction in blood flow and tissue perfusion in cerebral ischemia, it is unclear whether MPI works in intracranial hemorrhage. Our objective was to investigate the capability of MPI to detect intracranial hemorrhage in a murine model. Intracranial hemorrhage was induced through the injection of collagenase into the striatum of C57BL/6 mice. After the intravenous infusion of a long-circulating MPI-tailored tracer consisting of superparamagnetic iron oxides, we detected the intracranial hemorrhage in less than 3 min and could monitor hematoma expansion in real time. Multicontrast MPI can distinguish tracers based on their physical characteristics, core size, temperature, and viscosity. By employing multicontrast MPI, we were able to differentiate areas of liquid and coagulated blood within the hematoma, which could provide valuable information in surgical decision making. Multicontrast MPI also enabled simultaneous imaging of hemorrhage and cerebral perfusion, which is essential in the care of critically ill patients with increased intracranial pressure. We conclude that MPI can be used for real-time diagnosis of intracranial hemorrhage. This work is an essential step toward achieving the clinical translation of MPI for point-of-care monitoring of different stroke subtypes.
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http://dx.doi.org/10.1021/acsnano.0c06326DOI Listing
October 2020

Collaborative advance care planning in advanced cancer patients: col-ACP -study - study protocol of a randomised controlled trial.

BMC Palliat Care 2020 Aug 24;19(1):134. Epub 2020 Aug 24.

Department of Clinical Psychology and Psychotherapy, Philipps-University Marburg, Gutenbergstraße 18, 35032, Marburg, Germany.

Background: To assure patient-centred end-of-life care, palliative interventions need to account for patients' preferences. Advance care planning (ACP) is a structured approach that allows patients, relatives and physicians to discuss end-of-life decisions. Although ACP can improve several patient related outcomes, the implementation of ACP remains difficult. The col-ACP-study (collaborative advance care planning) will investigate a new ACP procedure (col-ACP-intervention (German: Hand-in-Hand Intervention)) in palliative cancer patients and their relatives that addresses individual values and targets barriers of communication before an ACP process.

Methods: In a randomised controlled trial, 270 cancer patients without curative treatment options and their relatives will receive either 1) col-ACP 2) a supportive intervention (active control group) or 3) standard medical care (TAU). col-ACP comprises two steps: a) addressing various barriers of patients and relatives that discourage them from discussing end-of-life issues followed by b) a regular, structured ACP procedure. The col-ACP-intervention consists of 6 sessions. Primary endpoint is the patients' quality of life 16 weeks after randomisation. Secondary endpoints include measurements of distress; depression; communication barriers; caregivers' quality of life; existence of ACP or advance directives; the consistence of end of life care; and others. Patients will be followed up for 13 months. Multivariate analyses will be carried out. Qualitative evaluation of the intervention will be conducted.

Discussion: Augmentation of a regular ACP program by a structured psycho-oncological intervention is an innovative approach to target barriers of communication about end-of-life issues. Study findings will help to understand the value of such a combined intervention in palliative care.

Trial Registration: ClinicalTrials.gov Identifier: NCT03387436 (Date of registration: 01/02/2018, retrospectively registered.
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http://dx.doi.org/10.1186/s12904-020-00629-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7445911PMC
August 2020

Analysis of ancient ceramics using terahertz imaging and photogrammetry.

Opt Express 2020 Jul;28(15):22255-22263

Imaging using terahertz time-domain spectroscopy is a valuable diagnostic tool for material inspection. However, in the case of samples with inhomogeneous shape and composition, the reliable extraction of spatially varying dielectric properties can be very challenging. Here, we demonstrate a new approach which combines THz-TDS with photogrammetric reconstruction. We show that this technique can be used to estimate the local refractive index of samples with a complex geometry. We employ this method to study samples of ancient pottery, and demonstrate that THz techniques can provide a valuable new tool for this branch of archaeological science.
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http://dx.doi.org/10.1364/OE.399336DOI Listing
July 2020

Terahertz beam steering using active diffraction grating fabricated by 3D printing.

Opt Express 2020 Jul;28(15):21737-21744

In this article, we propose variable-period diffraction gratings for terahertz frequencies. The design, fabrication and characterization of such devices are presented. Our measurements show the possibility to actively shift of the deflection angle for each frequency using this device. We also demonstrated that, when driven by a speaker, these variable gratings can be used for active beam steering with potential application in terahertz communications.
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http://dx.doi.org/10.1364/OE.399376DOI Listing
July 2020

Exploring the potential of photoluminescence spectroscopy in combination with Nile Red staining for microplastic detection.

Mar Pollut Bull 2020 Oct 17;159:111475. Epub 2020 Jul 17.

Department of Physics and Material Sciences Center, Philipps-University of Marburg, Germany.

The significant amount of plastic litter in the form of microplastics (size <5 mm) is garnering attention owing to its potential threat to marine life. Reliable, cost- and time-efficient analysis methods for monitoring microplastic abundance globally are still missing. Several studies proposed a fast detection method by binding the solvatochromic dye Nile Red on the surface of microplastics and using fluorescence microscopy for their detection. All the staining approaches reported so far differ in terms of Nile Red concentration, solvents, and staining procedure. Here, we compare the staining protocols published prior to 2019 and propose an optimized staining protocol. Furthermore, we explore the potential of Nile Red staining in combination with photoluminescence spectroscopy to identify the polymer type and to distinguish plastics from non-plastics.
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http://dx.doi.org/10.1016/j.marpolbul.2020.111475DOI Listing
October 2020

Association of genomic variants at the human leukocyte antigen locus with cervical cancer risk, HPV status and gene expression levels.

Int J Cancer 2020 11 10;147(9):2458-2468. Epub 2020 Jul 10.

Department of Gynaecology, Comprehensive Cancer Center, Hannover Medical School, Hannover, Germany.

The human leukocyte antigen (HLA) locus on chromosome 6 has been reported to be associated with cervical cancer. We investigated two independent single-nucleotide polymorphisms in a large case-control series of cervical dysplasia and carcinoma that has been newly established by the German Cervigen Consortium, comprising a total of 2481 cases and 1556 healthy females. We find significant associations for both variants, rs9272117 at HLA-DQA1 and rs2844511 at MICA and HCP5, with cervical disease. Both variants showed evidence of association with invasive cervical cancer (rs9272117: OR 0.89, 95% CI 0.79-0.99, P = .036; rs2844511: OR 1.17, 95% CI 1.04-1.31, P = .008) and with high-grade dysplasia (rs9272117: OR 0.78, 95% CI 0.70-0.87, P = 7.1 × 10 ; rs2844511: OR 1.13, 95% CI 1.01-1.26, P = .035), as well as in a combined analysis of both groups (rs9272117: OR 0.83, 95% CI 0.75-0.91, P = 6.9 × 10 ; rs2844511: OR 1.14, 95% CI 1.04-1.26, P = .005). Variant rs2844511, but not rs9272117, also showed modest evidence of association with low-grade dysplasia (OR 1.26, 95% CI 1.04-1.54, P = .019). In case-only analyses, rs2844511 tended to predict HPV status (P = .044) and rs9272117 tended to associate with HPV16 (P = .022). RNA studies in cervical samples showed a significant correlation in the transcript levels of MICA, HCP5 and HLA-DQA1, suggesting extensive co-regulation. All three genes were upregulated in HPV16-positive samples. In stratified analyses, rs9272117 was associated with HLA-DQA1 levels, specifically in HPV-positive samples, while rs2844511 was associated with MICA and HCP5 levels. The risk allele of rs2844511 was required for correlations between MICA or HCP5 with HLA-DQA1. Altogether, our results support 6p21.32-33 as the first consistent cervical cancer susceptibility locus and provide evidence for a link between genetic risk variants, HPV16 status and transcript levels of HLA-DQA1, HCP5 and MICA, which may contribute to tumor immune evasion.
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http://dx.doi.org/10.1002/ijc.33171DOI Listing
November 2020

Exploring the Potential of Time-Resolved Photoluminescence Spectroscopy for the Detection of Plastics.

Appl Spectrosc 2020 Sep;74(9):1161-1166

Department of Physics, Philipps-University Marburg, Marburg, Germany.

Accurate data on microplastic occurrence in aquatic and terrestrial ecosystems are a basic requirement for microplastic risk assessment and management. Existing analysis techniques like Raman spectroscopy and Fourier transform infrared (FT-IR) spectroscopy imaging are still time-consuming and depend on laborious sample preparation. Therefore, we investigate the potential of time-resolved photoluminescence spectroscopy as an alternative technique to identify plastic materials, and, for the first time determine the photoluminescence lifetime of a series of polymers and several non-plastic samples typically found in a marine environment. The obtained photoluminescence lifetimes can be used to distinguish between plastic and natural materials. Furthermore, they allow us to identify distinct types of plastics. Therefore, the described approach has the potential to identify materials either as a stand-alone technique or for pre-characterization of sample materials for otherwise time-consuming analytical methods such as Raman spectroscopy or FT-IR spectroscopy.
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http://dx.doi.org/10.1177/0003702820933282DOI Listing
September 2020

Free-Standing Complementary Asymmetric Metasurface for Terahertz Sensing Applications.

Sensors (Basel) 2020 Apr 16;20(8). Epub 2020 Apr 16.

Faculty of Physics, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany.

We designed and tested a highly sensitive metasurface device based on free-standing complementary asymmetric split-ring resonators at terahertz frequencies. It is utilized for sensing a galactose film. We characterized the device using the induced red shift of a Fano resonance observed in the THz transmission. The sensor has a high sensitivity of 91.7 GHz/RIU due to a significant interaction between the galactose overlayer and the metasurface.
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http://dx.doi.org/10.3390/s20082265DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7219036PMC
April 2020

Nonlinear refraction in CHNHPbBr single crystals.

Opt Lett 2020 Apr;45(8):2431-2434

We measure both nonlinear absorption and nonlinear refraction in a ${{\rm CH}_3}{{\rm NH}_3}{{\rm PbBr}_3}$CHNHPbBr single crystal using the Z-scan technique with femtosecond laser pulses. At 1000 nm, we obtain values of 5.2 cm/GW and ${+}{9.5} \cdot {{10}^{ - 14}}\;{{\rm cm}^2}/{\rm W}$+9.5⋅10cm/W for nonlinear absorption and nonlinear refraction, respectively. The sign and magnitude of the observed refractive nonlinearity are reproduced well by the two-band model. Our results suggest that the large nonlinear refractive index measured in perovskite nanostructures cannot be explained by an intrinsically high bound-electronic nonlinear refractive index in this emerging material class but is possibly caused by free carriers or quantum confinement effects.
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http://dx.doi.org/10.1364/OL.383917DOI Listing
April 2020

Trapping of ZnCl by bipyridyl-functionalized organotin sulfide clusters, and its effect on optical properties.

Chem Commun (Camb) 2020 Apr;56(35):4769-4772

Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, D-35043 Marburg, Germany.

We report the syntheses of two new organotin sulfide clusters with heteroaromatic substituents. A phenanthroline-functionalized tin sulfide cluster [(RPhenSn)4S6] (1; RPhen = CMe2CH2C(Me)N-NC(H)C12H7N2) and a bipyridyl-terminated cluster [(R4-bipySn)4S6] (2; R4-bipy = CMe2CH2C(Me)N-NC(H)-4-C10H7N2) were obtained from reactions of the hydrazone-functionalized organotin sulfide cluster [(RNSn)4S6] (RN = CMe2CH2C(Me)N-NH2) with 1,10-phenanthroline-5-carboxaldehyde or 2,2'-bipyridine-4-carbaldehyde. 1 and 2 were tested towards their capability of trapping metal ions by means of the terminal chelating ligands. The reaction of 2 with ZnCl2 afforded the cluster compound [(R4-bipyZnCl2Sn)4S6] (5), in which four ZnCl2 units are coordinated by the heteroaromatic organic groups. We discuss the structures and demonstrate the effect of ZnCl2 trapping on optical absorption and luminescence properties.
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http://dx.doi.org/10.1039/d0cc01887bDOI Listing
April 2020

Terahertz-spectroscopy for non-destructive determination of crystallinity of L-tartaric acid in smartFilms® and tablets made from paper.

Int J Pharm 2020 May 23;581:119253. Epub 2020 Mar 23.

Department of Pharmaceutics and Biopharmaceutics, Philipps-Universität Marburg, Robert-Koch-Str. 4, 35037 Marburg, Germany. Electronic address:

Newly developed active pharmaceutical ingredients (API) often experience low solubility in aqueous media and thus possess poor oral bioavailability. The SmartFilm®-technology is a novel approach to overcome poor solubility. The technique uses commercial paper in which API can be loaded in amorphous state, thus increasing dissolution rate dc/dt and solubility c when compared to bulk material. However, the preservation of the amorphous state is a prerequisite for an efficient use of the smartFilm-technology and thus the crystalline state needs to be inspected during storage. Preferably, this should be done non-destructively. Traditional techniques, such as x-ray diffraction (XRD) or differential scanning calorimetry (DSC), do not allow for non-destructive crystallinity investigations, whereas Terahertz (THz) spectroscopy is a non-destructive technique, that is sensitive to the crystalline state of many molecular crystals. Therefore, the potential of THz-spectroscopy for crystallinity state inspection of API in smartFilms and tablets made from smartFilms was investigated in this study. The THz results obtained were compared to results obtained from XRD and DSC measurements. Whereas DSC measurements failed to reliably detect crystalline API in the smartFilms, XRD and THz-spectroscopy showed similar results and revealed that it was possible to prepare smartFilms loaded with >23% (w/w) amorphous API. Results indicate the great potential of THz spectroscopy for the non-destructive determination of the crystalline state of APIs in smartFilms and/or tablets made from paper.
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http://dx.doi.org/10.1016/j.ijpharm.2020.119253DOI Listing
May 2020

RANKL and OPG and their influence on breast volume changes during pregnancy in healthy women.

Sci Rep 2020 03 20;10(1):5171. Epub 2020 Mar 20.

Department of Gynecology and Obstetrics, Comprehensive Cancer Center Erlangen-EMN, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg, Erlangen, Germany.

Breast cancer risk is reduced by number of pregnancies and breastfeeding duration, however studies of breast changes during or after pregnancy are rare. Breast volume changes - although not linked to breast cancer risk - might be an interesting phenotype in this context for correlative studies, as changes of breast volume vary between pregnant women. Serum receptor activator of nuclear factor kappa B ligand (RANKL) and its antagonist osteoprotegerin (OPG) were measured prospectively before gestational week 12, and three-dimensional breast volume assessments were performed. A linear regression model including breast volume at the start of pregnancy, RANKL, OPG, and other factors was used to predict breast volume at term. The mean breast volume was 413 mL at gestational week 12, increasing by a mean of 99 mL up to gestational week 40. In addition to body mass index and breast volume at the beginning of pregnancy, RANKL and OPG appeared to influence breast volume with a mean increase by 32 mL (P = 0.04) and a mean reduction by 27 mL (P = 0.04), respectively. Linking the RANKL/RANK/OPG pathway with breast volume changes supports further studies aiming at analysing breast changes during pregnancy with regard to breast cancer risk.
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http://dx.doi.org/10.1038/s41598-020-62070-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7083828PMC
March 2020

Concordance rate of vulvoscopic findings in detecting early vulvar neoplasia.

Gynecol Oncol 2020 05 24;157(2):463-468. Epub 2020 Feb 24.

Department of Gynecology and Obstetrics, Erlangen University Hospital, Comprehensive Cancer Center Erlangen-European Metropolitan Area of Nuremberg (CCC ER-EMN), Universitätsstrasse 21-23, 91054 Erlangen, Germany.

Purpose: Colposcopy-guided punch biopsy is a cornerstone method for diagnosing vulvar diseases. The aim of this study was to evaluate the concordance rate of clinical findings in vulvar diseases during examinations, in comparison with colposcopy-directed punch biopsy. We also developed a new classification to simplify the categorization of vulvoscopic findings.

Methods: The concordance rate of the clinical findings was compared with the final histology results from punch biopsies. The data were collected between January 2014 and May 2017 at the Erlangen University Hospital.

Results: A total of 482 colposcopy-directed punch biopsies of the vulva were obtained in 420 women. The overall concordance rate of the clinical findings in comparison with the histological vulvar punch-biopsy findings was 53.9% for all entities - benign lesions, lichen, low- and high-grade squamous intraepithelial lesions (LSIL/HSILs), and vulvar carcinoma. The concordance rate for detecting LSILs was 64.3% (45/70). The concordance rate for detecting HSILs was 62.3% and for Vulvar carcinoma 65.2%.

Conclusions: Punch biopsy of suspicious lesions continues to be a cornerstone in diagnosing HSILs and carcinoma of the vulva. Careful work-up of the vulva is recommended when patients have symptoms such as pruritus or pain. The new classification is more specific for diagnosing lesions in the vulva.
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http://dx.doi.org/10.1016/j.ygyno.2020.02.026DOI Listing
May 2020

Accuracy of colposcopic findings in detecting vaginal intraepithelial neoplasia: a retrospective study.

Arch Gynecol Obstet 2020 03 28;301(3):769-777. Epub 2020 Jan 28.

Department of Gynecology and Obstetrics, Erlangen University Hospital, Comprehensive Cancer Center Erlangen/European Metropolitan Area Nuremberg (CCC ER-EMN), Universitaetsstrasse 21-23, 91054, Erlangen, Germany.

Purpose: Malignancies of the vagina are rare, but colposcopy-directed biopsies play a major role in detecting vaginal intraepithelial lesions. Data of accuracy in detecting neoplasia of the vagina are very rare compared to accuracy in detecting cervical neoplasia. The aim of this study was to evaluate the accuracy of colposcopy-directed biopsy in comparison with clinical findings of the examiner.

Methods: The accuracy of colposcopy-directed biopsy was compared with the clinical finding in relation to the patient's age and the examiner's level of training. This was done in combination with PAP-smear, HPV-test results, and the history of other malignancies of the lower genital tract. The data were collected between January 2014 and February 2018 at the certified Dysplasia Unit of the University Hospital Erlangen.

Results: In total, 253 biopsies from 253 women from the vagina were obtained. The overall accuracy of biopsy in comparison with clinical finding was 52.17% for all entities-benign lesions, low-grade squamous intraepithelial lesions (LSILs), high-grade squamous intraepithelial lesions (HSILs), and vaginal carcinoma. The accuracy for detecting HSIL was 82.46% (47/57), with an underdiagnosis rate of 15.79% and an overdiagnosis rate of 1.79%.

Conclusion: With a sensitivity of over 80%, colposcopy-directed biopsy plays an important role in detecting vaginal-HSIL. A highly experienced practitioner is increasing the sensitivity in detecting vaginal-HSIL. Careful examination is required in women with a history of HSIL of the lower genital tract or with simultaneous neoplasia because they are of greater risk of developing vaginal malignancies. The combination of careful clinical work up, PAP-smear, HPV-testing, and colposcopy-guided biopsy is crucial in detecting vaginal-HSIL.
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http://dx.doi.org/10.1007/s00404-020-05441-5DOI Listing
March 2020

Correlation between referral cytology and in-house colposcopy-guided cytology for detecting early cervical neoplasia.

Arch Gynecol Obstet 2020 01 6;301(1):263-271. Epub 2019 Dec 6.

Department of Gynecology and Obstetrics, Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Universitätsstrasse 21-23, 91054, Erlangen, Germany.

Purpose: The current cervical cancer screening program in Germany recommends that the results showing suspected HPV infection should be further examined in specialized colposcopy units. This study aimed to correlate externally documented Pap smear results with in-house colposcopy-guided Pap cytology results and compare colposcopy-guided biopsy and postoperative histopathology results.

Methods: Clinical data were analyzed from 3627 examinations in 2844 patients who visited a university certified dysplasia unit from 2014 to 2017; 2212 patients underwent complete assessments, including Pap smear, colposcopy, HPV testing, colposcopy-guided biopsy, and/or surgery. The results were analyzed descriptively.

Results: External and in-house Pap results were consistent in 1054 ofthe 2212 patients (47.65%). Referral cytology showed a higher grade than in-house in 456 (20.61%) and a lower grade in 702 (31.74%). Using the histopathological findings as the gold standard, overdiagnosis in the referral cytology was noted in 180 patients (13.19%), underdiagnosis in 263 (19.27%), and concordant findings in 922 (67.55%). For in-house cytology, overdiagnosis was found in 133 patients (10.74%), underdiagnosis in 192 (15.51%), and accurate diagnosis with congruent cytology and histopathology findings in 913 (73.75%).

Conclusions: The rate of detection of cervical abnormalities differs significantly depending on whether the examination is performed routinely or in specialized units. Colposcopy-guided Pap smears correlate significantly better with histology than referral cytology results without colposcopic guidance. More severe lesions were also detected more accurately.
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http://dx.doi.org/10.1007/s00404-019-05389-1DOI Listing
January 2020

Diagnosis, Therapy and Follow-up of Vaginal Cancer and Its Precursors. Guideline of the DGGG and the DKG (S2k-Level, AWMF Registry No. 032/042, October 2018).

Geburtshilfe Frauenheilkd 2019 Oct 16;79(10):1060-1078. Epub 2019 Jul 16.

Klinik für Frauenheilkunde und Geburtshilfe, Universität Düsseldorf, Düsseldorf, Germany.

This is an official guideline, published and coordinated by the Gynecological Oncology Working Group (AGO) of the German Cancer Society (DKG) and the German Society for Gynecology and Obstetrics (DGGG). Vaginal cancers are rare tumors, which is why there is very little evidence on these tumors. Knowledge about the optimal clinical management is limited. This first German S2k guideline on vaginal cancer has aimed to compile the most current expert knowledge and offer new recommendations on the appropriate treatment as well as providing pointers about individually adapted therapies with lower morbidity rates than were previously generally available. The purpose of this guideline is also to set up a register to record data on treatment data and the course of disease as a means of obtaining evidence in future. The present S2k guideline was developed by members of the Vulvar und Vaginal Tumors Commission of the AGO in an independently moderated, structured, formal consensus process and the contents were agreed with the mandate holders of the participating scientific societies and organizations. To optimize the daily care of patients with vaginal cancer: 1. Monitor the spread pattern; 2. Follow the step-by-step diagnostic workup based on initial stage at detection; 3. As part of individualized clinical therapeutic management of vaginal cancer, follow the sentinel lymph node protocol described here, where possible; 4. Participate in the register study on vaginal cancer.
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http://dx.doi.org/10.1055/a-0919-4959DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6820713PMC
October 2019

Cancer patient utilisation of psychological care in Germany: The role of attitudes towards seeking help.

Eur J Cancer Care (Engl) 2019 Nov 30;28(6):e13165. Epub 2019 Sep 30.

Clinical Psychology and Psychotherapy, Philipps-University Marburg, Marburg, Germany.

Objective: Even if significantly distressed, many patients with cancer do not seek psychological help. There is growing evidence that attitudes are central barriers for help-seeking, and instruments to assess cancer patients' attitudes towards help-seeking are urgently needed. This study aimed to evaluate the German Attitudes towards Seeking Help after Cancer Scale (ASHCa-G) and investigated the relationship between patients' attitudes and psychological care utilisation.

Methods: The ASHCa-G was presented to 270 patients with cancer (age 63.0 ± 12.7 years, 44.8% women). Item analyses, principal component analysis and associations with age, social support, help-seeking intention and psychological care utilisation were calculated. A hierarchical logistic regression was performed to ascertain the leading role of attitudes in explaining psychological care utilisation.

Results: Principal component analysis supported a two-component solution, which showed good internal consistency for the positive attitudes (α = 0.80) and negative attitudes (α = 0.75) subscales. The associations with age, distress and help-seeking intention confirmed the validity of the ASHCa-G. Positive attitudes explained most variance of cancer patients' current psychological care utilisation.

Conclusion: The ASHCa-G seems to be a reliable and valid questionnaire for assessing attitudes towards seeking psychological help among patients with cancer. Clinical practice might profit from identifying attitudinal barriers that hinder patients with cancer from seeking psychological help.
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http://dx.doi.org/10.1111/ecc.13165DOI Listing
November 2019

THz tomography for detecting damages on wood caused by insects.

Appl Opt 2019 Aug;58(22):6063-6066

Annually, wood-destroying insects cause severe damage in forests. The widespread population of typographer (Ips typographus), a beetle species from the subfamily of bark beetles (Scolytidae) in Europe, mainly occurs in coniferous wood, especially in spruce (Picea abies), the most silviculturally relevant wood species. The typographer infestation is detected mainly by visual monitoring and without invasive techniques only recognizable at a late stage. Terahertz radiation has shown enormous potential in nondestructive testing. THz measurements in the time-domain performed with a robotic THz system can be used for 3D reconstruction of the internal structure of the samples. In this article, we report the detection of a change in the wood structure of spruce caused by typographer burrows.
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http://dx.doi.org/10.1364/AO.58.006063DOI Listing
August 2019

Room-Temperature Stimulated Emission and Lasing in Recrystallized Cesium Lead Bromide Perovskite Thin Films.

Adv Mater 2019 Sep 12;31(39):e1903717. Epub 2019 Aug 12.

Institute of Electronic Devices, University of Wuppertal, Rainer-Gruenter-Str. 21, 42119, Wuppertal, Germany.

Cesium lead halide perovskites are of interest for light-emitting diodes and lasers. So far, thin-films of CsPbX have typically afforded very low photoluminescence quantum yields (PL-QY < 20%) and amplified spontaneous emission (ASE) only at cryogenic temperatures, as defect related nonradiative recombination dominated at room temperature (RT). There is a current belief that, for efficient light emission from lead halide perovskites at RT, the charge carriers/excitons need to be confined on the nanometer scale, like in CsPbX nanoparticles (NPs). Here, thin films of cesium lead bromide, which show a high PL-QY of 68% and low-threshold ASE at RT, are presented. As-deposited layers are recrystallized by thermal imprint, which results in continuous films (100% coverage of the substrate), composed of large crystals with micrometer lateral extension. Using these layers, the first cesium lead bromide thin-film distributed feedback and vertical cavity surface emitting lasers with ultralow threshold at RT that do not rely on the use of NPs are demonstrated. It is foreseen that these results will have a broader impact beyond perovskite lasers and will advise a revision of the paradigm that efficient light emission from CsPbX perovskites can only be achieved with NPs.
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http://dx.doi.org/10.1002/adma.201903717DOI Listing
September 2019

Microcavity-enhanced Kerr nonlinearity in a vertical-external-cavity surface-emitting laser.

Opt Express 2019 Apr;27(9):11914-11929

Self-mode-locking has become an emerging path to the generation of ultrashort pulses with vertical-external-cavity surface-emitting lasers. In our work, a strong Kerr nonlinearity that is so far assumed to give rise to mode-locked operation is evidenced and a strong nonlinearity enhancement by the microcavity is revealed. We present wavelength-dependent measurements of the nonlinear absorption and nonlinear refractive index change in a gain chip using the Z-scan technique. We report negative nonlinear refraction up to 5x10 cm/W in magnitude in the (InGa)As/Ga(AsP) material system close to the laser design wavelength, which can lead to Kerr lensing. We show that by changing the angle of incidence of the probe beam with respect to the gain chip, the Kerr nonlinearity can be wavelength-tuned, shifting with the microcavity resonance. Such findings may ultimately lead to novel concepts with regard to tailored self-mode-locking behavior achievable by peculiar Kerr-lens chip designs for cost-effective, robust and compact fs-pulsed semiconductor lasers.
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http://dx.doi.org/10.1364/OE.27.011914DOI Listing
April 2019