Draft Genome of an AmpC-β-Lactamase Producing Serratia marcescens Isolate from Fresh farm Tomatoes in South Africa

Claussen Maike,Schmidt Stefan 한국미생물·생명공학회 2023 한국미생물·생명공학회지 Vol.51 No.3

Here we report essential features of the draft genome of an AmpC-β-lactamase-producing bacterial isolate obtained from farm tomatoes in South Africa. The isolate designated strain Tom1 featured a genome of 4950426 bp with a G+C% of 59.83. It was identified as Serratia marcescens by ribosomal multilocus sequence typing (rMLST), digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI), and phylogenetic analysis using reference genomes. Its genome encoded an AmpC-β-lactamase (blaSST-1), an efflux pump providing tetracycline resistance (tet(41)), and an aminoglycoside acetyltransferase (aac(6')-Ic). Additionally, genes encoding proteins involved in prodigiosin biosynthesis and associated with adherence, biofilm formation, virulence, and pathogenicity were detected.

녹색 사하라 식생 모의 시 질소 과정 및 토양 영향 분석

이주엽,홍진규,Martin Claussen,김정원,홍제우 한국기상학회 2021 한국기상학회 학술대회 논문집 Vol.2021 No.10

“녹색 사하라”로 알려진 8천 년 전 사하라 지역은 현재보다 온난하고 강수가 많았으며 식물이 광범위하게 존재하였다. 이는 현재와 다른 지구의 공전 궤도 효과와 함께, 식생-토양-강수의 복잡한 상호작용 결과로 알려져 있다. 따라서 녹색 사하라 시기의 식생 분포를 현실적으로 수치 모사하는 것은 지구시스템모델을 개선하고 기후 변화로 인한 생태계의 반응을 보다 잘 예측하기 위해서 중요하다. 하지만 현재까지 발달한 지구시스템모델링 기술에도 불구하고 현재의 모델들은 이러한 녹색 사하라의 강수와 식생을 여전히 잘 모의해내지 못하고 있다. 본 연구에서는 CESM (Community Earth System Model) 모델을 사용하여 녹색 사하라 시기의 강수와 식생을 모의하고, 토양의 생지화학 과정 및 물리적 특성이 녹색 사하라 시대의 식생 모사에 미치는 영향을 연구하였다. 본 연구 결과를 통하여 기후-식생-토양 사이의 상호작용에 대한 이해를 증진시킬 수 있었으며, 녹색 사하라 지역의 식생을 보다 현실적으로 수치 모사하기 위한 조건을 밝힐 수 있었다.

Changes in Muscular Lipids in Unilateral Isolated Hypertrophy of Gastrocnemius Muscle Can Be Revealed by 1H MR Spectroscopy

Klaus Brechtel,Juergen Machann,Margarete Pick,Juergen F. Schaefer,Claus D. Claussen,Fritz Schick 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.6

Objective: To test whether proton magnetic resonance spectroscopy (1H-MRS) reveals changes in the lipid content of the gastrocnemius muscle (GM) and soleus muscle (SOL) of a patient with unilateral isolated hypertrophy of the right GM. Materials and Methods: 1H-MRS was performed on a 1.5 Tesla (T) wholebody unit. Muscular lipids inside SOL and GM were assessed in both calves of the patient by a STEAM (stimulated echo acquisition mode) localization sequence. Results were compared to a control group of four healthy volunteers. Results: Total amount of muscular lipids in the hypertrophic GM of the patient was clearly increased compared to the controls (38.7 versus 21.8±3.5 a.u.) while intramyocellular lipids of the adjacent SOL were lower compared to the contralateral healthy leg. Conclusion: Muscular lipids are substrates for metabolism and can be assessed non-invasively by 1H-MRS. 1H-MRS is considered to be a helpful tool in clinical assessment of muscle metabolism in cases with muscular hypo- or hypertrophy. Objective: To test whether proton magnetic resonance spectroscopy (1H-MRS) reveals changes in the lipid content of the gastrocnemius muscle (GM) and soleus muscle (SOL) of a patient with unilateral isolated hypertrophy of the right GM. Materials and Methods: 1H-MRS was performed on a 1.5 Tesla (T) wholebody unit. Muscular lipids inside SOL and GM were assessed in both calves of the patient by a STEAM (stimulated echo acquisition mode) localization sequence. Results were compared to a control group of four healthy volunteers. Results: Total amount of muscular lipids in the hypertrophic GM of the patient was clearly increased compared to the controls (38.7 versus 21.8±3.5 a.u.) while intramyocellular lipids of the adjacent SOL were lower compared to the contralateral healthy leg. Conclusion: Muscular lipids are substrates for metabolism and can be assessed non-invasively by 1H-MRS. 1H-MRS is considered to be a helpful tool in clinical assessment of muscle metabolism in cases with muscular hypo- or hypertrophy.

Is There Any Additional Benefit of Contrast-Enhanced CT as Part of Routine PET/CT Protocols for the Differentiation of Suspicious Incidental Gastrointestinal 2-Deoxy-18F-FDG Uptake?

Cornelia Bettina Brendle,Philip Aschoff,Thomas Kratt,Christina Schraml,Matthias Reimold,Claus Detlef Claussen,Christina Anna Pfannenberg 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.6

Objective: Suspicious incidental gastrointestinal FDG uptake during positron-emission tomography/computed tomography (PET/CT) examinations can be caused by different diseases, including malignancies. However, differentiation with PET alone is difficult. The aim of this study was to investigate the potential of PET alone, contrast-enhanced CT (ceCT), and low-dose CT (ldCT) in routine PET/CT protocols for differentiation of incidental gastrointestinal lesions. Materials and Methods: Sixty patients with incidental gastrointestinal lesions who underwent a routine PET/CT protocol with ldCT and ceCT were retrospectively analysed. The PET lesions were evaluated regarding their FDG uptake patterns and the standard uptake value. The anatomical correlates in both CT protocols were compared in regard to the correct lesion classification with the reference standard endoscopy. Results: Sixty-two lesions were found in 60 patients (17 malignant, 10 premalignant, 5 benign, 13 inflammatory, 17 physiological). The differentiation of the FDG uptake patterns did not enable reliable lesion classification. The positive predictive value for pathology was 0.81 for ceCT in PET/CT and 0.70 for ldCT. Malignancies were detected in 100% of the patients by ceCT vs. 29.4% by ldCT. The false negative rate of ceCT for all pathologies was 31.1%, vs. 68.9% for ldCT. False positive results (17/62) could not be excluded sufficiently by either CT protocol. Conclusion: PET/ceCT protocols provide additional benefit especially in detecting gastrointestinal malignancies as a cause of suspicious incidental gastrointestinal FDG uptake. However, since follow-up endoscopy cannot be forgone due to the considerable false negative rate even with ceCT, the addition of ceCT to a routine PET/ldCT protocol cannot be recommended for this purpose.

Estimation of Radiation Exposure of 128-Slice 4D-Perfusion CT for the Assessment of Tumor Vascularity

Dominik Ketelsen,Marius Horger,Markus Buchgeister,Michael Fenchel,Christoph Thomas,Nadine Boehringer,Maximilian Schulze,Ilias Tsiflikas,Claus D. Claussen,Martin Heuschmid 대한영상의학회 2010 Korean Journal of Radiology Vol.11 No.5

Objective: We aimed to estimate the effective dose of 4D-Perfusion-CT protocols of the lung, liver, and pelvis for the assessment of tumor vascularity. Materials and Methods: An Alderson-Rando phantom equipped with thermoluminescent dosimeters was used to determine the effective dose values of 4DPerfusion-CT. Phantom measurements were performed on a 128-slice singlesource scanner in adaptive 4D-spiral-mode with bidirectional table movement and a total scan range of 69 mm over a time period of nearly 120 seconds (26 scans). Perfusion measurements were simulated for the lung, liver, and pelvis under the following conditions: lung (80 kV, 60 mAs), liver (80 kV/80 mAs and 80 kV/120 mAs), pelvis (100 kV/80 mAs and 100 kV/120 mAs). Results: Depending on gender, the evaluated body region and scan protocol, an effective whole-body dose between 2.9-12.2 mSv, was determined. The radiation exposure administered to gender-specific organs like the female breast tissue(lung perfusion) or to the ovaries (pelvic perfusion) led to an increase in the female specific dose by 86% and 100% in perfusion scans of the lung and the pelvis, respectively. Conclusion: Due to a significant radiation dose of 4D-perfusion-CT protocols, the responsible use of this new promising technique is mandatory. Gender- and organ-specific differences should be considered for indication and planning of tumor perfusion scans. Objective: We aimed to estimate the effective dose of 4D-Perfusion-CT protocols of the lung, liver, and pelvis for the assessment of tumor vascularity. Materials and Methods: An Alderson-Rando phantom equipped with thermoluminescent dosimeters was used to determine the effective dose values of 4DPerfusion-CT. Phantom measurements were performed on a 128-slice singlesource scanner in adaptive 4D-spiral-mode with bidirectional table movement and a total scan range of 69 mm over a time period of nearly 120 seconds (26 scans). Perfusion measurements were simulated for the lung, liver, and pelvis under the following conditions: lung (80 kV, 60 mAs), liver (80 kV/80 mAs and 80 kV/120 mAs), pelvis (100 kV/80 mAs and 100 kV/120 mAs). Results: Depending on gender, the evaluated body region and scan protocol, an effective whole-body dose between 2.9-12.2 mSv, was determined. The radiation exposure administered to gender-specific organs like the female breast tissue(lung perfusion) or to the ovaries (pelvic perfusion) led to an increase in the female specific dose by 86% and 100% in perfusion scans of the lung and the pelvis, respectively. Conclusion: Due to a significant radiation dose of 4D-perfusion-CT protocols, the responsible use of this new promising technique is mandatory. Gender- and organ-specific differences should be considered for indication and planning of tumor perfusion scans.

OH (1720 MHz) MASERS: A MULTIWAVELENGTH STUDY OF THE INTERACTION BETWEEN THE W51C SUPERNOVA REMNANT AND THE W51B STAR FORMING REGION

Brogan, C. L.,Goss, W. M.,Hunter, T. R.,Richards, A. M. S.,Chandler, C. J.,Lazendic, J. S.,Koo, B.-C.,Hoffman, I. M.,Claussen, M. J. IOP Publishing 2013 The Astrophysical journal Vol.771 No.2

<P>We present a comprehensive view of the W51B H II region complex and the W51C supernova remnant (SNR) using new radio observations from the VLA, VLBA, MERLIN, JCMT, and CSO along with archival data from Spitzer, ROSAT, ASCA, and Chandra. Our VLA data include the first lambda = 400 cm (74 MHz) continuum image of W51 at high resolution (88 ''). The 400 cm image shows non-thermal emission surrounding the G49.2-0.3 H II region, and a compact source of non-thermal emission (W51B_NT) coincident with the previously-identified OH (1720 MHz) maser spots, non-thermal 21 and 90 cm emission, and a hard X-ray source. W51B_NT falls within the region of high likelihood for the position of TeV gamma-ray emission. Using the VLBA, three OH (1720 MHz) maser spots are detected in the vicinity of W51B_NT with sizes of 60-300 AU and Zeeman effect magnetic field strengths of 1.5-2.2 mG. The multiwavelength data demonstrate that the northern end of the W51B HII region complex has been partly enveloped by the advancing W51C SNR and this interaction explains the presence of W51B_NT and the OH masers. This interaction also appears in the thermal molecular gas which partially encircles W51B_NT and exhibits narrow pre-shock (Delta v similar to 5 km s(-1)) and broad post-shock (Delta v similar to 20 km s(-1)) velocity components. RADEX radiative transfer modeling of these two components yield physical conditions consistent with the passage of a non-dissociative C-type shock. Confirmation of the W51B/W51C interaction provides additional evidence in favor of this region being one of the best candidates for hadronic particle acceleration known thus far.</P>