Article
Surgery
Samuel Hunter Dunn, Sanaa Tejani, Jaime P. Almandoz, Sarah E. Messiah, Jeffrey Schellinger, Elisa Morales Marroquin, Matthew Mathew, Jay Horton, Anna Tavakkoli
Summary: Transoral gastric outlet reduction (TORe) is a safe and effective treatment for post-prandial hypoglycemia and weight regain after Roux-en-Y gastric bypass (RYGB) in patients with symptoms refractory to medications and dietary changes.
SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES
(2023)
Article
Surgery
Samuel Hunter Dunn, Sanaa Tejani, Jaime P. Almandoz, Sarah E. Messiah, Jeffrey Schellinger, Elisa Morales Marroquin, Matthew Mathew, Jay Horton, Anna Tavakkoli
Summary: TORe is a safe and effective treatment for patients with refractory symptoms of post-prandial hypoglycemia and weight regain after RYGB.
SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES
(2023)
Article
Surgery
F-X Terryn, B. Majerus
Summary: Non insulinoma pancreatogenous hypoglycemia syndrome (NIPHS) is a complication associated with Roux-en-Y gastric bypass (RYGB) surgery, and there is currently no standard treatment. This case report describes a successful treatment of severe NIPHS after RYGB using laparoscopic reversal of gastric bypass and gastric banding to prevent weight regain.
INTERNATIONAL JOURNAL OF SURGERY CASE REPORTS
(2022)
Article
Medicine, General & Internal
Hiwot T. Workneh, Bijal Mehta, Anjali Grover
Summary: Bariatric surgery can lead to complications, including hypoglycemia. This case report describes a 78-year-old male who developed severe hypoglycemia despite no history of diabetes. Further investigation revealed a possible diagnosis of nesidioblastosis, an uncommon hypoglycemic syndrome associated with bariatric surgery. The patient was treated with medication and dietary guidance to manage the condition.
CUREUS JOURNAL OF MEDICAL SCIENCE
(2023)
Article
Surgery
Mauricio Gonzalez-Urquijo, David E. Hinojosa-Gonzalez, Ale Gibran Alam Gidi, Sofia Hurtado Arellano, Eduardo Flores-Villalba, Javier Rojas-Mendez
Summary: Revisional gastric bypass surgery for failed gastric banding patients showed higher complication rates compared to primary RYGB. Despite a greater postoperative weight increase in the revisional group at 12-month follow-up, the difference was not statistically significant. Changes in weight and BMI did not differ significantly between the two groups.
SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES
(2022)
Article
Endocrinology & Metabolism
Adam Barsi, Artur Beke, Beatrix Sarman
Summary: This article presents a successful management of a pregnant patient with endogenous hyperinsulinemic hypoglycemia, utilizing short-acting somatostatin analog octreotide and dietary changes to achieve good glycemic control, with regular monitoring of fetal development during pregnancy.
FRONTIERS IN ENDOCRINOLOGY
(2022)
Article
Surgery
Caroline C. Ohrstrom, Dorte L. Hansen, Urd Lynge Kielgast, Marianne Lerbok Bergmann, Simon Veedfald, Jens Juul Holst, Dorte Worm
Summary: This study evaluated counterregulatory responses during postprandial hypoglycemia in patients with postbariatric hypoglycemia who underwent Rouxen-Y gastric bypass surgery. The findings showed that individuals with postbariatric hypoglycemia had minor increases in counterregulatory hormones during postprandial hypoglycemia, but larger hormone responses occurred when glucose levels were lowered during treatment with sitagliptin.
SURGERY FOR OBESITY AND RELATED DISEASES
(2021)
Article
Biochemistry & Molecular Biology
Martin Philipp Dieterle, Ayman Husari, Sophie Nicole Prozmann, Hendrik Wiethoff, Albrecht Stenzinger, Manuel Roehrich, Uwe Pfeiffer, Wolfgang Ruediger Kiessling, Helena Engel, Harald Sourij, Thorsten Steinberg, Pascal Tomakidi, Stefan Kopf, Julia Szendroedi
Summary: Neurovegetative and autonomic symptoms can be caused by various diseases, including insulin-related disorders. This case study describes a young man who experienced recurrent presyncope, dizziness, and tachycardia for many years before being diagnosed with diffuse, adult-onset nesidioblastosis. Despite multiple diagnostic tests, the underlying cause remained unidentified until postprandial and exercise-induced hypoglycemia was detected. Surgery was eventually required due to symptom recurrence.
Review
Biochemistry & Molecular Biology
Martin Philipp Dieterle, Ayman Husari, Sophie Nicole Prozmann, Hendrik Wiethoff, Albrecht Stenzinger, Manuel Roehrich, Uwe Pfeiffer, Wolfgang Ruediger Kiessling, Helena Engel, Harald Sourij, Thorsten Steinberg, Pascal Tomakidi, Stefan Kopf, Julia Szendroedi
Summary: Differential diagnosis of hypoglycemia in non-diabetic adults is complex and includes endogenous hyperinsulinism. This rare disease, also known as nesidioblastosis or non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS), presents with unspecific symptoms and is often overlooked. Diagnosis involves clinical assessment, glucose tolerance testing, fasting, imaging, and insulin measurements. Current treatment options are limited, leading to surgical resection of the pancreas. More advanced and less invasive treatments are needed.
Article
Endocrinology & Metabolism
Clare J. Lee, Jeanne M. Clark, Josephine M. Egan, Olga D. Carlson, Michael Schweitzer, Susan Langan, Todd Brown
Summary: The study compared meal-stimulated hormonal responses in patients with postbariatric surgery hypoglycemia (PBH) after sleeve gastrectomy (SG) and after Roux-en-Y gastric bypass (RYGB). The results showed significant differences in glucagon and GLP-1 responses between the two groups, while insulin and GIP responses were similar.
JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM
(2022)
Article
Surgery
Elric Zweck, Matthias Hepprich, Marc Y. Donath
Summary: Background Postprandial hypoglycemia after bariatric surgery is a challenging disorder impacting quality of life. By analyzing baseline parameters, HbA1c and weight loss, in gastric bypass patients with suspected hypoglycemia, the study found that a combined score of weight loss divided by HbA1c achieved the best predictive value for symptomatic hypoglycemia during mixed meal testing.
Article
Surgery
Claude Tayar, Haydar A. Nasser, Dana Lawand, Ammar Ghazale
Summary: Post-bariatric surgery hypoglycemia is a complex condition seen in patients with a history of gastric bypass surgery. Non-surgical management is preferred initially, with surgical options considered in case of failure. The choice of surgery should be individualized based on the patient's condition.
Article
Endocrinology & Metabolism
Joanna Udden Hemmingsson, Carl-Eric Leijonmarck, Maria Klingvall
Summary: The study aimed to evaluate clinically applicable tools to diagnose PBH patients and prevent hypoglycemic complications. Results showed significant differences in Dumping Syndrome Rating Scale and C peptide levels between the PBH group and controls.
BMJ OPEN DIABETES RESEARCH & CARE
(2022)
Article
Endocrinology & Metabolism
Jumpei Saito, Hiroyo Kawasaki, Natsuho Adachi, Aiko Sasaki, Naho Yakuwa, Tomo Suzuki, Haruhiko Sago, Akimasa Yamatani, Reiko Horikawa, Atsuko Murashima
Summary: This case report evaluated the impact of diazoxide use on pregnant women and infants. The results showed that diazoxide can transfer from the mother to the fetus through the placenta, as well as through breast milk to the infant, but without any significant harmful effects on the infant.
GYNECOLOGICAL ENDOCRINOLOGY
(2022)
Article
Gastroenterology & Hepatology
Juan Pujol-Rafols, Ozlem Uyanik, Yuhamy Curbelo-Pena, Amr Al Abbas, Stefanie Devriendt, Anabela Guerra, Miguel F. Herrera, Jacques Himpens, Eva Pardina, Sjaak Pouwels, Almino Ramos, Rui J. Ribeiro, Bassem Safadi, Hugo Sanchez-Aguilar, Claire E. E. De Vries, Bart Van Wagensveld
Summary: This study analyzed the complications, mortality, and medium-term weight loss results after converting LAGB to OAGB. The results showed that the conversion is safe and effective, with the one-stage approach being preferred for non-complicated cases.
JOURNAL OF GASTROINTESTINAL SURGERY
(2022)
Article
Evolutionary Biology
Marco T. Neiber, Frank Walther, Pavel V. Kijashko, Levan Mumladze, Bernhard Hausdorf
Summary: Species distributed in the Caucasus and/or the adjacent Pontic Mountains are also found in the East Mediterranean region, potentially due to long-distance dispersal. Phylogenetic and population genetic analyses reveal species pairs with deep splits predating the aridification of the Anatolian Plateau, suggesting more continuous distributions before this event.
Article
Engineering, Biomedical
Nils Wegner, Martin Klein, Ronja Scholz, Daniel Kotzem, Marina Macias Barrientos, Frank Walther
Summary: Different implant materials have been used for decades to reconstruct damaged tissues, aiming to improve patient's quality of life. Fatigue strength is a critical factor in implant performance, and inaccurate estimation can lead to unexpected early failure. Using short-time testing methods can significantly reduce the number of tests needed to determine fatigue strength, providing a more efficient and application-oriented approach for selecting suitable implant materials.
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Juliane Moritz, Mirko Teschke, Axel Marquardt, Stefan Heinze, Mirko Heckert, Lukas Stepien, Elena Lopez, Frank Brueckner, Frank Walther, Christoph Leyens
Summary: This study investigates the effects of hot isostatic pressing (HIP) and subsequent two-step heat treatments on the microstructure and mechanical properties of titanium aluminide alloy fabricated via electron beam powder bed fusion (PBF-EB/M). The highest ultimate tensile strength is achieved after HIP due to the elimination of lack-of-fusion defects. Challenges originating from the PBF-EB/M process, such as local variations in chemical composition due to aluminum evaporation, affect the microstructures after heat treatment.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Juliane Moritz, Mirko Teschke, Axel Marquardt, Lukas Stepien, Elena Lopez, Frank Brueckner, Frank Walther, Christoph Leyens
Summary: This study investigates the influence of process parameters and heat treatments on the microstructure and defect distribution of Ti-43.5Al-4Nb-1Mo-0.1B (TNM-B1) samples produced by electron beam powder bed fusion (PBF-EB/M). By adjusting the volumetric energy densities during the PBF-EB/M process, the aluminum content in the additively manufactured samples was deliberately controlled. The results show that the microstructure after heat treatment is strongly dependent on the PBF-EB/M parameters and the associated aluminum evaporation. It is possible to produce locally adapted microstructures within one component by varying the process parameters and subsequent heat treatment.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Metallurgy & Metallurgical Engineering
J. Rozo Vasquez, H. Kanagarajah, B. Arian, L. Kersting, W. Homberg, A. Traechtler, F. Walther
Summary: This paper presents the characterization of microstructure evolution during flow forming of austenitic stainless steel AISI 304L. It is found that the formation of shear bands initiates phase transformation from gamma-austenite into alpha'-martensite. The distribution of strain-induced alpha'-martensite and its influence on material properties at different depths are studied. The results are well correlated with microhardness and micromagnetic measurements. The research contributes to the development of micromagnetic sensors for monitoring property evolution during flow forming.
PRAKTISCHE METALLOGRAPHIE-PRACTICAL METALLOGRAPHY
(2022)
Article
Automation & Control Systems
Lukas Kersting, Bahman Arian, Julian Rozo Vasquez, Ansgar Traechtler, Werner Homberg, Frank Walther
Summary: The automated and resource-efficient production of high-strength lightweight components is becoming more important in industries such as aircraft or vehicle construction. The conventional flow-forming process has limitations in terms of reproducibility and producing parts with well-defined material property distributions. A novel closed-loop property control system that manipulates the tool path of the flow forming actuator based on online property measurement during the process could enhance the manufacturing process. This paper presents a control system model for the flow-forming process of metastable austenitic stainless steel.
AT-AUTOMATISIERUNGSTECHNIK
(2023)
Article
Engineering, Mechanical
Jochen Tenkamp, Bastian Blinn, Tilmann Beck, Frank Walther
Summary: This study analyzed the microstructure and fatigue properties of precipitation hardening Al-Si cast alloys, and investigated the influence of various factors on fatigue behavior and fatigue damage tolerance. It was found that sand castings exhibited better fatigue properties and damage tolerance compared to die castings.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Composites
Selim Mrzljak, Benjamin Zanghellini, Lars Gerdes, Ramon Helwing, Reinhard Schuller, Gerhard Sinn, Helga Lichtenegger, Frank Walther, Harald Rennhofer
Summary: Nano-reinforcements have been shown to enhance the mechanical properties of CFRP, both in quasi-static and fatigue load conditions, and are a promising option for optimizing CFRP performance. However, the use of alignment techniques for oriented nano-reinforcements is still insufficiently studied. This research investigates the influence of oriented carbon nanofibres (CNF) on the mechanical properties of bidirectional CFRP.
JOURNAL OF COMPOSITE MATERIALS
(2023)
Article
Chemistry, Physical
Chengsong Cui, Felix Stern, Nils Ellendt, Volker Uhlenwinkel, Matthias Steinbacher, Jochen Tenkamp, Frank Walther, Rainer Fechte-Heinen
Summary: In this study, the researchers developed duplex stainless steel powders through atomization with different process gases and temperatures. Nitrogen-atomized powders showed higher nitrogen content while argon-atomized powders exhibited more gas porosity. Higher atomization gas temperatures resulted in finer powder particles. The duplex stainless steel powders demonstrated good processability in laser powder bed fusion.
Article
Materials Science, Multidisciplinary
Daniel Kotzem, Tizian Arold, Kevin Bleicher, Rajevan Raveendran, Thomas Niendorf, Frank Walther
Summary: Powder bed fusion (PBF) processes allow for the efficient manufacturing of complex components. This study focuses on lattice structures with varying mechanical properties and aims to understand the complex process-structure-property relationships in order to implement PBF manufactured lattice structures in safety-relevant applications. Ti6Al4V lattice structures with different lattice types (BCC and F2CCZ) were manufactured and evaluated in terms of microstructural features and mechanical behavior. Different in-situ measurement techniques were employed to analyze damage progression under quasi-static and cyclic loading.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Juliane Moritz, Mirko Teschke, Axel Marquardt, Lukas Stepien, Elena Lopez, Frank Brueckner, Frank Walther, Christoph Leyens
Summary: In powder bed fusion additive manufacturing, the commonly used parameter E-V may not be suitable as a design parameter, as different contributing parameters can affect part properties. This study systematically varied beam current, scan velocity, and line offset in electron beam powder bed fusion (PBF-EB) while maintaining a constant E-V for TNM-B1 alloy. The results showed that individual parameters, such as low beam currents, low-to-intermediate scan velocities, and low line offsets, were important for achieving even surfaces, high relative densities, and homogeneous microstructures.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Materials Science, Characterization & Testing
Yashar Sarafraz, Malte Brink, Nikolas Baak, Alexander Koch, Frank Walther
Summary: The micromagnetic Barkhausen noise was used as a nondestructive testing method to analyze the fatigue behavior of high-strength steels. The micromagnetic Barkhausen noise energy (MBNEnergy) was measured and correlated with digital image correlation to investigate the effect of stress and strain on MBNEnergy. Different steels were studied, and an increase in MBNEnergy was observed for the bainite phase steel 18MnCrMoV6, while no significant increase or change was observed for the ferrite-pearlite steels 38MnVS6 and 46MnVS5.
Article
Materials Science, Multidisciplinary
Julian Rozo Vasquez, Bahman Arian, Lukas Kersting, Werner Homberg, Ansgar Traechtler, Frank Walther
Summary: This paper evaluates the suitability of X-ray diffraction technique in characterizing the phase transformation during the metal forming of metastable austenitic steel AISI 304L. The XRD peaks at specific 2θ diffraction angles provide information about the phase amount. Various characterization techniques were used to analyze the results and establish a correlation between XRD measurements and the amount of martensite phase. XRD was validated as a suitable technique for characterizing the phase transformation of metastable austenites.
Article
Engineering, Mechanical
Felix Stern, Louis Becker, Jochen Tenkamp, Johannes Boes, Jonathan Lentz, Sebastian Weber, Frank Walther
Summary: The impact of nitrogen alloying on corrosion and corrosion fatigue behavior of austenitic stainless steel AISI 316L processed via laser beam powder bed fusion (PBF-LB) was investigated. The nitrogen alloyed steel showed improved pitting corrosion and fatigue behavior. A fracture mechanical approach was used to analyze the fatigue data and identify the improved defect tolerance due to nitrogen alloying.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Chemistry, Physical
Mohammed Intishar Nur, Meetkumar Soni, Mustafa Awd, Frank Walther
Summary: This study investigates the impact of internal defects on the fatigue life of selectively laser-melted specimens and proposes a correction factor hypothesis to improve the prediction method. It provides insights into how internal defects and loading situations affect fatigue life.