bluuebunny/crossref_metadata_2025 huggingface dataset:
Endoscopic ultrasound-guided fine-needle aspiration vs fine-needle biopsy for the diagnosis of pancreatic neuroendocrine tumors
Authors: Eusebi Leonardo H. , Thorburn Douglas , Toumpanakis Christos , Frazzoni Leonardo , Johnson Gavin , Vessal Sheida , Luong Tu Vinh , Caplin Martyn , Pereira Stephen P.
Published: October 2019

Background and study aims Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) as a method of obtaining preoperative diagnosis of pancreatic neuroendocrine tumors (PanNETs) has been reported in several series. Fine-needle biopsies (FNB) are increasingly employed to obtain core specimens during EUS. However, the differences in efficacy between these sampling methods in the diagnosis of PanNETs still needs to be defined.

Patients and methods Over a 13-year period, all patients who underwent EUS-guided tissue sampling of suspicious pancreatic lesions with clinical, endoscopic and pathologic details were entered into an electronic database. Lesions underwent EUS-FNA or FNB sampling, or a combination of the two. The accuracy and safety of different EUS-guided sampling methods for confirmed PanNETs were investigated.

Results A total of 91 patients (M/F: 42/49, median age: 57 years), who underwent 102 EUS procedures had a final diagnosis of PanNET. Both EUS-guided sampling modalities were used in 28 procedures, EUS-FNA alone was used in 61 cases, while EUS-FNB alone in 13 cases. Diagnostic yield of EUS-FNA and EUS-FNB alone, including the inadequate specimens, was 77.5 % (95 %CI: 68.9 – 86.2 %) and 85.4 % (95 %CI: 74.6 – 96.2 %), respectively. The combination of both sampling modalities established the diagnosis in 96.4 % of cases (27/28) (95 %CI: 89.6 – 100 %), significantly superior to EUS-FNA alone (P = 0.023). Diagnostic sensitivity among the adequate samples for EUS-FNA, EUS-FNB and for the combination of the two methods was 88.4 % (95 %CI: 80.9 – 96.0 %), 94.3 % (95 %CI: 86.6 – 100 %) and 100 % (95 %CI: 100 – 100 %). There was one reported complication, a post-FNA bleeding, treated conservatively.

Conclusions EUS-FNB improves diagnostic sensitivity and confers additional information to cytological assessment of PanNETs.
Clinical and financial impacts of introducing an endoscopic mucosal resection service for treatment of patients with large colonic polyps into a regional tertiary hospital
Authors: Worland Thomas , Cronin Oliver , Harrison Benjamin , Alexander Linda , Ding Nik , Ting Alvin , Dimopoulos Stephanie , Sykes Racheal , Alexander Sina
Published: October 2019

Background and study aims Endoscopic mucosal resection (EMR) of large sessile or laterally spreading colonic lesions is a safe alternative to surgery. We assessed reductions in Surgical Resection (SR) rates and associated clinical and financial benefits following the introduction of an EMR service to a large regional center.

Patients and methods Ongoing prospective intention-to-treat analysis of EMR was undertaken from time of service inception in 2009 to 2017. Retrospective data for SR of large sessile/laterally spreading colonic lesions were collected for the period 4 years before commencement of the EMR service (2005 – 2008) and 9 years after its introduction (2009 – 2017).

Results From 2005 to 2008, 32 surgical procedures were performed for non-malignant colonic neoplasia (50 % male, median age 68 years, median Length of Stay (LoS) 10 days). Following the introduction of the EMR service, there was a 56 % reduction in the number of patients referred for surgery (32 surgical procedures, 47 % male, median age 70 years, median LoS 8.5 days). During this period, EMR was successfully performed in 183 patients with 216 lesions resected (60 % male, median age 68 years, median LoS 1 day). Compared to the SR group, the EMR cohort had a lower peri-procedural complication rate (7.7 % vs 54.7 %, P < 0.0001), and shorter average LoS (1 vs 9 days, P < 0.0001). A cost saving of AUD $ 19 543.5 was seen per lesion removed with EMR compared to SR.

Conclusions The introduction of a dedicated EMR service into a large regional center as an alternative to SR can lead to a substantial decrease in unnecessary surgery with subsequent clinical and financial benefits.
Endoscopic negative pressure therapy (ENPT) for duodenal leakage – novel repair technique using open-pore film (OFD) and polyurethane-foam drainages (OPD)
Authors: Loske Gunnar , Rucktaeschel Frank , Schorsch Tobias , Moenkemueller Klaus , Mueller Christian Theodor
Published: October 2019

Background and study aims Endoscopic negative pressure therapy (ENPT) is used to close transmural defects in the rectum and esophagus. Very few reports have described ENPT to manage duodenal defects. This study was designed to demonstrate ENPT in a population of 11 patients with transmural duodenal leakages.

Patients and methods The method of ENPT was adapted for duodenal use. Open-pore polyurethane-foam or a thin, open-pore double-layered film was wrapped around the distal end of a gastroduodenal tube. First, this open-pore element was placed on the inner wound in the duodenum with endoscopy. Second, continuous negative pressure of –125 mmHg was applied with an electronic pump. Drains were changed after 2 to 7 days.

Results Eleven patients were treated with duodenal leaks. Eight defects occurred after operative closure of perforated duodenal ulcers, papillectomy or stricturoplasty, one anastomotic leakage after Billroth – 1 distal gastric resection, one iatrogenic perforation in endoscopic retrograde cholangiopancreatography, and one by a surgical drain. Median duration of therapy was 11 days (range 7 – 24 days). Complete healing of defects was achieved in all patients.

Conclusion ENPT is an innovative endoscopic alternative for treatment of transmural duodenal defects.
Gastrointestinal involvement in patients with vasculitis: IgA vasculitis and eosinophilic granulomatosis with polyangiitis
Authors: Kawasaki Keisuke , Nakamura Shotaro , Esaki Motohiro , Kurahara Koichi , Eizuka Makoto , Okamoto Yasuharu , Hirata Takashi , Hirahashi Minako , Oshiro Yumi , Yanai Shunichi , Sato Kunihiko , Toya Yosuke , Maemondo Makoto , Terayama Yasuo , Sugai Tamotsu , Matsumoto Takayuki
Published: October 2019

Background and study aims Among vasculitides, IgA vasculitis (IgAV) and eosinophilic granulomatosis with polyangiitis (EGPA) frequently damage the gastrointestinal tract. However, only a few studies have investigated the entire gastrointestinal tract in patients with IgAV or EGPA by endoscopy. The aim of this study was to clarify endoscopic characteristics of patients with IgAV and those with EGPA.

Patients and methods Clinicopathological and endoscopic findings were retrospectively compared between 33 patients with IgAV and 19 patients with EGPA.

Results Gastrointestinal involvement was observed in 33 patients with IgAV (100 %) and in 8 patients with EPGA (42 %; P = 0.0001). Duodenal involvement was more frequent in patients with IgAV (75.8 %) than in those with EGPA (21.1 %, P = 0.0002). Jejunoileal involvement was frequent in both groups (IgAV 94.4 %; EGPA 77.8 %). Gastric mucosal erythema was more frequent in patients with IgAV (18.2 %) than in those with EGPA (0 %, P = 0.0481). Duodenal mucosal erythema (IgAV 54.6 %; EGPA 21.1 %, P = 0.0227), ulcer (IgAV 33.3 %; EGPA 0 %, P = 0.0041), and hematoma-like protrusion (IgAV 21.1 %; EGPA 0 %, P = 0.039) were more frequently observed in patients with IgAV than in those with EGPA.

Conclusions Frequent duodenal involvement, gastric mucosal erythema, and duodenal lesions including erythema, ulcer, and hematoma-like protrusion are characteristic of patients with IgAV. Because jejunoileal involvement was frequent in both groups of patients, small-bowel endoscopies should be performed for diagnosis of small-bowel lesions in patients with IgAV and EGPA.
Additional value of linked color imaging in colonoscopy: a retrospective study
Authors: Sakamoto Taku , Tomizawa Yutaka , Cho Hourin , Takamaru Hiroyuki , Sekiguchi Masau , Yamada Masayoshi , Matsuda Takahisa , Murakami Yoshitaka , Saito Yutaka
Published: October 2019

Background and study aims Linked color imaging (LCI), a newly developed optical modality, enhances mucosal surface contrast. We aimed to evaluate the efficacy and feasibility of insertion-phase LCI in terms of additional benefit of colorectal polyp detection over that obtained with white light imaging (WLI).

Patients and methods We consecutively enrolled eligible patients from November 2017 to June 2018. During colonoscopy, LCI or WLI was alternatively applied on scope insertion and LCI was applied on scope withdrawal. Patients were divided into two groups according to the protocolized difference of imaging modality used in the scope insertion phase (LCI and WLI groups). Group differences in clinical outcomes were evaluated.

Results A total of 138 patients were enrolled in this study, with equal numbers of patients assigned to the LCI and WLI groups. Most of the lesions located in the proximal colon were detected during the withdrawal phase, without a difference in proportions between the two groups. However, in the LCI group, eight of 49 lesions (16 %) located in the sigmoid and rectosigmoid colon were only detected during the insertion phase, and no such lesions (0 %) were detected during the insertion phase in the WLI group (P = 0.045).

Conclusions This study showed the efficacy and feasibility of LCI in improving colorectal polyp detection in the sigmoid colon, especially during insertion. Further studies are warranted to validate the results of our single-center study.
Visus und Gesichtsfeld bei Drusenpapillen
Authors: Kelbsch Carina , Sonntag Anton , Wilhelm Helmut , Tonagel Felix
Published: October 2019

Hintergrund Es wurde vermutet, dass die mit Drusenpapillen assoziierten Gesichtsfeldausfälle im Laufe des Lebens stetig langsam zunehmen oder aber in der Adoleszenz entstehen und sich im Laufe des Lebens nur unwesentlich verschlechtern. Wir überprüften diese Annahmen.

Material und Methoden Aus dem Patientenverwaltungssystem der Universitäts-Augenklinik Tübingen wurden 255 konsekutive Fälle mit Drusenpapillen identifiziert, die Richtigkeit der Diagnose verifiziert und, soweit vorhanden und qualitativ verwertbar, die Gesichtsfelder quantifiziert. Zusätzlich wurde der Visus ausgewertet.

Ergebnisse In 104 Fällen lagen beidseitig qualitativ gute, quantifizierbare Gesichtsfelder vor. Der Anteil an Patienten mit ausgeprägten Gesichtsfeldausfällen fiel insgesamt gering aus. Nur 3 Patienten zeigten beidseitig einen Gesichtsfeldverlust von ≥ 50%. Beide Augen waren meistens vergleichbar betroffen. Ein höheres Alter war mit größeren Gesichtsfeldausfällen korreliert. Lediglich 1 Patient (0,4%) erreichte beidseitig nicht den Visus 0,3.

Diskussion Anhand unseres Patientenkollektivs ist eine kontinuierliche leichte Verschlechterung des Gesichtsfelds mit dem Alter anzunehmen. Sehr ausgeprägte Gesichtsfeldausfälle waren selten. Dasselbe galt auch für den Visus, der erst im Alter ab 60 Jahren leichte Beeinträchtigungen aufwies.
Moderate-intensity Exercise Training in Sole and Simultaneous Forms with Insulin Ameliorates the Experimental Type 1 Diabetes-induced Intrinsic Apoptosis in Testicular Tissue
Authors: Samadian Zahra , Azar Javad Tolouei , Moshari Sana , Razi Mazdak , Tofighi Asghar
Published: October 2019

The aim of this study was to investigate the ameliorative effect of moderate-intensity exercise training in sole and simultaneous forms with insulin on experimental type 1 diabetes (T1D)-induced apoptosis. A total of 36 mature male Wistar rats were divided into six equally sized groups, including sedentary control (Con), moderate-intensity exercise training (E-sole), sedentary T1D-induced (D-sole), moderate-exercise-trained T1D-induced (DE), insulin-treated sedentary T1D-induced (DI) and exercise-trained, and insulin-treated T1D-induced (DEI) groups. The 6-week exercise training intervention was involved 30 min of moderate-intensity running on a treadmill once daily (5 days/week). Next, tubular differentiation (TDI) and spermiogenesis (SPI) indices were assessed. The Bcl-2, Bax and caspase-3 expressions were determined using RT-PCR, immunohistochemistry and western blot techniques. Finally, the TUNEL staining was used to analyze the apoptosis ratio. The moderate-intensity exercise training in the sole and when simultaneously considered with insulin (DEI) maintained testicular cellularity, up-regulated Bcl-2 expression, reduced Bax expression and ameliorated the diabetes-induced apoptosis. We failed to show remarkable alterations in caspase-3 mRNA and protein levels in the DE group versus D-sole animals. In conclusion, the moderate-intensity exercise training is able to potentially protect testicular cells from T1D-induced intrinsic apoptosis via up-regulating Bcl-2 and downregulating Bax expressions. Moreover, it amplifies the insulin-induced anti-apoptotic impacts.
Advanced multispectral image-processing endoscopy system for visualizing two-dimensional hemoglobin saturation and relative hemoglobin concentration
Authors: Chiba Toru , Obara Yoshimi , Murata Masaharu , Akahoshi Tomohiko
Published: October 2019

Background and study aims The association of tumor hypoxia and vascularization with malignant progression is recognized, and detection by measuring tissue hemoglobin (Hb) saturation and concentration has attracted attention. In this study, we designed a simple algorithm and multispectral image-processing endoscopy system to map relative Hb concentration and Hb saturation for detection of tumors in small animal viscera in vivo.

Materials and methods We designed and validated an optical filter-equipped endoscope system for two-dimensional visualization of Hb concentration and saturation maps and used it in a real-time video examination. A simplified method based on spectral data capture and analysis of defuse reflection of mucosa, including image capture and data processing of the spectral features of Hb oxygenation, was developed.

Results An Hb saturation calibration curve was obtained. Then, differences in oxygenation levels between normal mucosa and in vivo tumors in a small animal model were determined by using the new method and endoscope system.

Conclusions A multispectral image-processing endoscopic system with a mapping frame rate comparable to that of white light imaging systems (7.5 frames/second) was developed.
Update Breast Cancer 2019 Part 4 – Diagnostic and Therapeutic Challenges of New, Personalised Therapies for Patients with Early Breast Cancer
Authors: Schütz Florian , Fasching Peter A. , Welslau Manfred , Hartkopf Andreas D. , Wöckel Achim , Lux Michael P. , Janni Wolfgang , Ettl Johannes , Lüftner Diana , Belleville Erik , Kolberg Hans-Christian , Overkamp Friedrich , Taran Florin-Andrei , Brucker Sara Y. , Wallwiener Markus , Tesch Hans , Fehm Tanja N. , Schneeweiss Andreas , Müller Volkmar
Published: October 2019

The further development of therapies for women with early breast cancer is progressing far more slowly than in the case of patients with advanced breast cancer and is additionally delayed compared to developments in metastatic breast cancer. Nonetheless, significant advancements have been able to be recorded recently. This review summarises the latest developments in view of the most recent publications and professional conferences. For hormone-receptor-positive patients, new aspects for the duration of antihormone therapy and with regard to the benefits of multigene tests have been published. In the case of HER2-positive patients, the value of post-neoadjuvant therapy and de-escalation of the therapy is discussed. In patients with triple-negative breast cancer, there is a question of whether the knowledge of the biological background of a homologous recombination deficiency (HRD) helps develop new therapies for this subtype. In particular the “use” of a BRCA1/2 mutation or the biological characteristic HRD as a potential motive for therapy plays a role here in specifying the significance of platinum therapy and therapy with PARP inhibitors.
Small Fiber Neuropathy
Authors: Zhou Lan
Published: October 2019

Small fiber neuropathy (SFN) is common, and can be associated with many medical conditions. The majority of the patients with SFN suffer from painful paresthesia which can negatively impact their quality of life. Skin biopsy with intraepidermal nerve fiber density evaluation is the gold standard diagnostic test. Autonomic function testing is useful when autonomic symptoms are present. Screening for associated conditions should be done in every patient, even when a known underlying associated condition is present, before the neuropathy evaluation. Etiology-specific treatment, lifestyle modification, and pain control are the key elements of SFN management. This article will review the clinical presentation, skin biopsy procedure, utility of diagnostic tests, associated conditions, management, and prognosis of SFN.
Vasculitic Neuropathies
Authors: Beachy Nathaniel , Satkowiak Kelsey , Gwathmey Kelly Graham
Published: October 2019

Vasculitic neuropathies are disorders that result from inflammation in the peripheral nerves' vascular supply, resulting in ischemic injury. These disorders may be a result of systemic inflammation or may be confined to the peripheral nervous system. Causative etiologies include primary systemic vasculitis, vasculitis secondary to other conditions such as primary connective tissue disorders, infectious, paraneoplastic, and drug-induced conditions, and nonsystemic vasculitic neuropathy. Early recognition and treatment of these conditions is imperative to prevent substantial morbidity and mortality. The goal of this review is to provide an organization of the vasculitic neuropathies and an overview of principles of diagnosis and treatment for the clinical neurologist.
Neuropathy Associated with Systemic Amyloidosis
Authors: Kaku Michelle , Berk John L.
Published: October 2019

Peripheral neuropathy occurs in the setting of both hereditary and acquired amyloidosis. The most common form of hereditary amyloidosis is caused by 1 of 140 mutations in the transthyretin (TTR) gene, which can lead to neuropathic hereditary transthyretin amyloidosis (hATTR; previously referred to as transthyretin familial amyloid polyneuropathy), whereas acquired immunoglobulin light chain (AL) amyloidosis is the most common acquired form. Patients typically present with a sensorimotor polyneuropathy, focal neuropathy such as carpal tunnel syndrome, or autonomic neuropathy. When neuropathy is the sole or dominant presenting symptom, the diagnosis is commonly delayed. With the advent of new drug therapies for AL amyloidosis and hATTR amyloidosis, including proteasome inhibitors, TTR silencers, and TTR protein stabilizers, the neurologist is uniquely positioned to diagnose neurologic manifestations of systemic amyloidosis, leading to earlier disease identification and treatment. This article reviews the epidemiology, clinical presentations, pathophysiology, diagnostic workup, and treatment of neuropathy in the setting of amyloidosis.
Inherited Neuropathies
Authors: Carroll Antonia S. , Burns Joshua , Nicholson Garth , Kiernan Matthew C. , Vucic Steve
Published: October 2019

The inherited neuropathies are a common and heterogeneous group of slowly progressive disorders affecting motor, sensory, and autonomic nerves. These hereditary conditions can be confined to the peripheral nervous system, termed the primary hereditary neuropathies, or can occur as part of a multisystem disease. Identification of systemic involvement is necessary to distinguish the primary and secondary hereditary neuropathies to prevent the misdiagnosis of potentially treatable entities. Recent genetic and technological advances have dramatically improved our understanding of the underlying pathophysiology of these inherited neuropathies and hence provide the correct milieu for the future development of disease-modifying therapies. This review provides clinical, neurophysiological, genetic, pathophysiological, and treatment insights into the primary inherited neuropathies, and those associated with multisystem diseases, including porphyria and mitochondrial disorders.
Dorsal Augmentation in Facial Profiloplasty
Authors: Jang Yong Ju , Yoo Shin Hyuk
Published: October 2019

Nasal profile line has central importance in forming an aesthetically balanced facial profile. Thus, rhinoplasty is a critically necessary surgery in shaping ideal profile line. For successful rhinoplasty, meticulous preoperative evaluation and proper planning should be performed before surgery. The nasal dorsum is the broadest and most prominent part of the nose; any minor imperfection is readily appreciated by an observer. Thus, dorsal augmentation is one of the most challenging areas in rhinoplasty as there is virtually no single ideal graft material and method for the nasal dorsum, which is free of aesthetic complication The surgeon should be able to discern the pattern of the abnormal nasal profile and to strategize the best possible surgical option to create a long-lasting, aesthetically pleasing dorsal line in good harmony with the overall facial profile. This study addresses our strategy to deal with various types of aesthetically unpleasant nasal profile line. The characteristics of augmentation materials and considerations in surgical technique are also addressed.
The Use of Spreader Grafts or Spreader Flaps—or Not—in Hump Reduction Rhinoplasty
Authors: Gerecci Deniz , Perkins Stephen W.
Published: October 2019

Hump reduction is one of the most common reasons patients seek cosmetic rhinoplasty. Spreader grafts or spreader flaps have become a key maneuver in supporting and reconstructing the nasal midvault after reductive profileplasty to prevent long-term functional and cosmetic sequelae. This article reviews the pertinent anatomy, describes indications for spreader graft or spreader flap placement, discusses surgical techniques and approaches for spreader graft placement, and describes complications of spreader graft use after hump reduction.
Reductive Nasal Profileplasty
Authors: Shadfar Scott
Published: October 2019

Reductive nasal profileplasty is often the pillar of aesthetic nasal surgery. The surgeon must be knowledgable in the key tenants of preoperative analysis and examination to better approach the core elements for hump takedown. Photo imaging or morphing is a practical and technically easy means to open the discussion with the patients to determine their specific goals and ensure that these goals align with their needs functionally. Various approaches can be taken dependent upon the demands from the patient's anatomy and surgical goals planned preoperatively. The component resection technique is described in detail, as well as discussions regarding the need to predict and prophylactically treat the possible long- and short-term sequelae that can occur with reductive nasal profileplasty. Complementary procedures should also be considered to achieve the most balanced nasal and facial aesthetic.
The Graduated Approach to Surgical Neck Contouring
Authors: Gerecci Deniz , Perkins Stephen W.
Published: October 2019

Achieving a more youthful neckline is one of the most common reasons why patients seek facial plastic surgery. A variety of treatment options are available to contour the neck, ranging from injectable medications to minimally invasive energy devices to surgery. A spectrum of surgical procedures can be offered to contour the neck, including liposuction, submentoplasty, necklift, and facelift, all with or without implants. The ideal neck aesthetic, pertinent anatomy, patient evaluation process, indications, and techniques for the aforementioned procedures are discussed in this article. A graduated approach to neck contouring based on the senior author's long-term experience is provided.
Comparative Analysis of Cerebral Magnetic Resonance Imaging Changes in Nontreated Infantile, Juvenile and Adult Patients with Niemann-Pick Disease Type C
Authors: Gburek-Augustat Janina , Groeschel Samuel , Kern Jan , Beck-Woedl Stefanie , Just Jennifer , Harzer Klaus , Stampfer Miriam , Kraegeloh-Mann Ingeborg
Published: October 2019

Aim The study aims to describe cerebral MRI in different onset forms of Niemann-Pick type C (NPC). Systematic MRI analyses in this rare lysosomal storage disease are lacking in the infantile and juvenile onset forms.

Methods Thirty-two cerebral MRI scans from 19 patients with NPC were assessed using a newly established and validated scoring system which addresses white matter changes and supratentorial versus infratentorial atrophy.

Results Seven scans were from six NPC patients with early infantile onset (<2 years of age), six scans were from three patients with late infantile onset (2–6 years), six scans from four with juvenile onset (6–15 years), and 13 from six with adult onset (>15 years). While supratentorial atrophy was the leading sign in the infantile groups, the juvenile and adult forms were characterized by both, infra- and supratentorial atrophy. White matter changes were found in nearly every patient; they increased with the disease duration in the earlier forms and were prominent in the later forms already early in the disease course.

Conclusion This is the first systematic and comparative MRI analysis in the different onset groups of NPC using a scoring system. Early during disease course, MRI showed different patterns in infantile compared with juvenile and adult onset NPC patients, for example, only supratentorial atrophy in juvenile versus global atrophy in adult onset patients. MRI changes provide an additional, early biomarker for NPC.
Identification of a Novel 19-bp Deletion Mutation in LTBP4 Using Exome Sequencing in Two Siblings with Autosomal Recessive Cutis Laxa Type 1C
Authors: Gupta Neerja , Langeh Nitika , Sridharan Aparajit , Kabra Madhulika
Published: October 2019

Autosomal recessive type I cutis laxa is genetically heterogeneous. Biallelic mutations in latent transforming growth factor β-binding protein 4 (LTBP4; MIM*604710) lead to type 1C cutis laxa due to nonsense, frameshift, single base pair indels, or duplication mutations. In this report, we describe the first Indian family with cutis laxa as a result of a novel 19 base pair homozygous deletion leading to premature termination of short isoform LTBP-4S.
Retrocondylar Far-Lateral Approach for Resection of a Craniocervical Junction Hemangioblastoma
Authors: Tai Alexander X. , Knudson Kathleen , Jean Walter C.
Published: October 2019

We present a case in which a retrocondylar far-lateral approach was utilized to resect a hemangioblastoma at the craniocervical junction. The patient was a 33-year-old man presenting with 2 months of symptoms referable to compression at the craniocervical junction (i.e., dizziness and gait instability). Though neurologically intact on exam, his imaging demonstrated a highly vascular cystic lesion dorsolateral to the medulla on the left consistent with a hemangioblastoma. Virtual reality software was critical to visualize the patient's lesion in relationship to the vertebral artery and draining vein (Fig. 1). A far-lateral retrocondylar suboccipital craniectomy with a C1 hemilamiectomy permitted resection of this lesion. The operative strategy was to address the lesion similar to an arteriovenous malformation by detaching the lesion from its arterial feeders first, and then addressing the lesion's draining vein (Fig. 2). Postoperative imaging demonstrated a gross-total resection and the patient had an uncomplicated postoperative course. This case demonstrates not only the lateral reach of a retrocondylar far-lateral approach; but also, clearly demonstrates an effective dissection strategy when approaching a hemangioblastoma.

The link to the video can be found at: https://youtu.be/M0szMOdhjfE.
Resection of von Hippel Lindau Related Brainstem Hemangioblastoma
Authors: Maggio Dominic , Rosenblum Jared S. , Chittiboina Prashant
Published: October 2019

Patients with von Hippel Lindau (VHL) disease develop multiple central nervous system hemangioblastomas (HB). The surgical resection of VHL-HBs is the standard of clinical care when these HBs become symptomatic due to tumor growth, edema, or cyst formation. VHL-HBs frequently present at the obex of the brainstem, making this a challenging surgical problem. Here, we present a case of a large symptomatic brainstem VHL-HB that was resected using a dorsal midline approach and midline myelotomy. This 35-year-old man with VHL disease and multiple prior resections of cerebellar hemangioblastomas presented with progressive bilateral upper extremity weakness, ataxia, and dysphagia. The accompanying two-dimensional (2D) video demonstrates the key techniques for resection of this brainstem hemangioblastoma, including recognizing the pial presentation, sharp pial/subpial dissection, and en bloc removal. Subsequently, we discuss circumferential dissection, identification, and division of feeding vessels. We also demonstrate key maneuvers to recognize and divide the main arterial pedicle while preserving the anterior spinal artery. The patient tolerated the resection without complication and the patient was discharged home after 6 days at his baseline neurologic function. This work was supported by the Intramural Research Program of the National Institutes of Health.

The link to the video can be found at: https://youtu.be/mb2VqcLpxDQ.
Physically stimulated nanotheranostics for next generation cancer therapy: Focus on magnetic and light stimulations
Authors: Thorat Nanasaheb D. , Tofail Syed A. M. , von Rechenberg Brigitte , Townley Helen , Brennan Grace , Silien Christophe , Yadav Hemraj M. , Steffen Thomas , Bauer Joanna
Published: October 2019

Physically or externally stimulated nanostructures often employ multimodality and show encouraging results at preclinical stage in cancer therapy. Specially designed smart nanostructures such as hybrid nanostructures are responsive to external physical stimuli such as light, magnetic field, electric, ultrasound, radio frequency, X-ray, etc. These physically responsive nanostructures have been widely explored as nonconventional innovative “nanotheranostics” in cancer therapies. Physically stimulated (particularly magnetic and light) nanotheranostics provide a unique combination of important properties to address key challenges in modern cancer therapy: (i) an active tumor targeting mechanism of therapeutic drugs driven by a physical force rather than passive antibody matching, (ii) an externally/remotely controlled drugs on-demand release mechanism, and (iii) a capability for advanced image guided tumor therapy and therapy monitoring. Although primarily addressed to the scientific community, this review offers valuable and accessible information for a wide range of readers interested in the current technological progress with direct relevance to the physics, chemistry, biomedical field, and theranostics. We herein cover magnetic and light-triggered modalities currently being developed for nonconventional cancer treatments. The physical basis of each modality is explained; so readers with a physics or, materials science background can easily grasp new developments in this field.
Turbulence and scale relativity
Authors: Nottale Laurent , Lehner Thierry
Published: October 2019

We develop a new formalism for the study of turbulence using the scale relativity framework (applied in v-space, following de Montera’s proposal). We first review some of the various ingredients which are at the heart of the scale relativity approach (scale dependence and fractality, chaotic paths, irreversibility) and recall that they indeed characterize fully developed turbulent flows. Then, we show that, in this framework, the time derivative of the Navier-Stokes equation can be transformed into a macroscopic Schrödinger-like equation. The local velocity Probability Distribution Function (PDF), Pv(v), is given by the squared modulus of a solution of this equation. This implies the presence of null minima Pv(vi) ≈ 0 in this PDF. We also predict a new acceleration component, Aq(v)=±Dv ∂v⁡lnPv, which is divergent in these minima. Then, we check these theoretical predictions by data analysis of available turbulence experiments: (1) Empty zones are in effect detected in observed Lagrangian velocity PDFs. (2) A direct proof of the existence of the new acceleration component is obtained by identifying it in the data of a laboratory turbulence experiment. (3) It precisely accounts for the intermittent bursts of the acceleration observed in experiments, separated by calm zones which correspond to Aq ≈ 0 and are shown to remain perfectly Gaussian. (4) Moreover, the shape of the acceleration PDF can be analytically predicted from Aq, and this theoretical PDF precisely fits the experimental data, including the large tails. (5) Finally, numerical simulations of this new process allow us to recover the observed autocorrelation functions of acceleration magnitude and the exponents of structure functions.
Growth of InGaN films on hardness-controlled bulk GaN substrates
Authors: Sumiya Masatomo , Fukuda Kiyotaka , Fujikura Hajime , Konno Taichiro , Suzuki Takayuki , Fujimoto Tetsuji , Yoshida Takehiro , Ueda Shigenori , Watanabe Kenji , Ohnishi Tsuyoshi , Honda Tohru
Published: October 2019

We carried out an evaluation of the crystalline quality of bulk GaN substrates and the properties of InGaN films grown on them. The Urbach energy estimated by photothermal deflection spectroscopy and the tail states near the valence band maximum determined by hard x-ray photoemission spectroscopy were larger for hardness-controlled bulk GaN (hard GaN) than those for conventional bulk GaN (conventional GaN). However, InGaN on hard GaN grows in a step-flow-like mode, while InGaN grown on conventional GaN exhibits spiral-like growth. The photoluminescence decay at room temperature for InGaN grown on the hard GaN was 470 ps, compared with 50 ps for that grown on the conventional GaN. This can be attributed to the suppression of spiral-like growth due to the resistance to deformation of the hard GaN. These results indicate that substrate hardness is one of the most important factors for III–V nitride growth on the bulk GaN substrate.
Trimodal radiography using sinusoidal phase modulating grating interferometry
Authors: Zan G. B. , Han H. J. , Wali F. , Wu Z. , Wang Q. P.
Published: October 2019

X-ray grating interferometry (XGI) provides complementary information to visualize the internal structure of an object better than conventional absorption-based imaging methods, thereby having the potential for future biomedical applications. In XGI, information retrieval is critical for qualitative and quantitative research. However, information retrieval based on the phase-stepping technique usually requires that the absolute spatial translations of these phase-stepping position series lie in the range of only a few hundred nanometers, making this technique prone to mechanical instabilities and motion artifacts. In this paper, trimodal radiography using sinusoidal phase modulating interferometry is studied. The theoretical analysis of the signal retrieval algorithm using four integrating buckets is derived, and numerical experiments are demonstrated. In the proposed method, the phase modulation is generated by shifting the grating following a sinusoidal curve while the signals are retrieved from the four frames obtained by integrating the time-varying intensity over the four quarters of the modulation period. Compared with the previously proposed method, this method is easier to implement due to relaxed requirements on the phase-shifting device; high speed and continuous data averaging will greatly promote the real applications of the X-ray grating interferometer.
Thermal properties of the dominant O – H complex in β-Ga2O3
Authors: Nickel N. H. , Lang F. , Villora E. G. , Shimamura K. , Rappich J.
Published: October 2019

Using infrared absorption spectroscopy of hydrogen passivated β-Ga2O3 the temperature dependence of the dominant O – H vibrational line was measured between 5 and 300 K. With increasing temperature, the vibrational line shifts by Δω = 7.8 cm-1 to lower frequency. This is accompanied by a broadening of the vibrational line from Γ = 0.61 to 8.18 cm-1. The data are discussed in terms of elastic and inelastic phonon scattering and exchange coupling. Moreover, the perturbation of the hydrogen potential is evaluated.
Intrinsically-limited timing jitter in molybdenum silicide superconducting nanowire single-photon detectors
Authors: Caloz Misael , Korzh Boris , Ramirez Edward , Schönenberger Christian , Warburton Richard J. , Zbinden Hugo , Shaw Matthew D. , Bussières Félix
Published: October 2019

Recent progress in the development of superconducting nanowire single-photon detectors (SNSPDs) has delivered excellent performance and has had a great impact on a range of research fields. The timing jitter, which denotes the temporal resolution of the detection, is a crucial parameter for many applications. Despite extensive work since their apparition, the lowest jitter achievable with SNSPDs is still not clear, and the origin of the intrinsic limits is not fully understood. Understanding its intrinsic behavior and limits is a mandatory step toward improvements. Here, we report our experimental study on the intrinsically-limited timing jitter in molybdenum silicide SNSPDs. We show that to reach intrinsic jitter, crucial properties such as the latching current and the kinetic inductance of the devices have to be understood. The dependence on the nanowire thickness and the energy dependence of the intrinsic jitter are quantified, and the origin of the limits is exhibited. System timing jitter of 6.0 ps at 532 nm and 10.6 ps at 1550 nm photon wavelength has been obtained.
Fluctuating exchange interactions enable quintet multiexciton formation in singlet fission
Authors: Collins Miles I. , McCamey Dane R. , Tayebjee Murad J. Y.
Published: October 2019

Several recent electron spin resonance studies have observed a quintet multiexciton state during the singlet fission process. Here, we provide a general theoretical explanation for the generation of this state by invoking a time-varying exchange coupling between pairs of triplet excitons and subsequently solving the relevant time-varying spin Hamiltonian for different rates at which the exchange coupling varies. We simulate experimental ESR spectra and draw qualitative conclusions about the adiabatic and diabatic transitions between triplet pair spin states.
Linear and nonlinear statistical response theories with prototype applications to sensitivity analysis and statistical control of complex turbulent dynamical systems
Authors: Majda Andrew J. , Qi Di
Published: October 2019

Statistical response theory provides an effective tool for the analysis and statistical prediction of high-dimensional complex turbulent systems involving a large number of unresolved unstable modes, for example, in climate change science. Recently, the linear and nonlinear response theories have shown promising developments in overcoming the curse-of-dimensionality in uncertain quantification and statistical control of turbulent systems by identifying the most sensitive response directions. We offer an extensive illustration of using the statistical response theory for a wide variety of challenging problems under a hierarchy of prototype models ranging from simple solvable equations to anisotropic geophysical turbulence. Directly applying the linear response operator for statistical responses is shown to only have limited skill for small perturbation ranges. For stronger nonlinearity and perturbations, a nonlinear reduced-order statistical model reduction strategy guaranteeing model fidelity and sensitivity provides a systematic framework to recover the multiscale variability in leading order statistics. The linear response operator is applied in the training phase for the optimal nonlinear model responses requiring only the unperturbed equilibrium statistics. The statistical response theory is further applied to the statistical control of inherently high-dimensional systems. The statistical response in the mean offers an efficient way to recover the control forcing from the statistical energy equation without the need to run the expensive model. Among all the testing examples, the statistical response strategy displays uniform robust skill in various dynamical regimes with distinct statistical features. Further applications of the statistical response theory include the prediction of extreme events and intermittency in turbulent passive transport and a rigorous saturation bound governing the total statistical growth from initial and external uncertainties.
Resolution limit of data-driven coarse-grained models spanning chemical space
Authors: Kanekal Kiran H. , Bereau Tristan
Published: October 2019

Increasing the efficiency of materials design remains a significant challenge given the large size of chemical compound space (CCS). The use of a chemically transferable coarse-grained model enables different molecular fragments to map to the same bead type, significantly increasing screening efficiency. Here, we propose new criteria for the design of coarse-grained models allowing for the optimization of their chemical transferability and evaluate the Martini model within this framework. We further investigate the scope of this transferability by parameterizing three Martini-like models in which the number of bead types ranges from 5 to 16. These force fields are fully compatible with existing Martini environments because they are parameterized by interpolating the Martini interaction matrix. We then implement a Bayesian approach to determining which chemical groups are likely to be present on fragments corresponding to specific bead types for each model. We demonstrate that a level of accuracy comparable to Martini is obtained with a force field with fewer bead types, using the water/octanol partitioning free energy (ΔGW→Ol) as our metric for comparison. However, the advantage of including more bead types is a reduction of uncertainty when back-mapping these bead types to specific chemistries. Just as reducing the size of the coarse-grained particles leads to a finer mapping of conformational space, increasing the number of bead types yields a finer mapping of CCS. Finally, we note that, due to the large size of fragments mapping to a single Martini bead, a resolution limit arises when using ΔGW→Ol as the only descriptor when coarse-graining CCS.
Micromagnetic analysis of magnetization reversal in Fe77.5Si7.5B15 amorphous glass-coated nanowires
Authors: Rotărescu C. , Chiriac H. , Lupu N. , Óvári T.-A.
Published: October 2019

A micromagnetic model based on the finite element method (FEM) is proposed in order to investigate the specific role of the magnetoelastic anisotropy in the axial magnetization reversal process of highly magnetostrictive amorphous glass-coated nanowires with cylindrical symmetry, prepared by means of rapid quenching from the melt. Using a radially distributed magnetoelastic anisotropy term, we demonstrate that both the magnitude and the shape of the anisotropy distribution affect the value of their nucleation field, and, in well-defined cases, of their switching field. The analysis provides a good explanation framework for the characteristics of magnetic bistability in magnetostrictive glass-coated amorphous nanowires, enhancing the potential applicability of these novel ferromagnetic amorphous nanosized materials.
PNR study of the phase transition in FeRh thin films
Authors: Bull C. , Barton C. W. , Griggs W. , Caruana A. , Kinane C. J. , Nutter P. W. , Thomson T.
Published: October 2019

The first order antiferromagnetic to ferromagnetic metamagnetic phase transition of equiatomic FeRh offers new opportunities for novel antiferromagnetic memories and spintronic devices with the caveat that it can be utilized in thin film structures (<50 nm). Here, we report a polarized neutron reflectivity (PNR) study for three representative film thicknesses (5, 20, and 50 nm) aimed at determining the physical and magnetic structure of FeRh at room temperature and partway through the transition. The PNR results are analyzed with reference to X-ray diffraction, X-ray reflectivity, and atomic force microscopy data which together provide a consistent description of the magnetic and physical state of the FeRh thin films. The data demonstrate that the nucleation of the ferromagnetic phase initiates at the MgO substrate, and results from structural and magnetic measurements demonstrate that the magnetic behavior and strain properties of FeRh correlate with the evolving topography of the three films investigated.
Instabilities and turbulence in low-β guide field reconnection exhausts with kinetic Riemann simulations
Authors: Zhang Qile , Drake J. F. , Swisdak M.
Published: October 2019

The role of turbulence in low-β, guide-field reconnection exhausts is explored in 2D reconnection and 2D and 3D Riemann simulations. The structure of the exhaust and associated turbulence is controlled by a pair of rotational discontinuities (RDs) at the exhaust boundary and a pair of slow shocks (SSs) that are generated by counterstreaming ions beams. In 2D, the exhaust develops large-amplitude striations at the ion Larmor radius scale that are produced by electron-beam-driven ion cyclotron waves. The electron beams driving the instability are injected into the exhaust from one of the RDs. However, in 3D Riemann simulations, the additional dimension (in the out-of-plane direction) results in strong Buneman and electron-electron streaming instabilities at the RD which suppress the electron beam formation and therefore the striations in the exhaust. The strength of the streaming instabilities at the RD is controlled by the ratio of the electron thermal speed to Alfvén speed, with the lower thermal speed being more unstable. In the 3D simulations, an ion-ion streaming instability acts to partially thermalize the counterstreaming ion beams at the SSs. This instability is controlled by the ratio of the sound speed to Alfvén speed and is expected to be stable in the low β solar corona. The results suggest that in a guide field reconnection exhaust with 1≫β>me/mi, the kinetic-scale turbulence that develops will be too weak to play a significant role in energy conversion and particle acceleration. Therefore, the energy conversion will be mostly controlled by laminar physics or multi-x-line reconnection.
Direct and converse magnetoelectric effects of sandwiched composites worked in shear-shear mode studied by uniform equivalent circuit
Authors: Zhang Xiaoli , Zhou Jian-Ping , Yao Xi , Yang Zupei , Zhang Guangbin
Published: October 2019

There are few theoretical and experimental studies on shear-shear (S-S) mode magnetoelectric composites due to the complex shear vibration theories and high resonance frequency. In this article, a uniform equivalent circuit is proposed to analyze direct magnetoelectric (DME) and converse magnetoelectric (CME) effects of S-S mode sandwiched composites. The results show DME and CME changes of S-S mode are similar to that of L-T mode and L-L mode, but S-S mode has a higher DME coefficient near the resonance frequency. This research provides an effective theoretical method for the ME research and a route for the ME devices at high frequency.