Ionic conductivity and relaxation dynamics in plastic crystals with nearly globular molecules.

We have performed a dielectric investigation of the ionic charge transport and the relaxation dynamics in plastic crystalline 1-cyano-adamantane (CNA) and in two mixtures of CNA with the related plastic crystals adamantane or 2-adamantanon. Ionic charge carriers were provided by adding 1% of Li salt. The molecules of these compounds have nearly globular shape and, thus, the so-called revolving-door mechanism assumed to promote ionic charge transport via molecular reorientations in other PC electrolytes should not be active here. Indeed, a comparison of the dc resistivity and the reorientational α-relaxation times in the investigated PCs reveals complete decoupling of both dynamics. Similar to other PCs, we find a significant mixing-induced enhancement of the ionic conductivity. Finally, these solid-state electrolytes reveal a second relaxation process, slower than the α-relaxation, which is related to ionic hopping. Due to the mentioned decoupling, it can be unequivocally detected and is not superimposed by the reorientational contributions as found for most other ionic conductors.

Characterization of the hydro-geological regime of Yangtze River basin using remotely-sensed and modeled products.

The hydrology of the Third Pole, Asia's freshwater tower, has shown considerable sensitivity to the impacts of climate change and human interventions, which affect the headwaters of many rivers that originate therein. For example, the Yangtze River has its basin (YRB) experiencing wetness of terrestrial water storage (TWS), whose rainfall seems to be the primary source as inferred from the previous studies. Consequently, it is crucial to understand the contributions of each TWS's sub-domain - i.e., groundwater (GWS); total water content (TWC) stored as soil moisture, ice/snow, and canopy; and the surface water (SWS) storages - on YRB's wetness. Hence, SWS, from altimetry and imagery satellites, and TWC, from Global Land Data Assimilation System, are inverted considering the same basis function as for TWS from the Gravity Recovery and Climate Experiment, which account for the differences in the resolutions inherent in each product. Furthermore, a "tie-in" signal approach is used to fit the temporal patterns of GWS, TWC, and SWS to TWS (i.e., the observations). Results show improvements in the reconstructed GWS series concerning standard deviation, correlation coefficient, and Nash-Sutcliffe efficiency of 22%, 27%, and 120%, respectively, regarding the use of the TWS-budget equation. The reconstructed time series of GWS, TWC, and SWS present an increase of 1.76, 2.69, and 0.14 mm per year (mm/yr) and that YRB loses water stored at its aquifers 55% of the time (regarding 2003-2016 period) based on the quantile function of storage (QFS). The QFS's slope shows that TWS has a fast and small storage potential w.r.t. GWS since inland waters and soil moisture reflect the dryness impacting TWS first. Despite the evidence of an increase of 19.05 mm/yr in annual precipitation, which seems to explain the bulk in TWS, further investigation to characterize controls on TWS memory within YRB is still necessary.

A three-dimensional topology optimization model for tooth-root morphology.

To obtain the root of a lower incisor through structural optimization, we used two methods: optimization with Solid Isotropic Material with Penalization (SIMP) and Soft-Kill Option (SKO). The optimization was carried out in combination with a finite element analysis in Abaqus/Standard. The model geometry was based on cone-beam tomography scans of 10 adult males with healthy bone-tooth interface. Our results demonstrate that the optimization method using SIMP for minimum compliance could not adequately predict the actual root shape. The SKO method, however, provided optimization results that were comparable to the natural root form and is therefore suitable to set up the basic topology of a dental root.

Impact Factors and Prediction of Popular Topics in a Journal.

The impact factor (IF) for 2015 was recently released and this could be the time to once again reflect on its use as a metric of a journal. Problems and concerns regarding the IF have been addressed extensively elsewhere 1 2. The principle of the IF for a given year is that it represents the average number of citations of articles published in the journal in the two previous years.While authors frequently cite the IF as a determining factor for submission, the IF does not predict how many times individual articles will be cited. In a study from a peer-reviewed cardiovascular journal, nearly half of all published articles were poorly cited, i. e., less than five citations in five years 3. A similar percentage seems to apply to our journal. In nearly all journals we estimate that the majority of citations relate to a minority of the articles. Some articles are never cited. 13 % of the articles published in our journal from 2010 to 2013 have never been cited. Even authors of poorly cited articles benefit from the IF since many institutions use the combined impact factors of their published papers to measure research activity and this may be reflected in their research budgets.The competition for the printed pages in the six annual issues of Ultraschall in der Medizin/European Journal of Ultrasound (UiM/EJU) has resulted in high rejection rates (between 80 % and 90 %). One negative review with recommendation of major revision may therefore result in rejection. Peer-review fraud where the submitting author listed recommended reviewers with fake email addresses supplying fabricated peer reviews has recently been described in the New England Journal of Medicine 4. Some of the editors of our journal believe they have experienced this as well. Fabricating reviews in order to get a high IF for an article is to be considered fraud and is inexcusable.One aspect of using impact factors as a measure of the quality of a journal is that the IF only goes back two years. There may be differences between journals for different medical specialties since the citations in some areas seem to "burn out" within a few years while some articles continue to be cited even after several years. Therefore, a citation window that is longer than 2 years has been proposed 5.For this editorial we took a look at the 60 articles published in UiM/EJU in 2010. Half of them were no longer being cited in 2015. However, 10 articles were cited more than 5 times in 2015, and 5 of these were cited more than 10 times 6 7 8 9 10. It therefore seems that many of our articles have a long scientific life and generate more citations than indicated by the IF. Moreover, some articles have the highest number of citations after three years when they are no longer contributing to the impact factor. The most frequently cited articles from 2010 were multicenter studies, recommendations, and papers on hot topics like contrast-enhanced ultrasound (CEUS) and elastography, but it should be noted that there were also articles on the same topics that were poorly cited.The same trending topics continued into 2013 now topped by European guidelines and recommendations 11 12 13. 9 of the 10 most cited articles we published in 2014 were on CEUS or elastography 14 15 16 17 18 19 20 21 22, but the most cited article from that year so far has been on peripheral nerves 23. Surprisingly many good scientific papers on obstetrics/fetal US and musculoskeletal US have low citation rates 24 25 26. Our predictions for 2016 based on the topics of submitted articles in the last 12 months are that CEUS and elastography will continue to be popular topics.It is also worth mentioning that there can be a discrepancy between which titles are cited and which are accessed online. In addition to international guidelines, our CME articles are usually popular according to online access. CME articles are well established educational papers but they are rarely cited for the IF. Looking at the most read full-text recent articles on our journal's website shows that multicenter studies as well as recommendations backed by a national society or by the EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) are still important 27 28 29 30 31 32 33. Upcoming important topics appear to be pediatric use of CEUS, simulation training and the introduction of ultrasound to medical students 34 35 36 37. Some of these are also backed by EFSUMB.A recent paper on the IF of radiology journals found that subspecialty radiology journals had a higher IF than general radiology journals 38. This could prove a challenge to interdisciplinary journals like ours but we take pride in continuing to cover all aspects of ultrasound in more than 15 fields.The distribution between reviews, original articles and case reports in a journal is worth addressing. An important aspect of a journal is the publication of original scientific research articles. CME articles, pictorials and letters are important for other reasons but are cited at a lower rate. The value of case reports with regard to the IF is low since they are rarely cited 39 and we have observed that some journals have abandoned the publication of case reports, thus leaving them to spin-off journals. The rationale is that keeping case reports in a journal will only increase the denominator, thereby decreasing the IF 39. At our journal we have seen a decline in case report submissions but still want to publish them and even put one case on the front cover of every issue. Case reports still hold an educational value 40 and are important to our readers.In conclusion, a healthy mix of original articles, CME articles, reviews and case reports combined with a few international guidelines and recommendations is important to UIM/EJU. Although we see popular topics like CEUS and elastography, it is not possible to predict which articles will be read or even cited based on the topic, with multicenter studies being the exception.

A Milestone: Approval of CEUS for Diagnostic Liver Imaging in Adults and Children in the USA.

The approval of microbubbles with the inert gas sulfur hexafluoride (SF6) and a palmitic acid shell (SonoVue(®), Bracco Geneva, CH) for the diagnostic imaging of liver tumors in adults and children by the FDA in the United States represents a milestone for contrast-enhanced ultrasound (CEUS).This warrants a look back at the history of the development of CEUS. The first publications based on echocardiographic observations of right ventricular contrast phenomena caused by tiny air bubbles following i. v. injection of indocyanine green appeared around 1970 1 2 3. A longer period of sporadic publications but no real progress then followed since, in contrast to X-ray methods, ultrasound works quite well without a contrast agent.It is noteworthy that the foundations for further development were primarily laid in Europe. The development and approval (1991) of the contrast agent Echovist(®) by a German contrast manufacturer for echocardiography unsuitable for passing through lungcapillaries 4 5 resulted in the first extracardiac indications, e. g. for detecting retrovesical reflux and tubal patency, in the mid-1980 s 6 7 8. The sensitivity of color Doppler was not able to compensate for the lack of an ultrasound contrast agent compared to CT with its obligatory contrast administration.Studies of SHU 508 - microbubbles of air moderately stabilized with galactose and palmitic acid - began in 1990 9 10 11 12 13 14 15 and the contrast agent was then introduced in 1995 in Germany as Levovist(®). The most important publications by Blomley, Cosgrove, Leen, and Albrecht are named here on a representative basis 16 17 18 19 20.SHU 508 along with other US contrast agents provided impressive proof of the superiority of CEUS for the diagnosis of liver metastases. However, practical application remained complicated and required skill and technical know-how because of a lack of suitable software on US units 21 22 23 24 25. The monograph regarding the use of contrast agent in the liver by Wermke and Gaßmann is impressive but unfortunately only available in German 26. In addition to being applied in the heart and the liver, CEUS was first used in transcranial applications 27 and in vessels 28, the kidneys 29, and the breast 30. Measurements at transit times were also of particular interest 31. It was difficult to convince ultrasound device manufacturers of the need to adapt US units to US contrast agents and not vice versa.The breakthrough came with low MI phase contrast inversion and the introduction of SonoVue(®) in many European countries in 2001. This more stable US contrast agent is easy to use and is becoming indispensable in diagnostic imaging of the liver 32 33 34 35 36 37 38 39 40. Studies have shown its excellent tolerability 41 and diagnostic reliability comparable to that of MDCT and MRI in the liver 42 43. Today it would be unimaginable to diagnose liver tumors without CEUS 44. This also applies to very small lesions 45 46.EFSUMB published the first CEUS guidelines in 2004 47 which have since been reissued and divided into hepatic 48 and extrahepatic applications 49. The first recommendations regarding quantitative assessment have also been published 50.The increasing scientific interest in CEUS is evident based on the greater number of PubMed hits for Echovist(®) (ca. 130), Levovist(®) (ca. 500) and SonoVue(®) (ca. 1500) as well as on the fact that publications regarding CEUS comprise almost 20 % of UiM/EJU articles in the last 10 years. The number of CEUS articles in UiM/EJU continues to be high 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75.In the clinical reality, CEUS has been able to become established alongside CT and MRI according to the saying "better is the enemy of good" 76 as the method of choice after B-mode ultrasound in the evaluation of liver tumor malignancy in Germany, where the technically challenging method is promoted. In the case of unclear CT and MRI findings, CEUS performed by an experienced examiner/clinician often provides the solution, particularly in the case of small lesions, and is the last resort before US-guided biopsy 45 46. However, there is a lack of competent CEUS examiners and Germany continues to be the world champion of X-ray examinations with no noticeable reverse trend. In almost every doctor's office and hospital, ultrasound costs are by far not fully covered, resulting in an extremely high frequency of CT use with CT being available to everyone regardless of insurance status.The USA is now in the starting position for CEUS. It will be exciting to see how the method will develop there. The FDA's decision to approve sulfur hexafluoride (Lumason(®) = SonoVue(®)) should be considered against the background of the radiation exposure caused by CT examinations and the fact that MRI using gadolinium-containing contrast agents is no longer considered noninvasive because of nephrogenic systemic fibrosis (NSF) and the accumulation of the agent in the cerebrum. An essential point of the campaign regarding the avoidance of diagnostic radiation exposure triggered in the USA by the publications of Brenner et al. 77 78 was that the agent was approved for use in the liver even for children 79 80 - still off label in Europe - without additional comprehensive studies due to the available scientific results and the very low side effects profile of Lumason(®) (= SonoVue(®)). It is admittedly unclear why other indications (except the heart which has been approved since 2014) are excluded even though the microbubbles as a pure blood pool contrast agent can be diagnostically used in the entire vascular system and bed of all organs. To our knowledge, there is no such restriction on the approval of X-ray contrast agents.Like echocardiography and emergency ultrasound, CEUS began in Europe but will probably only establish its final diagnostic value as a "reimport".This is a major opportunity to permanently define the role of Ultrasound as a highly valuable, patient-centered imaging method in the German health care system.This may prompt some of our international readers to reflect upon the role of CEUS in their own countries.

Regarding the Content and Goals of UIM/EJU.

The successful collaboration among Ultraschall in der Medizin/ European Journal of Ultrasound (UiM/EJU), DEGUM, ÖGUM and SGUM as well as Thieme Verlag was confirmed in the respective general meetings in Davos recently, and it was agreed that such cooperation should continue in coming years. Last year, in discussions with the previous DEGUM board of directors the issue of orientation of the content of UiM/EJU, among other things, was an essential topic. Briefly stated, the constructive criticism was: too much science, too little continuing education. It is worthwhile and necessary to address this criticism.The purpose of our clinically-oriented journal is to present the state of the art of multidisciplinary ultrasound in medicine, consistent with the objectives of scientific organizations as well to promote the analysis and communication of this medical technology to the user. This balancing act is difficult for our journal; the limited scope and high number of manuscript submissions result in a rejection rate of over 80 %. Consequently it is hardly possible to cover all special fields in every edition. Nevertheless, in almost 20 years of editorial activity, we have received fewer than five letters from readers criticizing our selection of content.As a journal with German roots, the bilingual diversified CME contributions represent the core of our continuing education opportunities, including pictorial essays and case reports, as well as consensus papers and articles on quality control. In conjunction with the EFSUMB, a series of guidelines has been published, available to everyone - not just subscribers of UiM/EJU. Guidelines are important, since they have an influence on the practice and quality of ultrasound applications in diagnosis and therapy. Calculated in terms of pages and percentages, this is more than just a little, since clinically-related scientific articles also represent the requirement for continuing education within the rules of the medical profession.Considered retrospectively, contents of recent volumes of UiM/EJU - apart from the large block of obstetrical articles - were dominated by CEUS, elastography, the breast and "small parts".Although CEUS has been established scientifically 1 2 3 4, but not really employed everywhere, additional articles are needed in order to help integrate the use of contrast agents in routine practice apart from examination of the liver 5 6 7 8 9 10. Likewise, we have endeavored to support elastography as a new technical feature of sonography. Examples of this are publications regarding its use in diagnosing diseases of the liver 11 12 13 14 15, breast 16 17 18 19 and the thyroid 20, as well as its use in examining the pancreas 21 and gastrointestinal tract 22.In addition, for the benefit of sonographers, who are used to observing associated fields from the sidelines, we have presented unexpected highlights, such as articles on peripheral nerves 23 24 25.The contents of this year's final edition present the common interdisciplinary perspective of the editorial team. In addition to a CME article on elastography in the diagnosis of breast cancer 26, we would particularly refer you to two prospective articles: on the importance of CEUS in the aftercare of colon cancer 27 and the value of high-frequency examination of the liver surface compared to elastography and laparoscopy when cirrhosis is suspected 28.Further articles on elastography 29 30 31 32 indicate that the possibilities and limitations of this technology have yet to be reached.As editors, we will be satisfied if the publication interests as many readers as possible, be it online or in the print version, and that they are able to read about new as well as established techniques. We are certain that the societies for ultrasound in medicine, UiM/EJU, and "our sonographic community" are excited to learn about scientific advancements, and we are pleased when, thanks to submissions by our active and innovative authors together with reviewers and our advisory committee, we can set our sights on new topics.

CEUS in hepatocellular carcinoma and intrahepatic cholangiocellular carcinoma in 320 patients - early or late washout matters: a subanalysis of the DEGUM multicenter trial.

PURPOSE: The aim of the study was the comparison of tumor vascularization and contrast enhancement in contrast-enhanced ultrasound (CEUS) for the characterization of hepatocellular carcinoma (HCC) and intrahepatic cholangiocellular carcinoma (ICC). We present data of the subpopulations HCC and ICC examined in the DEGUM multicenter trial for the characterization of focal liver lesions in clinical practice. MATERIALS AND METHODS: Based on the data of the DEGUM multicenter trial (1349 patients), all patients with histologically proven HCC (n = 278) and ICC (n = 42) were analyzed. The vascularity pattern and contrast enhancement pattern during the arterial, portal-venous and late phase were compared. RESULTS: An underlying liver cirrhosis was found in 214/278 patients with HCC (76.9 %) and 7/42 patients with ICC (16.7 %). In CEUS, HCC showed a global arterial hyperenhancement compared to ICC (HCC: tumor center: 60.3 %; tumor periphery: 75 %; ICC: tumor center: 16.7 %; tumor periphery: 40.5 %). ICC showed an initial contrast enhancement primarily at the tumor periphery (ICC: 85.7 % vs. HCC: 61 %) followed by an early portal-venous contrast washout in the tumor center (ICC: 85.8 % vs. HCC: 49.8 %) and tumor periphery (ICC: 66.7 % vs. HCC: 32.6 %). HCC showed a delayed contrast washout (late phase hypoenhancement: HCC: 75 % vs. ICC: 92.9 %). CONCLUSION: ICCs are rare in cirrhotic livers. CEUS can demonstrate differences in the vascularization patterns between HCC and ICC. HCC showed an arterial global hyperenhancement and delayed contrast washout in the late phase. ICCs are characterized by an arterial contrast enhancement at the tumor periphery with early contrast washout of the vascularized parts of the lesions in the portal-venous and late phase.

Importance of Abdominal Ultrasound in 17 Patients with Histologically Confirmed Autoimmune Pancreatitis (AIP).

PURPOSE: Autoimmune pancreatitis (AIP) is an independent, underdiagnosed, rare form of chronic pancreatitis. The goal of this study is to document ultrasound findings in histologically confirmed AIP in order to determine the diagnostic value of ultrasound. MATERIALS AND METHODS: 6 of 74 DEGUM instructors for internal medicine (level 3 and 2) provided anonymized clinical and sonographic data from 17 patients with histologically confirmed AIP. RESULTS: 9/17 patients had diffuse AIP, 8/17 had focal AIP, 14/17 suffered from upper abdominal pain, 9/17 had jaundice, and 3/9 had an elevated IgG4 level. Ultrasound showed diffuse hypoechoic organ enlargement in 9/17 cases and a hypoechoic tumor with an unclear border in 8/17 cases. AIP was verified by ultrasound-guided percutaneous core biopsy in 14 cases, by biopsy of the bile duct in 1 case, and by surgical biopsy in 2 cases. Involvement of the hepatobiliary system was present in 7/17 patients and autoimmune cholangitis was verified in 5 cases. All patients experienced remission after immunosuppressive treatment. The pancreatic duct had a normal width in 11 cases, was dilated in 5 cases, and was stenosed over a long stretch in 3 cases. Contrast-enhanced ultrasound did not show uniform signal increase but also no significantly reduced or absent perfusion. CONCLUSION: Ultrasound can be diagnostically useful if the clinical manifestations of AIP are known. While the diffuse form allows an ad-hoc suspected diagnosis, the focal form can only be suspected in the case of additional extrapancreatic involvement. Contrast-enhanced ultrasound (CEUS) contributes greatly to the differentiation from ductal adenocarcinoma in the case of focal AIP.

Prolonged heterogeneous liver enhancement on contrast-enhanced ultrasound.

INTRODUCTION: Prolonged heterogeneous liver enhancement (PHLE) is a rare phenomenon that is similar to the ultrasound findings of portal venous gas. The purpose of this report is to describe the phenomenon of PHLE after the injection of the ultrasound contrast agent SonoVue(®). PATIENTS AND METHODS: From 2000 to 2013, 13 patients with PHLE ("cloudy", "wool-like") after bolus injection of SonoVue(®) were observed. The height, weight, and body mass index (BMI) of the patients, and the number of injections were analyzed. In addition, the literature was reviewed. RESULTS: The phenomenon occurred as early as 2 minutes after bolus contrast administration and lasted up to 5 hours on both B-mode and contrast-specific ultrasound. 8/13 (62 %) patients received two or more boluses. None of the patients experienced SonoVue(®)-related side effects or health problems. The phenomenon was not reproducible in 3 patients who received a second SonoVue(®) injection 24 hours after receiving the first. CONCLUSION: This phenomenon is more likely to occur in patients who receive high-dose (or multiple) injections of UCA. It may occur as early as 2 minutes after contrast administration, and therefore, may affect the evaluation of focal liver lesions in the late phase. This phenomenon should not be misdiagnosed as a pathological finding of the liver.