bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating spatiotemporal variation in water chemistry of the upper Colorado River using longitudinal profiling
Authors: Hensley Robert T. , Spangler Margaret J. , DeVito Lauren F. , Decker Paul H. , Cohen Matthew J. , Gooseff Michael N. 
Published: December 2019

AbstractStream water chemistry is traditionally measured as variation over time at fixed sites, with sparse sites providing a crude understanding of spatial heterogeneity. An alternative Lagrangian reference frame measures changes with respect to both space and time as water travels through a network. Here, we collected sensor‐based measurements of water chemistry at high spatial resolution along nearly 500 km of the Upper Colorado River. Our objective was to understand sources of spatiotemporal heterogeneity across different solutes and determine whether longitudinal change manifests as smooth gradients as suggested by the River Continuum Concept (RCC) or as abrupt changes as suggested by the Serial Discontinuity Concept (SDC). Our results demonstrate that Lagrangian sampling integrates spatiotemporal variation, and profiles reflect processes that vary in both space and time and over different scales. Over each day of sampling, water temperature (T) and dissolved oxygen (DO) varied strongly in response to diel solar cycles, with most of the variation driven by sampling time rather than sampling location. Equilibration of T and DO with the atmosphere limited small scale spatial heterogeneity, with variation at the entire profile scale driven by regional climate gradients. As such, T and DO profiles more closely approximated the smooth gradients of the RCC (though including temporal sampling artefacts). Conversely, variation in specific conductance and nitrate (NO3‐N) was largely driven by spatial patterns of lateral inflows such as tributaries and groundwater. This resulted in discrete shifts in the profiles at or downstream of discontinuities, appearing as the profiles expected with the SDC. The concatenation of spatiotemporal variation that produces observed Lagrangian profiles presents interpretive challenges but also augments our understanding of where, how, and critically why water chemistry changes in time and space as it moves through river networks.
Potential high‐quality growing tea regions in Ecuador: an alternative cash crop for Ecuadorian small landholders
Authors: Rivera‐Parra José L , Peña‐Loyola Paula J 
Published: December 2019

AbstractBACKGROUNDAgriculture is the main means of subsistence for most of the population in developing countries. Crops that can increase their value with in situ processing have a big impact on the small landholder's economics. Moreover, crops such as coffee and cocoa beans have been very important for Ecuadorian farmers. In this study, we wanted to analyze if the climatic conditions exist for growing high‐quality tea in Ecuador and determine the areas that will be less affected by global climate change in the future.RESULTSWe used a GIS (geographic information systems) based analysis, together with ecological niche modeling to determine areas in Ecuador where Ceylon and Nilgiris tea varieties could be grown, which will maintain similar ecological conditions in the future, and have a high agricultural aptitude. In total, there are more than 150 000 ha in Ecuador that could be converted to high‐quality tea plantations, most of them in the coastal provinces, with some specific areas in the Andean foothills.CONCLUSIONEcuador has a significant amount of land with the potential to grow high‐quality tea, with no significant ecological niche modifications due to climate change in the long‐term future. Tea is a viable and potentially highly profitable crop for small landholders and should be considered by local stakeholders. © 2019 Society of Chemical Industry
The Association Between Ultrasound Features and Biological Properties of Invasive Breast Carcinoma Is Modified by Age, Tumor Size, and the Preoperative Axilla Status
Authors: Tong Yu‐yang , Sun Pei‐xuan , Zhou Jin , Shi Zhao‐ting , Chang Cai , Li Jia‐wei 
Published: December 2019

ObjectivesTo investigate the value of ultrasound (US) feature‐based models in predicting the proliferation and invasiveness of invasive breast cancer (IBC) and to compare the performance of models based solely on US features with models that combined US features, patient age, tumor size, and axilla status from US.MethodsWith ethical approval, 746 patients with a pathologic diagnosis of IBC were reviewed for preoperative clinical, US, and postoperative pathologic data. The proliferation and invasiveness properties of the IBC included the histologic grade and Ki‐67 status and lymphovascular invasion (LVI) and axillary lymph node metastasis (ALNM), respectively. Logistic regression analyses were used to identify independent risk factors for tumor proliferation and invasiveness.ResultsPosterior echo enhancement, calcification, a tumor size larger than 2 cm, and suspicion of ALNM from axillary US were independent risk factors for a high histologic grade and high Ki‐67 expression of IBC (P < .05). A posterior echo shadow, patient age younger than 45 years, and suspicious findings on axillary US imaging were independent variables for predicting the presence of LVI and ALNM in IBC (P < .05). Calcification was the independent factor for predicting LVI (P = .013). The predictive performance of the combined models was improved compared with the US feature‐based models, with a higher accuracy rate and negative predictive value. The area under curve of the combined models was also significantly higher than that of the single models (P < .05).ConclusionsCompared with the US feature‐based models, the combined models yielded better predictive performance. This may provide a more robust model to predict the tumor biological properties of IBC before surgery.
Numerical method for generalized time fractional KdV‐type equation
Authors: Kong Desong , Xu Yufeng , Zheng Zhoushun 
Published: December 2019

AbstractIn this article, an efficient numerical method for linearized and nonlinear generalized time‐fractional KdV‐type equations is proposed by combining the finite difference scheme and Petrov–Galerkin spectral method. The scale and weight functions involved in generalized fractional derivative cause too much difficulty in discretization and numerical analysis. Fortunately, motivated by finite difference method for fractional differential equation on graded mesh, the stability and convergence of the constructed method are established rigorously. It is proved that the full discretization schemes of generalized time‐fractional KdV‐type equation is unconditionally stable in linear case. While for nonlinear case, it is stable under a CFL condition and for not small ϵ, coefficient of the high‐order spatial differential term. In addition, the full discretization schemes with respect to linear and nonlinear cases respectively converge to the associated exact solutions with orders and , where τ, α, N and m accordingly indicate the time step size, the order of the fractional derivative, polynomial degree, and regularity of the exact solution. Numerical experiments are carried out to support the theoretical results.
MALDI–HRMS imaging and HPLC–HRESI–MSn characterisation of kaurane diterpenes in the fruits of Xylopia aethiopica (Dunal) A. Rich (Annonaceae)
Authors: Kyekyeku James Oppong , Asare‐Nkansah Samuel , Bekoe Samuel Oppong , Sezgin Selahaddin , Adosraku Reimmel Kwame , Spiteller Michael 
Published: December 2019

AbstractIntroductionKaurane diterpenes, notably xylopic acid, have demonstrated important biological activities including analgesia, anti‐oxidant, antimicrobial and cytotoxicity. The fruits of Xylopia aethiopica have been reported to be a rich source of kaurane diterpenes.ObjectiveAn analytical approach for detailed imaging and characterisation of selected kaurane diterpenes was developed using matrix‐assisted laser desorption/ionisation high‐resolution mass spectrometry (MALDI‐HRMS) imaging techniques and high‐performance liquid chromatography‐high resolution electrospray ionisation‐tandem mass spectrometry (HPLC‐HRESI‐MSn) studies, respectively.MethodsThe images of the compounds were constructed based on selected ions from their HRESI–MS spectra. The matrix employed comprised a solution of α–cyano–4–hydroxycinnamic acid (HCCA) in acetonitrile–water with trifluoroacetic acid (TFA). HPLC–HRESI–MSn measurements were conducted on an LTQ–Orbitrap spectrometer equipped with a heated electrospray ionisation (HESI)–II source.ResultsThe analytical strategy adopted showed the spatial distribution of the compounds in the fruits of X. aethiopica based on the dominant ions at m/z 301.2163 [M + H – HOCOCH3]+ and m/z 399.1932 [M + K]+ for xylopic acid, m/z 317.2111 [M + H]+ and m/z 355.1670 [M + K]+ for 15–oxo–ent–kaur–16–en–19–oic acid and m/z 303.2319 [M + H]+ for ent–kaur–16–en–19–oic acid. The fragmentation patterns of the compounds were proposed based on the HRESI–MSn measurements.ConclusionsThe study revealed the spatial variability, differential behaviours and specificity of the selected kaurane diterpenes in the fruit, seed and pericarp. The compounds under study were predominantly restricted to the pericarp of the fruit with trace amounts in the seed.
Fetal cardiac intervention—Perspectives from a single center
Authors: Guseh Stephanie H. , Friedman Kevin G. , Wilkins‐Haug Louise E. 
Published: December 2019

AbstractFetal cardiac intervention was first proposed in the early 1990s to impact cardiac development and survival of fetuses with fetal aortic stenosis and evolving hypoplastic left heart syndrome (HLHS). Although initial attempts of fetal aortic valvuloplasty were unsuccessful and carried a high rate of morbidity and mortality, our collaborative group at the Brigham and Women's Hospital and Boston Children's Hospital have reinvigorated the procedure using improvements in imaging, anesthesia, balloon catheters, and surgical techniques. Two decades of experience have now allowed us to document the safety of in utero intervention and to achieve a better understanding of the impact of midgestation intervention on developing HLHS. Research into underlying genetics, predictive biomarkers, and ways to incorporate stem cell technology will hopefully allow us to further refine the procedure to most benefit children with this historically lethal disease.
Impact of first trimester determination of abnormal cord insertion on twin‐to‐twin transfusion syndrome and other adverse outcomes in monochorionic diamniotic twins: A retrospective cohort study
Authors: Saito Mizue , Tokunaka Mayumi , Takita Hiroko , Goto Minako , Machi Maya , Sekiya Bunbu , Arakaki Tatsuya , Hamada Shoko , Oba Tomohiro , Matsuoka Ryu , Sekizawa Akihiko 
Published: December 2019

AbstractObjectiveTo assess the influence of abnormal cord insertion (CI) detected by first trimester ultrasonography on the development of twin‐to‐twin transfusion syndrome (TTTS) in monochorionic diamniotic (MCDA) twins.MethodIn this retrospective cohort study, consecutive patients with MCDA twins who underwent fetal ultrasound screening in the first trimester between January 2011 and January 2017 were enrolled. The CI sites were evaluated between 11 + 0 and 13 + 6 weeks' gestation. All twin pairs were assigned to the abnormal CI group (twin pair with velamentous cord insertion (VCI) and/or marginal cord insertion (MCI) in one or both twins) or the normal CI group (twin pair with both normal CI). The relationships of adverse outcomes in two groups were analyzed.ResultsA total of 109 MCDA twin pairs were examined; 15 cases were classified into the abnormal CI group and 94 cases into the normal CI group. The incidence of TTTS was significantly higher in the abnormal than in the normal CI group (26.7% vs 7.45%, P = .04). In patients who developed TTTS, all donors had VCI.ConclusionUltrasound evaluation of abnormal CI at 11 + 0 to 13 + 6 weeks' gestation in MCDA twins is valuable in the assessment of the risk for TTTS.
Click chemistry‐type crosslinking of a low‐conductivity polyethylene copolymer ternary blend for power cable insulation
Authors: Mauri Massimiliano , Hofmann Anna I , Gómez‐Heincke Diana , Kumara Sarath , Amir Masoud Pourrahimi  , Ouyang Yingwei , Hagstrand Per‐Ola , Gkourmpis Thomas , Xu Xiangdong , Prieto Oscar , Müller Christian 
Published: December 2019

AbstractHigh‐voltage direct‐current power cables are vital for the efficient transport of electricity derived from renewable sources of energy. The most widely used material for high‐voltage power cable insulation – low‐density polyethylene (LDPE) – is usually crosslinked with peroxides, a process that releases unwanted by‐products. Hence, by‐product‐free crosslinking concepts that mitigate the associated increase in electrical conductivity are in high demand. Click chemistry‐type crosslinking of polyethylene copolymer mixtures that contain glycidyl methacrylate and acrylic acid co‐monomers is a promising alternative, provided that the curing reaction can be controlled. Here, we demonstrate that the rate of the curing reaction can be adjusted by tuning the number of epoxy and carboxyl groups. Both dilution of copolymer mixtures with neat LDPE and the selection of copolymers with a lower co‐monomer content have an equivalent effect on the curing speed. Ternary blends that contain 50 wt% of neat LDPE feature an extended extrusion window of up to 170 °C. Instead, at 200 °C rapid curing is possible, leading to thermosets with a low direct‐current electrical conductivity of about 10−16 S cm−1 at an electric field of 20 kV mm−1 and 70 °C. The conductivity of the blends explored here is comparable to or even lower than values measured for both ultraclean LDPE and a peroxide‐cured commercial crosslinked polyethylene grade. Hence, click chemistry curing represents a promising alternative to radical crosslinking with peroxides. © 2019 Society of Chemical Industry
Totally laparoscopic and totally robotic surgery in patients with left‐sided colonic diverticulitis
Authors: Bilgin Ismail Ahmet , Bas Mustafa , Benlice Cigdem , Esen Eren , Ozben Volkan , Aytac Erman , Baca Bilgi , Hamzaoglu Ismail , Karahasanoglu Tayfun 
Published: December 2019

AbstractBackgroundIntroduction of the da Vinci Xi system has facilitated the use of robotics in colorectal surgery. Nevertheless, data on the outcomes of robotic surgery for the treatment of colonic diverticulitis have remained scarce.MethodsPatient demographics, clinical characteristics, and perioperative outcomes of the patients undergoing totally robotic with the da Vinci Xi system or laparoscopic surgery for left‐sided colonic diverticulitis (LCD) were compared.ResultsLaparoscopic and robotic groups included 22 and 20 patients, respectively. There were no significant differences between the two groups in terms of patient demographics, clinical characteristics, operative time, and postoperative complications. There were three conversions in the laparoscopy group and no conversion in the robotic group (P = 0.23). Conversion to open surgery was associated with postoperative morbidity (P = 0.02).ConclusionRobotic surgery is an applicable alternative for the treatment of LCD. Robotic approach may potentially lower the risk of operative morbidity by reducing the requirement of conversion.
Research on the accuracy of three‐dimensional localization and navigation in robot‐assisted spine surgery
Authors: Chen Long , Zhang Fengfeng , Zhan Wei , Gan Minfeng , Sun Lining 
Published: December 2019

AbstractBackgroundCompared with traditional surgical methods, which only rely on doctors' experience, three‐dimensional robot‐assisted navigation technology could locate the lesion more accurately.MethodsThe transformation principle of three‐dimensional navigation system was analyzed. The surgical path was planned on the reconstructed three‐dimensional model. The experimental data of positioning position and posture were used as two important parameters to evaluate the accuracy of the robot‐assisted spine surgery navigation system.ResultsThe final experimental results show that the accuracy of the positioning and navigation position of the robot‐assisted surgical navigation system was 2.54 ± 0.15mm (range 2.25‐2.76 mm). The accuracy of positioning and navigation posture was 2.55 °  ± 0.49°(range 1.92°‐3.21°).ConclusionIt could be seen the three‐dimensional positioning and navigation system proposed in this study had a high accuracy and could basically meet the basic accuracy requirements of spine surgery.
Dam reverse flow events influence limnological variables and fish assemblages of a downstream tributary in a Neotropical floodplain
Authors: Ferreira Karina , Lopes Taise Miranda , Affonso Igor de Paiva , Agostinho Angelo Antonio , Gomes Luiz Carlos 
Published: December 2019

AbstractWe used a dam‐free tributary (the Baía River) in the upper Paraná River floodplain downstream of a major dam in the Paraná River, Brazil to investigate the effects of dam‐regulated reverse flow on limnological variables and fish. We tested the hypotheses that limnological variables in tributaries change based on flow direction and that fish assemblages respond to this variation. Sampling sites were determined considering flow direction (normal or reverse) and position (near or far from the river mouth). Limnological variables showed higher values for transparency, oxygen, pH, and electrical conductivity at sites near the mouth of the Baía River during reverse flow. Species richness and evenness differed significantly in relation to position, with higher values closer to the Paraná River. The average standard length of fish species was higher near the mouth of the Baía River and during the reverse flow period. No significant differences in species abundance were found. Reverse flow into the Baía River brought nutrient‐poor water from the dammed Paraná River, thereby altering the limnological variables. This flow condition impelled the entry of species with higher average standard lengths. However, increased species richness and low evenness were due to the increase in species dispersal rates under all flow conditions. Our results emphasize that the effects of dams can extend several kilometres into the floodplain, provide basic knowledge on the effects of major dams on downstream pristine tributaries, and highlight the need for further studies to understand the wider influences.
Impact of prospective measurement of outflow tracts in prediction of coarctation of the aorta
Authors: Vigneswaran T. V. , Zidere V. , Chivers S. , Charakida M. , Akolekar R. , Simpson J. M. 
Published: December 2019

ABSTRACTObjectivesPrenatal diagnosis of coarctation of the aorta (CoA) is associated with reduced mortality and morbidity, however, accurate prenatal prediction remains challenging. To date, studies have used retrospective measurements of the outflow tracts to evaluate their potential to predict CoA. Our primary objective was to evaluate prospectively acquired measurements of the outflow tracts in fetuses with prenatally suspected CoA. A secondary aim was to report the postnatal prevalence of bicuspid aortic valve in this cohort.MethodsPregnancies with suspicion of isolated CoA and with a minimum of 6 months' postnatal follow‐up available were identified from the cardiac database of a tertiary fetal cardiology center in the UK, between January 2002 and December 2017. Measurement of the aortic valve, pulmonary valve, distal transverse aortic arch (DTAA) and arterial duct (AD) diameters were undertaken routinely in fetuses with suspected CoA during the study period. Z‐scores were computed using published reference ranges based on > 7000 fetuses from our own unit.ResultsOf 149 pregnancies with prenatally suspected CoA included in the study, CoA was confirmed within 6 months after birth in 77/149 (51.7%) cases. DTAA diameter Z‐score and the Z‐score of second‐trimester DTAA/AD diameter ratio were smaller in fetuses with postnatally confirmed CoA than those in false‐positive cases (–2.8 vs –1.9; P = 0.039 and –3.13 vs –2.61; P = 0.005, respectively). Multiple regression analysis demonstrated that the Z‐scores of DTAA and AD diameters were the only significant predictors of postnatal CoA (P = 0.001). Bicuspid aortic valve was identified in 30% of the false‐positive cases.ConclusionsMeasurement of DTAA and AD diameter Z‐scores can be used to ascertain risk for postnatal CoA in a selected cohort. The high incidence of bicuspid aortic valve in false‐positive cases merits further study with respect to both etiology and longer‐term significance. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Imaging in gynecological disease (18): clinical and ultrasound characteristics of urinary bladder malignancies
Authors: Knez J. , Nardelli F. , van den Bosch T. , Sladkevicius P. , Valentin L. , Jurkovic D. 
Published: December 2019

ABSTRACTObjectiveTo describe the clinical and ultrasound characteristics of urinary bladder malignancies diagnosed on transvaginal ultrasound in women presenting with suspected gynecological problems.MethodsThis was a multicenter retrospective study of women with a histological diagnosis of urinary bladder malignancy that was suspected on transvaginal ultrasound examination. The cases were collected from three centers that specialize in the use of pelvic ultrasound and had been examined between January 2007 and October 2018. Clinical data were obtained from the computer databases and all tumor images were assessed by two of the authors (D.J. and J.K.) to identify characteristic sonographic patterns. We compared the characteristics of tumors between women presenting with symptoms suspicious of urinary bladder malignancy and those without such symptoms.ResultsThirty women with a confirmed diagnosis of urinary bladder malignancy on histological examination were included. Median age at diagnosis was 70.5 (range 36–88) years. The most common presenting symptom was postmenopausal bleeding, which was recorded in 18 (60%) women. Ten (33%) women had symptoms suspicious of bladder malignancy, of whom six had unexplained visible hematuria, three had unexplained recurrent urinary tract infections and one had dysuria and microhematuria. On histological examination, 23 (77%) women were diagnosed with primary bladder malignancy whilst seven (23%) had metastases in the bladder from other primary tumors. Out of 23 primary tumors, 21 (91%) were of urothelial origin (12 low grade and nine high grade). Most low‐grade urothelial carcinomas appeared on ultrasound as irregular papillary growth (11/12, 92%) and were moderately to highly vascular on color Doppler examination (8/12, 67%). The ultrasound appearances of primary non‐urothelial and metastatic tumors varied, without a clear common morphological tumor pattern. The tumors found in women with symptoms suggestive of bladder malignancy did not differ unequivocally from those detected in other women in terms of size, ultrasound morphology, vascularity or histological type.ConclusionUrinary bladder malignancies can be detected in patients undergoing transvaginal ultrasound examination for suspected gynecological problems. Primary urothelial cancers have a relatively uniform morphological pattern, whilst the appearances of other bladder malignancies are more variable. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.