bluuebunny/crossref_metadata_2025 huggingface dataset:
The Discovery of Mesoproterozoic Oceanic Crust In North Qaidam UHP Belt, NW China
Authors: CHEN Danling , REN Yunfei
Published: May 2019

The North Qaidam is an Early Paleozoic UHP metamorphic belt located at the north margin of the Tibet plateau. Eclogites in this belt contain both continental‐and oceanic‐type ones. In which, the continental‐type eclogites have protolith ages of 750–850 Ma and WPB or CFB geochemical signatures and are believed to have formed in a continental rift or an incipient oceanic basin setting related to the breakup of the Rodinia supercontinent, their metamorphic ages (421–458 Ma) and P–T paths are comparable to their host gneisses; oceanic‐type eclogites have cumulate gabbro or E‐MORB geochemical signatures, their protolith and metamorphic ages are 510–516 Ma and 425–450 Ma, respectively(Zhang et al., 2008). Therefore, the North Qaidam UHP belt was thought to record the whole Neoprotoerozoic–Paleozoic Wilson cycle (Song et al., 2014). In this study, we reported three new kinds of eclogites: kyanite‐bearing eclogite, lawsonite pseudomorph‐bearing eclogite and double mineral eclogite. They occur as big lentoid blocks in regional granitic gneiss in the western part of the belt. Phase equilibrium modelling and zircon LA‐ICPMS U‐Pb dating show that all these three eclogites experienced a clockwise P–T path with peak metamorphic conditions close to or fall in the coesite stability field, and their peak metamorphic age were around 436‐439 Ma, similar to those continental‐type eclogites in this belt. But their protolith ages are between 1273 and 1070 Ma, and some of them recorded an amphibolite facies metamorphic age of 927 Ma, and geochemical data and zircon Lu‐Hf and O isotope analysis indicate these eclogites have features of present day N‐MORB. Combined with the existing results, we propose that the North Qaidam is a polycyclic composite orogenwhich recorded tectonic evolution of Mesoproterozoic ocean floor spreading, assembly and breakup of Rodinia supercontinent, Early Paleozoic oceanic deep subduction and subsequently continental deep subduction.
Petrological and zircon evidence for the Early Cretaceous granulite‐facies metamorphism in the Dabie orogen, China
Authors: GAO Xiaoying
Published: May 2019

An integrated study of petrology, mineralogy, geochemistry, and geochronology was carried out for contemporaneous mafic granulite and diorite from the Dabie orogen. The results provide evidence for granulite‐facies reworking of the ultrahigh‐pressure (UHP) metamorphic rock in the collisional orogen. Most zircons from the granulite are new growth, and their U‐Pb ages are clearly categorized into two groups at 122–127 Ma and 188.2 Ma. Although these two groups of zircons show similarly steep HREE patterns and variably negative Eu anomalies, the younger group has much higher U, Th and REE contents and Th/U ratios, much lower εHf(t) values than the older group. This suggests their growth is associated with different types of dehydration reactions. The older zircon domains contain mineral inclusions of Grt, Cpx and Qz, indicating their growth through metamorphic reactions at high pressures. In contrast, the young zircon domains would have grown through peritectic reaction at low to medium pressures. The younger granulite‐facies metamorphic age is in agreement not only with the adjacent diorite at 125.1 Ma in this study but also the voluminous emplacement of coeval mafic and felsic magmas in the Dabie orogen. Mineral separates from both mafic granulite and its adjacent diorite show uniformly lower δ18O values than normal mantle, similar to those for UHP eclogite‐facies metaigneous rocks in the Dabie orogen. In combination with major‐trace elements and zircon Lu‐Hf isotope compositions, it is inferred that the protolith of mafic granulites shares with the source rock of diorites, both being a kind of mafic metasomatites at the slab‐mantle interface in the continental subduction channel. This provides a direct link in petrogenesis between the granulitic, migmatic and magmatic rocks in the collisional orogen to active continental rifting, whereby high heat flow was transferred from the asthenospheric mantle into the thinned orogenic lithosphere for partia melting.
Study of antigorite Crystal Cell Parameters Changing with Temperature and Pressure by TEM
Authors: HEN Tingting , CHEN Jing
Published: May 2019

To determine the P‐T conditions of serpentinite without any specific metamorphic minerals is a difficult work, because the main mineral antigorite could stable at a wide P‐T range of about 400–700°C, 10–50 kbar. Observations from natural rocks and high‐pressure experiments both suggest that the length of a‐axis of antigorite (can calculate as m value) is related to temperature and pressure, which could be used as a thermobarometer. However, some researchers disagree with this point. In this study, transmission electron microscope (TEM) technique is used to measure the crystal structure of antigorite obtained by whole‐rock system high pressure experiments, and then compare with the experimental results in the predecessors’ MgO‐SiO2‐H2O (MSH) system, to find out the correlation between m value of antigorite and P‐T conditions in the whole‐rock system. According to this study, several conclusions have been drawn: (1) the m value of antigorite is elevated with increasing pressure; (2) the increase content of aluminum in antigorite migrate the m values to high temperature field; (3) as the temperature rises, the m value of antigorite decreases, and the water content increases.
Early Neoproterozoic mafic Rocks in the North Lhasa Terrane, Tibet: A relic of the Mozambique Ocean
Authors: HU Peiyuan
Published: May 2019

The Mozambique Ocean is postulated to mark the huge oceanic basin of the East African Orogen and separated the continental components of eastern and western Gondwana, but only limited studies have considered the production of its oceanic crust. Here we present a combined analysis of petrological, geochronological, geochemical, and Sr–Nd–Hf isotopic data for the Early Neoproterozoic gabbros in the North Lhasa terrane, Tibet. Zircons from the gabbros yielded concordant ages of ca. 913–901 Ma. The gabbros display N‐MORB compositions with limited subduction input and are characterized by high positive zircon εHf(t) (+5.3 to +12.1) and whole‐rock εNd(t) (+5.6 to +6.5) values. They have not experienced significant crustal contamination but their compositions have been modified by extensive fractional crystallization. They are most likely derived from relatively high degree partial melting (>20%) of a spinel lherzolite source in a depleted mantle. Combined with observations from previous studies, we suggest that the generation of these gabbros was probably related to the incipient formation of oceanic crust in a back‐arc basin and they may mark a relic of the eastern Mozambique Ocean. To our knowledge, they are the oldest oceanic relic in the Tibetan Plateau.
Detachment‐Accretion Formed the Xigaze Ophiolite along the Southern Margin of the Eurasian Plate in Southern Tibet
Authors: LI Yuan
Published: May 2019

Mantle peridotites predominate over the 130–120 Ma mafic rocks, which have a limited temporal interval. This characteristic distinguishes the ophiolite outcrops along the Yarlung Zangbo Sutrue Zone (YZSZ) in southern Tibet from more typical ophiolites, such as the Oman ophiolite. Here we present new structural field observations and identify the low‐angle detachment faults of the Xigaze ophiolite. We demonstrate that the extension associated with the detachment system was accommodated by accretion of mafic magma rather than by thinning and dismemberment. U‐Pb zircon ages from three groups of mafic intrusives closely related to the detachment faults show that the detachment system was initiated at ∼126 Ma and ceased at ∼123 Ma. A detailed study of the entire Xigaze ophiolite assemblage reveals that the ophiolite formed in situ at the southern margin of the Eurasian Plate, instead of being formed from fragments of tectonic slices.
Quartz paramorphs after former stishovite in UHP eclogite from the South Altyn Tagh, Western China and its Significance
Authors: LIU Liang , CHEN Danling , ZHANG Junfeng , KANG Lei , LIAO Xiaoying , REN Yunfei
Published: May 2019

The long prism/needle‐shaped polycrystalline quartz aggregates and square/parallelogram‐shaped singlephase quartz inclusions in omphacite and garnet of ultrahigh pressure eclogite were first discovered from the Jiangalesayi area, South Altyn UHP belt. Based on their morphology, these quartz inclusions are quartz paramorphs after stishovite. The minimum peak pressure of the eclogite is estimated to be >8–9 GPa at 800– 1000 °C based on the stability field of stishovite. This new evidence, together with previous stishovite exsolution microstructure in the gneiss from the same region, suggests an ultra‐deep subduction and exhumation of the South Altyn continental rocks to/from mantle depths in stishovite stability field. Evidence of ultra‐deep subduction of continental materials might be more common and diverse than previous thought.

Exhumation of subducted continental rocks from≥300 km has been considered impossible because they are denser than mantle at these depths. How did the stishovite bearing continental rocks of the South Altyn exhumated?

As we all know, the densities of stishovite (4.3 g/cm3) are much higher than coesite (2.9 g/cm3), and stishovite transforms into coesite with temperature increases. Density calculations were performed for subducted continental rocks along phase transition of stishovite to coesite, using the third‐order Birch‐Murnaghan equation of state based on mineral fractions obtained from experiments and Perple_X. The results show that the density of Siliceous rocks decrease remarkably, lower than the surrounding mantle in coesite stability field, whereas the density of Oligosiliceous and Silicon unsaturated rocks is higher than surrounding mantle.

Thus, we propose that the thermal induced transformation could provide an initial driven force for the exhumation of ultra‐deep subducted silica‐enriched felsic continental rocks. Temperature increase could be derived from an increased geothermal gradient from convective mantle or mantle plume. Mafic to ultra‐mafic rocks and silica‐deficient rocks may be captured by the upwelling subducted continental rocks and exhumated together.
Petrogenesis and PGE Abundances of High‐Cr and High‐Al Chromitites and Peridotites from the Bulqiza Ultramafic Massif, Eastern Mirdita Ophiolite, Albania
Authors: QIU Tian , YANG Jingsui , MILUSHI Ibrahim , WU Weiei , MEKSHIQI Nezir , XIONG Fahui , ZHANG Cong , SHEN Tingting
Published: May 2019

The Bulqiza ultmafic massif, which belongs to the eastern Mirdita ophiolite of northern Albania, is world renowned for its high‐Cr chromite resource. The high‐Cr chromitites commonly host in the mantle section, while high‐Al chromitites also present in massive dunite of the mantle‐crust transition zone (MTZ) in this massif. Chromian‐spinel in the MTZ high‐Al chromitites and MTZ dunites have much lower Cr# values [Cr/(Cr+Al)×100] (47.7–55.1 and 46.5–51.7, respectively) than those of chromian‐spinel in the high‐Cr chromitites (78.2–80.4), harzburgites (72.6–77.9) and mantle dunites (79.4–84.3). The high‐Cr chromitites are rich in IPGE relative to PPGE with 0.10–0.45 PPGE/IPGE ratios, whereas the high‐Al chromitites have higher PPGE/IPGE ratios between 1.20 and 7.80. The partial melting degrees of parental magmas for the high‐Cr chromitites are beyond the critical interval (> 25%) and thus prevented sulfide saturation and diluted Pt and Pd in melts, producing high‐Cr chromitites barren of Pt and Pd. However, the degrees for the high‐Al chromitites just enter the critical interval (20–25%) for the effective extraction of PGE from mantle sulfides, which may account for the enrichments of PPGE in high‐Al chromitites. The parental melts of the high‐Cr chromitites have Al2O3 and TiO2 contents of ∼10.6–11.4 wt.% and 0.14–0.31 wt.%, whereas the calculated Al2O3 and TiO2 for the high‐Al chromitites are ∼14.9–15.9 wt.% and 0.07–0.61 wt.%, respectively. The calculated melts in equilibrium with the high‐Cr chromitites are boninitic‐like, and those with high‐Al chromitites are MORB‐like but with hydrous, oxidized and TiO2‐poor affinities. To make a compromise between the inconsistence above, we proposed that coexistence of both types of chromitites in the Bulqiza ultramafic massif may reflect that their magma compositions transited from MORB‐like to boninitic‐like in a proto‐forearc setting during subduction initiation. Key words: Chromian‐spinel, Platinum‐group elements, high‐Cr and high‐Al chromitite, Mirdita ophiolite, Albania.
Fe Isotope Compositions of Cyprus Umbers
Authors: SUN Jian , ZHU Xiangkun , LI Zhihong
Published: May 2019

Submarine metalliferous sedimentary rocks are chemical precipitates resulted from hydrothermal exhalation near mid‐ocean ridge or faults. They record the submarine hydrothermal activity between lithosphere and hydrosphere and are critical for understanding Fe cycling in marine environment. Fe was expelled from the hydrothermal vent systems and was oxidized and precipitated in the ambient seawater, where the precipitation of hydrothermal Fe is largely controlled by oxidation state of seawater and is potentially revealed by its Fe isotope compositions. This hydrothermal process in modern hydrothermal vent systems have been well observed, but that for the ancient ones are still not well known. Umbers, or ferromanganoan sediments, overlying Troodos ophiolite in Cyprus of Mid‐Cretaceous age thus provides an excellent example for understanding the Fe cycles in ancient submarine hydrothermal process. Samples were collected from Margi village in Troodos and are mostly amorphous Fe‐Mn oxy‐hydroxides with very minor quartz, goethite, smectite and silicates such as clinopyroxene derived from the volcanic rocks. There is no terrestrial, detrital component. Samples were analyzed for their whole‐rock element and Fe isotope compositions. The results show that samples are composed mainly of SiO2 (13∼80 wt%), Fe2O3 (9∼54 wt%) and MnO (1.5∼10.4 wt%), with minor Al2O3 (0.7∼4.3 wt%). PAAS‐normalized REE patterns are near flat with significantly negative Ce anomalies (Ce/Ce* is from 0.2 to 0.5) and slightly positive Eu anomalies (Eu/Eu* is around 1.1), indicating a source from the oxidized seawater and the high‐temperature hydrothermal fluids. δ56FeIRMM‐014 values of samples are ‐0.32‰ to ‐0.15‰, with an average of ‐0.20‰, which are consistent with those of the hydrothermal fluids previously reported. The narrow Fe isotope compositions of Cyprus umbers that are close to those of submarine hydrothermal fluids indicates near complete oxidation of hydrothermal Fe2+ during its expulsion from the hydrothermal vent.
FTIR Spectroscopy Data and Carbon Isotope Characteristics of the Ophiolite‐hosted Diamonds
Authors: XU Xiangzhen , CARTIGNY Pierre , YANG Jingsui , DILEK Yildirim , XIONG Fahui , GUO Guolin
Published: May 2019

We report new δ13C ‐values data and N‐content and N‐aggregation state values for microdiamonds recovered from peridotites and chromitites of the Luobusa ophiolite (Tibet) and chromitites of the Ray‐Iz ophiolite in the Polar Urals (Russia). All analyzed microdiamonds contain significant nitrogen contents (from 108 up to 589 ± 20% atomic ppm) with a consistently low aggregation state, show identical IR spectra dominated by strong absorption between 1130 cm−1 and 1344 cm−1, and hence characterize Type Ib diamond. Microdiamonds from the Luobusa peridotites have δ13C ‐PDB‐values ranging from ‐28.7‰ to ‐16.9‰, and N‐contents from 151 to 589 atomic ppm. The δ13C and N‐content values for diamonds from the Luobusa chromitites are ‐29‰ to ‐15.5‰ and 152 to 428 atomic ppm, respectively. Microdiamonds from the Ray‐Iz chromitites show values varying from ‐27.6 ‰ to ‐21.6 ‰ in δ13C and from 108 to 499 atomic ppm in N. The carbon isotopes values bear similar features with previously analyzed metamorphic diamonds from other worldwide localities, but the samples are characterized by lower N‐contents. In every respect, they are different from diamonds occurring in kimberlites and impact craters. Our samples also differ from the few synthetic diamonds; we also analyzed showing enhanced δ13C ‐variability and less advanced aggregation state than synthetic diamonds. Our newly obtained N‐aggregation state and N‐content data are consistent with diamond formation over a narrow and rather cold temperature range (i.e. <950°C), and in a short residence time (i.e. within several million years) at high temperatures in the deep mantle.
An early Paleozoic Subduction Channel in the North Qilian Mountains, Northwestern China: Structural, Petrological and Chronological Constraints
Authors: ZHANG Jianxin , YU Xingxing
Published: May 2019

Detailed geological mapping, structural, petrological and chronological investigation allow us to place new constraints on the tectono‐thermal evolution of the North Qilian high pressure/low temperature (HP/LT) metamorphic belt. The North Qilian HP/LT metamorphic belt manly consists of eclogite, blueschist, metasedimentary rocks and serpentinite. Most of eclogites and mafic blueschists occur as lenses within metasedimentary rocks, and minor eclogites within serpentinite. Petrological and geochemistical data indicate that the protoliths of eclogite and mafic blueschist includes E‐, N‐MORB, OIB and arc basalt. Geochronology and Lu‐Hf isotope of detrital zircons from metasedimentary rocks indicate the detritus materials are derived from Qilian block and likely deposit in continental margin or fore‐arc basin. Zircon U‐Pb datings show that the protolith ages of eclogites vary between 500 Ma and 530 Ma, and the metamorphic age of eclogite between 460 and 489 Ma. The detrital zircon ages of metasedimentary rocks distribute between 532 and 2700 Ma. The structural data show that the deformation related to the subduction during prograde is recorded in eclogite blocks. In contrast, the dominant deformation structures are characterized by tight fold, sheath fold and penetrative foliation and lineation, which are recorded in various rocks, reflecting a top‐to‐the‐south shear sense and representing the deformation related to the exhumation. The petrological data suggest that the different rocks in the North Qilian HP/LT metamorphic belt equilibrated at different peak metamorphic conditions and recorded different P‐T path. Synthesizing the structural, petrological, geochemical and geochronological data suggest a subduction channel model related to oceanic subduction during Paleozoic in the North Qilian Mountains. The different HP/LT metamorphic rocks formed in different settings with various protolith ages were carried by the subducted oceanic crust into different depth in subduction channel, and experienced independent tectono‐thermal evolution inside subduction channel. The North Qilian HP/LT mélange reflects a fossil oceanic subduction channel.
Ultrahigh Pressure Metamorphism and Tectonic Evolution of Southwestern Tianshan Orogenic Belt, China: A Comprehensive Review
Authors: ZHANG Lifei , WANG Yang , ZHANG Lijuan , LÜ Zeng
Published: May 2019

Recently, a huge ultrahigh‐pressure (UHP) metamorphic belt of oceanic‐type has been recognized in southwestern (SW) Tianshan, China. Petrological studies show that the UHP metamorphic rocks of SW Tianshan orogenic belt include mafic eclogites and blueschists, felsic garnet phengite schists, marbles and serpentinites. The well‐preserved coesite inclusions were commonly found in eclogites, garnet phengite schists and marbles. Ti‐clinohumite and Ti‐chondrodite have been identified in UHP metamorphic serpentinites. Based on the PT pseudosection calculation and combined U‐Pb zircon dating, the P‐T‐t path has been outlined as four stages: cold subduction to UHP conditions before ∼320 Ma whose peak ultrahigh pressure is about 30 kbar at 500oC, heating decompression from the Pmax to the Tmax stage before 305 Ma whose peak temperature is about 600oC at 22kbar, then the early cold exhumation from amphibolite eclogite facies to epidote‐amphibolite facies metamorphism characterized by ITD PT path before 220 Ma and the last tectonic exhumation from epidote amphibolite facies to greenschist facies metamorphism. Combining with the syn‐subduction arc‐like 333‐326 Ma granitic rocks and 280‐260 Ma S‐type granites in the coeval low‐pressure and high‐temperature (LP‐HT) metamorphic belt, the tectonic evolution of Tianshan UHP metamorphic belt during late Cambrian to early Triassic has been proposed.
The Exhumation of Dabie Ultrahigh‐High Pressure Metamorphic Rocks Shown by the Deformation of Taihu‐Mamiao Shear zone
Authors: LI Liguo , LIANG Chao , XIANG Biwei
Published: May 2019

Since the discovery of high‐pressure metamorphic minerals such as coesite and diamond (Xu et al., 1992), the exhumation mode and process of the Dabie ultrahigh‐high pressure (UHP) rocks had become hot topics. For the exhumation process of UHP rocks, several explanation models had been proposed, and the subduction tunnel mode (Warren et al., 2008) seemed to be recognized by most scholars. A low rheological zone formed along the subduction, and the deep subduction material was rapidly exhumated by buoyancy or tectonic stress. In the tunnel, the exhuming rock moved at the opposite direction of the subduction. Following this model, the Dabie UHP rock exhumation structure would generally tend to NW, and show a top to SE shear sense (Fig 1a, b). However, the existing structural observations indicate that the UHP rocks tend to be S‐SE with the top to NW shear sense (Faure et al., 2003). Therefore, the more detailly analysis of the exhumation structure in the UHP rocks, especially in the exhuming shear zone is very necessary.
Petrological and Organic Geochemical Characteristics of Oil Sands from the Middle Jurassic Yan'an Formation in the Southern Ordos Basin, China
Authors: Ye Liang , Xuanlong Shan , Guoli Hao , Makeen Yousif M. , Abdullah Wan Hasiah , Ayinla Habeeb Ayoola , Lihua Tong , Rongsheng Zhao
Published: May 2019

An integrated petrological and geochemical analysis of surface and drilled oil sands was conducted to assess the organic matter origin/type, thermal maturity and paleoenvironment. Petrographic analysis of the oil sand used to establish the relationships between porosity and permeability with bulk density, RQI, NPI and FZI. The strong correlation between reservoir quality index (RQI) and permeability (R2 = 0.98) reveal that porosity has a good correlation to RQI. The biomarker signatures of the analyzed oil reveal predominance of subaquatic‐derived source input with mainly land plant materials. This was indicated based on the average concentration of αααC27:C28:C29 sterane 20R of about 38%, 22% and 40% respectively. This interpretation is also supported by high values of tricyclic terpane/αβC30 hopane and regular sterane/αβC30 hopane. An anoxic condition of deposition within a lacustrine paleoenvironment that attributed to the enhancement of the preservation of the organic matters in the area were indicated based on the low Pr/Ph ratios (average 0.74), low values of αβC31‐22R‐hopane/αβC30 hopane ratios and high C26/C25 tricyclic terpane ratios as well as the presence of gammacerane and a low water salinity. Biomarker maturity parameters show that the extracted oil sand has entered the early oil window stage.
Restored immune cell functions upon clearance of senescence in the irradiated splenic environment
Authors: Palacio Lina , Goyer Marie‐Lyn , Maggiorani Damien , Espinosa Andrea , Villeneuve Norbert , Bourbonnais Sara , Moquin‐Beaudry Gaël , Le Oanh , Demaria Marco , Davalos Albert R. , Decaluwe Hélène , Beauséjour Christian
Published: May 2019

Some studies show eliminating senescent cells rejuvenate aged mice and attenuate deleterious effects of chemotherapy. Nevertheless, it remains unclear whether senescence affects immune cell function. We provide evidence that exposure of mice to ionizing radiation (IR) promotes the senescent‐associated secretory phenotype (SASP) and expression of p16INK4a in splenic cell populations. We observe splenic T cells exhibit a reduced proliferative response when cultured with allogenic cells in vitro and following viral infection in vivo. Using p16‐3MR mice that allow elimination of p16INK4a‐positive cells with exposure to ganciclovir, we show that impaired T‐cell proliferation is partially reversed, mechanistically dependent on p16INK4a expression and the SASP. Moreover, we found macrophages isolated from irradiated spleens to have a reduced phagocytosis activity in vitro, a defect also restored by the elimination of p16INK4a expression. Our results provide molecular insight on how senescence‐inducing IR promotes loss of immune cell fitness, which suggest senolytic drugs may improve immune cell function in aged and patients undergoing cancer treatment.
A Research Agenda for Emergency Medicine–based Adolescent Sexual and Reproductive Health
Authors: Miller Melissa K. , Chernick Lauren S. , Goyal Monika K. , Reed Jennifer L. , Ahmad Fahd A. , Hoehn Erin F. , Pickett Michelle S. , Stukus Kristin , Mollen Cynthia J.
Published: May 2019

Objective

The objective was to identify key questions for emergency medicine (EM)‐based adolescent sexual and reproductive health and to develop an evidence‐based research agenda.

Methods

We recruited national content experts to serve as advisory group members and used a modified Delphi technique to develop consensus around actionable research questions related to EM‐based adolescent reproductive and sexual health care. Author subgroups conducted literature reviews and developed the initial list of research questions, which were iteratively refined with advisory members. External stakeholders then independently rated each item for its importance in expanding the evidence base (1 = not important to 5 = very important) via electronic survey.

Results

Our final list of 24 research questions included items that intersected all sexual and reproductive health topics as well as questions specific to human immunodeficiency virus/sexually transmitted infections (HIV/STIs), pregnancy prevention, confidentiality/consent, public health, and barriers and facilitators to care. External stakeholders rated items related to HIV/STI, cost‐effectiveness, brief intervention for sexual risk reduction, and implementation and dissemination as most important.

Conclusions

We identified critical questions to inform EM‐based adolescent sexual and reproductive health research. Because evidence‐based care has potential to improve health outcomes while reducing costs associated with HIV/STI and unintended pregnancy, funders and researchers should consider increasing attention to these key questions.
Spread pathways of the invasive weed Parthenium hysterophorus L.: The potential for water dispersal
Authors: Mao Runping , Nguyen Thi Lan Thi , Osunkoya Olusegun O. , Adkins Steve W.
Published: May 2019

Parthenium hysterophorus L. (Asteraceae) utilises multiple mechanisms to facilitate its dispersal. It has been speculated that the cypsela, the propagule of this species, can be dispersed by water under varying environmental conditions. Four experiments were conducted to test this hypothesis, using simulated shaking and immersion to test floating ability and viability of the propagule in water. The influence of the acidity of the immersion medium on cypsela viability was also examined. Our results revealed that the freshly harvested cypselae could float on river water for at least 20 days, although around 80% sank within a week if moderate or severe turbulence was applied. Sinkage was observed to be more rapid in naked seeds (within a day) than in cypsela (within a week). On still water surfaces, germination occurred within a week but extended to 1.5 weeks under turbulent conditions due to sinkage. In river water, initial germination of floating cypselae was greater (70%) under illuminated conditions as compared to dark conditions (20%). The viability of immersed cypselae was found to remain high in distilled water for 45 days, when immersion was in cool conditions (10 or 15°C). However, in moderate (20 and 24°C) or warm (25 and 30°C) conditions, the rate of viability loss increased, and at 34°C, around 50% of the cypselae died after 20 days of immersion. Similar trends for cypselae longevity were observed in studies using river and pond water; viability loss was faster, especially in pond water. In summary, a proportion of cypselae will float in turbulent water and could be carried significant distances in river systems. Immersed cypselae can remain viable for weeks and can germinate on contact with soil. Water bodies or floods are therefore considered as important pathways in parthenium weed dispersal; hence, post‐flood monitoring is strongly recommended to minimise its spread.
Effect of alpha‐lipoic acid and myoinositol on endometrial inflammasome from recurrent pregnancy loss women
Authors: Di Nicuolo Fiorella , D'Ippolito Silvia , Castellani Roberta , Rossi Esther Diana , Masciullo Valeria , Specchia Monia , Mariani Marco , Pontecorvi Alfredo , Scambia Giovanni , Di Simone Nicoletta
Published: May 2019

Problem

A significant increased expression/activation of one of the most well‐characterized inflammasomes, the NAcht leucine‐rich‐repeat protein‐3 (NALP‐3), in the endometrium from idiopathic recurrent pregnancy loss women (RPL) has been previously found by our research group. We therefore, suggested this event as being one of the molecular mechanisms altering endometrial inflammatory status during early pregnancy. In the present research, we attempt to investigate whether molecules with anti‐inflammatory activity, alpha‐lipoic acid (ALA), and/or myoinositol affect the endometrial NALP‐3 expression and activation.

Method of study

Women with a history of idiopathic RPL (n = 30) were included in the study and compared to a control group (n = 15). Endometrial tissues were collected by hysteroscopy during the mid‐luteal phase. RPL women underwent a three‐month prescription of tablets containing ALA plus myoinositol (Sinopol®). After treatment, hysteroscopic biopsies were repeated in RPL patients. Inflammasome expression was evaluated by immunohistochemical and Western blot analysis. NALP‐3 activation was studied by quantifying the secretion of both caspase‐1 and interleukin (IL)‐1ß and IL‐18 through ELISA. In ex vivo experiments, the effects of each molecule on endometrial inflammasome were studied.

Results

Sinopol® significantly reduced the RPL endometrial inflammasome expression and activation. ALA, but not myoinositol, significantly reduced the endometrial inflammasome expression and activity.

Conclusion

Our data suggest a role for ALA on RPL inflammasome. Understanding the mechanisms involved in RPL and the observation that specific molecules are able to interfere with such complex at the endometrium might provide new rational design approaches to a personalized evaluation of endometrial status and, ultimately, a targeted medicine.
Changing incidence of obstetric anal sphincter injuries—A result of formal prevention programs?
Authors: Jangö Hanna , Westergaard Hanne B. , Kjærbye‐Thygesen Anette , Langhoff‐Roos Jens , Lauenborg Jeannet
Published: May 2019

Introduction

Obstetric anal sphincter injuries (OASIS) are serious complications to vaginal delivery causing anal incontinence in 50% of the women in the long term. In Norway, the incidence of OASIS has been significantly reduced from 4%‐5% to 1%‐2% after implementation of prevention programs focusing on perineal protection. The aim of our study was to evaluate whether implementation of formal prevention programs was associated with a reduced incidence of OASIS over time.

Material and methods

We performed a historical cohort study, evaluating incidence, change of incidence and risk factors of OASIS during the years 2011‐2015 at the four delivery departments in the Capital Region of Denmark. Two of the four departments implemented formal prevention programs in 2012‐2013. We performed trend tests and uni‐ and multivariable analyses, adjusting for important risk factors and calculating interactions between risk factors.

Results

There were 75 173 vaginal deliveries during the study period; of those, 2670 (3.6%) were complicated by OASIS. The incidence of OASIS decreased during the study period from 4.3% (n = 636) in 2011 to 2.6% (n = 399) in 2015. There was a significant decrease in the incidence of OASIS at both the departments with formal prevention programs and those without. After adjustment for other important risk factors of OASIS, we found no significant difference in the risk reduction between departments with and without formal prevention programs.

Conclusions

We found that the general focus on prevention of OASIS in Denmark was associated with a significant decrease in the incidence of OASIS, but implementation of formal prevention programs did not lead to a further reduction. It is possible that more rigorous interventions at the hospitals with formal prevention programs could have resulted in a significant difference in incidence of OASIS.
Growth performance, carcass quality characteristics and colonic microbiota profiles in finishing pigs fed diets with different inclusion levels of rice distillers’ by‐product
Authors: Nguyen Cong Oanh , Bernard Taminiau , Pham Kim Dang , Do Duc Luc , Nassim Moula , Nguyen Thi Huyen , Nguyen Hoang Thinh , Georges Daube , Jérôme Bindelle , Vu Dinh Ton , Hornick Jean‐Luc
Published: May 2019

The aim of this study was to evaluate the effects of diets containing rice distillers’ by‐product (RDP) on growth performance, carcass characteristics, meat quality, and gut microbiota of fattening pigs. Twenty‐four crossbred finishing pigs (Duroc × Landrace × Yorkshire), 56.9 ± 3.1 kg initial body weight, were randomly allocated to three groups. For 56 days, pigs were fed one of three diets including RDP0 (control), RDP15 (15% RDP in DM), and RDP30 (30% RDP in DM). With RDP level in diet, average daily gain and backfat thickness linearly increased (p < 0.05), and drip loss tended to increase (p ≤ 0.08). In addition, 16S ribosomal RNA gene amplicon profiling showed that RDP was associated with modulation of colonic microbiota composition, especially at family and genus levels. Relative abundance of Porphyromonadaceae and Erysipelotrichaceae families in colonic digesta increased with inclusion of RDP, while that of Enterobacteriaceae decreased. The proportion of genera unclassified Erysipelotrichaceae, and Butyrivibrio increased as inclusion of RDP. These results indicate that up to 30% inclusion in diet of finishing pigs, RDP can modulate colonic microbiota composition, and induces an improvement of animal growth and fat deposition.
Morphological characteristics of the uterus and uterine cervix of the plains viscacha (Lagostomus maximus)
Authors: Flamini Mirta A. , Barbeito Claudio G. , Portiansky Enrique L.
Published: May 2019

The plains viscacha is a hystricognathi rodent with special reproductive characteristics. Despite poly‐ovulation of 800 oocytes, it generates a high embryonic mortality since from 10 to 12 implantations only one or two offspring are born. The present work analyses the morphological, morphometrical, histochemical and lectinhistochemical characteristics of the uterus and uterine cervix of pregnant and non‐pregnant viscacha. Anatomically, the uterus has two horns each one continued with a short cervix devoid of glands. The structure of the uterus is like that of other species; however, the proportion and size of its glands varies according to the physiological state. In viscacha, there is no uterine body and cervices cannot be differentiated externally. The formation of two sack bottoms is determined by the presence of a middle raphe in the cranial portion of the vagina. The so‐described anatomy is different from that described in other hystricognathi such as guinea pig and coypu. The cervix presents two microscopically differentiable regions: the endocervix and the ectocervix lined by epithelia with different characteristics. The general characteristics of the uterus of L. maximus do not show specific differences with those of other mammals that might explain its peculiar gestation.
Standardizing clinical care measures of rheumatic heart disease in pregnancy: A qualitative synthesis
Authors: Vaughan Geraldine , Dawson Angela , Peek Michael J. , Carapetis Jonathan R. , Sullivan Elizabeth A.
Published: May 2019

Background

Rheumatic heart disease (RHD) is a preventable cardiac condition that escalates risk in pregnancy. Models of care informed by evidence‐based clinical guidelines are essential to optimal health outcomes. There are no published reviews that systematically explore approaches to care provision for pregnant women with RHD and examine reported measures. The review objective was to improve understanding of how attributes of care for these women are reported and how they align with guidelines.

Methods

A search of 13 databases was supported by hand‐searching. Papers that met inclusion criteria were appraised using CASP/JBI checklists. A content analysis of extracted data from the findings sections of included papers was undertaken, informed by attributes of quality care identified previously from existing guidelines.

Results

The 43 included studies were predominantly conducted in tertiary care centers of low‐income and middle‐income countries. Cardiac guidelines were referred to in 25 of 43 studies. Poorer outcomes were associated with higher risk scores (detailed in 36 of 41 quantitative studies). Indicators associated with increased risk include anticoagulation during pregnancy (28 of 41 reported) and late booking (gestation documented in 15 of 41 studies). Limited access to cardiac interventions was discussed (19 of 43) in the context of poorer outcomes. Conversely, early assessment and access to regular multidisciplinary care were emphasized in promoting optimal outcomes for women and their babies.

Conclusions

Despite often complex care requirements in challenging environments, pregnancy provides an opportunity to strengthen health system responses and address whole‐of‐life health for women with RHD. A standard set of core indicators is proposed to more accurately benchmark care pathways, outcomes, and burden.
Amustaline‐glutathione pathogen‐reduced red blood cell concentrates for transfusion‐dependent thalassaemia
Authors: Aydinok Yesim , Piga Antonio , Origa Raffaella , Mufti Nina , Erickson Anna , North Anne , Waldhaus Katie , Ernst Christine , Lin Jin‐Sying , Huang Norman , Benjamin Richard J. , Corash Laurence
Published: May 2019

Transfusion‐dependent thalassaemia (TDT) requires red blood cell concentrates (RBCC) to prevent complications of anaemia, but carries risk of infection. Pathogen reduction of RBCC offers potential to reduce infectious risk. We evaluated the efficacy and safety of pathogen‐reduced (PR) Amustaline‐Glutathione (A‐GSH) RBCC for TDT. Patients were randomized to a blinded 2‐period crossover treatment sequence for six transfusions over 8–10 months with Control and A‐GSH‐RBCC. The efficacy outcome utilized non‐inferiority analysis with 90% power to detect a 15% difference in transfused haemoglobin (Hb), and the safety outcome was the incidence of antibodies to A‐GSH‐PR‐RBCC. By intent to treat (80 patients), 12·5 ± 1·9 RBCC were transfused in each period. Storage durations of A‐GSH and C‐RBCC were similar (8·9 days). Mean A‐GSH‐RBCC transfused Hb (g/kg/day) was not inferior to Control (0·113 ± 0·04 vs. 0·111 ± 0·04, P = 0·373, paired t‐test). The upper bound of the one‐sided 95% confidence interval for the treatment difference from the mixed effects model was 0·005 g/kg/day, within a non‐inferiority margin of 0·017 g/kg/day. A‐GSH‐RBCC mean pre‐transfusion Hb levels declined by 6·0 g/l. No antibodies to A‐GSH‐RBCC were detected, and there were no differences in adverse events. A‐GSH‐RBCCs offer potential to reduce infectious risk in TDT with a tolerable safety profile.
The epidemiology of amyloidosis in Queensland, Australia
Authors: Wisniowski Brendan , McLeod Donald S. A. , Adams Rebecca , Harvey Yasmin , Brown Ian , McGuire Lloyd , Armes Jane , Mollee Peter
Published: May 2019

Published studies on the epidemiology of amyloidosis have relied on death certificate data for case ascertainment. We estimated the incidence and mortality burden of amyloidosis among residents of the Australian state, Queensland, aged ≥20 years for the years 1999–2013 based on case ascertainment from histopathology reports. Information systems for participating laboratories were scrutinised to identify histopathology reports that documented a diagnosis of amyloidosis. Case mortality status was determined via linkage to the National Death Index. A total of 447 cases of amyloidosis were identified, with a median age at diagnosis of 66 years. A plasma cell dyscrasia was identified in 72% of patients who had paraprotein studies performed. The estimated incidence for Queenslanders aged ≥20 years was 12·1 cases per million person years. The median survival was 2·45 years. Age at diagnosis, presence of a paraprotein, earlier year of diagnosis, and inner regional location of residence (compared with residence in a major city) were independently associated with reduced survival. Our data confirms previously reported incidence data for amyloidosis of approximately 10 cases per million patient years and indicates that survival for Queensland patients with amyloidosis is improving, though it remains poor for the elderly and patients with AL amyloidosis.
Salvage high‐intensity focused ultrasound for locally recurrent prostate cancer after low‐dose‐rate brachytherapy: oncological and functional outcomes
Authors: Hostiou Thomas , Gelet Albert , Chapelon Jean‐Yves , Rouvière Olivier , Mège‐Lechevalier Florence , Lafon Cyril , Tonoli‐Catez Hélène , Badet Lionel , Crouzet Sébastien
Published: May 2019

Objectives

To evaluate the oncological and functional outcomes of salvage high‐intensity focused ultrasound (S‐HIFU) for locally recurrent prostate cancer after low‐dose‐rate (LDR) brachytherapy.

Patients and Methods

Clinical phase II studies (2003–2015) included 50 consecutive patients with post‐brachytherapy local recurrence treated by S‐HIFU. S‐HIFU was performed with post‐external beam radiotherapy (EBRT) parameters and, since 2008, with specific post‐brachytherapy parameters. Treatments were whole‐gland ablation and, since 2009, hemi‐ablation in cases of unilateral prostate cancer. The primary objective was to assess oncological outcomes: treatment failure‐free survival, progression‐free survival (PFS), overall survival (OS), cancer‐specific survival (CSS), and metastasis‐free survival (MFS) rates. The secondary objective was to evaluate adverse events, continence, and erectile function. Kaplan–Meier analysis estimated oncological outcomes.

Results

In all, 13 patients were treated with post‐EBRT parameters, 37 with post‐brachytherapy parameters, 35 with whole‐gland treatment, and 15 with hemi‐ablation. The median follow‐up was 4.6 years. After S‐HIFU, the median prostate‐specific antigen level was 0.3 ng/mL. At 6 years, treatment failure‐free survival, PFS, OS, CSS, and MFS rates were 41%, 45%, 93%, 98%, and 80%, respectively. Post‐brachytherapy compared with post‐EBRT parameters reduced Grade 2–3 incontinence (34% vs 62%, P = 0.015). Incontinence, bladder outlet obstruction and Grade ≥III complications were significantly reduced with hemi‐ablation compared with whole‐gland treatment (14% vs 54%, P < 0.001; 13% vs 46%, P = 0.03; 13% vs 63%, P = 0.001; respectively). Before S‐HIFU, 25 patients had a five‐item version of the International Index of Erectile Function score of ≥17, which was maintained in 48% at 12 months.

Conclusion

S‐HIFU for locally recurrent prostate cancer after LDR brachytherapy is associated with favourable survival rates at a price of significant morbidity. Dedicated post‐brachytherapy parameters and hemi‐ablation improve the safety of the treatment.
An exploration of care‐burden experienced by older caregivers of adults with intellectual disabilities in Ireland
Authors: Egan Caroline , Dalton Caroline Teresa
Published: May 2019

Accessible summary

Older family carers of an adult with an Intellectual disability were asked about how they sometimes feel when supporting another person.

Most carers felt a little stressed or strained.

Older carers felt less stressed than younger carers.

The value of supports that help carers was identified.

Background

People with intellectual disabilities are experiencing increased longevity, and in parallel, their family caregivers are also ageing. The literature identifies that these caregivers are at risk of burden. The aim of this study was to measure the level of caregiver burden among older carers of adults with intellectual disabilities in an Irish sample and to analyse the effect of socio‐demographic factors upon experiences of caregiver burden.

Materials and Methods

Thirty caregivers completed a survey questionnaire. Data were collected based upon participants’ self‐reports of burden using the Zarit Burden Interview (ZBI) and a socio‐demographic questionnaire. Data were analysed using SPSS version 24.

Results

Over 57% of carers indicated a mild‐to‐moderate level of burden. Analysis indicated that younger caregivers experience significantly higher levels of burden, when compared to older caregivers.

Conclusions

This study contributes to our understanding of burden among an Irish population of older caregivers supporting an adult with an intellectual disability. It identified that carers do experience burden. The importance of proactive assessments and supports for these caregivers was revealed. This study highlights a lack of Irish research in this area and may pave the way for future research which could build upon its findings.
Deciphering the canonical blockade of activated Hageman factor (FXIIa) by benzamidine in the coagulation cascade: A thorough dynamical perspective
Authors: Salifu Elliasu Y. , Agoni Clement , Olotu Fisayo A. , Dokurugu Yussif M. , Soliman Mahmoud E. S.
Published: May 2019

The experimental inhibitory potency of benzamidine (BEN) paved way for further design and development of inhibitors that target β‐FXIIa. Structural dynamics of the loops and catalytic residues that encompass the binding pocket of β‐FXIIa and all serine proteases are crucial to their overall activity. Employing molecular dynamics and post‐MD analysis, this study sorts to unravel the structural and molecular events that accompany the inhibitory activity of BEN on human β‐FXIIa upon selective non‐covalent binding. Analysis of conformational dynamics of crucial loops revealed prominent alterations of the original conformational posture of FXIIa, evidenced by increased flexibility, decreased compactness, and an increased exposure to solvent upon binding of BEN, which could have in turn interfered with the essential roles of these loops in enhancing their procoagulation interactions with biological substrates and cofactors, altogether resulting in the consequential inactivation of FXIIa. A sustained interaction of the catalytic triad residues and key residues of the autolysis loop impeded their roles in catalysis which equally enhanced the inhibitory potency of BEN toward β‐FXIIa evidenced by a favorable binding. Findings provide essential structural and molecular insights that could facilitate the structure‐based design of novel antithrombotic compounds with enhanced inhibitory activities and low therapeutic risk.