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Objective: To evaluate whether acupuncture pretreatment followed by letrozole leads to a higher live birth rate in PCOS when compared with letrozole alone. Design: Multicenter randomised controlled trial. Setting: Three hospitals in China. Population or Sample: Anovulatory women with PCOS aged from 20 to 40 years who had at least one patent tube. Methods: Participants were randomly assigned to receive acupuncture pretreatment followed by letrozole (pretreatment group) or letrozole alone (control group). Acupuncture pretreatment was given three times per week for 16 weeks, and letrozole was given five days per cycle for up to four cycles. Main outcome measures: The cumulative live birth rate (defined as a delivery after 20 weeks’ gestation). Results: The cumulative live birth rate was 41.1% (79/192) in the pretreatment group and 34.4% (66/192) in the control group with no significant difference between groups but was significantly higher in the pretreatment group (48/98, 49.0%) among those with baseline HOMA-IR

Spatial segmentation is a critical procedure in mass spectrometry imaging (MSI)-based biochemical analysis. However, the commonly used unsupervised MSI segmentation methods may lead to inappropriate segmentation results as the MSI data is characterized by high dimensionality and low signal-to-noise ratio. This process can be improved by the incorporation of precise prior knowledge, which is hard to obtain in most cases. In this study, we show that the incorporation of partial or coarse prior knowledge from different sources such as reference images or biological knowledge may also help to improve MSI segmentation results. Here, we propose a novel interactive segmentation strategy for MSI data called iSegMSI, which incorporates prior information in the form of scribble-regularization of the unsupervised model to fine-tune the segmentation results. By using two typical MSI data sets (including a whole-body mouse fetus and human thyroid cancer), the present results demonstrate the effectiveness of the iSegMSI strategy in improving the MSI segmentations. Specifically, the method can be used to subdivide a region into several subregions specified by the user-defined scribbles or to merge several subregions into a single region. Additionally, these fine-tuned results are highly tolerant to the imprecision of the scribbles. Our results suggest that the proposed iSegMSI method may be an effective preprocessing strategy to facilitate the analysis of MSI data.

EEG signals exhibit commonality and variability across subjects, sessions, and tasks. But most existing EEG studies focus on mean group effects (commonality) by averaging signals over trials and subjects. The substantial intra- and inter-subject variability of EEG has often been overlooked. The recently significant technological advances in machine learning, especially deep learning, have brought technological innovations to EEG signal application in many aspects, but there are still great challenges in cross-session, cross-task, and cross-subject EEG decoding. In this work, an EEG-based biometric competition based on a large-scale M3CV (A Multi-subject, Multi-session, and Multi-task Database for investigation of EEG Commonality and Variability) database was launched to better characterize and harness the intra- and inter-subject variability and promote the development of machine learning algorithm in this field. In the M3CV database, EEG signals were recorded from 106 subjects, of which 95 subjects repeated two sessions of the experiments on different days. The whole experiment consisted of 6 paradigms, including resting-state, transient-state sensory, steady-state sensory, cognitive oddball, motor execution, and steady-state sensory with selective attention with 14 types of EEG signals, 120,000 epochs. With the learning tasks of the identification and verification, the performance metrics and baseline methods were introduced in the competition. In general, the proposed M3CV dataset and the EEG-based biometric competition aim to provide the opportunity to develop advanced machine learning algorithms for achieving an in-depth understanding of the commonality and variability of EEG signals across subjects, sessions, and tasks.

Mass spectrometry imaging (MSI) could provide vast amounts of data at the temporal-spatial scale in heterogeneous biological specimens, which challenges us to segment accurately suborgans/microregions from complex MSI data. Several pipelines had been proposed for MSI spatial segmentation in the past decade. More importantly, data filtering was found to be an efficient procedure to improve the outcomes of MSI segmentation pipelines. It is not clear, however, how the filtering procedure affects the MSI segmentation. An improved pipeline was established by elaborating the filtering prioritization and filtering algorithm. Lipidomic-characteristic-based MSI data of a whole-body mouse fetus was used to evaluate the established pipeline on localization of the physiological position of suborgans by comparing with three commonly used pipelines and commercial SCiLS Lab software. Two structural measurements were used to quantify the performances of the pipelines including the percentage of abnormal edge pixel (PAEP) and CHAOS. Our results demonstrated that the established pipeline outperformed the other pipelines in visual inspection, spatial consistence, time-cost, and robustness analysis. For example, the dorsal pallium (isocortex) and hippocampal formation (Hpf) regions, midbrain, cerebellum, and brainstem on the mouse brain were annotated and located by the established pipeline. As a generic pipeline, the established pipeline could help with the accurate assessment and screening of drug/chemical-induced targeted organs and exploration of the progression and molecular mechanisms of diseases. The filter-based strategy is expected to become a critical component in the standard operating procedure of MSI data sets.

The dominant approach in investigating the individual reliability for event-related potentials (ERPs) is to extract peak-related features at electrodes showing the strongest group effects. Such a peak-based approach implicitly assumes ERP components showing a stronger group effect are also more reliable, but this assumption has not been substantially validated and few studies have investigated the reliability of ERPs beyond peaks. In this study, we performed a rigorous evaluation of the test-retest reliability of ERPs collected in a multisensory and cognitive experiment from 82 healthy adolescents, each having two sessions. By comparing group effects and individual reliability, we found that a stronger group-level response in ERPs did not guarantee higher reliability. A perspective of neural oscillation should be adopted for the analysis of reliability. Further, by simulating ERPs with an oscillation-based computational model, we found that the consistency between group-level ERP responses and individual reliability was modulated by inter-subject latency jitter and inter-trial variability. The current findings suggest that the conventional peak-based approach may underestimate the individual reliability in ERPs and a neural oscillation perspective on ERP reliability should be considered. Hence, a comprehensive evaluation of the reliability of ERP measurements should be considered in individual-level neurophysiological trait evaluation and psychiatric disorder diagnosis.

Background Traditional Chinese medicine (TCM) usually involves syndrome differentiation and treatment. Acupuncture, one form of TCM, requires the selection of appropriate acupoints and needling techniques, but many clinical trials on acupuncture have used fixed acupuncture protocols without accounting for individual patient differences. We have designed a multicenter randomized controlled trial (RCT) to evaluate whether personalized or fixed acupuncture increases the likelihood of live births in infertile women with polycystic ovary syndrome (PCOS) compared with letrozole or placebo letrozole. We hypothesize that letrozole is more effective than personalized acupuncture, which in turn is more effective than fixed acupuncture, and that placebo letrozole is the least effective intervention. Moreover, we hypothesize that personalized acupuncture is more likely to reduce the miscarriage rate and the risk of pregnancy complications compared with letrozole. Methods/design The study is designed as an assessor-blinded RCT. A total of 1100 infertile women with PCOS will be recruited from 28 hospitals and randomly allocated to 4 groups: personalized acupuncture, fixed acupuncture, letrozole, or placebo letrozole. They will receive treatment for 16 weeks, and the primary outcome is live birth. Secondary outcomes include ovulation rate, conception rate, pregnancy rate, pregnancy loss rate, changes in hormonal and metabolic parameters, and changes in quality of life scores. Adverse events will be recorded throughout the trial. All statistical analyses will be performed using IBM SPSS Statistics version 21.0 software (IBM Corp., Armonk, NY, USA), and a P value Discussion This study will be the first multicenter RCT to compare the effect of personalized or fixed acupuncture with letrozole or placebo letrozole on live birth in infertile women with PCOS. The findings will inform whether personalized acupuncture therapy can be considered an alternative treatment to improve the live birth rate in infertile women with PCOS. Trial registration ClinicalTrials.gov, NCT03625531. Registered on July 13, 2018. Chinese Clinical Trial Registry, ChiCTR1800017304. Registered on July 23, 2018.

EEG signals exhibit commonality and variability across subjects, sessions, and tasks. But most existing EEG studies focus on mean group effects (commonality) by averaging signals over trials and subjects. The substantial intra- and inter-subject variability of EEG have often been overlooked. The recently significant technological advances in machine learning, especially deep learning, have brought technological innovations to EEG signal application in many aspects, but there are still great challenges in cross-session, cross-task, and cross-subject EEG decoding. In this work, an EEG-based biometric competition based on a large-scale M

Introduction Female Genital Sexual Arousal Disorder (FGSAD) seriously affects women's quality of life and Sexual life, but it still lacks ideal FGSAD animal models for further study. Aim To establish a specific model of female genital sexual arousal disorder and explore the mechanisms resulting in FGSAD. Methods After delivery, female rats were guided by expansions of the vagina and ovariectomy (VD+OVX, n = 10); in VD group female rats were just extended by the vagina (VD, n = 10), in OVX group female rats were treated with ovariectomy (OVX, n = 10);the remaining had 1 longitudinal incision as sham group(n = 10). Outcomes Vaginal dilatation combined with ovariectomy in rats may reflect female genital sexual arousal disorder with high reproducibility and stability. Results Vaginal tissue of female rats in OVX group and VD+OVX group showed an increase in blood flow, decrease in muscle content compared to the sham group. The proportion of collagen fiber I/III decreased and the elastic fiber showed significant rupture and fragmentation; Structural reticular integrity was also significantly separated and broken from the muscle fibers. However, there was no significant difference in vaginal blood flow, fibers and vascular between VD group and Sham group. The damage of vaginal tissue in VD+OVX group was more significant than that in OVX and VD groups. Clinical Translation We have constructed a specific animal model that can provide clinical insights into the mechanism of FGSAD and serves as a good avenue for further research of its treatment. Strengths and Limitations Vaginal dilatation combined with ovariectomy in rats is a specific animal model with high reproducibility and stability, but we do acknowledge the shortcomings and limitation present in our study. Since genital arousal disorder has many different etiologies that impact the vagina, the clitoris and surrounding tissues, there is no “gold standard” model that different models attempt to investigate different etiologies. Conclusion The female genital sexual arousal disorder model established by vaginal dilatation combined with ovariectomy is a novel rat model with simple induction conditions, which pathogenic mechanism of female genital sexual arousal disorders maybe connected with the change of VEGF and MMP-9 in vaginal fibromuscular system and microvascular.

STUDY QUESTION Does acupuncture improve insulin sensitivity more effectively than metformin or sham acupuncture in women with polycystic ovary syndrome (PCOS) and insulin resistance (IR)? SUMMARY ANSWER Among women with PCOS and IR, acupuncture was not more effective than metformin or sham acupuncture in improving insulin sensitivity. WHAT IS KNOWN ALREADY Uncontrolled trials have shown that acupuncture improved insulin sensitivity with fewer side effects compared with metformin in women with PCOS and IR. However, data from randomized trials between acupuncture and metformin or sham acupuncture are lacking. STUDY DESIGN, SIZE, DURATION This was a three-armed randomized controlled trial enrolling a total of 342 women with PCOS and IR from three hospitals between November 2015 and February 2018, with a 3-month follow-up until October 2018. PARTICIPANTS/MATERIALS, SETTING, METHODS Women aged from 18 to 40 years with PCOS and homeostasis model assessment of insulin resistance (HOMA-IR) ≥2.14 were randomly assigned (n = 114 per group) to receive true acupuncture plus placebo (true acupuncture), metformin plus sham acupuncture (metformin, 0.5 g three times daily) or sham acupuncture plus placebo (sham acupuncture) for 4 months, with an additional 3-month follow-up. True or sham acupuncture was given three times per week, and 0.5 g metformin or placebo was given three times daily. The primary outcome was change in HOMA-IR from baseline to 4 months after baseline visit. Secondary outcomes included changes in the glucose AUC during an oral glucose tolerance test, BMI and side effects at 4 months after baseline visit. MAIN RESULTS AND THE ROLE OF CHANCE After 4 months of treatment, the changes of HOMA-IR were –0.5 (decreased 14.7%) in the true acupuncture group, –1.0 (decreased 25.0%) in the metformin group and –0.3 (decreased 8.6%) in the sham acupuncture group, when compared with baseline. True acupuncture is not as effective as metformin in improving HOMA-IR at 4 months after baseline visit (difference, 0.6; 95% CI, 0.1–1.1). No significant difference was found in change in HOMA-IR between true and sham acupuncture groups at 4 months after baseline visit (difference, –0.2; 95% CI, –0.7 to 0.3). During the 4 months of treatment, gastrointestinal side effects were more frequent in the metformin group, including diarrhea, nausea, loss of appetite, fatigue, vomiting and stomach discomfort (31.6%, 13.2%, 11.4%, 8.8%, 14.0% and 8.8%, respectively). Bruising was more common in the true acupuncture group (14.9%). LIMITATIONS, REASONS FOR CAUTION This study might have underestimated the sample size in the true acupuncture group with 4 months of treatment to enable detection of statistically significant changes in HOMA-IR with fixed acupuncture (i.e. a non-personalized protocol). Participants who withdrew because of pregnancy did not have further blood tests and this can introduce bias. WIDER IMPLICATIONS OF THE FINDINGS True acupuncture did not improve insulin sensitivity as effectively as metformin in women with PCOS and IR, but it is better than metformin in improving glucose metabolism (which might reduce the risk of type 2 diabetes) and has less side effects. Metformin had a higher incidence of gastrointestinal adverse effects than acupuncture groups, and thus acupuncture might be a non-pharmacological treatment with low risk for women with PCOS. Further studies are needed to evaluate the effect of acupuncture combined with metformin on insulin sensitivity in these women. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by grants 2017A020213004 and 2014A020221060 from the Science and Technology Planning Project of Guangdong Province. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER Clinicaltrials.gov number: NCT02491333. TRIAL REGISTRATION DATE 8 July 2015. DATE OF FIRST PATIENT’S ENROLLMENT 11 November 2015.

BACKGROUND traditional Chinese Medicine (TCM) usually involves syndrome and disease differentiation, and for acupuncture selection of appropriate points and skillful needling techniques. Many clinical trials on acupuncture used fixed acupuncture protocols without accounting for individual differences. We here design a multicenter randomized controlled trial (RCT) to evaluate whether personalized or fixed acupuncture increases the likelihood of live births for infertility in women with polycystic ovary syndrome (PCOS) compared with letrozole or placebo letrozole. We hypothesis that letrozole is more effective than personalized acupuncture, and personalized acupuncture is more effective than fixed acupuncture, which is more effective than placebo letrozole. Moreover, personalized acupuncture is more likely to reduce miscarriage rate and the risk of pregnancy complications than letrozole.METHODS / DESIGN The study is a randomized assessor-blind controlled trial. A total of 1,100 infertile women with PCOS will be recruited from 28 hospitals and randomly allocated into four groups: A) personalized acupuncture, B) fixed acupuncture, C) letrozole, or D) placebo letrozole. They will receive treatment for 16 weeks and the primary outcome is live birth. Secondary outcomes include ovulation rate, conception rate, pregnancy rate, pregnancy loss rate, changes in hormonal and metabolic parameters, and changes in quality-of-life scores. The adverse events (AEs) will be recorded throughout the trial. All statistical analyses will be performed using the SPSS program V.21.0 (SPSS, Chicago, Illinois, USA) and a p value

Additional file 1 : Supplementary file 1. SPIRIT 2013 checklist: recommended items to address in a clinical trial protocol and related documents.

Additional file 2 : Supplementary file 2. Patient information and consent.

White light has often been used for surface illumination to acquire images for digital image correlation (DIC) analysis. In recent years, fluorescent imaging technique has been introduced for illumination, surface deformation and topography measurements with applications on various materials including biomaterials (biofilms, etc.) at the microscale. Traditional imaging, with the use of white light, encounters technical issues such as specular reflection owing to moisture or smooth shiny surfaces (e.g., metallic or glass surfaces). As an alternative to white light, fluorescent imaging serves as a solution to resolve the issues of specular reflection. Fluorescent DIC techniques, especially the fluorescent stereo DIC, allow 3D surface profilometry and deformation measurements at the microscale and submicron scale. Fluorescent stereo imaging under a microscope utilizes emission wavelengths that are different from illumination wavelengths to ensure clear images on any surface that might give reflections at certain angles when white light is used, allowing accurate metrology and deformation measurement. In addition microscopic fluorescent imaging provides nanoscale resolutions surpassing Abbe’s diffraction limit. This paper provides a review of the recent advances in fluorescent DIC.

Oblique plate convergence is common, but it is not clear how the obliquity is achieved by continental fold-and-thrust belts. We address this problem in the Qilian Shan, northeastern Tibetan Plateau, using fieldwork observations, geomorphic analysis and elastic dislocation modeling of published geodetic data. A thrust dips SSW from the northern range front, and underlies steeper thrusts in the interior. Cenozoic thrust-related shortening across the Qilian Shan is ~155-175 km, based on two transects. Elastic dislocation modeling indicates that horizontal strain in the interseismic period is consistent with oblique slip on a single low angle detachment thrust below ~26 km depth, dipping SSW at ~17o. We suggest this detachment is located above North China Block crust, originally underthrust during Paleozoic orogeny. Horizontal shear strain is localized directly above the up-dip limit of creep on the detachment, and is coincident with the left-lateral Haiyuan Fault. This configuration implies oblique slip on the detachment below seismogenic depths is partitioned in the shallow crust onto separate strike-slip and thrust faults. This is consistent with strain partitioning in oceanic subduction zones, but has not previously been found by dislocation models of continental interiors. The marginal, strike-slip, Altyn Tagh Fault influences thrusting within the Qilian Shan for 100-200 km from the fault, but does not control the regional structure, where Paleozoic basement faults have been reactivated. The Qilian Shan resembles the main Tibetan Plateau in nascent form: active thrusts are marginal to an interior that is developing plateau characteristics, involving low relief, and low seismicity.

Fiber push-in nanoindentation is conducted on a unidirectional carbon fiber reinforced bismaleimide resin composite (IM7/BMI) after thermal oxidation to determine the interfacial shear strength. A unidirectional IM7/BMI laminated plate is isothermally oxidized under various conditions: in air for 2 months at 195 °C and 245 °C, and immersed in water for 2 years at room temperature to reach a moisture-saturated state. The water-immersed specimens are subsequently placed in a preheated environment at 260 °C to receive sudden heating, or are gradually heated at a rate of approximately 6 °C/min. A flat punch tip of 3 μm in diameter is used to push the fiber into the matrix while the resulting load-displacement data is recorded. From the load-displacement data, the interfacial shear strength is determined using a shear-lag model, which is verified by finite element method simulations. It is found that thermal oxidation at 245 °C in air leads to a significant reduction in interfacial shear strength of the IM7/BMI unidirectional composite, while thermal oxidation at 195 °C and moisture concentration have a negligible effect on the interfacial shear strength. For moisture-saturated specimens under a slow heating rate, there is no detectable reduction in the interfacial shear strength. In contrast, the moisture-saturated specimens under sudden heating show a significant reduction in interfacial shear strength. Scanning electron micrographs of IM7/BMI composite reveal that both thermal oxidation at 245 °C in air and sudden heating induced microcracks and debonding along the fiber/matrix interface, thereby weakening the interface, which is the origin of failure mechanism.

Graphene-derived macroscopic assemblies feature hierarchical nano- and microstructures that provide numerous routes for surface and interfacial functionalization achieving unconventional material properties. We report that the microstructural hierarchy of pristine chemically modified graphene films, featuring wrinkles, delamination of close-packed laminates, their ordered and disordered stacks, renders remarkable negative Poisson’s ratios ranging from −0.25 to −0.55. The mechanism proposed is validated by the experimental characterization and theoretical analysis. Based on the understanding of microstructural origins, pre-strech is applied to endow chemically modified graphene films with controlled negative Poisson’s ratios. Modulating the wavy textures of the inter-connected network of close-packed laminates in the chemically modified graphene films also yields finely-tuned negative Poisson’s ratios. These findings offer the key insights into rational design of films constructed from two-dimensional materials with negative Poisson’s ratios and mechanomutable performance., Negative Poisson’s ratio, offering unusual properties, is displayed by several materials and predicted for graphene. This work demonstrates such behaviors in monolithic films with interconnected networks of close-packed graphene laminates, and tunability through the chemistry and microstructures.

The effect of paleo-Pacific subduction on the geological evolution of the western Pacific and continental China is likely complex. Nevertheless, our analysis of the distribution of Mesozoic granitoids in the eastern continental China in space and time has led us to an interesting conclusion: The basement of the continental shelf beneath East and South China Seas may actually be of exotic origin geologically unrelated to the continental lithosphere of eastern China. By accepting the notion that the Jurassic–Cretaceous granitoids in the region are genetically associated with western Pacific subduction and the concept that subduction may cease to continue only if the trench is being jammed, then the termination of the granitoid magmatism throughout the vast region at ~88 ± 2 Ma manifests the likelihood of “sudden”, or shortly beforehand (~100 Ma), trench jam of the Mesozoic western Pacific subduction. Trench jam happens if the incoming “plate” or portion of the plate contains a sizeable mass that is too buoyant to subduct. The best candidate for such a buoyant and unsubductable mass is either an oceanic plateau or a micro-continent. We hypothesize that the basement of the Chinese continental shelf represents such an exotic, buoyant and unsubductable mass, rather than seaward extension of the continental lithosphere of eastern China. The locus of the jammed trench (i.e., the suture) is predictably located on the shelf in the vicinity of, and parallel to, the arc-curved coastal line of the southeast continental China. It is not straightforward to locate the locus in the northern section of the East China Sea shelf because of the more recent (

Glass beads are often used to examine simulation models for granular materials. The dynamic behavior of glass beads, however, has not been characterized accurately. In this paper, the dynamic behavior is characterized at high strain rates. To describe the beads used in these experiments, the size distribution was measured, and the bead-level mechanical properties were determined by nanoindentation. The dynamic compressive behavior of glass beads under confinement was characterized at strain rates near 400 s−1 using a long split Hopkinson pressure bar. The glass beads were confined inside a hollow cylinder of hardened steel and capped by cemented tungsten carbide cylindrical rods. The assembly was subjected to repeated shaking and tapping to consolidate the glass beads to attain a given bulk mass density. Experiments were conducted on dry unsorted beads at three initial mass densities (1.46, 1.54 and 1.61 g/cm3), sorted beads at three sizes (0.30, 0.212, and 0.106 mm), and partially saturated beads with average bead size of 0.212 mm at five water contents (0, 7, 14, 18 and 22 % by weight). Effect of initial mass density, bead size and water content on the dynamic volumetric and deviatoric response was investigated. The impacted beads were sorted for analysis of the particle size distribution. The compressibility was characterized in terms of the void ratio as a function of the axial pressure.

The Chagangnuoer deposit is a typical submarine volcanic rock-hosted skarn iron deposit, where orebodies mainly occur in andesitic rocks of the Dahalajunshan Formation (DF) with skarns well developed around orebodies. The volcanic rocks of the DF in the Chagangnuoer deposit display calc-alkaline characteristics. The ore-bearing andesitic rocks have high Sr-87/Sr-86((i)) (0.7058-0.7117) and low epsilon (Nd)(t) (-3.51 to 1.67). They probably formed through mixing of basaltic melts and the induced crustal melts. LA-ICP-MS U-Pb zircon ages of 250 and 305 Ma are obtained for the granite and granodiorite in the Chagangnuoer deposit, respectively, which are significantly younger than the timing of the skarn formation (316 Ma). These age data indicate that the granitoids have no contribution to the skarn and associated iron mineralization. This paper proposes a new genetic model for submarine volcanic rock-hosted skarn iron deposits, in which the iron mineralization, skarn formation and volcanic magmatism are necessary aspects of the same system; the iron separates and concentrates from the silicate magma in the form of Fe(II) carbonate complex. While this conceptual model is largely based on observations on the Chagangnuoer deposit, it may have general significance for skarn-type iron deposits associated with submarine volcanic rock sequences and warrants further testing and improvement.

Dynamic compressive behavior of a synthetic “natural soil” was investigated on an 85-ft split Hopkinson pressure bar. The “natural soil” was prepared by mixing a sorted dry clay and assorted dry Mason sand. The as-received moist clay (obtained from Boulder, Colorado) was first pulverized into powders, which were subsequently dried in oven at 105 °C for 2 days. The as-received Colorado Mason sand was dried under the same conditions. Then the clay was sieved to powers with dimensions smaller than #50 (0.3 mm) using ASTM E-11 standard sieves. The “natural soil” was obtained by mixing at different ratios of clay and sand at 5:100, 10:100, 20:100, 100:100 weight ratios. The mixed soil was capped inside a hardened steel tube, by two tungsten carbide rods at both ends in contact with the bars. This assembly was subjected to repetitive shaking to consolidate the soil to attain a desired bulk mass density; it was then placed between the incident steel bar and the transmission bar for dynamic compression. Through measurements of both axial and transverse responses of the cylindrical soil sample under confinement, both volumetric and deviatoric responses were determined. Both dry and water-saturated soil samples were characterized at high strain rates. The effects of different mixed ratio of clay/sand, and the water-saturation on the compressive behavior were investigated. The compressibility as a function of axial stress was determined. These results are compared with pure clay and sand samples.

The Caledonian-age Qilian Orogenic Belt at the northern margin of the Greater Tibetan Plateau comprises abundant granitoids that record the histories of the orogenesis. We report here our study of these granitoids from two localities. The Qingchengshan (QCS) pluton, which is situated in the eastern section of the Central Qilian Block, is dated at ~430–420 Ma. It has high-K calc-alkaline composition with high SiO2 (> 70 wt%), enrichment in large ion lithophile elements (LILEs), depletion in high field strength elements (HFSEs), and varying degrees of negative Sr and Eu anomalies. The granitoids in the Tongwei (TW) area, 150 km east of the QCS, are complex, the majority of which are dated at ~440 Ma, but there also exist younger, ~230 Ma intrusions genetically associated with the Qinling Orogeny. The Paleozoic TW intrusions also have high SiO2, fractionated REE (rare earth element) patterns, but a negligible Eu anomaly. The whole rock Sr-Nd-Hf isotopic compositions suggest that all these Paleozoic granitoids are consistent with melting-induced mixing of a two-component source, which is best interpreted as the combination of last fragments of subducted/subducting ocean crust with terrigenous sediments. The mantle isotopic signature of these granitoids (87Sr/86Sri: 0.7038 to 0.7100, eNd(t): −4.8 to −1.3, eHf(t): −0.7 to +4.0) reflects significant (~70 %) contribution of the ocean crust derived in no distant past from the mantle at ocean ridges with an inherited mantle isotopic signature. Partial melting of such ocean crust plus terrigenous sediments in response to the ocean closing and continental collision (between the Qilian and Alashan Blocks) under amphibolite facies conditions is responsible for the magmatism. Varying extents of fractional crystallization (±plagioclase, ±amphibole, ±garnet, ±zircon) of the parental magmas produced the observed QCS and TW granitoids. We note that sample HTC12–01 in the TW area shows an A-type or highly fractionated granite signature characterized by elevated abundances and a flat pattern of REEs, weak Nb-Ta anomaly, conspicuous negative Sr and Eu anomalies (Sr/Sr* = 0.09, Eu/Eu* = 0.22), and thus the high 87Sr/86Sr ratio (0.7851), and moderate eNd(t) (−4.9) and eHf(t) (−2.0), pointing to the significant mantle contribution. Compared with the Paleozoic granitoids, the ~230 Ma granitoids in the TW area represented by sample JPC12–02 have higher initial 87Sr/86Sr (0.7073) and lower eNd(t) (−6.2) and eHf(t) (−4.5) values, offering an ideal opportunity for future studies on tectonic effects of juxtaposition of younger orogenesis on an older orogen.

SPIRIT 2013 checklist. Recommended items to address in a clinical trial protocol and related documents. (PDF 106 kb)

The mechanical behavior of granular materials such as sand is not well understood due to its complex solid/fluid-like behavior. In this paper, Mason sand was investigated to determine the grain-level Young’s modulus and hardness by nanoindentation, and the mesoscale behavior through X-ray tomography of a sample in compression. Mason sand specimen was confined in a polycarbonate tube and compressed in the axial direction at ten axial compressive strains up to -21.8 % while its microstructures were observed. The mesoscale deformations were determined by incremental digital volume correlation of reconstructed volumetric images. A procedure for characterization of internal force chains is developed. The minor principal strains and their principal directions were obtained and used to determine the formation and evolution of force chains.

A polymer bonded sugar (PBS) cylindrical specimen, in which caster sugar grains are embedded in hydroxylterminated polybutadiene (HTPB) binder matrix, was compressed up to −31.5 % of compressive strain without confinement, while its internal microstructures were determined by X-ray micro-computed tomography. The reconstructed volumetric images were analyzed to determine three-dimensional (3D) morphologies and to investigate the damage and failure mechanisms. The image grayscale was filtered by threshold values to identify individual material constituents, and determine grain volume fraction. An incremental digital volume correlation (DVC) technique was developed to determine the internal deformations and to track the movement of individual sugar grains. The evolution of the internal 3D deformation of PBS is correlated to its microstructures, as well as debonding and void formation. The side length of a cubic representative volume element (RVE) for the PBS is determined as 10 times of the average grain size, based on the analysis of sugar volume fraction; it is consistent with the RVE size determined from convergence analysis of the average and the standard deviation of strain distribution. Image analysis indicates that void ratio can be used as an indicator to quantify the extent of damage. Debonding occurs at first in the inner core region, and then propagates to the outer annular region. Debonding is also determined as the primary mechanism for damage formation and evolution. Grain fracture was not observed during the uniaxial compression of this PBS specimen under a nominal strain of −31.5 % without confinement.

Monodisperse and spherical lanthanum bismuth titanate (Bi3.25La0.75Ti3O12, BLT) nanocrystals with an average size of ∼60 nm were synthesized by in situ crystallization of spherical gel particles (∼120 nm in diameter) at elevated temperatures in a carbonate environment. The gel particles were obtained by a sol-gel inverse mini-emulsion manipulation and a gelation process at 60°C. X-ray diffraction technique and Raman spectrum measurement were used to trace the formation of crystalline phases in the gel particles during heat treatment, and single-phase BLT nanocrystals were obtained after firing at 500°C for 4 h. The morphology and size of the gel particles and BLT nanocrystals were characterized by field-emission scanning electron microscopy and transmission electron microscopy. The possible mechanism underlying the formation of spherical BLT nanocrystals through a sol-gel inverse mini-emulsion approach was discussed.

Full-field thickness measurement for a thin transparent film is of interest for biological, medical, electronic, and packaging materials. It is a challenging task when the film is curvy, delicate and its thickness varies with location. We report herein a method to measure the thickness of a transparent (flat or curved) material and its topography using a stereo fluorescent profilometry technique. In this technique, two different types of fluorescent particles are deposited to both sides of the transparent film. Selected fluorescent excitation and emission are used to allow the observation of each one surface of the film at a time to determine the surface profile using stereo-based digital image correlation techniques. After the surface profiles for both surfaces are determined, subtraction of one surface profile from the other provides accurate thickness distribution of the film. Validation experiments were conducted using transparent films with known thickness. As an application, a measurement on a contact lens was conducted. The technique is appropriate for measurement of the full-field thickness of objects at other scales, such as soft transparent or translucent biofilms, with which thickness can hardly be measured accurately with other techniques.