bluuebunny/crossref_metadata_2025_split huggingface dataset:
CH3NH3PbI3 and HC(NH2)2PbI3 Powders Synthesized from Low‐Grade PbI2: Single Precursor for High‐Efficiency Perovskite Solar Cells
Authors: Zhang Yong , Kim Seul‐Gi , Lee Do‐Kyoung , Park Nam‐Gyu 
Published: May 2018

AbstractHigh‐efficiency perovskite solar cells are generally fabricated by using highly pure (>99.99 %) PbI2 mixed with an organic iodide in polar aprotic solvents. However, the use of such an expensive chemical may impede progress toward large‐scale industrial applications. Here, we report on the synthesis of perovskite powders by using inexpensive low‐grade (99 %) PbI2 and on the photovoltaic performance of perovskite solar cells prepared from a powder‐based single precursor. Pure APbI3 [A=methylammonium (MA) or formamidinium (FA)] perovskite powders were synthesized by treating low‐grade PbI2 with MAI or FAI in acetonitrile at ambient temperature. The structural phase purity was confirmed by X‐ray diffraction. The solar cell with a MAPbI3 film prepared from the synthesized perovskite powder demonstrated a power conversion efficiency (PCE) of 17.14 %, which is higher than the PCE of MAPbI3 films prepared by using both MAI and PbI2 as precursors (PCE=13.09 % for 99 % pure PbI2 and PCE=16.39 % for 99.9985 % pure PbI2). The synthesized powder showed better absorption and photoluminescence, which were responsible for the better photovoltaic performance. For the FAPbI3 powder, a solution with a yellow non‐perovskite δ‐FAPbI3 powder synthesized at room temperature was found to lead to a black perovskite film, whereas a solution with the black perovskite α‐FAPbI3 powder synthesized at 150 °C was not transformed into a black perovskite film. The α↔δ transition between the powder and film was assumed to correlate with the difference in the iodoplumbates in the powder‐dissolved solution. An average PCE of 17.21 % along with a smaller hysteresis [ΔPCE=PCEreverse−PCEforward)=1.53 %] was demonstrated from the perovskite solar cell prepared by using δ‐FAPbI3 powder; this PCE is higher than the average PCE of 17.05 % with a larger hysteresis (ΔPCE=2.71 %) for a device based on a conventional precursor solution dissolving MAI with high‐purity PbI2. The smaller hysteresis was indicative of fewer defects in the resulting FAPbI3 film prepared by using the δ‐FAPbI3 powder.
Modelling cross‐regulation in a single switched capacitor DC‐DC converter
Authors: Kushnerov Alexander 
Published: May 2018

SummaryThe letter proposes to model cross‐regulation in a dual‐output switched capacitor converter (SCC) by three equivalent resistances connected in delta circuit. It is shown that as opposed to linear equivalent (output) resistance of single‐output SCCs, these resistances are voltage‐controlled. The obtained analytical expressions have been verified by simulations and give correct results even if the output voltages change in wide range. The proposed analysis paves the way for modelling cross‐regulation in complex SCCs with multiple topologies and can be useful in studies of crosstalk through parasitic capacitances on chip.
A ZVS‐ZCS phase shift full bridge DC‐DC converter with secondary‐side control for battery charging applications
Authors: Saeed Junaid 
Published: May 2018

SummaryThe output power requirement of battery charging circuits can vary in a wide range, hence making the use of conventional phase shift full bridge DC‐DC converters infeasible because of poor light load efficiency. In this paper, a new ZVS‐ZCS phase shift full bridge topology with secondary‐side active control has been presented for battery charging applications. The proposed circuit uses 2 extra switches in series with the secondary‐side rectifier diodes, operating with phase shift PWM. With the assistance of transformer's magnetizing inductance, the proposed converter maintains zero voltage switching (ZVS) of the primary‐side switches over the entire load range. The secondary‐side switches regulate the output voltage/current and perform zero current switching (ZCS) independent of the amount of load current. The proposed converter exhibits a significantly better light load efficiency as compared with the conventional phase shift full bridge DC‐DC converter. The performance of the proposed converter has been analyzed on a 1‐kW hardware prototype, and experimental results have been included.
Effects of increased temperature on plant communities depend on landscape location and precipitation
Authors: Cowles Jane , Boldgiv Bazartseren , Liancourt Pierre , Petraitis Peter S. , Casper Brenda B. 
Published: May 2018

AbstractGlobal climate change is affecting and will continue to affect ecosystems worldwide. Specifically, temperature and precipitation are both expected to shift globally, and their separate and interactive effects will likely affect ecosystems differentially depending on current temperature, precipitation regimes, and other biotic and environmental factors. It is not currently understood how the effects of increasing temperature on plant communities may depend on either precipitation or where communities lie on soil moisture gradients. Such knowledge would play a crucial role in increasing our predictive ability for future effects of climate change in different systems. To this end, we conducted a multi‐factor global change experiment at two locations, differing in temperature, moisture, aspect, and plant community composition, on the same slope in the northern Mongolian steppe. The natural differences in temperature and moisture between locations served as a point of comparison for the experimental manipulations of temperature and precipitation. We conducted two separate experiments, one examining the effect of climate manipulation via open‐top chambers (OTCs) across the two different slope locations, the other a factorial OTC by watering experiment at one of the two locations. By combining these experiments, we were able to assess how OTCs impact plant productivity and diversity across a natural and manipulated range of soil moisture. We found that warming effects were context dependent, with the greatest negative impacts of warming on diversity in the warmer, drier upper slope location and in the unwatered plots. Our study is an important step in understanding how global change will affect ecosystems across multiple scales and locations.
Optogenetic stimulation: Understanding memory and treating deficits
Authors: Barnett S. C. , Perry B. A. L. , Dalrymple‐Alford J. C. , Parr‐Brownlie L. C. 
Published: May 2018

AbstractTechnology allowing genetically targeted cells to be modulated by light has revolutionized neuroscience in the past decade, and given rise to the field of optogenetic stimulation. For this, non‐native, light activated proteins (e.g., channelrhodopsin) are expressed in a specific cell phenotype (e.g., glutamatergic neurons) in a subset of central nervous system nuclei, and short pulses of light of a narrow wavelength (e.g., blue, 473 nm) are used to modulate cell activity. Cell activity can be increased or decreased depending on which light activated protein is used. We review how the greater precision provided by optogenetics has transformed the study of neural circuits, in terms of cognition and behavior, with a focus on learning and memory. We also explain how optogenetic modulation is facilitating a better understanding of the mechanistic underpinnings of some neurological and psychiatric conditions. Based on this research, we suggest that optogenetics may provide tools to improve memory in neurological conditions, particularly diencephalic amnesia and Alzheimer's disease.
Ablation of proliferating neural stem cells during early life is sufficient to reduce adult hippocampal neurogenesis
Authors: Youssef Mary , Krish Varsha S. , Kirshenbaum Greer S. , Atsak Piray , Lass Tamara J. , Lieberman Sophie R. , Leonardo E. David , Dranovsky Alex 
Published: May 2018

AbstractEnvironmental exposures during early life, but not during adolescence or adulthood, lead to persistent reductions in neurogenesis in the adult hippocampal dentate gyrus (DG). The mechanisms by which early life exposures lead to long‐term deficits in neurogenesis remain unclear. Here, we investigated whether targeted ablation of dividing neural stem cells during early life is sufficient to produce long‐term decreases in DG neurogenesis. Having previously found that the stem cell lineage is resistant to long‐term effects of transient ablation of dividing stem cells during adolescence or adulthood (Kirshenbaum, Lieberman, Briner, Leonardo, & Dranovsky, ), we used a similar pharmacogenetic approach to target dividing neural stem cells for elimination during early life periods sensitive to environmental insults. We then assessed the Nestin stem cell lineage in adulthood. We found that the adult neural stem cell reservoir was depleted following ablation during the first postnatal week, when stem cells were highly proliferative, but not during the third postnatal week, when stem cells were more quiescent. Remarkably, ablating proliferating stem cells during either the first or third postnatal week led to reduced adult neurogenesis out of proportion to the changes in the stem cell pool, indicating a disruption of the stem cell function or niche following stem cell ablation in early life. These results highlight the first three postnatal weeks as a series of sensitive periods during which elimination of dividing stem cells leads to lasting alterations in adult DG neurogenesis and stem cell function. These findings contribute to our understanding of the relationship between DG development and adult neurogenesis, as well as suggest a possible mechanism by which early life experiences may lead to lasting deficits in adult hippocampal neurogenesis.
Groundwater recharge amidst focused stormwater infiltration
Authors: Bhaskar Aditi S. , Hogan Dianna M. , Nimmo John R. , Perkins Kimberlie S. 
Published: May 2018

AbstractDistributed, infiltration‐based approaches to stormwater management are being implemented to mitigate effects of urban development on water resources. One of the goals of this type of storm water management, sometimes called low impact development or green infrastructure, is to maintain groundwater recharge and stream base flow at predevelopment levels. However, the connection between infiltration‐based stormwater management and groundwater recharge is not straightforward. Water infiltrated through stormwater facilities may be stored in soil moisture, taken up by evapotranspiration or contribute to recharge and eventually base flow. This study focused on a 1.1 km2 suburban, low impact development watershed in Clarksburg, Maryland, USA, that was urbanized and contained 73 infiltration‐based stormwater facilities. Continuous water table measurements were used to quantify the movement of infiltrated stormwater. Time series analyses were performed on hydrographs of 7 wells, and the episodic master recession method was used. Persistence in water levels, as measured by autocorrelation function, was found to be positively related to depth to water. Storm properties (precipitation rate and duration) and well location (proximity to the nearest stream) were significant in driving episodic recharge to precipitation ratios. The well that had the highest recharge to precipitation ratios and water table rises of up to 1.5 m in response to storm events was located furthest from the stream and down gradient of stormwater infiltration locations. This work may be considered in evaluating the effects of planned watershed‐scale infiltration‐based stormwater management on groundwater flow systems.
Assessment of groundwater recharge processes through karst vadose zone by cave percolation monitoring
Authors: Poulain Amaël , Watlet Arnaud , Kaufmann Olivier , Van Camp Michel , Jourde Hervé , Mazzilli Naomi , Rochez Gaëtan , Deleu Romain , Quinif Yves , Hallet Vincent 
Published: May 2018

AbstractRecharge processes of karst aquifers are difficult to assess given their strong heterogeneity and the poorly known effect of vadose zone on infiltration. However, recharge assessment is crucial for the evaluation of groundwater resources. Moreover, the vulnerability of karst aquifers depends on vadose zone behaviour because it is the place where most contamination takes place. In this work, an in situ experimental approach was performed to identify and quantify flow and storage processes occurring in karst vadose zone. Cave percolation monitoring and dye tracing were used to investigate unsaturated zone hydrological processes. Two flow components (diffuse and quick) were identified and, respectively, account for 66% and 34% of the recharge. Quickflow was found to be the result of bypass phenomenon in vadose zone related to water saturation. We identify the role of epikarst as a shunting area, most of the storage in the vadose zone occurring via the diffuse flow component in low permeability zones. Relationship between rainfall intensity and transit velocity was demonstrated, with 5 times higher velocities for the quick recharge mode than the diffuse mode. Modelling approach with KarstMod software allowed to simulate the hybrid recharge through vadose zone and shows promising chances to properly assess the recharge processes in karst aquifer based on simple physical models.
Low concentrations of permethrin and malathion induce numerical and structural abnormalities in KMT2A and IGH genes in vitro
Authors: Navarrete‐Meneses M. P. , Pedraza‐Meléndez A. I. , Salas‐Labadía C. , Moreno‐Lorenzana D. , Pérez‐Vera P. 
Published: May 2018

AbstractPesticides are commonly used worldwide and almost every human is potentially exposed to these chemicals. Exposure to pesticides such as permethrin and malathion has been associated with hematological malignancies in epidemiological studies. However, biological evidence showing if these chemicals induce genetic aberrations involved in the etiology of leukemia and lymphoma is missing. In our previous work, we have shown that a single high exposure (200 μm, 24 hours) of permethrin and malathion induce damage in genes associated with hematological malignancies in peripheral blood mononuclear cells analyzed by interphase fluorescence in situ hybridization (FISH). In the present study, we assessed by FISH whether exposure to low concentrations (0.1 μm, 72 hours) of permethrin and malathion induce aberrations in KMT2A and IGH genes, which are involved in the etiology of leukemia and lymphoma. Peripheral blood mononuclear cells were exposed to the chemicals, and damage in these genes was assessed on interphases and metaphases. We observed that both chemicals at low concentration induced structural aberrations in KMT2A and IGH genes. A higher level of damage was observed in KMT2A gene with malathion treatment and in IGH gene with permethrin exposure. We also observed numerical aberrations induced by these chemicals. The most frequent aberrations detected on interphase FISH were also observed on metaphases. Our results show that permethrin and malathion induce genetic damage in genes associated with hematological cancer, at concentrations biologically relevant. In addition, damage was observed on dividing cells, which suggests that these cells maintain their proliferation capacity in spite of the genetic damage they possess.
EBI2 in splenic and local immune responses and in autoimmunity
Authors: Barington L , Wanke F , Niss Arfelt K , Holst P J , Kurschus F C , Rosenkilde M M 
Published: May 2018

Abstract
The seven transmembrane G protein-coupled receptor EBV-induced gene 2 (EBI2), also known as GPR183, is expressed in particular in immune cells. Activated by its endogenous ligands, which are a group of oxysterols, it functions as a chemo-attractant receptor, mediating cell migration. In coordination with other receptors, EBI2 plays important roles in controlling the migration of immune cells during the course of a T-dependent Ab response in the spleen. In recent years, it has become clear that EBI2 also has other roles to play in the immune system. Thus, EBI2 seems to be involved in innate immune responses, such as those mediated by TLR signaling, and it has been implicated in regional immune responses, including immune responses in the CNS. In this review, we describe the functions of EBI2 in B cells, T cells, and dendritic cells during the course of a T-dependent Ab response in the spleen. Furthermore, we review the existing evidence supporting a role for EBI2 in local immune responses and in autoimmune diseases, with a special focus on immune responses in the CNS. Finally, we discuss which type of role EBI2 may play in autoimmune diseases, and we give our opinion about the paths of future research in EBI2.
Review on the roles of EBI2 in T-dependent antibody responses and its potential roles in local immune responses and autoimmunity.
Intravoxel incoherent motion (IVIM) imaging in human achilles tendon
Authors: Wengler Kenneth , Fukuda Takeshi , Tank Dharmesh , Huang Mingqian , Gould Elaine S. , Schweitzer Mark E. , He Xiang 
Published: May 2018

BackgroundLimited microcirculation has been implicated in Achilles tendinopathy and may affect healing and disease progression. Existing invasive and noninvasive approaches to evaluate tendon microcirculation lack sensitivity and spatial coverage.PurposeTo develop a novel Achilles tendon intravoxel incoherent motion (IVIM) MRI protocol to overcome the limitations from low tendon T2/T2* value and low intratendinous blood volume and blood velocity to evaluate tendon microcirculation.Study TypeProspective.SubjectsSixteen healthy male participants (age 31.0 ± 2.1) were recruited.Field Strength/SequenceA stimulated echo readout‐segmented echo planar imaging (ste‐RS‐EPI) IVIM sequence at 3.0T.AssessmentThe feasibility of the proposed ste‐RS‐EPI IVIM protocol combined with Achilles tendon magic angle effect was evaluated. The sensitivity of the protocol was assessed by an exercise‐induced intratendinous hemodynamic response in healthy participants. The vascular origin of the observed IVIM signal was validated by varying the diffusion mixing time and echo time.Statistical TestsTwo‐tailed t‐tests were used to evaluate differences (P < 0.05 was considered significant).ResultsConsistent with known tendon hypovascularity, the midportion Achilles tendon at baseline showed significantly lower IVIM‐derived perfusion fraction (fp) (3.1 ± 0.9%) compared to the proximal and distal Achilles tendon (6.0 ± 1.8% and 6.1 ± 2.0%, respectively; P < 0.01). Similarly, the midportion Achilles tendon exhibited significantly lower baseline blood flow index (D*×fp) (40.9 ± 19.2, 18.3 ± 5.3, and 32.0 ± 9.4 in proximal, midportion, and distal Achilles tendon, respectively; P < 0.01). Eccentric heel‐raise exercise led to ∼2 times increase of Achilles tendon blood flow in healthy participants. Consistent with its vascular origin, the estimated fp demonstrated a high dependency to IVIM protocol parameters, while the T1/T2‐corrected absolute intratendinous microvascular blood volume fraction (Vb) did not vary.Data ConclusionAchilles tendon ste‐RS‐EPI IVIM noninvasively assessed baseline values and exercise‐induced changes to tendon microcirculation in healthy tendon.Level of Evidence: 1Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2018;48:1690–1699
A randomized tensor singular value decomposition based on the t‐product
Authors: Zhang Jiani , Saibaba Arvind K. , Kilmer Misha E. , Aeron Shuchin 
Published: May 2018

SummaryThe tensor SVD (t‐SVD) for third‐order tensors, previously proposed in the literature, has been applied successfully in many fields, such as computed tomography, facial recognition, and video completion. In this paper, we propose a method that extends a well‐known randomized matrix method to the t‐SVD. This method can produce a factorization with similar properties to the t‐SVD, but it is more computationally efficient on very large data sets. We present details of the algorithms and theoretical results and provide numerical results that show the promise of our approach for compressing and analyzing image‐based data sets. We also present an improved analysis of the randomized and simultaneous iteration for matrices, which may be of independent interest to the scientific community. We also use these new results to address the convergence properties of the new and randomized tensor method as well.
Effects of physical activity on psychological well‐being outcomes in breast cancer survivors from prediagnosis to posttreatment survivorship
Authors: Aguiñaga Susan , Ehlers Diane K. , Cosman Josh , Severson Joan , Kramer Arthur F. , McAuley Edward 
Published: May 2018

AbstractObjectiveThe purpose of this study was to examine the effects of physical activity from prediagnosis to posttreatment survivorship on the psychological well‐being (PWB) outcomes of fatigue, depression, anxiety, and quality of life (QoL) in breast cancer survivors (BCS).MethodsParticipants (N = 387) completed a questionnaire battery by using an iPad‐based platform. Measures included self‐reported PA (before diagnosis and currently) and perceptions of fatigue, depression, anxiety, and QoL. Multivariate analysis of covariance was used to examine differences in PWB among BCS categorized into 1 of 4 physical activity levels: (a) low‐active prediagnosis, low‐active currently (low‐active maintainers; n = 128); (b) low‐active prediagnosis, active currently (increasers; n = 74); (c) active prediagnosis, low‐active currently (decreasers; n = 52); and (d) active prediagnosis, active currently (high‐active maintainers; n = 136). Participants were classified as active (≥24 units) or low‐active (<24 units) by using Godin Leisure‐Time Exercise Questionnaire cut‐points for health benefits.ResultsFatigue and depression were lowest, and QoL was highest among women in the high‐active maintainers category, followed by the increasers, low‐active maintainers, and decreasers. No differences in anxiety were observed across categories. Women in the high‐active maintainers category differed significantly in fatigue, depression, and QoL from both low‐active categories (low‐active maintainers and decreasers), P ≤ .001. Women in the increasers category also differed significantly in fatigue, depression, and QoL from the decreasers, P ≤ .01.ConclusionLow physical activity during survivorship was associated with greater fatigue and depression and lower QoL. Implications for cancer survivors: Efforts to help increase or maintain high levels of physical activity may be critical to helping BCS maintain their PWB.
A highly glucose-tolerant GH1 β-glucosidase with greater conversion rate of soybean isoflavones in monogastric animals
Authors: Cao Huifang , Zhang Yueqi , Shi Pengjun , Ma Rui , Yang Hong , Xia Wei , Cui Ying , Luo Huiying , Bai Yingguo , Yao Bin 
Published: May 2018

Abstract
In the feed industry, β-glucosidase has been widely used in the conversion of inactive and bounded soybean isoflavones into active aglycones. However, the conversion is frequently inhibited by the high concentration of intestinal glucose in monogastric animals. In this study, a GH1 β-glucosidase (AsBG1) with high specific activity, thermostability and glucose tolerance (IC50 = 800 mM) was identified. It showed great glucose tolerance against substrates with hydrophobic aryl ligands (such as pNPG and soy isoflavones). Using soybean meal as the substrate, AsBG1 exhibited higher hydrolysis efficiency than the GH3 counterpart Bgl3A with or without the presence of glucose in the reaction system. Furthermore, it is the first time to find that the endogenous β-glucosidase of soybean meal, mostly belonging to GH3, plays a role in the hydrolysis of soybean isoflavones and is highly sensitive to glucose. These findings lead to a conclusion that the GH1 rather than GH3 β-glucosidase has prosperous application advantages in the conversion of soybean isoflavones in the feed industry.