bluuebunny/crossref_metadata_2025 huggingface dataset:
Methamphetamine‐induced striatal dopamine release, behavior changes and neurotoxicity in BALB/c mice
Authors: Kita Taizo , Matsunari Yasumori , Saraya Tutomu , Shimada Keiji , O'Hara Kiichi , Kubo Kaoru , Wagner George C. , Nakashima Toshikatsu
Published: July 2002

The behaviors associated with the neurotoxic effects of methamphetamine were evaluated in BALB/c mice. Hyperthermia and behavioral observations were measured 60 min after each subcutaneous injection of methamphetamine (4×4 or 8 mg/kg) or saline, each given 2 h apart. The behavioral observations included stereotyped behaviors, incidence of hemorrhage in breast, salivation and self‐injurious behavior (SIB). Repeated administration of methamphetamine produced these behavioral changes and hyperthermia, but resulted in hypothermia by the final injection (8 mg/kg). In addition, the methamphetamine treatment induced a long‐lasting dopamine depletion of similar magnitude in the 4 and 8 mg/kg‐treated animals. In a time course study striatal monoamine levels were measured 60 min after each injection of these doses. The first and second injections of methamphetamine (8 mg/kg) produced a drastic increase in striatal 3‐methoxytyramine; this failed to occur after the third or fourth injection of the same dose. In contrast, 4 mg/kg of methamphetamine also produced an increase in 3‐methoxytyramine after the second and third injections of the drug and, in this case, these were maintained for the duration of the treatment. Striatal 3,4‐dihydroxyphenylacetic acid levels also drastically decreased following both doses of methamphetamine, suggesting inhibition of monoamine oxidase in striatum. Moreover, a single injection of methamphetamine increased striatal 2,3‐dihydroxybenzoic acid formation.

These results suggest that the incidence of hyperthermia, SIB and striatal dopamine neurotoxicity are closely linked to striatal dopamine release and inhibition of monoamine oxidase produced by methamphetamine in BALB/c mice.
Repeated prenatal corticosteroid administration delays myelination of the corpus callosum in fetal sheep
Authors: Huang W.L. , Harper C.G. , Evans S.F. , Newnham J.P. , Dunlop S.A.
Published: July 2002

Glucocorticoids regulate oligodendrocyte maturation and the myelin biosynthetic pathways. Synthetic glucocorticoids, the corticosteroids have been successfully used in clinical practice as a single course to enhance lung maturation and reduce mortality and morbidity in preterm infants with no long‐term neurologic or cognitive side effects. However, a trend has arisen to use repeated courses despite an absence of safety data from clinical trials. We examined the effects of clinically appropriate, maternally administrated, repeated courses of corticosteroids on myelination of the corpus callosum using sheep as a large animal model. The corpus callosum is a major white matter tract that undergoes protracted myelination, underpins higher order cognitive processing and developmental damage to which is associated with, for example, cerebral palsy, mental retardation and attention deficit hyperactivity disorder. Pregnant ewes were given saline or betamethasone (0.5 mg/kg) at 104, 111, 118 and 124 days gestation, stages equivalent to the third trimester in humans. Lambs were delivered at 145 days (term), perfused and the corpus callosum examined light and electron microscopically. Total axon numbers were unaffected (P>0.05). However, myelination was significantly delayed. Myelinated axons were 5.7% in the experimental group and 9.2% in controls (P<0.05); conversely, unmyelinated axons were 88.3 and 83.7% (P<0.05). Myelinated axon diameter and myelin sheath thickness were also reduced (0.68 vs. 0.94 and 0.11 vs. 0.14 μm, P<0.05). Our data suggest that repeated prenatal corticosteroid administration delays myelination of the corpus callosum and that further safety data are needed to evaluate clinical practice.
Phosphorylation events mediated by protein kinase Cα and ε participate in regulation of tau steady‐state levels and generation of certain “Alzheimer‐like” phospho‐epitopes
Authors: Boyce John J. , Shea Thomas B.
Published: July 2002

Hyperactivation of protein kinase C (PKC) in intact neuroblastoma cells by several methods increases site‐specific tau phosphorylation as shown by increases in paired helical filament‐1 (PHF‐1) and ALZ‐50 but not AT‐8 immunoreactivity. In the present study, the influence of PKC on tau metabolism was further examined by isoform‐specific antisense oligonucleotide‐mediated PKC downregulation in human SH‐SY‐5Y neuroblastoma cells and by generation of stably‐transfected subclones expressing isoform‐specific anti‐PKC mRNA sequences. Downregulation of PKCε by both of these methods reduced PHF‐1 and ALZ‐50 immunoreactivity, suggesting that this PKC isoform, perhaps via downstream kinase cascades, regulated tau phosphorylation events that normally generate these epitopes. By contrast, downregulation of either PKCε or PKCα reduced immunoreactivity towards the phosphate‐independent anti‐tau antibodies 5E2 and JM, suggesting that both of these isoforms participated in regulation of tau steady‐state levels. Downregulation of PKCβ did not affect any of the above changes. The above roles were apparently unique for PKCε and PKCα, since activation of multiple PKC isoforms by phorbol ester treatment andlor other calcium‐dependent kinase(s) by ionophore‐mediated calcium influx could not compensate for downregulation of PKCα or PKCε in maintaining tau steady‐state levels or PHF‐1/ALZ‐50 immunoreactivity, respectively. These findings suggest that hyperactivation of signal transduction pathways, including those regulated by PKC, could evoke changes in neuronal cells reminiscent of those seen in affected neurons in Alzheimer's disease.
A transient CD15 immunoreactive sling in the developing mouse cerebellum
Authors: Ashwell K.W.S. , Mai J.K.
Published: July 2002

The distribution of the 3‐fucosyl‐N‐acetyl‐lactosamine (FAL, CD15) epitope in the developing mouse cerebellum was examined with the aid of immunohistochemistry of paraffin sections. CD15 immunoreactivity first appeared at E15 as a discrete bundle of processes lying beneath, and slightly within, the deeper layers of the external granular layer. By E17, when the cerebellar anlagen had completed their midline fusion, these processes could be traced from the germinal trigone at the lateral limits of the cerebellar anlage around the posterior cerebellar midline to the opposite germinal trigone. By P2, this sling was no longer apparent and CD15 immunoreactivity was confined to astrocytes in the cerebellar white matter, surrounding the deep cerebellar nuclei.

The CD15 immunoreactive processes pursue an unusual trajectory through the developing cerebellum, unlike any other previously described axonal or glial process bundle in the cerebellum. From its trajectory and association with the ventricular surface it seems that this structure, which we have named the transverse cerebellar sling, is composed of glial processes, although it was not immunoreactive for S‐100 or glial fibrillary acidic protein. The transient appearance of this sling encircling the posterior cerebellum is suggestive of a role in prenatal cerebellar morphogenesis.
The neural cell adhesion molecule in synaptic plasticity and ageing
Authors: Rønn Lars C.B. , Berezin Vladimir , Bock Elisabeth
Published: July 2002

By mediating cell adhesion and signal transduction, the neural cell adhesion molecule (NCAM) regulates neurite outgrowth, fasciculation and target recognition in the developing nervous system. In addition, a number of studies suggest an important role for the NCAM in regeneration and learning in the adult nervous system. NCAM‐deficient mice are impaired in spatial learning. Moreover, by interfering with normal NCAM function by intracranial injections of NCAM‐antibodies, long‐term potentiation (LTP) in rat hippocampal slices and learning in rats and chicks have been inhibited. In the vertebrate nervous system, NCAM is the dominant carrier of polysialic acid (PSA), an unusual carbohydrate consisting of long homopolymers of sialic acid. The PSA–NCAM expression decreases markedly during development. However, an upregulation of polysialic acid (PSA) in restricted brain areas including the hippocampus has been observed following learning. Moreover, enzymatic removal of PSA results in impaired LTP and learning. In muscle, the PSA–NCAM expression is upregulated following denervation. This response is weakened in aging rats. The expression of NCAM and PSA have been shown to be regulated by neuronal activity suggesting that the NCAM may promote structural remodelling in an activity dependent manner associated with learning and regeneration.
Neuropsychiatric consultation in mentally retarded patients: a clinical report
Authors: Verhoeven WMA , Tuinier S
Published: July 2002

The present study describes the results of neuropsychiatric consultations in 70 institutionalized mentally retarded patients. On the basis of their major complaint, patients were assigned to eight overlapping categories. Diagnoses of a certain probability were established during multidisciplinary consensus meetings and classification was achieved according to ICD-10 criteria. In ten patients mental retardation was related to a specific syndrome; seizures or somatic comorbidity were present in 40 patients. The most frequent psychiatric diagnoses were: unspecified bipolar affective disorder (n = 14), depressive disorder (n = 6), impulse control disorder (n = 12), cycloid, transient, or schizoaffective psychotic disorder (n = 14), and (atypical) autism (n = 7). Recent history revealed a high occurrence of serious side effects of psychotropics or pharmacokinetic interactions. Appropriate pharmacological intervention resulted in an amelioration of the behavioural condition in about half of the patients. It is emphasized that psychiatric disorders frequently present with an atypical psychopathology and that stress- and anxiety-related disorders are most probably underdiagnosed.
Validation study of the French version of the Edinburgh Postnatal Depression Scale (EPDS): new results about use and psychometric properties
Authors: Guedeney N , Fermanian J
Published: July 2002

The validation of the French version of the Edinburgh Postnatal Depression Scale (EPDS), conducted on a sample of 87 women in the first 4 months of post-partum, is presented. The study of the sensitivity, specificity and predictive values versus research diagnosis criteria provide the cut-off score of 10.5 as the best (sensitivity: 0.80; specificity: 0.92). The EPDS as an index of severity of postnatal depression (PND) also had good criterion validity compared to the psychiatrist's assessment. Factor analysis shows that the internal structure of the EPDS is composed of two subscales which underline a more accurate description of PND. The reliability study confirms the good internal consistency of the global scale (Cronbach's alpha: 0.76) and its good short term test-retest reliability (0.98).
Socialism After Communism?: The Socioeconomic and Cultural Foundations of Left Politics in Post-Soviet Russia
Authors: Christensen Paul T.
Published: July 2002

This article examines socioeconomic foundations of leftist politics in post-Soviet Russia. It is often argued that the reemergence of left politics is the result of contingent factors connected to transitional crises. While this is one source of strength for the left, there are two more important and enduring sources: a “socialist value culture” among a large majority of Russians, and an emerging pseudo-capitalist system that is creating “traditional” class-based and left-leaning attitudes and affiliations among particular social groups. The article examines the extent of this value culture and the emergence of these attitudes and affiliations through an analysis of statistical data and interviews conducted with Russian workers and intelligentsia figures from 1994–1997.
How patients with heart failure are managed in Italy
Authors: Senni Michele , Gavazzi Antonello
Published: July 2002

In Italy, the National Health System is funded from the taxation system of the state. It is organized by general practitioners in the community and specialists in the hospitals. All Italian citizens are registered with one of the general practitioners. Patients with suspected heart failure are generally referred from the family practitioner to a higher level of medical care. Only a minority of patients with heart failure are cared for by cardiologists, either as in‐ or outpatients. Echocardiography is widely available; nevertheless, few patients admitted to internal medicine divisions receive an echocardiogram compared to cardiology units. The ACE inhibitor usage by Italian cardiologists in patients with heart failure is satisfied, and the use of beta blockers is increasing in Italy at this time. Since only a small proportion of patients with heart failure are followed by cardiologists in Italy, further efforts are necessary until internists and general practitioners could be involved in treatment trials in heart failure. The aim of this approach is to transfer the beneficial effects observed in the trials to clinical practice.
Mitochondrial protein import dysfunction: mitochondrial disease, neurodegenerative disease and cancer
Authors: Palmer Catherine S. , Anderson Alexander J. , Stojanovski Diana
Published: December 2020

The majority of proteins localised to mitochondria are encoded by the nuclear genome, with approximately 1500 proteins imported into mammalian mitochondria. Dysfunction in this fundamental cellular process is linked to a variety of pathologies including neuropathies, cardiovascular disorders, myopathies, neurodegenerative diseases and cancer, demonstrating the importance of mitochondrial protein import machinery for cellular function. Correct import of proteins into mitochondria requires the co‐ordinated activity of multimeric protein translocation and sorting machineries located in both the outer and inner mitochondrial membranes, directing the imported proteins to the destined mitochondrial compartment. This dynamic process maintains cellular homeostasis, and its dysregulation significantly affects cellular signalling pathways and metabolism. This review summarises current knowledge of the mammalian mitochondrial import machinery and the pathological consequences of mutation of its components. In addition, we will discuss the role of mitochondrial import in cancer, and our current understanding of the role of mitochondrial import in neurodegenerative diseases including Alzheimer's disease, Huntington's disease and Parkinson's disease.
Identification and characterization of the hemoglobin‐binding domain of hemoglobin receptor in Leishmania
Authors: Rastogi Ruchir , Verma Jitender Kumar , Singh Vijay , Krishnamurthy Ganga , Sood Chandni , Kapoor Anjali , Kumar Kamal , Ansari Irshad , Mukhopadhyay Amitabha
Published: December 2020

Leishmania internalize hemoglobin (Hb) via a specific receptor (HbR) for their survival. To identify the Hb‐binding domain of HbR, we cloned and expressed several truncated proteins of HbR and determined their ability to bind Hb. Our findings reveal that 90% of Hb‐binding activity is retained in HbR41–80 in comparison with HbR1–471. We synthesized a 40 amino acid peptide (SSEKMKQLTMYMIHEMVEGLEGRPSTVRMLPSFVYTSDPA) corresponding to HbR41–80 and found that it specifically binds Hb. Subsequently, we found that the HbR41–80 peptide completely blocks Hb uptake in both promastigote and amastigote forms of Leishmania and, thereby, inhibits the growth of the parasite. These results demonstrate that HbR41–80 is the Hb‐binding domain of HbR, which might be used as a potential therapeutic agent to inhibit the growth of Leishmania.
Novel method to determine recursive filtration and noise reduction in fluoroscopic imaging – a comparison of four different vendors
Authors: Konst Bente , Nøtthellen Jacob , Nalum Naess Stine , Båth Magnus
Published: December 2020

Purpose

This study attempted to develop a method to measure the applied recursive filtration and to determine the noise reduction of four different fluoroscopic systems. The study also attempted to elucidate the importance of considering the recursive filter for quality control tests concerning signal‐to‐noise ratio (SNR) or image quality. The vendor’s settings for recursive filtration factor (β) are, unfortunately, often not available. Hence, a method to determine the recursive filtration and associated noise reduction would be useful.

Method

The recursive filter was determined by using a single fluoroscopic series and the method presented in this study. The theoretical noise reduction based on the choice of β was presented. In addition, the corresponding noise reduction, evaluated as the ratio of the standard deviation of the pixel value between a series with β equal to zero (recursive filtration off) and β > 0, was determined for different pulse rates given by pulses per second (pps), doses (mAs) and recursive filter. The images were acquired using clinically relevant radiation quality and quantity.

Results

The presented method to measure the recursive filter exhibited high accuracy (1.08%) and precision (1.48%). The recursive filtration and noise reduction were measured for several settings for each vendor. The recursive filtration settings and associated recursive filtration factors for four different vendors were presented.

Conclusions

This study presented an accurate method to determine applied recursive filtration, which was easy to determine. Hence, for all quality control purposes, including noise evaluation, it was possible to consider the essential noise reduction given by the settings for recursive filtration. It was also possible to compare the recursive filtration settings and associated recursive filtration within and between vendors.
Implementation of a DVH Registry to provide constraints and continuous quality monitoring for pediatric CSI treatment planning
Authors: Sepulveda Esteban , Patrick Haley , Freeman Carolyn R. , Kildea John
Published: December 2020

Craniospinal irradiation (CSI) is a complex radiation therapy technique that is used for patients, often children and teenagers/young adults, with tumors that have a propensity to spread throughout the central nervous system such as medulloblastoma. CSI is associated with important long‐term side effects, the risk of which may be affected by numerous factors including radiation modality and technique. Lack of standardization for a technique that is used even in larger radiation oncology departments only a few times each year may be one such factor and the current ad hoc manner of planning new CSI patients may be greatly improved by implementing a dose–volume histogram registry (DVHR) to use previous patient data to facilitate prospective constraint guidance for organs at risk. In this work, we implemented a DVHR and used it to provide standardized constraints for CSI planning. Mann–Whitney U tests and mean differences at 95% confidence intervals were used to compare two cohorts (pre‐ and post‐DVHR intervention) at specific dosimetric points to determine if observed improvements in standardization were statistically significant. Through this approach, we have shown that the implementation of dosimetric constraints based on DVHR‐derived data helped improve the standardization of pediatric CSI planning at our center. The DVHR also provided guidance for a change in CSI technique, helping to achieve practice standardization across TomoTherapy and IMRT.
Combinatorial Photothermal 3D‐Printing Scaffold and Checkpoint Blockade Inhibits Growth/Metastasis of Breast Cancer to Bone and Accelerates Osteogenesis
Authors: He Chao , Yu Luodan , Yao Heliang , Chen Yu , Hao Yongqiang
Published: December 2020

Cancer metastases are the main causes for the high mortality of cancer. The current treatment modality for bone metastasis of breast cancer is dominantly destructive, which urges the engineering of multifunctional biomaterials, not only for eliminating primary/metastases tumors effectively but also for enhancing bone–tissue regeneration. Herein, an immune adjuvant (R837)‐loaded and niobium carbide (Nb2C) MXene‐modified 3D‐printing biodegradable scaffold (BG@NbSiR) is designed and constructed to effectively treat bone metastasis of breast cancer. The engineered BG@NbSiR scaffold can eradicate primary tumors, activate the immune response, suppress metastases, prevent tumor relapses (long‐term immunological memory) by synergizing with checkpoint blockade immunotherapy, and accelerate osteogenesis as evidenced by multiple in vivo murine models. In particular, single‐cell sequencing (scRNA‐seq) is employed to further determine the critical factors responding to BG@NbSiR scaffold‐based photothermia plus checkpoint blockade‐combined immunotherapy. Several gene functional terms are identified in both tumor biology (including copy number variation) and immune response, which further reveal the underlying therapeutic mechanisms from the perspective of single‐cell transcriptome. This work not only demonstrates the promising clinical application potentials of BG@NbSiR scaffold‐based therapy against bone metastasis of breast cancer, but also provides distinctive avenues to optimize the design and construction of multifunctional tissue‐engineering biomaterials based on single‐cell genomes.
Rational Engineering CoxOy Nanosheets via Phosphorous and Sulfur Dual‐Coupling for Enhancing Water Splitting and Zn–Air Battery
Authors: Doan Thi Luu Luyen , Tran Duy Thanh , Nguyen Dinh Chuong , Kim Do Hwan , Kim Nam Hoon , Lee Joong Hee
Published: December 2020

Herein, an efficient multifunctional catalyst based on phosphorus and sulfur dual‐doped cobalt oxide nanosheets supported by Cu@CuS nanowires is developed for water splitting and Zn–air batteries. The formation of such a unique heterostructure not only enhances the number and type of electroactive sites, but also leads to modulated electronic structure, which produces reasonable adsorption energy toward the reactant, thereby improving electrocatalytic efficiency. The catalyst demonstrates small overpotentials of 116 and 280 mA cm−2 to achieve 10 mA cm−2 for hydrogen and oxygen evolution, respectively. As a result, a developed electrolyzer displays a cell voltage of 1.52 V at 10 mA cm−2 and long‐term stability with a current response of 92.3% after operating for 30 h. Moreover, using such a catalyst in the fabrication of a Zn–air battery also leads to a cell voltage of 1.383 V, along with a power density of 130 mW cm−2 at 220 mA cm−2.
Intracellular Activation of Anticancer Therapeutics Using Polymeric Bioorthogonal Nanocatalysts
Authors: Zhang Xianzhi , Landis Ryan F. , Keshri Puspam , Cao‐Milán Roberto , Luther David C. , Gopalakrishnan Sanjana , Liu Yuanchang , Huang Rui , Li Gengtan , Malassiné Morgane , Uddin Imad , Rondon Brayan , Rotello Vincent M.
Published: December 2020

Bioorthogonal catalysis provides a promising strategy for imaging and therapeutic applications, providing controlled in situ activation of pro‐dyes and prodrugs. In this work, the use of a polymeric scaffold to encapsulate transition metal catalysts (TMCs), generating bioorthogonal “polyzymes,” is presented. These polyzymes enhance the stability of TMCs, protecting the catalytic centers from deactivation in biological media. The therapeutic potential of these polyzymes is demonstrated by the transformation of a nontoxic prodrug to an anticancer drug (mitoxantrone), leading to the cancer cell death in vitro.
An Alternating Irradiation Strategy‐Driven Combination Therapy of PDT and RNAi for Highly Efficient Inhibition of Tumor Growth and Metastasis
Authors: Yue Dong , Cai Xiaojun , Fan Mengni , Zhu Jingwu , Tian Jiang , Wu Lihuang , Jiang Qian , Gu Zhongwei
Published: December 2020

Hypoxia and hypoxia induced overexpression of vascular endothelial growth factor (VEGF) not only seriously affects the treatment effects of photodynamic therapy (PDT) but also promotes tumor metastasis. Herein, an alternating irradiation strategy (referred to as alternate use of low/high dose of light [ALHDL] irradiation)‐driven combination therapy of PDT and RNA interference (RNAi) is developed to synergistically inhibit tumor growth and metastasis. A cationic amphipathic peptide (ALS) served as a carrier in the co‐delivery system of photochlor (HPPH) and siVEGF (ALSH/siVEGF). At the beginning of ALHDL‐driven ALSH/siVEGF treatment, short‐term LDL irradiation can facilitate the tumor penetration, cellular uptake, and endosome escape of ALSH/siVEGF. Moreover, accompanied by HDL‐mediated rapid cell apoptosis and LDL‐mediated efficient VEGF silencing, the joint use of PDT and RNAi achieved remarkable antitumor effects both in vitro and in vivo. Importantly, benefited from the excellent performance of ALHDL in slowing the rapid deterioration of the anoxic environment of tumors, and ALSH/siVEGF treatment‐mediated highly improved VEGF silencing efficacy and inhibitory effect on angiogenesis, the liver and lung metastases of HeLa cells have been successfully suppressed. Together, this study clearly indicates that ALHDL‐driven combination therapy of PDT and RNAi is a highly effective modality for inhibition of tumor growth and metastasis.
Selective Ethanol Oxidation Reaction at the Rh–SnO2 Interface
Authors: Bai Shuxing , Xu Yong , Cao Kailei , Huang Xiaoqing
Published: December 2020

Direct ethanol fuel cells (DEFCs) are regarded as an attractive power source with high energy density, bio‐renewability, and convenient storage and transportation. However, the anodic reaction of DEFCs, that is, the ethanol oxidation reaction (EOR), suffers from poor efficiency due to the low selectivity to CO2 (C1 pathway) and high selectivity to CH3COOH (C2 pathway). In this study, the selective EOR to CO2 can be achieved at the Rh–SnO2 interface in SnO2–Rh nanosheets (NSs). The optimized catalyst of 0.2SnO2–Rh NSs/C exhibits excellent alkaline EOR performance with a mass activity of 213.2 mA mgRh−1 and a Faraday efficiency of 72.8% for the C1 pathway, which are 1.7 and 1.9 times higher than those of Rh NSs/C. Mechanism studies indicate that the strong synergy at the Rh–SnO2 interface significantly promotes the breaking of CC bond of C2H5OH to form CO2, and facilitates oxidation of the poisonous intermediates (*CO and *CH3) to suppress the deactivation of the catalyst. This work not only provides a highly selective, active, and stable catalyst for the EOR, but also promotes fundamental research for the design of efficient catalysts via interface modification.
Tunable Circular Dichroism by Photoluminescent Moiré Gratings
Authors: Aftenieva Olha , Schnepf Max , Mehlhorn Börge , König Tobias A. F.
Published: December 2020

In nanophotonics, there is a current demand for ultrathin, flexible nanostructures that are simultaneously easily tunable, demonstrate a high contrast, and have a strong response in photoluminescent polarization. In this work, the template‐assisted self‐assembly of water‐dispersed colloidal core–shell quantum dots into 1D light‐emitting sub‐micrometer gratings on a flexible substrate is demonstrated. Combining such structures with a light‐absorbing metallic counterpart by simple stacking at various angles results in a tunable Moiré pattern with strong lateral contrast. Furthermore, a combination with an identical emitter‐based grating leads to a chiroptical effect with a remarkably high degree of polarization of 0.72. Such a structure demonstrates direct circular polarized photoluminescence, for the first time, without a need for an additional chiral template as an intermediary. The suggested approach allows for reproducible, large‐area manufacturing at reasonable costs and is of potential use for chiroptical sensors, photonic circuit applications, or preventing counterfeit.
Device Design of Doping‐Controlled Homojunction Perovskite Solar Cells Omitting HTL and Exceeding 25% Efficiency
Authors: Lin Lingyan , Li Ping , Kang Zhenjing , Xiong Hao , Chen Yiting , Yan Qiong , Jiang Linqin , Qiu Yu
Published: December 2020

Hole‐transport‐layer (HTL)‐free carbon‐based perovskite solar cells (C‐PSCs) have attracted great attention due to their low production cost and simplified structure. Nevertheless, C‐PCSs have not yet realized the high conversion efficiency achieved in conventional PSCs with HTLs. A new design of n‐CH3NH3PbI3/p‐CH3NH3PbI3 homojunction is presented to attempt high efficiency HTL‐free C‐PSCs and its operation as a device is analyzed using solar cell capacitance simulator (SCAPS). Several parameters that can affect the device performance, such as perovskite layer doping concentration, thickness values, carrier mobility, and defect density, are explored and optimized. Under optimized conditions, a high power conversion efficiency of 25.07%, 15.6% relatively higher than conventional C‐PSC, can be obtained, indicating that the proposed homojunction‐based C‐PSC is promising because it highly simplifies the device structure and fabrication while maintaining high efficiency. This work points a way to commercialize HTL‐free PSCs for future industrial photovoltaics.
How Far Are We from Achieving Self‐Powered Flexible Health Monitoring Systems: An Energy Perspective
Authors: Yu Hui , Li Nan , Zhao Ni
Published: December 2020

The rapid development of flexible electronics and sensing technologies have made it possible for the detection of various human vital signs and biomarkers through an extremely light‐weight and soft device attached to the skin. To support such sensing devices for multi‐parameter tracking and continuous operation, a powerful energy supply unit, which is compact, mobile, and with high energy density and self‐charging capability, is desired. The recently emerged energy harvesting devices have demonstrated the potential of utilizing ambient and human‐based energy sources to power sensor systems. In this context, this review aims to investigate the question of whether the capacity of current flexible energy devices can meet the energy demand of wireless flexible sensor systems in long‐term health monitoring applications. First, the total energy demand of typical sensor systems is estimated by analyzing the energy consumption of each building block of the relevant systems. The design of the energy supply architecture is discussed by considering batteries/supercapacitors as the energy storage unit and photovoltaic, thermoelectric, piezoelectric, and triboelectric devices as the energy‐harvesting unit. Based on the analysis, health monitoring protocols that could be readily realized with self‐powered system designs are suggested and the core challenges for further development of the technologies for practical applications are identified.
Negatively‐Doped Conducting Polymers for Oxygen Reduction Reaction
Authors: Vagin Mikhail , Gueskine Viktor , Mitraka Evangelia , Wang Suhao , Singh Amritpal , Zozoulenko Igor , Berggren Magnus , Fabiano Simone , Crispin Xavier
Published: December 2020

The oxygen reduction reaction (ORR) limits the efficiency of oxygen‐associated energy conversion in fuel cells and air‐metal batteries. Today, expensive noble metal catalysts are often utilized to enhance the ORR and the resulting conversion efficiency in those devices. Hence, there is an intensive research to find efficient electrodes, exhibiting a favorable electronic structure, for ORR based on abundant materials that can be manufactured using low cost processes. In that context, metal‐free carbon‐based nanostructures and conducting polymers have been actively investigated. The negatively doped poly(benzimidazobenzophenanthroline) (BBL) as an efficient and stable oxygen cathode material is reported here. Compared to the benchmark p‐doped conducting polymer poly(3,4‐ethylendioxythiophene) (PEDOT), the BBL provides electrocatalysis that fully reduces dioxygen into water, via a (2 + 2)‐electron transfer pathway with hydrogen peroxide (H2O2) as an intermediate; while PEDOT limits the ORR to H2O2. It is demonstrated that n‐doped BBL is a promising air electrode material for low‐cost and ecofriendly model fuel cells, without the need of any co‐catalysts, and its performance is found to be superior to p‐doped PEDOT air electrodes.
Challenges and Opportunities in Utilizing MXenes of Carbides and Nitrides as Electrocatalysts
Authors: Wang Yan , Nian Yao , Biswas Akash N. , Li Wei , Han You , Chen Jingguang G.
Published: December 2020

Sustainable energy conversion processes often require electrochemical reactions powered by renewable energy sources. 2D transition metal carbides and nitrides (MXenes), an important and growing class of 2D materials, have been demonstrated to be promising candidates for heterogeneous electrocatalysis due to their unique electronic, physical, chemical, and mechanical properties. Significant efforts have been made in the development of MXenes and MXene‐derived electrocatalysts for various electrochemical reactions, including the hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, nitrogen reduction reaction, and methanol oxidation reaction. MXenes from earth‐abundant metals provide the potential for large‐scale applications, and their well‐defined structures allow for the identification of active sites and catalytic mechanisms. Herein, recent studies of MXenes in electrocatalysis are reviewed, and the challenges and opportunities for the design and fabrication of MXenes and MXene‐based materials with desired electrocatalytic properties are discussed.
One size does not fit all. How universal standards for normal height can hide deprivation and create false paradoxes
Authors: Hruschka Daniel J.
Published: December 2020

Public health practitioners and social scientists frequently compare height against one‐size‐fits‐all standards of human growth to assess well‐being, deprivation, and disease risk. However, underlying differences in height can make some naturally tall populations appear well‐off by universal standards, even though they live in severe states of deprivation. In this article, I describe the worldwide extent of these population differences in height and illustrate how using a universal yardstick to compare population height can create puzzling disparities (eg, between South Asia and sub‐Saharan Africa) while also underestimating childhood stunting in specific world regions (eg, West Africa and Haiti). I conclude by discussing potential challenges of developing and implementing population‐sensitive standards for assessing healthy development.
The Smelling Principle of Vetiver Oil, Unveiled by Chemical Synthesis
Authors: Ouyang Jie , Bae Hanyong , Jordi Samuel , Dao Quang Minh , Dossenbach Sandro , Dehn Stefanie , Lingnau Julia B. , Kanta De Chandra , Kraft Philip , List Benjamin
Published: December 2020

Vetiver oil, produced on a multiton‐scale from the roots of vetiver grass, is one of the finest and most popular perfumery materials, appearing in over a third of all fragrances. It is a complex mixture of hundreds of molecules and the specific odorant, responsible for its characteristic suave and sweet transparent, woody‐ambery smell, has remained a mystery until today. Herein, we prove by an eleven‐step chemical synthesis, employing a novel asymmetric organocatalytic Mukaiyama–Michael addition, that (+)‐2‐epi‐ziza‐6(13)en‐3‐one is the active smelling principle of vetiver oil. Its olfactory evaluation reveals a remarkable odor threshold of 29 picograms per liter air, responsible for the special sensuous aura it lends to perfumes and the quasi‐pheromone‐like effect it has on perfumers and consumers alike.
Fabrication of the superhydrophobic natural cellulosic paper with different wettability and oil/water separation application
Authors: Yun Tongtong , Tong Hao , Wang Yilin , Qian Fang , Cheng Yi , Lv Yanna , Lu Jie , Li Mengjie , Wang Haisong
Published: December 2020

Renewable superhydrophobic materials have attracted great attention due to their extensive applications in the fields such as cost‐effective and biodegradable oil/water separation field. Herein, we reported an eco‐friendly and facile methodology to develop the superhydrophobic cellulosic paper by immersion method using the ethanol solution of stearic acid. Furthermore, the treated cellulosic papers showed super‐hydrophobicity with water contact angle (WCA) above 153°. Interestingly, this method can realize superhydrophobic‐hydrophilic conversion by simply adjusting the temperature and is amenable for different substrates and with the WCA of 114‐162°. More importantly, the utilization of fluorinated reagents has been avoided, thereby minimizing the production cost and improving safety and environmental aspects. Meanwhile, the modified natural cellulosic paper is applied for oil–water separation, and its separation efficiency was as high as 95% after 10 cycles, indicating the good reusability of stearic acid modified filter papers. Consequently, this simple strategy based on the stearic acid immersion method thus provided an easy conversion of superhydrophobic‐hydrophilic interface and provided facile strategies for conversion of commercial quantitative filter paper to functional materials for oil/water separation.
Making apples from oranges: Comparing noncollapsible effect estimators and their standard errors after adjustment for different covariate sets
Authors: Daniel Rhian , Zhang Jingjing , Farewell Daniel
Published: December 2020

We revisit the well‐known but often misunderstood issue of (non)collapsibility of effect measures in regression models for binary and time‐to‐event outcomes. We describe an existing simple but largely ignored procedure for marginalizing estimates of conditional odds ratios and propose a similar procedure for marginalizing estimates of conditional hazard ratios (allowing for right censoring), demonstrating its performance in simulation studies and in a reanalysis of data from a small randomized trial in primary biliary cirrhosis patients. In addition, we aim to provide an educational summary of issues surrounding (non)collapsibility from a causal inference perspective and to promote the idea that the words conditional and adjusted (likewise marginal and unadjusted) should not be used interchangeably.
Comprehensive characterization of dihydrofolate reductase‐mediated gene amplification for the establishment of recombinant human embryonic kidney 293 cells producing monoclonal antibodies
Authors: Lee Sang Yoon , Baek Minhye , Lee Gyun Min
Published: December 2020

Human embryonic kidney 293 (HEK293) cells with glycosylation machinery have emerged as an alternative host cell line for stable expression of therapeutic glycoproteins. To characterize dihydrofolate reductase/methotrexate (DHFR/MTX)‐mediated gene amplification in HEK293 cells, an expression vector containing dhfr and monoclonal antibody (mAb) gene was transfected into dhfr‐deficient HEK293 cells generated by knocking out dhfr and dhfrl1 in HEK293E cells. Due to the improved selection stringency, mAb‐producing parental cell pools could be generated in the absence of MTX. When subjected to stepwise selection for increasing MTX concentrations such as 1, 10, and 100 nM, there was an increase in the specific mAb productivity (qmAb) of the parental cell pool upon DHFR/MTX‐mediated gene amplification. High producing (HP) clones with a qmAb of more than 2‐fold of the corresponding cell pool could be obtained using the limiting dilution method. The qmAb of most HP clones obtained from cell pools at elevated MTX concentrations significantly decreased during long‐term culture (3 months) in the absence of selection pressure. However, some HP clones could maintain high qmAb during long‐term culture. Taken together, a stable HP recombinant HEK293 cell line can be established using DHFR/MTX‐mediated gene amplification together with dhfr− HEK293 host cells.
A systematic review of higher education students' experiences of engaging with online therapy
Authors: Hanley Terry , Wyatt Claire
Published: December 2020

Aim

The prevalence of mental health difficulties and the demand for psychological support for students in higher education (HE) appear to be increasing. Online therapy is a widely accessible resource that could provide effective support; however, little is known about such provision. The aim of this study was therefore to answer the research question ‘What factors serve to influence higher education students' levels of engagement with online therapy?’

Method

A systematic review of qualitative scholarly and peer‐reviewed literature was conducted across 10 databases. Six papers met the inclusion criteria, were assessed for quality and were analysed using thematic synthesis.

Findings

Factors that serve to motivate HE students to engage with online therapy included the perception that it might enhance the quality of the therapeutic relationship, that it would facilitate more autonomy in the work, and that it might enable them to be anonymous and avoid face‐to‐face contact. In contrast, demotivating factors were primarily practical in nature. Fitting therapeutic work into their busy lives, technological challenges and persisting mental health stigma proved important factors.

Conclusion

This review synthesises the reasons why HE students might engage with or withdraw from online therapy. It highlights that students appear to view online therapy positively, but they can be inhibited by both personal and practical issues. Therapeutic services therefore need to ensure that information about the work they offer online is clear and transparent and that the platforms they work on are secure and stable. Finally, the need for further research, to keep abreast of technological developments, is recommended.
Safeguarding Children When Fabricated or Induced Illness Is Suspected or Proven: Reviewing the Experiences of Local Safeguarding Children Boards in England
Authors: Ratcliffe John , Gray Jenny , Bools Christopher , Wilson Richard , Wigfield Andrea , Mason Will
Published: December 2020

‘The views of representatives from… Local Safeguarding Children Boards (LSCBs) in England were sought on the challenges to safeguarding children from FII’

The fabrication or induction of illness (FII) is a relatively rare situation which can lead to serious physical and/or emotional harm to a child. FII is often difficult for professionals to identify and manage. In this study the views of representatives from the 147 Local Safeguarding Children Boards (LSCBs) in England were sought on the challenges to safeguarding children from FII, and how these might be overcome. Despite a low response rate of only 18 from the 147 LSCBs, 17 challenges were identified. The most reported were inadequate training and resources, poor multi‐agency collaboration, uncertainties and anxiety among professionals tasked with identifying FII, issues inherent in the relative rarity of FII and the variety of ways in which it can present. To overcome these challenges, LSCB respondents suggested that more training, specific to particular professions and using video case studies where possible, should be conducted on a wider scale, and consideration should be given to ensuring that professionals are familiar with relevant guidance.

Key Practitioner Messages

Professionals' uncertainties and anxieties are key challenges to safeguarding children from FII.

More training would help overcome professionals' uncertainties and anxieties.

Finding ways to ensure that all relevant professionals are familiar with existing guidance would support the development of greater knowledge about how best to respond to FII cases.

The inclusion of FII within broader safeguarding training, using video case studies and conducting profession‐specific training, may constitute ways to improve training and promote knowledge of the guidance.
A rare case of ectopic retrosternal goiter
Authors: Oh Shen Leong , Chia Clement L. K. , Ooi Oon Cheong , Sonawane Vikram , Rao Anil D. , Singaporewalla Reyaz
Published: December 2020

It is important for the clinician to be familiar with interpreting a variety of radiological modalities that provide vital information that will aid in the preoperative planning, counseling, and subsequent management of patients with retrosternal goiter.
Epicardial and transverse sinus fat pad near left atrium appendage; role of 3D echocardiography
Authors: Mohseni‐badalabadi Reza , Sahebjam Mohammad , Mohseni‐badalabadi Mehdi , Hosseini Kaveh
Published: December 2020

Pericardial fat pad in transverse sinus adjacent to left atrial appendage (LAA) is a rare condition that may resemble LAA thrombosis especially in suspected cases. More Trans‐esophageal echocardiography (TEE) angulations and also 3D TEE images are helpful tools to confirm the diagnosis.
Efficient CO2 Electroreduction on Ag2S Nanodots Modified CdS Nanorods as Cooperative Catalysts
Authors: Cheng Ling , Wang Yating , Li Yuhang , Shen Yi , Zhen Yue , Xing Zhanqi , Lin Liwan , Chen Aiping , Zhu Yihua , Li Chunzhong
Published: December 2020

CdS nanorods have been regarded as a promising candidate for electrocatalytic CO2 reduction compared with other chalcogenide catalysts, owing to the high Faradaic efficiency for producing CO in aqueous electrolyte. Unfortunately, the CO generation rate of the bare CdS is relatively low due to the poor intrinsic activity. In this work, we modify the surface of CdS nanorods by Ag2S nanodots to promote the CO2 reduction activity. With 5 wt % loading of Ag2S nanodots, we achieve the highest CO partial current density of 10.6 mA cm−2 at an applied potential of −1.1 V vs RHE, 11 % and 93 % enhancement compared to the separately synthesized CdS and Ag2S, respectively. When using flow cell to accelerate the CO2 mass transfer, the cooperative catalyst realizes ∼95 % Faradaic efficiency for C1 products with a fast CO2 reduction rate at a current density of 200 mA cm−2.
Exploratory N‐Protecting Group Manipulation for the Total Synthesis of Zwitterionic Shigella sonnei Oligosaccharides
Authors: Dhara Debashis , Mulard Laurence A.
Published: December 2020

Shigella sonnei surface polysaccharides are well‐established protective antigens against this major cause of diarrhoeal disease. They also qualify as unique zwitterionic polysaccharides (ZPSs) featuring a disaccharide repeating unit made of two 1,2‐trans linked rare aminodeoxy sugars, a 2‐acetamido‐2‐deoxy‐l‐altruronic acid (l‐AltpNAcA) and a 2‐acetamido‐4‐amino‐2,4,6‐trideoxy‐d‐galactopyranose (AAT). Herein, the stereoselective synthesis of S. sonnei oligosaccharides comprising two, three and four repeating units is reported for the first time. Several sets of up to seven protecting groups were explored, shedding light on the singular conformational behavior of protected altrosamine and altruronic residues. A disaccharide building block equipped with three distinct N‐protecting groups and featuring the uronate moiety already in place was designed to accomplish the iterative high yielding glycosylation at the axial 4‐OH of the altruronate component and achieve the challenging full deprotection step. Key to the successful route was the use of a diacetyl strategy whereby the N‐acetamido group of the l‐AltpNAcA is masked in the form of an imide.
Coordination Behavior of a P4‐Butterfly Complex towards Transition Metal Lewis Acids: Preservation versus Rearrangement
Authors: Müller Julian , Scheer Manfred
Published: December 2020

The reactivity of the P4 butterfly complex [{Cp’’’Fe(CO)2}2(μ,η1:1‐P4)] (1, Cp’’’=η5‐C5H2tBu3) towards divalent Co, Ni and Zn salts is investigated. The reaction with the bromide salts leads to [{Cp’’’Fe(CO)2}2(μ3,η2:1:1‐P4){MBr2}] (M=Co (2Co), Ni (2Ni), Zn (2Zn)) in which the P4 butterfly scaffold is preserved. The use of the weakly ligated Co complex [Co(NCCH3)6][SbF6]2, results in the formation of [{(Cp’’’Fe(CO)2)2(μ3,η4:1:1‐P4)}2Co][SbF6]3 (3), which represents the second example of a homoleptic‐like octaphospha‐metalla‐sandwich complex. The formation of the threefold positively charged complex 3 occurs via redox processes, which among others also enables the formation of [{Cp’’’Fe(CO)2}4(μ5,η4:1:1:1:1‐P8){Co(CO)2}][SbF6] (4), bearing a rare octaphosphabicyclo[3.3.0]octane unit as a ligand. On the other hand, the reaction with [Zn(NCCH3)4][PF6]2 yields the spiro complex [{(Cp’’’Fe(CO)2)2(μ3,η2:1:1‐P4)}2Zn][PF6]2 (5) under preservation of the initial structural motif.