bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of CB1 cannabinoid receptor activation on cerebellar granule cell nitric oxide synthase activity
Authors: Hillard Cecilia J , Muthian Shanmugam , Kearn Christopher S
Published: July 2002

Cerebellar granule cells (CGCs) express the CB1 subtype of cannabinoid receptor. CB1 receptor agonists Win 55212‐2, CP55940 and HU210 inhibit KCl‐induced activation of nitric oxide synthase (NOS) in CGCs. Win 55212‐2 has no effect on either basal NOS activity or on activation by N‐methyl‐D‐aspartate and its effect is abolished by pre‐treatment of the cells with pertussis toxin. The CB1 receptor antagonist/inverse agonist SR141716A both reverses the effects of Win 55212‐2 and produces an increase in NOS activity that is additive with KCl. These results support the hypothesis that activation of the CB1 receptor in CGCs results in a decreased influx of calcium in response to membrane depolarization, resulting in a decreased activation of neuronal NOS.
Protein kinase CK1 is a p53‐threonine 18 kinase which requires prior phosphorylation of serine 15
Authors: Dumaz Nicolas , Milne Diane M , Meek David W
Published: July 2002

p53 is a potent transcription factor which is regulated by sequential multisite phosphorylation and acetylation. In this paper, we identify threonine 18 of p53, a key site in regulating the interaction between p53 and its regulatory partner MDM2, as a novel site phosphorylated in vitro by purified recombinant casein kinase 1 (CK1) δ. Strikingly, phosphorylation of threonine 18 is dependent upon prior phosphorylation of serine 15. These data highlight an additional and physiologically important target residue for CK1 in p53 and suggest a potential mechanism by which sequential modification of a pivotal N‐terminal residue in p53 may occur following stress‐activated modification of serine 15.
A randomized controlled trial of low‐dose aspirin in women at risk from pre‐eclampsia
Authors: Byaruhanga R.N , Chipato T , Rusakaniko S
Published: July 2002

Objectives: To determine whether low‐dose aspirin reduces the incidence of pre‐eclampsia, reduces perinatal mortality and improves birth weights in pregnant women considered at high risk of developing pre‐eclampsia. Method: Two‐hundred fifty subjects were recruited from the antenatal clinics at Harare Central Hospital with either a previous history of pregnancy‐induced hypertension or pre‐existing chronic hypertension and were randomized to receive either 75 mg of aspirin (ASA) or placebo (PLA). Results: Two‐hundred thirty subjects (ASA, n=113; PLA, n=117) completed the trial. The odds of developing pre‐eclampsia for those on aspirin was 0.72 times those on placebo (95% CI, 0.34–1.52). The mean birth weight was 2774 g for those on aspirin and 2694 g for those on placebo (P=0.80). No difference was noted in the perinatal deaths (OR=0.38; 95% CI, 0.10–1.20). Conclusion: Prophylactic use of aspirin was not associated with a significant effect on the major pregnancy outcomes assessed in this study.
The acrosome reaction in human spermatozoa
Authors: Patrat Catherine , Serres Catherine , Jouannet Pierre
Published: July 2002

During gamete interaction, sperm acrosome reaction (AR) induced by oocyte investment is a prerequisite event for the spermatozoa to pass through the zona pellucida (ZP), fuse with and penetrate the oocyte. Progesterone (P4), secreted by cumulus cells, is an important cofactor for the occurrence of this exocytosis event. The AR results from the fusion between outer acrosomal and plasma membranes, leading to inner acrosomal membrane exposure. Binding of agonists, P4 or ZP3 glycoprotein, to plasma membrane sperm receptors activates intraspermatic signals and enzymatic pathways involved in the AR. Among the proteins or glycoproteins described as potential sperm receptors for ZP, Gi/Go protein‐coupled and tyrosine kinase receptors have been described. Sperm receptors for P4 are poorly characterized, except a putative GABAA‐like receptor. ZP‐ and P4‐promoted AR is mediated by an obligatory intracellular calcium increase, appearing first at the acrosome equatorial segment and spreading throughout the head. The plasma membrane channels involved in calcium entry are operated by a plasma membrane depolarization and protein phosphorylations mediated by protein kinase C and tyrosine kinase protein. Part of the calcium increase could also be due to intracellular store release through IP3‐ and nucleotide (cAMP)‐gated channels. Besides adenylate cyclase and phospholipase C activations, intracellular calcium increase also stimulates PLA2 activity and actin depolymerization, leading to membrane fusion. Evaluation of AR by staining or fluorescent probes can be useful to predict fertilization success and to direct the therapeutic strategy in male infertility.
pN collagen type III within tendon grafts used for anterior cruciate ligament reconstruction
Authors: Sluss J. R. , Liberti J. P. , Jiranek W. A. , Wayne J. S. , Zuelzer W. A.
Published: July 2002

This study measured the amount of immature collagen type III present in tendon rafts obtained from anterior cruciate ligament (ACL) reconstructions. These values were compared with those obtained from control grafts typically used for reconstruction — Achilles, patellar, and fascia lata — and also to the normal ACL. Analyses were performed using a commercially available radio‐immunoassay (RIA). The RIA made use of a rabbit polyclonal antibody specific to the amino terminus of procollagen type III. The specificity of the Ab was confirmed by a western blot. Fibril diameter of each of the above samples was measured by transmission electron microscopy (TEM). We thus were able to determine if there was a relationship between pN collagen III content and fibril diameter.

The mean amount of pN collagen type III in the normal tendon control group was 0.8 ± 0.3 ng/μg total protein (range 0.0–2.5 ng/μg). There was significantly greater pN collagen III (16 ± 3.7 ng/μg total protein) in the grafts containing an average fibril diameter <55 nm than in the normal tendons or ACL (P < 0.05). Grafts with an average fibril diameter >55 nm had similar levels of pN collagen III (1.0 ± 0.79 ng/μg) as the controls. There was also significantly less pN‐collagen III within the functional grafts (5.3 ± 1.9 ng/μg) as compared to failed grafts, (21.6 ± 5.1 ng/μg, P < 0.05).

These results indicate that incomplete processing of procollagen III may be responsible for some of the ultrastructural alterations seen in tendon grafts. Since ultrastructural organization is believed to influence mechanical properties of these tissues, pN collagen III levels may be a possible indicator of ligament or tendon weakness. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
Illusive transience of parvalbumin expression duringembryonic development of the primate spinal cord
Authors: Knyihár‐csillik Elizabeth , Rakic Pasko , Csillik Bertalan
Published: July 2002

Parvalbumin has been located by pre‐embedding light‐ and electron microscopicimmuno histochemical techniques in the spinal cords of monkey fetuses (Macaca fasciculata),ranging from E70 to E 123, and in young (P20) and young adult (3 years) Macaque monkeys.During the time window investigated, the main developmental events of parvalbumin‐containingneural elements are that parvalbumin‐positive dorsal root collaterals establish intercellularnetworks first around nerve cells of Clarkes nucleus, then in the motoneuron pool and finally inthe upper dorsal horn. In each of these areas, location of the parvalbumin‐positive network isgradually shifted from medial to lateral. Whenever an intercellular network is established, nervecells innervated by parvalbumin‐positive terminals of dorsal root collaterals start to expressparvalbumin. Immunoreactivity of dorsal root axons is transient ; it disappears first from theintercellular networks and, afterwards, also from the dorsal columns. However, the pericellularsynaptic terminals and their post‐synaptic nerve cells express parvalbumin into adulthood.

It is concluded that some of the large (Type A) dorsal root ganglion cells are the first onesin the spinal reflex pathway to express parvalbumin, which is elicited and gradually increased innerve cells synaptically innervated by parvalbumin‐positive axon terminals. This seems torepresent a specific case of activation (or desinhibiton) of the genome. Apparent transience ofparvalbumin is due to the specific geometry of primary sensory neurons equipped with extremelylong axonal processes, and the consequent specialities of axonal transport characteristics.
Correlations between standard auditory evoked potentials and symptomatology in a group of 50 schizophrenic patients
Authors: Bougerol T , Benraiss A , Scotto JC
Published: July 2002

Standard auditory evoked potentials (AEP) were recorded in 50 schizophrenic patients and 47 normal controls. All patients were rated on the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), the Scale for the Assessment of Positive Symptoms (SAPS), and the Positive and Negative Syndrome Scale (PANSS), and were classified in three groups (positive-type [n = 10], negative-type [n = 23]and mixed-type [n = 17]patients) according to the normative criteria suggested by Kay. The mean latencies of AEP components (N1, P2, N2) and mean peak-to-peak amplitudes (N1P2, P2N2) did not correlate with age, duration of illness, length of hospitalisation or neuroleptic dosage. The evoked response did not differ between the three groups of patients (positive, negative and mixed). There was only a trend (P = 0.075) to a longer N1 latency in the negative-type group and a shorter one in the positive-type group than in the mixed-type and the control groups. The latency of N1 component correlated significantly with negative symptoms of schizophrenia (SANS scores). This correlation was related to the severity of a depressive dimension of the disorder reflected by the “depressive factor” of BPRS or “affective flattening” and “avolition” subscales of SANS.
Performance and Persistence in Money Market Fund Returns
Authors: Domian Dale L. , Reichenstein William
Published: July 2002

We study the factors affecting the cross section of net returns of money market mutual finds from 1990 through 1994, and the persistence of relative returns across years. We find that the expense ratio is the most important factor in explaining differences in net returns. Government-only funds produce slightly lower returns than other-taxable funds, and economies of scale are evident only for the smaller funds. Money funds’ rel- ative returns show strong persistence. Most funds maintain stable expense ratios, so low-cost funds produce consistently high relative returns.
Clinical significance of clonal hematopoiesis in the interpretation of blood liquid biopsy
Authors: Chan Hiu Ting , Nagayama Satoshi , Chin Yoon Ming , Otaki Masumi , Hayashi Rie , Kiyotani Kazuma , Fukunaga Yosuke , Ueno Masashi , Nakamura Yusuke , Low Siew‐Kee
Published: May 2020

As the use of next‐generation sequencing (NGS) for plasma cell‐free DNA (cfDNA) continues to expand in clinical settings, accurate identification of circulating tumor DNA mutations is important to validate its use in the clinical management for cancer patients. Here, we aimed to characterize mutations including clonal hematopoiesis (CH)‐related mutations in plasma cfDNA and tumor tissues using the same ultradeep NGS assay and evaluate the clinical significance of CH‐related mutations on the interpretation of liquid biopsy results. Ultradeep targeted NGS using Oncomine Pan‐Cancer Panel was performed on matched surgically resected tumor tissues, peripheral blood cells (PBCs), and 120 plasma cfDNA samples from 38 colorectal cancer patients. The clinical significance of the CH‐related mutations in plasma cfDNA was evaluated by longitudinal monitoring of the postoperative plasma samples. Among the 38 patients, 74 nonsynonymous mutations were identified from tumor tissues and 64 mutations from the preoperative plasma samples. Eleven (17%) of the 64 mutations identified in plasma cfDNA were also detected in PBC DNA and were identified to be CH‐related mutations. Overall, 11 of 38 (29%) patients in this cohort harbored at least one CH‐related mutation in plasma cfDNA. These CH‐related mutations were continuously detected in subsequent postoperative plasma samples from three patients which could be misinterpreted as the presence of residual disease or as lack of treatment response. Our results indicated that it is essential to integrate the mutational information of PBCs to differentiate tumor‐derived from CH‐related mutations in liquid biopsy analysis. This would prevent the misinterpretation of results to avoid misinformed clinical management for cancer patients.
Diversity and Functional Dynamics of Fleshy Fruit Abscission Zones
Authors: Tranbarger Timothy J. , Tadeo Francisco R.
Published: May 2020

We examine the current knowledge about the abscission of fleshy fruit, in particular with regards to the development and function of the abscission zone (AZ). While tomato is currently the main model species to elucidate the mechanisms of fleshy fruit abscission, most studies on tomato focus on the development and function of the pedicel AZ, which is involved in both flower and ripe fruit abscission. However, the localization of the AZ within the pedicel is not the most common location of the AZ for fleshy fruit. Fleshy fruit can have one or more AZ, which can be found in different locations within the inflorescence and fruiting structure and fulfil different functions. In fact, most of the fleshy fruit species examined thus far have more than one AZ, which can be found at the boundary between the fruit and pedicel (often referred to as the calyx AZ), within the pedicel as with tomato, at the juncture of the pedicel and peduncle or at the juncture between peduncle and shoot/branch. In addition, the different AZs may be activated or function at different stages of development, under different environmental conditions, or have a completely different purpose, such as the abscission of fruitlets or mature fruit. Together, our current knowledge about AZs suggests that while there are similarities between different AZs in different locations or from different species, not all AZs are created equal, which may be reflected in the underlying molecular mechanisms that control their development and function.
Maize Nodal Roots
Authors: Blizard Sarah , Sparks Erin E.
Published: May 2020

Plant root systems are critical to plant health and productivity, but have been difficult to study due to their subterranean location. From the studies that have been completed, there is evidence that root type matters for both developmental mechanisms and root function. Roots can be divided into different types based on the plant grouping (eudicot versus monocot) or developmental point of origin (embryonic versus post‐embryonic). This article focuses on the post‐embryonic nodal roots of the monocot
Zea mays
(maize). Maize is the number one cultivated cereal crop worldwide, yet there is limited knowledge about the mature root system. This article presents what is known about the anatomy, morphology, genetic and molecular mechanisms, and environmental factors of maize nodal root development, as well as the current state of knowledge for nodal root function including water and nutrient uptake, symbioses, and lodging resistance. As the world population grows and the climate changes, maize nodal root development and function is one area that can be targeted to improve yield and stress resilience.
Highly Stable Contact Doping in Organic Field Effect Transistors by Dopant‐Blockade Method
Authors: Kim Youngrok , Broch Katharina , Lee Woocheol , Ahn Heebeom , Lee Jonghoon , Yoo Daekyoung , Kim Junwoo , Chung Seungjun , Sirringhaus Henning , Kang Keehoon , Lee Takhee
Published: May 2020

In organic device applications, a high contact resistance between metal electrodes and organic semiconductors prevents an efficient charge injection and extraction, which fundamentally limits the device performance. Recently, various contact doping methods have been reported as an effective way to resolve the contact resistance problem. However, the contact doping has not been explored extensively in organic field effect transistors (OFETs) due to dopant diffusion problem, which significantly degrades the device stability by damaging the ON/OFF switching performance. Here, the stability of a contact doping method is improved by incorporating “dopant‐blockade molecules” in the poly(2,5‐bis(3‐hexadecylthiophen‐2‐yl)thieno[3,2‐b]thiophene) (PBTTT) film in order to suppress the diffusion of the dopant molecules. By carefully selecting the dopant‐blockade molecules for effectively blocking the dopant diffusion paths, the ON/OFF ratio of PBTTT OFETs can be maintained over 2 months. This work will maximize the potential of OFETs by employing the contact doping method as a promising route toward resolving the contact resistance problem.
Towards Simplifying the Device Structure of High‐Performance Perovskite Solar Cells
Authors: Huang Yulan , Liu Tanghao , Liang Chao , Xia Junmin , Li Dongyang , Zhang Haichao , Amini Abbas , Xing Guichuan , Cheng Chun
Published: May 2020

Perovskite solar cells (PSCs) are considered one of the most promising next‐generation examples of high‐tech photovoltaic energy converters, as they possess an unprecedented power conversion efficiency with low cost. A typical high‐performance PSC generally contains a perovskite active layer sandwiched between an electron‐transport layer (ETL) and a hole‐transport layer (HTL). The ETL and HTL contribute to the charge extraction in the PSC. However, these additional two layers complicate the manufacturing process and raise the cost. To extend this technology for commercialization, it is highly desired that the structure of PSCs is further simplified without sacrificing their photovoltaic performances. Thus, ETL‐free or/and HTL‐free PSCs are developed and attract more and more interest. Herein, the commonly used methods in reducing the defect density and optimizing the energy levels in conventional PSCs in order to simplify their structures are summarized. Then, the development of diverse ETL‐free or/and HTL‐free PSCs is discussed, with the PSCs classified, including their working principles, implemented technologies, remaining challenges, and future perspectives. The aim is to redirect the way toward low‐cost and high‐performance PSCs with the simplest possible architecture.
Oxygen‐Vacancy‐Endurable Conductors with Enhanced Transparency Using Correlated 4d2 SrMoO3 Thin Films
Authors: Ha Youngkyoung , Lee Shinbuhm
Published: May 2020

Degenerately doped wide‐bandgap semiconductors, e.g., Sn‐doped In2O3, are the most conventional transparent conductors (TCs), but degradation of the TC performance by a doping bottleneck or instability due to oxygen vacancies is encountered. Recently, nondoped correlated metals have attracted great attention as a new strategy for developing next‐generation TCs. To date, most studies of this brand‐new type of TC have been biased toward 3d1 vanadates. Here, compared with 3d1 SrVO3, it is found that the 4d2 SrMoO3 thin films show promising TC properties: higher ultraviolet–visible transmittance of 80% and extremely low resistivity of 100 µΩ cm at room temperature. This enhancement in the SrMoO3 is ascribed to a p‐4d transition occurring at higher photon energy and a higher number of electrons in the outermost 4d orbitals, respectively. In addition, the TC properties of the correlated SrMoO3 are resistive to oxygen vacancies. Using spectroscopic ellipsometry, it is found that this robustness is attributed to the lack of formation of defect states near the Fermi level, which is different from the observation in conventional TCs. Taken together, the correlated 4d2 SrMoO3 is appealing for next‐generation oxygen‐vacancy‐endurable conductors with enhanced transparency.
High Solid‐State Near Infrared Emissive Organic Fluorophores from Thiadiazole[3,4‐c]Pyridine Derivatives for Efficient Simple Solution‐Processed Nondoped Near Infrared OLEDs
Authors: Therdkatanyuphong Pattarawadee , Chasing Pongsakorn , Kaiyasuan Chokchai , Boonnab Sumita , Sudyoadsuk Taweesak , Promarak Vinich
Published: May 2020

Many efforts have been dedicated to developing near infrared (NIR) fluorescent emitters with strong emission especially in the range of 700–1000 nm due to their potential applications in biomedical and optoelectronic fields. However, high solid state NIR emission fluorophores are still rare for applications. Herein, two efficient donor‐π‐acceptor type NIR emitters, C3HTP and C4HTP, are designed and synthesized by end‐capping two isomeric bis(n‐hexylthienyl)thiadiazole[3,4‐c]pyridines as π‐acceptor with structural bulky, electron rich tercarbazole moiety. They exhibit excellent solid state NIR emission with an emission peak at 725 nm, especially C3HTP, reaching a record high photoluminescence quantum yield (ΦPL) of 34% for NIR organic fluorescent materials. By taking advantage of their ΦPL values in the film state (ΦPL = 10–34%), suitable energy levels (highest occupied molecular orbital (HOMO) level ≈ −5.3 eV), high hole mobility (5.49 × 10−8 cm2 V−1 s−1) as well as good amorphous film forming ability by solution casting, they are used to fabricate a nondoped emissive layer (EML) in simple double‐layer solution processed NIR electroluminescent (EL) devices. The device containing C3HTP as the EML shows a NIR emission peaking at 726 nm and excellent EL performance with a high external quantum efficiency of 1.51%, which is the best solution processed nondoped NIR organic light‐emitting diodes reported to date. Importantly, this represents an advance in near infrared organic fluorescent materials and EL devices that meet the requirements of many applications.
A New Concept and Strategy for Photovoltaic and Thermoelectric Power Generation Based on Anisotropic Crystal Facet Unit
Authors: Li Yang , Luo Kai , Tao Ran , Wang Zhiyong , Chen Daifen , Shao Zongping
Published: May 2020

According to the classic concept of photovoltaic devices, p–n junctions and heterojunctions are indispensable for carrier separation. Herein, for the first time, a novel concept of “anisotropic crystal facet unit” is put forward and clarified for photovoltaic and thermoelectric power generation. Specifically, an “anisotropic crystal facet unit” in monocrystalline p‐Cu2O between the {100} and the {111} crystal faces is built, which can fulfill self‐motivated carrier separation, due to their natural energy difference. The “anisotropic crystal facet unit” devices can directly and efficiently convert light and heat into electricity, where the {100} and the {111} faces act as the cathode and the anode, respectively. Moreover, hot and cold regions are unnecessary when the “anisotropic crystal facet unit” is applied in thermoelectric conversion. These findings may update the understanding of solar cells and thermoelectric cells, and blaze a new trail through the development of efficient and low‐cost energy utilization technologies.
Engineered PD‐L1‐Expressing Platelets Reverse New‐Onset Type 1 Diabetes
Authors: Zhang Xudong , Kang Yang , Wang Jinqiang , Yan Junjie , Chen Qian , Cheng Hao , Huang Peng , Gu Zhen
Published: May 2020

The pathogenesis of Type 1 diabetes (T1D) arises from the destruction of insulin‐producing β‐cells by islet‐specific autoreactive T cells. Inhibition of islet‐specific autoreactive T cells to rescue β‐cells is a promising approach to treat new‐onset T1D. The immune checkpoint signal axis programmed death‐1/programmed death‐ligand 1 (PD‐1/PD‐L1) can effectively regulate the activity of T cells and prevent autoimmune attack. Here, megakaryocyte progenitor cells are genetically engineered to overexpress PD‐L1 to produce immunosuppressive platelets. The PD‐L1‐overexpressing platelets (designated PD‐L1 platelets) accumulate in the inflamed pancreas and may suppress the activity of pancreas autoreactive T cells in newly hyperglycemic non‐obese diabetic (NOD) mice, protecting the insulin‐producing β‐cells from destruction. Moreover, PD‐L1 platelet treatment also increases the percentage of the regulatory T cells (Tregs) and maintains immune tolerance in the pancreas. It is demonstrated that the rescue of β‐cells by PD‐L1 platelets can effectively maintain normoglycemia and reverse diabetes in newly hyperglycemic NOD mice.
A High‐Performance Carbonate‐Free Lithium|Garnet Interface Enabled by a Trace Amount of Sodium
Authors: Fu Xingjie , Wang Tiantian , Shen Wenzhong , Jiang Miaoli , Wang Youwei , Dai Qiushi , Wang Da , Qiu Zhenping , Zhang Yelong , Deng Kuirong , Zeng Qingguang , Zhao Ning , Guo Xiangxin , Liu Zheng , Liu Jianjun , Peng Zhangquan
Published: May 2020

Garnet‐type solid‐state electrolytes (SSEs) are promising for the realization of next‐generation high‐energy‐density Li metal batteries. However, a critical issue associated with the garnet electrolytes is the poor physical contact between the Li anode and the garnet SSE and the resultant high interfacial resistance. Here, it is reported that the Li|garnet interface challenge can be addressed by using Li metal doped with 0.5 wt% Na (denoted as Li*) and melt‐casting the Li* onto the garnet SSE surface. A mechanistic study, using Li6.4La3Zr1.4Ta0.6O12 (LLZTO) as a model SSE, reveals that Li2CO3 resides within the grain boundaries of newly polished LLZTO pellet, which is difficult to remove and hinders the wetting process. The Li* melt can phase‐transfer the Li2CO3 from the LLZTO grain boundary to the Li*’s top surface, and therefore facilitates the wetting process. The obtained Li*|LLZTO demonstrates a low interfacial resistance, high rate capability, and long cycle life, and can find applications in future all‐solid‐state batteries (e.g., Li*|LLZTO|LiFePO4).
A Lipid‐Nanopillar‐Array‐Based Immunosorbent Assay
Authors: Kim Jieun , Kim Sungi , Ahn Junhyoung , Lee JaeJong , Nam Jwa‐Min
Published: May 2020

Since infectious diseases, particularly viral infections, have threatened human health and caused huge economical losses globally, a rapid, sensitive, and selective virus detection platform is highly demanded. Enzyme‐linked immunosorbent assay (ELISA) with flat solid substrates has been dominantly used in detecting whole viruses for its straightforwardness and simplicity in assay protocols, but it often suffers from limited sensitivity, poor quantification range, and a time‐consuming assay procedure. Here, a lipid‐nanopillar‐array‐based immunosorbent assay (LNAIA) is developed with a nanopillar‐supported lipid bilayer substrate with fluorophore‐modified antibodies for rapid, sensitive, and quantitative detection of viruses. 3D nanopillar array structures and fluid antibodies with fluorophores facilitate faster and efficient target binding and rapid fluorophore localization for quick, reliable analysis on binding events with a conventional fluorescence microscopy setup. LNAIA enables quantification of H1N1 virus that targets down to 150 virus particles with 5‐orders‐of‐magnitude dynamic range within 25 min, which cannot be achieved with conventional ELISA platforms.
Water‐Resistant Conformal Hybrid Electrodes for Aquatic Endurable Electrocardiographic Monitoring
Authors: Ji Shaobo , Wan Changjin , Wang Ting , Li Qingsong , Chen Geng , Wang Jianwu , Liu Zhiyuan , Yang Hui , Liu Xijian , Chen Xiaodong
Published: May 2020

Underwater vital signs monitoring of respiratory rate, blood pressure, and the heart's status is essential for healthcare and sports management. Real‐time electrocardiography (ECG) monitoring underwater can be one solution for this. However, the current electrodes used for ECGs are not suitable for aquatic applications since they may lose their adhesiveness to skin, stable conductivity, or/and structural stability when immersed into water. Here, the design and fabrication of water‐resistant electrodes to repurpose stretchable electrodes for applications in an aquatic environment are reported. The electrodes are composed of stretchable metal–polymer composite film as the substrate and dopamine‐containing polymer as a coating. The polymer is designed to possess underwater adhesiveness from the dopamine motif, water stability from the main scaffold, and ionic conductivity from the carboxyl groups for signal transmission. Stable underwater conductivity and firm adhesion to skin allow the electrodes to collect reliable ECG signals under various conditions in water. It is shown that wearable devices incorporated with the water‐resistant electrodes can acquire real‐time ECG signals during swimming, which can be used for revealing the heart condition. These water‐resistant electrodes realize underwater detection of ECG signals and can be used for health monitoring and sports management during aquatic activities.
Entrapping Living Probiotics into Collagen Scaffolds: A New Class of Biomaterials for Antibiotic‐Free Therapy of Bacterial Vaginosis
Authors: González Ana , Sabio Laura , Hurtado Carmen , Ramírez‐Rodríguez Gloria B. , Bansal Vipul , Delgado‐López José M. , Dominguez‐Vera José M.
Published: May 2020

A new concept of biomaterials for antibiotic‐free therapy of bacterial vaginosis (BV) is here proposed. These biomaterials are obtained by entrapping two probiotic biofilms, viz., Lactobacillus fermentum (Lf) and Lactobacillus acidophilus (La) into scaffolds of self‐assembled collagen fibers (col). An in‐depth characterization and viability assays are performed on the resulting biomaterials. Results demonstrated that the collagen matrix plays a multifold role in improving the probiotic efficacy in a BV‐simulated environment: i) it acts as a host to the formation of the probiotic biofilm, ii) it protects live probiotics during storage under harsh conditions, iii) it enhances the metabolic activity of entrapped probiotics thereby restoring the pH of BV‐simulated microenvironment, and iv) it enhances the adhesion of probiotics to the simulated vaginal mucosa. These collective properties make these biomaterials as promising candidates for treating BV without antibiotics. In addition, the approach here presented can be adapted for the treatment of other complex microbial infections.
Photothermally Reconfigurable Shape Memory Magnetic Cilia
Authors: Liu Jessica A.‐C. , Evans Benjamin A. , Tracy Joseph B.
Published: May 2020

Stimulus‐responsive polymers are attractive for microactuators because they can be easily miniaturized and remotely actuated, enabling untethered operation. In this work, magnetic Fe microparticles are dispersed in a thermoplastic polyurethane shape memory polymer matrix and formed into artificial, magnetic cilia by solvent casting within the vertical magnetic field in the gap between two permanent magnets. Interactions of the magnetic moments of the microparticles, aligned by the applied magnetic field, drive self‐assembly of magnetic cilia along the field direction. The resulting magnetic cilia are reconfigurable using light and magnetic fields as remote stimuli. Temporary shapes obtained through combined magnetic actuation and photothermal heating can be locked by switching off the light and magnetic field. Subsequently turning on the light without the magnetic field drives recovery of the permanent shape. The permanent shape can also be reprogrammed after preparing the cilia by applying mechanical constraints and annealing at high temperature. Spatially controlled actuation is demonstrated by applying a mask for optical pattern transfer into the array of magnetic cilia. A theoretical model is developed for predicting the response of shape memory magnetic cilia and elucidates physical mechanisms behind observed phenomena, enabling the design and optimization of ciliary systems for specific applications.
Terahertz Sensing with Optimized Q/Veff Metasurface Cavities
Authors: Gupta Manoj , Singh Ranjan
Published: May 2020

Confinement of electromagnetic radiation in a subwavelength cavity is an important platform for strong light–matter interaction as it enables efficient design of photonic switches, modulators, and ultrasensitive sensors. Metallic metasurfaces consist of an array of planar cavities that allow easy access to confined electromagnetic modes on the surface. However, the radiative and nonradiative losses limit the quality factor (Q) of the resonantly confined mode. Therefore, metasurface designs with effectively low mode volume (Veff) cavities become extremely important for enhancing the photonic density of states. Here, a symmetric Lorentzian resonant metasurface with lower Veff is demonstrated as compared to asymmetric Fano resonators. Lower mode volume and optimized Q/Veff metasurfaces reveal enhanced sensitivity for ultrathin analyte overlayers deposited on metasurfaces signaling enhanced light–matter interaction. Such metasurfaces with tightly confined electromagnetic modes could find wide range of applications in the development of terahertz metadevices including ultrasensitive sensors, bandpass filters, and energy‐efficient modulators.
Flexible and Rewritable Non‐Volatile Photomemory Based on Inorganic Lanthanide‐Doped Photochromic Thin Films
Authors: Chen Haisheng , Dong Zhengang , Chen Wenwen , Sun Lu , Du Xiaona , Zhao Yanan , Chen Ping , Wu Zhenping , Liu Weiwei , Zhang Yang
Published: May 2020

Emerging wearable electronics are spurring unprecedented enthusiasm in the pursuit of next‐generation memory realizable on flexible substrates. Photochromic materials enable reversible manipulation and possess erasable/rewritable capability, which ensure them to be adequate candidates as optical memories. Nevertheless, it has been challenging to develop a flexible optical memory with organic photochromic elements that simultaneously meets the stringent thermo‐ and photostable requirements. Inorganic lanthanide Er3+‐doped bismuth layer‐structure ferroelectric Na0.5Bi2.5Nb2O9 (NBN:Er) exhibits superior photochromic performance. The coupling between lanthanide upconversion emission and photochromic effect enables rewritable and nondestructive readout characteristics. Low‐dimensional complex oxide materials have superior mechanical properties and can be subject to large strain by integration with flexible substrates. Recent advances in synthesizing high‐quality inorganic oxide films on flexible substrates provide new opportunities to build flexible optical memories with dramatically higher performance. Herein, NBN:Er thin films have been integrated with flexible polyimide substrates. These hybrid heterostructures demonstrate comprehensive robust characteristics that sustain well during the 105 bending cycles, and maintain stability over many write–read–erase cycles. This work addresses the main problems hampering the promising applications of inorganic photochromic materials and paves the way for developing more flexible and compact optical memories.
High‐Performance Broadband Photodetectors of Heterogeneous 2D Inorganic Molecular Sb2O3/Monolayer MoS2 Crystals Grown via Chemical Vapor Deposition
Authors: Ye Kun , Liu Lixuan , Huang Junquan , Nie Anmin , Zhai Kun , Wang Bochong , Wen Fusheng , Mu Congpu , Zhao Zhisheng , Gong Yongji , Xiang Jianyong , Tian Yongjun , Liu Zhongyuan
Published: May 2020

The newly emerged 2D materials heterostructures, including layered and nonlayered structures, are regarded as the building blocks for future high performance optoelectronic devices. However, it still remains a great challenge to directly synthesize 2D heterostructures for realizing broadband detection in photodetectors. In this work, the growth of vertically stacked inorganic molecular Sb2O3/monolayer MoS2 heterostructures through a two‐step chemical vapor deposition method is demonstrated, and high performance ultraviolet/near‐infrared photodetectors based on the achieved heterostructures are further developed. Excellent responsivity of 5.3 × 104 A W−1 and detectivity of 2.0 × 1015 Jones are obtained under 457 nm illumination. Additionally, the photodetection range can be extended to near‐infrared region. Maximum responsivity of 7.8 A W−1, detectivity of 3.4 × 1011 Jones, and fast response speed (<60 ms) are obtained under 1064 nm laser illumination at room temperature, which is far superior to those of the previously reported ultra‐thin 2D van de Waals heterostructures. The inorganic molecular Sb2O3/monolayer MoS2 heterostructures enrich the family of 2D materials heterostructures, showing potential applications in high performance functional electronics and optoelectronics.
Self‐Quenching‐Resistant Red Emissive Carbon Dots with High Stability for Warm White Light‐Emitting Diodes with a High Color Rendering Index
Authors: Zhang Xiaoqin , Yang Haiyao , Wan Zhijun , Su Ting , Zhang Xuejie , Zhuang Jianle , Lei Bingfu , Liu Yingliang , Hu Chaofan
Published: May 2020

Due to the excellent characteristics of energy‐saving, environmentally friendly and long‐life, the solid‐state lighting based on white light‐emitting diodes (WLEDs) is an emerging technology to replace traditional lighting solutions. However, the lack of red component of the most established method for fabricating commercial WLEDs results in high correlated color temperature (CCT) and low color rendering index (CRI). Herein, red‐emitting carbon dots (R‐CDs) with self‐quenching‐resistant property are synthesized using melamine and dithiosalicylic acid as precursors. In addition, R‐CDs exhibit high thermal and photostability under high temperature and strong blue light irradiation. On the basis of the unique features of R‐CDs, a WLED is fabricated by combining a blue‐LED chip with commercial Ce3+:Y3Al5O12 and R‐CDs phosphors, which exhibits warm white light with a color coordinate of (0.41, 0.38), a high CRI of 92.7 and a CCT of 3827 K. Besides, the WLED exhibits good optical stability upon the increase of drive current from 20 to 100 mA. The results suggest R‐CDs can be used as a color converter to fabricate high‐quality warm WLEDs.
Independent Energy Allocation of Dual‐Helical Multi‐Beams with Spin‐Selective Transmissive Metasurface
Authors: Ding Guowen , Chen Ke , Qian Guangxu , Zhao Junming , Jiang Tian , Feng Yijun , Wang Zhengbin
Published: May 2020

Although metasurfaces have provided unprecedented control of electromagnetic (EM) waves, it is still challenging for the arbitrary manipulation of spatial radiation modes, energy distribution, and spin state of EM wave especially in microwave frequencies. Here, a cascaded dual‐helicity‐decoupled transmissive metasurface to realize independent modulation of two orthogonal circularly polarized waves is proposed. Leveraging this appealing feature, distinct multiple beams with freely designed energy intensities for two spin states generated from a metasurface are demonstrated experimentally with high efficiency, providing full control of sophisticated wavefronts, spin states, and their energy allocations. Two proof‐of‐concept designs are implemented in microwave region, which may offer a new way to achieve spatially energy‐editable multifunctional devices that can be used in practical applications, such as beam forming, multiple target tracking, and wireless communications.
Extraordinary Temperature Dependent Second Harmonic Generation in Atomically Thin Layers of Transition‐Metal Dichalcogenides
Authors: Khan Ahmed Raza , Liu Boqing , Zhang Linglong , Zhu Yi , He Xin , Zhang Lijun , Lü Tieyu , Lu Yuerui
Published: May 2020

Atomically thin transition metal dichalcogenides (TMDs) are important semiconducting materials because of their interesting layer dependent properties. Recently, optical second harmonic generation (SHG) is used to probe layer number, lattice orientation, phase variation, and strain vector in ultrathin TMDs. Here, it is demonstrated that SHG response of ultrathin TMDs is highly sensitive to temperature modulation. Furthermore, temperature dependent SHG is found to show opposite trends for single layer and few odd layers (3L, 5L, 7L, etc.) of TMDs. A remarkable temperature dependent SHG enhancement (25.8%) is found in single layer molybdenum diselenide (MoSe2) using 900 nm laser excitation whereas few odd layers show significant temperature dependent SHG quenching which is found to be ‐55.2%, ‐31.02%, and ‐18.4% in case of 3L, 5L, and 7L of MoSe2. Temperature dependent SHG investigation with other TMDs, like MoS2, WS2, and WSe2, shows the similar trend which reveals an important structural characteristic for TMDs. Second order nonlinear susceptibility calculations considering weak van der Waal forces during thermal expansion in ultrathin TMDs show good agreement with the experimental findings. The results show SHG as a powerful and sensitive approach to investigate thermal variation in ultrathin TMDs.
Strategically Manipulated Polymer Solar Cells to Incorporate Plasmonically Enhanced Spectral Upconversion Backplane
Authors: Cho Ha‐Eun , Lee Na‐Kyung , Song Young Jin , Hong Jinwook , Kang Hyelim , Lim Soo Yeong , Lee Jaegab , Kim Hyung Min , Lee Nohyun , Cho Seok Ho , Lee Sung‐Min
Published: May 2020

Spectral upconversion systems placed underneath solar cells have the considerable potential for enhancement of the photovoltaic performance as they allow additional absorption for the solar photons with energy below the bandgap of active materials. However, their application to a type of ultrathin solar cells for achieving the meaningful benefit of the efficiency improvement is challenging, because a pre‐existing rear‐side reflector that substantially increases the photon absorption needs to be eliminated for photonic interaction between photovoltaic active layer and upconversion medium, and hence a level of cell efficiency becomes limited. Herein a facile strategy is presented that can circumvent the issue of performance deterioration arising from the expelled reflector for integrating plasmonically enhanced upconversion systems with ultrathin nonfullerene‐based polymer solar cells. By employing a wavelength‐selectively reflective rear electrode of metal/dielectric multilayer that enables the photon penetration only at excitation and emission wavelengths of the upconversion process, the effect of photocurrent improvement with uncompromising efficiency levels can be expected from the plasmonic upconversion backplane comprising NaYF4:Yb3+,Er3+ core‐shell nanoparticles and metallic nanostructure. Systematic studies of optical process and resulting device performance in both experiments and numerical modeling provide the optimal design scheme for high‐performance polymer solar cells assisted with upconversion systems.
All‐Solution Processed Multicolor Patterning Technique of Perovskite Nanocrystal for Color Pixel Array and Flexible Optoelectronic Devices
Authors: Jeon Sanghyun , Lee Sang Yeop , Kim Su‐Kyung , Kim Woosik , Park Taesung , Bang Junsung , Ahn Junhyuk , Woo Ho Kun , Chae Ji‐Yeon , Paik Taejong , Seong Tae‐Yeon , Oh Soong Ju
Published: May 2020

In the present study, a new patterning method is introduced through the surface modification and stabilization of perovskite nanocrystals, which is compatible with conventional photolithography process based on all‐solution processes. Chemically designed gel‐type silica‐coated CsPbX3 (X = Br, I, etc.) perovskite nanocrystals combined with dip coating method are introduced to form stable and uniform films. Analyses of the physical and chemical states of nanocrystals and investigation of the kinetics in silica formation are conducted. In an optimized condition, physically uniform and chemically stable perovskite thin films are deposited on various substrates such as flexible, stretchable substrates, or even nonflat objects. By adopting these advantages and developing stable photolithographic chemicals, the high resolution patterns are successfully patterned with green and red emitting CsPbBr3 and CsPbBr3I3−x perovskites with the size down to 5 µm of radius and even a multicolor pixel array which can be used for the color filter, light converting or detecting applications. Flexible white light emitting diode is also fabricated with a large color gamut coverage. This work provides a fundamental understanding of perovskite nanocrystals, and also offers a technological breakthrough enabling various optoelectronic applications.
Dimension Confinement Effect Boosted Ultrasensitive Colorimetric Signal Concentrating
Authors: Wang Peixian , Cai Zhenzhen , Li Jiguang , Li Yushu , Zu Baiyi , Dou Xincun
Published: May 2020

To understand the underlying fundamental mechanism affecting the optical sensitivity of a paper‐based substrate, a layered polyvinyl alcohol (PVA) network paper is proposed considering the physical geometry and chemical composition required to enhance the sensitivity. It is verified both theoretically and experimentally that the dimension confinement effect introduced by the Steiner network, layered and pore structures, as well as massive hydroxyl groups, play an essential role in enhancing the concentration signal on the surface. Trace chlorate droplets and particles are considered representative examples to prove the excellent structural design‐induced performance of the PVA network paper. A practical mass detection from potassium chlorate solution and particles could be as low as 9.9 pg and 0.34 fg, respectively, and the corresponding naked‐eye observation limit could reach 0.69 ng and 1.6 pg, respectively, assuming the distinguishable size for human eyes is 100 µm. Further, the detection time could be far less than 2 s, which is remarkably superior than the detection performance of the parallel filter paper counterpart. The dimension confinement effect demonstrated here is expected to be of great importance for advancing the development of paper‐based trace detection.
Complementary Dark and Bright Plasmonic Nanocavities with Controllable Energy Exchange for SERS Sensing
Authors: Liu Feifei , Zhang Xinping , Mu Yunyun , Lin Jing , Wang Meng , Ma He
Published: May 2020

A 3D nanocavity array with each unit composed of complementarily arranged downward and upward silver nanoshells is reported. Due to the underneath planar gold film, the two differently oriented nanoshells form alternatively closed and semi‐closed nanocavities, respectively, which support dark and bright resonance modes of localized surface plasmons (LSPs). For the symmetric design of such nanocavities, mutually independent multipolar LSPs are directly excited at normal incidence, so that the near‐field coupling between them is inhibited. However, when the geometrical symmetry is broken by introducing a breach on a common sidewall of the two adjacent nanocavities, strong interaction and consequently energy exchange between them become allowed. As a result, Fano coupling between the dark and bright LSPs is clearly observed as a sharp spectroscopic resonance. The most important feature of such a coupled dark‐ and bright‐plasmon system is that the resonance modes of two different LSPs can be tuned separately, enhancing largely the flexibility of the photophysical performance and controllability. In particular, these features enable promising applications of such structures in single‐molecular detection through fluorescence enhancement, surface enhanced Raman scattering (SERS), and surface plasmon lasers. SERS measurements verify excellent performance of such nanocavity arrays in high‐sensitivity detection of low‐concentration molecules.