Precision positioning is very important for automatic assembly and inspection in the electronic manufacturing process. In this paper, we propose a fast image alignment method using the ...expectation-maximization (E-M) technique. The proposed algorithm is especially applied to positioning and defect inspection of printed circuit boards (PCBs). It can well handle deformed or incomplete object shapes with translation, rotation, and scale changes. The Canny edge detector is used to generate the edge maps of images. The E-step of the E-M procedure finds mutual edge points in both compared images by assigning weights to individual edge points. The mutual edge points give larger weights, while the foreign edge points in two images have smaller weights. The M-step then calculates the geometric transformation parameters using the weighted edge points in individual images. For an edge point in one image, a fast spiral search is proposed to find its corresponding edge point with the shortest distance in the other image. The spiral search is carried out by a predetermined lookup table, and no computation is involved in the search process. The weight of each edge point is inversely proportional to the neighboring distance. Experimental results indicate that the proposed E-M positioning method can achieve a translation error less than 1 pixel and a rotation error smaller than 1° for PCB positioning.
Interfaces play a decisive role in perovskite solar cells’ power conversion efficiency and their long‐term durability. Small‐molecule hole‐transporting materials (HTMs) have grabbed enormous ...attention due to their structural flexibility, material properties, and stabilities, allowing for improved operational durability in perovskite photovoltaics. This study synthesizes and investigates a new class of benzimidazole‐based small molecules, named YJS001 and YJS003, serving as the HTMs to enable high‐efficiency mixed‐cation mixed‐halide perovskite solar cells. The benzimidazole‐based materials are dopant‐free HTMs composed of donor and acceptor building blocks that are designed to engineer the energy level alignment near the HTM/perovskite interface. Mixed‐cation mixed‐halide perovskites can be grown uniformly on both HTMs with large crystalline grains. It is discovered that the donor‐rich YJS003‐based solar cell exhibits a high open‐circuit voltage of 1.09 V with a champion power conversion efficiency of over 20%. Power‐dependent current–voltage characteristics of the solar cells are analyzed, from which the high performance of YJS003's excellent hole mobility and well‐aligned energy level is attributed. This work introduces a new class of benzimidazole‐based small molecules as HTMs, that paves the path for dopant free interface material development for commercialization of perovskite solar cells.
Two new hole‐transporting materials (HTMs) with acceptor‐rich (YJS001) and donor‐rich (YJS003) are synthesized and characterized for hybrid perovskite photovoltaics applications. Under similar conditions, the efficiency of HTM YJS001 and YJS003‐based devices is 17.43% and 20.81%, respectively. The superior performance of YJS003 over YJS001 is attributed to higher open‐circuit voltage and fill factor from good hole transport, lower trap density, and lower electric resistance of cells.
Despite expanding knowledge regarding the role of astroglia in regulating neuronal function, little is known about regional or functional subgroups of brain astroglia and how they may interact with ...neurons. We use an astroglia-specific promoter fragment in transgenic mice to identify an anatomically defined subset of adult gray matter astroglia. Using transcriptomic and histological analyses, we generate a combinatorial profile for the in vivo identification and characterization of this astroglia subpopulation. These astroglia are enriched in mouse cortical layer V; express distinct molecular markers, including Norrin and leucine-rich repeat-containing G-protein-coupled receptor 6 (LGR6), with corresponding layer-specific neuronal ligands; are found in the human cortex; and modulate neuronal activity. Astrocytic Norrin appears to regulate dendrites and spines; its loss, as occurring in Norrie disease, contributes to cortical dendritic spine loss. These studies provide evidence that human and rodent astroglia subtypes are regionally and functionally distinct, can regulate local neuronal dendrite and synaptic spine development, and contribute to disease.
A series of donor–acceptor–donor triazine‐based molecules with thermally activated delayed fluorescence (TADF) properties were synthesized to obtain highly efficient blue‐emitting OLEDs with ...non‐doped emitting layers (EMLs). The targeted molecules use a triazine core as the electron acceptor, and a benzene ring as the conjugated linker with different electron donors to alternate the energy level of the HOMO to further tune the emission color. The introduction of long alkyl chains on the triazine core inhibits the unwanted intermolecular D–D/A–A‐type π–π interactions, resulting in the intermolecular D–A charge transfer. The weak aggregation‐caused quenching (ACQ) effect caused by the suppressed intermolecular D–D/A–A‐type π–π interaction further enhances the emission. The crowded molecular structure allows the electron donor and acceptor to be nearly orthogonal, thereby reducing the energy gap between triplet and singlet excited states (ΔEST). As a result, blue‐emitting devices with TH‐2DMAC and TH‐2DPAC non‐doped EMLs showed satisfactory efficiencies of 12.8 % and 15.8 %, respectively, which is one of the highest external quantum efficiency (EQEs) reported for blue TADF emitters (λpeak<475 nm), demonstrating that our tailored molecular designs are promising strategies to endow OLEDs with excellent electroluminescent performances.
Getting the blues: A series of donor–acceptor–donor triazine‐based molecules with thermally activated delayed fluorescence (TADF) properties were synthesized to obtain highly efficient blue‐emitting OLEDs with non‐doped emitting layers (EMLs). The targeted molecules use a triazine core as the electron acceptor, and a benzene ring as the conjugated linker with different electron donors to alternate the energy level of the HOMO to further tune the emission color.
Aging, cancer, and longevity have been linked to intracellular Ca2+ signaling and nociceptive transient receptor potential (TRP) channels. We found that TRP canonical 7 (TRPC7) is a nociceptive ...mechanoreceptor and that TRPC7 channels specifically mediate the initiation of ultraviolet B (UVB)‐induced skin aging and tumor development due to p53 gene family mutations. Within 30 min after UVB irradiation, TRPC7 mediated UVB‐induced Ca2+ influx and the subsequent production of reactive oxygen species in skin cells. Notably, this function was unique to TRPC7 and was not observed for other TRP channels. In TRPC7 knockout mice, we did not observe the significant UVB‐associated pathology seen in wild‐type mice, including epidermal thickening, abnormal keratinocyte differentiation, and DNA damage response activation. TRPC7 knockout mice also had significantly fewer UVB‐induced cancerous tumors than did wild‐type mice, and UVB‐induced p53 gene family mutations were prevented in TRPC7 knockout mice. These results indicate that TRPC7 activity is pivotal in the initiation of UVB‐induced skin aging and tumorigenesis and that the reduction in TRPC7 activity suppresses the UVB‐induced aging process and tumor development. Our findings support that TRPC7 is a potential tumor initiator gene and that it causes cell aging and genomic instability, followed by a change in the activity of proto‐oncogenes and tumor suppressor genes to promote tumorigenesis.
Schematic representation of the role of TRPC7 as a potential tumor initiator gene in ultraviolet B (UVB)‐induced aging and cancer progression. UVB‐activated TRPC7 initiates skin aging via intracellular Ca2+ elevation, resulting in oxidative stress, DNA damage response activation, abnormal differentiation, and senescence inflammation response activation; this pathology is repaired with the activation of p53 to maintain tissue homeostasis. When homeostasis is no longer maintained and the aging process is activated, carcinogens promote cancer progression. TRPC7 initiates tumorigenesis by causing genomic instability, thereby changing the activity of proto‐oncogenes and tumor suppressor genes.
New cells are continuously added to the rodent olfactory bulb (OB), throughout development and in adults. These cells migrate tangentially from the subventricular zone along the rostral migratory ...stream to the OB, where they migrate radically from the center to periphery of the OB. Although different modalities of radial migration have been described in other brain regions, the mechanisms governing radial migration in the OB are still mostly unknown. Here, we identify a new modality of migration in which neuronal precursors migrate along blood vessels toward their destination. Our results show that half of the radially migrating cells associate with the vasculature in the granule cell layer of the OB, and in vivo time-lapse imaging demonstrates that they use blood vessels as a scaffold for their migration through an interaction with the extracellular matrix and perivascular astrocyte end feet. The present data provide evidence that a new modality of migration, vasophilic migration, is occurring in the adult brain and reveals a novel role of brain vasculature.
Cordyceps militaris is a well-known Chinese medicinal fungus that has been used as a nutraceutical food in several Asian countries. Cordycepin (3'-deoxyadenosine), a secondary metabolite produced ...from Cordyceps militaris, has been demonstrated to exert a wide spectrum of pharmacological activities, such as anti-microbial and anti-tumor activities. However, the effect of cordycepin on immunomodulation in broilers is poorly investigated. In the current study, we investigated the effect of cordycepin (9.69, 19.38, and 38.76 mg) from Cordyceps militaris hot water extract (CMHW) on growth performance and immunocompetence in broilers. Results showed that CMHW significantly decreased inducible nitric oxide synthase (iNOS) mRNA levels in the bursa of Fabricius after 4 weeks of feeding (P < 0.05). CMHW treatment reduced cyclooxygenase-2 (COX-2) mRNA levels in the spleen and bursa of Fabricius after 4 weeks of feeding (P < 0.05). Supplementation of CMHW for 3 days after vaccination reduced iNOS mRNA level in the spleen of 14 and 28 day-old broilers (P < 0.05). Prior to vaccination, CMHW pretreatment significantly down-regulated COX-2 mRNA levels in the spleen and bursa of Fabricius of 14-day-old broilers (P < 0.05). Furthermore, CMHW significantly reduced lipopolysaccharide (LPS)-induced iNOS and COX-2 mRNA levels in the spleen and bursa of Fabricius (P < 0.05). CMHW treatment attenuated LPS-induced IFN-γ expression in the spleen and bursa of Fabricius, whereas CMHW induced IL-4 expression in these organs in response to LPS challenge (P < 0.05). Taken together, these observations demonstrate that CMHW exerts an immunomodulatory role in broilers. CMHW is a potential novel feed additive with applications in inflammation-related diseases and bacterial infection in broilers.
The subventricular zone (SVZ) of the lateral ventricle develops from residual progenitors of the embryonic lateral ganglionic eminence (LGE) and maintains neurogenic activity throughout life. ...Precursors from LGE/SVZ migrate to the olfactory bulb (OB) where they differentiate into local interneurons, principally in the granule layer and glomerular layer (GL). By in situ dye labeling, we show that neonatal and adult SVZ progenitors differentially contribute to neurochemically distinct types of periglomerular interneurons in the GL. Namely, calbindin-positive periglomerular cells are preferentially generated during early life, whereas calretinin- and tyrosine hydroxylase-expressing neurons are mainly produced at later ages. Furthermore, homochronic/heterochronic transplantation demonstrates that progenitor cells isolated from the LGE or SVZ at different stages (embryonic day 15 and postnatal days 2 and 30) engraft into the SVZ of neonatal or adult mice, migrate to the OB, and differentiate into local interneurons, including granule and periglomerular cells as well as other types of interneurons. The total number of integrated cells and the relative proportion of granule or periglomerular neurons change, according to the donor age, whereas they are weakly influenced by the recipient age. Analysis of the neurochemical phenotypes acquired by transplanted cells in the GL shows that donor cells of different ages also differentiate according to their origin, regardless of the host age. This suggests that progenitor cells at different ontogenetic stages are intrinsically directed toward specific lineages. Neurogenic processes occurring during development and in adult OB are not equivalent and produce different types of periglomerular interneurons as a consequence of intrinsic properties of the SVZ progenitors.
Background /Purpose BRAF and NRAS mutations have been described in melanomas among Caucasians and some Asian populations. However, few large-scale studies have investigated the status and clinical ...significance of BRAF and NRAS mutations in a Taiwanese population. Methods Melanoma samples ( n = 119) were analyzed for mutations in exons 11 and 15 of the BRAF gene, and in exons 1 and 2 of the NRAS gene. The samples were studied in genomic DNA, using polymerase chain reaction amplification and Sanger sequencing. Mutations of the BRAF and NRAS genes were then correlated with clinicopathological features and patients' prognosis. Results The incidence of somatic mutations within the BRAF and NRAS genes was 14.3% (17/119 patients) and 10.1% (12/119 patients), respectively. Among the 17 patients with BRAF mutations, 15 (88.2%) had V600E mutations. BRAF mutation was frequently detected in younger patients ( p = 0.0035), in thin melanomas ( p = 0.0181), and in melanomas with less ulceration ( p = 0.0089). NRAS mutation was more often seen in patients with lymph node metastasis ( p = 0.0332). Both BRAF and NRAS mutations were not significantly correlated with overall survival and disease-free survival. Conclusion As BRAF and NRAS mutations are rare in Taiwan, BRAF- or NRAS- targeted therapies may be effective only for selected Taiwanese melanoma patients.
PDF
