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Owing to the high technology maturity of thermally activated delayed fluorescence (TADF) emitter design with a specific molecular shape, extremely high-performance organic light-emitting diodes (OLEDs) have recently been achieved

Three pyridine-carbonitrile-carbazole-based thermally activated delayed fluorescence (TADF) materials with highly sterically congested structures have been synthesized. The donor-acceptor-type TADF emitters (26-, 246-, and 35tCzPPC) consist of a 2,6-diphenylpyridine-3,5-dicarbonitrile core (PPC) as the acceptor and a di( t-butyl)carbazole-substituted phenyl group attached to C4 of the PC core as the donor. The molecules show a unique structure containing two consecutive large twisted angles along the donor and acceptor groups. The structure leads to a nearly complete space separation of the highest occupied molecular orbital and lowest unoccupied molecular orbital, a small Δ E

Exciplex emitters have emerged as an important class of thermally activated delayed fluorescence (TADF) materials for highly efficient OLEDs. A TADF exciplex emitter requires an intermolecular donor/acceptor pair. We have synthesized a bipolar donor-type material, DPSTPA, which was used to pair with known acceptor materials (2CzPN, 4CzIPN, or CzDBA). The OLEDs based on the exciplex emitters, DPSTPA/X, where X = 2CzPN and CzDBA, give green and orange-red colors with record-high external quantum efficiencies (EQEs) of 19.0 ± 0.6 and 14.6 ± 0.4%, respectively. In contrast, the exciplex pair DPSTPA/4CzIPN gave a very low photoluminescence quantum yield (PLQY) and a very low EQE value of the device. The DFT calculations indicate that the intermolecular distance between the donor and the acceptor plays a key factor for the PLQY and EQE. The observed low PLQY and the poor device performance for the DPSTPA/4CzIPN pair are probably because of the relatively long distance between the DPSTPA and 4CzIPN in the thin film caused by the four congested carbazole (Cz) groups of 4CzIPN, which effectively block the interaction of the nitrile acceptor with the triphenylamino donor of DPSTPA.

A convolutional neural network (CNN) is a deep learning algorithm based on the principle of human brain visual cortex processing and image recognition.To automatically identify the invasion depth and origin of esophageal lesions based on a CNN.A total of 1670 white-light images were used to train and validate the CNN system. The method proposed in this paper included the following two parts: (1) Location module, an object detection network, locating the classified main image feature regions of the image for subsequent classification tasks; and (2) Classification module, a traditional classification CNN, classifying the images cut out by the object detection network.The CNN system proposed in this study achieved an overall accuracy of 82.49%, sensitivity of 80.23%, and specificity of 90.56%. In this study, after follow-up pathology, 726 patients were compared for endoscopic pathology. The misdiagnosis rate of endoscopic diagnosis in the lesion invasion range was approximately 9.5%; 41 patients showed no lesion invasion to the muscularis propria, but 36 of them pathologically showed invasion to the superficial muscularis propria. The patients with invasion of the tunica adventitia were all treated by surgery with an accuracy rate of 100%. For the examination of submucosal lesions, the accuracy of endoscopic ultrasonography (EUS) was approximately 99.3%. Results of this study showed that EUS had a high accuracy rate for the origin of submucosal lesions, whereas the misdiagnosis rate was slightly high in the evaluation of the invasion scope of lesions. Misdiagnosis could be due to different operating and diagnostic levels of endoscopists, unclear ultrasound probes, and unclear lesions.This study is the first to recognize esophageal EUS images through deep learning, which can automatically identify the invasion depth and lesion origin of submucosal tumors and classify such tumors, thereby achieving good accuracy. In future studies, this method can provide guidance and help to clinical endoscopists.

Objectives: This study examines the practice of the regulation of Standards for Medical Exposure Quality Assurance (SMEQA) in Taiwan based on on-site quality audit for radiation therapy systems from 2016 to 2019. Methods: 81 radiation therapy departments, 141 linacs, 9 γ knife systems, 34 high dose rate brachytherapy systems, 20 Tomotherapys, and 6 Cyberknives were audited yearly. Data collection and analysis for each institute’s documents including QA procedure, ion chamber and electrometer calibration reports, and a questionnaire relating to machine type and staffing, were requested first and reviewed by auditors. On-site SMEQA core item measurements, including beam output, beam profile and energy constancy for external beam therapy systems, and the source strength, positioning, and timer accuracy for brachytherapy systems were audited second. More than 300 photon beams and more than 400 electron beams were measured each year. Results: There were approximately 8.9 radiotherapy units per million population, and 1.2 medical physicists per unit in Taiwan. For the output measurements, more than 78 and 75% of the photon beams and electron beams, respectively, from linacs were with deviations within ±1.0%. Photon beams have lower beam quality measurement deviations than electron beams. Including in-plane and cross-plane measurements, more than 90 and 85% photon and electron beams, respectively, were with flatness consistency within 1.0%. All audit measurements were within the SMEQA acceptance criteria. Conclusions: According to SMEQA regulations on-site QA audits were successfully carried out from 2016 to 2019 for all Taiwan radiotherapy units. The measurement results showed high quality machine performance in Taiwan. Advances in knowledge: Dosimetry audits with directly acquired measurement readings have lower uncertainties; allow immediate feedback, discussion, and adjustment in a timely manner. In addition to regulation system establishment and education and training implementation, the machine quality is closely related to machine maintenance implementation.

Purpose: This study examines the practice of the regulation of Standards for Medical Exposure Quality Assurance (SMEQA) in Taiwan based on on-site quality audit for radiation therapy systems from 2016 to 2019. Methods and Materials: about 81 radiation therapy departments, 141 medical linear accelerators, 9 gamma knifes, 34 high dose rate brachytherapy systems, 20 Tomotherapys and 6 Cyberknives were audited yearly. The inspection was implemented in two stages. Data collection and analysis for each institute’s documents including QA operating procedure, ion chamber and electrometer calibration reports, and a questionnaire relating to machine type and staffing, were requested first and reviewed by specially trained auditors. On-site measurements of SMEQA core items, including beam output, beam profile and energy constancy for external beam therapy systems, and the source strength, positioning and timer accuracy for brachytherapy systems were audited second. More than 300 photon beams were measured from linacs, Gamma knives, Cyberknives and Tomotherapys, and more than 400 electron beams from linacs each year.Results: The radiation treatment resource is about 8.9 therapy machines or 7.5 MV/MeV/ion beam therapy machines per million population, respectively, and there are on average about 1.20 medical physicists per radiation therapy unit in Taiwan. There were more than 78% and 75% of photon and electron beams respectively from linacs with deviations measured to the stated reference-point dose within 1.0%. Photon beams have lower beam quality measurement deviations than electron beams, and more than 90% of photon beams from linacs were within 1.0%. Including in-plane and cross-plane measurements, more than 90% and 85% of photon and electron beams respectively with flatness consistency within 1.0%. Beam symmetry as an absolute value has more than 75% of measurements within 1.0%. All audit measurements in this study were within the SMEQA acceptance criteria.Conclusions: On-site machine QA audits have been implemented from 2016 to 2019 for all radiation therapy units each year. The measurement results have shown a high quality machine performance in Taiwan.

Organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescence (TADF) materials are promising for the realization of highly efficient light emitters. However, such devices have so far suffered from efficiency roll-off at high luminance. Here, we report the design and synthesis of two diboron-based molecules, CzDBA and tBuCzDBA, which show excellent TADF properties and yield efficient OLEDs with very low efficiency roll-off. These donor–acceptor–donor (D–A–D) type and rod-like compounds concurrently generate TADF with a photoluminescence quantum yield of ~100% and an 84% horizontal dipole ratio in the thin film. A green OLED based on CzDBA exhibits a high external quantum efficiency of 37.8 ± 0.6%, a current efficiency of 139.6 ± 2.8 cd A−1 and a power efficiency of 121.6 ± 3.1 lm W−1 with an efficiency roll-off of only 0.3% at 1,000 cd m−2. The device has a peak emission wavelength of 528 nm and colour coordinates of the Commission International de l´Eclairage (CIE) of (0.31, 0.61), making it attractive for colour-display applications.

Simultaneous enhancement of out-coupling efficiency, internal quantum efficiency, and color purity in thermally activated delayed fluorescence (TADF) emitters is highly desired for the practical application of these materials. We designed and synthesized two isomeric TADF emitters, 2DPyM-mDTC and 3DPyM-pDTC, based on di(pyridinyl)methanone (DPyM) cores as the new electron-accepting units and di(tert-butyl)carbazole (DTC) as the electron-donating units. 3DPyM-pDTC, which is structurally nearly planar with a very small ΔEST, shows higher color purity, horizontal ratio, and quantum yield than 2DPyM-mDTC, which has a more flexible structure. An electroluminescence device based on 3DPyM-pDTC as the dopant emitter can reach an extremely high external quantum efficiency of 31.9% with a pure blue emission. This work also demonstrates a way to design materials with a high portion of horizontal molecular orientation to realize a highly efficient pure-blue device based on TADF emitters.

Two benzoylpyridine-carbazole based fluorescence materials DCBPy and DTCBPy, bearing two carbazolyl and 4-(t-butyl)carbazolyl groups, respectively, at the meta and ortho carbons of the benzoyl ring, were synthesized. These molecules show very small ΔEST of 0.03 and 0.04 eV and transient PL characteristics indicating that they are thermally activated delayed fluorescence (TADF) materials. In addition, they show extremely different photoluminescent quantum yields in solution and in the solid state: in cyclohexane the value are 14 and 36%, but in the thin films, the value increase to 88.0 and 91.4%, respectively. The OLEDs using DCBPy and DTCBPy as dopants emit blue and green light with EQEs of 24.0 and 27.2%, respectively, and with low efficiency roll-off at practical brightness level. The crystal structure of DTCBPy reveals a substantial interaction between the ortho donor (carbazolyl) and acceptor (4-pyridylcarbonyl) unit. This interaction between donor and acceptor substituents likely play a key role to achieve very small ΔEST with high photoluminescence quantum yield.

The hole-injection barrier between the anode and the hole-injection layer (HIL) is of critical importance to determine the device performance of organic light-emitting diodes (OLEDs). Here, we report on a record-high external quantum efficiency (EQE) (24.6% in green phosphorescence) of OLEDs fabricated on both rigid and flexible substrates, with the performance enhanced by the use of nearly defect-free and high-mobility boron-doped graphene as an effective anode and hexaazatriphenylene hexacarbonitrile as a new type of HIL. This new structure outperforms the existing graphene-based OLEDs, in which MoO3, AuCl3, or bis(trifluoromethanesulfonyl)amide are typically used as a doping source for the p-type graphene. The improvement of the OLED performance is attributed mainly to the appreciable increase of the hole conductivity in the nearly defect-free boron-doped monolayer graphene, along with the high work function achieved by the use of a newly developed hydrocarbon precursor containing boron in the graphene...

The present study investigated the neuroprotective effect of minocycline, a microglial inhibitor, against the retinal ischemia–reperfusion (IR) injury in the rat. The retinal IR injury was induced in Sprague–Dawley (SD) rats by infusing normal saline into anterior chamber of eye to create a higher intraocular pressure (IOP) than blood pressure for 45 min. Minocycline (45 and 90 mg/kg/day) was administered intraperitoneally to rats receiving IR injury. The neuroprotective effects were evaluated by morphometrical histology analysis 7 days after ischemia. The data was compared with the groups treated with saline and methylprenisolone (MP, 30 mg/kg, IV). The results showed that the retinal inner plexiform layer/outer nuclear layer (IPL/ONL) ratio was reduced following IR damage compared with that in the normal control. The IPL/ONL ratio was reduced to 43.5% in the IR-control group, 93.3% and 93.6% in the Mino-45 and Mino-90 group. The IPL/ONL ratio was preserved to 95.7% in the MP group. These results suggest that minocycline and methylprednisolone showed significantly good neuroprotective effects demonstrated in retinal histology of the rats under retinal IR injury.

Both mycelium and fruiting body of Antrodia camphorate, a traditional medicinal fungus of the family Polyporaceae in Taiwan, have been suggested to possess multiple biological functions. However, there is little information on the anticancer components and actions of mycelium of Antrodia camphorate. In the present study, the anticancer potential of synthesized maleimide derivatives, which have been isolated from mycelium of Antrodia camphorate, is examined. Comparing the cytotoxicity of two synthesized maleimide derivatives in four human cancer cell lines, camphorataimide B displayed potent efficacy. Then we investigated the impact of camphorataimide B on cell survival and cell cycle progression in vitro, and tumor growth in vivo in MDA-MB-231 breast cancer cells. Camphorataimide B decreased the cell viability and foci formation of MDA-MB-231 breast cancer cells. Further, camphorataimide B triggered apoptosis and blocked cell cycle progression of MDA-MB-231 breast cancer cells. Using immunoblotting analysis, camphorataimide B decrease the expression of cyclin-A and cyclin-B1. Moreover, we demonstrated for the first time that camphorataimide B inhibited cyclooxygenase-2 (COX-2) activity and protein expression in MDA-MB-231 cells. In nude mice study, camphorataimide B administration retarded the xenograft tumor growth of MDA-MB-231 cells. By immunohistochemical analysis, camphorataimide B decreased the expression of Ki-67 in xenograft tumor in vivo. It implied that camphorataimide B blocked cell cycle progression. Consistent with the cell culture investigation, camphorataimide B also reduced the expression of cyclin-A, cyclin-B1 and COX-2 in xenograft tumor. Thus, camphorataimide B may play a crucial role in prevention and therapy of malignant breast cancer.

Retinal ischemia is a common cause of visual impairment for humans and animals. The neuroprotective effects of lidocaine (LDC) and methylprednisolone (MP) upon retinal ischemic injury were investigated in a rat model. Sprague-Dawley rats were divided into 3 groups, the IR control, LDC and MP. A very high intraocular pressure (HIOP) and retinal ischemia were induced. In LDC group, LDC bolus (1.5 mg/kg) was i.v. injected 30 min before ischemia and then a constant rate infusion (CRI) with 2 mg/kg/hr was given until 60 min after reperfusion. In MP group, MP bolus (30 mg/kg) was i.v. administered twice at 2 min before and immediately after ischemia, respectively. The HIOP damage to retina was evaluated by electroretinogram (ERG) and morphometrical histology. The functional analysis of the retina by ERG revealed a 35.2% reduction of a-wave in the IR group, 49.7% reduction in the LDC group but no significant change in the MP group compared to normal controls. An 81.0% reduction of b-wave was observed in the IR group, 80.7% reduction in the LDC group and 17.6% reduction in the MP group. In the morphometrical histology, the retinal inner plexiform layer/outer nuclear layer (IPL/ONL) ratio was reduced to 48.8% in the IR group, 80.1% in the LDC group and 96.2% in MP group. In conclusion, the MP showed significantly good neuroprotective effects on retinal IR injury, and the LDC showed moderate neuroprotective effects demonstrated in retinal structure but not in retinal function.

A short synthesis of unsubstituted chrysene is described to provide a cheap source of this compound. This chrysene was used to prepare 3,6,9,12-tetrabromochrysene, which was subsequently transformed into various 3,6,9,12-tetrasubstituted chrysenes bearing four aryl, alkynyl, or amino groups by means of the Suzuki, Sonogashira, or Buchwald–Hartwig coupling reaction, respectively. These substituents result in large bathochromic shifts in the chrysene absorption and emission spectra. These new chrysene derivatives show blue fluorescent emission (401–471 nm) with high quantum yields (0.44–0.87). DFT calculations on these chrysenes rationalize well the substituent effects on their HOMO and LUMO energy levels. One representative chrysene (6g) was used as a blue fluorescent emitter in an OLED device that showed an outstanding external quantum efficiency (η = 6.31%) with blue emission [CIE (x, y) = (0.13, 0.20)] and a low turn-on voltage (3.0 V).

A method using 1H NMR and LC/MS with pattern recognition tools such as principal component analysis (PCA) and orthogonal projection to latent structure discriminant analysis (O-PLS-DA) was used to study the urinary metabolic profiles associated with an increase in urinary albumin in a general population. The normalized peak intensities obtained from 1H NMR and LC/MS with nonparametric two-tailed Mann-Whitney analysis was used for the identification of network of potential biomarkers corresponding to the increase of albumin in urine. The specificity of detecting the stated metabolites by 1H NMR and LC/MS was demonstrated. Our preliminary data obtained demonstrated that LC/MS may produce more distinctive metabolic profiles. For the patient group, changes in alanine, kyneurnic acid, and xanthurenic acid might be associated with changes in the tryptophan metabolism. At the same time, other metabolites that were involved in citric acid cycle, amino acid metabolism, and cellular functions were affected in the patient group. The proposed approach provided a comprehensive picture of the metabolic changes induced by the increase of protein in urine and demonstrated the advantages of using multiple diagnostic biomarkers. At the same time, the current work was demonstrated as a potential cost-effective solution of high-throughput analysis with pattern recognition tools as applied here in a real clinical situation.

Maxillary bone epithelial cyst is rare in dogs. A 5-year-old, spayed female miniature schnauzer developed a swelling below the nasal canthus of left eye. Plain radiograph demonstrated a 1.5 cm diameter of radiolucent lesion on the maxillary bone anteroventral to the eye, and contrast dacryocystorhinography confirmed an obstructed nasolarcrimal duct. The swelling showed poor response to antibiotic treatment but responded well to oral prednisolone. Exploratory surgery revealed a cyst-like structure filled with brown serous fluid. Histopathological examination of the removed cyst revealed a double cuboidal epithelial cyst. The dog recovered rapidly after surgery, and the swelling had not recurred for a 36-month follow-up. It is the first case of periorbital bone epithelial cyst reported in an adult miniature schnauzer.

A method using gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS) and (1)H NMR with pattern recognition tools such as principle components analysis (PCA) was used to study the human urinary metabolic profiles after the intake of green tea. From the normalized peak areas obtained from GC/MS and LC/MS and peak heights from (1)H NMR, statistical analyses were used in the identification of potential biomarkers. Metabolic profiling by GC/MS provided a different set of quantitative signatures of metabolites that can be used to characterize the molecular changes in human urine samples. A comparison of normalized metabonomics data for selected metabolites in human urine samples in the presence of potential overlapping peaks after tea ingestion from LC/MS and (1)H NMR showed the reliability of the current approach and method of normalization. The close agreements of LC/MS with (1)H NMR data showed that the effects of ion suppression in LC/MS for early eluting metabolites were not significant. Concurrently, the specificity of detecting the stated metabolites by (1)H NMR and LC/MS was demonstrated. Our data showed that a number of metabolites involved in glucose metabolism, citric acid cycle and amino acid metabolism were affected immediately after the intake of green tea. The proposed approach provided a more comprehensive picture of the metabolic changes after intake of green tea in human urine. The multiple analytical approach together with pattern recognition tools is a useful platform to study metabolic profiles after ingestion of botanicals and medicinal plants.

Ocimum gratissimum is used as a traditional folk medicine in many countries. The objective of this study was to evaluate the antioxidant activities of an aqueous O. gratissimum extract (OGE) and to evaluate its cytoprotective activity against hydrogen peroxide-induced toxicity in human HepG2 cells. The results revealed that the total phenolic content of the OGE reached 20%. In the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the OGE reduced up to 80% of the free radicals at a plateau concentration of 66.7 μg/mL. This indicates that OGE contains considerable free radical scavenging activity. In a dose-dependent manner, OGE pretreatment counteracted the decrease in cell viability in H2O2-treated HepG2 cells (p

Combretastatins, which are an important group of anticancer drugs, were isolated by Pettit et al. from the African tree Combretum caffrum in 1989. Additionally, Liang et al. have reported that ten coumestans were isolated from the roots of Hedysarum multijugum, which is a plant in Hedysarum Linn. of the family Leguminosae used as a folk herbal drug in northwest China. Coumestans comprise a class of naturally occurring products with a variety of biological activities including phytoestrogenic, antibacterial, antifungal, antimyotoxic, and phytoalexine effects. Due to their biological activities, the synthesis of Hedysarimcoumestan B is achieved in which the longest linear sequence is only eight steps in 50% overall yield from commercially available phloroglucinol. The key transformations in the synthesis are Stille coupling and DDQ oxidative-cyclization reactions. This synthetic strategy can be applied to give access to the demethylwedelolactone and wedelolactone, which were afforded from α-bromocoumarin in high 55% and 47% yields, respectively. In addition, CA-4 analogues are also synthesized by Pd-catalyzed coupling in overall yield 20∼28%. Furthmore, the molecular model was examined the interactions of proteins and ligands as well. Finally, the bioassay results show that the anti-invasion and anti-metastsis activity of wedelolactones in breast cancer are associated with inhibition of signaling pathway and promotion of chromatin remodeling. Camphorataimide B reduced the size and weigth of lung as well as lung colonization of MDA-MB-231 cells.