Substituent engineering of the diboron molecular architecture for a nondoped and ultrathin emitting layer.

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 via various doping techniques. Recently, undoped OLEDs have drawn immense attention because of their manufacturing cost reduction and procedure simplification. However, capable materials as host emitters are rare and precious because general fluorophores in high-concentration states suffer from serious aggregation-caused quenching (ACQ) and undergo exciton quenching. In this work, a series of diboron materials, CzDBA, iCzDBA, and tBuCzDBA, is introduced to realize the effect of steric hindrance and the molecular aspect ratio via experimental and theoretical studies. We computed transition electric dipole moment (TEDM) and molecular dynamics (MD) simulations as a proof-of-concept model to investigate the molecular stacking in neat films. It is worth noting that the pure tBuCzDBA film with a high horizontal ratio of 92% is employed to achieve a nondoped OLED with an excellent external quantum efficiency of 26.9%. In addition, we demonstrated the first ultrathin emitting layer (1 nm) TADF device, which exhibited outstanding power efficiency. This molecular design and high-performance devices show the potential of power-saving and economical fabrication for advanced OLEDs.

Investigation of Toxoplasma infection in zoo animals using multispecies ELISA and GRA7 nested PCR.

BACKGROUND: Toxoplasma is an obligate intracellular protozoan that causes an important zoonotic disease with a worldwide distribution. Felids are the definitive hosts of this parasite, while virtually all warm-blooded animals, including birds, serve as intermediate hosts. Four ring-tailed lemurs (Lemur catta) in the Taipei Zoo died of acute Toxoplasma infection in June 2019. Since then, Toxoplasma has occasionally been identified in this Zoo during necropsy of dead animals and PCR of animal blood samples. Therefore, a general survey of Toxoplasma infection in animals in the Zoo seems to be needed. METHODS AND RESULTS: An indirect multispecies ELISA was used for the first time to screen for Toxoplasma infection in 326 serum samples collected from 75 species of animals. The infection rate of Toxoplasma was 27% (88/326). A commercial latex agglutination (LAT) assay was used to re-examine the samples with doubtful and uncertain ELISA results (151 samples from 42 species). The infection rate increased to 36.2% (118/326), and the indirect multispecies ELISA appeared to be applicable to 31 of 75 species animals included in this study. Nested PCR assays targeting the dense granule protein 7 (GRA7) gene and B1 gene were also used to detect Toxoplasma in DNA samples extracted from 10 liver or blood specimens from 8 animals. GRA7 gene fragments were amplified from 8 samples from 7 animals, while B1 gene fragments were amplified from only 4 samples from 4 animals. From the B1 nested PCR and the sequence data of GRA7 fragments amplified from infectious specimens, the animals in the Zoo were speculated to have been infected by at least three different Toxoplasma variants. CONCLUSIONS: According to the serological investigation, we speculated that over one-third (36.2%) of animals in Taipei Zoo presented the infection of Toxoplasma, and the indirect multispecies ELISA we used can be applied to detect Toxoplasma infection in 31 animal species included in this study. Sequence analysis revealed that at least three Toxoplasma variants were infecting the animals of Taipei Zoo.

Application of endoscopic ultrasonography for detecting esophageal lesions based on convolutional neural network.

BACKGROUND: A convolutional neural network (CNN) is a deep learning algorithm based on the principle of human brain visual cortex processing and image recognition. AIM: To automatically identify the invasion depth and origin of esophageal lesions based on a CNN. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Molecular and serological detection of Toxoplasma gondii infection in mammals in the Taipei Zoo.

Toxoplasmosis caused by Toxoplasma gondii affects both conservation and public health efforts. In the Taipei Zoo, toxoplasmosis was diagnosed in ring-tailed lemurs and a meerkat in 2019 while a freeze-thaw meat strategy had been applied to carnivores before the event. To investigate the possible risk factors associated with T. gondii infection in the Taipei Zoo, 179 veterinary visiting mammals from 2019-2021 and six stray cats were included to detect anti-T. gondii IgG and IgM in their serum via ELISA, and T. gondii in their faeces and blood via PCR. Although the overall T. gondii IgG seroprevalence was 33.5% and PCR positivity was 16.2% in the zoo mammals, the correlation between T. gondii PCR and systemic IgG results was low. An omnivorous diet (adjusted OR = 0.4; 95% CI: 0.2-1.0), a herbivorous diet (adjusted OR = 3.2; 95% CI: 1.1-9.6), and animals in the Conservation Area where stray cats appeared (adjusted OR = 18.3; 95% CI: 3.9-85.9) were independent risk factors for T. gondii infection. The low T. gondii-specific IgM positivity (0.6%) suggests that most animals did not have acute T. gondii infection. In conclusion, our findings indirectly support that feeding frozen meat to carnivores, cleaning fresh food, and restricting access to stray cats to prevent faecal contaminants could prevent animals from T. gondii exposure.

Dosimetry audits in Taiwan radiotherapy departments.

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.

Acetyl-11-keto-ß-boswellic acid inhibits proliferation and induces apoptosis of gastric cancer cells through the phosphatase and tensin homolog /Akt/ cyclooxygenase-2 signaling pathway.

BACKGROUND: Gastric cancer is one of the most common malignant tumors of the digestive system worldwide, posing a serious danger to human health. Cyclooxygenase (COX)-2 plays an important role in the carcinogenesis and progression of gastric cancer. Acetyl-11-keto-ß-boswellic acid (AKBA) is a promising drug for cancer therapy, but its effects and mechanism of action on human gastric cancer remain unclear. AIM: To evaluate whether the phosphatase and tensin homolog (PTEN)/Akt/COX-2 signaling pathway is involved in the anti-tumor effect of AKBA in gastric cancer. METHODS: Human poorly differentiated BGC823 and moderately differentiated SGC7901 gastric cancer cells were routinely cultured in Roswell Park Memorial Institute 1640 medium supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin. Gastric cancer cell proliferation was determined by methyl thiazolyl tetrazolium colorimetric assay. Apoptosis was measured by flow cytometry. Cell migration was assessed using the wound-healing assay. Expression of Bcl-2, Bax, proliferating cell nuclear antigen, PTEN, p-Akt, and COX-2 were detected by Western blot analysis. A xenograft nude mouse model of human gastric cancer was established to evaluate the anti-cancer effect of AKBA in vivo. RESULTS: AKBA significantly inhibited the proliferation of gastric cancer cells in a dose- and time-dependent manner, inhibited migration in a time-dependent manner, and induced apoptosis in a dose-dependent manner in vitro; it also inhibited tumor growth in vivo. AKBA up-regulated the expression of PTEN and Bax, and down-regulated the expression of proliferating cell nuclear antigen, Bcl-2, p-Akt, and COX-2 in a dose-dependent manner. The PTEN inhibitor bpv (Hopic) reversed the high expression of PTEN and low expression of p-Akt and COX-2 that were induced by AKBA. The Akt inhibitor MK2206 combined with AKBA down- regulated the expression of p-Akt and COX-2, and the combined effect was better than that of AKBA alone. CONCLUSION: AKBA inhibits the proliferation and migration and promotes the apoptosis of gastric cancer cells through the PTEN/Akt/COX-2 signaling pathway.

Pyridine-Carbonitrile-Carbazole-Based Delayed Fluorescence Materials with Highly Congested Structures and Excellent OLED Performance.

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 EST value, and excellent TADF property. Moreover, the 26- and 246tCzPPC dopants favor a horizontal alignment enhancing the light outcoupling of the device. In contrast, 35tCzPPC favors a perpendicular alignment reducing the light outcoupling efficiency of the device. The 246tCzPPC-based devices show external quantum efficiency as high as 29.6% because of excellent TADF property, very high photoluminescence quantum yield, and high Θ value in the thin films. The device performance is the best among the pyridine-carbonitrile-based TADF emitters.

Exciplex Organic Light-Emitting Diodes with Nearly 20% External Quantum Efficiency: Effect of Intermolecular Steric Hindrance between the Donor and Acceptor Pair.

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.

High-Performance Organic Light-Emitting Diode with Substitutionally Boron-Doped Graphene Anode.

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 growth by chemical vapor deposition.

A New Molecular Design Based on Thermally Activated Delayed Fluorescence for Highly Efficient Organic Light Emitting Diodes.

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.

3,6,9,12-Tetrasubstituted chrysenes: synthesis, photophysical properties, and application as blue fluorescent OLED.

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).

Inhibition of cell survival, cell cycle progression, tumor growth and cyclooxygenase-2 activity in MDA-MB-231 breast cancer cells by camphorataimide B.

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.

The neuroprotective effects of lidocaine and methylprednisolone in a rat model of retinal ischemia-reperfusion injury.

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.

Combination of 1H nuclear magnetic resonance spectroscopy and liquid chromatography/mass spectrometry with pattern recognition techniques for evaluation of metabolic profile associated with albuminuria.

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 in an adult miniature schnauzer.

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.

Metabonomics investigation of human urine after ingestion of green tea with gas chromatography/mass spectrometry, liquid chromatography/mass spectrometry and (1)H NMR spectroscopy.

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.