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1.
Am J Cancer Res ; 14(5): 2103-2123, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38859837

RESUMEN

The lncRNA tumor protein translationally controlled 1-antisense RNA 1 (TPT1-AS1) is known for its oncogenic role in various cancers, but its impact on the pathological progression of prostate cancer remains unclear. Our previous study demonstrated that the RE1-silencing transcription factor (REST) regulates neuroendocrine differentiation (NED) in prostate cancer (PCA) by derepressing specific long non-coding RNAs (lncRNAs), including TPT1-AS1. In this study, we revealed that TPT1-AS1 is overexpressed in LNCaP and C4-2B cells after IL-6 and enzalutamide treatment. By analyzing The Cancer Genome Atlas (TCGA) prostate adenocarcinoma dataset, we detected upregulated TPT1-AS1 expression in neuroendocrine-associated PCA but not in prostate adenocarcinoma. Single-cell RNA sequencing data further confirmed the increased TPT1-AS1 levels in neuroendocrine prostate cancer (NEPC) cells. Surprisingly, functional experiments indicated that TPT1-AS1 overexpression had no stimulatory effect on NED in LNCaP cells and that TPT1-AS1 knockdown did not inhibit IL-6-induced NED. Transcriptomic analysis revealed the essential role of TPT1-AS1 in synaptogenesis and autophagy activation in neuroendocrine differentiated PCA cells induced by IL-6 and enzalutamide treatment. TPT1-AS1 was found to regulate the expression of autophagy-related genes that maintain neuroendocrine cell survival through autophagy activation. In conclusion, our data expand the current knowledge of REST-repressed lncRNAs in NED in PCA and highlight the contribution of TPT1-AS1 to protect neuroendocrine cells from cell death rather than inducing NED. Our study suggested that TPT1-AS1 plays a cytoprotective role in NEPC cells; thus, targeting TPT1-AS1 is a potential therapeutic strategy.

2.
Eur Spine J ; 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38937348

RESUMEN

PURPOSE: To investigate efficacy of 3-month teriparatide(TPD) and compare this treatment with vertebroplasty in terms of clinical and radiographic outcomes after osteoporotic vertebral compression fractures (OVCFs). METHODS: This is a retrospective matched cohort study. Patients who received conservative treatment with at least 3-month TPD treatment for acute OVCF with at least 6 months follow-up were included. Each enrolled TPD case was matched with 2 vertebroplasty cases using age and gender. 30 TPD cases and 60 vertebroplasty cases were enrolled. Patient-reported pain scores were obtained at diagnosis and 1, 3, 6 months after diagnosis. Radiographic parameters including middle body height, posterior body height, wedge angle and kyphotic angle were measured at diagnosis and 6 months after diagnosis. Fracture non-union and subsequent vertebral fracture were evaluated. RESULTS: TPD treatment showed inferior pain relief to vertebroplasty group at 1 month, but did not show difference at 3 and 6 months after diagnosis. In TPD cases, progression of vertebral body collapse was noted in terms of middle body height and wedge angle at final follow up. Instead, both middle body height and wedge angle increased significantly after operation in the vertebroplasty group. Fracture non-union was confirmed via MRI and 4 TPD patients were diagnosed with non-union (4/30, 13.3%). Subsequent compression fracture within 6 months was significant higher in vertebroplasty group (12/60, 20%) than in TPD group (1/30, 3.3%). CONCLUSION: In acute OVCFs, 3-month TPD treatment alone showed comparable pain improvement and less subsequent spine fracture than vertebroplasty.

3.
Pediatr Neonatol ; 65(2): 133-137, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37658029

RESUMEN

BACKGROUND: Previous classifications in polydactyly of the thumb were by the level of duplication on radiography. This study aimed to develop a practical algorithm based on physical characteristics for treatment guidelines. METHODS: The polydactylies were stratified using four physical characteristics: floating, symmetry, dominant side, and joint angulation/nail size. The algorithm identified the hypoplastic type and then stratified the polydactylies as symmetric and asymmetric. The asymmetric type was divided into ulnar dominant and radial dominant. The symmetric type was divided into adequate type and inadequate type. The prediction of treatments was studied retrospectively by the distribution of surgical procedures in 500 patients with 545 affected thumbs, by the new classification and the Wassel-Flatt classification. RESULTS: Of the 545 polydactylies, 78 (14.5%) were categorized as the hypoplastic type, 369 (67.5%) as the ulnar-dominant type, 8 (1.5%) as the radial-dominant type, 70 (12.8%) as the symmetric adequate nail type, and 20 (3.7%) as the symmetric inadequate type. Treatments were excision and reconstruction in 403 polydactylies (73.9%), simple excision in 135 polydactylies (24.8%), and the Bilhaut-Cloquet procedure, ray amputation, and on-top plasty procedures were only performed in 7 polydactylies (1.3%). The distribution of surgical procedures was distinct among the new classification types and was similar among the Wassel-Flatt types. CONCLUSIONS: The new classification stratified polydactylies by physical findings in a stepwise manner. Though surgical technical details are not included, this simple classification is useful for paediatricians and parents to understand how a surgical decision is made. LEVEL OF EVIDENCE: Diagnostic Level IV.


Asunto(s)
Procedimientos de Cirugía Plástica , Polidactilia , Pulgar/anomalías , Humanos , Pulgar/diagnóstico por imagen , Pulgar/cirugía , Estudios Retrospectivos , Polidactilia/diagnóstico por imagen , Polidactilia/cirugía
4.
Int Orthop ; 48(2): 537-545, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37897544

RESUMEN

PURPOSE: Linked component of total elbow arthroplasty (TEA) consisted of bushing and locking pins. Failure of linked components is a rare complication of TEA. This study aims to investigate the mechanism and consequence of failure of the linkage mechanism in TEA surgeries. METHODS: Between 2010 and 2021, five patients received revision operation due to linked component failure. Besides, two patients underwent primary operation at another institute were also analyzed due to failure of the linkage mechanism. RESULTS: All seven patients underwent primary TEA and mean age for primary TEA was 48 (range, 27-62). Two patients had TEA for post-traumatic arthritis, three patients for rheumatoid arthritis, and two patients for comminuted distal humerus fracture. The average time between primary TEA and revision TEA for linked component failure was 13.6 years. Three bushing wear and four locking pin dissociation were diagnosed according to pre-operative radiography. Elbow pain and swelling are the most common clinical symptoms. Severe osteolysis, periprosthetic fracture, and stem loosening were noted in three bushing wear cases. In four dissociation of locking pin cases, breakage of male locking pin phalanges was demonstrated in two patients. For revision procedures, both the locking pins and bushings were replaced. No patients in the study required additional surgery after the revision operation for linked component failure. CONCLUSION: Osteolysis, component loosening, periprosthetic fracture may be expected after linked component failure. Patients should be regularly followed up from short-term to long-term with radiography. Early diagnosis and intervention with linked component exchange can prevent extensive revision surgery.


Asunto(s)
Artritis Reumatoide , Artroplastia de Reemplazo de Codo , Articulación del Codo , Osteólisis , Fracturas Periprotésicas , Humanos , Masculino , Articulación del Codo/diagnóstico por imagen , Articulación del Codo/cirugía , Fracturas Periprotésicas/cirugía , Osteólisis/etiología , Codo/cirugía , Falla de Prótesis , Artroplastia de Reemplazo de Codo/efectos adversos , Artroplastia de Reemplazo de Codo/métodos , Artritis Reumatoide/complicaciones , Artritis Reumatoide/cirugía , Reoperación/efectos adversos , Estudios Retrospectivos , Resultado del Tratamiento
5.
Biomedicines ; 11(7)2023 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-37509459

RESUMEN

Ketamine has been abused as a psychedelic agent and causes diverse neurobehavioral changes. Adolescence is a critical developmental stage but vulnerable to substances and environmental stimuli. Growing evidence shows that ketamine affects glutamatergic neurotransmission, which is important for memory storage, addiction, and psychosis. To explore diverse biological responses, this study was designed to assess ketamine sensitivity in mice of different ages and strains. Male C57BL/6J and BALB/c mice were studied in adolescence and adulthood separately. An open field test assessed motor behavioral changes. After a 30-min baseline habituation, mice were injected with ketamine (0, 25, and 50 mg/kg), and their locomotion was measured for 60 min. Following ketamine injection, the travelled distance and speed significantly increased in C57BL/6J mice between both age groups (p < 0.01), but not in BALB/c mice. The pattern of hyperlocomotion showed that mice were delayed at the higher dose (50 mg/kg) compared to the lower dose (25 mg/kg) of ketamine treatment. Ketamine accentuated locomotor activation in adolescent C57BL/6J mice compared to adults, but not in the BALB/c strain. Here, we show that ketamine-induced locomotor behavior is modulated by dose and age. The discrepancy of neurobehaviors in the two strains of mice indicates that sensitivity to ketamine is biologically determined. This study suggests that individual vulnerability to ketamine's pharmacological responses varies biologically.

6.
Diagnostics (Basel) ; 13(13)2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37443622

RESUMEN

OBJECTIVE: Double-low CT aortography (DLCTA) is increasingly used in follow-up studies of aortic aneurysm after endovascular aneurysm repair (EVAR). However, whether DLCTA can reliably detect the presence of endoleak is not clear. METHODS: From February 2014 to October 2019, patients who received EVAR, underwent CT surveillance, and had at least one standard CTA protocol (120 kVp, 400 mg I/kg) and one DLCTA (70-80 kVp, 200 mg I/kg) were included. The integrated findings of the standard CTA and sequential change were considered as the reference standard for the presence of endoleak. RESULTS: In all, 36 patients received TEVAR and 24 patients received EVAR; 62 standard CTA and 167 DLCTA results were analyzed. There were 2 type I (3.3%) and 12 type II (20.0%) endoleaks in 14 patients (23.3%). The performance of DLCTA in the diagnosis of endoleak reached 100% accuracy compared to that of standard CTA in case of the correction of CT findings by an expert second reading. Compared to the standard CTA, DLCTA scan reduced the radiation dose by 71% and the iodine dose by 50%. CONCLUSIONS: DLCTA with 70-80 kVp and 200 mg I/kg can reliably detect the presence of endoleak after TEVAR/EVAR.

7.
ACS Omega ; 8(14): 13315-13322, 2023 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-37065037

RESUMEN

Capacitive deionization (CDI), a m ethod with notable advantages of relatively low energy consumption and environmental friendliness, has been widely used in desalination of saltwater. However, due to the weak electrical double-layer electrosorption of ions from water, CDI has suffered from low throughput capacity that may limit its commercial applications. Thus, it is of importance to develop a high-efficiency and engineering-feasible CDI process. Manganese and cobalt and their oxides, being faradic materials, have a relatively high pseudocapacitance, which can cause an increase of positive and negative charges on opposing electrodes. However, their low conductivity properties limit their electrochemical applications. Pseudocapacitive Mn3O4 nanoparticles encapsulated within a conducting carbon shell (Mn3O4@C) were prepared to enhance charge transfer and capacitance for CDI. Desalination performances of the Mn3O4@C (5-15 wt %) core-shell nanoparticles on activated carbon (AC) (Mn3O4@C/AC) serving as CDI electrodes have thus been investigated. The pseudocapacitive Mn3O4@C/AC electrodes with relatively low diffusion resistances have much greater capacitance (240-1300 F/g) than the pristine AC electrode (120 F/g). In situ synchrotron X-ray absorption near-edge structure spectra of the Mn3O4@C/AC electrodes during CDI (under 1.2 and -1.2 V for electrosorption and regeneration, respectively) demonstrate that reversible faradic redox reactions cause more negative charges on the negative electrode and more positive charges on the positive electrode. Consequently, the pseudocapacitive electrodes for CDI of saltwater ([NaCl] = 1000 ppm) show much better desalination performances with a high optimized salt removal (600 mg/g·day), electrosorption efficiency (48%), and electrosorption capacity (EC) (25 mg/g) than the AC electrodes (288 mg/g·day, 23%, and 12 mg/g, respectively). The Mn3O4@C/AC electrode has a maximum EC of 29 mg/g for CDI under +1.2 V. Also, the Mn3O4@C/AC electrodes have much higher pseudocapacitive electrosorption rate constants (0.0049-0.0087 h-1) than the AC electrode (0.0016 h-1). This work demonstrates the feasibility of high-efficiency CDI of saltwater for water recycling and reuse using the low-cost and easily fabricated pseudocapacitive Mn3O4@C/AC electrodes.

8.
Asian J Psychiatr ; 83: 103569, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37012199

RESUMEN

ChAdOx1 nCoV-19 vaccine (so called AZ vaccine), is widely used to prevent the SARS-CoV-2 pandemic and shows powerful effectiveness to deter community transmission. There are common immunogenicity-related side effects such as fever, myalgia, lethargy, and headache; however, rare report on the neuropsychiatric problems (Ramasamy et al., 2021). In Taiwan, more than 15,200,000 doses of AZ vaccine were injected by the end of 2022. Here we presented a unique case with separated episode of Ekbom's syndrome, also called delusion of parasitosis, and mania following successive AZ vaccination in three-month interval.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Manía , Humanos , ChAdOx1 nCoV-19 , COVID-19/prevención & control , Vacunas contra la COVID-19/efectos adversos , SARS-CoV-2 , Vacunación/efectos adversos
9.
J Hazard Mater ; 445: 130522, 2023 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-37055954

RESUMEN

The XANES/EXAFS data and quantum chemical simulations presented in this study demonstrate several features of the chemistry of arsenic compounds found in the condensates and solids generated in landfill gas (LFG) processing carried out for renewable natural gas (RNG) production. The XANES data show the decrease in the position of the absorption edge of As atoms, similar to that characteristic for sulfur-containing As solutes and solids. The EXAFS data show that the As-O and As-S distances in these matrixes are similar to those in thioarsenates. Quantum-chemical calculations demonstrated the close agreement between the experimental and modeled As-S and As-O distances determined for a range of methylated and thiolated arsenic solutes. These calculations also showed that the increase of the number of the As-S bonds in the coordination shell of arsenic is accompanied by a consistent decrease of the charges of As atoms. This decrease is correlated with the number of the As-S bonds, in agreement with the trend observed in the XANES data. These results provide insight into the intrinsic chemistry and reactivity of As species present in LFG matrixes; they may be helpful for the development of treatment methods to control arsenic in these systems.

10.
J Pediatr Orthop ; 43(4): e305-e309, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36728384

RESUMEN

BACKGROUND: The Wassel classification is commonly used for cases of radial polydactyly but has not been used to predict surgical outcomes. This study aimed to investigate the predictive factors of surgical outcomes using the Wassel type and symmetry of duplication. METHODS: Forty-five patients with 47 radial polydactylies were reviewed using the Japanese Society for Surgery of the Hand (JSSH) scores 4.6 years after minor thumb excision and reconstructive surgery. The symmetry index was defined as the metaphyseal width ratio of the minor thumb to the dominant thumb. The relationships between the JSSH scores and operation age, sex, side, follow-up duration, Wassel type, symmetric index, divergent angle, and joint angulation were analyzed by linear regression. RESULTS: The mean JSSH score of the 47 thumbs was 18.3 points (range, 15-20). Five thumbs had fair or poor outcomes (scores <17), all of which were Wassel type IV. The hypoplastic type had a better JSSH score (19.4) than other Wassel types. The symmetric index had a negative relationship with JSSH scores, especially for Wassel type IV (r=-0.68, P =0.001). Linear regression revealed that the symmetric index was the only independent factor significantly associated with JSSH scores among Wassel type IV polydactylies ( P <0.05). The receiver operating characteristic curve suggested a symmetric index <0.74 could predict good or excellent outcomes. CONCLUSION: The symmetry of the 2 duplicated thumbs is an important factor for surgical outcomes. The Wassel type IV polydactylies with a symmetric index >0.74 are at greater risk of fair or poor outcomes after excision and reconstruction, and further studies are warranted to confirm whether the Bilhaut-Cloquet procedure is a good choice. LEVEL OF EVIDENCE: Level IV-Case-control study.


Asunto(s)
Polidactilia , Pulgar , Humanos , Lactante , Pulgar/cirugía , Estudios de Casos y Controles , Polidactilia/cirugía , Resultado del Tratamiento
12.
Org Lett ; 24(37): 6767-6771, 2022 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-36099564

RESUMEN

(IPr)GaCl3/AgSbF6, AgSbF6, and GaCl3 catalyzed substitution of the hydroxyl of secondary and tertiary propargylic alcohols with organoboronic acids via C-C bond formation, and GaCl3 effectively synthesized all-carbon quaternary propargylic centers. These catalysts performed the substitution at carbons bearing alkyl substituents, which has been problematic for other systems. Highly hindered carbon stereocenters were thus produced, including quaternary centers bearing doubly ortho-substituted aryl rings, that are difficult to access with traditional methods.

13.
BMC Emerg Med ; 22(1): 77, 2022 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-35524167

RESUMEN

BACKGROUND: The sign of contrast agent pooling (C.A.P.) in dependent part of the venous system were reported in some case reports, which happened in the patients before sudden cardiac arrest. Until now, there is no solid evidence enough to address the importance of the sign. This study aimed to assess the accuracy of the C.A.P. sign in predicting imminent cardiac arrest and the association of the C.A.P. sign with patient's survival. METHODS: This is a retrospective cohort study. The study included all patients who visited the emergency department, who received contrast computed tomography (CT) scan and then experienced cardiac arrest at the emergency department (from January 1, 2016 to December 31, 2018). We evaluated the occurrence of the C.A.P. sign on the chest or abdominal CT scan, patients with ECMO were excluded. With positive C.A.P. sign, the primary outcome is whether in-hospital cardiac arrest happens within an hour; the accuracy of C.A.P. sign was calculated. The secondary outcome is survival to discharge. RESULTS: In the study, 128 patients were included. 8.6% (N = 11) patients had positive C.A.P. sign and 91.4% (N = 117) patients did not. The accuracy of C.A.P. sign in predicting cardiac arrest within 1 h was 85.94%. The C.A.P. sign had a positive association with IHCA within 1 h after the CT scan (adjusted odds ratio 7.35, 95% confidence interval [CI] 1.27 - 42.69). The relative risk (RR) of survival to discharge was 0.90 with positive C.A.P. sign (95% CI 0.85 - 0.96). CONCLUSIONS: The C.A.P. sign can be considered as an alarm for imminent cardiac arrest and poor prognosis. The patients with positive C.A.P. sign were more likely to experience imminent cardiac arrest; in contrast, less likely to survive. TRIAL REGISTRATION: IRB No.108107-E.


Asunto(s)
Reanimación Cardiopulmonar , Paro Cardíaco Extrahospitalario , Reanimación Cardiopulmonar/métodos , Medios de Contraste , Humanos , Oportunidad Relativa , Estudios Retrospectivos
14.
Behav Neurol ; 2022: 1048463, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35251367

RESUMEN

OBJECTIVE: The glutamate system plays a major role in the development of neuropsychiatric disorders such as addiction, epilepsy, dementia, and psychosis. MK-801 (dizocilpine), an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, could increase locomotor activity and stereotyped neurobehaviors mimicking schizophrenic-like features in the mouse model. The study would explore the neuropharmacological differences of risperidone and valproic acid on the MK-801-induced neurobehavioral changes. METHODS: The subjects were male C57BL/6J mice obtained from the National Laboratory Animal Center. Drug effects were assessed using the open field with a video-tracking system and gaiting tests. After habitation, risperidone (0, 0.1 mg/kg) or valproic acid (0, 200 mg/kg) was injected and ran locomotion for 30 mins. Sequentially, mice were followed by intraperitoneal injection (i.p.) with MK-801 (0, 0.2 mg/kg) and ran locomotion for 60 mins. Gaiting behaviors such as step angles, stride lengths, and stance widths were measured following the study drugs. RESULTS: The results showed that risperidone and valproic acid alone could not alter the locomotor activities. Following the MK-801 injection, the travelled distance and speed in the entire open field dramatically increased. The dose 0.1 mg/kg of risperidone could totally inhibit the MK-801-induced hyperlocomotion compared with that of the saline-injected group (p < 0.001). The valproic acid (200 mg/kg) partially suppressed the hyperlocomotion which is induced by MK801. CONCLUSION: The more dominant effect of risperidone to rescue MK-801 induced hyperlocomotion compared with that of valproic acid. The partial suppression of valproic acid may imply the psychopharmacological evidence as adjuvant effect to treat psychotic patients through tuning glutamatergic neurotransmission.


Asunto(s)
Maleato de Dizocilpina , Locomoción/efectos de los fármacos , Risperidona , Ácido Valproico , Animales , Maleato de Dizocilpina/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Receptores de N-Metil-D-Aspartato , Risperidona/farmacología , Ácido Valproico/farmacología
15.
Food Chem ; 375: 131649, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-34848093

RESUMEN

The delicate aroma of Bao-chung tea comes from oxidation, followed by fixation in the pan-firing step. Traditionally, the timing of pan-firing has been based on odor perception by tea masters and lacks relevant scientific research. Pan-firing at three different green-note intensities and three stirring sequences was used to explore the relationship between the compositions of volatile organic compounds (VOCs) before pan-firing and in the finished tea. Pan-firing decreased green leaf volatiles and increased the ratio of terpenoid volatiles. The characteristic VOCs of the finished tea were highly related to VOCs before pan-firing (R2 = 0.97). Principal component analysis revealed that the traditional judgment of the pan-firing step is based on nonanal, ß-linalool, and cis- and trans-linalool oxides. The timing of pan-firing is crucial for VOCs, and VOC composition before pan-firing can be used to predict desired tea aroma.


Asunto(s)
Odorantes , Compuestos Orgánicos Volátiles , Odorantes/análisis , Hojas de la Planta/química , , Terpenos , Compuestos Orgánicos Volátiles/análisis
16.
Optim Lett ; : 1-20, 2022 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-36597504

RESUMEN

When an infectious disease spreads, how to quickly vaccinate with a limited budget per time step to reduce the impact of the virus is very important. Specifically, vaccination will be carried out in every time step, and vaccinated nodes will no longer be infected. Meanwhile, the protection from vaccination can spread to the neighbors of a vaccinated node. Our goal is to efficiently find optimal and approximation solutions to our problem with various algorithms. In this paper, we first design an integer linear program to solve this problem. We then propose approximation algorithms of (1) Linear programming (LP) deterministic threshold rounding, (2) LP dependent randomized rounding, and (3) LP independent randomized rounding. We prove that the LP independent randomized rounding algorithm has a high probability of finding a feasible solution that gives an approximation ratio of ( 1 - δ ) , where a small constant δ between 0 and 1 reduces the lower bound on the feasibility probability. We also provide experimental results for three different rounding algorithms to show that they perform numerically well in terms of approximation ratios. These analytical and numerical studies allow each individual to adopt the most appropriate approximation algorithm to efficiently resolve the vaccination problem when her reliance on commercial optimization solvers is costly.

17.
Micromachines (Basel) ; 12(1)2021 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-33477391

RESUMEN

The operational duration of shaking tea leaves is a critical factor in the manufacture of oolong tea; this duration influences the formation of its flavor and fragrance. The current method to control the duration of fermentation relies on the olfactory sense of tea masters; they monitor the entire process through their olfactory sense, and their experience decides the duration of shaking and setting. Because of this human factor and olfactory fatigue, it is difficult to define an optimum duration of shaking and setting; an inappropriate duration of shaking and setting deteriorates the quality of the tea. In this study, we used metal-oxide-semiconductor gas sensors to establish an electronic nose (E-nose) system and tested its feasibility. This research was divided into two experiments: distinguishing samples at various stages and an on-line experiment. The samples of tea leaves at various stages exhibited large differences in the level of grassy smell. From the experience of practitioners and from previous research, the samples could be categorized into three groups: before the first shaking (BS1), before the shaking group, and after the shaking group. We input the experimental results into a linear discriminant analysis to decrease the dimensions and to classify the samples into various groups. The results show that the smell can also be categorized into three groups. After distinguishing the samples with large differences, we conducted an on-line experiment in a tea factory and tried to monitor the smell variation during the manufacturing process. The results from the E-nose were similar to those of the sense of practitioners, which means that an E-nose has the possibility to replace the sensory function of practitioners in the future.

18.
Inorg Chem ; 60(3): 1806-1813, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33464887

RESUMEN

An attractive catalytic pathway for the conversion of water to oxygen would involve two metal oxide centers combining in a constructive sense to make O═O. This prospect makes the study of certain dinuclear transition metal complexes particularly attractive. In this work, we describe the design and synthesis of two symmetrical bis-tridentate polypyridine ligands 6 and 12 that bind two RuII centers at a separation of 3.6 Šin 7 and 5.7 Šin 13. In the presence of CeIV at pH = 1, these systems oxidize water with the system having the more proximal metals being more reactive. In the case of the more proximal metal centers, the bridging ligand is a 3,6-disubstituted pyridazine which, under the influence of CeIV, cleaves into two [Ru(bpc)(pic)2CH3CN]+ fragments (14) which then function as the actual catalyst (bpc = 2,2'-bipyridine-6-carboxylate, pic = 4-methylpyridine). The second dinuclear catalyst contains a central pyrimidine ring which is less sensitive to oxidative decay and hence less reactive. Caution is advised in the use of CeIV as a sacrificial electron acceptor due to unexpected oxidative decay of the catalyst.

19.
Nat Nanotechnol ; 16(1): 58-62, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33169008

RESUMEN

Non-volatile resistive switching, also known as memristor1 effect, where an electric field switches the resistance states of a two-terminal device, has emerged as an important concept in the development of high-density information storage, computing and reconfigurable systems2-9. The past decade has witnessed substantial advances in non-volatile resistive switching materials such as metal oxides and solid electrolytes. It was long believed that leakage currents would prevent the observation of this phenomenon for nanometre-thin insulating layers. However, the recent discovery of non-volatile resistive switching in two-dimensional monolayers of transition metal dichalcogenide10,11 and hexagonal boron nitride12 sandwich structures (also known as atomristors) has refuted this belief and added a new materials dimension owing to the benefits of size scaling10,13. Here we elucidate the origin of the switching mechanism in atomic sheets using monolayer MoS2 as a model system. Atomistic imaging and spectroscopy reveal that metal substitution into a sulfur vacancy results in a non-volatile change in the resistance, which is corroborated by computational studies of defect structures and electronic states. These findings provide an atomistic understanding of non-volatile switching and open a new direction in precision defect engineering, down to a single defect, towards achieving the smallest memristor for applications in ultra-dense memory, neuromorphic computing and radio-frequency communication systems2,3,11.

20.
Antioxidants (Basel) ; 9(8)2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-32756347

RESUMEN

Some lichens provide the resources of common traditional medicines and show anticancer effects. However, the anticancer effect of Usnproliea barbata (U. barbata) is rarely investigated, especially for oral cancer cells. The aim of this study was to investigate the cell killing function of methanol extracts of U. barbata (MEUB) against oral cancer cells. MEUB shows preferential killing against a number of oral cancer cell lines (Ca9-22, OECM-1, CAL 27, HSC3, and SCC9) but rarely affects normal oral cell lines (HGF-1). Ca9-22 and OECM-1 cells display the highest sensitivity to MEUB and were chosen for concentration effect and time course experiments to address its cytotoxic mechanisms. MEUB induces apoptosis of oral cancer cells in terms of the findings from flow cytometric assays and Western blotting, such as subG1 accumulation, annexin V detection, and pancaspase activation as well as poly (ADP-ribose) polymerase (PARP) cleavage. MEUB induces oxidative stress and DNA damage of oral cancer cells following flow cytometric assays, such as reactive oxygen species (ROS)/mitochondrial superoxide (MitoSOX) production, mitochondrial membrane potential (MMP) depletion as well as overexpression of γH2AX and 8-oxo-2'deoxyguanosine (8-oxodG). All MEUB-induced changes in oral cancer cells were triggered by oxidative stress which was validated by pretreatment with antioxidant N-acetylcysteine (NAC). In conclusion, MEUB causes preferential killing of oral cancer cells and is associated with oxidative stress, apoptosis, and DNA damage.

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