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1.
Nature ; 615(7954): 823-829, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36991190

RESUMEN

Neural networks based on memristive devices1-3 have the ability to improve throughput and energy efficiency for machine learning4,5 and artificial intelligence6, especially in edge applications7-21. Because training a neural network model from scratch is costly in terms of hardware resources, time and energy, it is impractical to do it individually on billions of memristive neural networks distributed at the edge. A practical approach would be to download the synaptic weights obtained from the cloud training and program them directly into memristors for the commercialization of edge applications. Some post-tuning in memristor conductance could be done afterwards or during applications to adapt to specific situations. Therefore, in neural network applications, memristors require high-precision programmability to guarantee uniform and accurate performance across a large number of memristive networks22-28. This requires many distinguishable conductance levels on each memristive device, not only laboratory-made devices but also devices fabricated in factories. Analog memristors with many conductance states also benefit other applications, such as neural network training, scientific computing and even 'mortal computing'25,29,30. Here we report 2,048 conductance levels achieved with memristors in fully integrated chips with 256 × 256 memristor arrays monolithically integrated on complementary metal-oxide-semiconductor (CMOS) circuits in a commercial foundry. We have identified the underlying physics that previously limited the number of conductance levels that could be achieved in memristors and developed electrical operation protocols to avoid such limitations. These results provide insights into the fundamental understanding of the microscopic picture of memristive switching as well as approaches to enable high-precision memristors for various applications. Fig. 1 HIGH-PRECISION MEMRISTOR FOR NEUROMORPHIC COMPUTING.: a, Proposed scheme of the large-scale application of memristive neural networks for edge computing. Neural network training is performed in the cloud. The obtained weights are downloaded and accurately programmed into a massive number of memristor arrays distributed at the edge, which imposes high-precision requirements on memristive devices. b, An eight-inch wafer with memristors fabricated by a commercial semiconductor manufacturer. c, High-resolution transmission electron microscopy image of the cross-section view of a memristor. Pt and Ta serve as the bottom electrode (BE) and top electrode (TE), respectively. Scale bars, 1 µm and 100 nm (inset). d, Magnification of the memristor material stack. Scale bar, 5 nm. e, As-programmed (blue) and after-denoising (red) currents of a memristor are read by a constant voltage (0.2 V). The denoising process eliminated the large-amplitude RTN observed in the as-programmed state (see Methods). f, Magnification of three nearest-neighbour states after denoising. The current of each state was read by a constant voltage (0.2 V). No large-amplitude RTN was observed, and all of the states can be clearly distinguished. g, An individual memristor on the chip was tuned into 2,048 resistance levels by high-resolution off-chip driving circuitry, and each resistance level was read by a d.c. voltage sweeping from 0 to 0.2 V. The target resistance was set from 50 µS to 4,144 µS with a 2-µS interval between neighbouring levels. All readings at 0.2 V are less than 1 µS from the target conductance. Bottom inset, magnification of the resistance levels. Top inset, experimental results of an entire 256 × 256 array programmed by its 6-bit on-chip circuitry into 64 32 × 32 blocks, and each block is programmed into one of the 64 conductance levels. Each of the 256 × 256 memristors has been previously switched over one million cycles, demonstrating the high endurance and robustness of the devices.

2.
BMC Infect Dis ; 23(1): 461, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37430189

RESUMEN

BACKGROUND: Cryptosporidium is an intracellular protozoan that causes gastrointestinal symptoms in humans and animals. In immunocompromised patients and children under 5 years of age, the infection is severe and can be life-threatening due to severe diarrhea. CASE PRESENTATION: We report a case of urticaria associated with Cryptosporidium in a 17-month-old female Iranian child. The patient had moderate diarrhea (> 3 loose, watery stools but not more than 10 diarrhea stools in a day), weight loss, and acute urticarial (rash clears completely within 6 weeks). Since the child's father worked in livestock farming, the parasite may have been transferred from the cow or calve to the house and the child. Several Cryptosporidium oocysts were detected in the modified acid-fast staining of the child's stool sample. The patient was successfully treated with nitazoxanide (100 mg twice daily) and became negative for parasites three days after treatment and one week after discharge from the hospital. The child was observed to produce < 3 loose stools in the previous 24 h after 1-week post-treatment and after 6 months of follow-up. CONCLUSION: A number of parasites are associated with urticaria, but to our knowledge, there is no information on Cryptosporidium-induced urticaria. Therefore, our result may be evidence for the role of this parasite in the development of urticaria if other causes such as food allergies, autoimmune diseases and etc. don't role in urticaria.


Asunto(s)
Criptosporidiosis , Cryptosporidium , Urticaria , Animales , Bovinos , Humanos , Niño , Femenino , Preescolar , Lactante , Criptosporidiosis/diagnóstico , Criptosporidiosis/tratamiento farmacológico , Irán , Urticaria/tratamiento farmacológico , Urticaria/etiología , Diarrea/tratamiento farmacológico
3.
Curr Microbiol ; 79(9): 257, 2022 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-35852629

RESUMEN

The effective management of multidrug-resistant tuberculosis (MDR-TB) and the need for rapid and accurate screening of rifampin (RIF) and isoniazid (INH)-resistant Mycobacterium tuberculosis (Mtb) isolates are the most fundamental and difficult challenges facing the global TB control. The present study aimed to compare the diagnostic accuracy of high-resolution melting-curve analysis (HRMA) in comparison to multiplex allele-specific PCR (MAS-PCR) and xpert MTB/RIF as well as the conventional drug-susceptibility test (DST) and gene sequencing for the detection of INH and RIF resistance in the Mtb isolates. In the present study, a total of 431 Mtb isolates including 11 MDR (%2.55), 7 INH resistance (%1.62), two RIF resistance (%0.46), and 411 sensitive isolates were phenotypically confirmed. HRMA assay identified katG gene mutations and the mabA-inhA promoter region in 15 of 18 INH-resistant samples and rpoB gene mutations were successfully evaluated in 11 out of 13 RIF-resistant samples. The sensitivity and specificity of the HRMA method were 83.3% and 98.8% for INH and 84.6% and 99% for RIF, respectively. The most common mutation in RIF-resistance-determining region (RRDR) occurred at codon 531 (TCG → TTG)(84.6%) and then at codon 513 (CAA → GTA)(7.6%) and 526 (CAC → TAC) (7.6%), which resulted in the amino-acid changes. Also, 88.8% of INH-resistant samples had mutations in the katG gene and the mabA-inhA promoter region, of which the highest mutation occurred at codon 315 (AGC → ACC) of the katG gene. In conclusion, all these results indicated that the sensitivity and specificity of the HRM method were increased when the katG gene and the mabA-inhA promoter region were used as a target.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Antituberculosos/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/farmacología , Codón , Humanos , Isoniazida/farmacología , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa Multiplex , Mutación , Rifampin/farmacología , Esputo/microbiología , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Resistente a Múltiples Medicamentos/genética , Tuberculosis Resistente a Múltiples Medicamentos/microbiología
4.
Parasitol Res ; 121(7): 1817-1827, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35524788

RESUMEN

This study aimed to review published scientific literature on bed bugs in countries where insecticide resistance has been reported worldwide from 2000 to 2021. Electronic databases, including Scopus, PubMed, and WOS, were searched. Out of 606 articles found in the initial search, we selected 57 articles, of which 40 articles had reported on Cimex lectularius (C. lectularius), and 22 papers had reported on Cimex hemipterus (C. hemipterus). Most studies on insecticide resistance were carried out on C. lectularius in North America (14, 35%) and C. hemipterus in Asia (16, 72.7%). The most common method used to detect bed bug resistance to insecticides was toxicological bioassay with an overall random pooled effect size of 0.38 (95% CI: 0.23-0.53) in C. lectularius and 0.46 (95% CI: 0.27-0.65) in C. hemipterus. Resistance to pyrethroids was reported against C. lectularius with an overall pooled effect size of 0.75 (95% CI: 0.56-0.94) and C. hemipterus with an overall pooled effect size of 0.81 (95% CI: 0.57-0.93) in 33.40 (82.5%) and 19.22 (86.3%) published articles, respectively. A very high resistance level to pyrethroids in both studied species was observed, and resistance ratios at the highest level were 76389.3 and 315.5 in C. lectularius and C. hemipterus, respectively. Resistance mechanisms against pyrethroids were reported from most locations except Iran and Thailand, but these mechanisms were not studied in other insecticide groups. These reports indicate that chemical control options for bed bugs are limited. Therefore, a combination of chemical and non-chemical strategies is recommended for bed bug control.


Asunto(s)
Chinches , Infestaciones Ectoparasitarias , Insecticidas , Piretrinas , Animales , Resistencia a los Insecticidas , Insecticidas/farmacología , Piretrinas/farmacología , Tailandia
5.
BMC Vet Res ; 17(1): 185, 2021 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-33952280

RESUMEN

BACKGROUND: Platyhelminth infections of livestock can result in considerable economic losses. This study aims to evaluate the spatial frequency of cystic echinococcosis (CE), dicrocoeliasis, and fascioliasis in livestock slaughtered in Iran during the years 2015-2019 and estimate direct costs associated with organ condemnation due to these parasites. METHODS: Abattoir data from 413 abattoirs representing all 31 Iranian provinces were collected from the Iran Veterinary Organization. Infection prevalence was calculated per year at the province level. The Local Moran's I statistic was performed to evaluate spatial autocorrelation of animals positive at slaughter for the years 2015-2019. Direct costs associated with condemned livers were calculated for each parasitic condition, with costs associated with condemned lungs also included for CE. RESULTS: Overall prevalence values for the study timeframe were as follows: sheep and goat fascioliasis 1.56% (95% CI: 1.56-1.56%), cattle fascioliasis 3.86% (95% CI: 3.85-3.88%), sheep and goat dicrocoeliasis 4.63% (95% CI: 4.62-4.63%), cattle dicrocoeliasis 3.08% (95% CI: 3.07-3.09%), sheep and goat CE 5.32% (95% CI: 5.32-5.33%), and cattle CE 7.26% (95% CI: 7.24-7.28%). Northwest Iran had the highest prevalence of CE and fascioliasis. High infection areas for Dicrocoelium spp. included the provinces of Zanjan, Gilan, Qazvin, and Tehran, which are located in northern Iran. Direct economic losses for sheep and goat fascioliasis, dicrocoeliasis, and CE for the study period were US$13,842,759, US$41,771,377, and US$22,801,054, respectively. Direct economic losses for cattle fascioliasis, dicrocoeliasis, and CE for the study period were US$1,989,200, US$1,668,986, and US$2,656,568, respectively. CONCLUSION: Our findings provide valuable data for future monitoring of these important parasitic diseases in Iranian livestock. Disease control strategies are required to reduce the economic and public health impact of these platyhelminths.


Asunto(s)
Dicroceliasis/veterinaria , Equinococosis/veterinaria , Fascioliasis/veterinaria , Mataderos/estadística & datos numéricos , Animales , Bovinos , Enfermedades de los Bovinos/economía , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/parasitología , Dicroceliasis/economía , Dicroceliasis/epidemiología , Dicrocoelium , Equinococosis/economía , Equinococosis/epidemiología , Echinococcus , Fasciola , Fascioliasis/economía , Fascioliasis/epidemiología , Enfermedades de las Cabras/economía , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/parasitología , Cabras , Irán/epidemiología , Ganado/parasitología , Ovinos , Enfermedades de las Ovejas/economía , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/parasitología , Zoonosis/epidemiología , Zoonosis/parasitología
6.
BMC Pulm Med ; 21(1): 105, 2021 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-33765987

RESUMEN

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic and complex respiratory disorder associated with airflow limitation and increased inflammatory response of the lungs to harmful particles. The purpose of this original study was to describe the results and profile of the Shahrekord Prospective Epidemiological Research Studies in IrAN (PERSIAN) regarding COPD in southwestern Iran. METHODS: This study of asthma and respiratory diseases is a subcohort of the more extensive cohort study, i.e., Shahrekord PERSIAN cohort, a population-based prospective study on people aged 35-70 years in southwestern Iran (n = 10,075). The sample size of the subcohort was 8500 people. Annual follow-ups (person-year) of the cohort were designed to be conducted up to 2036. The instruments to collect data on various exposures were derived from the questionnaires previously developed in extensive multinational studies (occupational exposures, smoking, housing status, and fuel consumption, history of respiratory and chronic diseases, comorbidity, etc.). The Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the lower limit of normal (LLN) spirometric criteria were used to confirm COPD diagnosis. RESULTS: The response rate was 93.85%. The mean age of the participants was 49.48 ± 9.32; 47.9% were male, and 52.9% were female; nearly 16% of the population was current smokers; the fuel used by most of the participants for heating the house and cooking was gas. The most common comorbidity among participants was dyslipidemia; 30% of people have three or more comorbidities. According to GOLD and LLN criteria, the Prevalence of COPD was 3.6% and 8.4%, respectively. 4.3% of the participants had a history of chronic lung disease. The group of subjects with COPD had higher mean age, fewer years of schooling, a higher percentage of smokers with a smoking history of 10 or more pack years. 4.6% of patients had a history of chronic lung disease, 17.6% had a history of asthma in childhood, and 5.2% had a family history of respiratory and pulmonary diseases. CONCLUSION: Epidemiological research is necessary to create an appropriate framework to fight COPD. This framework requires a better description of men and women at risk of developing COPD and describing people with early-stage illnesses.


Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Adulto , Anciano , Asma/epidemiología , Comorbilidad , Femenino , Volumen Espiratorio Forzado , Humanos , Irán/epidemiología , Modelos Lineales , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Factores de Riesgo , Fumar/epidemiología , Espirometría/métodos , Encuestas y Cuestionarios , Capacidad Vital
7.
BMC Public Health ; 21(1): 7, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-33397340

RESUMEN

BACKGROUND: Response time to cardiovascular emergency medical requests is an important indicator in reducing cardiovascular disease (CVD) -related mortality. This study aimed to visualize the spatial-time distribution of response time, scene time, and call-to-hospital time of these emergency requests. We also identified patterns of clusters of CVD-related calls. METHODS: This cross-sectional study was conducted in Mashhad, north-eastern Iran, between August 2017 and December 2019. The response time to every CVD-related emergency medical request call was computed using spatial and classical statistical analyses. The Anselin Local Moran's I was performed to identify potential clusters in the patterns of CVD-related calls, response time, call-to-hospital arrival time, and scene-to-hospital arrival time at small area level (neighborhood level) in Mashhad, Iran. RESULTS: There were 84,239 CVD-related emergency request calls, 61.64% of which resulted in the transport of patients to clinical centers by EMS, while 2.62% of callers (a total of 2218 persons) died before EMS arrival. The number of CVD-related emergency calls increased by almost 7% between 2017 and 2018, and by 19% between 2017 and 2019. The peak time for calls was between 9 p.m. and 1 a.m., and the lowest number of calls were recorded between 3 a.m. and 9 a.m. Saturday was the busiest day of the week in terms of call volume. There were statistically significant clusters in the pattern of CVD-related calls in the south-eastern region of Mashhad. Further, we found a large spatial variation in scene-to-hospital arrival time and call-to-hospital arrival time in the area under study. CONCLUSION: The use of geographical information systems and spatial analyses in modelling and quantifying EMS response time provides a new vein of knowledge for decision makers in emergency services management. Spatial as well as temporal clustering of EMS calls were present in the study area. The reasons for clustering of unfavorable time indices for EMS response requires further exploration. This approach enables policymakers to design tailored interventions to improve response time and reduce CVD-related mortality.


Asunto(s)
Servicios Médicos de Urgencia , Servicio de Urgencia en Hospital , Estudios Transversales , Humanos , Irán/epidemiología , Políticas
8.
BMC Cancer ; 20(1): 1170, 2020 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-33256668

RESUMEN

BACKGROUND: The most common gender-specific malignancies are cancers of the breast and the prostate. In developing countries, cancer screening of all at risk is impractical because of healthcare resource limitations. Thus, determining high-risk areas might be an important first screening step. This study explores incidence patterns of potential high-risk clusters of breast and prostate cancers in southern Iran. METHODS: This cross-sectional study was conducted in the province of Kerman, South Iran. Patient data were aggregated at the county and district levels calculating the incidence rate per 100,000 people both for cancers of the breast and the prostate. We used the natural-break classification with five classes to produce descriptive maps. A spatial clustering analysis (Anselin Local Moran's I) was used to identify potential clusters and outliers in the pattern of these cancers from 2014 to 2017. RESULTS: There were 1350 breast cancer patients (including, 42 male cases) and 478 prostate cancer patients in the province of Kerman, Iran during the study period. After 45 years of age, the number of men with diagnosed prostate cancer increased similarly to that of breast cancer for women after 25 years of age. The age-standardised incidence rate of breast cancer for women showed an increase from 29.93 to 32.27 cases per 100,000 people and that of prostate cancer from 13.93 to 15.47 cases per 100,000 during 2014-2017. Cluster analysis at the county level identified high-high clusters of breast cancer in the north-western part of the province for all years studied, but the analysis at the district level showed high-high clusters for only two of the years. With regard to prostate cancer, cluster analysis at the county and district levels identified high-high clusters in this area of the province for two of the study years. CONCLUSIONS: North-western Kerman had a significantly higher incidence rate of both breast and prostate cancer than the average, which should help in designing tailored screening and surveillance systems. Furthermore, this study generates new hypotheses regarding the potential relationship between increased incidence of cancers in certain geographical areas and environmental risk factors.


Asunto(s)
Neoplasias de la Mama/epidemiología , Neoplasias de la Próstata/epidemiología , Adulto , Anciano , Análisis por Conglomerados , Estudios Transversales , Femenino , Historia del Siglo XXI , Humanos , Irán/epidemiología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Análisis Espacio-Temporal
9.
J Relig Health ; 56(4): 1311-1316, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27029474

RESUMEN

Nowadays, diabetes is prevalent, and it can leave severe psychotic effects and causes depression; thus, it is necessary to consider effective factors to fight against diabetic patients' mental conditions. It seems that the role of religion is significant, and by augmenting religious attitudes, diabetic patient's depression intensity can be decreased. The purpose of the present study is to examine the relationship between religious beliefs and depression of diabetic patients in diabetes clinic of Ali Asghar Hospital in Zahedan. This is a descriptive analytical and cross-sectional study. Out of total 350 diabetic patients, 70 were selected by easy sampling method. Data gathering tool was Bach's religious beliefs and depression standard questionnaires. K2 statistical test and Pearson's correlation index have been used for data analysis. SPSS software version 16 was used to analyze the data. The results of the study showed that there was not any relationship among age, sex, education, illness duration and family member's history of depression and depression. Results of the study showed that stronger religious beliefs decrease the depression severity (P < 0.001). Therefore, it is necessary to strengthen patient's religious attitudes by proper plans to decrease depression, and some strategies are presented in the study for these plans.


Asunto(s)
Trastorno Depresivo/epidemiología , Trastorno Depresivo/psicología , Diabetes Mellitus/epidemiología , Diabetes Mellitus/psicología , Religión y Psicología , Adulto , Comorbilidad , Estudios Transversales , Femenino , Humanos , Irán/epidemiología , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
10.
Tumour Biol ; 36(5): 3919-30, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25589462

RESUMEN

B cell precursor acute lymphoblastic leukemia (BCP-ALL) is the most common type of cancer in children. Dramatic improvements in primary therapy for childhood ALL have led to an overall cure rate of 80 %, providing opportunities for innovative combined-modality strategies that would increase cure rates while reducing the toxic side effects of current intensive regimens. In this study, we report that indole-3-carbinol (I3C), a natural phytochemical found in cruciferous vegetables, had anti-leukemic properties in BCP-ALL NALM-6 cells. I3C induced cell growth inhibition by G1 cell cycle arrest and triggered apoptosis in a dose- and time-dependent manner. p53, p21, and Bax proteins showed increased expression after I3C treatment. Real-time PCR analysis of pro-apoptotic p53 target genes revealed up-regulation of PUMA, NOXA, and Apaf-1. I3C also suppressed constitutive nuclear factor-κB (NF-κB) activation and inhibited the protein expression of NF-kappa B-regulated antiapoptotic (IAP1, Bcl-xL, Bcl-2, XIAP) and proliferative (c-Myc) gene products. Coadministration of I3C with the topoisomerase II inhibitor, doxorubicin, potentiates cytotoxic effects compared with either agent alone. Apoptosis induction by the drug combination was associated with enhanced caspase-9 activation and PARP cleavage. Furthermore, I3C abolished doxorubicin-induced NF-κB activity as evidenced by decreased nuclear accumulation of p65, inhibition of IκBα phosphorylation and its degradation, and decreased NF-κB DNA-binding activity. Western blot analysis revealed that doxorubicin-induced Bcl-2 protein expression was inhibited by I3C. Overall, our results indicated that using nontoxic agents, such as I3C, in combination with anthracyclines might provide a new insight into the development of novel combination therapies in childhood BCP-ALL.


Asunto(s)
Indoles/administración & dosificación , FN-kappa B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Proteína p53 Supresora de Tumor/genética , Apoptosis/efectos de los fármacos , Linfocitos B/efectos de los fármacos , Linfocitos B/patología , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Proteínas de Neoplasias/biosíntesis , Fosforilación/efectos de los fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Transducción de Señal/efectos de los fármacos , Factor de Necrosis Tumoral alfa/biosíntesis , Proteína p53 Supresora de Tumor/biosíntesis
11.
Surv Ophthalmol ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38942125

RESUMEN

Cystoid macular edema (CME) is a sight-threatening condition often associated with inflammatory and diabetic diseases. Early detection is crucial to prevent irreversible vision loss. Artificial intelligence (AI) has shown promise in automating CME diagnosis through optical coherence tomography (OCT) imaging, but its utility needs critical evaluation. This systematic review assesses the application of AI to diagnosis CME, specifically focusing on disorders like postoperative CME (Irvine Gass syndrome) and retinitis pigmentosa without obvious vasculopathy, using OCT imaging. A comprehensive search was conducted across 6 databases (PubMed, Scopus, Web of Science, Wiley, ScienceDirect, and IEEE) from 2018 to November, 2023. Twenty-three articles met the inclusion criteria and were selected for in-depth analysis. We evaluate AI's role in CME diagnosis and its performance in "detection", "classification" and "segmentation" of OCT retinal images. We found that convolutional neural network (CNN)-based methods consistently outperformed other machine learning techniques, achieving an average accuracy of over 96% in detecting and identifying CME from OCT images. Despite certain limitations such as dataset size and ethical concerns, the synergy between AI and OCT, particularly through CNNs, holds promise for significantly advancing CME diagnostics.

12.
Nat Commun ; 15(1): 703, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38267406

RESUMEN

Applications in photodetection, photochemistry, and active metamaterials and metasurfaces require fundamental understanding of ultrafast nonthermal and thermal electron processes in metallic nanosystems. Significant progress has been recently achieved in synthesis and investigation of low-loss monocrystalline gold, opening up opportunities for its use in ultrathin nanophotonic architectures. Here, we reveal fundamental differences in hot-electron thermalisation dynamics between monocrystalline and polycrystalline ultrathin (down to 10 nm thickness) gold films. Comparison of weak and strong excitation regimes showcases a counterintuitive unique interplay between thermalised and non-thermalised electron dynamics in mesoscopic gold with the important influence of the X-point interband transitions on the intraband electron relaxation. We also experimentally demonstrate the effect of hot-electron transfer into a substrate and the substrate thermal properties on electron-electron and electron-phonon scattering in ultrathin films. The hot-electron injection efficiency from monocrystalline gold into TiO2, approaching 9% is measured, close to the theoretical limit. These experimental and modelling results reveal the important role of crystallinity and interfaces on the microscopic electronic processes important in numerous applications.

13.
Toxicol Rep ; 12: 578-583, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38798985

RESUMEN

Pollution by heavy metals is a serious global problem due to its toxicity, abiotic characteristics, abundant sources, and cumulative behavior. On the other hand, considering the importance of rice consumption as an important part of nutrition in Lordegan and Ahvaz cities, this study was conducted to evaluate the carcinogenic risk of heavy metals lead, cadmium, zinc, nickel and in local Champa rice cultivated in these two cities. 16 Champa rice samples were collected from the fields of Lordegan and Ahvaz cities. The elements were read in three replicates by Varian 710-ES atomic emission device. The results showed that the concentration of cadmium and nickel in the cultivated rice in the two studied cities was within the range of the national standard of Iran and the Codex standard. Carcinogenic risk values for lead, cadmium and nickel in Champa Lordegan and Ahvaz rice were within the safe range. Also, the non-carcinogenic risk for these heavy metals in the two studied areas was less than 1 and was in the safe range. Rice pollution in Champa in Ahvaz can be due to the industrial nature of this city, and in Lordegan, it is due to pollution through pesticides, chemical fertilizers, and transportation. Long-term consumption of contaminated rice may endanger the health of residents of these areas. It is recommended to carry out regular and up-to-date monitoring strategies in these two cities to prevent the entry of these toxic heavy metals into the human food chain. Also, more studies are needed to evaluate the complete scenario and make definitive decisions.

14.
Light Sci Appl ; 13(1): 91, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38637531

RESUMEN

Luminescence constitutes a unique source of insight into hot carrier processes in metals, including those in plasmonic nanostructures used for sensing and energy applications. However, being weak in nature, metal luminescence remains poorly understood, its microscopic origin strongly debated, and its potential for unraveling nanoscale carrier dynamics largely unexploited. Here, we reveal quantum-mechanical effects in the luminescence emanating from thin monocrystalline gold flakes. Specifically, we present experimental evidence, supported by first-principles simulations, to demonstrate its photoluminescence origin (i.e., radiative emission from electron/hole recombination) when exciting in the interband regime. Our model allows us to identify changes to the measured gold luminescence due to quantum-mechanical effects as the gold film thickness is reduced. Excitingly, such effects are observable in the luminescence signal from flakes up to 40 nm in thickness, associated with the out-of-plane discreteness of the electronic band structure near the Fermi level. We qualitatively reproduce the observations with first-principles modeling, thus establishing a unified description of luminescence in gold monocrystalline flakes and enabling its widespread application as a probe of carrier dynamics and light-matter interactions in this material. Our study paves the way for future explorations of hot carriers and charge-transfer dynamics in a multitude of material systems.

15.
Front Genet ; 15: 1343094, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38425718

RESUMEN

Introduction: Mucopolysaccharidoses are a group of lysosomal storage disorders that include seven types that are classified based on the enzymes that are disrupted. Malfunction of these enzymes leads to the accumulation of glycosaminoglycans (GAGs) in various tissues. Due to genetic and clinical heterogeneity, diagnosing and distinguishing the different types is challenging. Genetic methods such as whole exome sequencing (WES) and Sanger sequencing are accurate methods for detecting pathogenic variants in patients. Methods: Thirty-two cases of mucopolysaccharidosis, predominantly from families with consanguineous marriages, were genetically examined. Out of these, fourteen cases underwent targeted sequencing, while the rest underwent WES. The results of WES were analyzed and the pathogenicity of the variants was examined using bioinformatics tools. In addition, a segregation analysis within families was carried out. Results: In most cases, a pathogenic or likely pathogenic variant was detected. Sixteen previously reported variants and six new variants were detected in the known IDS (c.458G>C, c.701del, c.920T>G), GNS (c.1430A>T), GALNS (c.1218_1221dup), and SGSH (c.149T>C) genes. Furthermore, we discovered a c.259G>C substitution in the NAGLU gene for the first time in three homozygous patients. This substitution was previously reported as heterozygous. Except for the variants related to the IDS gene, which were hemizygous, all the other variants were homozygous. Discussion: It appears that the high rate of consanguineous marriages in the families being studied has had a significant impact on the occurrence of this disease. Overall, these findings could expand the spectrum of pathogenic variants in mucopolysaccharidoses. Genetic methods, especially WES, are very accurate and can be used alone or in conjunction with other diagnostic methods for a more precise and rapid diagnosis of mucopolysaccharidoses. Additionally, they could be beneficial for family screening and disease prevention.

16.
Adv Mater ; 35(37): e2204778, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36036786

RESUMEN

A diffusive memristor is a promising building block for brain-inspired computing hardware. However, the randomness in the device relaxation dynamics limits the wide-range adoption of diffusive memristors in large arrays. In this work, the device stack is engineered to achieve a much-improved uniformity in the relaxation time (standard deviation σ reduced from ≈12 to ≈0.32 ms). The memristor is further connected with a resistor or a capacitor and the relaxation time is tuned between 1.13 µs and 1.25 ms, ranging from three orders of magnitude. The hierarchy of time surfaces (HOTS) algorithm, to utilize the tunable and uniform relaxation behavior for spike generation, is implemented. An accuracy of 77.3% is achieved in recognizing moving objects in the neuromorphic MNIST (N-MNIST) dataset. The work paves the way for building emerging neuromorphic computing hardware systems with ultralow power consumption.

17.
GMS Hyg Infect Control ; 18: Doc06, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36875332

RESUMEN

Background: Cat fleas (Ctenocephalides felis) are the most common ectoparasites of domestic cats and dogs worldwide. They can parasitize humans in many regions of the globe. Hospital infestation with fleas has not been reported in Iran, and the number of reported cases in the world is very low. Case presentation: Here we report and describe a hospital infestation with cat fleas in a number of health-care service personnel and nurses, which led to the development of skin lesions and severe itching. Conclusion: Diagnosing the parasite, removing it, and good health and medical management lead to satisfactory outcomes.

18.
Toxicol Rep ; 11: 471-480, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38075013

RESUMEN

Background: Heavy metals in street dust are one of the most important sources of pollutants in urban areas. This urban dust can be caused by industrial activities, traffic, erosion of buildings, and fossil fuels. The aim of this systematic review is to evaluate the ecological risk of heavy metals in the dust of Iran's provinces. Methods: This study was conducted in February 2023 in order to investigate the environmental risks associated with heavy metals associated with dust particles in Iran. The present study was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Finally, 9 studies were extracted from the search databases. Results: The ecological risk of heavy metals in the present study was as follows: Cd (258.26؛ CI: 83.53, 433) >Pb (52.58؛ CI: 37.15, 68.02) >Cu (24.44؛ CI: 16.74, 32.14)>Ni (14.75؛ CI: 12.68, 16.82)>As (13.53؛ CI: 10.20, 16.85)>Zn (6.32؛ CI: 3.76, 8.87)>V (3.18؛ CI: 2.65, 3.72)>Cr (2.73؛ CI: 2.19, 3.27)>Co (1.94؛ CI: 1.13, 2.74). The mean ranking of the studied Pb ecological risk is as follows: Shiraz.> Tehran > Ahvaz > Ilam > Abadan > Dezful. Conclusion: The ecological risk potential of Cd in Tehran was also much higher than the standard. Therefore, Tehran was the most polluted city studied in terms of the ecological risk potential of Cd (1611.41؛ CI: 1605.98, 1616.84) and Pb (86.54؛ CI: 71.46, 101.62). The average concentration as well as the ecological risk of Cr, Co, and V metals were lower than the standard. Therefore, controlling the sources of heavy metal emissions (especially lead and cadmium) is highly recommended.

19.
ACS Energy Lett ; 8(10): 4242-4250, 2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37854045

RESUMEN

Harnessing nonequilibrium hot carriers from plasmonic metal nanostructures constitutes a vibrant research field with the potential to control photochemical reactions, particularly for solar fuel generation. However, a comprehensive understanding of the interplay of plasmonic hot-carrier-driven processes in metal/semiconducting heterostructures has remained elusive. In this work, we reveal the complex interdependence among plasmon excitation, hot-carrier generation, transport, and interfacial collection in plasmonic photocatalytic devices, uniquely determining the charge injection efficiency at the solid/liquid interface. Measuring the internal quantum efficiency of ultrathin (14-33 nm) single-crystalline plasmonic gold (Au) nanoantenna arrays on titanium dioxide substrates, we find that the performance of the device is limited by hot hole collection at the metal/electrolyte interface. Our solid- and liquid-state experimental approach, combined with ab initio simulations, demonstrates more efficient collection of high-energy d-band holes traveling in the [111] orientation, enhancing oxidation reactions on {111} surfaces. These findings establish new guidelines for optimizing plasmonic photocatalytic systems and optoelectronic devices.

20.
Front Public Health ; 11: 1150148, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37841736

RESUMEN

Background: Breast Cancer (BC) is the most common cause of female mortality throughout the world. Promoting public awareness about this disease is the most crucial method of its prevention or control. The present study was carried out to determine the health literacy level and its related factors in women with BC. Methods: This cross-sectional study was conducted on BC patients undergoing chemotherapy in two teaching hospitals affiliated to Zahedan University of Medical Sciences in 2020. A total of 210 patients referred to these chemotherapy centers were selected by purposive sampling. The data collection tools included a demographic information form and a health literacy questionnaire for Iranian women with BC. The collected data were analyzed using descriptive and inferential statistics (logistic regression) in SPSS-22. p-values less than 0.05 were considered statistically significant. Results: The mean total score of the health literacy of women with BC undergoing chemotherapy was 40.35 ± 19.01, which suggests an insufficient health literacy. The health literacy had a significant relationship with variables including university education (OR = 4.41, p = 0.005) and supplementary insurance coverage (OR = 5.83, p < 0.001). Conclusion: The findings showed that university education and supplementary insurance coverage are associated with a higher health literacy among women with BC. Improving these factors and paying further attention to their role in the promotion of health literacy can help enhance the health literacy of women with BC.


Asunto(s)
Neoplasias de la Mama , Alfabetización en Salud , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Irán , Estudios Transversales , Conocimientos, Actitudes y Práctica en Salud
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