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1.
Sensors (Basel) ; 24(7)2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38610400

RESUMEN

Monitoring blood pressure, a parameter closely related to cardiovascular activity, can help predict imminent cardiovascular events. In this paper, a novel method is proposed to customize an existing mechanistic model of the cardiovascular system through feature extraction from cardiopulmonary acoustic signals to estimate blood pressure using artificial intelligence. As various factors, such as drug consumption, can alter the biomechanical properties of the cardiovascular system, the proposed method seeks to personalize the mechanistic model using information extracted from vibroacoustic sensors. Simulation results for the proposed approach are evaluated by calculating the error in blood pressure estimates compared to ground truth arterial line measurements, with the results showing promise for this method.


Asunto(s)
Inteligencia Artificial , Sistema Cardiovascular , Presión Sanguínea , Determinación de la Presión Sanguínea , Acústica
2.
Sci Total Environ ; 926: 171593, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38479525

RESUMEN

Pollen allergies, such as allergic rhinitis, are triggered by exposure to airborne pollen. They are a considerable global health burden, with their numbers expected to rise in the coming decades due to the advent of climate change and air pollution. The relationships that exist between pollens, meteorological, and environmental conditions are complex due to a lack of clarity on the nature and conditions associated with these interactions; therefore, it is challenging to describe their direct impacts on allergenic potential clearly. This article attempts to review evidence pertaining to the possible influence of meteorological factors and air pollutants on the allergic potential of pollen by studying the interactions that pollen undergoes, from its inception to atmospheric traversal to human exposure. This study classifies the evidence based on the nature of these interactions as physical, chemical, source, and biological, thereby simplifying the complexities in describing these interactions. Physical conditions facilitating pollen rupturing for tree, grass, and weed pollen, along with their mechanisms, are studied. The effects of pollen exposure to air pollutants and their impact on pollen allergenic potential are presented along with the possible outcomes following these interactions, such as pollen fragmentation (SPP generation), deposition of particulate matter on pollen exine, and modification of protein levels in-situ of pollen. This study also delves into evidence on plant-based (source and biological) interactions, which could indirectly influence the allergic potential of pollen. The current state of knowledge, open questions, and a brief overview of future research directions are outlined and discussed. We suggest that future studies should utilise a multi-disciplinary approach to better understand this complex system of pollen interactions that occur in nature.


Asunto(s)
Contaminantes Atmosféricos , Hipersensibilidad , Rinitis Alérgica Estacional , Humanos , Polen , Rinitis Alérgica Estacional/epidemiología , Rinitis Alérgica Estacional/etiología , Alérgenos
3.
Case Rep Oncol ; 17(1): 484-489, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38529343

RESUMEN

Introduction: Paraganglioma of the urinary bladder (PUB) is an extremely rare extra-adrenal catecholamine-secreting neuroendocrine tumor, accounting for only 0.05% of all bladder tumors and 1% of all pheochromocytomas. The clinical presentation of PUB can be diverse and challenging to diagnose. Case Presentation: This case report presents a 37-year-old man with post-micturition palpitation, headache, and sweating, with no history of hematuria or other irritative urinary symptoms. Ultrasound and contrast-enhanced computed tomography revealed a suspicious mass in the right posterolateral wall of the urinary bladder. Despite normal functional hormonal tests, the diagnosis of PUB was confirmed after surgical enucleation and histopathological examination. Conclusion: This report emphasizes the importance of considering PUB as a differential diagnosis in patients with post-micturition symptoms and paroxysmal hypertension, as well as the need for a multidisciplinary approach in the evaluation and management of such rare and complex cases. Early recognition and surgical intervention are crucial for optimal management and favorable clinical outcomes.

4.
Brain ; 147(7): 2471-2482, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38386308

RESUMEN

Neurodevelopmental disorders are major indications for genetic referral and have been linked to more than 1500 loci including genes encoding transcriptional regulators. The dysfunction of transcription factors often results in characteristic syndromic presentations; however, at least half of these patients lack a genetic diagnosis. The implementation of machine learning approaches has the potential to aid in the identification of new disease genes and delineate associated phenotypes. Next generation sequencing was performed in seven affected individuals with neurodevelopmental delay and dysmorphic features. Clinical characterization included reanalysis of available neuroimaging datasets and 2D portrait image analysis with GestaltMatcher. The functional consequences of ZSCAN10 loss were modelled in mouse embryonic stem cells (mESCs), including a knockout and a representative ZSCAN10 protein truncating variant. These models were characterized by gene expression and western blot analyses, chromatin immunoprecipitation and quantitative PCR (ChIP-qPCR) and immunofluorescence staining. Zscan10 knockout mouse embryos were generated and phenotyped. We prioritized bi-allelic ZSCAN10 loss-of-function variants in seven affected individuals from five unrelated families as the underlying molecular cause. RNA-sequencing analyses in Zscan10-/- mESCs indicated dysregulation of genes related to stem cell pluripotency. In addition, we established in mESCs the loss-of-function mechanism for a representative human ZSCAN10 protein truncating variant by showing alteration of its expression levels and subcellular localization, interfering with its binding to DNA enhancer targets. Deep phenotyping revealed global developmental delay, facial asymmetry and malformations of the outer ear as consistent clinical features. Cerebral MRI showed dysplasia of the semicircular canals as an anatomical correlate of sensorineural hearing loss. Facial asymmetry was confirmed as a clinical feature by GestaltMatcher and was recapitulated in the Zscan10 mouse model along with inner and outer ear malformations. Our findings provide evidence of a novel syndromic neurodevelopmental disorder caused by bi-allelic loss-of-function variants in ZSCAN10.


Asunto(s)
Ratones Noqueados , Trastornos del Neurodesarrollo , Animales , Ratones , Humanos , Femenino , Masculino , Trastornos del Neurodesarrollo/genética , Trastornos del Neurodesarrollo/patología , Factores de Transcripción/genética , Niño , Preescolar , Adolescente , Lactante
5.
Food Chem X ; 21: 101206, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38379801

RESUMEN

In this study, an attempt was made to meta-analyzed the concentration of potentially toxic elements (PTEs) in shrimps tissue of Mediterranean Sea and health risk of consumers was estimated. Search was conducted in international databases includes Scopus, PubMed, Embase, Science Direct and Web of Science from 1 January 2010 to 20 July 2023. The random effects model used to meta-analysis of concentration of PTEs in shrimp in subgroups. In addition, non-carcinogenic and carcinogenic risks for adults and children were calculated using target hazard quotient (THQ) and cancer risk (CR). Meta-analysis concentration of PTEs in shrimps was conducted using random effects model based on country subgroups. The rank order of PTEs based on mean (pooled) level in fillet of shrimps was Fe (15.395 mg/kg-ww) > Zn (10.428 mg/kg-ww) > Cu (6.941 mg/kg-ww) Pb (5.7 mg/kg-ww) > Ni (1.115 mg/kg-ww) > As (0.681 mg/kg-ww) > Cd (0.412 mg/kg-ww) > Hg (0.300 mg/kg-ww). THQ level in adults and children due to Cd and Pb in Italy was higher than 1 value. THQ level in adults and children due to Cu, Ni, Fe, Zn and inorganic As was lower than 1 value. CR due to inorganic As in Greece and Türkiye for adults and children was higher than 1E-6 value. Therefore, it was recommended to continuously monitor and reduce the concentration of PTEs in shrimps in Italy, Greece and Türkiye, especially.

6.
J Surg Case Rep ; 2023(12): rjad656, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38076314

RESUMEN

Large-cell undifferentiated carcinoma of the urinary bladder is an extremely rare and aggressive neoplasm. We present a unique case of painless gross hematuria and a past surgical history of cystolithotomy. The patient underwent transurethral resection of the bladder tumor, which revealed high-grade urothelial cell carcinoma with lamina propria involvement. Subsequent radical cystoprostatectomy with orthotopic neobladder urinary diversion and pelvic lymphadenectomy was performed, and the postoperative pathologic examination indicated large-cell undifferentiated. This case report highlights the importance of accurate diagnosis and management for this rare malignancy and adds to the limited existing literature on Large-cell undifferentiated carcinoma.

7.
Sci Rep ; 13(1): 21980, 2023 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-38082024

RESUMEN

Breast cancer detection at an early stage significantly increases the chances of successful treatment and survival. This study presents an electrochemical biosensor for detecting breast cancer cells, utilizing silver nanoclusters encapsulated by hemoglobin and Cu (II)-porphyrin-metal organic framework (BioMOF) in a graphene-incorporated nanohybrid probe. This Hb-AgNCs@MOF-G probe demonstrates high electrochemical activity, superior dispersity, porosity, and a large surface area for effective functionalization. Using a green ultrasonic-assisted stirring method, we fabricate ultra-small 5 nm particles that readily immobilize on a glassy carbon electrode, generating a detection signal when interacting with ferricyanide/ferrocyanide redox probes. The resulting immunosensor detects as few as 2 cells/mL using Electrochemical Impedance Spectroscopy (EIS) "signal on" and 16 cells/mL via Square Wave Voltammetry (SWV) "signal off", within a broad range of cell concentrations (102-5 × 104 cells/mL). Our designed sensor shows improved selectivity (5- to 16-fold) and robust detection in human blood with a recovery efficiency between 94.8-106% (EIS method) and 95.4-111% (SWV method). This sensor could streamline early cancer diagnosis and monitor patient treatment without requiring labelling or signal amplification. As a pioneering endeavor, we've utilized integrated porous MOFs with Hb-encapsulated silver nanoclusters in cancer detection, where these components collectively enhance the overall functionality.


Asunto(s)
Técnicas Biosensibles , Neoplasias de la Mama , Grafito , Nanopartículas del Metal , Humanos , Femenino , Grafito/química , Técnicas Biosensibles/métodos , Plata/química , Técnicas Electroquímicas/métodos , Inmunoensayo , Hemoglobinas , Neoplasias de la Mama/diagnóstico , Nanopartículas del Metal/química , Límite de Detección
8.
Tanaffos ; 22(1): 70-74, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37920323

RESUMEN

Background: Coronavirus disease 2019 (COVID-19) is a newly emerged disease with many unknown facets, so both the treatment and the cause of spreading this disease have remained mysterious so far. Materials and Methods: Based on the information of 4372 patients with COVID-19 referring to Dr. Masih Daneshvari Hospital in Tehran, the time-dependent changes in COVID-19 severity were investigated in this study using correlation analysis. Results: According to the results of this study, on average 154.80 patients were infected with mild to moderate COVID-19, and 39.06 were infected with severe COVID-19. The results of this study also indicated a descending trend in the number of patients with mild to moderate COVID-19 (r=-0.40, P-value=0.004) and an ascending trend in the number of patients with severe COVID-19 (r=0.43, P-value=0.003) overtime on a daily basis so that almost two patients were removed from those with mild to moderate COVID-19 and one was added to the patients with severe COVID-19 on average per day. Conclusion: Based on the current study results, it is concluded that COVID-19 severity will not be constant over time, and there is a probability of COVID-19 becoming more aggressive. Therefore, by the lack of timely control of the disease over time, we will witness an increased number of patients with severe COVID-19 and an increased number of hospitalizations in the intensive care unit (ICU) ward.

9.
J Hazard Mater ; 460: 132516, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37703733

RESUMEN

The increasing share of using biofuels in vehicles (mandated by current regulations) leads to a reduction in particle size, resulting in increased particle toxicity. However, existing regulations disregarded small particles (sub-23 nm) that are more toxic. This impact is more significant during vehicle cold-start operation, which is an inevitable frequent daily driving norm where after-treatment systems prove ineffective. This study investigates the impact of biofuel and lubricating oil (as a source of nanoparticles) on the concentration, size distribution, median diameter of PN and PM, and their proportion at size ranges within accumulation and nucleation modes during four phases of cold-start and warm-up engine operation (diesel-trucks/busses application). The fuels used were 10% and 15% biofuel and with the addition of 5% lubricating oil to the fuel. Results show that as the engine warms up, PN for all the fuels increases and the size of particles decreases. PN concentration with a fully warmed-up engine was up to 132% higher than the cold-start. Sub-23 nm particles accounted for a significant proportion of PN (9%) but a smaller proportion of PM (0.1%). The fuel blend with 5% lubricating oil showed a significant increase in PN concentration and a decrease in particle size during cold-start.

10.
Radiol Case Rep ; 18(11): 4103-4105, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37720918

RESUMEN

Zinner Syndrome is a rare congenital anomaly. It is considered a rare cause of male infertility and can cause a range of clinical manifestations that may lead to significant morbidity. The diagnosis of Zinner Syndrome requires a high index of suspicion, combined with a detailed clinical evaluation and imaging studies. Ultrasonography, computed tomography, and MRI are the imaging modalities of choice for the diagnosis of this condition. Radiological evaluation also plays a crucial role in the management of Zinner Syndrome. In symptomatic cases, surgical intervention may be necessary, and radiology is essential for surgical planning and postoperative monitoring. In this case report, we describe an uncommon case of a 35-year-old patient with vague scrotal pain and discuss the clinical presentation, diagnosis, and management of this rare condition. Prompt and accurate diagnosis is important to prevent the potential morbidity associated with this condition, such as recurrent epididymitis, urinary tract infections, and infertility.

11.
Pathol Res Pract ; 243: 154341, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36739754

RESUMEN

Breast cancer is the most frequently diagnosed malignant tumor in women and a major public health concern. NRF2 axis is a cellular protector signaling pathway protecting both normal and cancer cells from oxidative damage. NRF2 is a transcription factor that binds to the gene promoters containing antioxidant response element-like sequences. In this report, differential expression of NRF2 signaling pathway elements, as well as the correlation of NRF2 pathway mRNAs with various clinicopathologic characteristics, including molecular subtypes, tumor grade, tumor stage, and methylation status, has been investigated in breast cancer using METABRIC and TCGA datasets. In the current report, our findings revealed the deregulation of several NRF2 signaling elements in breast cancer patients. Moreover, there were negative correlations between the methylation of NRF2 genes and mRNA expression. The expression of NRF2 genes significantly varied between different breast cancer subtypes. In conclusion, substantial deregulation of NRF2 signaling components suggests an important role of these genes in breast cancer. Because of the clear associations between mRNA expression and methylation status, DNA methylation could be one of the mechanisms that regulate the NRF2 pathway in breast cancer. Differential expression of Hippo genes among various breast cancer molecular subtypes suggests that NRF2 signaling may function differently in different subtypes of breast cancer. Our data also highlights an interesting link between NRF2 components' transcription and tumor grade/stage in breast cancer.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/patología , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Pronóstico , Transcriptoma , Transducción de Señal/genética , ARN Mensajero/genética
12.
Pharmacol Rep ; 75(1): 189-198, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36334247

RESUMEN

BACKGROUND: It has been suggested that the anti-hyperglycemic effect of metformin could be associated with its impact on long non-coding RNA (lncRNA) expression levels. Accordingly, in the current study, we evaluated the effect of metformin on the expression of H19, MEG3, MALAT1, and GAS5 in in vitro and in vivo situations. METHODS: The effect of hyperglycemia and metformin treatment on the lncRNAs expression level was evaluated in HepG2 cells. A total of 179 age- and sex-matched subjects, including 88 newly diagnosed patients with type 2 diabetes (T2D) and 91 healthy volunteers, were included in the case-control phase of the study. Moreover, 40 newly diagnosed patients participated in the study's open-labeled non-controlled clinical trial phase. The expression levels of lncRNA in HepG2 cells and whole blood samples were determined using QRT-PCR. RESULTS: In vitro results showed that hyperglycemia induced H19 and MALAT1 and decreased GAS5 expression levels. Moreover, metformin decreased H19 and increased GAS5 expression in high glucose-treated cells. Case-control study findings revealed that the circulating levels of H19, MALAT1, and MEG3 were significantly elevated in T2D patients compared to the control subjects. Finally, results showed that the level of circulating H19 levels decreased while GAS5 increased in T2D patients after taking metformin for 2 months. CONCLUSION: The results of the current study provided evidence that metformin could exert its effect in the treatment of T2D by altering the expression levels of H19 and GAS5.


Asunto(s)
Diabetes Mellitus Tipo 2 , Metformina , ARN Largo no Codificante , Humanos , Metformina/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/genética , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Estudios de Casos y Controles
13.
Urologia ; 90(2): 236-243, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-35972023

RESUMEN

OBJECTIVE: The Gleason score is an essential factor for making decisions about prostate cancer management and its prognosis. Thus, we conducted this research to discover the histologic-grading accuracy of needle biopsy specimens, and to identify preoperative clinical and pathological factors that predict upgrading and downgrading from biopsy to radical prostatectomy specimen. PATIENTS AND METHODS: This study was performed on 570 patients who were referred to the medical centers affiliated with Shiraz University of Medical Sciences and underwent radical prostatectomy from 2013 to 2017. Concordance was evaluated between the Gleason score of needle biopsy and radical prostatectomy specimens. Predictors of upgrades and downgrades were assessed in univariate and multivariate logistic regression analyses. RESULTS: Scores were the same in 50% of cases, downgraded in 26%, and upgraded in 24%. The variables predicting a Gleason score upgrade were higher Prostate specific antigen level, larger tumors, and older age. Lower tumor volume, lower Prostate specific antigen, and low maximum percentage of cancer in cores were predictors of downgrading from Gleason score>6 to ⩽6. Also, Body mass index>30, smaller tumor size, and negative lymph nodes were predictors of downgrading from Gleason score>7 to 7. CONCLUSION: The correlation between biopsy and Radical prostatectomy Gleason scores was only 50%. After dividing them into the new grading groups, this coordination increased by only 5.6%. Physicians need to consider possible limitations of the Gleason score of biopsy and factors that can be predictive of upgrading to high-risk prostate cancer before making treatment decisions.


Asunto(s)
Próstata , Neoplasias de la Próstata , Masculino , Humanos , Próstata/patología , Antígeno Prostático Específico , Clasificación del Tumor , Prostatectomía , Biopsia , Neoplasias de la Próstata/cirugía
14.
Tanaffos ; 22(3): 332-336, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38638390

RESUMEN

Background: The disease process involves the occurrences happening during the disease and treatment course for the patient. Investigating this process is a significant and necessary issue for all diseases, including coronavirus disease 2019 (COVID-19). Materials and Methods: Using the information of 4372 patients with COVID-19 referring to Dr. Masih Daneshvari Hospital in Tehran during the COVID-19 epidemic, being hospitalized, cared for, and home quarantined due to having mild symptoms, the COVID-19 process and its related occurrences were investigated during the treatment course. Results: In the COVID-19 course, considering the disease severity, the likelihood of hospitalization in the general ward or the intensive care unit (ICU) ward, the likelihood of isolation or home quarantine, and the likelihood of occurrences such as recovery or death at the end of the disease course were taken into consideration. Based on the results of this study, the likelihood of hospitalization in the general ward, the ICU ward, and isolation or home quarantine was determined to be approximately 49.54%, 14.73%, and 35.73%, respectively. Also, for patients hospitalized in the general ward, the ICU ward, and isolated or home quarantined, the likelihood of recovery was estimated at approximately 64.79%, 10.82%, and 96.31%, respectively, and the likelihood of death was also estimated at about 35.21%, 89.18%, and 3.69% respectively. Conclusion: Investigating the COVID-19 process and estimating the likelihood of incidence of its related occurrences during the treatment course both create an accurate prognosis and provide the possibility of achieving an efficient treatment for these patients.

15.
Tanaffos ; 21(1): 70-77, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36258908

RESUMEN

Background: The success of treatment strategies to control the disease relapse requires determining factors affecting the incident short-time and long-time of disease relapse. Therefore, this study was aimed to identify the factors affecting of short-and long-time of occurrence of disease relapse in patients with tuberculosis (TB) using a parametric mixture cure model. Materials and Methods: In this historical cohort study; the data was collected from 4564 patients with TB who referred to the Tuberculosis and Lung Diseases Research Center of Dr. Masih Daneshvari Hospital from 2005 to 2015. In order to evaluate the factors affecting of short-and long-time of occurrence of disease relapse, a parametric mixture cure model was used. Results: In this study, the estimation of the annual incidence of TB relapse showed that the probability of recurrence in the first year is 1% and in the third and tenth years after treatment is 3% and 5%, respectively. In addition, the results of this study showed that the variables of residence, exposure to cigarette smoke, adverse effects of drug use, incarceration, and pulmonary and extra- pulmonary tuberculosis were the factors affecting the short-time recurrence of TB. The variables of drug use, pulmonary and extra- pulmonary tuberculosis, and also incarceration affected the long-term recurrence of this disease. Conclusion: Cure models by separating factors affecting the short-time occurrence from the long-time occurrence of disease relapse can provide more accurate information to researchers to control and reduce TB relapse.

16.
Rare Tumors ; 14: 20363613221103751, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35651782

RESUMEN

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare tumor of the soft tissue, usually located in lower extremities. There are rarely tumors reported in other anatomic locations. Herein, we report retroperitoneal PHAT in a male patient. A 41-year-old man was referred to our clinic due to an incidentally found retroperitoneal mass. Computed tomography (CT) scan showed a solid hypoechoic lesion containing fat component and calcified elements measuring about 80*72*45 mm in the right lower quadrant (RLQ) of the abdomen. Magnetic resonance imaging (MRI) showed circumscribe lesion measuring about 60 x 48 mm with partial enhancement and fat component. In pelvic exploration, a large mass was found that had encased the right external iliac artery and vein. Therefore, the mass and its surrounding iliac vessels were excised and removed en block. Then, the external iliac vessels were reconstructed with Gortex graft. No recurrence was found in 1 month and 3 months post-operation follow up. We report a pelvic retroperitoneal PHAT as a rare location of this tumor. It seems that PHAT must be considered in differential diagnosis in patients with soft tissue tumors in the pelvic cavity.

17.
Trop Anim Health Prod ; 53(5): 486, 2021 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-34586503

RESUMEN

The aim of this study was to evaluate the effects of partial replacement of forage and concentrate with pomegranate pulp silage (PPS) and dried pomegranate seed pulp (PSP) on performance, dry matter intake (DMI), and carcass characteristics of fattening Mehraban lambs. Twenty-four male lambs (mean body weight 27.0 ± 3.5 kg) were fed with three isonitrogenous and isoenergetic diets (n = 8 per diet), consisting of a control diet, a PPS diet containing 27.2% pomegranate pulp silage, and a PSP diet containing 31.4% dried pomegranate seed pulp. The experimental diets were fed ad libitum as total mixed rations for 65-day fattening period, on two meals per day, and then the growth performance, feed intake, and carcass characteristics were determined. The initial BW, final BW, average daily gain (ADG), and feed conversion ratio (FCR) were not different among the experimental diets. The amount of DMI in PSP diet was higher than that in the control diet (P = 0.023) but was not different between the control and PPS diets. There was no significant difference among diets for carcass characteristics. Using PPS and PSP in the diets decreased (P < 0.05) the kidney fat, but had no impact on the heart, liver, kidneys, spleen, and lungs. The results showed that PPS and PSP could be used to replace part of the diet for fattening lambs, while decreasing the dietary cost without having any negative effects on animal performance.


Asunto(s)
Granada (Fruta) , Ensilaje , Alimentación Animal/análisis , Animales , Semillas , Ovinos , Oveja Doméstica , Ensilaje/análisis
18.
Environ Pollut ; 290: 118052, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34479164

RESUMEN

In the transportation sector, the share of biofuels such as biodiesel is increasing and it is known that such fuels significantly affect NOx emissions. In addition to NOx emission from diesel engines, which is a significant challenge to vehicle manufacturers in the most recent emissions regulation (Euro 6.2), this study investigates NO2 which is a toxic emission that is currently unregulated but is a focus to be regulated in the next regulation (Euro 7). This manuscript studies how the increasing share of biofuels affects the NO2, NOx, and NO2/NOx ratio during cold-start (in which the after-treatment systems are not well-effective and mostly happens in urban areas). Using a turbocharged cummins diesel engine (with common-rail system) fueled with diesel and biofuel derived from coconut (10 and 20% blending ratio), this study divides the engine warm-up period into 7 stages and investigates official cold- and hot-operation periods in addition to some intermediate stages that are not defined as cold in the regulation and also cannot be considered as hot-operation. Engine coolant, lubricating oil and exhaust temperatures, injection timing, cylinder pressure, and rate of heat release data were used to explain the observed trends. Results showed that cold-operation NOx, NO2, and NO2/NOx ratio were 31-60%, 1.14-2.42 times, and 3-8% higher than the hot-operation, respectively. In most stages, NO2 and the NO2/NOx ratio with diesel had the lowest value and they increased with an increase of biofuel in the blend. An injection strategy change significantly shifted the in-cylinder pressure and heat release diagrams, aligned with the sudden NOx drop during the engine warm-up. The adverse effect of cold-operation on NOx emissions increased with increasing biofuel share.


Asunto(s)
Biocombustibles , Gasolina , Frío , Dióxido de Nitrógeno , Emisiones de Vehículos
19.
Environ Pollut ; 275: 116592, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33582631

RESUMEN

This study investigates the morphology and nanostructure of soot particles during cold-start and hot-start engine operation of a diesel engine using oxygenated fuels. The soot samples were analysed using transmission electron microscopy. The oxygen content in the fuel was varied between 0 and 12%. The results showed that the primary particles during cold-start have significantly smaller size when compared to hot-start engine operation. The addition of oxygenated fuels also resulted in smaller sized primary particles. Smaller radius of gyration and higher fractal dimension of soot aggregates during cold-start would mean smaller aggregate size with a more compact structure. Shorter fringes with a higher inter-fringe spacing for cold-start would mean lower graphitisation of soot particles that could be related to higher oxidation reactivity of soot particles.


Asunto(s)
Nanoestructuras , Hollín , Fractales , Gasolina/análisis , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Hollín/análisis , Emisiones de Vehículos/análisis
20.
Urol J ; 18(5): 497-502, 2021 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-33420781

RESUMEN

BACKGROUND: Experts recommend us to keep a safety guidewire during the process of upper urinary tract endoscopy, though there is a lack of high-level evidence to support  the efficacy and safety of  this opinion. This study conducted to compare the outcome of ureteral stone breakage in the presence or absence of safety guidewire. MATERIALS AND METHODS: Patients candidate for endoscopic breakage of ureteral stone using a semi-rigid ureteroscope, were randomly assigned in  two groups based on keeping a safety guidewire (group1)  or removing the guidewire (group2) before the process of breaking ureteral stone by lithoclast. Demographic factors, history of previous stone treatment, kidney function, stone location, symptoms duration and severity were recorded for each patient. Primary outcomes include success rate of stone treatment and secondary outcomes include number of attempts to enter to ureter, success rate of ureteral entry, success rate of stone achievement, stone migration rate and success rate of ureteral stent insertion. The recorded data were entered to the SPSS software and descriptive statistical analysis including power calculation and non-inferiority design for the primary and secondary outcomes, was performed. P-value less than 0.05 was considered significant. RESULTS: From January 2016 till May 2018, 320 patients were randomized with 160 patients in each arm. Considering the cases who were missed due to follow-up loss, there were 153 patients in group 1 and 147 patients in group 2 at the end of the study. Baseline data were equally distributed in both groups. Based on the initial analysis, the studied variables had no significant difference between two groups; though, according to the subgroup analysis of patients with proximal ureter stones, patients in Group 1 had higher rates of ureteral injury comparing to the patients in Group 2 (p=0.03). CONCLUSION: According to our findings, keeping the safety guidewire through the process of endoscopic stone breakage (stone size: less than 1.5Cm) seems to add no significant benefit to the procedure outcome, while it increases the ureteral injuries in the proximal ureter stones, but not in mid or distal ureter stones.


Asunto(s)
Litotricia , Cálculos Ureterales , Humanos , Litotricia/efectos adversos , Estudios Prospectivos , Resultado del Tratamiento , Cálculos Ureterales/terapia , Ureteroscopios , Ureteroscopía/efectos adversos
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