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BACKGROUND: Ophthalmic artery aneurysm (OAA) can be secured in endovascular or microsurgical approaches. Still there are controversies in technique selection and their long term outcomes. METHODS: All the patients with OAA were treated microsurgically and followed. Demographic data, neurological status, physical examination findings, angiographic data, operation details, and intraoperative and postoperative events were recorded and analyzed. P < 0.05 was considered significant. RESULTS: Among 55 patients, 38 were females (69.1%). Median preoperative glasgow coma scale (GCS), Fisher Grade, and Hunt and Hess(HH) scores were 15, 1 and 1, respectively. The most common neurologic manifestation was visual problems (n = 15). The most common anatomical projection was medial (43.6%) oriented lesions. 85.5% of them only had 1 ophthalmic aneurysm while multiple aneurysms were reported in 14.6%. In 52 patients temporary clip was used. in 21 patients (38.2%) intraoperative aneurysm rupture occurred. Larger aneurysm size and preoperative hydrocephalus were associated with higher rates of aneurysm rupture (P = 0.003 and 0.031). 28.5% of the patients with visual problems had clinical improvement in the postoperative period. The mean follow-up period was 5 years. Follow-up angiography showed a 100% obliteration rate with a 0.0% recurrence rate. Median values for follow-up glasgow outcome scale and modified Rankin scale were 5 and 0, respectively. favorable neurological outcomes were associated with better primary GCS and HH scores. CONCLUSION: OAA microsurgery is an effective and safe procedure with significant improvement in both visual and neurological status. Low recurrence rate and excellent clinical recovery are the most important advantages of microsurgery in OAA treatment.
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Aneurisma Intracraniano , Microcirurgia , Artéria Oftálmica , Humanos , Feminino , Masculino , Microcirurgia/métodos , Pessoa de Meia-Idade , Artéria Oftálmica/cirurgia , Adulto , Seguimentos , Aneurisma Intracraniano/cirurgia , Aneurisma Intracraniano/complicações , Idoso , Resultado do Tratamento , Estudos Retrospectivos , Adulto Jovem , AdolescenteRESUMO
This study introduced a new microextraction method named temperature-induced dispersive solid-phase extraction. The performance of the method was demonstrated with the determination of Sudan dyes in food and natural water samples. In this method, a low quantity of sorbent was added to the aqueous solution and the mixture was shaken manually for about one minute. Then, the solution was heated in an ultrasonic water bath, and the sorbent was dissolved. Subsequently, the solution was cooled down with ice water, and consequently, the solubility of the sorbent was reduced in the sample solution and became cloudy. The phase separation was accelerated by centrifugation. The upper liquid phase was picked up using a syringe, and the remainder was solved in methanol and introduced into the HPLC for analysis. Various parameters affecting the extraction yield were evaluated. Analytical parameters, including limits of detection (0.011-0.016 µg/L) and quantification (0.038-0.055 µg/L), relative standard deviations (2.3%-3.1%), and preconcentration factor (40) proved the high efficiency of the developed method for the analysis of Sudan dyes. The proposed method was used to measure Sudan dyes in water and food samples and showed good extraction recoveries (95.0%-103.5%).
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Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida , Temperatura , Concentração de Íons de Hidrogênio , Extração em Fase Sólida/métodos , Corantes/química , Cromatografia Líquida de Alta Pressão/métodos , Água/química , Análise de AlimentosRESUMO
This paper presents a new approach to measure the force required to detach a water (a polar liquid) droplet from a hydrophobic surface. This is done by partially cloaking the droplet with a high-surface-tension oil-based ferrofluid and using a magnet to apply a controllable body force to the resulting compound droplet. Placing the assembly on a sensitive scale, the magnet can then be brought closer to the droplet to detach it from the surface while recording the forces applied to the droplet. The work presented here is novel as it uses the concept of partial cloaking in which the solid-droplet contact area is not contaminated by the ferrofluid (and the measured forces do not need postprocessing). Our study is accompanied by numerical simulations aimed at improving our understanding of the interplay between the interfacial forces in a two-phase droplet under the influence of a strong (detaching) body force and at providing additional data for in-depth analyses of these forces. In particular, the minimum ferrofluid volume required for successful water droplet detachment from hydrophobic surfaces is computed for ferrofluids of different surface tensions, and they are compared to experimental data obtained from detaching water droplets from electrospun polystyrene coatings. It is also shown that the detachment force measured via partial cloaking is independent of the volume of the ferrofluid used for the experiment.
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BACKGROUND AND AIM: A growing body of literature suggests the association between dementia risk and proton pump inhibitor (PPI) use. Therefore, we aimed to investigate the association between PPI use and dementia risk. METHODS: An extensive literature search was performed in PubMed, Embase, and Cochrane till March 31, 2019. All the studies (cohort and case-control) assessing the association between PPI use and dementia risk were eligible for inclusion. Articles were selected based on the screening of title and abstract, data were extracted, and risk of bias was assessed using Newcastle-Ottawa scale. The primary outcome was pooled risk of dementia among PPI user as compared with non-PPI user. Secondary outcomes include dementia risk based on subgroups. Statistical analysis was performed using review manager software. RESULTS: Twelve studies (eight cohort and four case-control) were found to be eligible for inclusion. Majority of the studies were of high quality. Dementia was diagnosed based on International Classification of Diseases 9/10 codes in majority of the included studies. PPI use was not associated with the dementia risk, with a pooled relative risk (RR) of 1.05 (95% confidence interval [CI]: 0.96-1.15), P = 0.31. Subgroup analysis based on study design (cohort: P = 0.14; case-control: P = 0.14), sex (RR 1.25 [95% CI: 0.97-1.60], P = 0.08), histamine 2 receptor antagonist blockers (P = 0.93), and Alzheimer's disease (RR 1.00 [95% CI: 0.91-1.09], P = 0.93) revealed no significant association between PPI use and dementia risk. CONCLUSION: We found no significant association between PPI use and the risk of dementia or Alzheimer's disease.
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Demência/induzido quimicamente , Resultados Negativos , Inibidores da Bomba de Prótons/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RiscoRESUMO
Leveraging subwavelength resonant nanostructures, plasmonic metasurfaces have recently attracted much attention as a breakthrough concept for engineering optical waves both spatially and spectrally. However, inherent ohmic losses concomitant with low coupling efficiencies pose fundamental impediments over their practical applications. Not only can all-dielectric metasurfaces tackle such substantial drawbacks, but also their CMOS-compatible configurations support both Mie resonances that are invariant to the incident angle. Here, we report on a transmittive metasurface comprising arrayed silicon nanodisks embedded in a homogeneous dielectric medium to manipulate phase and amplitude of incident light locally and almost independently. By taking advantage of the interplay between the electric/magnetic resonances and employing general concepts of spatial Fourier transformation, a highly efficient metadevice is proposed to perform mathematical operations including solution of ordinary differential and integro-differential equations with constant coefficients. Our findings further substantiate dielectric metasurfaces as promising candidates for miniaturized, two-dimensional, and planar optical analog computing systems that are much thinner than their conventional lens-based counterparts.
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Pholcodine is an opiate derivative drug which is widely used in pediatric medicine. In this study, a chemiluminescence (CL) method is described that determines pholcodine in human plasma and syrup samples. This method is based on the fact that pholcodine can greatly enhance the weak CL emission of reaction between tris(1,10 phenanthroline)ruthenium(II), Ru(phen)32+ , and acidic Ce(IV). The CL mechanism is described in detail using UV-vis light, fluorescence and CL spectra. Effects of chemical variables were investigated and under optimum conditions, CL intensity was proportional to the pholcodine concentration over the range 4.0 × 10-8 to 8.0 × 10-6 mol L-1 . The limit of detection (LOD) (S/N = 3) was 2.5 × 10-8 mol L-1 . Percent of relative standard deviations (%RSD) for 3.0 × 10-7 and 3.0 × 10-6 mol L-1 of pholcodine was 2.9 and 4.0%, respectively. Effects of common ingredients were investigated and the method was applied successfully to the determination of pholcodine in syrup samples and human plasma.
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Cério/química , Codeína/análogos & derivados , Complexos de Coordenação/química , Formas de Dosagem , Medições Luminescentes/métodos , Morfolinas/análise , Morfolinas/sangue , Codeína/análise , Codeína/sangue , HumanosRESUMO
OBJECTIVE: The prevalence of degenerative scoliosis (DS) increases with age and an overall increase is seen due to the aging population. This study aims to evaluate the clinical and radiological outcomes after decompression and posterior fusion in patients with DS. METHODS: In this is prospective study, 43 patients with DS, aged 37 to 70 years, were eligible to undergo decompression and posterior fusion. Primary outcomes were low back pain (LBP) with or without radicular pain, which was evaluated preoperatively and at 12 and 24 months after surgery with the use of a visual analog scale (VAS), and the quality of life (QOL), which was assessed at the same time periods by the Oswestry Disability Index (ODI) questionnaire. The Cobb's method was used to measure the degree of scoliosis in each patient preoperatively and at 24 hours, 12 and 24 months after the surgery. RESULTS: VAS scores improved significantly from a mean of 8.18 preoperatively to 4.48 at 12 months and 3.07 at 24 months postoperatively (P < .001). The mean radicular pain scores also decreased significantly (P < .001). At postoperative 12 months, the mean ODI score was significantly lower than the mean preoperative ODI score (47.81 ± 16.06 vs. 72.18 ± 12.28; P = .001). ODI score at 24 months postoperatively was significantly better than the preoperative ODI (15.53 ± 7.21 vs. 72.18 ± 12.28; P = .016). The mean Cobb angle changed significantly from 31.4° ± 4.88 preoperatively to 3.28° ± 2.10 at 24 months postoperatively (P < .001). CONCLUSIONS: Our findings suggest that decompression and posterior fusion in the patients with DS is an effective surgical method which is associated with satisfying clinical results in terms of improvement of postoperative LBP, radicular pain, and QOL, and correction of Cobb angle at 12 and 24 months after the surgery and restoration of sagittal alignment at 2 months postoperatively.
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Descompressão Cirúrgica/métodos , Procedimentos Neurocirúrgicos/métodos , Escoliose/diagnóstico , Escoliose/cirurgia , Fusão Vertebral/métodos , Adulto , Idoso , Avaliação da Deficiência , Feminino , Humanos , Dor Lombar/diagnóstico , Dor Lombar/cirurgia , Vértebras Lombares/cirurgia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Medição da Dor , Complicações Pós-Operatórias/cirurgia , Estudos Prospectivos , Qualidade de Vida , Radiografia , Estenose Espinal/diagnóstico , Estenose Espinal/cirurgia , Inquéritos e Questionários , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Spins in solids are cornerstone elements of quantum spintronics. Leading contenders such as defects in diamond or individual phosphorus dopants in silicon have shown spectacular progress, but either lack established nanotechnology or an efficient spin/photon interface. Silicon carbide (SiC) combines the strength of both systems: it has a large bandgap with deep defects and benefits from mature fabrication techniques. Here, we report the characterization of photoluminescence and optical spin polarization from single silicon vacancies in SiC, and demonstrate that single spins can be addressed at room temperature. We show coherent control of a single defect spin and find long spin coherence times under ambient conditions. Our study provides evidence that SiC is a promising system for atomic-scale spintronics and quantum technology.
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In this Letter, we realize the concept of analog computing using an engineered gradient dielectric meta-reflect-array. The proposed configuration consists of individual subwavelength silicon nanobricks, in combination with a fused silica spacer and silver ground plane, realizing a reflection beam with full phase coverage of 2π degrees, as well as an amplitude range of 0 to 1. Spectrally overlapping electric and magnetic dipole resonances, such high-index dielectric metasurfaces can locally and independently manipulate the amplitude and phase of the incident electromagnetic wave. This practically feasible structure overcomes substantial limitations imposed by plasmonic metasurfaces such as absorption losses and low polarization conversion efficiency in the visible range. Using such CMOS-compatible and easily integrable platforms promises highly efficient ultrathin planar wave-based computing systems that circumvent the drawbacks of conventional bulky lens-based signal processors. Based on these key properties and the general concept of spatial Fourier transformation, we design and realize broadband mathematical operators such as the differentiator and integrator in the telecommunication wavelengths.
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A sensitive and selective method for the preconcentration and separation of sub µg L-1 levels of cadmium ions in aqueous solutions with high salt contents is described. The developed method is based on temperature-controlled ionic liquid dispersive liquid phase microextraction of cadmium using the 1-hexyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (ionic liquid (IL)) as an extractant followed by flame atomic absorption spectrometry determination. The extraction of cadmium ions from the aqueous solution into the fine droplets of IL was performed with dithizone as the chelating agent. Some predominant factors affecting the preconcentration of cadmium ions were evaluated and optimized. Under the optimum conditions, the calibration graph was linear over the concentration range from 0.6-20.0 µg L-1 of cadmium and the limit of detection (LOD) was 0.2 µg L-1. The enrichment factor was found to be 25. The developed method was successfully applied to the determination of cadmium in spinach and water samples.
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Métodos Analíticos de Preparação de Amostras/métodos , Cádmio/análise , Cádmio/isolamento & purificação , Microextração em Fase Líquida/métodos , Spinacia oleracea/química , Temperatura , Água/química , Concentração de Íons de Hidrogênio , Líquidos Iônicos/química , Sais/química , Fatores de Tempo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
Background: Effective skin rejuvenation treatments with RF technologies exist, with potential for personalized combination therapies based on individual factors. We compared microneedling and fractional RF laser effectiveness in rejuvenation, pore healing, and skin lightening. Method: The research was a non-randomized clinical trial study conducted in 2021 at Ilam Skin Clinic, Ilam, western Iran on people applying for rejuvenation, skin lightening and improvement of open pores. People were voluntarily divided into two groups based on personal preferences (group A: microneedling, 25 people, group B: fractional RF, 25 people). After data collection, SPSS22 software was used for data analysis. Results: The study revealed significant differences in the rates of low, moderate, and severe pain between the microneedling and fractional groups (10 vs. 16, 14 vs. 4, 1 vs. 5, respectively). Erythema showed no significant difference, with low, moderate, and severe cases reported in both groups. Swelling was lower in the microneedling group, but the difference was not significant. Bruising was similar in both groups, and staining was minimal. No herpes or infections were reported. The microneedling group showed better improvement in skin pores and skin lightening compared to the fractional group, with outcomes rated as good and excellent. Conclusion: Microneedling surpassed the fractional group in skin rejuvenation, lightening, and improved pores. Considering RF lasers are approximately three times more expensive than microneedling, the research indicates that choosing microneedling is not only more cost-effective but also a superior rejuvenation technique.
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BACKGROUND: Intracranial aneurysms are more commonly associated with inflammation as a cause of their development, progression, and rupture. Macrophages and other cells can express the CD68 antigen. The aim of this study was to assess the CD68 antigen levels in cerebral aneurysm (CA) patients compared to a control group at a referral center in Iran. METHODS: A case-control investigation was undertaken on 88 individuals (44 of whom were cases and 44 were controls). Individuals with CA as the case group consisted of 28 ruptured and 16 unruptured subgroups. Clinical, radiographic, and CD68 levels were evaluated and registered. RESULTS: The average age of the participants was 49 years. Males comprised 43.2% of the patients, while 56.8% were females (p = 0.002). There was a statistically significant difference in the CD68 levels between the two groups. There was no significant difference (p = 0.42) between the ruptured and unruptured subgroups (23.66 and 20.47, respectively) in this comparison. No significant correlation was seen between the patients' CD68 and Glasgow Coma Scale (GCS) levels and their aneurysm diameter (p = 0.74 and 0.45, respectively). A link between CD68 levels and age was found, but it was not statistically significant (r = 0.44 and p = 0.002). CONCLUSIONS: A possible involvement of CD68 as an inflammatory agent in the development of CAs but not in aneurysm rupture has been suggested. Inflammation and CD68 were positively associated with age. The CD68 antigen should be studied further in population-based cohort studies.
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Aneurisma Roto , Aneurisma Intracraniano , Masculino , Feminino , Humanos , Pessoa de Meia-Idade , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/complicações , Estudos de Casos e Controles , Molécula CD68 , Aneurisma Roto/complicações , Inflamação/complicações , Antígenos CD , Antígenos de Diferenciação Mielomonocítica , Estudos RetrospectivosRESUMO
BACKGROUND: SGLT-2 inhibitors, prescribed for type 2 diabetes, have a heightened risk of amputation. The FDA issued a warning in May 2017, leading to the inclusion of a cautionary label. Vigilance is essential for patients and healthcare providers to promptly identify and address potential limb complications associated with the use of SGLT-2 inhibitors. METHOD: A comprehensive search of electronic databases was conducted, covering the period from inception to May 2024. This systematic literature review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included studies was assessed using the Cochrane risk of bias (ROB) tool. Inclusion and exclusion criteria were predefined, and data extraction was performed to summarize the findings. RESULT: A total of 12 randomized control trial (RCT) studies were included in the present systematic review. 37,657 (54.89%) participants were randomly assigned to receive the different interventions of SGLT-2 inhibitor, whereas 30,959 (45.11%) received a placebo. Overall, 618 events were reported in the treatment group, whereas 396 events were reported in the placebo group. CONCLUSION: In conclusion, patients treated with SGLT-2 inhibitors did not have any significant difference in amputation occurrences compared to placebo across various studies. However, canagliflozin usage has led to higher amputation events in certain trials.
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Amputação Cirúrgica , Diabetes Mellitus Tipo 2 , Ensaios Clínicos Controlados Aleatórios como Assunto , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Amputação Cirúrgica/estatística & dados numéricos , Canagliflozina/uso terapêutico , Canagliflozina/efeitos adversos , Hipoglicemiantes/uso terapêutico , Hipoglicemiantes/efeitos adversosRESUMO
Key Clinical Message: Accurately identifying the ruptured aneurysm in patients with subarachnoid hemorrhage and multiple aneurysms is critical to prevent rebleeding and optimize outcomes. Vessel wall MRI with contrast can aid in pinpointing the culprit aneurysm, informing a tailored surgical or endovascular management strategy for these complex cases. In patients with subarachnoid hemorrhage (SAH) and multiple intracranial aneurysms, MRI with contrast and DSA are crucial for identifying the ruptured aneurysm, guiding a shift from endovascular to microsurgical clipping. Successful single-session treatment and absence of postsurgical deficits highlight the effectiveness of a multidisciplinary approach. Further research on optimal strategies is needed. Abstract: Multiple intracranial aneurysms make up approximately 20% of cases of aneurysmal SAH. In patients with aneurysmal SAH and multiple intracranial aneurysms, definite treatment of the ruptured aneurysm causing SAH is of the highest priority. However, identifying the bleeding source can be challenging, and it may not be recognizable by the hemorrhage pattern. Misdiagnosis and mistreatment of a ruptured aneurysm in a patient with multiple aneurysms can lead to bleeding recurrence and an undesirable outcome. We report a 65-year-old woman who presented with severe sudden onset headache. Neuroimaging studies revealed diffuse SAH and concurrent PICA and ACom aneurysm with triplicate A2. However, the ruptured aneurysm responsible for the patient's symptoms was not obvious based on routine neuroimaging studies. Magnetic resonance imaging with contrast was performed, revealing circumferential enhancement of the PICA aneurysm. In this report, we demonstrate the real-world effect of vessel wall MRI with contrast on decision-making regarding identifying the ruptured aneurysm and surgical planning in cases of multiple aneurysms. Furthermore, we show that MRI and aneurysm wall enhancement could be a promising option in detecting ruptured aneurysms in cases of multiple aneurysms.
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Background Plastic surgery has developed to benefit in a variety of challenging areas formerly handled by other disciplines. Medical students do not have a clear picture of plastic surgery as a career due to lacking scope, clinical practice, and understanding of plastic surgery as a clinical area of expertise, including general practitioners, nursing staff, medical trainees, and the general public, and misconceptions about the extent of reconstructive and plastic surgery. Methods A cross-sectional observational study was conducted on Kuwait University Medical students (2nd-7th Years) over a period of 1 month. A questionnaire and a consent form were provided to eligible students. The inclusion criteria were Kuwait University Medical students from 2nd to 7th Years with signed consent form. The response was collected via email sent in coordination with the Vice Dean of Student Affairs in the Faculty of Medicine. Using statistical package for the social sciences, responses were statistically analyzed. Pearson's chi-square test was used to calculate p -values, where p < 0.05 was considered statistically significant. Results A total of 244 eligible medical students, 121 males and 123 females, were included in the study, with a mean age of 21 (±2) years. Similarly, 126 (51.6%) were preclinical students (2nd-4th-year students), while 118 (48.4%) were clinical students (5th-7th-year students). About 79.8% of medical students believed that plastic surgery plays an essential role in trauma management, whereas 9.2% did not consider plastic surgery significant for trauma management. This study found that only 15.5% of medical students were interested in enrolling in plastic surgery residency after graduation, while 47.1% of students did not consider plastic surgery residency after graduation. However, 37.4% were uncertain. The two most driving factors in deciding on plastic surgery residency were expected income (61.8%) and lifestyle (14.3%). Conclusion Improving medical students' education quality can enhance their perception and awareness of plastic surgery. Students should be taught the broader scope of plastic surgery. The inclusion of formal training during undergraduation is the essence of time and should be added to or improved during plastic surgery rotations with more emphasis on reconstructive and hand/peripheral nerve surgery. Student-led interest groups can be a useful tool for educating students about their specialty.
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Interleukin-6 (IL-6), a pro-inflammatory cytokine, plays a crucial role in host immune defense and acute stress responses. Moreover, it modulates various cellular processes, including proliferation, apoptosis, angiogenesis, and differentiation. These effects are facilitated by various signaling pathways, particularly the signal transducer and activator of transcription 3 (STAT3) and Janus kinase 2 (JAK2). However, excessive IL-6 production and dysregulated signaling are associated with various cancers, promoting tumorigenesis by influencing all cancer hallmarks, such as apoptosis, survival, proliferation, angiogenesis, invasiveness, metastasis, and notably, metabolism. Emerging evidence indicates that selective inhibition of the IL-6 signaling pathway yields therapeutic benefits across diverse malignancies, such as multiple myeloma, prostate, colorectal, renal, ovarian, and lung cancers. Targeting key components of IL-6 signaling, such as IL-6Rs, gp130, STAT3, and JAK via monoclonal antibodies (mAbs) or small molecules, is a heavily researched approach in preclinical cancer studies. The purpose of this study is to offer an overview of the role of IL-6 and its signaling pathway in various cancer types. Furthermore, we discussed current preclinical and clinical studies focusing on targeting IL-6 signaling as a therapeutic strategy for various types of cancer.
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Interleucina-6 , Neoplasias , Transdução de Sinais , Humanos , Interleucina-6/metabolismo , Interleucina-6/antagonistas & inibidores , Neoplasias/metabolismo , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias/tratamento farmacológico , Animais , Progressão da Doença , Fator de Transcrição STAT3/metabolismo , Antineoplásicos/uso terapêuticoRESUMO
We report on optical detection of a single photostable Ce(3+) ion in an yttrium aluminium garnet (YAG) crystal and on its magneto-optical properties at room temperature. The spin quantum state of the emitting level of a single cerium ion in YAG can be initialized by a circularly polarized laser pulse. Coherent precession of the electron spin is read out by observing temporal behavior of circularly polarized fluorescence of the ion. This implies direct mapping of the spin quantum state of Ce(3+) ion onto the polarization state of the emitted photon and represents the quantum interface between a single spin and a single photon.
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A simple, rapid, and efficient dispersive liquid-liquid microextraction method, followed by UV-Vis spectrophotometry was developed for the preconcentration and determination of Pd ions in water samples. Pd ions react with α-furildioxime (chelating agent) to form a hydrophobic complex. Various parameters were altered to study and optimize their effects on the extraction efficiency, such as pH, ligand concentration, the type and volume of extraction and dispersive solvents, extraction time, and salt concentration. Under optimized conditions, the method exhibited an enrichment factor (C org/C aq) of 25 and recovery more than 98 % within a very short extraction time. The linearity of the method ranged from 10 to 200 µg L(-1). The limit of detection was 1.1 µg L(-1). The relative standard deviation for the concentration of 100 µg L(-1) of Pd was 2.3 % (n = 10). Finally, the developed method was successfully applied to the extraction and determination of Pd in tap, river, mineral, and sea water samples.
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Microextração em Fase Líquida/métodos , Paládio/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/químicaRESUMO
Arteriovenous fistula and spinal aneurysms like other vascular malformations can mimic radiculopathy and low back pain. Precise imaging work combined with a hybrid endovascular-microsurgical approach is the key element for the best clinical outcome.
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A new method of dispersive liquid-liquid microextraction (DLLME) combined with UV-Vis spectrophotometry was proposed for the determination of trace nickel using 2,2'-Furildioxime as chelating and spectrophotometric reagent. In the proposed approach chloroform and ethanol were used as extraction and dispersive solvents, respectively. Some factors influencing the extraction efficiency of nickel and its subsequent determination were studied and optimized, such as the extraction and dispersive solvent type and volume, pH of the sample solution, extraction time and ionic strength. Under the optimal conditions, the calibration curve was linear within the range of 5-180 µg L-1 of nickel with R2 = 0.9960. Limit of detection (3Sb/m) was 0.6 µg L-1 in the original solution and the relative standard deviation for ten replicate determination of 100 µg L-1 nickel was 2.9%. The proposed method has been applied for the determination of nickel in various water samples with satisfactory results.