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2D van der Waals heterostructure paves a path towards next generation semiconductor junctions for nanoelectronics devices in the post silicon era. Probing the band alignment at a real condition of such 2D contacts and experimental determination of its junction parameters is necessary to comprehend the charge diffusion and transport through such 2D nano-junctions. Here, we demonstrate the formation of the p-n junction at the MoS2/Black phosphorene (BP) interface and conduct a nanoscale investigation to experimentally measure the band alignment at real conditions by means of measuring the spatial distribution of built-in potential, built-in electric field, and depletion width using the Kelvin probe force microscopy (KPFM) technique. We show that optimization of lift scan height is critical for defining the depletion region of MoS2/BP with nanoscale precision using the KPFM technique. The variations in the built-in potential and built-in electric field with varying thicknesses of MoS2are revealed and calibrated.
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Obsessive Compulsive Disorder (OCD) is a common mental disorder that often causes great sufferance, with substantial impairment in social functioning and quality of life and affects family and significant relationships. Notwithstanding its severity, OCD is often not adequately diagnosed, or it is diagnosed with delay, leading often to a long latency between onset of the OCD symptoms and the start of adequate treatments. Several factors contribute to the complexity of OCD's clinical picture: early age of onset, chronic course, heterogeneity of symptoms, high rate of comorbidity with other psychiatric disorders, slow or partial response to therapy. Therefore, it is of primary importance for clinicians involved in diagnosing OCD, to assess all aspects of the disorder. This narrative review focuses on the global assessment of OCD, highlighting crucial areas to explore, pointing out the clinical features which are relevant for the treatment of the disorder, and giving an overview of the psychometric tools that can be useful during the screening procedure.
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Transtorno Obsessivo-Compulsivo , Qualidade de Vida , Comorbidade , Humanos , Transtorno Obsessivo-Compulsivo/diagnóstico , Transtorno Obsessivo-Compulsivo/epidemiologia , Transtorno Obsessivo-Compulsivo/psicologia , Psicometria , Ajustamento SocialRESUMO
Samples from a high-dimensional first-order auto-regressive process generated by an independently and identically distributed random innovation sequence are observed by a sender which can communicate only finitely many bits per unit time to a receiver. The receiver seeks to form an estimate of the process value at every time instant in real-time. We consider a time-slotted communication model in a slow-sampling regime where multiple communication slots occur between two sampling instants. We propose a successive update scheme which uses communication between sampling instants to refine estimates of the latest sample and study the following question: Is it better to collect communication of multiple slots to send better refined estimates, making the receiver wait more for every refinement, or to be fast but loose and send new information in every communication opportunity? We show that the fast but loose successive update scheme with ideal spherical codes is universally optimal asymptotically for a large dimension. However, most practical quantization codes for fixed dimensions do not meet the ideal performance required for this optimality, and they typically will have a bias in the form of a fixed additive error. Interestingly, our analysis shows that the fast but loose scheme is not an optimal choice in the presence of such errors, and a judiciously chosen frequency of updates outperforms it.
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White mould or stem rot, caused by Sclerotinia sclerotiorum (Lib.) de Bary, is a devastating fungal disease found in major potato cultivation areas worldwide. The aim of this study was to characterize genetic diversity in the S. sclerotiorum population from the main potato producing regions of India by means of morphological (mycelial growth, colony colour, number and distribution pattern of sclerotia) and molecular characteristics, as well as to evaluate the virulence of S. sclerotiorum isolates in potato for the first time. Among the S. sclerotiorum population analyzed, high phenotypic and genotypic diversity were observed. Using all the morphological characteristics, a dendrogram was constructed based on Gower's similarity coefficient that distributed all the isolates into three clusters at the 0.62 similarity coefficient. Carpogenic germination of apothecia revealed that larger sclerotia produced a greater number of apothecia while smaller sclerotia produced fewer apothecia. Pathogenicity test results revealed that out of 25 isolates, seven were highly aggressive, 14 were moderate and four had low aggressiveness, whilst isolates from Punjab were more pathogenic than those of Uttar Pradesh. Phylogenetic analysis of universal rice primer polymorphism showed high genetic variability within the isolates that grouped all the isolates in three evolutionary lineages in the resulting dendrogram and showed partial relationship with geographical locations of the isolates. Further, the findings suggest the occurrence of higher heterogeneity and genetic diversity among the S. sclerotiorum isolates that indicates the existence of both clonal and sexual reproduction in the pathogen population of potato producing areas in India.
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Ascomicetos/classificação , Ascomicetos/patogenicidade , Variação Genética , Doenças das Plantas/microbiologia , Solanum tuberosum/microbiologia , Ascomicetos/genética , Evolução Molecular , Índia , Fenótipo , Filogenia , Filogeografia , Análise de Sequência de DNA , VirulênciaRESUMO
PURPOSE: This study investigates the influence of blood perfusion variability within a tumour and the surrounding healthy tissue during nanoparticle-assisted thermal therapy. It seeks to define ideal therapeutic parameters for a wide range of perfusion rates to attain the desired thermal damage. MATERIAL AND METHODS: Pennes' bioheat model and the Arrhenius model are used to evaluate the thermal damage for a two-dimensional tumour surrounded by healthy tissue. A wide range of tumour perfusion rates were modelled, ranging from moderate to high perfusion in both a homogenously and a heterogeneously perfused tumour. RESULTS: For low perfusion rates, a temporal variation in blood perfusion does not critically influence the thermal damage. For moderately and highly perfused tumours, temporal variation in blood perfusion extends the thermal damage zone by 25-52% compared to a constant perfusion rate. For the tumour size and perfusion conditions under consideration, the ideal therapeutic parameters were found to be irradiation intensity of 1 W/cm(2), and irradiation duration of 105-150 s, for a nanoparticle volume fraction of 0.001%. CONCLUSIONS: It is concluded for low perfusion rates that due to shorter therapeutic duration, nanoparticle-assisted thermal therapy is relatively insensitive to changes in the perfusion rate during the therapy. For moderately and highly perfused tumours, a constant perfusion under-predicts the real thermal damage zone. This study concludes that for moderately and highly perfused tumours the spatial as well as temporal blood perfusion dynamics should be carefully accounted for to get a realistic estimate of thermal damage zone.
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Hipertermia Induzida , Modelos Biológicos , Nanopartículas/uso terapêutico , Neoplasias Cutâneas/irrigação sanguínea , Neoplasias Cutâneas/terapia , Fluxo Sanguíneo RegionalRESUMO
Sinus venosus atrial septal defect (SVASD) is located high in the atrial septum where the right superior vena cava (RSVC) enters the right atrium, and is commonly associated with partial anomalous pulmonary venous return of right upper pulmonary vein (RUPV) into RSVC. Transcatheter closure of such defects has not been described in the literature. We have developed an innovative technique to close this defect by transcatheter means. We present here a 35-year old patient with SVASD and anomalous drainage of RUPV in RSVC in whom we closed the defect along with rerouting of RUPV to left atrium (LA) using a 12 mm × 61 mm adventa V12 covered stent in the RSVC with good outcome.
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Anormalidades Múltiplas , Cateterismo Cardíaco/métodos , Procedimentos Cirúrgicos Cardíacos/métodos , Comunicação Interatrial/cirurgia , Veias Pulmonares/anormalidades , Malformações Vasculares/diagnóstico , Veia Cava Superior/anormalidades , Adulto , Ecocardiografia Transesofagiana , Feminino , Comunicação Interatrial/diagnóstico , Humanos , Tomografia Computadorizada por Raios XRESUMO
This study investigates the effect of the distribution of nanoparticles delivered to a skin tumour for the thermal ablation conditions attained during thermal therapy. Ultimate aim is to define a distribution of nanoparticles as well as a combination of other therapeutic parameters to attain thermal ablation temperatures (50-60 °C) within whole of the tumour region. Three different cases of nanoparticle distributions are analysed under controlled conditions for all other parameters viz. irradiation intensity and duration, and volume fraction of nanoparticles. Results show that distribution of nanoparticles into only the periphery of tumour resulted in desired thermal ablation temperature in whole of tumour. For the tumour size considered in this study, an irradiation intensity of 1.25 W/cm(2) for duration of 300 s and a nanoparticle volume fraction of 0.001% was optimal to attain a temperature of ≥53 °C within the whole tumour region. It is concluded that distribution of nanoparticles in peripheral region of tumour, along with a controlled combination of other parameters, seems favourable and provides a promising pathway for thermal ablation of a tumour subjected to nanoparticle assisted thermal therapy.
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Hipertermia Induzida , Modelos Biológicos , Nanopartículas/administração & dosagem , Neoplasias/metabolismo , Vias de Administração de Medicamentos , Nanopartículas/uso terapêutico , Neoplasias/terapia , Reprodutibilidade dos Testes , Distribuição TecidualRESUMO
INTRODUCTION: The pursuit of aesthetic attractiveness and increased awareness have contributed significantly to the growth of the cosmetic industry. However, it is crucial to recognize that even the minimal use of cosmetics may have harmful consequences for both the overall well-being and the broader community, an issue that has yet to be adequately recognized or addressed. OBJECTIVE: This study is aimed at providing insights into the usage pattern of consumer behavior regarding skin care products and to assess the prevalence and determinants of cosmetic-related adverse events among the general populace. MATERIALS AND METHODS: A community-based cross-sectional study was carried out for four months in a satellite city of the National Capital Region (NCR) of India. The data from 435 respondents was collected using a self-administered questionnaire and analyzed using frequencies and percentages. RESULTS: Among 435 participants, 32.9% experienced one or more adverse effects owing to the use of skincare products; the prevalence was higher in females (36.3%). Hair loss, allergies, and dry skin were the most frequently reported adverse effects. The majority of the adverse reactions were reported with soap (21%), followed by shampoo (17%). The gender-wise difference between adverse effects of skin care products was found to be statistically significant. CONCLUSION: To improve the system's efficiency, a comprehensive review of the current regulatory protocols for cosmetics is crucial. Additionally, it is essential to widely disseminate information on Cosmetovigilance and promote the reporting of any adverse effects of cosmetics within the community; this is the demand of the present time.
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Cosméticos , Feminino , Humanos , Cosméticos/efeitos adversos , Estudos Transversais , Índia/epidemiologia , Prevalência , Inquéritos e Questionários , MasculinoRESUMO
Frontal circuits play a critical role in motor, cognitive and affective processing, and their dysfunction may result in a variety of brain disorders. However, exactly which frontal domains mediate which (dys)functions remains largely elusive. We studied 534 deep brain stimulation electrodes implanted to treat four different brain disorders. By analyzing which connections were modulated for optimal therapeutic response across these disorders, we segregated the frontal cortex into circuits that had become dysfunctional in each of them. Dysfunctional circuits were topographically arranged from occipital to frontal, ranging from interconnections with sensorimotor cortices in dystonia, the primary motor cortex in Tourette's syndrome, the supplementary motor area in Parkinson's disease, to ventromedial prefrontal and anterior cingulate cortices in obsessive-compulsive disorder. Our findings highlight the integration of deep brain stimulation with brain connectomics as a powerful tool to explore couplings between brain structure and functional impairments in the human brain.
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Estimulação Encefálica Profunda , Córtex Motor , Doença de Parkinson , Humanos , Encéfalo , Córtex Motor/fisiologia , Doença de Parkinson/terapia , Mapeamento EncefálicoRESUMO
BACKGROUND: Deep brain stimulation (DBS) is a promising treatment option for treatment-refractory obsessive-compulsive disorder (OCD). Several stimulation targets have been used, mostly in and around the anterior limb of the internal capsule and ventral striatum. However, the precise target within this region remains a matter of debate. METHODS: Here, we retrospectively studied a multicenter cohort of 82 patients with OCD who underwent DBS of the ventral capsule/ventral striatum and mapped optimal stimulation sites in this region. RESULTS: DBS sweet-spot mapping performed on a discovery set of 58 patients revealed 2 optimal stimulation sites associated with improvements on the Yale-Brown Obsessive Compulsive Scale, one in the anterior limb of the internal capsule that overlapped with a previously identified OCD-DBS response tract and one in the region of the inferior thalamic peduncle and bed nucleus of the stria terminalis. Critically, the nucleus accumbens proper and anterior commissure were associated with beneficial but suboptimal clinical improvements. Moreover, overlap with the resulting sweet- and sour-spots significantly estimated variance in outcomes in an independent cohort of 22 patients from 2 additional DBS centers. Finally, beyond obsessive-compulsive symptoms, stimulation of the anterior site was associated with optimal outcomes for both depression and anxiety, while the posterior site was only associated with improvements in depression. CONCLUSIONS: Our results suggest how to refine targeting of DBS in OCD and may be helpful in guiding DBS programming in existing patients.
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Estimulação Encefálica Profunda , Cápsula Interna , Transtorno Obsessivo-Compulsivo , Humanos , Transtorno Obsessivo-Compulsivo/terapia , Estimulação Encefálica Profunda/métodos , Masculino , Feminino , Adulto , Estudos Retrospectivos , Pessoa de Meia-Idade , Cápsula Interna/diagnóstico por imagem , Estriado Ventral/diagnóstico por imagem , Estriado Ventral/fisiopatologia , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE: This study seeks to define parameters for gold nanorod assisted thermal therapy, to achieve the thermal ablation temperature (50-60°C) in the tumour region and spare healthy tissue surrounding the tumour. Also, a criterion for size selection of gold nanorods is described based on the role of optical coefficients. THEORY AND METHODS: In this study a tissue domain (comprising a 3 mm tumour and 7 mm of surrounding healthy tissue) embedded with gold nanorods is irradiated with electromagnetic radiation within the therapeutic wavelength band. Optical interaction is captured using light scattering theory (Mie-electrostatic approach). The resulting temperature field is evaluated using Penne's bioheat model. The effect of key parameters, namely irradiation intensity, irradiation duration and volume fraction, on tissue temperature is also modelled numerically. RESULTS: With increasing nanorod diameter - from 5 nm to 15 nm - the scattering coefficient increases â¼76 times as compared to a 1.7-fold increase in absorption coefficient. Scattering is considerably minimised by having smaller gold nanorods of 5 nm diameter. For this study, gold nanorods of 5 nm diameter and volume fraction 0.001%, irradiated with 50 W/m(2)-nm for 250 s ablated the tumour as well as spare healthy tissue 2 mm beyond the tumour region. CONCLUSION: Overall it may be concluded that tumour ablation as well as surrounding healthy tissue-sparing (within millimetres immediately adjacent to the tumour) can be achieved through a combination of specified parameters, namely diameter and volume fraction of gold nanorods, irradiation intensity and duration.
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Técnicas de Ablação/métodos , Ouro/administração & dosagem , Modelos Teóricos , Nanotubos , Neoplasias/terapia , Radiação Eletromagnética , Temperatura Alta , HumanosRESUMO
Frontal circuits play a critical role in motor, cognitive, and affective processing - and their dysfunction may result in a variety of brain disorders. However, exactly which frontal domains mediate which (dys)function remains largely elusive. Here, we study 534 deep brain stimulation electrodes implanted to treat four different brain disorders. By analyzing which connections were modulated for optimal therapeutic response across these disorders, we segregate the frontal cortex into circuits that became dysfunctional in each of them. Dysfunctional circuits were topographically arranged from occipital to rostral, ranging from interconnections with sensorimotor cortices in dystonia, with the primary motor cortex in Tourette's syndrome, the supplementary motor area in Parkinson's disease, to ventromedial prefrontal and anterior cingulate cortices in obsessive-compulsive disorder. Our findings highlight the integration of deep brain stimulation with brain connectomics as a powerful tool to explore couplings between brain structure and functional impairment in the human brain.
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Solar spectrum and sensitivity of human eyes peak at green wavelength range of visible light, and the materials that can respond to a larger part of the visible spectrum are highly sought after. Two-dimensional graphene-like zinc oxide (gZnO) is a wide band gap semiconductor, but photogeneration of electron-hole pairs in it at visible wavelengths has not been achieved so far. Here, the sub-band gap excitation in 2D zinc oxide layers covered with gold nanoparticles is reported. The sub-band gap excitation and corresponding emission are correlated with oxygen interstitials introduced by AuNP deposition in the gZnO lattice. Attachment of AuNPs on gZnO also leads to increased electron availability at oxygen sites of the gZnO lattice, which translates into greater electron availability for sub-band gap excitation. The plasmonically enhanced trap level to conduction band transition constitutes sub-band gap excitation and manifests itself in local surface potential measurements carried out using a Kelvin probe force microscope.
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(Appeared originally in Biological Psychiatry 2019; 85:726-734) Reprinted under Creative Commons CC-BY license.
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The number of confirmed cases of COVID-19 is often used as a proxy for the actual number of ground truth COVID-19-infected cases in both public discourse and policy making. However, the number of confirmed cases depends on the testing policy, and it is important to understand how the number of positive cases obtained using different testing policies reveals the unknown ground truth. We develop an agent-based simulation framework in Python that can simulate various testing policies as well as interventions such as lockdown based on them. The interaction between the agents can take into account various communities and mobility patterns. A distinguishing feature of our framework is the presence of another 'flu'-like illness with symptoms similar to COVID-19, that allows us to model the noise in selecting the pool of patients to be tested. We instantiate our model for the city of Bengaluru in India, using census data to distribute agents geographically, and traffic flow mobility data to model long-distance interactions and mixing. We use the simulation framework to compare the performance of three testing policies: Random Symptomatic Testing (RST), Contact Tracing (CT), and a new Location-Based Testing policy (LBT). We observe that if a sufficient fraction of symptomatic patients come out for testing, then RST can capture the ground truth quite closely even with very few daily tests. However, CT consistently captures more positive cases. Interestingly, our new LBT, which is operationally less intensive than CT, gives performance that is comparable with CT. In another direction, we compare the efficacy of these three testing policies in enabling lockdown, and observe that CT flattens the ground truth curve maximally, followed closely by LBT, and significantly better than RST.
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Cianose/etiologia , Técnica de Fontan/efeitos adversos , Átrios do Coração/diagnóstico por imagem , Veias Hepáticas/diagnóstico por imagem , Fístula Vascular/complicações , Fístula Vascular/terapia , Cateterismo Cardíaco/métodos , Criança , Cianose/terapia , Humanos , Masculino , Radiografia , Fístula Vascular/diagnóstico , Fístula Vascular/etiologiaRESUMO
BACKGROUND: Deep brain stimulation (DBS) is an emerging treatment for severe obsessive-compulsive disorder (OCD). We compared the efficacy of ventral capsule/ventral striatal (VC/VS) and anteromedial subthalamic nucleus (amSTN) DBS in the same patients and tested for mechanistic differences on mood and cognitive flexibility and associated neural circuitry. The possible synergistic benefit of DBS at both sites and cognitive behavioral therapy was explored. METHODS: Six patients with treatment-refractory OCD (5 men; Yale-Brown Obsessive Compulsive Scale score >32) entered double-blind counterbalanced phases of 12-week amSTN or VC/VS DBS, followed by 12-week open phases when amSTN and VC/VS were stimulated together, in which optimal stimulation parameters were achieved and adjunctive inpatient cognitive behavioral therapy was delivered. OCD and mood were assessed with standardized scales and cognitive flexibility with the Cambridge Neuropsychological Test Automated Battery Intra-Extra Dimensional Set-Shift task. Diffusion-weighted and intraoperative magnetic resonance imaging scans were performed for tractography from optimally activated electrode contacts. RESULTS: DBS at each site significantly and equivalently reduced OCD symptoms with little additional gain following combined stimulation. amSTN but not VC/VS DBS significantly improved cognitive flexibility, whereas VC/VS DBS had a greater effect on mood. The VC/VS effective site was within the VC. VC DBS connected primarily to the medial orbitofrontal cortex, and amSTN DBS to the lateral orbitofrontal cortex, dorsal anterior cingulate cortex, and dorsolateral prefrontal cortex. No further improvement followed cognitive behavioral therapy, reflecting a floor effect of DBS on OCD. CONCLUSIONS: Both the VC/VS and amSTN are effective targets for severe treatment-refractory OCD. Differential improvements in mood and cognitive flexibility and their associated connectivity suggest that DBS at these sites modulates distinct brain networks.
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Estimulação Encefálica Profunda , Transtorno Obsessivo-Compulsivo/terapia , Núcleo Subtalâmico/fisiopatologia , Estriado Ventral/fisiopatologia , Adulto , Método Duplo-Cego , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Transtorno Obsessivo-Compulsivo/diagnóstico por imagem , Transtorno Obsessivo-Compulsivo/fisiopatologia , Núcleo Subtalâmico/diagnóstico por imagem , Resultado do Tratamento , Estriado Ventral/diagnóstico por imagemRESUMO
Among inorganic nanomaterials, layered double hydroxides (LDHs) and gold nanoparticles (Au NPs) have received great attention in nanobiomedicine due to their unique properties. In this work, we have designed a nanohybrid of an LDH with Au NPs (LDH-Au) in order to use it for photothermal therapy, and optical and fluorescence imaging of cancer cells. The structural characteristics of the nanohybrid are investigated using X-ray diffraction, infrared spectroscopy, electron microscopy and elemental analyses. The extinction spectra of the nanohybrid exhibits broad absorption ranging from the visible to near infrared (NIR) region (500-1000 nm). The photothermal activity of the nanohybrid is explored using NIR laser irradiation. The electric field enhancement in the nanohybrid due to the interaction of Au NPs on the LDH is speculated through finite-difference time-domain (FDTD) calculations. The LDH-Au nanohybrid is found to be biocompatible with normal murine fibroblast (L929), human breast cancer (MCF-7) and cervical cancer (HeLa) cell lines up to a concentration of 1 mg mL-1. The nanohybrid is explored for in vitro photothermal therapy of MCF-7 and HeLa cell lines. As a photothermal agent, the nanohybrid shows that 10 min exposure to an 808 nm laser (500 mW) is adequate to inhibit about 70% of cancer cells. Further, the nanohybrid is tagged with FITC to study both optical and fluorescence imaging with MCF-7 cell lines. The results demonstrate that the LDH-Au nanohybrid provides an innovative approach to photothermal therapy, and optical and fluorescence imaging of cancer cells.
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The synthesis of gold nanoparticles using citrate reduction process has been revisited. A simplified room temperature approach to standard Turkevich synthesis is employed to obtain fairly monodisperse gold nanoparticles. The role of initial pH alongside the concentration ratio of reactants is explored for the size control of Au nanoparticles. The particle size distribution has been investigated using UV-vis spectroscopy and transmission electron microscope (TEM). At optimal pH of 5, gold nanoparticles obtained are highly monodisperse and spherical in shape and have narrower size distribution (sharp surface plasmon at 520 nm). For other pH conditions, particles are non-uniform and polydisperse, showing a red-shift in plasmon peak due to aggregation and large particle size distribution. The room temperature approach results in highly stable "colloidal" suspension of gold nanoparticles. The stability test through absorption spectroscopy indicates no sign of aggregation for a month. The rate of reduction of auric ionic species by citrate ions is determined via UV absorbance studies. The size of nanoparticles under various conditions is thus predicted using a theoretical model that incorporates nucleation, growth, and aggregation processes. The faster rate of reduction yields better size distribution for optimized pH and reactant concentrations. The model involves solving population balance equation for continuously evolving particle size distribution by discretization techniques. The particle sizes estimated from the simulations (13 to 25 nm) are close to the experimental ones (10 to 32 nm) and corroborate the similarity of reaction processes at 300 and 373 K (classical Turkevich reaction). Thus, substitution of experimentally measured rate of disappearance of auric ionic species into theoretical model enables us to capture the unusual experimental observations.