RESUMO
NIR spectroscopy is a non-destructive characterization tool for the blend uniformity (BU) assessment. However, NIR spectra of powder blends often contain overlapping physical and chemical information of the samples. Deconvoluting the information related to chemical properties from that associated with the physical effects is one of the major objectives of this work. We achieve this aim in two ways. Firstly, we identified various sources of variability that might affect the BU results. Secondly, we leverage the machine learning-based sophisticated data analytics processes. To accomplish the aforementioned objectives, calibration samples of amlodipine as an active pharmaceutical ingredient (API) with the concentrations ranging between 67 and 133% w/w (dose ~ 3.6% w/w), in powder blends containing excipients, were prepared using a gravimetric approach and assessed using NIR spectroscopic analysis, followed by HPLC measurements. The bias in NIR results was investigated by employing data quality metrics (DQM) and bias-variance decomposition (BVD). To overcome the bias, the clustered regression (non-parametric and linear) was applied. We assessed the model's performance by employing the hold-out and k-fold internal cross-validation (CV). NIR-based blend homogeneity with low mean absolute error and an interval estimates of 0.674 (mean) ± 0.218 (standard deviation) w/w was established. Additionally, bootstrapping-based CV was leveraged as part of the NIR method lifecycle management that demonstrated the mean absolute error (MAE) of BU ± 3.5% w/w and BU ± 1.5% w/w for model generalizability and model transferability, respectively. A workflow integrating machine learning to NIR spectral analysis was established and implemented. Impact of various data learning approaches on NIR spectral data.
Assuntos
Excipientes , Espectroscopia de Luz Próxima ao Infravermelho , Anlodipino , Artefatos , Viés , Calibragem , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Excipientes/química , Aprendizado de Máquina , Pós/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Comprimidos , Tecnologia Farmacêutica/métodosRESUMO
Rare diseases (RDs) are those that affect a small fraction of the total population. In India, where resources are scarce, the healthcare infrastructure and policy framework are focused on mitigating diseases that affect a large number of people. As a result,many cases ofRDs remain unreported, undiagnosed, and untreated. To understandthe currentlevel of RD awareness among healthcare professionals (HCPs) and researchers, as they are key stakeholders in diagnosis, treatment, policy making, and drug development, we conducted a survey based on identification of an RD, time for diagnosis, treatment options, and relationship with family history and geographic location. The survey was divided into two parts, one for researchers and the other for healthcare professionals, each consisting of 22 questions. We observed that among all our respondents, 31% of researchers and 29% of HCPs did not know the time required for diagnosis of a rare disease they mentioned in the survey. They identified the importance of family history but failed to realize its association with geographic location. The results from the exploratory study can provide information for enabling larger studies to develop recommendations and policies that can improve awareness about RDs in healthcare communities.
Assuntos
Atenção à Saúde , Doenças Raras , Humanos , Doenças Raras/diagnóstico , Doenças Raras/epidemiologia , Doenças Raras/genética , Inquéritos e Questionários , Índia/epidemiologiaRESUMO
The enhanced electron field emission (EFE) properties of high aspect ratio, vertically aligned SiNW-ZnO core-shell arrays are presented. These core-shell arrays are prepared by a thin, controlled, highly crystalline and conformal coating of zinc oxide as shell using the plasma assisted-atomic layer deposition (PA-ALD) route on vertically aligned silicon nanowire arrays core. The core-shell nanostuctures are confirmed by HRTEM imaging along with the individual elemental mapping demonstrating the conformal deposition of 10 nm ZnO on the SiNWs. EFE properties of va-SiNW-ZnO core-shell arrays showed a high emission current density of 51 µA cm(-2) and a low turn on field of 7.6 V µm(-1) (defined at a current density of 1 µA cm(-2)) compared to the 3.2 µA cm(-2) emission current density and 9.1 V µm(-1) turn on field for SiNWs. The field enhancement factor (ß) of 4227 for the devices demonstrates that these core-shell nanowire arrays are excellent field-emitters. Such an enhancement in the field emission originates from the details of the band structure of this peculiar material combination resulting in good electron transport from SiNW to ZnO as evident from the band diagram of the core-shell material. This is further supported by the conducting AFM studies where lowering in threshold voltage by 1 eV confirms the role of ZnO coating in the enhancement of the emission characteristics.
Assuntos
Nanofios/química , Silício/química , Óxido de Zinco/química , Condutividade Elétrica , Elétrons , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
A solution processed method for fabricating transition metal sulfides on fluorine doped tin oxide (FTO) as efficient counter electrodes in iodine/iodide based solar cells has been demonstrated. Conversion efficiencies of 7.01% and 6.50% were obtained for nickel and cobalt sulfides, respectively, comparable to the conventional thermally platinised FTO electrodes (7.32%). A comparable charge transfer resistance of Ni(3)S(2) and Co(8.4)S(8) to conventional Pt was found to be a key factor for such high efficiencies. Cyclic voltammetry, Kelvin probe microscopy, Electrochemical Impedance Spectroscopy, and Tafel polarization were performed to study the underlying reasons behind such efficient counter electrode performance.
RESUMO
The global burden of cervical cancer from low and middle-income groups is increasing at alarming rates with more than half a million women being diagnosed every year. Although the disease is largely preventable when screened and diagnosed in earlier stages, the development of resistance and relapse had resulted in a poor prognosis. Therefore, a comprehensive approach needs to be put forward to understand and develop new preventive and therapeutic strategies to effectively combat cancer. Recently, much attention has been diverted to plant-derivatives for the treatment as they exhibit potent anti-cancer properties and side-effects caused by chemotherapeutic agents can also be prevented. Oleanolic acid and Esculetin are natural compounds known for their anti-cancer properties. Hence, the present study investigates the effect and mechanism of these compounds on cervical carcinoma, using HeLa cells. Posttreatment, it was observed that these compounds inhibited proliferation by both arresting the cells in the sub G1 phase and inducing senescence. Also, a marked reduction in the migration and cell survival was observed, as evidenced by results obtained from wound healing assay and Annexin V-FITC/PI staining. Furthermore, studies on the expression pattern of genes involved in major signaling pathways demonstrated a profound effect of these compounds. Taken together, the results of our study suggest that both Oleanolic acid and esculetin serve as a plausible therapeutic agent.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Redes Reguladoras de Genes/efeitos dos fármacos , Ácido Oleanólico/farmacologia , Umbeliferonas/farmacologia , Neoplasias do Colo do Útero/genética , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Transdução de Sinais/efeitos dos fármacos , Neoplasias do Colo do Útero/tratamento farmacológicoRESUMO
Solution processed zinc tin oxide (ZTO) thin film transistors (TFTs) were fabricated by varying the Zn/Sn composition. The addition of Sn to the zinc oxide (ZnO) films resulted in improved electrical characteristics, with devices of Zn0.7Sn0.3O composition showing the highest mobility of 7.7 cm(2)/(V s). An improvement in subthreshold swings was also observed, indicative of a reduction of the interfacial trap densities. Mobility studies at low temperature have been carried out, which indicated that the activation energy was reduced with Sn incorporation. Kelvin probe force microscopy was performed on the films to evaluate work function and correlated to the metal-semiconductor barrier indicating Zn0.7Sn0.3O films had the smallest barrier for charge injection. Organic-inorganic hybrid complementary inverters with a maximum gain of 10 were fabricated by integrating ZTO TFTs with poly-3-hexylthiophene (P3HT) transistors.
RESUMO
We report a unipolar operation in reduced graphene oxide (RGO) field-effect transistors (FETs) via modification of the source/drain (S/D) electrode interfaces with self-assembled monolayers (SAMs) of 5-(4-hydroxyphenyl)-10,15,20-tri-(p-tolyl) zinc(II) porphyrin (Zn(II)TTPOH) molecules. The dipolar Zn(II)TTPOH molecules at the RGO/platinum (Pt) S/D interface results in an increase of the electron injection barrier and a reduction of the hole-injection barrier. Using dipole measurements from Kelvin probe force microscopy and highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) calculations from cyclic voltammetry, the electron and hole injection barriers were calculated to be 2.2 and 0.11 eV, respectively, indicating a higher barrier for electrons, compared to that of holes. A reduced gate modulation in the electron accumulation regime in RGO devices with SAM shows that unipolar RGO FETs can be attained using a low-cost, solution-processable fabrication technique.