Control of stress in silicon nitride thin films

Silicon nitride thin films of varying composition and thickness were deposited on silicon substrates by reactive rf diode sputtering of a silicon target using an argon/nitrogen gas mixture. Film stoichiometry could be controlled by varying the partial pressure of nitrogen, the total sputtering gas pressure and the target rf power. Films with refractive index of 2.01, the value for stoichiometric silicon nitride, could be obtained. Film stress was measured by wafer curvature; refractive index and thickness of deposited films were obtained by ellipsometry and interferometry measurements. The etch rate in buffered HF for films with refractive index 2.05 was 29A/min; as measured by JR spectroscopy these films had relatively low oxygen and hydrogen content. On increasing the film thickness from 300 A to 1900 A, the stress decreased from 4.45 x 109/m2 to 0.56 x 109N/m2 for a film with a refractive index of 2.05. It was observed that films with silicon in excess of the stoichiometric value and films with greater thickness exhibited reduced stress. Films with higher refractive index were obtained on reducing the nitrogen partial pressure and increasing the applied rf power. Since low temperature deposition is critical for reducing the stress developed in thin films, the substrate temperature during sputter deposition was maintained at 140°C(+/-10°C). The stress content of the unannealed NJIT films was observed to be higher by about a factor of 10 than the lowest stress value (2 x 108N/m2) obtained by plasma deposition followed by a 400°C postanneal for a 1000 A thick film. The lowest stress value obtained during this research was 0.98 x 109 N/m22, with 2.24 being the refractive index for this silicon rich film with a thickness of 700 A. The value for a 730 A thick film with index of 1.702 was 2.036 x 109 N/m2

ClimateNLP: Analyzing Public Sentiment Towards Climate Change Using Natural Language Processing

Climate change's impact on human health poses unprecedented and diverse challenges. Unless proactive measures based on solid evidence are implemented, these threats will likely escalate and continue to endanger human well-being. The escalating advancements in information and communication technologies have facilitated the widespread availability and utilization of social media platforms. Individuals utilize platforms such as Twitter and Facebook to express their opinions, thoughts, and critiques on diverse subjects, encompassing the pressing issue of climate change. The proliferation of climate change-related content on social media necessitates comprehensive analysis to glean meaningful insights. This paper employs natural language processing (NLP) techniques to analyze climate change discourse and quantify the sentiment of climate change-related tweets. We use ClimateBERT, a pretrained model fine-tuned specifically for the climate change domain. The objective is to discern the sentiment individuals express and uncover patterns in public opinion concerning climate change. Analyzing tweet sentiments allows a deeper comprehension of public perceptions, concerns, and emotions about this critical global challenge. The findings from this experiment unearth valuable insights into public sentiment and the entities associated with climate change discourse. Policymakers, researchers, and organizations can leverage such analyses to understand public perceptions, identify influential actors, and devise informed strategies to address climate change challenges

Digito-palmar dermatoglyphics in vitiligo – A case control study

AbstractBackgroundDermatoglyphics is a scientific study of epidermal ridges and their configuration on the volar skin. It is not established whether there is definite dermatoglyphic pattern which exists with vitiligo.ObjectivesTo study the finger and palmar dermatoglyphic patterns in vitiligo patients.MethodsThe study included a total 112 cases of vitiligo and 104 controls. Handprints of palmar surface and rolled fingerprints of 10 digits were subjected to detailed digito-palmar dermatoglyphic analysis.ResultsMale patients had increased percentage of total loops, total ulnar loops and finger ridge counts and increased true palmar patterns (TPP) in right hypothenar, right thenar and both interdigital area (ID)2. Decreased percentage of total radial loops, total whorls, total arches, TPP in right ID3, right ID4 and absolute finger ridge count was noted in male patients. Female cases showed an increased number of arches, true palmar pattern in right hypo- thenar, right ID1 and a-b ridge count along with decreased number of total loops, total ulnar loops, total radial loops, whorls, total finger ridge count, absolute finger ridge count, TPP in right ID2 and left ID3. In both the sexes, atd angle was found to be increased

Scrotal Dermatitis - Can we Consider it as a Separate Entity?

Scrotal dermatitis is a very common condition that has been easily overlooked by most dermatologists and treating physicians. The condition is easily mistaken for the common skin disorders affecting the area, like fungal infections. Scrotal dermatitis is not considered a separate disease entity and is usually considered a condition similar to the contact dermatitis occurring elsewhere. This article attempts to classify the condition as a separate disease entity and explains the various etiological factors and the pathogenesis of the condition. The various stages of the condition are also explained in detail. Newer treatment modalities like the use of narrow band UVB for the management of scrotal dermatitis is also highlighted in this article

Tissue-specific histochemical localization of iron and ferritin gene expression in transgenicindica rice Pusa Basmati (Oryza sativa L.)

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Recent Advances in Plasmonic Photocatalysis Based on TiO2 and Noble Metal Nanoparticles for Energy Conversion, Environmental Remediation, and Organic Synthesis

Plasmonic photocatalysis has emerged as a prominent and growing field. It enables the efficient use of sunlight as an abundant and renewable energy source to drive a myriad of chemical reactions. For instance, plasmonic photocatalysis in materials comprising TiO2 and plasmonic nanoparticles (NPs) enables effective charge carrier separation and the tuning of optical response to longer wavelength regions (visible and near infrared). In fact, TiO2-based materials and plasmonic effects are at the forefront of heterogeneous photocatalysis, having applications in energy conversion, production of liquid fuels, wastewater treatment, nitrogen fixation, and organic synthesis. This review aims to comprehensively summarize the fundamentals and to provide the guidelines for future work in the field of TiO2-based plasmonic photocatalysis comprising the above-mentioned applications. The concepts and state-of-the-art description of important parameters including the formation of Schottky junctions, hot electron generation and transfer, near field electromagnetic enhancement, plasmon resonance energy transfer, scattering, and photothermal heating effects have been covered in this review. Synthetic approaches and the effect of various physicochemical parameters in plasmon-mediated TiO2-based materials on performances are discussed. It is envisioned that this review may inspire and provide insights into the rational development of the next generation of TiO2-based plasmonic photocatalysts with target performances and enhanced selectivities.Peer reviewe

Dentin degradonomics ? The potential role of salivary MMP-8 in dentin caries

Dentin caries involves dissolution of minerals which eventually leads to degradation of organic matrix. This degradation which was thought to be by bacterial proteases is now considered to be orchestrated by endogenous collagenases such as Matrix Metalloproteinases (MMPs). This paper aims to estimate the salivary levels of MMP-8 in dental caries and also to asses the various risk factors that contribute to the formation of dental caries. A random sample of 75 adults aged 18-35 were included and categorized based on the number of caries lesions (MCL). Standard clinical examinations were performed, and stimulated saliva was collected and analyzed for concentrations of MMP-8 using enzyme-linked immunosorbent assay. Caries risk factors were assessed using a chair-side kit. Correlation of MMP-8 in varying MCL using Spearman?s correlation was done. Multiple linear regression analysis was done to asses the relationship between various caries risk factors with MMP-8 and MCL as dependent variable. The study results showed a statistically significant higher concentration of MMP-8 in carious group (MCL 1-2) and MCL ?3 compared to non-carious group. On correlating, the levels of MMP-8 were seen to be higher in MCL ?3 than in MCL = 0 and MCL 1-2. The mean MMP-8 of controls, MCL 1-2, and MCL ?3 were 131.34ng/ml, 230.14ng/ml, and 391.91ng/ml respectively. Multiple linear regression analysis with MMP-8 as the dependent variable revealed caries, buffer capacity and S. mutans count as significant variables. Using MCL as the dependent variable the only significant variable was MMP-8 levels. The study suggests that subjects with caries have elevated MMP-8 levels compared with subjects with no carious lesions. There is also a positive correlation between the number of carious lesions and MMP-8 levels suggesting that MMP-8 plays an important role in the degradation of dentin and causes progression of caries

The Relationship of Facet Joint Orientation and Tropism with Lumbar Disc Herniation and Degenerative Spondylolisthesis in the Lower Lumbar Spine

Study Design Retrospective study. Purpose This study aimed to clarify the relationship of both facet tropism (FT) and the sagittally aligned facet (SAF) joint with lumbar disc herniation (LDH) and degenerative spondylolisthesis (DS). Overview of Literature Despite several studies conducted, there is no consensus on the association of the SAF joint and FT with DH and DS. Methods Between June 2015 and December 2017, magnetic resonance imaging scans of 250 consecutive patients who underwent surgery for LDH and DS were analyzed. The facet angles at all the lower lumbar levels were calculated, and SAF and FT were noted. The relationship between the side of disc herniation and that of the SAF joint were also determined. Statistical analysis was performed, and the relation of SAF and FT to LDH and DS was noted. Results We observed a positive relationship between SAF and LDH at L4–5 and L5–S1 with a p-value of 0.02 (<0.05). FT demonstrated a positive association with LDH at L4–5 (p=0.047) but not at L3–4 or L5–S1. SAF demonstrated a positive relationship with DS at L3–4 (p<0.001) but not at L3–4 or L5–S1. FT demonstrated a significant relation with DS at L4–5 (p<0.001), whereas no positive association was observed at L3–4 and L5–S1. Conclusions The L4–5 level demonstrated a significant association with SAF and FT in LDH and DS. Moreover, SAF at L5–S1 demonstrated a positive association with LDH. These findings provide useful information for future longitudinal studies to elucidate the possible causes for such phenomena