Highly Monodisperse, Size Tunable Glucosamine Conjugated CdSe Quantum Dots for Enhanced Cellular Uptake and Bioimaging.

Semiconductor quantum dots (QDs) have been used in a variety of applications ranging from optoelectronics to biodiagnostic fields, primarily due to their size dependent fluorescent nature. CdSe nanocrystals (NCs) are generally synthesized via a hot injection method in an organic solvent. However, such NCs are insoluble in water and therefore preclude the direct usage toward biological systems. Thus, the preparation of more biocompatible water-soluble QDs with a high photoluminescent quantum yield (PLQY) is extremely important for imaging applications. Although previous literature has detailed on the synthesis of CdSe NCs in water, they suffer from poor size distribution and very low PLQY. The complex formation mechanism of CdSe NCs in an aqueous environment adversely affects the quality of NCs due to the presence of OH-, H+, and H2O moieties. Here in this article, we have presented the facile hydrothermal approach to obtain size tunable (2.9-5.1 nm), aqueous CdSe NCs with a narrow emission profile having ∼40 nm fwhm with 56% PLQY. Physicochemical properties of the synthesized water-soluble CdSe NCs were studied with the help of UV-vis, PL, XRD, FTIR, XPS, and HR-TEM analysis. Furthermore, the surface of the synthesized CdSe NCs was modified with d-glucosamine via EDC and NHS coupling to obtain a stable, biocompatible bioimaging probe. Furthermore, we demonstrated that their successful bioconjugation with glucosamine could facilitate effective internalization into the cellular matrix.

Potential impact of various surface ligands on the cellular uptake and biodistribution characteristics of red, green, and blue emitting Cu nanoclusters.

Surface functionalization has a prominent influence on tuning/manipulating the physicochemical properties of nanometer scaled materials. Ultrasmall sized nanoclusters with very few atoms have received enormous attention due to their bright fluorescence, biocompatibility, lower toxicity, good colloidal stability and strong photostability. These properties make them suitable for diagnostic applications. In this work, we intend to study the effect of surface functional ligands on their biodistribution both in vitro and in vivo organelle systems for bioimaging applications.

Factors Associated with Tuberculosis Mortality in Manjung District, Perak, Malaysia.

Background: Tuberculosis (TB) is a communicable disease which contributes to a major cause of ill health. Worldwide, it is one of the leading causes of death from a single infectious agent. Objectives: The study aimed to describe the epidemiology and factors associated with TB mortality in Manjung district, Perak, Malaysia. Methods: All confirmed TB cases from 2015 to 2020 registered in Manjung district under Sistem Maklumat Tibi (MyTB) were included. Factors associated with TB mortality were analysed by using simple and multiple logistic regression analysis. Results: A total of 742 TB cases were included in the analysis, from which 121 cases (16.3%) died before completing their treatment. The highest death was reported in 2020 (25.7%) and the lowest in 2019 (12.9%). From multiple logistic regression analysis, age 45 years old-64 years old (adjusted OR = 3.62; 95% CI: 1.38, 9.54), > 65 years old (adjusted OR = 8.67; 95% CI: 3.17, 23.74), non-Malaysian (adjusted OR = 5.18; 95% CI: 2.04, 13.14), cases notified by government hospitals (adjusted OR = 6.78; 95% CI: 3.04, 15.09), HIV-positive status (adjusted OR = 8.60; 95% CI: 3.58, 20.67) and HIV testing not offered/unknown (adjusted OR = 2.58; 95% CI: 1.18, 5.62) were significantly associated with TB mortality. Conclusion: This study found that TB patients who were 45 years old and above, positive HIV, late diagnosis and are foreigners had a higher risk for TB mortality. Early diagnosis, optimised screening and close monitoring should be practised to reduce TB mortality.

Effect of sinusoidal injection velocity on miscible viscous fingering of a finite sample: Nonlinear simulation.

The effect of a sinusoidal injection on the fingering instability in a miscible displacement in the application of liquid chromatography, pollutant contamination in aquifers, etc., is investigated. The injection velocity, U ( t ) is characterized by its amplitude of Γ and time-period of T . The solute transport, flow in porous media, and mass conservation in a two-dimensional porous media is modeled by the convection-diffusion equation, Darcy's equation, and the continuity equation, respectively. The numerical simulation is performed in COMSOL Multiphysics utilizing a finite-element based approach. The fingering dynamics for various time-period have been studied for two scenarios namely, injection-extraction ( Γ > 1 ) and extraction-injection ( Γ < - 1 ). The onset of fingers and vigorous mixing is observed for Γ > 1 , whereas for Γ < - 1 , the onset gets delayed. The viscosity contrast between the sample and the surrounding fluid is characterized by the log-mobility ratio R . When R > 0 the rare interface becomes unstable, while for R < 0 the frontal interface deformed. In the case of R < 0 , the extraction-injection process attenuates the fingering dynamics, which is beneficial in chromatographic separations or pollutant dispersion in underground aquifers. The injection-extraction process is observed to have a longer mixing length, indicating early interaction between both interfaces. The degree of mixing χ ( t ) is more pronounced for injection-extraction scenario and least for extraction-injection R < 0 , Γ = - 2 . The average convective forces are more dominant for Γ > 1 , R = 2 till the deformed rare interface interact with diffusive frontal interface. The average diffusive forces are significant for Γ < - 1 , R = - 2 which can be helpful in separation of chemicals in chromatography. This study therefore provided new insights into the role of alternate injection-extraction injections in altering the fingering dynamics of the miscible sample.

Ustilago maydis telomere protein Pot1 harbors an extra N-terminal OB fold and regulates homology-directed DNA repair factors in a dichotomous and context-dependent manner.

The telomere G-strand binding protein Pot1 plays multifaceted roles in telomere maintenance and protection. We examined the structure and activities of Pot1 in Ustilago maydis, a fungal model that recapitulates key features of mammalian telomere regulation. Compared to the well-characterized primate and fission yeast Pot1 orthologs, UmPot1 harbors an extra N-terminal OB-fold domain (OB-N), which was recently shown to be present in most metazoans. UmPot1 binds directly to Rad51 and regulates the latter's strand exchange activity. Deleting the OB-N domain, which is implicated in Rad51-binding, caused telomere shortening, suggesting that Pot1-Rad51 interaction facilitates telomere maintenance. Depleting Pot1 through transcriptional repression triggered growth arrest as well as rampant recombination, leading to multiple telomere aberrations. In addition, telomere repeat RNAs transcribed from both the G- and C-strand were dramatically up-regulated, and this was accompanied by elevated levels of telomere RNA-DNA hybrids. Telomere abnormalities of pot1-deficient cells were suppressed, and cell viability was restored by the deletion of genes encoding Rad51 or Brh2 (the BRCA2 ortholog), indicating that homology-directed repair (HDR) proteins are key mediators of telomere aberrations and cellular toxicity. Together, these observations underscore the complex physical and functional interactions between Pot1 and DNA repair factors, leading to context-dependent and dichotomous effects of HDR proteins on telomere maintenance and protection.

Reciprocal impacts of telomerase activity and ADRN/MES differentiation state in neuroblastoma tumor biology.

Telomere maintenance and tumor cell differentiation have been separately implicated in neuroblastoma malignancy. Their mechanistic connection is unclear. We analyzed neuroblastoma cell lines and morphologic subclones representing the adrenergic (ADRN) and mesenchymal (MES) differentiation states and uncovered sharp differences in their telomere protein and telomerase activity levels. Pharmacologic conversion of ADRN into MES cells elicited consistent and robust changes in the expression of telomere-related proteins. Conversely, stringent down-regulation of telomerase activity triggers the differentiation of ADRN into MES cells, which was reversible upon telomerase up-regulation. Interestingly, the MES differentiation state is associated with elevated levels of innate immunity factors, including key components of the DNA-sensing pathway. Accordingly, MES but not ADRN cells can mount a robust response to viral infections in vitro. A gene expression signature based on telomere and cell lineage-related factors can cluster neuroblastoma tumor samples into predominantly ADRN or MES-like groups, with distinct clinical outcomes. Our findings establish a strong mechanistic connection between telomere and differentiation and suggest that manipulating telomeres may suppress malignancy not only by limiting the tumor growth potential but also by inducing tumor cell differentiation and altering its immunogenicity.

Structurally distinct telomere-binding proteins in Ustilago maydis execute non-overlapping functions in telomere replication, recombination, and protection.

Duplex telomere binding proteins exhibit considerable structural and functional diversity in fungi. Herein we interrogate the activities and functions of two Myb-containing, duplex telomere repeat-binding factors in Ustilago maydis, a basidiomycete that is evolutionarily distant from the standard fungi. These two telomere-binding proteins, UmTay1 and UmTrf2, despite having distinct domain structures, exhibit comparable affinities and sequence specificity for the canonical telomere repeats. UmTay1 specializes in promoting telomere replication and an ALT-like pathway, most likely by modulating the helicase activity of Blm. UmTrf2, in contrast, is critical for telomere protection; transcriptional repression of Umtrf2 leads to severe growth defects and profound telomere aberrations. Comparative analysis of UmTay1 homologs in different phyla reveals broad functional diversity for this protein family and provides a case study for how DNA-binding proteins can acquire and lose functions at various chromosomal locations. Our findings also point to stimulatory effect of telomere protein on ALT in Ustilago maydis that may be conserved in other systems.

Application of Organic Fertilizers Affect the Citrus Leafminer, Phyllocnistis citrella (Lepidoptera: Gracillariidae) Infestation and Citrus Canker Disease in Nursery Plantations.

Citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is one of the most important insect pests of Pakistan's citrus nursery stock and caused extensive damage to young flushes. The organic compost is a widespread technique used to manage insect pests and plant diseases. Different composts (biofert, tara root and vermicompost) at 0.5 and 0.25 kg/plant concentration in comparison to NPK fertilizer at 0.4 and 0.2 g/plant were evaluated for CLM infestation and the associated citrus canker disease in nursery plantations of Citrus reticulata Blanco. Application of biofert at 0.5 kg/plant reduced the CLM infestation up to 54.5% during Fall-2016 and 39.1% during Summer-2017 in comparison to control treatment. The CLM larval density was also found lower by the application of biofert followed by vermicompost during both seasons. Both concentrations of biofert followed by vermicompost at 0.5 kg/plant resulted in remarkable protection against citrus canker disease in both flushes. The incidence of canker associated with CLM infested leaves was also studied and found lower by the application of biofert and vermicompost compared with control treatment. Conclusively, the soil amendment using biofert and vermicompost affects the CLM population and canker infection in nursery plantations. These organic fertilizers can be used in future citrus IPM programs as a tool to suppress the CLM population and citrus canker disease.

Tamboti wood ash and burnt goat dropping ash, safe alternatives to control cowpea weevils, Callosobruchus maculatus (Fabr.) (Coleoptera: Bruchidae) during storage for subsistence farming.

This study determined the effect of tamboti wood ash and burnt goat dropping ash along with a chemical insecticide (avi-klorpirifos) on the reproduction, egg hatchability, damage, and mortality of cowpea weevil (Callosobruchus maculatus Fabr.). The germination potential of treated cowpea seeds was also determined using a susceptible variety-Blackeye. Two hundred grams of clean cowpea seeds were mixed with 25 g of tamboti wood ash and goat dropping ash. These seeds were then infested with 5 pairs of newly emerged adults of C. maculatus under controlled laboratory conditions. The experiment revealed that both tamboti wood ash and goat dropping ash had negative effects on the efficiency of C. maculatus and significantly reduced the extent of damage. In germination test, these ashes showed a significant improvement in germinability of treated cowpea seeds. However, in all instances, tamboti wood ash proved to be much more effective than goat dropping ash. The study observed that these natural products have the potential to protect cowpea seeds from the damage caused by C. maculatus during storage and can, therefore, be used as an alternative pest management method against cowpea weevils.

Soft tissue cephalometric analysis applied to regional Indian population.

INTRODUCTION: Importance of soft tissue consideration in establishing treatment goals for orthodontics and orthognathic surgery has been recognized and various cephalometric analysis incorporating soft tissue parameters have evolved. The great variance in soft tissue drape of the human face and perception of esthetics exists and normative data based on one population group cannot be applied to all. The study was conducted to compare the standard soft tissue cephalometric analysis (STCA) norms with norms derived for population of western Uttar Pradesh region of India. MATERIALS AND METHODS: The sample consisted of lateral cephalograms taken in natural head position of 33 normal subjects (16 males, 17 females). The cephalograms were analyzed with soft tissue cephalometric analysis for orthodontic diagnosis and treatment planning, and the Student's t test was used to compare the difference in means between study population and standard STCA norms. RESULTS: Compared with established STCA norms, females in our study had steeper maxillary occlusal plane, more proclined mandibular incisors, and less protrusive lips. Both males and females showed an overall decrease in facial lengths, less prominent midface and mandibular structures and more convex profile compared with established norms for the White population. CONCLUSIONS: Statistically significant differences were found in certain key parameters of STCA for western Uttar Pradesh population when compared with established norms.

Neuromuscular dentistry: Occlusal diseases and posture.

Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture.

Arrowhead elastic for simultaneous correction of overjet and overbite.

Arrowhead elastic may be integrated with fixed appliances to achieve rapid correction of increased overjet and overbite during comprehensive orthodontic treatment. This technique is applicable in routine class II cases involving deep bite, during retention phase in growing children treated with twin block and postsurgically in adult hypodivergent cases.

Solitary median maxillary central incisor in association with hemifacial microsomia: A rare case report and review of literature.

Solitary median maxillary central incisor (SMMCI) is a rare dental anomaly. It is estimated to occur in 1:50,000 live births. The SMMCI tooth differs from the normal central incisor in that the crown form is symmetric and it develops and erupts precisely in the midline of the maxillary dental arch in both primary and permanent dentitions. Presence of SMMCI with hemifacial microsomia (HFM) is a very rare clinical condition. We report a case of HFM in a male of Indian origin who presented with SMMCI in both primary and permanent dentitions. The association of HFM with SMMCI may be due to defective development of neural crest cells and/or lack of space in maxilla.