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1.
Nanotechnology ; 35(29)2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38636460

RESUMEN

The tunability and controllability of conductance quantization mediated multilevel resistive switching (RS) memory devices, fabricated in crossbar geometry can be a promising alternative for boosting storage density. Here, we report fabrication of Cu/TiO2/Pt based RS devices in 8 × 8 crossbar geometry, which showed reliable bipolar RS operations. The crossbar devices showed excellent spatial and temporal variability, time retention and low switching voltage (<1 V) and current (∼100µA). Furthermore, during the reset switching, highly repeatable and reliable integral and half-integral quantized conductance (QC) was observed. The observed QC phenomenon was attributed to the two dimensional confinement of electrons as lateral width of the conducting filament (CF) matches the fermi wavelength. The magnitude and number of the QC steps were found to increase from ∼2.5 to 12.5 and from 5 to 18, respectively by increasing the compliance current (IC) from 50 to 800µA which also increased the diameter of the CF from ∼1.2 to 3.3 nm. The enhancement in both number and magnitude of QC states was explained using electrochemical dissolution mechanism of CF of varying diameter. A thicker CF, formed at higherIC, undergoes a gradual rupture during reset process yielding a greater number of QC steps compared to a thinner CF. The realisation of QC states in the crossbar Cu/TiO2/Pt device as well asICmediated tunability of their magnitude and number may find applications in high-density resistive memory storage devices and neuromorphic computing.

2.
Cancer Drug Resist ; 7: 11, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38510751

RESUMEN

Globally, cancer, as a major public health concern, poses a severe threat to people's well-being. Advanced and specialized therapies can now cure the majority of people with early-stage cancer. However, emerging resistance to traditional and novel chemotherapeutic drugs remains a serious issue in clinical medicine. Chemoresistance often leads to cancer recurrence, metastasis, and increased mortality, accounting for 90% of chemotherapy failures. Thus, it is important to understand the molecular mechanisms of chemoresistance and find novel therapeutic approaches for cancer treatment. Among the several factors responsible for chemoresistance, calcium (Ca2+) dysregulation plays a significant role in cancer progression and chemoresistance. Therefore, targeting this derailed Ca2+ signalling for cancer therapy has become an emerging research area. Of note, the Ca2+ signal and its proteins are a multifaceted and potent tool by which cells achieve specific outcomes. Depending on cell survival needs, Ca2+ is either upregulated or downregulated in both chemosensitive and chemoresistant cancer cells. Consequently, the appropriate treatment should be selected based on Ca2+ signalling dysregulation. This review discusses the role of Ca2+ in cancer cells and the targeting of Ca2+ channels, pumps, and exchangers. Furthermore, we have emphasised the role of Ca2+ in chemoresistance and therapeutic strategies. In conclusion, targeting Ca2+ signalling is a multifaceted process. Methods such as site-specific drug delivery, target-based drug-designing, and targeting two or more Ca2+ proteins simultaneously may be explored; however, further clinical studies are essential to validate Ca2+ blockers' anti-cancer efficacy.

3.
Arch Microbiol ; 206(3): 127, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38416201

RESUMEN

Globally, oral diseases affect nearly 3.5 billion people, accounting for 4.6% of the healthcare expenditure. Common oral diseases include dental caries and periodontal disease, associated with biofilms formed by cariogenic pathogens. Epidemiological studies associate carbohydrates with these diseases due to  the sugars metabolized by cariogenic pathogens. This review focuses on dental caries and periodontal pathogens, quorum sensing, lectin-carbohydrate interactions, and various sugar molecules. Cariogenic sugars significantly influence biofilms by enhancing pathogen adhesion, viability, and gene expressions associated with biofilm formation. Moreover, lectin-carbohydrate interactions contribute to biofilm stability. Disrupting these interactions is a potential strategy for oral disease prevention. The use of nanoparticles, such as quantum dots, provides novel insights into lectin-sugar interactions and the development of inhibitors. Additionally, nanomaterials like calcium phosphate nanoparticles neutralize acids and inhibit microbial growth. This overview emphasizes understanding the relationships between oral diseases, microbial communities, and sugars to devise preventive and therapeutic strategies against oral diseases.


Asunto(s)
Caries Dental , Microbiota , Humanos , Azúcares , Caries Dental/prevención & control , Biopelículas , Lectinas
4.
Cureus ; 15(11): e49554, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38156157

RESUMEN

BACKGROUND: Antimicrobial resistance is a pertinent issue in the healthcare sector, accounting for 1.27 million patient deaths worldwide. Dental practitioners account for 3% to 11% of total antibiotic prescriptions. Therefore, this study aimed to specifically assess their knowledge of antibiotic prescriptions, guidelines, and clinical practices. METHOD: Before conducting this knowledge, attitude, and practice (KAP) survey, study approval was obtained from the Scientific Review Board of Saveetha Dental College and Hospitals, Chennai, India. A total of 200 participants were randomly selected from the list of Indian Dental Association (Hyderabad chapter), and dental colleges, dental conferences, and peer suggestions. We received a total of 130 responses by the end of the survey. RESULTS: The survey revealed gaps in practitioners' KAP. Of those surveyed, 83 (63.85%) of the practitioners kept themselves updated about antibiotic guidelines and news, but many (94, 72.31%) were unaware of the WHO's access, watch, reserve (AWaRe) and antimicrobial stewardship concepts (103, 79.23%). A total of 111 (85.38%) practitioners considered cross-reactions with other medications, yet only 28 (21.5%) practitioners tested patients for antibiotic sensitivity. While 64 (49.23%) practitioners encountered patients who did not respond to antibiotics, 84 (64.62%) practitioners encountered patients who demanded antibiotics. CONCLUSION: This study highlights the lack of awareness about the WHO's AWaRe classification and antimicrobial stewardship among the majority of dental practitioners across Hyderabad. Misuse or overuse of antibiotics was indicated in this survey by both patients and dental practitioners. Prioritizing updates on antibiotic knowledge and guidelines and awareness of their use is important. It is essential to educate patients about the ill effects of self-prescribing antibiotics. Dental practitioners need to consider cross-reactions and antibiotic-sensitivity testing before prescribing antibiotics. Labeling the sensitivity of a particular antibiotic for specific microbes on packaging can help reduce misuse and the use of antibiotics for the wrong indications.

5.
J Biomater Appl ; 38(1): 39-50, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37343291

RESUMEN

Despite the availability of advanced treatments, cancer remains the second leading cause of death worldwide. This is due to the many challenges prevailing in the research field and cancer therapy. Resistance to therapy and side effects provide major hindrances to recovery from cancer. As a result, in addition to the aim of killing cancer cells, the focus should also be on reducing or preventing side effects of the treatment. To enhance the effectiveness of cancer treatment, many researchers are studying drug delivery systems based on silk proteins: fibroin and sericin. These proteins have high biocompatibility, biodegradability, and ease of modification. Consequently, many researchers have developed several formulations of silk proteins such as scaffolds, nanoparticles, and hydrogels by combining them with other materials or drugs. This review summarizes the use of silk proteins in various forms in cancer research and therapy. The use of silk proteins to study cancer cells, to deliver cancer drugs to a target site, in cancer thermal therapy, and as an anti-cancer agent is described here.


Asunto(s)
Fibroínas , Neoplasias , Sericinas , Sistemas de Liberación de Medicamentos , Fibroínas/uso terapéutico , Neoplasias/tratamiento farmacológico , Sericinas/uso terapéutico , Seda , Humanos
6.
J Contemp Dent Pract ; 23(4): 467-477, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35945843

RESUMEN

AIM: This review aims to explore the importance of silk hydrogel and its potential in tissue engineering (TE). BACKGROUND: Tissue engineering is a procedure that incorporates cells into the scaffold materials with suitable growth factors to regenerate injured tissue. For tissue formation in TE, the scaffold material plays a key role. Different forms of silk fibroin (SF), such as films, mats, hydrogels, and sponges, can be easily manufactured when SF is disintegrated into an aqueous solution. High precision procedures such as micropatterning and bioprinting of SF-based scaffolds have been used for enhanced fabrication. REVIEW RESULTS: In this narrative review, SF physicochemical and mechanical properties have been presented. We have also discussed SF fabrication techniques like electrospinning, spin coating, freeze-drying, and physiochemical cross-linking. The application of SF-based scaffolds for skeletal, tissue, joint, muscle, epidermal, tissue repair, and tympanic membrane regeneration has also been addressed. CONCLUSION: SF has excellent mechanical properties, tunability, biodegradability, biocompatibility, and bioresorbability. CLINICAL SIGNIFICANCE: Silk hydrogels are an ideal scaffold matrix material that will significantly impact tissue engineering applications, given the rapid scientific advancements in this field.


Asunto(s)
Fibroínas , Ingeniería de Tejidos , Materiales Biocompatibles/química , Fibroínas/química , Hidrogeles/química , Seda , Ingeniería de Tejidos/métodos , Andamios del Tejido/química
7.
Aquat Toxicol ; 202: 145-152, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30031254

RESUMEN

Triclosan and its metabolites are detected in a diverse aquatic environment and are major concerns for various aquatic organisms. The present study investigated the impact of acute and sub-lethal exposure of triclosan on behaviour, activities of acetylcholinesterase and selected antioxidant enzymes, haematological and serum gas-electrolyte parameters of Pangasianodon hypophthalmus. The 96 h LC50 of triclosan for P. hypophthalmus was estimated as 1458 µg L-1. Further, sub-lethal triclosan exposure to 1/15th (97 µg L-1), 1/10th (145 µg L-1) and 1/5th (291 µg L-1) of 96 h LC50 concentration for a period of 45 days lead to decrease in total erythrocyte count, haemoglobin content and packed cell volume of blood while total leukocyte count increased significantly (p < 0.05) as compared to control. A concentration-dependent increase in the serum chloride and decrease in partial pressure of oxygen in blood serum was noted on 45th day. An increased activity of catalase and superoxide dismutase in gill and liver tissues and inhibition of acetylcholinesterase activity in brain was observed on 15th, 30th and 45th day of exposure which was dependent on both - concentration of triclosan and duration of exposure. A significant high activity of glutathione-S-transferase in gill and liver tissue was observed in triclosan exposed groups in comparison to control during the experimental period. The study shows that long-term sub-lethal exposure of triclosan to fish can lead to several physiological alterations such as enzymatic scavenging of oxygen radicals and the normal neurological functions mediated by the enzyme acetylcholinesterase. With increasing anthropogenic activity, the study provides a convincing evidence for the necessity of a regulated use and safer disposal of triclosan to the environment.


Asunto(s)
Antioxidantes/metabolismo , Conducta Animal/efectos de los fármacos , Triclosán/toxicidad , Contaminantes Químicos del Agua/toxicidad , Acetilcolinesterasa/metabolismo , Animales , Análisis de los Gases de la Sangre , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Catalasa/metabolismo , Bagres/crecimiento & desarrollo , Bagres/metabolismo , Cloruros/sangre , Eritrocitos/citología , Eritrocitos/efectos de los fármacos , Branquias/efectos de los fármacos , Branquias/metabolismo , Glutatión Transferasa/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Oxígeno/sangre , Superóxido Dismutasa/metabolismo
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