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Electrical resistance usually originates from lattice imperfections. However, even a perfect lattice has a fundamental resistance limit, given by the Landauer1 conductance caused by a finite number of propagating electron modes. This resistance, shown by Sharvin2 to appear at the contacts of electronic devices, sets the ultimate conduction limit of non-interacting electrons. Recent years have seen growing evidence of hydrodynamic electronic phenomena3-18, prompting recent theories19,20 to ask whether an electronic fluid can radically break the fundamental Landauer-Sharvin limit. Here, we use single-electron-transistor imaging of electronic flow in high-mobility graphene Corbino disk devices to answer this question. First, by imaging ballistic flows at liquid-helium temperatures, we observe a Landauer-Sharvin resistance that does not appear at the contacts but is instead distributed throughout the bulk. This underpins the phase-space origin of this resistance-as emerging from spatial gradients in the number of conduction modes. At elevated temperatures, by identifying and accounting for electron-phonon scattering, we show the details of the purely hydrodynamic flow. Strikingly, we find that electron hydrodynamics eliminates the bulk Landauer-Sharvin resistance. Finally, by imaging spiralling magneto-hydrodynamic Corbino flows, we show the key emergent length scale predicted by hydrodynamic theories-the Gurzhi length. These observations demonstrate that electronic fluids can dramatically transcend the fundamental limitations of ballistic electrons, with important implications for fundamental science and future technologies.
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Mycobacterium tuberculosis encodes two chaperonin proteins, MtbCpn60.1 and MtbCpn60.2, that share substantial sequence similarity with the Escherichia coli chaperonin, GroEL. However, unlike GroEL, MtbCpn60.1 and MtbCpn60.2 purify as lower-order oligomers. Previous studies have shown that MtbCpn60.2 can functionally replace GroEL in E. coli, while the function of MtbCpn60.1 remained an enigma. Here, we demonstrate the molecular chaperone function of MtbCpn60.1 and MtbCpn60.2, by probing their ability to assist the folding of obligate chaperonin clients, DapA, FtsE and MetK, in an E. coli strain depleted of endogenous GroEL. We show that both MtbCpn60.1 and MtbCpn60.2 support cell survival and cell division by assisting the folding of DapA and FtsE, but only MtbCpn60.2 completely rescues GroEL-depleted E. coli cells. We also show that, unlike MtbCpn60.2, MtbCpn60.1 has limited ability to support cell growth and proliferation and assist the folding of MetK. Our findings suggest that the client pools of GroEL and MtbCpn60.2 overlap substantially, while MtbCpn60.1 folds only a small subset of GroEL clients. We conclude that the differences between MtbCpn60.1 and MtbCpn60.2 may be a consequence of their intrinsic sequence features, which affect their thermostability, efficiency, clientomes and modes of action.
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Proteínas de Escherichia coli , Mycobacterium tuberculosis , Humanos , Escherichia coli/genética , Escherichia coli/metabolismo , Proteostasis , Chaperoninas/genética , Chaperoninas/metabolismo , Chaperonas Moleculares/metabolismo , Pliegue de Proteína , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Transportadoras de Casetes de Unión a ATP/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Proteínas de Escherichia coli/metabolismoRESUMEN
Multiple mechanisms exist in a cell to cope with stress. Four independent stress-sensing kinases constitute the integrated stress response machinery of the mammalian cell, and they sense the stress signals and act by phosphorylating the eukaryotic initiation factor 2α (eIF2α) to arrest cellular translation. Eukaryotic initiation factor 2 alpha kinase 4 (eIF2AK4) is one of the four kinases and is activated under conditions of amino acid starvation, UV radiation, or RNA virus infection, resulting in shutdown of global translation. An earlier study in our laboratory constructed the protein interaction network of the hepatitis E virus (HEV) and identified eIF2AK4 as a host interaction partner of the genotype 1 (g1) HEV protease (PCP). Here, we report that PCP's association with the eIF2AK4 results in inhibition of self-association and concomitant loss of kinase activity of eIF2AK4. Site-directed mutagenesis of the 53rd phenylalanine residue of PCP abolishes its interaction with the eIF2AK4. Further, a genetically engineered HEV-expressing F53A mutant PCP shows poor replication efficiency. Collectively, these data identify an additional property of the g1-HEV PCP protein, through which it helps the virus in antagonizing eIF2AK4-mediated phosphorylation of the eIF2α, thus contributing to uninterrupted synthesis of viral proteins in the infected cells. IMPORTANCE Hepatitis E virus (HEV) is a major cause of acute viral hepatitis in humans. It causes chronic infection in organ transplant patients. Although the disease is self-limiting in normal individuals, it is associated with high mortality (~30%) in pregnant women. In an earlier study, we identified the interaction between the genotype 1 HEV protease (PCP) and cellular eukaryotic initiation factor 2 alpha kinase 4 (eIF2AK4). Since eIF2AK4 is a sensor of the cellular integrated stress response machinery, we evaluated the significance of the interaction between PCP and eIF2AK4. Here, we show that PCP competitively associates with and interferes with self-association of the eIF2AK4, thereby inhibiting its kinase activity. Lack of eIF2AK4 activity prevents phosphorylation-mediated inactivation of the cellular eIF2α, which is essential for initiation of cap-dependent translation. Thus, PCP behaves as a proviral factor, promoting uninterrupted synthesis of viral proteins in infected cells, which is crucial for survival and proliferation of the virus.
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Endopeptidasas , Virus de la Hepatitis E , Proteínas Serina-Treonina Quinasas , Proteínas Virales , Femenino , Humanos , Embarazo , Endopeptidasas/genética , Endopeptidasas/metabolismo , Factor 2 Eucariótico de Iniciación/metabolismo , Hepatitis E/virología , Virus de la Hepatitis E/enzimología , Fosforilación , Proteínas Virales/genética , Proteínas Virales/metabolismo , Replicación Viral/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Mutación , Aminoácidos/genética , Aminoácidos/metabolismoRESUMEN
Neisseria gonorrheae, the causative agent of genitourinary infections, has been associated with asymptomatic or recurrent infections and has the potential to form biofilms and induce inflammation and cell transformation. Herein, we aimed to use computational analysis to predict novel associations between chronic inflammation caused by gonorrhea infection and neoplastic transformation. Prioritization and gene enrichment strategies based on virulence and resistance genes utilizing essential genes from the DEG and PANTHER databases, respectively, were performed. Using the STRING database, proteinâprotein interaction networks were constructed with 55 nodes of bacterial proteins and 72 nodes of proteins involved in the host immune response. MCODE and cytoHubba were used to identify 12 bacterial hub proteins (murA, murB, murC, murD, murE, purN, purL, thyA, uvrB, kdsB, lpxC, and ftsH) and 19 human hub proteins, of which TNF, STAT3 and AKT1 had high significance. The PPI networks are based on the connectivity degree (K), betweenness centrality (BC), and closeness centrality (CC) values. Hub genes are vital for cell survival and growth, and their significance as potential drug targets is discussed. This computational study provides a comprehensive understanding of inflammation and carcinogenesis pathways that are activated during gonorrhea infection.
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Proteínas Bacterianas , Transformación Celular Neoplásica , Biología Computacional , Gonorrea , Neisseria gonorrhoeae , Mapas de Interacción de Proteínas , Humanos , Gonorrea/microbiología , Gonorrea/genética , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/patogenicidad , Mapas de Interacción de Proteínas/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Transformación Celular Neoplásica/genética , Genes Esenciales , Virulencia/genética , Inflamación/genética , Factores de Virulencia/genética , Interacciones Huésped-Patógeno/genética , MultiómicaRESUMEN
The design and development of novel antimicrobial agents are highly desired to combat the emergence of medication resistance against microorganisms that cause infections. A series of new pyrimidine-linked thiazolidinedione derivatives (5a-j) were synthesized, characterized, and their antimicrobial properties assessed in the current investigation. Here, novel pyrimidine-linked thiazolidinedione compounds were designed using the molecular hybridization approach. Elemental and spectral techniques were used to determine the structures of the synthesized hybrids. The majority of compounds showed encouraging antibacterial properties. Among the active compounds, 5g, 5i, and 5j showed 1.85, 1.15, and 1.38 times the activity of streptomycin against S. aureus, respectively, with MIC values of 6.4, 10.3, and 8.6 µM. With MIC values of 10.8, 21.9, and 15.4 µM, respectively, the compounds 5g, 5i, and 5j showed 2.14, 1.05, and 1.50 times the activity of linezolid against the methicillin-resistant S. aureus (MRSA) strain. Furthermore, when compared to the reference medications, compounds 5g, 5i, and 5j demonstrated broad-range antimicrobial efficacy against all tested strains of bacteria and fungus. Out of all the compounds that were investigated, compounds 5g, 5i, and 5j showed noteworthy anti-tubercular activity. 5g is the most effective, 1.59 times more effective than reference drug isoniazid. To anticipate the binding manner, the synthesized potent compounds were subjected to molecular docking into the active binding site of MRSA and the mycobacterial membrane protein large 3 (MmpL3) protein. The compounds 5g, 5i, and 5j may eventually serve as lead compounds in the search for antimicrobial and anti-TB therapeutic agents.
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Antiinfecciosos , Staphylococcus aureus Resistente a Meticilina , Tiazolidinedionas , Antituberculosos , Simulación del Acoplamiento Molecular , Staphylococcus aureus/metabolismo , Relación Estructura-Actividad , Antiinfecciosos/farmacología , Antibacterianos/química , Tiazolidinedionas/farmacología , Pirimidinas/farmacología , Pruebas de Sensibilidad Microbiana , Estructura MolecularRESUMEN
The novel genetically modified probiotic Bacillus subtilis ZB423 was assessed in a 90-day repeated-dose oral toxicity study adhering to Good Laboratory Practice (GLP) and Organization for Economic Cooperation and Development (OECD) guidelines. Spray-dried spores at a concentration of 1.1E12 CFU/g were administered at doses of 130, 260, and 519 mg/kg body weight/day correlating to 1.43 × 1011, 2.86 × 1011, and 5.71 × 1011 CFU/kg/day, respectively, by oral gavage to Wistar rats for a period of 90 consecutive days. Results showed no toxicologically relevant findings for B. subtilis ZB423 from measured parameters. The no observed adverse effect level (NOAEL) of B. subtilis ZB423 is 519 mg/kg body weight/day corresponding to 5.71 × 1011 CFU/kg/day for lyophilized B. subtilis ZB423 spores under the test conditions employed.
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In the present research, we have developed a model-based crisp logic function statistical classifier decision support system supplemented with treatment planning systems for radiation oncologists in the treatment of glioblastoma multiforme (GBM). This system is based on Monte Carlo radiation transport simulation and it recreates visualization of treatment environments on mathematical anthropomorphic brain (MAB) phantoms. Energy deposition within tumour tissue and normal tissues are graded by quality audit factors which ensure planned dose delivery to tumour site thereby minimising damages to healthy tissues. The proposed novel methodology predicts tumour growth response to radiation therapy from a patient-specific medicine quality audit perspective. Validation of the study was achieved by recreating thirty-eight patient-specific mathematical anthropomorphic brain phantoms of treatment environments by taking into consideration density variation and composition of brain tissues. Dose computations accomplished through water phantom, tissue-equivalent head phantoms are neither cost-effective, nor patient-specific customized and is often less accurate. The above-highlighted drawbacks can be overcome by using open-source Electron Gamma Shower (EGSnrc) software and clinical case reports for MAB phantom synthesis which would result in accurate dosimetry with due consideration to the time factors. Considerable dose deviations occur at the tumour site for environments with intraventricular glioblastoma, haematoma, abscess, trapped air and cranial flaps leading to quality factors with a lower logic value of 0. Logic value of 1 depicts higher dose deposition within healthy tissues and also leptomeninges for majority of the environments which results in radiation-induced laceration.
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Neoplasias Encefálicas , Glioblastoma , Método de Montecarlo , Glioblastoma/radioterapia , Humanos , Neoplasias Encefálicas/radioterapia , Fantasmas de Imagen , Planificación de la Radioterapia Asistida por Computador/métodos , Oncólogos de Radiación , Sistemas de Apoyo a Decisiones Clínicas , Dosificación RadioterapéuticaRESUMEN
OBJECTIVE: Measure and compare the mechanical properties, translucency, and fluoride-releasing capabilities of EQUIA Forte HT against Fuji IX GP and ChemFil Rock. MATERIALS AND METHODS: Ten specimens of each material were fabricated for compressive strength (CS), flexural strength (FS), and surface hardness analysis at 24 h and 7 days. The L*a*b* values were measured against a black-and-white background using a spectrophotometer to analyze the translucency parameter (TP). Fluoride release was recorded after 2 months of immersion in distilled water. The mean data was analyzed by 1- and 2-way ANOVA (α = 0.5). RESULTS: EQUIA Forte HT showed higher CS, surface hardness, and FS values (p < 0.05) compared with Fuji IX GIC, while no significant difference was found in FS values between EQUIA Forte HT and Chemfil Rock (p > 0.05). The EQUIA Forte HT exhibited significantly higher translucency in comparison to both ChemFil Rock (p < 0.001) and Fuji IX GICs (p < 0.05). An increase (p > 0.05) of fluoride release was observed for EQUIA Forte HT. CONCLUSION: The EQUIA Forte HT Glass-ionomer cements (GIC) offers enhanced translucency, improved strength, and enhanced fluoride-releasing properties compared to the traditionally used Fuji IX GIC and ChemFil Rock GICs. This material might have a wide range of clinical applications due to its improved strength and optical properties. CLINICAL SIGNIFICANCE: Glass-ionomer dental restorative materials possess unique advantageous characteristics. However, its poor mechanical and optical properties have typically limited its clinical applications. Efforts to improve these properties have resulted in enhanced GICs. EQUIA Forte HT GIC offers enhanced mechanical and optical properties with potential applications in posterior and anterior restorative procedures.
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Silicatos de Aluminio , Materiales Dentales , Fluoruros , Cementos de Ionómero Vítreo , Fuerza Compresiva , Dureza , Ensayo de MaterialesRESUMEN
PURPOSE: Denture fabrication has shifted from traditional heat-processed and auto-polymerizing materials to computer-aided design and computer-aided manufacturing (CAD-CAM) milled and printed materials. The monomer in traditional materials can induce an allergic reaction in some patients. With the rise in the edentulous population and increasing demand for the fabrication of dentures, these newer materials should be studied for monomer leaching. The purpose of this study was to evaluate the ratio of residual monomer in materials being used for denture bases: CAD-milled polymethylmethacrylate (PMMA), printed denture base resin, heat-processed PMMA, and auto-polymerizing PMMA comparatively. MATERIALS AND METHODS: Milled, printed, heat-activated, and auto-polymerizing denture base specimens (n = 3 for each group, each test run three times) were fabricated according to manufacturer recommendations. Specimens were first immersed in deuterated chloroform (CDCl3), a deuterated organic solvent, to evaluate monomer leaching and to observe physical properties of the materials. NMR spectroscopy was used to evaluate the dissolution of materials and residual monomer to crosslinked polymer ratios at 1, 4, and 9 days. A second group of specimens was then immersed in deuterium oxide (D2O) to evaluate if the residual monomers would leach out of the system. The solution was then analyzed using nuclear magnetic resonance (NMR) spectroscopy for 1 month. The deuterated forms of chloroform (CDCl3) and water (D2O) were used to enable sample characterization by NMR. RESULTS: While the heat-processed, auto-polymerizing, and milled specimens possessed residual monomers, no significant monomer leaching was noted in the printed specimen, while immersed in CDCl3. Similarly, the printed specimen was most resistant to dissolution, as compared to the rest; dissolution of the specimen is indicative of little to no cross-linking. No detectable dissolution of monomer was seen when all specimens were immersed in D2O for up to 1 month. CONCLUSIONS: Residual monomers were not found in the printed denture material in this study in either CDCl3 or D2O, whereas CAD-milled and traditionally processed denture bases still have residual monomers within their respective systems when immersed in organic solvent. None of the specimens tested leached monomers into D2O.
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Tetrahydrothiophenocucurbit[5 and 6]uril has been synthesized from tetrathiophenoglycoluril diether, providing thioether functionality at the exterior equatorial position of the cucurbituril cage. This functionality has been investigated for chemical modification through sulfoxide formation and subsequent Pummerer rearrangement to the acetoxy derivative of the tetrahydrothiophenocucurbit[5]uril. Nanoparticles of Au and Ag were prepared in the presence of tetrahydrothiophenocucurbit[6]uril, which curiously led to the formation of nanoparticle chains, growing in length over days to weeks.
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BACKGROUND AND OBJECTIVES: The aim of this study was to analyze factors associated with pathologic complete response (pCR) following neoadjuvant chemoradiation (NCRT) and esophagectomy for carcinoma of the esophagus (EC) and gastroesophageal junction (GEJ). METHODS: Patients with EC and GEJ tumors who received NCRT and underwent esophagectomy between January 2010 to March 2021 were included. Univariate and multivariate analyses were performed to evaluate the factors associated with pCR by comparing the patients who achieved pCR (pCR group) with those who did not achieve pCR (non-pCR group). RESULTS: A total of 321 patients were included in the study, with squamous cell carcinoma (SCC) accounting for the majority of cases (76%). One hundred and sixty (49.8%) patients had pCR. SCC histology and pretreatment radiographic node-negative status (cN0) were associated with pCR. Patients in the pCR group had significantly better overall and disease-free survival compared with patients in the non-pCR group. CONCLUSIONS: SCC histology and pretreatment radiographic node-negative status were associated with pCR. For patients with tumors of EC and GEJ who received NCRT and underwent esophagectomy, pCR was associated with improved prognosis compared with those not achieving pCR.
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Carcinoma de Células Escamosas , Neoplasias Esofágicas , Humanos , Esofagectomía , Terapia Neoadyuvante , Neoplasias Esofágicas/patología , Unión Esofagogástrica/patología , Carcinoma de Células Escamosas/patologíaRESUMEN
BACKGROUND: With changes in the epidemiology and treatment of chronic liver disease (CLD), the impact of various etiologies of liver disease on steatosis and advanced fibrosis are uncertain. METHODS: A retrospective study was conducted among liver disease patients of various etiologies undergoing transient elastography (TE) over a 9-year duration. RESULTS: Data for 2886 patients were analyzed and had the following demographics: The median age was 60 (IQR: 45-69) years, 51% were males, and ethnicity was predominantly Chinese (52.5%), followed by Malays (34%) and Indians (12.3%). The median CAP score was 272 (IQR: 219-319) dB/m and the median liver stiffness measurement (LSM) score was 6.5 (IQR: 4.9-9.7) kPa. Hepatic steatosis occurred across the spectrum of etiologies of CLD. Among patients with steatosis, the most common etiologies were nonalcoholic fatty liver disease (NAFLD) at 62% and chronic hepatitis B (CHB) at 26.3%. TE findings suggestive of cACLD (10.1-15 kPa) and highly suggestive of cACLD (>15 kPa) were observed in 11.3% and 12.4% of patients, respectively. NAFLD was found to be the most common etiology for cases with suggestive of cACLD (47.2%) and highly suggestive of cACLD (41.5%). CONCLUSION: Hepatic steatosis is common in CLD, regardless of etiology. Compared with other etiologies, NAFLD is now the leading cause of cACLD.
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Diagnóstico por Imagen de Elasticidad , Hepatitis B Crónica , Enfermedad del Hígado Graso no Alcohólico , Masculino , Adulto , Humanos , Persona de Mediana Edad , Femenino , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Hígado/patología , Estudios Retrospectivos , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/epidemiología , Hepatitis B Crónica/patología , Cirrosis Hepática/patologíaRESUMEN
Global warming is one of the serious threats that adversely affects the development and reproduction of silkworms. The ideal temperature for silkworms to carryout normal life activities is 20-30 °C. Certain bivoltine silkworms that are raised in tropical regions are thermotolerant. But, prolonged exposure to high temperatures may be fatal. In the present study, fifth instar larvae of bivoltine silkworm were exposed to heat shock at 40 ± 2 °C for a short period of one hour per day to examine the changes in the gut microflora. The study used high throughput sequencing to evaluate the impact of intestinal microbes of silkworms in response to high temperature. The findings demonstrated that elevated temperature has a negative impact on the intestinal microbes of silkworm compared to the control which were reared under the optimum temperature (25 ± 3° C). Four hundred and fifty eight (458) species of microbes were reported in the control group whereas only 434 species were reported in the temperature exposed group. The digestive process of silkworms may also be impaired by heat shock due to their effect on digestive enzymes. So, the results indicated that heat shock has an impact on the intestinal microflora of silkworms that control the activity of associated digestive enzymes which affects the digestion and nutritional intake, eventually impacting the growth and development of silkworm larvae and cocoons produced. The morphometric parameters of silkworm larvae and cocoons also showed a considerable drop when exposed to heat shock.
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Bombyx , Animales , ARN Ribosómico 16S/genética , Temperatura , Bacterias , Calor , LarvaRESUMEN
A new species of entomopathogenic fungus, Metarhizium indicum, which derives its species epithet after its Indian origin is reported here. The fungus was found to cause natural epizootics in leafhopper (Busoniomimus manjunathi) infesting Garcinia gummi-gutta (Malabar tamarind), an evergreen spice tree native to South and Southeast Asia, known for its use as a culinary flavourant, dietary supplement and traditional remedy for various human ailments. The fungus was found to cause more than 60% mortality in field collected insects. The identity of the new species was established based on its distinct morphological characteristics and multi-gene sequence data analyses. Phylogenetic analyses using internal transcribed spacer region (ITS), DNA lyase (APN2) and a concatenated set of four marker genes [translation elongation factor 1-alpha (TEF), ß-tubulin (BTUB), RNA polymerase II largest subunit (RPB1) and RNA polymerase II second largest subunit (RPB2)] along with marked differences in nucleotide composition and genetic distance unambiguously support our claim that the present fungus infecting Garcinia leafhopper is a new addition to the genus Metarhizium.
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Hemípteros , Metarhizium , Humanos , Animales , Metarhizium/genética , Filogenia , Insectos/microbiología , IndiaRESUMEN
The current challenges in cancer treatment using conventional therapies have made the emergence of nanotechnology with more advancements. The exponential growth of nanoscience has drawn to develop nanomaterials (NMs) with therapeutic activities. NMs have enormous potential in cancer treatment by altering the drug toxicity profile. Nanoparticles (NPs) with enhanced surface characteristics can diffuse more easily inside tumor cells, thus delivering an optimal concentration of drugs at tumor site while reducing the toxicity. Cancer cells can be targeted with greater affinity by utilizing NMs with tumor specific constituents. Furthermore, it bypasses the bottlenecks of indiscriminate biodistribution of the antitumor agent and high administration dosage. Here, we focus on the recent advances on the use of various nanomaterials for cancer treatment, including targeting cancer cell surfaces, tumor microenvironment (TME), organelles, and their mechanism of action. The paradigm shift in cancer management is achieved through the implementation of anticancer drug delivery using nano routes.
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Nanotecnología , Distribución TisularRESUMEN
BACKGROUND: The COVID-19 pandemic negatively impacted the quality of life of individuals around the world, including health care professionals. There has been little research that examines the role of resilience concerning the impact of COVID-19 on the quality of life of nursing students. This study aimed to determine how resilience influenced the quality of life among nursing students during the COVID-19 pandemic. METHODS: A cross-sectional research design was adopted for this study. A total of two hundred sixty-eight nursing students from three universities, South India responded in the web-based survey. Data was collected using self-reported questionnaires in June 2021. RESULTS: Our findings revealed that the participants' resilience was normal, which had a moderate impact on the quality of life of nursing students during the COVID-19 pandemic. The COVID-19 impact on QoL significantly differed with year of education (F = 3.087; p < 0.02) and university (F = 6.697, p < 0.001). Bivariate analysis revealed significant inverse relationships between the impact of COVID-19 on quality of life with resilience (r = -0.259; p < 0.001) and perceived knowledge on COVID-19(r = -0.168; p < 0.006). CONCLUSION: In our study, we found that resilience had a moderate impact on the quality of life of nursing students during the COVID-19 pandemic. Therefore, it is important to promote students' resilience and improve their quality of life during stressful situations.
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COVID-19 , Estudiantes de Enfermería , Humanos , Calidad de Vida , Factores Protectores , Estudios Transversales , PandemiasRESUMEN
PURPOSE: As the fabrication of computer-aided design (CAD) milled and 3D printed denture base resins with bonded denture teeth increase in popularity, there is a need for research comparing the shear bond stress of milled and printed denture base resins with bonded denture teeth to that of a conventional heat processed denture base. MATERIALS AND METHODS: Denture base resin specimens (n = 9) were fabricated according to manufacturers' instructions using a novel test design. Two milled (Ivobase CAD PMMA, Ivoclar Vivadent and Polident PMMA, Polident Dental) and two 3D printed (Denture Base LP Resin, Formlabs and Lucitone Digital Print, Dentsply Sirona) materials were used. Conventional heat processed polymethylmethacrylate was used as the control (Lucitone 199, Dentsply Sirona). Denture teeth (VITA Vitapan XL T44, #8, VITA Zahnfabrik) were bonded to their respective bases using denture tooth bonding agent (Ivobase CAD bonding system, Ivoclar). Specimens were aged in water for 600 hours at 37°C and loaded until failure in a Universal testing machine. Shear bond stress was calculated. All specimens were evaluated for mode of failure and select specimens under scanning electron microscope and vertical scanning interferometry. Data were analyzed with one-way ANOVA followed by Tukey test (IBM SPSS) and fracture analysis performed. RESULTS: Shear stress was highest for the heat processed control (mean = 180 N ±26.76) and Polident test groups (mean = 180 N ± 34.90). Milled specimens were not significantly different from the control (p = 0.076 for IvoBase CAD and 1.00 for Polident), while the printed groups were significantly different from the control (p = 0.012 for Formlabs Denture Base Resin and p = 0.00 for Carbon Lucitone Digital Print). Milled denture base resins performed similarly to heat processed denture base resin and better than 3D printed denture bases. CONCLUSION: For complete denture wearers, all resin materials used in this study may be clinically acceptable, as the sheer stress for all groups was higher than the reported maximum biting force of complete denture patients. However, for implant retained prostheses, the incorporation of additional retentive features should be considered when bonding denture teeth to printed bases. More research is needed to evaluate methods to increase the bond strength of denture teeth to printed denture base resins.
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Recubrimiento Dental Adhesivo , Polimetil Metacrilato , Humanos , Anciano , Polimetil Metacrilato/química , Bases para Dentadura , Diseño Asistido por Computadora , Ensayo de Materiales , Propiedades de SuperficieRESUMEN
The vaccination efficacy can indirectly be assessed through the quantification of neutralizing antibodies. Very few data are available on Covishield efficacy in terms of neutralizing antibody expression upon vaccination. This study is focused on profiling of neutralizing antibody expression during and after the Covishield two shot vaccination and observing COVID-19 infection in vaccinated participants during the period. SARS CoV-2 neutralizing antibody concentrations in samples were estimated using electrochemiluminescence immunoassay kit for Lifotronics eCL8000. The sampling had been done sequentially at 45th, 85th day after 1st dose and 15th day after 2nd dose Covishield vaccination. Parallelly, in order to confirm the total SARS CoV-2 IgG response in COVID-19 infection, measured the IgG using SARS CoV-2 IgG lateral flow immunoassay test kit. The subjects previously infected with COVID-19 before 1st dose vaccination demonstrated high neutralizing antibody (> 10AU/ml). In COVID-19 uninfected subjects, there was a sudden incline in neutralizing antibody after the 2nd dose. Infection with SARS CoV-2 between 1st and 2nd dose of Covishield vaccination implicate that the level of neutralizing antibody in serum after 1st dose was not adequate to combat the virus and prevent infection. We observed COVID-19 infection in participants even after 2nd dose of vaccination. Interestingly, there was no protection against SARS CoV-2 even with a high neutralizing antibody expression of 188.5 AU/mL after the 2nd dose. Findings of Covishield efficacy in different cohort samples before and after 2 doses of Covishield vaccination provide impetus for improvement or development of next generation vaccines.
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BACKGROUND: Anastomotic leak after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) remains a dreaded complication. There is no consensus statement regarding the optimal timing for bowel anastomoses to perform after or before HIPEC. METHODS: Patients who underwent CRS+HIPEC and had at least one bowel anastomosis were retrospectively analyzed to evaluate if timing of anastomosis done after or before HIPEC had an impact on bowel complication rates (anastomotic leak and perforation). RESULTS: From 2013 to 2019, 214 of 370 patients underwent CRS+HIPEC and had at least one bowel anastomosis. Of these 214 patients, 104 and 110 patients had anastomosis after and before HIPEC, respectively. A total of 324 anastomoses were performed, with a mean of 0.87 anastomoses per patient (range 1-4). The incidence of anastomotic leaks was comparable between the pre- and post-HIPEC groups (3.6% vs. 4.8%; p > 0.05), as was the bowel complication rate (7.6% vs. 7.2%). After multivariate analysis, prior surgical score >1 (odds ratio [OR] 4.3), recurrent cancers (OR 7.4), and more than two anastomosis (OR 3.8) were considered independent risk factors for bowel complications. CONCLUSION: Anastomosis of the bowel performed after or before HIPEC does not affect bowel complication rates (leak/perforation). Higher prior surgical score, surgery for recurrent cancers, and more than two bowel anastomosis are independent risk factors for predicting bowel complications. Prehabilitation, standardization of steps, immediate attention and repair of serosal tears, and thorough inspection of the bowel before closure helps to decrease bowel complications. The timing of anastomosis can be at the discretion of the surgeon.
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Quimioterapia Intraperitoneal Hipertérmica , Neoplasias Peritoneales , Anastomosis Quirúrgica/efectos adversos , Procedimientos Quirúrgicos de Citorreducción/efectos adversos , Humanos , Neoplasias Peritoneales/terapia , Estudios RetrospectivosRESUMEN
In this work, extract from leaves of Couroupita guianensis (C.guianensis) abul was used as a potential reducing agent for the synthesis of lanthanum oxide (La2O3) nanoparticles (NPs). In addition, the morphology and several physicochemical properties of the La2O3 NPs were improved by introducing the ionic liquid of 1-butyl 3-methyl imidazolium tetra fluoroborate (BMIM BF4) as a stabilizing agent. The structure of the La2O3 (without ionic liquid) and IL-La2O3 (with ionic liquid) NPs were analyzed by X-ray diffraction (XRD). The chemical composition of the synthesized NPs was analyzed using the energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) studies. Optical and morphological studies were also performed. The antibacterial, antioxidant, anti-inflammatory, anti-diabetic and anticancer properties of the La2O3 and IL-La2O3 NPs were evaluated.