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1.
J Fluoresc ; 2024 Apr 29.
Article in English | MEDLINE | ID: mdl-38683267

ABSTRACT

To explore the possible impact of 2-Phenylbenzimidazole-5-sulfonic acid (PBSA) on the function of a sunscreen, in this work we investigate the binding of copper metal ions (Cu2+) to PBSA. Due to the existence of an intrinsic interaction phenomenon between Cu2+ ions and PBSA molecules, the photoluminescence (PL) quenching arises owing to the charge transfer from PBSA to Cu2+ ions. The mechanism of fluorescence quenching is probed experimentally following excitation at 306 nm by evaluating various quenching parameters with the help of the Stern-Volmer plot. Through the assessment of the values of the Stern-Volmer constant ( K SV = 45.2 M - 1 ) and bimolecular quenching rate constant ( k q = 0.77 × 10 10 M - 1 . s - 1 ), it is deduced that the dynamic mode of PL quenching is operative between PBSA and Cu2+ ions. We evaluate the number of binding sites (n = 1) that advocate the presence of a single binding site in PBSA for Cu2+ ions. The numerical value of standard Gibbs free energy change, Δ G o ~ -27.485 kJ.mol-1 implies the spontaneous binding between Cu2+ ions and PBSA molecules. The results obtained give an insight into the mechanism of metal-induced PL quenching of water soluble PBSA sunscreen.

2.
BMC Oral Health ; 24(1): 874, 2024 Aug 02.
Article in English | MEDLINE | ID: mdl-39095892

ABSTRACT

BACKGROUND: Dental caries are common and troublesome and may affect individuals' health conditions. It is crucial to comprehend the caries experience for prevention, management, and enhancing oral health. Techniques such as CAMBRA can help assess an individual's risk factors for caries lesions. This study aims to assess the caries risk in five distinct regions of Saudi Arabia, utilizing the CAMBRA methodology. METHODS: This multiregional cross-sectional study was conducted at university dental clinics across the five regions of Saudi Arabia, using a Caries Management by Risk Assessment (CAMBRA) tool. This study used binary logistic regression analysis, the Pearson Chi-square test, and descriptive analysis as statistical methods. RESULTS: A total of 551 respondents participated in the study, with 59.7% being male and 40.3% being female. The age group with the highest proportion was 20-29, making up 31.6% of the participants. All participants exhibited at least one caries lesion (100%), with white spots (66.4%) and enamel lesions (56.1%) being the most prevalent. The moderate-risk category encompassed the largest proportion of participants, accounting for 60% of the total. High caries risk had a significant association with age group (P < 0.001), education (P < 0.001), profession (P < 0.001), and socio-economic status (P < 0.001). Furthermore, only age and socio-economic status showed a significant relationship with high caries risk in the multiple logistic regression. CONCLUSION: The CAMBRA tool indicates a high prevalence of moderate risk across the five regions of Saudi Arabia, identifying age and socio-economic status as significant predictors of caries risk.


Subject(s)
Dental Caries , Humans , Saudi Arabia/epidemiology , Dental Caries/epidemiology , Female , Male , Cross-Sectional Studies , Adult , Young Adult , Risk Factors , Middle Aged , Adolescent , Risk Assessment , Prevalence , Age Factors , Educational Status
3.
BMC Oral Health ; 24(1): 543, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38724952

ABSTRACT

BACKGROUND: In complex teeth like maxillary premolars, endodontic treatment success depends on a complete comprehension of root canal anatomy. The research on mandibular premolars' root canal anatomy has been extensive and well-documented in existing literature. However, there appears to be a notable gap in available data concerning the root canal anatomy of maxillary premolars. This study aimed to explore the root canal morphology of maxillary premolars using cone-beam computed tomography (CBCT) imaging, considering age and gender variations. METHODS: From 500 patient CBCT scans, 787 maxillary premolar teeth were evaluated. The sample was divided by gender and age (10-20, 21-30, 31-40, 41-50, 51-60, and 61 years and older). Ahmed et al. classification system was used to record root canal morphology. RESULTS: The most frequent classifications for right maxillary 1st premolars were 2MPM1 B1 L1 (39.03%) and 1MPM1 (2.81%), while the most frequent classifications for right maxillary 2nd premolars were 2MPM1 B1 L1 (39.08%) and 1MPM1 (17.85%). Most of the premolars typically had two roots (left maxillary first premolars: 81.5%, left maxillary second premolars: 82.7%, right maxillary first premolars: 74.4%, right maxillary second premolars: 75.7%). Left and right maxillary 1st premolars for classes 1MPM1 and 1MPM1-2-1 showed significant gender differences. For classifications 1MPM1 and 1MPM1-2-1, age-related changes were seen in the left and right maxillary first premolars. CONCLUSION: This study provides novel insights into the root canal anatomy of maxillary premolars within the Saudi population, addressing a notable gap in the literature specific to this demographic. Through CBCT imaging and analysis of large sample sizes, the complex and diverse nature of root canal morphology in these teeth among Saudi individuals is elucidated. The findings underscore the importance of CBCT imaging in precise treatment planning and decision-making tailored to the Saudi population. Consideration of age and gender-related variations further enhances understanding and aids in personalized endodontic interventions within this demographic.


Subject(s)
Bicuspid , Cone-Beam Computed Tomography , Dental Pulp Cavity , Maxilla , Humans , Bicuspid/diagnostic imaging , Bicuspid/anatomy & histology , Male , Female , Adolescent , Maxilla/diagnostic imaging , Maxilla/anatomy & histology , Dental Pulp Cavity/diagnostic imaging , Dental Pulp Cavity/anatomy & histology , Adult , Saudi Arabia , Middle Aged , Child , Cross-Sectional Studies , Young Adult , Sex Factors , Age Factors
4.
J Clin Pediatr Dent ; 48(2): 64-71, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38548634

ABSTRACT

Tooth avulsion is a frequently encountered dental emergency. Children are commonly reported group due to frequent sports activities, trauma, accidents and falls. Prompt emergency management is vital for long term success and to avoid morbidity. The study was aimed to assess the understanding of intern dentists about the emergency handling of avulsed teeth cases as mostly they are first responders among health care personnel. In this study a fourteen-item questionnaire with predefined responses was shared as online Google survey form with intern dentists of 5 different dental teaching hospitals of Islamabad, Pakistan. The duration of the study was 6 months (01 March 2022 to 31 August 2022). The questions were intended to collect personal information and to check level of knowledge and awareness about the management of avulsed tooth among the dental interns. The data was analyzed by statistical methods and is presented through tables and descriptive methods. In total, 152 participants completed the shared questionnaire. The vast majority (71%) of them were aware of the initial management of avulsed teeth, 49% were aware of the ideal transport medium for an avulsed tooth, (43%) were aware of the critical time for successful replantation, while (62%) had knowledge of the multiple factors responsible for the outcome of the tooth replantation. For majority of the statements, female participants had better knowledge as compared to their male counterparts. Statistically significant difference was noted for the statement "If you found the knocked-out tooth and it is dirty what will be your initial approach?" with female participants having better knowledge as compared to the male (p value = 0.005). Based on our study results, generally dental interns are well-informed but still lack expected level of awareness regarding the proper management protocol for avulsed tooth. Hence, improvement is needed regarding the effective handling of avulsed teeth cases.


Subject(s)
Tooth Avulsion , Child , Humans , Male , Female , Tooth Avulsion/therapy , Health Knowledge, Attitudes, Practice , Tooth Replantation/methods , Cross-Sectional Studies , Surveys and Questionnaires , Dentists
5.
J Org Chem ; 88(15): 11056-11068, 2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37462323

ABSTRACT

A palladium-catalyzed direct C-H arylation of indolines at C-7 position has been achieved at near-ambient temperature. The reaction was carried out with aryltriazene as a stable aryl source and electron shuttle to sustainably release aryl radical in situ under the action of promoter, and pyrimidine as a detachable directing group for the synthesis of 7-arylindolines under oxidant- and ligand-free conditions. Notably, this catalytic system can also be applied to the direct and site-selective arylation of tetrahydroquinolines (C-8) and carbazoles (C-1).

6.
J Fluoresc ; 33(6): 2523-2529, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37314535

ABSTRACT

In this article, we report the synthesis of graphene quantum dots (GQDs) by hydrothermal method and surface modified CdS quantum dots (QDs) via the colloidal method and the fabrication of their dyad. The CdS QDs functionalized by mercaptoacetic acid (MAA) attach to the GQDs via electrostatic interactions. Spectral overlapping between the emission spectrum of GQDs and the absorption spectrum of CdS QDs allows efficient Förster resonance energy transfer (FRET) from GQDs to the CdS QDs in the GQDs-CdS QDs dyads. The magnitude of FRET efficiency (E) and the rate of energy transfer (kE) assessed by the photoluminescence (PL) decay kinetics are ~61.84% and ⁓3.8 × 108 s- 1, respectively. These high values of FRET efficiency and energy transfer rate can be assigned to the existence of strong electrostatic interactions between GQDs and CdS QDs, which arise due to the presence of polar functionalities on the surface of both GQDs and CdS QDs. The understanding of energy transfer in the luminescent donor-acceptor FRET system is of significant importance and the practical implications of such FRET systems could overall improve the efficiency of photovoltaics, sensing, imaging and optoelectronic devices.

7.
Phys Chem Chem Phys ; 25(26): 17410-17419, 2023 Jul 05.
Article in English | MEDLINE | ID: mdl-37350276

ABSTRACT

The combination of halide perovskite NCs with graphene to design heterostructures has proven to be a promising candidate for energy applications, optoelectronics, and photocatalysis. Efficient light energy absorption in perovskite NC-graphene heterostructures is of fundamental importance owing to their optoelectronic applications. A detailed understanding of the important process for device action, particularly interfacial charge transfer (CT), has thus far lingered subtly. This study describes the influence of the different surface functionalities of graphene on the CT dynamics in FAPbBr3 NCs attached to functionalized graphene heterostructures. Functionalized graphenes i.e., graphene oxide (GO) and amino acids (alanine (Ala), tyrosine (Tyr) and cysteine (Cys)) functionalized GO, were synthesized. By assembling the heterostructures of functionalized graphene with NCs, the quenching of photoluminescence (PL) of the FAPbBr3 NCs was observed. The photo-generated hole transfer from FAPbBr3 to functionalized graphene is responsible for PL quenching, which is supported by time-resolved photoluminescence (TRPL) and cyclic voltammetry (CV) analysis. Our study revealed that the rate of CT and charge transfer efficiency (ECT) strongly depend on the nature of the functionalizing moieties. The highest hole transfer efficiency for NC-functionalized graphene heterostructures was observed in the case of cysteine-functionalized GO (88.84%) and the lowest with GO (38.15%). This suggests that cysteine-functionalized graphene is the best hole acceptor amongst all functionalized graphenes. This study offers a method to regulate energetics and investigate the extent of hole transfer in perovskite NCs and functionalized graphene heterostructures. These findings tend to draw new directions to stimulate advance research regarding the fundamental understanding of hole transfer in surface-modified donor-acceptor heterostructures for light harvesting assemblies, especially solar cells.

8.
Death Stud ; 47(4): 499-508, 2023.
Article in English | MEDLINE | ID: mdl-35854472

ABSTRACT

Little is known about public reactions to state security officials' suicide in Muslim countries like Pakistan. To explore readers' reactions in online comments, we analyzed 1,765 comments related to 10 news stories about suicide published in five mainstream English newspapers. The findings revealed six themes: stress, depression, and mental health issues; controversial investigation reports and misinformation; need for stronger accountability to address corruption in the country; criticizing media and security institutions; sympathy for the deceased and their families; and suicide and Islam. We recommend that suicide prevention organizations should monitor audience comments to devise and suggest resources for the public.


Subject(s)
Suicide , Humans , Suicide Prevention , Emotions , Social Responsibility , Pakistan , Mass Media
9.
BMC Oral Health ; 23(1): 291, 2023 05 15.
Article in English | MEDLINE | ID: mdl-37189077

ABSTRACT

BACKGROUND: The clinician should have complete knowledge of the normal anatomy of the root as well as complexities in the root canal configuration for a better outcome, as missed or improper handling of the canal system can lead to the failure of an entire endodontic procedure. The present study aims to assess the morphology of roots and canals in permanent mandibular premolars in the Saudi subpopulation with a new classification system. METHODS: The present study includes 1230 mandibular premolars (645 first premolars and 585-second premolars) from 500 CBCT images of the patients, including retrospective data. iCAT scanner system (Imaging Sciences International, Hatfield, PA, USA) was used to obtain the images; scanning of 8 × 8 cm images was performed at 120 KVp and 5-7 mA with a voxel size of 0.2 mm. The new method of classification presented by Ahmed et al. 2017 was used to record and classify the root canal morphology, followed by recording the differences regarding the age and gender of the patients. Comparison of canal morphology in lower permanent premolars and its association with gender and age of the patients was done by Chi-square test/ Fisher exact test; the significance level was set at 5% (p ≤ 0.05). RESULTS: The left mandibular 1st and 2nd premolars with one root were 47.31%, with two roots were 2.19%. However, three roots (0.24%) and C-shaped canals (0.24%) were reported only in the left mandibular 2nd premolar. The right mandibular 1st and 2nd premolars with one root were 47.56%, with two roots were 2.03%. The overall percentage of the number of roots and canals in the first and second premolars 1 PM 1 (88.38%), 2 PM 1 B 1 L 1 (3.5%), 2 PM B 1 L 1 (0.65%), 1 PM 1-2-1 (3.08%), 1 PM 1-2 (3.17%), 1 PM 1-2-1-2 (0.24%), 3 PMMB 1 DB 1 L1 (0.48%). However, the C-shaped canals (0.40%) were reported in right and left mandibular second premolars. No statistically significant difference was reported between mandibular premolars and gender. A statistically significant difference was reported between mandibular premolars and the age of the study subjects. CONCLUSION: Type I (1 TN 1) was the major root canal configuration in permanent mandibular premolars, which was higher among males. The CBCT imaging provides thorough details about the root canal morphology of lower premolars. These findings could support diagnosis, decision-making, and root canal treatment, for dental professionals.


Subject(s)
Spiral Cone-Beam Computed Tomography , Male , Humans , Bicuspid/diagnostic imaging , Bicuspid/anatomy & histology , Retrospective Studies , Saudi Arabia , Dental Pulp Cavity/diagnostic imaging , Dental Pulp Cavity/anatomy & histology , Tooth Root/diagnostic imaging , Tooth Root/anatomy & histology , Cone-Beam Computed Tomography/methods , Mandible/diagnostic imaging
10.
Medicina (Kaunas) ; 59(11)2023 Nov 03.
Article in English | MEDLINE | ID: mdl-38003997

ABSTRACT

Background and Objectives: This review focuses on reviewing studies from the literature regarding the effects of deep margin elevation on the surrounding periodontium. Materials and Methods: A review of the literature was carried out using the following online databases: Embase, The Cochrane Library, MEDLINE-PubMed and Google Scholar. Our search was limited to articles from 2010 to 2023. The search terms consisted of keywords and MeSH terms, which were 'deep margin elevation', 'coronal margin relocation', 'periodontium' and 'periodontal tissues'. The literature was searched thoroughly by two reviewers. Initially, the titles of the articles were extracted. After removing irrelevant and duplicate articles, abstracts were assessed for relevant articles. Finally, the reviewers analyzed full-text articles. Results: A total of twelve articles, including one randomized clinical trial, three systematic reviews, two prospective cohort, three case series, one a clinical study, one pilot study and one a retrospective study, were selected and analyzed. Conclusions: The review suggests potential benefits of Deep Margin Elevation (DME) over surgical crown lengthening due to reduced invasiveness, yet conclusive effects on periodontal tissue remain unclear, warranting further studies on clinical parameters and inflammatory biomarkers.


Subject(s)
Periodontal Ligament , Periodontium , Humans , Prospective Studies , Pilot Projects , Retrospective Studies , Randomized Controlled Trials as Topic
11.
Medicina (Kaunas) ; 59(4)2023 Mar 29.
Article in English | MEDLINE | ID: mdl-37109636

ABSTRACT

Background and objectives: Endodontic surgery has evolved over the last two decades. The use of state-of-the-art guided endodontic surgical procedures produces a predictable outcome in the healing of lesions of endodontic origin. The main objective of this review paper is to define and characterize guided surgical endodontics as well as its benefits and drawbacks by reviewing the most recent relevant scientific literature. Methods: A literature search was conducted using multiple databases comprising of MEDLINE (via PubMed), EMBASE, and Web of Science. The terms used for the search were 'guided endodontics', 'surgical endodontics', and 'endodontic microsurgery'. Results: In total, 1152 articles were obtained from the analysis of the databases. Unrelated articles from the available full text of 388 articles were excluded. A total of 45 studies were finally included in the review. Conclusions: Surgical-guided endodontics is a relatively new area of study that is still maturing. It has many applications such as root canal access and localization, microsurgical endodontics, endodontic retreatment, and glass fiber post removal. Additionally, it does not matter how experienced the operator is; the procedure can be completed for the patient in less time and provides greater accuracy and safety than conventional endodontics.


Subject(s)
Endodontics , Root Canal Therapy , Humans , Root Canal Therapy/methods , Endodontics/methods , Microsurgery/methods
12.
J Clin Pediatr Dent ; 47(4): 35-39, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37408344

ABSTRACT

It is imperative to manage children with empathy and concern for their well-being in order to carry out any dental procedure smoothly. Owing to the inherent fear of dental operatory, behaviour management of children is an important aspect of pediatric dental care. Many techniques are available to help manage the behaviour of children. It is, however important to educate parents about these techniques and to get their cooperation for these techniques to be used on their children.This study aimed to familiarize the parents with non-pharmacological behavior management techniques and to determine the parental acceptance of such techniques in children seeking dental treatment in specialty care dental units. A total of 303 parents were evaluated through online questionnaires in this research. They were shown videos of randomly selected non-pharmacologic behaviour management techniques including tell-show-do, positive reinforcement, modelling and voice control. Parents were asked to watch the videos and give their response on seven-items inquiring about their acceptance levels regarding the respective techniques. The responses were recorded on a Likert scales ranging from strongly disagree to strongly agree. According to parental acceptance score (PAS), positive reinforcement was the most accepted technique whereas voice control was the least acceptable technique. Majority of the parents were more receptive towards those techniques that involved a healthy and friendly communication between a dentist and the pediatric patient such as, positive reinforcement, tell show do and modelling. Most significantly the people having low socio-economic status (SES) in Pakistan were more acceptable of voice control than people with high SES.


Subject(s)
Child Behavior , Restraint, Physical , Child , Humans , Cross-Sectional Studies , Parents , Dental Care
13.
J Clin Pediatr Dent ; 47(4): 80-85, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37408350

ABSTRACT

Orthodontic treatment requires the cooperation of patients as well as orthodontists. Therefore, the aim of the study was to investigate and address the challenges and barriers orthodontists have in achieving the desired orthodontic results, as well as make recommendations for ways to address the stated problems and introduce new innovative technologies to the area of orthodontics. This qualitative study wasbased on the grounded theory. Twelve orthodontists participated in face-to-face interviews, which were primarily comprised of open-ended questions. Data analysis was carried out manually using the "by hand" method. Orthodontists between the age group of 29-42 were interviewed. The answers varied depending on the years of experience of the interviewees. Teenagers and boys were found to be most non-compliant with the treatment. The average treatment span ranged between 6 months for mild cases up to 3 years for severe orthodontic cases occurring most commonly in government hospitals. Patient compliance plays a major role in orthodontics. Poor oral hygiene maintenance, brackets breakage by patients, and missed appointments were the major concerns mentioned by participants and hindered getting the desired results. Patients' main worries were related to the cost of therapy, premolar extractions, the length of treatment, and the possibility of relapse. Patient counseling and reinforcement at the start of the treatment can help to overcome the challenges and barriers in orthodontics since patient motivation is a very important factor in obtaining the desired results. It is recommended to conduct more training sessions for the orthodontists in order to introduce them to new technological paradigms.


Subject(s)
Orthodontics , Male , Humans , Adult , Child , Adolescent , Orthodontists , Dental Care , Surveys and Questionnaires
14.
Sensors (Basel) ; 22(10)2022 May 15.
Article in English | MEDLINE | ID: mdl-35632164

ABSTRACT

A laser scanning confocal microscope (LSCM) is an effective scientific instrument for studying sub-micron structures, and it has been widely used in the field of biological detection. However, the illumination depth of LSCMs is limited due to the optical aberrations introduced by living biological tissue, which acts as an optical medium with a non-uniform refractive index, resulting in a significant dispersion of the focus of LSCM illumination light and, hence, a loss in the resolution of the image. In this study, to minimize the effect of optical aberrations, an image-based adaptive optics technology using an optimized stochastic parallel gradient descent (SPGD) algorithm with an adaptive coefficient is applied to the optical path of an LSCM system. The effectiveness of the proposed aberration correction approach is experimentally evaluated in the LSCM system. The results illustrate that the proposed adaptive optics system with an adaptive coefficient SPGD algorithm can effectively reduce the interference caused by aberrations during depth imaging.


Subject(s)
Algorithms , Optics and Photonics , Lasers , Microscopy, Confocal/methods
15.
BMC Oral Health ; 22(1): 171, 2022 05 10.
Article in English | MEDLINE | ID: mdl-35538514

ABSTRACT

BACKGROUND: Adequate knowledge of root canal morphology and possible variations is essential to achieve perfect root canal treatment and overcome treatment failure. Appropriate knowledge on root and canal morphology, communication, and documentation amongst dentists will be challenging from a diagnostic and successful treatment point of view. METHODS: A total of 3420 samples were included in this study from 285 cone-beam computed tomography images of the Saudi residents, including 171 males and 114 females aged 15 to 68 years from retrospective data dated from January 2018 to April 2021. The images were examined in sagittal, axial and coronal views using a 3D version software 1.0.10.6388. The number of canal and canal morphology was recorded using Vertucci and the new classification system. The SPSS 26 was used to conduct the statistical analysis as descriptive statistics such as mean; standard deviation and frequency were calculated. The Chi-square test analysed the data with the significance level set at 0.05. RESULTS: A total of 285 subjects participated in the study. Majority of the participants were Saudi nationals (80.7%), followed by Indian (7.4%), Pakistani (4.2%) and other nationalities. According to Vertucci and the new classification system, Type I and 1TN1 were the most common types, followed by Type III and Type IV, and then 1TN1-2-1 and 1TN1-2 in mandibular anteriors. The prevalence of canal variations in mandibular canine was higher in females than in males (P = 0.002). Maxillary laterals and mandibular anteriors showed the significant difference in the prevalence of root canal variation in relation to the ethnicity (P = 0.001) and age of the patients. Younger patients showed more variations than the older patients (P = 0.012, P = 0.023, P = 0.001, P = 0.001) in terms of maxillary laterals, mandibular central, laterals and canines, respectively. CONCLUSION: Mandibular permanent anteriors showed a wide range of canal variations and canal complexity. Males and females did not demonstrate a wide range of variation in the root canal morphology except for the canines in relation to the gender of the patients.


Subject(s)
Dental Pulp Cavity , Spiral Cone-Beam Computed Tomography , Cone-Beam Computed Tomography/methods , Dental Pulp Cavity/anatomy & histology , Dental Pulp Cavity/diagnostic imaging , Female , Humans , Male , Retrospective Studies , Saudi Arabia , Tooth Root/anatomy & histology
16.
J Fluoresc ; 31(4): 1055-1063, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33956267

ABSTRACT

Employing natural or artificial sunscreens is essential to protect the skin from ultraviolet radiations that cause premature aging and develop melanoma and other forms of skin cancer. The 2-Phenylbenzimidazole-5-sulfonic acid, commonly known as ensulizole is a water-soluble artificial sunscreen that absorb UV-B (280 nm - 315 nm) radiations and protects the skin against the harmful effects of these radiations. We have measured steady-state photoluminescence (SSPL) spectra and photoluminescence (PL) kinetics of this compound in various conditions. Steady-state absorption indicates a strong absorption feature at 303 nm and a weak one at 316 nm that have been identified as π → π* and n → π* transitions, respectively. The spectra of PL induced by these absorptions indicate that the PL of ensulizole is less Stokes-shifted in polar solvents and more Stokes-shifted in non-polar solvents. The average PL lifetime of ensulizole is longer in non-polar solvents than in polar solvents and it exhibits the shortest PL lifetime in aqueous medium that maximize its transition efficiency in water. This suggests in non-polar solvents intersystem crossing is the dominant mode of relaxation of the excited ππ* state. Furthermore, an increase of pH of ensulizole solution decreases the PL intensity and the lifetime. Stern-Volmer equation is employed to evaluate bimolecular quenching rate constant kq. The evaluation result suggests the diffusional dynamic mode of PL quenching is operative.


Subject(s)
Benzimidazoles , Sulfonic Acids , Kinetics , Sunscreening Agents , Water
17.
Nanotechnology ; 31(4): 045403, 2020 Jan 17.
Article in English | MEDLINE | ID: mdl-31604342

ABSTRACT

A high-performance supercapacitor electrode NiCo2S4 (NCS) nanosheet on SiO2@C core-shell nanospheres (SiO2@C-NCS nanocomposite) is prepared via simple an effective solution-based method. Benefiting from compositional and structural advantages, the as-prepared SiO2@C-NCS nanocomposite exhibits a high specific capacitance (625 F g-1 at 1 mA cm-2) and a stable cycling performance. An asymmetric supercapacitor (ASC) assembled with SiO2@C-NCS nanocomposite as a positive electrode and carbon nanotube paper as a negative electrode in aqueous KOH solution demonstrated a high energy density of 16 Wh kg-1 at an ultra-high specific power of 7200 W kg-1. These promising results suggest the possible application of mixed transition metal sulfides-based composites as advanced electrode materials for high-performance ASCs.

18.
Entropy (Basel) ; 22(10)2020 Oct 18.
Article in English | MEDLINE | ID: mdl-33286940

ABSTRACT

Magnetohydrodynamic nanofluid technologies are emerging in several areas including pharmacology, medicine and lubrication (smart tribology). The present study discusses the heat transfer and entropy generation of magnetohydrodynamic (MHD) Ag-water nanofluid flow over a stretching sheet with the effect of nanoparticles shape. Three different geometries of nanoparticles-sphere, blade and lamina-are considered. The problem is modeled in the form of momentum, energy and entropy equations. The homotopy analysis method (HAM) is used to find the analytical solution of momentum, energy and entropy equations. The variations of velocity profile, temperature profile, Nusselt number and entropy generation with the influences of physical parameters are discussed in graphical form. The results show that the performance of lamina-shaped nanoparticles is better in temperature distribution, heat transfer and enhancement of the entropy generation.

19.
Int J Mol Sci ; 20(15)2019 Jul 28.
Article in English | MEDLINE | ID: mdl-31357727

ABSTRACT

Magnetic fluid is a stable colloidal suspension of nano-sized, single-domain ferri/ferromagnetic particles dispersed in a liquid carrier. The liquid can be magnetized by the ferromagnetic particles aligned with the external magnetic field, which can be used as a wavefront corrector to correct the large aberrations up to more than 100 µm in adaptive optics (AO) systems. Since the measuring range of the wavefront sensor is normally small, the application of the magnetic fluid deformable mirror (MFDM) is limited with the WFS based AO system. In this paper, based on the MFDM model and the relationship between the second moment (SM) of the aberration gradients and the far-field intensity distribution, a model-based wavefront sensorless (WFSless) control algorithm is proposed for the MFDM. The correction performance of MFDM using the model-based control algorithm is evaluated in a WFSless AO system setup with a prototype MFDM, where a laser beam with unknown aberrations is supposed to produce a focused spot on the CCD. Experimental results show that the MFDM can be used to effectively compensate for unknown aberrations in the imaging system with the proposed model-based control algorithm.


Subject(s)
Colloids/chemistry , Magnetite Nanoparticles/chemistry , Magnets/chemistry , Algorithms , Magnetic Phenomena , Optics and Photonics
20.
J Pak Med Assoc ; 65(6): 593-6, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26060152

ABSTRACT

OBJECTIVE: To compare clinical outcome in patients undergoing conventional coronary artery bypass graft surgery who received intermittent antegrade warm blood cardioplegia or intermittent antegrade cold blood cardioplegia for myocardial protection. METHODS: The observational, prospective non-randomised analytical comparative study was conducted at the Punjab Institute of Cardiology, Lahore, and Chaudhry Pervaiz Elahi Institute of Cardiology, Multan, from September 2012 to October 2013, and comprised patients undergoing coronary artery bypass graft surgery. They were divided into two groups, with Group I having those who received intermittent antegrade warm blood cardioplegia, and Group II having those who received intermittent antegrade cold blood cardioplegia. SPSS 16 was used for statistical analysis. RESULTS: Of the 215 patients, 94(44%) were in Group I, and 121(56%) in Group II. Total surgical time in Group II was 119.26±22.24 minutes compared to 105.73±31.34 in Group I (p >0.0001). Spontaneous resumption of sinus rhythm and peri-operative myocardial infarction was statistically insignificant (p>0.05). There were 21(17.4%) patients in Group II to whom peri-operative myocardial infarction occurred compared to 9(9.6%) in Group I (p=0.10). CONCLUSIONS: Intermittent antegrade warm blood cardioplegia showed better myocardial protection in early postoperative period compared to intermittent antegrade cold blood cardioplegia.


Subject(s)
Coronary Artery Bypass/methods , Coronary Artery Disease/surgery , Heart Arrest, Induced/methods , Myocardial Infarction/prevention & control , Adult , Creatine Kinase, MB Form/blood , Female , Humans , Intra-Aortic Balloon Pumping/statistics & numerical data , Male , Middle Aged , Myocardial Infarction/blood , Myocardial Ischemia/blood , Myocardial Ischemia/prevention & control , Operative Time , Prospective Studies , Treatment Outcome
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