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1.
J Coll Physicians Surg Pak ; 33(7): 760-764, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37401216

RESUMO

OBJECTIVE: To analyse the predictive value of immature platelet fraction (IPF) as an independent diagnostic marker to differentiate between hyperdestructive and hypoproductive thrombocytopenia. STUDY DESIGN: Cross-sectional observational study. Place and Duration of the Study: Armed Forces Institute of Pathology Rawalpindi, from February to July 2022. METHODOLOGY: A total of 164 samples were included in the study by non-probability consecutive sampling. Among these, 80 were obtained from normal individuals serving as control; 43 were obtained from patients having hyperdestructive thrombocytopenia (idiopathic thrombocytopenia, thrombotic thrombocytopenic purpura, disseminated intravascular coagulation); and 41 were obtained from those hypoproductive thrombocytopenia (acute leukaemia, aplastic anaemia, chemotherapy). Sysmex automated haematology analyzer, XN-3000 was used to determine the immature platelet fraction (IPF) of the patients. ROC curves analysis was done to ascertain area under curve. RESULTS: Immature platelet fraction (IPF %) was significantly higher in consumptive / hyperdestructive thrombocytopenia group i.e. median (IQR), 21% (14.4-26.2) as compared to 6.5% (4.6-8.9) in hypoproductive thrombocytopenia, and 2.6% (1.3-4.1) in normal control group (p <0.001). Cut-off value with the highest sensitivity and specificity for IPF vs. normal population was 7.95% with sensitivity of 97.7% and specificity of 86%. CONCLUSION: Immature platelet fraction (IPF of 7.95%) possesses high diagnostic accuracy, sensitivity and specificity for differentiation between hyperdestructive vs. hypoproductive thrombocytopenia. It can be used as a reliable marker to differentiate between the two entities. KEY WORDS: Immature platelet fraction, Thrombocytopenia, Bone marrow failure, Peripheral destruction.


Assuntos
Pancitopenia , Trombocitopenia , Humanos , Contagem de Plaquetas , Estudos Transversais , Trombocitopenia/diagnóstico , Plaquetas , Transtornos da Insuficiência da Medula Óssea
2.
J Pak Med Assoc ; 73(3): 558-561, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36932759

RESUMO

Objective: To determine the frequency and patterns of bone marrow infiltration in non-Hodgkin lymphoma patients. METHODS: The cross-sectional study was conducted at the Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from April to October 2021, and comprised patients of either gender aged 20-80 years who had been diagnosed with non-Hodgkin lymphoma. Following assessment and as per standard protocol, bone marrow aspirate and trephine biopsy were done on all patients from the posterior superior iliac spine, and slides were prepared and assessed. Data was analysed using SPSS 25. RESULTS: Of the 100 patients, 67(67%) were males and 33(33%) were females. The overall mean age was 54.99±12 years, and mean duration of symptoms was 11.7±1.5 months. Diffuse large B-cell lymphoma was the commonest type 43(43%). Infiltration of marrow occurred in 38(38%) patients, with 12(12%) of them being cases of mantle cell lymphoma. The commonest infiltration pattern was diffuse in 17(17%) cases, followed by focal/nodular in 10(10%). CONCLUSIONS: Diffuse large B-cell lymphoma was found to be the commonest type of non-Hodgkin lymphoma, and marrow infiltration occurred most frequently in cases of mantle cell lymphoma.


Assuntos
Linfoma Difuso de Grandes Células B , Linfoma de Célula do Manto , Linfoma não Hodgkin , Masculino , Feminino , Adulto , Humanos , Pessoa de Meia-Idade , Idoso , Medula Óssea/patologia , Linfoma de Célula do Manto/patologia , Centros de Atenção Terciária , Estudos Transversais , Linfoma não Hodgkin/diagnóstico , Linfoma Difuso de Grandes Células B/epidemiologia , Linfoma Difuso de Grandes Células B/patologia , Biópsia/métodos
3.
J Coll Physicians Surg Pak ; 32(11): 1430-1434, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36377010

RESUMO

OBJECTIVE: To study the correlation of cytogenetic and molecular abnormalities on induction chemotherapy in childhood acute lymphoblastic leukaemia (ALL). STUDY DESIGN: Analytical study. PLACE AND DURATION OF STUDY: Department of Haematology, Armed Forces Institute of Pathology (AFIP), from March 2021 to August 2021. METHODOLOGY: Patients aged 1-18 years with newly diagnosed acute lymphoblastic leukaemia were inducted. Patients aged less than 1 year and more than 18 years were excluded from the study. The diagnosis was based on morphology, cytochemistry, flow cytometry, and cytogenetic/molecular analysis. Risk stratification was done on the basis of age, TLC, and cytogenetic/molecular defects. The UKALL 2011 protocol was used for treatment with regimen-A for standard risk and regimen-B for high-risk patients. Bone marrow was repeated on day 29 of induction therapy and blast percentage was assessed to establish post-induction remission. Association between cytogenetic / molecular abnormalities and post-induction remission status was analysed using chi-square test. RESULTS: There were total 142 patients with mean age of 6.4 + 3.6 years and a male- to-female ratio of 2.7:1. Immunophenotyping revealed 85.9% cases as B-cell ALL and 14.1% as T-cell ALL. The most frequent cytogenetic and molecular abnormalities were hyperdiploidy (19%), t(9;22)/BCR-ABL1(p190) (10.6%), complex karyotype (5.6%), E2A-PBX1 (8.5%), and TEL-AML1 (4.9%). A total of 127/142 (89.4%) achieved haematological remission after induction therapy with two deaths during induction therapy (1.4%). Post-induction remission rate in patients with favorable cytogenetic/molecular defects was 100% and in children with bad prognostic changes, the rate of remission was 69.2%. Chi-square test showed a significant association between cytogenetic/molecular abnormalities and post-induction remission (p-value <0.001). CONCLUSION: Cytogenetic and molecular abnormalities have a significant association with post-induction remission in children with acute lymphoblastic leukaemia. KEY WORDS: Acute lymphoblastic leukaemia, Cytogenetics, Chemotherapy, Induction, Remission.


Assuntos
Quimioterapia de Indução , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Criança , Masculino , Feminino , Pré-Escolar , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Citogenética , Aberrações Cromossômicas , Análise Citogenética , Prognóstico , Indução de Remissão
4.
J Coll Physicians Surg Pak ; 32(10): 1367-1369, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36205291

RESUMO

This study aimed to analyse the diagnostic accuracy of different laboratory parameters that can predict bone marrow metastasis. A cross-sectional analytical study was conducted at the Armed Forces Institute of Pathology (AFIP), Rawalpindi from March 2021 to August 2021. Bone marrow aspirates and biopsy procedures were done on 60 newly diagnosed cases of non-haematological malignancies as part of staging. Laboratory parameters noted for the study included peripheral blood smear findings, serum lactate dehydrogenase (LDH), radiological findings, and bone marrow aspirate/trephine biopsy results. Bone marrow metastasis was seen in 21/60 patients. The most common malignancies with bone marrow involvement were retinoblastoma and neuroblastoma. Laboratory findings showed no significant statistical difference in mean haemoglobin and total leukocyte count between cases and controls. Positive cases had a mean platelet count of 261.7 x 109/L and mean LDH of 750.1 U/L (p <0.05) for both parameters. ROC analysis showed the area under the curve (AUC) for LDH to be 0.969 (highly significant) showing a strong predictive value of LDH. Positive radiological findings were detected in only one case with bone marrow metastasis. The elevated level of serum LDH is not only cost-effective but also has high diagnostic accuracy to predict bone marrow metastasis. Key Words: Bone marrow, Biochemical, Lactate dehydrogenase, Metastasis, Non-haematological malignancies.


Assuntos
Neoplasias da Medula Óssea , Neoplasias Ósseas , Neuroblastoma , Neoplasias da Retina , Estudos Transversais , Humanos , Lactato Desidrogenases
5.
Radiat Prot Dosimetry ; 198(8): 491-502, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35718697

RESUMO

The radiofrequency field levels may increase in confined environments, such as underground mines, due to reflections from inner boundaries (walls and arches). This study investigated the specific absorption rate (SAR) in the head and torso of a miner wearing a wireless device in underground mine scenarios. Two high-resolution voxel models were used to analyse the effects of a tunnel structure, a metal arch and a safety helmet at 2.4 GHz and 868 MHz. The results indicated that the SAR increase is modest for all simulated underground mine scenarios and was maximum in the presence of a metal arch. At 868 MHz, some observed that the SAR was greater in deep tissues of the head and torso as compared to SAR at 2.4 GHz. Also, the torso is a better site for mounting wearable devices on the body to mitigate exposure.


Assuntos
Ondas de Rádio , Dispositivos Eletrônicos Vestíveis , Cabeça , Humanos , Tronco
6.
Cancer Treat Rev ; 106: 102381, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35395434

RESUMO

The randomized controlled trial (RCT) remains the preferred design to determine effectiveness of a novel intervention in patients with cancer. The accepted method of primary analysis of phase III trials of radical chemoradiotherapy is by intention to treat (ITT). Yet, investigators often resort to 'post hoc' analyses comparing only patients who received the treatment per protocol (PP). Analysis of treatment PP aims to maintain the comparable groups achieved by randomisation, whilst identifying a true or more accurate treatment effect if the planned chemoradiotherapy is optimally applied with full compliance. Poor compliance is recognised to be associated with inferior outcomes. Reasons for poor compliance if identified and understood, might influence the design of future trials. Yet this entire methodology risks substantial bias and is often disparaged. In localised squamous cell carcinoma of the anus (SCCA) chemoradiotherapy with concurrent 5-flurouracil (or capecitabine) and mitomycin C achieves high rates of local control, but results in substantial acute toxicities. Some novel radiotherapy techniques (intensity modulated radiotherapy (IMRT), meticulous organs-at-risk (OAR) contouring, and techniques such as sparing of PET-active bone marrow) appear to reduce acute toxicity. Good quality assurance in the design of trials, patient education, optimizing nutrition, proactive surveillance during treatment, and early interventions might also improve compliance. This review examines the recently published findings on compliance in the ACT II trial and data from other studies using chemoradiotherapy in SCCA to explore compliance.


Assuntos
Neoplasias do Ânus , Carcinoma de Células Escamosas , Radioterapia de Intensidade Modulada , Canal Anal , Neoplasias do Ânus/tratamento farmacológico , Neoplasias do Ânus/radioterapia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Quimiorradioterapia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
J Healthc Eng ; 2022: 5707930, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35437465

RESUMO

Facial expression is one of the most significant elements which can tell us about the mental state of any person. A human can convey approximately 55% of information nonverbally and the remaining almost 45% through verbal communication. Automatic facial expression recognition is presently one of the most difficult tasks in the computer science field. Applications of facial expression recognition (FER) are not just limited to understanding human behavior and monitoring person's mood and the mental state of humans. It is also penetrating into other fields such as criminology, holographic, smart healthcare systems, security systems, education, robotics, entertainment, and stress detection. Currently, facial expressions are playing an important role in medical sciences, particularly helping the patients with bipolar disease, whose mood changes very frequently. In this study, an algorithm, automated framework for facial detection using a convolutional neural network (FD-CNN) is proposed with four convolution layers and two hidden layers to improve accuracy. An extended Cohn-Kanade (CK+) dataset is used that includes facial images of different males and females with expressions such as anger, fear, disgust, contempt, neutral, happy, sad, and surprise. In this study, FD-CNN is performed in three major steps that include preprocessing, feature extraction, and classification. By using this proposed method, an accuracy of 94% is obtained in FER. In order to validate the proposed algorithm, K-fold cross-validation is performed. After validation, sensitivity and specificity are calculated which are 94.02% and 99.14%, respectively. Furthermore, the f1 score, recall, and precision are calculated to validate the quality of the model which is 84.07%, 78.22%, and 94.09%, respectively.


Assuntos
Aprendizado Profundo , Reconhecimento Facial , Face , Expressão Facial , Feminino , Humanos , Masculino , Redes Neurais de Computação
8.
Am J Blood Res ; 11(5): 498-503, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34824882

RESUMO

BACKGROUND: Fanconi anemia is an inherited bone marrow failure syndrome characterized by somatic abnormalities and an increased predisposition to malignancies. OBJECTIVE: To determine the clinical spectrum and evaluate the hematological parameters as well as highlight diagnosis by chromosomal breakage analysis of Fanconi anemia patients. MATERIAL AND METHODS: A total of 124 patients were diagnosed as having Fanconi anemia from August 2014 to May 2020 at Armed Forces Institute of Pathology, Rawalpindi, Pakistan. Clinical details, somatic abnormalities, radiological findings, lab parameters and result of chromosomal breakage analysis were noted and analyzed. RESULTS: One hundred and twenty four (14.29%) were diagnosed as having Fanconi anemia (FA) on chromosomal breakage test. Median age was 09 years 06 months. Male to female ratio was 1.9:1. Six of these patients exhibited mosaicism and were classified as FA mosaic. Somatic abnormalities were detected in 74 (59.7%) patients; the most common being skeletal abnormalities and short stature. CONCLUSION: Chromosomal breakage analysis is a cost-effective method for diagnosis of Fanconi anemia. Early diagnosis is pertinent for proper treatment and long term prognosis.

9.
Therap Adv Gastroenterol ; 14: 17562848211042200, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34567270

RESUMO

INTRODUCTION: The optimal approach to screening and risk stratification for non-alcoholic fatty liver disease is challenging given disease burden and variable progression. The aim of this study was to assess primary care physician and referring physician practice patterns regarding non-alcoholic fatty liver disease. METHODS: An anonymous nationwide survey was administered to primary care physicians, endocrinologists, and cardiologists in a: (1) tertiary academic hospital, (2) community hospital, and (3) the American College of Physicians Insider Panel. Survey domains assessed non-alcoholic fatty liver disease knowledge, recommendations for screening, risk stratification, treatment, and referral patterns. RESULTS: A total of 440 providers completed the survey (35.2% completion rate; N = 82 academic hospital, N = 21 community hospital, N = 337 American College of Physicians). Half were male (51.7%), 78% from internal medicine, with 5% subspecialists. Providers were knowledgeable regarding prevalence and risk factors for non-alcoholic fatty liver disease. 58% would support screening for non-alcoholic fatty liver disease and used liver enzymes to do so. Only 22.5% used serum biomarkers and 23% used transient elastography for risk stratification. Primary reason for referral was advanced fibrosis/cirrhosis. 80% reported barriers to treating non-alcoholic fatty liver disease. There was no consistent diet recommended. CONCLUSION: In this nationwide survey, we demonstrated that while overall disease knowledge was good, there was an important disconnect between current guidelines and real-world clinical practice. There is also significant heterogeneity in practice patterns for first-line therapy of non-alcoholic fatty liver disease and the majority of provider's report barriers to treating non-alcoholic fatty liver disease. These findings highlight the potential role for reevaluating screening and risk stratification recommendations in primary care to better align with needs in that setting.

10.
J Colloid Interface Sci ; 602: 699-711, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34153709

RESUMO

In the process of photocatalytic oxidation (PCO), titanium dioxide (TiO2) shows excellent capabilities. However, when TiO2 is used to remove volatile organic compounds (VOCs), there are some drawbacks including weak adsorption of gaseous contaminants, insufficient utilization of sunlight, and rapid recombination of photogenerated carriers. Herein, a TiO2-based ternary heterogeneous photocatalyst, g-C3N4/Ag-TiO2, was successfully fabricated to photodegrade gaseous acetaldehyde (one of the representatives of oxygenated VOCs) under visible light. Among the various samples, the g-C3N4/50 wt% Ag-TiO2 exhibited an excellent photocatalytic activity, which was 5.8 times of bare TiO2. The mineralization efficiency of acetaldehyde was also increased by 3.7 times compared to bare TiO2. The substantial improvement in the PCO performance of the ternary system can be associated with the good adsorption to acetaldehyde gas and light-harvesting capability, as well as improved charge separation process. The application of Langmuir-Hinshelwood kinetic model suggested that relative humidity played a significant role in the VOCs degradation. Also, the photodegradation of gaseous acetaldehyde primarily occurred on the catalysts surface. Based on several characterizations, i.e., UV-vis spectroscopy, photoluminescence spectrum, photocurrent spectroscopy and electron spin-resonance test, a suitable degradation mechanism is proposed. This study provides a novel ternary photocatalyst with improved photocatalytic performance and stability, which can be used for the low-concentration VOCs abatement in the indoor environment.

11.
J Hazard Mater ; 401: 123402, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-32763698

RESUMO

In this work, we have developed and optimized TiO2 nanoparticles decorated with carbon quantum dots to examine its potential use in the photocatalytic oxidation of aromatic ring containing gas-phase mixed volatile organic compounds, e.g., benzene, toluene, and p-xylene. Carbon quantum dots decorated TiO2 demonstrated good photodegradation efficiency in contrast to pure TiO2 under UV-vis light illumination. For example, with 0.5 wt% carbon quantum dots decorated on TiO2, 64 % of the mixed volatile organic compounds were photodegraded, while pure TiO2 only exhibited 44 % of the photodegradation efficiency. Also, the carbon quantum dots (0.5 wt%)/TiO2 nanocomposite demonstrated considerable photocatalytic activity within the visible region. On the other hand, pure TiO2 remained inactive within the visible region. The density functional theory study of the carbon quantum dots/TiO2 interface revealed that C 2p states of carbon quantum dots incorporated new energy states around the Fermi level near the lowest conduction band. This might be accountable for the improved charge separation process and better conductivity of the photogenerated electrons. The improved photocatalytic performance of the carbon quantum dots/TiO2 nanocomposites can be attributed to good light harvesting within the UV-vis region, charge separation, and adsorption capability.

12.
Blood Res ; 55(3): 146-150, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32883892

RESUMO

BACKGROUND: Rare inherited coagulation factor deficiencies constitute an important group of bleeding disorders. A higher frequency of these disorders is seen in areas of high consanguinity. Our aim was to study the prevalence and spectrum of rare inherited bleeding disorders, characterize the severity of the deficiencies, identify different clinical manifestations, and evaluate different treatments provided. METHODS: This cross-sectional study was conducted in the Department of Haematology, Armed Forces Institute of Pathology Rawalpindi, between January 2014 and December 2018. A detailed history was taken, and an examination was performed. The signs and symptoms were noted, and the patients were diagnosed on the basis of a coagulation profile. The disease severity was assessed using factor assays. RESULTS: Among 2,516 patients with suspected coagulation disorders, 774 (30.8%) had an inherited bleeding disorder. Of the 774 patients, 165 (21.3%) had a rare bleeding disorder; 91 (55.2%) of them were males, and 74 (44.9%) were females, with a male-to-female ratio of 1.2:1. The median patient age was 9 years 3 months. The most common disorder was factor VII deficiency (46 patients, 27.9%). The most common clinical presentation was bruising in 102 (61.8%) and gum bleeding in 91 (55.2%) patients. CONCLUSION: The most common rare bleeding disorder in our population is factor VII deficiency. The prevalence of these bleeding disorders is high in our population due to a high number of consanguineous marriages.

13.
J Ayub Med Coll Abbottabad ; 32(2): 179-183, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32583990

RESUMO

BACKGROUND: Mitral Annular Calcification (MAC) is a degenerative process involving the mitral valve and is a marker of advanced cardiovascular disease. Prevalence in the general population is upto 10% and increases in advanced age, diabetes mellitus, chronic kidney disease (CKD), end stage renal disease (upto 40%) and mitral valve prolapse.The aims of this study were to assess the prevalence of MAC in CKD5D patients and correlate with patients' characteristics. METHODS: Echocardiograms were obtained in 84 hemodialysis patients. Association of MAC with various patient characteristics was studied. Data was analysed using SPSS-22. RESULTS: The mean age of the patients was 63.38±12.3 years and 48 (57%) were males. Sixty-eight patients (81%) had DM and 79 (94%) had hypertension. MAC was present in 37 out of 84 (44%) patients. Sixty-four (72%) had IHD. The presence of MAC correlated significantly with IHD (Odds Ratio 6.42, p=0.006). Mean follow up of the patients was 30.30±29.22 months and 37 (44%) suffered mortality during this period. Patients on dialysis for longer than 36 months had an elevated risk of developing MAC (OR=3.32, p=0.019). Patients with the following risk factors: serum PO4 greater than 5.5 (OR=2.03), DM (OR=1.95), HTN (OR=3.35), Age >60 (OR=1.83), AFIB (OR=1.28); had an observable increase in incidence of MAC with time but they weren't statistically significant. CONCLUSIONS: Mitral Annular Calcification is common in hemodialysis patients and correlates significantly with IHD. Our findings support the recommendation by KDIGO 2017 guidelines on Mineral and Bone Disease on the use of echocardiography for the detection of valvular calcification.


Assuntos
Calcinose , Doenças das Valvas Cardíacas , Valva Mitral/fisiopatologia , Diálise Renal , Insuficiência Renal Crônica , Idoso , Calcinose/complicações , Calcinose/epidemiologia , Calcinose/fisiopatologia , Cardiomiopatias/complicações , Cardiomiopatias/fisiopatologia , Feminino , Doenças das Valvas Cardíacas/complicações , Doenças das Valvas Cardíacas/epidemiologia , Doenças das Valvas Cardíacas/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/mortalidade , Insuficiência Renal Crônica/terapia
14.
J Colloid Interface Sci ; 572: 374-383, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32272312

RESUMO

Most studies on the photodegradation of volatile organic compounds (VOCs) have focused on the synthesis of efficient photocatalysts. However, little attention has been paid to the band bending change of semiconductive photocatalysts after the adsorption of VOCs. Herein, we first disclose how the adsorption of two typical VOCs influences the band bending of P-type rutile TiO2 and consequently changes the amount of reactive radicals. This provides a new way to understand the experimental phenomenon of heterogeneous reactions. Theoretical computations of the adsorption model and zeta potential tests both verified that o-xylene is an acceptor molecule when it adsorbs on the TiO2 surface, and it tends to attract electrons from TiO2. In contrast, acetaldehyde is a donor molecule. A distinct electron transfer direction between TiO2 and adsorbed molecules (o-xylene and acetaldehyde) induces a different band bending degree. O-xylene adsorption alleviates the downward band bending of TiO2 itself, whereas acetaldehyde adsorption strengthens the downward band bending. The probability of electrons and holes reaching the TiO2 surface is influenced by this change, which has a considerable influence on the generation of active radicals. Consequently, o-xylene adsorption leads to more hydroxyl radical generation, and acetaldehyde adsorption results in less hydroxyl radical generation. As a result, hydroxyl radicals play the predominant role in the degradation of o-xylene, whereas the photocatalysis of acetaldehyde is dominant for superoxide radicals. In addition, the band bending of a semiconductor induced by gaseous molecule adsorption has the potential for application in gas sensors to improve sensitivity.

15.
J Hazard Mater ; 386: 121962, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31911380

RESUMO

Here, we report the photocatalytic oxidation (PCO) of o-xylene on carbon quantum dots (CQDs) modified TiO2 nanoparticles. The results demonstrated that with 1 wt% CQDs loading, 87 % of o-xylene (50 ppm) can be photodegraded, which is 55.3 % higher than pure TiO2 (56 %) under UV/visible light. This improved photocatalytic activity is associated with the important role of CQDs on TiO2 surface, which increased the o-xylene adsorption and facilitated the photogenerated hole-electron separation process. Also, the 1 wt%CQDs/TiO2 nanocomposite showed photocatalytic activity in the visible region (λ > 400 nm) compared to pure TiO2 (inactive). The DFT study revealed that o-xylene strongly adsorb on TiO2 (001) surface than (101) through π electrons of the aromatic ring. The in situ DRIFTS study showed that free OH groups on the photocatalyst surface could act as effective Lewis sides for the o-xylene adsorption. The interaction of π electrons of the aromatic ring and isolated OH groups was also observed. The FTIR peaks for CO2 increased in the case of CQDs/TiO2 nanocomposite contrasted to pure TiO2, which suggested that the presence of CQDs improved the mineralization potency of TiO2. These findings should affect the quest for a better photocatalyst to photodegrade VOCs.

16.
J Phys Condens Matter ; 32(20): 205501, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31945759

RESUMO

Structural and electronic properties of pristine two-dimensional group IV Xenes (X = C, Si, Ge, Sn, Pb) and hydrogenated Xenes are studied, using density functional theory (DFT) calculations with and without spin-orbit coupling (SOC). The pristine hexagonal monolayer Xenes show buckled structure upon relaxation except graphene. The buckling [Formula: see text] increases linearly from graphene to plumbene. The band structures without SOC of group-IV Xenes are semi-metallic. However, inclusion of SOC mainly opens the bandgap at the Dirac point. Semi hydrogenation leads to enhanced buckling in all Xenes which indicate a tendency towards more sp 3 like structures. The electronic structures of semi hydrogenated Xenes do not show Dirac cones. Spin polarized band structures show magnetism with magnetic moment of 1.0 [Formula: see text] and all SH Xenes are magnetic semiconductor except SH plumbene. Full hydrogenation vanishes buckling upon relaxation and the structure becomes planar implying sp 2-like hybridization. The band structures for fully hydrogenated Xenes turns out to be semiconducting and the Dirac cones also disappear. The bandgap changes from indirect to direct at FH stanene, while FH plumbene turns out to be semi-metallic. SOC gives rise to bandgap of 0.47 eV in FH plumbene, which is otherwise a semi-metal.

17.
J Colloid Interface Sci ; 555: 801-809, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31421560

RESUMO

Titanium dioxide (TiO2)-cadmium sulfide (CdS) hybrid nanoparticles on magnetic-cored dendrimers (MCDs) of the zero and first generations (G0 and G1, respectively) were synthesized under hydrothermal conditions. TiO2 was embedded with CdS to produce more radicals and suppress the recombination of photo-induced electrons and holes. A dendrimer with a magnetite core was used as a template to immobilize the TiO2/CdS nanocomposites. They were characterized via scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The obtained G0- and G1-MCD-TiO2/CdS exhibited high photocatalytic activity and was able to degrade methyl orange (MO) by 83.6 and 88.5%, respectively, in 120 min under ultraviolet irradiation. After 5 cycles, the MO degradation by G0- and G1-MCD-TiO2/CdS was 78.8 and 81.4%, respectively. The MCD-TiO2/CdS materials were easily recycled by applying an external magnetic field. G0-TiO2/CdS was more efficient in photocatalytic performance than G1-TiO2/CdS. Apparent quantum yields (AQYs) and figures of merit (FOMs) were calculated to quantify the photocatalytic performance. The AQYs of G0- and G1-MCD-TiO2/CdS were 3.48 × 10-5 and 3.69 × 10-5 molecules photon-1, respectively. The FOM of our proposed materials demonstrated its high capability for photocatalytic degradation of MO.

18.
Sci Rep ; 9(1): 7966, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138871

RESUMO

First-principles calculations based on density functional theory (DFT) are used to investigate the electronic structures and topological phase transition of arsenene under tensile and compressive strains. Buckling in arsenene strongly depends on compressive/tensile strain. The phonons band structures reveal that arsenene is dynamically stable up to 18% tensile strain and the frequency gap between the optical and acoustic branches decreases with strain. The electronic band structures show the direct bandgap decreases with tensile strain and then closes at 13% strain followed by band inversion. With spin-orbit coupling (SOC), the 14% strain-assisted topological insulator phase of arsenene is mainly governed by the p-orbitals. The SOC calculated bandgap is about 43 meV. No imaginary frequency in the phonons is observed in the topological phase of arsenene. The dynamically stable topological phase is accessed through Z2 topological invariant ν using the analysis of the parity of the wave functions at the time-reversal invariant momentum points. The calculated ν is shown to be 1, implying that arsenene is a topological insulator which can be a candidate material for nanoelectronic devices.

19.
Cureus ; 10(6): e2870, 2018 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-30148022

RESUMO

OBJECTIVE: To investigate the association of anemia with stroke severity in acute ischemic stroke patients. MATERIAL & METHODS: We enrolled 96 patients (mean age: 60.25 ± 11.92 years old) who were admitted to the stroke unit of Shifa International Hospital between 1st March 2015 and 31st August 2015. Each patient presented within 72 hours of onset of symptoms, underwent computed tomography (CT) of the head and blood tests, including hemoglobin concentration, on the first day of hospitalization. Stroke severity was assessed on admission using the National Institute of Health Stroke Scale. Anemia was evaluated according to the World Health Organization (WHO) criteria (men, <13 g/dL; women, <12 g/dL). We examined the frequency of anemia in patients with different severities of acute ischemic stroke. RESULTS: World Health Organization defined anemia was positive in 38 (39.6%) and negative in 58 (60.4%) patients. Among the patients who were positive for anemia, seven (18.4%) had a minor stroke, 10 (26.3%) had a moderately severe stroke, and 21 (55.3%) had a severe stroke. There was a significant association between anemia and stroke severity (P-value 0.000). CONCLUSION: Our data indicated that anemia was a frequent finding in acute ischemic stroke patients, with increasing frequency corresponding to stroke severity.

20.
BMJ Case Rep ; 20182018 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-29674397

RESUMO

A 68-year-old man, presented with 3 week history of infective symptoms and mild haemoptysis. Past medical history included severe emphysema and a chronic right upper lobe (RUL) cavity. He was discharged from follow-up a year ago in view of clinical and radiological stability; previous bronchoscopic examinations yielded no specific diagnosis. CT scan on admission confirmed complex cavitary consolidation of RUL. He developed massive haemoptysis requiring intubation and ventilation. CT pulmonary angiogram (CTPA) revealed 16 mm RUL pulmonary artery (PA) aneurysm which was successfully embolized. Sputum cultures, aspergillus antigen and rapidity of clinical progression suggested a diagnosis of subacute invasive aspergillosis (SAIA), prompting treatment with Voriconazole. Bronchoscopy showed blood ooze from RUL even after embolization. Unfortunately, patient continued to deteriorate and succumbed to profound septicaemia.


Assuntos
Aneurisma Infectado , Embolização Terapêutica/métodos , Hemoptise , Pneumonia , Aspergilose Pulmonar , Sepse , Voriconazol/administração & dosagem , Aneurisma Infectado/diagnóstico , Aneurisma Infectado/etiologia , Aneurisma Infectado/fisiopatologia , Aneurisma Infectado/terapia , Antifúngicos/administração & dosagem , Broncoscopia/métodos , Angiografia por Tomografia Computadorizada/métodos , Evolução Fatal , Hemoptise/diagnóstico , Hemoptise/etiologia , Hemoptise/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia/diagnóstico , Pneumonia/microbiologia , Pneumonia/fisiopatologia , Pneumonia/terapia , Aspergilose Pulmonar/complicações , Aspergilose Pulmonar/diagnóstico , Aspergilose Pulmonar/fisiopatologia , Aspergilose Pulmonar/terapia , Sepse/diagnóstico , Sepse/etiologia
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